Re: [PATCH v8 10/21] clk: tegra: clk-super: Add restore-context support

[Dmitry Osipenko]

09.08.2019 20:08, Sowjanya Komatineni ÐÐÑÐÑ:
> 
> On 8/9/19 5:17 AM, Dmitry Osipenko wrote:
>> 09.08.2019 2:46, Sowjanya Komatineni ÐÐÑÐÑ:
>>> This patch implements restore_context for clk_super_mux and clk_super.
>>>
>>> During system supend, core power goes off the and context of Tegra
>>> CAR registers is lost.
>>>
>>> So on system resume, context of super clock registers are restored
>>> to have them in same state as before suspend.
>>>
>>> Signed-off-by: Sowjanya Komatineni <skomatineni@xxxxxxxxxx>
>>> ---
>>> Â drivers/clk/tegra/clk-super.c | 21 +++++++++++++++++++++
>>> Â 1 file changed, 21 insertions(+)
>>>
>>> diff --git a/drivers/clk/tegra/clk-super.c b/drivers/clk/tegra/clk-super.c
>>> index e2a1e95a8db7..74c9e913e41c 100644
>>> --- a/drivers/clk/tegra/clk-super.c
>>> +++ b/drivers/clk/tegra/clk-super.c
>>> @@ -124,9 +124,18 @@ static int clk_super_set_parent(struct clk_hw *hw, u8 index)
>>> ÂÂÂÂÂ return err;
>>> Â }
>>> Â +static void clk_super_mux_restore_context(struct clk_hw *hw)
>>> +{
>>> +ÂÂÂ struct clk_hw *parent = clk_hw_get_parent(hw);
>>> +ÂÂÂ int parent_id = clk_hw_get_parent_index(hw, parent);
>>> +
>>> +ÂÂÂ clk_super_set_parent(hw, parent_id);
>> All Super clocks have a divider, including the "MUX". Thus I'm wondering
>> if there is a chance that divider's configuration may differ on resume
>> from what it was on suspend.
> 
> tegra_clk_register_super_mux which uses tegra_clk_super_mux_ops doesn't do divider rate
> programming.
> 
> I believe you are referring to sclk_divider, cclklp_divider, cclkg_divider...
> 
> these are registered as clk_divider and are restored during clk_divider resume.

Indeed, thanks for the clarification.