[PATCH-V2,12/12] Documentation: binding: add sclk adjustment properties to i2c-pxa

Message ID 1434383399-2370-13-git-send-email-vaibhav.hiremath@linaro.org
State New
Headers show

Commit Message

Vaibhav Hiremath June 15, 2015, 3:49 p.m.
With addition of PXA910 family of devices, the TWSI module supports
new feature which allows us to adjust SCLK.
With DT properties i2c-pxa driver takes input configuration
in nsec and converts it to respective bit-fields,

 - i2c-sclk-low-time-ns : SCLK low time (tlow)
   This property is used along with mode selection.
 - i2c-sclk-high-time-ns : SCLK high time (thigh)

Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
---
 Documentation/devicetree/bindings/i2c/i2c-pxa.txt | 13 +++++++++++++
 1 file changed, 13 insertions(+)

Comments

Vaibhav Hiremath June 16, 2015, 2:25 p.m. | #1
On Tuesday 16 June 2015 06:52 PM, Rob Herring wrote:
> On Mon, Jun 15, 2015 at 10:49 AM, Vaibhav Hiremath
> <vaibhav.hiremath@linaro.org> wrote:
>> With addition of PXA910 family of devices, the TWSI module supports
>> new feature which allows us to adjust SCLK.
>> With DT properties i2c-pxa driver takes input configuration
>> in nsec and converts it to respective bit-fields,
>>
>>   - i2c-sclk-low-time-ns : SCLK low time (tlow)
>>     This property is used along with mode selection.
>>   - i2c-sclk-high-time-ns : SCLK high time (thigh)
>>
>> Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
>> ---
>>   Documentation/devicetree/bindings/i2c/i2c-pxa.txt | 13 +++++++++++++
>>   1 file changed, 13 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/i2c/i2c-pxa.txt b/Documentation/devicetree/bindings/i2c/i2c-pxa.txt
>> index 9657db5..0fafd91 100644
>> --- a/Documentation/devicetree/bindings/i2c/i2c-pxa.txt
>> +++ b/Documentation/devicetree/bindings/i2c/i2c-pxa.txt
>> @@ -23,12 +23,25 @@ Optional properties :
>>    - i2c-disable-after-xfer : If set, driver will disable I2C module
>>      after msg xfer and enable it again before xfer.
>>
>> +   (Applicable to PXA910 family):
>> +
>> + - i2c-sclk-low-time-ns : SCLK low time (tlow), for standard/fast/high
>> +   speed mode.
>> +   This property is used along with mode selection. Driver uses this property
>> +   to set low/high time for standard and fast speed mode, as counter bit-field
>> +   is same for both.
>
> This belongs below both properties, and it should be clear that both
> properties are required if present.
>

Technically, both properties are required only in case of high_mode.

As mentioned above, in case of standard and fast mode we use tLow value.

Thanks,
Vaibhav
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Patch

diff --git a/Documentation/devicetree/bindings/i2c/i2c-pxa.txt b/Documentation/devicetree/bindings/i2c/i2c-pxa.txt
index 9657db5..0fafd91 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-pxa.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c-pxa.txt
@@ -23,12 +23,25 @@  Optional properties :
  - i2c-disable-after-xfer : If set, driver will disable I2C module
    after msg xfer and enable it again before xfer.
 
+   (Applicable to PXA910 family):
+
+ - i2c-sclk-low-time-ns : SCLK low time (tlow), for standard/fast/high
+   speed mode.
+   This property is used along with mode selection. Driver uses this property
+   to set low/high time for standard and fast speed mode, as counter bit-field
+   is same for both.
+ - i2c-sclk-high-time-ns : SCLK high time (thigh), Used in case of high speed
+   mode.
+
 Examples:
 	twsi1: i2c@d4011000 {
 		compatible = "mrvl,mmp-twsi";
 		reg = <0xd4011000 0x1000>;
 		interrupts = <7>;
 		mrvl,i2c-fast-mode;
+
+		i2c-sclk-low-time-ns = <988>;
+		i2c-sclk-high-time-ns = <988>;
 	};
 	
 	twsi2: i2c@d4025000 {