Re: [PATCH v7 13/13] V4L: Add driver for s5k4e5 image sensor

Hi Hans,

On Wed, Aug 21, 2013 at 1:54 PM, Hans Verkuil [off-list ref] wrote:

On Wed 21 August 2013 09:58:28 Tomasz Figa wrote:

quoted

Hi Hans,

On Wednesday 21 of August 2013 08:53:55 Hans Verkuil wrote:

quoted

On 08/21/2013 08:34 AM, Arun Kumar K wrote:

quoted

This patch adds subdev driver for Samsung S5K4E5 raw image sensor.
Like s5k6a3, it is also another fimc-is firmware controlled
sensor. This minimal sensor driver doesn't do any I2C communications
as its done by ISP firmware. It can be updated if needed to a
regular sensor driver by adding the I2C communication.

Signed-off-by: Arun Kumar K <redacted>
Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
---

 .../devicetree/bindings/media/i2c/s5k4e5.txt       |   43 +++
 drivers/media/i2c/Kconfig                          |    8 +
 drivers/media/i2c/Makefile                         |    1 +
 drivers/media/i2c/s5k4e5.c                         |  361
 ++++++++++++++++++++ 4 files changed, 413 insertions(+)
 create mode 100644
 Documentation/devicetree/bindings/media/i2c/s5k4e5.txt create mode
 100644 drivers/media/i2c/s5k4e5.c

...

quoted

diff --git a/drivers/media/i2c/s5k4e5.c b/drivers/media/i2c/s5k4e5.c
new file mode 100644
index 0000000..0a6ece6
--- /dev/null
+++ b/drivers/media/i2c/s5k4e5.c

@@ -0,0 +1,361 @@
+/*
+ * Samsung S5K4E5 image sensor driver
+ *
+ * Copyright (C) 2013 Samsung Electronics Co., Ltd.
+ * Author: Arun Kumar K <arun.kk@samsung.com>
+ *
+ * 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 S5K4E5_SENSOR_MAX_WIDTH          2576
+#define S5K4E5_SENSOR_MAX_HEIGHT 1930
+
+#define S5K4E5_SENSOR_ACTIVE_WIDTH       2560
+#define S5K4E5_SENSOR_ACTIVE_HEIGHT      1920
+
+#define S5K4E5_SENSOR_MIN_WIDTH          (32 + 16)
+#define S5K4E5_SENSOR_MIN_HEIGHT (32 + 10)
+
+#define S5K4E5_DEF_WIDTH         1296
+#define S5K4E5_DEF_HEIGHT                732
+
+#define S5K4E5_DRV_NAME                  "S5K4E5"
+#define S5K4E5_CLK_NAME                  "mclk"
+
+#define S5K4E5_NUM_SUPPLIES              2
+
+#define S5K4E5_DEF_CLK_FREQ              24000000
+
+/**
+ * struct s5k4e5 - s5k4e5 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 s5k4e5 {
+ struct device *dev;
+ struct v4l2_subdev subdev;
+ struct media_pad pad;
+ struct regulator_bulk_data supplies[S5K4E5_NUM_SUPPLIES];
+ int gpio_reset;
+ struct mutex lock;
+ struct v4l2_mbus_framefmt format;
+ struct clk *clock;
+ u32 clock_frequency;
+};
+
+static const char * const s5k4e5_supply_names[] = {
+ "svdda",
+ "svddio"
+};

I'm no regulator expert, but shouldn't this list come from the DT or
platform_data? Or are these names specific to this sensor?

This is a list of regulator input (aka supply) names. In other words those
are usually names of pins of the consumer device (s5k4e5 chip in this
case) to which the regulators are connected. They are used as lookup keys
when looking up regulators, either from device tree or lookup tables.

How does that work if you have two of these sensors? E.g. in a stereo-camera?
Can the regulator subsystem map those pins to the correct regulators?

Again, sorry for my ignorance in this area as I've never used it. I just
want to make sure this information is stored in the right place.

There are two regulator supplies needed for this sensor, and these pin names
are just used in the driver to differentiate them.

From the DT, we pass regulator node phandles with these properties

(supply names) which the driver uses.

Regards
Arun