leds: max77693: add support for V4L2 Flash sub-device

Add support for V4L2 Flash sub-device to the max77693 LED Flash class
driver. The support allows for V4L2 Flash sub-device to take the control
of the LED Flash class device.

Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Bryan Wu <cooloney@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>

diff --git a/drivers/leds/leds-max77693.c b/drivers/leds/leds-max77693.c
index eecaa92..b8b0eec 100644 (file)
--- a/drivers/leds/leds-max77693.c
+++ b/drivers/leds/leds-max77693.c
@@ -20,6 +20,7 @@
 #include <linux/regmap.h>
 #include <linux/slab.h>
 #include <linux/workqueue.h>
+#include <media/v4l2-flash-led-class.h>
 
 #define MODE_OFF               0
 #define MODE_FLASH(a)          (1 << (a))
@@ -62,6 +63,8 @@ struct max77693_sub_led {
        struct led_classdev_flash fled_cdev;
        /* assures led-triggers compatibility */
        struct work_struct work_brightness_set;
+       /* V4L2 Flash device */
+       struct v4l2_flash *v4l2_flash;
 
        /* brightness cache */
        unsigned int torch_brightness;
@@ -627,7 +630,8 @@ static int max77693_led_flash_timeout_set(
 }
 
 static int max77693_led_parse_dt(struct max77693_led_device *led,
-                               struct max77693_led_config_data *cfg)
+                               struct max77693_led_config_data *cfg,
+                               struct device_node **sub_nodes)
 {
        struct device *dev = &led->pdev->dev;
        struct max77693_sub_led *sub_leds = led->sub_leds;
@@ -674,6 +678,13 @@ static int max77693_led_parse_dt(struct max77693_led_device *led,
                        return -EINVAL;
                }
 
+               if (sub_nodes[fled_id]) {
+                       dev_err(dev,
+                               "Conflicting \"led-sources\" DT properties\n");
+                       return -EINVAL;
+               }
+
+               sub_nodes[fled_id] = child_node;
                sub_leds[fled_id].fled_id = fled_id;
 
                cfg->label[fled_id] =
@@ -786,11 +797,12 @@ static void max77693_led_validate_configuration(struct max77693_led_device *led,
 }
 
 static int max77693_led_get_configuration(struct max77693_led_device *led,
-                               struct max77693_led_config_data *cfg)
+                               struct max77693_led_config_data *cfg,
+                               struct device_node **sub_nodes)
 {
        int ret;
 
-       ret = max77693_led_parse_dt(led, cfg);
+       ret = max77693_led_parse_dt(led, cfg, sub_nodes);
        if (ret < 0)
                return ret;
 
@@ -838,6 +850,71 @@ static void max77693_init_flash_settings(struct max77693_sub_led *sub_led,
        setting->val = setting->max;
 }
 
+#if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
+
+static int max77693_led_external_strobe_set(
+                               struct v4l2_flash *v4l2_flash,
+                               bool enable)
+{
+       struct max77693_sub_led *sub_led =
+                               flcdev_to_sub_led(v4l2_flash->fled_cdev);
+       struct max77693_led_device *led = sub_led_to_led(sub_led);
+       int fled_id = sub_led->fled_id;
+       int ret;
+
+       mutex_lock(&led->lock);
+
+       if (enable)
+               ret = max77693_add_mode(led, MODE_FLASH_EXTERNAL(fled_id));
+       else
+               ret = max77693_clear_mode(led, MODE_FLASH_EXTERNAL(fled_id));
+
+       mutex_unlock(&led->lock);
+
+       return ret;
+}
+
+static void max77693_init_v4l2_flash_config(struct max77693_sub_led *sub_led,
+                               struct max77693_led_config_data *led_cfg,
+                               struct v4l2_flash_config *v4l2_sd_cfg)
+{
+       struct max77693_led_device *led = sub_led_to_led(sub_led);
+       struct device *dev = &led->pdev->dev;
+       struct max77693_dev *iodev = dev_get_drvdata(dev->parent);
+       struct i2c_client *i2c = iodev->i2c;
+       struct led_flash_setting *s;
+
+       snprintf(v4l2_sd_cfg->dev_name, sizeof(v4l2_sd_cfg->dev_name),
+                "%s %d-%04x", sub_led->fled_cdev.led_cdev.name,
+                i2c_adapter_id(i2c->adapter), i2c->addr);
+
+       s = &v4l2_sd_cfg->torch_intensity;
+       s->min = TORCH_IOUT_MIN;
+       s->max = sub_led->fled_cdev.led_cdev.max_brightness * TORCH_IOUT_STEP;
+       s->step = TORCH_IOUT_STEP;
+       s->val = s->max;
+
+       /* Init flash faults config */
+       v4l2_sd_cfg->flash_faults = LED_FAULT_OVER_VOLTAGE |
+                               LED_FAULT_SHORT_CIRCUIT |
+                               LED_FAULT_OVER_CURRENT;
+
+       v4l2_sd_cfg->has_external_strobe = true;
+}
+
+static const struct v4l2_flash_ops v4l2_flash_ops = {
+       .external_strobe_set = max77693_led_external_strobe_set,
+};
+#else
+static inline void max77693_init_v4l2_flash_config(
+                               struct max77693_sub_led *sub_led,
+                               struct max77693_led_config_data *led_cfg,
+                               struct v4l2_flash_config *v4l2_sd_cfg)
+{
+}
+static const struct v4l2_flash_ops v4l2_flash_ops;
+#endif
+
 static void max77693_init_fled_cdev(struct max77693_sub_led *sub_led,
                                struct max77693_led_config_data *led_cfg)
 {
@@ -870,12 +947,45 @@ static void max77693_init_fled_cdev(struct max77693_sub_led *sub_led,
        sub_led->flash_timeout = fled_cdev->timeout.val;
 }
 
+static int max77693_register_led(struct max77693_sub_led *sub_led,
+                                struct max77693_led_config_data *led_cfg,
+                                struct device_node *sub_node)
+{
+       struct max77693_led_device *led = sub_led_to_led(sub_led);
+       struct led_classdev_flash *fled_cdev = &sub_led->fled_cdev;
+       struct device *dev = &led->pdev->dev;
+       struct v4l2_flash_config v4l2_sd_cfg = {};
+       int ret;
+
+       /* Register in the LED subsystem */
+       ret = led_classdev_flash_register(dev, fled_cdev);
+       if (ret < 0)
+               return ret;
+
+       max77693_init_v4l2_flash_config(sub_led, led_cfg, &v4l2_sd_cfg);
+
+       /* Register in the V4L2 subsystem. */
+       sub_led->v4l2_flash = v4l2_flash_init(dev, sub_node, fled_cdev, NULL,
+                                             &v4l2_flash_ops, &v4l2_sd_cfg);
+       if (IS_ERR(sub_led->v4l2_flash)) {
+               ret = PTR_ERR(sub_led->v4l2_flash);
+               goto err_v4l2_flash_init;
+       }
+
+       return 0;
+
+err_v4l2_flash_init:
+       led_classdev_flash_unregister(fled_cdev);
+       return ret;
+}
+
 static int max77693_led_probe(struct platform_device *pdev)
 {
        struct device *dev = &pdev->dev;
        struct max77693_dev *iodev = dev_get_drvdata(dev->parent);
        struct max77693_led_device *led;
        struct max77693_sub_led *sub_leds;
+       struct device_node *sub_nodes[2] = {};
        struct max77693_led_config_data led_cfg = {};
        int init_fled_cdev[2], i, ret;
 
@@ -889,7 +999,7 @@ static int max77693_led_probe(struct platform_device *pdev)
        sub_leds = led->sub_leds;
 
        platform_set_drvdata(pdev, led);
-       ret = max77693_led_get_configuration(led, &led_cfg);
+       ret = max77693_led_get_configuration(led, &led_cfg, sub_nodes);
        if (ret < 0)
                return ret;
 
@@ -911,8 +1021,12 @@ static int max77693_led_probe(struct platform_device *pdev)
                /* Initialize LED Flash class device */
                max77693_init_fled_cdev(&sub_leds[i], &led_cfg);
 
-               /* Register LED Flash class device */
-               ret = led_classdev_flash_register(dev, &sub_leds[i].fled_cdev);
+               /*
+                * Register LED Flash class device and corresponding
+                * V4L2 Flash device.
+                */
+               ret = max77693_register_led(&sub_leds[i], &led_cfg,
+                                               sub_nodes[i]);
                if (ret < 0) {
                        /*
                         * At this moment FLED1 might have been already
@@ -931,6 +1045,7 @@ err_register_led2:
        /* It is possible than only FLED2 was to be registered */
        if (!init_fled_cdev[FLED1])
                goto err_register_led1;
+       v4l2_flash_release(sub_leds[FLED1].v4l2_flash);
        led_classdev_flash_unregister(&sub_leds[FLED1].fled_cdev);
 err_register_led1:
        mutex_destroy(&led->lock);
@@ -944,11 +1059,13 @@ static int max77693_led_remove(struct platform_device *pdev)
        struct max77693_sub_led *sub_leds = led->sub_leds;
 
        if (led->iout_joint || max77693_fled_used(led, FLED1)) {
+               v4l2_flash_release(sub_leds[FLED1].v4l2_flash);
                led_classdev_flash_unregister(&sub_leds[FLED1].fled_cdev);
                cancel_work_sync(&sub_leds[FLED1].work_brightness_set);
        }
 
        if (!led->iout_joint && max77693_fled_used(led, FLED2)) {
+               v4l2_flash_release(sub_leds[FLED2].v4l2_flash);
                led_classdev_flash_unregister(&sub_leds[FLED2].fled_cdev);
                cancel_work_sync(&sub_leds[FLED2].work_brightness_set);
        }