Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
[platform/kernel/linux-rpi.git] / drivers / leds / leds-wm831x-status.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * LED driver for WM831x status LEDs
4  *
5  * Copyright(C) 2009 Wolfson Microelectronics PLC.
6  */
7
8 #include <linux/kernel.h>
9 #include <linux/platform_device.h>
10 #include <linux/slab.h>
11 #include <linux/leds.h>
12 #include <linux/err.h>
13 #include <linux/mfd/wm831x/core.h>
14 #include <linux/mfd/wm831x/pdata.h>
15 #include <linux/mfd/wm831x/status.h>
16 #include <linux/module.h>
17
18
19 struct wm831x_status {
20         struct led_classdev cdev;
21         struct wm831x *wm831x;
22         struct mutex mutex;
23
24         spinlock_t value_lock;
25         int reg;     /* Control register */
26         int reg_val; /* Control register value */
27
28         int blink;
29         int blink_time;
30         int blink_cyc;
31         int src;
32         enum led_brightness brightness;
33 };
34
35 #define to_wm831x_status(led_cdev) \
36         container_of(led_cdev, struct wm831x_status, cdev)
37
38 static void wm831x_status_set(struct wm831x_status *led)
39 {
40         unsigned long flags;
41
42         mutex_lock(&led->mutex);
43
44         led->reg_val &= ~(WM831X_LED_SRC_MASK | WM831X_LED_MODE_MASK |
45                           WM831X_LED_DUTY_CYC_MASK | WM831X_LED_DUR_MASK);
46
47         spin_lock_irqsave(&led->value_lock, flags);
48
49         led->reg_val |= led->src << WM831X_LED_SRC_SHIFT;
50         if (led->blink) {
51                 led->reg_val |= 2 << WM831X_LED_MODE_SHIFT;
52                 led->reg_val |= led->blink_time << WM831X_LED_DUR_SHIFT;
53                 led->reg_val |= led->blink_cyc;
54         } else {
55                 if (led->brightness != LED_OFF)
56                         led->reg_val |= 1 << WM831X_LED_MODE_SHIFT;
57         }
58
59         spin_unlock_irqrestore(&led->value_lock, flags);
60
61         wm831x_reg_write(led->wm831x, led->reg, led->reg_val);
62
63         mutex_unlock(&led->mutex);
64 }
65
66 static int wm831x_status_brightness_set(struct led_classdev *led_cdev,
67                                          enum led_brightness value)
68 {
69         struct wm831x_status *led = to_wm831x_status(led_cdev);
70         unsigned long flags;
71
72         spin_lock_irqsave(&led->value_lock, flags);
73         led->brightness = value;
74         if (value == LED_OFF)
75                 led->blink = 0;
76         spin_unlock_irqrestore(&led->value_lock, flags);
77         wm831x_status_set(led);
78
79         return 0;
80 }
81
82 static int wm831x_status_blink_set(struct led_classdev *led_cdev,
83                                    unsigned long *delay_on,
84                                    unsigned long *delay_off)
85 {
86         struct wm831x_status *led = to_wm831x_status(led_cdev);
87         unsigned long flags;
88         int ret = 0;
89
90         /* Pick some defaults if we've not been given times */
91         if (*delay_on == 0 && *delay_off == 0) {
92                 *delay_on = 250;
93                 *delay_off = 250;
94         }
95
96         spin_lock_irqsave(&led->value_lock, flags);
97
98         /* We only have a limited selection of settings, see if we can
99          * support the configuration we're being given */
100         switch (*delay_on) {
101         case 1000:
102                 led->blink_time = 0;
103                 break;
104         case 250:
105                 led->blink_time = 1;
106                 break;
107         case 125:
108                 led->blink_time = 2;
109                 break;
110         case 62:
111         case 63:
112                 /* Actually 62.5ms */
113                 led->blink_time = 3;
114                 break;
115         default:
116                 ret = -EINVAL;
117                 break;
118         }
119
120         if (ret == 0) {
121                 switch (*delay_off / *delay_on) {
122                 case 1:
123                         led->blink_cyc = 0;
124                         break;
125                 case 3:
126                         led->blink_cyc = 1;
127                         break;
128                 case 4:
129                         led->blink_cyc = 2;
130                         break;
131                 case 8:
132                         led->blink_cyc = 3;
133                         break;
134                 default:
135                         ret = -EINVAL;
136                         break;
137                 }
138         }
139
140         if (ret == 0)
141                 led->blink = 1;
142         else
143                 led->blink = 0;
144
145         spin_unlock_irqrestore(&led->value_lock, flags);
146         wm831x_status_set(led);
147
148         return ret;
149 }
150
151 static const char * const led_src_texts[] = {
152         "otp",
153         "power",
154         "charger",
155         "soft",
156 };
157
158 static ssize_t src_show(struct device *dev,
159                         struct device_attribute *attr, char *buf)
160 {
161         struct led_classdev *led_cdev = dev_get_drvdata(dev);
162         struct wm831x_status *led = to_wm831x_status(led_cdev);
163         int i;
164         ssize_t ret = 0;
165
166         mutex_lock(&led->mutex);
167
168         for (i = 0; i < ARRAY_SIZE(led_src_texts); i++)
169                 if (i == led->src)
170                         ret += sprintf(&buf[ret], "[%s] ", led_src_texts[i]);
171                 else
172                         ret += sprintf(&buf[ret], "%s ", led_src_texts[i]);
173
174         mutex_unlock(&led->mutex);
175
176         ret += sprintf(&buf[ret], "\n");
177
178         return ret;
179 }
180
181 static ssize_t src_store(struct device *dev,
182                          struct device_attribute *attr,
183                          const char *buf, size_t size)
184 {
185         struct led_classdev *led_cdev = dev_get_drvdata(dev);
186         struct wm831x_status *led = to_wm831x_status(led_cdev);
187         int i;
188
189         i = sysfs_match_string(led_src_texts, buf);
190         if (i >= 0) {
191                 mutex_lock(&led->mutex);
192                 led->src = i;
193                 mutex_unlock(&led->mutex);
194                 wm831x_status_set(led);
195         }
196
197         return size;
198 }
199
200 static DEVICE_ATTR_RW(src);
201
202 static struct attribute *wm831x_status_attrs[] = {
203         &dev_attr_src.attr,
204         NULL
205 };
206 ATTRIBUTE_GROUPS(wm831x_status);
207
208 static int wm831x_status_probe(struct platform_device *pdev)
209 {
210         struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
211         struct wm831x_pdata *chip_pdata;
212         struct wm831x_status_pdata pdata;
213         struct wm831x_status *drvdata;
214         struct resource *res;
215         int id = pdev->id % ARRAY_SIZE(chip_pdata->status);
216         int ret;
217
218         res = platform_get_resource(pdev, IORESOURCE_REG, 0);
219         if (res == NULL) {
220                 dev_err(&pdev->dev, "No register resource\n");
221                 return -EINVAL;
222         }
223
224         drvdata = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_status),
225                                GFP_KERNEL);
226         if (!drvdata)
227                 return -ENOMEM;
228
229         drvdata->wm831x = wm831x;
230         drvdata->reg = res->start;
231
232         if (dev_get_platdata(wm831x->dev))
233                 chip_pdata = dev_get_platdata(wm831x->dev);
234         else
235                 chip_pdata = NULL;
236
237         memset(&pdata, 0, sizeof(pdata));
238         if (chip_pdata && chip_pdata->status[id])
239                 memcpy(&pdata, chip_pdata->status[id], sizeof(pdata));
240         else
241                 pdata.name = dev_name(&pdev->dev);
242
243         mutex_init(&drvdata->mutex);
244         spin_lock_init(&drvdata->value_lock);
245
246         /* We cache the configuration register and read startup values
247          * from it. */
248         drvdata->reg_val = wm831x_reg_read(wm831x, drvdata->reg);
249
250         if (drvdata->reg_val & WM831X_LED_MODE_MASK)
251                 drvdata->brightness = LED_FULL;
252         else
253                 drvdata->brightness = LED_OFF;
254
255         /* Set a default source if configured, otherwise leave the
256          * current hardware setting.
257          */
258         if (pdata.default_src == WM831X_STATUS_PRESERVE) {
259                 drvdata->src = drvdata->reg_val;
260                 drvdata->src &= WM831X_LED_SRC_MASK;
261                 drvdata->src >>= WM831X_LED_SRC_SHIFT;
262         } else {
263                 drvdata->src = pdata.default_src - 1;
264         }
265
266         drvdata->cdev.name = pdata.name;
267         drvdata->cdev.default_trigger = pdata.default_trigger;
268         drvdata->cdev.brightness_set_blocking = wm831x_status_brightness_set;
269         drvdata->cdev.blink_set = wm831x_status_blink_set;
270         drvdata->cdev.groups = wm831x_status_groups;
271
272         ret = led_classdev_register(wm831x->dev, &drvdata->cdev);
273         if (ret < 0) {
274                 dev_err(&pdev->dev, "Failed to register LED: %d\n", ret);
275                 return ret;
276         }
277
278         platform_set_drvdata(pdev, drvdata);
279
280         return 0;
281 }
282
283 static int wm831x_status_remove(struct platform_device *pdev)
284 {
285         struct wm831x_status *drvdata = platform_get_drvdata(pdev);
286
287         led_classdev_unregister(&drvdata->cdev);
288
289         return 0;
290 }
291
292 static struct platform_driver wm831x_status_driver = {
293         .driver = {
294                    .name = "wm831x-status",
295                    },
296         .probe = wm831x_status_probe,
297         .remove = wm831x_status_remove,
298 };
299
300 module_platform_driver(wm831x_status_driver);
301
302 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
303 MODULE_DESCRIPTION("WM831x status LED driver");
304 MODULE_LICENSE("GPL");
305 MODULE_ALIAS("platform:wm831x-status");