On Tue, 31 Mar 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 and validate at probe time that exactly one of > ent-gpios or vin-supply is provided. When ent-gpios is absent, the > driver uses enf-gpios for both flash and torch brightness control.
Do you? Where in probe() do you validate that? > Assisted-by: Claude:claude-opus-4.6 > Signed-off-by: Rudraksha Gupta <[email protected]> > --- > drivers/leds/flash/leds-rt8515.c | 100 > ++++++++++++++++++++++++++++++++------- > 1 file changed, 83 insertions(+), 17 deletions(-) > > diff --git a/drivers/leds/flash/leds-rt8515.c > b/drivers/leds/flash/leds-rt8515.c > index f6b439674c03..c7f0bdf804a7 100644 > --- a/drivers/leds/flash/leds-rt8515.c > +++ b/drivers/leds/flash/leds-rt8515.c > @@ -63,16 +63,44 @@ 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) > { > + int ret; > + > gpiod_set_value(rt->enable_flash, 0); '\n' > - gpiod_set_value(rt->enable_torch, 0); > + if (rt->enable_torch) > + gpiod_set_value(rt->enable_torch, 0); The gpiolib framework safely ignores NULL descriptors. Should we drop the 'if' check here for simplicity? > + > + /* Disable regulator */ > + ret = regulator_is_enabled(rt->reg); > + if (ret < 0) > + return ret; > + if (ret > 0) > + return regulator_disable(rt->reg); > + > + return 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; '\n' > + /* IC needs time to reset its brightness counter */ > + usleep_range(100, 200); '\n' > + /* Enable regulator */ > + ret = regulator_enable(rt->reg); > + if (ret) > + return ret; > > /* > * Toggling a GPIO line with a small delay increases the > @@ -84,6 +112,8 @@ static void rt8515_gpio_brightness_commit(struct gpio_desc > *gpiod, > gpiod_set_value(gpiod, 1); > udelay(1); > } > + > + return 0; > } > > /* This is setting the torch light level */ > @@ -92,23 +122,39 @@ 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_torch : rt->enable_flash, > brightness); rt->enable_torch ?: rt->enable_flash > + 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_torch : > + rt->enable_flash, 1); rt->enable_torch ?: rt->enable_flash > } > > +out: > mutex_unlock(&rt->lock); > > - return 0; > + return ret; > } > > static int rt8515_led_flash_strobe_set(struct led_classdev_flash *fled, > @@ -117,27 +163,33 @@ 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); > + ret = rt8515_gpio_brightness_commit(rt, rt->enable_flash, > brightness); > + if (ret) > + goto out; '\n' > /* 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); > + ret = rt8515_gpio_led_off(rt); > + if (ret) > + goto out; > } > > 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, > @@ -166,9 +218,12 @@ static const struct led_flash_ops rt8515_flash_ops = { > static void rt8515_powerdown_timer(struct timer_list *t) > { > struct rt8515 *rt = timer_container_of(rt, t, powerdown_timer); > + int ret; > > /* Turn the LED off */ > - rt8515_gpio_led_off(rt); > + ret = rt8515_gpio_led_off(rt); > + if (ret) > + dev_err(rt->dev, "failed to turn off LED (%d)\n", ret); > } This timer callback runs in atomic context, but 'rt8515_gpio_led_off()' now calls 'regulator_disable()', which might sleep. Should we consider using a delayed workqueue instead of a timer to avoid sleeping in an atomic context? > > static void rt8515_init_flash_timeout(struct rt8515 *rt) > @@ -298,12 +353,18 @@ 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"); > > + /* Optional VIN supply */ devm_regulator_get_optional()? > + rt->reg = devm_regulator_get(dev, "vin"); > + if (IS_ERR(rt->reg)) > + return dev_err_probe(dev, PTR_ERR(rt->reg), > + "failed to get vin supply\n"); > + > child = device_get_next_child_node(dev, NULL); > if (!child) { > dev_err(dev, > @@ -333,7 +394,12 @@ static int rt8515_probe(struct platform_device *pdev) > > fled->ops = &rt8515_flash_ops; > > - led->max_brightness = rt->torch_max_intensity; > + /* > + * If there is no separate torch pin, use the flash max intensity > + * as the 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; > > > -- > 2.53.0 > > -- Lee Jones [李琼斯]
