2 * LED driver for WM831x status LEDs
4 * Copyright(C) 2009 Wolfson Microelectronics PLC.
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.
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>
22 struct wm831x_status {
23 struct led_classdev cdev;
24 struct wm831x *wm831x;
25 struct work_struct work;
28 spinlock_t value_lock;
29 int reg; /* Control register */
30 int reg_val; /* Control register value */
36 enum led_brightness brightness;
39 #define to_wm831x_status(led_cdev) \
40 container_of(led_cdev, struct wm831x_status, cdev)
42 static void wm831x_status_work(struct work_struct *work)
44 struct wm831x_status *led = container_of(work, struct wm831x_status,
48 mutex_lock(&led->mutex);
50 led->reg_val &= ~(WM831X_LED_SRC_MASK | WM831X_LED_MODE_MASK |
51 WM831X_LED_DUTY_CYC_MASK | WM831X_LED_DUR_MASK);
53 spin_lock_irqsave(&led->value_lock, flags);
55 led->reg_val |= led->src << WM831X_LED_SRC_SHIFT;
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;
61 if (led->brightness != LED_OFF)
62 led->reg_val |= 1 << WM831X_LED_MODE_SHIFT;
65 spin_unlock_irqrestore(&led->value_lock, flags);
67 wm831x_reg_write(led->wm831x, led->reg, led->reg_val);
69 mutex_unlock(&led->mutex);
72 static void wm831x_status_set(struct led_classdev *led_cdev,
73 enum led_brightness value)
75 struct wm831x_status *led = to_wm831x_status(led_cdev);
78 spin_lock_irqsave(&led->value_lock, flags);
79 led->brightness = value;
82 schedule_work(&led->work);
83 spin_unlock_irqrestore(&led->value_lock, flags);
86 static int wm831x_status_blink_set(struct led_classdev *led_cdev,
87 unsigned long *delay_on,
88 unsigned long *delay_off)
90 struct wm831x_status *led = to_wm831x_status(led_cdev);
94 /* Pick some defaults if we've not been given times */
95 if (*delay_on == 0 && *delay_off == 0) {
100 spin_lock_irqsave(&led->value_lock, flags);
102 /* We only have a limited selection of settings, see if we can
103 * support the configuration we're being given */
116 /* Actually 62.5ms */
125 switch (*delay_off / *delay_on) {
149 /* Always update; if we fail turn off blinking since we expect
150 * a software fallback. */
151 schedule_work(&led->work);
153 spin_unlock_irqrestore(&led->value_lock, flags);
158 static const char *led_src_texts[] = {
165 static ssize_t wm831x_status_src_show(struct device *dev,
166 struct device_attribute *attr, char *buf)
168 struct led_classdev *led_cdev = dev_get_drvdata(dev);
169 struct wm831x_status *led = to_wm831x_status(led_cdev);
173 mutex_lock(&led->mutex);
175 for (i = 0; i < ARRAY_SIZE(led_src_texts); i++)
177 ret += sprintf(&buf[ret], "[%s] ", led_src_texts[i]);
179 ret += sprintf(&buf[ret], "%s ", led_src_texts[i]);
181 mutex_unlock(&led->mutex);
183 ret += sprintf(&buf[ret], "\n");
188 static ssize_t wm831x_status_src_store(struct device *dev,
189 struct device_attribute *attr,
190 const char *buf, size_t size)
192 struct led_classdev *led_cdev = dev_get_drvdata(dev);
193 struct wm831x_status *led = to_wm831x_status(led_cdev);
198 name[sizeof(name) - 1] = '\0';
199 strncpy(name, buf, sizeof(name) - 1);
202 if (len && name[len - 1] == '\n')
203 name[len - 1] = '\0';
205 for (i = 0; i < ARRAY_SIZE(led_src_texts); i++) {
206 if (!strcmp(name, led_src_texts[i])) {
207 mutex_lock(&led->mutex);
210 schedule_work(&led->work);
212 mutex_unlock(&led->mutex);
219 static DEVICE_ATTR(src, 0644, wm831x_status_src_show, wm831x_status_src_store);
221 static int wm831x_status_probe(struct platform_device *pdev)
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);
231 res = platform_get_resource(pdev, IORESOURCE_IO, 0);
233 dev_err(&pdev->dev, "No I/O resource\n");
238 drvdata = kzalloc(sizeof(struct wm831x_status), GFP_KERNEL);
241 dev_set_drvdata(&pdev->dev, drvdata);
243 drvdata->wm831x = wm831x;
244 drvdata->reg = res->start;
246 if (wm831x->dev->platform_data)
247 chip_pdata = wm831x->dev->platform_data;
251 memset(&pdata, 0, sizeof(pdata));
252 if (chip_pdata && chip_pdata->status[id])
253 memcpy(&pdata, chip_pdata->status[id], sizeof(pdata));
255 pdata.name = dev_name(&pdev->dev);
257 mutex_init(&drvdata->mutex);
258 INIT_WORK(&drvdata->work, wm831x_status_work);
259 spin_lock_init(&drvdata->value_lock);
261 /* We cache the configuration register and read startup values
263 drvdata->reg_val = wm831x_reg_read(wm831x, drvdata->reg);
265 if (drvdata->reg_val & WM831X_LED_MODE_MASK)
266 drvdata->brightness = LED_FULL;
268 drvdata->brightness = LED_OFF;
270 /* Set a default source if configured, otherwise leave the
271 * current hardware setting.
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;
278 drvdata->src = pdata.default_src - 1;
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;
286 ret = led_classdev_register(wm831x->dev, &drvdata->cdev);
288 dev_err(&pdev->dev, "Failed to register LED: %d\n", ret);
292 ret = device_create_file(drvdata->cdev.dev, &dev_attr_src);
295 "No source control for LED: %d\n", ret);
300 led_classdev_unregister(&drvdata->cdev);
306 static int wm831x_status_remove(struct platform_device *pdev)
308 struct wm831x_status *drvdata = platform_get_drvdata(pdev);
310 device_remove_file(drvdata->cdev.dev, &dev_attr_src);
311 led_classdev_unregister(&drvdata->cdev);
317 static struct platform_driver wm831x_status_driver = {
319 .name = "wm831x-status",
320 .owner = THIS_MODULE,
322 .probe = wm831x_status_probe,
323 .remove = wm831x_status_remove,
326 static int __devinit wm831x_status_init(void)
328 return platform_driver_register(&wm831x_status_driver);
330 module_init(wm831x_status_init);
332 static void wm831x_status_exit(void)
334 platform_driver_unregister(&wm831x_status_driver);
336 module_exit(wm831x_status_exit);
338 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
339 MODULE_DESCRIPTION("WM831x status LED driver");
340 MODULE_LICENSE("GPL");
341 MODULE_ALIAS("platform:wm831x-status");