From 92722b1bb1ebcba767f9c6ee499992ee33367268 Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Thu, 11 Jun 2009 14:17:48 +0100 Subject: leds: Further document parameters for blink_set() The documentation for the parameters of blink_set() was a bit hard to find so put some where I'd expected to find it. Signed-off-by: Mark Brown Signed-off-by: Richard Purdie --- include/linux/leds.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/leds.h b/include/linux/leds.h index 376fe07732e..c7f0b148df0 100644 --- a/include/linux/leds.h +++ b/include/linux/leds.h @@ -45,7 +45,9 @@ struct led_classdev { /* Get LED brightness level */ enum led_brightness (*brightness_get)(struct led_classdev *led_cdev); - /* Activate hardware accelerated blink */ + /* Activate hardware accelerated blink, delays are in + * miliseconds and if none is provided then a sensible default + * should be chosen. */ int (*blink_set)(struct led_classdev *led_cdev, unsigned long *delay_on, unsigned long *delay_off); -- cgit v1.2.3-70-g09d2 From 5054d39e327f76df022163a2ebd02e444c5d65f9 Mon Sep 17 00:00:00 2001 From: Antonio Ospite Date: Fri, 19 Jun 2009 13:55:42 +0200 Subject: leds: LED driver for National Semiconductor LP3944 Funlight Chip LEDs driver for National Semiconductor LP3944 Funlight Chip http://www.national.com/pf/LP/LP3944.html This helper chip can drive up to 8 leds, with two programmable DIM modes; it could even be used as a gpio expander but this driver assumes it is used as a led controller. The DIM modes are used to set _blink_ patterns for leds, the pattern is specified supplying two parameters: - period: from 0s to 1.6s - duty cycle: percentage of the period the led is on, from 0 to 100 LP3944 can be found on Motorola A910 smartphone, where it drives the rgb leds, the camera flash light and the displays backlights. Signed-off-by: Antonio Ospite Signed-off-by: Richard Purdie --- Documentation/leds-lp3944.txt | 50 +++++ drivers/leds/Kconfig | 11 + drivers/leds/Makefile | 1 + drivers/leds/leds-lp3944.c | 466 ++++++++++++++++++++++++++++++++++++++++++ include/linux/leds-lp3944.h | 53 +++++ 5 files changed, 581 insertions(+) create mode 100644 Documentation/leds-lp3944.txt create mode 100644 drivers/leds/leds-lp3944.c create mode 100644 include/linux/leds-lp3944.h (limited to 'include') diff --git a/Documentation/leds-lp3944.txt b/Documentation/leds-lp3944.txt new file mode 100644 index 00000000000..c6eda18b15e --- /dev/null +++ b/Documentation/leds-lp3944.txt @@ -0,0 +1,50 @@ +Kernel driver lp3944 +==================== + + * National Semiconductor LP3944 Fun-light Chip + Prefix: 'lp3944' + Addresses scanned: None (see the Notes section below) + Datasheet: Publicly available at the National Semiconductor website + http://www.national.com/pf/LP/LP3944.html + +Authors: + Antonio Ospite + + +Description +----------- +The LP3944 is a helper chip that can drive up to 8 leds, with two programmable +DIM modes; it could even be used as a gpio expander but this driver assumes it +is used as a led controller. + +The DIM modes are used to set _blink_ patterns for leds, the pattern is +specified supplying two parameters: + - period: from 0s to 1.6s + - duty cycle: percentage of the period the led is on, from 0 to 100 + +Setting a led in DIM0 or DIM1 mode makes it blink according to the pattern. +See the datasheet for details. + +LP3944 can be found on Motorola A910 smartphone, where it drives the rgb +leds, the camera flash light and the lcds power. + + +Notes +----- +The chip is used mainly in embedded contexts, so this driver expects it is +registered using the i2c_board_info mechanism. + +To register the chip at address 0x60 on adapter 0, set the platform data +according to include/linux/leds-lp3944.h, set the i2c board info: + + static struct i2c_board_info __initdata a910_i2c_board_info[] = { + { + I2C_BOARD_INFO("lp3944", 0x60), + .platform_data = &a910_lp3944_leds, + }, + }; + +and register it in the platform init function + + i2c_register_board_info(0, a910_i2c_board_info, + ARRAY_SIZE(a910_i2c_board_info)); diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig index cfcd6bf831c..7c8e7122aaa 100644 --- a/drivers/leds/Kconfig +++ b/drivers/leds/Kconfig @@ -146,6 +146,17 @@ config LEDS_GPIO_OF of_platform devices. For instance, LEDs which are listed in a "dts" file. +config LEDS_LP3944 + tristate "LED Support for N.S. LP3944 (Fun Light) I2C chip" + depends on LEDS_CLASS && I2C + help + This option enables support for LEDs connected to the National + Semiconductor LP3944 Lighting Management Unit (LMU) also known as + Fun Light Chip. + + To compile this driver as a module, choose M here: the + module will be called leds-lp3944. + config LEDS_CLEVO_MAIL tristate "Mail LED on Clevo notebook" depends on LEDS_CLASS && X86 && SERIO_I8042 && DMI diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile index 2d41c4dcf92..e8cdcf77a4c 100644 --- a/drivers/leds/Makefile +++ b/drivers/leds/Makefile @@ -20,6 +20,7 @@ obj-$(CONFIG_LEDS_COBALT_RAQ) += leds-cobalt-raq.o obj-$(CONFIG_LEDS_SUNFIRE) += leds-sunfire.o obj-$(CONFIG_LEDS_PCA9532) += leds-pca9532.o obj-$(CONFIG_LEDS_GPIO) += leds-gpio.o +obj-$(CONFIG_LEDS_LP3944) += leds-lp3944.o obj-$(CONFIG_LEDS_CLEVO_MAIL) += leds-clevo-mail.o obj-$(CONFIG_LEDS_HP6XX) += leds-hp6xx.o obj-$(CONFIG_LEDS_FSG) += leds-fsg.o diff --git a/drivers/leds/leds-lp3944.c b/drivers/leds/leds-lp3944.c new file mode 100644 index 00000000000..5946208ba26 --- /dev/null +++ b/drivers/leds/leds-lp3944.c @@ -0,0 +1,466 @@ +/* + * leds-lp3944.c - driver for National Semiconductor LP3944 Funlight Chip + * + * Copyright (C) 2009 Antonio Ospite + * + * 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. + * + */ + +/* + * I2C driver for National Semiconductor LP3944 Funlight Chip + * http://www.national.com/pf/LP/LP3944.html + * + * This helper chip can drive up to 8 leds, with two programmable DIM modes; + * it could even be used as a gpio expander but this driver assumes it is used + * as a led controller. + * + * The DIM modes are used to set _blink_ patterns for leds, the pattern is + * specified supplying two parameters: + * - period: from 0s to 1.6s + * - duty cycle: percentage of the period the led is on, from 0 to 100 + * + * LP3944 can be found on Motorola A910 smartphone, where it drives the rgb + * leds, the camera flash light and the displays backlights. + */ + +#include +#include +#include +#include +#include +#include + +/* Read Only Registers */ +#define LP3944_REG_INPUT1 0x00 /* LEDs 0-7 InputRegister (Read Only) */ +#define LP3944_REG_REGISTER1 0x01 /* None (Read Only) */ + +#define LP3944_REG_PSC0 0x02 /* Frequency Prescaler 0 (R/W) */ +#define LP3944_REG_PWM0 0x03 /* PWM Register 0 (R/W) */ +#define LP3944_REG_PSC1 0x04 /* Frequency Prescaler 1 (R/W) */ +#define LP3944_REG_PWM1 0x05 /* PWM Register 1 (R/W) */ +#define LP3944_REG_LS0 0x06 /* LEDs 0-3 Selector (R/W) */ +#define LP3944_REG_LS1 0x07 /* LEDs 4-7 Selector (R/W) */ + +/* These registers are not used to control leds in LP3944, they can store + * arbitrary values which the chip will ignore. + */ +#define LP3944_REG_REGISTER8 0x08 +#define LP3944_REG_REGISTER9 0x09 + +#define LP3944_DIM0 0 +#define LP3944_DIM1 1 + +/* period in ms */ +#define LP3944_PERIOD_MIN 0 +#define LP3944_PERIOD_MAX 1600 + +/* duty cycle is a percentage */ +#define LP3944_DUTY_CYCLE_MIN 0 +#define LP3944_DUTY_CYCLE_MAX 100 + +#define ldev_to_led(c) container_of(c, struct lp3944_led_data, ldev) + +/* Saved data */ +struct lp3944_led_data { + u8 id; + enum lp3944_type type; + enum lp3944_status status; + struct led_classdev ldev; + struct i2c_client *client; + struct work_struct work; +}; + +struct lp3944_data { + struct mutex lock; + struct i2c_client *client; + struct lp3944_led_data leds[LP3944_LEDS_MAX]; +}; + +static int lp3944_reg_read(struct i2c_client *client, u8 reg, u8 *value) +{ + int tmp; + + tmp = i2c_smbus_read_byte_data(client, reg); + if (tmp < 0) + return -EINVAL; + + *value = tmp; + + return 0; +} + +static int lp3944_reg_write(struct i2c_client *client, u8 reg, u8 value) +{ + return i2c_smbus_write_byte_data(client, reg, value); +} + +/** + * Set the period for DIM status + * + * @client: the i2c client + * @dim: either LP3944_DIM0 or LP3944_DIM1 + * @period: period of a blink, that is a on/off cycle, expressed in ms. + */ +static int lp3944_dim_set_period(struct i2c_client *client, u8 dim, u16 period) +{ + u8 psc_reg; + u8 psc_value; + int err; + + if (dim == LP3944_DIM0) + psc_reg = LP3944_REG_PSC0; + else if (dim == LP3944_DIM1) + psc_reg = LP3944_REG_PSC1; + else + return -EINVAL; + + /* Convert period to Prescaler value */ + if (period > LP3944_PERIOD_MAX) + return -EINVAL; + + psc_value = (period * 255) / LP3944_PERIOD_MAX; + + err = lp3944_reg_write(client, psc_reg, psc_value); + + return err; +} + +/** + * Set the duty cycle for DIM status + * + * @client: the i2c client + * @dim: either LP3944_DIM0 or LP3944_DIM1 + * @duty_cycle: percentage of a period during which a led is ON + */ +static int lp3944_dim_set_dutycycle(struct i2c_client *client, u8 dim, + u8 duty_cycle) +{ + u8 pwm_reg; + u8 pwm_value; + int err; + + if (dim == LP3944_DIM0) + pwm_reg = LP3944_REG_PWM0; + else if (dim == LP3944_DIM1) + pwm_reg = LP3944_REG_PWM1; + else + return -EINVAL; + + /* Convert duty cycle to PWM value */ + if (duty_cycle > LP3944_DUTY_CYCLE_MAX) + return -EINVAL; + + pwm_value = (duty_cycle * 255) / LP3944_DUTY_CYCLE_MAX; + + err = lp3944_reg_write(client, pwm_reg, pwm_value); + + return err; +} + +/** + * Set the led status + * + * @led: a lp3944_led_data structure + * @status: one of LP3944_LED_STATUS_OFF + * LP3944_LED_STATUS_ON + * LP3944_LED_STATUS_DIM0 + * LP3944_LED_STATUS_DIM1 + */ +static int lp3944_led_set(struct lp3944_led_data *led, u8 status) +{ + struct lp3944_data *data = i2c_get_clientdata(led->client); + u8 id = led->id; + u8 reg; + u8 val = 0; + int err; + + dev_dbg(&led->client->dev, "%s: %s, status before normalization:%d\n", + __func__, led->ldev.name, status); + + switch (id) { + case LP3944_LED0: + case LP3944_LED1: + case LP3944_LED2: + case LP3944_LED3: + reg = LP3944_REG_LS0; + break; + case LP3944_LED4: + case LP3944_LED5: + case LP3944_LED6: + case LP3944_LED7: + id -= LP3944_LED4; + reg = LP3944_REG_LS1; + break; + default: + return -EINVAL; + } + + if (status > LP3944_LED_STATUS_DIM1) + return -EINVAL; + + /* invert only 0 and 1, leave unchanged the other values, + * remember we are abusing status to set blink patterns + */ + if (led->type == LP3944_LED_TYPE_LED_INVERTED && status < 2) + status = 1 - status; + + mutex_lock(&data->lock); + lp3944_reg_read(led->client, reg, &val); + + val &= ~(LP3944_LED_STATUS_MASK << (id << 1)); + val |= (status << (id << 1)); + + dev_dbg(&led->client->dev, "%s: %s, reg:%d id:%d status:%d val:%#x\n", + __func__, led->ldev.name, reg, id, status, val); + + /* set led status */ + err = lp3944_reg_write(led->client, reg, val); + mutex_unlock(&data->lock); + + return err; +} + +static int lp3944_led_set_blink(struct led_classdev *led_cdev, + unsigned long *delay_on, + unsigned long *delay_off) +{ + struct lp3944_led_data *led = ldev_to_led(led_cdev); + u16 period; + u8 duty_cycle; + int err; + + /* units are in ms */ + if (*delay_on + *delay_off > LP3944_PERIOD_MAX) + return -EINVAL; + + if (*delay_on == 0 && *delay_off == 0) { + /* Special case: the leds subsystem requires a default user + * friendly blink pattern for the LED. Let's blink the led + * slowly (1Hz). + */ + *delay_on = 500; + *delay_off = 500; + } + + period = (*delay_on) + (*delay_off); + + /* duty_cycle is the percentage of period during which the led is ON */ + duty_cycle = 100 * (*delay_on) / period; + + /* invert duty cycle for inverted leds, this has the same effect of + * swapping delay_on and delay_off + */ + if (led->type == LP3944_LED_TYPE_LED_INVERTED) + duty_cycle = 100 - duty_cycle; + + /* NOTE: using always the first DIM mode, this means that all leds + * will have the same blinking pattern. + * + * We could find a way later to have two leds blinking in hardware + * with different patterns at the same time, falling back to software + * control for the other ones. + */ + err = lp3944_dim_set_period(led->client, LP3944_DIM0, period); + if (err) + return err; + + err = lp3944_dim_set_dutycycle(led->client, LP3944_DIM0, duty_cycle); + if (err) + return err; + + dev_dbg(&led->client->dev, "%s: OK hardware accelerated blink!\n", + __func__); + + led->status = LP3944_LED_STATUS_DIM0; + schedule_work(&led->work); + + return 0; +} + +static void lp3944_led_set_brightness(struct led_classdev *led_cdev, + enum led_brightness brightness) +{ + struct lp3944_led_data *led = ldev_to_led(led_cdev); + + dev_dbg(&led->client->dev, "%s: %s, %d\n", + __func__, led_cdev->name, brightness); + + led->status = brightness; + schedule_work(&led->work); +} + +static void lp3944_led_work(struct work_struct *work) +{ + struct lp3944_led_data *led; + + led = container_of(work, struct lp3944_led_data, work); + lp3944_led_set(led, led->status); +} + +static int lp3944_configure(struct i2c_client *client, + struct lp3944_data *data, + struct lp3944_platform_data *pdata) +{ + int i, err = 0; + + for (i = 0; i < pdata->leds_size; i++) { + struct lp3944_led *pled = &pdata->leds[i]; + struct lp3944_led_data *led = &data->leds[i]; + led->client = client; + led->id = i; + + switch (pled->type) { + + case LP3944_LED_TYPE_LED: + case LP3944_LED_TYPE_LED_INVERTED: + led->type = pled->type; + led->status = pled->status; + led->ldev.name = pled->name; + led->ldev.max_brightness = 1; + led->ldev.brightness_set = lp3944_led_set_brightness; + led->ldev.blink_set = lp3944_led_set_blink; + led->ldev.flags = LED_CORE_SUSPENDRESUME; + + INIT_WORK(&led->work, lp3944_led_work); + err = led_classdev_register(&client->dev, &led->ldev); + if (err < 0) { + dev_err(&client->dev, + "couldn't register LED %s\n", + led->ldev.name); + goto exit; + } + + /* to expose the default value to userspace */ + led->ldev.brightness = led->status; + + /* Set the default led status */ + err = lp3944_led_set(led, led->status); + if (err < 0) { + dev_err(&client->dev, + "%s couldn't set STATUS %d\n", + led->ldev.name, led->status); + goto exit; + } + break; + + case LP3944_LED_TYPE_NONE: + default: + break; + + } + } + return 0; + +exit: + if (i > 0) + for (i = i - 1; i >= 0; i--) + switch (pdata->leds[i].type) { + + case LP3944_LED_TYPE_LED: + case LP3944_LED_TYPE_LED_INVERTED: + led_classdev_unregister(&data->leds[i].ldev); + cancel_work_sync(&data->leds[i].work); + break; + + case LP3944_LED_TYPE_NONE: + default: + break; + } + + return err; +} + +static int __devinit lp3944_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct lp3944_platform_data *lp3944_pdata = client->dev.platform_data; + struct lp3944_data *data; + + if (lp3944_pdata == NULL) { + dev_err(&client->dev, "no platform data\n"); + return -EINVAL; + } + + /* Let's see whether this adapter can support what we need. */ + if (!i2c_check_functionality(client->adapter, + I2C_FUNC_SMBUS_BYTE_DATA)) { + dev_err(&client->dev, "insufficient functionality!\n"); + return -ENODEV; + } + + data = kzalloc(sizeof(struct lp3944_data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->client = client; + i2c_set_clientdata(client, data); + + mutex_init(&data->lock); + + dev_info(&client->dev, "lp3944 enabled\n"); + + lp3944_configure(client, data, lp3944_pdata); + return 0; +} + +static int __devexit lp3944_remove(struct i2c_client *client) +{ + struct lp3944_platform_data *pdata = client->dev.platform_data; + struct lp3944_data *data = i2c_get_clientdata(client); + int i; + + for (i = 0; i < pdata->leds_size; i++) + switch (data->leds[i].type) { + case LP3944_LED_TYPE_LED: + case LP3944_LED_TYPE_LED_INVERTED: + led_classdev_unregister(&data->leds[i].ldev); + cancel_work_sync(&data->leds[i].work); + break; + + case LP3944_LED_TYPE_NONE: + default: + break; + } + + kfree(data); + i2c_set_clientdata(client, NULL); + + return 0; +} + +/* lp3944 i2c driver struct */ +static const struct i2c_device_id lp3944_id[] = { + {"lp3944", 0}, + {} +}; + +MODULE_DEVICE_TABLE(i2c, lp3944_id); + +static struct i2c_driver lp3944_driver = { + .driver = { + .name = "lp3944", + }, + .probe = lp3944_probe, + .remove = __devexit_p(lp3944_remove), + .id_table = lp3944_id, +}; + +static int __init lp3944_module_init(void) +{ + return i2c_add_driver(&lp3944_driver); +} + +static void __exit lp3944_module_exit(void) +{ + i2c_del_driver(&lp3944_driver); +} + +module_init(lp3944_module_init); +module_exit(lp3944_module_exit); + +MODULE_AUTHOR("Antonio Ospite "); +MODULE_DESCRIPTION("LP3944 Fun Light Chip"); +MODULE_LICENSE("GPL"); diff --git a/include/linux/leds-lp3944.h b/include/linux/leds-lp3944.h new file mode 100644 index 00000000000..afc9f9fd70f --- /dev/null +++ b/include/linux/leds-lp3944.h @@ -0,0 +1,53 @@ +/* + * leds-lp3944.h - platform data structure for lp3944 led controller + * + * Copyright (C) 2009 Antonio Ospite + * + * 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. + * + */ + +#ifndef __LINUX_LEDS_LP3944_H +#define __LINUX_LEDS_LP3944_H + +#include +#include + +#define LP3944_LED0 0 +#define LP3944_LED1 1 +#define LP3944_LED2 2 +#define LP3944_LED3 3 +#define LP3944_LED4 4 +#define LP3944_LED5 5 +#define LP3944_LED6 6 +#define LP3944_LED7 7 +#define LP3944_LEDS_MAX 8 + +#define LP3944_LED_STATUS_MASK 0x03 +enum lp3944_status { + LP3944_LED_STATUS_OFF = 0x0, + LP3944_LED_STATUS_ON = 0x1, + LP3944_LED_STATUS_DIM0 = 0x2, + LP3944_LED_STATUS_DIM1 = 0x3 +}; + +enum lp3944_type { + LP3944_LED_TYPE_NONE, + LP3944_LED_TYPE_LED, + LP3944_LED_TYPE_LED_INVERTED, +}; + +struct lp3944_led { + char *name; + enum lp3944_type type; + enum lp3944_status status; +}; + +struct lp3944_platform_data { + struct lp3944_led leds[LP3944_LEDS_MAX]; + u8 leds_size; +}; + +#endif /* __LINUX_LEDS_LP3944_H */ -- cgit v1.2.3-70-g09d2 From ed88bae6918fa990cbfe47316bd0f790121aaf00 Mon Sep 17 00:00:00 2001 From: Trent Piepho Date: Tue, 12 May 2009 15:33:12 -0700 Subject: leds: Add options to have GPIO LEDs start on or keep their state There already is a "default-on" trigger but there are problems with it. For one, it's a inefficient way to do it and requires led trigger support to be compiled in. But the real reason is that is produces a glitch on the LED. The GPIO is allocate with the LED *off*, then *later* when the trigger runs it is turned back on. If the LED was already on via the GPIO's reset default or action of the firmware, this produces a glitch where the LED goes from on to off to on. While normally this is fast enough that it wouldn't be noticeable to a human observer, there are still serious problems. One is that there may be something else on the GPIO line, like a hardware alarm or watchdog, that is fast enough to notice the glitch. Another is that the kernel may panic before the LED is turned back on, thus hanging with the LED in the wrong state. This is not just speculation, but actually happened to me with an embedded system that has an LED which should turn off when the kernel finishes booting, which was left in the incorrect state due to a bug in the OF LED binding code. We also let GPIO LEDs get their initial value from whatever the current state of the GPIO line is. On some systems the LEDs are put into some state by the firmware or hardware before Linux boots, and it is desired to have them keep this state which is otherwise unknown to Linux. This requires that the underlying GPIO driver support reading the value of output GPIOs. Some drivers support this and some do not. The platform device binding gains a field in the platform data "default_state" that controls this. There are three constants defined to select from on, off, or keeping the current state. The OpenFirmware binding uses a property named "default-state" that can be set to "on", "off", or "keep". The default if the property isn't present is off. Signed-off-by: Trent Piepho Acked-by: Grant Likely Acked-by: Wolfram Sang Acked-by: Sean MacLennan Signed-off-by: Richard Purdie --- Documentation/powerpc/dts-bindings/gpio/led.txt | 17 ++++++++++++++++- drivers/leds/leds-gpio.c | 20 +++++++++++++++++--- include/linux/leds.h | 9 +++++++-- 3 files changed, 40 insertions(+), 6 deletions(-) (limited to 'include') diff --git a/Documentation/powerpc/dts-bindings/gpio/led.txt b/Documentation/powerpc/dts-bindings/gpio/led.txt index 4fe14deedc0..064db928c3c 100644 --- a/Documentation/powerpc/dts-bindings/gpio/led.txt +++ b/Documentation/powerpc/dts-bindings/gpio/led.txt @@ -16,10 +16,17 @@ LED sub-node properties: string defining the trigger assigned to the LED. Current triggers are: "backlight" - LED will act as a back-light, controlled by the framebuffer system - "default-on" - LED will turn on + "default-on" - LED will turn on, but see "default-state" below "heartbeat" - LED "double" flashes at a load average based rate "ide-disk" - LED indicates disk activity "timer" - LED flashes at a fixed, configurable rate +- default-state: (optional) The initial state of the LED. Valid + values are "on", "off", and "keep". If the LED is already on or off + and the default-state property is set the to same value, then no + glitch should be produced where the LED momentarily turns off (or + on). The "keep" setting will keep the LED at whatever its current + state is, without producing a glitch. The default is off if this + property is not present. Examples: @@ -30,14 +37,22 @@ leds { gpios = <&mcu_pio 0 1>; /* Active low */ linux,default-trigger = "ide-disk"; }; + + fault { + gpios = <&mcu_pio 1 0>; + /* Keep LED on if BIOS detected hardware fault */ + default-state = "keep"; + }; }; run-control { compatible = "gpio-leds"; red { gpios = <&mpc8572 6 0>; + default-state = "off"; }; green { gpios = <&mpc8572 7 0>; + default-state = "on"; }; } diff --git a/drivers/leds/leds-gpio.c b/drivers/leds/leds-gpio.c index 76895e69104..6b06638eb5b 100644 --- a/drivers/leds/leds-gpio.c +++ b/drivers/leds/leds-gpio.c @@ -76,7 +76,7 @@ static int __devinit create_gpio_led(const struct gpio_led *template, struct gpio_led_data *led_dat, struct device *parent, int (*blink_set)(unsigned, unsigned long *, unsigned long *)) { - int ret; + int ret, state; /* skip leds that aren't available */ if (!gpio_is_valid(template->gpio)) { @@ -99,11 +99,15 @@ static int __devinit create_gpio_led(const struct gpio_led *template, led_dat->cdev.blink_set = gpio_blink_set; } led_dat->cdev.brightness_set = gpio_led_set; - led_dat->cdev.brightness = LED_OFF; + if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP) + state = !!gpio_get_value(led_dat->gpio) ^ led_dat->active_low; + else + state = (template->default_state == LEDS_GPIO_DEFSTATE_ON); + led_dat->cdev.brightness = state ? LED_FULL : LED_OFF; if (!template->retain_state_suspended) led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME; - ret = gpio_direction_output(led_dat->gpio, led_dat->active_low); + ret = gpio_direction_output(led_dat->gpio, led_dat->active_low ^ state); if (ret < 0) goto err; @@ -223,12 +227,22 @@ static int __devinit of_gpio_leds_probe(struct of_device *ofdev, memset(&led, 0, sizeof(led)); for_each_child_of_node(np, child) { enum of_gpio_flags flags; + const char *state; led.gpio = of_get_gpio_flags(child, 0, &flags); led.active_low = flags & OF_GPIO_ACTIVE_LOW; led.name = of_get_property(child, "label", NULL) ? : child->name; led.default_trigger = of_get_property(child, "linux,default-trigger", NULL); + state = of_get_property(child, "default-state", NULL); + if (state) { + if (!strcmp(state, "keep")) + led.default_state = LEDS_GPIO_DEFSTATE_KEEP; + else if(!strcmp(state, "on")) + led.default_state = LEDS_GPIO_DEFSTATE_ON; + else + led.default_state = LEDS_GPIO_DEFSTATE_OFF; + } ret = create_gpio_led(&led, &pdata->led_data[pdata->num_leds++], &ofdev->dev, NULL); diff --git a/include/linux/leds.h b/include/linux/leds.h index c7f0b148df0..62af62915cf 100644 --- a/include/linux/leds.h +++ b/include/linux/leds.h @@ -143,9 +143,14 @@ struct gpio_led { const char *name; const char *default_trigger; unsigned gpio; - u8 active_low : 1; - u8 retain_state_suspended : 1; + unsigned active_low : 1; + unsigned retain_state_suspended : 1; + unsigned default_state : 2; + /* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */ }; +#define LEDS_GPIO_DEFSTATE_OFF 0 +#define LEDS_GPIO_DEFSTATE_ON 1 +#define LEDS_GPIO_DEFSTATE_KEEP 2 struct gpio_led_platform_data { int num_leds; -- cgit v1.2.3-70-g09d2 From a1dd8c617217322614f0465ae347895c4b58e1ab Mon Sep 17 00:00:00 2001 From: Richard Purdie Date: Mon, 22 Jun 2009 14:54:13 +0100 Subject: leds: Futher document blink_set Futher document blink_set function pointer Signed-off-by: Richard Purdie --- include/linux/leds.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/leds.h b/include/linux/leds.h index 62af62915cf..d8bf9665e70 100644 --- a/include/linux/leds.h +++ b/include/linux/leds.h @@ -47,7 +47,8 @@ struct led_classdev { /* Activate hardware accelerated blink, delays are in * miliseconds and if none is provided then a sensible default - * should be chosen. */ + * should be chosen. The call can adjust the timings if it can't + * match the values specified exactly. */ int (*blink_set)(struct led_classdev *led_cdev, unsigned long *delay_on, unsigned long *delay_off); -- cgit v1.2.3-70-g09d2