From 0c36ec31473593aa937ff04f3b3b630e81512734 Mon Sep 17 00:00:00 2001 From: Juergen Beisert Date: Mon, 21 Jul 2008 14:21:34 -0700 Subject: gpio: gpio driver for max7301 SPI GPIO expander Maxim's MAX7301 is an SPI GPIO expander with 28 GPIOs. Note: MAX7301's interrupt feature is not supported yet. [akpm@linux-foundation.org: coding-style fixes] [g.liakhovetski@pengutronix.de: Fix inaccuracies in comments, check spi_setup() return code, mask off high byte in max7301_read()] Signed-off-by: Juergen Beisert Signed-off-by: Guennadi Liakhovetski Cc: Russell King Signed-off-by: David Brownell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/gpio/Kconfig | 6 + drivers/gpio/Makefile | 1 + drivers/gpio/max7301.c | 339 +++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 346 insertions(+) create mode 100644 drivers/gpio/max7301.c (limited to 'drivers/gpio') diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index 008c38ba774..9e0c4fbfc51 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -69,6 +69,12 @@ config GPIO_PCF857X comment "SPI GPIO expanders:" +config GPIO_MAX7301 + tristate "Maxim MAX7301 GPIO expander" + depends on SPI_MASTER + help + gpio driver for Maxim MAX7301 SPI GPIO expander. + config GPIO_MCP23S08 tristate "Microchip MCP23S08 I/O expander" depends on SPI_MASTER diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index fdde9923cf3..16e796dc541 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -4,6 +4,7 @@ ccflags-$(CONFIG_DEBUG_GPIO) += -DDEBUG obj-$(CONFIG_HAVE_GPIO_LIB) += gpiolib.o +obj-$(CONFIG_GPIO_MAX7301) += max7301.o obj-$(CONFIG_GPIO_MCP23S08) += mcp23s08.o obj-$(CONFIG_GPIO_PCA953X) += pca953x.o obj-$(CONFIG_GPIO_PCF857X) += pcf857x.o diff --git a/drivers/gpio/max7301.c b/drivers/gpio/max7301.c new file mode 100644 index 00000000000..39c795ad831 --- /dev/null +++ b/drivers/gpio/max7301.c @@ -0,0 +1,339 @@ +/** + * drivers/gpio/max7301.c + * + * Copyright (C) 2006 Juergen Beisert, Pengutronix + * Copyright (C) 2008 Guennadi Liakhovetski, Pengutronix + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * The Maxim's MAX7301 device is an SPI driven GPIO expander. There are + * 28 GPIOs. 8 of them can trigger an interrupt. See datasheet for more + * details + * Note: + * - DIN must be stable at the rising edge of clock. + * - when writing: + * - always clock in 16 clocks at once + * - at DIN: D15 first, D0 last + * - D0..D7 = databyte, D8..D14 = commandbyte + * - D15 = low -> write command + * - when reading + * - always clock in 16 clocks at once + * - at DIN: D15 first, D0 last + * - D0..D7 = dummy, D8..D14 = register address + * - D15 = high -> read command + * - raise CS and assert it again + * - always clock in 16 clocks at once + * - at DOUT: D15 first, D0 last + * - D0..D7 contains the data from the first cycle + * + * The driver exports a standard gpiochip interface + */ + +#include +#include +#include +#include +#include +#include + +#define DRIVER_NAME "max7301" + +/* + * Pin configurations, see MAX7301 datasheet page 6 + */ +#define PIN_CONFIG_MASK 0x03 +#define PIN_CONFIG_IN_PULLUP 0x03 +#define PIN_CONFIG_IN_WO_PULLUP 0x02 +#define PIN_CONFIG_OUT 0x01 + +#define PIN_NUMBER 28 + + +/* + * Some registers must be read back to modify. + * To save time we cache them here in memory + */ +struct max7301 { + struct mutex lock; + u8 port_config[8]; /* field 0 is unused */ + u32 out_level; /* cached output levels */ + struct gpio_chip chip; + struct spi_device *spi; +}; + +/** + * max7301_write - Write a new register content + * @spi: The SPI device + * @reg: Register offset + * @val: Value to write + * + * A write to the MAX7301 means one message with one transfer + * + * Returns 0 if successful or a negative value on error + */ +static int max7301_write(struct spi_device *spi, unsigned int reg, unsigned int val) +{ + u16 word = ((reg & 0x7F) << 8) | (val & 0xFF); + return spi_write(spi, (const u8 *)&word, sizeof(word)); +} + +/** + * max7301_read - Read back register content + * @spi: The SPI device + * @reg: Register offset + * + * A read from the MAX7301 means two transfers; here, one message each + * + * Returns positive 8 bit value from device if successful or a + * negative value on error + */ +static int max7301_read(struct spi_device *spi, unsigned int reg) +{ + int ret; + u16 word; + + word = 0x8000 | (reg << 8); + ret = spi_write(spi, (const u8 *)&word, sizeof(word)); + if (ret) + return ret; + /* + * This relies on the fact, that a transfer with NULL tx_buf shifts out + * zero bytes (=NOOP for MAX7301) + */ + ret = spi_read(spi, (u8 *)&word, sizeof(word)); + if (ret) + return ret; + return word & 0xff; +} + +static int max7301_direction_input(struct gpio_chip *chip, unsigned offset) +{ + struct max7301 *ts = container_of(chip, struct max7301, chip); + u8 *config; + int ret; + + /* First 4 pins are unused in the controller */ + offset += 4; + + config = &ts->port_config[offset >> 2]; + + mutex_lock(&ts->lock); + + /* Standard GPIO API doesn't support pull-ups, has to be extended. + * Hard-coding no pollup for now. */ + *config = (*config & ~(3 << (offset & 3))) | (1 << (offset & 3)); + + ret = max7301_write(ts->spi, 0x08 + (offset >> 2), *config); + + mutex_unlock(&ts->lock); + + return ret; +} + +static int __max7301_set(struct max7301 *ts, unsigned offset, int value) +{ + if (value) { + ts->out_level |= 1 << offset; + return max7301_write(ts->spi, 0x20 + offset, 0x01); + } else { + ts->out_level &= ~(1 << offset); + return max7301_write(ts->spi, 0x20 + offset, 0x00); + } +} + +static int max7301_direction_output(struct gpio_chip *chip, unsigned offset, + int value) +{ + struct max7301 *ts = container_of(chip, struct max7301, chip); + u8 *config; + int ret; + + /* First 4 pins are unused in the controller */ + offset += 4; + + config = &ts->port_config[offset >> 2]; + + mutex_lock(&ts->lock); + + *config = (*config & ~(3 << (offset & 3))) | (1 << (offset & 3)); + + ret = __max7301_set(ts, offset, value); + + if (!ret) + ret = max7301_write(ts->spi, 0x08 + (offset >> 2), *config); + + mutex_unlock(&ts->lock); + + return ret; +} + +static int max7301_get(struct gpio_chip *chip, unsigned offset) +{ + struct max7301 *ts = container_of(chip, struct max7301, chip); + int config, level = -EINVAL; + + /* First 4 pins are unused in the controller */ + offset += 4; + + mutex_lock(&ts->lock); + + config = (ts->port_config[offset >> 2] >> ((offset & 3) * 2)) & 3; + + switch (config) { + case 1: + /* Output: return cached level */ + level = !!(ts->out_level & (1 << offset)); + break; + case 2: + case 3: + /* Input: read out */ + level = max7301_read(ts->spi, 0x20 + offset) & 0x01; + } + mutex_unlock(&ts->lock); + + return level; +} + +static void max7301_set(struct gpio_chip *chip, unsigned offset, int value) +{ + struct max7301 *ts = container_of(chip, struct max7301, chip); + + /* First 4 pins are unused in the controller */ + offset += 4; + + mutex_lock(&ts->lock); + + __max7301_set(ts, offset, value); + + mutex_unlock(&ts->lock); +} + +static int __devinit max7301_probe(struct spi_device *spi) +{ + struct max7301 *ts; + struct max7301_platform_data *pdata; + int i, ret; + + pdata = spi->dev.platform_data; + if (!pdata || !pdata->base) + return -ENODEV; + + /* + * bits_per_word cannot be configured in platform data + */ + spi->bits_per_word = 16; + + ret = spi_setup(spi); + if (ret < 0) + return ret; + + ts = kzalloc(sizeof(struct max7301), GFP_KERNEL); + if (!ts) + return -ENOMEM; + + mutex_init(&ts->lock); + + dev_set_drvdata(&spi->dev, ts); + + /* Power up the chip and disable IRQ output */ + max7301_write(spi, 0x04, 0x01); + + ts->spi = spi; + + ts->chip.label = DRIVER_NAME, + + ts->chip.direction_input = max7301_direction_input; + ts->chip.get = max7301_get; + ts->chip.direction_output = max7301_direction_output; + ts->chip.set = max7301_set; + + ts->chip.base = pdata->base; + ts->chip.ngpio = PIN_NUMBER; + ts->chip.can_sleep = 1; + ts->chip.dev = &spi->dev; + ts->chip.owner = THIS_MODULE; + + ret = gpiochip_add(&ts->chip); + if (ret) + goto exit_destroy; + + /* + * tristate all pins in hardware and cache the + * register values for later use. + */ + for (i = 1; i < 8; i++) { + int j; + /* 0xAA means input with internal pullup disabled */ + max7301_write(spi, 0x08 + i, 0xAA); + ts->port_config[i] = 0xAA; + for (j = 0; j < 4; j++) { + int idx = ts->chip.base + (i - 1) * 4 + j; + ret = gpio_direction_input(idx); + if (ret) + goto exit_remove; + gpio_free(idx); + } + } + return ret; + +exit_remove: + gpiochip_remove(&ts->chip); +exit_destroy: + dev_set_drvdata(&spi->dev, NULL); + mutex_destroy(&ts->lock); + kfree(ts); + return ret; +} + +static int max7301_remove(struct spi_device *spi) +{ + struct max7301 *ts; + int ret; + + ts = dev_get_drvdata(&spi->dev); + if (ts == NULL) + return -ENODEV; + + dev_set_drvdata(&spi->dev, NULL); + + /* Power down the chip and disable IRQ output */ + max7301_write(spi, 0x04, 0x00); + + ret = gpiochip_remove(&ts->chip); + if (!ret) { + mutex_destroy(&ts->lock); + kfree(ts); + } else + dev_err(&spi->dev, "Failed to remove the GPIO controller: %d\n", + ret); + + return ret; +} + +static struct spi_driver max7301_driver = { + .driver = { + .name = DRIVER_NAME, + .owner = THIS_MODULE, + }, + .probe = max7301_probe, + .remove = __devexit_p(max7301_remove), +}; + +static int __init max7301_init(void) +{ + return spi_register_driver(&max7301_driver); +} + +static void __exit max7301_exit(void) +{ + spi_unregister_driver(&max7301_driver); +} + +module_init(max7301_init); +module_exit(max7301_exit); + +MODULE_AUTHOR("Juergen Beisert"); +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("MAX7301 SPI based GPIO-Expander"); -- cgit v1.2.3-70-g09d2 From 1673ad52bd9a3c747e596a76e65c55981ea651e3 Mon Sep 17 00:00:00 2001 From: David Brownell Date: Mon, 21 Jul 2008 14:21:34 -0700 Subject: gpio: pcf857x: add lock and handle more chips Two small updates to the pcf857x driver: (a) the max732[89] chips are also second sources for the pcf8574/a, and (b) add a mutex to prevent trashing the cached state. Adding the lock is effectively a bugfix, although it seems unlikely that anyone would have run into the issue it protects against. Signed-off-by: David Brownell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/gpio/Kconfig | 5 +++-- drivers/gpio/pcf857x.c | 33 +++++++++++++++++++++++++++++---- 2 files changed, 32 insertions(+), 6 deletions(-) (limited to 'drivers/gpio') diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index 9e0c4fbfc51..fced1909cbb 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -45,7 +45,7 @@ config GPIO_PCA953X will be called pca953x. config GPIO_PCF857X - tristate "PCF857x, PCA857x, and PCA967x I2C GPIO expanders" + tristate "PCF857x, PCA{85,96}7x, and MAX732[89] I2C GPIO expanders" depends on I2C help Say yes here to provide access to most "quasi-bidirectional" I2C @@ -54,7 +54,8 @@ config GPIO_PCF857X some of them. Compatible models include: 8 bits: pcf8574, pcf8574a, pca8574, pca8574a, - pca9670, pca9672, pca9674, pca9674a + pca9670, pca9672, pca9674, pca9674a, + max7328, max7329 16 bits: pcf8575, pcf8575c, pca8575, pca9671, pca9673, pca9675 diff --git a/drivers/gpio/pcf857x.c b/drivers/gpio/pcf857x.c index aa6cc8b2a2b..d25d356c4f2 100644 --- a/drivers/gpio/pcf857x.c +++ b/drivers/gpio/pcf857x.c @@ -37,6 +37,8 @@ static const struct i2c_device_id pcf857x_id[] = { { "pca9671", 16 }, { "pca9673", 16 }, { "pca9675", 16 }, + { "max7328", 8 }, + { "max7329", 8 }, { } }; MODULE_DEVICE_TABLE(i2c, pcf857x_id); @@ -56,6 +58,7 @@ MODULE_DEVICE_TABLE(i2c, pcf857x_id); struct pcf857x { struct gpio_chip chip; struct i2c_client *client; + struct mutex lock; /* protect 'out' */ unsigned out; /* software latch */ }; @@ -66,9 +69,14 @@ struct pcf857x { static int pcf857x_input8(struct gpio_chip *chip, unsigned offset) { struct pcf857x *gpio = container_of(chip, struct pcf857x, chip); + int status; + mutex_lock(&gpio->lock); gpio->out |= (1 << offset); - return i2c_smbus_write_byte(gpio->client, gpio->out); + status = i2c_smbus_write_byte(gpio->client, gpio->out); + mutex_unlock(&gpio->lock); + + return status; } static int pcf857x_get8(struct gpio_chip *chip, unsigned offset) @@ -84,12 +92,17 @@ static int pcf857x_output8(struct gpio_chip *chip, unsigned offset, int value) { struct pcf857x *gpio = container_of(chip, struct pcf857x, chip); unsigned bit = 1 << offset; + int status; + mutex_lock(&gpio->lock); if (value) gpio->out |= bit; else gpio->out &= ~bit; - return i2c_smbus_write_byte(gpio->client, gpio->out); + status = i2c_smbus_write_byte(gpio->client, gpio->out); + mutex_unlock(&gpio->lock); + + return status; } static void pcf857x_set8(struct gpio_chip *chip, unsigned offset, int value) @@ -124,9 +137,14 @@ static int i2c_read_le16(struct i2c_client *client) static int pcf857x_input16(struct gpio_chip *chip, unsigned offset) { struct pcf857x *gpio = container_of(chip, struct pcf857x, chip); + int status; + mutex_lock(&gpio->lock); gpio->out |= (1 << offset); - return i2c_write_le16(gpio->client, gpio->out); + status = i2c_write_le16(gpio->client, gpio->out); + mutex_unlock(&gpio->lock); + + return status; } static int pcf857x_get16(struct gpio_chip *chip, unsigned offset) @@ -142,12 +160,17 @@ static int pcf857x_output16(struct gpio_chip *chip, unsigned offset, int value) { struct pcf857x *gpio = container_of(chip, struct pcf857x, chip); unsigned bit = 1 << offset; + int status; + mutex_lock(&gpio->lock); if (value) gpio->out |= bit; else gpio->out &= ~bit; - return i2c_write_le16(gpio->client, gpio->out); + status = i2c_write_le16(gpio->client, gpio->out); + mutex_unlock(&gpio->lock); + + return status; } static void pcf857x_set16(struct gpio_chip *chip, unsigned offset, int value) @@ -173,6 +196,8 @@ static int pcf857x_probe(struct i2c_client *client, if (!gpio) return -ENOMEM; + mutex_init(&gpio->lock); + gpio->chip.base = pdata->gpio_base; gpio->chip.can_sleep = 1; gpio->chip.owner = THIS_MODULE; -- cgit v1.2.3-70-g09d2 From d8f388d8dc8d4f36539dd37c1fff62cc404ea0fc Mon Sep 17 00:00:00 2001 From: David Brownell Date: Fri, 25 Jul 2008 01:46:07 -0700 Subject: gpio: sysfs interface This adds a simple sysfs interface for GPIOs. /sys/class/gpio /export ... asks the kernel to export a GPIO to userspace /unexport ... to return a GPIO to the kernel /gpioN ... for each exported GPIO #N /value ... always readable, writes fail for input GPIOs /direction ... r/w as: in, out (default low); write high, low /gpiochipN ... for each gpiochip; #N is its first GPIO /base ... (r/o) same as N /label ... (r/o) descriptive, not necessarily unique /ngpio ... (r/o) number of GPIOs; numbered N .. N+(ngpio - 1) GPIOs claimed by kernel code may be exported by its owner using a new gpio_export() call, which should be most useful for driver debugging. Such exports may optionally be done without a "direction" attribute. Userspace may ask to take over a GPIO by writing to a sysfs control file, helping to cope with incomplete board support or other "one-off" requirements that don't merit full kernel support: echo 23 > /sys/class/gpio/export ... will gpio_request(23, "sysfs") and gpio_export(23); use /sys/class/gpio/gpio-23/direction to (re)configure it, when that GPIO can be used as both input and output. echo 23 > /sys/class/gpio/unexport ... will gpio_free(23), when it was exported as above The extra D-space footprint is a few hundred bytes, except for the sysfs resources associated with each exported GPIO. The additional I-space footprint is about two thirds of the current size of gpiolib (!). Since no /dev node creation is involved, no "udev" support is needed. Related changes: * This adds a device pointer to "struct gpio_chip". When GPIO providers initialize that, sysfs gpio class devices become children of that device instead of being "virtual" devices. * The (few) gpio_chip providers which have such a device node have been updated. * Some gpio_chip drivers also needed to update their module "owner" field ... for which missing kerneldoc was added. * Some gpio_chips don't support input GPIOs. Those GPIOs are now flagged appropriately when the chip is registered. Based on previous patches, and discussion both on and off LKML. A Documentation/ABI/testing/sysfs-gpio update is ready to submit once this merges to mainline. [akpm@linux-foundation.org: a few maintenance build fixes] Signed-off-by: David Brownell Cc: Guennadi Liakhovetski Cc: Greg KH Cc: Kay Sievers Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/gpio.txt | 123 +++++++++- arch/arm/plat-omap/gpio.c | 3 + arch/avr32/mach-at32ap/pio.c | 2 + drivers/gpio/Kconfig | 15 ++ drivers/gpio/gpiolib.c | 536 +++++++++++++++++++++++++++++++++++++++++-- drivers/gpio/mcp23s08.c | 1 + drivers/gpio/pca953x.c | 1 + drivers/gpio/pcf857x.c | 1 + drivers/i2c/chips/tps65010.c | 2 + drivers/mfd/htc-egpio.c | 2 + include/asm-generic/gpio.h | 33 ++- include/linux/gpio.h | 13 ++ 12 files changed, 712 insertions(+), 20 deletions(-) (limited to 'drivers/gpio') diff --git a/Documentation/gpio.txt b/Documentation/gpio.txt index c35ca9e40d4..8b69811a964 100644 --- a/Documentation/gpio.txt +++ b/Documentation/gpio.txt @@ -347,15 +347,12 @@ necessarily be nonportable. Dynamic definition of GPIOs is not currently standard; for example, as a side effect of configuring an add-on board with some GPIO expanders. -These calls are purely for kernel space, but a userspace API could be built -on top of them. - GPIO implementor's framework (OPTIONAL) ======================================= As noted earlier, there is an optional implementation framework making it easier for platforms to support different kinds of GPIO controller using -the same programming interface. +the same programming interface. This framework is called "gpiolib". As a debugging aid, if debugfs is available a /sys/kernel/debug/gpio file will be found there. That will list all the controllers registered through @@ -439,4 +436,120 @@ becomes available. That may mean the device should not be registered until calls for that GPIO can work. One way to address such dependencies is for such gpio_chip controllers to provide setup() and teardown() callbacks to board specific code; those board specific callbacks would register devices -once all the necessary resources are available. +once all the necessary resources are available, and remove them later when +the GPIO controller device becomes unavailable. + + +Sysfs Interface for Userspace (OPTIONAL) +======================================== +Platforms which use the "gpiolib" implementors framework may choose to +configure a sysfs user interface to GPIOs. This is different from the +debugfs interface, since it provides control over GPIO direction and +value instead of just showing a gpio state summary. Plus, it could be +present on production systems without debugging support. + +Given approprate hardware documentation for the system, userspace could +know for example that GPIO #23 controls the write protect line used to +protect boot loader segments in flash memory. System upgrade procedures +may need to temporarily remove that protection, first importing a GPIO, +then changing its output state, then updating the code before re-enabling +the write protection. In normal use, GPIO #23 would never be touched, +and the kernel would have no need to know about it. + +Again depending on appropriate hardware documentation, on some systems +userspace GPIO can be used to determine system configuration data that +standard kernels won't know about. And for some tasks, simple userspace +GPIO drivers could be all that the system really needs. + +Note that standard kernel drivers exist for common "LEDs and Buttons" +GPIO tasks: "leds-gpio" and "gpio_keys", respectively. Use those +instead of talking directly to the GPIOs; they integrate with kernel +frameworks better than your userspace code could. + + +Paths in Sysfs +-------------- +There are three kinds of entry in /sys/class/gpio: + + - Control interfaces used to get userspace control over GPIOs; + + - GPIOs themselves; and + + - GPIO controllers ("gpio_chip" instances). + +That's in addition to standard files including the "device" symlink. + +The control interfaces are write-only: + + /sys/class/gpio/ + + "export" ... Userspace may ask the kernel to export control of + a GPIO to userspace by writing its number to this file. + + Example: "echo 19 > export" will create a "gpio19" node + for GPIO #19, if that's not requested by kernel code. + + "unexport" ... Reverses the effect of exporting to userspace. + + Example: "echo 19 > unexport" will remove a "gpio19" + node exported using the "export" file. + +GPIO signals have paths like /sys/class/gpio/gpio42/ (for GPIO #42) +and have the following read/write attributes: + + /sys/class/gpio/gpioN/ + + "direction" ... reads as either "in" or "out". This value may + normally be written. Writing as "out" defaults to + initializing the value as low. To ensure glitch free + operation, values "low" and "high" may be written to + configure the GPIO as an output with that initial value. + + Note that this attribute *will not exist* if the kernel + doesn't support changing the direction of a GPIO, or + it was exported by kernel code that didn't explicitly + allow userspace to reconfigure this GPIO's direction. + + "value" ... reads as either 0 (low) or 1 (high). If the GPIO + is configured as an output, this value may be written; + any nonzero value is treated as high. + +GPIO controllers have paths like /sys/class/gpio/chipchip42/ (for the +controller implementing GPIOs starting at #42) and have the following +read-only attributes: + + /sys/class/gpio/gpiochipN/ + + "base" ... same as N, the first GPIO managed by this chip + + "label" ... provided for diagnostics (not always unique) + + "ngpio" ... how many GPIOs this manges (N to N + ngpio - 1) + +Board documentation should in most cases cover what GPIOs are used for +what purposes. However, those numbers are not always stable; GPIOs on +a daughtercard might be different depending on the base board being used, +or other cards in the stack. In such cases, you may need to use the +gpiochip nodes (possibly in conjunction with schematics) to determine +the correct GPIO number to use for a given signal. + + +Exporting from Kernel code +-------------------------- +Kernel code can explicitly manage exports of GPIOs which have already been +requested using gpio_request(): + + /* export the GPIO to userspace */ + int gpio_export(unsigned gpio, bool direction_may_change); + + /* reverse gpio_export() */ + void gpio_unexport(); + +After a kernel driver requests a GPIO, it may only be made available in +the sysfs interface by gpio_export(). The driver can control whether the +signal direction may change. This helps drivers prevent userspace code +from accidentally clobbering important system state. + +This explicit exporting can help with debugging (by making some kinds +of experiments easier), or can provide an always-there interface that's +suitable for documenting as part of a board support package. diff --git a/arch/arm/plat-omap/gpio.c b/arch/arm/plat-omap/gpio.c index 1903a3491ee..d8e9c2c3f0f 100644 --- a/arch/arm/plat-omap/gpio.c +++ b/arch/arm/plat-omap/gpio.c @@ -1488,6 +1488,9 @@ static int __init _omap_gpio_init(void) bank->chip.set = gpio_set; if (bank_is_mpuio(bank)) { bank->chip.label = "mpuio"; +#ifdef CONFIG_ARCH_OMAP1 + bank->chip.dev = &omap_mpuio_device.dev; +#endif bank->chip.base = OMAP_MPUIO(0); } else { bank->chip.label = "gpio"; diff --git a/arch/avr32/mach-at32ap/pio.c b/arch/avr32/mach-at32ap/pio.c index 60da03ba711..296294f8ed8 100644 --- a/arch/avr32/mach-at32ap/pio.c +++ b/arch/avr32/mach-at32ap/pio.c @@ -360,6 +360,8 @@ static int __init pio_probe(struct platform_device *pdev) pio->chip.label = pio->name; pio->chip.base = pdev->id * 32; pio->chip.ngpio = 32; + pio->chip.dev = &pdev->dev; + pio->chip.owner = THIS_MODULE; pio->chip.direction_input = direction_input; pio->chip.get = gpio_get; diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index fced1909cbb..6ec0e35b98e 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -23,6 +23,21 @@ config DEBUG_GPIO slower. The diagnostics help catch the type of setup errors that are most common when setting up new platforms or boards. +config GPIO_SYSFS + bool "/sys/class/gpio/... (sysfs interface)" + depends on SYSFS && EXPERIMENTAL + help + Say Y here to add a sysfs interface for GPIOs. + + This is mostly useful to work around omissions in a system's + kernel support. Those are common in custom and semicustom + hardware assembled using standard kernels with a minimum of + custom patches. In those cases, userspace code may import + a given GPIO from the kernel, if no kernel driver requested it. + + Kernel drivers may also request that a particular GPIO be + exported to userspace; this can be useful when debugging. + # put expanders in the right section, in alphabetical order comment "I2C GPIO expanders:" diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index beaf6b3a37d..8d2940517c9 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -2,8 +2,11 @@ #include #include #include - -#include +#include +#include +#include +#include +#include /* Optional implementation infrastructure for GPIO interfaces. @@ -44,6 +47,8 @@ struct gpio_desc { #define FLAG_REQUESTED 0 #define FLAG_IS_OUT 1 #define FLAG_RESERVED 2 +#define FLAG_EXPORT 3 /* protected by sysfs_lock */ +#define FLAG_SYSFS 4 /* exported via /sys/class/gpio/control */ #ifdef CONFIG_DEBUG_FS const char *label; @@ -151,6 +156,482 @@ err: return ret; } +#ifdef CONFIG_GPIO_SYSFS + +/* lock protects against unexport_gpio() being called while + * sysfs files are active. + */ +static DEFINE_MUTEX(sysfs_lock); + +/* + * /sys/class/gpio/gpioN... only for GPIOs that are exported + * /direction + * * MAY BE OMITTED if kernel won't allow direction changes + * * is read/write as "in" or "out" + * * may also be written as "high" or "low", initializing + * output value as specified ("out" implies "low") + * /value + * * always readable, subject to hardware behavior + * * may be writable, as zero/nonzero + * + * REVISIT there will likely be an attribute for configuring async + * notifications, e.g. to specify polling interval or IRQ trigger type + * that would for example trigger a poll() on the "value". + */ + +static ssize_t gpio_direction_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + const struct gpio_desc *desc = dev_get_drvdata(dev); + ssize_t status; + + mutex_lock(&sysfs_lock); + + if (!test_bit(FLAG_EXPORT, &desc->flags)) + status = -EIO; + else + status = sprintf(buf, "%s\n", + test_bit(FLAG_IS_OUT, &desc->flags) + ? "out" : "in"); + + mutex_unlock(&sysfs_lock); + return status; +} + +static ssize_t gpio_direction_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t size) +{ + const struct gpio_desc *desc = dev_get_drvdata(dev); + unsigned gpio = desc - gpio_desc; + ssize_t status; + + mutex_lock(&sysfs_lock); + + if (!test_bit(FLAG_EXPORT, &desc->flags)) + status = -EIO; + else if (sysfs_streq(buf, "high")) + status = gpio_direction_output(gpio, 1); + else if (sysfs_streq(buf, "out") || sysfs_streq(buf, "low")) + status = gpio_direction_output(gpio, 0); + else if (sysfs_streq(buf, "in")) + status = gpio_direction_input(gpio); + else + status = -EINVAL; + + mutex_unlock(&sysfs_lock); + return status ? : size; +} + +static const DEVICE_ATTR(direction, 0644, + gpio_direction_show, gpio_direction_store); + +static ssize_t gpio_value_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + const struct gpio_desc *desc = dev_get_drvdata(dev); + unsigned gpio = desc - gpio_desc; + ssize_t status; + + mutex_lock(&sysfs_lock); + + if (!test_bit(FLAG_EXPORT, &desc->flags)) + status = -EIO; + else + status = sprintf(buf, "%d\n", gpio_get_value_cansleep(gpio)); + + mutex_unlock(&sysfs_lock); + return status; +} + +static ssize_t gpio_value_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t size) +{ + const struct gpio_desc *desc = dev_get_drvdata(dev); + unsigned gpio = desc - gpio_desc; + ssize_t status; + + mutex_lock(&sysfs_lock); + + if (!test_bit(FLAG_EXPORT, &desc->flags)) + status = -EIO; + else if (!test_bit(FLAG_IS_OUT, &desc->flags)) + status = -EPERM; + else { + long value; + + status = strict_strtol(buf, 0, &value); + if (status == 0) { + gpio_set_value_cansleep(gpio, value != 0); + status = size; + } + } + + mutex_unlock(&sysfs_lock); + return status; +} + +static /*const*/ DEVICE_ATTR(value, 0644, + gpio_value_show, gpio_value_store); + +static const struct attribute *gpio_attrs[] = { + &dev_attr_direction.attr, + &dev_attr_value.attr, + NULL, +}; + +static const struct attribute_group gpio_attr_group = { + .attrs = (struct attribute **) gpio_attrs, +}; + +/* + * /sys/class/gpio/gpiochipN/ + * /base ... matching gpio_chip.base (N) + * /label ... matching gpio_chip.label + * /ngpio ... matching gpio_chip.ngpio + */ + +static ssize_t chip_base_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + const struct gpio_chip *chip = dev_get_drvdata(dev); + + return sprintf(buf, "%d\n", chip->base); +} +static DEVICE_ATTR(base, 0444, chip_base_show, NULL); + +static ssize_t chip_label_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + const struct gpio_chip *chip = dev_get_drvdata(dev); + + return sprintf(buf, "%s\n", chip->label ? : ""); +} +static DEVICE_ATTR(label, 0444, chip_label_show, NULL); + +static ssize_t chip_ngpio_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + const struct gpio_chip *chip = dev_get_drvdata(dev); + + return sprintf(buf, "%u\n", chip->ngpio); +} +static DEVICE_ATTR(ngpio, 0444, chip_ngpio_show, NULL); + +static const struct attribute *gpiochip_attrs[] = { + &dev_attr_base.attr, + &dev_attr_label.attr, + &dev_attr_ngpio.attr, + NULL, +}; + +static const struct attribute_group gpiochip_attr_group = { + .attrs = (struct attribute **) gpiochip_attrs, +}; + +/* + * /sys/class/gpio/export ... write-only + * integer N ... number of GPIO to export (full access) + * /sys/class/gpio/unexport ... write-only + * integer N ... number of GPIO to unexport + */ +static ssize_t export_store(struct class *class, const char *buf, size_t len) +{ + long gpio; + int status; + + status = strict_strtol(buf, 0, &gpio); + if (status < 0) + goto done; + + /* No extra locking here; FLAG_SYSFS just signifies that the + * request and export were done by on behalf of userspace, so + * they may be undone on its behalf too. + */ + + status = gpio_request(gpio, "sysfs"); + if (status < 0) + goto done; + + status = gpio_export(gpio, true); + if (status < 0) + gpio_free(gpio); + else + set_bit(FLAG_SYSFS, &gpio_desc[gpio].flags); + +done: + if (status) + pr_debug("%s: status %d\n", __func__, status); + return status ? : len; +} + +static ssize_t unexport_store(struct class *class, const char *buf, size_t len) +{ + long gpio; + int status; + + status = strict_strtol(buf, 0, &gpio); + if (status < 0) + goto done; + + status = -EINVAL; + + /* reject bogus commands (gpio_unexport ignores them) */ + if (!gpio_is_valid(gpio)) + goto done; + + /* No extra locking here; FLAG_SYSFS just signifies that the + * request and export were done by on behalf of userspace, so + * they may be undone on its behalf too. + */ + if (test_and_clear_bit(FLAG_SYSFS, &gpio_desc[gpio].flags)) { + status = 0; + gpio_free(gpio); + } +done: + if (status) + pr_debug("%s: status %d\n", __func__, status); + return status ? : len; +} + +static struct class_attribute gpio_class_attrs[] = { + __ATTR(export, 0200, NULL, export_store), + __ATTR(unexport, 0200, NULL, unexport_store), + __ATTR_NULL, +}; + +static struct class gpio_class = { + .name = "gpio", + .owner = THIS_MODULE, + + .class_attrs = gpio_class_attrs, +}; + + +/** + * gpio_export - export a GPIO through sysfs + * @gpio: gpio to make available, already requested + * @direction_may_change: true if userspace may change gpio direction + * Context: arch_initcall or later + * + * When drivers want to make a GPIO accessible to userspace after they + * have requested it -- perhaps while debugging, or as part of their + * public interface -- they may use this routine. If the GPIO can + * change direction (some can't) and the caller allows it, userspace + * will see "direction" sysfs attribute which may be used to change + * the gpio's direction. A "value" attribute will always be provided. + * + * Returns zero on success, else an error. + */ +int gpio_export(unsigned gpio, bool direction_may_change) +{ + unsigned long flags; + struct gpio_desc *desc; + int status = -EINVAL; + + /* can't export until sysfs is available ... */ + if (!gpio_class.p) { + pr_debug("%s: called too early!\n", __func__); + return -ENOENT; + } + + if (!gpio_is_valid(gpio)) + goto done; + + mutex_lock(&sysfs_lock); + + spin_lock_irqsave(&gpio_lock, flags); + desc = &gpio_desc[gpio]; + if (test_bit(FLAG_REQUESTED, &desc->flags) + && !test_bit(FLAG_EXPORT, &desc->flags)) { + status = 0; + if (!desc->chip->direction_input + || !desc->chip->direction_output) + direction_may_change = false; + } + spin_unlock_irqrestore(&gpio_lock, flags); + + if (status == 0) { + struct device *dev; + + dev = device_create(&gpio_class, desc->chip->dev, MKDEV(0, 0), + desc, "gpio%d", gpio); + if (dev) { + if (direction_may_change) + status = sysfs_create_group(&dev->kobj, + &gpio_attr_group); + else + status = device_create_file(dev, + &dev_attr_value); + if (status != 0) + device_unregister(dev); + } else + status = -ENODEV; + if (status == 0) + set_bit(FLAG_EXPORT, &desc->flags); + } + + mutex_unlock(&sysfs_lock); + +done: + if (status) + pr_debug("%s: gpio%d status %d\n", __func__, gpio, status); + + return status; +} +EXPORT_SYMBOL_GPL(gpio_export); + +static int match_export(struct device *dev, void *data) +{ + return dev_get_drvdata(dev) == data; +} + +/** + * gpio_unexport - reverse effect of gpio_export() + * @gpio: gpio to make unavailable + * + * This is implicit on gpio_free(). + */ +void gpio_unexport(unsigned gpio) +{ + struct gpio_desc *desc; + int status = -EINVAL; + + if (!gpio_is_valid(gpio)) + goto done; + + mutex_lock(&sysfs_lock); + + desc = &gpio_desc[gpio]; + if (test_bit(FLAG_EXPORT, &desc->flags)) { + struct device *dev = NULL; + + dev = class_find_device(&gpio_class, NULL, desc, match_export); + if (dev) { + clear_bit(FLAG_EXPORT, &desc->flags); + put_device(dev); + device_unregister(dev); + status = 0; + } else + status = -ENODEV; + } + + mutex_unlock(&sysfs_lock); +done: + if (status) + pr_debug("%s: gpio%d status %d\n", __func__, gpio, status); +} +EXPORT_SYMBOL_GPL(gpio_unexport); + +static int gpiochip_export(struct gpio_chip *chip) +{ + int status; + struct device *dev; + + /* Many systems register gpio chips for SOC support very early, + * before driver model support is available. In those cases we + * export this later, in gpiolib_sysfs_init() ... here we just + * verify that _some_ field of gpio_class got initialized. + */ + if (!gpio_class.p) + return 0; + + /* use chip->base for the ID; it's already known to be unique */ + mutex_lock(&sysfs_lock); + dev = device_create(&gpio_class, chip->dev, MKDEV(0, 0), chip, + "gpiochip%d", chip->base); + if (dev) { + status = sysfs_create_group(&dev->kobj, + &gpiochip_attr_group); + } else + status = -ENODEV; + chip->exported = (status == 0); + mutex_unlock(&sysfs_lock); + + if (status) { + unsigned long flags; + unsigned gpio; + + spin_lock_irqsave(&gpio_lock, flags); + gpio = chip->base; + while (gpio_desc[gpio].chip == chip) + gpio_desc[gpio++].chip = NULL; + spin_unlock_irqrestore(&gpio_lock, flags); + + pr_debug("%s: chip %s status %d\n", __func__, + chip->label, status); + } + + return status; +} + +static void gpiochip_unexport(struct gpio_chip *chip) +{ + int status; + struct device *dev; + + mutex_lock(&sysfs_lock); + dev = class_find_device(&gpio_class, NULL, chip, match_export); + if (dev) { + put_device(dev); + device_unregister(dev); + chip->exported = 0; + status = 0; + } else + status = -ENODEV; + mutex_unlock(&sysfs_lock); + + if (status) + pr_debug("%s: chip %s status %d\n", __func__, + chip->label, status); +} + +static int __init gpiolib_sysfs_init(void) +{ + int status; + unsigned long flags; + unsigned gpio; + + status = class_register(&gpio_class); + if (status < 0) + return status; + + /* Scan and register the gpio_chips which registered very + * early (e.g. before the class_register above was called). + * + * We run before arch_initcall() so chip->dev nodes can have + * registered, and so arch_initcall() can always gpio_export(). + */ + spin_lock_irqsave(&gpio_lock, flags); + for (gpio = 0; gpio < ARCH_NR_GPIOS; gpio++) { + struct gpio_chip *chip; + + chip = gpio_desc[gpio].chip; + if (!chip || chip->exported) + continue; + + spin_unlock_irqrestore(&gpio_lock, flags); + status = gpiochip_export(chip); + spin_lock_irqsave(&gpio_lock, flags); + } + spin_unlock_irqrestore(&gpio_lock, flags); + + + return status; +} +postcore_initcall(gpiolib_sysfs_init); + +#else +static inline int gpiochip_export(struct gpio_chip *chip) +{ + return 0; +} + +static inline void gpiochip_unexport(struct gpio_chip *chip) +{ +} + +#endif /* CONFIG_GPIO_SYSFS */ + /** * gpiochip_add() - register a gpio_chip * @chip: the chip to register, with chip->base initialized @@ -160,6 +641,11 @@ err: * because the chip->base is invalid or already associated with a * different chip. Otherwise it returns zero as a success code. * + * When gpiochip_add() is called very early during boot, so that GPIOs + * can be freely used, the chip->dev device must be registered before + * the gpio framework's arch_initcall(). Otherwise sysfs initialization + * for GPIOs will fail rudely. + * * If chip->base is negative, this requests dynamic assignment of * a range of valid GPIOs. */ @@ -182,7 +668,7 @@ int gpiochip_add(struct gpio_chip *chip) base = gpiochip_find_base(chip->ngpio); if (base < 0) { status = base; - goto fail_unlock; + goto unlock; } chip->base = base; } @@ -197,12 +683,23 @@ int gpiochip_add(struct gpio_chip *chip) if (status == 0) { for (id = base; id < base + chip->ngpio; id++) { gpio_desc[id].chip = chip; - gpio_desc[id].flags = 0; + + /* REVISIT: most hardware initializes GPIOs as + * inputs (often with pullups enabled) so power + * usage is minimized. Linux code should set the + * gpio direction first thing; but until it does, + * we may expose the wrong direction in sysfs. + */ + gpio_desc[id].flags = !chip->direction_input + ? (1 << FLAG_IS_OUT) + : 0; } } -fail_unlock: +unlock: spin_unlock_irqrestore(&gpio_lock, flags); + if (status == 0) + status = gpiochip_export(chip); fail: /* failures here can mean systems won't boot... */ if (status) @@ -239,6 +736,10 @@ int gpiochip_remove(struct gpio_chip *chip) } spin_unlock_irqrestore(&gpio_lock, flags); + + if (status == 0) + gpiochip_unexport(chip); + return status; } EXPORT_SYMBOL_GPL(gpiochip_remove); @@ -296,6 +797,8 @@ void gpio_free(unsigned gpio) return; } + gpio_unexport(gpio); + spin_lock_irqsave(&gpio_lock, flags); desc = &gpio_desc[gpio]; @@ -534,10 +1037,6 @@ EXPORT_SYMBOL_GPL(gpio_set_value_cansleep); #ifdef CONFIG_DEBUG_FS -#include -#include - - static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip) { unsigned i; @@ -614,17 +1113,28 @@ static int gpiolib_show(struct seq_file *s, void *unused) /* REVISIT this isn't locked against gpio_chip removal ... */ for (gpio = 0; gpio_is_valid(gpio); gpio++) { + struct device *dev; + if (chip == gpio_desc[gpio].chip) continue; chip = gpio_desc[gpio].chip; if (!chip) continue; - seq_printf(s, "%sGPIOs %d-%d, %s%s:\n", + seq_printf(s, "%sGPIOs %d-%d", started ? "\n" : "", - chip->base, chip->base + chip->ngpio - 1, - chip->label ? : "generic", - chip->can_sleep ? ", can sleep" : ""); + chip->base, chip->base + chip->ngpio - 1); + dev = chip->dev; + if (dev) + seq_printf(s, ", %s/%s", + dev->bus ? dev->bus->name : "no-bus", + dev->bus_id); + if (chip->label) + seq_printf(s, ", %s", chip->label); + if (chip->can_sleep) + seq_printf(s, ", can sleep"); + seq_printf(s, ":\n"); + started = 1; if (chip->dbg_show) chip->dbg_show(s, chip); diff --git a/drivers/gpio/mcp23s08.c b/drivers/gpio/mcp23s08.c index 7f92fdd5f0e..7efd7d3a81f 100644 --- a/drivers/gpio/mcp23s08.c +++ b/drivers/gpio/mcp23s08.c @@ -239,6 +239,7 @@ static int mcp23s08_probe(struct spi_device *spi) mcp->chip.base = pdata->base; mcp->chip.ngpio = 8; mcp->chip.can_sleep = 1; + mcp->chip.dev = &spi->dev; mcp->chip.owner = THIS_MODULE; spi_set_drvdata(spi, mcp); diff --git a/drivers/gpio/pca953x.c b/drivers/gpio/pca953x.c index a380730b61a..cc8468692ae 100644 --- a/drivers/gpio/pca953x.c +++ b/drivers/gpio/pca953x.c @@ -188,6 +188,7 @@ static void pca953x_setup_gpio(struct pca953x_chip *chip, int gpios) gc->base = chip->gpio_start; gc->ngpio = gpios; gc->label = chip->client->name; + gc->dev = &chip->client->dev; gc->owner = THIS_MODULE; } diff --git a/drivers/gpio/pcf857x.c b/drivers/gpio/pcf857x.c index d25d356c4f2..fc9c6ae739e 100644 --- a/drivers/gpio/pcf857x.c +++ b/drivers/gpio/pcf857x.c @@ -200,6 +200,7 @@ static int pcf857x_probe(struct i2c_client *client, gpio->chip.base = pdata->gpio_base; gpio->chip.can_sleep = 1; + gpio->chip.dev = &client->dev; gpio->chip.owner = THIS_MODULE; /* NOTE: the OnSemi jlc1562b is also largely compatible with diff --git a/drivers/i2c/chips/tps65010.c b/drivers/i2c/chips/tps65010.c index 85949685191..cf02e8fceb4 100644 --- a/drivers/i2c/chips/tps65010.c +++ b/drivers/i2c/chips/tps65010.c @@ -636,6 +636,8 @@ static int tps65010_probe(struct i2c_client *client, tps->outmask = board->outmask; tps->chip.label = client->name; + tps->chip.dev = &client->dev; + tps->chip.owner = THIS_MODULE; tps->chip.set = tps65010_gpio_set; tps->chip.direction_output = tps65010_output; diff --git a/drivers/mfd/htc-egpio.c b/drivers/mfd/htc-egpio.c index 8872cc07751..6be43172dc6 100644 --- a/drivers/mfd/htc-egpio.c +++ b/drivers/mfd/htc-egpio.c @@ -318,6 +318,8 @@ static int __init egpio_probe(struct platform_device *pdev) ei->chip[i].dev = &(pdev->dev); chip = &(ei->chip[i].chip); chip->label = "htc-egpio"; + chip->dev = &pdev->dev; + chip->owner = THIS_MODULE; chip->get = egpio_get; chip->set = egpio_set; chip->direction_input = egpio_direction_input; diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h index 6be061d09da..1beff5166e5 100644 --- a/include/asm-generic/gpio.h +++ b/include/asm-generic/gpio.h @@ -32,6 +32,8 @@ struct module; /** * struct gpio_chip - abstract a GPIO controller * @label: for diagnostics + * @dev: optional device providing the GPIOs + * @owner: helps prevent removal of modules exporting active GPIOs * @direction_input: configures signal "offset" as input, or returns error * @get: returns value for signal "offset"; for output signals this * returns either the value actually sensed, or zero @@ -59,6 +61,7 @@ struct module; */ struct gpio_chip { char *label; + struct device *dev; struct module *owner; int (*direction_input)(struct gpio_chip *chip, @@ -74,6 +77,7 @@ struct gpio_chip { int base; u16 ngpio; unsigned can_sleep:1; + unsigned exported:1; }; extern const char *gpiochip_is_requested(struct gpio_chip *chip, @@ -108,7 +112,18 @@ extern void __gpio_set_value(unsigned gpio, int value); extern int __gpio_cansleep(unsigned gpio); -#else +#ifdef CONFIG_GPIO_SYSFS + +/* + * A sysfs interface can be exported by individual drivers if they want, + * but more typically is configured entirely from userspace. + */ +extern int gpio_export(unsigned gpio, bool direction_may_change); +extern void gpio_unexport(unsigned gpio); + +#endif /* CONFIG_GPIO_SYSFS */ + +#else /* !CONFIG_HAVE_GPIO_LIB */ static inline int gpio_is_valid(int number) { @@ -137,6 +152,20 @@ static inline void gpio_set_value_cansleep(unsigned gpio, int value) gpio_set_value(gpio, value); } -#endif +#endif /* !CONFIG_HAVE_GPIO_LIB */ + +#ifndef CONFIG_GPIO_SYSFS + +/* sysfs support is only available with gpiolib, where it's optional */ + +static inline int gpio_export(unsigned gpio, bool direction_may_change) +{ + return -ENOSYS; +} + +static inline void gpio_unexport(unsigned gpio) +{ +} +#endif /* CONFIG_GPIO_SYSFS */ #endif /* _ASM_GENERIC_GPIO_H */ diff --git a/include/linux/gpio.h b/include/linux/gpio.h index 98be6c5762b..730a20b8357 100644 --- a/include/linux/gpio.h +++ b/include/linux/gpio.h @@ -79,6 +79,19 @@ static inline void gpio_set_value_cansleep(unsigned gpio, int value) WARN_ON(1); } +static inline int gpio_export(unsigned gpio, bool direction_may_change) +{ + /* GPIO can never have been requested or set as {in,out}put */ + WARN_ON(1); + return -EINVAL; +} + +static inline void gpio_unexport(unsigned gpio) +{ + /* GPIO can never have been exported */ + WARN_ON(1); +} + static inline int gpio_to_irq(unsigned gpio) { /* GPIO can never have been requested or set as input */ -- cgit v1.2.3-70-g09d2 From 8f1cc3b10e6ee0c5c7c8ed27f8771c4f252b4862 Mon Sep 17 00:00:00 2001 From: David Brownell Date: Fri, 25 Jul 2008 01:46:09 -0700 Subject: gpio: mcp23s08 handles multiple chips per chipselect Teach the mcp23s08 driver about a curious feature of these chips: up to four of them can share the same chipselect, with the SPI signals wired in parallel, by matching two bits in the first protocol byte against two address lines on the chip. This is handled by three software changes: * Platform data now holds an array of per-chip structs, not just one chip's address and pullup configuration. * Probe() and remove() now use another level of structure, wrapping an instance of the original structure for each mcp23s08 chip sharing that chipselect. * The HAEN bit is set, so that the hardware address bits can no longer be ignored (boot firmware may not have enabled them). The "one struct per chip" preserves the guts of the current code, but platform_data will need minor changes. OLD: /* incorrect "slave" ID may not have mattered */ .slave = 3, .pullups = BIT(3) | BIT(1) | BIT(0), NEW: /* slave address _must_ match chip's wiring */ .chip[3] = { .is_present = true, .pullups = BIT(3) | BIT(1) | BIT(0), }, There's no change in how things _behave_ for spi_device nodes with a single mcp23s08 chip. New multi-chip configurations assign GPIOs in sequence, without holes. The spi_device just resembles a bigger controller, but internally it has multiple gpio_chip instances. Signed-off-by: David Brownell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/gpio/mcp23s08.c | 133 +++++++++++++++++++++++++++++++++---------- include/linux/spi/mcp23s08.h | 25 +++++--- 2 files changed, 118 insertions(+), 40 deletions(-) (limited to 'drivers/gpio') diff --git a/drivers/gpio/mcp23s08.c b/drivers/gpio/mcp23s08.c index 7efd7d3a81f..8a1b405fefd 100644 --- a/drivers/gpio/mcp23s08.c +++ b/drivers/gpio/mcp23s08.c @@ -40,15 +40,26 @@ struct mcp23s08 { struct spi_device *spi; u8 addr; + u8 cache[11]; /* lock protects the cached values */ struct mutex lock; - u8 cache[11]; struct gpio_chip chip; struct work_struct work; }; +/* A given spi_device can represent up to four mcp23s08 chips + * sharing the same chipselect but using different addresses + * (e.g. chips #0 and #3 might be populated, but not #1 or $2). + * Driver data holds all the per-chip data. + */ +struct mcp23s08_driver_data { + unsigned ngpio; + struct mcp23s08 *mcp[4]; + struct mcp23s08 chip[]; +}; + static int mcp23s08_read(struct mcp23s08 *mcp, unsigned reg) { u8 tx[2], rx[1]; @@ -208,25 +219,18 @@ done: /*----------------------------------------------------------------------*/ -static int mcp23s08_probe(struct spi_device *spi) +static int mcp23s08_probe_one(struct spi_device *spi, unsigned addr, + unsigned base, unsigned pullups) { - struct mcp23s08 *mcp; - struct mcp23s08_platform_data *pdata; + struct mcp23s08_driver_data *data = spi_get_drvdata(spi); + struct mcp23s08 *mcp = data->mcp[addr]; int status; int do_update = 0; - pdata = spi->dev.platform_data; - if (!pdata || pdata->slave > 3 || !pdata->base) - return -ENODEV; - - mcp = kzalloc(sizeof *mcp, GFP_KERNEL); - if (!mcp) - return -ENOMEM; - mutex_init(&mcp->lock); mcp->spi = spi; - mcp->addr = 0x40 | (pdata->slave << 1); + mcp->addr = 0x40 | (addr << 1); mcp->chip.label = "mcp23s08", @@ -236,27 +240,28 @@ static int mcp23s08_probe(struct spi_device *spi) mcp->chip.set = mcp23s08_set; mcp->chip.dbg_show = mcp23s08_dbg_show; - mcp->chip.base = pdata->base; + mcp->chip.base = base; mcp->chip.ngpio = 8; mcp->chip.can_sleep = 1; mcp->chip.dev = &spi->dev; mcp->chip.owner = THIS_MODULE; - spi_set_drvdata(spi, mcp); - - /* verify MCP_IOCON.SEQOP = 0, so sequential reads work */ + /* verify MCP_IOCON.SEQOP = 0, so sequential reads work, + * and MCP_IOCON.HAEN = 1, so we work with all chips. + */ status = mcp23s08_read(mcp, MCP_IOCON); if (status < 0) goto fail; - if (status & IOCON_SEQOP) { + if ((status & IOCON_SEQOP) || !(status & IOCON_HAEN)) { status &= ~IOCON_SEQOP; + status |= IOCON_HAEN; status = mcp23s08_write(mcp, MCP_IOCON, (u8) status); if (status < 0) goto fail; } /* configure ~100K pullups */ - status = mcp23s08_write(mcp, MCP_GPPU, pdata->pullups); + status = mcp23s08_write(mcp, MCP_GPPU, pullups); if (status < 0) goto fail; @@ -283,11 +288,58 @@ static int mcp23s08_probe(struct spi_device *spi) tx[1] = MCP_IPOL; memcpy(&tx[2], &mcp->cache[MCP_IPOL], sizeof(tx) - 2); status = spi_write_then_read(mcp->spi, tx, sizeof tx, NULL, 0); - - /* FIXME check status... */ + if (status < 0) + goto fail; } status = gpiochip_add(&mcp->chip); +fail: + if (status < 0) + dev_dbg(&spi->dev, "can't setup chip %d, --> %d\n", + addr, status); + return status; +} + +static int mcp23s08_probe(struct spi_device *spi) +{ + struct mcp23s08_platform_data *pdata; + unsigned addr; + unsigned chips = 0; + struct mcp23s08_driver_data *data; + int status; + unsigned base; + + pdata = spi->dev.platform_data; + if (!pdata || !gpio_is_valid(pdata->base)) + return -ENODEV; + + for (addr = 0; addr < 4; addr++) { + if (!pdata->chip[addr].is_present) + continue; + chips++; + } + if (!chips) + return -ENODEV; + + data = kzalloc(sizeof *data + chips * sizeof(struct mcp23s08), + GFP_KERNEL); + if (!data) + return -ENOMEM; + spi_set_drvdata(spi, data); + + base = pdata->base; + for (addr = 0; addr < 4; addr++) { + if (!pdata->chip[addr].is_present) + continue; + chips--; + data->mcp[addr] = &data->chip[chips]; + status = mcp23s08_probe_one(spi, addr, base, + pdata->chip[addr].pullups); + if (status < 0) + goto fail; + base += 8; + } + data->ngpio = base - pdata->base; /* NOTE: these chips have a relatively sane IRQ framework, with * per-signal masking and level/edge triggering. It's not yet @@ -295,8 +347,9 @@ static int mcp23s08_probe(struct spi_device *spi) */ if (pdata->setup) { - status = pdata->setup(spi, mcp->chip.base, - mcp->chip.ngpio, pdata->context); + status = pdata->setup(spi, + pdata->base, data->ngpio, + pdata->context); if (status < 0) dev_dbg(&spi->dev, "setup --> %d\n", status); } @@ -304,19 +357,29 @@ static int mcp23s08_probe(struct spi_device *spi) return 0; fail: - kfree(mcp); + for (addr = 0; addr < 4; addr++) { + int tmp; + + if (!data->mcp[addr]) + continue; + tmp = gpiochip_remove(&data->mcp[addr]->chip); + if (tmp < 0) + dev_err(&spi->dev, "%s --> %d\n", "remove", tmp); + } + kfree(data); return status; } static int mcp23s08_remove(struct spi_device *spi) { - struct mcp23s08 *mcp = spi_get_drvdata(spi); + struct mcp23s08_driver_data *data = spi_get_drvdata(spi); struct mcp23s08_platform_data *pdata = spi->dev.platform_data; + unsigned addr; int status = 0; if (pdata->teardown) { status = pdata->teardown(spi, - mcp->chip.base, mcp->chip.ngpio, + pdata->base, data->ngpio, pdata->context); if (status < 0) { dev_err(&spi->dev, "%s --> %d\n", "teardown", status); @@ -324,11 +387,20 @@ static int mcp23s08_remove(struct spi_device *spi) } } - status = gpiochip_remove(&mcp->chip); + for (addr = 0; addr < 4; addr++) { + int tmp; + + if (!data->mcp[addr]) + continue; + + tmp = gpiochip_remove(&data->mcp[addr]->chip); + if (tmp < 0) { + dev_err(&spi->dev, "%s --> %d\n", "remove", tmp); + status = tmp; + } + } if (status == 0) - kfree(mcp); - else - dev_err(&spi->dev, "%s --> %d\n", "remove", status); + kfree(data); return status; } @@ -356,4 +428,3 @@ static void __exit mcp23s08_exit(void) module_exit(mcp23s08_exit); MODULE_LICENSE("GPL"); - diff --git a/include/linux/spi/mcp23s08.h b/include/linux/spi/mcp23s08.h index 835ddf47d45..22ef107d770 100644 --- a/include/linux/spi/mcp23s08.h +++ b/include/linux/spi/mcp23s08.h @@ -1,18 +1,25 @@ -/* FIXME driver should be able to handle all four slaves that - * can be hooked up to each chipselect, as well as IRQs... - */ +/* FIXME driver should be able to handle IRQs... */ + +struct mcp23s08_chip_info { + bool is_present; /* true iff populated */ + u8 pullups; /* BIT(x) means enable pullup x */ +}; struct mcp23s08_platform_data { - /* four slaves can share one SPI chipselect */ - u8 slave; + /* Four slaves (numbered 0..3) can share one SPI chipselect, and + * will provide 8..32 GPIOs using 1..4 gpio_chip instances. + */ + struct mcp23s08_chip_info chip[4]; - /* number assigned to the first GPIO */ + /* "base" is the number of the first GPIO. Dynamic assignment is + * not currently supported, and even if there are gaps in chip + * addressing the GPIO numbers are sequential .. so for example + * if only slaves 0 and 3 are present, their GPIOs range from + * base to base+15. + */ unsigned base; - /* pins with pullups */ - u8 pullups; - void *context; /* param to setup/teardown */ int (*setup)(struct spi_device *spi, -- cgit v1.2.3-70-g09d2 From ff1d5c2f0268f4e32103536e2e65480b5b7b6530 Mon Sep 17 00:00:00 2001 From: Michael Buesch Date: Fri, 25 Jul 2008 01:46:10 -0700 Subject: gpio: add bt8xxgpio driver This adds the bt8xxgpio driver. The purpose of the bt8xxgpio driver is to export all of the 24 GPIO pins available on Brooktree 8xx chips to the kernel GPIO infrastructure. This makes it possible to use a physically modified BT8xx card as cheap digital GPIO card. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Michael Buesch Cc: David Brownell Cc: Stephen Rothwell Cc: Mauro Carvalho Chehab Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/bt8xxgpio.txt | 67 +++++++++ MAINTAINERS | 6 + drivers/gpio/Kconfig | 18 +++ drivers/gpio/Makefile | 1 + drivers/gpio/bt8xxgpio.c | 348 ++++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 440 insertions(+) create mode 100644 Documentation/bt8xxgpio.txt create mode 100644 drivers/gpio/bt8xxgpio.c (limited to 'drivers/gpio') diff --git a/Documentation/bt8xxgpio.txt b/Documentation/bt8xxgpio.txt new file mode 100644 index 00000000000..d8297e4ebd2 --- /dev/null +++ b/Documentation/bt8xxgpio.txt @@ -0,0 +1,67 @@ +=============================================================== +== BT8XXGPIO driver == +== == +== A driver for a selfmade cheap BT8xx based PCI GPIO-card == +== == +== For advanced documentation, see == +== http://www.bu3sch.de/btgpio.php == +=============================================================== + + +A generic digital 24-port PCI GPIO card can be built out of an ordinary +Brooktree bt848, bt849, bt878 or bt879 based analog TV tuner card. The +Brooktree chip is used in old analog Hauppauge WinTV PCI cards. You can easily +find them used for low prices on the net. + +The bt8xx chip does have 24 digital GPIO ports. +These ports are accessible via 24 pins on the SMD chip package. + + +============================================== +== How to physically access the GPIO pins == +============================================== + +The are several ways to access these pins. One might unsolder the whole chip +and put it on a custom PCI board, or one might only unsolder each individual +GPIO pin and solder that to some tiny wire. As the chip package really is tiny +there are some advanced soldering skills needed in any case. + +The physical pinouts are drawn in the following ASCII art. +The GPIO pins are marked with G00-G23 + + G G G G G G G G G G G G G G G G G G + 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 + 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 + | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | + --------------------------------------------------------------------------- + --| ^ ^ |-- + --| pin 86 pin 67 |-- + --| |-- + --| pin 61 > |-- G18 + --| |-- G19 + --| |-- G20 + --| |-- G21 + --| |-- G22 + --| pin 56 > |-- G23 + --| |-- + --| Brooktree 878/879 |-- + --| |-- + --| |-- + --| |-- + --| |-- + --| |-- + --| |-- + --| |-- + --| |-- + --| |-- + --| |-- + --| |-- + --| |-- + --| |-- + --| O |-- + --| |-- + --------------------------------------------------------------------------- + | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | + ^ + This is pin 1 + diff --git a/MAINTAINERS b/MAINTAINERS index be05ef9b7b4..4cbf6016a9b 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -1043,6 +1043,12 @@ M: fujita.tomonori@lab.ntt.co.jp L: linux-scsi@vger.kernel.org S: Supported +BT8XXGPIO DRIVER +P: Michael Buesch +M: mb@bu3sch.de +W: http://bu3sch.de/btgpio.php +S: Maintained + BTTV VIDEO4LINUX DRIVER P: Mauro Carvalho Chehab M: mchehab@infradead.org diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index 6ec0e35b98e..de202dbe530 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -83,6 +83,24 @@ config GPIO_PCF857X This driver provides an in-kernel interface to those GPIOs using platform-neutral GPIO calls. +comment "PCI GPIO expanders:" + +config GPIO_BT8XX + tristate "BT8XX GPIO abuser" + depends on PCI && VIDEO_BT848=n + help + The BT8xx frame grabber chip has 24 GPIO pins than can be abused + as a cheap PCI GPIO card. + + This chip can be found on Miro, Hauppauge and STB TV-cards. + + The card needs to be physically altered for using it as a + GPIO card. For more information on how to build a GPIO card + from a BT8xx TV card, see the documentation file at + Documentation/bt8xxgpio.txt + + If unsure, say N. + comment "SPI GPIO expanders:" config GPIO_MAX7301 diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index 16e796dc541..eeb2f2b2028 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -8,3 +8,4 @@ obj-$(CONFIG_GPIO_MAX7301) += max7301.o obj-$(CONFIG_GPIO_MCP23S08) += mcp23s08.o obj-$(CONFIG_GPIO_PCA953X) += pca953x.o obj-$(CONFIG_GPIO_PCF857X) += pcf857x.o +obj-$(CONFIG_GPIO_BT8XX) += bt8xxgpio.o diff --git a/drivers/gpio/bt8xxgpio.c b/drivers/gpio/bt8xxgpio.c new file mode 100644 index 00000000000..7a1168249dd --- /dev/null +++ b/drivers/gpio/bt8xxgpio.c @@ -0,0 +1,348 @@ +/* + + bt8xx GPIO abuser + + Copyright (C) 2008 Michael Buesch + + Please do _only_ contact the people listed _above_ with issues related to this driver. + All the other people listed below are not related to this driver. Their names + are only here, because this driver is derived from the bt848 driver. + + + Derived from the bt848 driver: + + Copyright (C) 1996,97,98 Ralph Metzler + & Marcus Metzler + (c) 1999-2002 Gerd Knorr + + some v4l2 code lines are taken from Justin's bttv2 driver which is + (c) 2000 Justin Schoeman + + V4L1 removal from: + (c) 2005-2006 Nickolay V. Shmyrev + + Fixes to be fully V4L2 compliant by + (c) 2006 Mauro Carvalho Chehab + + Cropping and overscan support + Copyright (C) 2005, 2006 Michael H. Schimek + Sponsored by OPQ Systems AB + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. +*/ + +#include +#include +#include + +#include + +/* Steal the hardware definitions from the bttv driver. */ +#include "../media/video/bt8xx/bt848.h" + + +#define BT8XXGPIO_NR_GPIOS 24 /* We have 24 GPIO pins */ + + +struct bt8xxgpio { + spinlock_t lock; + + void __iomem *mmio; + struct pci_dev *pdev; + struct gpio_chip gpio; + +#ifdef CONFIG_PM + u32 saved_outen; + u32 saved_data; +#endif +}; + +#define bgwrite(dat, adr) writel((dat), bg->mmio+(adr)) +#define bgread(adr) readl(bg->mmio+(adr)) + + +static int modparam_gpiobase = -1/* dynamic */; +module_param_named(gpiobase, modparam_gpiobase, int, 0444); +MODULE_PARM_DESC(gpiobase, "The GPIO number base. -1 means dynamic, which is the default."); + + +static int bt8xxgpio_gpio_direction_input(struct gpio_chip *gpio, unsigned nr) +{ + struct bt8xxgpio *bg = container_of(gpio, struct bt8xxgpio, gpio); + unsigned long flags; + u32 outen, data; + + spin_lock_irqsave(&bg->lock, flags); + + data = bgread(BT848_GPIO_DATA); + data &= ~(1 << nr); + bgwrite(data, BT848_GPIO_DATA); + + outen = bgread(BT848_GPIO_OUT_EN); + outen &= ~(1 << nr); + bgwrite(outen, BT848_GPIO_OUT_EN); + + spin_unlock_irqrestore(&bg->lock, flags); + + return 0; +} + +static int bt8xxgpio_gpio_get(struct gpio_chip *gpio, unsigned nr) +{ + struct bt8xxgpio *bg = container_of(gpio, struct bt8xxgpio, gpio); + unsigned long flags; + u32 val; + + spin_lock_irqsave(&bg->lock, flags); + val = bgread(BT848_GPIO_DATA); + spin_unlock_irqrestore(&bg->lock, flags); + + return !!(val & (1 << nr)); +} + +static int bt8xxgpio_gpio_direction_output(struct gpio_chip *gpio, + unsigned nr, int val) +{ + struct bt8xxgpio *bg = container_of(gpio, struct bt8xxgpio, gpio); + unsigned long flags; + u32 outen, data; + + spin_lock_irqsave(&bg->lock, flags); + + outen = bgread(BT848_GPIO_OUT_EN); + outen |= (1 << nr); + bgwrite(outen, BT848_GPIO_OUT_EN); + + data = bgread(BT848_GPIO_DATA); + if (val) + data |= (1 << nr); + else + data &= ~(1 << nr); + bgwrite(data, BT848_GPIO_DATA); + + spin_unlock_irqrestore(&bg->lock, flags); + + return 0; +} + +static void bt8xxgpio_gpio_set(struct gpio_chip *gpio, + unsigned nr, int val) +{ + struct bt8xxgpio *bg = container_of(gpio, struct bt8xxgpio, gpio); + unsigned long flags; + u32 data; + + spin_lock_irqsave(&bg->lock, flags); + + data = bgread(BT848_GPIO_DATA); + if (val) + data |= (1 << nr); + else + data &= ~(1 << nr); + bgwrite(data, BT848_GPIO_DATA); + + spin_unlock_irqrestore(&bg->lock, flags); +} + +static void bt8xxgpio_gpio_setup(struct bt8xxgpio *bg) +{ + struct gpio_chip *c = &bg->gpio; + + c->label = bg->pdev->dev.bus_id; + c->owner = THIS_MODULE; + c->direction_input = bt8xxgpio_gpio_direction_input; + c->get = bt8xxgpio_gpio_get; + c->direction_output = bt8xxgpio_gpio_direction_output; + c->set = bt8xxgpio_gpio_set; + c->dbg_show = NULL; + c->base = modparam_gpiobase; + c->ngpio = BT8XXGPIO_NR_GPIOS; + c->can_sleep = 0; +} + +static int bt8xxgpio_probe(struct pci_dev *dev, + const struct pci_device_id *pci_id) +{ + struct bt8xxgpio *bg; + int err; + + bg = kzalloc(sizeof(*bg), GFP_KERNEL); + if (!bg) + return -ENOMEM; + + bg->pdev = dev; + spin_lock_init(&bg->lock); + + err = pci_enable_device(dev); + if (err) { + printk(KERN_ERR "bt8xxgpio: Can't enable device.\n"); + goto err_freebg; + } + if (!request_mem_region(pci_resource_start(dev, 0), + pci_resource_len(dev, 0), + "bt8xxgpio")) { + printk(KERN_WARNING "bt8xxgpio: Can't request iomem (0x%llx).\n", + (unsigned long long)pci_resource_start(dev, 0)); + err = -EBUSY; + goto err_disable; + } + pci_set_master(dev); + pci_set_drvdata(dev, bg); + + bg->mmio = ioremap(pci_resource_start(dev, 0), 0x1000); + if (!bg->mmio) { + printk(KERN_ERR "bt8xxgpio: ioremap() failed\n"); + err = -EIO; + goto err_release_mem; + } + + /* Disable interrupts */ + bgwrite(0, BT848_INT_MASK); + + /* gpio init */ + bgwrite(0, BT848_GPIO_DMA_CTL); + bgwrite(0, BT848_GPIO_REG_INP); + bgwrite(0, BT848_GPIO_OUT_EN); + + bt8xxgpio_gpio_setup(bg); + err = gpiochip_add(&bg->gpio); + if (err) { + printk(KERN_ERR "bt8xxgpio: Failed to register GPIOs\n"); + goto err_release_mem; + } + + printk(KERN_INFO "bt8xxgpio: Abusing BT8xx card for GPIOs %d to %d\n", + bg->gpio.base, bg->gpio.base + BT8XXGPIO_NR_GPIOS - 1); + + return 0; + +err_release_mem: + release_mem_region(pci_resource_start(dev, 0), + pci_resource_len(dev, 0)); + pci_set_drvdata(dev, NULL); +err_disable: + pci_disable_device(dev); +err_freebg: + kfree(bg); + + return err; +} + +static void bt8xxgpio_remove(struct pci_dev *pdev) +{ + struct bt8xxgpio *bg = pci_get_drvdata(pdev); + + gpiochip_remove(&bg->gpio); + + bgwrite(0, BT848_INT_MASK); + bgwrite(~0x0, BT848_INT_STAT); + bgwrite(0x0, BT848_GPIO_OUT_EN); + + iounmap(bg->mmio); + release_mem_region(pci_resource_start(pdev, 0), + pci_resource_len(pdev, 0)); + pci_disable_device(pdev); + + pci_set_drvdata(pdev, NULL); + kfree(bg); +} + +#ifdef CONFIG_PM +static int bt8xxgpio_suspend(struct pci_dev *pdev, pm_message_t state) +{ + struct bt8xxgpio *bg = pci_get_drvdata(pdev); + unsigned long flags; + + spin_lock_irqsave(&bg->lock, flags); + + bg->saved_outen = bgread(BT848_GPIO_OUT_EN); + bg->saved_data = bgread(BT848_GPIO_DATA); + + bgwrite(0, BT848_INT_MASK); + bgwrite(~0x0, BT848_INT_STAT); + bgwrite(0x0, BT848_GPIO_OUT_EN); + + spin_unlock_irqrestore(&bg->lock, flags); + + pci_save_state(pdev); + pci_disable_device(pdev); + pci_set_power_state(pdev, pci_choose_state(pdev, state)); + + return 0; +} + +static int bt8xxgpio_resume(struct pci_dev *pdev) +{ + struct bt8xxgpio *bg = pci_get_drvdata(pdev); + unsigned long flags; + int err; + + pci_set_power_state(pdev, 0); + err = pci_enable_device(pdev); + if (err) + return err; + pci_restore_state(pdev); + + spin_lock_irqsave(&bg->lock, flags); + + bgwrite(0, BT848_INT_MASK); + bgwrite(0, BT848_GPIO_DMA_CTL); + bgwrite(0, BT848_GPIO_REG_INP); + bgwrite(bg->saved_outen, BT848_GPIO_OUT_EN); + bgwrite(bg->saved_data & bg->saved_outen, + BT848_GPIO_DATA); + + spin_unlock_irqrestore(&bg->lock, flags); + + return 0; +} +#else +#define bt8xxgpio_suspend NULL +#define bt8xxgpio_resume NULL +#endif /* CONFIG_PM */ + +static struct pci_device_id bt8xxgpio_pci_tbl[] = { + { PCI_DEVICE(PCI_VENDOR_ID_BROOKTREE, PCI_DEVICE_ID_BT848) }, + { PCI_DEVICE(PCI_VENDOR_ID_BROOKTREE, PCI_DEVICE_ID_BT849) }, + { PCI_DEVICE(PCI_VENDOR_ID_BROOKTREE, PCI_DEVICE_ID_BT878) }, + { PCI_DEVICE(PCI_VENDOR_ID_BROOKTREE, PCI_DEVICE_ID_BT879) }, + { 0, }, +}; +MODULE_DEVICE_TABLE(pci, bt8xxgpio_pci_tbl); + +static struct pci_driver bt8xxgpio_pci_driver = { + .name = "bt8xxgpio", + .id_table = bt8xxgpio_pci_tbl, + .probe = bt8xxgpio_probe, + .remove = bt8xxgpio_remove, + .suspend = bt8xxgpio_suspend, + .resume = bt8xxgpio_resume, +}; + +static int bt8xxgpio_init(void) +{ + return pci_register_driver(&bt8xxgpio_pci_driver); +} +module_init(bt8xxgpio_init) + +static void bt8xxgpio_exit(void) +{ + pci_unregister_driver(&bt8xxgpio_pci_driver); +} +module_exit(bt8xxgpio_exit) + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Michael Buesch"); +MODULE_DESCRIPTION("Abuse a BT8xx framegrabber card as generic GPIO card"); -- cgit v1.2.3-70-g09d2 From 7444a72effa632fcd8edc566f880d96fe213c73b Mon Sep 17 00:00:00 2001 From: Michael Buesch Date: Fri, 25 Jul 2008 01:46:11 -0700 Subject: gpiolib: allow user-selection This patch adds functionality to the gpio-lib subsystem to make it possible to enable the gpio-lib code even if the architecture code didn't request to get it built in. The archtitecture code does still need to implement the gpiolib accessor functions in its asm/gpio.h file. This patch adds the implementations for x86 and PPC. With these changes it is possible to run generic GPIO expansion cards on every architecture that implements the trivial wrapper functions. Support for more architectures can easily be added. Signed-off-by: Michael Buesch Cc: Benjamin Herrenschmidt Cc: Stephen Rothwell Cc: David Brownell Cc: Russell King Cc: Haavard Skinnemoen Cc: Jesper Nilsson Cc: Ralf Baechle Cc: Paul Mackerras Cc: Benjamin Herrenschmidt Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Jean Delvare Cc: Samuel Ortiz Cc: Kumar Gala Cc: Sam Ravnborg Cc: Adrian Bunk Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/gpio.txt | 12 +++++++- arch/arm/Kconfig | 8 +++--- arch/avr32/Kconfig | 2 +- arch/mips/Kconfig | 2 +- arch/powerpc/Kconfig | 1 + arch/powerpc/platforms/52xx/Kconfig | 2 +- arch/powerpc/sysdev/qe_lib/Kconfig | 2 +- arch/x86/Kconfig | 1 + drivers/Makefile | 2 +- drivers/gpio/Kconfig | 33 ++++++++++++++++++--- drivers/gpio/Makefile | 2 +- drivers/i2c/chips/Kconfig | 2 +- drivers/mfd/Kconfig | 4 +-- drivers/of/Kconfig | 2 +- include/asm-generic/gpio.h | 2 +- include/asm-mips/mach-generic/gpio.h | 2 +- include/asm-powerpc/gpio.h | 4 +-- include/asm-x86/gpio.h | 56 ++++++++++++++++++++++++++++++++++++ 18 files changed, 116 insertions(+), 23 deletions(-) (limited to 'drivers/gpio') diff --git a/Documentation/gpio.txt b/Documentation/gpio.txt index 8b69811a964..18022e249c5 100644 --- a/Documentation/gpio.txt +++ b/Documentation/gpio.txt @@ -389,11 +389,21 @@ either NULL or the label associated with that GPIO when it was requested. Platform Support ---------------- -To support this framework, a platform's Kconfig will "select HAVE_GPIO_LIB" +To support this framework, a platform's Kconfig will "select" either +ARCH_REQUIRE_GPIOLIB or ARCH_WANT_OPTIONAL_GPIOLIB and arrange that its includes and defines three functions: gpio_get_value(), gpio_set_value(), and gpio_cansleep(). They may also want to provide a custom value for ARCH_NR_GPIOS. +ARCH_REQUIRE_GPIOLIB means that the gpio-lib code will always get compiled +into the kernel on that architecture. + +ARCH_WANT_OPTIONAL_GPIOLIB means the gpio-lib code defaults to off and the user +can enable it and build it into the kernel optionally. + +If neither of these options are selected, the platform does not support +GPIOs through GPIO-lib and the code cannot be enabled by the user. + Trivial implementations of those functions can directly use framework code, which always dispatches through the gpio_chip: diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 6fb4f03369f..dabb015aa40 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -268,7 +268,7 @@ config ARCH_EP93XX select GENERIC_GPIO select HAVE_CLK select HAVE_CLK - select HAVE_GPIO_LIB + select ARCH_REQUIRE_GPIOLIB help This enables support for the Cirrus EP93xx series of CPUs. @@ -447,7 +447,7 @@ config ARCH_PXA select ARCH_MTD_XIP select GENERIC_GPIO select HAVE_CLK - select HAVE_GPIO_LIB + select ARCH_REQUIRE_GPIOLIB select GENERIC_TIME select GENERIC_CLOCKEVENTS select TICK_ONESHOT @@ -479,7 +479,7 @@ config ARCH_SA1100 select GENERIC_CLOCKEVENTS select HAVE_CLK select TICK_ONESHOT - select HAVE_GPIO_LIB + select ARCH_REQUIRE_GPIOLIB help Support for StrongARM 11x0 based boards. @@ -522,7 +522,7 @@ config ARCH_OMAP bool "TI OMAP" select GENERIC_GPIO select HAVE_CLK - select HAVE_GPIO_LIB + select ARCH_REQUIRE_GPIOLIB select GENERIC_TIME select GENERIC_CLOCKEVENTS help diff --git a/arch/avr32/Kconfig b/arch/avr32/Kconfig index df4adefedb4..7c239a91627 100644 --- a/arch/avr32/Kconfig +++ b/arch/avr32/Kconfig @@ -88,7 +88,7 @@ config PLATFORM_AT32AP select SUBARCH_AVR32B select MMU select PERFORMANCE_COUNTERS - select HAVE_GPIO_LIB + select ARCH_REQUIRE_GPIOLIB select GENERIC_ALLOCATOR # diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index b9c754f4070..b4c4eaa5dd2 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -713,7 +713,7 @@ config CSRC_SB1250 config GPIO_TXX9 select GENERIC_GPIO - select HAVE_GPIO_LIB + select ARCH_REQUIRE_GPIOLIB bool config CFE diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index de6b49cd6be..fe88418167c 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -110,6 +110,7 @@ config PPC default y select HAVE_DYNAMIC_FTRACE select HAVE_FTRACE + select ARCH_WANT_OPTIONAL_GPIOLIB select HAVE_IDE select HAVE_IOREMAP_PROT select HAVE_EFFICIENT_UNALIGNED_ACCESS diff --git a/arch/powerpc/platforms/52xx/Kconfig b/arch/powerpc/platforms/52xx/Kconfig index d664b1bce38..ccbd4958412 100644 --- a/arch/powerpc/platforms/52xx/Kconfig +++ b/arch/powerpc/platforms/52xx/Kconfig @@ -48,6 +48,6 @@ config PPC_MPC5200_BUGFIX config PPC_MPC5200_GPIO bool "MPC5200 GPIO support" depends on PPC_MPC52xx - select HAVE_GPIO_LIB + select ARCH_REQUIRE_GPIOLIB help Enable gpiolib support for mpc5200 based boards diff --git a/arch/powerpc/sysdev/qe_lib/Kconfig b/arch/powerpc/sysdev/qe_lib/Kconfig index 4bb18f57901..1ce546462be 100644 --- a/arch/powerpc/sysdev/qe_lib/Kconfig +++ b/arch/powerpc/sysdev/qe_lib/Kconfig @@ -29,7 +29,7 @@ config QE_GPIO bool "QE GPIO support" depends on QUICC_ENGINE select GENERIC_GPIO - select HAVE_GPIO_LIB + select ARCH_REQUIRE_GPIOLIB help Say Y here if you're going to use hardware that connects to the QE GPIOs. diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 66f3ab05b18..e3cba0b4560 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -23,6 +23,7 @@ config X86 select HAVE_OPROFILE select HAVE_IOREMAP_PROT select HAVE_KPROBES + select ARCH_WANT_OPTIONAL_GPIOLIB if !X86_RDC321X select HAVE_KRETPROBES select HAVE_DYNAMIC_FTRACE select HAVE_FTRACE diff --git a/drivers/Makefile b/drivers/Makefile index 808e0ae66aa..54ec5e718c0 100644 --- a/drivers/Makefile +++ b/drivers/Makefile @@ -5,7 +5,7 @@ # Rewritten to use lists instead of if-statements. # -obj-$(CONFIG_HAVE_GPIO_LIB) += gpio/ +obj-y += gpio/ obj-$(CONFIG_PCI) += pci/ obj-$(CONFIG_PARISC) += parisc/ obj-$(CONFIG_RAPIDIO) += rapidio/ diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index de202dbe530..5a355f82916 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -2,15 +2,40 @@ # GPIO infrastructure and expanders # -config HAVE_GPIO_LIB +config ARCH_WANT_OPTIONAL_GPIOLIB bool + help + Select this config option from the architecture Kconfig, if + it is possible to use gpiolib on the architecture, but let the + user decide whether to actually build it or not. + Select this instead of ARCH_REQUIRE_GPIOLIB, if your architecture does + not depend on GPIOs being available, but rather let the user + decide whether he needs it or not. + +config ARCH_REQUIRE_GPIOLIB + bool + select GPIOLIB help Platforms select gpiolib if they use this infrastructure for all their GPIOs, usually starting with ones integrated into SOC processors. + Selecting this from the architecture code will cause the gpiolib + code to always get built in. + + + +menuconfig GPIOLIB + bool "GPIO Support" + depends on ARCH_WANT_OPTIONAL_GPIOLIB || ARCH_REQUIRE_GPIOLIB + select GENERIC_GPIO + help + This enables GPIO support through the generic GPIO library. + You only need to enable this, if you also want to enable + one or more of the GPIO expansion card drivers below. + + If unsure, say N. -menu "GPIO Support" - depends on HAVE_GPIO_LIB +if GPIOLIB config DEBUG_GPIO bool "Debug GPIO calls" @@ -116,4 +141,4 @@ config GPIO_MCP23S08 SPI driver for Microchip MCP23S08 I/O expander. This provides a GPIO interface supporting inputs and outputs. -endmenu +endif diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index eeb2f2b2028..8c45948d1fe 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -2,7 +2,7 @@ ccflags-$(CONFIG_DEBUG_GPIO) += -DDEBUG -obj-$(CONFIG_HAVE_GPIO_LIB) += gpiolib.o +obj-$(CONFIG_GPIOLIB) += gpiolib.o obj-$(CONFIG_GPIO_MAX7301) += max7301.o obj-$(CONFIG_GPIO_MCP23S08) += mcp23s08.o diff --git a/drivers/i2c/chips/Kconfig b/drivers/i2c/chips/Kconfig index 50e0a465374..a95cb9465d6 100644 --- a/drivers/i2c/chips/Kconfig +++ b/drivers/i2c/chips/Kconfig @@ -126,7 +126,7 @@ config ISP1301_OMAP config TPS65010 tristate "TPS6501x Power Management chips" - depends on HAVE_GPIO_LIB + depends on GPIOLIB default y if MACH_OMAP_H2 || MACH_OMAP_H3 || MACH_OMAP_OSK help If you say yes here you get support for the TPS6501x series of diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig index bac9e973ece..1f57a99fd96 100644 --- a/drivers/mfd/Kconfig +++ b/drivers/mfd/Kconfig @@ -36,7 +36,7 @@ config MFD_ASIC3 config HTC_EGPIO bool "HTC EGPIO support" - depends on GENERIC_HARDIRQS && HAVE_GPIO_LIB && ARM + depends on GENERIC_HARDIRQS && GPIOLIB && ARM help This driver supports the CPLD egpio chip present on several HTC phones. It provides basic support for input @@ -52,7 +52,7 @@ config HTC_PASIC3 config MFD_TC6393XB bool "Support Toshiba TC6393XB" - depends on HAVE_GPIO_LIB + depends on GPIOLIB select MFD_CORE help Support for Toshiba Mobile IO Controller TC6393XB diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig index 3a7a11a75fb..1d7ec312934 100644 --- a/drivers/of/Kconfig +++ b/drivers/of/Kconfig @@ -4,7 +4,7 @@ config OF_DEVICE config OF_GPIO def_bool y - depends on OF && PPC_OF && HAVE_GPIO_LIB + depends on OF && PPC_OF && GPIOLIB help OpenFirmware GPIO accessors diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h index 1beff5166e5..a3034d20ebd 100644 --- a/include/asm-generic/gpio.h +++ b/include/asm-generic/gpio.h @@ -3,7 +3,7 @@ #include -#ifdef CONFIG_HAVE_GPIO_LIB +#ifdef CONFIG_GPIOLIB #include diff --git a/include/asm-mips/mach-generic/gpio.h b/include/asm-mips/mach-generic/gpio.h index e6b376bd9d0..b4e70208da6 100644 --- a/include/asm-mips/mach-generic/gpio.h +++ b/include/asm-mips/mach-generic/gpio.h @@ -1,7 +1,7 @@ #ifndef __ASM_MACH_GENERIC_GPIO_H #define __ASM_MACH_GENERIC_GPIO_H -#ifdef CONFIG_HAVE_GPIO_LIB +#ifdef CONFIG_GPIOLIB #define gpio_get_value __gpio_get_value #define gpio_set_value __gpio_set_value #define gpio_cansleep __gpio_cansleep diff --git a/include/asm-powerpc/gpio.h b/include/asm-powerpc/gpio.h index 77ad3a890f3..ea04632399d 100644 --- a/include/asm-powerpc/gpio.h +++ b/include/asm-powerpc/gpio.h @@ -17,7 +17,7 @@ #include #include -#ifdef CONFIG_HAVE_GPIO_LIB +#ifdef CONFIG_GPIOLIB /* * We don't (yet) implement inlined/rapid versions for on-chip gpios. @@ -51,6 +51,6 @@ static inline int irq_to_gpio(unsigned int irq) return -EINVAL; } -#endif /* CONFIG_HAVE_GPIO_LIB */ +#endif /* CONFIG_GPIOLIB */ #endif /* __ASM_POWERPC_GPIO_H */ diff --git a/include/asm-x86/gpio.h b/include/asm-x86/gpio.h index ff87fca0caf..116e9147fe6 100644 --- a/include/asm-x86/gpio.h +++ b/include/asm-x86/gpio.h @@ -1,6 +1,62 @@ +/* + * Generic GPIO API implementation for x86. + * + * Derived from the generic GPIO API for powerpc: + * + * Copyright (c) 2007-2008 MontaVista Software, Inc. + * + * Author: Anton Vorontsov + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + #ifndef _ASM_I386_GPIO_H #define _ASM_I386_GPIO_H +#ifdef CONFIG_X86_RDC321X #include +#else /* CONFIG_X86_RDC321X */ + +#include + +#ifdef CONFIG_GPIOLIB + +/* + * Just call gpiolib. + */ +static inline int gpio_get_value(unsigned int gpio) +{ + return __gpio_get_value(gpio); +} + +static inline void gpio_set_value(unsigned int gpio, int value) +{ + __gpio_set_value(gpio, value); +} + +static inline int gpio_cansleep(unsigned int gpio) +{ + return __gpio_cansleep(gpio); +} + +/* + * Not implemented, yet. + */ +static inline int gpio_to_irq(unsigned int gpio) +{ + return -ENOSYS; +} + +static inline int irq_to_gpio(unsigned int irq) +{ + return -EINVAL; +} + +#endif /* CONFIG_GPIOLIB */ + +#endif /* CONFIG_X86_RDC321X */ #endif /* _ASM_I386_GPIO_H */ -- cgit v1.2.3-70-g09d2 From bbcd6d543de335bf81e96477f46a60a8bf51039c Mon Sep 17 00:00:00 2001 From: Eric Miao Date: Fri, 25 Jul 2008 01:46:14 -0700 Subject: gpio: max732x driver This adds a driver supporting a family of I2C port expanders from Maxim, which includes the MAX7319 and MAX7320-7327 chips. [dbrownell@users.sourceforge.net: minor fixes] Signed-off-by: Jack Ren Signed-off-by: Eric Miao Acked-by: Jean Delvare Signed-off-by: David Brownell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/gpio/Kconfig | 19 +++ drivers/gpio/Makefile | 1 + drivers/gpio/max732x.c | 385 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/i2c/max732x.h | 19 +++ 4 files changed, 424 insertions(+) create mode 100644 drivers/gpio/max732x.c create mode 100644 include/linux/i2c/max732x.h (limited to 'drivers/gpio') diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index 5a355f82916..dbd42d6c93a 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -67,6 +67,25 @@ config GPIO_SYSFS comment "I2C GPIO expanders:" +config GPIO_MAX732X + tristate "MAX7319, MAX7320-7327 I2C Port Expanders" + depends on I2C + help + Say yes here to support the MAX7319, MAX7320-7327 series of I2C + Port Expanders. Each IO port on these chips has a fixed role of + Input (designated by 'I'), Push-Pull Output ('O'), or Open-Drain + Input and Output (designed by 'P'). The combinations are listed + below: + + 8 bits: max7319 (8I), max7320 (8O), max7321 (8P), + max7322 (4I4O), max7323 (4P4O) + + 16 bits: max7324 (8I8O), max7325 (8P8O), + max7326 (4I12O), max7327 (4P12O) + + Board setup code must specify the model to use, and the start + number for these GPIOs. + config GPIO_PCA953X tristate "PCA953x, PCA955x, and MAX7310 I/O ports" depends on I2C diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index 8c45948d1fe..01b4bbde195 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -5,6 +5,7 @@ ccflags-$(CONFIG_DEBUG_GPIO) += -DDEBUG obj-$(CONFIG_GPIOLIB) += gpiolib.o obj-$(CONFIG_GPIO_MAX7301) += max7301.o +obj-$(CONFIG_GPIO_MAX732X) += max732x.o obj-$(CONFIG_GPIO_MCP23S08) += mcp23s08.o obj-$(CONFIG_GPIO_PCA953X) += pca953x.o obj-$(CONFIG_GPIO_PCF857X) += pcf857x.o diff --git a/drivers/gpio/max732x.c b/drivers/gpio/max732x.c new file mode 100644 index 00000000000..b51c8135ca2 --- /dev/null +++ b/drivers/gpio/max732x.c @@ -0,0 +1,385 @@ +/* + * max732x.c - I2C Port Expander with 8/16 I/O + * + * Copyright (C) 2007 Marvell International Ltd. + * Copyright (C) 2008 Jack Ren + * Copyright (C) 2008 Eric Miao + * + * Derived from drivers/gpio/pca953x.c + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License. + */ + +#include +#include +#include +#include +#include + +#include +#include + + +/* + * Each port of MAX732x (including MAX7319) falls into one of the + * following three types: + * + * - Push Pull Output + * - Input + * - Open Drain I/O + * + * designated by 'O', 'I' and 'P' individually according to MAXIM's + * datasheets. + * + * There are two groups of I/O ports, each group usually includes + * up to 8 I/O ports, and is accessed by a specific I2C address: + * + * - Group A : by I2C address 0b'110xxxx + * - Group B : by I2C address 0b'101xxxx + * + * where 'xxxx' is decided by the connections of pin AD2/AD0. The + * address used also affects the initial state of output signals. + * + * Within each group of ports, there are five known combinations of + * I/O ports: 4I4O, 4P4O, 8I, 8P, 8O, see the definitions below for + * the detailed organization of these ports. + * + * GPIO numbers start from 'gpio_base + 0' to 'gpio_base + 8/16', + * and GPIOs from GROUP_A are numbered before those from GROUP_B + * (if there are two groups). + * + * NOTE: MAX7328/MAX7329 are drop-in replacements for PCF8574/a, so + * they are not supported by this driver. + */ + +#define PORT_NONE 0x0 /* '/' No Port */ +#define PORT_OUTPUT 0x1 /* 'O' Push-Pull, Output Only */ +#define PORT_INPUT 0x2 /* 'I' Input Only */ +#define PORT_OPENDRAIN 0x3 /* 'P' Open-Drain, I/O */ + +#define IO_4I4O 0x5AA5 /* O7 O6 I5 I4 I3 I2 O1 O0 */ +#define IO_4P4O 0x5FF5 /* O7 O6 P5 P4 P3 P2 O1 O0 */ +#define IO_8I 0xAAAA /* I7 I6 I5 I4 I3 I2 I1 I0 */ +#define IO_8P 0xFFFF /* P7 P6 P5 P4 P3 P2 P1 P0 */ +#define IO_8O 0x5555 /* O7 O6 O5 O4 O3 O2 O1 O0 */ + +#define GROUP_A(x) ((x) & 0xffff) /* I2C Addr: 0b'110xxxx */ +#define GROUP_B(x) ((x) << 16) /* I2C Addr: 0b'101xxxx */ + +static const struct i2c_device_id max732x_id[] = { + { "max7319", GROUP_A(IO_8I) }, + { "max7320", GROUP_B(IO_8O) }, + { "max7321", GROUP_A(IO_8P) }, + { "max7322", GROUP_A(IO_4I4O) }, + { "max7323", GROUP_A(IO_4P4O) }, + { "max7324", GROUP_A(IO_8I) | GROUP_B(IO_8O) }, + { "max7325", GROUP_A(IO_8P) | GROUP_B(IO_8O) }, + { "max7326", GROUP_A(IO_4I4O) | GROUP_B(IO_8O) }, + { "max7327", GROUP_A(IO_4P4O) | GROUP_B(IO_8O) }, + { }, +}; +MODULE_DEVICE_TABLE(i2c, max732x_id); + +struct max732x_chip { + struct gpio_chip gpio_chip; + + struct i2c_client *client; /* "main" client */ + struct i2c_client *client_dummy; + struct i2c_client *client_group_a; + struct i2c_client *client_group_b; + + unsigned int mask_group_a; + unsigned int dir_input; + unsigned int dir_output; + + struct mutex lock; + uint8_t reg_out[2]; +}; + +static int max732x_write(struct max732x_chip *chip, int group_a, uint8_t val) +{ + struct i2c_client *client; + int ret; + + client = group_a ? chip->client_group_a : chip->client_group_b; + ret = i2c_smbus_write_byte(client, val); + if (ret < 0) { + dev_err(&client->dev, "failed writing\n"); + return ret; + } + + return 0; +} + +static int max732x_read(struct max732x_chip *chip, int group_a, uint8_t *val) +{ + struct i2c_client *client; + int ret; + + client = group_a ? chip->client_group_a : chip->client_group_b; + ret = i2c_smbus_read_byte(client); + if (ret < 0) { + dev_err(&client->dev, "failed reading\n"); + return ret; + } + + *val = (uint8_t)ret; + return 0; +} + +static inline int is_group_a(struct max732x_chip *chip, unsigned off) +{ + return (1u << off) & chip->mask_group_a; +} + +static int max732x_gpio_get_value(struct gpio_chip *gc, unsigned off) +{ + struct max732x_chip *chip; + uint8_t reg_val; + int ret; + + chip = container_of(gc, struct max732x_chip, gpio_chip); + + ret = max732x_read(chip, is_group_a(chip, off), ®_val); + if (ret < 0) + return 0; + + return reg_val & (1u << (off & 0x7)); +} + +static void max732x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val) +{ + struct max732x_chip *chip; + uint8_t reg_out, mask = 1u << (off & 0x7); + int ret; + + chip = container_of(gc, struct max732x_chip, gpio_chip); + + mutex_lock(&chip->lock); + + reg_out = (off > 7) ? chip->reg_out[1] : chip->reg_out[0]; + reg_out = (val) ? reg_out | mask : reg_out & ~mask; + + ret = max732x_write(chip, is_group_a(chip, off), reg_out); + if (ret < 0) + goto out; + + /* update the shadow register then */ + if (off > 7) + chip->reg_out[1] = reg_out; + else + chip->reg_out[0] = reg_out; +out: + mutex_unlock(&chip->lock); +} + +static int max732x_gpio_direction_input(struct gpio_chip *gc, unsigned off) +{ + struct max732x_chip *chip; + unsigned int mask = 1u << off; + + chip = container_of(gc, struct max732x_chip, gpio_chip); + + if ((mask & chip->dir_input) == 0) { + dev_dbg(&chip->client->dev, "%s port %d is output only\n", + chip->client->name, off); + return -EACCES; + } + + return 0; +} + +static int max732x_gpio_direction_output(struct gpio_chip *gc, + unsigned off, int val) +{ + struct max732x_chip *chip; + unsigned int mask = 1u << off; + + chip = container_of(gc, struct max732x_chip, gpio_chip); + + if ((mask & chip->dir_output) == 0) { + dev_dbg(&chip->client->dev, "%s port %d is input only\n", + chip->client->name, off); + return -EACCES; + } + + max732x_gpio_set_value(gc, off, val); + return 0; +} + +static int __devinit max732x_setup_gpio(struct max732x_chip *chip, + const struct i2c_device_id *id, + unsigned gpio_start) +{ + struct gpio_chip *gc = &chip->gpio_chip; + uint32_t id_data = id->driver_data; + int i, port = 0; + + for (i = 0; i < 16; i++, id_data >>= 2) { + unsigned int mask = 1 << port; + + switch (id_data & 0x3) { + case PORT_OUTPUT: + chip->dir_output |= mask; + break; + case PORT_INPUT: + chip->dir_input |= mask; + break; + case PORT_OPENDRAIN: + chip->dir_output |= mask; + chip->dir_input |= mask; + break; + default: + continue; + } + + if (i < 8) + chip->mask_group_a |= mask; + port++; + } + + if (chip->dir_input) + gc->direction_input = max732x_gpio_direction_input; + if (chip->dir_output) { + gc->direction_output = max732x_gpio_direction_output; + gc->set = max732x_gpio_set_value; + } + gc->get = max732x_gpio_get_value; + gc->can_sleep = 1; + + gc->base = gpio_start; + gc->ngpio = port; + gc->label = chip->client->name; + gc->owner = THIS_MODULE; + + return port; +} + +static int __devinit max732x_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct max732x_platform_data *pdata; + struct max732x_chip *chip; + struct i2c_client *c; + uint16_t addr_a, addr_b; + int ret, nr_port; + + pdata = client->dev.platform_data; + if (pdata == NULL) + return -ENODEV; + + chip = kzalloc(sizeof(struct max732x_chip), GFP_KERNEL); + if (chip == NULL) + return -ENOMEM; + chip->client = client; + + nr_port = max732x_setup_gpio(chip, id, pdata->gpio_base); + + addr_a = (client->addr & 0x0f) | 0x60; + addr_b = (client->addr & 0x0f) | 0x50; + + switch (client->addr & 0x70) { + case 0x60: + chip->client_group_a = client; + if (nr_port > 7) { + c = i2c_new_dummy(client->adapter, addr_b); + chip->client_group_b = chip->client_dummy = c; + } + break; + case 0x50: + chip->client_group_b = client; + if (nr_port > 7) { + c = i2c_new_dummy(client->adapter, addr_a); + chip->client_group_a = chip->client_dummy = c; + } + break; + default: + dev_err(&client->dev, "invalid I2C address specified %02x\n", + client->addr); + ret = -EINVAL; + goto out_failed; + } + + mutex_init(&chip->lock); + + max732x_read(chip, is_group_a(chip, 0), &chip->reg_out[0]); + if (nr_port > 7) + max732x_read(chip, is_group_a(chip, 8), &chip->reg_out[1]); + + ret = gpiochip_add(&chip->gpio_chip); + if (ret) + goto out_failed; + + if (pdata->setup) { + ret = pdata->setup(client, chip->gpio_chip.base, + chip->gpio_chip.ngpio, pdata->context); + if (ret < 0) + dev_warn(&client->dev, "setup failed, %d\n", ret); + } + + i2c_set_clientdata(client, chip); + return 0; + +out_failed: + kfree(chip); + return ret; +} + +static int __devexit max732x_remove(struct i2c_client *client) +{ + struct max732x_platform_data *pdata = client->dev.platform_data; + struct max732x_chip *chip = i2c_get_clientdata(client); + int ret; + + if (pdata->teardown) { + ret = pdata->teardown(client, chip->gpio_chip.base, + chip->gpio_chip.ngpio, pdata->context); + if (ret < 0) { + dev_err(&client->dev, "%s failed, %d\n", + "teardown", ret); + return ret; + } + } + + ret = gpiochip_remove(&chip->gpio_chip); + if (ret) { + dev_err(&client->dev, "%s failed, %d\n", + "gpiochip_remove()", ret); + return ret; + } + + /* unregister any dummy i2c_client */ + if (chip->client_dummy) + i2c_unregister_device(chip->client_dummy); + + kfree(chip); + return 0; +} + +static struct i2c_driver max732x_driver = { + .driver = { + .name = "max732x", + .owner = THIS_MODULE, + }, + .probe = max732x_probe, + .remove = __devexit_p(max732x_remove), + .id_table = max732x_id, +}; + +static int __init max732x_init(void) +{ + return i2c_add_driver(&max732x_driver); +} +module_init(max732x_init); + +static void __exit max732x_exit(void) +{ + i2c_del_driver(&max732x_driver); +} +module_exit(max732x_exit); + +MODULE_AUTHOR("Eric Miao "); +MODULE_DESCRIPTION("GPIO expander driver for MAX732X"); +MODULE_LICENSE("GPL"); diff --git a/include/linux/i2c/max732x.h b/include/linux/i2c/max732x.h new file mode 100644 index 00000000000..e10336631c6 --- /dev/null +++ b/include/linux/i2c/max732x.h @@ -0,0 +1,19 @@ +#ifndef __LINUX_I2C_MAX732X_H +#define __LINUX_I2C_MAX732X_H + +/* platform data for the MAX732x 8/16-bit I/O expander driver */ + +struct max732x_platform_data { + /* number of the first GPIO */ + unsigned gpio_base; + + void *context; /* param to setup/teardown */ + + int (*setup)(struct i2c_client *client, + unsigned gpio, unsigned ngpio, + void *context); + int (*teardown)(struct i2c_client *client, + unsigned gpio, unsigned ngpio, + void *context); +}; +#endif /* __LINUX_I2C_MAX732X_H */ -- cgit v1.2.3-70-g09d2