[deliverable/linux.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;

	/*
	 * 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
	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>
	18	#include <linux/list.h>
	19	#include <linux/of.h>
	20	#include <linux/of_address.h>
	21	#include <linux/of_platform.h>
	22	#include <linux/platform_data/syscon.h>
	23	#include <linux/platform_device.h>
	24	#include <linux/regmap.h>
	25	#include <linux/mfd/syscon.h>
	26	#include <linux/slab.h>
	27
	28	static struct platform_driver syscon_driver;
	29
	30	static DEFINE_SPINLOCK(syscon_list_slock);
	31	static LIST_HEAD(syscon_list);
	32
	33	struct syscon {
	34	struct device_node *np;
	35	struct regmap *regmap;
	36	struct list_head list;
	37	};
	38
	39	static const struct regmap_config syscon_regmap_config = {
	40	.reg_bits = 32,
	41	.val_bits = 32,
	42	.reg_stride = 4,
	43	};
	44
	45	static struct syscon of_syscon_register(struct device_node np)
	46	{
	47	struct syscon *syscon;
	48	struct regmap *regmap;
	49	void __iomem *base;
	50	u32 reg_io_width;
	51	int ret;
	52	struct regmap_config syscon_config = syscon_regmap_config;
	53	struct resource res;
	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
	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));
	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;
	76	else if (of_property_read_bool(np, "little-endian"))
	77	syscon_config.val_format_endian = REGMAP_ENDIAN_LITTLE;
	78
	79	/*
	80	* search for reg-io-width property in DT. If it is not provided,
	81	* default to 4 bytes. regmap_init_mmio will return an error if values
	82	* are invalid so there is no need to check them here.
	83	*/
	84	ret = of_property_read_u32(np, "reg-io-width", &reg_io_width);
	85	if (ret)
	86	reg_io_width = 4;
	87
	88	syscon_config.reg_stride = reg_io_width;
	89	syscon_config.val_bits = reg_io_width * 8;
	90	syscon_config.max_register = resource_size(&res) - reg_io_width;
	91
	92	regmap = regmap_init_mmio(NULL, base, &syscon_config);
	93	if (IS_ERR(regmap)) {
	94	pr_err("regmap init failed\n");
	95	ret = PTR_ERR(regmap);
	96	goto err_regmap;
	97	}
	98
	99	syscon->regmap = regmap;
	100	syscon->np = np;
	101
	102	spin_lock(&syscon_list_slock);
	103	list_add_tail(&syscon->list, &syscon_list);
	104	spin_unlock(&syscon_list_slock);
	105
	106	return syscon;
	107
	108	err_regmap:
	109	iounmap(base);
	110	err_map:
	111	kfree(syscon);
	112	return ERR_PTR(ret);
	113	}
	114
	115	struct regmap syscon_node_to_regmap(struct device_node np)
	116	{
	117	struct syscon entry, syscon = NULL;
	118
	119	spin_lock(&syscon_list_slock);
	120
	121	list_for_each_entry(entry, &syscon_list, list)
	122	if (entry->np == np) {
	123	syscon = entry;
	124	break;
	125	}
	126
	127	spin_unlock(&syscon_list_slock);
	128
	129	if (!syscon)
	130	syscon = of_syscon_register(np);
	131
	132	if (IS_ERR(syscon))
	133	return ERR_CAST(syscon);
	134
	135	return syscon->regmap;
	136	}
	137	EXPORT_SYMBOL_GPL(syscon_node_to_regmap);
	138
	139	struct regmap syscon_regmap_lookup_by_compatible(const char s)
	140	{
	141	struct device_node *syscon_np;
	142	struct regmap *regmap;
	143
	144	syscon_np = of_find_compatible_node(NULL, NULL, s);
	145	if (!syscon_np)
	146	return ERR_PTR(-ENODEV);
	147
	148	regmap = syscon_node_to_regmap(syscon_np);
	149	of_node_put(syscon_np);
	150
	151	return regmap;
	152	}
	153	EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_compatible);
	154
	155	static int syscon_match_pdevname(struct device dev, void data)
	156	{
	157	return !strcmp(dev_name(dev), (const char *)data);
	158	}
	159
	160	struct regmap syscon_regmap_lookup_by_pdevname(const char s)
	161	{
	162	struct device *dev;
	163	struct syscon *syscon;
	164
	165	dev = driver_find_device(&syscon_driver.driver, NULL, (void *)s,
	166	syscon_match_pdevname);
	167	if (!dev)
	168	return ERR_PTR(-EPROBE_DEFER);
	169
	170	syscon = dev_get_drvdata(dev);
	171
	172	return syscon->regmap;
	173	}
	174	EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_pdevname);
	175
	176	struct regmap syscon_regmap_lookup_by_phandle(struct device_node np,
	177	const char *property)
	178	{
	179	struct device_node *syscon_np;
	180	struct regmap *regmap;
	181
	182	if (property)
	183	syscon_np = of_parse_phandle(np, property, 0);
	184	else
	185	syscon_np = np;
	186
	187	if (!syscon_np)
	188	return ERR_PTR(-ENODEV);
	189
	190	regmap = syscon_node_to_regmap(syscon_np);
	191	of_node_put(syscon_np);
	192
	193	return regmap;
	194	}
	195	EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle);
	196
	197	static int syscon_probe(struct platform_device *pdev)
	198	{
	199	struct device *dev = &pdev->dev;
	200	struct syscon_platform_data *pdata = dev_get_platdata(dev);
	201	struct syscon *syscon;
	202	struct regmap_config syscon_config = syscon_regmap_config;
	203	struct resource *res;
	204	void __iomem *base;
	205
	206	syscon = devm_kzalloc(dev, sizeof(*syscon), GFP_KERNEL);
	207	if (!syscon)
	208	return -ENOMEM;
	209
	210	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	211	if (!res)
	212	return -ENOENT;
	213
	214	base = devm_ioremap(dev, res->start, resource_size(res));
	215	if (!base)
	216	return -ENOMEM;
	217
	218	syscon_config.max_register = res->end - res->start - 3;
	219	if (pdata)
	220	syscon_config.name = pdata->label;
	221	syscon->regmap = devm_regmap_init_mmio(dev, base, &syscon_config);
	222	if (IS_ERR(syscon->regmap)) {
	223	dev_err(dev, "regmap init failed\n");
	224	return PTR_ERR(syscon->regmap);
	225	}
	226
	227	platform_set_drvdata(pdev, syscon);
	228
	229	dev_dbg(dev, "regmap %pR registered\n", res);
	230
	231	return 0;
	232	}
	233
	234	static const struct platform_device_id syscon_ids[] = {
	235	{ "syscon", },
	236	{ }
	237	};
	238
	239	static struct platform_driver syscon_driver = {
	240	.driver = {
	241	.name = "syscon",
	242	},
	243	.probe = syscon_probe,
	244	.id_table = syscon_ids,
	245	};
	246
	247	static int __init syscon_init(void)
	248	{
	249	return platform_driver_register(&syscon_driver);
	250	}
	251	postcore_initcall(syscon_init);
	252
	253	static void __exit syscon_exit(void)
	254	{
	255	platform_driver_unregister(&syscon_driver);
	256	}
	257	module_exit(syscon_exit);
	258
	259	MODULE_AUTHOR("Dong Aisheng <dong.aisheng@linaro.org>");
	260	MODULE_DESCRIPTION("System Control driver");
	261	MODULE_LICENSE("GPL v2");