// SPDX-License-Identifier: GPL-2.0-or-later/* * System Control Driver * * Copyright (C) 2012 Freescale Semiconductor, Inc. * Copyright (C) 2012 Linaro Ltd. * * Author: Dong Aisheng <dong.aisheng@linaro.org> */ #include <linux/clk.h>#include <linux/err.h>#include <linux/hwspinlock.h>#include <linux/io.h>#include <linux/init.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, bool check_clk){	struct clk *clk;	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; 	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);			fallthrough;		case -EPROBE_DEFER:			goto err_regmap;		}	} 	syscon_config.name = kasprintf(GFP_KERNEL, "%pOFn@%llx", np,				       (u64)res.start);	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;	} 	if (check_clk) {		clk = of_clk_get(np, 0);		if (IS_ERR(clk)) {			ret = PTR_ERR(clk);			/* clock is optional */			if (ret != -ENOENT)				goto err_clk;		} else {			ret = regmap_mmio_attach_clk(regmap, clk);			if (ret)				goto err_attach;		}	} 	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_attach:	if (!IS_ERR(clk))		clk_put(clk);err_clk:	regmap_exit(regmap);err_regmap:	iounmap(base);	kfree(syscon_config.name);err_map:	kfree(syscon);	return ERR_PTR(ret);} static struct regmap *device_node_get_regmap(struct device_node *np,					     bool check_clk){	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, check_clk); 	if (IS_ERR(syscon))		return ERR_CAST(syscon); 	return syscon->regmap;} struct regmap *device_node_to_regmap(struct device_node *np){	return device_node_get_regmap(np, false);}EXPORT_SYMBOL_GPL(device_node_to_regmap); struct regmap *syscon_node_to_regmap(struct device_node *np){	if (!of_device_is_compatible(np, "syscon"))		return ERR_PTR(-EINVAL); 	return device_node_get_regmap(np, true);}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); 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); struct regmap *syscon_regmap_lookup_by_phandle_args(struct device_node *np,					const char *property,					int arg_count,					unsigned int *out_args){	struct device_node *syscon_np;	struct of_phandle_args args;	struct regmap *regmap;	unsigned int index;	int rc; 	rc = of_parse_phandle_with_fixed_args(np, property, arg_count,			0, &args);	if (rc)		return ERR_PTR(rc); 	syscon_np = args.np;	if (!syscon_np)		return ERR_PTR(-ENODEV); 	regmap = syscon_node_to_regmap(syscon_np);	for (index = 0; index < arg_count; index++)		out_args[index] = args.args[index];	of_node_put(syscon_np); 	return regmap;}EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle_args); /* * It behaves the same as syscon_regmap_lookup_by_phandle() except where * there is no regmap phandle. In this case, instead of returning -ENODEV, * the function returns NULL. */struct regmap *syscon_regmap_lookup_by_phandle_optional(struct device_node *np,					const char *property){	struct regmap *regmap; 	regmap = syscon_regmap_lookup_by_phandle(np, property);	if (IS_ERR(regmap) && PTR_ERR(regmap) == -ENODEV)		return NULL; 	return regmap;}EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle_optional); 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 = resource_size(res) - 4;	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);