[linux-2.6-block.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/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 = 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 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_ERR_OR_ZERO(gg_data.out_gpio));
	return gg_data.out_gpio;
}
EXPORT_SYMBOL(of_get_named_gpiod_flags);

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_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>
bea4dbee	15	#include <linux/err.h>
863fbf49	16	#include <linux/errno.h>
2e13cba8	17	#include <linux/module.h>
863fbf49	18	#include <linux/io.h>
af8b6375	19	#include <linux/gpio/consumer.h>
863fbf49	20	#include <linux/of.h>
2e13cba8	21	#include <linux/of_address.h>
863fbf49	22	#include <linux/of_gpio.h>
f23f1516	23	#include <linux/pinctrl/pinctrl.h>
2e13cba8	24	#include <linux/slab.h>
863fbf49	25
af8b6375 AC	26	struct gpio_desc;
af8b6375 AC	27
0df2c999	28	/* Private data structure for of_gpiochip_find_and_xlate */
3d0f7cf0 GL	29	struct gg_data {
	30	enum of_gpio_flags *flags;
	31	struct of_phandle_args gpiospec;
	32
af8b6375	33	struct gpio_desc *out_gpio;
3d0f7cf0 GL	34	};
	35
	36	/* Private function for resolving node pointer to gpio_chip */
	37	static int of_gpiochip_find_and_xlate(struct gpio_chip gc, void data)
	38	{
	39	struct gg_data *gg_data = data;
	40	int ret;
	41
	42	if ((gc->of_node != gg_data->gpiospec.np) \|\|
	43	(gc->of_gpio_n_cells != gg_data->gpiospec.args_count) \|\|
	44	(!gc->of_xlate))
	45	return false;
	46
	47	ret = gc->of_xlate(gc, &gg_data->gpiospec, gg_data->flags);
	48	if (ret < 0)
	49	return false;
	50
ccd9726e	51	gg_data->out_gpio = gpiochip_get_desc(gc, ret);
3d0f7cf0 GL	52	return true;
	53	}
	54
863fbf49	55	/**
af8b6375	56	* of_get_named_gpiod_flags() - Get a GPIO descriptor and flags for GPIO API
863fbf49	57	* @np: device node to get GPIO from
a6b09191	58	* @propname: property name containing gpio specifier(s)
863fbf49	59	* @index: index of the GPIO
b908b53d	60	* @flags: a flags pointer to fill in
863fbf49	61	*
af8b6375	62	* Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
b908b53d AV	63	* value on the error condition. If @flags is not NULL the function also fills
b908b53d AV	64	* in flags for the GPIO.
863fbf49	65	*/
af8b6375 AC	66	struct gpio_desc of_get_named_gpiod_flags(struct device_node np,
af8b6375 AC	67	const char propname, int index, enum of_gpio_flags flags)
863fbf49	68	{
4fbb0022 RS	69	/* Return -EPROBE_DEFER to support probe() functions to be called
	70	* later when the GPIO actually becomes available
	71	*/
af8b6375 AC	72	struct gg_data gg_data = {
	73	.flags = flags,
	74	.out_gpio = ERR_PTR(-EPROBE_DEFER)
	75	};
64b60e09	76	int ret;
3d0f7cf0 GL	77
	78	/* .of_xlate might decide to not fill in the flags, so clear it. */
	79	if (flags)
	80	*flags = 0;
863fbf49	81
15c9a0ac	82	ret = of_parse_phandle_with_args(np, propname, "#gpio-cells", index,
3d0f7cf0	83	&gg_data.gpiospec);
64b60e09	84	if (ret) {
eddf8176 LW	85	pr_debug("%s: can't parse gpios property of node '%s[%d]'\n",
eddf8176 LW	86	__func__, np->full_name, index);
af8b6375	87	return ERR_PTR(ret);
863fbf49 AV	88	}
863fbf49 AV	89
3d0f7cf0	90	gpiochip_find(&gg_data, of_gpiochip_find_and_xlate);
863fbf49	91
3d0f7cf0	92	of_node_put(gg_data.gpiospec.np);
af8b6375	93	pr_debug("%s exited with status %d\n", __func__,
bea4dbee	94	PTR_ERR_OR_ZERO(gg_data.out_gpio));
3d0f7cf0	95	return gg_data.out_gpio;
863fbf49	96	}
af8b6375	97	EXPORT_SYMBOL(of_get_named_gpiod_flags);
863fbf49	98
f01d9075 AC	99	int of_get_named_gpio_flags(struct device_node np, const char list_name,
	100	int index, enum of_gpio_flags *flags)
	101	{
	102	struct gpio_desc *desc;
	103
	104	desc = of_get_named_gpiod_flags(np, list_name, index, flags);
	105
	106	if (IS_ERR(desc))
	107	return PTR_ERR(desc);
	108	else
	109	return desc_to_gpio(desc);
	110	}
	111	EXPORT_SYMBOL(of_get_named_gpio_flags);
	112
863fbf49	113	/**
b908b53d	114	* of_gpio_simple_xlate - translate gpio_spec to the GPIO number and flags
a19e3da5	115	* @gc: pointer to the gpio_chip structure
863fbf49 AV	116	* @np: device node of the GPIO chip
863fbf49 AV	117	* @gpio_spec: gpio specifier as found in the device tree
b908b53d	118	* @flags: a flags pointer to fill in
863fbf49 AV	119	*
	120	* This is simple translation function, suitable for the most 1:1 mapped
	121	* gpio chips. This function performs only one sanity check: whether gpio
	122	* is less than ngpios (that is specified in the gpio_chip).
	123	*/
15c9a0ac GL	124	int of_gpio_simple_xlate(struct gpio_chip *gc,
15c9a0ac GL	125	const struct of_phandle_args gpiospec, u32 flags)
863fbf49	126	{
b908b53d AV	127	/*
	128	* We're discouraging gpio_cells < 2, since that way you'll have to
	129	* write your own xlate function (that will have to retrive the GPIO
	130	* number and the flags from a single gpio cell -- this is possible,
	131	* but not recommended).
	132	*/
a19e3da5	133	if (gc->of_gpio_n_cells < 2) {
b908b53d AV	134	WARN_ON(1);
	135	return -EINVAL;
	136	}
	137
15c9a0ac GL	138	if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells))
	139	return -EINVAL;
	140
6270d830	141	if (gpiospec->args[0] >= gc->ngpio)
863fbf49 AV	142	return -EINVAL;
863fbf49 AV	143
b908b53d	144	if (flags)
15c9a0ac	145	*flags = gpiospec->args[1];
b908b53d	146
15c9a0ac	147	return gpiospec->args[0];
863fbf49	148	}
3038bbdf	149	EXPORT_SYMBOL(of_gpio_simple_xlate);
863fbf49	150
863fbf49 AV	151	/**
	152	* of_mm_gpiochip_add - Add memory mapped GPIO chip (bank)
	153	* @np: device node of the GPIO chip
	154	* @mm_gc: pointer to the of_mm_gpio_chip allocated structure
	155	*
	156	* To use this function you should allocate and fill mm_gc with:
	157	*
	158	* 1) In the gpio_chip structure:
	159	* - all the callbacks
a19e3da5 AV	160	* - of_gpio_n_cells
a19e3da5 AV	161	* - of_xlate callback (optional)
863fbf49 AV	162	*
	163	* 3) In the of_mm_gpio_chip structure:
	164	* - save_regs callback (optional)
	165	*
	166	* If succeeded, this function will map bank's memory and will
	167	* do all necessary work for you. Then you'll able to use .regs
	168	* to manage GPIOs from the callbacks.
	169	*/
	170	int of_mm_gpiochip_add(struct device_node *np,
	171	struct of_mm_gpio_chip *mm_gc)
	172	{
	173	int ret = -ENOMEM;
a19e3da5	174	struct gpio_chip *gc = &mm_gc->gc;
863fbf49 AV	175
	176	gc->label = kstrdup(np->full_name, GFP_KERNEL);
	177	if (!gc->label)
	178	goto err0;
	179
	180	mm_gc->regs = of_iomap(np, 0);
	181	if (!mm_gc->regs)
	182	goto err1;
	183
21451155	184	gc->base = -1;
863fbf49	185
863fbf49 AV	186	if (mm_gc->save_regs)
	187	mm_gc->save_regs(mm_gc);
	188
a19e3da5	189	mm_gc->gc.of_node = np;
863fbf49 AV	190
	191	ret = gpiochip_add(gc);
	192	if (ret)
	193	goto err2;
	194
863fbf49 AV	195	return 0;
863fbf49 AV	196	err2:
863fbf49 AV	197	iounmap(mm_gc->regs);
	198	err1:
	199	kfree(gc->label);
	200	err0:
	201	pr_err("%s: GPIO chip registration failed with status %d\n",
	202	np->full_name, ret);
	203	return ret;
	204	}
	205	EXPORT_SYMBOL(of_mm_gpiochip_add);
594fa265	206
f23f1516	207	#ifdef CONFIG_PINCTRL
167c1af9	208	static void of_gpiochip_add_pin_range(struct gpio_chip *chip)
f23f1516 SH	209	{
f23f1516 SH	210	struct device_node *np = chip->of_node;
f23f1516	211	struct of_phandle_args pinspec;
1e63d7b9	212	struct pinctrl_dev *pctldev;
f23f1516	213	int index = 0, ret;
586a87e6 CR	214	const char *name;
	215	static const char group_names_propname[] = "gpio-ranges-group-names";
	216	struct property *group_names;
f23f1516 SH	217
	218	if (!np)
	219	return;
	220
586a87e6 CR	221	group_names = of_find_property(np, group_names_propname, NULL);
586a87e6 CR	222
ad4e1a7c	223	for (;; index++) {
d9fe0039 SW	224	ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3,
d9fe0039 SW	225	index, &pinspec);
f23f1516 SH	226	if (ret)
	227	break;
	228
1e63d7b9 LW	229	pctldev = of_pinctrl_get(pinspec.np);
1e63d7b9 LW	230	if (!pctldev)
f23f1516	231	break;
f23f1516	232
586a87e6 CR	233	if (pinspec.args[2]) {
	234	if (group_names) {
	235	ret = of_property_read_string_index(np,
	236	group_names_propname,
	237	index, &name);
	238	if (strlen(name)) {
	239	pr_err("%s: Group name of numeric GPIO ranges must be the empty string.\n",
	240	np->full_name);
	241	break;
	242	}
	243	}
	244	/* npins != 0: linear range */
	245	ret = gpiochip_add_pin_range(chip,
	246	pinctrl_dev_get_devname(pctldev),
	247	pinspec.args[0],
	248	pinspec.args[1],
	249	pinspec.args[2]);
	250	if (ret)
	251	break;
	252	} else {
	253	/* npins == 0: special range */
	254	if (pinspec.args[1]) {
	255	pr_err("%s: Illegal gpio-range format.\n",
	256	np->full_name);
	257	break;
	258	}
	259
	260	if (!group_names) {
	261	pr_err("%s: GPIO group range requested but no %s property.\n",
	262	np->full_name, group_names_propname);
	263	break;
	264	}
	265
	266	ret = of_property_read_string_index(np,
	267	group_names_propname,
	268	index, &name);
	269	if (ret)
	270	break;
	271
	272	if (!strlen(name)) {
	273	pr_err("%s: Group name of GPIO group range cannot be the empty string.\n",
	274	np->full_name);
	275	break;
	276	}
	277
	278	ret = gpiochip_add_pingroup_range(chip, pctldev,
	279	pinspec.args[0], name);
	280	if (ret)
	281	break;
	282	}
ad4e1a7c	283	}
f23f1516 SH	284	}
f23f1516 SH	285
f23f1516	286	#else
167c1af9	287	static void of_gpiochip_add_pin_range(struct gpio_chip *chip) {}
f23f1516 SH	288	#endif
f23f1516 SH	289
391c970c AV	290	void of_gpiochip_add(struct gpio_chip *chip)
	291	{
	292	if ((!chip->of_node) && (chip->dev))
	293	chip->of_node = chip->dev->of_node;
	294
	295	if (!chip->of_node)
	296	return;
	297
	298	if (!chip->of_xlate) {
	299	chip->of_gpio_n_cells = 2;
	300	chip->of_xlate = of_gpio_simple_xlate;
	301	}
	302
f23f1516	303	of_gpiochip_add_pin_range(chip);
391c970c AV	304	of_node_get(chip->of_node);
	305	}
	306
	307	void of_gpiochip_remove(struct gpio_chip *chip)
	308	{
e93fa3f2	309	gpiochip_remove_pin_ranges(chip);
f23f1516	310
391c970c AV	311	if (chip->of_node)
	312	of_node_put(chip->of_node);
	313	}