Commit d1d564ec authored by Bartosz Golaszewski's avatar Bartosz Golaszewski
Browse files

gpio: move hogs into GPIO core 



Refactor line hogging code by moving the parts duplicated in
gpiolib-acpi-core.c and gpiolib-of.c into gpiolib.c, leaving just the
OF-specific bits in the latter.

This makes fwnode the primary API for setting up hogs and allows to use
software nodes in addition to ACPI and OF nodes.

Reviewed-by: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: default avatarLinus Walleij <linusw@kernel.org>
Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patch.msgid.link/20260309-gpio-hog-fwnode-v2-2-4e61f3dbf06a@oss.qualcomm.com


Signed-off-by: default avatarBartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
parent bbee90e7

drivers/gpio/gpiolib-acpi-core.c

+0 −70
Original line number Diff line number Diff line
@@ -1220,75 +1220,6 @@ static void acpi_gpiochip_free_regions(struct acpi_gpio_chip *achip) 
	}

}



static struct gpio_desc *

acpi_gpiochip_parse_own_gpio(struct acpi_gpio_chip *achip,

			     struct fwnode_handle *fwnode,

			     const char **name,

			     unsigned long *lflags,

			     enum gpiod_flags *dflags)

{

	struct gpio_chip *chip = achip->chip;

	struct gpio_desc *desc;

	u32 gpios[2];

	int ret;



	*lflags = GPIO_LOOKUP_FLAGS_DEFAULT;

	*dflags = GPIOD_ASIS;

	*name = NULL;



	ret = fwnode_property_read_u32_array(fwnode, "gpios", gpios,

					     ARRAY_SIZE(gpios));

	if (ret < 0)

		return ERR_PTR(ret);



	desc = gpiochip_get_desc(chip, gpios[0]);

	if (IS_ERR(desc))

		return desc;



	if (gpios[1])

		*lflags |= GPIO_ACTIVE_LOW;



	if (fwnode_property_present(fwnode, "input"))

		*dflags |= GPIOD_IN;

	else if (fwnode_property_present(fwnode, "output-low"))

		*dflags |= GPIOD_OUT_LOW;

	else if (fwnode_property_present(fwnode, "output-high"))

		*dflags |= GPIOD_OUT_HIGH;

	else

		return ERR_PTR(-EINVAL);



	fwnode_property_read_string(fwnode, "line-name", name);



	return desc;

}



static void acpi_gpiochip_scan_gpios(struct acpi_gpio_chip *achip)

{

	struct gpio_chip *chip = achip->chip;



	device_for_each_child_node_scoped(chip->parent, fwnode) {

		unsigned long lflags;

		enum gpiod_flags dflags;

		struct gpio_desc *desc;

		const char *name;

		int ret;



		if (!fwnode_property_present(fwnode, "gpio-hog"))

			continue;



		desc = acpi_gpiochip_parse_own_gpio(achip, fwnode, &name,

						    &lflags, &dflags);

		if (IS_ERR(desc))

			continue;



		ret = gpiod_hog(desc, name, lflags, dflags);

		if (ret) {

			dev_err(chip->parent, "Failed to hog GPIO\n");

			return;

		}

	}

}



void acpi_gpiochip_add(struct gpio_chip *chip)

{

	struct acpi_gpio_chip *acpi_gpio;
@@ -1321,7 +1252,6 @@ void acpi_gpiochip_add(struct gpio_chip *chip) 
	}



	acpi_gpiochip_request_regions(acpi_gpio);

	acpi_gpiochip_scan_gpios(acpi_gpio);

	acpi_dev_clear_dependencies(adev);

}

drivers/gpio/gpiolib-of.c

+16 −127
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ 
#include <linux/device.h>

#include <linux/err.h>

#include <linux/errno.h>

#include <linux/fwnode.h>

#include <linux/io.h>

#include <linux/module.h>

#include <linux/of.h>
@@ -712,139 +713,26 @@ struct gpio_desc *of_find_gpio(struct device_node *np, const char *con_id, 
	return desc;

}



/**

 * of_parse_own_gpio() - Get a GPIO hog descriptor, names and flags for GPIO API

 * @np:		device node to get GPIO from

 * @chip:	GPIO chip whose hog is parsed

 * @idx:	Index of the GPIO to parse

 * @name:	GPIO line name

 * @lflags:	bitmask of gpio_lookup_flags GPIO_* values - returned from

 *		of_find_gpio() or of_parse_own_gpio()

 * @dflags:	gpiod_flags - optional GPIO initialization flags

 *

 * Returns:

 * GPIO descriptor to use with Linux GPIO API, or one of the errno

 * value on the error condition.

 */

static struct gpio_desc *of_parse_own_gpio(struct device_node *np,

					   struct gpio_chip *chip,

					   unsigned int idx, const char **name,

					   unsigned long *lflags,

					   enum gpiod_flags *dflags)

int of_gpiochip_get_lflags(struct gpio_chip *chip,

			   struct fwnode_reference_args *gpiospec,

			   unsigned long *lflags)

{

	struct device_node *chip_np;

	enum of_gpio_flags xlate_flags;

	struct of_phandle_args gpiospec;

	struct of_phandle_args args;

	struct gpio_desc *desc;

	unsigned int i;

	u32 tmp;

	int ret;



	chip_np = dev_of_node(&chip->gpiodev->dev);

	if (!chip_np)

		return ERR_PTR(-EINVAL);



	xlate_flags = 0;

	*lflags = GPIO_LOOKUP_FLAGS_DEFAULT;

	*dflags = GPIOD_ASIS;



	ret = of_property_read_u32(chip_np, "#gpio-cells", &tmp);

	if (ret)

		return ERR_PTR(ret);

	args.np = to_of_node(gpiospec->fwnode);

	args.args_count = gpiospec->nargs;



	gpiospec.np = chip_np;

	gpiospec.args_count = tmp;



	for (i = 0; i < tmp; i++) {

		ret = of_property_read_u32_index(np, "gpios", idx * tmp + i,

						 &gpiospec.args[i]);

		if (ret)

			return ERR_PTR(ret);

	}

	for (int i = 0; i < args.args_count; i++)

		args.args[i] = gpiospec->args[i];



	desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, &xlate_flags);

	desc = of_xlate_and_get_gpiod_flags(chip, &args, &xlate_flags);

	if (IS_ERR(desc))

		return desc;

		return PTR_ERR(desc);



	*lflags = of_convert_gpio_flags(xlate_flags);



	if (of_property_read_bool(np, "input"))

		*dflags |= GPIOD_IN;

	else if (of_property_read_bool(np, "output-low"))

		*dflags |= GPIOD_OUT_LOW;

	else if (of_property_read_bool(np, "output-high"))

		*dflags |= GPIOD_OUT_HIGH;

	else {

		pr_warn("GPIO line %d (%pOFn): no hogging state specified, bailing out\n",

			desc_to_gpio(desc), np);

		return ERR_PTR(-EINVAL);

	}



	if (name && of_property_read_string(np, "line-name", name))

		*name = np->name;



	return desc;

}



/**

 * of_gpiochip_add_hog - Add all hogs in a hog device node

 * @chip:	gpio chip to act on

 * @hog:	device node describing the hogs

 *

 * Returns:

 * 0 on success, or negative errno on failure.

 */

static int of_gpiochip_add_hog(struct gpio_chip *chip, struct device_node *hog)

{

	enum gpiod_flags dflags;

	struct gpio_desc *desc;

	unsigned long lflags;

	const char *name;

	unsigned int i;

	int ret;



	for (i = 0;; i++) {

		desc = of_parse_own_gpio(hog, chip, i, &name, &lflags, &dflags);

		if (IS_ERR(desc))

			break;



		ret = gpiod_hog(desc, name, lflags, dflags);

		if (ret < 0)

			return ret;



#ifdef CONFIG_OF_DYNAMIC

		WRITE_ONCE(desc->hog, hog);

#endif

	}



	return 0;

}



/**

 * of_gpiochip_scan_gpios - Scan gpio-controller for gpio definitions

 * @chip:	gpio chip to act on

 *

 * This is only used by of_gpiochip_add to request/set GPIO initial

 * configuration.

 *

 * Returns:

 * 0 on success, or negative errno on failure.

 */

static int of_gpiochip_scan_gpios(struct gpio_chip *chip)

{

	int ret;



	for_each_available_child_of_node_scoped(dev_of_node(&chip->gpiodev->dev), np) {

		if (!of_property_read_bool(np, "gpio-hog"))

			continue;



		ret = of_gpiochip_add_hog(chip, np);

		if (ret < 0)

			return ret;



		of_node_set_flag(np, OF_POPULATED);

	}



	return 0;

}
@@ -899,7 +787,7 @@ static int of_gpio_notify(struct notifier_block *nb, unsigned long action, 
		if (!gdev)

			return NOTIFY_DONE;	/* not for us */



		ret = of_gpiochip_add_hog(gpio_device_get_chip(gdev), rd->dn);

		ret = gpiochip_add_hog(gpio_device_get_chip(gdev), of_fwnode_handle(rd->dn));

		if (ret < 0) {

			pr_err("%s: failed to add hogs for %pOF\n", __func__,

			       rd->dn);
@@ -1178,9 +1066,10 @@ int of_gpiochip_add(struct gpio_chip *chip) 


	of_node_get(np);



	ret = of_gpiochip_scan_gpios(chip);

	if (ret)

		of_node_put(np);

	for_each_available_child_of_node_scoped(np, child) {

		if (of_property_read_bool(child, "gpio-hog"))

			of_node_set_flag(child, OF_POPULATED);

	}



	return ret;

}

drivers/gpio/gpiolib-of.h

+10 −0
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ 


struct device_node;

struct fwnode_handle;

struct fwnode_reference_args;



struct gpio_chip;

struct gpio_desc;
@@ -24,6 +25,9 @@ int of_gpiochip_add(struct gpio_chip *gc); 
void of_gpiochip_remove(struct gpio_chip *gc);

bool of_gpiochip_instance_match(struct gpio_chip *gc, unsigned int index);

int of_gpio_count(const struct fwnode_handle *fwnode, const char *con_id);

int of_gpiochip_get_lflags(struct gpio_chip *chip,

			   struct fwnode_reference_args *gpiospec,

			   unsigned long *lflags);

#else

static inline struct gpio_desc *of_find_gpio(struct device_node *np,

					     const char *con_id,
@@ -44,6 +48,12 @@ static inline int of_gpio_count(const struct fwnode_handle *fwnode, 
{

	return 0;

}

static inline int of_gpiochip_get_lflags(struct gpio_chip *chip,

					 struct fwnode_reference_args *gpiospec,

					 unsigned long *lflags)

{

	return -ENOENT;

}

#endif /* CONFIG_OF_GPIO */



extern struct notifier_block gpio_of_notifier;

drivers/gpio/gpiolib.c

+96 −2
Original line number Diff line number Diff line
@@ -948,7 +948,7 @@ static void gpiochip_machine_hog(struct gpio_chip *gc, struct gpiod_hog *hog) 
			  __func__, gc->label, hog->chip_hwnum, rv);

}



static void machine_gpiochip_add(struct gpio_chip *gc)

static void gpiochip_machine_hog_lines(struct gpio_chip *gc)

{

	struct gpiod_hog *hog;
@@ -960,6 +960,98 @@ static void machine_gpiochip_add(struct gpio_chip *gc) 
	}

}



int gpiochip_add_hog(struct gpio_chip *gc, struct fwnode_handle *fwnode)

{

	struct fwnode_handle *gc_node = dev_fwnode(&gc->gpiodev->dev);

	struct fwnode_reference_args gpiospec;

	enum gpiod_flags dflags;

	struct gpio_desc *desc;

	unsigned long lflags;

	const char *name;

	int ret, argc;

	u32 gpios[3]; /* We support up to three-cell bindings. */

	u32 cells;



	lflags = GPIO_LOOKUP_FLAGS_DEFAULT;

	dflags = GPIOD_ASIS;

	name = NULL;



	argc = fwnode_property_count_u32(fwnode, "gpios");

	if (argc < 0)

		return argc;

	if (argc > 3)

		return -EINVAL;



	ret = fwnode_property_read_u32_array(fwnode, "gpios", gpios, argc);

	if (ret < 0)

		return ret;



	if (is_of_node(fwnode)) {

		/*

		 * OF-nodes need some additional special handling for

		 * translating of devicetree flags.

		 */

		ret = fwnode_property_read_u32(gc_node, "#gpio-cells", &cells);

		if (ret)

			return ret;

		if (!ret && argc != cells)

			return -EINVAL;



		memset(&gpiospec, 0, sizeof(gpiospec));

		gpiospec.fwnode = fwnode;

		gpiospec.nargs = argc;



		for (int i = 0; i < argc; i++)

			gpiospec.args[i] = gpios[i];



		ret = of_gpiochip_get_lflags(gc, &gpiospec, &lflags);

		if (ret)

			return ret;

	} else {

		/*

		 * GPIO_ACTIVE_LOW is currently the only lookup flag

		 * supported for non-OF firmware nodes.

		 */

		if (gpios[1])

			lflags |= GPIO_ACTIVE_LOW;

	}



	if (fwnode_property_present(fwnode, "input"))

		dflags |= GPIOD_IN;

	else if (fwnode_property_present(fwnode, "output-low"))

		dflags |= GPIOD_OUT_LOW;

	else if (fwnode_property_present(fwnode, "output-high"))

		dflags |= GPIOD_OUT_HIGH;

	else

		return -EINVAL;



	fwnode_property_read_string(fwnode, "line-name", &name);



	desc = gpiochip_get_desc(gc, gpios[0]);

	if (IS_ERR(desc))

		return PTR_ERR(desc);



	return gpiod_hog(desc, name, lflags, dflags);

}



static int gpiochip_hog_lines(struct gpio_chip *gc)

{

	int ret;



	device_for_each_child_node_scoped(&gc->gpiodev->dev, fwnode) {

		if (!fwnode_property_present(fwnode, "gpio-hog"))

			continue;



		ret = gpiochip_add_hog(gc, fwnode);

		if (ret)

			return ret;

	}



	gpiochip_machine_hog_lines(gc);



	return 0;

}



static void gpiochip_setup_devs(void)

{

	struct gpio_device *gdev;
@@ -1209,7 +1301,9 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, 


	acpi_gpiochip_add(gc);



	machine_gpiochip_add(gc);

	ret = gpiochip_hog_lines(gc);

	if (ret)

		goto err_remove_of_chip;



	ret = gpiochip_irqchip_init_valid_mask(gc);

	if (ret)

drivers/gpio/gpiolib.h

+3 −0
Original line number Diff line number Diff line
@@ -23,6 +23,8 @@ 


#define GPIOCHIP_NAME	"gpiochip"



struct fwnode_handle;



/**

 * struct gpio_device - internal state container for GPIO devices

 * @dev: the GPIO device struct
@@ -274,6 +276,7 @@ int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id, 
int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce);

int gpiod_hog(struct gpio_desc *desc, const char *name,

		unsigned long lflags, enum gpiod_flags dflags);

int gpiochip_add_hog(struct gpio_chip *gc, struct fwnode_handle *fwnode);

int gpiochip_get_ngpios(struct gpio_chip *gc, struct device *dev);

struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc, unsigned int hwnum);

const char *gpiod_get_label(struct gpio_desc *desc);