[PATCH 1/5] dt-bindings: i2c-stm32: Document the STM32F7 I2C bindings

[M'boumba Cedric Madianga]

This patch adds the documentation of device tree bindings for STM32F7 I2C

Signed-off-by: M'boumba Cedric Madianga <cedric.madianga at gmail.com>
---
 .../devicetree/bindings/i2c/i2c-stm32.txt          | 22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/i2c/i2c-stm32.txt b/Documentation/devicetree/bindings/i2c/i2c-stm32.txt
index 78eaf7b..8288724 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-stm32.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c-stm32.txt
@@ -1,7 +1,9 @@
 * I2C controller embedded in STMicroelectronics STM32 I2C platform
 
 Required properties :
-- compatible : Must be "st,stm32f4-i2c"
+- compatible : Must be one of the following
+  - "st,stm32f4-i2c"
+  - "st,stm32f7-i2c"
 - reg : Offset and length of the register set for the device
 - interrupts : Must contain the interrupt id for I2C event and then the
   interrupt id for I2C error.
@@ -14,8 +16,22 @@ Required properties :
 
 Optional properties :
 - clock-frequency : Desired I2C bus clock frequency in Hz. If not specified,
-  the default 100 kHz frequency will be used. As only Normal and Fast modes
-  are supported, possible values are 100000 and 400000.
+  the default 100 kHz frequency will be used.
+  For STM32F4 SoC Standard-mode and Fast-mode are supported, possible values are
+  100000 and 400000.
+  For STM32F7 SoC, Standard-mode, Fast-mode and Fast-mode Plus are supported,
+  possible values are 100000, 400000 and 1000000.
+- st,i2c-timing : A 32-bit I2C timing refister value.
+  This value is only required for "st,stm32f7-i2c".
+  A specific external tool delivered by ST is used to compute the value to be
+  set here according to i2C speed frequency, i2c clock source frequency,
+  i2c rise time and i2c fall time inputs.
+  - bit 31:28: PRESC[3:0]: Timing prescaler
+  - bit 27:24: Reserved
+  - bit 23:20: SCLDEL[3:0]: Data setup time
+  - bit 19:16: SDADEL[3:0]: Data hold time
+  - bit 15:8:  SCLH[7:0]: SCL high period
+  - bit 7:0:   SCLL[7:0]: SCL low period
 
 Example :
 
-- 
1.9.1