[PATCH v4 0/7] pinctrl: Add generic pinctrl for board-level mux chips

[PATCH v4 0/7] pinctrl: Add generic pinctrl for board-level mux chips

[Frank Li]

Add a generic pinctrl binding for board-level pinmux chips that are
controlled through the multiplexer subsystem.

On some boards, especially development boards, external mux chips are used
to switch SoC signals between different peripherals (e.g. MMC and UART).
The mux select lines are often driven by a GPIO expander over I2C,
as illustrated below:

        ┌──────┐      ┌─────┐
        │ SOC  │      │     │    ┌───────┐
        │      │      │     │───►│ MMC   │
        │      │      │ MUX │    └───────┘
        │      ├─────►│     │    ┌───────┐
        │      │      │     │───►│ UART  │
        │      │      └─────┘    └───────┘
        │      │         ▲
        │      │    ┌────┴──────────────┐
        │ I2C  ├───►│ GPIO Expander     │
        └──────┘    └───────────────────┘

Traditionally, gpio-hog is used to configure the onboard mux at boot.
However, the GPIO expander may probe later than consumer devices such as
MMC. As a result, the MUX might not be configured when the peripheral
driver probes, leading to initialization failures or data transfer errors.

Introduce a generic pinctrl binding that models the board-level MUX as a
pin control provider and builds proper device links between the MUX, its
GPIO controller, and peripheral devices. This ensures correct probe
ordering and reliable mux configuration.

The implementation leverages the standard multiplexer subsystem, which
provides broad support for onboard mux controllers and avoids the need for
per-driver custom MUX handling

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
Changes in v4:
- use Conor Dooley suggest to extract funciton pinctrl_generic_pins_to_map()
- Link to v3: https://lore.kernel.org/r/20260311-pinctrl-mux-v3-0-236b1c17bf9b@nxp.com

Changes in v3:
- collect rob's review tag for binding
- extend and use pinctrl_generic_pins_function_dt_node_to_map()
- add judgement about
commit 2243a87d90b42eb38bc281957df3e57c712b5e56
"pinctrl: avoid duplicated calling enable_pinmux_setting for a pin"

which call pinmux_disable_setting() before pinmux_enable_setting() when
switch state. It is actually what wanted. Previous remove .disable() to
avoid hardware glitch when switch state.

New .release_mux() call intent just release software resource, like lock,
don't touch hardware register. No glitch involve. Comments already added

Linus Walleij:
  I hope this answer all of your questions. If I missed, let me know

- Link to v2: https://lore.kernel.org/r/20260225-pinctrl-mux-v2-0-1436a25fa454@nxp.com

Changes in v2:
- Add release_mux callback,
  test insmod/rmmod, mux_state_(de)select() called.
- Link to v1: https://lore.kernel.org/r/20260219-pinctrl-mux-v1-0-678d21637788@nxp.com

---
Frank Li (7):
      mux: add devm_mux_control_get_from_np() to get mux from child node
      dt-bindings: pinctrl: Add generic pinctrl for board-level mux chips
      pinctrl: extract pinctrl_generic_to_map() from pinctrl_generic_pins_function_dt_node_to_map()
      pinctrl: add optional .release_mux() callback
      pinctrl: add generic board-level pinctrl driver using mux framework
      arm64: dts: imx8mp-evk: add board-level mux for CAN2 and MICFIL
      arm64: dts: imx8mp-evk: add flexcan2 overlay file

 .../bindings/pinctrl/pinctrl-multiplexer.yaml      |  57 ++++++
 .../devicetree/bindings/pinctrl/pinctrl.yaml       |   2 +-
 arch/arm64/boot/dts/freescale/Makefile             |   4 +
 .../boot/dts/freescale/imx8mp-evk-flexcan2.dtso    |  15 ++
 arch/arm64/boot/dts/freescale/imx8mp-evk.dts       |  23 ++-
 drivers/mux/core.c                                 |  40 +++--
 drivers/pinctrl/Kconfig                            |   9 +
 drivers/pinctrl/Makefile                           |   1 +
 drivers/pinctrl/pinconf.h                          |  18 ++
 drivers/pinctrl/pinctrl-generic-mux.c              | 197 +++++++++++++++++++++
 drivers/pinctrl/pinctrl-generic.c                  |  91 ++++++----
 drivers/pinctrl/pinmux.c                           |   5 +
 include/linux/mux/consumer.h                       |  16 +-
 include/linux/pinctrl/pinmux.h                     |   5 +
 14 files changed, 425 insertions(+), 58 deletions(-)
---
base-commit: ff76d257e86235eb07ef33db8644a517c48d1c3f
change-id: 20260213-pinctrl-mux-df9c5b661540

Best regards,
--
Frank Li <Frank.Li@nxp.com>

[PATCH v4 1/7] mux: add devm_mux_control_get_from_np() to get mux from child node

[Frank Li]

Add new API devm_mux_control_get_from_np() to retrieve a mux control from
a specified child device node.

Make devm_mux_control_get() call devm_mux_control_get_from_np() with a NULL
node parameter, which defaults to using the device's own of_node.

Support the following DT schema:

pinctrl@0 {
    uart-func {
            mux-state = <&mux_chip 0>;
    };

    spi-func {
            mux-state = <&mux_chip 1>;
    };
};

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
change from v1 to v4
- none
---
 drivers/mux/core.c           | 40 ++++++++++++++++++++++++----------------
 include/linux/mux/consumer.h | 16 ++++++++++++----
 2 files changed, 36 insertions(+), 20 deletions(-)

diff --git a/drivers/mux/core.c b/drivers/mux/core.c
index a3840fe0995fe0125432d34edd8ab0f2cd1a6e9a..bdd959389b4ee1b0b8a7367fadf2c148c8f2f0b1 100644
--- a/drivers/mux/core.c
+++ b/drivers/mux/core.c
@@ -522,13 +522,15 @@ static struct mux_chip *of_find_mux_chip_by_node(struct device_node *np)
  * @mux_name: The name identifying the mux-control.
  * @state: Pointer to where the requested state is returned, or NULL when
  *         the required multiplexer states are handled by other means.
+ * @node: the device nodes, use dev->of_node if it is NULL.
  *
  * Return: A pointer to the mux-control, or an ERR_PTR with a negative errno.
  */
 static struct mux_control *mux_get(struct device *dev, const char *mux_name,
-				   unsigned int *state)
+				   unsigned int *state,
+				   struct device_node *node)
 {
-	struct device_node *np = dev->of_node;
+	struct device_node *np = node ? node : dev->of_node;
 	struct of_phandle_args args;
 	struct mux_chip *mux_chip;
 	unsigned int controller;
@@ -617,7 +619,7 @@ static struct mux_control *mux_get(struct device *dev, const char *mux_name,
  */
 struct mux_control *mux_control_get(struct device *dev, const char *mux_name)
 {
-	return mux_get(dev, mux_name, NULL);
+	return mux_get(dev, mux_name, NULL, NULL);
 }
 EXPORT_SYMBOL_GPL(mux_control_get);
 
@@ -641,15 +643,17 @@ static void devm_mux_control_release(struct device *dev, void *res)
 }
 
 /**
- * devm_mux_control_get() - Get the mux-control for a device, with resource
- *			    management.
+ * devm_mux_control_get_from_np() - Get the mux-control for a device, with
+ *				    resource management.
  * @dev: The device that needs a mux-control.
  * @mux_name: The name identifying the mux-control.
+ * @np: the device nodes, use dev->of_node if it is NULL.
  *
  * Return: Pointer to the mux-control, or an ERR_PTR with a negative errno.
  */
-struct mux_control *devm_mux_control_get(struct device *dev,
-					 const char *mux_name)
+struct mux_control *
+devm_mux_control_get_from_np(struct device *dev, const char *mux_name,
+			     struct device_node *np)
 {
 	struct mux_control **ptr, *mux;
 
@@ -668,16 +672,18 @@ struct mux_control *devm_mux_control_get(struct device *dev,
 
 	return mux;
 }
-EXPORT_SYMBOL_GPL(devm_mux_control_get);
+EXPORT_SYMBOL_GPL(devm_mux_control_get_from_np);
 
 /*
  * mux_state_get() - Get the mux-state for a device.
  * @dev: The device that needs a mux-state.
  * @mux_name: The name identifying the mux-state.
+ * @np: the device nodes, use dev->of_node if it is NULL.
  *
  * Return: A pointer to the mux-state, or an ERR_PTR with a negative errno.
  */
-static struct mux_state *mux_state_get(struct device *dev, const char *mux_name)
+static struct mux_state *
+mux_state_get(struct device *dev, const char *mux_name, struct device_node *np)
 {
 	struct mux_state *mstate;
 
@@ -685,7 +691,7 @@ static struct mux_state *mux_state_get(struct device *dev, const char *mux_name)
 	if (!mstate)
 		return ERR_PTR(-ENOMEM);
 
-	mstate->mux = mux_get(dev, mux_name, &mstate->state);
+	mstate->mux = mux_get(dev, mux_name, &mstate->state, np);
 	if (IS_ERR(mstate->mux)) {
 		int err = PTR_ERR(mstate->mux);
 
@@ -716,15 +722,17 @@ static void devm_mux_state_release(struct device *dev, void *res)
 }
 
 /**
- * devm_mux_state_get() - Get the mux-state for a device, with resource
- *			  management.
+ * devm_mux_state_get_from_np() - Get the mux-state for a device, with resource
+ *				  management.
  * @dev: The device that needs a mux-control.
  * @mux_name: The name identifying the mux-control.
+ * @np: the device nodes, use dev->of_node if it is NULL.
  *
  * Return: Pointer to the mux-state, or an ERR_PTR with a negative errno.
  */
-struct mux_state *devm_mux_state_get(struct device *dev,
-				     const char *mux_name)
+struct mux_state *
+devm_mux_state_get_from_np(struct device *dev, const char *mux_name,
+			   struct device_node *np)
 {
 	struct mux_state **ptr, *mstate;
 
@@ -732,7 +740,7 @@ struct mux_state *devm_mux_state_get(struct device *dev,
 	if (!ptr)
 		return ERR_PTR(-ENOMEM);
 
-	mstate = mux_state_get(dev, mux_name);
+	mstate = mux_state_get(dev, mux_name, np);
 	if (IS_ERR(mstate)) {
 		devres_free(ptr);
 		return mstate;
@@ -743,7 +751,7 @@ struct mux_state *devm_mux_state_get(struct device *dev,
 
 	return mstate;
 }
-EXPORT_SYMBOL_GPL(devm_mux_state_get);
+EXPORT_SYMBOL_GPL(devm_mux_state_get_from_np);
 
 /*
  * Using subsys_initcall instead of module_init here to try to ensure - for
diff --git a/include/linux/mux/consumer.h b/include/linux/mux/consumer.h
index 2e25c838f8312532040441ee618424b76378aad7..6300e091035323dd6158d52a55a109d43ef120aa 100644
--- a/include/linux/mux/consumer.h
+++ b/include/linux/mux/consumer.h
@@ -56,9 +56,17 @@ int mux_state_deselect(struct mux_state *mstate);
 struct mux_control *mux_control_get(struct device *dev, const char *mux_name);
 void mux_control_put(struct mux_control *mux);
 
-struct mux_control *devm_mux_control_get(struct device *dev,
-					 const char *mux_name);
-struct mux_state *devm_mux_state_get(struct device *dev,
-				     const char *mux_name);
+struct mux_control *
+devm_mux_control_get_from_np(struct device *dev, const char *mux_name,
+			     struct device_node *np);
+
+#define devm_mux_control_get(dev, mux_name)		\
+	devm_mux_control_get_from_np(dev, mux_name, NULL)
+
+struct mux_state *
+devm_mux_state_get_from_np(struct device *dev, const char *mux_name,
+			   struct device_node *np);
+#define devm_mux_state_get(dev, mux_name)		\
+	devm_mux_state_get_from_np(dev, mux_name, NULL)
 
 #endif /* _LINUX_MUX_CONSUMER_H */

-- 
2.43.0

[PATCH v4 2/7] dt-bindings: pinctrl: Add generic pinctrl for board-level mux chips

[Frank Li]

Add a generic pinctrl binding for board-level pinmux chips that are
controlled through the multiplexer subsystem.

On some boards, especially development boards, external mux chips are used
to switch SoC signals between different peripherals (e.g. MMC and UART).
The mux select lines are often driven by a GPIO expander over I2C,
as illustrated below:

	┌──────┐      ┌─────┐
	│ SOC  │      │     │    ┌───────┐
	│      │      │     │───►│ MMC   │
	│      │      │ MUX │    └───────┘
	│      ├─────►│     │    ┌───────┐
	│      │      │     │───►│ UART  │
	│      │      └─────┘    └───────┘
	│      │         ▲
	│      │    ┌────┴──────────────┐
	│ I2C  ├───►│ GPIO Expander     │
	└──────┘    └───────────────────┘

Traditionally, gpio-hog is used to configure the onboard mux at boot.
However, the GPIO expander may probe later than consumer devices such as
MMC. As a result, the MUX might not be configured when the peripheral
driver probes, leading to initialization failures or data transfer errors.

Introduce a generic pinctrl binding that models the board-level MUX as a
pin control provider and builds proper device links between the MUX, its
GPIO controller, and peripheral devices. This ensures correct probe
ordering and reliable mux configuration.

The implementation leverages the standard multiplexer subsystem, which
provides broad support for onboard mux controllers and avoids the need for
per-driver custom MUX handling.

Allow pinctrl-* pattern as node name because this pinctrl device have not
reg property.

Reviewed-by: Linus Walleij <linusw@kernel.org>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
Change in v4
- add Linus Walleij's review by tags

change in v3:
- collect rob's reviewed-by tag.

change in v2:
 - change descriptions for device, not for driver
 - add missed additionalProperties: false
---
 .../bindings/pinctrl/pinctrl-multiplexer.yaml      | 57 ++++++++++++++++++++++
 .../devicetree/bindings/pinctrl/pinctrl.yaml       |  2 +-
 2 files changed, 58 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/pinctrl/pinctrl-multiplexer.yaml b/Documentation/devicetree/bindings/pinctrl/pinctrl-multiplexer.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..2b0385ed879b70b24ca9c39b098c3840d08d7482
--- /dev/null
+++ b/Documentation/devicetree/bindings/pinctrl/pinctrl-multiplexer.yaml
@@ -0,0 +1,57 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pinctrl/pinctrl-multiplexer.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Generic pinctrl device for on-board MUX Chips
+
+maintainers:
+  - Frank Li <Frank.Li@nxp.com>
+
+description:
+  Generic pinctrl device for on-board MUX Chips, which switch SoC signals
+  between different peripherals (e.g. MMC and UART).
+
+  The MUX select lines are often driven by a I2C GPIO expander.
+
+properties:
+  compatible:
+    const: pinctrl-multiplexer
+
+patternProperties:
+  '-grp$':
+    type: object
+    additionalProperties: false
+    properties:
+      mux-states:
+        maxItems: 1
+
+    required:
+      - mux-states
+
+required:
+  - compatible
+
+allOf:
+  - $ref: pinctrl.yaml#
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    pinctrl-mux {
+        compatible = "pinctrl-multiplexer";
+
+        uart-grp {
+            mux-states = <&mux 0>;
+        };
+
+        spi-grp {
+            mux-states = <&mux 1>;
+        };
+
+        i2c-grp {
+            mux-states = <&mux 2>;
+        };
+    };
diff --git a/Documentation/devicetree/bindings/pinctrl/pinctrl.yaml b/Documentation/devicetree/bindings/pinctrl/pinctrl.yaml
index 290438826c507ec6725f486d18cf686aa7c35e67..20176bf3074757de30f208e69b968a6bd6125273 100644
--- a/Documentation/devicetree/bindings/pinctrl/pinctrl.yaml
+++ b/Documentation/devicetree/bindings/pinctrl/pinctrl.yaml
@@ -27,7 +27,7 @@ description: |
 
 properties:
   $nodename:
-    pattern: "^(pinctrl|pinmux)(@[0-9a-f]+)?$"
+    pattern: "^(pinctrl|pinmux)(@[0-9a-f]+|-[a-z0-9]+)?$"
 
   "#pinctrl-cells":
     description: >

-- 
2.43.0

[PATCH v4 3/7] pinctrl: extract pinctrl_generic_to_map() from pinctrl_generic_pins_function_dt_node_to_map()

[Frank Li]

Refactor pinctrl_generic_pins_function_dt_subnode_to_map() by separating DT
parsing logic from map creation. Introduce a new helper
pinctrl_generic_to_map() to handle mapping to kernel data structures, while
keeping DT property parsing in the subnode function.

Improve code structure and enables easier reuse for platforms using
different DT properties (e.g. pinmux) without modifying the
dt_node_to_map-style callback API. Avoid unnecessary coupling to
pinctrl_generic_pins_function_dt_node_to_map(), which provides
functionality not needed when the phandle target is unambiguous.

Maximize code reuse and provide a cleaner extension point for future
pinctrl drivers.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
change in v4
- new patch
---
 drivers/pinctrl/pinconf.h         | 18 ++++++++
 drivers/pinctrl/pinctrl-generic.c | 91 ++++++++++++++++++++++++---------------
 2 files changed, 74 insertions(+), 35 deletions(-)

diff --git a/drivers/pinctrl/pinconf.h b/drivers/pinctrl/pinconf.h
index 2880adef476e68950ffdd540ea42cdee6a16ec27..ffdabddb9660324ed8886a2e8dcacff7e1c6c529 100644
--- a/drivers/pinctrl/pinconf.h
+++ b/drivers/pinctrl/pinconf.h
@@ -166,6 +166,13 @@ int pinctrl_generic_pins_function_dt_node_to_map(struct pinctrl_dev *pctldev,
 						 struct device_node *np,
 						 struct pinctrl_map **maps,
 						 unsigned int *num_maps);
+
+int
+pinctrl_generic_to_map(struct pinctrl_dev *pctldev, struct device_node *parent,
+		       struct device_node *np, struct pinctrl_map **maps,
+		       unsigned int *num_maps, unsigned int *num_reserved_maps,
+		       const char **group_name, unsigned int ngroups,
+		       const char **functions, unsigned int *pins);
 #else
 static inline int
 pinctrl_generic_pins_function_dt_node_to_map(struct pinctrl_dev *pctldev,
@@ -175,4 +182,15 @@ pinctrl_generic_pins_function_dt_node_to_map(struct pinctrl_dev *pctldev,
 {
 	return -ENOTSUPP;
 }
+
+static inline int
+pinctrl_generic_to_map(struct pinctrl_dev *pctldev, struct device_node *parent,
+		       struct device_node *np, struct pinctrl_map **maps,
+		       unsigned int *num_maps, unsigned int *num_reserved_maps,
+		       const char **group_name, unsigned int ngroups,
+		       const char **functions, unsigned int *pins,
+		       void *function_data)
+{
+	return -ENOTSUPP;
+}
 #endif
diff --git a/drivers/pinctrl/pinctrl-generic.c b/drivers/pinctrl/pinctrl-generic.c
index efb39c6a670331775855efdc8566102b5c6202ef..20a216ae63e91b69985ea4cfcd0b57103c6ca950 100644
--- a/drivers/pinctrl/pinctrl-generic.c
+++ b/drivers/pinctrl/pinctrl-generic.c
@@ -17,29 +17,18 @@
 #include "pinctrl-utils.h"
 #include "pinmux.h"
 
-static int pinctrl_generic_pins_function_dt_subnode_to_map(struct pinctrl_dev *pctldev,
-							   struct device_node *parent,
-							   struct device_node *np,
-							   struct pinctrl_map **maps,
-							   unsigned int *num_maps,
-							   unsigned int *num_reserved_maps,
-							   const char **group_names,
-							   unsigned int ngroups)
+int
+pinctrl_generic_to_map(struct pinctrl_dev *pctldev, struct device_node *parent,
+		       struct device_node *np, struct pinctrl_map **maps,
+		       unsigned int *num_maps, unsigned int *num_reserved_maps,
+		       const char **group_names, unsigned int ngroups,
+		       const char **functions, unsigned int *pins)
 {
 	struct device *dev = pctldev->dev;
-	const char **functions;
+	int npins, ret, reserve = 1;
+	unsigned int num_configs;
 	const char *group_name;
 	unsigned long *configs;
-	unsigned int num_configs, pin, *pins;
-	int npins, ret, reserve = 1;
-
-	npins = of_property_count_u32_elems(np, "pins");
-
-	if (npins < 1) {
-		dev_err(dev, "invalid pinctrl group %pOFn.%pOFn %d\n",
-			parent, np, npins);
-		return npins;
-	}
 
 	group_name = devm_kasprintf(dev, GFP_KERNEL, "%pOFn.%pOFn", parent, np);
 	if (!group_name)
@@ -51,22 +40,6 @@ static int pinctrl_generic_pins_function_dt_subnode_to_map(struct pinctrl_dev *p
 	if (!pins)
 		return -ENOMEM;
 
-	functions = devm_kcalloc(dev, npins, sizeof(*functions), GFP_KERNEL);
-	if (!functions)
-		return -ENOMEM;
-
-	for (int i = 0; i < npins; i++) {
-		ret = of_property_read_u32_index(np, "pins", i, &pin);
-		if (ret)
-			return ret;
-
-		pins[i] = pin;
-
-		ret = of_property_read_string(np, "function", &functions[i]);
-		if (ret)
-			return ret;
-	}
-
 	ret = pinctrl_utils_reserve_map(pctldev, maps, num_reserved_maps, num_maps, reserve);
 	if (ret)
 		return ret;
@@ -103,6 +76,54 @@ static int pinctrl_generic_pins_function_dt_subnode_to_map(struct pinctrl_dev *p
 	return 0;
 };
 
+static int
+pinctrl_generic_pins_function_dt_subnode_to_map(struct pinctrl_dev *pctldev,
+						struct device_node *parent,
+						struct device_node *np,
+						struct pinctrl_map **maps,
+						unsigned int *num_maps,
+						unsigned int *num_reserved_maps,
+						const char **group_names,
+						unsigned int ngroups)
+{
+	struct device *dev = pctldev->dev;
+	unsigned int pin, *pins;
+	const char **functions;
+	int npins, ret;
+
+	npins = of_property_count_u32_elems(np, "pins");
+
+	if (npins < 1) {
+		dev_err(dev, "invalid pinctrl group %pOFn.%pOFn %d\n",
+			parent, np, npins);
+		return npins;
+	}
+
+	pins = devm_kcalloc(dev, npins, sizeof(*pins), GFP_KERNEL);
+	if (!pins)
+		return -ENOMEM;
+
+	functions = devm_kcalloc(dev, npins, sizeof(*functions), GFP_KERNEL);
+	if (!functions)
+		return -ENOMEM;
+
+	for (int i = 0; i < npins; i++) {
+		ret = of_property_read_u32_index(np, "pins", i, &pin);
+		if (ret)
+			return ret;
+
+		pins[i] = pin;
+
+		ret = of_property_read_string(np, "function", &functions[i]);
+		if (ret)
+			return ret;
+	}
+
+	return pinctrl_generic_to_map(pctldev, parent, np, maps, num_maps,
+				      num_reserved_maps, group_names, ngroups,
+				      functions, pins);
+}
+
 /*
  * For platforms that do not define groups or functions in the driver, but
  * instead use the devicetree to describe them. This function will, unlike

-- 
2.43.0

Re: [PATCH v4 3/7] pinctrl: extract pinctrl_generic_to_map() from pinctrl_generic_pins_function_dt_node_to_map()

[Conor Dooley]

[-- Attachment #1: Type: text/plain, Size: 4227 bytes --]

On Wed, Mar 25, 2026 at 07:04:12PM -0400, Frank Li wrote:

> diff --git a/drivers/pinctrl/pinctrl-generic.c b/drivers/pinctrl/pinctrl-generic.c
> index efb39c6a670331775855efdc8566102b5c6202ef..20a216ae63e91b69985ea4cfcd0b57103c6ca950 100644
> --- a/drivers/pinctrl/pinctrl-generic.c
> +++ b/drivers/pinctrl/pinctrl-generic.c
> @@ -17,29 +17,18 @@
>  #include "pinctrl-utils.h"
>  #include "pinmux.h"
>  
> -static int pinctrl_generic_pins_function_dt_subnode_to_map(struct pinctrl_dev *pctldev,

> +int
> +pinctrl_generic_to_map(struct pinctrl_dev *pctldev, struct device_node *parent,

Can you drop this stylistic change please? The 

> +		       struct device_node *np, struct pinctrl_map **maps,
> +		       unsigned int *num_maps, unsigned int *num_reserved_maps,
> +		       const char **group_names, unsigned int ngroups,
> +		       const char **functions, unsigned int *pins)
>  {
>  	struct device *dev = pctldev->dev;
> -	const char **functions;
> +	int npins, ret, reserve = 1;
> +	unsigned int num_configs;
>  	const char *group_name;
>  	unsigned long *configs;
> -	unsigned int num_configs, pin, *pins;
> -	int npins, ret, reserve = 1;
> -
> -	npins = of_property_count_u32_elems(np, "pins");
> -
> -	if (npins < 1) {
> -		dev_err(dev, "invalid pinctrl group %pOFn.%pOFn %d\n",
> -			parent, np, npins);
> -		return npins;
> -	}
>  
>  	group_name = devm_kasprintf(dev, GFP_KERNEL, "%pOFn.%pOFn", parent, np);
>  	if (!group_name)
> @@ -51,22 +40,6 @@ static int pinctrl_generic_pins_function_dt_subnode_to_map(struct pinctrl_dev *p
>  	if (!pins)
>  		return -ENOMEM;

This looks suspect. You've left the pins allocation behind:
	pins = devm_kcalloc(dev, npins, sizeof(*pins), GFP_KERNEL);
	if (!pins)
		return -ENOMEM;
but pinctrl_generic_pins_function_dt_subnode_to_map() has already
populated this array before calling the function.

Also, this should probably be
Suggested-by: Conor Dooley <conor.dooley@microchip.com>

Cheers,
Conor.

>  
> -	functions = devm_kcalloc(dev, npins, sizeof(*functions), GFP_KERNEL);
> -	if (!functions)
> -		return -ENOMEM;
> -
> -	for (int i = 0; i < npins; i++) {
> -		ret = of_property_read_u32_index(np, "pins", i, &pin);
> -		if (ret)
> -			return ret;
> -
> -		pins[i] = pin;
> -
> -		ret = of_property_read_string(np, "function", &functions[i]);
> -		if (ret)
> -			return ret;
> -	}
> -
>  	ret = pinctrl_utils_reserve_map(pctldev, maps, num_reserved_maps, num_maps, reserve);
>  	if (ret)
>  		return ret;
> @@ -103,6 +76,54 @@ static int pinctrl_generic_pins_function_dt_subnode_to_map(struct pinctrl_dev *p
>  	return 0;
>  };
>  
> +static int
> +pinctrl_generic_pins_function_dt_subnode_to_map(struct pinctrl_dev *pctldev,
> +						struct device_node *parent,
> +						struct device_node *np,
> +						struct pinctrl_map **maps,
> +						unsigned int *num_maps,
> +						unsigned int *num_reserved_maps,
> +						const char **group_names,
> +						unsigned int ngroups)
> +{
> +	struct device *dev = pctldev->dev;
> +	unsigned int pin, *pins;
> +	const char **functions;
> +	int npins, ret;
> +
> +	npins = of_property_count_u32_elems(np, "pins");
> +
> +	if (npins < 1) {
> +		dev_err(dev, "invalid pinctrl group %pOFn.%pOFn %d\n",
> +			parent, np, npins);
> +		return npins;
> +	}
> +
> +	pins = devm_kcalloc(dev, npins, sizeof(*pins), GFP_KERNEL);
> +	if (!pins)
> +		return -ENOMEM;
> +
> +	functions = devm_kcalloc(dev, npins, sizeof(*functions), GFP_KERNEL);
> +	if (!functions)
> +		return -ENOMEM;
> +
> +	for (int i = 0; i < npins; i++) {
> +		ret = of_property_read_u32_index(np, "pins", i, &pin);
> +		if (ret)
> +			return ret;
> +
> +		pins[i] = pin;
> +
> +		ret = of_property_read_string(np, "function", &functions[i]);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	return pinctrl_generic_to_map(pctldev, parent, np, maps, num_maps,
> +				      num_reserved_maps, group_names, ngroups,
> +				      functions, pins);
> +}
> +
>  /*
>   * For platforms that do not define groups or functions in the driver, but
>   * instead use the devicetree to describe them. This function will, unlike
> 
> -- 
> 2.43.0
> 

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Re: [PATCH v4 3/7] pinctrl: extract pinctrl_generic_to_map() from pinctrl_generic_pins_function_dt_node_to_map()

[Conor Dooley]

[-- Attachment #1: Type: text/plain, Size: 4792 bytes --]

On Thu, Mar 26, 2026 at 06:52:12PM +0000, Conor Dooley wrote:
> On Wed, Mar 25, 2026 at 07:04:12PM -0400, Frank Li wrote:
> 
> > diff --git a/drivers/pinctrl/pinctrl-generic.c b/drivers/pinctrl/pinctrl-generic.c
> > index efb39c6a670331775855efdc8566102b5c6202ef..20a216ae63e91b69985ea4cfcd0b57103c6ca950 100644
> > --- a/drivers/pinctrl/pinctrl-generic.c
> > +++ b/drivers/pinctrl/pinctrl-generic.c
> > @@ -17,29 +17,18 @@
> >  #include "pinctrl-utils.h"
> >  #include "pinmux.h"
> >  
> > -static int pinctrl_generic_pins_function_dt_subnode_to_map(struct pinctrl_dev *pctldev,
> 
> > +int
> > +pinctrl_generic_to_map(struct pinctrl_dev *pctldev, struct device_node *parent,
> 
> Can you drop this stylistic change please? The 

Whoops, cut myself off. To be clear, what I am asking for is to keep the
"int" etc on the same line as the function name. This function is new,
but you did it for the existing function too and the comparison is here.

> 
> > +		       struct device_node *np, struct pinctrl_map **maps,
> > +		       unsigned int *num_maps, unsigned int *num_reserved_maps,
> > +		       const char **group_names, unsigned int ngroups,
> > +		       const char **functions, unsigned int *pins)
> >  {
> >  	struct device *dev = pctldev->dev;
> > -	const char **functions;
> > +	int npins, ret, reserve = 1;
> > +	unsigned int num_configs;
> >  	const char *group_name;
> >  	unsigned long *configs;
> > -	unsigned int num_configs, pin, *pins;
> > -	int npins, ret, reserve = 1;
> > -
> > -	npins = of_property_count_u32_elems(np, "pins");
> > -
> > -	if (npins < 1) {
> > -		dev_err(dev, "invalid pinctrl group %pOFn.%pOFn %d\n",
> > -			parent, np, npins);
> > -		return npins;
> > -	}
> >  
> >  	group_name = devm_kasprintf(dev, GFP_KERNEL, "%pOFn.%pOFn", parent, np);
> >  	if (!group_name)
> > @@ -51,22 +40,6 @@ static int pinctrl_generic_pins_function_dt_subnode_to_map(struct pinctrl_dev *p
> >  	if (!pins)
> >  		return -ENOMEM;
> 
> This looks suspect. You've left the pins allocation behind:
> 	pins = devm_kcalloc(dev, npins, sizeof(*pins), GFP_KERNEL);
> 	if (!pins)
> 		return -ENOMEM;
> but pinctrl_generic_pins_function_dt_subnode_to_map() has already
> populated this array before calling the function.
> 
> Also, this should probably be
> Suggested-by: Conor Dooley <conor.dooley@microchip.com>
> 
> Cheers,
> Conor.
> 
> >  
> > -	functions = devm_kcalloc(dev, npins, sizeof(*functions), GFP_KERNEL);
> > -	if (!functions)
> > -		return -ENOMEM;
> > -
> > -	for (int i = 0; i < npins; i++) {
> > -		ret = of_property_read_u32_index(np, "pins", i, &pin);
> > -		if (ret)
> > -			return ret;
> > -
> > -		pins[i] = pin;
> > -
> > -		ret = of_property_read_string(np, "function", &functions[i]);
> > -		if (ret)
> > -			return ret;
> > -	}
> > -
> >  	ret = pinctrl_utils_reserve_map(pctldev, maps, num_reserved_maps, num_maps, reserve);
> >  	if (ret)
> >  		return ret;
> > @@ -103,6 +76,54 @@ static int pinctrl_generic_pins_function_dt_subnode_to_map(struct pinctrl_dev *p
> >  	return 0;
> >  };
> >  
> > +static int
> > +pinctrl_generic_pins_function_dt_subnode_to_map(struct pinctrl_dev *pctldev,
> > +						struct device_node *parent,
> > +						struct device_node *np,
> > +						struct pinctrl_map **maps,
> > +						unsigned int *num_maps,
> > +						unsigned int *num_reserved_maps,
> > +						const char **group_names,
> > +						unsigned int ngroups)
> > +{
> > +	struct device *dev = pctldev->dev;
> > +	unsigned int pin, *pins;
> > +	const char **functions;
> > +	int npins, ret;
> > +
> > +	npins = of_property_count_u32_elems(np, "pins");
> > +
> > +	if (npins < 1) {
> > +		dev_err(dev, "invalid pinctrl group %pOFn.%pOFn %d\n",
> > +			parent, np, npins);
> > +		return npins;
> > +	}
> > +
> > +	pins = devm_kcalloc(dev, npins, sizeof(*pins), GFP_KERNEL);
> > +	if (!pins)
> > +		return -ENOMEM;
> > +
> > +	functions = devm_kcalloc(dev, npins, sizeof(*functions), GFP_KERNEL);
> > +	if (!functions)
> > +		return -ENOMEM;
> > +
> > +	for (int i = 0; i < npins; i++) {
> > +		ret = of_property_read_u32_index(np, "pins", i, &pin);
> > +		if (ret)
> > +			return ret;
> > +
> > +		pins[i] = pin;
> > +
> > +		ret = of_property_read_string(np, "function", &functions[i]);
> > +		if (ret)
> > +			return ret;
> > +	}
> > +
> > +	return pinctrl_generic_to_map(pctldev, parent, np, maps, num_maps,
> > +				      num_reserved_maps, group_names, ngroups,
> > +				      functions, pins);
> > +}
> > +
> >  /*
> >   * For platforms that do not define groups or functions in the driver, but
> >   * instead use the devicetree to describe them. This function will, unlike
> > 
> > -- 
> > 2.43.0
> > 



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Re: [PATCH v4 3/7] pinctrl: extract pinctrl_generic_to_map() from pinctrl_generic_pins_function_dt_node_to_map()

[Frank Li]

On Thu, Mar 26, 2026 at 06:55:01PM +0000, Conor Dooley wrote:
> On Thu, Mar 26, 2026 at 06:52:12PM +0000, Conor Dooley wrote:
> > On Wed, Mar 25, 2026 at 07:04:12PM -0400, Frank Li wrote:
> >
> > > diff --git a/drivers/pinctrl/pinctrl-generic.c b/drivers/pinctrl/pinctrl-generic.c
> > > index efb39c6a670331775855efdc8566102b5c6202ef..20a216ae63e91b69985ea4cfcd0b57103c6ca950 100644
> > > --- a/drivers/pinctrl/pinctrl-generic.c
> > > +++ b/drivers/pinctrl/pinctrl-generic.c
> > > @@ -17,29 +17,18 @@
> > >  #include "pinctrl-utils.h"
> > >  #include "pinmux.h"
> > >
> > > -static int pinctrl_generic_pins_function_dt_subnode_to_map(struct pinctrl_dev *pctldev,
> >
> > > +int
> > > +pinctrl_generic_to_map(struct pinctrl_dev *pctldev, struct device_node *parent,
> >
> > Can you drop this stylistic change please? The
>
> Whoops, cut myself off. To be clear, what I am asking for is to keep the
> "int" etc on the same line as the function name. This function is new,
> but you did it for the existing function too and the comparison is here.
>
> >
> > > +		       struct device_node *np, struct pinctrl_map **maps,
> > > +		       unsigned int *num_maps, unsigned int *num_reserved_maps,
> > > +		       const char **group_names, unsigned int ngroups,
> > > +		       const char **functions, unsigned int *pins)
> > >  {
> > >  	struct device *dev = pctldev->dev;
> > > -	const char **functions;
> > > +	int npins, ret, reserve = 1;
> > > +	unsigned int num_configs;
> > >  	const char *group_name;
> > >  	unsigned long *configs;
> > > -	unsigned int num_configs, pin, *pins;
> > > -	int npins, ret, reserve = 1;
> > > -
> > > -	npins = of_property_count_u32_elems(np, "pins");
> > > -
> > > -	if (npins < 1) {
> > > -		dev_err(dev, "invalid pinctrl group %pOFn.%pOFn %d\n",
> > > -			parent, np, npins);
> > > -		return npins;
> > > -	}
> > >
> > >  	group_name = devm_kasprintf(dev, GFP_KERNEL, "%pOFn.%pOFn", parent, np);
> > >  	if (!group_name)
> > > @@ -51,22 +40,6 @@ static int pinctrl_generic_pins_function_dt_subnode_to_map(struct pinctrl_dev *p
> > >  	if (!pins)
> > >  		return -ENOMEM;
> >
> > This looks suspect. You've left the pins allocation behind:
> > 	pins = devm_kcalloc(dev, npins, sizeof(*pins), GFP_KERNEL);
> > 	if (!pins)
> > 		return -ENOMEM;
> > but pinctrl_generic_pins_function_dt_subnode_to_map() has already
> > populated this array before calling the function.

what's means?

pinctrl_generic_pins_function_dt_subnode_to_map()
{
	pins = devm_kcalloc(dev, npins, sizeof(*pins), GFP_KERNEL);
	...
	pinctrl_generic_to_map();
}

pinctrl_generic_pins_function_dt_subnode_to_map() have not use this array.

Frank
> >
> > Also, this should probably be
> > Suggested-by: Conor Dooley <conor.dooley@microchip.com>
> >
> > Cheers,
> > Conor.
> >
> > >
> > > -	functions = devm_kcalloc(dev, npins, sizeof(*functions), GFP_KERNEL);
> > > -	if (!functions)
> > > -		return -ENOMEM;
> > > -
> > > -	for (int i = 0; i < npins; i++) {
> > > -		ret = of_property_read_u32_index(np, "pins", i, &pin);
> > > -		if (ret)
> > > -			return ret;
> > > -
> > > -		pins[i] = pin;
> > > -
> > > -		ret = of_property_read_string(np, "function", &functions[i]);
> > > -		if (ret)
> > > -			return ret;
> > > -	}
> > > -
> > >  	ret = pinctrl_utils_reserve_map(pctldev, maps, num_reserved_maps, num_maps, reserve);
> > >  	if (ret)
> > >  		return ret;
> > > @@ -103,6 +76,54 @@ static int pinctrl_generic_pins_function_dt_subnode_to_map(struct pinctrl_dev *p
> > >  	return 0;
> > >  };
> > >
> > > +static int
> > > +pinctrl_generic_pins_function_dt_subnode_to_map(struct pinctrl_dev *pctldev,
> > > +						struct device_node *parent,
> > > +						struct device_node *np,
> > > +						struct pinctrl_map **maps,
> > > +						unsigned int *num_maps,
> > > +						unsigned int *num_reserved_maps,
> > > +						const char **group_names,
> > > +						unsigned int ngroups)
> > > +{
> > > +	struct device *dev = pctldev->dev;
> > > +	unsigned int pin, *pins;
> > > +	const char **functions;
> > > +	int npins, ret;
> > > +
> > > +	npins = of_property_count_u32_elems(np, "pins");
> > > +
> > > +	if (npins < 1) {
> > > +		dev_err(dev, "invalid pinctrl group %pOFn.%pOFn %d\n",
> > > +			parent, np, npins);
> > > +		return npins;
> > > +	}
> > > +
> > > +	pins = devm_kcalloc(dev, npins, sizeof(*pins), GFP_KERNEL);
> > > +	if (!pins)
> > > +		return -ENOMEM;
> > > +
> > > +	functions = devm_kcalloc(dev, npins, sizeof(*functions), GFP_KERNEL);
> > > +	if (!functions)
> > > +		return -ENOMEM;
> > > +
> > > +	for (int i = 0; i < npins; i++) {
> > > +		ret = of_property_read_u32_index(np, "pins", i, &pin);
> > > +		if (ret)
> > > +			return ret;
> > > +
> > > +		pins[i] = pin;
> > > +
> > > +		ret = of_property_read_string(np, "function", &functions[i]);
> > > +		if (ret)
> > > +			return ret;
> > > +	}
> > > +
> > > +	return pinctrl_generic_to_map(pctldev, parent, np, maps, num_maps,
> > > +				      num_reserved_maps, group_names, ngroups,
> > > +				      functions, pins);
> > > +}
> > > +
> > >  /*
> > >   * For platforms that do not define groups or functions in the driver, but
> > >   * instead use the devicetree to describe them. This function will, unlike
> > >
> > > --
> > > 2.43.0
> > >
>
>

Re: [PATCH v4 3/7] pinctrl: extract pinctrl_generic_to_map() from pinctrl_generic_pins_function_dt_node_to_map()

[Conor Dooley]

[-- Attachment #1: Type: text/plain, Size: 5910 bytes --]

On Thu, Mar 26, 2026 at 03:47:06PM -0400, Frank Li wrote:
> On Thu, Mar 26, 2026 at 06:55:01PM +0000, Conor Dooley wrote:
> > On Thu, Mar 26, 2026 at 06:52:12PM +0000, Conor Dooley wrote:
> > > On Wed, Mar 25, 2026 at 07:04:12PM -0400, Frank Li wrote:
> > >
> > > > diff --git a/drivers/pinctrl/pinctrl-generic.c b/drivers/pinctrl/pinctrl-generic.c
> > > > index efb39c6a670331775855efdc8566102b5c6202ef..20a216ae63e91b69985ea4cfcd0b57103c6ca950 100644
> > > > --- a/drivers/pinctrl/pinctrl-generic.c
> > > > +++ b/drivers/pinctrl/pinctrl-generic.c
> > > > @@ -17,29 +17,18 @@
> > > >  #include "pinctrl-utils.h"
> > > >  #include "pinmux.h"
> > > >
> > > > -static int pinctrl_generic_pins_function_dt_subnode_to_map(struct pinctrl_dev *pctldev,
> > >
> > > > +int
> > > > +pinctrl_generic_to_map(struct pinctrl_dev *pctldev, struct device_node *parent,
> > >
> > > Can you drop this stylistic change please? The
> >
> > Whoops, cut myself off. To be clear, what I am asking for is to keep the
> > "int" etc on the same line as the function name. This function is new,
> > but you did it for the existing function too and the comparison is here.
> >
> > >
> > > > +		       struct device_node *np, struct pinctrl_map **maps,
> > > > +		       unsigned int *num_maps, unsigned int *num_reserved_maps,
> > > > +		       const char **group_names, unsigned int ngroups,
> > > > +		       const char **functions, unsigned int *pins)
> > > >  {
> > > >  	struct device *dev = pctldev->dev;
> > > > -	const char **functions;
> > > > +	int npins, ret, reserve = 1;
> > > > +	unsigned int num_configs;
> > > >  	const char *group_name;
> > > >  	unsigned long *configs;
> > > > -	unsigned int num_configs, pin, *pins;
> > > > -	int npins, ret, reserve = 1;
> > > > -
> > > > -	npins = of_property_count_u32_elems(np, "pins");
> > > > -
> > > > -	if (npins < 1) {
> > > > -		dev_err(dev, "invalid pinctrl group %pOFn.%pOFn %d\n",
> > > > -			parent, np, npins);
> > > > -		return npins;
> > > > -	}
> > > >
> > > >  	group_name = devm_kasprintf(dev, GFP_KERNEL, "%pOFn.%pOFn", parent, np);
> > > >  	if (!group_name)
> > > > @@ -51,22 +40,6 @@ static int pinctrl_generic_pins_function_dt_subnode_to_map(struct pinctrl_dev *p
> > > >  	if (!pins)
> > > >  		return -ENOMEM;
> > >
> > > This looks suspect. You've left the pins allocation behind:
> > > 	pins = devm_kcalloc(dev, npins, sizeof(*pins), GFP_KERNEL);
> > > 	if (!pins)
> > > 		return -ENOMEM;
> > > but pinctrl_generic_pins_function_dt_subnode_to_map() has already
> > > populated this array before calling the function.
> 
> what's means?

It means you broke my driver by not removing this allocation from
pinctrl_generic_to_map().

> 
> pinctrl_generic_pins_function_dt_subnode_to_map()
> {
> 	pins = devm_kcalloc(dev, npins, sizeof(*pins), GFP_KERNEL);
> 	...
> 	pinctrl_generic_to_map();
> }
> 
> pinctrl_generic_pins_function_dt_subnode_to_map() have not use this array.

I have no idea what this statement means.

> 
> Frank
> > >
> > > Also, this should probably be
> > > Suggested-by: Conor Dooley <conor.dooley@microchip.com>
> > >
> > > Cheers,
> > > Conor.
> > >
> > > >
> > > > -	functions = devm_kcalloc(dev, npins, sizeof(*functions), GFP_KERNEL);
> > > > -	if (!functions)
> > > > -		return -ENOMEM;
> > > > -
> > > > -	for (int i = 0; i < npins; i++) {
> > > > -		ret = of_property_read_u32_index(np, "pins", i, &pin);
> > > > -		if (ret)
> > > > -			return ret;
> > > > -
> > > > -		pins[i] = pin;
> > > > -
> > > > -		ret = of_property_read_string(np, "function", &functions[i]);
> > > > -		if (ret)
> > > > -			return ret;
> > > > -	}
> > > > -
> > > >  	ret = pinctrl_utils_reserve_map(pctldev, maps, num_reserved_maps, num_maps, reserve);
> > > >  	if (ret)
> > > >  		return ret;
> > > > @@ -103,6 +76,54 @@ static int pinctrl_generic_pins_function_dt_subnode_to_map(struct pinctrl_dev *p
> > > >  	return 0;
> > > >  };
> > > >
> > > > +static int
> > > > +pinctrl_generic_pins_function_dt_subnode_to_map(struct pinctrl_dev *pctldev,
> > > > +						struct device_node *parent,
> > > > +						struct device_node *np,
> > > > +						struct pinctrl_map **maps,
> > > > +						unsigned int *num_maps,
> > > > +						unsigned int *num_reserved_maps,
> > > > +						const char **group_names,
> > > > +						unsigned int ngroups)
> > > > +{
> > > > +	struct device *dev = pctldev->dev;
> > > > +	unsigned int pin, *pins;
> > > > +	const char **functions;
> > > > +	int npins, ret;
> > > > +
> > > > +	npins = of_property_count_u32_elems(np, "pins");
> > > > +
> > > > +	if (npins < 1) {
> > > > +		dev_err(dev, "invalid pinctrl group %pOFn.%pOFn %d\n",
> > > > +			parent, np, npins);
> > > > +		return npins;
> > > > +	}
> > > > +
> > > > +	pins = devm_kcalloc(dev, npins, sizeof(*pins), GFP_KERNEL);
> > > > +	if (!pins)
> > > > +		return -ENOMEM;
> > > > +
> > > > +	functions = devm_kcalloc(dev, npins, sizeof(*functions), GFP_KERNEL);
> > > > +	if (!functions)
> > > > +		return -ENOMEM;
> > > > +
> > > > +	for (int i = 0; i < npins; i++) {
> > > > +		ret = of_property_read_u32_index(np, "pins", i, &pin);
> > > > +		if (ret)
> > > > +			return ret;
> > > > +
> > > > +		pins[i] = pin;
> > > > +
> > > > +		ret = of_property_read_string(np, "function", &functions[i]);
> > > > +		if (ret)
> > > > +			return ret;
> > > > +	}
> > > > +
> > > > +	return pinctrl_generic_to_map(pctldev, parent, np, maps, num_maps,
> > > > +				      num_reserved_maps, group_names, ngroups,
> > > > +				      functions, pins);
> > > > +}
> > > > +
> > > >  /*
> > > >   * For platforms that do not define groups or functions in the driver, but
> > > >   * instead use the devicetree to describe them. This function will, unlike
> > > >
> > > > --
> > > > 2.43.0
> > > >
> >
> >
> 
> 

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Re: [PATCH v4 3/7] pinctrl: extract pinctrl_generic_to_map() from pinctrl_generic_pins_function_dt_node_to_map()

[Conor Dooley]

[-- Attachment #1: Type: text/plain, Size: 6834 bytes --]

On Wed, Mar 25, 2026 at 07:04:12PM -0400, Frank Li wrote:
> Refactor pinctrl_generic_pins_function_dt_subnode_to_map() by separating DT
> parsing logic from map creation. Introduce a new helper
> pinctrl_generic_to_map() to handle mapping to kernel data structures, while
> keeping DT property parsing in the subnode function.
> 
> Improve code structure and enables easier reuse for platforms using
> different DT properties (e.g. pinmux) without modifying the
> dt_node_to_map-style callback API. Avoid unnecessary coupling to
> pinctrl_generic_pins_function_dt_node_to_map(), which provides
> functionality not needed when the phandle target is unambiguous.
> 
> Maximize code reuse and provide a cleaner extension point for future
> pinctrl drivers.
> 
> Signed-off-by: Frank Li <Frank.Li@nxp.com>
> ---
> change in v4
> - new patch
> ---
>  drivers/pinctrl/pinconf.h         | 18 ++++++++
>  drivers/pinctrl/pinctrl-generic.c | 91 ++++++++++++++++++++++++---------------
>  2 files changed, 74 insertions(+), 35 deletions(-)
> 
> diff --git a/drivers/pinctrl/pinconf.h b/drivers/pinctrl/pinconf.h
> index 2880adef476e68950ffdd540ea42cdee6a16ec27..ffdabddb9660324ed8886a2e8dcacff7e1c6c529 100644
> --- a/drivers/pinctrl/pinconf.h
> +++ b/drivers/pinctrl/pinconf.h
> @@ -166,6 +166,13 @@ int pinctrl_generic_pins_function_dt_node_to_map(struct pinctrl_dev *pctldev,
>  						 struct device_node *np,
>  						 struct pinctrl_map **maps,
>  						 unsigned int *num_maps);
> +
> +int
> +pinctrl_generic_to_map(struct pinctrl_dev *pctldev, struct device_node *parent,
> +		       struct device_node *np, struct pinctrl_map **maps,
> +		       unsigned int *num_maps, unsigned int *num_reserved_maps,
> +		       const char **group_name, unsigned int ngroups,
> +		       const char **functions, unsigned int *pins);
>  #else
>  static inline int
>  pinctrl_generic_pins_function_dt_node_to_map(struct pinctrl_dev *pctldev,
> @@ -175,4 +182,15 @@ pinctrl_generic_pins_function_dt_node_to_map(struct pinctrl_dev *pctldev,
>  {
>  	return -ENOTSUPP;
>  }
> +
> +static inline int
> +pinctrl_generic_to_map(struct pinctrl_dev *pctldev, struct device_node *parent,
> +		       struct device_node *np, struct pinctrl_map **maps,
> +		       unsigned int *num_maps, unsigned int *num_reserved_maps,
> +		       const char **group_name, unsigned int ngroups,
> +		       const char **functions, unsigned int *pins,
> +		       void *function_data)
> +{
> +	return -ENOTSUPP;
> +}
>  #endif
> diff --git a/drivers/pinctrl/pinctrl-generic.c b/drivers/pinctrl/pinctrl-generic.c
> index efb39c6a670331775855efdc8566102b5c6202ef..20a216ae63e91b69985ea4cfcd0b57103c6ca950 100644
> --- a/drivers/pinctrl/pinctrl-generic.c
> +++ b/drivers/pinctrl/pinctrl-generic.c
> @@ -17,29 +17,18 @@
>  #include "pinctrl-utils.h"
>  #include "pinmux.h"
>  
> -static int pinctrl_generic_pins_function_dt_subnode_to_map(struct pinctrl_dev *pctldev,
> -							   struct device_node *parent,
> -							   struct device_node *np,
> -							   struct pinctrl_map **maps,
> -							   unsigned int *num_maps,
> -							   unsigned int *num_reserved_maps,
> -							   const char **group_names,
> -							   unsigned int ngroups)
> +int
> +pinctrl_generic_to_map(struct pinctrl_dev *pctldev, struct device_node *parent,
> +		       struct device_node *np, struct pinctrl_map **maps,
> +		       unsigned int *num_maps, unsigned int *num_reserved_maps,
> +		       const char **group_names, unsigned int ngroups,
> +		       const char **functions, unsigned int *pins)

npins needs to be an argument to this function also, otherwise
pinctrl_generic_add_group() uses it uninitialised...

>  {
>  	struct device *dev = pctldev->dev;
> -	const char **functions;
> +	int npins, ret, reserve = 1;

...because you're declaring it here when it's something set by the dt
parsing code in pinctrl_generic_pins_function_dt_subnode_to_map()...

> +	unsigned int num_configs;
>  	const char *group_name;
>  	unsigned long *configs;
> -	unsigned int num_configs, pin, *pins;
> -	int npins, ret, reserve = 1;
> -
> -	npins = of_property_count_u32_elems(np, "pins");
> -
> -	if (npins < 1) {
> -		dev_err(dev, "invalid pinctrl group %pOFn.%pOFn %d\n",
> -			parent, np, npins);
> -		return npins;
> -	}
>  
>  	group_name = devm_kasprintf(dev, GFP_KERNEL, "%pOFn.%pOFn", parent, np);
>  	if (!group_name)
> @@ -51,22 +40,6 @@ static int pinctrl_generic_pins_function_dt_subnode_to_map(struct pinctrl_dev *p
>  	if (!pins)
>  		return -ENOMEM;
>  
> -	functions = devm_kcalloc(dev, npins, sizeof(*functions), GFP_KERNEL);
> -	if (!functions)
> -		return -ENOMEM;
> -
> -	for (int i = 0; i < npins; i++) {
> -		ret = of_property_read_u32_index(np, "pins", i, &pin);
> -		if (ret)
> -			return ret;
> -
> -		pins[i] = pin;
> -
> -		ret = of_property_read_string(np, "function", &functions[i]);
> -		if (ret)
> -			return ret;
> -	}
> -
>  	ret = pinctrl_utils_reserve_map(pctldev, maps, num_reserved_maps, num_maps, reserve);
>  	if (ret)
>  		return ret;
> @@ -103,6 +76,54 @@ static int pinctrl_generic_pins_function_dt_subnode_to_map(struct pinctrl_dev *p
>  	return 0;
>  };
>  
> +static int
> +pinctrl_generic_pins_function_dt_subnode_to_map(struct pinctrl_dev *pctldev,
> +						struct device_node *parent,
> +						struct device_node *np,
> +						struct pinctrl_map **maps,
> +						unsigned int *num_maps,
> +						unsigned int *num_reserved_maps,
> +						const char **group_names,
> +						unsigned int ngroups)
> +{
> +	struct device *dev = pctldev->dev;
> +	unsigned int pin, *pins;
> +	const char **functions;
> +	int npins, ret;
> +
> +	npins = of_property_count_u32_elems(np, "pins");

...down here.

> +
> +	if (npins < 1) {
> +		dev_err(dev, "invalid pinctrl group %pOFn.%pOFn %d\n",
> +			parent, np, npins);
> +		return npins;
> +	}
> +
> +	pins = devm_kcalloc(dev, npins, sizeof(*pins), GFP_KERNEL);
> +	if (!pins)
> +		return -ENOMEM;
> +
> +	functions = devm_kcalloc(dev, npins, sizeof(*functions), GFP_KERNEL);
> +	if (!functions)
> +		return -ENOMEM;
> +
> +	for (int i = 0; i < npins; i++) {
> +		ret = of_property_read_u32_index(np, "pins", i, &pin);
> +		if (ret)
> +			return ret;
> +
> +		pins[i] = pin;
> +
> +		ret = of_property_read_string(np, "function", &functions[i]);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	return pinctrl_generic_to_map(pctldev, parent, np, maps, num_maps,
> +				      num_reserved_maps, group_names, ngroups,
> +				      functions, pins);
> +}
> +
>  /*
>   * For platforms that do not define groups or functions in the driver, but
>   * instead use the devicetree to describe them. This function will, unlike
> 
> -- 
> 2.43.0
> 

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Re: [PATCH v4 3/7] pinctrl: extract pinctrl_generic_to_map() from pinctrl_generic_pins_function_dt_node_to_map()

[Frank Li]

On Fri, Mar 27, 2026 at 12:09:32AM +0000, Conor Dooley wrote:
> On Wed, Mar 25, 2026 at 07:04:12PM -0400, Frank Li wrote:
> > Refactor pinctrl_generic_pins_function_dt_subnode_to_map() by separating DT
> > parsing logic from map creation. Introduce a new helper
> > pinctrl_generic_to_map() to handle mapping to kernel data structures, while
> > keeping DT property parsing in the subnode function.
> >
> > Improve code structure and enables easier reuse for platforms using
> > different DT properties (e.g. pinmux) without modifying the
> > dt_node_to_map-style callback API. Avoid unnecessary coupling to
> > pinctrl_generic_pins_function_dt_node_to_map(), which provides
> > functionality not needed when the phandle target is unambiguous.
> >
> > Maximize code reuse and provide a cleaner extension point for future
> > pinctrl drivers.
> >
> > Signed-off-by: Frank Li <Frank.Li@nxp.com>
> > ---
> > change in v4
> > - new patch
> > ---
> >  drivers/pinctrl/pinconf.h         | 18 ++++++++
> >  drivers/pinctrl/pinctrl-generic.c | 91 ++++++++++++++++++++++++---------------
> >  2 files changed, 74 insertions(+), 35 deletions(-)
> >
> > diff --git a/drivers/pinctrl/pinconf.h b/drivers/pinctrl/pinconf.h
> > index 2880adef476e68950ffdd540ea42cdee6a16ec27..ffdabddb9660324ed8886a2e8dcacff7e1c6c529 100644
> > --- a/drivers/pinctrl/pinconf.h
> > +++ b/drivers/pinctrl/pinconf.h
> > @@ -166,6 +166,13 @@ int pinctrl_generic_pins_function_dt_node_to_map(struct pinctrl_dev *pctldev,
> >  						 struct device_node *np,
> >  						 struct pinctrl_map **maps,
> >  						 unsigned int *num_maps);
> > +
> > +int
> > +pinctrl_generic_to_map(struct pinctrl_dev *pctldev, struct device_node *parent,
> > +		       struct device_node *np, struct pinctrl_map **maps,
> > +		       unsigned int *num_maps, unsigned int *num_reserved_maps,
> > +		       const char **group_name, unsigned int ngroups,
> > +		       const char **functions, unsigned int *pins);
> >  #else
> >  static inline int
> >  pinctrl_generic_pins_function_dt_node_to_map(struct pinctrl_dev *pctldev,
> > @@ -175,4 +182,15 @@ pinctrl_generic_pins_function_dt_node_to_map(struct pinctrl_dev *pctldev,
> >  {
> >  	return -ENOTSUPP;
> >  }
> > +
> > +static inline int
> > +pinctrl_generic_to_map(struct pinctrl_dev *pctldev, struct device_node *parent,
> > +		       struct device_node *np, struct pinctrl_map **maps,
> > +		       unsigned int *num_maps, unsigned int *num_reserved_maps,
> > +		       const char **group_name, unsigned int ngroups,
> > +		       const char **functions, unsigned int *pins,
> > +		       void *function_data)
> > +{
> > +	return -ENOTSUPP;
> > +}
> >  #endif
> > diff --git a/drivers/pinctrl/pinctrl-generic.c b/drivers/pinctrl/pinctrl-generic.c
> > index efb39c6a670331775855efdc8566102b5c6202ef..20a216ae63e91b69985ea4cfcd0b57103c6ca950 100644
> > --- a/drivers/pinctrl/pinctrl-generic.c
> > +++ b/drivers/pinctrl/pinctrl-generic.c
> > @@ -17,29 +17,18 @@
> >  #include "pinctrl-utils.h"
> >  #include "pinmux.h"
> >
> > -static int pinctrl_generic_pins_function_dt_subnode_to_map(struct pinctrl_dev *pctldev,
> > -							   struct device_node *parent,
> > -							   struct device_node *np,
> > -							   struct pinctrl_map **maps,
> > -							   unsigned int *num_maps,
> > -							   unsigned int *num_reserved_maps,
> > -							   const char **group_names,
> > -							   unsigned int ngroups)
> > +int
> > +pinctrl_generic_to_map(struct pinctrl_dev *pctldev, struct device_node *parent,
> > +		       struct device_node *np, struct pinctrl_map **maps,
> > +		       unsigned int *num_maps, unsigned int *num_reserved_maps,
> > +		       const char **group_names, unsigned int ngroups,
> > +		       const char **functions, unsigned int *pins)
>
> npins needs to be an argument to this function also, otherwise
> pinctrl_generic_add_group() uses it uninitialised...

Is this one the root cause of then broken? I am not sure why compiler have
not report waring for it.

Frank
> >

Re: [PATCH v4 3/7] pinctrl: extract pinctrl_generic_to_map() from pinctrl_generic_pins_function_dt_node_to_map()

[Conor Dooley]

[-- Attachment #1: Type: text/plain, Size: 4641 bytes --]

On Fri, Mar 27, 2026 at 12:54:42PM -0400, Frank Li wrote:
> On Fri, Mar 27, 2026 at 12:09:32AM +0000, Conor Dooley wrote:
> > On Wed, Mar 25, 2026 at 07:04:12PM -0400, Frank Li wrote:
> > > Refactor pinctrl_generic_pins_function_dt_subnode_to_map() by separating DT
> > > parsing logic from map creation. Introduce a new helper
> > > pinctrl_generic_to_map() to handle mapping to kernel data structures, while
> > > keeping DT property parsing in the subnode function.
> > >
> > > Improve code structure and enables easier reuse for platforms using
> > > different DT properties (e.g. pinmux) without modifying the
> > > dt_node_to_map-style callback API. Avoid unnecessary coupling to
> > > pinctrl_generic_pins_function_dt_node_to_map(), which provides
> > > functionality not needed when the phandle target is unambiguous.
> > >
> > > Maximize code reuse and provide a cleaner extension point for future
> > > pinctrl drivers.
> > >
> > > Signed-off-by: Frank Li <Frank.Li@nxp.com>
> > > ---
> > > change in v4
> > > - new patch
> > > ---
> > >  drivers/pinctrl/pinconf.h         | 18 ++++++++
> > >  drivers/pinctrl/pinctrl-generic.c | 91 ++++++++++++++++++++++++---------------
> > >  2 files changed, 74 insertions(+), 35 deletions(-)
> > >
> > > diff --git a/drivers/pinctrl/pinconf.h b/drivers/pinctrl/pinconf.h
> > > index 2880adef476e68950ffdd540ea42cdee6a16ec27..ffdabddb9660324ed8886a2e8dcacff7e1c6c529 100644
> > > --- a/drivers/pinctrl/pinconf.h
> > > +++ b/drivers/pinctrl/pinconf.h
> > > @@ -166,6 +166,13 @@ int pinctrl_generic_pins_function_dt_node_to_map(struct pinctrl_dev *pctldev,
> > >  						 struct device_node *np,
> > >  						 struct pinctrl_map **maps,
> > >  						 unsigned int *num_maps);
> > > +
> > > +int
> > > +pinctrl_generic_to_map(struct pinctrl_dev *pctldev, struct device_node *parent,
> > > +		       struct device_node *np, struct pinctrl_map **maps,
> > > +		       unsigned int *num_maps, unsigned int *num_reserved_maps,
> > > +		       const char **group_name, unsigned int ngroups,
> > > +		       const char **functions, unsigned int *pins);
> > >  #else
> > >  static inline int
> > >  pinctrl_generic_pins_function_dt_node_to_map(struct pinctrl_dev *pctldev,
> > > @@ -175,4 +182,15 @@ pinctrl_generic_pins_function_dt_node_to_map(struct pinctrl_dev *pctldev,
> > >  {
> > >  	return -ENOTSUPP;
> > >  }
> > > +
> > > +static inline int
> > > +pinctrl_generic_to_map(struct pinctrl_dev *pctldev, struct device_node *parent,
> > > +		       struct device_node *np, struct pinctrl_map **maps,
> > > +		       unsigned int *num_maps, unsigned int *num_reserved_maps,
> > > +		       const char **group_name, unsigned int ngroups,
> > > +		       const char **functions, unsigned int *pins,
> > > +		       void *function_data)
> > > +{
> > > +	return -ENOTSUPP;
> > > +}
> > >  #endif
> > > diff --git a/drivers/pinctrl/pinctrl-generic.c b/drivers/pinctrl/pinctrl-generic.c
> > > index efb39c6a670331775855efdc8566102b5c6202ef..20a216ae63e91b69985ea4cfcd0b57103c6ca950 100644
> > > --- a/drivers/pinctrl/pinctrl-generic.c
> > > +++ b/drivers/pinctrl/pinctrl-generic.c
> > > @@ -17,29 +17,18 @@
> > >  #include "pinctrl-utils.h"
> > >  #include "pinmux.h"
> > >
> > > -static int pinctrl_generic_pins_function_dt_subnode_to_map(struct pinctrl_dev *pctldev,
> > > -							   struct device_node *parent,
> > > -							   struct device_node *np,
> > > -							   struct pinctrl_map **maps,
> > > -							   unsigned int *num_maps,
> > > -							   unsigned int *num_reserved_maps,
> > > -							   const char **group_names,
> > > -							   unsigned int ngroups)
> > > +int
> > > +pinctrl_generic_to_map(struct pinctrl_dev *pctldev, struct device_node *parent,
> > > +		       struct device_node *np, struct pinctrl_map **maps,
> > > +		       unsigned int *num_maps, unsigned int *num_reserved_maps,
> > > +		       const char **group_names, unsigned int ngroups,
> > > +		       const char **functions, unsigned int *pins)
> >
> > npins needs to be an argument to this function also, otherwise
> > pinctrl_generic_add_group() uses it uninitialised...
> 
> Is this one the root cause of then broken?

No, this is not the cause of the breakage. I can't believe I still have
to say that. Go read the code and you'll see why that allocation thing
is problematic.

> I am not sure why compiler have not report waring for it.

It did, that's how I found it. Used uninitialised warnings are normally
from clang, so your toolchain might not have seen it. clangd integration
with my editor is how I saw it.

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[PATCH v4 4/7] pinctrl: add optional .release_mux() callback

[Frank Li]

Add an optional .release_mux() callback to struct pinmux_ops.

Some drivers acquire additional resources in .set_mux(), such as software
locks. These resources may need to be released when the mux function is no
longer active. Introducing a dedicated .release_mux() callback allows
drivers to clean up such resources.

The callback is optional and does not affect existing drivers.

Commit 2243a87d90b42 ("pinctrl: avoid duplicated calling
enable_pinmux_setting for a pin") removed the .disable() callback
to resolve two issues:

  1. desc->mux_usecount increasing monotonically
  2. Hardware glitches caused by repeated .disable()/.enable() calls

Adding .release_mux() does not reintroduce those problems. The callback is
intended only for releasing driver-side resources (e.g. locks) and must not
modify hardware registers.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
change in v4
- none

change in v3
- Add judgement about 2243a87d90b42 ("pinctrl: avoid duplicated calling
enable_pinmux_setting for a pin") in commit message.
---
 drivers/pinctrl/pinmux.c       | 5 +++++
 include/linux/pinctrl/pinmux.h | 5 +++++
 2 files changed, 10 insertions(+)

diff --git a/drivers/pinctrl/pinmux.c b/drivers/pinctrl/pinmux.c
index 3a8dd184ba3d670e01a890427e19af59b65eb813..c705bc182266c596c4e6c820f5e3ffcadbbb2838 100644
--- a/drivers/pinctrl/pinmux.c
+++ b/drivers/pinctrl/pinmux.c
@@ -517,6 +517,7 @@ void pinmux_disable_setting(const struct pinctrl_setting *setting)
 {
 	struct pinctrl_dev *pctldev = setting->pctldev;
 	const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
+	const struct pinmux_ops *ops = pctldev->desc->pmxops;
 	int ret = 0;
 	const unsigned int *pins = NULL;
 	unsigned int num_pins = 0;
@@ -563,6 +564,10 @@ void pinmux_disable_setting(const struct pinctrl_setting *setting)
 				 pins[i], desc->name, gname);
 		}
 	}
+
+	if (ops->release_mux)
+		ops->release_mux(pctldev, setting->data.mux.func,
+				 setting->data.mux.group);
 }
 
 #ifdef CONFIG_DEBUG_FS
diff --git a/include/linux/pinctrl/pinmux.h b/include/linux/pinctrl/pinmux.h
index 094bbe2fd6fd5ea3c5fdf5b6d6d9a7639700b50b..77664937eeb273eef440988c4cf833dbc6f10758 100644
--- a/include/linux/pinctrl/pinmux.h
+++ b/include/linux/pinctrl/pinmux.h
@@ -51,6 +51,8 @@ struct pinctrl_gpio_range;
  *	are handled by the pinmux subsystem. The @func_selector selects a
  *	certain function whereas @group_selector selects a certain set of pins
  *	to be used. On simple controllers the latter argument may be ignored
+ * @release_mux: Release software resources acquired by @set_mux. This callback
+ *	must not change hardware state to avoid glitches when switching mux.
  * @gpio_request_enable: requests and enables GPIO on a certain pin.
  *	Implement this only if you can mux every pin individually as GPIO. The
  *	affected GPIO range is passed along with an offset(pin number) into that
@@ -80,6 +82,9 @@ struct pinmux_ops {
 				  unsigned int selector);
 	int (*set_mux) (struct pinctrl_dev *pctldev, unsigned int func_selector,
 			unsigned int group_selector);
+	void (*release_mux) (struct pinctrl_dev *pctldev,
+			     unsigned int func_selector,
+			     unsigned int group_selector);
 	int (*gpio_request_enable) (struct pinctrl_dev *pctldev,
 				    struct pinctrl_gpio_range *range,
 				    unsigned int offset);

-- 
2.43.0

[PATCH v4 5/7] pinctrl: add generic board-level pinctrl driver using mux framework

[Frank Li]

Many boards use on-board mux chips (often controlled by GPIOs from an I2C
expander) to switch shared signals between peripherals.

Add a generic pinctrl driver built on top of the mux framework to
centralize mux handling and avoid probe ordering issues. Keep board-level
routing out of individual drivers and supports boot-time only mux
selection.

Ensure correct probe ordering, especially when the GPIO expander is probed
later.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
chagne in v4:
- use new pinctrl_generic_pins_to_map()

change in v3:
- use pinctrl_generic_pins_function_dt_node_to_map() and
pinctrl_utils_free_map().

change in v2:
- fix copywrite by add nxp
- fix if (!*map) check
- add release_mux to call mux_state_deselect()
---
 drivers/pinctrl/Kconfig               |   9 ++
 drivers/pinctrl/Makefile              |   1 +
 drivers/pinctrl/pinctrl-generic-mux.c | 197 ++++++++++++++++++++++++++++++++++
 3 files changed, 207 insertions(+)

diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
index afecd9407f5354f5b92223f8cd80d2f7a08f8e7d..b6d4755e67510786c34f890c5e7a3fcf0adf45e4 100644
--- a/drivers/pinctrl/Kconfig
+++ b/drivers/pinctrl/Kconfig
@@ -274,6 +274,15 @@ config PINCTRL_GEMINI
 	select GENERIC_PINCONF
 	select MFD_SYSCON
 
+config PINCTRL_GENERIC_MUX
+	tristate "Generic Pinctrl driver by using multiplexer"
+	depends on MULTIPLEXER
+	select PINMUX
+	select GENERIC_PINCTRL
+	help
+          Generic pinctrl driver by MULTIPLEXER framework to control on
+          board pin selection.
+
 config PINCTRL_INGENIC
 	bool "Pinctrl driver for the Ingenic JZ47xx SoCs"
 	default MACH_INGENIC
diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile
index f7d5d5f76d0c8becc0aa1d77c68b6ced924ea264..fcd1703440d24579636e8ddb6cbd83a0a982dfb7 100644
--- a/drivers/pinctrl/Makefile
+++ b/drivers/pinctrl/Makefile
@@ -29,6 +29,7 @@ obj-$(CONFIG_PINCTRL_EQUILIBRIUM)   += pinctrl-equilibrium.o
 obj-$(CONFIG_PINCTRL_EP93XX)	+= pinctrl-ep93xx.o
 obj-$(CONFIG_PINCTRL_EYEQ5)	+= pinctrl-eyeq5.o
 obj-$(CONFIG_PINCTRL_GEMINI)	+= pinctrl-gemini.o
+obj-$(CONFIG_PINCTRL_GENERIC_MUX) += pinctrl-generic-mux.o
 obj-$(CONFIG_PINCTRL_INGENIC)	+= pinctrl-ingenic.o
 obj-$(CONFIG_PINCTRL_K210)	+= pinctrl-k210.o
 obj-$(CONFIG_PINCTRL_K230)	+= pinctrl-k230.o
diff --git a/drivers/pinctrl/pinctrl-generic-mux.c b/drivers/pinctrl/pinctrl-generic-mux.c
new file mode 100644
index 0000000000000000000000000000000000000000..d1c1ff16a78dfd9ea66c51e9f70af1839844bcec
--- /dev/null
+++ b/drivers/pinctrl/pinctrl-generic-mux.c
@@ -0,0 +1,197 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Generic Pin Control Driver for Board-Level Mux Chips
+ * Copyright 2026 NXP
+ */
+
+#include <linux/cleanup.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/mutex.h>
+#include <linux/mux/consumer.h>
+#include <linux/platform_device.h>
+#include <linux/pinctrl/pinconf-generic.h>
+#include <linux/pinctrl/pinctrl.h>
+#include <linux/pinctrl/pinmux.h>
+#include <linux/slab.h>
+
+#include "core.h"
+#include "pinconf.h"
+#include "pinmux.h"
+#include "pinctrl-utils.h"
+
+struct mux_pin_function {
+	struct mux_state *mux_state;
+};
+
+struct mux_pinctrl {
+	struct device *dev;
+	struct pinctrl_dev *pctl;
+
+	/* mutex protect [pinctrl|pinmux]_generic functions */
+	struct mutex lock;
+	int cur_select;
+};
+
+static int
+mux_pinmux_dt_node_to_map(struct pinctrl_dev *pctldev,
+			  struct device_node *np_config,
+			  struct pinctrl_map **maps, unsigned int *num_maps)
+{
+	unsigned int num_reserved_maps = 0;
+	struct mux_pin_function *function;
+	const char **group_names;
+	int ret;
+
+	function = devm_kzalloc(pctldev->dev, sizeof(*function), GFP_KERNEL);
+	if (!function)
+		return -ENOMEM;
+
+	group_names = devm_kcalloc(pctldev->dev, 1, sizeof(*group_names), GFP_KERNEL);
+	if (!group_names)
+		return -ENOMEM;
+
+	function->mux_state = devm_mux_state_get_from_np(pctldev->dev, NULL, np_config);
+	if (IS_ERR(function->mux_state))
+		return PTR_ERR(function->mux_state);
+
+	ret = pinctrl_generic_to_map(pctldev, np_config, np_config, maps,
+				     num_maps, &num_reserved_maps, group_names,
+				     0, &np_config->name, NULL);
+
+	if (ret)
+		return ret;
+
+	ret = pinmux_generic_add_function(pctldev, np_config->name, group_names,
+					  1, function);
+	if (ret < 0) {
+		pinctrl_utils_free_map(pctldev, *maps, *num_maps);
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct pinctrl_ops mux_pinctrl_ops = {
+	.get_groups_count = pinctrl_generic_get_group_count,
+	.get_group_name = pinctrl_generic_get_group_name,
+	.get_group_pins = pinctrl_generic_get_group_pins,
+	.dt_node_to_map = mux_pinmux_dt_node_to_map,
+	.dt_free_map = pinctrl_utils_free_map,
+};
+
+static int mux_pinmux_set_mux(struct pinctrl_dev *pctldev,
+			      unsigned int func_selector,
+			      unsigned int group_selector)
+{
+	struct mux_pinctrl *mpctl = pinctrl_dev_get_drvdata(pctldev);
+	const struct function_desc *function;
+	struct mux_pin_function *func;
+	int ret;
+
+	guard(mutex)(&mpctl->lock);
+
+	function = pinmux_generic_get_function(pctldev, func_selector);
+	func = function->data;
+
+	if (mpctl->cur_select == func_selector)
+		return 0;
+
+	if (mpctl->cur_select >= 0 && mpctl->cur_select != func_selector)
+		return -EINVAL;
+
+	ret = mux_state_select(func->mux_state);
+	if (ret)
+		return ret;
+
+	mpctl->cur_select = func_selector;
+
+	return 0;
+}
+
+static void mux_pinmux_release_mux(struct pinctrl_dev *pctldev,
+				   unsigned int func_selector,
+				   unsigned int group_selector)
+{
+	struct mux_pinctrl *mpctl = pinctrl_dev_get_drvdata(pctldev);
+	const struct function_desc *function;
+	struct mux_pin_function *func;
+
+	guard(mutex)(&mpctl->lock);
+
+	function = pinmux_generic_get_function(pctldev, func_selector);
+	func = function->data;
+
+	mux_state_deselect(func->mux_state);
+
+	mpctl->cur_select = -1;
+}
+
+static const struct pinmux_ops mux_pinmux_ops = {
+	.get_functions_count = pinmux_generic_get_function_count,
+	.get_function_name = pinmux_generic_get_function_name,
+	.get_function_groups = pinmux_generic_get_function_groups,
+	.set_mux = mux_pinmux_set_mux,
+	.release_mux = mux_pinmux_release_mux,
+};
+
+static int mux_pinctrl_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct mux_pinctrl *mpctl;
+	struct pinctrl_desc *pctl_desc;
+	int ret;
+
+	mpctl = devm_kzalloc(dev, sizeof(*mpctl), GFP_KERNEL);
+	if (!mpctl)
+		return -ENOMEM;
+
+	mpctl->dev = dev;
+	mpctl->cur_select = -1;
+
+	platform_set_drvdata(pdev, mpctl);
+
+	pctl_desc = devm_kzalloc(dev, sizeof(*pctl_desc), GFP_KERNEL);
+	if (!pctl_desc)
+		return -ENOMEM;
+
+	ret = devm_mutex_init(dev, &mpctl->lock);
+	if (ret)
+		return ret;
+
+	pctl_desc->name = dev_name(dev);
+	pctl_desc->owner = THIS_MODULE;
+	pctl_desc->pctlops = &mux_pinctrl_ops;
+	pctl_desc->pmxops = &mux_pinmux_ops;
+
+	ret = devm_pinctrl_register_and_init(dev, pctl_desc, mpctl,
+					     &mpctl->pctl);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to register pinctrl.\n");
+
+	ret = pinctrl_enable(mpctl->pctl);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to enable pinctrl.\n");
+
+	return 0;
+}
+
+static const struct of_device_id mux_pinctrl_of_match[] = {
+	{ .compatible = "pinctrl-multiplexer" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, mux_pinctrl_of_match);
+
+static struct platform_driver mux_pinctrl_driver = {
+	.driver = {
+		.name = "generic-pinctrl-mux",
+		.of_match_table = mux_pinctrl_of_match,
+	},
+	.probe = mux_pinctrl_probe,
+};
+module_platform_driver(mux_pinctrl_driver);
+
+MODULE_AUTHOR("Frank Li <Frank.Li@nxp.com>");
+MODULE_DESCRIPTION("Generic Pin Control Driver for Board-Level Mux Chips");
+MODULE_LICENSE("GPL");
+

-- 
2.43.0

[PATCH v4 6/7] arm64: dts: imx8mp-evk: add board-level mux for CAN2 and MICFIL

[Frank Li]

The board integrates an on-board mux to route shared signals to either
CAN2 or PDM (MICFIL). The mux is controlled by a GPIO.

Add a pinctrl-based multiplexer node to describe this routing and ensure
proper probe ordering of the dependent devices.

Previously, MICFIL operation implicitly depended on the default level of
PCA6416 GPIO3. After adding the pinctrl-multiplexer, make the dependency
explicit.

Reviewed-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
change in v3 - v4
- none
change in v2
- update commit message to show why need update PDM MICIFL.
---
 arch/arm64/boot/dts/freescale/imx8mp-evk.dts | 23 +++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/boot/dts/freescale/imx8mp-evk.dts b/arch/arm64/boot/dts/freescale/imx8mp-evk.dts
index b256be710ea1281465f5cecc7a3b979f2c068e43..1341ee27239fd41a26117adc9023524ce50420a7 100644
--- a/arch/arm64/boot/dts/freescale/imx8mp-evk.dts
+++ b/arch/arm64/boot/dts/freescale/imx8mp-evk.dts
@@ -50,6 +50,25 @@ status {
 		};
 	};
 
+	can_mux: mux-controller-0 {
+		compatible = "gpio-mux";
+		#mux-control-cells = <0>;
+		#mux-state-cells = <1>;
+		mux-gpios = <&pca6416 3 GPIO_ACTIVE_HIGH>;
+	};
+
+	can_mux_pinctrl: pinctrl-gpiomux {
+		compatible = "pinctrl-multiplexer";
+
+		can_fun: can-grp {
+			mux-states = <&can_mux 1>;
+		};
+
+		pdm_fun: pdm-grp {
+			mux-states = <&can_mux 0>;
+		};
+	};
+
 	memory@40000000 {
 		device_type = "memory";
 		reg = <0x0 0x40000000 0 0xc0000000>,
@@ -446,7 +465,7 @@ &flexcan1 {
 
 &flexcan2 {
 	pinctrl-names = "default";
-	pinctrl-0 = <&pinctrl_flexcan2>;
+	pinctrl-0 = <&pinctrl_flexcan2>, <&can_fun>;
 	phys = <&flexcan_phy 1>;
 	status = "disabled";/* can2 pin conflict with pdm */
 };
@@ -712,7 +731,7 @@ &lcdif3 {
 &micfil {
 	#sound-dai-cells = <0>;
 	pinctrl-names = "default";
-	pinctrl-0 = <&pinctrl_pdm>;
+	pinctrl-0 = <&pinctrl_pdm>, <&pdm_fun>;
 	assigned-clocks = <&clk IMX8MP_CLK_PDM>;
 	assigned-clock-parents = <&clk IMX8MP_AUDIO_PLL1_OUT>;
 	assigned-clock-rates = <196608000>;

-- 
2.43.0

[PATCH v4 7/7] arm64: dts: imx8mp-evk: add flexcan2 overlay file

[Frank Li]

Add flexcan2 overlay file, which enable flexcan2 node and disable micfil
node.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
change in v3-v4
- none
---
 arch/arm64/boot/dts/freescale/Makefile                 |  4 ++++
 arch/arm64/boot/dts/freescale/imx8mp-evk-flexcan2.dtso | 15 +++++++++++++++
 2 files changed, 19 insertions(+)

diff --git a/arch/arm64/boot/dts/freescale/Makefile b/arch/arm64/boot/dts/freescale/Makefile
index 700bab4d3e6001fe6cf460fcb09cfe57acc77e36..bd377191a68a6167d5f9a65184d19c789a4223ee 100644
--- a/arch/arm64/boot/dts/freescale/Makefile
+++ b/arch/arm64/boot/dts/freescale/Makefile
@@ -233,6 +233,10 @@ dtb-$(CONFIG_ARCH_MXC) += imx8mp-dhcom-pdk3.dtb
 dtb-$(CONFIG_ARCH_MXC) += imx8mp-dhcom-picoitx.dtb
 dtb-$(CONFIG_ARCH_MXC) += imx8mp-edm-g-wb.dtb
 dtb-$(CONFIG_ARCH_MXC) += imx8mp-evk.dtb
+
+imx8mp-evk-flexcan2-dtbs += imx8mp-evk.dtb imx8mp-evk-flexcan2.dtbo
+dtb-$(CONFIG_ARCH_MXC) += imx8mp-evk-flexcan2.dtb
+
 dtb-$(CONFIG_ARCH_MXC) += imx8mp-frdm.dtb
 dtb-$(CONFIG_ARCH_MXC) += imx8mp-hummingboard-mate.dtb
 dtb-$(CONFIG_ARCH_MXC) += imx8mp-hummingboard-pro.dtb
diff --git a/arch/arm64/boot/dts/freescale/imx8mp-evk-flexcan2.dtso b/arch/arm64/boot/dts/freescale/imx8mp-evk-flexcan2.dtso
new file mode 100644
index 0000000000000000000000000000000000000000..f7d2674c45f72353a20300300e98c8a1eba4a2a6
--- /dev/null
+++ b/arch/arm64/boot/dts/freescale/imx8mp-evk-flexcan2.dtso
@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+/*
+ * Copyright 2026 NXP
+ */
+
+/dts-v1/;
+/plugin/;
+
+&flexcan2 {
+        status = "okay"; /* can2 pin conflict with pdm */
+};
+
+&micfil {
+        status = "disabled";
+};

-- 
2.43.0