[PATCH v2 1/2] leds: rt4505: Add support for Richtek RT4505 flash LED controller

From: cy_huang
Date: Sun Nov 01 2020 - 21:43:44 EST


From: ChiYuan Huang <cy_huang@xxxxxxxxxxx>

Add support for RT4505 flash LED controller. It can support up to 1.5A
flash current with hardware timeout and low input voltage protection.

Signed-off-by: ChiYuan Huang <cy_huang@xxxxxxxxxxx>
---
Changes since v1 to v2

- Create flash directory into drvers/leds.
- Coding style fix to meet 80 charactors per line limit.
- Refine the description in the Kconfig help text.
- Change all descriptions for 'led' text to uppercase 'LED'.

---
drivers/leds/Kconfig | 2 +
drivers/leds/Makefile | 3 +
drivers/leds/flash/Kconfig | 17 ++
drivers/leds/flash/Makefile | 2 +
drivers/leds/flash/leds-rt4505.c | 430 +++++++++++++++++++++++++++++++++++++++
5 files changed, 454 insertions(+)
create mode 100644 drivers/leds/flash/Kconfig
create mode 100644 drivers/leds/flash/Makefile
create mode 100644 drivers/leds/flash/leds-rt4505.c

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 849d3c5..e4ad5ab 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -30,6 +30,8 @@ config LEDS_CLASS_FLASH
for the flash related features of a LED device. It can be built
as a module.

+source "drivers/leds/flash/Kconfig"
+
config LEDS_CLASS_MULTICOLOR
tristate "LED Multicolor Class Support"
depends on LEDS_CLASS
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index 73e603e..1564a83 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -103,5 +103,8 @@ obj-$(CONFIG_LEDS_SPI_BYTE) += leds-spi-byte.o
# LED Userspace Drivers
obj-$(CONFIG_LEDS_USER) += uleds.o

+# LED Flash Drivers
+obj-y += flash/
+
# LED Triggers
obj-$(CONFIG_LEDS_TRIGGERS) += trigger/
diff --git a/drivers/leds/flash/Kconfig b/drivers/leds/flash/Kconfig
new file mode 100644
index 00000000..df32764
--- /dev/null
+++ b/drivers/leds/flash/Kconfig
@@ -0,0 +1,17 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+menu "LED Flash Chip support"
+ depends on LEDS_CLASS_FLASH
+
+config LEDS_RT4505
+ tristate "LED support for RT4505 flashlight controller"
+ depends on I2C && OF
+ depends on V4L2_FLASH_LED_CLASS || !V4L2_FLASH_LED_CLASS
+ select REGMAP_I2C
+ help
+ This option enables support for the RT4505 flash LED controller.
+ RT4505 includes torch and flash functions with programmable current.
+ And it's commonly used to compensate the illuminance for the camera
+ inside the mobile product like as phones or tablets.
+
+endmenu
diff --git a/drivers/leds/flash/Makefile b/drivers/leds/flash/Makefile
new file mode 100644
index 00000000..1b2eded
--- /dev/null
+++ b/drivers/leds/flash/Makefile
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_LEDS_RT4505) += leds-rt4505.o
diff --git a/drivers/leds/flash/leds-rt4505.c b/drivers/leds/flash/leds-rt4505.c
new file mode 100644
index 00000000..ee129ab
--- /dev/null
+++ b/drivers/leds/flash/leds-rt4505.c
@@ -0,0 +1,430 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/bitops.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/led-class-flash.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <media/v4l2-flash-led-class.h>
+
+#define RT4505_REG_RESET 0x0
+#define RT4505_REG_CONFIG 0x8
+#define RT4505_REG_ILED 0x9
+#define RT4505_REG_ENABLE 0xA
+#define RT4505_REG_FLAGS 0xB
+
+#define RT4505_RESET_MASK BIT(7)
+#define RT4505_FLASHTO_MASK GENMASK(2, 0)
+#define RT4505_ITORCH_MASK GENMASK(7, 5)
+#define RT4505_ITORCH_SHIFT 5
+#define RT4505_IFLASH_MASK GENMASK(4, 0)
+#define RT4505_ENABLE_MASK GENMASK(5, 0)
+#define RT4505_TORCH_SET (BIT(0) | BIT(4))
+#define RT4505_FLASH_SET (BIT(0) | BIT(1) | BIT(2) | BIT(4))
+#define RT4505_EXT_FLASH_SET (BIT(0) | BIT(1) | BIT(4) | BIT(5))
+#define RT4505_FLASH_GET (BIT(0) | BIT(1) | BIT(4))
+#define RT4505_OVP_MASK BIT(3)
+#define RT4505_SHORT_MASK BIT(2)
+#define RT4505_OTP_MASK BIT(1)
+#define RT4505_TIMEOUT_MASK BIT(0)
+
+#define RT4505_ITORCH_MINUA 46000
+#define RT4505_ITORCH_MAXUA 375000
+#define RT4505_ITORCH_STPUA 47000
+#define RT4505_IFLASH_MINUA 93750
+#define RT4505_IFLASH_MAXUA 1500000
+#define RT4505_IFLASH_STPUA 93750
+#define RT4505_FLASHTO_MINUS 100000
+#define RT4505_FLASHTO_MAXUS 800000
+#define RT4505_FLASHTO_STPUS 100000
+
+struct rt4505_priv {
+ struct device *dev;
+ struct regmap *regmap;
+ struct mutex lock;
+ struct led_classdev_flash flash;
+ struct v4l2_flash *v4l2_flash;
+};
+
+static int rt4505_torch_brightness_set(struct led_classdev *lcdev,
+ enum led_brightness level)
+{
+ struct rt4505_priv *priv =
+ container_of(lcdev, struct rt4505_priv, flash.led_cdev);
+ u32 val = 0;
+ int ret;
+
+ mutex_lock(&priv->lock);
+
+ if (level != LED_OFF) {
+ ret = regmap_update_bits(priv->regmap,
+ RT4505_REG_ILED, RT4505_ITORCH_MASK,
+ (level - 1) << RT4505_ITORCH_SHIFT);
+ if (ret)
+ goto unlock;
+
+ val = RT4505_TORCH_SET;
+ }
+
+ ret = regmap_update_bits(priv->regmap, RT4505_REG_ENABLE,
+ RT4505_ENABLE_MASK, val);
+
+unlock:
+ mutex_unlock(&priv->lock);
+ return ret;
+}
+
+static enum led_brightness rt4505_torch_brightness_get(
+ struct led_classdev *lcdev)
+{
+ struct rt4505_priv *priv =
+ container_of(lcdev, struct rt4505_priv, flash.led_cdev);
+ u32 val;
+ int ret;
+
+ mutex_lock(&priv->lock);
+
+ ret = regmap_read(priv->regmap, RT4505_REG_ENABLE, &val);
+ if (ret) {
+ dev_err(lcdev->dev, "Failed to get LED enable\n");
+ ret = LED_OFF;
+ goto unlock;
+ }
+
+ if ((val & RT4505_ENABLE_MASK) != RT4505_TORCH_SET) {
+ ret = LED_OFF;
+ goto unlock;
+ }
+
+ ret = regmap_read(priv->regmap, RT4505_REG_ILED, &val);
+ if (ret) {
+ dev_err(lcdev->dev, "Failed to get LED brightness\n");
+ ret = LED_OFF;
+ goto unlock;
+ }
+
+ ret = ((val & RT4505_ITORCH_MASK) >> RT4505_ITORCH_SHIFT) + 1;
+
+unlock:
+ mutex_unlock(&priv->lock);
+ return ret;
+}
+
+static int rt4505_flash_brightness_set(struct led_classdev_flash *fled_cdev,
+ u32 brightness)
+{
+ struct rt4505_priv *priv =
+ container_of(fled_cdev, struct rt4505_priv, flash);
+ struct led_flash_setting *s = &fled_cdev->brightness;
+ u32 val = (brightness - s->min) / s->step;
+ int ret;
+
+ mutex_lock(&priv->lock);
+ ret = regmap_update_bits(priv->regmap, RT4505_REG_ILED,
+ RT4505_IFLASH_MASK, val);
+ mutex_unlock(&priv->lock);
+
+ return ret;
+}
+
+static int rt4505_flash_strobe_set(struct led_classdev_flash *fled_cdev,
+ bool state)
+{
+ struct rt4505_priv *priv =
+ container_of(fled_cdev, struct rt4505_priv, flash);
+ u32 val = state ? RT4505_FLASH_SET : 0;
+ int ret;
+
+ mutex_lock(&priv->lock);
+ ret = regmap_update_bits(priv->regmap, RT4505_REG_ENABLE,
+ RT4505_ENABLE_MASK, val);
+ mutex_unlock(&priv->lock);
+
+ return ret;
+}
+
+static int rt4505_flash_strobe_get(struct led_classdev_flash *fled_cdev,
+ bool *state)
+{
+ struct rt4505_priv *priv =
+ container_of(fled_cdev, struct rt4505_priv, flash);
+ u32 val;
+ int ret;
+
+ mutex_lock(&priv->lock);
+
+ ret = regmap_read(priv->regmap, RT4505_REG_ENABLE, &val);
+ if (ret)
+ goto unlock;
+
+ *state = (val & RT4505_FLASH_GET) == RT4505_FLASH_GET;
+
+unlock:
+ mutex_unlock(&priv->lock);
+ return ret;
+}
+
+static int rt4505_flash_timeout_set(struct led_classdev_flash *fled_cdev,
+ u32 timeout)
+{
+ struct rt4505_priv *priv =
+ container_of(fled_cdev, struct rt4505_priv, flash);
+ struct led_flash_setting *s = &fled_cdev->timeout;
+ u32 val = (timeout - s->min) / s->step;
+ int ret;
+
+ mutex_lock(&priv->lock);
+ ret = regmap_update_bits(priv->regmap, RT4505_REG_CONFIG,
+ RT4505_FLASHTO_MASK, val);
+ mutex_unlock(&priv->lock);
+
+ return ret;
+}
+
+static int rt4505_fault_get(struct led_classdev_flash *fled_cdev, u32 *fault)
+{
+ struct rt4505_priv *priv =
+ container_of(fled_cdev, struct rt4505_priv, flash);
+ u32 val, led_faults = 0;
+ int ret;
+
+ ret = regmap_read(priv->regmap, RT4505_REG_FLAGS, &val);
+ if (ret)
+ return ret;
+
+ if (val & RT4505_OVP_MASK)
+ led_faults |= LED_FAULT_OVER_VOLTAGE;
+
+ if (val & RT4505_SHORT_MASK)
+ led_faults |= LED_FAULT_SHORT_CIRCUIT;
+
+ if (val & RT4505_OTP_MASK)
+ led_faults |= LED_FAULT_OVER_TEMPERATURE;
+
+ if (val & RT4505_TIMEOUT_MASK)
+ led_faults |= LED_FAULT_TIMEOUT;
+
+ *fault = led_faults;
+ return 0;
+}
+
+static const struct led_flash_ops rt4505_flash_ops = {
+ .flash_brightness_set = rt4505_flash_brightness_set,
+ .strobe_set = rt4505_flash_strobe_set,
+ .strobe_get = rt4505_flash_strobe_get,
+ .timeout_set = rt4505_flash_timeout_set,
+ .fault_get = rt4505_fault_get,
+};
+
+static bool rt4505_is_accessible_reg(struct device *dev, unsigned int reg)
+{
+ if (reg == RT4505_REG_RESET ||
+ (reg >= RT4505_REG_CONFIG && reg <= RT4505_REG_FLAGS))
+ return true;
+ return false;
+}
+
+static const struct regmap_config rt4505_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .max_register = RT4505_REG_FLAGS,
+
+ .readable_reg = rt4505_is_accessible_reg,
+ .writeable_reg = rt4505_is_accessible_reg,
+};
+
+#if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
+static int rt4505_flash_external_strobe_set(struct v4l2_flash *v4l2_flash,
+ bool enable)
+{
+ struct led_classdev_flash *flash = v4l2_flash->fled_cdev;
+ struct rt4505_priv *priv =
+ container_of(flash, struct rt4505_priv, flash);
+ u32 val = enable ? RT4505_EXT_FLASH_SET : 0;
+ int ret;
+
+ mutex_lock(&priv->lock);
+ ret = regmap_update_bits(priv->regmap, RT4505_REG_ENABLE,
+ RT4505_ENABLE_MASK, val);
+ mutex_unlock(&priv->lock);
+
+ return ret;
+}
+
+static const struct v4l2_flash_ops v4l2_flash_ops = {
+ .external_strobe_set = rt4505_flash_external_strobe_set,
+};
+
+static void rt4505_init_v4l2_config(struct rt4505_priv *priv,
+ struct v4l2_flash_config *config)
+{
+ struct led_classdev_flash *flash = &priv->flash;
+ struct led_classdev *lcdev = &flash->led_cdev;
+ struct led_flash_setting *s;
+
+ strscpy(config->dev_name, lcdev->dev->kobj.name,
+ sizeof(config->dev_name));
+
+ s = &config->intensity;
+ s->min = RT4505_ITORCH_MINUA;
+ s->step = RT4505_ITORCH_STPUA;
+ s->max = s->val = s->min + (lcdev->max_brightness - 1) * s->step;
+
+ config->flash_faults = LED_FAULT_OVER_VOLTAGE |
+ LED_FAULT_SHORT_CIRCUIT |
+ LED_FAULT_LED_OVER_TEMPERATURE |
+ LED_FAULT_TIMEOUT;
+ config->has_external_strobe = 1;
+}
+#else
+static const struct v4l2_flash_ops v4l2_flash_ops;
+static void rt4505_init_v4l2_config(struct rt4505_priv *priv,
+ struct v4l2_flash_config *config)
+{
+}
+#endif
+
+static void rt4505_init_flash_properties(struct rt4505_priv *priv,
+ struct fwnode_handle *child)
+{
+ struct led_classdev_flash *flash = &priv->flash;
+ struct led_classdev *lcdev = &flash->led_cdev;
+ struct led_flash_setting *s;
+ u32 val;
+ int ret;
+
+ ret = fwnode_property_read_u32(child, "led-max-microamp", &val);
+ if (ret) {
+ dev_warn(priv->dev, "led-max-microamp DT property missing\n");
+ val = RT4505_ITORCH_MINUA;
+ } else
+ val = clamp_val(val, RT4505_ITORCH_MINUA, RT4505_ITORCH_MAXUA);
+
+ lcdev->max_brightness =
+ (val - RT4505_ITORCH_MINUA) / RT4505_ITORCH_STPUA + 1;
+ lcdev->brightness_set_blocking = rt4505_torch_brightness_set;
+ lcdev->brightness_get = rt4505_torch_brightness_get;
+ lcdev->flags |= LED_DEV_CAP_FLASH;
+
+ ret = fwnode_property_read_u32(child, "flash-max-microamp", &val);
+ if (ret) {
+ dev_warn(priv->dev, "flash-max-microamp DT property missing\n");
+ val = RT4505_IFLASH_MINUA;
+ } else
+ val = clamp_val(val, RT4505_IFLASH_MINUA, RT4505_IFLASH_MAXUA);
+
+ s = &flash->brightness;
+ s->min = RT4505_IFLASH_MINUA;
+ s->step = RT4505_IFLASH_STPUA;
+ s->max = s->val = val;
+
+ ret = fwnode_property_read_u32(child, "flash-max-timeout-us", &val);
+ if (ret) {
+ dev_warn(priv->dev,
+ "flash-max-timeout-us DT property missing\n");
+ val = RT4505_FLASHTO_MINUS;
+ } else
+ val = clamp_val(val, RT4505_FLASHTO_MINUS,
+ RT4505_FLASHTO_MAXUS);
+
+ s = &flash->timeout;
+ s->min = RT4505_FLASHTO_MINUS;
+ s->step = RT4505_FLASHTO_STPUS;
+ s->max = s->val = val;
+
+ flash->ops = &rt4505_flash_ops;
+}
+
+static int rt4505_probe(struct i2c_client *client)
+{
+ struct rt4505_priv *priv;
+ struct fwnode_handle *child;
+ struct led_init_data init_data = {};
+ struct v4l2_flash_config v4l2_config = {};
+ int ret;
+
+ priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->dev = &client->dev;
+ mutex_init(&priv->lock);
+
+ priv->regmap = devm_regmap_init_i2c(client, &rt4505_regmap_config);
+ if (IS_ERR(priv->regmap)) {
+ dev_err(priv->dev, "Failed to allocate register map\n");
+ return PTR_ERR(priv->regmap);
+ }
+
+ ret = regmap_write(priv->regmap, RT4505_REG_RESET, RT4505_RESET_MASK);
+ if (ret) {
+ dev_err(priv->dev, "Failed to reset registers\n");
+ return ret;
+ }
+
+ child = fwnode_get_next_available_child_node(client->dev.fwnode, NULL);
+ if (!child) {
+ dev_err(priv->dev, "Failed to get child node\n");
+ return -EINVAL;
+ }
+ init_data.fwnode = child;
+
+ rt4505_init_flash_properties(priv, child);
+ ret = devm_led_classdev_flash_register_ext(priv->dev, &priv->flash,
+ &init_data);
+ if (ret) {
+ dev_err(priv->dev, "Failed to register flash\n");
+ return ret;
+ }
+
+ rt4505_init_v4l2_config(priv, &v4l2_config);
+ priv->v4l2_flash = v4l2_flash_init(priv->dev, init_data.fwnode,
+ &priv->flash, &v4l2_flash_ops,
+ &v4l2_config);
+ if (IS_ERR(priv->v4l2_flash)) {
+ dev_err(priv->dev, "Failed to register v4l2 flash\n");
+ return PTR_ERR(priv->v4l2_flash);
+ }
+
+ i2c_set_clientdata(client, priv);
+ return 0;
+}
+
+static int rt4505_remove(struct i2c_client *client)
+{
+ struct rt4505_priv *priv = i2c_get_clientdata(client);
+
+ v4l2_flash_release(priv->v4l2_flash);
+ return 0;
+}
+
+static void rt4505_shutdown(struct i2c_client *client)
+{
+ struct rt4505_priv *priv = i2c_get_clientdata(client);
+
+ /* Reset registers to make sure all off before shutdown */
+ regmap_write(priv->regmap, RT4505_REG_RESET, RT4505_RESET_MASK);
+}
+
+static const struct of_device_id __maybe_unused rt4505_leds_match[] = {
+ { .compatible = "richtek,rt4505", },
+ {}
+};
+MODULE_DEVICE_TABLE(of, rt4505_leds_match);
+
+static struct i2c_driver rt4505_driver = {
+ .driver = {
+ .name = "rt4505",
+ .of_match_table = of_match_ptr(rt4505_leds_match),
+ },
+ .probe_new = rt4505_probe,
+ .remove = rt4505_remove,
+ .shutdown = rt4505_shutdown,
+};
+module_i2c_driver(rt4505_driver);
+
+MODULE_AUTHOR("ChiYuan Huang <cy_huang@xxxxxxxxxxx>");
+MODULE_LICENSE("GPL v2");
--
2.7.4