1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Awinic AW20036/AW20054/AW20072/AW20108 LED driver
4 *
5 * Copyright (c) 2023, SberDevices. All Rights Reserved.
6 *
7 * Author: Martin Kurbanov <mmkurbanov@sberdevices.ru>
8 */
9
10#include <linux/bitfield.h>
11#include <linux/bits.h>
12#include <linux/container_of.h>
13#include <linux/gpio/consumer.h>
14#include <linux/i2c.h>
15#include <linux/leds.h>
16#include <linux/mod_devicetable.h>
17#include <linux/module.h>
18#include <linux/mutex.h>
19#include <linux/regmap.h>
20#include <linux/time.h>
21#include <linux/units.h>
22
23#define AW200XX_DIM_MAX (BIT(6) - 1)
24#define AW200XX_FADE_MAX (BIT(8) - 1)
25#define AW200XX_IMAX_DEFAULT_uA 60000
26#define AW200XX_IMAX_MAX_uA 160000
27#define AW200XX_IMAX_MIN_uA 3300
28
29/* Page 0 */
30#define AW200XX_REG_PAGE0_BASE 0xc000
31
32/* Select page register */
33#define AW200XX_REG_PAGE 0xF0
34#define AW200XX_PAGE_MASK (GENMASK(7, 6) | GENMASK(2, 0))
35#define AW200XX_PAGE_SHIFT 0
36#define AW200XX_NUM_PAGES 6
37#define AW200XX_PAGE_SIZE 256
38#define AW200XX_REG(page, reg) \
39 (AW200XX_REG_PAGE0_BASE + (page) * AW200XX_PAGE_SIZE + (reg))
40#define AW200XX_REG_MAX \
41 AW200XX_REG(AW200XX_NUM_PAGES - 1, AW200XX_PAGE_SIZE - 1)
42#define AW200XX_PAGE0 0
43#define AW200XX_PAGE1 1
44#define AW200XX_PAGE2 2
45#define AW200XX_PAGE3 3
46#define AW200XX_PAGE4 4
47#define AW200XX_PAGE5 5
48
49/* Chip ID register */
50#define AW200XX_REG_IDR AW200XX_REG(AW200XX_PAGE0, 0x00)
51#define AW200XX_IDR_CHIPID 0x18
52
53/* Sleep mode register */
54#define AW200XX_REG_SLPCR AW200XX_REG(AW200XX_PAGE0, 0x01)
55#define AW200XX_SLPCR_ACTIVE 0x00
56
57/* Reset register */
58#define AW200XX_REG_RSTR AW200XX_REG(AW200XX_PAGE0, 0x02)
59#define AW200XX_RSTR_RESET 0x01
60
61/* Global current configuration register */
62#define AW200XX_REG_GCCR AW200XX_REG(AW200XX_PAGE0, 0x03)
63#define AW200XX_GCCR_IMAX_MASK GENMASK(7, 4)
64#define AW200XX_GCCR_IMAX(x) ((x) << 4)
65#define AW200XX_GCCR_ALLON BIT(3)
66
67/* Fast clear display control register */
68#define AW200XX_REG_FCD AW200XX_REG(AW200XX_PAGE0, 0x04)
69#define AW200XX_FCD_CLEAR 0x01
70
71/* Display size configuration */
72#define AW200XX_REG_DSIZE AW200XX_REG(AW200XX_PAGE0, 0x80)
73#define AW200XX_DSIZE_COLUMNS_MAX 12
74
75#define AW200XX_LED2REG(x, columns) \
76 ((x) + (((x) / (columns)) * (AW200XX_DSIZE_COLUMNS_MAX - (columns))))
77
78/* DIM current configuration register on page 1 */
79#define AW200XX_REG_DIM_PAGE1(x, columns) \
80 AW200XX_REG(AW200XX_PAGE1, AW200XX_LED2REG(x, columns))
81
82/*
83 * DIM current configuration register (page 4).
84 * The even address for current DIM configuration.
85 * The odd address for current FADE configuration
86 */
87#define AW200XX_REG_DIM(x, columns) \
88 AW200XX_REG(AW200XX_PAGE4, AW200XX_LED2REG(x, columns) * 2)
89#define AW200XX_REG_DIM2FADE(x) ((x) + 1)
90#define AW200XX_REG_FADE2DIM(fade) \
91 DIV_ROUND_UP((fade) * AW200XX_DIM_MAX, AW200XX_FADE_MAX)
92
93/*
94 * Duty ratio of display scan (see p.15 of datasheet for formula):
95 * duty = (592us / 600.5us) * (1 / (display_rows + 1))
96 *
97 * Multiply to 1000 (MILLI) to improve the accuracy of calculations.
98 */
99#define AW200XX_DUTY_RATIO(rows) \
100 (((592UL * USEC_PER_SEC) / 600500UL) * (MILLI / (rows)) / MILLI)
101
102struct aw200xx_chipdef {
103 u32 channels;
104 u32 display_size_rows_max;
105 u32 display_size_columns;
106};
107
108struct aw200xx_led {
109 struct led_classdev cdev;
110 struct aw200xx *chip;
111 int dim;
112 u32 num;
113};
114
115struct aw200xx {
116 const struct aw200xx_chipdef *cdef;
117 struct i2c_client *client;
118 struct regmap *regmap;
119 struct mutex mutex;
120 u32 num_leds;
121 u32 display_rows;
122 struct gpio_desc *hwen;
123 struct aw200xx_led leds[] __counted_by(num_leds);
124};
125
126static ssize_t dim_show(struct device *dev, struct device_attribute *devattr,
127 char *buf)
128{
129 struct led_classdev *cdev = dev_get_drvdata(dev);
130 struct aw200xx_led *led = container_of(cdev, struct aw200xx_led, cdev);
131 int dim = led->dim;
132
133 if (dim < 0)
134 return sysfs_emit(buf, fmt: "auto\n");
135
136 return sysfs_emit(buf, fmt: "%d\n", dim);
137}
138
139static ssize_t dim_store(struct device *dev, struct device_attribute *devattr,
140 const char *buf, size_t count)
141{
142 struct led_classdev *cdev = dev_get_drvdata(dev);
143 struct aw200xx_led *led = container_of(cdev, struct aw200xx_led, cdev);
144 struct aw200xx *chip = led->chip;
145 u32 columns = chip->cdef->display_size_columns;
146 int dim;
147 ssize_t ret;
148
149 if (sysfs_streq(s1: buf, s2: "auto")) {
150 dim = -1;
151 } else {
152 ret = kstrtoint(s: buf, base: 0, res: &dim);
153 if (ret)
154 return ret;
155
156 if (dim > AW200XX_DIM_MAX)
157 return -EINVAL;
158 }
159
160 mutex_lock(&chip->mutex);
161
162 if (dim >= 0) {
163 ret = regmap_write(map: chip->regmap,
164 AW200XX_REG_DIM_PAGE1(led->num, columns),
165 val: dim);
166 if (ret)
167 goto out_unlock;
168 }
169
170 led->dim = dim;
171 ret = count;
172
173out_unlock:
174 mutex_unlock(lock: &chip->mutex);
175 return ret;
176}
177static DEVICE_ATTR_RW(dim);
178
179static struct attribute *dim_attrs[] = {
180 &dev_attr_dim.attr,
181 NULL
182};
183ATTRIBUTE_GROUPS(dim);
184
185static int aw200xx_brightness_set(struct led_classdev *cdev,
186 enum led_brightness brightness)
187{
188 struct aw200xx_led *led = container_of(cdev, struct aw200xx_led, cdev);
189 struct aw200xx *chip = led->chip;
190 int dim;
191 u32 reg;
192 int ret;
193
194 mutex_lock(&chip->mutex);
195
196 reg = AW200XX_REG_DIM(led->num, chip->cdef->display_size_columns);
197
198 dim = led->dim;
199 if (dim < 0)
200 dim = AW200XX_REG_FADE2DIM(brightness);
201
202 ret = regmap_write(map: chip->regmap, reg, val: dim);
203 if (ret)
204 goto out_unlock;
205
206 ret = regmap_write(map: chip->regmap,
207 AW200XX_REG_DIM2FADE(reg), val: brightness);
208
209out_unlock:
210 mutex_unlock(lock: &chip->mutex);
211
212 return ret;
213}
214
215static u32 aw200xx_imax_from_global(const struct aw200xx *const chip,
216 u32 global_imax_uA)
217{
218 u64 led_imax_uA;
219
220 /*
221 * The output current of each LED (see p.14 of datasheet for formula):
222 * Iled = Imax * (dim / 63) * ((fade + 1) / 256) * duty
223 *
224 * The value of duty is determined by the following formula:
225 * duty = (592us / 600.5us) * (1 / (display_rows + 1))
226 *
227 * Calculated for the maximum values of fade and dim.
228 * We divide by 1000 because we earlier multiplied by 1000 to improve
229 * accuracy when calculating the duty.
230 */
231 led_imax_uA = global_imax_uA * AW200XX_DUTY_RATIO(chip->display_rows);
232 do_div(led_imax_uA, MILLI);
233
234 return led_imax_uA;
235}
236
237static u32 aw200xx_imax_to_global(const struct aw200xx *const chip,
238 u32 led_imax_uA)
239{
240 u32 duty = AW200XX_DUTY_RATIO(chip->display_rows);
241
242 /* The output current of each LED (see p.14 of datasheet for formula) */
243 return (led_imax_uA * 1000U) / duty;
244}
245
246#define AW200XX_IMAX_MULTIPLIER1 10000
247#define AW200XX_IMAX_MULTIPLIER2 3333
248#define AW200XX_IMAX_BASE_VAL1 0
249#define AW200XX_IMAX_BASE_VAL2 8
250
251/*
252 * The AW200XX has a 4-bit register (GCCR) to configure the global current,
253 * which ranges from 3.3mA to 160mA. The following table indicates the values
254 * of the global current, divided into two parts:
255 *
256 * +-----------+-----------------+-----------+-----------------+
257 * | reg value | global max (mA) | reg value | global max (mA) |
258 * +-----------+-----------------+-----------+-----------------+
259 * | 0 | 10 | 8 | 3.3 |
260 * | 1 | 20 | 9 | 6.7 |
261 * | 2 | 30 | 10 | 10 |
262 * | 3 | 40 | 11 | 13.3 |
263 * | 4 | 60 | 12 | 20 |
264 * | 5 | 80 | 13 | 26.7 |
265 * | 6 | 120 | 14 | 40 |
266 * | 7 | 160 | 15 | 53.3 |
267 * +-----------+-----------------+-----------+-----------------+
268 *
269 * The left part with a multiplier of 10, and the right part with a multiplier
270 * of 3.3.
271 * So we have two formulas to calculate the global current:
272 * for the left part of the table:
273 * imax = coefficient * 10
274 *
275 * for the right part of the table:
276 * imax = coefficient * 3.3
277 *
278 * The coefficient table consists of the following values:
279 * 1, 2, 3, 4, 6, 8, 12, 16.
280 */
281static int aw200xx_set_imax(const struct aw200xx *const chip,
282 u32 led_imax_uA)
283{
284 u32 g_imax_uA = aw200xx_imax_to_global(chip, led_imax_uA);
285 static const u32 coeff_table[] = {1, 2, 3, 4, 6, 8, 12, 16};
286 u32 gccr_imax = UINT_MAX;
287 u32 cur_imax = 0;
288 int i;
289
290 for (i = 0; i < ARRAY_SIZE(coeff_table); i++) {
291 u32 imax;
292
293 /* select closest ones */
294 imax = coeff_table[i] * AW200XX_IMAX_MULTIPLIER1;
295 if (g_imax_uA >= imax && imax > cur_imax) {
296 cur_imax = imax;
297 gccr_imax = i + AW200XX_IMAX_BASE_VAL1;
298 }
299
300 imax = coeff_table[i] * AW200XX_IMAX_MULTIPLIER2;
301 imax = DIV_ROUND_CLOSEST(imax, 100) * 100;
302 if (g_imax_uA >= imax && imax > cur_imax) {
303 cur_imax = imax;
304 gccr_imax = i + AW200XX_IMAX_BASE_VAL2;
305 }
306 }
307
308 if (gccr_imax == UINT_MAX)
309 return -EINVAL;
310
311 return regmap_update_bits(map: chip->regmap, AW200XX_REG_GCCR,
312 AW200XX_GCCR_IMAX_MASK,
313 AW200XX_GCCR_IMAX(gccr_imax));
314}
315
316static int aw200xx_chip_reset(const struct aw200xx *const chip)
317{
318 int ret;
319
320 ret = regmap_write(map: chip->regmap, AW200XX_REG_RSTR, AW200XX_RSTR_RESET);
321 if (ret)
322 return ret;
323
324 /* According to the datasheet software reset takes at least 1ms */
325 fsleep(usecs: 1000);
326
327 regcache_mark_dirty(map: chip->regmap);
328 return regmap_write(map: chip->regmap, AW200XX_REG_FCD, AW200XX_FCD_CLEAR);
329}
330
331static int aw200xx_chip_init(const struct aw200xx *const chip)
332{
333 int ret;
334
335 ret = regmap_write(map: chip->regmap, AW200XX_REG_DSIZE,
336 val: chip->display_rows - 1);
337 if (ret)
338 return ret;
339
340 ret = regmap_write(map: chip->regmap, AW200XX_REG_SLPCR,
341 AW200XX_SLPCR_ACTIVE);
342 if (ret)
343 return ret;
344
345 return regmap_update_bits(map: chip->regmap, AW200XX_REG_GCCR,
346 AW200XX_GCCR_ALLON, AW200XX_GCCR_ALLON);
347}
348
349static int aw200xx_chip_check(const struct aw200xx *const chip)
350{
351 struct device *dev = &chip->client->dev;
352 u32 chipid;
353 int ret;
354
355 ret = regmap_read(map: chip->regmap, AW200XX_REG_IDR, val: &chipid);
356 if (ret)
357 return dev_err_probe(dev, err: ret, fmt: "Failed to read chip ID\n");
358
359 if (chipid != AW200XX_IDR_CHIPID)
360 return dev_err_probe(dev, err: -ENODEV,
361 fmt: "Chip reported wrong ID: %x\n", chipid);
362
363 return 0;
364}
365
366static void aw200xx_enable(const struct aw200xx *const chip)
367{
368 gpiod_set_value_cansleep(desc: chip->hwen, value: 1);
369
370 /*
371 * After HWEN pin set high the chip begins to load the OTP information,
372 * which takes 200us to complete. About 200us wait time is needed for
373 * internal oscillator startup and display SRAM initialization. After
374 * display SRAM initialization, the registers in page1 to page5 can be
375 * configured via i2c interface.
376 */
377 fsleep(usecs: 400);
378}
379
380static void aw200xx_disable(const struct aw200xx *const chip)
381{
382 gpiod_set_value_cansleep(desc: chip->hwen, value: 0);
383}
384
385static int aw200xx_probe_get_display_rows(struct device *dev,
386 struct aw200xx *chip)
387{
388 struct fwnode_handle *child;
389 u32 max_source = 0;
390
391 device_for_each_child_node(dev, child) {
392 u32 source;
393 int ret;
394
395 ret = fwnode_property_read_u32(fwnode: child, propname: "reg", val: &source);
396 if (ret || source >= chip->cdef->channels)
397 continue;
398
399 max_source = max(max_source, source);
400 }
401
402 if (max_source == 0)
403 return -EINVAL;
404
405 chip->display_rows = max_source / chip->cdef->display_size_columns + 1;
406
407 return 0;
408}
409
410static int aw200xx_probe_fw(struct device *dev, struct aw200xx *chip)
411{
412 u32 current_min, current_max, min_uA;
413 int ret;
414 int i;
415
416 ret = aw200xx_probe_get_display_rows(dev, chip);
417 if (ret)
418 return dev_err_probe(dev, err: ret,
419 fmt: "No valid led definitions found\n");
420
421 current_max = aw200xx_imax_from_global(chip, AW200XX_IMAX_MAX_uA);
422 current_min = aw200xx_imax_from_global(chip, AW200XX_IMAX_MIN_uA);
423 min_uA = UINT_MAX;
424 i = 0;
425
426 device_for_each_child_node_scoped(dev, child) {
427 struct led_init_data init_data = {};
428 struct aw200xx_led *led;
429 u32 source, imax;
430
431 ret = fwnode_property_read_u32(fwnode: child, propname: "reg", val: &source);
432 if (ret) {
433 dev_err(dev, "Missing reg property\n");
434 chip->num_leds--;
435 continue;
436 }
437
438 if (source >= chip->cdef->channels) {
439 dev_err(dev, "LED reg %u out of range (max %u)\n",
440 source, chip->cdef->channels);
441 chip->num_leds--;
442 continue;
443 }
444
445 ret = fwnode_property_read_u32(fwnode: child, propname: "led-max-microamp",
446 val: &imax);
447 if (ret) {
448 dev_info(&chip->client->dev,
449 "DT property led-max-microamp is missing\n");
450 } else if (imax < current_min || imax > current_max) {
451 dev_err(dev, "Invalid value %u for led-max-microamp\n",
452 imax);
453 chip->num_leds--;
454 continue;
455 } else {
456 min_uA = min(min_uA, imax);
457 }
458
459 led = &chip->leds[i];
460 led->dim = -1;
461 led->num = source;
462 led->chip = chip;
463 led->cdev.brightness_set_blocking = aw200xx_brightness_set;
464 led->cdev.max_brightness = AW200XX_FADE_MAX;
465 led->cdev.groups = dim_groups;
466 init_data.fwnode = child;
467
468 ret = devm_led_classdev_register_ext(parent: dev, led_cdev: &led->cdev,
469 init_data: &init_data);
470 if (ret)
471 break;
472
473 i++;
474 }
475
476 if (!chip->num_leds)
477 return -EINVAL;
478
479 if (min_uA == UINT_MAX) {
480 min_uA = aw200xx_imax_from_global(chip,
481 AW200XX_IMAX_DEFAULT_uA);
482 }
483
484 return aw200xx_set_imax(chip, led_imax_uA: min_uA);
485}
486
487static const struct regmap_range_cfg aw200xx_ranges[] = {
488 {
489 .name = "aw200xx",
490 .range_min = 0,
491 .range_max = AW200XX_REG_MAX,
492 .selector_reg = AW200XX_REG_PAGE,
493 .selector_mask = AW200XX_PAGE_MASK,
494 .selector_shift = AW200XX_PAGE_SHIFT,
495 .window_start = 0,
496 .window_len = AW200XX_PAGE_SIZE,
497 },
498};
499
500static const struct regmap_range aw200xx_writeonly_ranges[] = {
501 regmap_reg_range(AW200XX_REG(AW200XX_PAGE1, 0x00), AW200XX_REG_MAX),
502};
503
504static const struct regmap_access_table aw200xx_readable_table = {
505 .no_ranges = aw200xx_writeonly_ranges,
506 .n_no_ranges = ARRAY_SIZE(aw200xx_writeonly_ranges),
507};
508
509static const struct regmap_range aw200xx_readonly_ranges[] = {
510 regmap_reg_range(AW200XX_REG_IDR, AW200XX_REG_IDR),
511};
512
513static const struct regmap_access_table aw200xx_writeable_table = {
514 .no_ranges = aw200xx_readonly_ranges,
515 .n_no_ranges = ARRAY_SIZE(aw200xx_readonly_ranges),
516};
517
518static const struct regmap_config aw200xx_regmap_config = {
519 .reg_bits = 8,
520 .val_bits = 8,
521 .max_register = AW200XX_REG_MAX,
522 .ranges = aw200xx_ranges,
523 .num_ranges = ARRAY_SIZE(aw200xx_ranges),
524 .rd_table = &aw200xx_readable_table,
525 .wr_table = &aw200xx_writeable_table,
526 .cache_type = REGCACHE_MAPLE,
527 .disable_locking = true,
528};
529
530static void aw200xx_chip_reset_action(void *data)
531{
532 aw200xx_chip_reset(chip: data);
533}
534
535static void aw200xx_disable_action(void *data)
536{
537 aw200xx_disable(chip: data);
538}
539
540static int aw200xx_probe(struct i2c_client *client)
541{
542 const struct aw200xx_chipdef *cdef;
543 struct aw200xx *chip;
544 int count;
545 int ret;
546
547 cdef = device_get_match_data(dev: &client->dev);
548 if (!cdef)
549 return -ENODEV;
550
551 count = device_get_child_node_count(dev: &client->dev);
552 if (!count || count > cdef->channels)
553 return dev_err_probe(dev: &client->dev, err: -EINVAL,
554 fmt: "Incorrect number of leds (%d)", count);
555
556 chip = devm_kzalloc(dev: &client->dev, struct_size(chip, leds, count),
557 GFP_KERNEL);
558 if (!chip)
559 return -ENOMEM;
560
561 chip->cdef = cdef;
562 chip->num_leds = count;
563 chip->client = client;
564 i2c_set_clientdata(client, data: chip);
565
566 chip->regmap = devm_regmap_init_i2c(client, &aw200xx_regmap_config);
567 if (IS_ERR(ptr: chip->regmap))
568 return PTR_ERR(ptr: chip->regmap);
569
570 chip->hwen = devm_gpiod_get_optional(dev: &client->dev, con_id: "enable",
571 flags: GPIOD_OUT_HIGH);
572 if (IS_ERR(ptr: chip->hwen))
573 return dev_err_probe(dev: &client->dev, err: PTR_ERR(ptr: chip->hwen),
574 fmt: "Cannot get enable GPIO");
575
576 aw200xx_enable(chip);
577
578 ret = devm_add_action(&client->dev, aw200xx_disable_action, chip);
579 if (ret)
580 return ret;
581
582 ret = aw200xx_chip_check(chip);
583 if (ret)
584 return ret;
585
586 ret = devm_mutex_init(&client->dev, &chip->mutex);
587 if (ret)
588 return ret;
589
590 /* Need a lock now since after call aw200xx_probe_fw, sysfs nodes created */
591 mutex_lock(&chip->mutex);
592
593 ret = aw200xx_chip_reset(chip);
594 if (ret)
595 goto out_unlock;
596
597 ret = devm_add_action(&client->dev, aw200xx_chip_reset_action, chip);
598 if (ret)
599 goto out_unlock;
600
601 ret = aw200xx_probe_fw(dev: &client->dev, chip);
602 if (ret)
603 goto out_unlock;
604
605 ret = aw200xx_chip_init(chip);
606
607out_unlock:
608 if (ret)
609 aw200xx_disable(chip);
610
611 mutex_unlock(lock: &chip->mutex);
612 return ret;
613}
614
615static const struct aw200xx_chipdef aw20036_cdef = {
616 .channels = 36,
617 .display_size_rows_max = 3,
618 .display_size_columns = 12,
619};
620
621static const struct aw200xx_chipdef aw20054_cdef = {
622 .channels = 54,
623 .display_size_rows_max = 6,
624 .display_size_columns = 9,
625};
626
627static const struct aw200xx_chipdef aw20072_cdef = {
628 .channels = 72,
629 .display_size_rows_max = 6,
630 .display_size_columns = 12,
631};
632
633static const struct aw200xx_chipdef aw20108_cdef = {
634 .channels = 108,
635 .display_size_rows_max = 9,
636 .display_size_columns = 12,
637};
638
639static const struct i2c_device_id aw200xx_id[] = {
640 { "aw20036" },
641 { "aw20054" },
642 { "aw20072" },
643 { "aw20108" },
644 {}
645};
646MODULE_DEVICE_TABLE(i2c, aw200xx_id);
647
648static const struct of_device_id aw200xx_match_table[] = {
649 { .compatible = "awinic,aw20036", .data = &aw20036_cdef, },
650 { .compatible = "awinic,aw20054", .data = &aw20054_cdef, },
651 { .compatible = "awinic,aw20072", .data = &aw20072_cdef, },
652 { .compatible = "awinic,aw20108", .data = &aw20108_cdef, },
653 {}
654};
655MODULE_DEVICE_TABLE(of, aw200xx_match_table);
656
657static struct i2c_driver aw200xx_driver = {
658 .driver = {
659 .name = "aw200xx",
660 .of_match_table = aw200xx_match_table,
661 },
662 .probe = aw200xx_probe,
663 .id_table = aw200xx_id,
664};
665module_i2c_driver(aw200xx_driver);
666
667MODULE_AUTHOR("Martin Kurbanov <mmkurbanov@sberdevices.ru>");
668MODULE_DESCRIPTION("AW200XX LED driver");
669MODULE_LICENSE("GPL");
670

source code of linux/drivers/leds/leds-aw200xx.c