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
17 #define AN30259A_MAX_LEDS 3
18
19 #define AN30259A_REG_SRESET 0x00
20 #define AN30259A_LED_SRESET BIT(0)
21
22 /* LED power registers */
23 #define AN30259A_REG_LED_ON 0x01
24 #define AN30259A_LED_EN(x) BIT((x) - 1)
25 #define AN30259A_LED_SLOPE(x) BIT(((x) - 1) + 4)
26
27 #define AN30259A_REG_LEDCC(x) (0x03 + ((x) - 1))
28
29 /* slope control registers */
30 #define AN30259A_REG_SLOPE(x) (0x06 + ((x) - 1))
31 #define AN30259A_LED_SLOPETIME1(x) (x)
32 #define AN30259A_LED_SLOPETIME2(x) ((x) << 4)
33
34 #define AN30259A_REG_LEDCNT1(x) (0x09 + (4 * ((x) - 1)))
35 #define AN30259A_LED_DUTYMAX(x) ((x) << 4)
36 #define AN30259A_LED_DUTYMID(x) (x)
37
38 #define AN30259A_REG_LEDCNT2(x) (0x0A + (4 * ((x) - 1)))
39 #define AN30259A_LED_DELAY(x) ((x) << 4)
40 #define AN30259A_LED_DUTYMIN(x) (x)
41
42 /* detention time control (length of each slope step) */
43 #define AN30259A_REG_LEDCNT3(x) (0x0B + (4 * ((x) - 1)))
44 #define AN30259A_LED_DT1(x) (x)
45 #define AN30259A_LED_DT2(x) ((x) << 4)
46
47 #define AN30259A_REG_LEDCNT4(x) (0x0C + (4 * ((x) - 1)))
48 #define AN30259A_LED_DT3(x) (x)
49 #define AN30259A_LED_DT4(x) ((x) << 4)
50
51 #define AN30259A_REG_MAX 0x14
52
53 #define AN30259A_BLINK_MAX_TIME 7500 /* ms */
54 #define AN30259A_SLOPE_RESOLUTION 500 /* ms */
55
56 #define AN30259A_NAME "an30259a"
57
58 #define STATE_OFF 0
59 #define STATE_KEEP 1
60 #define STATE_ON 2
61
62 struct an30259a;
63
64 struct an30259a_led {
65 struct an30259a *chip;
66 struct fwnode_handle *fwnode;
67 struct led_classdev cdev;
68 u32 num;
69 u32 default_state;
70 bool sloping;
71 };
72
73 struct an30259a {
74 struct mutex mutex; /* held when writing to registers */
75 struct i2c_client *client;
76 struct an30259a_led leds[AN30259A_MAX_LEDS];
77 struct regmap *regmap;
78 int num_leds;
79 };
80
an30259a_brightness_set(struct led_classdev * cdev,enum led_brightness brightness)81 static int an30259a_brightness_set(struct led_classdev *cdev,
82 enum led_brightness brightness)
83 {
84 struct an30259a_led *led;
85 int ret;
86 unsigned int led_on;
87
88 led = container_of(cdev, struct an30259a_led, cdev);
89 mutex_lock(&led->chip->mutex);
90
91 ret = regmap_read(led->chip->regmap, AN30259A_REG_LED_ON, &led_on);
92 if (ret)
93 goto error;
94
95 switch (brightness) {
96 case LED_OFF:
97 led_on &= ~AN30259A_LED_EN(led->num);
98 led_on &= ~AN30259A_LED_SLOPE(led->num);
99 led->sloping = false;
100 break;
101 default:
102 led_on |= AN30259A_LED_EN(led->num);
103 if (led->sloping)
104 led_on |= AN30259A_LED_SLOPE(led->num);
105 ret = regmap_write(led->chip->regmap,
106 AN30259A_REG_LEDCNT1(led->num),
107 AN30259A_LED_DUTYMAX(0xf) |
108 AN30259A_LED_DUTYMID(0xf));
109 if (ret)
110 goto error;
111 break;
112 }
113
114 ret = regmap_write(led->chip->regmap, AN30259A_REG_LED_ON, led_on);
115 if (ret)
116 goto error;
117
118 ret = regmap_write(led->chip->regmap, AN30259A_REG_LEDCC(led->num),
119 brightness);
120
121 error:
122 mutex_unlock(&led->chip->mutex);
123
124 return ret;
125 }
126
an30259a_blink_set(struct led_classdev * cdev,unsigned long * delay_off,unsigned long * delay_on)127 static int an30259a_blink_set(struct led_classdev *cdev,
128 unsigned long *delay_off, unsigned long *delay_on)
129 {
130 struct an30259a_led *led;
131 int ret, num;
132 unsigned int led_on;
133 unsigned long off = *delay_off, on = *delay_on;
134
135 led = container_of(cdev, struct an30259a_led, cdev);
136
137 mutex_lock(&led->chip->mutex);
138 num = led->num;
139
140 /* slope time can only be a multiple of 500ms. */
141 if (off % AN30259A_SLOPE_RESOLUTION || on % AN30259A_SLOPE_RESOLUTION) {
142 ret = -EINVAL;
143 goto error;
144 }
145
146 /* up to a maximum of 7500ms. */
147 if (off > AN30259A_BLINK_MAX_TIME || on > AN30259A_BLINK_MAX_TIME) {
148 ret = -EINVAL;
149 goto error;
150 }
151
152 /* if no blink specified, default to 1 Hz. */
153 if (!off && !on) {
154 *delay_off = off = 500;
155 *delay_on = on = 500;
156 }
157
158 /* convert into values the HW will understand. */
159 off /= AN30259A_SLOPE_RESOLUTION;
160 on /= AN30259A_SLOPE_RESOLUTION;
161
162 /* duty min should be zero (=off), delay should be zero. */
163 ret = regmap_write(led->chip->regmap, AN30259A_REG_LEDCNT2(num),
164 AN30259A_LED_DELAY(0) | AN30259A_LED_DUTYMIN(0));
165 if (ret)
166 goto error;
167
168 /* reset detention time (no "breathing" effect). */
169 ret = regmap_write(led->chip->regmap, AN30259A_REG_LEDCNT3(num),
170 AN30259A_LED_DT1(0) | AN30259A_LED_DT2(0));
171 if (ret)
172 goto error;
173 ret = regmap_write(led->chip->regmap, AN30259A_REG_LEDCNT4(num),
174 AN30259A_LED_DT3(0) | AN30259A_LED_DT4(0));
175 if (ret)
176 goto error;
177
178 /* slope time controls on/off cycle length. */
179 ret = regmap_write(led->chip->regmap, AN30259A_REG_SLOPE(num),
180 AN30259A_LED_SLOPETIME1(off) |
181 AN30259A_LED_SLOPETIME2(on));
182 if (ret)
183 goto error;
184
185 /* Finally, enable slope mode. */
186 ret = regmap_read(led->chip->regmap, AN30259A_REG_LED_ON, &led_on);
187 if (ret)
188 goto error;
189
190 led_on |= AN30259A_LED_SLOPE(num) | AN30259A_LED_EN(led->num);
191
192 ret = regmap_write(led->chip->regmap, AN30259A_REG_LED_ON, led_on);
193
194 if (!ret)
195 led->sloping = true;
196 error:
197 mutex_unlock(&led->chip->mutex);
198
199 return ret;
200 }
201
an30259a_dt_init(struct i2c_client * client,struct an30259a * chip)202 static int an30259a_dt_init(struct i2c_client *client,
203 struct an30259a *chip)
204 {
205 struct device_node *np = dev_of_node(&client->dev), *child;
206 int count, ret;
207 int i = 0;
208 const char *str;
209 struct an30259a_led *led;
210
211 count = of_get_available_child_count(np);
212 if (!count || count > AN30259A_MAX_LEDS)
213 return -EINVAL;
214
215 for_each_available_child_of_node(np, child) {
216 u32 source;
217
218 ret = of_property_read_u32(child, "reg", &source);
219 if (ret != 0 || !source || source > AN30259A_MAX_LEDS) {
220 dev_err(&client->dev, "Couldn't read LED address: %d\n",
221 ret);
222 count--;
223 continue;
224 }
225
226 led = &chip->leds[i];
227
228 led->num = source;
229 led->chip = chip;
230 led->fwnode = of_fwnode_handle(child);
231
232 if (!of_property_read_string(child, "default-state", &str)) {
233 if (!strcmp(str, "on"))
234 led->default_state = STATE_ON;
235 else if (!strcmp(str, "keep"))
236 led->default_state = STATE_KEEP;
237 else
238 led->default_state = STATE_OFF;
239 }
240
241 i++;
242 }
243
244 if (!count)
245 return -EINVAL;
246
247 chip->num_leds = i;
248
249 return 0;
250 }
251
252 static const struct regmap_config an30259a_regmap_config = {
253 .reg_bits = 8,
254 .val_bits = 8,
255 .max_register = AN30259A_REG_MAX,
256 };
257
an30259a_init_default_state(struct an30259a_led * led)258 static void an30259a_init_default_state(struct an30259a_led *led)
259 {
260 struct an30259a *chip = led->chip;
261 int led_on, err;
262
263 switch (led->default_state) {
264 case STATE_ON:
265 led->cdev.brightness = LED_FULL;
266 break;
267 case STATE_KEEP:
268 err = regmap_read(chip->regmap, AN30259A_REG_LED_ON, &led_on);
269 if (err)
270 break;
271
272 if (!(led_on & AN30259A_LED_EN(led->num))) {
273 led->cdev.brightness = LED_OFF;
274 break;
275 }
276 regmap_read(chip->regmap, AN30259A_REG_LEDCC(led->num),
277 &led->cdev.brightness);
278 break;
279 default:
280 led->cdev.brightness = LED_OFF;
281 }
282
283 an30259a_brightness_set(&led->cdev, led->cdev.brightness);
284 }
285
an30259a_probe(struct i2c_client * client)286 static int an30259a_probe(struct i2c_client *client)
287 {
288 struct an30259a *chip;
289 int i, err;
290
291 chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
292 if (!chip)
293 return -ENOMEM;
294
295 err = an30259a_dt_init(client, chip);
296 if (err < 0)
297 return err;
298
299 mutex_init(&chip->mutex);
300 chip->client = client;
301 i2c_set_clientdata(client, chip);
302
303 chip->regmap = devm_regmap_init_i2c(client, &an30259a_regmap_config);
304
305 if (IS_ERR(chip->regmap)) {
306 err = PTR_ERR(chip->regmap);
307 dev_err(&client->dev, "Failed to allocate register map: %d\n",
308 err);
309 goto exit;
310 }
311
312 for (i = 0; i < chip->num_leds; i++) {
313 struct led_init_data init_data = {};
314
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 init_data.fwnode = chip->leds[i].fwnode;
321 init_data.devicename = AN30259A_NAME;
322 init_data.default_label = ":";
323
324 err = devm_led_classdev_register_ext(&client->dev,
325 &chip->leds[i].cdev,
326 &init_data);
327 if (err < 0)
328 goto exit;
329 }
330 return 0;
331
332 exit:
333 mutex_destroy(&chip->mutex);
334 return err;
335 }
336
an30259a_remove(struct i2c_client * client)337 static int an30259a_remove(struct i2c_client *client)
338 {
339 struct an30259a *chip = i2c_get_clientdata(client);
340
341 mutex_destroy(&chip->mutex);
342
343 return 0;
344 }
345
346 static const struct of_device_id an30259a_match_table[] = {
347 { .compatible = "panasonic,an30259a", },
348 { /* sentinel */ },
349 };
350
351 MODULE_DEVICE_TABLE(of, an30259a_match_table);
352
353 static const struct i2c_device_id an30259a_id[] = {
354 { "an30259a", 0 },
355 { /* sentinel */ },
356 };
357 MODULE_DEVICE_TABLE(i2c, an30259a_id);
358
359 static struct i2c_driver an30259a_driver = {
360 .driver = {
361 .name = "leds-an30259a",
362 .of_match_table = of_match_ptr(an30259a_match_table),
363 },
364 .probe_new = an30259a_probe,
365 .remove = an30259a_remove,
366 .id_table = an30259a_id,
367 };
368
369 module_i2c_driver(an30259a_driver);
370
371 MODULE_AUTHOR("Simon Shields <simon@lineageos.org>");
372 MODULE_DESCRIPTION("AN30259A LED driver");
373 MODULE_LICENSE("GPL v2");
374