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19#include <linux/device.h>
20#include <linux/mutex.h>
21#include <linux/err.h>
22#include <linux/slab.h>
23#include <linux/kdev_t.h>
24#include <linux/pwm.h>
25
26struct pwm_export {
27 struct device child;
28 struct pwm_device *pwm;
29};
30
31static struct pwm_export *child_to_pwm_export(struct device *child)
32{
33 return container_of(child, struct pwm_export, child);
34}
35
36static struct pwm_device *child_to_pwm_device(struct device *child)
37{
38 struct pwm_export *export = child_to_pwm_export(child);
39
40 return export->pwm;
41}
42
43static ssize_t period_show(struct device *child,
44 struct device_attribute *attr,
45 char *buf)
46{
47 const struct pwm_device *pwm = child_to_pwm_device(child);
48
49 return sprintf(buf, "%u\n", pwm_get_period(pwm));
50}
51
52static ssize_t period_store(struct device *child,
53 struct device_attribute *attr,
54 const char *buf, size_t size)
55{
56 struct pwm_device *pwm = child_to_pwm_device(child);
57 unsigned int val;
58 int ret;
59
60 ret = kstrtouint(buf, 0, &val);
61 if (ret)
62 return ret;
63
64 ret = pwm_config(pwm, pwm_get_duty_cycle(pwm), val);
65
66 return ret ? : size;
67}
68
69static ssize_t duty_cycle_show(struct device *child,
70 struct device_attribute *attr,
71 char *buf)
72{
73 const struct pwm_device *pwm = child_to_pwm_device(child);
74
75 return sprintf(buf, "%u\n", pwm_get_duty_cycle(pwm));
76}
77
78static ssize_t duty_cycle_store(struct device *child,
79 struct device_attribute *attr,
80 const char *buf, size_t size)
81{
82 struct pwm_device *pwm = child_to_pwm_device(child);
83 unsigned int val;
84 int ret;
85
86 ret = kstrtouint(buf, 0, &val);
87 if (ret)
88 return ret;
89
90 ret = pwm_config(pwm, val, pwm_get_period(pwm));
91
92 return ret ? : size;
93}
94
95static ssize_t enable_show(struct device *child,
96 struct device_attribute *attr,
97 char *buf)
98{
99 const struct pwm_device *pwm = child_to_pwm_device(child);
100
101 return sprintf(buf, "%d\n", pwm_is_enabled(pwm));
102}
103
104static ssize_t enable_store(struct device *child,
105 struct device_attribute *attr,
106 const char *buf, size_t size)
107{
108 struct pwm_device *pwm = child_to_pwm_device(child);
109 int val, ret;
110
111 ret = kstrtoint(buf, 0, &val);
112 if (ret)
113 return ret;
114
115 switch (val) {
116 case 0:
117 pwm_disable(pwm);
118 break;
119 case 1:
120 ret = pwm_enable(pwm);
121 break;
122 default:
123 ret = -EINVAL;
124 break;
125 }
126
127 return ret ? : size;
128}
129
130static ssize_t polarity_show(struct device *child,
131 struct device_attribute *attr,
132 char *buf)
133{
134 const struct pwm_device *pwm = child_to_pwm_device(child);
135 const char *polarity = "unknown";
136
137 switch (pwm_get_polarity(pwm)) {
138 case PWM_POLARITY_NORMAL:
139 polarity = "normal";
140 break;
141
142 case PWM_POLARITY_INVERSED:
143 polarity = "inversed";
144 break;
145 }
146
147 return sprintf(buf, "%s\n", polarity);
148}
149
150static ssize_t polarity_store(struct device *child,
151 struct device_attribute *attr,
152 const char *buf, size_t size)
153{
154 struct pwm_device *pwm = child_to_pwm_device(child);
155 enum pwm_polarity polarity;
156 int ret;
157
158 if (sysfs_streq(buf, "normal"))
159 polarity = PWM_POLARITY_NORMAL;
160 else if (sysfs_streq(buf, "inversed"))
161 polarity = PWM_POLARITY_INVERSED;
162 else
163 return -EINVAL;
164
165 ret = pwm_set_polarity(pwm, polarity);
166
167 return ret ? : size;
168}
169
170static DEVICE_ATTR_RW(period);
171static DEVICE_ATTR_RW(duty_cycle);
172static DEVICE_ATTR_RW(enable);
173static DEVICE_ATTR_RW(polarity);
174
175static struct attribute *pwm_attrs[] = {
176 &dev_attr_period.attr,
177 &dev_attr_duty_cycle.attr,
178 &dev_attr_enable.attr,
179 &dev_attr_polarity.attr,
180 NULL
181};
182ATTRIBUTE_GROUPS(pwm);
183
184static void pwm_export_release(struct device *child)
185{
186 struct pwm_export *export = child_to_pwm_export(child);
187
188 kfree(export);
189}
190
191static int pwm_export_child(struct device *parent, struct pwm_device *pwm)
192{
193 struct pwm_export *export;
194 int ret;
195
196 if (test_and_set_bit(PWMF_EXPORTED, &pwm->flags))
197 return -EBUSY;
198
199 export = kzalloc(sizeof(*export), GFP_KERNEL);
200 if (!export) {
201 clear_bit(PWMF_EXPORTED, &pwm->flags);
202 return -ENOMEM;
203 }
204
205 export->pwm = pwm;
206
207 export->child.release = pwm_export_release;
208 export->child.parent = parent;
209 export->child.devt = MKDEV(0, 0);
210 export->child.groups = pwm_groups;
211 dev_set_name(&export->child, "pwm%u", pwm->hwpwm);
212
213 ret = device_register(&export->child);
214 if (ret) {
215 clear_bit(PWMF_EXPORTED, &pwm->flags);
216 kfree(export);
217 return ret;
218 }
219
220 return 0;
221}
222
223static int pwm_unexport_match(struct device *child, void *data)
224{
225 return child_to_pwm_device(child) == data;
226}
227
228static int pwm_unexport_child(struct device *parent, struct pwm_device *pwm)
229{
230 struct device *child;
231
232 if (!test_and_clear_bit(PWMF_EXPORTED, &pwm->flags))
233 return -ENODEV;
234
235 child = device_find_child(parent, pwm, pwm_unexport_match);
236 if (!child)
237 return -ENODEV;
238
239
240 put_device(child);
241 device_unregister(child);
242 pwm_put(pwm);
243
244 return 0;
245}
246
247static ssize_t export_store(struct device *parent,
248 struct device_attribute *attr,
249 const char *buf, size_t len)
250{
251 struct pwm_chip *chip = dev_get_drvdata(parent);
252 struct pwm_device *pwm;
253 unsigned int hwpwm;
254 int ret;
255
256 ret = kstrtouint(buf, 0, &hwpwm);
257 if (ret < 0)
258 return ret;
259
260 if (hwpwm >= chip->npwm)
261 return -ENODEV;
262
263 pwm = pwm_request_from_chip(chip, hwpwm, "sysfs");
264 if (IS_ERR(pwm))
265 return PTR_ERR(pwm);
266
267 ret = pwm_export_child(parent, pwm);
268 if (ret < 0)
269 pwm_put(pwm);
270
271 return ret ? : len;
272}
273static DEVICE_ATTR_WO(export);
274
275static ssize_t unexport_store(struct device *parent,
276 struct device_attribute *attr,
277 const char *buf, size_t len)
278{
279 struct pwm_chip *chip = dev_get_drvdata(parent);
280 unsigned int hwpwm;
281 int ret;
282
283 ret = kstrtouint(buf, 0, &hwpwm);
284 if (ret < 0)
285 return ret;
286
287 if (hwpwm >= chip->npwm)
288 return -ENODEV;
289
290 ret = pwm_unexport_child(parent, &chip->pwms[hwpwm]);
291
292 return ret ? : len;
293}
294static DEVICE_ATTR_WO(unexport);
295
296static ssize_t npwm_show(struct device *parent, struct device_attribute *attr,
297 char *buf)
298{
299 const struct pwm_chip *chip = dev_get_drvdata(parent);
300
301 return sprintf(buf, "%u\n", chip->npwm);
302}
303static DEVICE_ATTR_RO(npwm);
304
305static struct attribute *pwm_chip_attrs[] = {
306 &dev_attr_export.attr,
307 &dev_attr_unexport.attr,
308 &dev_attr_npwm.attr,
309 NULL,
310};
311ATTRIBUTE_GROUPS(pwm_chip);
312
313static struct class pwm_class = {
314 .name = "pwm",
315 .owner = THIS_MODULE,
316 .dev_groups = pwm_chip_groups,
317};
318
319static int pwmchip_sysfs_match(struct device *parent, const void *data)
320{
321 return dev_get_drvdata(parent) == data;
322}
323
324void pwmchip_sysfs_export(struct pwm_chip *chip)
325{
326 struct device *parent;
327
328
329
330
331
332 parent = device_create(&pwm_class, chip->dev, MKDEV(0, 0), chip,
333 "pwmchip%d", chip->base);
334 if (IS_ERR(parent)) {
335 dev_warn(chip->dev,
336 "device_create failed for pwm_chip sysfs export\n");
337 }
338}
339
340void pwmchip_sysfs_unexport(struct pwm_chip *chip)
341{
342 struct device *parent;
343
344 parent = class_find_device(&pwm_class, NULL, chip,
345 pwmchip_sysfs_match);
346 if (parent) {
347
348 put_device(parent);
349 device_unregister(parent);
350 }
351}
352
353static int __init pwm_sysfs_init(void)
354{
355 return class_register(&pwm_class);
356}
357subsys_initcall(pwm_sysfs_init);
358
