lkml.org 
[lkml]   [2019]   [Aug]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH v8 05/21] clk: tegra: pll: Save and restore pll context
From
Date

On 8/9/19 10:50 AM, Dmitry Osipenko wrote:
> 09.08.2019 20:39, Sowjanya Komatineni пишет:
>> On 8/9/19 4:33 AM, Dmitry Osipenko wrote:
>>> 09.08.2019 2:46, Sowjanya Komatineni пишет:
>>>> This patch implements save and restore of PLL context.
>>>>
>>>> During system suspend, core power goes off and looses the settings
>>>> of the Tegra CAR controller registers.
>>>>
>>>> So during suspend entry pll context is stored and on resume it is
>>>> restored back along with its state.
>>>>
>>>> Acked-by: Thierry Reding <treding@nvidia.com>
>>>> Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
>>>> ---
>>>>   drivers/clk/tegra/clk-pll.c | 88 ++++++++++++++++++++++++++++-----------------
>>>>   drivers/clk/tegra/clk.h     |  2 ++
>>>>   2 files changed, 58 insertions(+), 32 deletions(-)
>>>>
>>>> diff --git a/drivers/clk/tegra/clk-pll.c b/drivers/clk/tegra/clk-pll.c
>>>> index 1583f5fc992f..e52add2bbdbb 100644
>>>> --- a/drivers/clk/tegra/clk-pll.c
>>>> +++ b/drivers/clk/tegra/clk-pll.c
>>>> @@ -1008,6 +1008,28 @@ static unsigned long clk_plle_recalc_rate(struct clk_hw *hw,
>>>>       return rate;
>>>>   }
>>>>   +static void tegra_clk_pll_restore_context(struct clk_hw *hw)
>>>> +{
>>>> +    struct tegra_clk_pll *pll = to_clk_pll(hw);
>>>> +    struct clk_hw *parent = clk_hw_get_parent(hw);
>>>> +    unsigned long parent_rate = clk_hw_get_rate(parent);
>>>> +    unsigned long rate = clk_hw_get_rate(hw);
>>>> +    u32 val;
>>>> +
>>>> +    if (clk_pll_is_enabled(hw))
>>>> +        return;
>>>> +
>>>> +    if (pll->params->set_defaults)
>>>> +        pll->params->set_defaults(pll);
>>>> +
>>>> +    clk_pll_set_rate(hw, rate, parent_rate);
>>>> +
>>>> +    if (!__clk_get_enable_count(hw->clk))
>>> What about orphaned clocks? Is enable_count > 0 for them?
>> There are no orphaned pll clocks.
> Sorry, I meant the "clk_ignore_unused".

clocks with CLK_IGNORE_UNUSED are taken care by clk driver.

clk_disable_unused checks for clocks with this flag and if they are not
enabled it will enable them.

So by the time suspend happens enable_count is > 0


\
 
 \ /
  Last update: 2019-08-09 20:53    [W:1.960 / U:0.384 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site