Merge tag 'gpio-aggregator-refactoring-for-v6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux into devel

Immutable branch for the pinctrl tree to pull from

Refactor the gpio-aggregator module as a prerequisite for merging the
pin controller driver for AAEON UP boards.

Signed-off-by: Linus Walleij <[e-mail]>

drivers/gpio/gpio-aggregator.c

···
 #include <linux/configfs.h>
 #include <linux/ctype.h>
 #include <linux/delay.h>
+#include <linux/export.h>
 #include <linux/idr.h>
 #include <linux/kernel.h>
 #include <linux/list.h>
···
 
 #include <linux/gpio/consumer.h>
 #include <linux/gpio/driver.h>
+#include <linux/gpio/forwarder.h>
 #include <linux/gpio/machine.h>
 
 #include "dev-sync-probe.h"
···
 		spinlock_t slock;	/* protects tmp[] if !can_sleep */
 	};
 	struct gpiochip_fwd_timing *delay_timings;
+	void *data;
+	unsigned long *valid_mask;
 	unsigned long tmp[];		/* values and descs for multiple ops */
 };
 
···
 
 #define fwd_tmp_size(ngpios)	(BITS_TO_LONGS((ngpios)) + (ngpios))
 
+static int gpio_fwd_request(struct gpio_chip *chip, unsigned int offset)
+{
+	struct gpiochip_fwd *fwd = gpiochip_get_data(chip);
+
+	return test_bit(offset, fwd->valid_mask) ? 0 : -ENODEV;
+}
+
 static int gpio_fwd_get_direction(struct gpio_chip *chip, unsigned int offset)
 {
 	struct gpiochip_fwd *fwd = gpiochip_get_data(chip);
+
+	/*
+	 * get_direction() is called during gpiochip registration, return
+	 * -ENODEV if there is no GPIO desc for the line.
+	 */
+	if (!test_bit(offset, fwd->valid_mask))
+		return -ENODEV;
 
 	return gpiod_get_direction(fwd->descs[offset]);
 }
···
 	return line;
 }
 
-static int gpiochip_fwd_setup_delay_line(struct device *dev, struct gpio_chip *chip,
-					 struct gpiochip_fwd *fwd)
+static int gpiochip_fwd_setup_delay_line(struct gpiochip_fwd *fwd)
 {
-	fwd->delay_timings = devm_kcalloc(dev, chip->ngpio,
+	struct gpio_chip *chip = &fwd->chip;
+
+	fwd->delay_timings = devm_kcalloc(chip->parent, chip->ngpio,
 					  sizeof(*fwd->delay_timings),
 					  GFP_KERNEL);
 	if (!fwd->delay_timings)
···
 	return 0;
 }
 #else
-static int gpiochip_fwd_setup_delay_line(struct device *dev, struct gpio_chip *chip,
-					 struct gpiochip_fwd *fwd)
+static int gpiochip_fwd_setup_delay_line(struct gpiochip_fwd *fwd)
 {
 	return 0;
 }
 #endif	/* !CONFIG_OF_GPIO */
 
 /**
+ * gpiochip_fwd_get_gpiochip - Get the GPIO chip for the GPIO forwarder
+ * @fwd: GPIO forwarder
+ *
+ * Returns: The GPIO chip for the GPIO forwarder
+ */
+struct gpio_chip *gpiochip_fwd_get_gpiochip(struct gpiochip_fwd *fwd)
+{
+	return &fwd->chip;
+}
+EXPORT_SYMBOL_NS_GPL(gpiochip_fwd_get_gpiochip, "GPIO_FORWARDER");
+
+/**
+ * gpiochip_fwd_get_data - Get driver-private data for the GPIO forwarder
+ * @fwd: GPIO forwarder
+ *
+ * Returns: The driver-private data for the GPIO forwarder
+ */
+void *gpiochip_fwd_get_data(struct gpiochip_fwd *fwd)
+{
+	return fwd->data;
+}
+EXPORT_SYMBOL_NS_GPL(gpiochip_fwd_get_data, "GPIO_FORWARDER");
+
+/**
+ * gpiochip_fwd_gpio_request - Request a line of the GPIO forwarder
+ * @fwd: GPIO forwarder
+ * @offset: the offset of the line to request
+ *
+ * Returns: 0 on success, or negative errno on failure.
+ */
+int gpiochip_fwd_gpio_request(struct gpiochip_fwd *fwd, unsigned int offset)
+{
+	struct gpio_chip *gc = gpiochip_fwd_get_gpiochip(fwd);
+
+	return gpio_fwd_request(gc, offset);
+}
+EXPORT_SYMBOL_NS_GPL(gpiochip_fwd_gpio_request, "GPIO_FORWARDER");
+
+/**
+ * gpiochip_fwd_gpio_get_direction - Return the current direction of a GPIO forwarder line
+ * @fwd: GPIO forwarder
+ * @offset: the offset of the line
+ *
+ * Returns: 0 for output, 1 for input, or an error code in case of error.
+ */
+int gpiochip_fwd_gpio_get_direction(struct gpiochip_fwd *fwd, unsigned int offset)
+{
+	struct gpio_chip *gc = gpiochip_fwd_get_gpiochip(fwd);
+
+	return gpio_fwd_get_direction(gc, offset);
+}
+EXPORT_SYMBOL_NS_GPL(gpiochip_fwd_gpio_get_direction, "GPIO_FORWARDER");
+
+/**
+ * gpiochip_fwd_gpio_direction_output - Set a GPIO forwarder line direction to
+ * output
+ * @fwd: GPIO forwarder
+ * @offset: the offset of the line
+ * @value: value to set
+ *
+ * Returns: 0 on success, or negative errno on failure.
+ */
+int gpiochip_fwd_gpio_direction_output(struct gpiochip_fwd *fwd, unsigned int offset,
+				       int value)
+{
+	struct gpio_chip *gc = gpiochip_fwd_get_gpiochip(fwd);
+
+	return gpio_fwd_direction_output(gc, offset, value);
+}
+EXPORT_SYMBOL_NS_GPL(gpiochip_fwd_gpio_direction_output, "GPIO_FORWARDER");
+
+/**
+ * gpiochip_fwd_gpio_direction_input - Set a GPIO forwarder line direction to input
+ * @fwd: GPIO forwarder
+ * @offset: the offset of the line
+ *
+ * Returns: 0 on success, or negative errno on failure.
+ */
+int gpiochip_fwd_gpio_direction_input(struct gpiochip_fwd *fwd, unsigned int offset)
+{
+	struct gpio_chip *gc = gpiochip_fwd_get_gpiochip(fwd);
+
+	return gpio_fwd_direction_input(gc, offset);
+}
+EXPORT_SYMBOL_NS_GPL(gpiochip_fwd_gpio_direction_input, "GPIO_FORWARDER");
+
+/**
+ * gpiochip_fwd_gpio_get - Return a GPIO forwarder line's value
+ * @fwd: GPIO forwarder
+ * @offset: the offset of the line
+ *
+ * Returns: The GPIO's logical value, i.e. taking the ACTIVE_LOW status into
+ * account, or negative errno on failure.
+ */
+int gpiochip_fwd_gpio_get(struct gpiochip_fwd *fwd, unsigned int offset)
+{
+	struct gpio_chip *gc = gpiochip_fwd_get_gpiochip(fwd);
+
+	return gpio_fwd_get(gc, offset);
+}
+EXPORT_SYMBOL_NS_GPL(gpiochip_fwd_gpio_get, "GPIO_FORWARDER");
+
+/**
+ * gpiochip_fwd_gpio_get_multiple - Get values for multiple GPIO forwarder lines
+ * @fwd: GPIO forwarder
+ * @mask: bit mask array; one bit per line; BITS_PER_LONG bits per word defines
+ *        which lines are to be read
+ * @bits: bit value array; one bit per line; BITS_PER_LONG bits per word will
+ *        contains the read values for the lines specified by mask
+ *
+ * Returns: 0 on success, or negative errno on failure.
+ */
+int gpiochip_fwd_gpio_get_multiple(struct gpiochip_fwd *fwd, unsigned long *mask,
+				   unsigned long *bits)
+{
+	struct gpio_chip *gc = gpiochip_fwd_get_gpiochip(fwd);
+
+	return gpio_fwd_get_multiple_locked(gc, mask, bits);
+}
+EXPORT_SYMBOL_NS_GPL(gpiochip_fwd_gpio_get_multiple, "GPIO_FORWARDER");
+
+/**
+ * gpiochip_fwd_gpio_set - Assign value to a GPIO forwarder line.
+ * @fwd: GPIO forwarder
+ * @offset: the offset of the line
+ * @value: value to set
+ *
+ * Returns: 0 on success, or negative errno on failure.
+ */
+int gpiochip_fwd_gpio_set(struct gpiochip_fwd *fwd, unsigned int offset, int value)
+{
+	struct gpio_chip *gc = gpiochip_fwd_get_gpiochip(fwd);
+
+	return gpio_fwd_set(gc, offset, value);
+}
+EXPORT_SYMBOL_NS_GPL(gpiochip_fwd_gpio_set, "GPIO_FORWARDER");
+
+/**
+ * gpiochip_fwd_gpio_set_multiple - Assign values to multiple GPIO forwarder lines
+ * @fwd: GPIO forwarder
+ * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
+ *        defines which outputs are to be changed
+ * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
+ *        defines the values the outputs specified by mask are to be set to
+ *
+ * Returns: 0 on success, or negative errno on failure.
+ */
+int gpiochip_fwd_gpio_set_multiple(struct gpiochip_fwd *fwd, unsigned long *mask,
+				   unsigned long *bits)
+{
+	struct gpio_chip *gc = gpiochip_fwd_get_gpiochip(fwd);
+
+	return gpio_fwd_set_multiple_locked(gc, mask, bits);
+}
+EXPORT_SYMBOL_NS_GPL(gpiochip_fwd_gpio_set_multiple, "GPIO_FORWARDER");
+
+/**
+ * gpiochip_fwd_gpio_set_config - Set @config for a GPIO forwarder line
+ * @fwd: GPIO forwarder
+ * @offset: the offset of the line
+ * @config: Same packed config format as generic pinconf
+ *
+ * Returns: 0 on success, %-ENOTSUPP if the controller doesn't support setting
+ * the configuration.
+ */
+int gpiochip_fwd_gpio_set_config(struct gpiochip_fwd *fwd, unsigned int offset,
+				 unsigned long config)
+{
+	struct gpio_chip *gc = gpiochip_fwd_get_gpiochip(fwd);
+
+	return gpio_fwd_set_config(gc, offset, config);
+}
+EXPORT_SYMBOL_NS_GPL(gpiochip_fwd_gpio_set_config, "GPIO_FORWARDER");
+
+/**
+ * gpiochip_fwd_gpio_to_irq - Return the IRQ corresponding to a GPIO forwarder line
+ * @fwd: GPIO forwarder
+ * @offset: the offset of the line
+ *
+ * Returns: The Linux IRQ corresponding to the passed line, or an error code in
+ * case of error.
+ */
+int gpiochip_fwd_gpio_to_irq(struct gpiochip_fwd *fwd, unsigned int offset)
+{
+	struct gpio_chip *gc = gpiochip_fwd_get_gpiochip(fwd);
+
+	return gpio_fwd_to_irq(gc, offset);
+}
+EXPORT_SYMBOL_NS_GPL(gpiochip_fwd_gpio_to_irq, "GPIO_FORWARDER");
+
+/**
+ * devm_gpiochip_fwd_alloc - Allocate and initialize a new GPIO forwarder
+ * @dev: Parent device pointer
+ * @ngpios: Number of GPIOs in the forwarder
+ *
+ * Returns: An opaque object pointer, or an ERR_PTR()-encoded negative error
+ * code on failure.
+ */
+struct gpiochip_fwd *devm_gpiochip_fwd_alloc(struct device *dev,
+					     unsigned int ngpios)
+{
+	struct gpiochip_fwd *fwd;
+	struct gpio_chip *chip;
+
+	fwd = devm_kzalloc(dev, struct_size(fwd, tmp, fwd_tmp_size(ngpios)), GFP_KERNEL);
+	if (!fwd)
+		return ERR_PTR(-ENOMEM);
+
+	fwd->descs = devm_kcalloc(dev, ngpios, sizeof(*fwd->descs), GFP_KERNEL);
+	if (!fwd->descs)
+		return ERR_PTR(-ENOMEM);
+
+	fwd->valid_mask = devm_bitmap_zalloc(dev, ngpios, GFP_KERNEL);
+	if (!fwd->valid_mask)
+		return ERR_PTR(-ENOMEM);
+
+	chip = &fwd->chip;
+
+	chip->label = dev_name(dev);
+	chip->parent = dev;
+	chip->owner = THIS_MODULE;
+	chip->request = gpio_fwd_request;
+	chip->get_direction = gpio_fwd_get_direction;
+	chip->direction_input = gpio_fwd_direction_input;
+	chip->direction_output = gpio_fwd_direction_output;
+	chip->get = gpio_fwd_get;
+	chip->get_multiple = gpio_fwd_get_multiple_locked;
+	chip->set = gpio_fwd_set;
+	chip->set_multiple = gpio_fwd_set_multiple_locked;
+	chip->to_irq = gpio_fwd_to_irq;
+	chip->base = -1;
+	chip->ngpio = ngpios;
+
+	return fwd;
+}
+EXPORT_SYMBOL_NS_GPL(devm_gpiochip_fwd_alloc, "GPIO_FORWARDER");
+
+/**
+ * gpiochip_fwd_desc_add - Add a GPIO desc in the forwarder
+ * @fwd: GPIO forwarder
+ * @desc: GPIO descriptor to register
+ * @offset: offset for the GPIO in the forwarder
+ *
+ * Returns: 0 on success, or negative errno on failure.
+ */
+int gpiochip_fwd_desc_add(struct gpiochip_fwd *fwd, struct gpio_desc *desc,
+			  unsigned int offset)
+{
+	struct gpio_chip *chip = &fwd->chip;
+
+	if (offset > chip->ngpio)
+		return -EINVAL;
+
+	if (test_and_set_bit(offset, fwd->valid_mask))
+		return -EEXIST;
+
+	/*
+	 * If any of the GPIO lines are sleeping, then the entire forwarder
+	 * will be sleeping.
+	 */
+	if (gpiod_cansleep(desc))
+		chip->can_sleep = true;
+
+	fwd->descs[offset] = desc;
+
+	dev_dbg(chip->parent, "%u => gpio %d irq %d\n", offset,
+		desc_to_gpio(desc), gpiod_to_irq(desc));
+
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(gpiochip_fwd_desc_add, "GPIO_FORWARDER");
+
+/**
+ * gpiochip_fwd_desc_free - Remove a GPIO desc from the forwarder
+ * @fwd: GPIO forwarder
+ * @offset: offset of GPIO desc to remove
+ */
+void gpiochip_fwd_desc_free(struct gpiochip_fwd *fwd, unsigned int offset)
+{
+	if (test_and_clear_bit(offset, fwd->valid_mask))
+		gpiod_put(fwd->descs[offset]);
+}
+EXPORT_SYMBOL_NS_GPL(gpiochip_fwd_desc_free, "GPIO_FORWARDER");
+
+/**
+ * gpiochip_fwd_register - Register a GPIO forwarder
+ * @fwd: GPIO forwarder
+ * @data: driver-private data associated with this forwarder
+ *
+ * Returns: 0 on success, or negative errno on failure.
+ */
+int gpiochip_fwd_register(struct gpiochip_fwd *fwd, void *data)
+{
+	struct gpio_chip *chip = &fwd->chip;
+
+	/*
+	 * Some gpio_desc were not registered. They will be registered at runtime
+	 * but we have to suppose they can sleep.
+	 */
+	if (!bitmap_full(fwd->valid_mask, chip->ngpio))
+		chip->can_sleep = true;
+
+	if (chip->can_sleep)
+		mutex_init(&fwd->mlock);
+	else
+		spin_lock_init(&fwd->slock);
+
+	fwd->data = data;
+
+	return devm_gpiochip_add_data(chip->parent, chip, fwd);
+}
+EXPORT_SYMBOL_NS_GPL(gpiochip_fwd_register, "GPIO_FORWARDER");
+
+/**
  * gpiochip_fwd_create() - Create a new GPIO forwarder
  * @dev: Parent device pointer
  * @ngpios: Number of GPIOs in the forwarder.
  * @descs: Array containing the GPIO descriptors to forward to.
- *         This array must contain @ngpios entries, and must not be deallocated
- *         before the forwarder has been destroyed again.
+ *         This array must contain @ngpios entries, and can be deallocated
+ *         as the forwarder has its own array.
  * @features: Bitwise ORed features as defined with FWD_FEATURE_*.
  *
  * This function creates a new gpiochip, which forwards all GPIO operations to
···
 						struct gpio_desc *descs[],
 						unsigned long features)
 {
-	const char *label = dev_name(dev);
 	struct gpiochip_fwd *fwd;
-	struct gpio_chip *chip;
 	unsigned int i;
 	int error;
 
-	fwd = devm_kzalloc(dev, struct_size(fwd, tmp, fwd_tmp_size(ngpios)),
-			   GFP_KERNEL);
-	if (!fwd)
-		return ERR_PTR(-ENOMEM);
+	fwd = devm_gpiochip_fwd_alloc(dev, ngpios);
+	if (IS_ERR(fwd))
+		return fwd;
 
-	chip = &fwd->chip;
-
-	/*
-	 * If any of the GPIO lines are sleeping, then the entire forwarder
-	 * will be sleeping.
-	 * If any of the chips support .set_config(), then the forwarder will
-	 * support setting configs.
-	 */
 	for (i = 0; i < ngpios; i++) {
-		struct gpio_chip *parent = gpiod_to_chip(descs[i]);
-
-		dev_dbg(dev, "%u => gpio %d irq %d\n", i,
-			desc_to_gpio(descs[i]), gpiod_to_irq(descs[i]));
-
-		if (gpiod_cansleep(descs[i]))
-			chip->can_sleep = true;
-		if (parent && parent->set_config)
-			chip->set_config = gpio_fwd_set_config;
-	}
-
-	chip->label = label;
-	chip->parent = dev;
-	chip->owner = THIS_MODULE;
-	chip->get_direction = gpio_fwd_get_direction;
-	chip->direction_input = gpio_fwd_direction_input;
-	chip->direction_output = gpio_fwd_direction_output;
-	chip->get = gpio_fwd_get;
-	chip->get_multiple = gpio_fwd_get_multiple_locked;
-	chip->set = gpio_fwd_set;
-	chip->set_multiple = gpio_fwd_set_multiple_locked;
-	chip->to_irq = gpio_fwd_to_irq;
-	chip->base = -1;
-	chip->ngpio = ngpios;
-	fwd->descs = descs;
-
-	if (chip->can_sleep)
-		mutex_init(&fwd->mlock);
-	else
-		spin_lock_init(&fwd->slock);
-
-	if (features & FWD_FEATURE_DELAY) {
-		error = gpiochip_fwd_setup_delay_line(dev, chip, fwd);
+		error = gpiochip_fwd_desc_add(fwd, descs[i], i);
 		if (error)
 			return ERR_PTR(error);
 	}
 
-	error = devm_gpiochip_add_data(dev, chip, fwd);
+	if (features & FWD_FEATURE_DELAY) {
+		error = gpiochip_fwd_setup_delay_line(fwd);
+		if (error)
+			return ERR_PTR(error);
+	}
+
+	error = gpiochip_fwd_register(fwd, NULL);
 	if (error)
 		return ERR_PTR(error);
 
···
 		return PTR_ERR(fwd);
 
 	platform_set_drvdata(pdev, fwd);
+	devm_kfree(dev, descs);
 	return 0;
 }
 

drivers/gpio/gpiolib.c

···
 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
 
 /**
- * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
+ * gpiochip_add_pin_range_with_pins() - add a range for GPIO <-> pin mapping
  * @gc: the gpiochip to add the range for
  * @pinctl_name: the dev_name() of the pin controller to map to
  * @gpio_offset: the start offset in the current gpio_chip number space
  * @pin_offset: the start offset in the pin controller number space
+ * @pins: the list of non consecutive pins to accumulate in this range (if not
+ *	NULL, pin_offset is ignored by pinctrl core)
  * @npins: the number of pins from the offset of each pin space (GPIO and
  *	pin controller) to accumulate in this range
  *
···
  * Returns:
  * 0 on success, or a negative errno on failure.
  */
-int gpiochip_add_pin_range(struct gpio_chip *gc, const char *pinctl_name,
-			   unsigned int gpio_offset, unsigned int pin_offset,
-			   unsigned int npins)
+int gpiochip_add_pin_range_with_pins(struct gpio_chip *gc,
+				     const char *pinctl_name,
+				     unsigned int gpio_offset,
+				     unsigned int pin_offset,
+				     unsigned int const *pins,
+				     unsigned int npins)
 {
 	struct gpio_pin_range *pin_range;
 	struct gpio_device *gdev = gc->gpiodev;
···
 	pin_range->range.name = gc->label;
 	pin_range->range.base = gdev->base + gpio_offset;
 	pin_range->range.pin_base = pin_offset;
+	pin_range->range.pins = pins;
 	pin_range->range.npins = npins;
 	pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
 			&pin_range->range);
···
 		kfree(pin_range);
 		return ret;
 	}
-	chip_dbg(gc, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
-		 gpio_offset, gpio_offset + npins - 1,
-		 pinctl_name,
-		 pin_offset, pin_offset + npins - 1);
+	if (pin_range->range.pins)
+		chip_dbg(gc, "created GPIO range %d->%d ==> %s %d sparse PIN range { %d, ... }",
+			 gpio_offset, gpio_offset + npins - 1,
+			 pinctl_name, npins, pins[0]);
+	else
+		chip_dbg(gc, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
+			 gpio_offset, gpio_offset + npins - 1,
+			 pinctl_name,
+			 pin_offset, pin_offset + npins - 1);
 
 	list_add_tail(&pin_range->node, &gdev->pin_ranges);
 
 	return 0;
 }
-EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
+EXPORT_SYMBOL_GPL(gpiochip_add_pin_range_with_pins);
 
 /**
  * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings

include/linux/gpio/driver.h

···
 
 #ifdef CONFIG_PINCTRL
 
-int gpiochip_add_pin_range(struct gpio_chip *gc, const char *pinctl_name,
-			   unsigned int gpio_offset, unsigned int pin_offset,
-			   unsigned int npins);
+int gpiochip_add_pin_range_with_pins(struct gpio_chip *gc,
+				     const char *pinctl_name,
+				     unsigned int gpio_offset,
+				     unsigned int pin_offset,
+				     unsigned int const *pins,
+				     unsigned int npins);
 int gpiochip_add_pingroup_range(struct gpio_chip *gc,
 			struct pinctrl_dev *pctldev,
 			unsigned int gpio_offset, const char *pin_group);
 void gpiochip_remove_pin_ranges(struct gpio_chip *gc);
 
+static inline int
+gpiochip_add_pin_range(struct gpio_chip *gc,
+		       const char *pinctl_name,
+		       unsigned int gpio_offset,
+		       unsigned int pin_offset,
+		       unsigned int npins)
+{
+	return gpiochip_add_pin_range_with_pins(gc, pinctl_name, gpio_offset,
+						pin_offset, NULL, npins);
+}
+
+static inline int
+gpiochip_add_sparse_pin_range(struct gpio_chip *gc,
+			      const char *pinctl_name,
+			      unsigned int gpio_offset,
+			      unsigned int const *pins,
+			      unsigned int npins)
+{
+	return gpiochip_add_pin_range_with_pins(gc, pinctl_name, gpio_offset, 0,
+						pins, npins);
+}
 #else /* ! CONFIG_PINCTRL */
+
+static inline int
+gpiochip_add_pin_range_with_pins(struct gpio_chip *gc,
+				 const char *pinctl_name,
+				 unsigned int gpio_offset,
+				 unsigned int pin_offset,
+				 unsigned int npins)
+{
+	return 0;
+}
 
 static inline int
 gpiochip_add_pin_range(struct gpio_chip *gc, const char *pinctl_name,
···
 {
 	return 0;
 }
+
+static inline int
+gpiochip_add_sparse_pin_range(struct gpio_chip *gc,
+			      const char *pinctl_name,
+			      unsigned int gpio_offset,
+			      unsigned int const *pins,
+			      unsigned int npins)
+{
+	return 0;
+}
+
 static inline int
 gpiochip_add_pingroup_range(struct gpio_chip *gc,
 			struct pinctrl_dev *pctldev,

include/linux/gpio/forwarder.h

···
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __LINUX_GPIO_FORWARDER_H
+#define __LINUX_GPIO_FORWARDER_H
+
+struct gpio_desc;
+struct gpio_chip;
+struct gpiochip_fwd;
+
+struct gpiochip_fwd *devm_gpiochip_fwd_alloc(struct device *dev,
+					     unsigned int ngpios);
+int gpiochip_fwd_desc_add(struct gpiochip_fwd *fwd,
+			  struct gpio_desc *desc, unsigned int offset);
+void gpiochip_fwd_desc_free(struct gpiochip_fwd *fwd, unsigned int offset);
+int gpiochip_fwd_register(struct gpiochip_fwd *fwd, void *data);
+
+struct gpio_chip *gpiochip_fwd_get_gpiochip(struct gpiochip_fwd *fwd);
+
+void *gpiochip_fwd_get_data(struct gpiochip_fwd *fwd);
+
+int gpiochip_fwd_gpio_request(struct gpiochip_fwd *fwd, unsigned int offset);
+int gpiochip_fwd_gpio_get_direction(struct gpiochip_fwd *fwd,
+				    unsigned int offset);
+int gpiochip_fwd_gpio_direction_input(struct gpiochip_fwd *fwd,
+				      unsigned int offset);
+int gpiochip_fwd_gpio_direction_output(struct gpiochip_fwd *fwd,
+				       unsigned int offset,
+				       int value);
+int gpiochip_fwd_gpio_get(struct gpiochip_fwd *fwd, unsigned int offset);
+int gpiochip_fwd_gpio_get_multiple(struct gpiochip_fwd *fwd,
+				   unsigned long *mask,
+				   unsigned long *bits);
+int gpiochip_fwd_gpio_set(struct gpiochip_fwd *fwd, unsigned int offset,
+			  int value);
+int gpiochip_fwd_gpio_set_multiple(struct gpiochip_fwd *fwd,
+				   unsigned long *mask,
+				   unsigned long *bits);
+int gpiochip_fwd_gpio_set_config(struct gpiochip_fwd *fwd, unsigned int offset,
+				 unsigned long config);
+int gpiochip_fwd_gpio_to_irq(struct gpiochip_fwd *fwd, unsigned int offset);
+
+#endif

include/linux/string_choices.h

···
 }
 #define str_low_high(v)		str_high_low(!(v))
 
+static inline const char *str_input_output(bool v)
+{
+	return v ? "input" : "output";
+}
+#define str_output_input(v)	str_input_output(!(v))
+
 static inline const char *str_on_off(bool v)
 {
 	return v ? "on" : "off";