1
2
3
4
5
6
7
8
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 = of_iomap(np, 0);
64 if (!base) {
65 ret = -ENOMEM;
66 goto err_map;
67 }
68
69
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
79
80
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
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
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
258
259
260
261
262
263struct regmap *syscon_regmap_lookup_by_phandle_optional(struct device_node *np,
264 const char *property)
265{
266 struct regmap *regmap;
267
268 regmap = syscon_regmap_lookup_by_phandle(np, property);
269 if (IS_ERR(regmap) && PTR_ERR(regmap) == -ENODEV)
270 return NULL;
271
272 return regmap;
273}
274EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle_optional);
275
276static int syscon_probe(struct platform_device *pdev)
277{
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;
283 void __iomem *base;
284
285 syscon = devm_kzalloc(dev, sizeof(*syscon), GFP_KERNEL);
286 if (!syscon)
287 return -ENOMEM;
288
289 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
290 if (!res)
291 return -ENOENT;
292
293 base = devm_ioremap(dev, res->start, resource_size(res));
294 if (!base)
295 return -ENOMEM;
296
297 syscon_config.max_register = resource_size(res) - 4;
298 if (pdata)
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);
304 }
305
306 platform_set_drvdata(pdev, syscon);
307
308 dev_dbg(dev, "regmap %pR registered\n", res);
309
310 return 0;
311}
312
313static const struct platform_device_id syscon_ids[] = {
314 { "syscon", },
315 { }
316};
317
318static struct platform_driver syscon_driver = {
319 .driver = {
320 .name = "syscon",
321 },
322 .probe = syscon_probe,
323 .id_table = syscon_ids,
324};
325
326static int __init syscon_init(void)
327{
328 return platform_driver_register(&syscon_driver);
329}
330postcore_initcall(syscon_init);
331
