s5k5baf: add camera sensor driver

Driver for Samsung S5K5BAF UXGA 1/5" 2M CMOS Image Sensor
with embedded SoC ISP.
The driver exposes the sensor as two V4L2 subdevices:
- S5K5BAF-CIS - pure CMOS Image Sensor, fixed 1600x1200 format,
  no controls.
- S5K5BAF-ISP - Image Signal Processor, formats up to 1600x1200,
  pre/post ISP cropping, downscaling via selection API, controls.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
---
Hi,

This is the 8th iteration of the patch.
I have applied suggestions from Laurent, Sylwester and Mark, thanks.
One exeception, I have left static struct v4l2_rect s5k5baf_cis_rect
not const due to fact its address is passed to function which could
modify its arguments, of course it never modifies s5k5baf_cis_rect.

Regards
Andrzej

v8
- improved description of data-lanes binding,
- added algorithm caching,
- added comments to functions,
- video bus type checking moved to probe,
- clk_get/put moved to probe,
- moved streaming checking under mutex,
- use proper functions for endian conversion,
- cosmetic changes

v7
- changed description of 'clock-frequency' DT property

v6
- endpoint node presence is now optional,
- added asynchronous subdev registration support and clock
  handling,
- use named gpios in DT bindings

v5
- removed hflip/vflip device tree properties

v4
- GPL changed to GPLv2,
- bitfields replaced by u8,
- cosmetic changes,
- corrected s_stream flow,
- gpio pins are no longer exported,
- added I2C addresses to subdev names,
- CIS subdev registration postponed after
  succesfull HW initialization,
- added enums for pads,
- selections are initialized only during probe,
- default resolution changed to 1600x1200,
- state->error pattern removed from few other functions,
- entity link creation moved to registered callback.

v3:
- narrowed state->error usage to i2c and power errors,
- private gain controls replaced by red/blue balance user controls,
- added checks to devicetree gpio node parsing

v2:
- lower-cased driver name,
- removed underscore from regulator names,
- removed platform data code,
- v4l controls grouped in anonymous structs,
- added s5k5baf_clear_error function,
- private controls definitions moved to uapi header file,
- added v4l2-controls.h reservation for private controls,
- corrected subdev registered/unregistered code,
- .log_status sudbev op set to v4l2 helper,
- moved entity link creation to probe routines,
- added cleanup on error to probe function.

1 files changed, 58 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/media/samsung-s5k5baf.txt b/Documentation/devicetree/bindings/media/samsung-s5k5baf.txt
new file mode 100644
index 00000000000..e60017edabe
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/samsung-s5k5baf.txt
@@ -0,0 +1,58 @@
+Samsung S5K5BAF UXGA 1/5" 2M CMOS Image Sensor with embedded SoC ISP
+--------------------------------------------------------------------
+
+Required properties:
+
+- compatible	  : "samsung,s5k5baf";
+- reg		  : I2C slave address of the sensor;
+- vdda-supply	  : analog power supply 2.8V (2.6V to 3.0V);
+- vddreg-supply	  : regulator input power supply 1.8V (1.7V to 1.9V)
+		    or 2.8V (2.6V to 3.0);
+- vddio-supply	  : I/O power supply 1.8V (1.65V to 1.95V)
+		    or 2.8V (2.5V to 3.1V);
+- stbyn-gpios	  : GPIO connected to STBYN pin;
+- rstn-gpios	  : GPIO connected to RSTN pin;
+- clocks	  : the sensor's master clock specifier (from the common
+		    clock bindings);
+- clock-names	  : must be "mclk";
+
+Optional properties:
+
+- clock-frequency : the frequency at which the "mclk" clock should be
+		    configured to operate, in Hz; if this property is not
+		    specified default 24 MHz value will be used.
+
+The device node should contain one 'port' child node with one child 'endpoint'
+node, according to the bindings defined in Documentation/devicetree/bindings/
+media/video-interfaces.txt. The following are properties specific to those
+nodes.
+
+endpoint node
+-------------
+
+- data-lanes : (optional) specifies MIPI CSI-2 data lanes as covered in
+  video-interfaces.txt. This sensor doesn't support data lane remapping
+  and physical lane indexes in subsequent elements of the array should
+  have consecutive values.
+
+Example:
+
+s5k5bafx@2d {
+	compatible = "samsung,s5k5baf";
+	reg = <0x2d>;
+	vdda-supply = <&cam_io_en_reg>;
+	vddreg-supply = <&vt_core_15v_reg>;
+	vddio-supply = <&vtcam_reg>;
+	stbyn-gpios = <&gpl2 0 1>;
+	rstn-gpios = <&gpl2 1 1>;
+	clock-names = "mclk";
+	clocks = <&clock_cam 0>;
+	clock-frequency = <24000000>;
+
+	port {
+		s5k5bafx_ep: endpoint {
+			remote-endpoint = <&csis1_ep>;
+			data-lanes = <1>;
+		};
+	};
+};