i2c: add CSR SiRFprimaII on-chip I2C controllers driver

SiRFprimaII is the latest generation application processor from CSR’s
multi-function SoC product family.
The SoC support codes are in arch/arm/mach-prima2 from Linux mainline
3.0.
There are two I2C controllers on primaII, features include:
* Two I2C controller modules are on chip
* RISC I/O bus read write register
* Up to 16 bytes data buffer for issuing commands and writing data
  at the same time
* Up to 16 commands, and receiving read data 16 bytes at a time
* Error INT report (ACK check)
* No-ACK bus protocols (SCCB bus protocols)

Signed-off-by: Zhiwu Song <Zhiwu.Song@csr.com>
Signed-off-by: Xiangzhen Ye <Xiangzhen.Ye@csr.com>
Signed-off-by: Yuping Luo <Yuping.Luo@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

1 files changed, 19 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/i2c/sirf-i2c.txt b/Documentation/devicetree/bindings/i2c/sirf-i2c.txt
new file mode 100644
index 00000000000..7baf9e133fa
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/sirf-i2c.txt
@@ -0,0 +1,19 @@
+I2C for SiRFprimaII platforms
+
+Required properties :
+- compatible : Must be "sirf,prima2-i2c"
+- reg: physical base address of the controller and length of memory mapped
+     region.
+- interrupts: interrupt number to the cpu.
+
+Optional properties:
+- clock-frequency : Constains desired I2C/HS-I2C bus clock frequency in Hz.
+  The absence of the propoerty indicates the default frequency 100 kHz.
+
+Examples :
+
+i2c0: i2c@b00e0000 {
+    compatible = "sirf,prima2-i2c";
+    reg = <0xb00e0000 0x10000>;
+    interrupts = <24>;
+};