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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/cleanup.h>
12#include <linux/clk.h>
13#include <linux/err.h>
14#include <linux/hwspinlock.h>
15#include <linux/io.h>
16#include <linux/init.h>
17#include <linux/list.h>
18#include <linux/mutex.h>
19#include <linux/of.h>
20#include <linux/of_address.h>
21#include <linux/of_platform.h>
22#include <linux/platform_data/syscon.h>
23#include <linux/platform_device.h>
24#include <linux/regmap.h>
25#include <linux/reset.h>
26#include <linux/mfd/syscon.h>
27#include <linux/slab.h>
28
29static struct platform_driver syscon_driver;
30
31static DEFINE_MUTEX(syscon_list_lock);
32static LIST_HEAD(syscon_list);
33
34struct syscon {
35 struct device_node *np;
36 struct regmap *regmap;
37 struct reset_control *reset;
38 struct list_head list;
39};
40
41static const struct regmap_config syscon_regmap_config = {
42 .reg_bits = 32,
43 .val_bits = 32,
44 .reg_stride = 4,
45};
46
47static struct syscon *of_syscon_register(struct device_node *np, bool check_res)
48{
49 struct clk *clk;
50 struct regmap *regmap;
51 void __iomem *base;
52 u32 reg_io_width;
53 int ret;
54 struct regmap_config syscon_config = syscon_regmap_config;
55 struct resource res;
56 struct reset_control *reset;
57
58 WARN_ON(!mutex_is_locked(&syscon_list_lock));
59
60 struct syscon *syscon __free(kfree) = kzalloc(sizeof(*syscon), GFP_KERNEL);
61 if (!syscon)
62 return ERR_PTR(-ENOMEM);
63
64 if (of_address_to_resource(np, 0, &res))
65 return ERR_PTR(-ENOMEM);
66
67 base = of_iomap(np, 0);
68 if (!base)
69 return ERR_PTR(-ENOMEM);
70
71 /* Parse the device's DT node for an endianness specification */
72 if (of_property_read_bool(np, "big-endian"))
73 syscon_config.val_format_endian = REGMAP_ENDIAN_BIG;
74 else if (of_property_read_bool(np, "little-endian"))
75 syscon_config.val_format_endian = REGMAP_ENDIAN_LITTLE;
76 else if (of_property_read_bool(np, "native-endian"))
77 syscon_config.val_format_endian = REGMAP_ENDIAN_NATIVE;
78
79 /*
80 * search for reg-io-width property in DT. If it is not provided,
81 * default to 4 bytes. regmap_init_mmio will return an error if values
82 * are invalid so there is no need to check them here.
83 */
84 ret = of_property_read_u32(np, "reg-io-width", ®_io_width);
85 if (ret)
86 reg_io_width = 4;
87
88 ret = of_hwspin_lock_get_id(np, 0);
89 if (ret > 0 || (IS_ENABLED(CONFIG_HWSPINLOCK) && ret == 0)) {
90 syscon_config.use_hwlock = true;
91 syscon_config.hwlock_id = ret;
92 syscon_config.hwlock_mode = HWLOCK_IRQSTATE;
93 } else if (ret < 0) {
94 switch (ret) {
95 case -ENOENT:
96 /* Ignore missing hwlock, it's optional. */
97 break;
98 default:
99 pr_err("Failed to retrieve valid hwlock: %d\n", ret);
100 fallthrough;
101 case -EPROBE_DEFER:
102 goto err_regmap;
103 }
104 }
105
106 syscon_config.name = kasprintf(GFP_KERNEL, "%pOFn@%pa", np, &res.start);
107 if (!syscon_config.name) {
108 ret = -ENOMEM;
109 goto err_regmap;
110 }
111 syscon_config.reg_stride = reg_io_width;
112 syscon_config.val_bits = reg_io_width * 8;
113 syscon_config.max_register = resource_size(&res) - reg_io_width;
114 if (!syscon_config.max_register)
115 syscon_config.max_register_is_0 = true;
116
117 regmap = regmap_init_mmio(NULL, base, &syscon_config);
118 kfree(syscon_config.name);
119 if (IS_ERR(regmap)) {
120 pr_err("regmap init failed\n");
121 ret = PTR_ERR(regmap);
122 goto err_regmap;
123 }
124
125 if (check_res) {
126 clk = of_clk_get(np, 0);
127 if (IS_ERR(clk)) {
128 ret = PTR_ERR(clk);
129 /* clock is optional */
130 if (ret != -ENOENT)
131 goto err_clk;
132 } else {
133 ret = regmap_mmio_attach_clk(regmap, clk);
134 if (ret)
135 goto err_attach_clk;
136 }
137
138 reset = of_reset_control_get_optional_exclusive(np, NULL);
139 if (IS_ERR(reset)) {
140 ret = PTR_ERR(reset);
141 goto err_attach_clk;
142 }
143
144 ret = reset_control_deassert(reset);
145 if (ret)
146 goto err_reset;
147 }
148
149 syscon->regmap = regmap;
150 syscon->np = np;
151
152 list_add_tail(&syscon->list, &syscon_list);
153
154 return_ptr(syscon);
155
156err_reset:
157 reset_control_put(reset);
158err_attach_clk:
159 if (!IS_ERR(clk))
160 clk_put(clk);
161err_clk:
162 regmap_exit(regmap);
163err_regmap:
164 iounmap(base);
165 return ERR_PTR(ret);
166}
167
168static struct regmap *device_node_get_regmap(struct device_node *np,
169 bool check_res)
170{
171 struct syscon *entry, *syscon = NULL;
172
173 mutex_lock(&syscon_list_lock);
174
175 list_for_each_entry(entry, &syscon_list, list)
176 if (entry->np == np) {
177 syscon = entry;
178 break;
179 }
180
181 if (!syscon)
182 syscon = of_syscon_register(np, check_res);
183
184 mutex_unlock(&syscon_list_lock);
185
186 if (IS_ERR(syscon))
187 return ERR_CAST(syscon);
188
189 return syscon->regmap;
190}
191
192/**
193 * of_syscon_register_regmap() - Register regmap for specified device node
194 * @np: Device tree node
195 * @regmap: Pointer to regmap object
196 *
197 * Register an externally created regmap object with syscon for the specified
198 * device tree node. This regmap will then be returned to client drivers using
199 * the syscon_regmap_lookup_by_phandle() API.
200 *
201 * Return: 0 on success, negative error code on failure.
202 */
203int of_syscon_register_regmap(struct device_node *np, struct regmap *regmap)
204{
205 struct syscon *entry, *syscon = NULL;
206 int ret;
207
208 if (!np || !regmap)
209 return -EINVAL;
210
211 syscon = kzalloc(sizeof(*syscon), GFP_KERNEL);
212 if (!syscon)
213 return -ENOMEM;
214
215 /* check if syscon entry already exists */
216 mutex_lock(&syscon_list_lock);
217
218 list_for_each_entry(entry, &syscon_list, list)
219 if (entry->np == np) {
220 ret = -EEXIST;
221 goto err_unlock;
222 }
223
224 syscon->regmap = regmap;
225 syscon->np = np;
226
227 /* register the regmap in syscon list */
228 list_add_tail(&syscon->list, &syscon_list);
229 mutex_unlock(&syscon_list_lock);
230
231 return 0;
232
233err_unlock:
234 mutex_unlock(&syscon_list_lock);
235 kfree(syscon);
236 return ret;
237}
238EXPORT_SYMBOL_GPL(of_syscon_register_regmap);
239
240struct regmap *device_node_to_regmap(struct device_node *np)
241{
242 return device_node_get_regmap(np, false);
243}
244EXPORT_SYMBOL_GPL(device_node_to_regmap);
245
246struct regmap *syscon_node_to_regmap(struct device_node *np)
247{
248 if (!of_device_is_compatible(np, "syscon"))
249 return ERR_PTR(-EINVAL);
250
251 return device_node_get_regmap(np, true);
252}
253EXPORT_SYMBOL_GPL(syscon_node_to_regmap);
254
255struct regmap *syscon_regmap_lookup_by_compatible(const char *s)
256{
257 struct device_node *syscon_np;
258 struct regmap *regmap;
259
260 syscon_np = of_find_compatible_node(NULL, NULL, s);
261 if (!syscon_np)
262 return ERR_PTR(-ENODEV);
263
264 regmap = syscon_node_to_regmap(syscon_np);
265 of_node_put(syscon_np);
266
267 return regmap;
268}
269EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_compatible);
270
271struct regmap *syscon_regmap_lookup_by_phandle(struct device_node *np,
272 const char *property)
273{
274 struct device_node *syscon_np;
275 struct regmap *regmap;
276
277 if (property)
278 syscon_np = of_parse_phandle(np, property, 0);
279 else
280 syscon_np = np;
281
282 if (!syscon_np)
283 return ERR_PTR(-ENODEV);
284
285 regmap = syscon_node_to_regmap(syscon_np);
286
287 if (property)
288 of_node_put(syscon_np);
289
290 return regmap;
291}
292EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle);
293
294struct regmap *syscon_regmap_lookup_by_phandle_args(struct device_node *np,
295 const char *property,
296 int arg_count,
297 unsigned int *out_args)
298{
299 struct device_node *syscon_np;
300 struct of_phandle_args args;
301 struct regmap *regmap;
302 unsigned int index;
303 int rc;
304
305 rc = of_parse_phandle_with_fixed_args(np, property, arg_count,
306 0, &args);
307 if (rc)
308 return ERR_PTR(rc);
309
310 syscon_np = args.np;
311 if (!syscon_np)
312 return ERR_PTR(-ENODEV);
313
314 regmap = syscon_node_to_regmap(syscon_np);
315 for (index = 0; index < arg_count; index++)
316 out_args[index] = args.args[index];
317 of_node_put(syscon_np);
318
319 return regmap;
320}
321EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle_args);
322
323/*
324 * It behaves the same as syscon_regmap_lookup_by_phandle() except where
325 * there is no regmap phandle. In this case, instead of returning -ENODEV,
326 * the function returns NULL.
327 */
328struct regmap *syscon_regmap_lookup_by_phandle_optional(struct device_node *np,
329 const char *property)
330{
331 struct regmap *regmap;
332
333 regmap = syscon_regmap_lookup_by_phandle(np, property);
334 if (IS_ERR(regmap) && PTR_ERR(regmap) == -ENODEV)
335 return NULL;
336
337 return regmap;
338}
339EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle_optional);
340
341static int syscon_probe(struct platform_device *pdev)
342{
343 struct device *dev = &pdev->dev;
344 struct syscon_platform_data *pdata = dev_get_platdata(dev);
345 struct syscon *syscon;
346 struct regmap_config syscon_config = syscon_regmap_config;
347 struct resource *res;
348 void __iomem *base;
349
350 syscon = devm_kzalloc(dev, sizeof(*syscon), GFP_KERNEL);
351 if (!syscon)
352 return -ENOMEM;
353
354 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
355 if (!res)
356 return -ENOENT;
357
358 base = devm_ioremap(dev, res->start, resource_size(res));
359 if (!base)
360 return -ENOMEM;
361
362 syscon_config.max_register = resource_size(res) - 4;
363 if (!syscon_config.max_register)
364 syscon_config.max_register_is_0 = true;
365
366 if (pdata)
367 syscon_config.name = pdata->label;
368 syscon->regmap = devm_regmap_init_mmio(dev, base, &syscon_config);
369 if (IS_ERR(syscon->regmap)) {
370 dev_err(dev, "regmap init failed\n");
371 return PTR_ERR(syscon->regmap);
372 }
373
374 platform_set_drvdata(pdev, syscon);
375
376 dev_dbg(dev, "regmap %pR registered\n", res);
377
378 return 0;
379}
380
381static const struct platform_device_id syscon_ids[] = {
382 { "syscon", },
383 { }
384};
385
386static struct platform_driver syscon_driver = {
387 .driver = {
388 .name = "syscon",
389 },
390 .probe = syscon_probe,
391 .id_table = syscon_ids,
392};
393
394static int __init syscon_init(void)
395{
396 return platform_driver_register(&syscon_driver);
397}
398postcore_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/list.h>
19#include <linux/of.h>
20#include <linux/of_address.h>
21#include <linux/of_platform.h>
22#include <linux/platform_data/syscon.h>
23#include <linux/platform_device.h>
24#include <linux/regmap.h>
25#include <linux/mfd/syscon.h>
26#include <linux/slab.h>
27
28static struct platform_driver syscon_driver;
29
30static DEFINE_SPINLOCK(syscon_list_slock);
31static LIST_HEAD(syscon_list);
32
33struct syscon {
34 struct device_node *np;
35 struct regmap *regmap;
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)
46{
47 struct syscon *syscon;
48 struct regmap *regmap;
49 void __iomem *base;
50 u32 reg_io_width;
51 int ret;
52 struct regmap_config syscon_config = syscon_regmap_config;
53 struct resource res;
54
55 if (!of_device_is_compatible(np, "syscon"))
56 return ERR_PTR(-EINVAL);
57
58 syscon = kzalloc(sizeof(*syscon), GFP_KERNEL);
59 if (!syscon)
60 return ERR_PTR(-ENOMEM);
61
62 if (of_address_to_resource(np, 0, &res)) {
63 ret = -ENOMEM;
64 goto err_map;
65 }
66
67 base = ioremap(res.start, resource_size(&res));
68 if (!base) {
69 ret = -ENOMEM;
70 goto err_map;
71 }
72
73 /* Parse the device's DT node for an endianness specification */
74 if (of_property_read_bool(np, "big-endian"))
75 syscon_config.val_format_endian = REGMAP_ENDIAN_BIG;
76 else if (of_property_read_bool(np, "little-endian"))
77 syscon_config.val_format_endian = REGMAP_ENDIAN_LITTLE;
78 else if (of_property_read_bool(np, "native-endian"))
79 syscon_config.val_format_endian = REGMAP_ENDIAN_NATIVE;
80
81 /*
82 * search for reg-io-width property in DT. If it is not provided,
83 * default to 4 bytes. regmap_init_mmio will return an error if values
84 * are invalid so there is no need to check them here.
85 */
86 ret = of_property_read_u32(np, "reg-io-width", ®_io_width);
87 if (ret)
88 reg_io_width = 4;
89
90 syscon_config.reg_stride = reg_io_width;
91 syscon_config.val_bits = reg_io_width * 8;
92 syscon_config.max_register = resource_size(&res) - reg_io_width;
93
94 regmap = regmap_init_mmio(NULL, base, &syscon_config);
95 if (IS_ERR(regmap)) {
96 pr_err("regmap init failed\n");
97 ret = PTR_ERR(regmap);
98 goto err_regmap;
99 }
100
101 syscon->regmap = regmap;
102 syscon->np = np;
103
104 spin_lock(&syscon_list_slock);
105 list_add_tail(&syscon->list, &syscon_list);
106 spin_unlock(&syscon_list_slock);
107
108 return syscon;
109
110err_regmap:
111 iounmap(base);
112err_map:
113 kfree(syscon);
114 return ERR_PTR(ret);
115}
116
117struct regmap *syscon_node_to_regmap(struct device_node *np)
118{
119 struct syscon *entry, *syscon = NULL;
120
121 spin_lock(&syscon_list_slock);
122
123 list_for_each_entry(entry, &syscon_list, list)
124 if (entry->np == np) {
125 syscon = entry;
126 break;
127 }
128
129 spin_unlock(&syscon_list_slock);
130
131 if (!syscon)
132 syscon = of_syscon_register(np);
133
134 if (IS_ERR(syscon))
135 return ERR_CAST(syscon);
136
137 return syscon->regmap;
138}
139EXPORT_SYMBOL_GPL(syscon_node_to_regmap);
140
141struct regmap *syscon_regmap_lookup_by_compatible(const char *s)
142{
143 struct device_node *syscon_np;
144 struct regmap *regmap;
145
146 syscon_np = of_find_compatible_node(NULL, NULL, s);
147 if (!syscon_np)
148 return ERR_PTR(-ENODEV);
149
150 regmap = syscon_node_to_regmap(syscon_np);
151 of_node_put(syscon_np);
152
153 return regmap;
154}
155EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_compatible);
156
157static int syscon_match_pdevname(struct device *dev, void *data)
158{
159 return !strcmp(dev_name(dev), (const char *)data);
160}
161
162struct regmap *syscon_regmap_lookup_by_pdevname(const char *s)
163{
164 struct device *dev;
165 struct syscon *syscon;
166
167 dev = driver_find_device(&syscon_driver.driver, NULL, (void *)s,
168 syscon_match_pdevname);
169 if (!dev)
170 return ERR_PTR(-EPROBE_DEFER);
171
172 syscon = dev_get_drvdata(dev);
173
174 return syscon->regmap;
175}
176EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_pdevname);
177
178struct regmap *syscon_regmap_lookup_by_phandle(struct device_node *np,
179 const char *property)
180{
181 struct device_node *syscon_np;
182 struct regmap *regmap;
183
184 if (property)
185 syscon_np = of_parse_phandle(np, property, 0);
186 else
187 syscon_np = np;
188
189 if (!syscon_np)
190 return ERR_PTR(-ENODEV);
191
192 regmap = syscon_node_to_regmap(syscon_np);
193 of_node_put(syscon_np);
194
195 return regmap;
196}
197EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle);
198
199static int syscon_probe(struct platform_device *pdev)
200{
201 struct device *dev = &pdev->dev;
202 struct syscon_platform_data *pdata = dev_get_platdata(dev);
203 struct syscon *syscon;
204 struct regmap_config syscon_config = syscon_regmap_config;
205 struct resource *res;
206 void __iomem *base;
207
208 syscon = devm_kzalloc(dev, sizeof(*syscon), GFP_KERNEL);
209 if (!syscon)
210 return -ENOMEM;
211
212 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
213 if (!res)
214 return -ENOENT;
215
216 base = devm_ioremap(dev, res->start, resource_size(res));
217 if (!base)
218 return -ENOMEM;
219
220 syscon_config.max_register = res->end - res->start - 3;
221 if (pdata)
222 syscon_config.name = pdata->label;
223 syscon->regmap = devm_regmap_init_mmio(dev, base, &syscon_config);
224 if (IS_ERR(syscon->regmap)) {
225 dev_err(dev, "regmap init failed\n");
226 return PTR_ERR(syscon->regmap);
227 }
228
229 platform_set_drvdata(pdev, syscon);
230
231 dev_dbg(dev, "regmap %pR registered\n", res);
232
233 return 0;
234}
235
236static const struct platform_device_id syscon_ids[] = {
237 { "syscon", },
238 { }
239};
240
241static struct platform_driver syscon_driver = {
242 .driver = {
243 .name = "syscon",
244 },
245 .probe = syscon_probe,
246 .id_table = syscon_ids,
247};
248
249static int __init syscon_init(void)
250{
251 return platform_driver_register(&syscon_driver);
252}
253postcore_initcall(syscon_init);
254
255static void __exit syscon_exit(void)
256{
257 platform_driver_unregister(&syscon_driver);
258}
259module_exit(syscon_exit);
260
261MODULE_AUTHOR("Dong Aisheng <dong.aisheng@linaro.org>");
262MODULE_DESCRIPTION("System Control driver");
263MODULE_LICENSE("GPL v2");