[mirror_ubuntu-artful-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/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>

#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 the gpio chip, but the translation failed.
		 * Return true to stop looking and return the translation
		 * error via out_gpio
		 */
		gg_data->out_gpio = ERR_PTR(ret);
		return true;
	 }

	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_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);

/**
 * 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 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);
	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
1bd6b601	26	#include "gpiolib.h"
af8b6375	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);
7b8792bb HH	48	if (ret < 0) {
	49	/* We've found the gpio chip, but the translation failed.
	50	* Return true to stop looking and return the translation
	51	* error via out_gpio
	52	*/
	53	gg_data->out_gpio = ERR_PTR(ret);
	54	return true;
	55	}
3d0f7cf0	56
ccd9726e	57	gg_data->out_gpio = gpiochip_get_desc(gc, ret);
3d0f7cf0 GL	58	return true;
	59	}
	60
863fbf49	61	/**
af8b6375	62	* of_get_named_gpiod_flags() - Get a GPIO descriptor and flags for GPIO API
863fbf49	63	* @np: device node to get GPIO from
a6b09191	64	* @propname: property name containing gpio specifier(s)
863fbf49	65	* @index: index of the GPIO
b908b53d	66	* @flags: a flags pointer to fill in
863fbf49	67	*
af8b6375	68	* Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
b908b53d AV	69	* value on the error condition. If @flags is not NULL the function also fills
b908b53d AV	70	* in flags for the GPIO.
863fbf49	71	*/
af8b6375 AC	72	struct gpio_desc of_get_named_gpiod_flags(struct device_node np,
af8b6375 AC	73	const char propname, int index, enum of_gpio_flags flags)
863fbf49	74	{
4fbb0022 RS	75	/* Return -EPROBE_DEFER to support probe() functions to be called
	76	* later when the GPIO actually becomes available
	77	*/
af8b6375 AC	78	struct gg_data gg_data = {
	79	.flags = flags,
	80	.out_gpio = ERR_PTR(-EPROBE_DEFER)
	81	};
64b60e09	82	int ret;
3d0f7cf0 GL	83
	84	/* .of_xlate might decide to not fill in the flags, so clear it. */
	85	if (flags)
	86	*flags = 0;
863fbf49	87
15c9a0ac	88	ret = of_parse_phandle_with_args(np, propname, "#gpio-cells", index,
3d0f7cf0	89	&gg_data.gpiospec);
64b60e09	90	if (ret) {
85ea29ac TB	91	pr_debug("%s: can't parse '%s' property of node '%s[%d]'\n",
85ea29ac TB	92	__func__, propname, np->full_name, index);
af8b6375	93	return ERR_PTR(ret);
863fbf49 AV	94	}
863fbf49 AV	95
3d0f7cf0	96	gpiochip_find(&gg_data, of_gpiochip_find_and_xlate);
863fbf49	97
3d0f7cf0	98	of_node_put(gg_data.gpiospec.np);
85ea29ac TB	99	pr_debug("%s: parsed '%s' property of node '%s[%d]' - status (%d)\n",
85ea29ac TB	100	__func__, propname, np->full_name, index,
bea4dbee	101	PTR_ERR_OR_ZERO(gg_data.out_gpio));
3d0f7cf0	102	return gg_data.out_gpio;
863fbf49	103	}
863fbf49	104
f01d9075 AC	105	int of_get_named_gpio_flags(struct device_node np, const char list_name,
	106	int index, enum of_gpio_flags *flags)
	107	{
	108	struct gpio_desc *desc;
	109
	110	desc = of_get_named_gpiod_flags(np, list_name, index, flags);
	111
	112	if (IS_ERR(desc))
	113	return PTR_ERR(desc);
	114	else
	115	return desc_to_gpio(desc);
	116	}
	117	EXPORT_SYMBOL(of_get_named_gpio_flags);
	118
863fbf49	119	/**
b908b53d	120	* of_gpio_simple_xlate - translate gpio_spec to the GPIO number and flags
a19e3da5	121	* @gc: pointer to the gpio_chip structure
863fbf49 AV	122	* @np: device node of the GPIO chip
863fbf49 AV	123	* @gpio_spec: gpio specifier as found in the device tree
b908b53d	124	* @flags: a flags pointer to fill in
863fbf49 AV	125	*
	126	* This is simple translation function, suitable for the most 1:1 mapped
	127	* gpio chips. This function performs only one sanity check: whether gpio
	128	* is less than ngpios (that is specified in the gpio_chip).
	129	*/
15c9a0ac GL	130	int of_gpio_simple_xlate(struct gpio_chip *gc,
15c9a0ac GL	131	const struct of_phandle_args gpiospec, u32 flags)
863fbf49	132	{
b908b53d AV	133	/*
	134	* We're discouraging gpio_cells < 2, since that way you'll have to
	135	* write your own xlate function (that will have to retrive the GPIO
	136	* number and the flags from a single gpio cell -- this is possible,
	137	* but not recommended).
	138	*/
a19e3da5	139	if (gc->of_gpio_n_cells < 2) {
b908b53d AV	140	WARN_ON(1);
	141	return -EINVAL;
	142	}
	143
15c9a0ac GL	144	if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells))
	145	return -EINVAL;
	146
6270d830	147	if (gpiospec->args[0] >= gc->ngpio)
863fbf49 AV	148	return -EINVAL;
863fbf49 AV	149
b908b53d	150	if (flags)
15c9a0ac	151	*flags = gpiospec->args[1];
b908b53d	152
15c9a0ac	153	return gpiospec->args[0];
863fbf49	154	}
3038bbdf	155	EXPORT_SYMBOL(of_gpio_simple_xlate);
863fbf49	156
863fbf49 AV	157	/**
	158	* of_mm_gpiochip_add - Add memory mapped GPIO chip (bank)
	159	* @np: device node of the GPIO chip
	160	* @mm_gc: pointer to the of_mm_gpio_chip allocated structure
	161	*
	162	* To use this function you should allocate and fill mm_gc with:
	163	*
	164	* 1) In the gpio_chip structure:
	165	* - all the callbacks
a19e3da5 AV	166	* - of_gpio_n_cells
a19e3da5 AV	167	* - of_xlate callback (optional)
863fbf49 AV	168	*
	169	* 3) In the of_mm_gpio_chip structure:
	170	* - save_regs callback (optional)
	171	*
	172	* If succeeded, this function will map bank's memory and will
	173	* do all necessary work for you. Then you'll able to use .regs
	174	* to manage GPIOs from the callbacks.
	175	*/
	176	int of_mm_gpiochip_add(struct device_node *np,
	177	struct of_mm_gpio_chip *mm_gc)
	178	{
	179	int ret = -ENOMEM;
a19e3da5	180	struct gpio_chip *gc = &mm_gc->gc;
863fbf49 AV	181
	182	gc->label = kstrdup(np->full_name, GFP_KERNEL);
	183	if (!gc->label)
	184	goto err0;
	185
	186	mm_gc->regs = of_iomap(np, 0);
	187	if (!mm_gc->regs)
	188	goto err1;
	189
21451155	190	gc->base = -1;
863fbf49	191
863fbf49 AV	192	if (mm_gc->save_regs)
	193	mm_gc->save_regs(mm_gc);
	194
a19e3da5	195	mm_gc->gc.of_node = np;
863fbf49 AV	196
	197	ret = gpiochip_add(gc);
	198	if (ret)
	199	goto err2;
	200
863fbf49 AV	201	return 0;
863fbf49 AV	202	err2:
863fbf49 AV	203	iounmap(mm_gc->regs);
	204	err1:
	205	kfree(gc->label);
	206	err0:
	207	pr_err("%s: GPIO chip registration failed with status %d\n",
	208	np->full_name, ret);
	209	return ret;
	210	}
	211	EXPORT_SYMBOL(of_mm_gpiochip_add);
594fa265	212
d621e8ba RRD	213	/**
	214	* of_mm_gpiochip_remove - Remove memory mapped GPIO chip (bank)
	215	* @mm_gc: pointer to the of_mm_gpio_chip allocated structure
	216	*/
	217	void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc)
	218	{
	219	struct gpio_chip *gc = &mm_gc->gc;
	220
	221	if (!mm_gc)
	222	return;
	223
	224	gpiochip_remove(gc);
	225	iounmap(mm_gc->regs);
	226	kfree(gc->label);
	227	}
	228	EXPORT_SYMBOL(of_mm_gpiochip_remove);
	229
f23f1516	230	#ifdef CONFIG_PINCTRL
167c1af9	231	static void of_gpiochip_add_pin_range(struct gpio_chip *chip)
f23f1516 SH	232	{
f23f1516 SH	233	struct device_node *np = chip->of_node;
f23f1516	234	struct of_phandle_args pinspec;
1e63d7b9	235	struct pinctrl_dev *pctldev;
f23f1516	236	int index = 0, ret;
586a87e6 CR	237	const char *name;
	238	static const char group_names_propname[] = "gpio-ranges-group-names";
	239	struct property *group_names;
f23f1516 SH	240
	241	if (!np)
	242	return;
	243
586a87e6 CR	244	group_names = of_find_property(np, group_names_propname, NULL);
586a87e6 CR	245
ad4e1a7c	246	for (;; index++) {
d9fe0039 SW	247	ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3,
d9fe0039 SW	248	index, &pinspec);
f23f1516 SH	249	if (ret)
	250	break;
	251
1e63d7b9 LW	252	pctldev = of_pinctrl_get(pinspec.np);
1e63d7b9 LW	253	if (!pctldev)
f23f1516	254	break;
f23f1516	255
586a87e6 CR	256	if (pinspec.args[2]) {
	257	if (group_names) {
	258	ret = of_property_read_string_index(np,
	259	group_names_propname,
	260	index, &name);
	261	if (strlen(name)) {
	262	pr_err("%s: Group name of numeric GPIO ranges must be the empty string.\n",
	263	np->full_name);
	264	break;
	265	}
	266	}
	267	/* npins != 0: linear range */
	268	ret = gpiochip_add_pin_range(chip,
	269	pinctrl_dev_get_devname(pctldev),
	270	pinspec.args[0],
	271	pinspec.args[1],
	272	pinspec.args[2]);
	273	if (ret)
	274	break;
	275	} else {
	276	/* npins == 0: special range */
	277	if (pinspec.args[1]) {
	278	pr_err("%s: Illegal gpio-range format.\n",
	279	np->full_name);
	280	break;
	281	}
	282
	283	if (!group_names) {
	284	pr_err("%s: GPIO group range requested but no %s property.\n",
	285	np->full_name, group_names_propname);
	286	break;
	287	}
	288
	289	ret = of_property_read_string_index(np,
	290	group_names_propname,
	291	index, &name);
	292	if (ret)
	293	break;
	294
	295	if (!strlen(name)) {
	296	pr_err("%s: Group name of GPIO group range cannot be the empty string.\n",
	297	np->full_name);
	298	break;
	299	}
	300
	301	ret = gpiochip_add_pingroup_range(chip, pctldev,
	302	pinspec.args[0], name);
	303	if (ret)
	304	break;
	305	}
ad4e1a7c	306	}
f23f1516 SH	307	}
f23f1516 SH	308
f23f1516	309	#else
167c1af9	310	static void of_gpiochip_add_pin_range(struct gpio_chip *chip) {}
f23f1516 SH	311	#endif
f23f1516 SH	312
391c970c AV	313	void of_gpiochip_add(struct gpio_chip *chip)
	314	{
	315	if ((!chip->of_node) && (chip->dev))
	316	chip->of_node = chip->dev->of_node;
	317
	318	if (!chip->of_node)
	319	return;
	320
	321	if (!chip->of_xlate) {
	322	chip->of_gpio_n_cells = 2;
	323	chip->of_xlate = of_gpio_simple_xlate;
	324	}
	325
f23f1516	326	of_gpiochip_add_pin_range(chip);
391c970c AV	327	of_node_get(chip->of_node);
	328	}
	329
	330	void of_gpiochip_remove(struct gpio_chip *chip)
	331	{
e93fa3f2	332	gpiochip_remove_pin_ranges(chip);
8a691550	333	of_node_put(chip->of_node);
391c970c	334	}