From 9b7a0c40de6c5c04371f8cdb9153a0a5a0af5243 Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Thu, 25 Oct 2012 18:23:53 +0200 Subject: i2c: mux: Add dt support to i2c-mux-gpio driver Allow the i2c-mux-gpio to be used by a device tree enabled device. The bindings are inspired by the one found in the i2c-mux-pinctrl driver. Signed-off-by: Maxime Ripard Reviewed-by: Stephen Warren Acked-by: Peter Korsgaard [wsa: fixed some whitespace] Signed-off-by: Wolfram Sang --- .../devicetree/bindings/i2c/i2c-mux-gpio.txt | 81 ++++++++++++++++++++++ 1 file changed, 81 insertions(+) create mode 100644 Documentation/devicetree/bindings/i2c/i2c-mux-gpio.txt (limited to 'Documentation') diff --git a/Documentation/devicetree/bindings/i2c/i2c-mux-gpio.txt b/Documentation/devicetree/bindings/i2c/i2c-mux-gpio.txt new file mode 100644 index 00000000000..66709a82554 --- /dev/null +++ b/Documentation/devicetree/bindings/i2c/i2c-mux-gpio.txt @@ -0,0 +1,81 @@ +GPIO-based I2C Bus Mux + +This binding describes an I2C bus multiplexer that uses GPIOs to +route the I2C signals. + + +-----+ +-----+ + | dev | | dev | + +------------+ +-----+ +-----+ + | SoC | | | + | | /--------+--------+ + | +------+ | +------+ child bus A, on GPIO value set to 0 + | | I2C |-|--| Mux | + | +------+ | +--+---+ child bus B, on GPIO value set to 1 + | | | \----------+--------+--------+ + | +------+ | | | | | + | | GPIO |-|-----+ +-----+ +-----+ +-----+ + | +------+ | | dev | | dev | | dev | + +------------+ +-----+ +-----+ +-----+ + +Required properties: +- compatible: i2c-mux-gpio +- i2c-parent: The phandle of the I2C bus that this multiplexer's master-side + port is connected to. +- mux-gpios: list of gpios used to control the muxer +* Standard I2C mux properties. See mux.txt in this directory. +* I2C child bus nodes. See mux.txt in this directory. + +Optional properties: +- idle-state: value to set the muxer to when idle. When no value is + given, it defaults to the last value used. + +For each i2c child node, an I2C child bus will be created. They will +be numbered based on their order in the device tree. + +Whenever an access is made to a device on a child bus, the value set +in the revelant node's reg property will be output using the list of +GPIOs, the first in the list holding the least-significant value. + +If an idle state is defined, using the idle-state (optional) property, +whenever an access is not being made to a device on a child bus, the +GPIOs will be set according to the idle value. + +If an idle state is not defined, the most recently used value will be +left programmed into hardware whenever no access is being made to a +device on a child bus. + +Example: + i2cmux { + compatible = "i2c-mux-gpio"; + #address-cells = <1>; + #size-cells = <0>; + mux-gpios = <&gpio1 22 0 &gpio1 23 0>; + i2c-parent = <&i2c1>; + + i2c@1 { + reg = <1>; + #address-cells = <1>; + #size-cells = <0>; + + ssd1307: oled@3c { + compatible = "solomon,ssd1307fb-i2c"; + reg = <0x3c>; + pwms = <&pwm 4 3000>; + reset-gpios = <&gpio2 7 1>; + reset-active-low; + }; + }; + + i2c@3 { + reg = <3>; + #address-cells = <1>; + #size-cells = <0>; + + pca9555: pca9555@20 { + compatible = "nxp,pca9555"; + gpio-controller; + #gpio-cells = <2>; + reg = <0x20>; + }; + }; + }; -- cgit v1.2.3-70-g09d2 From 2693ac69880a33d4d9df6f128415b65e745f00ba Mon Sep 17 00:00:00 2001 From: Tomasz Figa Date: Tue, 13 Nov 2012 11:33:40 +0100 Subject: i2c: s3c2410: Add support for pinctrl This patch adds support for pin configuration using pinctrl subsystem to the i2c-s3c2410 driver. Signed-off-by: Tomasz Figa Signed-off-by: Kyungmin Park Signed-off-by: Wolfram Sang --- .../devicetree/bindings/i2c/samsung-i2c.txt | 20 ++++++++++++++++---- drivers/i2c/busses/i2c-s3c2410.c | 12 ++++++++---- 2 files changed, 24 insertions(+), 8 deletions(-) (limited to 'Documentation') diff --git a/Documentation/devicetree/bindings/i2c/samsung-i2c.txt b/Documentation/devicetree/bindings/i2c/samsung-i2c.txt index b6cb5a12c67..e9611ace879 100644 --- a/Documentation/devicetree/bindings/i2c/samsung-i2c.txt +++ b/Documentation/devicetree/bindings/i2c/samsung-i2c.txt @@ -13,11 +13,17 @@ Required properties: - interrupts: interrupt number to the cpu. - samsung,i2c-sda-delay: Delay (in ns) applied to data line (SDA) edges. +Required for all cases except "samsung,s3c2440-hdmiphy-i2c": + - Samsung GPIO variant (deprecated): + - gpios: The order of the gpios should be the following: . + The gpio specifier depends on the gpio controller. Required in all + cases except for "samsung,s3c2440-hdmiphy-i2c" whose input/output + lines are permanently wired to the respective clienta + - Pinctrl variant (preferred, if available): + - pinctrl-0: Pin control group to be used for this controller. + - pinctrl-names: Should contain only one value - "default". + Optional properties: - - gpios: The order of the gpios should be the following: . - The gpio specifier depends on the gpio controller. Required in all - cases except for "samsung,s3c2440-hdmiphy-i2c" whose input/output - lines are permanently wired to the respective client - samsung,i2c-slave-addr: Slave address in multi-master enviroment. If not specified, default value is 0. - samsung,i2c-max-bus-freq: Desired frequency in Hz of the bus. If not @@ -31,8 +37,14 @@ Example: interrupts = <345>; samsung,i2c-sda-delay = <100>; samsung,i2c-max-bus-freq = <100000>; + /* Samsung GPIO variant begins here */ gpios = <&gpd1 2 0 /* SDA */ &gpd1 3 0 /* SCL */>; + /* Samsung GPIO variant ends here */ + /* Pinctrl variant begins here */ + pinctrl-0 = <&i2c3_bus>; + pinctrl-names = "default"; + /* Pinctrl variant ends here */ #address-cells = <1>; #size-cells = <0>; diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c index f82d11f9b8f..40e2d40bbdb 100644 --- a/drivers/i2c/busses/i2c-s3c2410.c +++ b/drivers/i2c/busses/i2c-s3c2410.c @@ -38,6 +38,7 @@ #include #include #include +#include #include @@ -82,6 +83,7 @@ struct s3c24xx_i2c { struct s3c2410_platform_i2c *pdata; int gpios[2]; + struct pinctrl *pctrl; #ifdef CONFIG_CPU_FREQ struct notifier_block freq_transition; #endif @@ -860,9 +862,8 @@ static int s3c24xx_i2c_init(struct s3c24xx_i2c *i2c) if (pdata->cfg_gpio) pdata->cfg_gpio(to_platform_device(i2c->dev)); - else - if (s3c24xx_i2c_parse_dt_gpio(i2c)) - return -EINVAL; + else if (IS_ERR(i2c->pctrl) && s3c24xx_i2c_parse_dt_gpio(i2c)) + return -EINVAL; /* write slave address */ @@ -1003,6 +1004,8 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev) i2c->adap.algo_data = i2c; i2c->adap.dev.parent = &pdev->dev; + i2c->pctrl = devm_pinctrl_get_select_default(i2c->dev); + /* initialise the i2c controller */ ret = s3c24xx_i2c_init(i2c); @@ -1092,7 +1095,8 @@ static int s3c24xx_i2c_remove(struct platform_device *pdev) clk_disable_unprepare(i2c->clk); clk_put(i2c->clk); - s3c24xx_i2c_dt_gpio_free(i2c); + if (pdev->dev.of_node && IS_ERR(i2c->pctrl)) + s3c24xx_i2c_dt_gpio_free(i2c); return 0; } -- cgit v1.2.3-70-g09d2 From a000b8c1e30115800d3de86b4b058cadd9cba59d Mon Sep 17 00:00:00 2001 From: Andreas Larsson Date: Thu, 15 Nov 2012 16:50:59 +0100 Subject: i2c: ocores: Add support for the GRLIB port of the controller and use function pointers for getreg and setreg functions The registers in the GRLIB port of the controller are 32-bit and in big endian byte order. The PRELOW and PREHIGH registers are merged into one register. The subsequent registers have their offset decreased accordingly. Hence the register access needs to be handled in a non-standard manner using custom getreg and setreg functions. Add setreg and getreg functions for different register widths and let oc_setreg and oc_getreg use function pointers to call the appropriate functions. A type is added as the data of the of match table entries. A new entry with a different compatible string is added to the table. The type of that entry triggers usage of the custom grlib functions by setting the setreg and getreg function pointers. Signed-off-by: Andreas Larsson Signed-off-by: Wolfram Sang --- .../devicetree/bindings/i2c/i2c-ocores.txt | 2 +- drivers/i2c/busses/i2c-ocores.c | 138 ++++++++++++++++++--- 2 files changed, 121 insertions(+), 19 deletions(-) (limited to 'Documentation') diff --git a/Documentation/devicetree/bindings/i2c/i2c-ocores.txt b/Documentation/devicetree/bindings/i2c/i2c-ocores.txt index c15781f4dc8..1637c298a1b 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-ocores.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-ocores.txt @@ -1,7 +1,7 @@ Device tree configuration for i2c-ocores Required properties: -- compatible : "opencores,i2c-ocores" +- compatible : "opencores,i2c-ocores" or "aeroflexgaisler,i2cmst" - reg : bus address start and address range size of device - interrupts : interrupt number - clock-frequency : frequency of bus clock in Hz diff --git a/drivers/i2c/busses/i2c-ocores.c b/drivers/i2c/busses/i2c-ocores.c index dafd26beecb..0ea84199b50 100644 --- a/drivers/i2c/busses/i2c-ocores.c +++ b/drivers/i2c/busses/i2c-ocores.c @@ -4,6 +4,9 @@ * * Peter Korsgaard * + * Support for the GRLIB port of the controller by + * Andreas Larsson + * * This file is licensed under the terms of the GNU General Public License * version 2. This program is licensed "as is" without any warranty of any * kind, whether express or implied. @@ -38,6 +41,8 @@ struct ocores_i2c { int nmsgs; int state; /* see STATE_ */ int clock_khz; + void (*setreg)(struct ocores_i2c *i2c, int reg, u8 value); + u8 (*getreg)(struct ocores_i2c *i2c, int reg); }; /* registers */ @@ -71,24 +76,81 @@ struct ocores_i2c { #define STATE_READ 3 #define STATE_ERROR 4 -static inline void oc_setreg(struct ocores_i2c *i2c, int reg, u8 value) +#define TYPE_OCORES 0 +#define TYPE_GRLIB 1 + +static void oc_setreg_8(struct ocores_i2c *i2c, int reg, u8 value) { - if (i2c->reg_io_width == 4) - iowrite32(value, i2c->base + (reg << i2c->reg_shift)); - else if (i2c->reg_io_width == 2) - iowrite16(value, i2c->base + (reg << i2c->reg_shift)); + iowrite8(value, i2c->base + (reg << i2c->reg_shift)); +} + +static void oc_setreg_16(struct ocores_i2c *i2c, int reg, u8 value) +{ + iowrite16(value, i2c->base + (reg << i2c->reg_shift)); +} + +static void oc_setreg_32(struct ocores_i2c *i2c, int reg, u8 value) +{ + iowrite32(value, i2c->base + (reg << i2c->reg_shift)); +} + +static inline u8 oc_getreg_8(struct ocores_i2c *i2c, int reg) +{ + return ioread8(i2c->base + (reg << i2c->reg_shift)); +} + +static inline u8 oc_getreg_16(struct ocores_i2c *i2c, int reg) +{ + return ioread16(i2c->base + (reg << i2c->reg_shift)); +} + +static inline u8 oc_getreg_32(struct ocores_i2c *i2c, int reg) +{ + return ioread32(i2c->base + (reg << i2c->reg_shift)); +} + +/* Read and write functions for the GRLIB port of the controller. Registers are + * 32-bit big endian and the PRELOW and PREHIGH registers are merged into one + * register. The subsequent registers has their offset decreased accordingly. */ +static u8 oc_getreg_grlib(struct ocores_i2c *i2c, int reg) +{ + u32 rd; + int rreg = reg; + if (reg != OCI2C_PRELOW) + rreg--; + rd = ioread32be(i2c->base + (rreg << i2c->reg_shift)); + if (reg == OCI2C_PREHIGH) + return (u8)(rd >> 8); else - iowrite8(value, i2c->base + (reg << i2c->reg_shift)); + return (u8)rd; +} + +static void oc_setreg_grlib(struct ocores_i2c *i2c, int reg, u8 value) +{ + u32 curr, wr; + int rreg = reg; + if (reg != OCI2C_PRELOW) + rreg--; + if (reg == OCI2C_PRELOW || reg == OCI2C_PREHIGH) { + curr = ioread32be(i2c->base + (rreg << i2c->reg_shift)); + if (reg == OCI2C_PRELOW) + wr = (curr & 0xff00) | value; + else + wr = (((u32)value) << 8) | (curr & 0xff); + } else { + wr = value; + } + iowrite32be(wr, i2c->base + (rreg << i2c->reg_shift)); +} + +static inline void oc_setreg(struct ocores_i2c *i2c, int reg, u8 value) +{ + i2c->setreg(i2c, reg, value); } static inline u8 oc_getreg(struct ocores_i2c *i2c, int reg) { - if (i2c->reg_io_width == 4) - return ioread32(i2c->base + (reg << i2c->reg_shift)); - else if (i2c->reg_io_width == 2) - return ioread16(i2c->base + (reg << i2c->reg_shift)); - else - return ioread8(i2c->base + (reg << i2c->reg_shift)); + return i2c->getreg(i2c, reg); } static void ocores_process(struct ocores_i2c *i2c) @@ -227,11 +289,25 @@ static struct i2c_adapter ocores_adapter = { .algo = &ocores_algorithm, }; +static struct of_device_id ocores_i2c_match[] = { + { + .compatible = "opencores,i2c-ocores", + .data = (void *)TYPE_OCORES, + }, + { + .compatible = "aeroflexgaisler,i2cmst", + .data = (void *)TYPE_GRLIB, + }, + {}, +}; +MODULE_DEVICE_TABLE(of, ocores_i2c_match); + #ifdef CONFIG_OF static int ocores_i2c_of_probe(struct platform_device *pdev, struct ocores_i2c *i2c) { struct device_node *np = pdev->dev.of_node; + const struct of_device_id *match; u32 val; if (of_property_read_u32(np, "reg-shift", &i2c->reg_shift)) { @@ -257,6 +333,14 @@ static int ocores_i2c_of_probe(struct platform_device *pdev, of_property_read_u32(pdev->dev.of_node, "reg-io-width", &i2c->reg_io_width); + + match = of_match_node(ocores_i2c_match, pdev->dev.of_node); + if (match && (int)match->data == TYPE_GRLIB) { + dev_dbg(&pdev->dev, "GRLIB variant of i2c-ocores\n"); + i2c->setreg = oc_setreg_grlib; + i2c->getreg = oc_getreg_grlib; + } + return 0; } #else @@ -302,6 +386,30 @@ static int __devinit ocores_i2c_probe(struct platform_device *pdev) if (i2c->reg_io_width == 0) i2c->reg_io_width = 1; /* Set to default value */ + if (!i2c->setreg || !i2c->getreg) { + switch (i2c->reg_io_width) { + case 1: + i2c->setreg = oc_setreg_8; + i2c->getreg = oc_getreg_8; + break; + + case 2: + i2c->setreg = oc_setreg_16; + i2c->getreg = oc_getreg_16; + break; + + case 4: + i2c->setreg = oc_setreg_32; + i2c->getreg = oc_getreg_32; + break; + + default: + dev_err(&pdev->dev, "Unsupported I/O width (%d)\n", + i2c->reg_io_width); + return -EINVAL; + } + } + ocores_init(i2c); init_waitqueue_head(&i2c->wait); @@ -379,12 +487,6 @@ static SIMPLE_DEV_PM_OPS(ocores_i2c_pm, ocores_i2c_suspend, ocores_i2c_resume); #define OCORES_I2C_PM NULL #endif -static struct of_device_id ocores_i2c_match[] = { - { .compatible = "opencores,i2c-ocores", }, - {}, -}; -MODULE_DEVICE_TABLE(of, ocores_i2c_match); - static struct platform_driver ocores_i2c_driver = { .probe = ocores_i2c_probe, .remove = __devexit_p(ocores_i2c_remove), -- cgit v1.2.3-70-g09d2 From 0857ba3c24c308f42a242fe8a1894772750230ce Mon Sep 17 00:00:00 2001 From: Aaro Koskinen Date: Sun, 18 Nov 2012 18:36:19 +0200 Subject: i2c: i2c-cbus-gpio: introduce driver Add i2c driver to enable access to devices behind CBUS on Nokia Internet Tablets. The patch also adds CBUS I2C configuration for N8x0 which is one of the users of this driver. Acked-by: Felipe Balbi Acked-by: Tony Lindgren Signed-off-by: Aaro Koskinen Signed-off-by: Wolfram Sang --- .../devicetree/bindings/i2c/i2c-cbus-gpio.txt | 27 ++ arch/arm/mach-omap2/board-n8x0.c | 42 +++ drivers/i2c/busses/Kconfig | 10 + drivers/i2c/busses/Makefile | 1 + drivers/i2c/busses/i2c-cbus-gpio.c | 300 +++++++++++++++++++++ include/linux/platform_data/i2c-cbus-gpio.h | 27 ++ 6 files changed, 407 insertions(+) create mode 100644 Documentation/devicetree/bindings/i2c/i2c-cbus-gpio.txt create mode 100644 drivers/i2c/busses/i2c-cbus-gpio.c create mode 100644 include/linux/platform_data/i2c-cbus-gpio.h (limited to 'Documentation') diff --git a/Documentation/devicetree/bindings/i2c/i2c-cbus-gpio.txt b/Documentation/devicetree/bindings/i2c/i2c-cbus-gpio.txt new file mode 100644 index 00000000000..8ce9cd2855b --- /dev/null +++ b/Documentation/devicetree/bindings/i2c/i2c-cbus-gpio.txt @@ -0,0 +1,27 @@ +Device tree bindings for i2c-cbus-gpio driver + +Required properties: + - compatible = "i2c-cbus-gpio"; + - gpios: clk, dat, sel + - #address-cells = <1>; + - #size-cells = <0>; + +Optional properties: + - child nodes conforming to i2c bus binding + +Example: + +i2c@0 { + compatible = "i2c-cbus-gpio"; + gpios = <&gpio 66 0 /* clk */ + &gpio 65 0 /* dat */ + &gpio 64 0 /* sel */ + >; + #address-cells = <1>; + #size-cells = <0>; + + retu-mfd: retu@1 { + compatible = "retu-mfd"; + reg = <0x1>; + }; +}; diff --git a/arch/arm/mach-omap2/board-n8x0.c b/arch/arm/mach-omap2/board-n8x0.c index d95f727ca39..bbfd74263c4 100644 --- a/arch/arm/mach-omap2/board-n8x0.c +++ b/arch/arm/mach-omap2/board-n8x0.c @@ -16,10 +16,12 @@ #include #include #include +#include #include #include #include #include +#include #include #include #include @@ -39,6 +41,45 @@ #define TUSB6010_GPIO_ENABLE 0 #define TUSB6010_DMACHAN 0x3f +#if defined(CONFIG_I2C_CBUS_GPIO) || defined(CONFIG_I2C_CBUS_GPIO_MODULE) +static struct i2c_cbus_platform_data n8x0_cbus_data = { + .clk_gpio = 66, + .dat_gpio = 65, + .sel_gpio = 64, +}; + +static struct platform_device n8x0_cbus_device = { + .name = "i2c-cbus-gpio", + .id = 3, + .dev = { + .platform_data = &n8x0_cbus_data, + }, +}; + +static struct i2c_board_info n8x0_i2c_board_info_3[] __initdata = { + { + I2C_BOARD_INFO("retu-mfd", 0x01), + }, +}; + +static void __init n8x0_cbus_init(void) +{ + const int retu_irq_gpio = 108; + + if (gpio_request_one(retu_irq_gpio, GPIOF_IN, "Retu IRQ")) + return; + irq_set_irq_type(gpio_to_irq(retu_irq_gpio), IRQ_TYPE_EDGE_RISING); + n8x0_i2c_board_info_3[0].irq = gpio_to_irq(retu_irq_gpio); + i2c_register_board_info(3, n8x0_i2c_board_info_3, + ARRAY_SIZE(n8x0_i2c_board_info_3)); + platform_device_register(&n8x0_cbus_device); +} +#else /* CONFIG_I2C_CBUS_GPIO */ +static void __init n8x0_cbus_init(void) +{ +} +#endif /* CONFIG_I2C_CBUS_GPIO */ + #if defined(CONFIG_USB_MUSB_TUSB6010) || defined(CONFIG_USB_MUSB_TUSB6010_MODULE) /* * Enable or disable power to TUSB6010. When enabling, turn on 3.3 V and @@ -677,6 +718,7 @@ static void __init n8x0_init_machine(void) gpmc_onenand_init(board_onenand_data); n8x0_mmc_init(); n8x0_usb_init(); + n8x0_cbus_init(); } MACHINE_START(NOKIA_N800, "Nokia N800") diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index e9df4612b7e..e949edf644d 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -337,6 +337,16 @@ config I2C_BLACKFIN_TWI_CLK_KHZ help The unit of the TWI clock is kHz. +config I2C_CBUS_GPIO + tristate "CBUS I2C driver" + depends on GENERIC_GPIO + help + Support for CBUS access using I2C API. Mostly relevant for Nokia + Internet Tablets (770, N800 and N810). + + This driver can also be built as a module. If so, the module + will be called i2c-cbus-gpio. + config I2C_CPM tristate "Freescale CPM1 or CPM2 (MPC8xx/826x)" depends on (CPM1 || CPM2) && OF_I2C diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 395b516ffa0..f9e3e0b5c82 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -31,6 +31,7 @@ obj-$(CONFIG_I2C_POWERMAC) += i2c-powermac.o obj-$(CONFIG_I2C_AT91) += i2c-at91.o obj-$(CONFIG_I2C_AU1550) += i2c-au1550.o obj-$(CONFIG_I2C_BLACKFIN_TWI) += i2c-bfin-twi.o +obj-$(CONFIG_I2C_CBUS_GPIO) += i2c-cbus-gpio.o obj-$(CONFIG_I2C_CPM) += i2c-cpm.o obj-$(CONFIG_I2C_DAVINCI) += i2c-davinci.o obj-$(CONFIG_I2C_DESIGNWARE_CORE) += i2c-designware-core.o diff --git a/drivers/i2c/busses/i2c-cbus-gpio.c b/drivers/i2c/busses/i2c-cbus-gpio.c new file mode 100644 index 00000000000..98386d65931 --- /dev/null +++ b/drivers/i2c/busses/i2c-cbus-gpio.c @@ -0,0 +1,300 @@ +/* + * CBUS I2C driver for Nokia Internet Tablets. + * + * Copyright (C) 2004-2010 Nokia Corporation + * + * Based on code written by Juha Yrjölä, David Weinehall, Mikko Ylinen and + * Felipe Balbi. Converted to I2C driver by Aaro Koskinen. + * + * This file is subject to the terms and conditions of the GNU General + * Public License. See the file "COPYING" in the main directory of this + * archive for more details. + * + * 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. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* + * Bit counts are derived from Nokia implementation. These should be checked + * if other CBUS implementations appear. + */ +#define CBUS_ADDR_BITS 3 +#define CBUS_REG_BITS 5 + +struct cbus_host { + spinlock_t lock; /* host lock */ + struct device *dev; + int clk_gpio; + int dat_gpio; + int sel_gpio; +}; + +/** + * cbus_send_bit - sends one bit over the bus + * @host: the host we're using + * @bit: one bit of information to send + */ +static void cbus_send_bit(struct cbus_host *host, unsigned bit) +{ + gpio_set_value(host->dat_gpio, bit ? 1 : 0); + gpio_set_value(host->clk_gpio, 1); + gpio_set_value(host->clk_gpio, 0); +} + +/** + * cbus_send_data - sends @len amount of data over the bus + * @host: the host we're using + * @data: the data to send + * @len: size of the transfer + */ +static void cbus_send_data(struct cbus_host *host, unsigned data, unsigned len) +{ + int i; + + for (i = len; i > 0; i--) + cbus_send_bit(host, data & (1 << (i - 1))); +} + +/** + * cbus_receive_bit - receives one bit from the bus + * @host: the host we're using + */ +static int cbus_receive_bit(struct cbus_host *host) +{ + int ret; + + gpio_set_value(host->clk_gpio, 1); + ret = gpio_get_value(host->dat_gpio); + gpio_set_value(host->clk_gpio, 0); + return ret; +} + +/** + * cbus_receive_word - receives 16-bit word from the bus + * @host: the host we're using + */ +static int cbus_receive_word(struct cbus_host *host) +{ + int ret = 0; + int i; + + for (i = 16; i > 0; i--) { + int bit = cbus_receive_bit(host); + + if (bit < 0) + return bit; + + if (bit) + ret |= 1 << (i - 1); + } + return ret; +} + +/** + * cbus_transfer - transfers data over the bus + * @host: the host we're using + * @rw: read/write flag + * @dev: device address + * @reg: register address + * @data: if @rw == I2C_SBUS_WRITE data to send otherwise 0 + */ +static int cbus_transfer(struct cbus_host *host, char rw, unsigned dev, + unsigned reg, unsigned data) +{ + unsigned long flags; + int ret; + + /* We don't want interrupts disturbing our transfer */ + spin_lock_irqsave(&host->lock, flags); + + /* Reset state and start of transfer, SEL stays down during transfer */ + gpio_set_value(host->sel_gpio, 0); + + /* Set the DAT pin to output */ + gpio_direction_output(host->dat_gpio, 1); + + /* Send the device address */ + cbus_send_data(host, dev, CBUS_ADDR_BITS); + + /* Send the rw flag */ + cbus_send_bit(host, rw == I2C_SMBUS_READ); + + /* Send the register address */ + cbus_send_data(host, reg, CBUS_REG_BITS); + + if (rw == I2C_SMBUS_WRITE) { + cbus_send_data(host, data, 16); + ret = 0; + } else { + ret = gpio_direction_input(host->dat_gpio); + if (ret) { + dev_dbg(host->dev, "failed setting direction\n"); + goto out; + } + gpio_set_value(host->clk_gpio, 1); + + ret = cbus_receive_word(host); + if (ret < 0) { + dev_dbg(host->dev, "failed receiving data\n"); + goto out; + } + } + + /* Indicate end of transfer, SEL goes up until next transfer */ + gpio_set_value(host->sel_gpio, 1); + gpio_set_value(host->clk_gpio, 1); + gpio_set_value(host->clk_gpio, 0); + +out: + spin_unlock_irqrestore(&host->lock, flags); + + return ret; +} + +static int cbus_i2c_smbus_xfer(struct i2c_adapter *adapter, + u16 addr, + unsigned short flags, + char read_write, + u8 command, + int size, + union i2c_smbus_data *data) +{ + struct cbus_host *chost = i2c_get_adapdata(adapter); + int ret; + + if (size != I2C_SMBUS_WORD_DATA) + return -EINVAL; + + ret = cbus_transfer(chost, read_write == I2C_SMBUS_READ, addr, + command, data->word); + if (ret < 0) + return ret; + + if (read_write == I2C_SMBUS_READ) + data->word = ret; + + return 0; +} + +static u32 cbus_i2c_func(struct i2c_adapter *adapter) +{ + return I2C_FUNC_SMBUS_READ_WORD_DATA | I2C_FUNC_SMBUS_WRITE_WORD_DATA; +} + +static const struct i2c_algorithm cbus_i2c_algo = { + .smbus_xfer = cbus_i2c_smbus_xfer, + .functionality = cbus_i2c_func, +}; + +static int cbus_i2c_remove(struct platform_device *pdev) +{ + struct i2c_adapter *adapter = platform_get_drvdata(pdev); + + return i2c_del_adapter(adapter); +} + +static int cbus_i2c_probe(struct platform_device *pdev) +{ + struct i2c_adapter *adapter; + struct cbus_host *chost; + int ret; + + adapter = devm_kzalloc(&pdev->dev, sizeof(struct i2c_adapter), + GFP_KERNEL); + if (!adapter) + return -ENOMEM; + + chost = devm_kzalloc(&pdev->dev, sizeof(*chost), GFP_KERNEL); + if (!chost) + return -ENOMEM; + + if (pdev->dev.of_node) { + struct device_node *dnode = pdev->dev.of_node; + if (of_gpio_count(dnode) != 3) + return -ENODEV; + chost->clk_gpio = of_get_gpio(dnode, 0); + chost->dat_gpio = of_get_gpio(dnode, 1); + chost->sel_gpio = of_get_gpio(dnode, 2); + } else if (pdev->dev.platform_data) { + struct i2c_cbus_platform_data *pdata = pdev->dev.platform_data; + chost->clk_gpio = pdata->clk_gpio; + chost->dat_gpio = pdata->dat_gpio; + chost->sel_gpio = pdata->sel_gpio; + } else { + return -ENODEV; + } + + adapter->owner = THIS_MODULE; + adapter->class = I2C_CLASS_HWMON; + adapter->dev.parent = &pdev->dev; + adapter->nr = pdev->id; + adapter->timeout = HZ; + adapter->algo = &cbus_i2c_algo; + strlcpy(adapter->name, "CBUS I2C adapter", sizeof(adapter->name)); + + spin_lock_init(&chost->lock); + chost->dev = &pdev->dev; + + ret = devm_gpio_request_one(&pdev->dev, chost->clk_gpio, + GPIOF_OUT_INIT_LOW, "CBUS clk"); + if (ret) + return ret; + + ret = devm_gpio_request_one(&pdev->dev, chost->dat_gpio, GPIOF_IN, + "CBUS data"); + if (ret) + return ret; + + ret = devm_gpio_request_one(&pdev->dev, chost->sel_gpio, + GPIOF_OUT_INIT_HIGH, "CBUS sel"); + if (ret) + return ret; + + i2c_set_adapdata(adapter, chost); + platform_set_drvdata(pdev, adapter); + + return i2c_add_numbered_adapter(adapter); +} + +#if defined(CONFIG_OF) +static const struct of_device_id i2c_cbus_dt_ids[] = { + { .compatible = "i2c-cbus-gpio", }, + { } +}; +MODULE_DEVICE_TABLE(of, i2c_cbus_dt_ids); +#endif + +static struct platform_driver cbus_i2c_driver = { + .probe = cbus_i2c_probe, + .remove = cbus_i2c_remove, + .driver = { + .owner = THIS_MODULE, + .name = "i2c-cbus-gpio", + }, +}; +module_platform_driver(cbus_i2c_driver); + +MODULE_ALIAS("platform:i2c-cbus-gpio"); +MODULE_DESCRIPTION("CBUS I2C driver"); +MODULE_AUTHOR("Juha Yrjölä"); +MODULE_AUTHOR("David Weinehall"); +MODULE_AUTHOR("Mikko Ylinen"); +MODULE_AUTHOR("Felipe Balbi"); +MODULE_AUTHOR("Aaro Koskinen "); +MODULE_LICENSE("GPL"); diff --git a/include/linux/platform_data/i2c-cbus-gpio.h b/include/linux/platform_data/i2c-cbus-gpio.h new file mode 100644 index 00000000000..6faa992a950 --- /dev/null +++ b/include/linux/platform_data/i2c-cbus-gpio.h @@ -0,0 +1,27 @@ +/* + * i2c-cbus-gpio.h - CBUS I2C platform_data definition + * + * Copyright (C) 2004-2009 Nokia Corporation + * + * Written by Felipe Balbi and Aaro Koskinen. + * + * This file is subject to the terms and conditions of the GNU General + * Public License. See the file "COPYING" in the main directory of this + * archive for more details. + * + * 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. + */ + +#ifndef __INCLUDE_LINUX_I2C_CBUS_GPIO_H +#define __INCLUDE_LINUX_I2C_CBUS_GPIO_H + +struct i2c_cbus_platform_data { + int dat_gpio; + int clk_gpio; + int sel_gpio; +}; + +#endif /* __INCLUDE_LINUX_I2C_CBUS_GPIO_H */ -- cgit v1.2.3-70-g09d2