[media] V4L: Add driver for s5k6a3 image sensor

This patch adds subdev driver for Samsung S5K6A3 raw image sensor.
As it is intended at the moment to be used only with the Exynos
FIMC-IS (camera ISP) subsystem it is pretty minimal subdev driver.
It doesn't do any I2C communication since the sensor is controlled
by the ISP and its own firmware.
This driver, if needed, can be updated in future into a regular
subdev driver where the main CPU communicates with the sensor
directly.

Signed-off-by: Sylwester Nawrocki <[e-mail]>
Acked-by: Kyungmin Park <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/i2c/Kconfig

···
 	  This is a V4L2 sensor-level driver for Samsung S5K6AA(FX) 1.3M
 	  camera sensor with an embedded SoC image signal processor.
 
+config VIDEO_S5K6A3
+	tristate "Samsung S5K6A3 sensor support"
+	depends on MEDIA_CAMERA_SUPPORT
+	depends on I2C && VIDEO_V4L2 && VIDEO_V4L2_SUBDEV_API
+	---help---
+	  This is a V4L2 sensor-level driver for Samsung S5K6A3 raw
+	  camera sensor.
+
 config VIDEO_S5K4ECGX
         tristate "Samsung S5K4ECGX sensor support"
         depends on I2C && VIDEO_V4L2 && VIDEO_V4L2_SUBDEV_API

drivers/media/i2c/Makefile

···
 obj-$(CONFIG_VIDEO_SR030PC30)	+= sr030pc30.o
 obj-$(CONFIG_VIDEO_NOON010PC30)	+= noon010pc30.o
 obj-$(CONFIG_VIDEO_S5K6AA)	+= s5k6aa.o
+obj-$(CONFIG_VIDEO_S5K6A3)	+= s5k6a3.o
 obj-$(CONFIG_VIDEO_S5K4ECGX)	+= s5k4ecgx.o
 obj-$(CONFIG_VIDEO_S5K5BAF)	+= s5k5baf.o
 obj-$(CONFIG_VIDEO_S5C73M3)	+= s5c73m3/

drivers/media/i2c/s5k6a3.c

···
+/*
+ * Samsung S5K6A3 image sensor driver
+ *
+ * Copyright (C) 2013 Samsung Electronics Co., Ltd.
+ * Author: Sylwester Nawrocki <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/gpio.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_gpio.h>
+#include <linux/pm_runtime.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+#include <linux/videodev2.h>
+#include <media/v4l2-async.h>
+#include <media/v4l2-subdev.h>
+
+#define S5K6A3_SENSOR_MAX_WIDTH		1412
+#define S5K6A3_SENSOR_MAX_HEIGHT	1412
+#define S5K6A3_SENSOR_MIN_WIDTH		32
+#define S5K6A3_SENSOR_MIN_HEIGHT	32
+
+#define S5K6A3_DEFAULT_WIDTH		1296
+#define S5K6A3_DEFAULT_HEIGHT		732
+
+#define S5K6A3_DRV_NAME			"S5K6A3"
+#define S5K6A3_CLK_NAME			"extclk"
+#define S5K6A3_DEFAULT_CLK_FREQ		24000000U
+
+enum {
+	S5K6A3_SUPP_VDDA,
+	S5K6A3_SUPP_VDDIO,
+	S5K6A3_SUPP_AFVDD,
+	S5K6A3_NUM_SUPPLIES,
+};
+
+/**
+ * struct s5k6a3 - fimc-is sensor data structure
+ * @dev: pointer to this I2C client device structure
+ * @subdev: the image sensor's v4l2 subdev
+ * @pad: subdev media source pad
+ * @supplies: image sensor's voltage regulator supplies
+ * @gpio_reset: GPIO connected to the sensor's reset pin
+ * @lock: mutex protecting the structure's members below
+ * @format: media bus format at the sensor's source pad
+ */
+struct s5k6a3 {
+	struct device *dev;
+	struct v4l2_subdev subdev;
+	struct media_pad pad;
+	struct regulator_bulk_data supplies[S5K6A3_NUM_SUPPLIES];
+	int gpio_reset;
+	struct mutex lock;
+	struct v4l2_mbus_framefmt format;
+	struct clk *clock;
+	u32 clock_frequency;
+	int power_count;
+};
+
+static const char * const s5k6a3_supply_names[] = {
+	[S5K6A3_SUPP_VDDA]	= "svdda",
+	[S5K6A3_SUPP_VDDIO]	= "svddio",
+	[S5K6A3_SUPP_AFVDD]	= "afvdd",
+};
+
+static inline struct s5k6a3 *sd_to_s5k6a3(struct v4l2_subdev *sd)
+{
+	return container_of(sd, struct s5k6a3, subdev);
+}
+
+static const struct v4l2_mbus_framefmt s5k6a3_formats[] = {
+	{
+		.code = V4L2_MBUS_FMT_SGRBG10_1X10,
+		.colorspace = V4L2_COLORSPACE_SRGB,
+		.field = V4L2_FIELD_NONE,
+	}
+};
+
+static const struct v4l2_mbus_framefmt *find_sensor_format(
+	struct v4l2_mbus_framefmt *mf)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(s5k6a3_formats); i++)
+		if (mf->code == s5k6a3_formats[i].code)
+			return &s5k6a3_formats[i];
+
+	return &s5k6a3_formats[0];
+}
+
+static int s5k6a3_enum_mbus_code(struct v4l2_subdev *sd,
+				  struct v4l2_subdev_fh *fh,
+				  struct v4l2_subdev_mbus_code_enum *code)
+{
+	if (code->index >= ARRAY_SIZE(s5k6a3_formats))
+		return -EINVAL;
+
+	code->code = s5k6a3_formats[code->index].code;
+	return 0;
+}
+
+static void s5k6a3_try_format(struct v4l2_mbus_framefmt *mf)
+{
+	const struct v4l2_mbus_framefmt *fmt;
+
+	fmt = find_sensor_format(mf);
+	mf->code = fmt->code;
+	v4l_bound_align_image(&mf->width, S5K6A3_SENSOR_MIN_WIDTH,
+			      S5K6A3_SENSOR_MAX_WIDTH, 0,
+			      &mf->height, S5K6A3_SENSOR_MIN_HEIGHT,
+			      S5K6A3_SENSOR_MAX_HEIGHT, 0, 0);
+}
+
+static struct v4l2_mbus_framefmt *__s5k6a3_get_format(
+		struct s5k6a3 *sensor, struct v4l2_subdev_fh *fh,
+		u32 pad, enum v4l2_subdev_format_whence which)
+{
+	if (which == V4L2_SUBDEV_FORMAT_TRY)
+		return fh ? v4l2_subdev_get_try_format(fh, pad) : NULL;
+
+	return &sensor->format;
+}
+
+static int s5k6a3_set_fmt(struct v4l2_subdev *sd,
+				  struct v4l2_subdev_fh *fh,
+				  struct v4l2_subdev_format *fmt)
+{
+	struct s5k6a3 *sensor = sd_to_s5k6a3(sd);
+	struct v4l2_mbus_framefmt *mf;
+
+	s5k6a3_try_format(&fmt->format);
+
+	mf = __s5k6a3_get_format(sensor, fh, fmt->pad, fmt->which);
+	if (mf) {
+		mutex_lock(&sensor->lock);
+		if (fmt->which == V4L2_SUBDEV_FORMAT_ACTIVE)
+			*mf = fmt->format;
+		mutex_unlock(&sensor->lock);
+	}
+	return 0;
+}
+
+static int s5k6a3_get_fmt(struct v4l2_subdev *sd,
+				  struct v4l2_subdev_fh *fh,
+				  struct v4l2_subdev_format *fmt)
+{
+	struct s5k6a3 *sensor = sd_to_s5k6a3(sd);
+	struct v4l2_mbus_framefmt *mf;
+
+	mf = __s5k6a3_get_format(sensor, fh, fmt->pad, fmt->which);
+
+	mutex_lock(&sensor->lock);
+	fmt->format = *mf;
+	mutex_unlock(&sensor->lock);
+	return 0;
+}
+
+static struct v4l2_subdev_pad_ops s5k6a3_pad_ops = {
+	.enum_mbus_code	= s5k6a3_enum_mbus_code,
+	.get_fmt	= s5k6a3_get_fmt,
+	.set_fmt	= s5k6a3_set_fmt,
+};
+
+static int s5k6a3_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
+{
+	struct v4l2_mbus_framefmt *format = v4l2_subdev_get_try_format(fh, 0);
+
+	*format		= s5k6a3_formats[0];
+	format->width	= S5K6A3_DEFAULT_WIDTH;
+	format->height	= S5K6A3_DEFAULT_HEIGHT;
+
+	return 0;
+}
+
+static const struct v4l2_subdev_internal_ops s5k6a3_sd_internal_ops = {
+	.open = s5k6a3_open,
+};
+
+static int __s5k6a3_power_on(struct s5k6a3 *sensor)
+{
+	int i = S5K6A3_SUPP_VDDA;
+	int ret;
+
+	ret = clk_set_rate(sensor->clock, sensor->clock_frequency);
+	if (ret < 0)
+		return ret;
+
+	ret = pm_runtime_get(sensor->dev);
+	if (ret < 0)
+		return ret;
+
+	ret = regulator_enable(sensor->supplies[i].consumer);
+	if (ret < 0)
+		goto error_rpm_put;
+
+	ret = clk_prepare_enable(sensor->clock);
+	if (ret < 0)
+		goto error_reg_dis;
+
+	for (i++; i < S5K6A3_NUM_SUPPLIES; i++) {
+		ret = regulator_enable(sensor->supplies[i].consumer);
+		if (ret < 0)
+			goto error_reg_dis;
+	}
+
+	gpio_set_value(sensor->gpio_reset, 1);
+	usleep_range(600, 800);
+	gpio_set_value(sensor->gpio_reset, 0);
+	usleep_range(600, 800);
+	gpio_set_value(sensor->gpio_reset, 1);
+
+	/* Delay needed for the sensor initialization */
+	msleep(20);
+	return 0;
+
+error_reg_dis:
+	for (--i; i >= 0; --i)
+		regulator_disable(sensor->supplies[i].consumer);
+error_rpm_put:
+	pm_runtime_put(sensor->dev);
+	return ret;
+}
+
+static int __s5k6a3_power_off(struct s5k6a3 *sensor)
+{
+	int i;
+
+	gpio_set_value(sensor->gpio_reset, 0);
+
+	for (i = S5K6A3_NUM_SUPPLIES - 1; i >= 0; i--)
+		regulator_disable(sensor->supplies[i].consumer);
+
+	clk_disable_unprepare(sensor->clock);
+	pm_runtime_put(sensor->dev);
+	return 0;
+}
+
+static int s5k6a3_s_power(struct v4l2_subdev *sd, int on)
+{
+	struct s5k6a3 *sensor = sd_to_s5k6a3(sd);
+	int ret = 0;
+
+	mutex_lock(&sensor->lock);
+
+	if (sensor->power_count == !on) {
+		if (on)
+			ret = __s5k6a3_power_on(sensor);
+		else
+			ret = __s5k6a3_power_off(sensor);
+
+		if (ret == 0)
+			sensor->power_count += on ? 1 : -1;
+	}
+
+	mutex_unlock(&sensor->lock);
+	return ret;
+}
+
+static struct v4l2_subdev_core_ops s5k6a3_core_ops = {
+	.s_power = s5k6a3_s_power,
+};
+
+static struct v4l2_subdev_ops s5k6a3_subdev_ops = {
+	.core = &s5k6a3_core_ops,
+	.pad = &s5k6a3_pad_ops,
+};
+
+static int s5k6a3_probe(struct i2c_client *client,
+				const struct i2c_device_id *id)
+{
+	struct device *dev = &client->dev;
+	struct s5k6a3 *sensor;
+	struct v4l2_subdev *sd;
+	int gpio, i, ret;
+
+	sensor = devm_kzalloc(dev, sizeof(*sensor), GFP_KERNEL);
+	if (!sensor)
+		return -ENOMEM;
+
+	mutex_init(&sensor->lock);
+	sensor->gpio_reset = -EINVAL;
+	sensor->clock = ERR_PTR(-EINVAL);
+	sensor->dev = dev;
+
+	sensor->clock = devm_clk_get(sensor->dev, S5K6A3_CLK_NAME);
+	if (IS_ERR(sensor->clock))
+		return PTR_ERR(sensor->clock);
+
+	gpio = of_get_gpio_flags(dev->of_node, 0, NULL);
+	if (!gpio_is_valid(gpio))
+		return gpio;
+
+	ret = devm_gpio_request_one(dev, gpio, GPIOF_OUT_INIT_LOW,
+						S5K6A3_DRV_NAME);
+	if (ret < 0)
+		return ret;
+
+	sensor->gpio_reset = gpio;
+
+	if (of_property_read_u32(dev->of_node, "clock-frequency",
+				 &sensor->clock_frequency)) {
+		sensor->clock_frequency = S5K6A3_DEFAULT_CLK_FREQ;
+		dev_info(dev, "using default %u Hz clock frequency\n",
+					sensor->clock_frequency);
+	}
+
+	for (i = 0; i < S5K6A3_NUM_SUPPLIES; i++)
+		sensor->supplies[i].supply = s5k6a3_supply_names[i];
+
+	ret = devm_regulator_bulk_get(&client->dev, S5K6A3_NUM_SUPPLIES,
+				      sensor->supplies);
+	if (ret < 0)
+		return ret;
+
+	sd = &sensor->subdev;
+	v4l2_i2c_subdev_init(sd, client, &s5k6a3_subdev_ops);
+	sensor->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
+	sd->internal_ops = &s5k6a3_sd_internal_ops;
+
+	sensor->format.code = s5k6a3_formats[0].code;
+	sensor->format.width = S5K6A3_DEFAULT_WIDTH;
+	sensor->format.height = S5K6A3_DEFAULT_HEIGHT;
+
+	sensor->pad.flags = MEDIA_PAD_FL_SOURCE;
+	ret = media_entity_init(&sd->entity, 1, &sensor->pad, 0);
+	if (ret < 0)
+		return ret;
+
+	pm_runtime_no_callbacks(dev);
+	pm_runtime_enable(dev);
+
+	ret = v4l2_async_register_subdev(sd);
+
+	if (ret < 0) {
+		pm_runtime_disable(&client->dev);
+		media_entity_cleanup(&sd->entity);
+	}
+
+	return ret;
+}
+
+static int s5k6a3_remove(struct i2c_client *client)
+{
+	struct v4l2_subdev *sd = i2c_get_clientdata(client);
+
+	pm_runtime_disable(&client->dev);
+	v4l2_async_unregister_subdev(sd);
+	media_entity_cleanup(&sd->entity);
+	return 0;
+}
+
+static const struct i2c_device_id s5k6a3_ids[] = {
+	{ }
+};
+
+#ifdef CONFIG_OF
+static const struct of_device_id s5k6a3_of_match[] = {
+	{ .compatible = "samsung,s5k6a3" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, s5k6a3_of_match);
+#endif
+
+static struct i2c_driver s5k6a3_driver = {
+	.driver = {
+		.of_match_table	= of_match_ptr(s5k6a3_of_match),
+		.name		= S5K6A3_DRV_NAME,
+		.owner		= THIS_MODULE,
+	},
+	.probe		= s5k6a3_probe,
+	.remove		= s5k6a3_remove,
+	.id_table	= s5k6a3_ids,
+};
+
+module_i2c_driver(s5k6a3_driver);
+
+MODULE_DESCRIPTION("S5K6A3 image sensor subdev driver");
+MODULE_AUTHOR("Sylwester Nawrocki <[e-mail]>");
+MODULE_LICENSE("GPL v2");