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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/mfd/syscon.h>
24#include <linux/slab.h>
25
26static struct platform_driver syscon_driver;
27
28static DEFINE_SPINLOCK(syscon_list_slock);
29static LIST_HEAD(syscon_list);
30
31struct syscon {
32 struct device_node *np;
33 struct regmap *regmap;
34 struct list_head list;
35};
36
37static const struct regmap_config syscon_regmap_config = {
38 .reg_bits = 32,
39 .val_bits = 32,
40 .reg_stride = 4,
41};
42
43static struct syscon *of_syscon_register(struct device_node *np, bool check_clk)
44{
45 struct clk *clk;
46 struct syscon *syscon;
47 struct regmap *regmap;
48 void __iomem *base;
49 u32 reg_io_width;
50 int ret;
51 struct regmap_config syscon_config = syscon_regmap_config;
52 struct resource res;
53
54 syscon = kzalloc(sizeof(*syscon), GFP_KERNEL);
55 if (!syscon)
56 return ERR_PTR(-ENOMEM);
57
58 if (of_address_to_resource(np, 0, &res)) {
59 ret = -ENOMEM;
60 goto err_map;
61 }
62
63 base = ioremap(res.start, resource_size(&res));
64 if (!base) {
65 ret = -ENOMEM;
66 goto err_map;
67 }
68
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;
76
77 /*
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.
81 */
82 ret = of_property_read_u32(np, "reg-io-width", ®_io_width);
83 if (ret)
84 reg_io_width = 4;
85
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;
91 } else if (ret < 0) {
92 switch (ret) {
93 case -ENOENT:
94 /* Ignore missing hwlock, it's optional. */
95 break;
96 default:
97 pr_err("Failed to retrieve valid hwlock: %d\n", ret);
98 fallthrough;
99 case -EPROBE_DEFER:
100 goto err_regmap;
101 }
102 }
103
104 syscon_config.name = kasprintf(GFP_KERNEL, "%pOFn@%llx", np,
105 (u64)res.start);
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;
109
110 regmap = regmap_init_mmio(NULL, base, &syscon_config);
111 kfree(syscon_config.name);
112 if (IS_ERR(regmap)) {
113 pr_err("regmap init failed\n");
114 ret = PTR_ERR(regmap);
115 goto err_regmap;
116 }
117
118 if (check_clk) {
119 clk = of_clk_get(np, 0);
120 if (IS_ERR(clk)) {
121 ret = PTR_ERR(clk);
122 /* clock is optional */
123 if (ret != -ENOENT)
124 goto err_clk;
125 } else {
126 ret = regmap_mmio_attach_clk(regmap, clk);
127 if (ret)
128 goto err_attach;
129 }
130 }
131
132 syscon->regmap = regmap;
133 syscon->np = np;
134
135 spin_lock(&syscon_list_slock);
136 list_add_tail(&syscon->list, &syscon_list);
137 spin_unlock(&syscon_list_slock);
138
139 return syscon;
140
141err_attach:
142 if (!IS_ERR(clk))
143 clk_put(clk);
144err_clk:
145 regmap_exit(regmap);
146err_regmap:
147 iounmap(base);
148err_map:
149 kfree(syscon);
150 return ERR_PTR(ret);
151}
152
153static struct regmap *device_node_get_regmap(struct device_node *np,
154 bool check_clk)
155{
156 struct syscon *entry, *syscon = NULL;
157
158 spin_lock(&syscon_list_slock);
159
160 list_for_each_entry(entry, &syscon_list, list)
161 if (entry->np == np) {
162 syscon = entry;
163 break;
164 }
165
166 spin_unlock(&syscon_list_slock);
167
168 if (!syscon)
169 syscon = of_syscon_register(np, check_clk);
170
171 if (IS_ERR(syscon))
172 return ERR_CAST(syscon);
173
174 return syscon->regmap;
175}
176
177struct regmap *device_node_to_regmap(struct device_node *np)
178{
179 return device_node_get_regmap(np, false);
180}
181EXPORT_SYMBOL_GPL(device_node_to_regmap);
182
183struct regmap *syscon_node_to_regmap(struct device_node *np)
184{
185 if (!of_device_is_compatible(np, "syscon"))
186 return ERR_PTR(-EINVAL);
187
188 return device_node_get_regmap(np, true);
189}
190EXPORT_SYMBOL_GPL(syscon_node_to_regmap);
191
192struct regmap *syscon_regmap_lookup_by_compatible(const char *s)
193{
194 struct device_node *syscon_np;
195 struct regmap *regmap;
196
197 syscon_np = of_find_compatible_node(NULL, NULL, s);
198 if (!syscon_np)
199 return ERR_PTR(-ENODEV);
200
201 regmap = syscon_node_to_regmap(syscon_np);
202 of_node_put(syscon_np);
203
204 return regmap;
205}
206EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_compatible);
207
208struct regmap *syscon_regmap_lookup_by_phandle(struct device_node *np,
209 const char *property)
210{
211 struct device_node *syscon_np;
212 struct regmap *regmap;
213
214 if (property)
215 syscon_np = of_parse_phandle(np, property, 0);
216 else
217 syscon_np = np;
218
219 if (!syscon_np)
220 return ERR_PTR(-ENODEV);
221
222 regmap = syscon_node_to_regmap(syscon_np);
223 of_node_put(syscon_np);
224
225 return regmap;
226}
227EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle);
228
229struct regmap *syscon_regmap_lookup_by_phandle_args(struct device_node *np,
230 const char *property,
231 int arg_count,
232 unsigned int *out_args)
233{
234 struct device_node *syscon_np;
235 struct of_phandle_args args;
236 struct regmap *regmap;
237 unsigned int index;
238 int rc;
239
240 rc = of_parse_phandle_with_fixed_args(np, property, arg_count,
241 0, &args);
242 if (rc)
243 return ERR_PTR(rc);
244
245 syscon_np = args.np;
246 if (!syscon_np)
247 return ERR_PTR(-ENODEV);
248
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);
253
254 return regmap;
255}
256EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle_args);
257
258static int syscon_probe(struct platform_device *pdev)
259{
260 struct device *dev = &pdev->dev;
261 struct syscon_platform_data *pdata = dev_get_platdata(dev);
262 struct syscon *syscon;
263 struct regmap_config syscon_config = syscon_regmap_config;
264 struct resource *res;
265 void __iomem *base;
266
267 syscon = devm_kzalloc(dev, sizeof(*syscon), GFP_KERNEL);
268 if (!syscon)
269 return -ENOMEM;
270
271 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
272 if (!res)
273 return -ENOENT;
274
275 base = devm_ioremap(dev, res->start, resource_size(res));
276 if (!base)
277 return -ENOMEM;
278
279 syscon_config.max_register = resource_size(res) - 4;
280 if (pdata)
281 syscon_config.name = pdata->label;
282 syscon->regmap = devm_regmap_init_mmio(dev, base, &syscon_config);
283 if (IS_ERR(syscon->regmap)) {
284 dev_err(dev, "regmap init failed\n");
285 return PTR_ERR(syscon->regmap);
286 }
287
288 platform_set_drvdata(pdev, syscon);
289
290 dev_dbg(dev, "regmap %pR registered\n", res);
291
292 return 0;
293}
294
295static const struct platform_device_id syscon_ids[] = {
296 { "syscon", },
297 { }
298};
299
300static struct platform_driver syscon_driver = {
301 .driver = {
302 .name = "syscon",
303 },
304 .probe = syscon_probe,
305 .id_table = syscon_ids,
306};
307
308static int __init syscon_init(void)
309{
310 return platform_driver_register(&syscon_driver);
311}
312postcore_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/hwspinlock.h>
17#include <linux/io.h>
18#include <linux/module.h>
19#include <linux/list.h>
20#include <linux/of.h>
21#include <linux/of_address.h>
22#include <linux/of_platform.h>
23#include <linux/platform_data/syscon.h>
24#include <linux/platform_device.h>
25#include <linux/regmap.h>
26#include <linux/mfd/syscon.h>
27#include <linux/slab.h>
28
29static struct platform_driver syscon_driver;
30
31static DEFINE_SPINLOCK(syscon_list_slock);
32static LIST_HEAD(syscon_list);
33
34struct syscon {
35 struct device_node *np;
36 struct regmap *regmap;
37 struct list_head list;
38};
39
40static const struct regmap_config syscon_regmap_config = {
41 .reg_bits = 32,
42 .val_bits = 32,
43 .reg_stride = 4,
44};
45
46static struct syscon *of_syscon_register(struct device_node *np)
47{
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
56 if (!of_device_is_compatible(np, "syscon"))
57 return ERR_PTR(-EINVAL);
58
59 syscon = kzalloc(sizeof(*syscon), GFP_KERNEL);
60 if (!syscon)
61 return ERR_PTR(-ENOMEM);
62
63 if (of_address_to_resource(np, 0, &res)) {
64 ret = -ENOMEM;
65 goto err_map;
66 }
67
68 base = ioremap(res.start, resource_size(&res));
69 if (!base) {
70 ret = -ENOMEM;
71 goto err_map;
72 }
73
74 /* Parse the device's DT node for an endianness specification */
75 if (of_property_read_bool(np, "big-endian"))
76 syscon_config.val_format_endian = REGMAP_ENDIAN_BIG;
77 else if (of_property_read_bool(np, "little-endian"))
78 syscon_config.val_format_endian = REGMAP_ENDIAN_LITTLE;
79 else if (of_property_read_bool(np, "native-endian"))
80 syscon_config.val_format_endian = REGMAP_ENDIAN_NATIVE;
81
82 /*
83 * search for reg-io-width property in DT. If it is not provided,
84 * default to 4 bytes. regmap_init_mmio will return an error if values
85 * are invalid so there is no need to check them here.
86 */
87 ret = of_property_read_u32(np, "reg-io-width", ®_io_width);
88 if (ret)
89 reg_io_width = 4;
90
91 ret = of_hwspin_lock_get_id(np, 0);
92 if (ret > 0 || (IS_ENABLED(CONFIG_HWSPINLOCK) && ret == 0)) {
93 syscon_config.use_hwlock = true;
94 syscon_config.hwlock_id = ret;
95 syscon_config.hwlock_mode = HWLOCK_IRQSTATE;
96 } else if (ret < 0) {
97 switch (ret) {
98 case -ENOENT:
99 /* Ignore missing hwlock, it's optional. */
100 break;
101 default:
102 pr_err("Failed to retrieve valid hwlock: %d\n", ret);
103 /* fall-through */
104 case -EPROBE_DEFER:
105 goto err_regmap;
106 }
107 }
108
109 syscon_config.reg_stride = reg_io_width;
110 syscon_config.val_bits = reg_io_width * 8;
111 syscon_config.max_register = resource_size(&res) - reg_io_width;
112
113 regmap = regmap_init_mmio(NULL, base, &syscon_config);
114 if (IS_ERR(regmap)) {
115 pr_err("regmap init failed\n");
116 ret = PTR_ERR(regmap);
117 goto err_regmap;
118 }
119
120 syscon->regmap = regmap;
121 syscon->np = np;
122
123 spin_lock(&syscon_list_slock);
124 list_add_tail(&syscon->list, &syscon_list);
125 spin_unlock(&syscon_list_slock);
126
127 return syscon;
128
129err_regmap:
130 iounmap(base);
131err_map:
132 kfree(syscon);
133 return ERR_PTR(ret);
134}
135
136struct regmap *syscon_node_to_regmap(struct device_node *np)
137{
138 struct syscon *entry, *syscon = NULL;
139
140 spin_lock(&syscon_list_slock);
141
142 list_for_each_entry(entry, &syscon_list, list)
143 if (entry->np == np) {
144 syscon = entry;
145 break;
146 }
147
148 spin_unlock(&syscon_list_slock);
149
150 if (!syscon)
151 syscon = of_syscon_register(np);
152
153 if (IS_ERR(syscon))
154 return ERR_CAST(syscon);
155
156 return syscon->regmap;
157}
158EXPORT_SYMBOL_GPL(syscon_node_to_regmap);
159
160struct regmap *syscon_regmap_lookup_by_compatible(const char *s)
161{
162 struct device_node *syscon_np;
163 struct regmap *regmap;
164
165 syscon_np = of_find_compatible_node(NULL, NULL, s);
166 if (!syscon_np)
167 return ERR_PTR(-ENODEV);
168
169 regmap = syscon_node_to_regmap(syscon_np);
170 of_node_put(syscon_np);
171
172 return regmap;
173}
174EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_compatible);
175
176static int syscon_match_pdevname(struct device *dev, void *data)
177{
178 return !strcmp(dev_name(dev), (const char *)data);
179}
180
181struct regmap *syscon_regmap_lookup_by_pdevname(const char *s)
182{
183 struct device *dev;
184 struct syscon *syscon;
185
186 dev = driver_find_device(&syscon_driver.driver, NULL, (void *)s,
187 syscon_match_pdevname);
188 if (!dev)
189 return ERR_PTR(-EPROBE_DEFER);
190
191 syscon = dev_get_drvdata(dev);
192
193 return syscon->regmap;
194}
195EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_pdevname);
196
197struct regmap *syscon_regmap_lookup_by_phandle(struct device_node *np,
198 const char *property)
199{
200 struct device_node *syscon_np;
201 struct regmap *regmap;
202
203 if (property)
204 syscon_np = of_parse_phandle(np, property, 0);
205 else
206 syscon_np = np;
207
208 if (!syscon_np)
209 return ERR_PTR(-ENODEV);
210
211 regmap = syscon_node_to_regmap(syscon_np);
212 of_node_put(syscon_np);
213
214 return regmap;
215}
216EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle);
217
218static int syscon_probe(struct platform_device *pdev)
219{
220 struct device *dev = &pdev->dev;
221 struct syscon_platform_data *pdata = dev_get_platdata(dev);
222 struct syscon *syscon;
223 struct regmap_config syscon_config = syscon_regmap_config;
224 struct resource *res;
225 void __iomem *base;
226
227 syscon = devm_kzalloc(dev, sizeof(*syscon), GFP_KERNEL);
228 if (!syscon)
229 return -ENOMEM;
230
231 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
232 if (!res)
233 return -ENOENT;
234
235 base = devm_ioremap(dev, res->start, resource_size(res));
236 if (!base)
237 return -ENOMEM;
238
239 syscon_config.max_register = res->end - res->start - 3;
240 if (pdata)
241 syscon_config.name = pdata->label;
242 syscon->regmap = devm_regmap_init_mmio(dev, base, &syscon_config);
243 if (IS_ERR(syscon->regmap)) {
244 dev_err(dev, "regmap init failed\n");
245 return PTR_ERR(syscon->regmap);
246 }
247
248 platform_set_drvdata(pdev, syscon);
249
250 dev_dbg(dev, "regmap %pR registered\n", res);
251
252 return 0;
253}
254
255static const struct platform_device_id syscon_ids[] = {
256 { "syscon", },
257 { }
258};
259
260static struct platform_driver syscon_driver = {
261 .driver = {
262 .name = "syscon",
263 },
264 .probe = syscon_probe,
265 .id_table = syscon_ids,
266};
267
268static int __init syscon_init(void)
269{
270 return platform_driver_register(&syscon_driver);
271}
272postcore_initcall(syscon_init);
273
274static void __exit syscon_exit(void)
275{
276 platform_driver_unregister(&syscon_driver);
277}
278module_exit(syscon_exit);
279
280MODULE_AUTHOR("Dong Aisheng <dong.aisheng@linaro.org>");
281MODULE_DESCRIPTION("System Control driver");
282MODULE_LICENSE("GPL v2");