Add support for V4L2 Flash sub-device to the aat1290 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.anaszew...@samsung.com>
Acked-by: Kyungmin Park <kyungmin.p...@samsung.com>
Cc: Bryan Wu <coolo...@gmail.com>
Cc: Richard Purdie <rpur...@rpsys.net>
Cc: Sakari Ailus <sakari.ai...@iki.fi>
---
 drivers/leds/Kconfig        |    1 +
 drivers/leds/leds-aat1290.c |  186 ++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 185 insertions(+), 2 deletions(-)

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 6e141d6..986876e 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -46,6 +46,7 @@ config LEDS_AAT1290
        tristate "LED support for the AAT1290"
        depends on LEDS_CLASS_FLASH
        depends on OF
+       depends on PINCTRL
        help
         This option enables support for the LEDs on the AAT1290.
 
diff --git a/drivers/leds/leds-aat1290.c b/drivers/leds/leds-aat1290.c
index 456f9a9d..6100b6b 100644
--- a/drivers/leds/leds-aat1290.c
+++ b/drivers/leds/leds-aat1290.c
@@ -17,9 +17,11 @@
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/of.h>
+#include <linux/pinctrl/consumer.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/workqueue.h>
+#include <media/v4l2-flash.h>
 
 #define AAT1290_MOVIE_MODE_CURRENT_ADDR        17
 #define AAT1290_MAX_MM_CURR_PERCENT_0  16
@@ -46,6 +48,11 @@
 
 #define AAT1290_NAME                   "aat1290"
 
+#if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
+/* Number of AAT1290 devices in the system. */
+static unsigned int dev_count;
+#endif
+
 
 struct aat1290_led_settings {
        struct led_flash_setting torch_brightness;
@@ -60,11 +67,17 @@ struct aat1290_led {
 
        /* related LED Flash class device */
        struct led_classdev_flash fled_cdev;
+       /* V4L2 Flash device */
+       struct v4l2_flash *v4l2_flash;
 
        /* FLEN pin */
        struct gpio_desc *gpio_fl_en;
        /* EN|SET pin  */
        struct gpio_desc *gpio_en_set;
+#if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
+       /* movie mode current scale */
+       int *mm_current_scale;
+#endif
 
        /* maximum flash timeout */
        u32 max_flash_tm;
@@ -231,11 +244,16 @@ static int aat1290_led_flash_timeout_set(struct 
led_classdev_flash *fled_cdev,
        return 0;
 }
 
-static int aat1290_led_parse_dt(struct aat1290_led *led)
+static int aat1290_led_parse_dt(struct aat1290_led *led,
+                       struct device_node **sub_node,
+                       struct v4l2_flash_ctrl_config *v4l2_flash_config)
 {
        struct led_classdev *led_cdev = &led->fled_cdev.led_cdev;
        struct device *dev = &led->pdev->dev;
        struct device_node *child_node;
+#if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
+       struct pinctrl *pinctrl;
+#endif
        int ret = 0;
 
        led->gpio_fl_en = devm_gpiod_get(dev, "flen");
@@ -252,6 +270,17 @@ static int aat1290_led_parse_dt(struct aat1290_led *led)
                return ret;
        }
 
+#if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
+       pinctrl = devm_pinctrl_get_select_default(&led->pdev->dev);
+       if (IS_ERR(pinctrl)) {
+               v4l2_flash_config->has_external_strobe = false;
+               dev_info(dev,
+                        "No support for external strobe detected.\n");
+       } else {
+               v4l2_flash_config->has_external_strobe = true;
+       }
+#endif
+
        child_node = of_get_next_available_child(dev->of_node, NULL);
        if (!child_node) {
                dev_err(dev, "No DT child node found for connected LED.\n");
@@ -277,6 +306,8 @@ static int aat1290_led_parse_dt(struct aat1290_led *led)
                return ret;
        }
 
+       *sub_node = child_node;
+
        return ret;
 }
 
@@ -285,6 +316,15 @@ static void aat1290_init_flash_settings(struct aat1290_led 
*led,
 {
        struct led_flash_setting *setting;
 
+#if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
+       /* Init flash intensity setting */
+       setting = &s->torch_brightness;
+       setting->min = led->mm_current_scale[0];
+       setting->max = led->mm_current_scale[AAT1290_MM_CURRENT_SCALE_SIZE - 1];
+       setting->step = 1;
+       setting->val = setting->max;
+#endif
+
        /* Init flash timeout setting */
        setting = &s->flash_timeout;
        setting->min = led->max_flash_tm / AAT1290_FLASH_TM_NUM_LEVELS;
@@ -293,6 +333,113 @@ static void aat1290_init_flash_settings(struct 
aat1290_led *led,
        setting->val = setting->max;
 }
 
+#if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
+enum led_brightness aat1290_intensity_to_brightness(
+                                       struct v4l2_flash *v4l2_flash,
+                                       s32 intensity)
+{
+       struct led_classdev_flash *fled_cdev = v4l2_flash->fled_cdev;
+       struct aat1290_led *led = fled_cdev_to_led(fled_cdev);
+       int i;
+
+       for (i = AAT1290_MM_CURRENT_SCALE_SIZE - 1; i >= 0; --i)
+               if (intensity >= led->mm_current_scale[i])
+                       return i + 1;
+
+       return 1;
+}
+
+s32 aat1290_brightness_to_intensity(struct v4l2_flash *v4l2_flash,
+                                       enum led_brightness brightness)
+{
+       struct led_classdev_flash *fled_cdev = v4l2_flash->fled_cdev;
+       struct aat1290_led *led = fled_cdev_to_led(fled_cdev);
+
+       return led->mm_current_scale[brightness - 1];
+}
+
+static int aat1290_led_external_strobe_set(struct v4l2_flash *v4l2_flash,
+                                               bool enable)
+{
+       struct aat1290_led *led = fled_cdev_to_led(v4l2_flash->fled_cdev);
+       struct led_classdev_flash *fled_cdev = v4l2_flash->fled_cdev;
+       struct led_classdev *led_cdev = &fled_cdev->led_cdev;
+       struct pinctrl *pinctrl;
+
+       gpiod_direction_output(led->gpio_fl_en, 0);
+       gpiod_direction_output(led->gpio_en_set, 0);
+
+       led->movie_mode = false;
+       led_cdev->brightness = 0;
+
+       pinctrl = devm_pinctrl_get_select(&led->pdev->dev,
+                                               enable ? "isp" : "host");
+       if (IS_ERR(pinctrl)) {
+               dev_warn(&led->pdev->dev, "Unable to switch strobe source.\n");
+               return PTR_ERR(pinctrl);
+       }
+
+       return 0;
+}
+
+int init_mm_current_scale(struct aat1290_led *led)
+{
+       int max_mm_current_percent[] = { 20, 22, 25, 28, 32, 36, 40, 45, 50, 56,
+                                               63, 71, 79, 89, 100 };
+       int i, max_mm_current = AAT1290_MAX_MM_CURRENT(led->max_flash_current);
+
+       led->mm_current_scale = devm_kzalloc(&led->pdev->dev,
+                                               sizeof(max_mm_current_percent),
+                                               GFP_KERNEL);
+       if (!led->mm_current_scale)
+               return -ENOMEM;
+
+       for (i = 0; i < AAT1290_MM_CURRENT_SCALE_SIZE; ++i)
+               led->mm_current_scale[i] = max_mm_current *
+                                         max_mm_current_percent[i] / 100;
+
+       return 0;
+}
+
+static void aat1290_init_v4l2_ctrl_config(struct aat1290_led *led,
+                                       struct aat1290_led_settings *s,
+                                       struct v4l2_flash_ctrl_config *config)
+{
+       struct led_flash_setting *setting;
+       struct v4l2_ctrl_config *c;
+       char suffix[10];
+
+       if (++dev_count > 1)
+               snprintf(suffix, sizeof(suffix), "_%d", dev_count);
+
+       snprintf(config->dev_name, sizeof(config->dev_name), "%s%s",
+                AAT1290_NAME, dev_count > 1 ? suffix : "");
+
+       c = &config->intensity;
+       setting = &s->torch_brightness;
+       c->min = setting->min;
+       c->max = setting->max;
+       c->step = setting->step;
+       c->def = setting->val;
+
+       c = &config->flash_timeout;
+       setting = &s->flash_timeout;
+       c->min = setting->min;
+       c->max = setting->max;
+       c->step = setting->step;
+       c->def = setting->val;
+}
+
+static const struct v4l2_flash_ops v4l2_flash_ops = {
+       .external_strobe_set = aat1290_led_external_strobe_set,
+       .intensity_to_led_brightness = aat1290_intensity_to_brightness,
+       .led_brightness_to_intensity = aat1290_brightness_to_intensity,
+};
+#else
+#define aat1290_init_v4l2_ctrl_config(led, s, config)
+#define init_mm_current_scale(led) (0)
+#endif
+
 static const struct led_flash_ops flash_ops = {
        .strobe_set = aat1290_led_flash_strobe_set,
        .timeout_set = aat1290_led_flash_timeout_set,
@@ -301,10 +448,12 @@ static const struct led_flash_ops flash_ops = {
 static int aat1290_led_probe(struct platform_device *pdev)
 {
        struct device *dev = &pdev->dev;
+       struct device_node *sub_node = NULL;
        struct aat1290_led *led;
        struct led_classdev *led_cdev;
        struct led_classdev_flash *fled_cdev;
        struct aat1290_led_settings settings;
+       struct v4l2_flash_ctrl_config v4l2_flash_config = {};
        int ret;
 
        led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);
@@ -317,16 +466,27 @@ static int aat1290_led_probe(struct platform_device *pdev)
        fled_cdev = &led->fled_cdev;
        led_cdev = &fled_cdev->led_cdev;
 
-       ret = aat1290_led_parse_dt(led);
+       ret = aat1290_led_parse_dt(led, &sub_node, &v4l2_flash_config);
        if (ret < 0)
                return ret;
 
        if (!led_cdev->name)
                led_cdev->name = AAT1290_NAME;
 
+       /*
+        * Init non-linear movie mode current scale basing
+        * on the max flash current from Device Tree binding.
+        */
+       ret = init_mm_current_scale(led);
+       if (ret < 0)
+               return ret;
+
        /* Init flash settings */
        aat1290_init_flash_settings(led, &settings);
 
+       /* Init V4L2 Flash controls basing on initialized settings */
+       aat1290_init_v4l2_ctrl_config(led, &settings, &v4l2_flash_config);
+
        fled_cdev->timeout = settings.flash_timeout;
        fled_cdev->ops = &flash_ops;
 
@@ -345,18 +505,40 @@ static int aat1290_led_probe(struct platform_device *pdev)
 
        mutex_init(&led->lock);
 
+       led_cdev->dev->of_node = sub_node;
+
+       /* Create V4L2 Flash subdev. */
+       led->v4l2_flash = v4l2_flash_init(fled_cdev,
+                                         &v4l2_flash_ops,
+                                         &v4l2_flash_config);
+       if (IS_ERR(led->v4l2_flash)) {
+               ret = PTR_ERR(led->v4l2_flash);
+               goto error_v4l2_flash_init;
+       }
+
        return 0;
+
+error_v4l2_flash_init:
+       led_classdev_flash_unregister(fled_cdev);
+       mutex_destroy(&led->lock);
+
+       return ret;
 }
 
 static int aat1290_led_remove(struct platform_device *pdev)
 {
        struct aat1290_led *led = platform_get_drvdata(pdev);
 
+       v4l2_flash_release(led->v4l2_flash);
        led_classdev_flash_unregister(&led->fled_cdev);
        cancel_work_sync(&led->work_brightness_set);
 
        mutex_destroy(&led->lock);
 
+#if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
+       --dev_count;
+#endif
+
        return 0;
 }
 
-- 
1.7.9.5

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