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>
21 #include <linux/module.h>
24 struct wm831x_status {
25 struct led_classdev cdev;
26 struct wm831x *wm831x;
27 struct work_struct work;
30 spinlock_t value_lock;
31 int reg; /* Control register */
32 int reg_val; /* Control register value */
38 enum led_brightness brightness;
41 #define to_wm831x_status(led_cdev) \
42 container_of(led_cdev, struct wm831x_status, cdev)
44 static void wm831x_status_work(struct work_struct *work)
46 struct wm831x_status *led = container_of(work, struct wm831x_status,
50 mutex_lock(&led->mutex);
52 led->reg_val &= ~(WM831X_LED_SRC_MASK | WM831X_LED_MODE_MASK |
53 WM831X_LED_DUTY_CYC_MASK | WM831X_LED_DUR_MASK);
55 spin_lock_irqsave(&led->value_lock, flags);
57 led->reg_val |= led->src << WM831X_LED_SRC_SHIFT;
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;
63 if (led->brightness != LED_OFF)
64 led->reg_val |= 1 << WM831X_LED_MODE_SHIFT;
67 spin_unlock_irqrestore(&led->value_lock, flags);
69 wm831x_reg_write(led->wm831x, led->reg, led->reg_val);
71 mutex_unlock(&led->mutex);
74 static void wm831x_status_set(struct led_classdev *led_cdev,
75 enum led_brightness value)
77 struct wm831x_status *led = to_wm831x_status(led_cdev);
80 spin_lock_irqsave(&led->value_lock, flags);
81 led->brightness = value;
84 schedule_work(&led->work);
85 spin_unlock_irqrestore(&led->value_lock, flags);
88 static int wm831x_status_blink_set(struct led_classdev *led_cdev,
89 unsigned long *delay_on,
90 unsigned long *delay_off)
92 struct wm831x_status *led = to_wm831x_status(led_cdev);
96 /* Pick some defaults if we've not been given times */
97 if (*delay_on == 0 && *delay_off == 0) {
102 spin_lock_irqsave(&led->value_lock, flags);
104 /* We only have a limited selection of settings, see if we can
105 * support the configuration we're being given */
118 /* Actually 62.5ms */
127 switch (*delay_off / *delay_on) {
151 /* Always update; if we fail turn off blinking since we expect
152 * a software fallback. */
153 schedule_work(&led->work);
155 spin_unlock_irqrestore(&led->value_lock, flags);
160 static const char *led_src_texts[] = {
167 static ssize_t wm831x_status_src_show(struct device *dev,
168 struct device_attribute *attr, char *buf)
170 struct led_classdev *led_cdev = dev_get_drvdata(dev);
171 struct wm831x_status *led = to_wm831x_status(led_cdev);
175 mutex_lock(&led->mutex);
177 for (i = 0; i < ARRAY_SIZE(led_src_texts); i++)
179 ret += sprintf(&buf[ret], "[%s] ", led_src_texts[i]);
181 ret += sprintf(&buf[ret], "%s ", led_src_texts[i]);
183 mutex_unlock(&led->mutex);
185 ret += sprintf(&buf[ret], "\n");
190 static ssize_t wm831x_status_src_store(struct device *dev,
191 struct device_attribute *attr,
192 const char *buf, size_t size)
194 struct led_classdev *led_cdev = dev_get_drvdata(dev);
195 struct wm831x_status *led = to_wm831x_status(led_cdev);
200 name[sizeof(name) - 1] = '\0';
201 strncpy(name, buf, sizeof(name) - 1);
204 if (len && name[len - 1] == '\n')
205 name[len - 1] = '\0';
207 for (i = 0; i < ARRAY_SIZE(led_src_texts); i++) {
208 if (!strcmp(name, led_src_texts[i])) {
209 mutex_lock(&led->mutex);
212 schedule_work(&led->work);
214 mutex_unlock(&led->mutex);
221 static DEVICE_ATTR(src, 0644, wm831x_status_src_show, wm831x_status_src_store);
223 static int wm831x_status_probe(struct platform_device *pdev)
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);
233 res = platform_get_resource(pdev, IORESOURCE_IO, 0);
235 dev_err(&pdev->dev, "No I/O resource\n");
240 drvdata = kzalloc(sizeof(struct wm831x_status), GFP_KERNEL);
243 dev_set_drvdata(&pdev->dev, drvdata);
245 drvdata->wm831x = wm831x;
246 drvdata->reg = res->start;
248 if (wm831x->dev->platform_data)
249 chip_pdata = wm831x->dev->platform_data;
253 memset(&pdata, 0, sizeof(pdata));
254 if (chip_pdata && chip_pdata->status[id])
255 memcpy(&pdata, chip_pdata->status[id], sizeof(pdata));
257 pdata.name = dev_name(&pdev->dev);
259 mutex_init(&drvdata->mutex);
260 INIT_WORK(&drvdata->work, wm831x_status_work);
261 spin_lock_init(&drvdata->value_lock);
263 /* We cache the configuration register and read startup values
265 drvdata->reg_val = wm831x_reg_read(wm831x, drvdata->reg);
267 if (drvdata->reg_val & WM831X_LED_MODE_MASK)
268 drvdata->brightness = LED_FULL;
270 drvdata->brightness = LED_OFF;
272 /* Set a default source if configured, otherwise leave the
273 * current hardware setting.
275 if (pdata.default_src == WM831X_STATUS_PRESERVE) {
276 drvdata->src = drvdata->reg_val;
277 drvdata->src &= WM831X_LED_SRC_MASK;
278 drvdata->src >>= WM831X_LED_SRC_SHIFT;
280 drvdata->src = pdata.default_src - 1;
283 drvdata->cdev.name = pdata.name;
284 drvdata->cdev.default_trigger = pdata.default_trigger;
285 drvdata->cdev.brightness_set = wm831x_status_set;
286 drvdata->cdev.blink_set = wm831x_status_blink_set;
288 ret = led_classdev_register(wm831x->dev, &drvdata->cdev);
290 dev_err(&pdev->dev, "Failed to register LED: %d\n", ret);
294 ret = device_create_file(drvdata->cdev.dev, &dev_attr_src);
297 "No source control for LED: %d\n", ret);
302 led_classdev_unregister(&drvdata->cdev);
308 static int wm831x_status_remove(struct platform_device *pdev)
310 struct wm831x_status *drvdata = platform_get_drvdata(pdev);
312 device_remove_file(drvdata->cdev.dev, &dev_attr_src);
313 led_classdev_unregister(&drvdata->cdev);
319 static struct platform_driver wm831x_status_driver = {
321 .name = "wm831x-status",
322 .owner = THIS_MODULE,
324 .probe = wm831x_status_probe,
325 .remove = wm831x_status_remove,
328 static int __devinit wm831x_status_init(void)
330 return platform_driver_register(&wm831x_status_driver);
332 module_init(wm831x_status_init);
334 static void wm831x_status_exit(void)
336 platform_driver_unregister(&wm831x_status_driver);
338 module_exit(wm831x_status_exit);
340 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
341 MODULE_DESCRIPTION("WM831x status LED driver");
342 MODULE_LICENSE("GPL");
343 MODULE_ALIAS("platform:wm831x-status");