mbox series

[0/4] clk: qcom: gdsc: Handle supply regulators

Message ID 20200319053902.3415984-1-bjorn.andersson@linaro.org
Headers show
Series clk: qcom: gdsc: Handle supply regulators | expand

Message

Bjorn Andersson March 19, 2020, 5:38 a.m. UTC 
Handle supply regulators for GDSCs to allow probe deferral when regulators are
not yet present/enabled and to allow the GDSC to enable/disable dependencies as
needed.

Bjorn Andersson (3):
  clk: qcom: gdsc: Handle GDSC regulator supplies
  clk: qcom: mmcc-msm8996: Properly describe GPU_GX gdsc
  arm64: dts: qcom: msm8996: Make GPU node control GPU_GX GDSC

Rajendra Nayak (1):
  arm64: dts: qcom: db820c: Add s2 regulator in pmi8994

 .../devicetree/bindings/clock/qcom,mmcc.yaml  |  4 ++++
 arch/arm64/boot/dts/qcom/apq8096-db820c.dtsi  | 14 +++++++++++
 arch/arm64/boot/dts/qcom/msm8996.dtsi         |  2 +-
 arch/arm64/boot/dts/qcom/pmi8994.dtsi         |  6 +++++
 drivers/clk/qcom/gdsc.c                       | 24 +++++++++++++++++++
 drivers/clk/qcom/gdsc.h                       |  4 ++++
 drivers/clk/qcom/mmcc-msm8996.c               |  2 ++
 7 files changed, 55 insertions(+), 1 deletion(-)

Comments

Stephen Boyd March 20, 2020, 11:31 p.m. UTC | #1 
Quoting Bjorn Andersson (2020-03-18 22:38:59)
> Certain GDSCs, such as the GPU_GX on MSM8996, requires that the upstream
> regulator supply is powered in order to be turned on.
> 
> It's not guaranteed that the bootloader will leave these supplies on and
> the driver core will attempt to enable any GDSCs before allowing the
> individual drivers to probe defer on the PMIC regulator driver not yet
> being present.
> 
> So the gdsc driver needs to be made aware of supplying regulators and
> probe defer on their absence, and it needs to enable and disable the
> regulator accordingly.
> 
> Voltage adjustments of the supplying regulator are deferred to the
> client drivers themselves.
> 
> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> ---

Ok. Looks mostly fine to me.

>  drivers/clk/qcom/gdsc.c | 24 ++++++++++++++++++++++++
>  drivers/clk/qcom/gdsc.h |  4 ++++
>  2 files changed, 28 insertions(+)
> 
> diff --git a/drivers/clk/qcom/gdsc.c b/drivers/clk/qcom/gdsc.c
> index a250f59708d8..3528789cc9d0 100644
> --- a/drivers/clk/qcom/gdsc.c
> +++ b/drivers/clk/qcom/gdsc.c
> @@ -13,6 +13,7 @@
>  #include <linux/regmap.h>
>  #include <linux/reset-controller.h>
>  #include <linux/slab.h>
> +#include <linux/regulator/consumer.h>

Alphabetical?

>  #include "gdsc.h"
>  
>  #define PWR_ON_MASK            BIT(31)
> @@ -371,6 +385,16 @@ int gdsc_register(struct gdsc_desc *desc,
>         if (!data->domains)
>                 return -ENOMEM;
>  
> +       /* Resolve any regulator supplies */

Drop the comment please, it's just saying what the code is doing.

> +       for (i = 0; i < num; i++) {
> +               if (!scs[i] || !scs[i]->supply)
> +                       continue;
> +
> +               scs[i]->rsupply = devm_regulator_get(dev, scs[i]->supply);
> +               if (IS_ERR(scs[i]->rsupply))
> +                       return PTR_ERR(scs[i]->rsupply);
> +       }
> +
>         data->num_domains = num;
>         for (i = 0; i < num; i++) {
>                 if (!scs[i])
Stephen Boyd March 21, 2020, 6:43 p.m. UTC | #2 
Quoting Bjorn Andersson (2020-03-20 22:16:12)
> On Fri 20 Mar 16:31 PDT 2020, Stephen Boyd wrote:
> 
> > Quoting Bjorn Andersson (2020-03-18 22:39:00)
> > > diff --git a/Documentation/devicetree/bindings/clock/qcom,mmcc.yaml b/Documentation/devicetree/bindings/clock/qcom,mmcc.yaml
> > > index 85518494ce43..65d9aa790581 100644
> > > --- a/Documentation/devicetree/bindings/clock/qcom,mmcc.yaml
> > > +++ b/Documentation/devicetree/bindings/clock/qcom,mmcc.yaml
> > > @@ -67,6 +67,10 @@ properties:
> > >      description:
> > >         Protected clock specifier list as per common clock binding
> > >  
> > > +  vdd_gfx-supply:
> > 
> > Why not vdd-gfx-supply? What's with the underscore?
> > 
> 
> The pad is named "VDD_GFX" in the datasheet and the schematics. I see
> that we've started y/_/-/ in some of the newly added bindings, would you
> prefer I follow this?

If the datasheet has this then I guess it's fine. I'll wait for Rob to
ack.
Rob Herring March 30, 2020, 11:10 p.m. UTC | #3 
On Sat, Mar 21, 2020 at 11:43:12AM -0700, Stephen Boyd wrote:
> Quoting Bjorn Andersson (2020-03-20 22:16:12)
> > On Fri 20 Mar 16:31 PDT 2020, Stephen Boyd wrote:
> > 
> > > Quoting Bjorn Andersson (2020-03-18 22:39:00)
> > > > diff --git a/Documentation/devicetree/bindings/clock/qcom,mmcc.yaml b/Documentation/devicetree/bindings/clock/qcom,mmcc.yaml
> > > > index 85518494ce43..65d9aa790581 100644
> > > > --- a/Documentation/devicetree/bindings/clock/qcom,mmcc.yaml
> > > > +++ b/Documentation/devicetree/bindings/clock/qcom,mmcc.yaml
> > > > @@ -67,6 +67,10 @@ properties:
> > > >      description:
> > > >         Protected clock specifier list as per common clock binding
> > > >  
> > > > +  vdd_gfx-supply:
> > > 
> > > Why not vdd-gfx-supply? What's with the underscore?
> > > 
> > 
> > The pad is named "VDD_GFX" in the datasheet and the schematics. I see
> > that we've started y/_/-/ in some of the newly added bindings, would you
> > prefer I follow this?
> 
> If the datasheet has this then I guess it's fine. I'll wait for Rob to
> ack.

vddgfx or vdd-gfx.

Rob
Taniya Das March 31, 2020, 5:35 a.m. UTC | #4 
Hi Stephen,

I think the upstream design always wanted the client/consumer to enable 
the GPU Rail and then turn ON the GDSC?

Why are we going ahead with adding the support of regulator in the GDSC 
driver?

On 3/19/2020 11:08 AM, Bjorn Andersson wrote:
> Certain GDSCs, such as the GPU_GX on MSM8996, requires that the upstream
> regulator supply is powered in order to be turned on.
> 
> It's not guaranteed that the bootloader will leave these supplies on and
> the driver core will attempt to enable any GDSCs before allowing the
> individual drivers to probe defer on the PMIC regulator driver not yet
> being present.
> 
> So the gdsc driver needs to be made aware of supplying regulators and
> probe defer on their absence, and it needs to enable and disable the
> regulator accordingly.
> 
> Voltage adjustments of the supplying regulator are deferred to the
> client drivers themselves.
> 
> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> ---
>   drivers/clk/qcom/gdsc.c | 24 ++++++++++++++++++++++++
>   drivers/clk/qcom/gdsc.h |  4 ++++
>   2 files changed, 28 insertions(+)
> 
> diff --git a/drivers/clk/qcom/gdsc.c b/drivers/clk/qcom/gdsc.c
> index a250f59708d8..3528789cc9d0 100644
> --- a/drivers/clk/qcom/gdsc.c
> +++ b/drivers/clk/qcom/gdsc.c
> @@ -13,6 +13,7 @@
>   #include <linux/regmap.h>
>   #include <linux/reset-controller.h>
>   #include <linux/slab.h>
> +#include <linux/regulator/consumer.h>
>   #include "gdsc.h"
>   
>   #define PWR_ON_MASK		BIT(31)
> @@ -112,6 +113,12 @@ static int gdsc_toggle_logic(struct gdsc *sc, enum gdsc_status status)
>   	int ret;
>   	u32 val = (status == GDSC_ON) ? 0 : SW_COLLAPSE_MASK;
>   
> +	if (status == GDSC_ON && sc->rsupply) {
> +		ret = regulator_enable(sc->rsupply);
> +		if (ret < 0)
> +			return ret;
> +	}
> +
>   	ret = regmap_update_bits(sc->regmap, sc->gdscr, SW_COLLAPSE_MASK, val);
>   	if (ret)
>   		return ret;
> @@ -143,6 +150,13 @@ static int gdsc_toggle_logic(struct gdsc *sc, enum gdsc_status status)
>   
>   	ret = gdsc_poll_status(sc, status);
>   	WARN(ret, "%s status stuck at 'o%s'", sc->pd.name, status ? "ff" : "n");
> +
> +	if (!ret && status == GDSC_OFF && sc->rsupply) {
> +		ret = regulator_disable(sc->rsupply);
> +		if (ret < 0)
> +			return ret;
> +	}
> +
>   	return ret;
>   }
>   
> @@ -371,6 +385,16 @@ int gdsc_register(struct gdsc_desc *desc,
>   	if (!data->domains)
>   		return -ENOMEM;
>   
> +	/* Resolve any regulator supplies */
> +	for (i = 0; i < num; i++) {
> +		if (!scs[i] || !scs[i]->supply)
> +			continue;
> +
> +		scs[i]->rsupply = devm_regulator_get(dev, scs[i]->supply);
> +		if (IS_ERR(scs[i]->rsupply))
> +			return PTR_ERR(scs[i]->rsupply);
> +	}
> +
>   	data->num_domains = num;
>   	for (i = 0; i < num; i++) {
>   		if (!scs[i])
> diff --git a/drivers/clk/qcom/gdsc.h b/drivers/clk/qcom/gdsc.h
> index 64cdc8cf0d4d..c36fc26dcdff 100644
> --- a/drivers/clk/qcom/gdsc.h
> +++ b/drivers/clk/qcom/gdsc.h
> @@ -10,6 +10,7 @@
>   #include <linux/pm_domain.h>
>   
>   struct regmap;
> +struct regulator;
>   struct reset_controller_dev;
>   
>   /**
> @@ -52,6 +53,9 @@ struct gdsc {
>   	struct reset_controller_dev	*rcdev;
>   	unsigned int			*resets;
>   	unsigned int			reset_count;
> +
> +	const char 			*supply;
> +	struct regulator		*rsupply;
>   };
>   
>   struct gdsc_desc {
>