This adds a driver for the Richtek RT8515 dual channel
torch/flash white LED driver.
This LED driver is found in some mobile phones from
Samsung such as the GT-S7710 and GT-I8190.
A V4L interface is added.
I do not have any datsheet for the Richtek RT8515.
In the outoftree code that exists for example for Asus
Zenfone the intensity is set to min/max in percent
(0-100%) so the numerals 1-100 step 1 so the same as
the brightness. I do not know the actuall current
this results in.
Cc: Sakari Ailus <sakari.ailus@xxxxxx>
Cc: newbytee@xxxxxxxxxxxxxx
Cc: Stephan Gerhold <stephan@xxxxxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
---
Changelog v2->v3:
- Expand commit message.
- Add Sakari to Cc.
- Resend.
ChangeLog v1->v2:
- Break out routine to bitbang the brightness on a
GPIO pin.
- Do not hardcode the LED name so that the framework
can name it from DT properties.
---
drivers/leds/Kconfig | 11 ++
drivers/leds/Makefile | 1 +
drivers/leds/leds-rt8515.c | 303 +++++++++++++++++++++++++++++++++++++
3 files changed, 315 insertions(+)
create mode 100644 drivers/leds/leds-rt8515.c
diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 849d3c5f908e..df632608d732 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -913,6 +913,17 @@ config LEDS_IP30
To compile this driver as a module, choose M here: the module
will be called leds-ip30.
+config LEDS_RT8515
+ tristate "LED support for Richtek RT8515 flash/torch LED"
+ depends on LEDS_CLASS_FLASH
+ depends on GPIOLIB
+ help
+ This option enables support for the Richtek RT8515 flash
+ and torch LEDs found on some mobile phones.
+
+ To compile this driver as a module, choose M here: the module
+ will be called leds-rt8515.
+
config LEDS_SGM3140
tristate "LED support for the SGM3140"
depends on LEDS_CLASS_FLASH
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index 73e603e1727e..aa6b2a19e051 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -80,6 +80,7 @@ obj-$(CONFIG_LEDS_PM8058) += leds-pm8058.o
obj-$(CONFIG_LEDS_POWERNV) += leds-powernv.o
obj-$(CONFIG_LEDS_PWM) += leds-pwm.o
obj-$(CONFIG_LEDS_REGULATOR) += leds-regulator.o
+obj-$(CONFIG_LEDS_RT8515) += leds-rt8515.o
obj-$(CONFIG_LEDS_S3C24XX) += leds-s3c24xx.o
obj-$(CONFIG_LEDS_SC27XX_BLTC) += leds-sc27xx-bltc.o
obj-$(CONFIG_LEDS_SGM3140) += leds-sgm3140.o
diff --git a/drivers/leds/leds-rt8515.c b/drivers/leds/leds-rt8515.c
new file mode 100644
index 000000000000..a87019b7eebe
--- /dev/null
+++ b/drivers/leds/leds-rt8515.c
@@ -0,0 +1,303 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * LED driver for Richtek RT8515 flash/torch white LEDs
+ * found on some Samsung mobile phones.
+ * This is a 1.5A Boost dual channel driver produced around 2011.
+ *
+ * Linus Walleij <linus.walleij@xxxxxxxxxx>
+ */
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/gpio/consumer.h>
+#include <linux/led-class-flash.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+
+#include <media/v4l2-flash-led-class.h>
+
+#define RT8515_FLASH_MAX 16
+#define RT8515_TORCH_MAX 100
+
+#define RT8515_TIMEOUT_DEFAULT 250000U /* 250ms */
+#define RT8515_MAX_TIMEOUT_DEFAULT 300000U /* 300ms */
+
+struct rt8515 {
+ struct led_classdev_flash fled;
+ struct v4l2_flash *v4l2_flash;
+ struct mutex lock;
+ struct regulator *reg;
+ struct gpio_desc *ent;
+ struct gpio_desc *enf;
+ struct timer_list powerdown_timer;
+ u32 max_timeout; /* Flash max timeout */
+};
+
+static struct rt8515 *to_rt8515(struct led_classdev_flash *fled)
+{
+ return container_of(fled, struct rt8515, fled);
+}
+
+static void rt8515_gpio_brightness_commit(struct gpio_desc *gpiod,
+ int brightness)
+{
+ int i;
+
+ /*
+ * 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);
+ udelay(1);
+ gpiod_set_value(gpiod, 1);
+ udelay(1);
+ }
+}
+
+/* This is setting the torch light level */
+static int rt8515_led_brightness_set(struct led_classdev *led,
+ enum led_brightness brightness)
+{
+ struct led_classdev_flash *fled = lcdev_to_flcdev(led);
+ struct rt8515 *rt = to_rt8515(fled);
+
+ mutex_lock(&rt->lock);
+
+ if (brightness == LED_OFF) {
+ /* Off */
+ gpiod_set_value(rt->enf, 0);
+ gpiod_set_value(rt->ent, 0);
+ } else if (brightness < RT8515_TORCH_MAX) {
+ /* Step it up to movie mode brightness using the flash pin */
+ rt8515_gpio_brightness_commit(rt->ent, brightness);
+ } else {
+ /* Max torch brightness requested */
+ gpiod_set_value(rt->ent, 1);
+ }
+
+ mutex_unlock(&rt->lock);
+
+ return 0;
+}
+
+static int rt8515_led_flash_strobe_set(struct led_classdev_flash *fled,
+ bool state)
+{
+ struct rt8515 *rt = to_rt8515(fled);
+ struct led_flash_setting *timeout = &fled->timeout;
+ int brightness = 4; /* max 16 */
+
+ mutex_lock(&rt->lock);
+
+ if (state) {
+ /* Enable LED flash mode and set brightness */
+ rt8515_gpio_brightness_commit(rt->enf, brightness);
+ /* Set timeout */
+ mod_timer(&rt->powerdown_timer,
+ jiffies + usecs_to_jiffies(timeout->val));
+ } else {
+ del_timer_sync(&rt->powerdown_timer);
+ /* Turn the LED off */
+ gpiod_set_value(rt->enf, 0);
+ gpiod_set_value(rt->ent, 0);
+ }
+
+ fled->led_cdev.brightness = LED_OFF;
+ /* After this the torch LED will be disabled */
+
+ mutex_unlock(&rt->lock);
+
+ return 0;
+}
+
+static int rt8515_led_flash_strobe_get(struct led_classdev_flash *fled,
+ bool *state)
+{
+ struct rt8515 *rt = to_rt8515(fled);
+
+ *state = timer_pending(&rt->powerdown_timer);
+
+ return 0;
+}
+
+static int rt8515_led_flash_timeout_set(struct led_classdev_flash *fled,
+ u32 timeout)
+{
+ /* The timeout is stored in the led-class-flash core */
+ return 0;
+}
+
+static const struct led_flash_ops rt8515_flash_ops = {
+ .strobe_set = rt8515_led_flash_strobe_set,
+ .strobe_get = rt8515_led_flash_strobe_get,
+ .timeout_set = rt8515_led_flash_timeout_set,
+};
+
+static void rt8515_powerdown_timer(struct timer_list *t)
+{
+ struct rt8515 *rt = from_timer(rt, t, powerdown_timer);
+
+ /* Turn the LED off */
+ gpiod_set_value(rt->enf, 0);
+ gpiod_set_value(rt->ent, 0);
+}
+
+static void rt8515_init_flash_timeout(struct rt8515 *rt)
+{
+ struct led_classdev_flash *fled = &rt->fled;
+ struct led_flash_setting *s;
+
+ /* Init flash timeout setting */
+ s = &fled->timeout;
+ s->min = 1;
+ s->max = rt->max_timeout;
+ s->step = 1;
+ /*
+ * Set default timeout to RT8515_DEFAULT_TIMEOUT except if
+ * max_timeout from DT is lower.
+ */
+ s->val = min(rt->max_timeout, RT8515_TIMEOUT_DEFAULT);
+}
+
+#if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
+/* Configure the V2L2 flash subdevice */
+static void rt8515_init_v4l2_flash_config(struct rt8515 *rt,
+ struct v4l2_flash_config *v4l2_sd_cfg)
+{
+ struct led_classdev *led = &rt->fled.led_cdev;
+ struct led_flash_setting *s;
+
+ strscpy(v4l2_sd_cfg->dev_name, led->dev->kobj.name,
+ sizeof(v4l2_sd_cfg->dev_name));
+
+ /* Init flash intensity setting */
+ s = &v4l2_sd_cfg->intensity;
+ s->min = 0;
+ s->max = rt->fled.led_cdev.max_brightness;
+ s->step = 1;
+ s->val = s->max;
+}
+
+#else
+static void rt8515_init_v4l2_flash_config(struct rt8515 *rt,
+ struct v4l2_flash_config *v4l2_sd_cfg)
+{
+}
+#endif
+
+static int rt8515_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct fwnode_handle *child;
+ struct rt8515 *rt;
+ struct led_classdev *led;
+ struct led_classdev_flash *fled;
+ struct led_init_data init_data = {};
+ struct v4l2_flash_config v4l2_sd_cfg = {};
+ int ret;
+
+ rt = devm_kzalloc(dev, sizeof(*rt), GFP_KERNEL);
+ if (!rt)
+ return -ENOMEM;
+
+ fled = &rt->fled;
+ led = &fled->led_cdev;
+
+ /* ENF - Enable Flash line */
+ rt->enf = devm_gpiod_get(dev, "enf", GPIOD_OUT_LOW);
+ if (IS_ERR(rt->enf)) {
+ dev_err(dev, "cannot get ENF (enable flash) GPIO\n");
+ return PTR_ERR(rt->enf);
+ }
+
+ /* ENT - Enable Torch line */
+ rt->ent = devm_gpiod_get(dev, "ent", GPIOD_OUT_LOW);
+ if (IS_ERR(rt->ent)) {
+ dev_err(dev, "cannot get ENT (enable torch) GPIO\n");
+ return PTR_ERR(rt->ent);
+ }
+
+ child = fwnode_get_next_available_child_node(dev->fwnode, NULL);
+ if (!child) {
+ dev_err(dev,
+ "No fwnode child node found for connected LED.\n");
+ return -EINVAL;
+ }
+ init_data.fwnode = child;
+
+ ret = fwnode_property_read_u32(child, "flash-max-timeout-us",
+ &rt->max_timeout);
+ if (ret) {
+ rt->max_timeout = RT8515_MAX_TIMEOUT_DEFAULT;
+ dev_warn(dev,
+ "flash-max-timeout-us property missing\n");
+ }
+ timer_setup(&rt->powerdown_timer, rt8515_powerdown_timer, 0);
+ rt8515_init_flash_timeout(rt);
+
+ fled->ops = &rt8515_flash_ops;
+
+ led->max_brightness = RT8515_TORCH_MAX;
+ led->brightness_set_blocking = rt8515_led_brightness_set;
+ led->flags |= LED_CORE_SUSPENDRESUME | LED_DEV_CAP_FLASH;
+
+ mutex_init(&rt->lock);
+
+ platform_set_drvdata(pdev, rt);
+
+ ret = devm_led_classdev_flash_register_ext(dev, fled, &init_data);
+ if (ret) {
+ dev_err(dev, "can't register LED %s\n", led->name);
+ mutex_destroy(&rt->lock);
+ return ret;
+ }
+
+ rt8515_init_v4l2_flash_config(rt, &v4l2_sd_cfg);
+
+ /* Create a V4L2 Flash device if V4L2 flash is enabled */
+ rt->v4l2_flash = v4l2_flash_init(dev, child, fled, NULL, &v4l2_sd_cfg);
+ if (IS_ERR(rt->v4l2_flash)) {
+ ret = PTR_ERR(rt->v4l2_flash);
+ dev_err(dev, "failed to register V4L2 flash device (%d)\n",
+ ret);
+ /*
+ * Continue without the V4L2 flash
+ * (we still have the classdev)
+ */
+ }
+
+ return 0;
+}
+
+static int rt8515_remove(struct platform_device *pdev)
+{
+ struct rt8515 *rt = platform_get_drvdata(pdev);
+
+ v4l2_flash_release(rt->v4l2_flash);
+ del_timer_sync(&rt->powerdown_timer);
+ mutex_destroy(&rt->lock);
+
+ return 0;
+}
+
+static const struct of_device_id rt8515_match[] = {
+ { .compatible = "richtek,rt8515", },
+ { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, rt8515_match);
+
+static struct platform_driver rt8515_driver = {
+ .driver = {
+ .name = "rt8515",
+ .of_match_table = rt8515_match,
+ },
+ .probe = rt8515_probe,
+ .remove = rt8515_remove,
+};
+module_platform_driver(rt8515_driver);
+
+MODULE_AUTHOR("Linus Walleij <linus.walleij@xxxxxxxxxx>");
+MODULE_DESCRIPTION("Richtek RT8515 LED driver");
+MODULE_LICENSE("GPL v2");
--
2.26.2
