[PATCH v2 2/4] dt-bindings: Document the STM32F4 clock bindings

Daniel Thompson daniel.thompson at linaro.org
Mon Jun 1 00:46:59 PDT 2015


On 30/05/15 10:21, Maxime Coquelin wrote:
> HI Daniel,
>
> On 05/30/2015 09:54 AM, Daniel Thompson wrote:
>> This adds documentation of device tree bindings for the clock related
>> portions of the STM32 RCC block.
>>
>> Signed-off-by: Daniel Thompson <daniel.thompson at linaro.org>
>> ---
>>   .../devicetree/bindings/clock/st,stm32-rcc.txt     | 65
>> ++++++++++++++++++++++
>>   1 file changed, 65 insertions(+)
>> <snip>
>> +Example:
>> +
>> +    /* Gated clock, AHB1 bit 0 (GPIOA) */
>> +    ... {
>> +        clocks = <&rcc 0 0>
>> +    };
>> +
>> +    /* Gated clock, AHB2 bit 4 (GPIOA) */
> s/GPIOA/CRYP/

Oops! Will fix.


>> +    ... {
>> +        clocks = <&rcc 0 36>
>> +    };
>> +
>> +Specifying other clocks
>> +=======================
>> +
>> +The primary index must be set to 1.
>> +
>> +The secondary index is bound with the following magic numbers:
>> +
>> +    0    SYSTICK
>> +    1    FCLK
> How do you plan to handle the SAI & I2S clocks?
> By adding index 3?

Pretty much. Tentatively I'm thinking of:

	2	I2S clocks
	3	SAI1_A clock
	4	SAI1_B clock
	5	LCD-TFT clock

Note: Sort order is based on the vertical ordering in the clock tree 
diagram in the data sheet.

Only reason not to include these in the bindings immediately is that I 
wanted to check how/if these clocks are gated. The clock tree diagram 
shows them having individual clock gates so before proposing them using 
magic numbers I wanted to double check if these values can be identified 
at gates clocks.


Daniel.



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