1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * System Control Driver
5 * Copyright (C) 2012 Freescale Semiconductor, Inc.
6 * Copyright (C) 2012 Linaro Ltd.
11 #include <linux/clk.h>
12 #include <linux/err.h>
13 #include <linux/hwspinlock.h>
15 #include <linux/init.h>
16 #include <linux/list.h>
18 #include <linux/of_address.h>
19 #include <linux/of_platform.h>
20 #include <linux/platform_data/syscon.h>
21 #include <linux/platform_device.h>
22 #include <linux/regmap.h>
23 #include <linux/mfd/syscon.h>
24 #include <linux/slab.h>
26 static struct platform_driver syscon_driver;
28 static DEFINE_SPINLOCK(syscon_list_slock);
29 static LIST_HEAD(syscon_list);
32 struct device_node *np;
33 struct regmap *regmap;
34 struct list_head list;
37 static const struct regmap_config syscon_regmap_config = {
43 static struct syscon *of_syscon_register(struct device_node *np, bool check_clk)
46 struct syscon *syscon;
47 struct regmap *regmap;
51 struct regmap_config syscon_config = syscon_regmap_config;
54 syscon = kzalloc(sizeof(*syscon), GFP_KERNEL);
56 return ERR_PTR(-ENOMEM);
58 if (of_address_to_resource(np, 0, &res)) {
63 base = ioremap(res.start, resource_size(&res));
69 /* Parse the device's DT node for an endianness specification */
70 if (of_property_read_bool(np, "big-endian"))
71 syscon_config.val_format_endian = REGMAP_ENDIAN_BIG;
72 else if (of_property_read_bool(np, "little-endian"))
73 syscon_config.val_format_endian = REGMAP_ENDIAN_LITTLE;
74 else if (of_property_read_bool(np, "native-endian"))
75 syscon_config.val_format_endian = REGMAP_ENDIAN_NATIVE;
78 * search for reg-io-width property in DT. If it is not provided,
79 * default to 4 bytes. regmap_init_mmio will return an error if values
80 * are invalid so there is no need to check them here.
82 ret = of_property_read_u32(np, "reg-io-width", ®_io_width);
86 ret = of_hwspin_lock_get_id(np, 0);
87 if (ret > 0 || (IS_ENABLED(CONFIG_HWSPINLOCK) && ret == 0)) {
88 syscon_config.use_hwlock = true;
89 syscon_config.hwlock_id = ret;
90 syscon_config.hwlock_mode = HWLOCK_IRQSTATE;
94 /* Ignore missing hwlock, it's optional. */
97 pr_err("Failed to retrieve valid hwlock: %d\n", ret);
104 syscon_config.name = of_node_full_name(np);
105 syscon_config.reg_stride = reg_io_width;
106 syscon_config.val_bits = reg_io_width * 8;
107 syscon_config.max_register = resource_size(&res) - reg_io_width;
109 regmap = regmap_init_mmio(NULL, base, &syscon_config);
110 if (IS_ERR(regmap)) {
111 pr_err("regmap init failed\n");
112 ret = PTR_ERR(regmap);
117 clk = of_clk_get(np, 0);
120 /* clock is optional */
124 ret = regmap_mmio_attach_clk(regmap, clk);
130 syscon->regmap = regmap;
133 spin_lock(&syscon_list_slock);
134 list_add_tail(&syscon->list, &syscon_list);
135 spin_unlock(&syscon_list_slock);
151 static struct regmap *device_node_get_regmap(struct device_node *np,
154 struct syscon *entry, *syscon = NULL;
156 spin_lock(&syscon_list_slock);
158 list_for_each_entry(entry, &syscon_list, list)
159 if (entry->np == np) {
164 spin_unlock(&syscon_list_slock);
167 syscon = of_syscon_register(np, check_clk);
170 return ERR_CAST(syscon);
172 return syscon->regmap;
175 struct regmap *device_node_to_regmap(struct device_node *np)
177 return device_node_get_regmap(np, false);
179 EXPORT_SYMBOL_GPL(device_node_to_regmap);
181 struct regmap *syscon_node_to_regmap(struct device_node *np)
183 if (!of_device_is_compatible(np, "syscon"))
184 return ERR_PTR(-EINVAL);
186 return device_node_get_regmap(np, true);
188 EXPORT_SYMBOL_GPL(syscon_node_to_regmap);
190 struct regmap *syscon_regmap_lookup_by_compatible(const char *s)
192 struct device_node *syscon_np;
193 struct regmap *regmap;
195 syscon_np = of_find_compatible_node(NULL, NULL, s);
197 return ERR_PTR(-ENODEV);
199 regmap = syscon_node_to_regmap(syscon_np);
200 of_node_put(syscon_np);
204 EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_compatible);
206 struct regmap *syscon_regmap_lookup_by_phandle(struct device_node *np,
207 const char *property)
209 struct device_node *syscon_np;
210 struct regmap *regmap;
213 syscon_np = of_parse_phandle(np, property, 0);
218 return ERR_PTR(-ENODEV);
220 regmap = syscon_node_to_regmap(syscon_np);
221 of_node_put(syscon_np);
225 EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle);
227 struct regmap *syscon_regmap_lookup_by_phandle_args(struct device_node *np,
228 const char *property,
230 unsigned int *out_args)
232 struct device_node *syscon_np;
233 struct of_phandle_args args;
234 struct regmap *regmap;
238 rc = of_parse_phandle_with_fixed_args(np, property, arg_count,
245 return ERR_PTR(-ENODEV);
247 regmap = syscon_node_to_regmap(syscon_np);
248 for (index = 0; index < arg_count; index++)
249 out_args[index] = args.args[index];
250 of_node_put(syscon_np);
254 EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle_args);
256 static int syscon_probe(struct platform_device *pdev)
258 struct device *dev = &pdev->dev;
259 struct syscon_platform_data *pdata = dev_get_platdata(dev);
260 struct syscon *syscon;
261 struct regmap_config syscon_config = syscon_regmap_config;
262 struct resource *res;
265 syscon = devm_kzalloc(dev, sizeof(*syscon), GFP_KERNEL);
269 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
273 base = devm_ioremap(dev, res->start, resource_size(res));
277 syscon_config.max_register = resource_size(res) - 4;
279 syscon_config.name = pdata->label;
280 syscon->regmap = devm_regmap_init_mmio(dev, base, &syscon_config);
281 if (IS_ERR(syscon->regmap)) {
282 dev_err(dev, "regmap init failed\n");
283 return PTR_ERR(syscon->regmap);
286 platform_set_drvdata(pdev, syscon);
288 dev_dbg(dev, "regmap %pR registered\n", res);
293 static const struct platform_device_id syscon_ids[] = {
298 static struct platform_driver syscon_driver = {
302 .probe = syscon_probe,
303 .id_table = syscon_ids,
306 static int __init syscon_init(void)
308 return platform_driver_register(&syscon_driver);
310 postcore_initcall(syscon_init);