From: Rudraksha Gupta <[email protected]> Extend the RT8515 driver to support flash ICs that use only a single GPIO for both flash and torch modes (no separate ENT pin), with an optional vin regulator that gates power to the flash IC.
Assisted-by: Claude:claude-opus-4.6 Reviewed-by: Linus Walleij <[email protected]> Signed-off-by: Rudraksha Gupta <[email protected]> --- drivers/leds/flash/leds-rt8515.c | 147 ++++++++++++++++++++++++++++----------- 1 file changed, 107 insertions(+), 40 deletions(-) diff --git a/drivers/leds/flash/leds-rt8515.c b/drivers/leds/flash/leds-rt8515.c index 00904cc90ed6..541f61e13f01 100644 --- a/drivers/leds/flash/leds-rt8515.c +++ b/drivers/leds/flash/leds-rt8515.c @@ -30,6 +30,7 @@ #include <linux/platform_device.h> #include <linux/property.h> #include <linux/regulator/consumer.h> +#include <linux/workqueue.h> #include <media/v4l2-flash-led-class.h> @@ -43,6 +44,9 @@ #define RT8515_TIMEOUT_US 250000U #define RT8515_MAX_TIMEOUT_US 300000U +#define RT8515_OFF 0 +#define RT8515_ON 1 + struct rt8515 { struct led_classdev_flash fled; struct device *dev; @@ -51,7 +55,7 @@ struct rt8515 { struct regulator *reg; struct gpio_desc *enable_torch; struct gpio_desc *enable_flash; - struct timer_list powerdown_timer; + struct delayed_work powerdown_work; u32 max_timeout; /* Flash max timeout */ int flash_max_intensity; int torch_max_intensity; @@ -62,27 +66,50 @@ static struct rt8515 *to_rt8515(struct led_classdev_flash *fled) return container_of(fled, struct rt8515, fled); } -static void rt8515_gpio_led_off(struct rt8515 *rt) +static int rt8515_gpio_led_off(struct rt8515 *rt) { - gpiod_set_value(rt->enable_flash, 0); - gpiod_set_value(rt->enable_torch, 0); + gpiod_set_value(rt->enable_flash, RT8515_OFF); + gpiod_set_value(rt->enable_torch, RT8515_OFF); + + if (!rt->reg) + return 0; + + return regulator_is_enabled(rt->reg) > 0 ? regulator_disable(rt->reg) : 0; } -static void rt8515_gpio_brightness_commit(struct gpio_desc *gpiod, - int brightness) +static int rt8515_gpio_brightness_commit(struct rt8515 *rt, struct gpio_desc *gpiod, int brightness) { - int i; + int ret; + + /* + * Reset the IC to start brightness from zero, + * then re-enable and pulse to the desired level. + */ + ret = rt8515_gpio_led_off(rt); + if (ret) + return ret; + + /* IC needs time to reset its brightness counter */ + usleep_range(100, 200); + + if (rt->reg) { + ret = regulator_enable(rt->reg); + if (ret) + return ret; + } /* * Toggling a GPIO line with a small delay increases the * brightness one step at a time. */ - for (i = 0; i < brightness; i++) { - gpiod_set_value(gpiod, 0); + for (int i = 0; i < brightness; i++) { + gpiod_set_value(gpiod, RT8515_OFF); udelay(1); - gpiod_set_value(gpiod, 1); + gpiod_set_value(gpiod, RT8515_ON); udelay(1); } + + return 0; } /* This is setting the torch light level */ @@ -91,23 +118,37 @@ static int rt8515_led_brightness_set(struct led_classdev *led, { struct led_classdev_flash *fled = lcdev_to_flcdev(led); struct rt8515 *rt = to_rt8515(fled); + int ret = 0; mutex_lock(&rt->lock); if (brightness == LED_OFF) { - /* Off */ - rt8515_gpio_led_off(rt); + ret = rt8515_gpio_led_off(rt); + if (ret) + goto out; } else if (brightness < RT8515_TORCH_MAX) { - /* Step it up to movie mode brightness using the flash pin */ - rt8515_gpio_brightness_commit(rt->enable_torch, brightness); + /* + * Step it up to movie mode brightness. + * If there is no separate torch pin, use the flash pin + * for torch as well. + */ + ret = rt8515_gpio_brightness_commit(rt, + rt->enable_torch ?: rt->enable_flash, brightness); + if (ret) + goto out; } else { - /* Max torch brightness requested */ - gpiod_set_value(rt->enable_torch, 1); + /* + * Max torch brightness requested. + * If there is no separate torch pin, use the flash pin + * for torch as well. + */ + gpiod_set_value(rt->enable_torch ?: rt->enable_flash, RT8515_ON); } +out: mutex_unlock(&rt->lock); - return 0; + return ret; } static int rt8515_led_flash_strobe_set(struct led_classdev_flash *fled, @@ -116,27 +157,35 @@ static int rt8515_led_flash_strobe_set(struct led_classdev_flash *fled, struct rt8515 *rt = to_rt8515(fled); struct led_flash_setting *timeout = &fled->timeout; int brightness = rt->flash_max_intensity; + int ret; + + if (!state) { + cancel_delayed_work_sync(&rt->powerdown_work); + mutex_lock(&rt->lock); + ret = rt8515_gpio_led_off(rt); + if (!ret) + fled->led_cdev.brightness = LED_OFF; + mutex_unlock(&rt->lock); + return ret; + } mutex_lock(&rt->lock); - if (state) { - /* Enable LED flash mode and set brightness */ - rt8515_gpio_brightness_commit(rt->enable_flash, brightness); - /* Set timeout */ - mod_timer(&rt->powerdown_timer, - jiffies + usecs_to_jiffies(timeout->val)); - } else { - timer_delete_sync(&rt->powerdown_timer); - /* Turn the LED off */ - rt8515_gpio_led_off(rt); - } + /* Enable LED flash mode and set brightness */ + ret = rt8515_gpio_brightness_commit(rt, rt->enable_flash, brightness); + if (ret) + goto out; + + /* Set timeout */ + schedule_delayed_work(&rt->powerdown_work, usecs_to_jiffies(timeout->val)); fled->led_cdev.brightness = LED_OFF; /* After this the torch LED will be disabled */ +out: mutex_unlock(&rt->lock); - return 0; + return ret; } static int rt8515_led_flash_strobe_get(struct led_classdev_flash *fled, @@ -144,7 +193,7 @@ static int rt8515_led_flash_strobe_get(struct led_classdev_flash *fled, { struct rt8515 *rt = to_rt8515(fled); - *state = timer_pending(&rt->powerdown_timer); + *state = delayed_work_pending(&rt->powerdown_work); return 0; } @@ -162,12 +211,17 @@ static const struct led_flash_ops rt8515_flash_ops = { .timeout_set = rt8515_led_flash_timeout_set, }; -static void rt8515_powerdown_timer(struct timer_list *t) +static void rt8515_powerdown_work(struct work_struct *work) { - struct rt8515 *rt = timer_container_of(rt, t, powerdown_timer); + struct rt8515 *rt = container_of(work, struct rt8515, powerdown_work.work); + int ret; + + mutex_lock(&rt->lock); + ret = rt8515_gpio_led_off(rt); + mutex_unlock(&rt->lock); - /* Turn the LED off */ - rt8515_gpio_led_off(rt); + if (ret) + dev_err(rt->dev, "failed to turn off LED (%d)\n", ret); } static void rt8515_init_flash_timeout(struct rt8515 *rt) @@ -297,11 +351,19 @@ static int rt8515_probe(struct platform_device *pdev) return dev_err_probe(dev, PTR_ERR(rt->enable_flash), "cannot get ENF (enable flash) GPIO\n"); - /* ENT - Enable Torch line */ - rt->enable_torch = devm_gpiod_get(dev, "ent", GPIOD_OUT_LOW); + /* ENT - Enable Torch line (optional for single-GPIO flash ICs) */ + rt->enable_torch = devm_gpiod_get_optional(dev, "ent", GPIOD_OUT_LOW); if (IS_ERR(rt->enable_torch)) return dev_err_probe(dev, PTR_ERR(rt->enable_torch), - "cannot get ENT (enable torch) GPIO\n"); + "Failed to obtain the Enable Torch GPIO\n"); + + rt->reg = devm_regulator_get_optional(dev, "vin"); + if (IS_ERR(rt->reg)) { + ret = PTR_ERR(rt->reg); + if (ret != -ENODEV) + return dev_err_probe(dev, ret, "Failed to obtain the input supply\n"); + rt->reg = NULL; + } child = device_get_next_child_node(dev, NULL); if (!child) { @@ -327,12 +389,17 @@ static int rt8515_probe(struct platform_device *pdev) dev_warn(dev, "flash-max-timeout-us property missing\n"); } - timer_setup(&rt->powerdown_timer, rt8515_powerdown_timer, 0); + INIT_DELAYED_WORK(&rt->powerdown_work, rt8515_powerdown_work); rt8515_init_flash_timeout(rt); fled->ops = &rt8515_flash_ops; - led->max_brightness = rt->torch_max_intensity; + /* + * If there is no separate torch pin, use flash max intensity + * as max brightness instead. + */ + led->max_brightness = rt->enable_torch ? + rt->torch_max_intensity : rt->flash_max_intensity; led->brightness_set_blocking = rt8515_led_brightness_set; led->flags |= LED_CORE_SUSPENDRESUME | LED_DEV_CAP_FLASH; @@ -371,7 +438,7 @@ static void rt8515_remove(struct platform_device *pdev) struct rt8515 *rt = platform_get_drvdata(pdev); rt8515_v4l2_flash_release(rt); - timer_delete_sync(&rt->powerdown_timer); + cancel_delayed_work_sync(&rt->powerdown_work); mutex_destroy(&rt->lock); } -- 2.55.0
