lkml.org 
[lkml]   [2019]   [Dec]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH v3 03/15] soc: tegra: Add Tegra PMC clock registrations into PMC driver
From
Date

On 12/7/19 8:00 AM, Dmitry Osipenko wrote:
> 07.12.2019 18:53, Dmitry Osipenko пишет:
>> 07.12.2019 18:47, Dmitry Osipenko пишет:
>>> 07.12.2019 17:28, Dmitry Osipenko пишет:
>>>> 06.12.2019 05:48, Sowjanya Komatineni пишет:
>>>>> Tegra210 and prior Tegra PMC has clk_out_1, clk_out_2, clk_out_3 with
>>>>> mux and gate for each of these clocks.
>>>>>
>>>>> Currently these PMC clocks are registered by Tegra clock driver using
>>>>> clk_register_mux and clk_register_gate by passing PMC base address
>>>>> and register offsets and PMC programming for these clocks happens
>>>>> through direct PMC access by the clock driver.
>>>>>
>>>>> With this, when PMC is in secure mode any direct PMC access from the
>>>>> non-secure world does not go through and these clocks will not be
>>>>> functional.
>>>>>
>>>>> This patch adds these clocks registration with PMC as a clock provider
>>>>> for these clocks. clk_ops callback implementations for these clocks
>>>>> uses tegra_pmc_readl and tegra_pmc_writel which supports PMC programming
>>>>> in secure mode and non-secure mode.
>>>>>
>>>>> Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
>>>>> ---
>>> [snip]
>>>
>>>>> +
>>>>> +static const struct clk_ops pmc_clk_gate_ops = {
>>>>> + .is_enabled = pmc_clk_is_enabled,
>>>>> + .enable = pmc_clk_enable,
>>>>> + .disable = pmc_clk_disable,
>>>>> +};
>>>> What's the benefit of separating GATE from the MUX?
>>>>
>>>> I think it could be a single clock.
>>> According to TRM:
>>>
>>> 1. GATE and MUX are separate entities.
>>>
>>> 2. GATE is the parent of MUX (see PMC's CLK_OUT paths diagram in TRM).
>>>
>>> 3. PMC doesn't gate EXTPERIPH clock but could "force-enable" it, correct?
>> 4. clk_m_div2/4 are internal PMC OSC dividers and thus these clocks
>> should belong to PMC.
> Also, it should be "osc" and not "clk_m".

I followed the same parents as it were in existing clk-tegra-pmc driver.

Yeah they are wrong and they should be from osc and not clk_m.

Will fix in next version.

\
 
 \ /
  Last update: 2019-12-07 21:00    [W:0.062 / U:8.736 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site