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/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>
23 struct wm831x_status {
24 struct led_classdev cdev;
25 struct wm831x *wm831x;
26 struct work_struct work;
29 spinlock_t value_lock;
30 int reg; /* Control register */
31 int reg_val; /* Control register value */
37 enum led_brightness brightness;
40 #define to_wm831x_status(led_cdev) \
41 container_of(led_cdev, struct wm831x_status, cdev)
43 static void wm831x_status_work(struct work_struct *work)
45 struct wm831x_status *led = container_of(work, struct wm831x_status,
49 mutex_lock(&led->mutex);
51 led->reg_val &= ~(WM831X_LED_SRC_MASK | WM831X_LED_MODE_MASK |
52 WM831X_LED_DUTY_CYC_MASK | WM831X_LED_DUR_MASK);
54 spin_lock_irqsave(&led->value_lock, flags);
56 led->reg_val |= led->src << WM831X_LED_SRC_SHIFT;
58 led->reg_val |= 2 << WM831X_LED_MODE_SHIFT;
59 led->reg_val |= led->blink_time << WM831X_LED_DUR_SHIFT;
60 led->reg_val |= led->blink_cyc;
62 if (led->brightness != LED_OFF)
63 led->reg_val |= 1 << WM831X_LED_MODE_SHIFT;
66 spin_unlock_irqrestore(&led->value_lock, flags);
68 wm831x_reg_write(led->wm831x, led->reg, led->reg_val);
70 mutex_unlock(&led->mutex);
73 static void wm831x_status_set(struct led_classdev *led_cdev,
74 enum led_brightness value)
76 struct wm831x_status *led = to_wm831x_status(led_cdev);
79 spin_lock_irqsave(&led->value_lock, flags);
80 led->brightness = value;
83 schedule_work(&led->work);
84 spin_unlock_irqrestore(&led->value_lock, flags);
87 static int wm831x_status_blink_set(struct led_classdev *led_cdev,
88 unsigned long *delay_on,
89 unsigned long *delay_off)
91 struct wm831x_status *led = to_wm831x_status(led_cdev);
95 /* Pick some defaults if we've not been given times */
96 if (*delay_on == 0 && *delay_off == 0) {
101 spin_lock_irqsave(&led->value_lock, flags);
103 /* We only have a limited selection of settings, see if we can
104 * support the configuration we're being given */
117 /* Actually 62.5ms */
126 switch (*delay_off / *delay_on) {
150 /* Always update; if we fail turn off blinking since we expect
151 * a software fallback. */
152 schedule_work(&led->work);
154 spin_unlock_irqrestore(&led->value_lock, flags);
159 static const char *led_src_texts[] = {
166 static ssize_t wm831x_status_src_show(struct device *dev,
167 struct device_attribute *attr, char *buf)
169 struct led_classdev *led_cdev = dev_get_drvdata(dev);
170 struct wm831x_status *led = to_wm831x_status(led_cdev);
174 mutex_lock(&led->mutex);
176 for (i = 0; i < ARRAY_SIZE(led_src_texts); i++)
178 ret += sprintf(&buf[ret], "[%s] ", led_src_texts[i]);
180 ret += sprintf(&buf[ret], "%s ", led_src_texts[i]);
182 mutex_unlock(&led->mutex);
184 ret += sprintf(&buf[ret], "\n");
189 static ssize_t wm831x_status_src_store(struct device *dev,
190 struct device_attribute *attr,
191 const char *buf, size_t size)
193 struct led_classdev *led_cdev = dev_get_drvdata(dev);
194 struct wm831x_status *led = to_wm831x_status(led_cdev);
199 name[sizeof(name) - 1] = '\0';
200 strncpy(name, buf, sizeof(name) - 1);
203 if (len && name[len - 1] == '\n')
204 name[len - 1] = '\0';
206 for (i = 0; i < ARRAY_SIZE(led_src_texts); i++) {
207 if (!strcmp(name, led_src_texts[i])) {
208 mutex_lock(&led->mutex);
211 schedule_work(&led->work);
213 mutex_unlock(&led->mutex);
220 static DEVICE_ATTR(src, 0644, wm831x_status_src_show, wm831x_status_src_store);
222 static int wm831x_status_probe(struct platform_device *pdev)
224 struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
225 struct wm831x_pdata *chip_pdata;
226 struct wm831x_status_pdata pdata;
227 struct wm831x_status *drvdata;
228 struct resource *res;
229 int id = pdev->id % ARRAY_SIZE(chip_pdata->status);
232 res = platform_get_resource(pdev, IORESOURCE_IO, 0);
234 dev_err(&pdev->dev, "No I/O resource\n");
239 drvdata = kzalloc(sizeof(struct wm831x_status), GFP_KERNEL);
242 dev_set_drvdata(&pdev->dev, drvdata);
244 drvdata->wm831x = wm831x;
245 drvdata->reg = res->start;
247 if (wm831x->dev->platform_data)
248 chip_pdata = wm831x->dev->platform_data;
252 memset(&pdata, 0, sizeof(pdata));
253 if (chip_pdata && chip_pdata->status[id])
254 memcpy(&pdata, chip_pdata->status[id], sizeof(pdata));
256 pdata.name = dev_name(&pdev->dev);
258 mutex_init(&drvdata->mutex);
259 INIT_WORK(&drvdata->work, wm831x_status_work);
260 spin_lock_init(&drvdata->value_lock);
262 /* We cache the configuration register and read startup values
264 drvdata->reg_val = wm831x_reg_read(wm831x, drvdata->reg);
266 if (drvdata->reg_val & WM831X_LED_MODE_MASK)
267 drvdata->brightness = LED_FULL;
269 drvdata->brightness = LED_OFF;
271 /* Set a default source if configured, otherwise leave the
272 * current hardware setting.
274 if (pdata.default_src == WM831X_STATUS_PRESERVE) {
275 drvdata->src = drvdata->reg_val;
276 drvdata->src &= WM831X_LED_SRC_MASK;
277 drvdata->src >>= WM831X_LED_SRC_SHIFT;
279 drvdata->src = pdata.default_src - 1;
282 drvdata->cdev.name = pdata.name;
283 drvdata->cdev.default_trigger = pdata.default_trigger;
284 drvdata->cdev.brightness_set = wm831x_status_set;
285 drvdata->cdev.blink_set = wm831x_status_blink_set;
287 ret = led_classdev_register(wm831x->dev, &drvdata->cdev);
289 dev_err(&pdev->dev, "Failed to register LED: %d\n", ret);
293 ret = device_create_file(drvdata->cdev.dev, &dev_attr_src);
296 "No source control for LED: %d\n", ret);
301 led_classdev_unregister(&drvdata->cdev);
307 static int wm831x_status_remove(struct platform_device *pdev)
309 struct wm831x_status *drvdata = platform_get_drvdata(pdev);
311 device_remove_file(drvdata->cdev.dev, &dev_attr_src);
312 led_classdev_unregister(&drvdata->cdev);
318 static struct platform_driver wm831x_status_driver = {
320 .name = "wm831x-status",
321 .owner = THIS_MODULE,
323 .probe = wm831x_status_probe,
324 .remove = wm831x_status_remove,
327 static int __devinit wm831x_status_init(void)
329 return platform_driver_register(&wm831x_status_driver);
331 module_init(wm831x_status_init);
333 static void wm831x_status_exit(void)
335 platform_driver_unregister(&wm831x_status_driver);
337 module_exit(wm831x_status_exit);
339 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
340 MODULE_DESCRIPTION("WM831x status LED driver");
341 MODULE_LICENSE("GPL");
342 MODULE_ALIAS("platform:wm831x-status");