Hi,
On 08/21/2013 08:34 AM, Arun Kumar K wrote:
+++ b/Documentation/devicetree/bindings/media/exynos5250-camera.txt
@@ -0,0 +1,126 @@
+Samsung EXYNOS5 SoC Camera Subsystem
+------------------------------------
+
+The Exynos5 SoC Camera subsystem comprises of multiple sub-devices
+represented by separate device tree nodes. Currently this includes: FIMC-LITE,
+MIPI CSIS and FIMC-IS.
+
+The sub-device nodes are referenced using phandles in the common 'camera' node
+which also includes common properties of the whole subsystem not really
+specific to any single sub-device, like common camera port pins or the common
+camera bus clocks.
+
+Common 'camera' node
+--------------------
+
+Required properties:
+
+- compatible : must be "samsung,exynos5250-fimc"
+- clocks : list of clock specifiers, corresponding to entries in
+ the clock-names property
+- clock-names : must contain "sclk_bayer" entry
+- samsung,csis : list of phandles to the mipi-csis device nodes
+- samsung,fimc-lite : list of phandles to the fimc-lite device nodes
+- samsung,fimc-is : phandle to the fimc-is device node
+
+The pinctrl bindings defined in ../pinctrl/pinctrl-bindings.txt must be used
+to define a required pinctrl state named "default".
+
+'parallel-ports' node
+---------------------
+
+This node should contain child 'port' nodes specifying active parallel video
+input ports. It includes camera A, camera B and RGB bay inputs.
+'reg' property in the port nodes specifies the input type:
+ 1 - parallel camport A
+ 2 - parallel camport B
+ 5 - RGB camera bay
+
+3, 4 are for MIPI CSI-2 bus and are already described in samsung-mipi-csis.txt
+
+Image sensor nodes
+------------------
+
+The sensor device nodes should be added to their control bus controller (e.g.
+I2C0) nodes and linked to a port node in the csis or the parallel-ports node,
+using the common video interfaces bindings, defined in video-interfaces.txt.
+
+Example:
[...]
+ /* MIPI CSI-2 bus IF sensor */
+ s5c73m3: sensor@1a {
...
+ port {
+ s5c73m3_1: endpoint {
+ data-lanes =<1 2 3 4>;
+ remote-endpoint =<&csis0_ep>;
+ };
+ };
+ };
+
+ camera {
+ compatible = "samsung,exynos5250-fimc";
+ #address-cells =<1>;
+ #size-cells =<1>;
+ status = "okay";
+
+ pinctrl-names = "default";
+ pinctrl-0 =<&cam_port_a_clk_active>;
+
+ samsung,csis =<&csis_0>,<&csis_1>;
+ samsung,fimc-lite =<&fimc_lite_0>,<&fimc_lite_1>,<&fimc_lite_2>;
+ samsung,fimc-is =<&fimc_is>;
+
+ /* parallel camera ports */
+ parallel-ports {
+ /* camera A input */
+ port@1 {
+ reg =<1>;
+ camport_a_ep: endpoint {
+ remote-endpoint =<&s5k6aa_ep>;
+ bus-width =<8>;
+ hsync-active =<0>;
+ vsync-active =<1>;
+ pclk-sample =<1>;
+ };
+ };
+ };
+ };
I'd like to propose a little re-design of this binding. The reason is that
I've noticed issues related to the power domain and FIMC-LITE, FIMC-IS
clocks
handling sequences. This lead to a failure to disable the ISP power domain
and to complete the system suspend/resume cycle. Not sure if this happens on
Exynos5 SoCs, nevertheless IMHO it would be more reasonable to make
FIMC-LITE
device nodes child nodes of FIMC-IS. FIMC-LITE seems to be an integral part
of the FIMC-IS subsystem.
Then fimc-is node would be placed at root level, with fimc-lite nodes as its
subnodes:
fimc-is {
compatible = "exynos5250-fimc-is";
reg = <...>;
...
#address-cells = <1>;
#size-cells = <1>;
ranges;
fimc_lite_0: fimc-lite@12390000 {
compatible = "samsung,exynos4212-fimc-lite";
...
};
fimc_lite_1: fimc-lite@123A0000 {
compatible = "samsung,exynos4212-fimc-lite";
...
};
fimc_lite_2: fimc-lite@123B0000 {
compatible = "samsung,exynos4212-fimc-lite";
...
};
i2c0_isp: i2c-isp@12130000 {
...
};
...
};
Once FIMC-IS driver has probed it would call of_platform_populate() and
would instantiate all FIMC-IS subsystem sub-devices, including FIMC-LITEs.
I think it's more correct from the hardware structure point of view and it
would allow us to have the required control on the initialization and power/
clock sequences. Especially that you might not be able to control the order
of registration of the exynos5250-fimc-is and fimc-is-i2c drivers, once the
I2C bus controller is outside of the exynos5-fimc-is module.
Besides, I would propose to make mipi-csis nodes subnodes of the camera
node. Then the top level camera driver would call of_platform_populate()
to instantiate MIPI-CSIS devices. That feels better than using samsung,csis
property pointing to mipi-csis nodes.
Sorry about somewhat going in circles with that, hopefully this is the
last change before this driver can be queued upstream.
--
Thanks,
Sylwester
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