[PATCH 08/13] leds: leds-gpio: Add support for GPIO descriptors

Rafael J. Wysocki
2014-10-07T00:16:14Z

From: Mika Westerberg <mika.westerberg@linux.intel.com>

GPIO descriptors are the preferred way over legacy GPIO numbers
nowadays. Convert the driver to use GPIO descriptors internally but
still allow passing legacy GPIO numbers from platform data to support
existing platforms.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Bryan Wu <cooloney@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
drivers/leds/leds-gpio.c | 80 +++++++++++++++++++++++++++---------------------
include/linux/leds.h | 1 +
2 files changed, 46 insertions(+), 35 deletions(-)

diff --git a/drivers/leds/leds-gpio.c b/drivers/leds/leds-gpio.c
index 57ff20f..c84e913 100644
--- a/drivers/leds/leds-gpio.c
+++ b/drivers/leds/leds-gpio.c
@@ -13,6 +13,7 @@
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
#include <linux/leds.h>
#include <linux/of.h>
#include <linux/of_platform.h>
@@ -24,11 +25,10 @@

struct gpio_led_data {
struct led_classdev cdev;
- unsigned gpio;
+ struct gpio_desc *gpiod;
struct work_struct work;
u8 new_level;
u8 can_sleep;
- u8 active_low;
u8 blinking;
int (*platform_gpio_blink_set)(unsigned gpio, int state,
unsigned long *delay_on, unsigned long *delay_off);
@@ -40,12 +40,16 @@ static void gpio_led_work(struct work_struct *work)
container_of(work, struct gpio_led_data, work);

if (led_dat->blinking) {
- led_dat->platform_gpio_blink_set(led_dat->gpio,
- led_dat->new_level,
- NULL, NULL);
+ int gpio = desc_to_gpio(led_dat->gpiod);
+ int level = led_dat->new_level;
+
+ if (gpiod_is_active_low(led_dat->gpiod))
+ level = !level;
+
+ led_dat->platform_gpio_blink_set(gpio, level, NULL, NULL);
led_dat->blinking = 0;
} else
- gpio_set_value_cansleep(led_dat->gpio, led_dat->new_level);
+ gpiod_set_value_cansleep(led_dat->gpiod, led_dat->new_level);
}

static void gpio_led_set(struct led_classdev *led_cdev,
@@ -60,9 +64,6 @@ static void gpio_led_set(struct led_classdev *led_cdev,
else
level = 1;

- if (led_dat->active_low)
- level = !level;
-
/* Setting GPIOs with I2C/etc requires a task context, and we don't
* seem to have a reliable way to know if we're already in one; so
* let's just assume the worst.
@@ -72,11 +73,16 @@ static void gpio_led_set(struct led_classdev *led_cdev,
schedule_work(&led_dat->work);
} else {
if (led_dat->blinking) {
- led_dat->platform_gpio_blink_set(led_dat->gpio, level,
- NULL, NULL);
+ int gpio = desc_to_gpio(led_dat->gpiod);
+
+ if (gpiod_is_active_low(led_dat->gpiod))
+ level = !level;
+
+ led_dat->platform_gpio_blink_set(gpio, level, NULL,
+ NULL);
led_dat->blinking = 0;
} else
- gpio_set_value(led_dat->gpio, level);
+ gpiod_set_value(led_dat->gpiod, level);
}
}

@@ -85,9 +91,10 @@ static int gpio_blink_set(struct led_classdev *led_cdev,
{
struct gpio_led_data *led_dat =
container_of(led_cdev, struct gpio_led_data, cdev);
+ int gpio = desc_to_gpio(led_dat->gpiod);

led_dat->blinking = 1;
- return led_dat->platform_gpio_blink_set(led_dat->gpio, GPIO_LED_BLINK,
+ return led_dat->platform_gpio_blink_set(gpio, GPIO_LED_BLINK,
delay_on, delay_off);
}

@@ -97,24 +104,33 @@ static int create_gpio_led(const struct gpio_led *template,
{
int ret, state;

- led_dat->gpio = -1;
+ if (!template->gpiod) {
+ unsigned long flags = 0;

- /* skip leds that aren't available */
- if (!gpio_is_valid(template->gpio)) {
- dev_info(parent, "Skipping unavailable LED gpio %d (%s)\n",
- template->gpio, template->name);
- return 0;
- }
+ /* skip leds that aren't available */
+ if (!gpio_is_valid(template->gpio)) {
+ dev_info(parent, "Skipping unavailable LED gpio %d (%s)\n",
+ template->gpio, template->name);
+ return 0;
+ }

- ret = devm_gpio_request(parent, template->gpio, template->name);
- if (ret < 0)
- return ret;
+ if (template->active_low)
+ flags |= GPIOF_ACTIVE_LOW;
+
+ ret = devm_gpio_request_one(parent, template->gpio, flags,
+ template->name);
+ if (ret < 0)
+ return ret;
+
+ led_dat->gpiod = gpio_to_desc(template->gpio);
+ if (IS_ERR(led_dat->gpiod))
+ return PTR_ERR(led_dat->gpiod);
+ }

led_dat->cdev.name = template->name;
led_dat->cdev.default_trigger = template->default_trigger;
- led_dat->gpio = template->gpio;
- led_dat->can_sleep = gpio_cansleep(template->gpio);
- led_dat->active_low = template->active_low;
+ led_dat->gpiod = template->gpiod;
+ led_dat->can_sleep = gpiod_cansleep(template->gpiod);
led_dat->blinking = 0;
if (blink_set) {
led_dat->platform_gpio_blink_set = blink_set;
@@ -122,30 +138,24 @@ static int create_gpio_led(const struct gpio_led *template,
}
led_dat->cdev.brightness_set = gpio_led_set;
if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP)
- state = !!gpio_get_value_cansleep(led_dat->gpio) ^ led_dat->active_low;
+ state = !!gpiod_get_value_cansleep(led_dat->gpiod);
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 ^ state);
+ ret = gpiod_direction_output(led_dat->gpiod, state);
if (ret < 0)
return ret;

INIT_WORK(&led_dat->work, gpio_led_work);

- ret = led_classdev_register(parent, &led_dat->cdev);
- if (ret < 0)
- return ret;
-
- return 0;
+ return led_classdev_register(parent, &led_dat->cdev);
}

static void delete_gpio_led(struct gpio_led_data *led)
{
- if (!gpio_is_valid(led->gpio))
- return;
led_classdev_unregister(&led->cdev);
cancel_work_sync(&led->work);
}
diff --git a/include/linux/leds.h b/include/linux/leds.h
index e436864..879a113 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -246,6 +246,7 @@ struct led_platform_data {
struct gpio_led {
const char *name;
const char *default_trigger;
+ struct gpio_desc *gpiod;
unsigned gpio;
unsigned active_low : 1;
unsigned retain_state_suspended : 1;
--
1.9.3