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>
22 struct light_state_t {
32 struct wm831x_status {
33 struct led_classdev cdev;
34 struct wm831x *wm831x;
35 struct work_struct work;
38 spinlock_t value_lock;
39 int reg; /* Control register */
40 int reg_val; /* Control register value */
46 enum led_brightness brightness;
49 #define to_wm831x_status(led_cdev) \
50 container_of(led_cdev, struct wm831x_status, cdev)
52 static void wm831x_status_work(struct work_struct *work)
54 struct wm831x_status *led = container_of(work, struct wm831x_status,
58 mutex_lock(&led->mutex);
60 led->reg_val &= ~(WM831X_LED_SRC_MASK | WM831X_LED_MODE_MASK |
61 WM831X_LED_DUTY_CYC_MASK | WM831X_LED_DUR_MASK);
63 spin_lock_irqsave(&led->value_lock, flags);
65 led->reg_val |= led->src << WM831X_LED_SRC_SHIFT;
67 led->reg_val |= 2 << WM831X_LED_MODE_SHIFT;
68 led->reg_val |= led->blink_time << WM831X_LED_DUR_SHIFT;
69 led->reg_val |= led->blink_cyc;
71 if (led->brightness != LED_OFF)
72 led->reg_val |= 1 << WM831X_LED_MODE_SHIFT;
75 spin_unlock_irqrestore(&led->value_lock, flags);
77 wm831x_reg_write(led->wm831x, led->reg, led->reg_val);
79 mutex_unlock(&led->mutex);
82 static void wm831x_status_set(struct led_classdev *led_cdev,
83 enum led_brightness value)
85 struct wm831x_status *led = to_wm831x_status(led_cdev);
88 spin_lock_irqsave(&led->value_lock, flags);
89 led->brightness = value;
92 schedule_work(&led->work);
93 spin_unlock_irqrestore(&led->value_lock, flags);
96 static int wm831x_status_blink_set(struct led_classdev *led_cdev,
97 unsigned long *delay_on,
98 unsigned long *delay_off)
100 struct wm831x_status *led = to_wm831x_status(led_cdev);
104 /* Pick some defaults if we've not been given times */
105 if (*delay_on == 0 && *delay_off == 0) {
110 spin_lock_irqsave(&led->value_lock, flags);
112 /* We only have a limited selection of settings, see if we can
113 * support the configuration we're being given */
126 /* Actually 62.5ms */
135 switch (*delay_off / *delay_on) {
159 /* Always update; if we fail turn off blinking since we expect
160 * a software fallback. */
161 schedule_work(&led->work);
163 spin_unlock_irqrestore(&led->value_lock, flags);
168 static ssize_t wm831x_status_blink_store(struct device *dev,
169 struct device_attribute *attr,
170 const char *buf, size_t size)
172 struct led_classdev *led_cdev = dev_get_drvdata(dev);
173 struct wm831x_status *led = to_wm831x_status(led_cdev);
174 struct light_state_t *light_state = NULL;
177 enum led_brightness value;
178 unsigned int delay_on, delay_off, mode, color;
180 if (size != sizeof (struct light_state_t)) {
181 printk("%s: set led blink err\n", __func__);
185 light_state = (struct light_state_t *)buf;
189 value = light_state->brightness;
190 delay_on = light_state->onms;
191 delay_off = light_state->offms;
192 mode = light_state->mode;
193 color = light_state->color;
195 //printk("%s: color = %#x delay_on = %d delya_off = %d brightness = %d mode = %d\n",
196 // __func__, color, delay_on, delay_off, value, mode);
197 if (delay_on == 0 && delay_off == 0) {
202 spin_lock_irqsave(&led->value_lock, flags);
217 /* Actually 62.5ms */
226 switch (delay_off / delay_on) {
251 led->brightness = mode;
252 if (led->brightness == LED_OFF)
255 schedule_work(&led->work);
257 spin_unlock_irqrestore(&led->value_lock, flags);
262 static DEVICE_ATTR(blink, 0777, NULL, wm831x_status_blink_store);
264 static const char *led_src_texts[] = {
271 static ssize_t wm831x_status_src_show(struct device *dev,
272 struct device_attribute *attr, char *buf)
274 struct led_classdev *led_cdev = dev_get_drvdata(dev);
275 struct wm831x_status *led = to_wm831x_status(led_cdev);
279 mutex_lock(&led->mutex);
281 for (i = 0; i < ARRAY_SIZE(led_src_texts); i++)
283 ret += sprintf(&buf[ret], "[%s] ", led_src_texts[i]);
285 ret += sprintf(&buf[ret], "%s ", led_src_texts[i]);
287 mutex_unlock(&led->mutex);
289 ret += sprintf(&buf[ret], "\n");
294 static ssize_t wm831x_status_src_store(struct device *dev,
295 struct device_attribute *attr,
296 const char *buf, size_t size)
298 struct led_classdev *led_cdev = dev_get_drvdata(dev);
299 struct wm831x_status *led = to_wm831x_status(led_cdev);
304 name[sizeof(name) - 1] = '\0';
305 strncpy(name, buf, sizeof(name) - 1);
308 if (len && name[len - 1] == '\n')
309 name[len - 1] = '\0';
311 for (i = 0; i < ARRAY_SIZE(led_src_texts); i++) {
312 if (!strcmp(name, led_src_texts[i])) {
313 mutex_lock(&led->mutex);
316 schedule_work(&led->work);
318 mutex_unlock(&led->mutex);
325 static DEVICE_ATTR(src, 0644, wm831x_status_src_show, wm831x_status_src_store);
327 static int wm831x_status_probe(struct platform_device *pdev)
329 struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
330 struct wm831x_pdata *chip_pdata;
331 struct wm831x_status_pdata pdata;
332 struct wm831x_status *drvdata;
333 struct resource *res;
334 int id = pdev->id % ARRAY_SIZE(chip_pdata->status);
337 res = platform_get_resource(pdev, IORESOURCE_IO, 0);
339 dev_err(&pdev->dev, "No I/O resource\n");
344 drvdata = kzalloc(sizeof(struct wm831x_status), GFP_KERNEL);
347 dev_set_drvdata(&pdev->dev, drvdata);
349 drvdata->wm831x = wm831x;
350 drvdata->reg = res->start;
352 if (wm831x->dev->platform_data)
353 chip_pdata = wm831x->dev->platform_data;
357 memset(&pdata, 0, sizeof(pdata));
358 if (chip_pdata && chip_pdata->status[id])
359 memcpy(&pdata, chip_pdata->status[id], sizeof(pdata));
361 pdata.name = dev_name(&pdev->dev);
363 mutex_init(&drvdata->mutex);
364 INIT_WORK(&drvdata->work, wm831x_status_work);
365 spin_lock_init(&drvdata->value_lock);
367 /* We cache the configuration register and read startup values
369 drvdata->reg_val = wm831x_reg_read(wm831x, drvdata->reg);
370 if (drvdata->reg == WM831X_STATUS_LED_2)
371 wm831x_reg_write(wm831x, drvdata->reg, 0xc027);
373 if (drvdata->reg_val & WM831X_LED_MODE_MASK)
374 drvdata->brightness = LED_FULL;
376 drvdata->brightness = LED_OFF;
378 /* Set a default source if configured, otherwise leave the
379 * current hardware setting.
381 if (pdata.default_src == WM831X_STATUS_PRESERVE) {
382 drvdata->src = drvdata->reg_val;
383 drvdata->src &= WM831X_LED_SRC_MASK;
384 drvdata->src >>= WM831X_LED_SRC_SHIFT;
386 drvdata->src = pdata.default_src - 1;
389 drvdata->cdev.name = pdata.name;
390 drvdata->cdev.default_trigger = pdata.default_trigger;
391 drvdata->cdev.brightness_set = wm831x_status_set;
392 drvdata->cdev.blink_set = wm831x_status_blink_set;
394 ret = led_classdev_register(wm831x->dev, &drvdata->cdev);
396 dev_err(&pdev->dev, "Failed to register LED: %d\n", ret);
400 ret = device_create_file(drvdata->cdev.dev, &dev_attr_blink);
403 "LED no blink function: %d\n", ret);
405 ret = device_create_file(drvdata->cdev.dev, &dev_attr_src);
408 "No source control for LED: %d\n", ret);
413 led_classdev_unregister(&drvdata->cdev);
419 static int wm831x_status_remove(struct platform_device *pdev)
421 struct wm831x_status *drvdata = platform_get_drvdata(pdev);
423 device_remove_file(drvdata->cdev.dev, &dev_attr_src);
424 led_classdev_unregister(&drvdata->cdev);
430 static struct platform_driver wm831x_status_driver = {
432 .name = "wm831x-status",
433 .owner = THIS_MODULE,
435 .probe = wm831x_status_probe,
436 .remove = wm831x_status_remove,
439 static int __devinit wm831x_status_init(void)
441 return platform_driver_register(&wm831x_status_driver);
443 module_init(wm831x_status_init);
445 static void wm831x_status_exit(void)
447 platform_driver_unregister(&wm831x_status_driver);
449 module_exit(wm831x_status_exit);
451 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
452 MODULE_DESCRIPTION("WM831x status LED driver");
453 MODULE_LICENSE("GPL");
454 MODULE_ALIAS("platform:wm831x-status");