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1 | // SPDX-License-Identifier: GPL-2.0+ |
2 | // | |
3 | // Driver for Panasonic AN30259A 3-channel LED driver | |
4 | // | |
5 | // Copyright (c) 2018 Simon Shields <simon@lineageos.org> | |
6 | // | |
7 | // Datasheet: | |
8 | // https://www.alliedelec.com/m/d/a9d2b3ee87c2d1a535a41dd747b1c247.pdf | |
9 | ||
10 | #include <linux/i2c.h> | |
11 | #include <linux/leds.h> | |
12 | #include <linux/module.h> | |
13 | #include <linux/mutex.h> | |
14 | #include <linux/of.h> | |
15 | #include <linux/regmap.h> | |
16 | #include <uapi/linux/uleds.h> | |
17 | ||
18 | #define AN30259A_MAX_LEDS 3 | |
19 | ||
20 | #define AN30259A_REG_SRESET 0x00 | |
21 | #define AN30259A_LED_SRESET BIT(0) | |
22 | ||
23 | /* LED power registers */ | |
24 | #define AN30259A_REG_LED_ON 0x01 | |
25 | #define AN30259A_LED_EN(x) BIT((x) - 1) | |
26 | #define AN30259A_LED_SLOPE(x) BIT(((x) - 1) + 4) | |
27 | ||
28 | #define AN30259A_REG_LEDCC(x) (0x03 + ((x) - 1)) | |
29 | ||
30 | /* slope control registers */ | |
31 | #define AN30259A_REG_SLOPE(x) (0x06 + ((x) - 1)) | |
32 | #define AN30259A_LED_SLOPETIME1(x) (x) | |
33 | #define AN30259A_LED_SLOPETIME2(x) ((x) << 4) | |
34 | ||
35 | #define AN30259A_REG_LEDCNT1(x) (0x09 + (4 * ((x) - 1))) | |
36 | #define AN30259A_LED_DUTYMAX(x) ((x) << 4) | |
37 | #define AN30259A_LED_DUTYMID(x) (x) | |
38 | ||
39 | #define AN30259A_REG_LEDCNT2(x) (0x0A + (4 * ((x) - 1))) | |
40 | #define AN30259A_LED_DELAY(x) ((x) << 4) | |
41 | #define AN30259A_LED_DUTYMIN(x) (x) | |
42 | ||
43 | /* detention time control (length of each slope step) */ | |
44 | #define AN30259A_REG_LEDCNT3(x) (0x0B + (4 * ((x) - 1))) | |
45 | #define AN30259A_LED_DT1(x) (x) | |
46 | #define AN30259A_LED_DT2(x) ((x) << 4) | |
47 | ||
48 | #define AN30259A_REG_LEDCNT4(x) (0x0C + (4 * ((x) - 1))) | |
49 | #define AN30259A_LED_DT3(x) (x) | |
50 | #define AN30259A_LED_DT4(x) ((x) << 4) | |
51 | ||
52 | #define AN30259A_REG_MAX 0x14 | |
53 | ||
54 | #define AN30259A_BLINK_MAX_TIME 7500 /* ms */ | |
55 | #define AN30259A_SLOPE_RESOLUTION 500 /* ms */ | |
56 | ||
57 | #define STATE_OFF 0 | |
58 | #define STATE_KEEP 1 | |
59 | #define STATE_ON 2 | |
60 | ||
61 | struct an30259a; | |
62 | ||
63 | struct an30259a_led { | |
64 | struct an30259a *chip; | |
65 | struct led_classdev cdev; | |
66 | u32 num; | |
67 | u32 default_state; | |
68 | bool sloping; | |
69 | char label[LED_MAX_NAME_SIZE]; | |
70 | }; | |
71 | ||
72 | struct an30259a { | |
73 | struct mutex mutex; /* held when writing to registers */ | |
74 | struct i2c_client *client; | |
75 | struct an30259a_led leds[AN30259A_MAX_LEDS]; | |
76 | struct regmap *regmap; | |
77 | int num_leds; | |
78 | }; | |
79 | ||
80 | static int an30259a_brightness_set(struct led_classdev *cdev, | |
81 | enum led_brightness brightness) | |
82 | { | |
83 | struct an30259a_led *led; | |
84 | int ret; | |
85 | unsigned int led_on; | |
86 | ||
87 | led = container_of(cdev, struct an30259a_led, cdev); | |
88 | mutex_lock(&led->chip->mutex); | |
89 | ||
90 | ret = regmap_read(led->chip->regmap, AN30259A_REG_LED_ON, &led_on); | |
91 | if (ret) | |
92 | goto error; | |
93 | ||
94 | switch (brightness) { | |
95 | case LED_OFF: | |
96 | led_on &= ~AN30259A_LED_EN(led->num); | |
97 | led_on &= ~AN30259A_LED_SLOPE(led->num); | |
98 | led->sloping = false; | |
99 | break; | |
100 | default: | |
101 | led_on |= AN30259A_LED_EN(led->num); | |
102 | if (led->sloping) | |
103 | led_on |= AN30259A_LED_SLOPE(led->num); | |
104 | ret = regmap_write(led->chip->regmap, | |
105 | AN30259A_REG_LEDCNT1(led->num), | |
106 | AN30259A_LED_DUTYMAX(0xf) | | |
107 | AN30259A_LED_DUTYMID(0xf)); | |
108 | if (ret) | |
109 | goto error; | |
110 | break; | |
111 | } | |
112 | ||
113 | ret = regmap_write(led->chip->regmap, AN30259A_REG_LED_ON, led_on); | |
114 | if (ret) | |
115 | goto error; | |
116 | ||
117 | ret = regmap_write(led->chip->regmap, AN30259A_REG_LEDCC(led->num), | |
118 | brightness); | |
119 | ||
120 | error: | |
121 | mutex_unlock(&led->chip->mutex); | |
122 | ||
123 | return ret; | |
124 | } | |
125 | ||
126 | static int an30259a_blink_set(struct led_classdev *cdev, | |
127 | unsigned long *delay_off, unsigned long *delay_on) | |
128 | { | |
129 | struct an30259a_led *led; | |
130 | int ret, num; | |
131 | unsigned int led_on; | |
132 | unsigned long off = *delay_off, on = *delay_on; | |
133 | ||
134 | led = container_of(cdev, struct an30259a_led, cdev); | |
135 | ||
136 | mutex_lock(&led->chip->mutex); | |
137 | num = led->num; | |
138 | ||
139 | /* slope time can only be a multiple of 500ms. */ | |
140 | if (off % AN30259A_SLOPE_RESOLUTION || on % AN30259A_SLOPE_RESOLUTION) { | |
141 | ret = -EINVAL; | |
142 | goto error; | |
143 | } | |
144 | ||
145 | /* up to a maximum of 7500ms. */ | |
146 | if (off > AN30259A_BLINK_MAX_TIME || on > AN30259A_BLINK_MAX_TIME) { | |
147 | ret = -EINVAL; | |
148 | goto error; | |
149 | } | |
150 | ||
151 | /* if no blink specified, default to 1 Hz. */ | |
152 | if (!off && !on) { | |
153 | *delay_off = off = 500; | |
154 | *delay_on = on = 500; | |
155 | } | |
156 | ||
157 | /* convert into values the HW will understand. */ | |
158 | off /= AN30259A_SLOPE_RESOLUTION; | |
159 | on /= AN30259A_SLOPE_RESOLUTION; | |
160 | ||
161 | /* duty min should be zero (=off), delay should be zero. */ | |
162 | ret = regmap_write(led->chip->regmap, AN30259A_REG_LEDCNT2(num), | |
163 | AN30259A_LED_DELAY(0) | AN30259A_LED_DUTYMIN(0)); | |
164 | if (ret) | |
165 | goto error; | |
166 | ||
167 | /* reset detention time (no "breathing" effect). */ | |
168 | ret = regmap_write(led->chip->regmap, AN30259A_REG_LEDCNT3(num), | |
169 | AN30259A_LED_DT1(0) | AN30259A_LED_DT2(0)); | |
170 | if (ret) | |
171 | goto error; | |
172 | ret = regmap_write(led->chip->regmap, AN30259A_REG_LEDCNT4(num), | |
173 | AN30259A_LED_DT3(0) | AN30259A_LED_DT4(0)); | |
174 | if (ret) | |
175 | goto error; | |
176 | ||
177 | /* slope time controls on/off cycle length. */ | |
178 | ret = regmap_write(led->chip->regmap, AN30259A_REG_SLOPE(num), | |
179 | AN30259A_LED_SLOPETIME1(off) | | |
180 | AN30259A_LED_SLOPETIME2(on)); | |
181 | if (ret) | |
182 | goto error; | |
183 | ||
184 | /* Finally, enable slope mode. */ | |
185 | ret = regmap_read(led->chip->regmap, AN30259A_REG_LED_ON, &led_on); | |
186 | if (ret) | |
187 | goto error; | |
188 | ||
189 | led_on |= AN30259A_LED_SLOPE(num) | AN30259A_LED_EN(led->num); | |
190 | ||
191 | ret = regmap_write(led->chip->regmap, AN30259A_REG_LED_ON, led_on); | |
192 | ||
193 | if (!ret) | |
194 | led->sloping = true; | |
195 | error: | |
196 | mutex_unlock(&led->chip->mutex); | |
197 | ||
198 | return ret; | |
199 | } | |
200 | ||
201 | static int an30259a_dt_init(struct i2c_client *client, | |
202 | struct an30259a *chip) | |
203 | { | |
204 | struct device_node *np = client->dev.of_node, *child; | |
205 | int count, ret; | |
206 | int i = 0; | |
207 | const char *str; | |
208 | struct an30259a_led *led; | |
209 | ||
210 | count = of_get_child_count(np); | |
211 | if (!count || count > AN30259A_MAX_LEDS) | |
212 | return -EINVAL; | |
213 | ||
214 | for_each_available_child_of_node(np, child) { | |
215 | u32 source; | |
216 | ||
217 | ret = of_property_read_u32(child, "reg", &source); | |
218 | if (ret != 0 || !source || source > AN30259A_MAX_LEDS) { | |
219 | dev_err(&client->dev, "Couldn't read LED address: %d\n", | |
220 | ret); | |
221 | count--; | |
222 | continue; | |
223 | } | |
224 | ||
225 | led = &chip->leds[i]; | |
226 | ||
227 | led->num = source; | |
228 | led->chip = chip; | |
229 | ||
230 | if (of_property_read_string(child, "label", &str)) | |
231 | snprintf(led->label, sizeof(led->label), "an30259a::"); | |
232 | else | |
233 | snprintf(led->label, sizeof(led->label), "an30259a:%s", | |
234 | str); | |
235 | ||
236 | led->cdev.name = led->label; | |
237 | ||
238 | if (!of_property_read_string(child, "default-state", &str)) { | |
239 | if (!strcmp(str, "on")) | |
240 | led->default_state = STATE_ON; | |
241 | else if (!strcmp(str, "keep")) | |
242 | led->default_state = STATE_KEEP; | |
243 | else | |
244 | led->default_state = STATE_OFF; | |
245 | } | |
246 | ||
247 | of_property_read_string(child, "linux,default-trigger", | |
248 | &led->cdev.default_trigger); | |
249 | ||
250 | i++; | |
251 | } | |
252 | ||
253 | if (!count) | |
254 | return -EINVAL; | |
255 | ||
256 | chip->num_leds = i; | |
257 | ||
258 | return 0; | |
259 | } | |
260 | ||
261 | static const struct regmap_config an30259a_regmap_config = { | |
262 | .reg_bits = 8, | |
263 | .val_bits = 8, | |
264 | .max_register = AN30259A_REG_MAX, | |
265 | }; | |
266 | ||
267 | static void an30259a_init_default_state(struct an30259a_led *led) | |
268 | { | |
269 | struct an30259a *chip = led->chip; | |
270 | int led_on, err; | |
271 | ||
272 | switch (led->default_state) { | |
273 | case STATE_ON: | |
274 | led->cdev.brightness = LED_FULL; | |
275 | break; | |
276 | case STATE_KEEP: | |
277 | err = regmap_read(chip->regmap, AN30259A_REG_LED_ON, &led_on); | |
278 | if (err) | |
279 | break; | |
280 | ||
281 | if (!(led_on & AN30259A_LED_EN(led->num))) { | |
282 | led->cdev.brightness = LED_OFF; | |
283 | break; | |
284 | } | |
285 | regmap_read(chip->regmap, AN30259A_REG_LEDCC(led->num), | |
286 | &led->cdev.brightness); | |
287 | break; | |
288 | default: | |
289 | led->cdev.brightness = LED_OFF; | |
290 | } | |
291 | ||
292 | an30259a_brightness_set(&led->cdev, led->cdev.brightness); | |
293 | } | |
294 | ||
295 | static int an30259a_probe(struct i2c_client *client) | |
296 | { | |
297 | struct an30259a *chip; | |
298 | int i, err; | |
299 | ||
300 | chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL); | |
301 | if (!chip) | |
302 | return -ENOMEM; | |
303 | ||
304 | err = an30259a_dt_init(client, chip); | |
305 | if (err < 0) | |
306 | return err; | |
307 | ||
308 | mutex_init(&chip->mutex); | |
309 | chip->client = client; | |
310 | i2c_set_clientdata(client, chip); | |
311 | ||
312 | chip->regmap = devm_regmap_init_i2c(client, &an30259a_regmap_config); | |
313 | ||
314 | for (i = 0; i < chip->num_leds; i++) { | |
315 | an30259a_init_default_state(&chip->leds[i]); | |
316 | chip->leds[i].cdev.brightness_set_blocking = | |
317 | an30259a_brightness_set; | |
318 | chip->leds[i].cdev.blink_set = an30259a_blink_set; | |
319 | ||
320 | err = devm_led_classdev_register(&client->dev, | |
321 | &chip->leds[i].cdev); | |
322 | if (err < 0) | |
323 | goto exit; | |
324 | } | |
325 | return 0; | |
326 | ||
327 | exit: | |
328 | mutex_destroy(&chip->mutex); | |
329 | return err; | |
330 | } | |
331 | ||
332 | static int an30259a_remove(struct i2c_client *client) | |
333 | { | |
334 | struct an30259a *chip = i2c_get_clientdata(client); | |
335 | ||
336 | mutex_destroy(&chip->mutex); | |
337 | ||
338 | return 0; | |
339 | } | |
340 | ||
341 | static const struct of_device_id an30259a_match_table[] = { | |
342 | { .compatible = "panasonic,an30259a", }, | |
343 | { /* sentinel */ }, | |
344 | }; | |
345 | ||
346 | MODULE_DEVICE_TABLE(of, an30259a_match_table); | |
347 | ||
348 | static const struct i2c_device_id an30259a_id[] = { | |
349 | { "an30259a", 0 }, | |
350 | { /* sentinel */ }, | |
351 | }; | |
352 | MODULE_DEVICE_TABLE(i2c, an30259a_id); | |
353 | ||
354 | static struct i2c_driver an30259a_driver = { | |
355 | .driver = { | |
356 | .name = "leds-an32059a", | |
357 | .of_match_table = of_match_ptr(an30259a_match_table), | |
358 | }, | |
359 | .probe_new = an30259a_probe, | |
360 | .remove = an30259a_remove, | |
361 | .id_table = an30259a_id, | |
362 | }; | |
363 | ||
364 | module_i2c_driver(an30259a_driver); | |
365 | ||
366 | MODULE_AUTHOR("Simon Shields <simon@lineageos.org>"); | |
367 | MODULE_DESCRIPTION("AN32059A LED driver"); | |
368 | MODULE_LICENSE("GPL v2"); |