[PATCH v4 0/6] Add support for software nodes to gpiolib

[PATCH v4 0/6] Add support for software nodes to gpiolib

[Dmitry Torokhov]

This series attempts to add support for software nodes to gpiolib, using
software node references. This allows us to convert more drivers to the
generic device properties and drop support for custom platform data.

To describe a GPIO via software nodes we can create the following data
items:

/* Node representing the GPIO controller/GPIO bank */
static const struct software_node gpio_bank_b_node = {
        .name = "B",
};

/*
 * Properties that will be assigned to a software node assigned to
 * the device that used platform data.
 */
static const struct property_entry simone_key_enter_props[] = {
        PROPERTY_ENTRY_U32("linux,code", KEY_ENTER),
        PROPERTY_ENTRY_STRING("label", "enter"),
        PROPERTY_ENTRY_REF("gpios", &gpio_bank_b_node, 123, GPIO_ACTIVE_LOW),
        { }
};

The code in gpiolib handling software nodes uses the name in the
software node representing GPIO controller to locate the actual instance
of GPIO controller.

To: Linus Walleij <linus.walleij@linaro.org>
To: Bartosz Golaszewski <brgl@bgdev.pl>
To: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: linux-gpio@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-acpi@vger.kernel.org

---
Changes in v4:
- Rebased on top of next-20221111
- Added Andy's reviewed-by for patch #6
- Link to v3: https://lore.kernel.org/r/20221031-gpiolib-swnode-v3-0-0282162b0fa4@gmail.com

Changes in v3:
- Addressed more Andy's comments
- Link to v2: https://lore.kernel.org/r/20221031-gpiolib-swnode-v2-0-81f55af5fa0e@gmail.com

Changes in v2:
- reworked the series to be independent of other in-flight patches.
  That meant keeping devm_gpiod_get_from_of_node() for now.
- removed handling of secondary nodes, it deserves a separate patch
  series
- fixed refcounting when handling swnodes (Andy)
- added include/linux/gpio/property.h with PROPERTY_ENTRY_GPIO (Andy)
- addressed most of the rest of Andy's comments
- collected reviewed-by and acked-by
- Link to v1: https://lore.kernel.org/r/20221031-gpiolib-swnode-v1-0-a0ab48d229c7@gmail.com

---
Dmitry Torokhov (6):
      gpiolib: of: change of_find_gpio() to accept device node
      gpiolib: acpi: change acpi_find_gpio() to accept firmware node
      gpiolib: acpi: teach acpi_find_gpio() to handle data-only nodes
      gpiolib: acpi: avoid leaking ACPI details into upper gpiolib layers
      gpiolib: consolidate GPIO lookups
      gpiolib: add support for software nodes

 drivers/gpio/Makefile         |   1 +
 drivers/gpio/gpiolib-acpi.c   | 132 +++++++++++++++-----------
 drivers/gpio/gpiolib-acpi.h   |  54 +----------
 drivers/gpio/gpiolib-of.c     |   7 +-
 drivers/gpio/gpiolib-of.h     |   4 +-
 drivers/gpio/gpiolib-swnode.c | 123 +++++++++++++++++++++++++
 drivers/gpio/gpiolib-swnode.h |  14 +++
 drivers/gpio/gpiolib.c        | 209 ++++++++++++++++--------------------------
 include/linux/gpio/property.h |  11 +++
 9 files changed, 315 insertions(+), 240 deletions(-)
---
base-commit: f8f60f322f0640c8edda2942ca5f84b7a27c417a
change-id: 20221031-gpiolib-swnode-948203f49b23

-- 
Dmitry

[PATCH v4 1/6] gpiolib: of: change of_find_gpio() to accept device node

[Dmitry Torokhov]

In preparation of switching all OF-based GPIO lookups to go through
of_find_gpio() let's change it to accept device node as its argument as
we do not always have access to device structure.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
 drivers/gpio/gpiolib-of.c | 7 +++----
 drivers/gpio/gpiolib-of.h | 4 ++--
 drivers/gpio/gpiolib.c    | 5 +++--
 3 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index 4be3c21aa718..596b8e21700e 100644
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -605,7 +605,7 @@ static const of_find_gpio_quirk of_find_gpio_quirks[] = {
 	NULL
 };
 
-struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
+struct gpio_desc *of_find_gpio(struct device_node *np, const char *con_id,
 			       unsigned int idx, unsigned long *flags)
 {
 	char prop_name[32]; /* 32 is max size of property name */
@@ -623,8 +623,7 @@ struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
 			snprintf(prop_name, sizeof(prop_name), "%s",
 				 gpio_suffixes[i]);
 
-		desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx,
-						&of_flags);
+		desc = of_get_named_gpiod_flags(np, prop_name, idx, &of_flags);
 
 		if (!gpiod_not_found(desc))
 			break;
@@ -632,7 +631,7 @@ struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
 
 	/* Properly named GPIO was not found, try workarounds */
 	for (q = of_find_gpio_quirks; gpiod_not_found(desc) && *q; q++)
-		desc = (*q)(dev->of_node, con_id, idx, &of_flags);
+		desc = (*q)(np, con_id, idx, &of_flags);
 
 	if (IS_ERR(desc))
 		return desc;
diff --git a/drivers/gpio/gpiolib-of.h b/drivers/gpio/gpiolib-of.h
index 2a2f7d17fa7e..a6c593e6766c 100644
--- a/drivers/gpio/gpiolib-of.h
+++ b/drivers/gpio/gpiolib-of.h
@@ -16,7 +16,7 @@ struct gpio_desc;
 struct gpio_device;
 
 #ifdef CONFIG_OF_GPIO
-struct gpio_desc *of_find_gpio(struct device *dev,
+struct gpio_desc *of_find_gpio(struct device_node *np,
 			       const char *con_id,
 			       unsigned int idx,
 			       unsigned long *lookupflags);
@@ -25,7 +25,7 @@ void of_gpiochip_remove(struct gpio_chip *gc);
 int of_gpio_get_count(struct device *dev, const char *con_id);
 void of_gpio_dev_init(struct gpio_chip *gc, struct gpio_device *gdev);
 #else
-static inline struct gpio_desc *of_find_gpio(struct device *dev,
+static inline struct gpio_desc *of_find_gpio(struct device_node *np,
 					     const char *con_id,
 					     unsigned int idx,
 					     unsigned long *lookupflags)
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 11fb7ec883e9..a80fc8abb03f 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -4122,14 +4122,15 @@ struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
 	int ret;
 	/* Maybe we have a device name, maybe not */
 	const char *devname = dev ? dev_name(dev) : "?";
-	const struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
+	struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
 
 	dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
 
 	/* Using device tree? */
 	if (is_of_node(fwnode)) {
 		dev_dbg(dev, "using device tree for GPIO lookup\n");
-		desc = of_find_gpio(dev, con_id, idx, &lookupflags);
+		desc = of_find_gpio(to_of_node(fwnode),
+				    con_id, idx, &lookupflags);
 	} else if (is_acpi_node(fwnode)) {
 		dev_dbg(dev, "using ACPI for GPIO lookup\n");
 		desc = acpi_find_gpio(dev, con_id, idx, &flags, &lookupflags);

-- 
b4 0.11.0-dev-28747

[PATCH v4 2/6] gpiolib: acpi: change acpi_find_gpio() to accept firmware node

[Dmitry Torokhov]

In preparation of switching all ACPI-based GPIO lookups to go through
acpi_find_gpio() let's change it to accept device node as its argument
as we do not always have access to device structure.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
 drivers/gpio/gpiolib-acpi.c | 8 ++++++--
 drivers/gpio/gpiolib-acpi.h | 4 ++--
 drivers/gpio/gpiolib.c      | 3 ++-
 3 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c
index 064ba5150fd4..ccb74e208989 100644
--- a/drivers/gpio/gpiolib-acpi.c
+++ b/drivers/gpio/gpiolib-acpi.c
@@ -906,18 +906,22 @@ static bool acpi_can_fallback_to_crs(struct acpi_device *adev,
 	return con_id == NULL;
 }
 
-struct gpio_desc *acpi_find_gpio(struct device *dev,
+struct gpio_desc *acpi_find_gpio(struct fwnode_handle *fwnode,
 				 const char *con_id,
 				 unsigned int idx,
 				 enum gpiod_flags *dflags,
 				 unsigned long *lookupflags)
 {
-	struct acpi_device *adev = ACPI_COMPANION(dev);
+	struct acpi_device *adev;
 	struct acpi_gpio_info info;
 	struct gpio_desc *desc;
 	char propname[32];
 	int i;
 
+	adev = to_acpi_device_node(fwnode);
+	if (!adev)
+		return ERR_PTR(-ENODEV);
+
 	/* Try first from _DSD */
 	for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
 		if (con_id) {
diff --git a/drivers/gpio/gpiolib-acpi.h b/drivers/gpio/gpiolib-acpi.h
index 01e0cb480a00..bd1f9b92ea9e 100644
--- a/drivers/gpio/gpiolib-acpi.h
+++ b/drivers/gpio/gpiolib-acpi.h
@@ -60,7 +60,7 @@ int acpi_gpio_update_gpiod_flags(enum gpiod_flags *flags,
 int acpi_gpio_update_gpiod_lookup_flags(unsigned long *lookupflags,
 					struct acpi_gpio_info *info);
 
-struct gpio_desc *acpi_find_gpio(struct device *dev,
+struct gpio_desc *acpi_find_gpio(struct fwnode_handle *fwnode,
 				 const char *con_id,
 				 unsigned int idx,
 				 enum gpiod_flags *dflags,
@@ -95,7 +95,7 @@ acpi_gpio_update_gpiod_lookup_flags(unsigned long *lookupflags,
 }
 
 static inline struct gpio_desc *
-acpi_find_gpio(struct device *dev, const char *con_id,
+acpi_find_gpio(struct fwnode_handle *fwnode, const char *con_id,
 	       unsigned int idx, enum gpiod_flags *dflags,
 	       unsigned long *lookupflags)
 {
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index a80fc8abb03f..e874bb0ef685 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -4133,7 +4133,8 @@ struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
 				    con_id, idx, &lookupflags);
 	} else if (is_acpi_node(fwnode)) {
 		dev_dbg(dev, "using ACPI for GPIO lookup\n");
-		desc = acpi_find_gpio(dev, con_id, idx, &flags, &lookupflags);
+		desc = acpi_find_gpio(fwnode,
+				      con_id, idx, &flags, &lookupflags);
 	}
 
 	/*

-- 
b4 0.11.0-dev-28747

[PATCH v4 3/6] gpiolib: acpi: teach acpi_find_gpio() to handle data-only nodes

[Dmitry Torokhov]

In preparation of switching all ACPI-based GPIO lookups to go through
acpi_find_gpio() we need to make sure it can handle data-only ACPI
nodes, same as existing acpi_node_get_gpiod().

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
 drivers/gpio/gpiolib-acpi.c | 76 +++++++++++++++++++++++++++++----------------
 1 file changed, 50 insertions(+), 26 deletions(-)

diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c
index ccb74e208989..d51bf2a3203d 100644
--- a/drivers/gpio/gpiolib-acpi.c
+++ b/drivers/gpio/gpiolib-acpi.c
@@ -864,8 +864,9 @@ static int acpi_gpio_property_lookup(struct fwnode_handle *fwnode,
  * function only returns the first.
  */
 static struct gpio_desc *acpi_get_gpiod_by_index(struct acpi_device *adev,
-					  const char *propname, int index,
-					  struct acpi_gpio_info *info)
+						 const char *propname,
+						 int index,
+						 struct acpi_gpio_info *info)
 {
 	struct acpi_gpio_lookup lookup;
 	int ret;
@@ -896,6 +897,44 @@ static struct gpio_desc *acpi_get_gpiod_by_index(struct acpi_device *adev,
 	return ret ? ERR_PTR(ret) : lookup.desc;
 }
 
+/**
+ * acpi_get_gpiod_from_data() - get a GPIO descriptor from ACPI data node
+ * @fwnode: pointer to an ACPI firmware node to get the GPIO information from
+ * @propname: Property name of the GPIO
+ * @index: index of GpioIo/GpioInt resource (starting from %0)
+ * @info: info pointer to fill in (optional)
+ *
+ * This function uses the property-based GPIO lookup to get to the GPIO
+ * resource with the relevant information from a data-only ACPI firmware node
+ * and uses that to obtain the GPIO descriptor to return.
+ *
+ * If the GPIO cannot be translated or there is an error an ERR_PTR is
+ * returned.
+ */
+static struct gpio_desc *acpi_get_gpiod_from_data(struct fwnode_handle *fwnode,
+						  const char *propname,
+						  int index,
+						  struct acpi_gpio_info *info)
+{
+	struct acpi_gpio_lookup lookup;
+	int ret;
+
+	if (!is_acpi_data_node(fwnode))
+		return ERR_PTR(-ENODEV);
+
+	if (!propname)
+		return ERR_PTR(-EINVAL);
+
+	lookup.index = index;
+
+	ret = acpi_gpio_property_lookup(fwnode, propname, index, &lookup);
+	if (ret)
+		return ERR_PTR(ret);
+
+	ret = acpi_gpio_resource_lookup(&lookup, info);
+	return ret ? ERR_PTR(ret) : lookup.desc;
+}
+
 static bool acpi_can_fallback_to_crs(struct acpi_device *adev,
 				     const char *con_id)
 {
@@ -912,16 +951,12 @@ struct gpio_desc *acpi_find_gpio(struct fwnode_handle *fwnode,
 				 enum gpiod_flags *dflags,
 				 unsigned long *lookupflags)
 {
-	struct acpi_device *adev;
+	struct acpi_device *adev = to_acpi_device_node(fwnode);
 	struct acpi_gpio_info info;
 	struct gpio_desc *desc;
 	char propname[32];
 	int i;
 
-	adev = to_acpi_device_node(fwnode);
-	if (!adev)
-		return ERR_PTR(-ENODEV);
-
 	/* Try first from _DSD */
 	for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
 		if (con_id) {
@@ -932,7 +967,12 @@ struct gpio_desc *acpi_find_gpio(struct fwnode_handle *fwnode,
 				 gpio_suffixes[i]);
 		}
 
-		desc = acpi_get_gpiod_by_index(adev, propname, idx, &info);
+		if (adev)
+			desc = acpi_get_gpiod_by_index(adev,
+						       propname, idx, &info);
+		else
+			desc = acpi_get_gpiod_from_data(fwnode,
+						        propname, idx, &info);
 		if (!IS_ERR(desc))
 			break;
 		if (PTR_ERR(desc) == -EPROBE_DEFER)
@@ -941,7 +981,7 @@ struct gpio_desc *acpi_find_gpio(struct fwnode_handle *fwnode,
 
 	/* Then from plain _CRS GPIOs */
 	if (IS_ERR(desc)) {
-		if (!acpi_can_fallback_to_crs(adev, con_id))
+		if (!adev || !acpi_can_fallback_to_crs(adev, con_id))
 			return ERR_PTR(-ENOENT);
 
 		desc = acpi_get_gpiod_by_index(adev, NULL, idx, &info);
@@ -979,29 +1019,13 @@ struct gpio_desc *acpi_node_get_gpiod(struct fwnode_handle *fwnode,
 				      const char *propname, int index,
 				      struct acpi_gpio_info *info)
 {
-	struct acpi_gpio_lookup lookup;
 	struct acpi_device *adev;
-	int ret;
 
 	adev = to_acpi_device_node(fwnode);
 	if (adev)
 		return acpi_get_gpiod_by_index(adev, propname, index, info);
 
-	if (!is_acpi_data_node(fwnode))
-		return ERR_PTR(-ENODEV);
-
-	if (!propname)
-		return ERR_PTR(-EINVAL);
-
-	memset(&lookup, 0, sizeof(lookup));
-	lookup.index = index;
-
-	ret = acpi_gpio_property_lookup(fwnode, propname, index, &lookup);
-	if (ret)
-		return ERR_PTR(ret);
-
-	ret = acpi_gpio_resource_lookup(&lookup, info);
-	return ret ? ERR_PTR(ret) : lookup.desc;
+	return acpi_get_gpiod_from_data(fwnode, propname, index, info);
 }
 
 /**

-- 
b4 0.11.0-dev-28747

[PATCH v4 4/6] gpiolib: acpi: avoid leaking ACPI details into upper gpiolib layers

[Dmitry Torokhov]

There is no need for the generic parts of GPIOLIB to be aware of
implementation details of ACPI-bases lookups.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
 drivers/gpio/gpiolib-acpi.c | 51 ++++++++++++++++++++++++++++++++++++++-------
 drivers/gpio/gpiolib-acpi.h | 46 +++-------------------------------------
 drivers/gpio/gpiolib.c      |  8 ++-----
 3 files changed, 48 insertions(+), 57 deletions(-)

diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c
index d51bf2a3203d..1bc386032ca8 100644
--- a/drivers/gpio/gpiolib-acpi.c
+++ b/drivers/gpio/gpiolib-acpi.c
@@ -89,6 +89,30 @@ struct acpi_gpio_chip {
 	struct list_head deferred_req_irqs_list_entry;
 };
 
+/**
+ * struct acpi_gpio_info - ACPI GPIO specific information
+ * @adev: reference to ACPI device which consumes GPIO resource
+ * @flags: GPIO initialization flags
+ * @gpioint: if %true this GPIO is of type GpioInt otherwise type is GpioIo
+ * @pin_config: pin bias as provided by ACPI
+ * @polarity: interrupt polarity as provided by ACPI
+ * @triggering: triggering type as provided by ACPI
+ * @wake_capable: wake capability as provided by ACPI
+ * @debounce: debounce timeout as provided by ACPI
+ * @quirks: Linux specific quirks as provided by struct acpi_gpio_mapping
+ */
+struct acpi_gpio_info {
+	struct acpi_device *adev;
+	enum gpiod_flags flags;
+	bool gpioint;
+	int pin_config;
+	int polarity;
+	int triggering;
+	bool wake_capable;
+	unsigned int debounce;
+	unsigned int quirks;
+};
+
 /*
  * For GPIO chips which call acpi_gpiochip_request_interrupts() before late_init
  * (so builtin drivers) we register the ACPI GpioInt IRQ handlers from a
@@ -670,8 +694,8 @@ __acpi_gpio_update_gpiod_flags(enum gpiod_flags *flags, enum gpiod_flags update)
 	return ret;
 }
 
-int
-acpi_gpio_update_gpiod_flags(enum gpiod_flags *flags, struct acpi_gpio_info *info)
+static int acpi_gpio_update_gpiod_flags(enum gpiod_flags *flags,
+				        struct acpi_gpio_info *info)
 {
 	struct device *dev = &info->adev->dev;
 	enum gpiod_flags old = *flags;
@@ -690,8 +714,8 @@ acpi_gpio_update_gpiod_flags(enum gpiod_flags *flags, struct acpi_gpio_info *inf
 	return ret;
 }
 
-int acpi_gpio_update_gpiod_lookup_flags(unsigned long *lookupflags,
-					struct acpi_gpio_info *info)
+static int acpi_gpio_update_gpiod_lookup_flags(unsigned long *lookupflags,
+					       struct acpi_gpio_info *info)
 {
 	switch (info->pin_config) {
 	case ACPI_PIN_CONFIG_PULLUP:
@@ -1005,7 +1029,8 @@ struct gpio_desc *acpi_find_gpio(struct fwnode_handle *fwnode,
  * @fwnode: pointer to an ACPI firmware node to get the GPIO information from
  * @propname: Property name of the GPIO
  * @index: index of GpioIo/GpioInt resource (starting from %0)
- * @info: info pointer to fill in (optional)
+ * @lflags: bitmask of gpio_lookup_flags GPIO_* values
+ * @dflags: gpiod initialization flags
  *
  * If @fwnode is an ACPI device object, call acpi_get_gpiod_by_index() for it.
  * Otherwise (i.e. it is a data-only non-device object), use the property-based
@@ -1017,15 +1042,25 @@ struct gpio_desc *acpi_find_gpio(struct fwnode_handle *fwnode,
  */
 struct gpio_desc *acpi_node_get_gpiod(struct fwnode_handle *fwnode,
 				      const char *propname, int index,
-				      struct acpi_gpio_info *info)
+				      unsigned long *lflags,
+				      enum gpiod_flags *dflags)
 {
+	struct acpi_gpio_info info;
 	struct acpi_device *adev;
+	struct gpio_desc *desc;
 
 	adev = to_acpi_device_node(fwnode);
 	if (adev)
-		return acpi_get_gpiod_by_index(adev, propname, index, info);
+		desc = acpi_get_gpiod_by_index(adev, propname, index, &info);
+	else
+		desc = acpi_get_gpiod_from_data(fwnode, propname, index, &info);
 
-	return acpi_get_gpiod_from_data(fwnode, propname, index, info);
+	if (!IS_ERR(desc)) {
+		acpi_gpio_update_gpiod_flags(dflags, &info);
+		acpi_gpio_update_gpiod_lookup_flags(lflags, &info);
+	}
+
+	return desc;
 }
 
 /**
diff --git a/drivers/gpio/gpiolib-acpi.h b/drivers/gpio/gpiolib-acpi.h
index bd1f9b92ea9e..8880615327ac 100644
--- a/drivers/gpio/gpiolib-acpi.h
+++ b/drivers/gpio/gpiolib-acpi.h
@@ -22,30 +22,6 @@ struct gpio_chip;
 struct gpio_desc;
 struct gpio_device;
 
-/**
- * struct acpi_gpio_info - ACPI GPIO specific information
- * @adev: reference to ACPI device which consumes GPIO resource
- * @flags: GPIO initialization flags
- * @gpioint: if %true this GPIO is of type GpioInt otherwise type is GpioIo
- * @pin_config: pin bias as provided by ACPI
- * @polarity: interrupt polarity as provided by ACPI
- * @triggering: triggering type as provided by ACPI
- * @wake_capable: wake capability as provided by ACPI
- * @debounce: debounce timeout as provided by ACPI
- * @quirks: Linux specific quirks as provided by struct acpi_gpio_mapping
- */
-struct acpi_gpio_info {
-	struct acpi_device *adev;
-	enum gpiod_flags flags;
-	bool gpioint;
-	int pin_config;
-	int polarity;
-	int triggering;
-	bool wake_capable;
-	unsigned int debounce;
-	unsigned int quirks;
-};
-
 #ifdef CONFIG_ACPI
 void acpi_gpiochip_add(struct gpio_chip *chip);
 void acpi_gpiochip_remove(struct gpio_chip *chip);
@@ -55,11 +31,6 @@ void acpi_gpio_dev_init(struct gpio_chip *gc, struct gpio_device *gdev);
 void acpi_gpiochip_request_interrupts(struct gpio_chip *chip);
 void acpi_gpiochip_free_interrupts(struct gpio_chip *chip);
 
-int acpi_gpio_update_gpiod_flags(enum gpiod_flags *flags,
-				 struct acpi_gpio_info *info);
-int acpi_gpio_update_gpiod_lookup_flags(unsigned long *lookupflags,
-					struct acpi_gpio_info *info);
-
 struct gpio_desc *acpi_find_gpio(struct fwnode_handle *fwnode,
 				 const char *con_id,
 				 unsigned int idx,
@@ -67,7 +38,8 @@ struct gpio_desc *acpi_find_gpio(struct fwnode_handle *fwnode,
 				 unsigned long *lookupflags);
 struct gpio_desc *acpi_node_get_gpiod(struct fwnode_handle *fwnode,
 				      const char *propname, int index,
-				      struct acpi_gpio_info *info);
+				      unsigned long *lflags,
+				      enum gpiod_flags *dflags);
 
 int acpi_gpio_count(struct device *dev, const char *con_id);
 #else
@@ -82,18 +54,6 @@ acpi_gpiochip_request_interrupts(struct gpio_chip *chip) { }
 static inline void
 acpi_gpiochip_free_interrupts(struct gpio_chip *chip) { }
 
-static inline int
-acpi_gpio_update_gpiod_flags(enum gpiod_flags *flags, struct acpi_gpio_info *info)
-{
-	return 0;
-}
-static inline int
-acpi_gpio_update_gpiod_lookup_flags(unsigned long *lookupflags,
-				    struct acpi_gpio_info *info)
-{
-	return 0;
-}
-
 static inline struct gpio_desc *
 acpi_find_gpio(struct fwnode_handle *fwnode, const char *con_id,
 	       unsigned int idx, enum gpiod_flags *dflags,
@@ -103,7 +63,7 @@ acpi_find_gpio(struct fwnode_handle *fwnode, const char *con_id,
 }
 static inline struct gpio_desc *
 acpi_node_get_gpiod(struct fwnode_handle *fwnode, const char *propname,
-		    int index, struct acpi_gpio_info *info)
+		    int index, unsigned long *lflags, enum gpiod_flags *dflags)
 {
 	return ERR_PTR(-ENXIO);
 }
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index e874bb0ef685..b213f5f93ae0 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -3890,14 +3890,10 @@ static struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
 					      label);
 		return desc;
 	} else if (is_acpi_node(fwnode)) {
-		struct acpi_gpio_info info;
-
-		desc = acpi_node_get_gpiod(fwnode, propname, index, &info);
+		desc = acpi_node_get_gpiod(fwnode, propname, index,
+					   &lflags, &dflags);
 		if (IS_ERR(desc))
 			return desc;
-
-		acpi_gpio_update_gpiod_flags(&dflags, &info);
-		acpi_gpio_update_gpiod_lookup_flags(&lflags, &info);
 	} else {
 		return ERR_PTR(-EINVAL);
 	}

-- 
b4 0.11.0-dev-28747

[PATCH v4 5/6] gpiolib: consolidate GPIO lookups

[Dmitry Torokhov]

Ensure that all paths to obtain/look up GPIOD from generic
consumer-visible APIs go through the new gpiod_find_and_request()
helper, so that we can easily extend it with support for new firmware
mechanisms.

The only exception is OF-specific [devm_]gpiod_get_from_of_node() API
that is still being used by a couple of drivers and will be removed as
soon as patches converting them to use generic fwnode/device APIs are
accepted.

Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
 drivers/gpio/gpiolib-acpi.c |  39 ---------
 drivers/gpio/gpiolib-acpi.h |  10 ---
 drivers/gpio/gpiolib.c      | 204 +++++++++++++++++---------------------------
 3 files changed, 76 insertions(+), 177 deletions(-)

diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c
index 1bc386032ca8..bed0380c5136 100644
--- a/drivers/gpio/gpiolib-acpi.c
+++ b/drivers/gpio/gpiolib-acpi.c
@@ -1024,45 +1024,6 @@ struct gpio_desc *acpi_find_gpio(struct fwnode_handle *fwnode,
 	return desc;
 }
 
-/**
- * acpi_node_get_gpiod() - get a GPIO descriptor from ACPI resources
- * @fwnode: pointer to an ACPI firmware node to get the GPIO information from
- * @propname: Property name of the GPIO
- * @index: index of GpioIo/GpioInt resource (starting from %0)
- * @lflags: bitmask of gpio_lookup_flags GPIO_* values
- * @dflags: gpiod initialization flags
- *
- * If @fwnode is an ACPI device object, call acpi_get_gpiod_by_index() for it.
- * Otherwise (i.e. it is a data-only non-device object), use the property-based
- * GPIO lookup to get to the GPIO resource with the relevant information and use
- * that to obtain the GPIO descriptor to return.
- *
- * If the GPIO cannot be translated or there is an error an ERR_PTR is
- * returned.
- */
-struct gpio_desc *acpi_node_get_gpiod(struct fwnode_handle *fwnode,
-				      const char *propname, int index,
-				      unsigned long *lflags,
-				      enum gpiod_flags *dflags)
-{
-	struct acpi_gpio_info info;
-	struct acpi_device *adev;
-	struct gpio_desc *desc;
-
-	adev = to_acpi_device_node(fwnode);
-	if (adev)
-		desc = acpi_get_gpiod_by_index(adev, propname, index, &info);
-	else
-		desc = acpi_get_gpiod_from_data(fwnode, propname, index, &info);
-
-	if (!IS_ERR(desc)) {
-		acpi_gpio_update_gpiod_flags(dflags, &info);
-		acpi_gpio_update_gpiod_lookup_flags(lflags, &info);
-	}
-
-	return desc;
-}
-
 /**
  * acpi_dev_gpio_irq_wake_get_by() - Find GpioInt and translate it to Linux IRQ number
  * @adev: pointer to a ACPI device to get IRQ from
diff --git a/drivers/gpio/gpiolib-acpi.h b/drivers/gpio/gpiolib-acpi.h
index 8880615327ac..9475f99a9694 100644
--- a/drivers/gpio/gpiolib-acpi.h
+++ b/drivers/gpio/gpiolib-acpi.h
@@ -36,10 +36,6 @@ struct gpio_desc *acpi_find_gpio(struct fwnode_handle *fwnode,
 				 unsigned int idx,
 				 enum gpiod_flags *dflags,
 				 unsigned long *lookupflags);
-struct gpio_desc *acpi_node_get_gpiod(struct fwnode_handle *fwnode,
-				      const char *propname, int index,
-				      unsigned long *lflags,
-				      enum gpiod_flags *dflags);
 
 int acpi_gpio_count(struct device *dev, const char *con_id);
 #else
@@ -61,12 +57,6 @@ acpi_find_gpio(struct fwnode_handle *fwnode, const char *con_id,
 {
 	return ERR_PTR(-ENOENT);
 }
-static inline struct gpio_desc *
-acpi_node_get_gpiod(struct fwnode_handle *fwnode, const char *propname,
-		    int index, unsigned long *lflags, enum gpiod_flags *dflags)
-{
-	return ERR_PTR(-ENXIO);
-}
 static inline int acpi_gpio_count(struct device *dev, const char *con_id)
 {
 	return -ENODEV;
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index b213f5f93ae0..7f739096c4cf 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -366,7 +366,7 @@ static int gpiochip_set_desc_names(struct gpio_chip *gc)
 static int devprop_gpiochip_set_names(struct gpio_chip *chip)
 {
 	struct gpio_device *gdev = chip->gpiodev;
-	struct fwnode_handle *fwnode = dev_fwnode(&gdev->dev);
+	const struct fwnode_handle *fwnode = dev_fwnode(&gdev->dev);
 	const char **names;
 	int ret, i;
 	int count;
@@ -3853,58 +3853,84 @@ static int platform_gpio_count(struct device *dev, const char *con_id)
 	return count;
 }
 
-/**
- * fwnode_get_named_gpiod - obtain a GPIO from firmware node
- * @fwnode:	handle of the firmware node
- * @propname:	name of the firmware property representing the GPIO
- * @index:	index of the GPIO to obtain for the consumer
- * @dflags:	GPIO initialization flags
- * @label:	label to attach to the requested GPIO
- *
- * This function can be used for drivers that get their configuration
- * from opaque firmware.
- *
- * The function properly finds the corresponding GPIO using whatever is the
- * underlying firmware interface and then makes sure that the GPIO
- * descriptor is requested before it is returned to the caller.
- *
- * Returns:
- * On successful request the GPIO pin is configured in accordance with
- * provided @dflags.
- *
- * In case of error an ERR_PTR() is returned.
- */
-static struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
-						const char *propname, int index,
-						enum gpiod_flags dflags,
-						const char *label)
+static struct gpio_desc *gpiod_find_by_fwnode(struct fwnode_handle *fwnode,
+					      struct device *consumer,
+					      const char *con_id,
+					      unsigned int idx,
+					      enum gpiod_flags *flags,
+					      unsigned long *lookupflags)
 {
-	unsigned long lflags = GPIO_LOOKUP_FLAGS_DEFAULT;
-	struct gpio_desc *desc = ERR_PTR(-ENODEV);
-	int ret;
+	struct gpio_desc *desc = ERR_PTR(-ENOENT);
 
 	if (is_of_node(fwnode)) {
-		desc = gpiod_get_from_of_node(to_of_node(fwnode),
-					      propname, index,
-					      dflags,
-					      label);
-		return desc;
+		dev_dbg(consumer, "using DT '%pfw' for '%s' GPIO lookup\n",
+			fwnode, con_id);
+		desc = of_find_gpio(to_of_node(fwnode), con_id, idx, lookupflags);
 	} else if (is_acpi_node(fwnode)) {
-		desc = acpi_node_get_gpiod(fwnode, propname, index,
-					   &lflags, &dflags);
-		if (IS_ERR(desc))
-			return desc;
-	} else {
-		return ERR_PTR(-EINVAL);
+		dev_dbg(consumer, "using ACPI '%pfw' for '%s' GPIO lookup\n",
+			fwnode, con_id);
+		desc = acpi_find_gpio(fwnode, con_id, idx, flags, lookupflags);
 	}
 
-	/* Currently only ACPI takes this path */
+	return desc;
+}
+
+static struct gpio_desc *gpiod_find_and_request(struct device *consumer,
+						struct fwnode_handle *fwnode,
+						const char *con_id,
+						unsigned int idx,
+						enum gpiod_flags flags,
+						const char *label,
+						bool platform_lookup_allowed)
+{
+	struct gpio_desc *desc = ERR_PTR(-ENOENT);
+	unsigned long lookupflags;
+	int ret;
+
+	if (!IS_ERR_OR_NULL(fwnode))
+		desc = gpiod_find_by_fwnode(fwnode, consumer, con_id, idx,
+					    &flags, &lookupflags);
+
+	if (gpiod_not_found(desc) && platform_lookup_allowed) {
+		/*
+		 * Either we are not using DT or ACPI, or their lookup did not
+		 * return a result. In that case, use platform lookup as a
+		 * fallback.
+		 */
+		dev_dbg(consumer, "using lookup tables for GPIO lookup\n");
+		desc = gpiod_find(consumer, con_id, idx, &lookupflags);
+	}
+
+	if (IS_ERR(desc)) {
+		dev_dbg(consumer, "No GPIO consumer %s found\n", con_id);
+		return desc;
+	}
+
+	/*
+	 * If a connection label was passed use that, else attempt to use
+	 * the device name as label
+	 */
 	ret = gpiod_request(desc, label);
-	if (ret)
-		return ERR_PTR(ret);
+	if (ret) {
+		if (!(ret == -EBUSY && flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE))
+			return ERR_PTR(ret);
+
+		/*
+		 * This happens when there are several consumers for
+		 * the same GPIO line: we just return here without
+		 * further initialization. It is a bit of a hack.
+		 * This is necessary to support fixed regulators.
+		 *
+		 * FIXME: Make this more sane and safe.
+		 */
+		dev_info(consumer,
+			 "nonexclusive access to GPIO for %s\n", con_id);
+		return desc;
+	}
 
-	ret = gpiod_configure_flags(desc, propname, lflags, dflags);
+	ret = gpiod_configure_flags(desc, con_id, lookupflags, flags);
 	if (ret < 0) {
+		dev_dbg(consumer, "setup of GPIO %s failed\n", con_id);
 		gpiod_put(desc);
 		return ERR_PTR(ret);
 	}
@@ -3937,29 +3963,12 @@ static struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
  * In case of error an ERR_PTR() is returned.
  */
 struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode,
-					 const char *con_id, int index,
+					 const char *con_id,
+					 int index,
 					 enum gpiod_flags flags,
 					 const char *label)
 {
-	struct gpio_desc *desc;
-	char prop_name[32]; /* 32 is max size of property name */
-	unsigned int i;
-
-	for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
-		if (con_id)
-			snprintf(prop_name, sizeof(prop_name), "%s-%s",
-					    con_id, gpio_suffixes[i]);
-		else
-			snprintf(prop_name, sizeof(prop_name), "%s",
-					    gpio_suffixes[i]);
-
-		desc = fwnode_get_named_gpiod(fwnode, prop_name, index, flags,
-					      label);
-		if (!gpiod_not_found(desc))
-			break;
-	}
-
-	return desc;
+	return gpiod_find_and_request(NULL, fwnode, con_id, index, flags, label, false);
 }
 EXPORT_SYMBOL_GPL(fwnode_gpiod_get_index);
 
@@ -4113,72 +4122,11 @@ struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
 					       unsigned int idx,
 					       enum gpiod_flags flags)
 {
-	unsigned long lookupflags = GPIO_LOOKUP_FLAGS_DEFAULT;
-	struct gpio_desc *desc = NULL;
-	int ret;
-	/* Maybe we have a device name, maybe not */
-	const char *devname = dev ? dev_name(dev) : "?";
 	struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
+	const char *devname = dev ? dev_name(dev) : "?";
+	const char *label = con_id ?: devname;
 
-	dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
-
-	/* Using device tree? */
-	if (is_of_node(fwnode)) {
-		dev_dbg(dev, "using device tree for GPIO lookup\n");
-		desc = of_find_gpio(to_of_node(fwnode),
-				    con_id, idx, &lookupflags);
-	} else if (is_acpi_node(fwnode)) {
-		dev_dbg(dev, "using ACPI for GPIO lookup\n");
-		desc = acpi_find_gpio(fwnode,
-				      con_id, idx, &flags, &lookupflags);
-	}
-
-	/*
-	 * Either we are not using DT or ACPI, or their lookup did not return
-	 * a result. In that case, use platform lookup as a fallback.
-	 */
-	if (!desc || gpiod_not_found(desc)) {
-		dev_dbg(dev, "using lookup tables for GPIO lookup\n");
-		desc = gpiod_find(dev, con_id, idx, &lookupflags);
-	}
-
-	if (IS_ERR(desc)) {
-		dev_dbg(dev, "No GPIO consumer %s found\n", con_id);
-		return desc;
-	}
-
-	/*
-	 * If a connection label was passed use that, else attempt to use
-	 * the device name as label
-	 */
-	ret = gpiod_request(desc, con_id ?: devname);
-	if (ret) {
-		if (!(ret == -EBUSY && flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE))
-			return ERR_PTR(ret);
-
-		/*
-		 * This happens when there are several consumers for
-		 * the same GPIO line: we just return here without
-		 * further initialization. It is a bit of a hack.
-		 * This is necessary to support fixed regulators.
-		 *
-		 * FIXME: Make this more sane and safe.
-		 */
-		dev_info(dev, "nonexclusive access to GPIO for %s\n", con_id ?: devname);
-		return desc;
-	}
-
-	ret = gpiod_configure_flags(desc, con_id, lookupflags, flags);
-	if (ret < 0) {
-		dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
-		gpiod_put(desc);
-		return ERR_PTR(ret);
-	}
-
-	blocking_notifier_call_chain(&desc->gdev->notifier,
-				     GPIOLINE_CHANGED_REQUESTED, desc);
-
-	return desc;
+	return gpiod_find_and_request(dev, fwnode, con_id, idx, flags, label, true);
 }
 EXPORT_SYMBOL_GPL(gpiod_get_index);
 

-- 
b4 0.11.0-dev-28747

[PATCH v4 6/6] gpiolib: add support for software nodes

[Dmitry Torokhov]

Now that static device properties understand notion of child nodes and
references, let's teach gpiolib to handle them:

- GPIOs are represented as a references to software nodes representing
  gpiochip
- references must have 2 arguments - GPIO number within the chip and
  GPIO flags (GPIO_ACTIVE_LOW/GPIO_ACTIVE_HIGH, etc)
- a new PROPERTY_ENTRY_GPIO() macro is supplied to ensure the above
- name of the software node representing gpiochip must match label of
  the gpiochip, as we use it to locate gpiochip structure at runtime

The following illustrates use of software nodes to describe a "System"
button that is currently specified via use of gpio_keys_platform_data
in arch/mips/alchemy/board-mtx1.c. It follows bindings specified in
Documentation/devicetree/bindings/input/gpio-keys.yaml.

static const struct software_node mxt1_gpiochip2_node = {
	.name = "alchemy-gpio2",
};

static const struct property_entry mtx1_gpio_button_props[] = {
	PROPERTY_ENTRY_U32("linux,code", BTN_0),
	PROPERTY_ENTRY_STRING("label", "System button"),
	PROPERTY_ENTRY_GPIO("gpios", &mxt1_gpiochip2_node, 7, GPIO_ACTIVE_LOW),
	{ }
};

Similarly, arch/arm/mach-tegra/board-paz00.c can be converted to:

static const struct software_node tegra_gpiochip_node = {
	.name = "tegra-gpio",
};

static struct property_entry wifi_rfkill_prop[] __initdata = {
	PROPERTY_ENTRY_STRING("name", "wifi_rfkill"),
	PROPERTY_ENTRY_STRING("type", "wlan"),
	PROPERTY_ENTRY_GPIO("reset-gpios",
			    &tegra_gpiochip_node, 25, GPIO_ACTIVE_HIGH);
	PROPERTY_ENTRY_GPIO("shutdown-gpios",
			    &tegra_gpiochip_node, 85, GPIO_ACTIVE_HIGH);
	{ },
};

static struct platform_device wifi_rfkill_device = {
	.name	= "rfkill_gpio",
	.id	= -1,
};

...

	software_node_register(&tegra_gpiochip_node);
	device_create_managed_software_node(&wifi_rfkill_device.dev,
					    wifi_rfkill_prop, NULL);

Acked-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
 drivers/gpio/Makefile         |   1 +
 drivers/gpio/gpiolib-swnode.c | 123 ++++++++++++++++++++++++++++++++++++++++++
 drivers/gpio/gpiolib-swnode.h |  14 +++++
 drivers/gpio/gpiolib.c        |   7 +++
 include/linux/gpio/property.h |  11 ++++
 5 files changed, 156 insertions(+)

diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 8629e9eaf79e..010587025fc8 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -10,6 +10,7 @@ obj-$(CONFIG_OF_GPIO)		+= gpiolib-of.o
 obj-$(CONFIG_GPIO_CDEV)		+= gpiolib-cdev.o
 obj-$(CONFIG_GPIO_SYSFS)	+= gpiolib-sysfs.o
 obj-$(CONFIG_GPIO_ACPI)		+= gpiolib-acpi.o
+obj-$(CONFIG_GPIOLIB)		+= gpiolib-swnode.o
 
 # Device drivers. Generally keep list sorted alphabetically
 obj-$(CONFIG_GPIO_REGMAP)	+= gpio-regmap.o
diff --git a/drivers/gpio/gpiolib-swnode.c b/drivers/gpio/gpiolib-swnode.c
new file mode 100644
index 000000000000..dd9ccac214d1
--- /dev/null
+++ b/drivers/gpio/gpiolib-swnode.c
@@ -0,0 +1,123 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Software Node helpers for the GPIO API
+ *
+ * Copyright 2022 Google LLC
+ */
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/gpio/consumer.h>
+#include <linux/gpio/driver.h>
+#include <linux/kernel.h>
+#include <linux/printk.h>
+#include <linux/property.h>
+#include <linux/string.h>
+
+#include "gpiolib.h"
+#include "gpiolib-swnode.h"
+
+static void swnode_format_propname(const char *con_id, char *propname,
+				   size_t max_size)
+{
+	/*
+	 * Note we do not need to try both -gpios and -gpio suffixes,
+	 * as, unlike OF and ACPI, we can fix software nodes to conform
+	 * to the proper binding.
+	 */
+	if (con_id)
+		snprintf(propname, max_size, "%s-gpios", con_id);
+	else
+		strscpy(propname, "gpios", max_size);
+}
+
+static int swnode_gpiochip_match_name(struct gpio_chip *chip, void *data)
+{
+	return !strcmp(chip->label, data);
+}
+
+static struct gpio_chip *swnode_get_chip(struct fwnode_handle *fwnode)
+{
+	const struct software_node *chip_node;
+	struct gpio_chip *chip;
+
+	chip_node = to_software_node(fwnode);
+	if (!chip_node || !chip_node->name)
+		return ERR_PTR(-EINVAL);
+
+	chip = gpiochip_find((void *)chip_node->name, swnode_gpiochip_match_name);
+	return chip ?: ERR_PTR(-EPROBE_DEFER);
+}
+
+struct gpio_desc *swnode_find_gpio(struct fwnode_handle *fwnode,
+				   const char *con_id, unsigned int idx,
+				   unsigned long *flags)
+{
+	const struct software_node *swnode;
+	struct fwnode_reference_args args;
+	struct gpio_chip *chip;
+	struct gpio_desc *desc;
+	char propname[32]; /* 32 is max size of property name */
+	int error;
+
+	swnode = to_software_node(fwnode);
+	if (!swnode)
+		return ERR_PTR(-EINVAL);
+
+	swnode_format_propname(con_id, propname, sizeof(propname));
+
+	/*
+	 * We expect all swnode-described GPIOs have GPIO number and
+	 * polarity arguments, hence nargs is set to 2.
+	 */
+	error = fwnode_property_get_reference_args(fwnode, propname, NULL, 2, idx, &args);
+	if (error) {
+		pr_debug("%s: can't parse '%s' property of node '%pfwP[%d]'\n",
+			__func__, propname, fwnode, idx);
+		return ERR_PTR(error);
+	}
+
+	chip = swnode_get_chip(args.fwnode);
+	fwnode_handle_put(args.fwnode);
+	if (IS_ERR(chip))
+		return ERR_CAST(chip);
+
+	desc = gpiochip_get_desc(chip, args.args[0]);
+	*flags = args.args[1]; /* We expect native GPIO flags */
+
+	pr_debug("%s: parsed '%s' property of node '%pfwP[%d]' - status (%d)\n",
+		 __func__, propname, fwnode, idx, PTR_ERR_OR_ZERO(desc));
+
+	return desc;
+}
+
+/**
+ * swnode_gpio_count - count the GPIOs associated with a device / function
+ * @fwnode:	firmware node of the GPIO consumer, can be %NULL for
+ *		system-global GPIOs
+ * @con_id:	function within the GPIO consumer
+ *
+ * Return:
+ * The number of GPIOs associated with a device / function or %-ENOENT,
+ * if no GPIO has been assigned to the requested function.
+ */
+int swnode_gpio_count(const struct fwnode_handle *fwnode, const char *con_id)
+{
+	struct fwnode_reference_args args;
+	char propname[32];
+	int count;
+
+	swnode_format_propname(con_id, propname, sizeof(propname));
+
+	/*
+	 * This is not very efficient, but GPIO lists usually have only
+	 * 1 or 2 entries.
+	 */
+	count = 0;
+	while (fwnode_property_get_reference_args(fwnode, propname, NULL, 0,
+						  count, &args) == 0) {
+		fwnode_handle_put(args.fwnode);
+		count++;
+	}
+
+	return count ?: -ENOENT;
+}
diff --git a/drivers/gpio/gpiolib-swnode.h b/drivers/gpio/gpiolib-swnode.h
new file mode 100644
index 000000000000..af849e56f6bc
--- /dev/null
+++ b/drivers/gpio/gpiolib-swnode.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef GPIOLIB_SWNODE_H
+#define GPIOLIB_SWNODE_H
+
+struct fwnode_handle;
+struct gpio_desc;
+
+struct gpio_desc *swnode_find_gpio(struct fwnode_handle *fwnode,
+				   const char *con_id, unsigned int idx,
+				   unsigned long *flags);
+int swnode_gpio_count(const struct fwnode_handle *fwnode, const char *con_id);
+
+#endif /* GPIOLIB_SWNODE_H */
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 7f739096c4cf..7936d54a2e30 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -26,6 +26,7 @@
 #include "gpiolib.h"
 #include "gpiolib-of.h"
 #include "gpiolib-acpi.h"
+#include "gpiolib-swnode.h"
 #include "gpiolib-cdev.h"
 #include "gpiolib-sysfs.h"
 
@@ -3870,6 +3871,10 @@ static struct gpio_desc *gpiod_find_by_fwnode(struct fwnode_handle *fwnode,
 		dev_dbg(consumer, "using ACPI '%pfw' for '%s' GPIO lookup\n",
 			fwnode, con_id);
 		desc = acpi_find_gpio(fwnode, con_id, idx, flags, lookupflags);
+	} else if (is_software_node(fwnode)) {
+		dev_dbg(consumer, "using swnode '%pfw' for '%s' GPIO lookup\n",
+			fwnode, con_id);
+		desc = swnode_find_gpio(fwnode, con_id, idx, lookupflags);
 	}
 
 	return desc;
@@ -3987,6 +3992,8 @@ int gpiod_count(struct device *dev, const char *con_id)
 		count = of_gpio_get_count(dev, con_id);
 	else if (is_acpi_node(fwnode))
 		count = acpi_gpio_count(dev, con_id);
+	else if (is_software_node(fwnode))
+		count = swnode_gpio_count(fwnode, con_id);
 
 	if (count < 0)
 		count = platform_gpio_count(dev, con_id);
diff --git a/include/linux/gpio/property.h b/include/linux/gpio/property.h
new file mode 100644
index 000000000000..6c75c8bd44a0
--- /dev/null
+++ b/include/linux/gpio/property.h
@@ -0,0 +1,11 @@
+// SPDX-License-Identifier: GPL-2.0+
+#ifndef __LINUX_GPIO_PROPERTY_H
+#define __LINUX_GPIO_PROPERTY_H
+
+#include <dt-bindings/gpio/gpio.h> /* for GPIO_* flags */
+#include <linux/property.h>
+
+#define PROPERTY_ENTRY_GPIO(_name_, _chip_node_, _idx_, _flags_) \
+	PROPERTY_ENTRY_REF(_name_, _chip_node_, _idx_, _flags_)
+
+#endif /* __LINUX_GPIO_PROPERTY_H */

-- 
b4 0.11.0-dev-28747

Re: [PATCH v4 5/6] gpiolib: consolidate GPIO lookups

[Andy Shevchenko]

On Fri, Nov 11, 2022 at 02:19:07PM -0800, Dmitry Torokhov wrote:
> Ensure that all paths to obtain/look up GPIOD from generic
> consumer-visible APIs go through the new gpiod_find_and_request()
> helper, so that we can easily extend it with support for new firmware
> mechanisms.
> 
> The only exception is OF-specific [devm_]gpiod_get_from_of_node() API
> that is still being used by a couple of drivers and will be removed as
> soon as patches converting them to use generic fwnode/device APIs are
> accepted.

...

> +static struct gpio_desc *gpiod_find_and_request(struct device *consumer,
> +						struct fwnode_handle *fwnode,
> +						const char *con_id,
> +						unsigned int idx,
> +						enum gpiod_flags flags,
> +						const char *label,
> +						bool platform_lookup_allowed)
> +{
> +	struct gpio_desc *desc = ERR_PTR(-ENOENT);
> +	unsigned long lookupflags;
> +	int ret;

> +	if (!IS_ERR_OR_NULL(fwnode))

Just for the record. I haven't given my tag to this patch, because I think that
the above check (and respective assignment above) are redundant. Even comment
inside the below condition clarifies the point of the meaning of descriptor
being not found. Besides that many of device property APIs designed the way
that input fwnode can be invalid.

Nevertheless, we agreed with Dmitry that this disagreement should be solved on
maintainer's level, while it doesn't affect code functionality.

The rest of the patch is fine.

> +		desc = gpiod_find_by_fwnode(fwnode, consumer, con_id, idx,
> +					    &flags, &lookupflags);
> +
> +	if (gpiod_not_found(desc) && platform_lookup_allowed) {
> +		/*
> +		 * Either we are not using DT or ACPI, or their lookup did not
> +		 * return a result. In that case, use platform lookup as a
> +		 * fallback.
> +		 */
> +		dev_dbg(consumer, "using lookup tables for GPIO lookup\n");
> +		desc = gpiod_find(consumer, con_id, idx, &lookupflags);
> +	}
> +
> +	if (IS_ERR(desc)) {
> +		dev_dbg(consumer, "No GPIO consumer %s found\n", con_id);
> +		return desc;
> +	}

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v4 5/6] gpiolib: consolidate GPIO lookups

[Bartosz Golaszewski]

On Sun, Nov 13, 2022 at 2:07 PM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
>
> On Fri, Nov 11, 2022 at 02:19:07PM -0800, Dmitry Torokhov wrote:
> > Ensure that all paths to obtain/look up GPIOD from generic
> > consumer-visible APIs go through the new gpiod_find_and_request()
> > helper, so that we can easily extend it with support for new firmware
> > mechanisms.
> >
> > The only exception is OF-specific [devm_]gpiod_get_from_of_node() API
> > that is still being used by a couple of drivers and will be removed as
> > soon as patches converting them to use generic fwnode/device APIs are
> > accepted.
>
> ...
>
> > +static struct gpio_desc *gpiod_find_and_request(struct device *consumer,
> > +                                             struct fwnode_handle *fwnode,
> > +                                             const char *con_id,
> > +                                             unsigned int idx,
> > +                                             enum gpiod_flags flags,
> > +                                             const char *label,
> > +                                             bool platform_lookup_allowed)
> > +{
> > +     struct gpio_desc *desc = ERR_PTR(-ENOENT);
> > +     unsigned long lookupflags;
> > +     int ret;
>
> > +     if (!IS_ERR_OR_NULL(fwnode))
>
> Just for the record. I haven't given my tag to this patch, because I think that
> the above check (and respective assignment above) are redundant. Even comment
> inside the below condition clarifies the point of the meaning of descriptor
> being not found. Besides that many of device property APIs designed the way
> that input fwnode can be invalid.
>
> Nevertheless, we agreed with Dmitry that this disagreement should be solved on
> maintainer's level, while it doesn't affect code functionality.
>
> The rest of the patch is fine.
>

Noted. :)

I'm fine with Dmitry's explanation. It doesn't hurt so let's go with
the author's intention.

Bart

Re: [PATCH v4 0/6] Add support for software nodes to gpiolib

[Bartosz Golaszewski]

On Fri, Nov 11, 2022 at 11:19 PM Dmitry Torokhov
<dmitry.torokhov@gmail.com> wrote:
>
> This series attempts to add support for software nodes to gpiolib, using
> software node references. This allows us to convert more drivers to the
> generic device properties and drop support for custom platform data.
>
> To describe a GPIO via software nodes we can create the following data
> items:
>
> /* Node representing the GPIO controller/GPIO bank */
> static const struct software_node gpio_bank_b_node = {
>         .name = "B",
> };
>
> /*
>  * Properties that will be assigned to a software node assigned to
>  * the device that used platform data.
>  */
> static const struct property_entry simone_key_enter_props[] = {
>         PROPERTY_ENTRY_U32("linux,code", KEY_ENTER),
>         PROPERTY_ENTRY_STRING("label", "enter"),
>         PROPERTY_ENTRY_REF("gpios", &gpio_bank_b_node, 123, GPIO_ACTIVE_LOW),
>         { }
> };
>
> The code in gpiolib handling software nodes uses the name in the
> software node representing GPIO controller to locate the actual instance
> of GPIO controller.
>
> To: Linus Walleij <linus.walleij@linaro.org>
> To: Bartosz Golaszewski <brgl@bgdev.pl>
> To: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Cc: linux-gpio@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: linux-acpi@vger.kernel.org
>
> ---
> Changes in v4:
> - Rebased on top of next-20221111
> - Added Andy's reviewed-by for patch #6
> - Link to v3: https://lore.kernel.org/r/20221031-gpiolib-swnode-v3-0-0282162b0fa4@gmail.com
>
> Changes in v3:
> - Addressed more Andy's comments
> - Link to v2: https://lore.kernel.org/r/20221031-gpiolib-swnode-v2-0-81f55af5fa0e@gmail.com
>
> Changes in v2:
> - reworked the series to be independent of other in-flight patches.
>   That meant keeping devm_gpiod_get_from_of_node() for now.
> - removed handling of secondary nodes, it deserves a separate patch
>   series
> - fixed refcounting when handling swnodes (Andy)
> - added include/linux/gpio/property.h with PROPERTY_ENTRY_GPIO (Andy)
> - addressed most of the rest of Andy's comments
> - collected reviewed-by and acked-by
> - Link to v1: https://lore.kernel.org/r/20221031-gpiolib-swnode-v1-0-a0ab48d229c7@gmail.com
>
> ---
> Dmitry Torokhov (6):
>       gpiolib: of: change of_find_gpio() to accept device node
>       gpiolib: acpi: change acpi_find_gpio() to accept firmware node
>       gpiolib: acpi: teach acpi_find_gpio() to handle data-only nodes
>       gpiolib: acpi: avoid leaking ACPI details into upper gpiolib layers
>       gpiolib: consolidate GPIO lookups
>       gpiolib: add support for software nodes
>
>  drivers/gpio/Makefile         |   1 +
>  drivers/gpio/gpiolib-acpi.c   | 132 +++++++++++++++-----------
>  drivers/gpio/gpiolib-acpi.h   |  54 +----------
>  drivers/gpio/gpiolib-of.c     |   7 +-
>  drivers/gpio/gpiolib-of.h     |   4 +-
>  drivers/gpio/gpiolib-swnode.c | 123 +++++++++++++++++++++++++
>  drivers/gpio/gpiolib-swnode.h |  14 +++
>  drivers/gpio/gpiolib.c        | 209 ++++++++++++++++--------------------------
>  include/linux/gpio/property.h |  11 +++
>  9 files changed, 315 insertions(+), 240 deletions(-)
> ---
> base-commit: f8f60f322f0640c8edda2942ca5f84b7a27c417a
> change-id: 20221031-gpiolib-swnode-948203f49b23
>
> --
> Dmitry
>

I still had some fuzz when applying, can you for the future rebase on
top of the GPIO for-next branch?

Anyway: series applied.

Bart

Re: [PATCH v4 0/6] Add support for software nodes to gpiolib

[Dmitry Torokhov]

On Tue, Nov 15, 2022 at 11:28:17AM +0100, Bartosz Golaszewski wrote:
> On Fri, Nov 11, 2022 at 11:19 PM Dmitry Torokhov
> <dmitry.torokhov@gmail.com> wrote:
> >
> > This series attempts to add support for software nodes to gpiolib, using
> > software node references. This allows us to convert more drivers to the
> > generic device properties and drop support for custom platform data.
> >
> > To describe a GPIO via software nodes we can create the following data
> > items:
> >
> > /* Node representing the GPIO controller/GPIO bank */
> > static const struct software_node gpio_bank_b_node = {
> >         .name = "B",
> > };
> >
> > /*
> >  * Properties that will be assigned to a software node assigned to
> >  * the device that used platform data.
> >  */
> > static const struct property_entry simone_key_enter_props[] = {
> >         PROPERTY_ENTRY_U32("linux,code", KEY_ENTER),
> >         PROPERTY_ENTRY_STRING("label", "enter"),
> >         PROPERTY_ENTRY_REF("gpios", &gpio_bank_b_node, 123, GPIO_ACTIVE_LOW),
> >         { }
> > };
> >
> > The code in gpiolib handling software nodes uses the name in the
> > software node representing GPIO controller to locate the actual instance
> > of GPIO controller.
> >
> > To: Linus Walleij <linus.walleij@linaro.org>
> > To: Bartosz Golaszewski <brgl@bgdev.pl>
> > To: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> > Cc: linux-gpio@vger.kernel.org
> > Cc: linux-kernel@vger.kernel.org
> > Cc: linux-acpi@vger.kernel.org
> >
> > ---
> > Changes in v4:
> > - Rebased on top of next-20221111
> > - Added Andy's reviewed-by for patch #6
> > - Link to v3: https://lore.kernel.org/r/20221031-gpiolib-swnode-v3-0-0282162b0fa4@gmail.com
> >
> > Changes in v3:
> > - Addressed more Andy's comments
> > - Link to v2: https://lore.kernel.org/r/20221031-gpiolib-swnode-v2-0-81f55af5fa0e@gmail.com
> >
> > Changes in v2:
> > - reworked the series to be independent of other in-flight patches.
> >   That meant keeping devm_gpiod_get_from_of_node() for now.
> > - removed handling of secondary nodes, it deserves a separate patch
> >   series
> > - fixed refcounting when handling swnodes (Andy)
> > - added include/linux/gpio/property.h with PROPERTY_ENTRY_GPIO (Andy)
> > - addressed most of the rest of Andy's comments
> > - collected reviewed-by and acked-by
> > - Link to v1: https://lore.kernel.org/r/20221031-gpiolib-swnode-v1-0-a0ab48d229c7@gmail.com
> >
> > ---
> > Dmitry Torokhov (6):
> >       gpiolib: of: change of_find_gpio() to accept device node
> >       gpiolib: acpi: change acpi_find_gpio() to accept firmware node
> >       gpiolib: acpi: teach acpi_find_gpio() to handle data-only nodes
> >       gpiolib: acpi: avoid leaking ACPI details into upper gpiolib layers
> >       gpiolib: consolidate GPIO lookups
> >       gpiolib: add support for software nodes
> >
> >  drivers/gpio/Makefile         |   1 +
> >  drivers/gpio/gpiolib-acpi.c   | 132 +++++++++++++++-----------
> >  drivers/gpio/gpiolib-acpi.h   |  54 +----------
> >  drivers/gpio/gpiolib-of.c     |   7 +-
> >  drivers/gpio/gpiolib-of.h     |   4 +-
> >  drivers/gpio/gpiolib-swnode.c | 123 +++++++++++++++++++++++++
> >  drivers/gpio/gpiolib-swnode.h |  14 +++
> >  drivers/gpio/gpiolib.c        | 209 ++++++++++++++++--------------------------
> >  include/linux/gpio/property.h |  11 +++
> >  9 files changed, 315 insertions(+), 240 deletions(-)
> > ---
> > base-commit: f8f60f322f0640c8edda2942ca5f84b7a27c417a
> > change-id: 20221031-gpiolib-swnode-948203f49b23
> >
> > --
> > Dmitry
> >
> 
> I still had some fuzz when applying, can you for the future rebase on
> top of the GPIO for-next branch?

OK, I will, but I thought it is feeding into the next tree?

> 
> Anyway: series applied.

Thanks!

-- 
Dmitry

Re: [PATCH v4 0/6] Add support for software nodes to gpiolib

[Andy Shevchenko]

On Tue, Nov 15, 2022 at 03:19:16PM -0800, Dmitry Torokhov wrote:
> On Tue, Nov 15, 2022 at 11:28:17AM +0100, Bartosz Golaszewski wrote:
> > On Fri, Nov 11, 2022 at 11:19 PM Dmitry Torokhov
> > <dmitry.torokhov@gmail.com> wrote:

...

> > I still had some fuzz when applying, can you for the future rebase on
> > top of the GPIO for-next branch?
> 
> OK, I will, but I thought it is feeding into the next tree?

It has ~2-3 days latency usually.

-- 
With Best Regards,
Andy Shevchenko