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.
8 * Author: Dong Aisheng <dong.aisheng@linaro.org>
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 = kasprintf(GFP_KERNEL, "%pOFn@%llx", np,
106 syscon_config.reg_stride = reg_io_width;
107 syscon_config.val_bits = reg_io_width * 8;
108 syscon_config.max_register = resource_size(&res) - reg_io_width;
110 regmap = regmap_init_mmio(NULL, base, &syscon_config);
111 if (IS_ERR(regmap)) {
112 pr_err("regmap init failed\n");
113 ret = PTR_ERR(regmap);
118 clk = of_clk_get(np, 0);
121 /* clock is optional */
125 ret = regmap_mmio_attach_clk(regmap, clk);
131 syscon->regmap = regmap;
134 spin_lock(&syscon_list_slock);
135 list_add_tail(&syscon->list, &syscon_list);
136 spin_unlock(&syscon_list_slock);
147 kfree(syscon_config.name);
153 static struct regmap *device_node_get_regmap(struct device_node *np,
156 struct syscon *entry, *syscon = NULL;
158 spin_lock(&syscon_list_slock);
160 list_for_each_entry(entry, &syscon_list, list)
161 if (entry->np == np) {
166 spin_unlock(&syscon_list_slock);
169 syscon = of_syscon_register(np, check_clk);
172 return ERR_CAST(syscon);
174 return syscon->regmap;
177 struct regmap *device_node_to_regmap(struct device_node *np)
179 return device_node_get_regmap(np, false);
181 EXPORT_SYMBOL_GPL(device_node_to_regmap);
183 struct regmap *syscon_node_to_regmap(struct device_node *np)
185 if (!of_device_is_compatible(np, "syscon"))
186 return ERR_PTR(-EINVAL);
188 return device_node_get_regmap(np, true);
190 EXPORT_SYMBOL_GPL(syscon_node_to_regmap);
192 struct regmap *syscon_regmap_lookup_by_compatible(const char *s)
194 struct device_node *syscon_np;
195 struct regmap *regmap;
197 syscon_np = of_find_compatible_node(NULL, NULL, s);
199 return ERR_PTR(-ENODEV);
201 regmap = syscon_node_to_regmap(syscon_np);
202 of_node_put(syscon_np);
206 EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_compatible);
208 struct regmap *syscon_regmap_lookup_by_phandle(struct device_node *np,
209 const char *property)
211 struct device_node *syscon_np;
212 struct regmap *regmap;
215 syscon_np = of_parse_phandle(np, property, 0);
220 return ERR_PTR(-ENODEV);
222 regmap = syscon_node_to_regmap(syscon_np);
223 of_node_put(syscon_np);
227 EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle);
229 struct regmap *syscon_regmap_lookup_by_phandle_args(struct device_node *np,
230 const char *property,
232 unsigned int *out_args)
234 struct device_node *syscon_np;
235 struct of_phandle_args args;
236 struct regmap *regmap;
240 rc = of_parse_phandle_with_fixed_args(np, property, arg_count,
247 return ERR_PTR(-ENODEV);
249 regmap = syscon_node_to_regmap(syscon_np);
250 for (index = 0; index < arg_count; index++)
251 out_args[index] = args.args[index];
252 of_node_put(syscon_np);
256 EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle_args);
259 * It behaves the same as syscon_regmap_lookup_by_phandle() except where
260 * there is no regmap phandle. In this case, instead of returning -ENODEV,
261 * the function returns NULL.
263 struct regmap *syscon_regmap_lookup_by_phandle_optional(struct device_node *np,
264 const char *property)
266 struct regmap *regmap;
268 regmap = syscon_regmap_lookup_by_phandle(np, property);
269 if (IS_ERR(regmap) && PTR_ERR(regmap) == -ENODEV)
274 EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle_optional);
276 static int syscon_probe(struct platform_device *pdev)
278 struct device *dev = &pdev->dev;
279 struct syscon_platform_data *pdata = dev_get_platdata(dev);
280 struct syscon *syscon;
281 struct regmap_config syscon_config = syscon_regmap_config;
282 struct resource *res;
285 syscon = devm_kzalloc(dev, sizeof(*syscon), GFP_KERNEL);
289 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
293 base = devm_ioremap(dev, res->start, resource_size(res));
297 syscon_config.max_register = resource_size(res) - 4;
299 syscon_config.name = pdata->label;
300 syscon->regmap = devm_regmap_init_mmio(dev, base, &syscon_config);
301 if (IS_ERR(syscon->regmap)) {
302 dev_err(dev, "regmap init failed\n");
303 return PTR_ERR(syscon->regmap);
306 platform_set_drvdata(pdev, syscon);
308 dev_dbg(dev, "regmap %pR registered\n", res);
313 static const struct platform_device_id syscon_ids[] = {
318 static struct platform_driver syscon_driver = {
322 .probe = syscon_probe,
323 .id_table = syscon_ids,
326 static int __init syscon_init(void)
328 return platform_driver_register(&syscon_driver);
330 postcore_initcall(syscon_init);