[mirror_ubuntu-artful-kernel.git] / drivers / mfd / syscon.c

/*
 * System Control Driver
 *
 * Copyright (C) 2012 Freescale Semiconductor, Inc.
 * Copyright (C) 2012 Linaro Ltd.
 *
 * Author: Dong Aisheng <dong.aisheng@linaro.org>
 *
 * 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/err.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/list.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/platform_data/syscon.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/mfd/syscon.h>
#include <linux/slab.h>

static struct platform_driver syscon_driver;

static DEFINE_SPINLOCK(syscon_list_slock);
static LIST_HEAD(syscon_list);

struct syscon {
	struct device_node *np;
	struct regmap *regmap;
	struct list_head list;
};

static const struct regmap_config syscon_regmap_config = {
	.reg_bits = 32,
	.val_bits = 32,
	.reg_stride = 4,
};

static struct syscon *of_syscon_register(struct device_node *np)
{
	struct syscon *syscon;
	struct regmap *regmap;
	void __iomem *base;
	u32 reg_io_width;
	int ret;
	struct regmap_config syscon_config = syscon_regmap_config;
	struct resource res;

	if (!of_device_is_compatible(np, "syscon"))
		return ERR_PTR(-EINVAL);

	syscon = kzalloc(sizeof(*syscon), GFP_KERNEL);
	if (!syscon)
		return ERR_PTR(-ENOMEM);

	if (of_address_to_resource(np, 0, &res)) {
		ret = -ENOMEM;
		goto err_map;
	}

	base = ioremap(res.start, resource_size(&res));
	if (!base) {
		ret = -ENOMEM;
		goto err_map;
	}

	/* Parse the device's DT node for an endianness specification */
	if (of_property_read_bool(np, "big-endian"))
		syscon_config.val_format_endian = REGMAP_ENDIAN_BIG;
	else if (of_property_read_bool(np, "little-endian"))
		syscon_config.val_format_endian = REGMAP_ENDIAN_LITTLE;
	else if (of_property_read_bool(np, "native-endian"))
		syscon_config.val_format_endian = REGMAP_ENDIAN_NATIVE;

	/*
	 * search for reg-io-width property in DT. If it is not provided,
	 * default to 4 bytes. regmap_init_mmio will return an error if values
	 * are invalid so there is no need to check them here.
	 */
	ret = of_property_read_u32(np, "reg-io-width", &reg_io_width);
	if (ret)
		reg_io_width = 4;

	syscon_config.reg_stride = reg_io_width;
	syscon_config.val_bits = reg_io_width * 8;
	syscon_config.max_register = resource_size(&res) - reg_io_width;

	regmap = regmap_init_mmio(NULL, base, &syscon_config);
	if (IS_ERR(regmap)) {
		pr_err("regmap init failed\n");
		ret = PTR_ERR(regmap);
		goto err_regmap;
	}

	syscon->regmap = regmap;
	syscon->np = np;

	spin_lock(&syscon_list_slock);
	list_add_tail(&syscon->list, &syscon_list);
	spin_unlock(&syscon_list_slock);

	return syscon;

err_regmap:
	iounmap(base);
err_map:
	kfree(syscon);
	return ERR_PTR(ret);
}

struct regmap *syscon_node_to_regmap(struct device_node *np)
{
	struct syscon *entry, *syscon = NULL;

	spin_lock(&syscon_list_slock);

	list_for_each_entry(entry, &syscon_list, list)
		if (entry->np == np) {
			syscon = entry;
			break;
		}

	spin_unlock(&syscon_list_slock);

	if (!syscon)
		syscon = of_syscon_register(np);

	if (IS_ERR(syscon))
		return ERR_CAST(syscon);

	return syscon->regmap;
}
EXPORT_SYMBOL_GPL(syscon_node_to_regmap);

struct regmap *syscon_regmap_lookup_by_compatible(const char *s)
{
	struct device_node *syscon_np;
	struct regmap *regmap;

	syscon_np = of_find_compatible_node(NULL, NULL, s);
	if (!syscon_np)
		return ERR_PTR(-ENODEV);

	regmap = syscon_node_to_regmap(syscon_np);
	of_node_put(syscon_np);

	return regmap;
}
EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_compatible);

static int syscon_match_pdevname(struct device *dev, void *data)
{
	return !strcmp(dev_name(dev), (const char *)data);
}

struct regmap *syscon_regmap_lookup_by_pdevname(const char *s)
{
	struct device *dev;
	struct syscon *syscon;

	dev = driver_find_device(&syscon_driver.driver, NULL, (void *)s,
				 syscon_match_pdevname);
	if (!dev)
		return ERR_PTR(-EPROBE_DEFER);

	syscon = dev_get_drvdata(dev);

	return syscon->regmap;
}
EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_pdevname);

struct regmap *syscon_regmap_lookup_by_phandle(struct device_node *np,
					const char *property)
{
	struct device_node *syscon_np;
	struct regmap *regmap;

	if (property)
		syscon_np = of_parse_phandle(np, property, 0);
	else
		syscon_np = np;

	if (!syscon_np)
		return ERR_PTR(-ENODEV);

	regmap = syscon_node_to_regmap(syscon_np);
	of_node_put(syscon_np);

	return regmap;
}
EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle);

static int syscon_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct syscon_platform_data *pdata = dev_get_platdata(dev);
	struct syscon *syscon;
	struct regmap_config syscon_config = syscon_regmap_config;
	struct resource *res;
	void __iomem *base;

	syscon = devm_kzalloc(dev, sizeof(*syscon), GFP_KERNEL);
	if (!syscon)
		return -ENOMEM;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res)
		return -ENOENT;

	base = devm_ioremap(dev, res->start, resource_size(res));
	if (!base)
		return -ENOMEM;

	syscon_config.max_register = res->end - res->start - 3;
	if (pdata)
		syscon_config.name = pdata->label;
	syscon->regmap = devm_regmap_init_mmio(dev, base, &syscon_config);
	if (IS_ERR(syscon->regmap)) {
		dev_err(dev, "regmap init failed\n");
		return PTR_ERR(syscon->regmap);
	}

	platform_set_drvdata(pdev, syscon);

	dev_dbg(dev, "regmap %pR registered\n", res);

	return 0;
}

static const struct platform_device_id syscon_ids[] = {
	{ "syscon", },
	{ }
};

static struct platform_driver syscon_driver = {
	.driver = {
		.name = "syscon",
	},
	.probe		= syscon_probe,
	.id_table	= syscon_ids,
};

static int __init syscon_init(void)
{
	return platform_driver_register(&syscon_driver);
}
postcore_initcall(syscon_init);

static void __exit syscon_exit(void)
{
	platform_driver_unregister(&syscon_driver);
}
module_exit(syscon_exit);

MODULE_AUTHOR("Dong Aisheng <dong.aisheng@linaro.org>");
MODULE_DESCRIPTION("System Control driver");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
87d68730 DA	1	/*
	2	* System Control Driver
	3	*
	4	* Copyright (C) 2012 Freescale Semiconductor, Inc.
	5	* Copyright (C) 2012 Linaro Ltd.
	6	*
	7	* Author: Dong Aisheng <dong.aisheng@linaro.org>
	8	*
	9	* This program is free software; you can redistribute it and/or modify
	10	* it under the terms of the GNU General Public License as published by
	11	* the Free Software Foundation; either version 2 of the License, or
	12	* (at your option) any later version.
	13	*/
	14
	15	#include <linux/err.h>
	16	#include <linux/io.h>
	17	#include <linux/module.h>
bdb0066d	18	#include <linux/list.h>
87d68730 DA	19	#include <linux/of.h>
	20	#include <linux/of_address.h>
	21	#include <linux/of_platform.h>
29f9b6cf	22	#include <linux/platform_data/syscon.h>
87d68730 DA	23	#include <linux/platform_device.h>
87d68730 DA	24	#include <linux/regmap.h>
75177dee	25	#include <linux/mfd/syscon.h>
bdb0066d	26	#include <linux/slab.h>
87d68730 DA	27
	28	static struct platform_driver syscon_driver;
	29
bdb0066d PD	30	static DEFINE_SPINLOCK(syscon_list_slock);
	31	static LIST_HEAD(syscon_list);
	32
87d68730	33	struct syscon {
bdb0066d	34	struct device_node *np;
87d68730	35	struct regmap *regmap;
bdb0066d PD	36	struct list_head list;
	37	};
	38
c131045d	39	static const struct regmap_config syscon_regmap_config = {
bdb0066d PD	40	.reg_bits = 32,
	41	.val_bits = 32,
	42	.reg_stride = 4,
87d68730 DA	43	};
87d68730 DA	44
bdb0066d	45	static struct syscon of_syscon_register(struct device_node np)
87d68730	46	{
bdb0066d PD	47	struct syscon *syscon;
	48	struct regmap *regmap;
	49	void __iomem *base;
db2fb60c	50	u32 reg_io_width;
bdb0066d PD	51	int ret;
bdb0066d PD	52	struct regmap_config syscon_config = syscon_regmap_config;
ca668f0e	53	struct resource res;
bdb0066d PD	54
	55	if (!of_device_is_compatible(np, "syscon"))
	56	return ERR_PTR(-EINVAL);
	57
	58	syscon = kzalloc(sizeof(*syscon), GFP_KERNEL);
	59	if (!syscon)
	60	return ERR_PTR(-ENOMEM);
	61
ca668f0e PZ	62	if (of_address_to_resource(np, 0, &res)) {
	63	ret = -ENOMEM;
	64	goto err_map;
	65	}
	66
	67	base = ioremap(res.start, resource_size(&res));
bdb0066d PD	68	if (!base) {
	69	ret = -ENOMEM;
	70	goto err_map;
	71	}
	72
	73	/* Parse the device's DT node for an endianness specification */
	74	if (of_property_read_bool(np, "big-endian"))
	75	syscon_config.val_format_endian = REGMAP_ENDIAN_BIG;
d29ccdb3	76	else if (of_property_read_bool(np, "little-endian"))
bdb0066d	77	syscon_config.val_format_endian = REGMAP_ENDIAN_LITTLE;
d29ccdb3 PB	78	else if (of_property_read_bool(np, "native-endian"))
d29ccdb3 PB	79	syscon_config.val_format_endian = REGMAP_ENDIAN_NATIVE;
bdb0066d	80
db2fb60c DR	81	/*
	82	* search for reg-io-width property in DT. If it is not provided,
	83	* default to 4 bytes. regmap_init_mmio will return an error if values
	84	* are invalid so there is no need to check them here.
	85	*/
	86	ret = of_property_read_u32(np, "reg-io-width", &reg_io_width);
	87	if (ret)
	88	reg_io_width = 4;
	89
	90	syscon_config.reg_stride = reg_io_width;
	91	syscon_config.val_bits = reg_io_width * 8;
ca668f0e	92	syscon_config.max_register = resource_size(&res) - reg_io_width;
db2fb60c	93
bdb0066d PD	94	regmap = regmap_init_mmio(NULL, base, &syscon_config);
	95	if (IS_ERR(regmap)) {
	96	pr_err("regmap init failed\n");
	97	ret = PTR_ERR(regmap);
	98	goto err_regmap;
	99	}
	100
	101	syscon->regmap = regmap;
	102	syscon->np = np;
	103
	104	spin_lock(&syscon_list_slock);
	105	list_add_tail(&syscon->list, &syscon_list);
	106	spin_unlock(&syscon_list_slock);
87d68730	107
bdb0066d PD	108	return syscon;
	109
	110	err_regmap:
	111	iounmap(base);
	112	err_map:
	113	kfree(syscon);
	114	return ERR_PTR(ret);
87d68730 DA	115	}
	116
	117	struct regmap syscon_node_to_regmap(struct device_node np)
	118	{
bdb0066d	119	struct syscon entry, syscon = NULL;
87d68730	120
bdb0066d	121	spin_lock(&syscon_list_slock);
87d68730	122
bdb0066d PD	123	list_for_each_entry(entry, &syscon_list, list)
	124	if (entry->np == np) {
	125	syscon = entry;
	126	break;
	127	}
	128
	129	spin_unlock(&syscon_list_slock);
	130
	131	if (!syscon)
	132	syscon = of_syscon_register(np);
	133
	134	if (IS_ERR(syscon))
	135	return ERR_CAST(syscon);
87d68730 DA	136
	137	return syscon->regmap;
	138	}
	139	EXPORT_SYMBOL_GPL(syscon_node_to_regmap);
	140
	141	struct regmap syscon_regmap_lookup_by_compatible(const char s)
	142	{
	143	struct device_node *syscon_np;
	144	struct regmap *regmap;
	145
	146	syscon_np = of_find_compatible_node(NULL, NULL, s);
	147	if (!syscon_np)
	148	return ERR_PTR(-ENODEV);
	149
	150	regmap = syscon_node_to_regmap(syscon_np);
	151	of_node_put(syscon_np);
	152
	153	return regmap;
	154	}
	155	EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_compatible);
	156
5ab3a89a AS	157	static int syscon_match_pdevname(struct device dev, void data)
5ab3a89a AS	158	{
5ab3a89a AS	159	return !strcmp(dev_name(dev), (const char *)data);
	160	}
	161
	162	struct regmap syscon_regmap_lookup_by_pdevname(const char s)
	163	{
	164	struct device *dev;
	165	struct syscon *syscon;
	166
	167	dev = driver_find_device(&syscon_driver.driver, NULL, (void *)s,
	168	syscon_match_pdevname);
	169	if (!dev)
	170	return ERR_PTR(-EPROBE_DEFER);
	171
	172	syscon = dev_get_drvdata(dev);
	173
	174	return syscon->regmap;
	175	}
	176	EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_pdevname);
	177
87d68730 DA	178	struct regmap syscon_regmap_lookup_by_phandle(struct device_node np,
	179	const char *property)
	180	{
	181	struct device_node *syscon_np;
	182	struct regmap *regmap;
	183
45330bb4 PD	184	if (property)
	185	syscon_np = of_parse_phandle(np, property, 0);
	186	else
	187	syscon_np = np;
	188
87d68730 DA	189	if (!syscon_np)
	190	return ERR_PTR(-ENODEV);
	191
	192	regmap = syscon_node_to_regmap(syscon_np);
	193	of_node_put(syscon_np);
	194
	195	return regmap;
	196	}
	197	EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle);
	198
f791be49	199	static int syscon_probe(struct platform_device *pdev)
87d68730 DA	200	{
87d68730 DA	201	struct device *dev = &pdev->dev;
29f9b6cf	202	struct syscon_platform_data *pdata = dev_get_platdata(dev);
87d68730	203	struct syscon *syscon;
c131045d	204	struct regmap_config syscon_config = syscon_regmap_config;
5ab3a89a	205	struct resource *res;
f10111cc	206	void __iomem *base;
87d68730	207
5ab3a89a	208	syscon = devm_kzalloc(dev, sizeof(*syscon), GFP_KERNEL);
87d68730 DA	209	if (!syscon)
	210	return -ENOMEM;
	211
5ab3a89a AS	212	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	213	if (!res)
	214	return -ENOENT;
87d68730	215
f10111cc AS	216	base = devm_ioremap(dev, res->start, resource_size(res));
f10111cc AS	217	if (!base)
5ab3a89a	218	return -ENOMEM;
87d68730	219
c131045d	220	syscon_config.max_register = res->end - res->start - 3;
29f9b6cf	221	if (pdata)
c131045d PZ	222	syscon_config.name = pdata->label;
c131045d PZ	223	syscon->regmap = devm_regmap_init_mmio(dev, base, &syscon_config);
87d68730 DA	224	if (IS_ERR(syscon->regmap)) {
	225	dev_err(dev, "regmap init failed\n");
	226	return PTR_ERR(syscon->regmap);
	227	}
	228
87d68730 DA	229	platform_set_drvdata(pdev, syscon);
87d68730 DA	230
38d8974e	231	dev_dbg(dev, "regmap %pR registered\n", res);
87d68730 DA	232
	233	return 0;
	234	}
	235
5ab3a89a AS	236	static const struct platform_device_id syscon_ids[] = {
	237	{ "syscon", },
	238	{ }
	239	};
87d68730 DA	240
	241	static struct platform_driver syscon_driver = {
	242	.driver = {
	243	.name = "syscon",
87d68730 DA	244	},
87d68730 DA	245	.probe = syscon_probe,
5ab3a89a	246	.id_table = syscon_ids,
87d68730 DA	247	};
	248
	249	static int __init syscon_init(void)
	250	{
	251	return platform_driver_register(&syscon_driver);
	252	}
	253	postcore_initcall(syscon_init);
	254
	255	static void __exit syscon_exit(void)
	256	{
	257	platform_driver_unregister(&syscon_driver);
	258	}
	259	module_exit(syscon_exit);
	260
	261	MODULE_AUTHOR("Dong Aisheng <dong.aisheng@linaro.org>");
	262	MODULE_DESCRIPTION("System Control driver");
	263	MODULE_LICENSE("GPL v2");