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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
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 syscon_config.reg_stride = reg_io_width;
89 syscon_config.val_bits = reg_io_width * 8;
90 syscon_config.max_register = resource_size(&res) - reg_io_width;
91
92 regmap = regmap_init_mmio(NULL, base, &syscon_config);
93 if (IS_ERR(regmap)) {
94 pr_err("regmap init failed\n");
95 ret = PTR_ERR(regmap);
96 goto err_regmap;
97 }
98
99 syscon->regmap = regmap;
100 syscon->np = np;
101
102 spin_lock(&syscon_list_slock);
103 list_add_tail(&syscon->list, &syscon_list);
104 spin_unlock(&syscon_list_slock);
105
106 return syscon;
107
108err_regmap:
109 iounmap(base);
110err_map:
111 kfree(syscon);
112 return ERR_PTR(ret);
113}
114
115struct regmap *syscon_node_to_regmap(struct device_node *np)
116{
117 struct syscon *entry, *syscon = NULL;
118
119 spin_lock(&syscon_list_slock);
120
121 list_for_each_entry(entry, &syscon_list, list)
122 if (entry->np == np) {
123 syscon = entry;
124 break;
125 }
126
127 spin_unlock(&syscon_list_slock);
128
129 if (!syscon)
130 syscon = of_syscon_register(np);
131
132 if (IS_ERR(syscon))
133 return ERR_CAST(syscon);
134
135 return syscon->regmap;
136}
137EXPORT_SYMBOL_GPL(syscon_node_to_regmap);
138
139struct regmap *syscon_regmap_lookup_by_compatible(const char *s)
140{
141 struct device_node *syscon_np;
142 struct regmap *regmap;
143
144 syscon_np = of_find_compatible_node(NULL, NULL, s);
145 if (!syscon_np)
146 return ERR_PTR(-ENODEV);
147
148 regmap = syscon_node_to_regmap(syscon_np);
149 of_node_put(syscon_np);
150
151 return regmap;
152}
153EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_compatible);
154
155static int syscon_match_pdevname(struct device *dev, void *data)
156{
157 return !strcmp(dev_name(dev), (const char *)data);
158}
159
160struct regmap *syscon_regmap_lookup_by_pdevname(const char *s)
161{
162 struct device *dev;
163 struct syscon *syscon;
164
165 dev = driver_find_device(&syscon_driver.driver, NULL, (void *)s,
166 syscon_match_pdevname);
167 if (!dev)
168 return ERR_PTR(-EPROBE_DEFER);
169
170 syscon = dev_get_drvdata(dev);
171
172 return syscon->regmap;
173}
174EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_pdevname);
175
176struct regmap *syscon_regmap_lookup_by_phandle(struct device_node *np,
177 const char *property)
178{
179 struct device_node *syscon_np;
180 struct regmap *regmap;
181
182 if (property)
183 syscon_np = of_parse_phandle(np, property, 0);
184 else
185 syscon_np = np;
186
187 if (!syscon_np)
188 return ERR_PTR(-ENODEV);
189
190 regmap = syscon_node_to_regmap(syscon_np);
191 of_node_put(syscon_np);
192
193 return regmap;
194}
195EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle);
196
197static int syscon_probe(struct platform_device *pdev)
198{
199 struct device *dev = &pdev->dev;
200 struct syscon_platform_data *pdata = dev_get_platdata(dev);
201 struct syscon *syscon;
202 struct regmap_config syscon_config = syscon_regmap_config;
203 struct resource *res;
204 void __iomem *base;
205
206 syscon = devm_kzalloc(dev, sizeof(*syscon), GFP_KERNEL);
207 if (!syscon)
208 return -ENOMEM;
209
210 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
211 if (!res)
212 return -ENOENT;
213
214 base = devm_ioremap(dev, res->start, resource_size(res));
215 if (!base)
216 return -ENOMEM;
217
218 syscon_config.max_register = res->end - res->start - 3;
219 if (pdata)
220 syscon_config.name = pdata->label;
221 syscon->regmap = devm_regmap_init_mmio(dev, base, &syscon_config);
222 if (IS_ERR(syscon->regmap)) {
223 dev_err(dev, "regmap init failed\n");
224 return PTR_ERR(syscon->regmap);
225 }
226
227 platform_set_drvdata(pdev, syscon);
228
229 dev_dbg(dev, "regmap %pR registered\n", res);
230
231 return 0;
232}
233
234static const struct platform_device_id syscon_ids[] = {
235 { "syscon", },
236 { }
237};
238
239static struct platform_driver syscon_driver = {
240 .driver = {
241 .name = "syscon",
242 },
243 .probe = syscon_probe,
244 .id_table = syscon_ids,
245};
246
247static int __init syscon_init(void)
248{
249 return platform_driver_register(&syscon_driver);
250}
251postcore_initcall(syscon_init);
252
253static void __exit syscon_exit(void)
254{
255 platform_driver_unregister(&syscon_driver);
256}
257module_exit(syscon_exit);
258
259MODULE_AUTHOR("Dong Aisheng <dong.aisheng@linaro.org>");
260MODULE_DESCRIPTION("System Control driver");
261MODULE_LICENSE("GPL v2");
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 /* fall-through */
99 case -EPROBE_DEFER:
100 goto err_regmap;
101 }
102 }
103
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;
108 syscon_config.name = of_node_full_name(np);
109
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);
114 goto err_regmap;
115 }
116
117 if (check_clk) {
118 clk = of_clk_get(np, 0);
119 if (IS_ERR(clk)) {
120 ret = PTR_ERR(clk);
121 /* clock is optional */
122 if (ret != -ENOENT)
123 goto err_clk;
124 } else {
125 ret = regmap_mmio_attach_clk(regmap, clk);
126 if (ret)
127 goto err_attach;
128 }
129 }
130
131 syscon->regmap = regmap;
132 syscon->np = np;
133
134 spin_lock(&syscon_list_slock);
135 list_add_tail(&syscon->list, &syscon_list);
136 spin_unlock(&syscon_list_slock);
137
138 return syscon;
139
140err_attach:
141 if (!IS_ERR(clk))
142 clk_put(clk);
143err_clk:
144 regmap_exit(regmap);
145err_regmap:
146 iounmap(base);
147err_map:
148 kfree(syscon);
149 return ERR_PTR(ret);
150}
151
152static struct regmap *device_node_get_regmap(struct device_node *np,
153 bool check_clk)
154{
155 struct syscon *entry, *syscon = NULL;
156
157 spin_lock(&syscon_list_slock);
158
159 list_for_each_entry(entry, &syscon_list, list)
160 if (entry->np == np) {
161 syscon = entry;
162 break;
163 }
164
165 spin_unlock(&syscon_list_slock);
166
167 if (!syscon)
168 syscon = of_syscon_register(np, check_clk);
169
170 if (IS_ERR(syscon))
171 return ERR_CAST(syscon);
172
173 return syscon->regmap;
174}
175
176struct regmap *device_node_to_regmap(struct device_node *np)
177{
178 return device_node_get_regmap(np, false);
179}
180EXPORT_SYMBOL_GPL(device_node_to_regmap);
181
182struct regmap *syscon_node_to_regmap(struct device_node *np)
183{
184 if (!of_device_is_compatible(np, "syscon"))
185 return ERR_PTR(-EINVAL);
186
187 return device_node_get_regmap(np, true);
188}
189EXPORT_SYMBOL_GPL(syscon_node_to_regmap);
190
191struct regmap *syscon_regmap_lookup_by_compatible(const char *s)
192{
193 struct device_node *syscon_np;
194 struct regmap *regmap;
195
196 syscon_np = of_find_compatible_node(NULL, NULL, s);
197 if (!syscon_np)
198 return ERR_PTR(-ENODEV);
199
200 regmap = syscon_node_to_regmap(syscon_np);
201 of_node_put(syscon_np);
202
203 return regmap;
204}
205EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_compatible);
206
207struct regmap *syscon_regmap_lookup_by_phandle(struct device_node *np,
208 const char *property)
209{
210 struct device_node *syscon_np;
211 struct regmap *regmap;
212
213 if (property)
214 syscon_np = of_parse_phandle(np, property, 0);
215 else
216 syscon_np = np;
217
218 if (!syscon_np)
219 return ERR_PTR(-ENODEV);
220
221 regmap = syscon_node_to_regmap(syscon_np);
222 of_node_put(syscon_np);
223
224 return regmap;
225}
226EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle);
227
228static int syscon_probe(struct platform_device *pdev)
229{
230 struct device *dev = &pdev->dev;
231 struct syscon_platform_data *pdata = dev_get_platdata(dev);
232 struct syscon *syscon;
233 struct regmap_config syscon_config = syscon_regmap_config;
234 struct resource *res;
235 void __iomem *base;
236
237 syscon = devm_kzalloc(dev, sizeof(*syscon), GFP_KERNEL);
238 if (!syscon)
239 return -ENOMEM;
240
241 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
242 if (!res)
243 return -ENOENT;
244
245 base = devm_ioremap(dev, res->start, resource_size(res));
246 if (!base)
247 return -ENOMEM;
248
249 syscon_config.max_register = res->end - res->start - 3;
250 if (pdata)
251 syscon_config.name = pdata->label;
252 syscon->regmap = devm_regmap_init_mmio(dev, base, &syscon_config);
253 if (IS_ERR(syscon->regmap)) {
254 dev_err(dev, "regmap init failed\n");
255 return PTR_ERR(syscon->regmap);
256 }
257
258 platform_set_drvdata(pdev, syscon);
259
260 dev_dbg(dev, "regmap %pR registered\n", res);
261
262 return 0;
263}
264
265static const struct platform_device_id syscon_ids[] = {
266 { "syscon", },
267 { }
268};
269
270static struct platform_driver syscon_driver = {
271 .driver = {
272 .name = "syscon",
273 },
274 .probe = syscon_probe,
275 .id_table = syscon_ids,
276};
277
278static int __init syscon_init(void)
279{
280 return platform_driver_register(&syscon_driver);
281}
282postcore_initcall(syscon_init);