/* * 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");