1 // SPDX-License-Identifier: GPL-2.0+
2 // Driver for Awinic AW2013 3-channel LED driver
3
4 #include <linux/i2c.h>
5 #include <linux/leds.h>
6 #include <linux/module.h>
7 #include <linux/regulator/consumer.h>
8 #include <linux/mutex.h>
9 #include <linux/of.h>
10 #include <linux/regmap.h>
11
12 #define AW2013_MAX_LEDS 3
13
14 /* Reset and ID register */
15 #define AW2013_RSTR 0x00
16 #define AW2013_RSTR_RESET 0x55
17 #define AW2013_RSTR_CHIP_ID 0x33
18
19 /* Global control register */
20 #define AW2013_GCR 0x01
21 #define AW2013_GCR_ENABLE BIT(0)
22
23 /* LED channel enable register */
24 #define AW2013_LCTR 0x30
25 #define AW2013_LCTR_LE(x) BIT((x))
26
27 /* LED channel control registers */
28 #define AW2013_LCFG(x) (0x31 + (x))
29 #define AW2013_LCFG_IMAX_MASK (BIT(0) | BIT(1)) // Should be 0-3
30 #define AW2013_LCFG_MD BIT(4)
31 #define AW2013_LCFG_FI BIT(5)
32 #define AW2013_LCFG_FO BIT(6)
33
34 /* LED channel PWM registers */
35 #define AW2013_REG_PWM(x) (0x34 + (x))
36
37 /* LED channel timing registers */
38 #define AW2013_LEDT0(x) (0x37 + (x) * 3)
39 #define AW2013_LEDT0_T1(x) ((x) << 4) // Should be 0-7
40 #define AW2013_LEDT0_T2(x) (x) // Should be 0-5
41
42 #define AW2013_LEDT1(x) (0x38 + (x) * 3)
43 #define AW2013_LEDT1_T3(x) ((x) << 4) // Should be 0-7
44 #define AW2013_LEDT1_T4(x) (x) // Should be 0-7
45
46 #define AW2013_LEDT2(x) (0x39 + (x) * 3)
47 #define AW2013_LEDT2_T0(x) ((x) << 4) // Should be 0-8
48 #define AW2013_LEDT2_REPEAT(x) (x) // Should be 0-15
49
50 #define AW2013_REG_MAX 0x77
51
52 #define AW2013_TIME_STEP 130 /* ms */
53
54 struct aw2013;
55
56 struct aw2013_led {
57 struct aw2013 *chip;
58 struct led_classdev cdev;
59 u32 num;
60 unsigned int imax;
61 };
62
63 struct aw2013 {
64 struct mutex mutex; /* held when writing to registers */
65 struct regulator_bulk_data regulators[2];
66 struct i2c_client *client;
67 struct aw2013_led leds[AW2013_MAX_LEDS];
68 struct regmap *regmap;
69 int num_leds;
70 bool enabled;
71 };
72
aw2013_chip_init(struct aw2013 * chip)73 static int aw2013_chip_init(struct aw2013 *chip)
74 {
75 int i, ret;
76
77 ret = regmap_write(chip->regmap, AW2013_GCR, AW2013_GCR_ENABLE);
78 if (ret) {
79 dev_err(&chip->client->dev, "Failed to enable the chip: %d\n",
80 ret);
81 return ret;
82 }
83
84 for (i = 0; i < chip->num_leds; i++) {
85 ret = regmap_update_bits(chip->regmap,
86 AW2013_LCFG(chip->leds[i].num),
87 AW2013_LCFG_IMAX_MASK,
88 chip->leds[i].imax);
89 if (ret) {
90 dev_err(&chip->client->dev,
91 "Failed to set maximum current for led %d: %d\n",
92 chip->leds[i].num, ret);
93 return ret;
94 }
95 }
96
97 return ret;
98 }
99
aw2013_chip_disable(struct aw2013 * chip)100 static void aw2013_chip_disable(struct aw2013 *chip)
101 {
102 int ret;
103
104 if (!chip->enabled)
105 return;
106
107 regmap_write(chip->regmap, AW2013_GCR, 0);
108
109 ret = regulator_bulk_disable(ARRAY_SIZE(chip->regulators),
110 chip->regulators);
111 if (ret) {
112 dev_err(&chip->client->dev,
113 "Failed to disable regulators: %d\n", ret);
114 return;
115 }
116
117 chip->enabled = false;
118 }
119
aw2013_chip_enable(struct aw2013 * chip)120 static int aw2013_chip_enable(struct aw2013 *chip)
121 {
122 int ret;
123
124 if (chip->enabled)
125 return 0;
126
127 ret = regulator_bulk_enable(ARRAY_SIZE(chip->regulators),
128 chip->regulators);
129 if (ret) {
130 dev_err(&chip->client->dev,
131 "Failed to enable regulators: %d\n", ret);
132 return ret;
133 }
134 chip->enabled = true;
135
136 ret = aw2013_chip_init(chip);
137 if (ret)
138 aw2013_chip_disable(chip);
139
140 return ret;
141 }
142
aw2013_chip_in_use(struct aw2013 * chip)143 static bool aw2013_chip_in_use(struct aw2013 *chip)
144 {
145 int i;
146
147 for (i = 0; i < chip->num_leds; i++)
148 if (chip->leds[i].cdev.brightness)
149 return true;
150
151 return false;
152 }
153
aw2013_brightness_set(struct led_classdev * cdev,enum led_brightness brightness)154 static int aw2013_brightness_set(struct led_classdev *cdev,
155 enum led_brightness brightness)
156 {
157 struct aw2013_led *led = container_of(cdev, struct aw2013_led, cdev);
158 int ret, num;
159
160 mutex_lock(&led->chip->mutex);
161
162 if (aw2013_chip_in_use(led->chip)) {
163 ret = aw2013_chip_enable(led->chip);
164 if (ret)
165 goto error;
166 }
167
168 num = led->num;
169
170 ret = regmap_write(led->chip->regmap, AW2013_REG_PWM(num), brightness);
171 if (ret)
172 goto error;
173
174 if (brightness) {
175 ret = regmap_update_bits(led->chip->regmap, AW2013_LCTR,
176 AW2013_LCTR_LE(num), 0xFF);
177 } else {
178 ret = regmap_update_bits(led->chip->regmap, AW2013_LCTR,
179 AW2013_LCTR_LE(num), 0);
180 if (ret)
181 goto error;
182 ret = regmap_update_bits(led->chip->regmap, AW2013_LCFG(num),
183 AW2013_LCFG_MD, 0);
184 }
185 if (ret)
186 goto error;
187
188 if (!aw2013_chip_in_use(led->chip))
189 aw2013_chip_disable(led->chip);
190
191 error:
192 mutex_unlock(&led->chip->mutex);
193
194 return ret;
195 }
196
aw2013_blink_set(struct led_classdev * cdev,unsigned long * delay_on,unsigned long * delay_off)197 static int aw2013_blink_set(struct led_classdev *cdev,
198 unsigned long *delay_on, unsigned long *delay_off)
199 {
200 struct aw2013_led *led = container_of(cdev, struct aw2013_led, cdev);
201 int ret, num = led->num;
202 unsigned long off = 0, on = 0;
203
204 /* If no blink specified, default to 1 Hz. */
205 if (!*delay_off && !*delay_on) {
206 *delay_off = 500;
207 *delay_on = 500;
208 }
209
210 if (!led->cdev.brightness) {
211 led->cdev.brightness = LED_FULL;
212 ret = aw2013_brightness_set(&led->cdev, led->cdev.brightness);
213 if (ret)
214 return ret;
215 }
216
217 /* Never on - just set to off */
218 if (!*delay_on) {
219 led->cdev.brightness = LED_OFF;
220 return aw2013_brightness_set(&led->cdev, LED_OFF);
221 }
222
223 mutex_lock(&led->chip->mutex);
224
225 /* Never off - brightness is already set, disable blinking */
226 if (!*delay_off) {
227 ret = regmap_update_bits(led->chip->regmap, AW2013_LCFG(num),
228 AW2013_LCFG_MD, 0);
229 goto out;
230 }
231
232 /* Convert into values the HW will understand. */
233 off = min(5, ilog2((*delay_off - 1) / AW2013_TIME_STEP) + 1);
234 on = min(7, ilog2((*delay_on - 1) / AW2013_TIME_STEP) + 1);
235
236 *delay_off = BIT(off) * AW2013_TIME_STEP;
237 *delay_on = BIT(on) * AW2013_TIME_STEP;
238
239 /* Set timings */
240 ret = regmap_write(led->chip->regmap,
241 AW2013_LEDT0(num), AW2013_LEDT0_T2(on));
242 if (ret)
243 goto out;
244 ret = regmap_write(led->chip->regmap,
245 AW2013_LEDT1(num), AW2013_LEDT1_T4(off));
246 if (ret)
247 goto out;
248
249 /* Finally, enable the LED */
250 ret = regmap_update_bits(led->chip->regmap, AW2013_LCFG(num),
251 AW2013_LCFG_MD, 0xFF);
252 if (ret)
253 goto out;
254
255 ret = regmap_update_bits(led->chip->regmap, AW2013_LCTR,
256 AW2013_LCTR_LE(num), 0xFF);
257
258 out:
259 mutex_unlock(&led->chip->mutex);
260
261 return ret;
262 }
263
aw2013_probe_dt(struct aw2013 * chip)264 static int aw2013_probe_dt(struct aw2013 *chip)
265 {
266 struct device_node *np = dev_of_node(&chip->client->dev);
267 int count, ret = 0, i = 0;
268 struct aw2013_led *led;
269
270 count = of_get_available_child_count(np);
271 if (!count || count > AW2013_MAX_LEDS)
272 return -EINVAL;
273
274 regmap_write(chip->regmap, AW2013_RSTR, AW2013_RSTR_RESET);
275
276 for_each_available_child_of_node_scoped(np, child) {
277 struct led_init_data init_data = {};
278 u32 source;
279 u32 imax;
280
281 ret = of_property_read_u32(child, "reg", &source);
282 if (ret != 0 || source >= AW2013_MAX_LEDS) {
283 dev_err(&chip->client->dev,
284 "Couldn't read LED address: %d\n", ret);
285 count--;
286 continue;
287 }
288
289 led = &chip->leds[i];
290 led->num = source;
291 led->chip = chip;
292 init_data.fwnode = of_fwnode_handle(child);
293
294 if (!of_property_read_u32(child, "led-max-microamp", &imax)) {
295 led->imax = min_t(u32, imax / 5000, 3);
296 } else {
297 led->imax = 1; // 5mA
298 dev_info(&chip->client->dev,
299 "DT property led-max-microamp is missing\n");
300 }
301
302 led->cdev.brightness_set_blocking = aw2013_brightness_set;
303 led->cdev.blink_set = aw2013_blink_set;
304
305 ret = devm_led_classdev_register_ext(&chip->client->dev,
306 &led->cdev, &init_data);
307 if (ret < 0)
308 return ret;
309
310 i++;
311 }
312
313 if (!count)
314 return -EINVAL;
315
316 chip->num_leds = i;
317
318 return 0;
319 }
320
aw2013_chip_disable_action(void * data)321 static void aw2013_chip_disable_action(void *data)
322 {
323 aw2013_chip_disable(data);
324 }
325
326 static const struct regmap_config aw2013_regmap_config = {
327 .reg_bits = 8,
328 .val_bits = 8,
329 .max_register = AW2013_REG_MAX,
330 };
331
aw2013_probe(struct i2c_client * client)332 static int aw2013_probe(struct i2c_client *client)
333 {
334 struct aw2013 *chip;
335 int ret;
336 unsigned int chipid;
337
338 chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
339 if (!chip)
340 return -ENOMEM;
341
342 ret = devm_mutex_init(&client->dev, &chip->mutex);
343 if (ret)
344 return ret;
345
346 mutex_lock(&chip->mutex);
347
348 chip->client = client;
349 i2c_set_clientdata(client, chip);
350
351 chip->regmap = devm_regmap_init_i2c(client, &aw2013_regmap_config);
352 if (IS_ERR(chip->regmap)) {
353 ret = PTR_ERR(chip->regmap);
354 dev_err(&client->dev, "Failed to allocate register map: %d\n",
355 ret);
356 goto error;
357 }
358
359 chip->regulators[0].supply = "vcc";
360 chip->regulators[1].supply = "vio";
361 ret = devm_regulator_bulk_get(&client->dev,
362 ARRAY_SIZE(chip->regulators),
363 chip->regulators);
364 if (ret < 0) {
365 if (ret != -EPROBE_DEFER)
366 dev_err(&client->dev,
367 "Failed to request regulators: %d\n", ret);
368 goto error;
369 }
370
371 ret = regulator_bulk_enable(ARRAY_SIZE(chip->regulators),
372 chip->regulators);
373 if (ret) {
374 dev_err(&client->dev,
375 "Failed to enable regulators: %d\n", ret);
376 goto error;
377 }
378
379 ret = regmap_read(chip->regmap, AW2013_RSTR, &chipid);
380 if (ret) {
381 dev_err(&client->dev, "Failed to read chip ID: %d\n",
382 ret);
383 goto error_reg;
384 }
385
386 if (chipid != AW2013_RSTR_CHIP_ID) {
387 dev_err(&client->dev, "Chip reported wrong ID: %x\n",
388 chipid);
389 ret = -ENODEV;
390 goto error_reg;
391 }
392
393 ret = devm_add_action(&client->dev, aw2013_chip_disable_action, chip);
394 if (ret)
395 goto error_reg;
396
397 ret = aw2013_probe_dt(chip);
398 if (ret < 0)
399 goto error_reg;
400
401 ret = regulator_bulk_disable(ARRAY_SIZE(chip->regulators),
402 chip->regulators);
403 if (ret) {
404 dev_err(&client->dev,
405 "Failed to disable regulators: %d\n", ret);
406 goto error;
407 }
408
409 mutex_unlock(&chip->mutex);
410
411 return 0;
412
413 error_reg:
414 regulator_bulk_disable(ARRAY_SIZE(chip->regulators),
415 chip->regulators);
416
417 error:
418 mutex_unlock(&chip->mutex);
419 return ret;
420 }
421
422 static const struct of_device_id aw2013_match_table[] = {
423 { .compatible = "awinic,aw2013", },
424 { /* sentinel */ },
425 };
426
427 MODULE_DEVICE_TABLE(of, aw2013_match_table);
428
429 static struct i2c_driver aw2013_driver = {
430 .driver = {
431 .name = "leds-aw2013",
432 .of_match_table = aw2013_match_table,
433 },
434 .probe = aw2013_probe,
435 };
436
437 module_i2c_driver(aw2013_driver);
438
439 MODULE_AUTHOR("Nikita Travkin <nikitos.tr@gmail.com>");
440 MODULE_DESCRIPTION("AW2013 LED driver");
441 MODULE_LICENSE("GPL v2");
442