[deliverable/linux.git] / drivers / gpio / gpiolib-of.c

/*
 * OF helpers for the GPIO API
 *
 * Copyright (c) 2007-2008  MontaVista Software, Inc.
 *
 * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <linux/device.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/io.h>
#include <linux/io-mapping.h>
#include <linux/gpio/consumer.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_gpio.h>
#include <linux/pinctrl/pinctrl.h>
#include <linux/slab.h>
#include <linux/gpio/machine.h>

#include "gpiolib.h"

/* Private data structure for of_gpiochip_find_and_xlate */
struct gg_data {
	enum of_gpio_flags *flags;
	struct of_phandle_args gpiospec;

	struct gpio_desc *out_gpio;
};

/* Private function for resolving node pointer to gpio_chip */
static int of_gpiochip_find_and_xlate(struct gpio_chip *gc, void *data)
{
	struct gg_data *gg_data = data;
	int ret;

	if ((gc->of_node != gg_data->gpiospec.np) ||
	    (gc->of_gpio_n_cells != gg_data->gpiospec.args_count) ||
	    (!gc->of_xlate))
		return false;

	ret = gc->of_xlate(gc, &gg_data->gpiospec, gg_data->flags);
	if (ret < 0) {
		/* We've found a gpio chip, but the translation failed.
		 * Store translation error in out_gpio.
		 * Return false to keep looking, as more than one gpio chip
		 * could be registered per of-node.
		 */
		gg_data->out_gpio = ERR_PTR(ret);
		return false;
	 }

	gg_data->out_gpio = gpiochip_get_desc(gc, ret);
	return true;
}

/**
 * of_get_named_gpiod_flags() - Get a GPIO descriptor and flags for GPIO API
 * @np:		device node to get GPIO from
 * @propname:	property name containing gpio specifier(s)
 * @index:	index of the GPIO
 * @flags:	a flags pointer to fill in
 *
 * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
 * value on the error condition. If @flags is not NULL the function also fills
 * in flags for the GPIO.
 */
struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np,
		     const char *propname, int index, enum of_gpio_flags *flags)
{
	/* Return -EPROBE_DEFER to support probe() functions to be called
	 * later when the GPIO actually becomes available
	 */
	struct gg_data gg_data = {
		.flags = flags,
		.out_gpio = ERR_PTR(-EPROBE_DEFER)
	};
	int ret;

	/* .of_xlate might decide to not fill in the flags, so clear it. */
	if (flags)
		*flags = 0;

	ret = of_parse_phandle_with_args(np, propname, "#gpio-cells", index,
					 &gg_data.gpiospec);
	if (ret) {
		pr_debug("%s: can't parse '%s' property of node '%s[%d]'\n",
			__func__, propname, np->full_name, index);
		return ERR_PTR(ret);
	}

	gpiochip_find(&gg_data, of_gpiochip_find_and_xlate);

	of_node_put(gg_data.gpiospec.np);
	pr_debug("%s: parsed '%s' property of node '%s[%d]' - status (%d)\n",
		 __func__, propname, np->full_name, index,
		 PTR_ERR_OR_ZERO(gg_data.out_gpio));
	return gg_data.out_gpio;
}

int of_get_named_gpio_flags(struct device_node *np, const char *list_name,
			    int index, enum of_gpio_flags *flags)
{
	struct gpio_desc *desc;

	desc = of_get_named_gpiod_flags(np, list_name, index, flags);

	if (IS_ERR(desc))
		return PTR_ERR(desc);
	else
		return desc_to_gpio(desc);
}
EXPORT_SYMBOL(of_get_named_gpio_flags);

/**
 * of_parse_own_gpio() - Get a GPIO hog descriptor, names and flags for GPIO API
 * @np:		device node to get GPIO from
 * @name:	GPIO line name
 * @lflags:	gpio_lookup_flags - 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,
					   const char **name,
					   enum gpio_lookup_flags *lflags,
					   enum gpiod_flags *dflags)
{
	struct device_node *chip_np;
	enum of_gpio_flags xlate_flags;
	struct gg_data gg_data = {
		.flags = &xlate_flags,
	};
	u32 tmp;
	int i, ret;

	chip_np = np->parent;
	if (!chip_np)
		return ERR_PTR(-EINVAL);

	xlate_flags = 0;
	*lflags = 0;
	*dflags = 0;

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

	if (tmp > MAX_PHANDLE_ARGS)
		return ERR_PTR(-EINVAL);

	gg_data.gpiospec.args_count = tmp;
	gg_data.gpiospec.np = chip_np;
	for (i = 0; i < tmp; i++) {
		ret = of_property_read_u32_index(np, "gpios", i,
					   &gg_data.gpiospec.args[i]);
		if (ret)
			return ERR_PTR(ret);
	}

	gpiochip_find(&gg_data, of_gpiochip_find_and_xlate);
	if (!gg_data.out_gpio) {
		if (np->parent == np)
			return ERR_PTR(-ENXIO);
		else
			return ERR_PTR(-EINVAL);
	}

	if (xlate_flags & OF_GPIO_ACTIVE_LOW)
		*lflags |= GPIO_ACTIVE_LOW;

	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 (%s): no hogging state specified, bailing out\n",
			desc_to_gpio(gg_data.out_gpio), np->name);
		return ERR_PTR(-EINVAL);
	}

	if (name && of_property_read_string(np, "line-name", name))
		*name = np->name;

	return gg_data.out_gpio;
}

/**
 * of_gpiochip_set_names() - set up the names of the lines
 * @chip: GPIO chip whose lines should be named, if possible
 */
static void of_gpiochip_set_names(struct gpio_chip *gc)
{
	struct gpio_device *gdev = gc->gpiodev;
	struct device_node *np = gc->of_node;
	int i;
	int nstrings;

	nstrings = of_property_count_strings(np, "gpio-line-names");
	if (nstrings <= 0)
		/* Lines names not present */
		return;

	/* This is normally not what you want */
	if (gdev->ngpio != nstrings)
		dev_info(&gdev->dev, "gpio-line-names specifies %d line "
			 "names but there are %d lines on the chip\n",
			 nstrings, gdev->ngpio);

	/*
	 * Make sure to not index beyond the end of the number of descriptors
	 * of the GPIO device.
	 */
	for (i = 0; i < gdev->ngpio; i++) {
		const char *name;
		int ret;

		ret = of_property_read_string_index(np,
						    "gpio-line-names",
						    i,
						    &name);
		if (ret) {
			if (ret != -ENODATA)
                                dev_err(&gdev->dev,
                                        "unable to name line %d: %d\n",
                                        i, ret);
			break;
		}
		gdev->descs[i].name = name;
	}
}

/**
 * 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.
 * It retures error if it fails otherwise 0 on success.
 */
static int of_gpiochip_scan_gpios(struct gpio_chip *chip)
{
	struct gpio_desc *desc = NULL;
	struct device_node *np;
	const char *name;
	enum gpio_lookup_flags lflags;
	enum gpiod_flags dflags;
	int ret;

	for_each_available_child_of_node(chip->of_node, np) {
		if (!of_property_read_bool(np, "gpio-hog"))
			continue;

		desc = of_parse_own_gpio(np, &name, &lflags, &dflags);
		if (IS_ERR(desc))
			continue;

		ret = gpiod_hog(desc, name, lflags, dflags);
		if (ret < 0)
			return ret;
	}

	return 0;
}

/**
 * of_gpio_simple_xlate - translate gpio_spec to the GPIO number and flags
 * @gc:		pointer to the gpio_chip structure
 * @np:		device node of the GPIO chip
 * @gpio_spec:	gpio specifier as found in the device tree
 * @flags:	a flags pointer to fill in
 *
 * This is simple translation function, suitable for the most 1:1 mapped
 * gpio chips. This function performs only one sanity check: whether gpio
 * is less than ngpios (that is specified in the gpio_chip).
 */
int of_gpio_simple_xlate(struct gpio_chip *gc,
			 const struct of_phandle_args *gpiospec, u32 *flags)
{
	/*
	 * We're discouraging gpio_cells < 2, since that way you'll have to
	 * write your own xlate function (that will have to retrieve the GPIO
	 * number and the flags from a single gpio cell -- this is possible,
	 * but not recommended).
	 */
	if (gc->of_gpio_n_cells < 2) {
		WARN_ON(1);
		return -EINVAL;
	}

	if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells))
		return -EINVAL;

	if (gpiospec->args[0] >= gc->ngpio)
		return -EINVAL;

	if (flags)
		*flags = gpiospec->args[1];

	return gpiospec->args[0];
}
EXPORT_SYMBOL(of_gpio_simple_xlate);

/**
 * of_mm_gpiochip_add_data - Add memory mapped GPIO chip (bank)
 * @np:		device node of the GPIO chip
 * @mm_gc:	pointer to the of_mm_gpio_chip allocated structure
 * @data:	driver data to store in the struct gpio_chip
 *
 * To use this function you should allocate and fill mm_gc with:
 *
 * 1) In the gpio_chip structure:
 *    - all the callbacks
 *    - of_gpio_n_cells
 *    - of_xlate callback (optional)
 *
 * 3) In the of_mm_gpio_chip structure:
 *    - save_regs callback (optional)
 *
 * If succeeded, this function will map bank's memory and will
 * do all necessary work for you. Then you'll able to use .regs
 * to manage GPIOs from the callbacks.
 */
int of_mm_gpiochip_add_data(struct device_node *np,
			    struct of_mm_gpio_chip *mm_gc,
			    void *data)
{
	int ret = -ENOMEM;
	struct gpio_chip *gc = &mm_gc->gc;

	gc->label = kstrdup(np->full_name, GFP_KERNEL);
	if (!gc->label)
		goto err0;

	mm_gc->regs = of_iomap(np, 0);
	if (!mm_gc->regs)
		goto err1;

	gc->base = -1;

	if (mm_gc->save_regs)
		mm_gc->save_regs(mm_gc);

	mm_gc->gc.of_node = np;

	ret = gpiochip_add_data(gc, data);
	if (ret)
		goto err2;

	return 0;
err2:
	iounmap(mm_gc->regs);
err1:
	kfree(gc->label);
err0:
	pr_err("%s: GPIO chip registration failed with status %d\n",
	       np->full_name, ret);
	return ret;
}
EXPORT_SYMBOL(of_mm_gpiochip_add_data);

/**
 * of_mm_gpiochip_remove - Remove memory mapped GPIO chip (bank)
 * @mm_gc:	pointer to the of_mm_gpio_chip allocated structure
 */
void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc)
{
	struct gpio_chip *gc = &mm_gc->gc;

	if (!mm_gc)
		return;

	gpiochip_remove(gc);
	iounmap(mm_gc->regs);
	kfree(gc->label);
}
EXPORT_SYMBOL(of_mm_gpiochip_remove);

#ifdef CONFIG_PINCTRL
static int of_gpiochip_add_pin_range(struct gpio_chip *chip)
{
	struct device_node *np = chip->of_node;
	struct of_phandle_args pinspec;
	struct pinctrl_dev *pctldev;
	int index = 0, ret;
	const char *name;
	static const char group_names_propname[] = "gpio-ranges-group-names";
	struct property *group_names;

	if (!np)
		return 0;

	group_names = of_find_property(np, group_names_propname, NULL);

	for (;; index++) {
		ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3,
				index, &pinspec);
		if (ret)
			break;

		pctldev = of_pinctrl_get(pinspec.np);
		if (!pctldev)
			return -EPROBE_DEFER;

		if (pinspec.args[2]) {
			if (group_names) {
				of_property_read_string_index(np,
						group_names_propname,
						index, &name);
				if (strlen(name)) {
					pr_err("%s: Group name of numeric GPIO ranges must be the empty string.\n",
						np->full_name);
					break;
				}
			}
			/* npins != 0: linear range */
			ret = gpiochip_add_pin_range(chip,
					pinctrl_dev_get_devname(pctldev),
					pinspec.args[0],
					pinspec.args[1],
					pinspec.args[2]);
			if (ret)
				return ret;
		} else {
			/* npins == 0: special range */
			if (pinspec.args[1]) {
				pr_err("%s: Illegal gpio-range format.\n",
					np->full_name);
				break;
			}

			if (!group_names) {
				pr_err("%s: GPIO group range requested but no %s property.\n",
					np->full_name, group_names_propname);
				break;
			}

			ret = of_property_read_string_index(np,
						group_names_propname,
						index, &name);
			if (ret)
				break;

			if (!strlen(name)) {
				pr_err("%s: Group name of GPIO group range cannot be the empty string.\n",
				np->full_name);
				break;
			}

			ret = gpiochip_add_pingroup_range(chip, pctldev,
						pinspec.args[0], name);
			if (ret)
				return ret;
		}
	}

	return 0;
}

#else
static int of_gpiochip_add_pin_range(struct gpio_chip *chip) { return 0; }
#endif

int of_gpiochip_add(struct gpio_chip *chip)
{
	int status;

	if ((!chip->of_node) && (chip->parent))
		chip->of_node = chip->parent->of_node;

	if (!chip->of_node)
		return 0;

	if (!chip->of_xlate) {
		chip->of_gpio_n_cells = 2;
		chip->of_xlate = of_gpio_simple_xlate;
	}

	status = of_gpiochip_add_pin_range(chip);
	if (status)
		return status;

	/* If the chip defines names itself, these take precedence */
	if (!chip->names)
		of_gpiochip_set_names(chip);

	of_node_get(chip->of_node);

	return of_gpiochip_scan_gpios(chip);
}

void of_gpiochip_remove(struct gpio_chip *chip)
{
	gpiochip_remove_pin_ranges(chip);
	of_node_put(chip->of_node);
}
Commit	Line	Data
863fbf49 AV	1	/*
	2	* OF helpers for the GPIO API
	3	*
	4	* Copyright (c) 2007-2008 MontaVista Software, Inc.
	5	*
	6	* Author: Anton Vorontsov <avorontsov@ru.mvista.com>
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License as published by
	10	* the Free Software Foundation; either version 2 of the License, or
	11	* (at your option) any later version.
	12	*/
	13
2e13cba8	14	#include <linux/device.h>
bea4dbee	15	#include <linux/err.h>
863fbf49	16	#include <linux/errno.h>
2e13cba8	17	#include <linux/module.h>
863fbf49	18	#include <linux/io.h>
7d4defe2	19	#include <linux/io-mapping.h>
af8b6375	20	#include <linux/gpio/consumer.h>
863fbf49	21	#include <linux/of.h>
2e13cba8	22	#include <linux/of_address.h>
863fbf49	23	#include <linux/of_gpio.h>
f23f1516	24	#include <linux/pinctrl/pinctrl.h>
2e13cba8	25	#include <linux/slab.h>
f625d460	26	#include <linux/gpio/machine.h>
863fbf49	27
1bd6b601	28	#include "gpiolib.h"
af8b6375	29
0df2c999	30	/* Private data structure for of_gpiochip_find_and_xlate */
3d0f7cf0 GL	31	struct gg_data {
	32	enum of_gpio_flags *flags;
	33	struct of_phandle_args gpiospec;
	34
af8b6375	35	struct gpio_desc *out_gpio;
3d0f7cf0 GL	36	};
	37
	38	/* Private function for resolving node pointer to gpio_chip */
	39	static int of_gpiochip_find_and_xlate(struct gpio_chip gc, void data)
	40	{
	41	struct gg_data *gg_data = data;
	42	int ret;
	43
	44	if ((gc->of_node != gg_data->gpiospec.np) \|\|
	45	(gc->of_gpio_n_cells != gg_data->gpiospec.args_count) \|\|
	46	(!gc->of_xlate))
	47	return false;
	48
	49	ret = gc->of_xlate(gc, &gg_data->gpiospec, gg_data->flags);
7b8792bb	50	if (ret < 0) {
9cf75e9e HH	51	/* We've found a gpio chip, but the translation failed.
	52	* Store translation error in out_gpio.
	53	* Return false to keep looking, as more than one gpio chip
	54	* could be registered per of-node.
7b8792bb HH	55	*/
7b8792bb HH	56	gg_data->out_gpio = ERR_PTR(ret);
9cf75e9e	57	return false;
7b8792bb	58	}
3d0f7cf0	59
ccd9726e	60	gg_data->out_gpio = gpiochip_get_desc(gc, ret);
3d0f7cf0 GL	61	return true;
	62	}
	63
863fbf49	64	/**
af8b6375	65	* of_get_named_gpiod_flags() - Get a GPIO descriptor and flags for GPIO API
863fbf49	66	* @np: device node to get GPIO from
a6b09191	67	* @propname: property name containing gpio specifier(s)
863fbf49	68	* @index: index of the GPIO
b908b53d	69	* @flags: a flags pointer to fill in
863fbf49	70	*
af8b6375	71	* Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
b908b53d AV	72	* value on the error condition. If @flags is not NULL the function also fills
b908b53d AV	73	* in flags for the GPIO.
863fbf49	74	*/
af8b6375 AC	75	struct gpio_desc of_get_named_gpiod_flags(struct device_node np,
af8b6375 AC	76	const char propname, int index, enum of_gpio_flags flags)
863fbf49	77	{
4fbb0022 RS	78	/* Return -EPROBE_DEFER to support probe() functions to be called
	79	* later when the GPIO actually becomes available
	80	*/
af8b6375 AC	81	struct gg_data gg_data = {
	82	.flags = flags,
	83	.out_gpio = ERR_PTR(-EPROBE_DEFER)
	84	};
64b60e09	85	int ret;
3d0f7cf0 GL	86
	87	/* .of_xlate might decide to not fill in the flags, so clear it. */
	88	if (flags)
	89	*flags = 0;
863fbf49	90
15c9a0ac	91	ret = of_parse_phandle_with_args(np, propname, "#gpio-cells", index,
3d0f7cf0	92	&gg_data.gpiospec);
64b60e09	93	if (ret) {
85ea29ac TB	94	pr_debug("%s: can't parse '%s' property of node '%s[%d]'\n",
85ea29ac TB	95	__func__, propname, np->full_name, index);
af8b6375	96	return ERR_PTR(ret);
863fbf49 AV	97	}
863fbf49 AV	98
3d0f7cf0	99	gpiochip_find(&gg_data, of_gpiochip_find_and_xlate);
863fbf49	100
3d0f7cf0	101	of_node_put(gg_data.gpiospec.np);
85ea29ac TB	102	pr_debug("%s: parsed '%s' property of node '%s[%d]' - status (%d)\n",
85ea29ac TB	103	__func__, propname, np->full_name, index,
bea4dbee	104	PTR_ERR_OR_ZERO(gg_data.out_gpio));
3d0f7cf0	105	return gg_data.out_gpio;
863fbf49	106	}
863fbf49	107
f01d9075 AC	108	int of_get_named_gpio_flags(struct device_node np, const char list_name,
	109	int index, enum of_gpio_flags *flags)
	110	{
	111	struct gpio_desc *desc;
	112
	113	desc = of_get_named_gpiod_flags(np, list_name, index, flags);
	114
	115	if (IS_ERR(desc))
	116	return PTR_ERR(desc);
	117	else
	118	return desc_to_gpio(desc);
	119	}
	120	EXPORT_SYMBOL(of_get_named_gpio_flags);
	121
f625d460	122	/**
fd7337fd	123	* of_parse_own_gpio() - Get a GPIO hog descriptor, names and flags for GPIO API
f625d460 BP	124	* @np: device node to get GPIO from
	125	* @name: GPIO line name
	126	* @lflags: gpio_lookup_flags - returned from of_find_gpio() or
fd7337fd	127	* of_parse_own_gpio()
f625d460 BP	128	* @dflags: gpiod_flags - optional GPIO initialization flags
	129	*
	130	* Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
	131	* value on the error condition.
	132	*/
fd7337fd MP	133	static struct gpio_desc of_parse_own_gpio(struct device_node np,
	134	const char **name,
	135	enum gpio_lookup_flags *lflags,
	136	enum gpiod_flags *dflags)
f625d460 BP	137	{
	138	struct device_node *chip_np;
	139	enum of_gpio_flags xlate_flags;
f625d460 BP	140	struct gg_data gg_data = {
	141	.flags = &xlate_flags,
	142	};
	143	u32 tmp;
	144	int i, ret;
	145
	146	chip_np = np->parent;
	147	if (!chip_np)
	148	return ERR_PTR(-EINVAL);
	149
	150	xlate_flags = 0;
	151	*lflags = 0;
	152	*dflags = 0;
	153
	154	ret = of_property_read_u32(chip_np, "#gpio-cells", &tmp);
	155	if (ret)
	156	return ERR_PTR(ret);
	157
	158	if (tmp > MAX_PHANDLE_ARGS)
	159	return ERR_PTR(-EINVAL);
	160
	161	gg_data.gpiospec.args_count = tmp;
	162	gg_data.gpiospec.np = chip_np;
	163	for (i = 0; i < tmp; i++) {
	164	ret = of_property_read_u32_index(np, "gpios", i,
	165	&gg_data.gpiospec.args[i]);
	166	if (ret)
	167	return ERR_PTR(ret);
	168	}
	169
	170	gpiochip_find(&gg_data, of_gpiochip_find_and_xlate);
	171	if (!gg_data.out_gpio) {
	172	if (np->parent == np)
	173	return ERR_PTR(-ENXIO);
	174	else
	175	return ERR_PTR(-EINVAL);
	176	}
	177
	178	if (xlate_flags & OF_GPIO_ACTIVE_LOW)
	179	*lflags \|= GPIO_ACTIVE_LOW;
	180
	181	if (of_property_read_bool(np, "input"))
	182	*dflags \|= GPIOD_IN;
	183	else if (of_property_read_bool(np, "output-low"))
	184	*dflags \|= GPIOD_OUT_LOW;
	185	else if (of_property_read_bool(np, "output-high"))
	186	*dflags \|= GPIOD_OUT_HIGH;
	187	else {
	188	pr_warn("GPIO line %d (%s): no hogging state specified, bailing out\n",
	189	desc_to_gpio(gg_data.out_gpio), np->name);
	190	return ERR_PTR(-EINVAL);
	191	}
	192
	193	if (name && of_property_read_string(np, "line-name", name))
	194	*name = np->name;
	195
39561e8b	196	return gg_data.out_gpio;
f625d460 BP	197	}
f625d460 BP	198
fd9c5531 LW	199	/**
	200	* of_gpiochip_set_names() - set up the names of the lines
	201	* @chip: GPIO chip whose lines should be named, if possible
	202	*/
	203	static void of_gpiochip_set_names(struct gpio_chip *gc)
	204	{
	205	struct gpio_device *gdev = gc->gpiodev;
	206	struct device_node *np = gc->of_node;
	207	int i;
	208	int nstrings;
	209
	210	nstrings = of_property_count_strings(np, "gpio-line-names");
	211	if (nstrings <= 0)
	212	/* Lines names not present */
	213	return;
	214
	215	/* This is normally not what you want */
	216	if (gdev->ngpio != nstrings)
	217	dev_info(&gdev->dev, "gpio-line-names specifies %d line "
	218	"names but there are %d lines on the chip\n",
	219	nstrings, gdev->ngpio);
	220
	221	/*
	222	* Make sure to not index beyond the end of the number of descriptors
	223	* of the GPIO device.
	224	*/
	225	for (i = 0; i < gdev->ngpio; i++) {
	226	const char *name;
	227	int ret;
	228
	229	ret = of_property_read_string_index(np,
	230	"gpio-line-names",
	231	i,
	232	&name);
	233	if (ret) {
	234	if (ret != -ENODATA)
	235	dev_err(&gdev->dev,
	236	"unable to name line %d: %d\n",
	237	i, ret);
	238	break;
	239	}
	240	gdev->descs[i].name = name;
	241	}
	242	}
	243
f625d460	244	/**
fd7337fd	245	* of_gpiochip_scan_gpios - Scan gpio-controller for gpio definitions
f625d460 BP	246	* @chip: gpio chip to act on
	247	*
	248	* This is only used by of_gpiochip_add to request/set GPIO initial
	249	* configuration.
dfbd379b	250	* It retures error if it fails otherwise 0 on success.
f625d460	251	*/
dfbd379b	252	static int of_gpiochip_scan_gpios(struct gpio_chip *chip)
f625d460 BP	253	{
	254	struct gpio_desc *desc = NULL;
	255	struct device_node *np;
	256	const char *name;
	257	enum gpio_lookup_flags lflags;
	258	enum gpiod_flags dflags;
dfbd379b	259	int ret;
f625d460	260
d1279d94	261	for_each_available_child_of_node(chip->of_node, np) {
f625d460 BP	262	if (!of_property_read_bool(np, "gpio-hog"))
	263	continue;
	264
fd7337fd	265	desc = of_parse_own_gpio(np, &name, &lflags, &dflags);
f625d460 BP	266	if (IS_ERR(desc))
	267	continue;
	268
dfbd379b LD	269	ret = gpiod_hog(desc, name, lflags, dflags);
	270	if (ret < 0)
	271	return ret;
f625d460	272	}
dfbd379b LD	273
dfbd379b LD	274	return 0;
f625d460 BP	275	}
f625d460 BP	276
863fbf49	277	/**
b908b53d	278	* of_gpio_simple_xlate - translate gpio_spec to the GPIO number and flags
a19e3da5	279	* @gc: pointer to the gpio_chip structure
863fbf49 AV	280	* @np: device node of the GPIO chip
863fbf49 AV	281	* @gpio_spec: gpio specifier as found in the device tree
b908b53d	282	* @flags: a flags pointer to fill in
863fbf49 AV	283	*
	284	* This is simple translation function, suitable for the most 1:1 mapped
	285	* gpio chips. This function performs only one sanity check: whether gpio
	286	* is less than ngpios (that is specified in the gpio_chip).
	287	*/
15c9a0ac GL	288	int of_gpio_simple_xlate(struct gpio_chip *gc,
15c9a0ac GL	289	const struct of_phandle_args gpiospec, u32 flags)
863fbf49	290	{
b908b53d AV	291	/*
b908b53d AV	292	* We're discouraging gpio_cells < 2, since that way you'll have to
20a8a968	293	* write your own xlate function (that will have to retrieve the GPIO
b908b53d AV	294	* number and the flags from a single gpio cell -- this is possible,
	295	* but not recommended).
	296	*/
a19e3da5	297	if (gc->of_gpio_n_cells < 2) {
b908b53d AV	298	WARN_ON(1);
	299	return -EINVAL;
	300	}
	301
15c9a0ac GL	302	if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells))
	303	return -EINVAL;
	304
6270d830	305	if (gpiospec->args[0] >= gc->ngpio)
863fbf49 AV	306	return -EINVAL;
863fbf49 AV	307
b908b53d	308	if (flags)
15c9a0ac	309	*flags = gpiospec->args[1];
b908b53d	310
15c9a0ac	311	return gpiospec->args[0];
863fbf49	312	}
3038bbdf	313	EXPORT_SYMBOL(of_gpio_simple_xlate);
863fbf49	314
863fbf49	315	/**
3208b0f0	316	* of_mm_gpiochip_add_data - Add memory mapped GPIO chip (bank)
863fbf49 AV	317	* @np: device node of the GPIO chip
863fbf49 AV	318	* @mm_gc: pointer to the of_mm_gpio_chip allocated structure
3208b0f0	319	* @data: driver data to store in the struct gpio_chip
863fbf49 AV	320	*
	321	* To use this function you should allocate and fill mm_gc with:
	322	*
	323	* 1) In the gpio_chip structure:
	324	* - all the callbacks
a19e3da5 AV	325	* - of_gpio_n_cells
a19e3da5 AV	326	* - of_xlate callback (optional)
863fbf49 AV	327	*
	328	* 3) In the of_mm_gpio_chip structure:
	329	* - save_regs callback (optional)
	330	*
	331	* If succeeded, this function will map bank's memory and will
	332	* do all necessary work for you. Then you'll able to use .regs
	333	* to manage GPIOs from the callbacks.
	334	*/
3208b0f0 LW	335	int of_mm_gpiochip_add_data(struct device_node *np,
	336	struct of_mm_gpio_chip *mm_gc,
	337	void *data)
863fbf49 AV	338	{
863fbf49 AV	339	int ret = -ENOMEM;
a19e3da5	340	struct gpio_chip *gc = &mm_gc->gc;
863fbf49 AV	341
	342	gc->label = kstrdup(np->full_name, GFP_KERNEL);
	343	if (!gc->label)
	344	goto err0;
	345
	346	mm_gc->regs = of_iomap(np, 0);
	347	if (!mm_gc->regs)
	348	goto err1;
	349
21451155	350	gc->base = -1;
863fbf49	351
863fbf49 AV	352	if (mm_gc->save_regs)
	353	mm_gc->save_regs(mm_gc);
	354
a19e3da5	355	mm_gc->gc.of_node = np;
863fbf49	356
3208b0f0	357	ret = gpiochip_add_data(gc, data);
863fbf49 AV	358	if (ret)
	359	goto err2;
	360
863fbf49 AV	361	return 0;
863fbf49 AV	362	err2:
863fbf49 AV	363	iounmap(mm_gc->regs);
	364	err1:
	365	kfree(gc->label);
	366	err0:
	367	pr_err("%s: GPIO chip registration failed with status %d\n",
	368	np->full_name, ret);
	369	return ret;
	370	}
3208b0f0	371	EXPORT_SYMBOL(of_mm_gpiochip_add_data);
594fa265	372
d621e8ba RRD	373	/**
	374	* of_mm_gpiochip_remove - Remove memory mapped GPIO chip (bank)
	375	* @mm_gc: pointer to the of_mm_gpio_chip allocated structure
	376	*/
	377	void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc)
	378	{
	379	struct gpio_chip *gc = &mm_gc->gc;
	380
	381	if (!mm_gc)
	382	return;
	383
	384	gpiochip_remove(gc);
	385	iounmap(mm_gc->regs);
	386	kfree(gc->label);
	387	}
	388	EXPORT_SYMBOL(of_mm_gpiochip_remove);
	389
f23f1516	390	#ifdef CONFIG_PINCTRL
28355f81	391	static int of_gpiochip_add_pin_range(struct gpio_chip *chip)
f23f1516 SH	392	{
f23f1516 SH	393	struct device_node *np = chip->of_node;
f23f1516	394	struct of_phandle_args pinspec;
1e63d7b9	395	struct pinctrl_dev *pctldev;
f23f1516	396	int index = 0, ret;
586a87e6 CR	397	const char *name;
	398	static const char group_names_propname[] = "gpio-ranges-group-names";
	399	struct property *group_names;
f23f1516 SH	400
f23f1516 SH	401	if (!np)
28355f81	402	return 0;
f23f1516	403
586a87e6 CR	404	group_names = of_find_property(np, group_names_propname, NULL);
586a87e6 CR	405
ad4e1a7c	406	for (;; index++) {
d9fe0039 SW	407	ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3,
d9fe0039 SW	408	index, &pinspec);
f23f1516 SH	409	if (ret)
	410	break;
	411
1e63d7b9 LW	412	pctldev = of_pinctrl_get(pinspec.np);
1e63d7b9 LW	413	if (!pctldev)
28355f81	414	return -EPROBE_DEFER;
f23f1516	415
586a87e6 CR	416	if (pinspec.args[2]) {
586a87e6 CR	417	if (group_names) {
72858602	418	of_property_read_string_index(np,
586a87e6 CR	419	group_names_propname,
	420	index, &name);
	421	if (strlen(name)) {
	422	pr_err("%s: Group name of numeric GPIO ranges must be the empty string.\n",
	423	np->full_name);
	424	break;
	425	}
	426	}
	427	/* npins != 0: linear range */
	428	ret = gpiochip_add_pin_range(chip,
	429	pinctrl_dev_get_devname(pctldev),
	430	pinspec.args[0],
	431	pinspec.args[1],
	432	pinspec.args[2]);
	433	if (ret)
28355f81	434	return ret;
586a87e6 CR	435	} else {
	436	/* npins == 0: special range */
	437	if (pinspec.args[1]) {
	438	pr_err("%s: Illegal gpio-range format.\n",
	439	np->full_name);
	440	break;
	441	}
	442
	443	if (!group_names) {
	444	pr_err("%s: GPIO group range requested but no %s property.\n",
	445	np->full_name, group_names_propname);
	446	break;
	447	}
	448
	449	ret = of_property_read_string_index(np,
	450	group_names_propname,
	451	index, &name);
	452	if (ret)
	453	break;
	454
	455	if (!strlen(name)) {
	456	pr_err("%s: Group name of GPIO group range cannot be the empty string.\n",
	457	np->full_name);
	458	break;
	459	}
	460
	461	ret = gpiochip_add_pingroup_range(chip, pctldev,
	462	pinspec.args[0], name);
	463	if (ret)
28355f81	464	return ret;
586a87e6	465	}
ad4e1a7c	466	}
28355f81 TV	467
28355f81 TV	468	return 0;
f23f1516 SH	469	}
f23f1516 SH	470
f23f1516	471	#else
28355f81	472	static int of_gpiochip_add_pin_range(struct gpio_chip *chip) { return 0; }
f23f1516 SH	473	#endif
f23f1516 SH	474
28355f81	475	int of_gpiochip_add(struct gpio_chip *chip)
391c970c	476	{
28355f81 TV	477	int status;
28355f81 TV	478
58383c78 LW	479	if ((!chip->of_node) && (chip->parent))
58383c78 LW	480	chip->of_node = chip->parent->of_node;
391c970c AV	481
391c970c AV	482	if (!chip->of_node)
28355f81	483	return 0;
391c970c AV	484
	485	if (!chip->of_xlate) {
	486	chip->of_gpio_n_cells = 2;
	487	chip->of_xlate = of_gpio_simple_xlate;
	488	}
	489
28355f81 TV	490	status = of_gpiochip_add_pin_range(chip);
	491	if (status)
	492	return status;
	493
fd9c5531 LW	494	/* If the chip defines names itself, these take precedence */
	495	if (!chip->names)
	496	of_gpiochip_set_names(chip);
	497
391c970c	498	of_node_get(chip->of_node);
f625d460	499
dfbd379b	500	return of_gpiochip_scan_gpios(chip);
391c970c AV	501	}
	502
	503	void of_gpiochip_remove(struct gpio_chip *chip)
	504	{
e93fa3f2	505	gpiochip_remove_pin_ranges(chip);
8a691550	506	of_node_put(chip->of_node);
391c970c	507	}