/* Sashiko Automation: Reviewed (0 Findings) */ On Wed, 27 May 2026, Rudraksha Gupta via B4 Relay wrote:
> 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. > > When vin-supply is provided, the driver enables the regulator before > activating the LED and disables it when turning off. > > Make ent-gpios optional. When ent-gpios is absent, the driver uses > enf-gpios for both flash and torch brightness control. > > 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 | 148 > +++++++++++++++++++++++++++++---------- > 1 file changed, 112 insertions(+), 36 deletions(-) > > diff --git a/drivers/leds/flash/leds-rt8515.c > b/drivers/leds/flash/leds-rt8515.c > index f6b439674c03..0fb84d98211d 100644 > --- 'a/drivers/leds/flash/leds-rt8515.c' > +++ 'b/drivers/leds/flash/leds-rt8515.c' > @@ -31,6 +31,7 @@ > #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> > > @@ -44,6 +45,9 @@ > #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; > @@ -52,7 +56,7 @@ 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; > @@ -63,27 +67,57 @@ 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); > + int ret = 0; > + > + gpiod_set_value(rt->enable_flash, RT8515_OFF); > + gpiod_set_value(rt->enable_torch, RT8515_OFF); > + > + if (!rt->reg) > + return ret; This is odd. I'd argue that this actually hurts readability. Just return 0 here and drop the initialisation when on creation. > + > + ret = regulator_is_enabled(rt->reg); > + if (ret > 0) > + ret = regulator_disable(rt->reg); > + > + return ret; What about: return regulator_is_enabled(rt->reg) ? regulator_disable(rt->reg) : 0; Or, if you're not a fan of ternary operators: if (regulator_is_enabled(rt->reg)) return regulator_disable(rt->reg); return 0; Both of those allow you to drop 'ret' altogether. > } > > -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; Place this inside the for loop: for (int i = 0; ... > + 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); > + 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 */ > @@ -92,23 +126,38 @@ 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 */ Suggest we remove this comment whilst we're in here. > - 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, > @@ -117,27 +166,36 @@ 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 = 0; > > - 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); > + if (!state) { > + cancel_delayed_work_sync(&rt->powerdown_work); > + mutex_lock(&rt->lock); > /* Turn the LED off */ And here. > - rt8515_gpio_led_off(rt); > + ret = rt8515_gpio_led_off(rt); > + if (!ret) > + fled->led_cdev.brightness = LED_OFF; > + mutex_unlock(&rt->lock); > + return ret; > } > > + mutex_lock(&rt->lock); > + > + /* 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, > @@ -145,7 +203,7 @@ 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; > } > @@ -163,12 +221,18 @@ 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; > > /* Turn the LED off */ Seriously? =;-) > - rt8515_gpio_led_off(rt); > + mutex_lock(&rt->lock); > + ret = rt8515_gpio_led_off(rt); > + mutex_unlock(&rt->lock); > + > + if (ret) > + dev_err(rt->dev, "failed to turn off LED (%d)\n", ret); > } > > static void rt8515_init_flash_timeout(struct rt8515 *rt) > @@ -298,11 +362,18 @@ 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)) { > + if (PTR_ERR(rt->reg) == -EPROBE_DEFER) > + return -EPROBE_DEFER; > + rt->reg = NULL; -EPROBE_DEFER is the only error message we're handling? What about if an -ENOMEM occurs? We're now masking that. > + } > > child = device_get_next_child_node(dev, NULL); > if (!child) { > @@ -328,12 +399,17 @@ 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; > > @@ -372,7 +448,7 @@ 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); > } > > > -- > 2.54.0 > > -- Lee Jones
