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
19struct 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
38static 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
66static 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
82static 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
151static const char * const led_src_texts[] = {
152	"otp",
153	"power",
154	"charger",
155	"soft",
156};
157
158static 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
181static 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
200static DEVICE_ATTR_RW(src);
201
202static struct attribute *wm831x_status_attrs[] = {
203	&dev_attr_src.attr,
204	NULL
205};
206ATTRIBUTE_GROUPS(wm831x_status);
207
208static 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
283static void 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
290static struct platform_driver wm831x_status_driver = {
291	.driver = {
292		   .name = "wm831x-status",
293		   },
294	.probe = wm831x_status_probe,
295	.remove_new = wm831x_status_remove,
296};
297
298module_platform_driver(wm831x_status_driver);
299
300MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
301MODULE_DESCRIPTION("WM831x status LED driver");
302MODULE_LICENSE("GPL");
303MODULE_ALIAS("platform:wm831x-status");
304