Commit 802c51a8 authored by Bartosz Golaszewski's avatar Bartosz Golaszewski
Browse files

gpiolib: fix hogs with multiple lines 



After moving GPIO hog handling into GPIOLIB core, we accidentally stopped
supporting devicetree hog definitions with multiple lines like so:

	hog {
		gpio-hog;
		gpios = <3 0>, <4 GPIO_ACTIVE_LOW>;
		output-high;
		line-name = "foo";
	};

Restore this functionality to fix reported regressions.

Fixes: d1d564ec ("gpio: move hogs into GPIO core")
Reported-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
Closes: https://lore.kernel.org/all/CAMuHMdX6RuZXAozrF5m625ZepJTVVr4pcyKczSk12MedWvoejw@mail.gmail.com/


Tested-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/20260330-gpio-hogs-multiple-v3-1-175c3839ad9f@oss.qualcomm.com


Signed-off-by: default avatarBartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
parent af475c16

drivers/gpio/gpiolib.c

+54 −38
Original line number Diff line number Diff line
@@ -938,12 +938,18 @@ 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;

	const char *name = NULL;

	struct gpio_desc *desc;

	unsigned int num_hogs;

	unsigned long lflags;

	const char *name;

	int ret, argc;

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

	u32 cells;

	/*

	 * For devicetree-based systems, this needs to be defined in bindings

	 * and there's no real default value. For other firmware descriptions

	 * it makes the most sense to use 2 cells for the GPIO offset and

	 * request flags.

	 */

	u32 cells = 2;



	lflags = GPIO_LOOKUP_FLAGS_DEFAULT;

	dflags = GPIOD_ASIS;
@@ -952,30 +958,46 @@ int gpiochip_add_hog(struct gpio_chip *gc, struct fwnode_handle *fwnode) 
	argc = fwnode_property_count_u32(fwnode, "gpios");

	if (argc < 0)

		return argc;

	if (argc > 3)



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

	if (ret && is_of_node(fwnode))

		return ret;

	if (argc % cells)

		return -EINVAL;



	num_hogs = argc / cells;



	u32 *gpios __free(kfree) = kzalloc_objs(*gpios, argc);

	if (!gpios)

		return -ENOMEM;



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

	if (ret < 0)

		return ret;



	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);



	for (unsigned int i = 0; i < num_hogs; i++) {

		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;

			gpiospec.nargs = cells;



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

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

			for (unsigned int j = 0; j < cells; j++)

				gpiospec.args[j] = gpios[i * cells + j];



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

			if (ret)
@@ -985,26 +1007,20 @@ int gpiochip_add_hog(struct gpio_chip *gc, struct fwnode_handle *fwnode) 
			 * GPIO_ACTIVE_LOW is currently the only lookup flag

			 * supported for non-OF firmware nodes.

			 */

		if (gpios[1])

			if (gpios[i * cells + 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]);

		desc = gpiochip_get_desc(gc, gpios[i * cells]);

		if (IS_ERR(desc))

			return PTR_ERR(desc);



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

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

		if (ret)

			return ret;

	}



	return 0;

}



static int gpiochip_hog_lines(struct gpio_chip *gc)