[linux.git] / drivers / mfd / syscon.c

/*
 * System Control Driver
 *
 * Copyright (C) 2012 Freescale Semiconductor, Inc.
 * Copyright (C) 2012 Linaro Ltd.
 *
 * Author: Dong Aisheng <[email protected]>
 *
 * 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/hwspinlock.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;

	ret = of_hwspin_lock_get_id(np, 0);
	if (ret > 0 || (IS_ENABLED(CONFIG_HWSPINLOCK) && ret == 0)) {
		syscon_config.use_hwlock = true;
		syscon_config.hwlock_id = ret;
		syscon_config.hwlock_mode = HWLOCK_IRQSTATE;
	} else if (ret < 0) {
		switch (ret) {
		case -ENOENT:
			/* Ignore missing hwlock, it's optional. */
			break;
		default:
			pr_err("Failed to retrieve valid hwlock: %d\n", ret);
			/* fall-through */
		case -EPROBE_DEFER:
			goto err_regmap;
		}
	}

	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 <[email protected]>");
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 <[email protected]>
	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>
3bafc09e	16	#include <linux/hwspinlock.h>
87d68730 DA	17	#include <linux/io.h>
87d68730 DA	18	#include <linux/module.h>
bdb0066d	19	#include <linux/list.h>
87d68730 DA	20	#include <linux/of.h>
	21	#include <linux/of_address.h>
	22	#include <linux/of_platform.h>
29f9b6cf	23	#include <linux/platform_data/syscon.h>
87d68730 DA	24	#include <linux/platform_device.h>
87d68730 DA	25	#include <linux/regmap.h>
75177dee	26	#include <linux/mfd/syscon.h>
bdb0066d	27	#include <linux/slab.h>
87d68730 DA	28
	29	static struct platform_driver syscon_driver;
	30
bdb0066d PD	31	static DEFINE_SPINLOCK(syscon_list_slock);
	32	static LIST_HEAD(syscon_list);
	33
87d68730	34	struct syscon {
bdb0066d	35	struct device_node *np;
87d68730	36	struct regmap *regmap;
bdb0066d PD	37	struct list_head list;
	38	};
	39
c131045d	40	static const struct regmap_config syscon_regmap_config = {
bdb0066d PD	41	.reg_bits = 32,
	42	.val_bits = 32,
	43	.reg_stride = 4,
87d68730 DA	44	};
87d68730 DA	45
bdb0066d	46	static struct syscon of_syscon_register(struct device_node np)
87d68730	47	{
bdb0066d PD	48	struct syscon *syscon;
	49	struct regmap *regmap;
	50	void __iomem *base;
db2fb60c	51	u32 reg_io_width;
bdb0066d PD	52	int ret;
bdb0066d PD	53	struct regmap_config syscon_config = syscon_regmap_config;
ca668f0e	54	struct resource res;
bdb0066d PD	55
	56	if (!of_device_is_compatible(np, "syscon"))
	57	return ERR_PTR(-EINVAL);
	58
	59	syscon = kzalloc(sizeof(*syscon), GFP_KERNEL);
	60	if (!syscon)
	61	return ERR_PTR(-ENOMEM);
	62
ca668f0e PZ	63	if (of_address_to_resource(np, 0, &res)) {
	64	ret = -ENOMEM;
	65	goto err_map;
	66	}
	67
	68	base = ioremap(res.start, resource_size(&res));
bdb0066d PD	69	if (!base) {
	70	ret = -ENOMEM;
	71	goto err_map;
	72	}
	73
	74	/* Parse the device's DT node for an endianness specification */
	75	if (of_property_read_bool(np, "big-endian"))
	76	syscon_config.val_format_endian = REGMAP_ENDIAN_BIG;
d29ccdb3	77	else if (of_property_read_bool(np, "little-endian"))
bdb0066d	78	syscon_config.val_format_endian = REGMAP_ENDIAN_LITTLE;
d29ccdb3 PB	79	else if (of_property_read_bool(np, "native-endian"))
d29ccdb3 PB	80	syscon_config.val_format_endian = REGMAP_ENDIAN_NATIVE;
bdb0066d	81
db2fb60c DR	82	/*
	83	* search for reg-io-width property in DT. If it is not provided,
	84	* default to 4 bytes. regmap_init_mmio will return an error if values
	85	* are invalid so there is no need to check them here.
	86	*/
	87	ret = of_property_read_u32(np, "reg-io-width", &reg_io_width);
	88	if (ret)
	89	reg_io_width = 4;
	90
3bafc09e BW	91	ret = of_hwspin_lock_get_id(np, 0);
	92	if (ret > 0 \|\| (IS_ENABLED(CONFIG_HWSPINLOCK) && ret == 0)) {
	93	syscon_config.use_hwlock = true;
	94	syscon_config.hwlock_id = ret;
	95	syscon_config.hwlock_mode = HWLOCK_IRQSTATE;
	96	} else if (ret < 0) {
	97	switch (ret) {
	98	case -ENOENT:
	99	/* Ignore missing hwlock, it's optional. */
	100	break;
	101	default:
	102	pr_err("Failed to retrieve valid hwlock: %d\n", ret);
	103	/* fall-through */
	104	case -EPROBE_DEFER:
	105	goto err_regmap;
	106	}
	107	}
	108
db2fb60c DR	109	syscon_config.reg_stride = reg_io_width;
db2fb60c DR	110	syscon_config.val_bits = reg_io_width * 8;
ca668f0e	111	syscon_config.max_register = resource_size(&res) - reg_io_width;
db2fb60c	112
bdb0066d PD	113	regmap = regmap_init_mmio(NULL, base, &syscon_config);
	114	if (IS_ERR(regmap)) {
	115	pr_err("regmap init failed\n");
	116	ret = PTR_ERR(regmap);
	117	goto err_regmap;
	118	}
	119
	120	syscon->regmap = regmap;
	121	syscon->np = np;
	122
	123	spin_lock(&syscon_list_slock);
	124	list_add_tail(&syscon->list, &syscon_list);
	125	spin_unlock(&syscon_list_slock);
87d68730	126
bdb0066d PD	127	return syscon;
	128
	129	err_regmap:
	130	iounmap(base);
	131	err_map:
	132	kfree(syscon);
	133	return ERR_PTR(ret);
87d68730 DA	134	}
	135
	136	struct regmap syscon_node_to_regmap(struct device_node np)
	137	{
bdb0066d	138	struct syscon entry, syscon = NULL;
87d68730	139
bdb0066d	140	spin_lock(&syscon_list_slock);
87d68730	141
bdb0066d PD	142	list_for_each_entry(entry, &syscon_list, list)
	143	if (entry->np == np) {
	144	syscon = entry;
	145	break;
	146	}
	147
	148	spin_unlock(&syscon_list_slock);
	149
	150	if (!syscon)
	151	syscon = of_syscon_register(np);
	152
	153	if (IS_ERR(syscon))
	154	return ERR_CAST(syscon);
87d68730 DA	155
	156	return syscon->regmap;
	157	}
	158	EXPORT_SYMBOL_GPL(syscon_node_to_regmap);
	159
	160	struct regmap syscon_regmap_lookup_by_compatible(const char s)
	161	{
	162	struct device_node *syscon_np;
	163	struct regmap *regmap;
	164
	165	syscon_np = of_find_compatible_node(NULL, NULL, s);
	166	if (!syscon_np)
	167	return ERR_PTR(-ENODEV);
	168
	169	regmap = syscon_node_to_regmap(syscon_np);
	170	of_node_put(syscon_np);
	171
	172	return regmap;
	173	}
	174	EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_compatible);
	175
5ab3a89a AS	176	static int syscon_match_pdevname(struct device dev, void data)
5ab3a89a AS	177	{
5ab3a89a AS	178	return !strcmp(dev_name(dev), (const char *)data);
	179	}
	180
	181	struct regmap syscon_regmap_lookup_by_pdevname(const char s)
	182	{
	183	struct device *dev;
	184	struct syscon *syscon;
	185
	186	dev = driver_find_device(&syscon_driver.driver, NULL, (void *)s,
	187	syscon_match_pdevname);
	188	if (!dev)
	189	return ERR_PTR(-EPROBE_DEFER);
	190
	191	syscon = dev_get_drvdata(dev);
	192
	193	return syscon->regmap;
	194	}
	195	EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_pdevname);
	196
87d68730 DA	197	struct regmap syscon_regmap_lookup_by_phandle(struct device_node np,
	198	const char *property)
	199	{
	200	struct device_node *syscon_np;
	201	struct regmap *regmap;
	202
45330bb4 PD	203	if (property)
	204	syscon_np = of_parse_phandle(np, property, 0);
	205	else
	206	syscon_np = np;
	207
87d68730 DA	208	if (!syscon_np)
	209	return ERR_PTR(-ENODEV);
	210
	211	regmap = syscon_node_to_regmap(syscon_np);
	212	of_node_put(syscon_np);
	213
	214	return regmap;
	215	}
	216	EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle);
	217
f791be49	218	static int syscon_probe(struct platform_device *pdev)
87d68730 DA	219	{
87d68730 DA	220	struct device *dev = &pdev->dev;
29f9b6cf	221	struct syscon_platform_data *pdata = dev_get_platdata(dev);
87d68730	222	struct syscon *syscon;
c131045d	223	struct regmap_config syscon_config = syscon_regmap_config;
5ab3a89a	224	struct resource *res;
f10111cc	225	void __iomem *base;
87d68730	226
5ab3a89a	227	syscon = devm_kzalloc(dev, sizeof(*syscon), GFP_KERNEL);
87d68730 DA	228	if (!syscon)
	229	return -ENOMEM;
	230
5ab3a89a AS	231	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	232	if (!res)
	233	return -ENOENT;
87d68730	234
f10111cc AS	235	base = devm_ioremap(dev, res->start, resource_size(res));
f10111cc AS	236	if (!base)
5ab3a89a	237	return -ENOMEM;
87d68730	238
c131045d	239	syscon_config.max_register = res->end - res->start - 3;
29f9b6cf	240	if (pdata)
c131045d PZ	241	syscon_config.name = pdata->label;
c131045d PZ	242	syscon->regmap = devm_regmap_init_mmio(dev, base, &syscon_config);
87d68730 DA	243	if (IS_ERR(syscon->regmap)) {
	244	dev_err(dev, "regmap init failed\n");
	245	return PTR_ERR(syscon->regmap);
	246	}
	247
87d68730 DA	248	platform_set_drvdata(pdev, syscon);
87d68730 DA	249
38d8974e	250	dev_dbg(dev, "regmap %pR registered\n", res);
87d68730 DA	251
	252	return 0;
	253	}
	254
5ab3a89a AS	255	static const struct platform_device_id syscon_ids[] = {
	256	{ "syscon", },
	257	{ }
	258	};
87d68730 DA	259
	260	static struct platform_driver syscon_driver = {
	261	.driver = {
	262	.name = "syscon",
87d68730 DA	263	},
87d68730 DA	264	.probe = syscon_probe,
5ab3a89a	265	.id_table = syscon_ids,
87d68730 DA	266	};
	267
	268	static int __init syscon_init(void)
	269	{
	270	return platform_driver_register(&syscon_driver);
	271	}
	272	postcore_initcall(syscon_init);
	273
	274	static void __exit syscon_exit(void)
	275	{
	276	platform_driver_unregister(&syscon_driver);
	277	}
	278	module_exit(syscon_exit);
	279
	280	MODULE_AUTHOR("Dong Aisheng <[email protected]>");
	281	MODULE_DESCRIPTION("System Control driver");
	282	MODULE_LICENSE("GPL v2");