On 12/5/18 17:08, Stephen Boyd wrote:
> Quoting Sylwester Nawrocki (2018-12-05 02:57:32)
>> On 12/4/18 19:40, Stephen Boyd wrote:
>>> Quoting Kamil Konieczny (2018-12-04 08:52:48)
>>>> +
>>>> +static const unsigned long imem_clk_regs[] __initconst = {
[...]
>>>> +};
>>>> +
>>>> +static const struct samsung_gate_clock imem_gate_clks[] __initconst = {
>>>> + /* ENABLE_ACLK_IMEM */
>>>> + GATE(CLK_ACLK_AXI2AHB_IMEMH, "aclk_axi2ahb_imemh", "aclk_imem_200",
>>>> + ENABLE_ACLK_IMEM, 24, 0, 0),
>>
>> I don't think that clock will ever need to be disabled/enabled, so I would
>> drop this definition. The clock will remain in its default state after reset
>> (enabled).
>>
>>>> + GATE(CLK_ACLK_AXIDS_SROMC, "aclk_axids_sromc", "aclk_imem_200",
>>>> + ENABLE_ACLK_IMEM, 23, CLK_IGNORE_UNUSED, 0),
>>>
>>> Why is there so much use of CLK_IGNORE_UNUSED in this file?
>>
>> I suppose CLK_IGNORE_UNUSED is needed because there is no drivers that
>> would enable required clocks. For some clocks the flag could probably
>> indeed just be omitted, e.g. SLIMSSS clocks.
>>
>> I'm inclined to just define clocks that we are confident about and which
>> are needed now. i.e. the SSS IP block clocks. So in include/dt-bindings/
>> clock/exynos5433.h we would have something like:
>
> Agreed, it doesn't make much sense to add clk support for clks that
> you'll never need to modify one way or the other.
>
>>
>> +/* CMU_IMEM */
>> +#define CLK_ACLK_SSS 1
>> +#define CLK_PCLK_SSS 40
>>
>> +#define IMEM_NR_CLK 41
>>
>> The other clocks could be added later as needed by someone who has
>> detailed knowledge about respective peripheral blocks.
>>
>
> The slow addition of new clks to the binding header file makes for an
> integration problem, so can we try to expose any clks that we know about
> now as defines and make them not work if the driver isn't implementing
> support for those clks? That way the binding is not changing but the
> implementation can decide to support or not support certain clks.
That makes a lot of sense to me. Then all we have to do now is to drop
some of the entries in the imem_gate_clks array above.
--
Regards,
Sylwester
