blob: c586d05e336a5ed6327dd331f90fb2597f2974da [file] [log] [blame]
Mark Brownc746b552009-09-05 14:09:21 +01001/*
2 * LED driver for WM831x status LEDs
3 *
4 * Copyright(C) 2009 Wolfson Microelectronics PLC.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 */
11
12#include <linux/kernel.h>
13#include <linux/init.h>
14#include <linux/platform_device.h>
15#include <linux/leds.h>
16#include <linux/err.h>
17#include <linux/mfd/wm831x/core.h>
18#include <linux/mfd/wm831x/pdata.h>
19#include <linux/mfd/wm831x/status.h>
20
21
22struct wm831x_status {
23 struct led_classdev cdev;
24 struct wm831x *wm831x;
25 struct work_struct work;
26 struct mutex mutex;
27
28 spinlock_t value_lock;
29 int reg; /* Control register */
30 int reg_val; /* Control register value */
31
32 int blink;
33 int blink_time;
34 int blink_cyc;
35 int src;
36 enum led_brightness brightness;
37};
38
39#define to_wm831x_status(led_cdev) \
40 container_of(led_cdev, struct wm831x_status, cdev)
41
42static void wm831x_status_work(struct work_struct *work)
43{
44 struct wm831x_status *led = container_of(work, struct wm831x_status,
45 work);
46 unsigned long flags;
47
48 mutex_lock(&led->mutex);
49
50 led->reg_val &= ~(WM831X_LED_SRC_MASK | WM831X_LED_MODE_MASK |
51 WM831X_LED_DUTY_CYC_MASK | WM831X_LED_DUR_MASK);
52
53 spin_lock_irqsave(&led->value_lock, flags);
54
55 led->reg_val |= led->src << WM831X_LED_SRC_SHIFT;
56 if (led->blink) {
57 led->reg_val |= 2 << WM831X_LED_MODE_SHIFT;
58 led->reg_val |= led->blink_time << WM831X_LED_DUR_SHIFT;
59 led->reg_val |= led->blink_cyc;
60 } else {
61 if (led->brightness != LED_OFF)
62 led->reg_val |= 1 << WM831X_LED_MODE_SHIFT;
63 }
64
65 spin_unlock_irqrestore(&led->value_lock, flags);
66
67 wm831x_reg_write(led->wm831x, led->reg, led->reg_val);
68
69 mutex_unlock(&led->mutex);
70}
71
72static void wm831x_status_set(struct led_classdev *led_cdev,
73 enum led_brightness value)
74{
75 struct wm831x_status *led = to_wm831x_status(led_cdev);
76 unsigned long flags;
77
78 spin_lock_irqsave(&led->value_lock, flags);
79 led->brightness = value;
80 if (value == LED_OFF)
81 led->blink = 0;
82 schedule_work(&led->work);
83 spin_unlock_irqrestore(&led->value_lock, flags);
84}
85
86static int wm831x_status_blink_set(struct led_classdev *led_cdev,
87 unsigned long *delay_on,
88 unsigned long *delay_off)
89{
90 struct wm831x_status *led = to_wm831x_status(led_cdev);
91 unsigned long flags;
92 int ret = 0;
93
94 /* Pick some defaults if we've not been given times */
95 if (*delay_on == 0 && *delay_off == 0) {
96 *delay_on = 250;
97 *delay_off = 250;
98 }
99
100 spin_lock_irqsave(&led->value_lock, flags);
101
102 /* We only have a limited selection of settings, see if we can
103 * support the configuration we're being given */
104 switch (*delay_on) {
105 case 1000:
106 led->blink_time = 0;
107 break;
108 case 250:
109 led->blink_time = 1;
110 break;
111 case 125:
112 led->blink_time = 2;
113 break;
114 case 62:
115 case 63:
116 /* Actually 62.5ms */
117 led->blink_time = 3;
118 break;
119 default:
120 ret = -EINVAL;
121 break;
122 }
123
124 if (ret == 0) {
125 switch (*delay_off / *delay_on) {
126 case 1:
127 led->blink_cyc = 0;
128 break;
129 case 3:
130 led->blink_cyc = 1;
131 break;
132 case 4:
133 led->blink_cyc = 2;
134 break;
135 case 8:
136 led->blink_cyc = 3;
137 break;
138 default:
139 ret = -EINVAL;
140 break;
141 }
142 }
143
144 if (ret == 0)
145 led->blink = 1;
146 else
147 led->blink = 0;
148
149 /* Always update; if we fail turn off blinking since we expect
150 * a software fallback. */
151 schedule_work(&led->work);
152
153 spin_unlock_irqrestore(&led->value_lock, flags);
154
155 return ret;
156}
157
158static const char *led_src_texts[] = {
159 "otp",
160 "power",
161 "charger",
162 "soft",
163};
164
165static ssize_t wm831x_status_src_show(struct device *dev,
166 struct device_attribute *attr, char *buf)
167{
168 struct led_classdev *led_cdev = dev_get_drvdata(dev);
169 struct wm831x_status *led = to_wm831x_status(led_cdev);
170 int i;
171 ssize_t ret = 0;
172
173 mutex_lock(&led->mutex);
174
175 for (i = 0; i < ARRAY_SIZE(led_src_texts); i++)
176 if (i == led->src)
177 ret += sprintf(&buf[ret], "[%s] ", led_src_texts[i]);
178 else
179 ret += sprintf(&buf[ret], "%s ", led_src_texts[i]);
180
181 mutex_unlock(&led->mutex);
182
183 ret += sprintf(&buf[ret], "\n");
184
185 return ret;
186}
187
188static ssize_t wm831x_status_src_store(struct device *dev,
189 struct device_attribute *attr,
190 const char *buf, size_t size)
191{
192 struct led_classdev *led_cdev = dev_get_drvdata(dev);
193 struct wm831x_status *led = to_wm831x_status(led_cdev);
194 char name[20];
195 int i;
196 size_t len;
197
198 name[sizeof(name) - 1] = '\0';
199 strncpy(name, buf, sizeof(name) - 1);
200 len = strlen(name);
201
202 if (len && name[len - 1] == '\n')
203 name[len - 1] = '\0';
204
205 for (i = 0; i < ARRAY_SIZE(led_src_texts); i++) {
206 if (!strcmp(name, led_src_texts[i])) {
207 mutex_lock(&led->mutex);
208
209 led->src = i;
210 schedule_work(&led->work);
211
212 mutex_unlock(&led->mutex);
213 }
214 }
215
216 return size;
217}
218
219static DEVICE_ATTR(src, 0644, wm831x_status_src_show, wm831x_status_src_store);
220
221static int wm831x_status_probe(struct platform_device *pdev)
222{
223 struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
224 struct wm831x_pdata *chip_pdata;
225 struct wm831x_status_pdata pdata;
226 struct wm831x_status *drvdata;
227 struct resource *res;
228 int id = pdev->id % ARRAY_SIZE(chip_pdata->status);
229 int ret;
230
231 res = platform_get_resource(pdev, IORESOURCE_IO, 0);
232 if (res == NULL) {
233 dev_err(&pdev->dev, "No I/O resource\n");
234 ret = -EINVAL;
235 goto err;
236 }
237
238 drvdata = kzalloc(sizeof(struct wm831x_status), GFP_KERNEL);
239 if (!drvdata)
240 return -ENOMEM;
241 dev_set_drvdata(&pdev->dev, drvdata);
242
243 drvdata->wm831x = wm831x;
244 drvdata->reg = res->start;
245
246 if (wm831x->dev->platform_data)
247 chip_pdata = wm831x->dev->platform_data;
248 else
249 chip_pdata = NULL;
250
251 memset(&pdata, 0, sizeof(pdata));
252 if (chip_pdata && chip_pdata->status[id])
253 memcpy(&pdata, chip_pdata->status[id], sizeof(pdata));
254 else
255 pdata.name = dev_name(&pdev->dev);
256
257 mutex_init(&drvdata->mutex);
258 INIT_WORK(&drvdata->work, wm831x_status_work);
259 spin_lock_init(&drvdata->value_lock);
260
261 /* We cache the configuration register and read startup values
262 * from it. */
263 drvdata->reg_val = wm831x_reg_read(wm831x, drvdata->reg);
264
265 if (drvdata->reg_val & WM831X_LED_MODE_MASK)
266 drvdata->brightness = LED_FULL;
267 else
268 drvdata->brightness = LED_OFF;
269
270 /* Set a default source if configured, otherwise leave the
271 * current hardware setting.
272 */
273 if (pdata.default_src == WM831X_STATUS_PRESERVE) {
274 drvdata->src = drvdata->reg_val;
275 drvdata->src &= WM831X_LED_SRC_MASK;
276 drvdata->src >>= WM831X_LED_SRC_SHIFT;
277 } else {
278 drvdata->src = pdata.default_src - 1;
279 }
280
281 drvdata->cdev.name = pdata.name;
282 drvdata->cdev.default_trigger = pdata.default_trigger;
283 drvdata->cdev.brightness_set = wm831x_status_set;
284 drvdata->cdev.blink_set = wm831x_status_blink_set;
285
286 ret = led_classdev_register(wm831x->dev, &drvdata->cdev);
287 if (ret < 0) {
288 dev_err(&pdev->dev, "Failed to register LED: %d\n", ret);
289 goto err_led;
290 }
291
292 ret = device_create_file(drvdata->cdev.dev, &dev_attr_src);
293 if (ret != 0)
294 dev_err(&pdev->dev,
295 "No source control for LED: %d\n", ret);
296
297 return 0;
298
299err_led:
300 led_classdev_unregister(&drvdata->cdev);
301 kfree(drvdata);
302err:
303 return ret;
304}
305
306static int wm831x_status_remove(struct platform_device *pdev)
307{
308 struct wm831x_status *drvdata = platform_get_drvdata(pdev);
309
310 device_remove_file(drvdata->cdev.dev, &dev_attr_src);
311 led_classdev_unregister(&drvdata->cdev);
312 kfree(drvdata);
313
314 return 0;
315}
316
317static struct platform_driver wm831x_status_driver = {
318 .driver = {
319 .name = "wm831x-status",
320 .owner = THIS_MODULE,
321 },
322 .probe = wm831x_status_probe,
323 .remove = wm831x_status_remove,
324};
325
326static int __devinit wm831x_status_init(void)
327{
328 return platform_driver_register(&wm831x_status_driver);
329}
330module_init(wm831x_status_init);
331
332static void wm831x_status_exit(void)
333{
334 platform_driver_unregister(&wm831x_status_driver);
335}
336module_exit(wm831x_status_exit);
337
338MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
339MODULE_DESCRIPTION("WM831x status LED driver");
340MODULE_LICENSE("GPL");
341MODULE_ALIAS("platform:wm831x-status");