[PATCH v3 0/6] Add drive-strength in Meson pinctrl driver

[PATCH v3 0/6] Add drive-strength in Meson pinctrl driver

[Guillaume La Roque]

The purpose of this patchset is to add drive-strength support in meson pinconf
driver. This is a new feature that was added on the g12a. It is critical for us
to support this since many functions are failing with default pad drive-strength.

The value achievable by the SoC are 0.5mA, 2.5mA, 3mA and 4mA and the DT property
'drive-strength' is expressed in mA.
So this patch add another generic property "drive-strength-uA". The change to do so
would be minimal and could be benefit to other platforms later on.

Cheers
Guillaume

Changes since v2:
- update driver-strength-uA property to be compliant with DT documentation
- rework patch series for better understanding
- rework set_bias function

Changes since v1:
- fix missing break
- implement new pinctrl generic property "drive-strength-uA"

[1] https://lkml.kernel.org/r/20190314163725.7918-1-jbrunet@baylibre.com


Guillaume La Roque (6):
  dt-bindings: pinctrl: add a 'drive-strength-microamp' property
  pinctrl: generic: add new 'drive-strength-microamp' property support
  dt-bindings: pinctrl: meson: Add drive-strength-microamp property
  pinctrl: meson: Rework enable/disable bias part
  pinctrl: meson: add support of drive-strength-microamp
  pinctrl: meson: g12a: add DS bank value

 .../bindings/pinctrl/meson,pinctrl.txt        |   4 +
 .../bindings/pinctrl/pinctrl-bindings.txt     |   3 +
 drivers/pinctrl/meson/pinctrl-meson-g12a.c    |  36 ++--
 drivers/pinctrl/meson/pinctrl-meson.c         | 177 +++++++++++++++---
 drivers/pinctrl/meson/pinctrl-meson.h         |  18 +-
 drivers/pinctrl/pinconf-generic.c             |   2 +
 include/linux/pinctrl/pinconf-generic.h       |   3 +
 7 files changed, 195 insertions(+), 48 deletions(-)

-- 
2.17.1


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[PATCH v3 1/6] dt-bindings: pinctrl: add a 'drive-strength-microamp' property

[Guillaume La Roque]

This property allow drive-strength parameter in uA instead of mA.

Signed-off-by: Guillaume La Roque <glaroque@baylibre.com>
---
 Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt b/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
index cef2b5855d60..84adce9f2a75 100644
--- a/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
+++ b/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
@@ -258,6 +258,7 @@ drive-push-pull		- drive actively high and low
 drive-open-drain	- drive with open drain
 drive-open-source	- drive with open source
 drive-strength		- sink or source at most X mA
+drive-strength-microamp	- sink or source at most X uA
 input-enable		- enable input on pin (no effect on output, such as
 			  enabling an input buffer)
 input-disable		- disable input on pin (no effect on output, such as
@@ -326,6 +327,8 @@ arguments are described below.
 
 - drive-strength takes as argument the target strength in mA.
 
+- drive-strength-microamp takes as argument the target strength in uA.
+
 - input-debounce takes the debounce time in usec as argument
   or 0 to disable debouncing
 
-- 
2.17.1


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Re: [PATCH v3 1/6] dt-bindings: pinctrl: add a 'drive-strength-microamp' property

[Martin Blumenstingl]

On Tue, May 7, 2019 at 1:57 PM Guillaume La Roque <glaroque@baylibre.com> wrote:
>
> This property allow drive-strength parameter in uA instead of mA.
>
> Signed-off-by: Guillaume La Roque <glaroque@baylibre.com>
Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>

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[PATCH v3 2/6] pinctrl: generic: add new 'drive-strength-microamp' property support

[Guillaume La Roque]

Add drive-strength-microamp property support to allow drive strength in uA

Signed-off-by: Guillaume La Roque <glaroque@baylibre.com>
---
 drivers/pinctrl/pinconf-generic.c       | 2 ++
 include/linux/pinctrl/pinconf-generic.h | 3 +++
 2 files changed, 5 insertions(+)

diff --git a/drivers/pinctrl/pinconf-generic.c b/drivers/pinctrl/pinconf-generic.c
index b4f7f8a458ea..d0cbdb1ad76a 100644
--- a/drivers/pinctrl/pinconf-generic.c
+++ b/drivers/pinctrl/pinconf-generic.c
@@ -39,6 +39,7 @@ static const struct pin_config_item conf_items[] = {
 	PCONFDUMP(PIN_CONFIG_DRIVE_OPEN_SOURCE, "output drive open source", NULL, false),
 	PCONFDUMP(PIN_CONFIG_DRIVE_PUSH_PULL, "output drive push pull", NULL, false),
 	PCONFDUMP(PIN_CONFIG_DRIVE_STRENGTH, "output drive strength", "mA", true),
+	PCONFDUMP(PIN_CONFIG_DRIVE_STRENGTH_UA, "output drive strength", "uA", true),
 	PCONFDUMP(PIN_CONFIG_INPUT_DEBOUNCE, "input debounce", "usec", true),
 	PCONFDUMP(PIN_CONFIG_INPUT_ENABLE, "input enabled", NULL, false),
 	PCONFDUMP(PIN_CONFIG_INPUT_SCHMITT, "input schmitt trigger", NULL, false),
@@ -167,6 +168,7 @@ static const struct pinconf_generic_params dt_params[] = {
 	{ "drive-open-source", PIN_CONFIG_DRIVE_OPEN_SOURCE, 0 },
 	{ "drive-push-pull", PIN_CONFIG_DRIVE_PUSH_PULL, 0 },
 	{ "drive-strength", PIN_CONFIG_DRIVE_STRENGTH, 0 },
+	{ "drive-strength-microamp", PIN_CONFIG_DRIVE_STRENGTH_UA, 0 },
 	{ "input-debounce", PIN_CONFIG_INPUT_DEBOUNCE, 0 },
 	{ "input-disable", PIN_CONFIG_INPUT_ENABLE, 0 },
 	{ "input-enable", PIN_CONFIG_INPUT_ENABLE, 1 },
diff --git a/include/linux/pinctrl/pinconf-generic.h b/include/linux/pinctrl/pinconf-generic.h
index 6c0680641108..72d06d6a3099 100644
--- a/include/linux/pinctrl/pinconf-generic.h
+++ b/include/linux/pinctrl/pinconf-generic.h
@@ -55,6 +55,8 @@
  *	push-pull mode, the argument is ignored.
  * @PIN_CONFIG_DRIVE_STRENGTH: the pin will sink or source at most the current
  *	passed as argument. The argument is in mA.
+ * @PIN_CONFIG_DRIVE_STRENGTH_UA: the pin will sink or source at most the current
+ *	passed as argument. The argument is in uA.
  * @PIN_CONFIG_INPUT_DEBOUNCE: this will configure the pin to debounce mode,
  *	which means it will wait for signals to settle when reading inputs. The
  *	argument gives the debounce time in usecs. Setting the
@@ -112,6 +114,7 @@ enum pin_config_param {
 	PIN_CONFIG_DRIVE_OPEN_SOURCE,
 	PIN_CONFIG_DRIVE_PUSH_PULL,
 	PIN_CONFIG_DRIVE_STRENGTH,
+	PIN_CONFIG_DRIVE_STRENGTH_UA,
 	PIN_CONFIG_INPUT_DEBOUNCE,
 	PIN_CONFIG_INPUT_ENABLE,
 	PIN_CONFIG_INPUT_SCHMITT,
-- 
2.17.1


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[PATCH v3 3/6] dt-bindings: pinctrl: meson: Add drive-strength-microamp property

[Guillaume La Roque]

Add optional drive-strength-microamp property

Signed-off-by: Guillaume La Roque <glaroque@baylibre.com>
---
 Documentation/devicetree/bindings/pinctrl/meson,pinctrl.txt | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Documentation/devicetree/bindings/pinctrl/meson,pinctrl.txt b/Documentation/devicetree/bindings/pinctrl/meson,pinctrl.txt
index a47dd990a8d3..a7618605bf1e 100644
--- a/Documentation/devicetree/bindings/pinctrl/meson,pinctrl.txt
+++ b/Documentation/devicetree/bindings/pinctrl/meson,pinctrl.txt
@@ -51,6 +51,10 @@ Configuration nodes support the generic properties "bias-disable",
 "bias-pull-up" and "bias-pull-down", described in file
 pinctrl-bindings.txt
 
+Optional properties :
+ - drive-strength-microamp: Drive strength for the specified pins in uA.
+			    This property is only valid for G12A and newer.
+
 === Example ===
 
 	pinctrl: pinctrl@c1109880 {
-- 
2.17.1


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Re: [PATCH v3 3/6] dt-bindings: pinctrl: meson: Add drive-strength-microamp property

[Martin Blumenstingl]

On Tue, May 7, 2019 at 1:57 PM Guillaume La Roque <glaroque@baylibre.com> wrote:
>
> Add optional drive-strength-microamp property
>
> Signed-off-by: Guillaume La Roque <glaroque@baylibre.com>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>

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[PATCH v3 4/6] pinctrl: meson: Rework enable/disable bias part

[Guillaume La Roque]

rework bias enable/disable part to prepare drive-strength integration

Signed-off-by: Guillaume La Roque <glaroque@baylibre.com>
---
 drivers/pinctrl/meson/pinctrl-meson.c | 79 ++++++++++++++++-----------
 1 file changed, 48 insertions(+), 31 deletions(-)

diff --git a/drivers/pinctrl/meson/pinctrl-meson.c b/drivers/pinctrl/meson/pinctrl-meson.c
index 96a4a72708e4..a216a7537564 100644
--- a/drivers/pinctrl/meson/pinctrl-meson.c
+++ b/drivers/pinctrl/meson/pinctrl-meson.c
@@ -174,13 +174,57 @@ int meson_pmx_get_groups(struct pinctrl_dev *pcdev, unsigned selector,
 	return 0;
 }
 
+static int meson_pinconf_disable_bias(struct meson_pinctrl *pc,
+				      unsigned int pin)
+{
+	struct meson_bank *bank;
+	unsigned int reg, bit = 0;
+	int ret;
+
+	ret = meson_get_bank(pc, pin, &bank);
+	if (ret)
+		return ret;
+	meson_calc_reg_and_bit(bank, pin, REG_PULLEN, &reg, &bit);
+	ret = regmap_update_bits(pc->reg_pullen, reg, BIT(bit), 0);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int meson_pinconf_enable_bias(struct meson_pinctrl *pc, unsigned int pin,
+				     bool pull_up)
+{
+	struct meson_bank *bank;
+	unsigned int reg, bit, val = 0;
+	int ret;
+
+	ret = meson_get_bank(pc, pin, &bank);
+	if (ret)
+		return ret;
+
+	meson_calc_reg_and_bit(bank, pin, REG_PULL, &reg, &bit);
+	if (pull_up)
+		val = BIT(bit);
+
+	ret = regmap_update_bits(pc->reg_pull, reg, BIT(bit), val);
+	if (ret)
+		return ret;
+
+	meson_calc_reg_and_bit(bank, pin, REG_PULLEN, &reg, &bit);
+	ret = regmap_update_bits(pc->reg_pullen, reg, BIT(bit),	BIT(bit));
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
 static int meson_pinconf_set(struct pinctrl_dev *pcdev, unsigned int pin,
 			     unsigned long *configs, unsigned num_configs)
 {
 	struct meson_pinctrl *pc = pinctrl_dev_get_drvdata(pcdev);
 	struct meson_bank *bank;
 	enum pin_config_param param;
-	unsigned int reg, bit;
 	int i, ret;
 
 	ret = meson_get_bank(pc, pin, &bank);
@@ -192,44 +236,17 @@ static int meson_pinconf_set(struct pinctrl_dev *pcdev, unsigned int pin,
 
 		switch (param) {
 		case PIN_CONFIG_BIAS_DISABLE:
-			dev_dbg(pc->dev, "pin %u: disable bias\n", pin);
-
-			meson_calc_reg_and_bit(bank, pin, REG_PULLEN, &reg,
-					       &bit);
-			ret = regmap_update_bits(pc->reg_pullen, reg,
-						 BIT(bit), 0);
+			ret = meson_pinconf_disable_bias(pc, pin);
 			if (ret)
 				return ret;
 			break;
 		case PIN_CONFIG_BIAS_PULL_UP:
-			dev_dbg(pc->dev, "pin %u: enable pull-up\n", pin);
-
-			meson_calc_reg_and_bit(bank, pin, REG_PULLEN,
-					       &reg, &bit);
-			ret = regmap_update_bits(pc->reg_pullen, reg,
-						 BIT(bit), BIT(bit));
-			if (ret)
-				return ret;
-
-			meson_calc_reg_and_bit(bank, pin, REG_PULL, &reg, &bit);
-			ret = regmap_update_bits(pc->reg_pull, reg,
-						 BIT(bit), BIT(bit));
+			ret = meson_pinconf_enable_bias(pc, pin, 1);
 			if (ret)
 				return ret;
 			break;
 		case PIN_CONFIG_BIAS_PULL_DOWN:
-			dev_dbg(pc->dev, "pin %u: enable pull-down\n", pin);
-
-			meson_calc_reg_and_bit(bank, pin, REG_PULLEN,
-					       &reg, &bit);
-			ret = regmap_update_bits(pc->reg_pullen, reg,
-						 BIT(bit), BIT(bit));
-			if (ret)
-				return ret;
-
-			meson_calc_reg_and_bit(bank, pin, REG_PULL, &reg, &bit);
-			ret = regmap_update_bits(pc->reg_pull, reg,
-						 BIT(bit), 0);
+			ret = meson_pinconf_enable_bias(pc, pin, 0);
 			if (ret)
 				return ret;
 			break;
-- 
2.17.1


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Re: [PATCH v3 4/6] pinctrl: meson: Rework enable/disable bias part

[Martin Blumenstingl]

Hi Guillaume,

On Tue, May 7, 2019 at 1:57 PM Guillaume La Roque <glaroque@baylibre.com> wrote:
>
> rework bias enable/disable part to prepare drive-strength integration
if it was my patch I would add "no functional changes" at the end to
make it explicit that this only changes the structure of the code.

>
> Signed-off-by: Guillaume La Roque <glaroque@baylibre.com>
with the minor comments from below addressed:
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>

> ---
>  drivers/pinctrl/meson/pinctrl-meson.c | 79 ++++++++++++++++-----------
>  1 file changed, 48 insertions(+), 31 deletions(-)
>
> diff --git a/drivers/pinctrl/meson/pinctrl-meson.c b/drivers/pinctrl/meson/pinctrl-meson.c
> index 96a4a72708e4..a216a7537564 100644
> --- a/drivers/pinctrl/meson/pinctrl-meson.c
> +++ b/drivers/pinctrl/meson/pinctrl-meson.c
> @@ -174,13 +174,57 @@ int meson_pmx_get_groups(struct pinctrl_dev *pcdev, unsigned selector,
>         return 0;
>  }
>
> +static int meson_pinconf_disable_bias(struct meson_pinctrl *pc,
> +                                     unsigned int pin)
> +{
> +       struct meson_bank *bank;
> +       unsigned int reg, bit = 0;
> +       int ret;
> +
> +       ret = meson_get_bank(pc, pin, &bank);
> +       if (ret)
> +               return ret;
add an empty line here to keep it consistent with the rest of the code

[...]
>  static int meson_pinconf_set(struct pinctrl_dev *pcdev, unsigned int pin,
>                              unsigned long *configs, unsigned num_configs)
>  {
>         struct meson_pinctrl *pc = pinctrl_dev_get_drvdata(pcdev);
>         struct meson_bank *bank;
bank is not read anymore (it's passed to meson_get_bank to set it, but
then it's not read, which is probably why my compiler doesn't
complain)

>         enum pin_config_param param;
> -       unsigned int reg, bit;
>         int i, ret;
>
>         ret = meson_get_bank(pc, pin, &bank);
> @@ -192,44 +236,17 @@ static int meson_pinconf_set(struct pinctrl_dev *pcdev, unsigned int pin,
>
>                 switch (param) {
>                 case PIN_CONFIG_BIAS_DISABLE:
> -                       dev_dbg(pc->dev, "pin %u: disable bias\n", pin);
> -
> -                       meson_calc_reg_and_bit(bank, pin, REG_PULLEN, &reg,
> -                                              &bit);
> -                       ret = regmap_update_bits(pc->reg_pullen, reg,
> -                                                BIT(bit), 0);
> +                       ret = meson_pinconf_disable_bias(pc, pin);
>                         if (ret)
>                                 return ret;
>                         break;
>                 case PIN_CONFIG_BIAS_PULL_UP:
> -                       dev_dbg(pc->dev, "pin %u: enable pull-up\n", pin);
> -
> -                       meson_calc_reg_and_bit(bank, pin, REG_PULLEN,
> -                                              &reg, &bit);
> -                       ret = regmap_update_bits(pc->reg_pullen, reg,
> -                                                BIT(bit), BIT(bit));
> -                       if (ret)
> -                               return ret;
> -
> -                       meson_calc_reg_and_bit(bank, pin, REG_PULL, &reg, &bit);
> -                       ret = regmap_update_bits(pc->reg_pull, reg,
> -                                                BIT(bit), BIT(bit));
> +                       ret = meson_pinconf_enable_bias(pc, pin, 1);
use "true" instead of "1"?

>                         if (ret)
>                                 return ret;
>                         break;
>                 case PIN_CONFIG_BIAS_PULL_DOWN:
> -                       dev_dbg(pc->dev, "pin %u: enable pull-down\n", pin);
> -
> -                       meson_calc_reg_and_bit(bank, pin, REG_PULLEN,
> -                                              &reg, &bit);
> -                       ret = regmap_update_bits(pc->reg_pullen, reg,
> -                                                BIT(bit), BIT(bit));
> -                       if (ret)
> -                               return ret;
> -
> -                       meson_calc_reg_and_bit(bank, pin, REG_PULL, &reg, &bit);
> -                       ret = regmap_update_bits(pc->reg_pull, reg,
> -                                                BIT(bit), 0);
> +                       ret = meson_pinconf_enable_bias(pc, pin, 0);
use "false" instead of "0"?

one overall comment: thank you for working on this!
in my opinion it's a good preparation step to ensure that
meson_pinconf_set is easy to understand even if we add more
functionality here


Regards
Martin

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Re: [PATCH v3 4/6] pinctrl: meson: Rework enable/disable bias part

[guillaume La Roque]

hi Martin,

same as previous patch i will do a new serie with your comments.


On 5/7/19 7:53 PM, Martin Blumenstingl wrote:
> Hi Guillaume,
>
> On Tue, May 7, 2019 at 1:57 PM Guillaume La Roque <glaroque@baylibre.com> wrote:
>> rework bias enable/disable part to prepare drive-strength integration
> if it was my patch I would add "no functional changes" at the end to
> make it explicit that this only changes the structure of the code.
>
>> Signed-off-by: Guillaume La Roque <glaroque@baylibre.com>
> with the minor comments from below addressed:
> Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
>
>> ---
>>  drivers/pinctrl/meson/pinctrl-meson.c | 79 ++++++++++++++++-----------
>>  1 file changed, 48 insertions(+), 31 deletions(-)
>>
>> diff --git a/drivers/pinctrl/meson/pinctrl-meson.c b/drivers/pinctrl/meson/pinctrl-meson.c
>> index 96a4a72708e4..a216a7537564 100644
>> --- a/drivers/pinctrl/meson/pinctrl-meson.c
>> +++ b/drivers/pinctrl/meson/pinctrl-meson.c
>> @@ -174,13 +174,57 @@ int meson_pmx_get_groups(struct pinctrl_dev *pcdev, unsigned selector,
>>         return 0;
>>  }
>>
>> +static int meson_pinconf_disable_bias(struct meson_pinctrl *pc,
>> +                                     unsigned int pin)
>> +{
>> +       struct meson_bank *bank;
>> +       unsigned int reg, bit = 0;
>> +       int ret;
>> +
>> +       ret = meson_get_bank(pc, pin, &bank);
>> +       if (ret)
>> +               return ret;
> add an empty line here to keep it consistent with the rest of the code
>
> [...]
>>  static int meson_pinconf_set(struct pinctrl_dev *pcdev, unsigned int pin,
>>                              unsigned long *configs, unsigned num_configs)
>>  {
>>         struct meson_pinctrl *pc = pinctrl_dev_get_drvdata(pcdev);
>>         struct meson_bank *bank;
> bank is not read anymore (it's passed to meson_get_bank to set it, but
> then it's not read, which is probably why my compiler doesn't
> complain)
>
>>         enum pin_config_param param;
>> -       unsigned int reg, bit;
>>         int i, ret;
>>
>>         ret = meson_get_bank(pc, pin, &bank);
>> @@ -192,44 +236,17 @@ static int meson_pinconf_set(struct pinctrl_dev *pcdev, unsigned int pin,
>>
>>                 switch (param) {
>>                 case PIN_CONFIG_BIAS_DISABLE:
>> -                       dev_dbg(pc->dev, "pin %u: disable bias\n", pin);
>> -
>> -                       meson_calc_reg_and_bit(bank, pin, REG_PULLEN, &reg,
>> -                                              &bit);
>> -                       ret = regmap_update_bits(pc->reg_pullen, reg,
>> -                                                BIT(bit), 0);
>> +                       ret = meson_pinconf_disable_bias(pc, pin);
>>                         if (ret)
>>                                 return ret;
>>                         break;
>>                 case PIN_CONFIG_BIAS_PULL_UP:
>> -                       dev_dbg(pc->dev, "pin %u: enable pull-up\n", pin);
>> -
>> -                       meson_calc_reg_and_bit(bank, pin, REG_PULLEN,
>> -                                              &reg, &bit);
>> -                       ret = regmap_update_bits(pc->reg_pullen, reg,
>> -                                                BIT(bit), BIT(bit));
>> -                       if (ret)
>> -                               return ret;
>> -
>> -                       meson_calc_reg_and_bit(bank, pin, REG_PULL, &reg, &bit);
>> -                       ret = regmap_update_bits(pc->reg_pull, reg,
>> -                                                BIT(bit), BIT(bit));
>> +                       ret = meson_pinconf_enable_bias(pc, pin, 1);
> use "true" instead of "1"?
>
>>                         if (ret)
>>                                 return ret;
>>                         break;
>>                 case PIN_CONFIG_BIAS_PULL_DOWN:
>> -                       dev_dbg(pc->dev, "pin %u: enable pull-down\n", pin);
>> -
>> -                       meson_calc_reg_and_bit(bank, pin, REG_PULLEN,
>> -                                              &reg, &bit);
>> -                       ret = regmap_update_bits(pc->reg_pullen, reg,
>> -                                                BIT(bit), BIT(bit));
>> -                       if (ret)
>> -                               return ret;
>> -
>> -                       meson_calc_reg_and_bit(bank, pin, REG_PULL, &reg, &bit);
>> -                       ret = regmap_update_bits(pc->reg_pull, reg,
>> -                                                BIT(bit), 0);
>> +                       ret = meson_pinconf_enable_bias(pc, pin, 0);
> use "false" instead of "0"?
>
> one overall comment: thank you for working on this!
> in my opinion it's a good preparation step to ensure that
> meson_pinconf_set is easy to understand even if we add more
> functionality here
>
>
> Regards
> Martin


guillaume


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[PATCH v3 5/6] pinctrl: meson: add support of drive-strength-microamp

[Guillaume La Roque]

drive-strength-microamp is a new feature needed for G12A SoC.
the default DS setting after boot is usually 500uA and it is not enough for
many functions. We need to be able to set the drive strength to reliably
enable things like MMC, I2C, etc ...

Signed-off-by: Guillaume La Roque <glaroque@baylibre.com>
---
 drivers/pinctrl/meson/pinctrl-meson.c | 102 ++++++++++++++++++++++++++
 drivers/pinctrl/meson/pinctrl-meson.h |  18 ++++-
 2 files changed, 119 insertions(+), 1 deletion(-)

diff --git a/drivers/pinctrl/meson/pinctrl-meson.c b/drivers/pinctrl/meson/pinctrl-meson.c
index a216a7537564..3da867c13f47 100644
--- a/drivers/pinctrl/meson/pinctrl-meson.c
+++ b/drivers/pinctrl/meson/pinctrl-meson.c
@@ -219,12 +219,56 @@ static int meson_pinconf_enable_bias(struct meson_pinctrl *pc, unsigned int pin,
 	return 0;
 }
 
+static int meson_pinconf_set_drive_strength(struct meson_pinctrl *pc,
+					    unsigned int pin,
+					    u16 drive_strength_ua)
+{
+	struct meson_bank *bank;
+	unsigned int reg, bit;
+	unsigned int ds_val;
+	int ret;
+
+	if (!pc->reg_ds) {
+		dev_err(pc->dev, "drive-strength not supported\n");
+		return -ENOTSUPP;
+	}
+
+	ret = meson_get_bank(pc, pin, &bank);
+	if (ret)
+		return ret;
+
+	meson_calc_reg_and_bit(bank, pin, REG_DS, &reg, &bit);
+	bit = bit << 1;
+
+	if (drive_strength_ua <= 500) {
+		ds_val = MESON_PINCONF_DRV_500UA;
+	} else if (drive_strength_ua <= 2500) {
+		ds_val = MESON_PINCONF_DRV_2500UA;
+	} else if (drive_strength_ua <= 3000) {
+		ds_val = MESON_PINCONF_DRV_3000UA;
+	} else if (drive_strength_ua <= 4000) {
+		ds_val = MESON_PINCONF_DRV_4000UA;
+	} else {
+		dev_warn_once(pc->dev,
+			      "pin %u: invalid drive-strength : %d , default to 4mA\n",
+			      pin, drive_strength_ua);
+		ds_val = MESON_PINCONF_DRV_4000UA;
+	}
+
+	ret = regmap_update_bits(pc->reg_ds, reg, 0x3 << bit, ds_val << bit);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
 static int meson_pinconf_set(struct pinctrl_dev *pcdev, unsigned int pin,
 			     unsigned long *configs, unsigned num_configs)
 {
 	struct meson_pinctrl *pc = pinctrl_dev_get_drvdata(pcdev);
 	struct meson_bank *bank;
 	enum pin_config_param param;
+	unsigned int drive_strength_ua;
 	int i, ret;
 
 	ret = meson_get_bank(pc, pin, &bank);
@@ -250,6 +294,14 @@ static int meson_pinconf_set(struct pinctrl_dev *pcdev, unsigned int pin,
 			if (ret)
 				return ret;
 			break;
+		case PIN_CONFIG_DRIVE_STRENGTH_UA:
+			drive_strength_ua =
+				pinconf_to_config_argument(configs[i]);
+			ret = meson_pinconf_set_drive_strength
+				(pc, pin, drive_strength_ua);
+			if (ret)
+				return ret;
+			break;
 		default:
 			return -ENOTSUPP;
 		}
@@ -292,12 +344,57 @@ static int meson_pinconf_get_pull(struct meson_pinctrl *pc, unsigned int pin)
 	return conf;
 }
 
+static int meson_pinconf_get_drive_strength(struct meson_pinctrl *pc,
+					    unsigned int pin,
+					    u16 *drive_strength_ua)
+{
+	struct meson_bank *bank;
+	unsigned int reg, bit;
+	unsigned int val;
+	int ret;
+
+	if (!pc->reg_ds) {
+		dev_err(pc->dev, "drive-strength not supported\n");
+		return -ENOTSUPP;
+	}
+
+	ret = meson_get_bank(pc, pin, &bank);
+	if (ret)
+		return ret;
+
+	meson_calc_reg_and_bit(bank, pin, REG_DS, &reg, &bit);
+
+	ret = regmap_read(pc->reg_ds, reg, &val);
+	if (ret)
+		return ret;
+
+	switch ((val >> bit) & 0x3) {
+	case MESON_PINCONF_DRV_500UA:
+		*drive_strength_ua = 500;
+		break;
+	case MESON_PINCONF_DRV_2500UA:
+		*drive_strength_ua = 2500;
+		break;
+	case MESON_PINCONF_DRV_3000UA:
+		*drive_strength_ua = 3000;
+		break;
+	case MESON_PINCONF_DRV_4000UA:
+		*drive_strength_ua = 4000;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 static int meson_pinconf_get(struct pinctrl_dev *pcdev, unsigned int pin,
 			     unsigned long *config)
 {
 	struct meson_pinctrl *pc = pinctrl_dev_get_drvdata(pcdev);
 	enum pin_config_param param = pinconf_to_config_param(*config);
 	u16 arg;
+	int ret;
 
 	switch (param) {
 	case PIN_CONFIG_BIAS_DISABLE:
@@ -308,6 +405,11 @@ static int meson_pinconf_get(struct pinctrl_dev *pcdev, unsigned int pin,
 		else
 			return -EINVAL;
 		break;
+	case PIN_CONFIG_DRIVE_STRENGTH_UA:
+		ret = meson_pinconf_get_drive_strength(pc, pin, &arg);
+		if (ret)
+			return ret;
+		break;
 	default:
 		return -ENOTSUPP;
 	}
diff --git a/drivers/pinctrl/meson/pinctrl-meson.h b/drivers/pinctrl/meson/pinctrl-meson.h
index 5eaab925f427..cd955fb7c2ce 100644
--- a/drivers/pinctrl/meson/pinctrl-meson.h
+++ b/drivers/pinctrl/meson/pinctrl-meson.h
@@ -71,9 +71,20 @@ enum meson_reg_type {
 	REG_DIR,
 	REG_OUT,
 	REG_IN,
+	REG_DS,
 	NUM_REG,
 };
 
+/**
+ * enum meson_pinconf_drv - value of drive-strength supported
+ */
+enum meson_pinconf_drv {
+	MESON_PINCONF_DRV_500UA,
+	MESON_PINCONF_DRV_2500UA,
+	MESON_PINCONF_DRV_3000UA,
+	MESON_PINCONF_DRV_4000UA,
+};
+
 /**
  * struct meson bank
  *
@@ -132,7 +143,8 @@ struct meson_pinctrl {
 		.num_groups = ARRAY_SIZE(fn ## _groups),		\
 	}
 
-#define BANK(n, f, l, fi, li, per, peb, pr, pb, dr, db, or, ob, ir, ib)	\
+#define BANK_DS(n, f, l, fi, li, per, peb, pr, pb, dr, db, or, ob, ir, ib,     \
+		dsr, dsb)                                                      \
 	{								\
 		.name		= n,					\
 		.first		= f,					\
@@ -145,9 +157,13 @@ struct meson_pinctrl {
 			[REG_DIR]	= { dr, db },			\
 			[REG_OUT]	= { or, ob },			\
 			[REG_IN]	= { ir, ib },			\
+			[REG_DS]	= { dsr, dsb },			\
 		},							\
 	 }
 
+#define BANK(n, f, l, fi, li, per, peb, pr, pb, dr, db, or, ob, ir, ib) \
+	BANK_DS(n, f, l, fi, li, per, peb, pr, pb, dr, db, or, ob, ir, ib, 0, 0)
+
 #define MESON_PIN(x) PINCTRL_PIN(x, #x)
 
 /* Common pmx functions */
-- 
2.17.1


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Re: [PATCH v3 5/6] pinctrl: meson: add support of drive-strength-microamp

[Martin Blumenstingl]

On Tue, May 7, 2019 at 1:57 PM Guillaume La Roque <glaroque@baylibre.com> wrote:
>
> drive-strength-microamp is a new feature needed for G12A SoC.
> the default DS setting after boot is usually 500uA and it is not enough for
> many functions. We need to be able to set the drive strength to reliably
> enable things like MMC, I2C, etc ...
>
> Signed-off-by: Guillaume La Roque <glaroque@baylibre.com>
with the comments below addressed:
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>

> ---
>  drivers/pinctrl/meson/pinctrl-meson.c | 102 ++++++++++++++++++++++++++
>  drivers/pinctrl/meson/pinctrl-meson.h |  18 ++++-
>  2 files changed, 119 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/pinctrl/meson/pinctrl-meson.c b/drivers/pinctrl/meson/pinctrl-meson.c
> index a216a7537564..3da867c13f47 100644
> --- a/drivers/pinctrl/meson/pinctrl-meson.c
> +++ b/drivers/pinctrl/meson/pinctrl-meson.c
> @@ -219,12 +219,56 @@ static int meson_pinconf_enable_bias(struct meson_pinctrl *pc, unsigned int pin,
>         return 0;
>  }
>
> +static int meson_pinconf_set_drive_strength(struct meson_pinctrl *pc,
> +                                           unsigned int pin,
> +                                           u16 drive_strength_ua)
> +{
> +       struct meson_bank *bank;
> +       unsigned int reg, bit;
> +       unsigned int ds_val;
you can move ds_val to the line above

[...]
> +       if (!pc->reg_ds) {
> +               dev_err(pc->dev, "drive-strength not supported\n");
I'm getting this on one of my Meson8m2 boards:
$ # cat /sys/kernel/debug/pinctrl/c1109880.pinctrl-pinctrl-meson/pinconf-pins
...
[  874.748531] meson8-pinctrl c1109880.pinctrl: drive-strength not supported
[  874.755278] meson8-pinctrl c1109880.pinctrl: drive-strength not supported
[  874.762086] meson8-pinctrl c1109880.pinctrl: drive-strength not supported
Pin config settings per pin
Format: pin (name): configs
pin 0 (GPIOX_0): input bias disabled
pin 1 (GPIOX_1): input bias disabled
pin 2 (GPIOX_2): input bias disabled
...

I believe we are not supposed to complain when getting the
drive-strength when reg_ds is absent.
all pre-G12A SoCs don't have reg_ds, so we don't need to error-out in
that case (because that's perfectly valid)

[...]
> +static int meson_pinconf_get_drive_strength(struct meson_pinctrl *pc,
> +                                           unsigned int pin,
> +                                           u16 *drive_strength_ua)
> +{
> +       struct meson_bank *bank;
> +       unsigned int reg, bit;
> +       unsigned int val;
> +       int ret;
> +
> +       if (!pc->reg_ds) {
> +               dev_err(pc->dev, "drive-strength not supported\n");
based on your previous explanation (that you want to inform the .dts
author that he's doing something wrong) I'm happy with this error if
Linus W. doesn't veto this.


Regards
Martin

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Re: [PATCH v3 5/6] pinctrl: meson: add support of drive-strength-microamp

[guillaume La Roque]

hi martin,


thanks for review, i will do a new series to remove err log on get_drive_strength

and integrate your comment


On 5/7/19 8:18 PM, Martin Blumenstingl wrote:
> On Tue, May 7, 2019 at 1:57 PM Guillaume La Roque <glaroque@baylibre.com> wrote:
>> drive-strength-microamp is a new feature needed for G12A SoC.
>> the default DS setting after boot is usually 500uA and it is not enough for
>> many functions. We need to be able to set the drive strength to reliably
>> enable things like MMC, I2C, etc ...
>>
>> Signed-off-by: Guillaume La Roque <glaroque@baylibre.com>
> with the comments below addressed:
> Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
>
>> ---
>>  drivers/pinctrl/meson/pinctrl-meson.c | 102 ++++++++++++++++++++++++++
>>  drivers/pinctrl/meson/pinctrl-meson.h |  18 ++++-
>>  2 files changed, 119 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/pinctrl/meson/pinctrl-meson.c b/drivers/pinctrl/meson/pinctrl-meson.c
>> index a216a7537564..3da867c13f47 100644
>> --- a/drivers/pinctrl/meson/pinctrl-meson.c
>> +++ b/drivers/pinctrl/meson/pinctrl-meson.c
>> @@ -219,12 +219,56 @@ static int meson_pinconf_enable_bias(struct meson_pinctrl *pc, unsigned int pin,
>>         return 0;
>>  }
>>
>> +static int meson_pinconf_set_drive_strength(struct meson_pinctrl *pc,
>> +                                           unsigned int pin,
>> +                                           u16 drive_strength_ua)
>> +{
>> +       struct meson_bank *bank;
>> +       unsigned int reg, bit;
>> +       unsigned int ds_val;
> you can move ds_val to the line above
>
> [...]
>> +       if (!pc->reg_ds) {
>> +               dev_err(pc->dev, "drive-strength not supported\n");
> I'm getting this on one of my Meson8m2 boards:
> $ # cat /sys/kernel/debug/pinctrl/c1109880.pinctrl-pinctrl-meson/pinconf-pins
> ...
> [  874.748531] meson8-pinctrl c1109880.pinctrl: drive-strength not supported
> [  874.755278] meson8-pinctrl c1109880.pinctrl: drive-strength not supported
> [  874.762086] meson8-pinctrl c1109880.pinctrl: drive-strength not supported
> Pin config settings per pin
> Format: pin (name): configs
> pin 0 (GPIOX_0): input bias disabled
> pin 1 (GPIOX_1): input bias disabled
> pin 2 (GPIOX_2): input bias disabled
> ...
>
> I believe we are not supposed to complain when getting the
> drive-strength when reg_ds is absent.
> all pre-G12A SoCs don't have reg_ds, so we don't need to error-out in
> that case (because that's perfectly valid)
>
> [...]
>> +static int meson_pinconf_get_drive_strength(struct meson_pinctrl *pc,
>> +                                           unsigned int pin,
>> +                                           u16 *drive_strength_ua)
>> +{
>> +       struct meson_bank *bank;
>> +       unsigned int reg, bit;
>> +       unsigned int val;
>> +       int ret;
>> +
>> +       if (!pc->reg_ds) {
>> +               dev_err(pc->dev, "drive-strength not supported\n");
> based on your previous explanation (that you want to inform the .dts
> author that he's doing something wrong) I'm happy with this error if
> Linus W. doesn't veto this.
>
>
> Regards
> Martin


Guillaume


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[PATCH v3 6/6] pinctrl: meson: g12a: add DS bank value

[Guillaume La Roque]

add drive-strength bank register and bit value for G12A SoC

Signed-off-by: Guillaume La Roque <glaroque@baylibre.com>
---
 drivers/pinctrl/meson/pinctrl-meson-g12a.c | 36 +++++++++++-----------
 1 file changed, 18 insertions(+), 18 deletions(-)

diff --git a/drivers/pinctrl/meson/pinctrl-meson-g12a.c b/drivers/pinctrl/meson/pinctrl-meson-g12a.c
index d494492e98e9..3475cd7bd2af 100644
--- a/drivers/pinctrl/meson/pinctrl-meson-g12a.c
+++ b/drivers/pinctrl/meson/pinctrl-meson-g12a.c
@@ -1304,28 +1304,28 @@ static struct meson_pmx_func meson_g12a_aobus_functions[] = {
 };
 
 static struct meson_bank meson_g12a_periphs_banks[] = {
-	/* name  first  last  irq  pullen  pull  dir  out  in */
-	BANK("Z",    GPIOZ_0,    GPIOZ_15, 12, 27,
-	     4,  0,  4,  0,  12,  0,  13, 0,  14, 0),
-	BANK("H",    GPIOH_0,    GPIOH_8, 28, 36,
-	     3,  0,  3,  0,  9,  0,  10,  0,  11,  0),
-	BANK("BOOT", BOOT_0,     BOOT_15,  37, 52,
-	     0,  0,  0,  0,  0, 0,  1, 0,  2, 0),
-	BANK("C",    GPIOC_0,    GPIOC_7,  53, 60,
-	     1,  0,  1,  0,  3, 0,  4, 0,  5, 0),
-	BANK("A",    GPIOA_0,    GPIOA_15,  61, 76,
-	     5,  0,  5,  0,  16,  0,  17,  0,  18,  0),
-	BANK("X",    GPIOX_0,    GPIOX_19,   77, 96,
-	     2,  0,  2,  0,  6,  0,  7,  0,  8,  0),
+	/* name  first  last  irq  pullen  pull  dir  out  in  ds */
+	BANK_DS("Z",    GPIOZ_0,    GPIOZ_15, 12, 27,
+		4,  0,  4,  0,  12,  0,  13, 0,  14, 0, 5, 0),
+	BANK_DS("H",    GPIOH_0,    GPIOH_8, 28, 36,
+		3,  0,  3,  0,  9,  0,  10,  0,  11,  0, 4, 0),
+	BANK_DS("BOOT", BOOT_0,     BOOT_15,  37, 52,
+		0,  0,  0,  0,  0, 0,  1, 0,  2, 0, 0, 0),
+	BANK_DS("C",    GPIOC_0,    GPIOC_7,  53, 60,
+		1,  0,  1,  0,  3, 0,  4, 0,  5, 0, 1, 0),
+	BANK_DS("A",    GPIOA_0,    GPIOA_15,  61, 76,
+		5,  0,  5,  0,  16,  0,  17,  0,  18,  0, 6, 0),
+	BANK_DS("X",    GPIOX_0,    GPIOX_19,   77, 96,
+		2,  0,  2,  0,  6,  0,  7,  0,  8,  0, 2, 0),
 };
 
 static struct meson_bank meson_g12a_aobus_banks[] = {
-	/* name  first  last  irq  pullen  pull  dir  out  in  */
-	BANK("AO",   GPIOAO_0,  GPIOAO_11,  0, 11,
-	     3,  0,  2, 0,  0,  0,  4, 0,  1,  0),
+	/* name  first  last  irq  pullen  pull  dir  out  in  ds */
+	BANK_DS("AO", GPIOAO_0, GPIOAO_11, 0, 11, 3, 0, 2, 0, 0, 0, 4, 0, 1, 0,
+		0, 0),
 	/* GPIOE actually located in the AO bank */
-	BANK("E",   GPIOE_0,  GPIOE_2,   97, 99,
-	     3,  16,  2, 16,  0,  16,  4, 16,  1,  16),
+	BANK_DS("E", GPIOE_0, GPIOE_2, 97, 99, 3, 16, 2, 16, 0, 16, 4, 16, 1,
+		16, 1, 0),
 };
 
 static struct meson_pmx_bank meson_g12a_periphs_pmx_banks[] = {
-- 
2.17.1


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Re: [PATCH v3 6/6] pinctrl: meson: g12a: add DS bank value

[Martin Blumenstingl]

On Tue, May 7, 2019 at 1:57 PM Guillaume La Roque <glaroque@baylibre.com> wrote:
>
> add drive-strength bank register and bit value for G12A SoC
>
> Signed-off-by: Guillaume La Roque <glaroque@baylibre.com>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>

[...]
> +       /* name  first  last  irq  pullen  pull  dir  out  in  ds */
> +       BANK_DS("Z",    GPIOZ_0,    GPIOZ_15, 12, 27,
> +               4,  0,  4,  0,  12,  0,  13, 0,  14, 0, 5, 0),
> +       BANK_DS("H",    GPIOH_0,    GPIOH_8, 28, 36,
> +               3,  0,  3,  0,  9,  0,  10,  0,  11,  0, 4, 0),
a note for myself (because I keep forgetting this)
"5, 0" stands for:
- the register PAD_DS_REG5A as seen in the public S922X datasheet from
Hardkernel on page 224
- starting at bit 0

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Re: [PATCH v3 0/6] Add drive-strength in Meson pinctrl driver

[Jerome Brunet]

On Tue, 2019-05-07 at 13:57 +0200, Guillaume La Roque wrote:
> The purpose of this patchset is to add drive-strength support in meson pinconf
> driver. This is a new feature that was added on the g12a. It is critical for us
> to support this since many functions are failing with default pad drive-strength.
> 
> The value achievable by the SoC are 0.5mA, 2.5mA, 3mA and 4mA and the DT property
> 'drive-strength' is expressed in mA.
> So this patch add another generic property "drive-strength-uA". The change to do so
> would be minimal and could be benefit to other platforms later on.
> 
> Cheers
> Guillaume
> 
> Changes since v2:
> - update driver-strength-uA property to be compliant with DT documentation
> - rework patch series for better understanding
> - rework set_bias function
> 
> Changes since v1:
> - fix missing break
> - implement new pinctrl generic property "drive-strength-uA"
> 
> [1] https://lkml.kernel.org/r/20190314163725.7918-1-jbrunet@baylibre.com
> 
> 
> Guillaume La Roque (6):
>   dt-bindings: pinctrl: add a 'drive-strength-microamp' property
>   pinctrl: generic: add new 'drive-strength-microamp' property support
>   dt-bindings: pinctrl: meson: Add drive-strength-microamp property
>   pinctrl: meson: Rework enable/disable bias part
>   pinctrl: meson: add support of drive-strength-microamp
>   pinctrl: meson: g12a: add DS bank value
> 
>  .../bindings/pinctrl/meson,pinctrl.txt        |   4 +
>  .../bindings/pinctrl/pinctrl-bindings.txt     |   3 +
>  drivers/pinctrl/meson/pinctrl-meson-g12a.c    |  36 ++--
>  drivers/pinctrl/meson/pinctrl-meson.c         | 177 +++++++++++++++---
>  drivers/pinctrl/meson/pinctrl-meson.h         |  18 +-
>  drivers/pinctrl/pinconf-generic.c             |   2 +
>  include/linux/pinctrl/pinconf-generic.h       |   3 +
>  7 files changed, 195 insertions(+), 48 deletions(-)
> 

Tested-by: Jerome Brunet <jbrunet@baylibre.com>


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Re: [PATCH v3 0/6] Add drive-strength in Meson pinctrl driver

[Martin Blumenstingl]

On Tue, May 7, 2019 at 1:57 PM Guillaume La Roque <glaroque@baylibre.com> wrote:
>
> The purpose of this patchset is to add drive-strength support in meson pinconf
> driver. This is a new feature that was added on the g12a. It is critical for us
> to support this since many functions are failing with default pad drive-strength.
>
> The value achievable by the SoC are 0.5mA, 2.5mA, 3mA and 4mA and the DT property
> 'drive-strength' is expressed in mA.
> So this patch add another generic property "drive-strength-uA". The change to do so
> would be minimal and could be benefit to other platforms later on.
>
> Cheers
> Guillaume
>
> Changes since v2:
> - update driver-strength-uA property to be compliant with DT documentation
> - rework patch series for better understanding
> - rework set_bias function
>
> Changes since v1:
> - fix missing break
> - implement new pinctrl generic property "drive-strength-uA"
>
> [1] https://lkml.kernel.org/r/20190314163725.7918-1-jbrunet@baylibre.com
>
>
> Guillaume La Roque (6):
>   dt-bindings: pinctrl: add a 'drive-strength-microamp' property
>   pinctrl: generic: add new 'drive-strength-microamp' property support
>   dt-bindings: pinctrl: meson: Add drive-strength-microamp property
>   pinctrl: meson: Rework enable/disable bias part
>   pinctrl: meson: add support of drive-strength-microamp
>   pinctrl: meson: g12a: add DS bank value
>
>  .../bindings/pinctrl/meson,pinctrl.txt        |   4 +
>  .../bindings/pinctrl/pinctrl-bindings.txt     |   3 +
>  drivers/pinctrl/meson/pinctrl-meson-g12a.c    |  36 ++--
>  drivers/pinctrl/meson/pinctrl-meson.c         | 177 +++++++++++++++---
>  drivers/pinctrl/meson/pinctrl-meson.h         |  18 +-
>  drivers/pinctrl/pinconf-generic.c             |   2 +
>  include/linux/pinctrl/pinconf-generic.h       |   3 +
>  7 files changed, 195 insertions(+), 48 deletions(-)
I gave this a go on one of my Meson8m2 boards:
[Meson8m2 doesn't support drive strength and still boots without any
crashes or obvious regressions]
Tested-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>

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