1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * leds-tca6507
4 *
5 * The TCA6507 is a programmable LED controller that can drive 7
6 * separate lines either by holding them low, or by pulsing them
7 * with modulated width.
8 * The modulation can be varied in a simple pattern to produce a
9 * blink or double-blink.
10 *
11 * This driver can configure each line either as a 'GPIO' which is
12 * out-only (pull-up resistor required) or as an LED with variable
13 * brightness and hardware-assisted blinking.
14 *
15 * Apart from OFF and ON there are three programmable brightness
16 * levels which can be programmed from 0 to 15 and indicate how many
17 * 500usec intervals in each 8msec that the led is 'on'. The levels
18 * are named MASTER, BANK0 and BANK1.
19 *
20 * There are two different blink rates that can be programmed, each
21 * with separate time for rise, on, fall, off and second-off. Thus if
22 * 3 or more different non-trivial rates are required, software must
23 * be used for the extra rates. The two different blink rates must
24 * align with the two levels BANK0 and BANK1. This driver does not
25 * support double-blink so 'second-off' always matches 'off'.
26 *
27 * Only 16 different times can be programmed in a roughly logarithmic
28 * scale from 64ms to 16320ms. To be precise the possible times are:
29 * 0, 64, 128, 192, 256, 384, 512, 768,
30 * 1024, 1536, 2048, 3072, 4096, 5760, 8128, 16320
31 *
32 * Times that cannot be closely matched with these must be handled in
33 * software. This driver allows 12.5% error in matching.
34 *
35 * This driver does not allow rise/fall rates to be set explicitly.
36 * When trying to match a given 'on' or 'off' period, an appropriate
37 * pair of 'change' and 'hold' times are chosen to get a close match.
38 * If the target delay is even, the 'change' number will be the
39 * smaller; if odd, the 'hold' number will be the smaller.
40
41 * Choosing pairs of delays with 12.5% errors allows us to match
42 * delays in the ranges: 56-72, 112-144, 168-216, 224-27504,
43 * 28560-36720.
44 * 26% of the achievable sums can be matched by multiple pairings.
45 * For example 1536 == 1536+0, 1024+512, or 768+768.
46 * This driver will always choose the pairing with the least
47 * maximum - 768+768 in this case. Other pairings are not available.
48 *
49 * Access to the 3 levels and 2 blinks are on a first-come,
50 * first-served basis. Access can be shared by multiple leds if they
51 * have the same level and either same blink rates, or some don't
52 * blink. When a led changes, it relinquishes access and tries again,
53 * so it might lose access to hardware blink.
54 *
55 * If a blink engine cannot be allocated, software blink is used. If
56 * the desired brightness cannot be allocated, the closest available
57 * non-zero brightness is used. As 'full' is always available, the
58 * worst case would be to have two different blink rates at '1', with
59 * Max at '2', then other leds will have to choose between '2' and
60 * '16'. Hopefully this is not likely.
61 *
62 * Each bank (BANK0 and BANK1) has two usage counts - LEDs using the
63 * brightness and LEDs using the blink. It can only be reprogrammed
64 * when the appropriate counter is zero. The MASTER level has a
65 * single usage count.
66 *
67 * Each LED has programmable 'on' and 'off' time as milliseconds.
68 * With each there is a flag saying if it was explicitly requested or
69 * defaulted. Similarly the banks know if each time was explicit or a
70 * default. Defaults are permitted to be changed freely - they are
71 * not recognised when matching.
72 */
73
74#include <linux/module.h>
75#include <linux/slab.h>
76#include <linux/leds.h>
77#include <linux/err.h>
78#include <linux/i2c.h>
79#include <linux/gpio/driver.h>
80#include <linux/property.h>
81#include <linux/workqueue.h>
82
83/* LED select registers determine the source that drives LED outputs */
84#define TCA6507_LS_LED_OFF 0x0 /* Output HI-Z (off) */
85#define TCA6507_LS_LED_OFF1 0x1 /* Output HI-Z (off) - not used */
86#define TCA6507_LS_LED_PWM0 0x2 /* Output LOW with Bank0 rate */
87#define TCA6507_LS_LED_PWM1 0x3 /* Output LOW with Bank1 rate */
88#define TCA6507_LS_LED_ON 0x4 /* Output LOW (on) */
89#define TCA6507_LS_LED_MIR 0x5 /* Output LOW with Master Intensity */
90#define TCA6507_LS_BLINK0 0x6 /* Blink at Bank0 rate */
91#define TCA6507_LS_BLINK1 0x7 /* Blink at Bank1 rate */
92
93struct tca6507_platform_data {
94 struct led_platform_data leds;
95};
96
97#define TCA6507_MAKE_GPIO 1
98
99enum {
100 BANK0,
101 BANK1,
102 MASTER,
103};
104static int bank_source[3] = {
105 TCA6507_LS_LED_PWM0,
106 TCA6507_LS_LED_PWM1,
107 TCA6507_LS_LED_MIR,
108};
109static int blink_source[2] = {
110 TCA6507_LS_BLINK0,
111 TCA6507_LS_BLINK1,
112};
113
114/* PWM registers */
115#define TCA6507_REG_CNT 11
116
117/*
118 * 0x00, 0x01, 0x02 encode the TCA6507_LS_* values, each output
119 * owns one bit in each register
120 */
121#define TCA6507_FADE_ON 0x03
122#define TCA6507_FULL_ON 0x04
123#define TCA6507_FADE_OFF 0x05
124#define TCA6507_FIRST_OFF 0x06
125#define TCA6507_SECOND_OFF 0x07
126#define TCA6507_MAX_INTENSITY 0x08
127#define TCA6507_MASTER_INTENSITY 0x09
128#define TCA6507_INITIALIZE 0x0A
129
130#define INIT_CODE 0x8
131
132#define TIMECODES 16
133static int time_codes[TIMECODES] = {
134 0, 64, 128, 192, 256, 384, 512, 768,
135 1024, 1536, 2048, 3072, 4096, 5760, 8128, 16320
136};
137
138/* Convert an led.brightness level (0..255) to a TCA6507 level (0..15) */
139static inline int TO_LEVEL(int brightness)
140{
141 return brightness >> 4;
142}
143
144/* ...and convert back */
145static inline int TO_BRIGHT(int level)
146{
147 if (level)
148 return (level << 4) | 0xf;
149 return 0;
150}
151
152#define NUM_LEDS 7
153struct tca6507_chip {
154 int reg_set; /* One bit per register where
155 * a '1' means the register
156 * should be written */
157 u8 reg_file[TCA6507_REG_CNT];
158 /* Bank 2 is Master Intensity and doesn't use times */
159 struct bank {
160 int level;
161 int ontime, offtime;
162 int on_dflt, off_dflt;
163 int time_use, level_use;
164 } bank[3];
165 struct i2c_client *client;
166 struct work_struct work;
167 spinlock_t lock;
168
169 struct tca6507_led {
170 struct tca6507_chip *chip;
171 struct led_classdev led_cdev;
172 int num;
173 int ontime, offtime;
174 int on_dflt, off_dflt;
175 int bank; /* Bank used, or -1 */
176 int blink; /* Set if hardware-blinking */
177 } leds[NUM_LEDS];
178#ifdef CONFIG_GPIOLIB
179 struct gpio_chip gpio;
180 int gpio_map[NUM_LEDS];
181#endif
182};
183
184static const struct i2c_device_id tca6507_id[] = {
185 { "tca6507" },
186 { }
187};
188MODULE_DEVICE_TABLE(i2c, tca6507_id);
189
190static int choose_times(int msec, int *c1p, int *c2p)
191{
192 /*
193 * Choose two timecodes which add to 'msec' as near as
194 * possible. The first returned is the 'on' or 'off' time.
195 * The second is to be used as a 'fade-on' or 'fade-off' time.
196 * If 'msec' is even, the first will not be smaller than the
197 * second. If 'msec' is odd, the first will not be larger
198 * than the second.
199 * If we cannot get a sum within 1/8 of 'msec' fail with
200 * -EINVAL, otherwise return the sum that was achieved, plus 1
201 * if the first is smaller.
202 * If two possibilities are equally good (e.g. 512+0,
203 * 256+256), choose the first pair so there is more
204 * change-time visible (i.e. it is softer).
205 */
206 int c1, c2;
207 int tmax = msec * 9 / 8;
208 int tmin = msec * 7 / 8;
209 int diff = 65536;
210
211 /* We start at '1' to ensure we never even think of choosing a
212 * total time of '0'.
213 */
214 for (c1 = 1; c1 < TIMECODES; c1++) {
215 int t = time_codes[c1];
216 if (t*2 < tmin)
217 continue;
218 if (t > tmax)
219 break;
220 for (c2 = 0; c2 <= c1; c2++) {
221 int tt = t + time_codes[c2];
222 int d;
223 if (tt < tmin)
224 continue;
225 if (tt > tmax)
226 break;
227 /* This works! */
228 d = abs(msec - tt);
229 if (d >= diff)
230 continue;
231 /* Best yet */
232 *c1p = c1;
233 *c2p = c2;
234 diff = d;
235 if (d == 0)
236 return msec;
237 }
238 }
239 if (diff < 65536) {
240 int actual;
241 if (msec & 1) {
242 swap(*c2p, *c1p);
243 }
244 actual = time_codes[*c1p] + time_codes[*c2p];
245 if (*c1p < *c2p)
246 return actual + 1;
247 else
248 return actual;
249 }
250 /* No close match */
251 return -EINVAL;
252}
253
254/*
255 * Update the register file with the appropriate 3-bit state for the
256 * given led.
257 */
258static void set_select(struct tca6507_chip *tca, int led, int val)
259{
260 int mask = (1 << led);
261 int bit;
262
263 for (bit = 0; bit < 3; bit++) {
264 int n = tca->reg_file[bit] & ~mask;
265 if (val & (1 << bit))
266 n |= mask;
267 if (tca->reg_file[bit] != n) {
268 tca->reg_file[bit] = n;
269 tca->reg_set |= (1 << bit);
270 }
271 }
272}
273
274/* Update the register file with the appropriate 4-bit code for one
275 * bank or other. This can be used for timers, for levels, or for
276 * initialization.
277 */
278static void set_code(struct tca6507_chip *tca, int reg, int bank, int new)
279{
280 int mask = 0xF;
281 int n;
282 if (bank) {
283 mask <<= 4;
284 new <<= 4;
285 }
286 n = tca->reg_file[reg] & ~mask;
287 n |= new;
288 if (tca->reg_file[reg] != n) {
289 tca->reg_file[reg] = n;
290 tca->reg_set |= 1 << reg;
291 }
292}
293
294/* Update brightness level. */
295static void set_level(struct tca6507_chip *tca, int bank, int level)
296{
297 switch (bank) {
298 case BANK0:
299 case BANK1:
300 set_code(tca, TCA6507_MAX_INTENSITY, bank, new: level);
301 break;
302 case MASTER:
303 set_code(tca, TCA6507_MASTER_INTENSITY, bank: 0, new: level);
304 break;
305 }
306 tca->bank[bank].level = level;
307}
308
309/* Record all relevant time codes for a given bank */
310static void set_times(struct tca6507_chip *tca, int bank)
311{
312 int c1, c2;
313 int result;
314
315 result = choose_times(msec: tca->bank[bank].ontime, c1p: &c1, c2p: &c2);
316 if (result < 0)
317 return;
318 dev_dbg(&tca->client->dev,
319 "Chose on times %d(%d) %d(%d) for %dms\n",
320 c1, time_codes[c1],
321 c2, time_codes[c2], tca->bank[bank].ontime);
322 set_code(tca, TCA6507_FADE_ON, bank, new: c2);
323 set_code(tca, TCA6507_FULL_ON, bank, new: c1);
324 tca->bank[bank].ontime = result;
325
326 result = choose_times(msec: tca->bank[bank].offtime, c1p: &c1, c2p: &c2);
327 dev_dbg(&tca->client->dev,
328 "Chose off times %d(%d) %d(%d) for %dms\n",
329 c1, time_codes[c1],
330 c2, time_codes[c2], tca->bank[bank].offtime);
331 set_code(tca, TCA6507_FADE_OFF, bank, new: c2);
332 set_code(tca, TCA6507_FIRST_OFF, bank, new: c1);
333 set_code(tca, TCA6507_SECOND_OFF, bank, new: c1);
334 tca->bank[bank].offtime = result;
335
336 set_code(tca, TCA6507_INITIALIZE, bank, INIT_CODE);
337}
338
339/* Write all needed register of tca6507 */
340
341static void tca6507_work(struct work_struct *work)
342{
343 struct tca6507_chip *tca = container_of(work, struct tca6507_chip,
344 work);
345 struct i2c_client *cl = tca->client;
346 int set;
347 u8 file[TCA6507_REG_CNT];
348 int r;
349
350 spin_lock_irq(lock: &tca->lock);
351 set = tca->reg_set;
352 memcpy(file, tca->reg_file, TCA6507_REG_CNT);
353 tca->reg_set = 0;
354 spin_unlock_irq(lock: &tca->lock);
355
356 for (r = 0; r < TCA6507_REG_CNT; r++)
357 if (set & (1<<r))
358 i2c_smbus_write_byte_data(client: cl, command: r, value: file[r]);
359}
360
361static void led_release(struct tca6507_led *led)
362{
363 /* If led owns any resource, release it. */
364 struct tca6507_chip *tca = led->chip;
365 if (led->bank >= 0) {
366 struct bank *b = tca->bank + led->bank;
367 if (led->blink)
368 b->time_use--;
369 b->level_use--;
370 }
371 led->blink = 0;
372 led->bank = -1;
373}
374
375static int led_prepare(struct tca6507_led *led)
376{
377 /* Assign this led to a bank, configuring that bank if
378 * necessary. */
379 int level = TO_LEVEL(brightness: led->led_cdev.brightness);
380 struct tca6507_chip *tca = led->chip;
381 int c1, c2;
382 int i;
383 struct bank *b;
384 int need_init = 0;
385
386 led->led_cdev.brightness = TO_BRIGHT(level);
387 if (level == 0) {
388 set_select(tca, led: led->num, TCA6507_LS_LED_OFF);
389 return 0;
390 }
391
392 if (led->ontime == 0 || led->offtime == 0) {
393 /*
394 * Just set the brightness, choosing first usable
395 * bank. If none perfect, choose best. Count
396 * backwards so we check MASTER bank first to avoid
397 * wasting a timer.
398 */
399 int best = -1;/* full-on */
400 int diff = 15-level;
401
402 if (level == 15) {
403 set_select(tca, led: led->num, TCA6507_LS_LED_ON);
404 return 0;
405 }
406
407 for (i = MASTER; i >= BANK0; i--) {
408 int d;
409 if (tca->bank[i].level == level ||
410 tca->bank[i].level_use == 0) {
411 best = i;
412 break;
413 }
414 d = abs(level - tca->bank[i].level);
415 if (d < diff) {
416 diff = d;
417 best = i;
418 }
419 }
420 if (best == -1) {
421 /* Best brightness is full-on */
422 set_select(tca, led: led->num, TCA6507_LS_LED_ON);
423 led->led_cdev.brightness = LED_FULL;
424 return 0;
425 }
426
427 if (!tca->bank[best].level_use)
428 set_level(tca, bank: best, level);
429
430 tca->bank[best].level_use++;
431 led->bank = best;
432 set_select(tca, led: led->num, val: bank_source[best]);
433 led->led_cdev.brightness = TO_BRIGHT(level: tca->bank[best].level);
434 return 0;
435 }
436
437 /*
438 * We have on/off time so we need to try to allocate a timing
439 * bank. First check if times are compatible with hardware
440 * and give up if not.
441 */
442 if (choose_times(msec: led->ontime, c1p: &c1, c2p: &c2) < 0)
443 return -EINVAL;
444 if (choose_times(msec: led->offtime, c1p: &c1, c2p: &c2) < 0)
445 return -EINVAL;
446
447 for (i = BANK0; i <= BANK1; i++) {
448 if (tca->bank[i].level_use == 0)
449 /* not in use - it is ours! */
450 break;
451 if (tca->bank[i].level != level)
452 /* Incompatible level - skip */
453 /* FIX: if timer matches we maybe should consider
454 * this anyway...
455 */
456 continue;
457
458 if (tca->bank[i].time_use == 0)
459 /* Timer not in use, and level matches - use it */
460 break;
461
462 if (!(tca->bank[i].on_dflt ||
463 led->on_dflt ||
464 tca->bank[i].ontime == led->ontime))
465 /* on time is incompatible */
466 continue;
467
468 if (!(tca->bank[i].off_dflt ||
469 led->off_dflt ||
470 tca->bank[i].offtime == led->offtime))
471 /* off time is incompatible */
472 continue;
473
474 /* looks like a suitable match */
475 break;
476 }
477
478 if (i > BANK1)
479 /* Nothing matches - how sad */
480 return -EINVAL;
481
482 b = &tca->bank[i];
483 if (b->level_use == 0)
484 set_level(tca, bank: i, level);
485 b->level_use++;
486 led->bank = i;
487
488 if (b->on_dflt ||
489 !led->on_dflt ||
490 b->time_use == 0) {
491 b->ontime = led->ontime;
492 b->on_dflt = led->on_dflt;
493 need_init = 1;
494 }
495
496 if (b->off_dflt ||
497 !led->off_dflt ||
498 b->time_use == 0) {
499 b->offtime = led->offtime;
500 b->off_dflt = led->off_dflt;
501 need_init = 1;
502 }
503
504 if (need_init)
505 set_times(tca, bank: i);
506
507 led->ontime = b->ontime;
508 led->offtime = b->offtime;
509
510 b->time_use++;
511 led->blink = 1;
512 led->led_cdev.brightness = TO_BRIGHT(level: b->level);
513 set_select(tca, led: led->num, val: blink_source[i]);
514 return 0;
515}
516
517static int led_assign(struct tca6507_led *led)
518{
519 struct tca6507_chip *tca = led->chip;
520 int err;
521 unsigned long flags;
522
523 spin_lock_irqsave(&tca->lock, flags);
524 led_release(led);
525 err = led_prepare(led);
526 if (err) {
527 /*
528 * Can only fail on timer setup. In that case we need
529 * to re-establish as steady level.
530 */
531 led->ontime = 0;
532 led->offtime = 0;
533 led_prepare(led);
534 }
535 spin_unlock_irqrestore(lock: &tca->lock, flags);
536
537 if (tca->reg_set)
538 schedule_work(work: &tca->work);
539 return err;
540}
541
542static void tca6507_brightness_set(struct led_classdev *led_cdev,
543 enum led_brightness brightness)
544{
545 struct tca6507_led *led = container_of(led_cdev, struct tca6507_led,
546 led_cdev);
547 led->led_cdev.brightness = brightness;
548 led->ontime = 0;
549 led->offtime = 0;
550 led_assign(led);
551}
552
553static int tca6507_blink_set(struct led_classdev *led_cdev,
554 unsigned long *delay_on,
555 unsigned long *delay_off)
556{
557 struct tca6507_led *led = container_of(led_cdev, struct tca6507_led,
558 led_cdev);
559
560 if (*delay_on == 0)
561 led->on_dflt = 1;
562 else if (delay_on != &led_cdev->blink_delay_on)
563 led->on_dflt = 0;
564 led->ontime = *delay_on;
565
566 if (*delay_off == 0)
567 led->off_dflt = 1;
568 else if (delay_off != &led_cdev->blink_delay_off)
569 led->off_dflt = 0;
570 led->offtime = *delay_off;
571
572 if (led->ontime == 0)
573 led->ontime = 512;
574 if (led->offtime == 0)
575 led->offtime = 512;
576
577 if (led->led_cdev.brightness == LED_OFF)
578 led->led_cdev.brightness = LED_FULL;
579 if (led_assign(led) < 0) {
580 led->ontime = 0;
581 led->offtime = 0;
582 led->led_cdev.brightness = LED_OFF;
583 return -EINVAL;
584 }
585 *delay_on = led->ontime;
586 *delay_off = led->offtime;
587 return 0;
588}
589
590#ifdef CONFIG_GPIOLIB
591static void tca6507_gpio_set_value(struct gpio_chip *gc,
592 unsigned offset, int val)
593{
594 struct tca6507_chip *tca = gpiochip_get_data(gc);
595 unsigned long flags;
596
597 spin_lock_irqsave(&tca->lock, flags);
598 /*
599 * 'OFF' is floating high, and 'ON' is pulled down, so it has
600 * the inverse sense of 'val'.
601 */
602 set_select(tca, led: tca->gpio_map[offset],
603 val: val ? TCA6507_LS_LED_OFF : TCA6507_LS_LED_ON);
604 spin_unlock_irqrestore(lock: &tca->lock, flags);
605 if (tca->reg_set)
606 schedule_work(work: &tca->work);
607}
608
609static int tca6507_gpio_direction_output(struct gpio_chip *gc,
610 unsigned offset, int val)
611{
612 tca6507_gpio_set_value(gc, offset, val);
613 return 0;
614}
615
616static int tca6507_probe_gpios(struct device *dev,
617 struct tca6507_chip *tca,
618 struct tca6507_platform_data *pdata)
619{
620 int err;
621 int i = 0;
622 int gpios = 0;
623
624 for (i = 0; i < NUM_LEDS; i++)
625 if (pdata->leds.leds[i].name && pdata->leds.leds[i].flags) {
626 /* Configure as a gpio */
627 tca->gpio_map[gpios] = i;
628 gpios++;
629 }
630
631 if (!gpios)
632 return 0;
633
634 tca->gpio.label = "gpio-tca6507";
635 tca->gpio.ngpio = gpios;
636 tca->gpio.base = -1;
637 tca->gpio.owner = THIS_MODULE;
638 tca->gpio.direction_output = tca6507_gpio_direction_output;
639 tca->gpio.set = tca6507_gpio_set_value;
640 tca->gpio.parent = dev;
641 err = gpiochip_add_data(&tca->gpio, tca);
642 if (err) {
643 tca->gpio.ngpio = 0;
644 return err;
645 }
646 return 0;
647}
648
649static void tca6507_remove_gpio(struct tca6507_chip *tca)
650{
651 if (tca->gpio.ngpio)
652 gpiochip_remove(gc: &tca->gpio);
653}
654#else /* CONFIG_GPIOLIB */
655static int tca6507_probe_gpios(struct device *dev,
656 struct tca6507_chip *tca,
657 struct tca6507_platform_data *pdata)
658{
659 return 0;
660}
661static void tca6507_remove_gpio(struct tca6507_chip *tca)
662{
663}
664#endif /* CONFIG_GPIOLIB */
665
666static struct tca6507_platform_data *
667tca6507_led_dt_init(struct device *dev)
668{
669 struct tca6507_platform_data *pdata;
670 struct fwnode_handle *child;
671 struct led_info *tca_leds;
672 int count;
673
674 count = device_get_child_node_count(dev);
675 if (!count || count > NUM_LEDS)
676 return ERR_PTR(error: -ENODEV);
677
678 tca_leds = devm_kcalloc(dev, NUM_LEDS, size: sizeof(struct led_info),
679 GFP_KERNEL);
680 if (!tca_leds)
681 return ERR_PTR(error: -ENOMEM);
682
683 device_for_each_child_node(dev, child) {
684 struct led_info led;
685 u32 reg;
686 int ret;
687
688 if (fwnode_property_read_string(fwnode: child, propname: "label", val: &led.name))
689 led.name = fwnode_get_name(fwnode: child);
690
691 if (fwnode_property_read_string(fwnode: child, propname: "linux,default-trigger",
692 val: &led.default_trigger))
693 led.default_trigger = NULL;
694
695 led.flags = 0;
696 if (fwnode_device_is_compatible(fwnode: child, compat: "gpio"))
697 led.flags |= TCA6507_MAKE_GPIO;
698
699 ret = fwnode_property_read_u32(fwnode: child, propname: "reg", val: &reg);
700 if (ret || reg >= NUM_LEDS) {
701 fwnode_handle_put(fwnode: child);
702 return ERR_PTR(error: ret ? : -EINVAL);
703 }
704
705 tca_leds[reg] = led;
706 }
707
708 pdata = devm_kzalloc(dev, size: sizeof(struct tca6507_platform_data),
709 GFP_KERNEL);
710 if (!pdata)
711 return ERR_PTR(error: -ENOMEM);
712
713 pdata->leds.leds = tca_leds;
714 pdata->leds.num_leds = NUM_LEDS;
715
716 return pdata;
717}
718
719static const struct of_device_id __maybe_unused of_tca6507_leds_match[] = {
720 { .compatible = "ti,tca6507", },
721 {},
722};
723MODULE_DEVICE_TABLE(of, of_tca6507_leds_match);
724
725static int tca6507_probe(struct i2c_client *client)
726{
727 struct device *dev = &client->dev;
728 struct i2c_adapter *adapter;
729 struct tca6507_chip *tca;
730 struct tca6507_platform_data *pdata;
731 int err;
732 int i = 0;
733
734 adapter = client->adapter;
735
736 if (!i2c_check_functionality(adap: adapter, I2C_FUNC_I2C))
737 return -EIO;
738
739 pdata = tca6507_led_dt_init(dev);
740 if (IS_ERR(ptr: pdata)) {
741 dev_err(dev, "Need %d entries in platform-data list\n", NUM_LEDS);
742 return PTR_ERR(ptr: pdata);
743 }
744 tca = devm_kzalloc(dev, size: sizeof(*tca), GFP_KERNEL);
745 if (!tca)
746 return -ENOMEM;
747
748 tca->client = client;
749 INIT_WORK(&tca->work, tca6507_work);
750 spin_lock_init(&tca->lock);
751 i2c_set_clientdata(client, data: tca);
752
753 for (i = 0; i < NUM_LEDS; i++) {
754 struct tca6507_led *l = tca->leds + i;
755
756 l->chip = tca;
757 l->num = i;
758 if (pdata->leds.leds[i].name && !pdata->leds.leds[i].flags) {
759 l->led_cdev.name = pdata->leds.leds[i].name;
760 l->led_cdev.default_trigger
761 = pdata->leds.leds[i].default_trigger;
762 l->led_cdev.brightness_set = tca6507_brightness_set;
763 l->led_cdev.blink_set = tca6507_blink_set;
764 l->bank = -1;
765 err = led_classdev_register(parent: dev, led_cdev: &l->led_cdev);
766 if (err < 0)
767 goto exit;
768 }
769 }
770 err = tca6507_probe_gpios(dev, tca, pdata);
771 if (err)
772 goto exit;
773 /* set all registers to known state - zero */
774 tca->reg_set = 0x7f;
775 schedule_work(work: &tca->work);
776
777 return 0;
778exit:
779 while (i--) {
780 if (tca->leds[i].led_cdev.name)
781 led_classdev_unregister(led_cdev: &tca->leds[i].led_cdev);
782 }
783 return err;
784}
785
786static void tca6507_remove(struct i2c_client *client)
787{
788 int i;
789 struct tca6507_chip *tca = i2c_get_clientdata(client);
790 struct tca6507_led *tca_leds = tca->leds;
791
792 for (i = 0; i < NUM_LEDS; i++) {
793 if (tca_leds[i].led_cdev.name)
794 led_classdev_unregister(led_cdev: &tca_leds[i].led_cdev);
795 }
796 tca6507_remove_gpio(tca);
797 cancel_work_sync(work: &tca->work);
798}
799
800static struct i2c_driver tca6507_driver = {
801 .driver = {
802 .name = "leds-tca6507",
803 .of_match_table = of_match_ptr(of_tca6507_leds_match),
804 },
805 .probe = tca6507_probe,
806 .remove = tca6507_remove,
807 .id_table = tca6507_id,
808};
809
810module_i2c_driver(tca6507_driver);
811
812MODULE_AUTHOR("NeilBrown <neilb@suse.de>");
813MODULE_DESCRIPTION("TCA6507 LED/GPO driver");
814MODULE_LICENSE("GPL v2");
815

source code of linux/drivers/leds/leds-tca6507.c