[mirror_ubuntu-hirsute-kernel.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/errno.h>
#include <linux/module.h>
#include <linux/io.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>

struct gpio_desc;

/* 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)
		return false;

	gg_data->out_gpio = gpio_to_desc(ret + gc->base);
	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 gpios property of node '%s[%d]'\n",
			__func__, 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 exited with status %d\n", __func__,
		 PTR_RET(gg_data.out_gpio));
	return gg_data.out_gpio;
}
EXPORT_SYMBOL(of_get_named_gpiod_flags);

/**
 * 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 retrive 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 - Add memory mapped GPIO chip (bank)
 * @np:		device node of the GPIO chip
 * @mm_gc:	pointer to the of_mm_gpio_chip allocated structure
 *
 * 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(struct device_node *np,
		       struct of_mm_gpio_chip *mm_gc)
{
	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(gc);
	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);

#ifdef CONFIG_PINCTRL
static void 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;

	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)
			break;

		if (pinspec.args[2]) {
			if (group_names) {
				ret = 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)
				break;
		} 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)
				break;
		}
	}
}

#else
static void of_gpiochip_add_pin_range(struct gpio_chip *chip) {}
#endif

void of_gpiochip_add(struct gpio_chip *chip)
{
	if ((!chip->of_node) && (chip->dev))
		chip->of_node = chip->dev->of_node;

	if (!chip->of_node)
		return;

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

	of_gpiochip_add_pin_range(chip);
	of_node_get(chip->of_node);
}

void of_gpiochip_remove(struct gpio_chip *chip)
{
	gpiochip_remove_pin_ranges(chip);

	if (chip->of_node)
		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>
863fbf49	15	#include <linux/errno.h>
2e13cba8	16	#include <linux/module.h>
863fbf49	17	#include <linux/io.h>
af8b6375	18	#include <linux/gpio/consumer.h>
863fbf49	19	#include <linux/of.h>
2e13cba8	20	#include <linux/of_address.h>
863fbf49	21	#include <linux/of_gpio.h>
f23f1516	22	#include <linux/pinctrl/pinctrl.h>
2e13cba8	23	#include <linux/slab.h>
863fbf49	24
af8b6375 AC	25	struct gpio_desc;
af8b6375 AC	26
0df2c999	27	/* Private data structure for of_gpiochip_find_and_xlate */
3d0f7cf0 GL	28	struct gg_data {
	29	enum of_gpio_flags *flags;
	30	struct of_phandle_args gpiospec;
	31
af8b6375	32	struct gpio_desc *out_gpio;
3d0f7cf0 GL	33	};
	34
	35	/* Private function for resolving node pointer to gpio_chip */
	36	static int of_gpiochip_find_and_xlate(struct gpio_chip gc, void data)
	37	{
	38	struct gg_data *gg_data = data;
	39	int ret;
	40
	41	if ((gc->of_node != gg_data->gpiospec.np) \|\|
	42	(gc->of_gpio_n_cells != gg_data->gpiospec.args_count) \|\|
	43	(!gc->of_xlate))
	44	return false;
	45
	46	ret = gc->of_xlate(gc, &gg_data->gpiospec, gg_data->flags);
	47	if (ret < 0)
	48	return false;
	49
af8b6375	50	gg_data->out_gpio = gpio_to_desc(ret + gc->base);
3d0f7cf0 GL	51	return true;
	52	}
	53
863fbf49	54	/**
af8b6375	55	* of_get_named_gpiod_flags() - Get a GPIO descriptor and flags for GPIO API
863fbf49	56	* @np: device node to get GPIO from
a6b09191	57	* @propname: property name containing gpio specifier(s)
863fbf49	58	* @index: index of the GPIO
b908b53d	59	* @flags: a flags pointer to fill in
863fbf49	60	*
af8b6375	61	* Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
b908b53d AV	62	* value on the error condition. If @flags is not NULL the function also fills
b908b53d AV	63	* in flags for the GPIO.
863fbf49	64	*/
af8b6375 AC	65	struct gpio_desc of_get_named_gpiod_flags(struct device_node np,
af8b6375 AC	66	const char propname, int index, enum of_gpio_flags flags)
863fbf49	67	{
4fbb0022 RS	68	/* Return -EPROBE_DEFER to support probe() functions to be called
	69	* later when the GPIO actually becomes available
	70	*/
af8b6375 AC	71	struct gg_data gg_data = {
	72	.flags = flags,
	73	.out_gpio = ERR_PTR(-EPROBE_DEFER)
	74	};
64b60e09	75	int ret;
3d0f7cf0 GL	76
	77	/* .of_xlate might decide to not fill in the flags, so clear it. */
	78	if (flags)
	79	*flags = 0;
863fbf49	80
15c9a0ac	81	ret = of_parse_phandle_with_args(np, propname, "#gpio-cells", index,
3d0f7cf0	82	&gg_data.gpiospec);
64b60e09	83	if (ret) {
eddf8176 LW	84	pr_debug("%s: can't parse gpios property of node '%s[%d]'\n",
eddf8176 LW	85	__func__, np->full_name, index);
af8b6375	86	return ERR_PTR(ret);
863fbf49 AV	87	}
863fbf49 AV	88
3d0f7cf0	89	gpiochip_find(&gg_data, of_gpiochip_find_and_xlate);
863fbf49	90
3d0f7cf0	91	of_node_put(gg_data.gpiospec.np);
af8b6375 AC	92	pr_debug("%s exited with status %d\n", __func__,
af8b6375 AC	93	PTR_RET(gg_data.out_gpio));
3d0f7cf0	94	return gg_data.out_gpio;
863fbf49	95	}
af8b6375	96	EXPORT_SYMBOL(of_get_named_gpiod_flags);
863fbf49 AV	97
863fbf49 AV	98	/**
b908b53d	99	* of_gpio_simple_xlate - translate gpio_spec to the GPIO number and flags
a19e3da5	100	* @gc: pointer to the gpio_chip structure
863fbf49 AV	101	* @np: device node of the GPIO chip
863fbf49 AV	102	* @gpio_spec: gpio specifier as found in the device tree
b908b53d	103	* @flags: a flags pointer to fill in
863fbf49 AV	104	*
	105	* This is simple translation function, suitable for the most 1:1 mapped
	106	* gpio chips. This function performs only one sanity check: whether gpio
	107	* is less than ngpios (that is specified in the gpio_chip).
	108	*/
15c9a0ac GL	109	int of_gpio_simple_xlate(struct gpio_chip *gc,
15c9a0ac GL	110	const struct of_phandle_args gpiospec, u32 flags)
863fbf49	111	{
b908b53d AV	112	/*
	113	* We're discouraging gpio_cells < 2, since that way you'll have to
	114	* write your own xlate function (that will have to retrive the GPIO
	115	* number and the flags from a single gpio cell -- this is possible,
	116	* but not recommended).
	117	*/
a19e3da5	118	if (gc->of_gpio_n_cells < 2) {
b908b53d AV	119	WARN_ON(1);
	120	return -EINVAL;
	121	}
	122
15c9a0ac GL	123	if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells))
	124	return -EINVAL;
	125
6270d830	126	if (gpiospec->args[0] >= gc->ngpio)
863fbf49 AV	127	return -EINVAL;
863fbf49 AV	128
b908b53d	129	if (flags)
15c9a0ac	130	*flags = gpiospec->args[1];
b908b53d	131
15c9a0ac	132	return gpiospec->args[0];
863fbf49	133	}
3038bbdf	134	EXPORT_SYMBOL(of_gpio_simple_xlate);
863fbf49	135
863fbf49 AV	136	/**
	137	* of_mm_gpiochip_add - Add memory mapped GPIO chip (bank)
	138	* @np: device node of the GPIO chip
	139	* @mm_gc: pointer to the of_mm_gpio_chip allocated structure
	140	*
	141	* To use this function you should allocate and fill mm_gc with:
	142	*
	143	* 1) In the gpio_chip structure:
	144	* - all the callbacks
a19e3da5 AV	145	* - of_gpio_n_cells
a19e3da5 AV	146	* - of_xlate callback (optional)
863fbf49 AV	147	*
	148	* 3) In the of_mm_gpio_chip structure:
	149	* - save_regs callback (optional)
	150	*
	151	* If succeeded, this function will map bank's memory and will
	152	* do all necessary work for you. Then you'll able to use .regs
	153	* to manage GPIOs from the callbacks.
	154	*/
	155	int of_mm_gpiochip_add(struct device_node *np,
	156	struct of_mm_gpio_chip *mm_gc)
	157	{
	158	int ret = -ENOMEM;
a19e3da5	159	struct gpio_chip *gc = &mm_gc->gc;
863fbf49 AV	160
	161	gc->label = kstrdup(np->full_name, GFP_KERNEL);
	162	if (!gc->label)
	163	goto err0;
	164
	165	mm_gc->regs = of_iomap(np, 0);
	166	if (!mm_gc->regs)
	167	goto err1;
	168
21451155	169	gc->base = -1;
863fbf49	170
863fbf49 AV	171	if (mm_gc->save_regs)
	172	mm_gc->save_regs(mm_gc);
	173
a19e3da5	174	mm_gc->gc.of_node = np;
863fbf49 AV	175
	176	ret = gpiochip_add(gc);
	177	if (ret)
	178	goto err2;
	179
863fbf49 AV	180	return 0;
863fbf49 AV	181	err2:
863fbf49 AV	182	iounmap(mm_gc->regs);
	183	err1:
	184	kfree(gc->label);
	185	err0:
	186	pr_err("%s: GPIO chip registration failed with status %d\n",
	187	np->full_name, ret);
	188	return ret;
	189	}
	190	EXPORT_SYMBOL(of_mm_gpiochip_add);
594fa265	191
f23f1516	192	#ifdef CONFIG_PINCTRL
167c1af9	193	static void of_gpiochip_add_pin_range(struct gpio_chip *chip)
f23f1516 SH	194	{
f23f1516 SH	195	struct device_node *np = chip->of_node;
f23f1516	196	struct of_phandle_args pinspec;
1e63d7b9	197	struct pinctrl_dev *pctldev;
f23f1516	198	int index = 0, ret;
586a87e6 CR	199	const char *name;
	200	static const char group_names_propname[] = "gpio-ranges-group-names";
	201	struct property *group_names;
f23f1516 SH	202
	203	if (!np)
	204	return;
	205
586a87e6 CR	206	group_names = of_find_property(np, group_names_propname, NULL);
586a87e6 CR	207
ad4e1a7c	208	for (;; index++) {
d9fe0039 SW	209	ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3,
d9fe0039 SW	210	index, &pinspec);
f23f1516 SH	211	if (ret)
	212	break;
	213
1e63d7b9 LW	214	pctldev = of_pinctrl_get(pinspec.np);
1e63d7b9 LW	215	if (!pctldev)
f23f1516	216	break;
f23f1516	217
586a87e6 CR	218	if (pinspec.args[2]) {
	219	if (group_names) {
	220	ret = of_property_read_string_index(np,
	221	group_names_propname,
	222	index, &name);
	223	if (strlen(name)) {
	224	pr_err("%s: Group name of numeric GPIO ranges must be the empty string.\n",
	225	np->full_name);
	226	break;
	227	}
	228	}
	229	/* npins != 0: linear range */
	230	ret = gpiochip_add_pin_range(chip,
	231	pinctrl_dev_get_devname(pctldev),
	232	pinspec.args[0],
	233	pinspec.args[1],
	234	pinspec.args[2]);
	235	if (ret)
	236	break;
	237	} else {
	238	/* npins == 0: special range */
	239	if (pinspec.args[1]) {
	240	pr_err("%s: Illegal gpio-range format.\n",
	241	np->full_name);
	242	break;
	243	}
	244
	245	if (!group_names) {
	246	pr_err("%s: GPIO group range requested but no %s property.\n",
	247	np->full_name, group_names_propname);
	248	break;
	249	}
	250
	251	ret = of_property_read_string_index(np,
	252	group_names_propname,
	253	index, &name);
	254	if (ret)
	255	break;
	256
	257	if (!strlen(name)) {
	258	pr_err("%s: Group name of GPIO group range cannot be the empty string.\n",
	259	np->full_name);
	260	break;
	261	}
	262
	263	ret = gpiochip_add_pingroup_range(chip, pctldev,
	264	pinspec.args[0], name);
	265	if (ret)
	266	break;
	267	}
ad4e1a7c	268	}
f23f1516 SH	269	}
f23f1516 SH	270
f23f1516	271	#else
167c1af9	272	static void of_gpiochip_add_pin_range(struct gpio_chip *chip) {}
f23f1516 SH	273	#endif
f23f1516 SH	274
391c970c AV	275	void of_gpiochip_add(struct gpio_chip *chip)
	276	{
	277	if ((!chip->of_node) && (chip->dev))
	278	chip->of_node = chip->dev->of_node;
	279
	280	if (!chip->of_node)
	281	return;
	282
	283	if (!chip->of_xlate) {
	284	chip->of_gpio_n_cells = 2;
	285	chip->of_xlate = of_gpio_simple_xlate;
	286	}
	287
f23f1516	288	of_gpiochip_add_pin_range(chip);
391c970c AV	289	of_node_get(chip->of_node);
	290	}
	291
	292	void of_gpiochip_remove(struct gpio_chip *chip)
	293	{
e93fa3f2	294	gpiochip_remove_pin_ranges(chip);
f23f1516	295
391c970c AV	296	if (chip->of_node)
	297	of_node_put(chip->of_node);
	298	}