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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * System Control Driver
4 *
5 * Copyright (C) 2012 Freescale Semiconductor, Inc.
6 * Copyright (C) 2012 Linaro Ltd.
7 *
8 * Author: Dong Aisheng <dong.aisheng@linaro.org>
9 */
10
11#include <linux/clk.h>
12#include <linux/err.h>
13#include <linux/hwspinlock.h>
14#include <linux/io.h>
15#include <linux/init.h>
16#include <linux/list.h>
17#include <linux/of.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/reset.h>
24#include <linux/mfd/syscon.h>
25#include <linux/slab.h>
26
27static struct platform_driver syscon_driver;
28
29static DEFINE_SPINLOCK(syscon_list_slock);
30static LIST_HEAD(syscon_list);
31
32struct syscon {
33 struct device_node *np;
34 struct regmap *regmap;
35 struct reset_control *reset;
36 struct list_head list;
37};
38
39static const struct regmap_config syscon_regmap_config = {
40 .reg_bits = 32,
41 .val_bits = 32,
42 .reg_stride = 4,
43};
44
45static struct syscon *of_syscon_register(struct device_node *np, bool check_res)
46{
47 struct clk *clk;
48 struct syscon *syscon;
49 struct regmap *regmap;
50 void __iomem *base;
51 u32 reg_io_width;
52 int ret;
53 struct regmap_config syscon_config = syscon_regmap_config;
54 struct resource res;
55 struct reset_control *reset;
56
57 syscon = kzalloc(sizeof(*syscon), GFP_KERNEL);
58 if (!syscon)
59 return ERR_PTR(-ENOMEM);
60
61 if (of_address_to_resource(np, 0, &res)) {
62 ret = -ENOMEM;
63 goto err_map;
64 }
65
66 base = of_iomap(np, 0);
67 if (!base) {
68 ret = -ENOMEM;
69 goto err_map;
70 }
71
72 /* Parse the device's DT node for an endianness specification */
73 if (of_property_read_bool(np, "big-endian"))
74 syscon_config.val_format_endian = REGMAP_ENDIAN_BIG;
75 else if (of_property_read_bool(np, "little-endian"))
76 syscon_config.val_format_endian = REGMAP_ENDIAN_LITTLE;
77 else if (of_property_read_bool(np, "native-endian"))
78 syscon_config.val_format_endian = REGMAP_ENDIAN_NATIVE;
79
80 /*
81 * search for reg-io-width property in DT. If it is not provided,
82 * default to 4 bytes. regmap_init_mmio will return an error if values
83 * are invalid so there is no need to check them here.
84 */
85 ret = of_property_read_u32(np, "reg-io-width", ®_io_width);
86 if (ret)
87 reg_io_width = 4;
88
89 ret = of_hwspin_lock_get_id(np, 0);
90 if (ret > 0 || (IS_ENABLED(CONFIG_HWSPINLOCK) && ret == 0)) {
91 syscon_config.use_hwlock = true;
92 syscon_config.hwlock_id = ret;
93 syscon_config.hwlock_mode = HWLOCK_IRQSTATE;
94 } else if (ret < 0) {
95 switch (ret) {
96 case -ENOENT:
97 /* Ignore missing hwlock, it's optional. */
98 break;
99 default:
100 pr_err("Failed to retrieve valid hwlock: %d\n", ret);
101 fallthrough;
102 case -EPROBE_DEFER:
103 goto err_regmap;
104 }
105 }
106
107 syscon_config.name = kasprintf(GFP_KERNEL, "%pOFn@%pa", np, &res.start);
108 if (!syscon_config.name) {
109 ret = -ENOMEM;
110 goto err_regmap;
111 }
112 syscon_config.reg_stride = reg_io_width;
113 syscon_config.val_bits = reg_io_width * 8;
114 syscon_config.max_register = resource_size(&res) - reg_io_width;
115
116 regmap = regmap_init_mmio(NULL, base, &syscon_config);
117 kfree(syscon_config.name);
118 if (IS_ERR(regmap)) {
119 pr_err("regmap init failed\n");
120 ret = PTR_ERR(regmap);
121 goto err_regmap;
122 }
123
124 if (check_res) {
125 clk = of_clk_get(np, 0);
126 if (IS_ERR(clk)) {
127 ret = PTR_ERR(clk);
128 /* clock is optional */
129 if (ret != -ENOENT)
130 goto err_clk;
131 } else {
132 ret = regmap_mmio_attach_clk(regmap, clk);
133 if (ret)
134 goto err_attach_clk;
135 }
136
137 reset = of_reset_control_get_optional_exclusive(np, NULL);
138 if (IS_ERR(reset)) {
139 ret = PTR_ERR(reset);
140 goto err_attach_clk;
141 }
142
143 ret = reset_control_deassert(reset);
144 if (ret)
145 goto err_reset;
146 }
147
148 syscon->regmap = regmap;
149 syscon->np = np;
150
151 spin_lock(&syscon_list_slock);
152 list_add_tail(&syscon->list, &syscon_list);
153 spin_unlock(&syscon_list_slock);
154
155 return syscon;
156
157err_reset:
158 reset_control_put(reset);
159err_attach_clk:
160 if (!IS_ERR(clk))
161 clk_put(clk);
162err_clk:
163 regmap_exit(regmap);
164err_regmap:
165 iounmap(base);
166err_map:
167 kfree(syscon);
168 return ERR_PTR(ret);
169}
170
171static struct regmap *device_node_get_regmap(struct device_node *np,
172 bool check_res)
173{
174 struct syscon *entry, *syscon = NULL;
175
176 spin_lock(&syscon_list_slock);
177
178 list_for_each_entry(entry, &syscon_list, list)
179 if (entry->np == np) {
180 syscon = entry;
181 break;
182 }
183
184 spin_unlock(&syscon_list_slock);
185
186 if (!syscon)
187 syscon = of_syscon_register(np, check_res);
188
189 if (IS_ERR(syscon))
190 return ERR_CAST(syscon);
191
192 return syscon->regmap;
193}
194
195struct regmap *device_node_to_regmap(struct device_node *np)
196{
197 return device_node_get_regmap(np, false);
198}
199EXPORT_SYMBOL_GPL(device_node_to_regmap);
200
201struct regmap *syscon_node_to_regmap(struct device_node *np)
202{
203 if (!of_device_is_compatible(np, "syscon"))
204 return ERR_PTR(-EINVAL);
205
206 return device_node_get_regmap(np, true);
207}
208EXPORT_SYMBOL_GPL(syscon_node_to_regmap);
209
210struct regmap *syscon_regmap_lookup_by_compatible(const char *s)
211{
212 struct device_node *syscon_np;
213 struct regmap *regmap;
214
215 syscon_np = of_find_compatible_node(NULL, NULL, s);
216 if (!syscon_np)
217 return ERR_PTR(-ENODEV);
218
219 regmap = syscon_node_to_regmap(syscon_np);
220 of_node_put(syscon_np);
221
222 return regmap;
223}
224EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_compatible);
225
226struct regmap *syscon_regmap_lookup_by_phandle(struct device_node *np,
227 const char *property)
228{
229 struct device_node *syscon_np;
230 struct regmap *regmap;
231
232 if (property)
233 syscon_np = of_parse_phandle(np, property, 0);
234 else
235 syscon_np = np;
236
237 if (!syscon_np)
238 return ERR_PTR(-ENODEV);
239
240 regmap = syscon_node_to_regmap(syscon_np);
241 of_node_put(syscon_np);
242
243 return regmap;
244}
245EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle);
246
247struct regmap *syscon_regmap_lookup_by_phandle_args(struct device_node *np,
248 const char *property,
249 int arg_count,
250 unsigned int *out_args)
251{
252 struct device_node *syscon_np;
253 struct of_phandle_args args;
254 struct regmap *regmap;
255 unsigned int index;
256 int rc;
257
258 rc = of_parse_phandle_with_fixed_args(np, property, arg_count,
259 0, &args);
260 if (rc)
261 return ERR_PTR(rc);
262
263 syscon_np = args.np;
264 if (!syscon_np)
265 return ERR_PTR(-ENODEV);
266
267 regmap = syscon_node_to_regmap(syscon_np);
268 for (index = 0; index < arg_count; index++)
269 out_args[index] = args.args[index];
270 of_node_put(syscon_np);
271
272 return regmap;
273}
274EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle_args);
275
276/*
277 * It behaves the same as syscon_regmap_lookup_by_phandle() except where
278 * there is no regmap phandle. In this case, instead of returning -ENODEV,
279 * the function returns NULL.
280 */
281struct regmap *syscon_regmap_lookup_by_phandle_optional(struct device_node *np,
282 const char *property)
283{
284 struct regmap *regmap;
285
286 regmap = syscon_regmap_lookup_by_phandle(np, property);
287 if (IS_ERR(regmap) && PTR_ERR(regmap) == -ENODEV)
288 return NULL;
289
290 return regmap;
291}
292EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle_optional);
293
294static int syscon_probe(struct platform_device *pdev)
295{
296 struct device *dev = &pdev->dev;
297 struct syscon_platform_data *pdata = dev_get_platdata(dev);
298 struct syscon *syscon;
299 struct regmap_config syscon_config = syscon_regmap_config;
300 struct resource *res;
301 void __iomem *base;
302
303 syscon = devm_kzalloc(dev, sizeof(*syscon), GFP_KERNEL);
304 if (!syscon)
305 return -ENOMEM;
306
307 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
308 if (!res)
309 return -ENOENT;
310
311 base = devm_ioremap(dev, res->start, resource_size(res));
312 if (!base)
313 return -ENOMEM;
314
315 syscon_config.max_register = resource_size(res) - 4;
316 if (pdata)
317 syscon_config.name = pdata->label;
318 syscon->regmap = devm_regmap_init_mmio(dev, base, &syscon_config);
319 if (IS_ERR(syscon->regmap)) {
320 dev_err(dev, "regmap init failed\n");
321 return PTR_ERR(syscon->regmap);
322 }
323
324 platform_set_drvdata(pdev, syscon);
325
326 dev_dbg(dev, "regmap %pR registered\n", res);
327
328 return 0;
329}
330
331static const struct platform_device_id syscon_ids[] = {
332 { "syscon", },
333 { }
334};
335
336static struct platform_driver syscon_driver = {
337 .driver = {
338 .name = "syscon",
339 },
340 .probe = syscon_probe,
341 .id_table = syscon_ids,
342};
343
344static int __init syscon_init(void)
345{
346 return platform_driver_register(&syscon_driver);
347}
348postcore_initcall(syscon_init);
1/*
2 * System Control Driver
3 *
4 * Copyright (C) 2012 Freescale Semiconductor, Inc.
5 * Copyright (C) 2012 Linaro Ltd.
6 *
7 * Author: Dong Aisheng <dong.aisheng@linaro.org>
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>
16#include <linux/io.h>
17#include <linux/module.h>
18#include <linux/of.h>
19#include <linux/of_address.h>
20#include <linux/of_platform.h>
21#include <linux/platform_device.h>
22#include <linux/regmap.h>
23#include <linux/mfd/syscon.h>
24
25static struct platform_driver syscon_driver;
26
27struct syscon {
28 struct regmap *regmap;
29};
30
31static int syscon_match_node(struct device *dev, void *data)
32{
33 struct device_node *dn = data;
34
35 return (dev->of_node == dn) ? 1 : 0;
36}
37
38struct regmap *syscon_node_to_regmap(struct device_node *np)
39{
40 struct syscon *syscon;
41 struct device *dev;
42
43 dev = driver_find_device(&syscon_driver.driver, NULL, np,
44 syscon_match_node);
45 if (!dev)
46 return ERR_PTR(-EPROBE_DEFER);
47
48 syscon = dev_get_drvdata(dev);
49
50 return syscon->regmap;
51}
52EXPORT_SYMBOL_GPL(syscon_node_to_regmap);
53
54struct regmap *syscon_regmap_lookup_by_compatible(const char *s)
55{
56 struct device_node *syscon_np;
57 struct regmap *regmap;
58
59 syscon_np = of_find_compatible_node(NULL, NULL, s);
60 if (!syscon_np)
61 return ERR_PTR(-ENODEV);
62
63 regmap = syscon_node_to_regmap(syscon_np);
64 of_node_put(syscon_np);
65
66 return regmap;
67}
68EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_compatible);
69
70static int syscon_match_pdevname(struct device *dev, void *data)
71{
72 return !strcmp(dev_name(dev), (const char *)data);
73}
74
75struct regmap *syscon_regmap_lookup_by_pdevname(const char *s)
76{
77 struct device *dev;
78 struct syscon *syscon;
79
80 dev = driver_find_device(&syscon_driver.driver, NULL, (void *)s,
81 syscon_match_pdevname);
82 if (!dev)
83 return ERR_PTR(-EPROBE_DEFER);
84
85 syscon = dev_get_drvdata(dev);
86
87 return syscon->regmap;
88}
89EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_pdevname);
90
91struct regmap *syscon_regmap_lookup_by_phandle(struct device_node *np,
92 const char *property)
93{
94 struct device_node *syscon_np;
95 struct regmap *regmap;
96
97 syscon_np = of_parse_phandle(np, property, 0);
98 if (!syscon_np)
99 return ERR_PTR(-ENODEV);
100
101 regmap = syscon_node_to_regmap(syscon_np);
102 of_node_put(syscon_np);
103
104 return regmap;
105}
106EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle);
107
108static const struct of_device_id of_syscon_match[] = {
109 { .compatible = "syscon", },
110 { },
111};
112
113static struct regmap_config syscon_regmap_config = {
114 .reg_bits = 32,
115 .val_bits = 32,
116 .reg_stride = 4,
117};
118
119static int syscon_probe(struct platform_device *pdev)
120{
121 struct device *dev = &pdev->dev;
122 struct syscon *syscon;
123 struct resource *res;
124 void __iomem *base;
125
126 syscon = devm_kzalloc(dev, sizeof(*syscon), GFP_KERNEL);
127 if (!syscon)
128 return -ENOMEM;
129
130 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
131 if (!res)
132 return -ENOENT;
133
134 base = devm_ioremap(dev, res->start, resource_size(res));
135 if (!base)
136 return -ENOMEM;
137
138 syscon_regmap_config.max_register = res->end - res->start - 3;
139 syscon->regmap = devm_regmap_init_mmio(dev, base,
140 &syscon_regmap_config);
141 if (IS_ERR(syscon->regmap)) {
142 dev_err(dev, "regmap init failed\n");
143 return PTR_ERR(syscon->regmap);
144 }
145
146 platform_set_drvdata(pdev, syscon);
147
148 dev_dbg(dev, "regmap %pR registered\n", res);
149
150 return 0;
151}
152
153static const struct platform_device_id syscon_ids[] = {
154 { "syscon", },
155 { }
156};
157
158static struct platform_driver syscon_driver = {
159 .driver = {
160 .name = "syscon",
161 .owner = THIS_MODULE,
162 .of_match_table = of_syscon_match,
163 },
164 .probe = syscon_probe,
165 .id_table = syscon_ids,
166};
167
168static int __init syscon_init(void)
169{
170 return platform_driver_register(&syscon_driver);
171}
172postcore_initcall(syscon_init);
173
174static void __exit syscon_exit(void)
175{
176 platform_driver_unregister(&syscon_driver);
177}
178module_exit(syscon_exit);
179
180MODULE_AUTHOR("Dong Aisheng <dong.aisheng@linaro.org>");
181MODULE_DESCRIPTION("System Control driver");
182MODULE_LICENSE("GPL v2");