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/platform_device.h>
14 #include <linux/slab.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>
20 #include <linux/module.h>
23 struct wm831x_status {
24 struct led_classdev cdev;
25 struct wm831x *wm831x;
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_set(struct wm831x_status *led)
46 mutex_lock(&led->mutex);
48 led->reg_val &= ~(WM831X_LED_SRC_MASK | WM831X_LED_MODE_MASK |
49 WM831X_LED_DUTY_CYC_MASK | WM831X_LED_DUR_MASK);
51 spin_lock_irqsave(&led->value_lock, flags);
53 led->reg_val |= led->src << WM831X_LED_SRC_SHIFT;
55 led->reg_val |= 2 << WM831X_LED_MODE_SHIFT;
56 led->reg_val |= led->blink_time << WM831X_LED_DUR_SHIFT;
57 led->reg_val |= led->blink_cyc;
59 if (led->brightness != LED_OFF)
60 led->reg_val |= 1 << WM831X_LED_MODE_SHIFT;
63 spin_unlock_irqrestore(&led->value_lock, flags);
65 wm831x_reg_write(led->wm831x, led->reg, led->reg_val);
67 mutex_unlock(&led->mutex);
70 static int wm831x_status_brightness_set(struct led_classdev *led_cdev,
71 enum led_brightness value)
73 struct wm831x_status *led = to_wm831x_status(led_cdev);
76 spin_lock_irqsave(&led->value_lock, flags);
77 led->brightness = value;
80 spin_unlock_irqrestore(&led->value_lock, flags);
81 wm831x_status_set(led);
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 spin_unlock_irqrestore(&led->value_lock, flags);
150 wm831x_status_set(led);
155 static const char * const led_src_texts[] = {
162 static ssize_t wm831x_status_src_show(struct device *dev,
163 struct device_attribute *attr, char *buf)
165 struct led_classdev *led_cdev = dev_get_drvdata(dev);
166 struct wm831x_status *led = to_wm831x_status(led_cdev);
170 mutex_lock(&led->mutex);
172 for (i = 0; i < ARRAY_SIZE(led_src_texts); i++)
174 ret += sprintf(&buf[ret], "[%s] ", led_src_texts[i]);
176 ret += sprintf(&buf[ret], "%s ", led_src_texts[i]);
178 mutex_unlock(&led->mutex);
180 ret += sprintf(&buf[ret], "\n");
185 static ssize_t wm831x_status_src_store(struct device *dev,
186 struct device_attribute *attr,
187 const char *buf, size_t size)
189 struct led_classdev *led_cdev = dev_get_drvdata(dev);
190 struct wm831x_status *led = to_wm831x_status(led_cdev);
195 name[sizeof(name) - 1] = '\0';
196 strncpy(name, buf, sizeof(name) - 1);
199 if (len && name[len - 1] == '\n')
200 name[len - 1] = '\0';
202 for (i = 0; i < ARRAY_SIZE(led_src_texts); i++) {
203 if (!strcmp(name, led_src_texts[i])) {
204 mutex_lock(&led->mutex);
206 mutex_unlock(&led->mutex);
207 wm831x_status_set(led);
214 static DEVICE_ATTR(src, 0644, wm831x_status_src_show, wm831x_status_src_store);
216 static struct attribute *wm831x_status_attrs[] = {
220 ATTRIBUTE_GROUPS(wm831x_status);
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_REG, 0);
234 dev_err(&pdev->dev, "No register resource\n");
238 drvdata = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_status),
243 drvdata->wm831x = wm831x;
244 drvdata->reg = res->start;
246 if (dev_get_platdata(wm831x->dev))
247 chip_pdata = dev_get_platdata(wm831x->dev);
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 spin_lock_init(&drvdata->value_lock);
260 /* We cache the configuration register and read startup values
262 drvdata->reg_val = wm831x_reg_read(wm831x, drvdata->reg);
264 if (drvdata->reg_val & WM831X_LED_MODE_MASK)
265 drvdata->brightness = LED_FULL;
267 drvdata->brightness = LED_OFF;
269 /* Set a default source if configured, otherwise leave the
270 * current hardware setting.
272 if (pdata.default_src == WM831X_STATUS_PRESERVE) {
273 drvdata->src = drvdata->reg_val;
274 drvdata->src &= WM831X_LED_SRC_MASK;
275 drvdata->src >>= WM831X_LED_SRC_SHIFT;
277 drvdata->src = pdata.default_src - 1;
280 drvdata->cdev.name = pdata.name;
281 drvdata->cdev.default_trigger = pdata.default_trigger;
282 drvdata->cdev.brightness_set_blocking = wm831x_status_brightness_set;
283 drvdata->cdev.blink_set = wm831x_status_blink_set;
284 drvdata->cdev.groups = wm831x_status_groups;
286 ret = devm_led_classdev_register(wm831x->dev, &drvdata->cdev);
288 dev_err(&pdev->dev, "Failed to register LED: %d\n", ret);
295 static struct platform_driver wm831x_status_driver = {
297 .name = "wm831x-status",
299 .probe = wm831x_status_probe,
302 module_platform_driver(wm831x_status_driver);
304 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
305 MODULE_DESCRIPTION("WM831x status LED driver");
306 MODULE_LICENSE("GPL");
307 MODULE_ALIAS("platform:wm831x-status");