[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.name = of_node_full_name(np);
	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;
	syscon_config.name = of_node_full_name(np);

	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
408d1d57	109	syscon_config.name = of_node_full_name(np);
db2fb60c DR	110	syscon_config.reg_stride = reg_io_width;
db2fb60c DR	111	syscon_config.val_bits = reg_io_width * 8;
ca668f0e	112	syscon_config.max_register = resource_size(&res) - reg_io_width;
500f9ff5	113	syscon_config.name = of_node_full_name(np);
db2fb60c	114
bdb0066d PD	115	regmap = regmap_init_mmio(NULL, base, &syscon_config);
	116	if (IS_ERR(regmap)) {
	117	pr_err("regmap init failed\n");
	118	ret = PTR_ERR(regmap);
	119	goto err_regmap;
	120	}
	121
	122	syscon->regmap = regmap;
	123	syscon->np = np;
	124
	125	spin_lock(&syscon_list_slock);
	126	list_add_tail(&syscon->list, &syscon_list);
	127	spin_unlock(&syscon_list_slock);
87d68730	128
bdb0066d PD	129	return syscon;
	130
	131	err_regmap:
	132	iounmap(base);
	133	err_map:
	134	kfree(syscon);
	135	return ERR_PTR(ret);
87d68730 DA	136	}
	137
	138	struct regmap syscon_node_to_regmap(struct device_node np)
	139	{
bdb0066d	140	struct syscon entry, syscon = NULL;
87d68730	141
bdb0066d	142	spin_lock(&syscon_list_slock);
87d68730	143
bdb0066d PD	144	list_for_each_entry(entry, &syscon_list, list)
	145	if (entry->np == np) {
	146	syscon = entry;
	147	break;
	148	}
	149
	150	spin_unlock(&syscon_list_slock);
	151
	152	if (!syscon)
	153	syscon = of_syscon_register(np);
	154
	155	if (IS_ERR(syscon))
	156	return ERR_CAST(syscon);
87d68730 DA	157
	158	return syscon->regmap;
	159	}
	160	EXPORT_SYMBOL_GPL(syscon_node_to_regmap);
	161
	162	struct regmap syscon_regmap_lookup_by_compatible(const char s)
	163	{
	164	struct device_node *syscon_np;
	165	struct regmap *regmap;
	166
	167	syscon_np = of_find_compatible_node(NULL, NULL, s);
	168	if (!syscon_np)
	169	return ERR_PTR(-ENODEV);
	170
	171	regmap = syscon_node_to_regmap(syscon_np);
	172	of_node_put(syscon_np);
	173
	174	return regmap;
	175	}
	176	EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_compatible);
	177
5ab3a89a AS	178	static int syscon_match_pdevname(struct device dev, void data)
5ab3a89a AS	179	{
5ab3a89a AS	180	return !strcmp(dev_name(dev), (const char *)data);
	181	}
	182
	183	struct regmap syscon_regmap_lookup_by_pdevname(const char s)
	184	{
	185	struct device *dev;
	186	struct syscon *syscon;
	187
	188	dev = driver_find_device(&syscon_driver.driver, NULL, (void *)s,
	189	syscon_match_pdevname);
	190	if (!dev)
	191	return ERR_PTR(-EPROBE_DEFER);
	192
	193	syscon = dev_get_drvdata(dev);
	194
	195	return syscon->regmap;
	196	}
	197	EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_pdevname);
	198
87d68730 DA	199	struct regmap syscon_regmap_lookup_by_phandle(struct device_node np,
	200	const char *property)
	201	{
	202	struct device_node *syscon_np;
	203	struct regmap *regmap;
	204
45330bb4 PD	205	if (property)
	206	syscon_np = of_parse_phandle(np, property, 0);
	207	else
	208	syscon_np = np;
	209
87d68730 DA	210	if (!syscon_np)
	211	return ERR_PTR(-ENODEV);
	212
	213	regmap = syscon_node_to_regmap(syscon_np);
	214	of_node_put(syscon_np);
	215
	216	return regmap;
	217	}
	218	EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle);
	219
f791be49	220	static int syscon_probe(struct platform_device *pdev)
87d68730 DA	221	{
87d68730 DA	222	struct device *dev = &pdev->dev;
29f9b6cf	223	struct syscon_platform_data *pdata = dev_get_platdata(dev);
87d68730	224	struct syscon *syscon;
c131045d	225	struct regmap_config syscon_config = syscon_regmap_config;
5ab3a89a	226	struct resource *res;
f10111cc	227	void __iomem *base;
87d68730	228
5ab3a89a	229	syscon = devm_kzalloc(dev, sizeof(*syscon), GFP_KERNEL);
87d68730 DA	230	if (!syscon)
	231	return -ENOMEM;
	232
5ab3a89a AS	233	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	234	if (!res)
	235	return -ENOENT;
87d68730	236
f10111cc AS	237	base = devm_ioremap(dev, res->start, resource_size(res));
f10111cc AS	238	if (!base)
5ab3a89a	239	return -ENOMEM;
87d68730	240
c131045d	241	syscon_config.max_register = res->end - res->start - 3;
29f9b6cf	242	if (pdata)
c131045d PZ	243	syscon_config.name = pdata->label;
c131045d PZ	244	syscon->regmap = devm_regmap_init_mmio(dev, base, &syscon_config);
87d68730 DA	245	if (IS_ERR(syscon->regmap)) {
	246	dev_err(dev, "regmap init failed\n");
	247	return PTR_ERR(syscon->regmap);
	248	}
	249
87d68730 DA	250	platform_set_drvdata(pdev, syscon);
87d68730 DA	251
38d8974e	252	dev_dbg(dev, "regmap %pR registered\n", res);
87d68730 DA	253
	254	return 0;
	255	}
	256
5ab3a89a AS	257	static const struct platform_device_id syscon_ids[] = {
	258	{ "syscon", },
	259	{ }
	260	};
87d68730 DA	261
	262	static struct platform_driver syscon_driver = {
	263	.driver = {
	264	.name = "syscon",
87d68730 DA	265	},
87d68730 DA	266	.probe = syscon_probe,
5ab3a89a	267	.id_table = syscon_ids,
87d68730 DA	268	};
	269
	270	static int __init syscon_init(void)
	271	{
	272	return platform_driver_register(&syscon_driver);
	273	}
	274	postcore_initcall(syscon_init);
	275
	276	static void __exit syscon_exit(void)
	277	{
	278	platform_driver_unregister(&syscon_driver);
	279	}
	280	module_exit(syscon_exit);
	281
	282	MODULE_AUTHOR("Dong Aisheng <[email protected]>");
	283	MODULE_DESCRIPTION("System Control driver");
	284	MODULE_LICENSE("GPL v2");