1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * LED driver for WM8350 driven LEDS. |
4 | * |
5 | * Copyright(C) 2007, 2008 Wolfson Microelectronics PLC. |
6 | */ |
7 | |
8 | #include <linux/kernel.h> |
9 | #include <linux/platform_device.h> |
10 | #include <linux/leds.h> |
11 | #include <linux/err.h> |
12 | #include <linux/mfd/wm8350/pmic.h> |
13 | #include <linux/regulator/consumer.h> |
14 | #include <linux/slab.h> |
15 | #include <linux/module.h> |
16 | |
17 | /* Microamps */ |
18 | static const int isink_cur[] = { |
19 | 4, |
20 | 5, |
21 | 6, |
22 | 7, |
23 | 8, |
24 | 10, |
25 | 11, |
26 | 14, |
27 | 16, |
28 | 19, |
29 | 23, |
30 | 27, |
31 | 32, |
32 | 39, |
33 | 46, |
34 | 54, |
35 | 65, |
36 | 77, |
37 | 92, |
38 | 109, |
39 | 130, |
40 | 154, |
41 | 183, |
42 | 218, |
43 | 259, |
44 | 308, |
45 | 367, |
46 | 436, |
47 | 518, |
48 | 616, |
49 | 733, |
50 | 872, |
51 | 1037, |
52 | 1233, |
53 | 1466, |
54 | 1744, |
55 | 2073, |
56 | 2466, |
57 | 2933, |
58 | 3487, |
59 | 4147, |
60 | 4932, |
61 | 5865, |
62 | 6975, |
63 | 8294, |
64 | 9864, |
65 | 11730, |
66 | 13949, |
67 | 16589, |
68 | 19728, |
69 | 23460, |
70 | 27899, |
71 | 33178, |
72 | 39455, |
73 | 46920, |
74 | 55798, |
75 | 66355, |
76 | 78910, |
77 | 93840, |
78 | 111596, |
79 | 132710, |
80 | 157820, |
81 | 187681, |
82 | 223191 |
83 | }; |
84 | |
85 | #define to_wm8350_led(led_cdev) \ |
86 | container_of(led_cdev, struct wm8350_led, cdev) |
87 | |
88 | static int wm8350_led_enable(struct wm8350_led *led) |
89 | { |
90 | int ret = 0; |
91 | |
92 | if (led->enabled) |
93 | return ret; |
94 | |
95 | ret = regulator_enable(regulator: led->isink); |
96 | if (ret != 0) { |
97 | dev_err(led->cdev.dev, "Failed to enable ISINK: %d\n" , ret); |
98 | return ret; |
99 | } |
100 | |
101 | ret = regulator_enable(regulator: led->dcdc); |
102 | if (ret != 0) { |
103 | dev_err(led->cdev.dev, "Failed to enable DCDC: %d\n" , ret); |
104 | regulator_disable(regulator: led->isink); |
105 | return ret; |
106 | } |
107 | |
108 | led->enabled = 1; |
109 | |
110 | return ret; |
111 | } |
112 | |
113 | static int wm8350_led_disable(struct wm8350_led *led) |
114 | { |
115 | int ret = 0; |
116 | |
117 | if (!led->enabled) |
118 | return ret; |
119 | |
120 | ret = regulator_disable(regulator: led->dcdc); |
121 | if (ret != 0) { |
122 | dev_err(led->cdev.dev, "Failed to disable DCDC: %d\n" , ret); |
123 | return ret; |
124 | } |
125 | |
126 | ret = regulator_disable(regulator: led->isink); |
127 | if (ret != 0) { |
128 | dev_err(led->cdev.dev, "Failed to disable ISINK: %d\n" , ret); |
129 | ret = regulator_enable(regulator: led->dcdc); |
130 | if (ret != 0) |
131 | dev_err(led->cdev.dev, "Failed to reenable DCDC: %d\n" , |
132 | ret); |
133 | return ret; |
134 | } |
135 | |
136 | led->enabled = 0; |
137 | |
138 | return ret; |
139 | } |
140 | |
141 | static int wm8350_led_set(struct led_classdev *led_cdev, |
142 | enum led_brightness value) |
143 | { |
144 | struct wm8350_led *led = to_wm8350_led(led_cdev); |
145 | unsigned long flags; |
146 | int ret; |
147 | int uA; |
148 | |
149 | led->value = value; |
150 | |
151 | spin_lock_irqsave(&led->value_lock, flags); |
152 | |
153 | if (led->value == LED_OFF) { |
154 | spin_unlock_irqrestore(lock: &led->value_lock, flags); |
155 | return wm8350_led_disable(led); |
156 | } |
157 | |
158 | /* This scales linearly into the index of valid current |
159 | * settings which results in a linear scaling of perceived |
160 | * brightness due to the non-linear current settings provided |
161 | * by the hardware. |
162 | */ |
163 | uA = (led->max_uA_index * led->value) / LED_FULL; |
164 | spin_unlock_irqrestore(lock: &led->value_lock, flags); |
165 | BUG_ON(uA >= ARRAY_SIZE(isink_cur)); |
166 | |
167 | ret = regulator_set_current_limit(regulator: led->isink, min_uA: isink_cur[uA], |
168 | max_uA: isink_cur[uA]); |
169 | if (ret != 0) { |
170 | dev_err(led->cdev.dev, "Failed to set %duA: %d\n" , |
171 | isink_cur[uA], ret); |
172 | return ret; |
173 | } |
174 | |
175 | return wm8350_led_enable(led); |
176 | } |
177 | |
178 | static void wm8350_led_shutdown(struct platform_device *pdev) |
179 | { |
180 | struct wm8350_led *led = platform_get_drvdata(pdev); |
181 | |
182 | led->value = LED_OFF; |
183 | wm8350_led_disable(led); |
184 | } |
185 | |
186 | static int wm8350_led_probe(struct platform_device *pdev) |
187 | { |
188 | struct regulator *isink, *dcdc; |
189 | struct wm8350_led *led; |
190 | struct wm8350_led_platform_data *pdata = dev_get_platdata(dev: &pdev->dev); |
191 | int i; |
192 | |
193 | if (pdata == NULL) { |
194 | dev_err(&pdev->dev, "no platform data\n" ); |
195 | return -ENODEV; |
196 | } |
197 | |
198 | if (pdata->max_uA < isink_cur[0]) { |
199 | dev_err(&pdev->dev, "Invalid maximum current %duA\n" , |
200 | pdata->max_uA); |
201 | return -EINVAL; |
202 | } |
203 | |
204 | isink = devm_regulator_get(dev: &pdev->dev, id: "led_isink" ); |
205 | if (IS_ERR(ptr: isink)) { |
206 | dev_err(&pdev->dev, "%s: can't get ISINK\n" , __func__); |
207 | return PTR_ERR(ptr: isink); |
208 | } |
209 | |
210 | dcdc = devm_regulator_get(dev: &pdev->dev, id: "led_vcc" ); |
211 | if (IS_ERR(ptr: dcdc)) { |
212 | dev_err(&pdev->dev, "%s: can't get DCDC\n" , __func__); |
213 | return PTR_ERR(ptr: dcdc); |
214 | } |
215 | |
216 | led = devm_kzalloc(dev: &pdev->dev, size: sizeof(*led), GFP_KERNEL); |
217 | if (led == NULL) |
218 | return -ENOMEM; |
219 | |
220 | led->cdev.brightness_set_blocking = wm8350_led_set; |
221 | led->cdev.default_trigger = pdata->default_trigger; |
222 | led->cdev.name = pdata->name; |
223 | led->cdev.flags |= LED_CORE_SUSPENDRESUME; |
224 | led->enabled = regulator_is_enabled(regulator: isink); |
225 | led->isink = isink; |
226 | led->dcdc = dcdc; |
227 | |
228 | for (i = 0; i < ARRAY_SIZE(isink_cur) - 1; i++) |
229 | if (isink_cur[i] >= pdata->max_uA) |
230 | break; |
231 | led->max_uA_index = i; |
232 | if (pdata->max_uA != isink_cur[i]) |
233 | dev_warn(&pdev->dev, |
234 | "Maximum current %duA is not directly supported," |
235 | " check platform data\n" , |
236 | pdata->max_uA); |
237 | |
238 | spin_lock_init(&led->value_lock); |
239 | led->value = LED_OFF; |
240 | platform_set_drvdata(pdev, data: led); |
241 | |
242 | return led_classdev_register(parent: &pdev->dev, led_cdev: &led->cdev); |
243 | } |
244 | |
245 | static void wm8350_led_remove(struct platform_device *pdev) |
246 | { |
247 | struct wm8350_led *led = platform_get_drvdata(pdev); |
248 | |
249 | led_classdev_unregister(led_cdev: &led->cdev); |
250 | wm8350_led_disable(led); |
251 | } |
252 | |
253 | static struct platform_driver wm8350_led_driver = { |
254 | .driver = { |
255 | .name = "wm8350-led" , |
256 | }, |
257 | .probe = wm8350_led_probe, |
258 | .remove_new = wm8350_led_remove, |
259 | .shutdown = wm8350_led_shutdown, |
260 | }; |
261 | |
262 | module_platform_driver(wm8350_led_driver); |
263 | |
264 | MODULE_AUTHOR("Mark Brown" ); |
265 | MODULE_DESCRIPTION("WM8350 LED driver" ); |
266 | MODULE_LICENSE("GPL" ); |
267 | MODULE_ALIAS("platform:wm8350-led" ); |
268 | |