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