[RFC 0/7] pinctrl-scmi: Add GPIO support

[RFC 0/7] pinctrl-scmi: Add GPIO support

[Dan Carpenter]

This patchset adds GPIO support to the SCMI pin control driver.
AKASHI Takahiro did some of that work earlier, but we decided to make
this a part of the pinctrl driver instead of a separate GPIO driver.

I'm not really sure how the device tree stuff wires it all in.  I've
been using a mock driver on SCP with virtio to test it.

Dan Carpenter (7):
  firmware: arm_scmi: move boiler plate code into the get info functions
  firmware: arm_scmi: add is_gpio() function
  pinctrl: introduce pinctrl_gpio_get_config()
  pinctrl-scmi: implement PIN_CONFIG_INPUT_VALUE
  pinctrl: Delete PIN_CONFIG_OUTPUT_IMPEDANCE_OHMS support
  pinctrl-scmi: Add GPIO support
  pinctrl-scmi: remove unused struct member

 drivers/firmware/arm_scmi/pinctrl.c     | 146 +++++++++-------
 drivers/pinctrl/core.c                  |  35 ++++
 drivers/pinctrl/pinctrl-scmi.c          | 213 +++++++++++++++++++++++-
 include/linux/pinctrl/consumer.h        |   9 +
 include/linux/pinctrl/pinconf-generic.h |   3 +
 include/linux/scmi_protocol.h           |   2 +
 6 files changed, 339 insertions(+), 69 deletions(-)

-- 
2.47.2

[RFC 3/7] pinctrl: introduce pinctrl_gpio_get_config()

[Dan Carpenter]

From: AKASHI Takahiro <takahiro.akashi@linaro.org>

This is a counterpart of pinctrl_gpio_set_config(), which will initially
be used to implement gpio_get interface in SCMI pinctrl based GPIO driver.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
---
 drivers/pinctrl/core.c           | 35 ++++++++++++++++++++++++++++++++
 include/linux/pinctrl/consumer.h |  9 ++++++++
 2 files changed, 44 insertions(+)

diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
index 4bdbf6bb26e2..4310f9e2118b 100644
--- a/drivers/pinctrl/core.c
+++ b/drivers/pinctrl/core.c
@@ -30,6 +30,7 @@
 #include <linux/pinctrl/consumer.h>
 #include <linux/pinctrl/devinfo.h>
 #include <linux/pinctrl/machine.h>
+#include <linux/pinctrl/pinconf.h>
 #include <linux/pinctrl/pinctrl.h>
 
 #include "core.h"
@@ -937,6 +938,40 @@ int pinctrl_gpio_set_config(struct gpio_chip *gc, unsigned int offset,
 }
 EXPORT_SYMBOL_GPL(pinctrl_gpio_set_config);
 
+/**
+ * pinctrl_gpio_get_config() - Get the config for a given GPIO pin
+ * @gc: GPIO chip structure from the GPIO subsystem
+ * @offset: hardware offset of the GPIO relative to the controller
+  * @config: the configuration to query.  On success it holds the result
+ */
+int pinctrl_gpio_get_config(struct gpio_chip *gc, unsigned int offset, unsigned long *config)
+{
+	struct pinctrl_gpio_range *range;
+	const struct pinconf_ops *ops;
+	struct pinctrl_dev *pctldev;
+	int ret, pin;
+
+	ret = pinctrl_get_device_gpio_range(gc, offset, &pctldev, &range);
+	if (ret)
+		return ret;
+
+	ops = pctldev->desc->confops;
+	if (!ops || !ops->pin_config_get)
+		return -EINVAL;
+
+	mutex_lock(&pctldev->mutex);
+	pin = gpio_to_pin(range, gc, offset);
+	ret = ops->pin_config_get(pctldev, pin, config);
+	mutex_unlock(&pctldev->mutex);
+
+	if (ret)
+		return ret;
+
+	*config = pinconf_to_config_argument(*config);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pinctrl_gpio_get_config);
+
 static struct pinctrl_state *find_state(struct pinctrl *p,
 					const char *name)
 {
diff --git a/include/linux/pinctrl/consumer.h b/include/linux/pinctrl/consumer.h
index 73de70362b98..e5815b3382dc 100644
--- a/include/linux/pinctrl/consumer.h
+++ b/include/linux/pinctrl/consumer.h
@@ -35,6 +35,8 @@ int pinctrl_gpio_direction_output(struct gpio_chip *gc,
 				  unsigned int offset);
 int pinctrl_gpio_set_config(struct gpio_chip *gc, unsigned int offset,
 				unsigned long config);
+int pinctrl_gpio_get_config(struct gpio_chip *gc, unsigned int offset,
+			    unsigned long *config);
 
 struct pinctrl * __must_check pinctrl_get(struct device *dev);
 void pinctrl_put(struct pinctrl *p);
@@ -96,6 +98,13 @@ pinctrl_gpio_direction_output(struct gpio_chip *gc, unsigned int offset)
 	return 0;
 }
 
+static inline int
+pinctrl_gpio_get_config(struct gpio_chip *gc, unsigned int offset,
+			unsigned long *config)
+{
+	return 0;
+}
+
 static inline int
 pinctrl_gpio_set_config(struct gpio_chip *gc, unsigned int offset,
 			    unsigned long config)
-- 
2.47.2

[RFC 4/7] pinctrl-scmi: add PIN_CONFIG_INPUT_VALUE

[Dan Carpenter]

In SCMI the value of the pin is just another configuration option.  Add
this as an option in the pin_config_param enum and creating a mapping to
SCMI_PIN_INPUT_VALUE in pinctrl_scmi_map_pinconf_type()

Since this is an RFC patch, I'm going to comment that I think the SCMI
pinctrl driver misuses the PIN_CONFIG_OUTPUT enum.  It should be for
enabling and disabling output on pins which can serve as both input and
output.  Enabling it is supposed to write a 1 and disabling it is
supposed to write a 0 but we use that side effect to write 1s and 0s.  I
did't change this because it would break userspace but I'd like to add a
PIN_CONFIG_OUTPUT_VALUE enum as well and use that in the GPIO driver.
But in this patchset I just use PIN_CONFIG_OUTPUT.

Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
---
 drivers/pinctrl/pinctrl-scmi.c          | 3 +++
 include/linux/pinctrl/pinconf-generic.h | 3 +++
 2 files changed, 6 insertions(+)

diff --git a/drivers/pinctrl/pinctrl-scmi.c b/drivers/pinctrl/pinctrl-scmi.c
index df4bbcd7d1d5..362a6d2c3c68 100644
--- a/drivers/pinctrl/pinctrl-scmi.c
+++ b/drivers/pinctrl/pinctrl-scmi.c
@@ -250,6 +250,9 @@ static int pinctrl_scmi_map_pinconf_type(enum pin_config_param param,
 	case PIN_CONFIG_INPUT_SCHMITT_ENABLE:
 		*type = SCMI_PIN_INPUT_MODE;
 		break;
+	case PIN_CONFIG_INPUT_VALUE:
+		*type = SCMI_PIN_INPUT_VALUE;
+		break;
 	case PIN_CONFIG_MODE_LOW_POWER:
 		*type = SCMI_PIN_LOW_POWER_MODE;
 		break;
diff --git a/include/linux/pinctrl/pinconf-generic.h b/include/linux/pinctrl/pinconf-generic.h
index 1bcf071b860e..b37838171581 100644
--- a/include/linux/pinctrl/pinconf-generic.h
+++ b/include/linux/pinctrl/pinconf-generic.h
@@ -83,6 +83,8 @@ struct pinctrl_map;
  *      schmitt-trigger mode is disabled.
  * @PIN_CONFIG_INPUT_SCHMITT_UV: this will configure an input pin to run in
  *	schmitt-trigger mode. The argument is in uV.
+ * @PIN_CONFIG_INPUT_VALUE: This is used in SCMI to read the value from the
+ *	pin.
  * @PIN_CONFIG_MODE_LOW_POWER: this will configure the pin for low power
  *	operation, if several modes of operation are supported these can be
  *	passed in the argument on a custom form, else just use argument 1
@@ -135,6 +137,7 @@ enum pin_config_param {
 	PIN_CONFIG_INPUT_SCHMITT,
 	PIN_CONFIG_INPUT_SCHMITT_ENABLE,
 	PIN_CONFIG_INPUT_SCHMITT_UV,
+	PIN_CONFIG_INPUT_VALUE,
 	PIN_CONFIG_MODE_LOW_POWER,
 	PIN_CONFIG_MODE_PWM,
 	PIN_CONFIG_OUTPUT,
-- 
2.47.2

[RFC 5/7] pinctrl: Delete PIN_CONFIG_OUTPUT_IMPEDANCE_OHMS support

[Dan Carpenter]

The argument for PIN_CONFIG_OUTPUT_IMPEDANCE_OHMS is supposed to
be expressed in terms of ohms.  But the pinctrl-scmi driver was
implementing it the same as PIN_CONFIG_OUTPUT and writing either a
zero or one to the pin.

The SCMI protocol doesn't have an support configuration type so just
delete this code instead of fixing it.

Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
---
 drivers/pinctrl/pinctrl-scmi.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/pinctrl/pinctrl-scmi.c b/drivers/pinctrl/pinctrl-scmi.c
index 362a6d2c3c68..f369f0354e43 100644
--- a/drivers/pinctrl/pinctrl-scmi.c
+++ b/drivers/pinctrl/pinctrl-scmi.c
@@ -262,9 +262,6 @@ static int pinctrl_scmi_map_pinconf_type(enum pin_config_param param,
 	case PIN_CONFIG_OUTPUT_ENABLE:
 		*type = SCMI_PIN_OUTPUT_MODE;
 		break;
-	case PIN_CONFIG_OUTPUT_IMPEDANCE_OHMS:
-		*type = SCMI_PIN_OUTPUT_VALUE;
-		break;
 	case PIN_CONFIG_POWER_SOURCE:
 		*type = SCMI_PIN_POWER_SOURCE;
 		break;
-- 
2.47.2

[RFC 6/7] pinctrl-scmi: Add GPIO support

[Dan Carpenter]

This adds GPIO support to the SCMI pin controller driver.  It's an RFC
patch because I'm not really sure how these are used and so I don't
know how they should be configured via devicetree.  I've labeled the
places where I think devicetree configuration would go with a FIXME.

This driver was based on work from Takahiro AKASHI.

Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
---
 drivers/pinctrl/pinctrl-scmi.c | 206 ++++++++++++++++++++++++++++++++-
 1 file changed, 205 insertions(+), 1 deletion(-)

diff --git a/drivers/pinctrl/pinctrl-scmi.c b/drivers/pinctrl/pinctrl-scmi.c
index f369f0354e43..40b432aa4756 100644
--- a/drivers/pinctrl/pinctrl-scmi.c
+++ b/drivers/pinctrl/pinctrl-scmi.c
@@ -6,6 +6,7 @@
  * Copyright 2024 NXP
  */
 
+#include <linux/bitmap.h>
 #include <linux/device.h>
 #include <linux/err.h>
 #include <linux/errno.h>
@@ -16,6 +17,9 @@
 #include <linux/slab.h>
 #include <linux/types.h>
 
+#include <linux/gpio/driver.h>
+
+#include <linux/pinctrl/consumer.h>
 #include <linux/pinctrl/machine.h>
 #include <linux/pinctrl/pinconf.h>
 #include <linux/pinctrl/pinconf-generic.h>
@@ -42,6 +46,7 @@ struct scmi_pinctrl {
 	unsigned int nr_functions;
 	struct pinctrl_pin_desc *pins;
 	unsigned int nr_pins;
+	struct gpio_chip *gc;
 };
 
 static int pinctrl_scmi_get_groups_count(struct pinctrl_dev *pctldev)
@@ -505,6 +510,197 @@ static int pinctrl_scmi_get_pins(struct scmi_pinctrl *pmx,
 	return 0;
 }
 
+static int pinctrl_gpio_init_valid_mask(struct gpio_chip *gc,
+				    unsigned long *valid_mask,
+				    unsigned int ngpios)
+{
+	bitmap_fill(valid_mask, ngpios);
+	return 0;
+}
+
+static int pinctrl_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
+{
+	unsigned long config;
+	bool in, out;
+	int ret;
+
+	config = PIN_CONFIG_INPUT_ENABLE;
+	ret = pinctrl_gpio_get_config(gc, offset, &config);
+	if (ret)
+		return ret;
+	in = config;
+
+	config = PIN_CONFIG_OUTPUT_ENABLE;
+	ret = pinctrl_gpio_get_config(gc, offset, &config);
+	if (ret)
+		return ret;
+	out = config;
+
+	/* Consistency check - in theory both can be enabled! */
+	if (in && !out)
+		return GPIO_LINE_DIRECTION_IN;
+	if (!in && out)
+		return GPIO_LINE_DIRECTION_OUT;
+
+	return -EINVAL;
+}
+
+static int pinctrl_gpio_direction_output_wrapper(struct gpio_chip *gc,
+						 unsigned int offset, int val)
+{
+	return pinctrl_gpio_direction_output(gc, offset);
+}
+
+static int pinctrl_gpio_get(struct gpio_chip *gc, unsigned int offset)
+{
+	unsigned long config;
+	int ret;
+
+	config = PIN_CONFIG_INPUT_VALUE;
+	ret = pinctrl_gpio_get_config(gc, offset, &config);
+	if (ret)
+		return ret;
+
+	return config;
+}
+
+static void pinctrl_gpio_set(struct gpio_chip *gc, unsigned int offset, int val)
+{
+	unsigned long config;
+
+	config = PIN_CONF_PACKED(PIN_CONFIG_OUTPUT, val);
+	pinctrl_gpio_set_config(gc, offset, config);
+}
+
+static int pinctrl_gc_to_func(struct gpio_chip *gc)
+{
+	struct scmi_pinctrl *pmx = gpiochip_get_data(gc);
+
+	return (gc - pmx->gc);
+}
+
+static int gpio_add_pin_ranges(struct gpio_chip *gc)
+{
+	struct scmi_pinctrl *pmx = gpiochip_get_data(gc);
+	const char * const *p_groups;
+	unsigned int n_groups;
+	int func = pinctrl_gc_to_func(gc);
+	int group;
+	int ret;
+
+	ret = pmx->pctl_desc.pmxops->get_function_groups(pmx->pctldev, func, &p_groups, &n_groups);
+	if (ret)
+		return ret;
+
+	// FIXME: fix the correct group from the device tree
+	for (group = 0; group < n_groups; group++) {
+		ret = gpiochip_add_pingroup_range(gc, pmx->pctldev, 0, p_groups[group]);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int get_nr_pins_in_function(struct scmi_pinctrl *pmx, int func)
+{
+	const char * const *pin_groups;
+	unsigned int n_groups;
+	const unsigned int *pins;
+	unsigned int n_pins;
+	int total = 0;
+	int i, ret;
+
+	// FIXME: get the correct number of gc.ngpio
+	// Find the right group from the device tree
+	ret = pmx->pctl_desc.pmxops->get_function_groups(pmx->pctldev, func, &pin_groups, &n_groups);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < n_groups; i++) {
+		ret = pinctrl_get_group_pins(pmx->pctldev, pin_groups[i], &pins, &n_pins);
+		if (ret)
+			return ret;
+		total += n_pins;
+	}
+
+	return total;
+}
+
+static int register_scmi_pinctrl_gpio_handler(struct device *dev, struct scmi_pinctrl *pmx)
+{
+	struct fwnode_handle *gpio = NULL;
+	int ret, i;
+
+	gpio = fwnode_get_named_child_node(dev->fwnode, "gpio");
+	if (!gpio)
+		return 0;
+
+	pmx->gc = devm_kcalloc(dev, pmx->nr_functions, sizeof(*pmx->gc), GFP_KERNEL);
+	if (!pmx->gc)
+		return -ENOMEM;
+
+	for (i = 0; i < pmx->nr_functions; i++) {
+		const char *fn_name;
+
+		ret = pinctrl_ops->is_gpio(pmx->ph, i, FUNCTION_TYPE);
+		if (ret < 0)
+			return ret;
+		if (ret == false)
+			continue;
+
+		ret = pinctrl_ops->name_get(pmx->ph, i, FUNCTION_TYPE, &fn_name);
+		if (ret)
+			return ret;
+
+		pmx->gc[i].label = devm_kasprintf(dev, GFP_KERNEL, "%s", fn_name);
+		if (!pmx->gc[i].label)
+			return -ENOMEM;
+
+		pmx->gc[i].owner = THIS_MODULE;
+		pmx->gc[i].get = pinctrl_gpio_get;
+		pmx->gc[i].set = pinctrl_gpio_set;
+		pmx->gc[i].get_direction = pinctrl_gpio_get_direction;
+		pmx->gc[i].direction_input = pinctrl_gpio_direction_input;
+		pmx->gc[i].direction_output = pinctrl_gpio_direction_output_wrapper;
+		pmx->gc[i].add_pin_ranges = gpio_add_pin_ranges;
+
+		// FIXME: verify that this is correct
+		pmx->gc[i].can_sleep = true;
+
+		ret = get_nr_pins_in_function(pmx, i);
+		if (ret < 0)
+			return ret;
+		pmx->gc[i].ngpio = ret;
+
+		pmx->gc[i].init_valid_mask = pinctrl_gpio_init_valid_mask;
+		pmx->gc[i].parent = dev;
+		pmx->gc[i].base = -1;
+	}
+
+	return 0;
+}
+
+static int scmi_gpiochip_add_data(struct device *dev, struct scmi_pinctrl *pmx)
+{
+	int ret;
+	int i;
+
+	for (i = 0; i < pmx->nr_functions; i++) {
+		ret = pinctrl_ops->is_gpio(pmx->ph, i, FUNCTION_TYPE);
+		if (ret < 0)
+			return ret;
+		if (ret == false)
+			continue;
+
+		ret = devm_gpiochip_add_data(dev, &pmx->gc[i], pmx);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
 static const char * const scmi_pinctrl_blocklist[] = {
 	"fsl,imx95",
 	NULL
@@ -558,7 +754,15 @@ static int scmi_pinctrl_probe(struct scmi_device *sdev)
 	if (!pmx->functions)
 		return -ENOMEM;
 
-	return pinctrl_enable(pmx->pctldev);
+	ret = register_scmi_pinctrl_gpio_handler(dev, pmx);
+	if (ret)
+		return ret;
+
+	ret = pinctrl_enable(pmx->pctldev);
+	if (ret)
+		return ret;
+
+	return scmi_gpiochip_add_data(dev, pmx);
 }
 
 static const struct scmi_device_id scmi_id_table[] = {
-- 
2.47.2

[RFC 7/7] pinctrl-scmi: remove unused struct member

[Dan Carpenter]

The ->nr_pins is not used so delete that.

Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
---
 drivers/pinctrl/pinctrl-scmi.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/pinctrl/pinctrl-scmi.c b/drivers/pinctrl/pinctrl-scmi.c
index 40b432aa4756..d1f3c126c3cb 100644
--- a/drivers/pinctrl/pinctrl-scmi.c
+++ b/drivers/pinctrl/pinctrl-scmi.c
@@ -45,7 +45,6 @@ struct scmi_pinctrl {
 	struct pinfunction *functions;
 	unsigned int nr_functions;
 	struct pinctrl_pin_desc *pins;
-	unsigned int nr_pins;
 	struct gpio_chip *gc;
 };
 
-- 
2.47.2

Re: [RFC 3/7] pinctrl: introduce pinctrl_gpio_get_config()

[ALOK TIWARI]

Hi Dan,


Thanks for your patch.

On 05-05-2025 17:07, Dan Carpenter wrote:
> From: AKASHI Takahiro <takahiro.akashi@linaro.org>
> 
> This is a counterpart of pinctrl_gpio_set_config(), which will initially
> be used to implement gpio_get interface in SCMI pinctrl based GPIO driver.
> 
> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
> ---
>   drivers/pinctrl/core.c           | 35 ++++++++++++++++++++++++++++++++
>   include/linux/pinctrl/consumer.h |  9 ++++++++
>   2 files changed, 44 insertions(+)
> 
> diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
> index 4bdbf6bb26e2..4310f9e2118b 100644
> --- a/drivers/pinctrl/core.c
> +++ b/drivers/pinctrl/core.c
> @@ -30,6 +30,7 @@
>   #include <linux/pinctrl/consumer.h>
>   #include <linux/pinctrl/devinfo.h>
>   #include <linux/pinctrl/machine.h>
> +#include <linux/pinctrl/pinconf.h>
>   #include <linux/pinctrl/pinctrl.h>
>   
>   #include "core.h"
> @@ -937,6 +938,40 @@ int pinctrl_gpio_set_config(struct gpio_chip *gc, unsigned int offset,
>   }
>   EXPORT_SYMBOL_GPL(pinctrl_gpio_set_config);
>   
> +/**
> + * pinctrl_gpio_get_config() - Get the config for a given GPIO pin
> + * @gc: GPIO chip structure from the GPIO subsystem
> + * @offset: hardware offset of the GPIO relative to the controller
> +  * @config: the configuration to query.  On success it holds the result

remove extra ' ' before * @config and On.

> + */
> +int pinctrl_gpio_get_config(struct gpio_chip *gc, unsigned int offset, unsigned long *config)
> +{
> +	struct pinctrl_gpio_range *range;
> +	const struct pinconf_ops *ops;
> +	struct pinctrl_dev *pctldev;
> +	int ret, pin;
> +
> +	ret = pinctrl_get_device_gpio_range(gc, offset, &pctldev, &range);
> +	if (ret)
> +		return ret;
> +
> +	ops = pctldev->desc->confops;
> +	if (!ops || !ops->pin_config_get)
> +		return -EINVAL;
> +
> +	mutex_lock(&pctldev->mutex);
> +	pin = gpio_to_pin(range, gc, offset);
> +	ret = ops->pin_config_get(pctldev, pin, config);

can we add reason here, as now we are not calling pin_config_get_for_pin()

https://lore.kernel.org/all/20231002021602.260100-3-takahiro.akashi@linaro.org/

> +	mutex_unlock(&pctldev->mutex);
> +
> +	if (ret)
> +		return ret;
> +
> +	*config = pinconf_to_config_argument(*config);

a '\n' before return.

> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(pinctrl_gpio_get_config);
> +
>   static struct pinctrl_state *find_state(struct pinctrl *p,
>   					const char *name)
>   {


Thanks,
Alok

Re: [RFC 0/7] pinctrl-scmi: Add GPIO support

[Khaled Ali Ahmed]

Good morning Dan,
Regarding the scmi_pinctrl stack design, what we have made in the SW is that the stack can communicate with multiple drivers with only two constraints:
1- Implement the interfacing APIs. which is declared by the object "struct mod_pinctrl_drv_api".
2- Integrate itself with the scmi_pinctrl HAL or backend as you prefer.
Also, we have an example I can discuss if you like.

thanks in advance

________________________________________
From: Dan Carpenter <dan.carpenter@linaro.org>
Sent: Monday, May 5, 2025 12:36 PM
To: Linus Walleij <linus.walleij@linaro.org>
Cc: arm-scmi@vger.kernel.org <arm-scmi@vger.kernel.org>; Bartosz Golaszewski <brgl@bgdev.pl>; Cristian Marussi <Cristian.Marussi@arm.com>; linux-arm-kernel@lists.infradead.org <linux-arm-kernel@lists.infradead.org>; linux-gpio@vger.kernel.org <linux-gpio@vger.kernel.org>; linux-kernel@vger.kernel.org <linux-kernel@vger.kernel.org>; Sudeep Holla <Sudeep.Holla@arm.com>; Vincent Guittot <vincent.guittot@linaro.org>; Khaled Ali Ahmed <Khaled.AliAhmed@arm.com>; Girish Pathak <Girish.Pathak@arm.com>; Peng Fan <peng.fan@nxp.com>; Takahiro AKASHI <akashi.tkhro@gmail.com>
Subject: [RFC 0/7] pinctrl-scmi: Add GPIO support
 
This patchset adds GPIO support to the SCMI pin control driver.
AKASHI Takahiro did some of that work earlier, but we decided to make
this a part of the pinctrl driver instead of a separate GPIO driver.

I'm not really sure how the device tree stuff wires it all in.  I've
been using a mock driver on SCP with virtio to test it.

Dan Carpenter (7):
  firmware: arm_scmi: move boiler plate code into the get info functions
  firmware: arm_scmi: add is_gpio() function
  pinctrl: introduce pinctrl_gpio_get_config()
  pinctrl-scmi: implement PIN_CONFIG_INPUT_VALUE
  pinctrl: Delete PIN_CONFIG_OUTPUT_IMPEDANCE_OHMS support
  pinctrl-scmi: Add GPIO support
  pinctrl-scmi: remove unused struct member

 drivers/firmware/arm_scmi/pinctrl.c     | 146 +++++++++-------
 drivers/pinctrl/core.c                  |  35 ++++
 drivers/pinctrl/pinctrl-scmi.c          | 213 +++++++++++++++++++++++-
 include/linux/pinctrl/consumer.h        |   9 +
 include/linux/pinctrl/pinconf-generic.h |   3 +
 include/linux/scmi_protocol.h           |   2 +
 6 files changed, 339 insertions(+), 69 deletions(-)

--
2.47.2

Re: [RFC 3/7] pinctrl: introduce pinctrl_gpio_get_config()

[Dan Carpenter]

On Mon, May 05, 2025 at 10:00:35PM +0530, ALOK TIWARI wrote:
> > +int pinctrl_gpio_get_config(struct gpio_chip *gc, unsigned int offset, unsigned long *config)
> > +{
> > +	struct pinctrl_gpio_range *range;
> > +	const struct pinconf_ops *ops;
> > +	struct pinctrl_dev *pctldev;
> > +	int ret, pin;
> > +
> > +	ret = pinctrl_get_device_gpio_range(gc, offset, &pctldev, &range);
> > +	if (ret)
> > +		return ret;
> > +
> > +	ops = pctldev->desc->confops;
> > +	if (!ops || !ops->pin_config_get)
> > +		return -EINVAL;
> > +
> > +	mutex_lock(&pctldev->mutex);
> > +	pin = gpio_to_pin(range, gc, offset);
> > +	ret = ops->pin_config_get(pctldev, pin, config);
> 
> can we add reason here, as now we are not calling pin_config_get_for_pin()
> 
> https://lore.kernel.org/all/20231002021602.260100-3-takahiro.akashi@linaro.org/
> 

I don't even know why I changed that.  Using pin_config_get_for_pin()
works and it's cleaner.

regards,
dan carpenter