[PATCH/RFC,v11,20/20] leds: aat1290: add support for V4L2 Flash sub-device

Commit Message

Jacek Anaszewski Feb. 18, 2015, 4:20 p.m. UTC

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 <[e-mail]>
Acked-by: Kyungmin Park <[e-mail]>
Cc: Bryan Wu <[e-mail]>
Cc: Richard Purdie <[e-mail]>
Cc: Sakari Ailus <[e-mail]>
---
 drivers/leds/leds-aat1290.c |  163 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 163 insertions(+)

Patch

diff --git a/drivers/leds/leds-aat1290.c b/drivers/leds/leds-aat1290.c
index b217f0a..0e32be7 100644
--- a/drivers/leds/leds-aat1290.c
+++ b/drivers/leds/leds-aat1290.c
@@ -20,6 +20,7 @@ 
 #include <linux/of_gpio.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
+#include <media/v4l2-flash.h>
 #include <linux/workqueue.h>
 
 #define AAT1290_MOVIE_MODE_CURRENT_ADDR	17
@@ -46,6 +47,9 @@ 
 #define AAT1290_MM_CURRENT_SCALE_SIZE	15
 
 struct aat1290_led_settings {
+#if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
+	struct led_flash_setting torch_brightness;
+#endif
 	struct led_flash_setting flash_timeout;
 };
 
@@ -57,11 +61,19 @@  struct aat1290_led {
 
 	/* related LED Flash class device */
 	struct led_classdev_flash fled_cdev;
+	/* V4L2 Flash device */
+	struct v4l2_flash *v4l2_flash;
 
 	/* FLEN pin */
 	int flen_gpio;
 	/* EN|SET pin  */
 	int en_set_gpio;
+#if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
+	/* chooses flash strobe source - external or SoC gpio */
+	int ext_strobe_gpio;
+	/* movie mode current scale */
+	int *mm_current_scale;
+#endif
 
 	/* maximum flash timeout */
 	u32 max_flash_tm;
@@ -279,6 +291,15 @@  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;
@@ -287,6 +308,97 @@  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);
+
+	led->movie_mode = false;
+	gpio_set_value(led->flen_gpio, 0);
+	gpio_set_value(led->en_set_gpio, 0);
+	gpio_set_value(led->ext_strobe_gpio, enable);
+
+	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;
+
+	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;
+
+	config->has_external_strobe = gpio_is_valid(led->ext_strobe_gpio);
+}
+
+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,
@@ -299,6 +411,10 @@  static int aat1290_led_probe(struct platform_device *pdev)
 	struct aat1290_led *led;
 	struct led_classdev *led_cdev;
 	struct led_classdev_flash *fled_cdev;
+#if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
+	struct v4l2_flash_ctrl_config v4l2_flash_config;
+	int ext_strobe_gpio;
+#endif
 	struct aat1290_led_settings settings;
 	int flen_gpio, enset_gpio, ret;
 
@@ -342,6 +458,21 @@  static int aat1290_led_probe(struct platform_device *pdev)
 	}
 	led->en_set_gpio = enset_gpio;
 
+#if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
+	ext_strobe_gpio = of_get_gpio(dev_node, 2);
+	if (gpio_is_valid(ext_strobe_gpio)) {
+		ret = devm_gpio_request_one(dev, ext_strobe_gpio, GPIOF_DIR_OUT,
+						"aat1290_en_hw_strobe");
+		if (ret < 0) {
+			dev_err(dev,
+				"failed to request GPIO %d, error %d\n",
+							ext_strobe_gpio, ret);
+			return ret;
+		}
+	}
+	led->ext_strobe_gpio = ext_strobe_gpio;
+#endif
+
 	fled_cdev = &led->fled_cdev;
 	led_cdev = &fled_cdev->led_cdev;
 
@@ -349,9 +480,20 @@  static int aat1290_led_probe(struct platform_device *pdev)
 	if (ret < 0)
 		return ret;
 
+	/*
+	 * Initialize 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;
 
@@ -370,13 +512,34 @@  static int aat1290_led_probe(struct platform_device *pdev)
 
 	mutex_init(&led->lock);
 
+	of_node_get(dev_node);
+	led_cdev->dev->of_node = dev_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:
+	of_node_put(dev_node);
+	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);
+	of_node_put(led->fled_cdev.led_cdev.dev->of_node);
 	led_classdev_flash_unregister(&led->fled_cdev);
 	cancel_work_sync(&led->work_brightness_set);