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[RESEND,v3,0/5] PM: domains: Add control for switching back and forth to HW control

Message ID 20231101-gdsc-hwctrl-v3-0-0740ae6b2b04@linaro.org
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Series PM: domains: Add control for switching back and forth to HW control | expand

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Abel Vesa Nov. 1, 2023, 9:04 a.m. UTC
This is just a resend of v3:
https://lore.kernel.org/lkml/20230923115008.1698384-1-abel.vesa@linaro.org/

Signed-off-by: Abel Vesa <abel.vesa@linaro.org>
---
Abel Vesa (1):
      PM: domains: Add the domain HW-managed mode to the summary

Jagadeesh Kona (3):
      clk: qcom: gdsc: Add set and get hwmode callbacks to switch GDSC mode
      clk: qcom: Use HW_CTRL_TRIGGER flag to switch video GDSC to HW mode
      venus: pm_helpers: Use dev_pm_genpd_set_hwmode to switch GDSC mode

Ulf Hansson (1):
      PM: domains: Allow devices attached to genpd to be managed by HW

 drivers/base/power/domain.c                    | 84 +++++++++++++++++++++++++-
 drivers/clk/qcom/gdsc.c                        | 32 ++++++++++
 drivers/clk/qcom/gdsc.h                        |  1 +
 drivers/clk/qcom/videocc-sc7180.c              |  2 +-
 drivers/clk/qcom/videocc-sc7280.c              |  2 +-
 drivers/clk/qcom/videocc-sdm845.c              |  4 +-
 drivers/clk/qcom/videocc-sm8250.c              |  4 +-
 drivers/clk/qcom/videocc-sm8550.c              |  4 +-
 drivers/media/platform/qcom/venus/core.c       |  4 ++
 drivers/media/platform/qcom/venus/core.h       |  1 +
 drivers/media/platform/qcom/venus/pm_helpers.c | 47 ++++++--------
 include/linux/pm_domain.h                      | 17 ++++++
 12 files changed, 165 insertions(+), 37 deletions(-)
---
base-commit: fa7d0c17278644aa691f96d08bef8001b762f9cd
change-id: 20231101-gdsc-hwctrl-13f01ea60cbd

Best regards,

Comments

Greg KH Nov. 1, 2023, 11:07 a.m. UTC | #1
On Wed, Nov 01, 2023 at 11:04:06AM +0200, Abel Vesa wrote:
> This is just a resend of v3:
> https://lore.kernel.org/lkml/20230923115008.1698384-1-abel.vesa@linaro.org/

Why?

It's the middle of the merge window, not much we can do until -rc1 is
out...

thanks,

greg k-h
Dmitry Baryshkov Nov. 1, 2023, 9:26 p.m. UTC | #2
On Wed, 1 Nov 2023 at 11:08, Abel Vesa <abel.vesa@linaro.org> wrote:
>
> From: Ulf Hansson <ulf.hansson@linaro.org>
>
> Some power-domains may be capable of relying on the HW to control the power
> for a device that's hooked up to it. Typically, for these kinds of
> configurations the device doesn't really need to be attached to a PM domain
> (genpd), from Linux point of view. However, in some cases the behaviour of
> the power-domain and its device can be changed in runtime.
>
> To allow a consumer driver to change the behaviour of the PM domain for its
> device, let's provide a new function, dev_pm_genpd_set_hwmode(). Moreover,
> let's add a corresponding optional genpd callback, ->set_hwmode_dev(),
> which the genpd provider should implement if it can support switching
> between HW controlled mode and SW controlled mode. Similarly, add the
> dev_pm_genpd_get_hwmode() to allow consumers to read the current mode and
> its corresponding optional genpd callback, ->get_hwmode_dev(), which the
> genpd provider can also implement for reading back the mode from the
> hardware.
>
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> Signed-off-by: Abel Vesa <abel.vesa@linaro.org>

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Dmitry Baryshkov Nov. 1, 2023, 9:28 p.m. UTC | #3
On Wed, 1 Nov 2023 at 11:06, Abel Vesa <abel.vesa@linaro.org> wrote:
>
> From: Jagadeesh Kona <quic_jkona@quicinc.com>
>
> Add support for set and get hwmode callbacks to switch the GDSC between
> SW and HW modes. Currently, the GDSC is moved to HW control mode
> using HW_CTRL flag and if this flag is present, GDSC is moved to HW
> mode as part of GDSC enable itself. The intention is to keep the
> HW_CTRL flag functionality as is, since many older chipsets still use
> this flag.
>
> Introduce a new HW_CTRL_TRIGGER flag to switch the GDSC back and forth
> between HW/SW modes dynamically at runtime. If HW_CTRL_TRIGGER flag is
> present, register set_hwmode_dev callback to switch the GDSC mode which
> can be invoked from consumer drivers using dev_pm_genpd_set_hwmode
> function. Unlike HW_CTRL flag, HW_CTRL_TRIGGER won't move the GDSC to HW
> control mode as part of GDSC enable itself, GDSC will be moved to HW
> control mode only when consumer driver explicity calls
> dev_pm_genpd_set_hwmode to switch to HW mode. Also add the
> dev_pm_genpd_get_hwmode to allow the consumers to read the actual
> HW/SW mode from hardware.

Can we add two new flags:
- HW_CTRL_TRIGGER
- DEFAULT_HW_TRIGGER

And then define HW_CTRL as HW_CTRL_TRIGGER | DEFAULT_HW_TRIGGER ?

This way older platforms will keep existing behaviour, but can
gradually migrate to the new callbacks?

>
> Signed-off-by: Jagadeesh Kona <quic_jkona@quicinc.com>
> Signed-off-by: Abel Vesa <abel.vesa@linaro.org>
> ---
>  drivers/clk/qcom/gdsc.c | 32 ++++++++++++++++++++++++++++++++
>  drivers/clk/qcom/gdsc.h |  1 +
>  2 files changed, 33 insertions(+)
>
> diff --git a/drivers/clk/qcom/gdsc.c b/drivers/clk/qcom/gdsc.c
> index 5358e28122ab..c763524cd5da 100644
> --- a/drivers/clk/qcom/gdsc.c
> +++ b/drivers/clk/qcom/gdsc.c
> @@ -363,6 +363,34 @@ static int gdsc_disable(struct generic_pm_domain *domain)
>         return 0;
>  }
>
> +static int gdsc_set_hwmode(struct generic_pm_domain *domain, struct device *dev, bool mode)
> +{
> +       struct gdsc *sc = domain_to_gdsc(domain);
> +
> +       if (sc->rsupply && !regulator_is_enabled(sc->rsupply)) {
> +               pr_err("Cannot set mode while parent is disabled\n");
> +               return -EIO;
> +       }
> +
> +       return gdsc_hwctrl(sc, mode);
> +}
> +
> +static bool gdsc_get_hwmode(struct generic_pm_domain *domain, struct device *dev)
> +{
> +       struct gdsc *sc = domain_to_gdsc(domain);
> +       u32 val;
> +       int ret;
> +
> +       ret = regmap_read(sc->regmap, sc->gdscr, &val);
> +       if (ret)
> +               return ret;
> +
> +       if (val & HW_CONTROL_MASK)
> +               return true;
> +
> +       return false;
> +}
> +
>  static int gdsc_init(struct gdsc *sc)
>  {
>         u32 mask, val;
> @@ -451,6 +479,10 @@ static int gdsc_init(struct gdsc *sc)
>                 sc->pd.power_off = gdsc_disable;
>         if (!sc->pd.power_on)
>                 sc->pd.power_on = gdsc_enable;
> +       if (sc->flags & HW_CTRL_TRIGGER) {
> +               sc->pd.set_hwmode_dev = gdsc_set_hwmode;
> +               sc->pd.get_hwmode_dev = gdsc_get_hwmode;
> +       }
>
>         ret = pm_genpd_init(&sc->pd, NULL, !on);
>         if (ret)
> diff --git a/drivers/clk/qcom/gdsc.h b/drivers/clk/qcom/gdsc.h
> index 803512688336..1e2779b823d1 100644
> --- a/drivers/clk/qcom/gdsc.h
> +++ b/drivers/clk/qcom/gdsc.h
> @@ -67,6 +67,7 @@ struct gdsc {
>  #define ALWAYS_ON      BIT(6)
>  #define RETAIN_FF_ENABLE       BIT(7)
>  #define NO_RET_PERIPH  BIT(8)
> +#define HW_CTRL_TRIGGER        BIT(9)
>         struct reset_controller_dev     *rcdev;
>         unsigned int                    *resets;
>         unsigned int                    reset_count;
>
> --
> 2.34.1
>
Jagadeesh Kona Nov. 10, 2023, 8:32 a.m. UTC | #4
On 11/2/2023 2:58 AM, Dmitry Baryshkov wrote:
> On Wed, 1 Nov 2023 at 11:06, Abel Vesa <abel.vesa@linaro.org> wrote:
>>
>> From: Jagadeesh Kona <quic_jkona@quicinc.com>
>>
>> Add support for set and get hwmode callbacks to switch the GDSC between
>> SW and HW modes. Currently, the GDSC is moved to HW control mode
>> using HW_CTRL flag and if this flag is present, GDSC is moved to HW
>> mode as part of GDSC enable itself. The intention is to keep the
>> HW_CTRL flag functionality as is, since many older chipsets still use
>> this flag.
>>
>> Introduce a new HW_CTRL_TRIGGER flag to switch the GDSC back and forth
>> between HW/SW modes dynamically at runtime. If HW_CTRL_TRIGGER flag is
>> present, register set_hwmode_dev callback to switch the GDSC mode which
>> can be invoked from consumer drivers using dev_pm_genpd_set_hwmode
>> function. Unlike HW_CTRL flag, HW_CTRL_TRIGGER won't move the GDSC to HW
>> control mode as part of GDSC enable itself, GDSC will be moved to HW
>> control mode only when consumer driver explicity calls
>> dev_pm_genpd_set_hwmode to switch to HW mode. Also add the
>> dev_pm_genpd_get_hwmode to allow the consumers to read the actual
>> HW/SW mode from hardware.
> 
> Can we add two new flags:
> - HW_CTRL_TRIGGER
> - DEFAULT_HW_TRIGGER
> 
> And then define HW_CTRL as HW_CTRL_TRIGGER | DEFAULT_HW_TRIGGER ?
> 
> This way older platforms will keep existing behaviour, but can
> gradually migrate to the new callbacks?
> 

Thanks Dmitry for your review,

The current usecases we have for GDSC's are either use the existing 
HW_CTRL flag to switch the GDSC to HW mode in gdsc_enable() and back to 
SW mode in gdsc_disable(). The second usecase is don't switch GDSC mode 
in gdsc_enable() & gdsc_disable() at all, and switch the GDSC mode only 
in new callbacks when consumers explicitly request it using 
dev_pm_genpd_set_hwmode(), this can be achieved using the new 
HW_CTRL_TRIGGER flag.

By defining HW_CTRL as HW_CTRL_TRIGGER | DEFAULT_HW_TRIGGER, it switches 
the GDSC mode both in enable & disable callbacks and in new callbacks as 
well. But we currently don't have any usecase that requires this behaviour.

Thanks,
Jagadeesh

>>
>> Signed-off-by: Jagadeesh Kona <quic_jkona@quicinc.com>
>> Signed-off-by: Abel Vesa <abel.vesa@linaro.org>
>> ---
>>   drivers/clk/qcom/gdsc.c | 32 ++++++++++++++++++++++++++++++++
>>   drivers/clk/qcom/gdsc.h |  1 +
>>   2 files changed, 33 insertions(+)
>>
>> diff --git a/drivers/clk/qcom/gdsc.c b/drivers/clk/qcom/gdsc.c
>> index 5358e28122ab..c763524cd5da 100644
>> --- a/drivers/clk/qcom/gdsc.c
>> +++ b/drivers/clk/qcom/gdsc.c
>> @@ -363,6 +363,34 @@ static int gdsc_disable(struct generic_pm_domain *domain)
>>          return 0;
>>   }
>>
>> +static int gdsc_set_hwmode(struct generic_pm_domain *domain, struct device *dev, bool mode)
>> +{
>> +       struct gdsc *sc = domain_to_gdsc(domain);
>> +
>> +       if (sc->rsupply && !regulator_is_enabled(sc->rsupply)) {
>> +               pr_err("Cannot set mode while parent is disabled\n");
>> +               return -EIO;
>> +       }
>> +
>> +       return gdsc_hwctrl(sc, mode);
>> +}
>> +
>> +static bool gdsc_get_hwmode(struct generic_pm_domain *domain, struct device *dev)
>> +{
>> +       struct gdsc *sc = domain_to_gdsc(domain);
>> +       u32 val;
>> +       int ret;
>> +
>> +       ret = regmap_read(sc->regmap, sc->gdscr, &val);
>> +       if (ret)
>> +               return ret;
>> +
>> +       if (val & HW_CONTROL_MASK)
>> +               return true;
>> +
>> +       return false;
>> +}
>> +
>>   static int gdsc_init(struct gdsc *sc)
>>   {
>>          u32 mask, val;
>> @@ -451,6 +479,10 @@ static int gdsc_init(struct gdsc *sc)
>>                  sc->pd.power_off = gdsc_disable;
>>          if (!sc->pd.power_on)
>>                  sc->pd.power_on = gdsc_enable;
>> +       if (sc->flags & HW_CTRL_TRIGGER) {
>> +               sc->pd.set_hwmode_dev = gdsc_set_hwmode;
>> +               sc->pd.get_hwmode_dev = gdsc_get_hwmode;
>> +       }
>>
>>          ret = pm_genpd_init(&sc->pd, NULL, !on);
>>          if (ret)
>> diff --git a/drivers/clk/qcom/gdsc.h b/drivers/clk/qcom/gdsc.h
>> index 803512688336..1e2779b823d1 100644
>> --- a/drivers/clk/qcom/gdsc.h
>> +++ b/drivers/clk/qcom/gdsc.h
>> @@ -67,6 +67,7 @@ struct gdsc {
>>   #define ALWAYS_ON      BIT(6)
>>   #define RETAIN_FF_ENABLE       BIT(7)
>>   #define NO_RET_PERIPH  BIT(8)
>> +#define HW_CTRL_TRIGGER        BIT(9)
>>          struct reset_controller_dev     *rcdev;
>>          unsigned int                    *resets;
>>          unsigned int                    reset_count;
>>
>> --
>> 2.34.1
>>
> 
>