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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright 2007-2008 Extreme Engineering Solutions, Inc.
4 *
5 * Author: Nate Case <ncase@xes-inc.com>
6 *
7 * LED driver for various PCA955x I2C LED drivers
8 *
9 * Supported devices:
10 *
11 * Device Description 7-bit slave address
12 * ------ ----------- -------------------
13 * PCA9550 2-bit driver 0x60 .. 0x61
14 * PCA9551 8-bit driver 0x60 .. 0x67
15 * PCA9552 16-bit driver 0x60 .. 0x67
16 * PCA9553/01 4-bit driver 0x62
17 * PCA9553/02 4-bit driver 0x63
18 *
19 * Philips PCA955x LED driver chips follow a register map as shown below:
20 *
21 * Control Register Description
22 * ---------------- -----------
23 * 0x0 Input register 0
24 * ..
25 * NUM_INPUT_REGS - 1 Last Input register X
26 *
27 * NUM_INPUT_REGS Frequency prescaler 0
28 * NUM_INPUT_REGS + 1 PWM register 0
29 * NUM_INPUT_REGS + 2 Frequency prescaler 1
30 * NUM_INPUT_REGS + 3 PWM register 1
31 *
32 * NUM_INPUT_REGS + 4 LED selector 0
33 * NUM_INPUT_REGS + 4
34 * + NUM_LED_REGS - 1 Last LED selector
35 *
36 * where NUM_INPUT_REGS and NUM_LED_REGS vary depending on how many
37 * bits the chip supports.
38 */
39
40#include <linux/bitops.h>
41#include <linux/ctype.h>
42#include <linux/delay.h>
43#include <linux/err.h>
44#include <linux/gpio/driver.h>
45#include <linux/i2c.h>
46#include <linux/leds.h>
47#include <linux/module.h>
48#include <linux/of.h>
49#include <linux/property.h>
50#include <linux/slab.h>
51#include <linux/string.h>
52
53#include <dt-bindings/leds/leds-pca955x.h>
54
55/* LED select registers determine the source that drives LED outputs */
56#define PCA955X_LS_LED_ON 0x0 /* Output LOW */
57#define PCA955X_LS_LED_OFF 0x1 /* Output HI-Z */
58#define PCA955X_LS_BLINK0 0x2 /* Blink at PWM0 rate */
59#define PCA955X_LS_BLINK1 0x3 /* Blink at PWM1 rate */
60
61#define PCA955X_GPIO_INPUT LED_OFF
62#define PCA955X_GPIO_HIGH LED_OFF
63#define PCA955X_GPIO_LOW LED_FULL
64
65enum pca955x_type {
66 pca9550,
67 pca9551,
68 pca9552,
69 ibm_pca9552,
70 pca9553,
71};
72
73struct pca955x_chipdef {
74 int bits;
75 u8 slv_addr; /* 7-bit slave address mask */
76 int slv_addr_shift; /* Number of bits to ignore */
77};
78
79static const struct pca955x_chipdef pca955x_chipdefs[] = {
80 [pca9550] = {
81 .bits = 2,
82 .slv_addr = /* 110000x */ 0x60,
83 .slv_addr_shift = 1,
84 },
85 [pca9551] = {
86 .bits = 8,
87 .slv_addr = /* 1100xxx */ 0x60,
88 .slv_addr_shift = 3,
89 },
90 [pca9552] = {
91 .bits = 16,
92 .slv_addr = /* 1100xxx */ 0x60,
93 .slv_addr_shift = 3,
94 },
95 [ibm_pca9552] = {
96 .bits = 16,
97 .slv_addr = /* 0110xxx */ 0x30,
98 .slv_addr_shift = 3,
99 },
100 [pca9553] = {
101 .bits = 4,
102 .slv_addr = /* 110001x */ 0x62,
103 .slv_addr_shift = 1,
104 },
105};
106
107struct pca955x {
108 struct mutex lock;
109 struct pca955x_led *leds;
110 const struct pca955x_chipdef *chipdef;
111 struct i2c_client *client;
112 unsigned long active_pins;
113#ifdef CONFIG_LEDS_PCA955X_GPIO
114 struct gpio_chip gpio;
115#endif
116};
117
118struct pca955x_led {
119 struct pca955x *pca955x;
120 struct led_classdev led_cdev;
121 int led_num; /* 0 .. 15 potentially */
122 u32 type;
123 enum led_default_state default_state;
124 struct fwnode_handle *fwnode;
125};
126
127struct pca955x_platform_data {
128 struct pca955x_led *leds;
129 int num_leds;
130};
131
132/* 8 bits per input register */
133static inline int pca95xx_num_input_regs(int bits)
134{
135 return (bits + 7) / 8;
136}
137
138/*
139 * Return an LED selector register value based on an existing one, with
140 * the appropriate 2-bit state value set for the given LED number (0-3).
141 */
142static inline u8 pca955x_ledsel(u8 oldval, int led_num, int state)
143{
144 return (oldval & (~(0x3 << (led_num << 1)))) |
145 ((state & 0x3) << (led_num << 1));
146}
147
148/*
149 * Write to frequency prescaler register, used to program the
150 * period of the PWM output. period = (PSCx + 1) / 38
151 */
152static int pca955x_write_psc(struct i2c_client *client, int n, u8 val)
153{
154 struct pca955x *pca955x = i2c_get_clientdata(client);
155 u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + (2 * n);
156 int ret;
157
158 ret = i2c_smbus_write_byte_data(client, cmd, val);
159 if (ret < 0)
160 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
161 __func__, n, val, ret);
162 return ret;
163}
164
165/*
166 * Write to PWM register, which determines the duty cycle of the
167 * output. LED is OFF when the count is less than the value of this
168 * register, and ON when it is greater. If PWMx == 0, LED is always OFF.
169 *
170 * Duty cycle is (256 - PWMx) / 256
171 */
172static int pca955x_write_pwm(struct i2c_client *client, int n, u8 val)
173{
174 struct pca955x *pca955x = i2c_get_clientdata(client);
175 u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + (2 * n);
176 int ret;
177
178 ret = i2c_smbus_write_byte_data(client, cmd, val);
179 if (ret < 0)
180 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
181 __func__, n, val, ret);
182 return ret;
183}
184
185/*
186 * Write to LED selector register, which determines the source that
187 * drives the LED output.
188 */
189static int pca955x_write_ls(struct i2c_client *client, int n, u8 val)
190{
191 struct pca955x *pca955x = i2c_get_clientdata(client);
192 u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n;
193 int ret;
194
195 ret = i2c_smbus_write_byte_data(client, cmd, val);
196 if (ret < 0)
197 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
198 __func__, n, val, ret);
199 return ret;
200}
201
202/*
203 * Read the LED selector register, which determines the source that
204 * drives the LED output.
205 */
206static int pca955x_read_ls(struct i2c_client *client, int n, u8 *val)
207{
208 struct pca955x *pca955x = i2c_get_clientdata(client);
209 u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n;
210 int ret;
211
212 ret = i2c_smbus_read_byte_data(client, cmd);
213 if (ret < 0) {
214 dev_err(&client->dev, "%s: reg 0x%x, err %d\n",
215 __func__, n, ret);
216 return ret;
217 }
218 *val = (u8)ret;
219 return 0;
220}
221
222static int pca955x_read_pwm(struct i2c_client *client, int n, u8 *val)
223{
224 struct pca955x *pca955x = i2c_get_clientdata(client);
225 u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + (2 * n);
226 int ret;
227
228 ret = i2c_smbus_read_byte_data(client, cmd);
229 if (ret < 0) {
230 dev_err(&client->dev, "%s: reg 0x%x, err %d\n",
231 __func__, n, ret);
232 return ret;
233 }
234 *val = (u8)ret;
235 return 0;
236}
237
238static enum led_brightness pca955x_led_get(struct led_classdev *led_cdev)
239{
240 struct pca955x_led *pca955x_led = container_of(led_cdev,
241 struct pca955x_led,
242 led_cdev);
243 struct pca955x *pca955x = pca955x_led->pca955x;
244 u8 ls, pwm;
245 int ret;
246
247 ret = pca955x_read_ls(pca955x->client, pca955x_led->led_num / 4, &ls);
248 if (ret)
249 return ret;
250
251 ls = (ls >> ((pca955x_led->led_num % 4) << 1)) & 0x3;
252 switch (ls) {
253 case PCA955X_LS_LED_ON:
254 ret = LED_FULL;
255 break;
256 case PCA955X_LS_LED_OFF:
257 ret = LED_OFF;
258 break;
259 case PCA955X_LS_BLINK0:
260 ret = LED_HALF;
261 break;
262 case PCA955X_LS_BLINK1:
263 ret = pca955x_read_pwm(pca955x->client, 1, &pwm);
264 if (ret)
265 return ret;
266 ret = 255 - pwm;
267 break;
268 }
269
270 return ret;
271}
272
273static int pca955x_led_set(struct led_classdev *led_cdev,
274 enum led_brightness value)
275{
276 struct pca955x_led *pca955x_led;
277 struct pca955x *pca955x;
278 u8 ls;
279 int chip_ls; /* which LSx to use (0-3 potentially) */
280 int ls_led; /* which set of bits within LSx to use (0-3) */
281 int ret;
282
283 pca955x_led = container_of(led_cdev, struct pca955x_led, led_cdev);
284 pca955x = pca955x_led->pca955x;
285
286 chip_ls = pca955x_led->led_num / 4;
287 ls_led = pca955x_led->led_num % 4;
288
289 mutex_lock(&pca955x->lock);
290
291 ret = pca955x_read_ls(pca955x->client, chip_ls, &ls);
292 if (ret)
293 goto out;
294
295 switch (value) {
296 case LED_FULL:
297 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_ON);
298 break;
299 case LED_OFF:
300 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_OFF);
301 break;
302 case LED_HALF:
303 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK0);
304 break;
305 default:
306 /*
307 * Use PWM1 for all other values. This has the unwanted
308 * side effect of making all LEDs on the chip share the
309 * same brightness level if set to a value other than
310 * OFF, HALF, or FULL. But, this is probably better than
311 * just turning off for all other values.
312 */
313 ret = pca955x_write_pwm(pca955x->client, 1, 255 - value);
314 if (ret)
315 goto out;
316 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK1);
317 break;
318 }
319
320 ret = pca955x_write_ls(pca955x->client, chip_ls, ls);
321
322out:
323 mutex_unlock(&pca955x->lock);
324
325 return ret;
326}
327
328#ifdef CONFIG_LEDS_PCA955X_GPIO
329/*
330 * Read the INPUT register, which contains the state of LEDs.
331 */
332static int pca955x_read_input(struct i2c_client *client, int n, u8 *val)
333{
334 int ret = i2c_smbus_read_byte_data(client, n);
335
336 if (ret < 0) {
337 dev_err(&client->dev, "%s: reg 0x%x, err %d\n",
338 __func__, n, ret);
339 return ret;
340 }
341 *val = (u8)ret;
342 return 0;
343
344}
345
346static int pca955x_gpio_request_pin(struct gpio_chip *gc, unsigned int offset)
347{
348 struct pca955x *pca955x = gpiochip_get_data(gc);
349
350 return test_and_set_bit(offset, &pca955x->active_pins) ? -EBUSY : 0;
351}
352
353static void pca955x_gpio_free_pin(struct gpio_chip *gc, unsigned int offset)
354{
355 struct pca955x *pca955x = gpiochip_get_data(gc);
356
357 clear_bit(offset, &pca955x->active_pins);
358}
359
360static int pca955x_set_value(struct gpio_chip *gc, unsigned int offset,
361 int val)
362{
363 struct pca955x *pca955x = gpiochip_get_data(gc);
364 struct pca955x_led *led = &pca955x->leds[offset];
365
366 if (val)
367 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_HIGH);
368
369 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_LOW);
370}
371
372static void pca955x_gpio_set_value(struct gpio_chip *gc, unsigned int offset,
373 int val)
374{
375 pca955x_set_value(gc, offset, val);
376}
377
378static int pca955x_gpio_get_value(struct gpio_chip *gc, unsigned int offset)
379{
380 struct pca955x *pca955x = gpiochip_get_data(gc);
381 struct pca955x_led *led = &pca955x->leds[offset];
382 u8 reg = 0;
383
384 /* There is nothing we can do about errors */
385 pca955x_read_input(pca955x->client, led->led_num / 8, ®);
386
387 return !!(reg & (1 << (led->led_num % 8)));
388}
389
390static int pca955x_gpio_direction_input(struct gpio_chip *gc,
391 unsigned int offset)
392{
393 struct pca955x *pca955x = gpiochip_get_data(gc);
394 struct pca955x_led *led = &pca955x->leds[offset];
395
396 /* To use as input ensure pin is not driven. */
397 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_INPUT);
398}
399
400static int pca955x_gpio_direction_output(struct gpio_chip *gc,
401 unsigned int offset, int val)
402{
403 return pca955x_set_value(gc, offset, val);
404}
405#endif /* CONFIG_LEDS_PCA955X_GPIO */
406
407static struct pca955x_platform_data *
408pca955x_get_pdata(struct i2c_client *client, const struct pca955x_chipdef *chip)
409{
410 struct pca955x_platform_data *pdata;
411 struct pca955x_led *led;
412 struct fwnode_handle *child;
413 int count;
414
415 count = device_get_child_node_count(&client->dev);
416 if (count > chip->bits)
417 return ERR_PTR(-ENODEV);
418
419 pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL);
420 if (!pdata)
421 return ERR_PTR(-ENOMEM);
422
423 pdata->leds = devm_kcalloc(&client->dev,
424 chip->bits, sizeof(struct pca955x_led),
425 GFP_KERNEL);
426 if (!pdata->leds)
427 return ERR_PTR(-ENOMEM);
428
429 device_for_each_child_node(&client->dev, child) {
430 u32 reg;
431 int res;
432
433 res = fwnode_property_read_u32(child, "reg", ®);
434 if ((res != 0) || (reg >= chip->bits))
435 continue;
436
437 led = &pdata->leds[reg];
438 led->type = PCA955X_TYPE_LED;
439 led->fwnode = child;
440 led->default_state = led_init_default_state_get(child);
441
442 fwnode_property_read_u32(child, "type", &led->type);
443 }
444
445 pdata->num_leds = chip->bits;
446
447 return pdata;
448}
449
450static int pca955x_probe(struct i2c_client *client)
451{
452 struct pca955x *pca955x;
453 struct pca955x_led *pca955x_led;
454 const struct pca955x_chipdef *chip;
455 struct led_classdev *led;
456 struct led_init_data init_data;
457 struct i2c_adapter *adapter;
458 int i, err;
459 struct pca955x_platform_data *pdata;
460 bool set_default_label = false;
461 bool keep_pwm = false;
462 char default_label[8];
463
464 chip = i2c_get_match_data(client);
465 if (!chip)
466 return dev_err_probe(&client->dev, -ENODEV, "unknown chip\n");
467
468 adapter = client->adapter;
469 pdata = dev_get_platdata(&client->dev);
470 if (!pdata) {
471 pdata = pca955x_get_pdata(client, chip);
472 if (IS_ERR(pdata))
473 return PTR_ERR(pdata);
474 }
475
476 /* Make sure the slave address / chip type combo given is possible */
477 if ((client->addr & ~((1 << chip->slv_addr_shift) - 1)) !=
478 chip->slv_addr) {
479 dev_err(&client->dev, "invalid slave address %02x\n",
480 client->addr);
481 return -ENODEV;
482 }
483
484 dev_info(&client->dev, "leds-pca955x: Using %s %d-bit LED driver at "
485 "slave address 0x%02x\n", client->name, chip->bits,
486 client->addr);
487
488 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
489 return -EIO;
490
491 if (pdata->num_leds != chip->bits) {
492 dev_err(&client->dev,
493 "board info claims %d LEDs on a %d-bit chip\n",
494 pdata->num_leds, chip->bits);
495 return -ENODEV;
496 }
497
498 pca955x = devm_kzalloc(&client->dev, sizeof(*pca955x), GFP_KERNEL);
499 if (!pca955x)
500 return -ENOMEM;
501
502 pca955x->leds = devm_kcalloc(&client->dev, chip->bits,
503 sizeof(*pca955x_led), GFP_KERNEL);
504 if (!pca955x->leds)
505 return -ENOMEM;
506
507 i2c_set_clientdata(client, pca955x);
508
509 mutex_init(&pca955x->lock);
510 pca955x->client = client;
511 pca955x->chipdef = chip;
512
513 init_data.devname_mandatory = false;
514 init_data.devicename = "pca955x";
515
516 for (i = 0; i < chip->bits; i++) {
517 pca955x_led = &pca955x->leds[i];
518 pca955x_led->led_num = i;
519 pca955x_led->pca955x = pca955x;
520 pca955x_led->type = pdata->leds[i].type;
521
522 switch (pca955x_led->type) {
523 case PCA955X_TYPE_NONE:
524 case PCA955X_TYPE_GPIO:
525 break;
526 case PCA955X_TYPE_LED:
527 led = &pca955x_led->led_cdev;
528 led->brightness_set_blocking = pca955x_led_set;
529 led->brightness_get = pca955x_led_get;
530
531 if (pdata->leds[i].default_state == LEDS_DEFSTATE_OFF) {
532 err = pca955x_led_set(led, LED_OFF);
533 if (err)
534 return err;
535 } else if (pdata->leds[i].default_state == LEDS_DEFSTATE_ON) {
536 err = pca955x_led_set(led, LED_FULL);
537 if (err)
538 return err;
539 }
540
541 init_data.fwnode = pdata->leds[i].fwnode;
542
543 if (is_of_node(init_data.fwnode)) {
544 if (to_of_node(init_data.fwnode)->name[0] ==
545 '\0')
546 set_default_label = true;
547 else
548 set_default_label = false;
549 } else {
550 set_default_label = true;
551 }
552
553 if (set_default_label) {
554 snprintf(default_label, sizeof(default_label),
555 "%d", i);
556 init_data.default_label = default_label;
557 } else {
558 init_data.default_label = NULL;
559 }
560
561 err = devm_led_classdev_register_ext(&client->dev, led,
562 &init_data);
563 if (err)
564 return err;
565
566 set_bit(i, &pca955x->active_pins);
567
568 /*
569 * For default-state == "keep", let the core update the
570 * brightness from the hardware, then check the
571 * brightness to see if it's using PWM1. If so, PWM1
572 * should not be written below.
573 */
574 if (pdata->leds[i].default_state == LEDS_DEFSTATE_KEEP) {
575 if (led->brightness != LED_FULL &&
576 led->brightness != LED_OFF &&
577 led->brightness != LED_HALF)
578 keep_pwm = true;
579 }
580 }
581 }
582
583 /* PWM0 is used for half brightness or 50% duty cycle */
584 err = pca955x_write_pwm(client, 0, 255 - LED_HALF);
585 if (err)
586 return err;
587
588 if (!keep_pwm) {
589 /* PWM1 is used for variable brightness, default to OFF */
590 err = pca955x_write_pwm(client, 1, 0);
591 if (err)
592 return err;
593 }
594
595 /* Set to fast frequency so we do not see flashing */
596 err = pca955x_write_psc(client, 0, 0);
597 if (err)
598 return err;
599 err = pca955x_write_psc(client, 1, 0);
600 if (err)
601 return err;
602
603#ifdef CONFIG_LEDS_PCA955X_GPIO
604 pca955x->gpio.label = "gpio-pca955x";
605 pca955x->gpio.direction_input = pca955x_gpio_direction_input;
606 pca955x->gpio.direction_output = pca955x_gpio_direction_output;
607 pca955x->gpio.set = pca955x_gpio_set_value;
608 pca955x->gpio.get = pca955x_gpio_get_value;
609 pca955x->gpio.request = pca955x_gpio_request_pin;
610 pca955x->gpio.free = pca955x_gpio_free_pin;
611 pca955x->gpio.can_sleep = 1;
612 pca955x->gpio.base = -1;
613 pca955x->gpio.ngpio = chip->bits;
614 pca955x->gpio.parent = &client->dev;
615 pca955x->gpio.owner = THIS_MODULE;
616
617 err = devm_gpiochip_add_data(&client->dev, &pca955x->gpio,
618 pca955x);
619 if (err) {
620 /* Use data->gpio.dev as a flag for freeing gpiochip */
621 pca955x->gpio.parent = NULL;
622 dev_warn(&client->dev, "could not add gpiochip\n");
623 return err;
624 }
625 dev_info(&client->dev, "gpios %i...%i\n",
626 pca955x->gpio.base, pca955x->gpio.base +
627 pca955x->gpio.ngpio - 1);
628#endif
629
630 return 0;
631}
632
633static const struct i2c_device_id pca955x_id[] = {
634 { "pca9550", (kernel_ulong_t)&pca955x_chipdefs[pca9550] },
635 { "pca9551", (kernel_ulong_t)&pca955x_chipdefs[pca9551] },
636 { "pca9552", (kernel_ulong_t)&pca955x_chipdefs[pca9552] },
637 { "ibm-pca9552", (kernel_ulong_t)&pca955x_chipdefs[ibm_pca9552] },
638 { "pca9553", (kernel_ulong_t)&pca955x_chipdefs[pca9553] },
639 {}
640};
641MODULE_DEVICE_TABLE(i2c, pca955x_id);
642
643static const struct of_device_id of_pca955x_match[] = {
644 { .compatible = "nxp,pca9550", .data = &pca955x_chipdefs[pca9550] },
645 { .compatible = "nxp,pca9551", .data = &pca955x_chipdefs[pca9551] },
646 { .compatible = "nxp,pca9552", .data = &pca955x_chipdefs[pca9552] },
647 { .compatible = "ibm,pca9552", .data = &pca955x_chipdefs[ibm_pca9552] },
648 { .compatible = "nxp,pca9553", .data = &pca955x_chipdefs[pca9553] },
649 {}
650};
651MODULE_DEVICE_TABLE(of, of_pca955x_match);
652
653static struct i2c_driver pca955x_driver = {
654 .driver = {
655 .name = "leds-pca955x",
656 .of_match_table = of_pca955x_match,
657 },
658 .probe = pca955x_probe,
659 .id_table = pca955x_id,
660};
661
662module_i2c_driver(pca955x_driver);
663
664MODULE_AUTHOR("Nate Case <ncase@xes-inc.com>");
665MODULE_DESCRIPTION("PCA955x LED driver");
666MODULE_LICENSE("GPL v2");
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright 2007-2008 Extreme Engineering Solutions, Inc.
4 *
5 * Author: Nate Case <ncase@xes-inc.com>
6 *
7 * LED driver for various PCA955x I2C LED drivers
8 *
9 * Supported devices:
10 *
11 * Device Description 7-bit slave address
12 * ------ ----------- -------------------
13 * PCA9550 2-bit driver 0x60 .. 0x61
14 * PCA9551 8-bit driver 0x60 .. 0x67
15 * PCA9552 16-bit driver 0x60 .. 0x67
16 * PCA9553/01 4-bit driver 0x62
17 * PCA9553/02 4-bit driver 0x63
18 *
19 * Philips PCA955x LED driver chips follow a register map as shown below:
20 *
21 * Control Register Description
22 * ---------------- -----------
23 * 0x0 Input register 0
24 * ..
25 * NUM_INPUT_REGS - 1 Last Input register X
26 *
27 * NUM_INPUT_REGS Frequency prescaler 0
28 * NUM_INPUT_REGS + 1 PWM register 0
29 * NUM_INPUT_REGS + 2 Frequency prescaler 1
30 * NUM_INPUT_REGS + 3 PWM register 1
31 *
32 * NUM_INPUT_REGS + 4 LED selector 0
33 * NUM_INPUT_REGS + 4
34 * + NUM_LED_REGS - 1 Last LED selector
35 *
36 * where NUM_INPUT_REGS and NUM_LED_REGS vary depending on how many
37 * bits the chip supports.
38 */
39
40#include <linux/ctype.h>
41#include <linux/delay.h>
42#include <linux/err.h>
43#include <linux/gpio/driver.h>
44#include <linux/i2c.h>
45#include <linux/leds.h>
46#include <linux/module.h>
47#include <linux/of.h>
48#include <linux/property.h>
49#include <linux/slab.h>
50#include <linux/string.h>
51
52#include <dt-bindings/leds/leds-pca955x.h>
53
54/* LED select registers determine the source that drives LED outputs */
55#define PCA955X_LS_LED_ON 0x0 /* Output LOW */
56#define PCA955X_LS_LED_OFF 0x1 /* Output HI-Z */
57#define PCA955X_LS_BLINK0 0x2 /* Blink at PWM0 rate */
58#define PCA955X_LS_BLINK1 0x3 /* Blink at PWM1 rate */
59
60#define PCA955X_GPIO_INPUT LED_OFF
61#define PCA955X_GPIO_HIGH LED_OFF
62#define PCA955X_GPIO_LOW LED_FULL
63
64enum pca955x_type {
65 pca9550,
66 pca9551,
67 pca9552,
68 ibm_pca9552,
69 pca9553,
70};
71
72struct pca955x_chipdef {
73 int bits;
74 u8 slv_addr; /* 7-bit slave address mask */
75 int slv_addr_shift; /* Number of bits to ignore */
76};
77
78static struct pca955x_chipdef pca955x_chipdefs[] = {
79 [pca9550] = {
80 .bits = 2,
81 .slv_addr = /* 110000x */ 0x60,
82 .slv_addr_shift = 1,
83 },
84 [pca9551] = {
85 .bits = 8,
86 .slv_addr = /* 1100xxx */ 0x60,
87 .slv_addr_shift = 3,
88 },
89 [pca9552] = {
90 .bits = 16,
91 .slv_addr = /* 1100xxx */ 0x60,
92 .slv_addr_shift = 3,
93 },
94 [ibm_pca9552] = {
95 .bits = 16,
96 .slv_addr = /* 0110xxx */ 0x30,
97 .slv_addr_shift = 3,
98 },
99 [pca9553] = {
100 .bits = 4,
101 .slv_addr = /* 110001x */ 0x62,
102 .slv_addr_shift = 1,
103 },
104};
105
106static const struct i2c_device_id pca955x_id[] = {
107 { "pca9550", pca9550 },
108 { "pca9551", pca9551 },
109 { "pca9552", pca9552 },
110 { "ibm-pca9552", ibm_pca9552 },
111 { "pca9553", pca9553 },
112 { }
113};
114MODULE_DEVICE_TABLE(i2c, pca955x_id);
115
116struct pca955x {
117 struct mutex lock;
118 struct pca955x_led *leds;
119 struct pca955x_chipdef *chipdef;
120 struct i2c_client *client;
121#ifdef CONFIG_LEDS_PCA955X_GPIO
122 struct gpio_chip gpio;
123#endif
124};
125
126struct pca955x_led {
127 struct pca955x *pca955x;
128 struct led_classdev led_cdev;
129 int led_num; /* 0 .. 15 potentially */
130 char name[32];
131 u32 type;
132 const char *default_trigger;
133};
134
135struct pca955x_platform_data {
136 struct pca955x_led *leds;
137 int num_leds;
138};
139
140/* 8 bits per input register */
141static inline int pca95xx_num_input_regs(int bits)
142{
143 return (bits + 7) / 8;
144}
145
146/* 4 bits per LED selector register */
147static inline int pca95xx_num_led_regs(int bits)
148{
149 return (bits + 3) / 4;
150}
151
152/*
153 * Return an LED selector register value based on an existing one, with
154 * the appropriate 2-bit state value set for the given LED number (0-3).
155 */
156static inline u8 pca955x_ledsel(u8 oldval, int led_num, int state)
157{
158 return (oldval & (~(0x3 << (led_num << 1)))) |
159 ((state & 0x3) << (led_num << 1));
160}
161
162/*
163 * Write to frequency prescaler register, used to program the
164 * period of the PWM output. period = (PSCx + 1) / 38
165 */
166static int pca955x_write_psc(struct i2c_client *client, int n, u8 val)
167{
168 struct pca955x *pca955x = i2c_get_clientdata(client);
169 int ret;
170
171 ret = i2c_smbus_write_byte_data(client,
172 pca95xx_num_input_regs(pca955x->chipdef->bits) + 2*n,
173 val);
174 if (ret < 0)
175 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
176 __func__, n, val, ret);
177 return ret;
178}
179
180/*
181 * Write to PWM register, which determines the duty cycle of the
182 * output. LED is OFF when the count is less than the value of this
183 * register, and ON when it is greater. If PWMx == 0, LED is always OFF.
184 *
185 * Duty cycle is (256 - PWMx) / 256
186 */
187static int pca955x_write_pwm(struct i2c_client *client, int n, u8 val)
188{
189 struct pca955x *pca955x = i2c_get_clientdata(client);
190 int ret;
191
192 ret = i2c_smbus_write_byte_data(client,
193 pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + 2*n,
194 val);
195 if (ret < 0)
196 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
197 __func__, n, val, ret);
198 return ret;
199}
200
201/*
202 * Write to LED selector register, which determines the source that
203 * drives the LED output.
204 */
205static int pca955x_write_ls(struct i2c_client *client, int n, u8 val)
206{
207 struct pca955x *pca955x = i2c_get_clientdata(client);
208 int ret;
209
210 ret = i2c_smbus_write_byte_data(client,
211 pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n,
212 val);
213 if (ret < 0)
214 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
215 __func__, n, val, ret);
216 return ret;
217}
218
219/*
220 * Read the LED selector register, which determines the source that
221 * drives the LED output.
222 */
223static int pca955x_read_ls(struct i2c_client *client, int n, u8 *val)
224{
225 struct pca955x *pca955x = i2c_get_clientdata(client);
226 int ret;
227
228 ret = i2c_smbus_read_byte_data(client,
229 pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n);
230 if (ret < 0) {
231 dev_err(&client->dev, "%s: reg 0x%x, err %d\n",
232 __func__, n, ret);
233 return ret;
234 }
235 *val = (u8)ret;
236 return 0;
237}
238
239static int pca955x_led_set(struct led_classdev *led_cdev,
240 enum led_brightness value)
241{
242 struct pca955x_led *pca955x_led;
243 struct pca955x *pca955x;
244 u8 ls;
245 int chip_ls; /* which LSx to use (0-3 potentially) */
246 int ls_led; /* which set of bits within LSx to use (0-3) */
247 int ret;
248
249 pca955x_led = container_of(led_cdev, struct pca955x_led, led_cdev);
250 pca955x = pca955x_led->pca955x;
251
252 chip_ls = pca955x_led->led_num / 4;
253 ls_led = pca955x_led->led_num % 4;
254
255 mutex_lock(&pca955x->lock);
256
257 ret = pca955x_read_ls(pca955x->client, chip_ls, &ls);
258 if (ret)
259 goto out;
260
261 switch (value) {
262 case LED_FULL:
263 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_ON);
264 break;
265 case LED_OFF:
266 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_OFF);
267 break;
268 case LED_HALF:
269 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK0);
270 break;
271 default:
272 /*
273 * Use PWM1 for all other values. This has the unwanted
274 * side effect of making all LEDs on the chip share the
275 * same brightness level if set to a value other than
276 * OFF, HALF, or FULL. But, this is probably better than
277 * just turning off for all other values.
278 */
279 ret = pca955x_write_pwm(pca955x->client, 1, 255 - value);
280 if (ret)
281 goto out;
282 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK1);
283 break;
284 }
285
286 ret = pca955x_write_ls(pca955x->client, chip_ls, ls);
287
288out:
289 mutex_unlock(&pca955x->lock);
290
291 return ret;
292}
293
294#ifdef CONFIG_LEDS_PCA955X_GPIO
295/*
296 * Read the INPUT register, which contains the state of LEDs.
297 */
298static int pca955x_read_input(struct i2c_client *client, int n, u8 *val)
299{
300 int ret = i2c_smbus_read_byte_data(client, n);
301
302 if (ret < 0) {
303 dev_err(&client->dev, "%s: reg 0x%x, err %d\n",
304 __func__, n, ret);
305 return ret;
306 }
307 *val = (u8)ret;
308 return 0;
309
310}
311
312static int pca955x_gpio_request_pin(struct gpio_chip *gc, unsigned int offset)
313{
314 struct pca955x *pca955x = gpiochip_get_data(gc);
315 struct pca955x_led *led = &pca955x->leds[offset];
316
317 if (led->type == PCA955X_TYPE_GPIO)
318 return 0;
319
320 return -EBUSY;
321}
322
323static int pca955x_set_value(struct gpio_chip *gc, unsigned int offset,
324 int val)
325{
326 struct pca955x *pca955x = gpiochip_get_data(gc);
327 struct pca955x_led *led = &pca955x->leds[offset];
328
329 if (val)
330 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_HIGH);
331
332 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_LOW);
333}
334
335static void pca955x_gpio_set_value(struct gpio_chip *gc, unsigned int offset,
336 int val)
337{
338 pca955x_set_value(gc, offset, val);
339}
340
341static int pca955x_gpio_get_value(struct gpio_chip *gc, unsigned int offset)
342{
343 struct pca955x *pca955x = gpiochip_get_data(gc);
344 struct pca955x_led *led = &pca955x->leds[offset];
345 u8 reg = 0;
346
347 /* There is nothing we can do about errors */
348 pca955x_read_input(pca955x->client, led->led_num / 8, ®);
349
350 return !!(reg & (1 << (led->led_num % 8)));
351}
352
353static int pca955x_gpio_direction_input(struct gpio_chip *gc,
354 unsigned int offset)
355{
356 struct pca955x *pca955x = gpiochip_get_data(gc);
357 struct pca955x_led *led = &pca955x->leds[offset];
358
359 /* To use as input ensure pin is not driven. */
360 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_INPUT);
361}
362
363static int pca955x_gpio_direction_output(struct gpio_chip *gc,
364 unsigned int offset, int val)
365{
366 return pca955x_set_value(gc, offset, val);
367}
368#endif /* CONFIG_LEDS_PCA955X_GPIO */
369
370static struct pca955x_platform_data *
371pca955x_get_pdata(struct i2c_client *client, struct pca955x_chipdef *chip)
372{
373 struct pca955x_platform_data *pdata;
374 struct fwnode_handle *child;
375 int count;
376
377 count = device_get_child_node_count(&client->dev);
378 if (!count || count > chip->bits)
379 return ERR_PTR(-ENODEV);
380
381 pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL);
382 if (!pdata)
383 return ERR_PTR(-ENOMEM);
384
385 pdata->leds = devm_kcalloc(&client->dev,
386 chip->bits, sizeof(struct pca955x_led),
387 GFP_KERNEL);
388 if (!pdata->leds)
389 return ERR_PTR(-ENOMEM);
390
391 device_for_each_child_node(&client->dev, child) {
392 const char *name;
393 u32 reg;
394 int res;
395
396 res = fwnode_property_read_u32(child, "reg", ®);
397 if ((res != 0) || (reg >= chip->bits))
398 continue;
399
400 res = fwnode_property_read_string(child, "label", &name);
401 if ((res != 0) && is_of_node(child))
402 name = to_of_node(child)->name;
403
404 snprintf(pdata->leds[reg].name, sizeof(pdata->leds[reg].name),
405 "%s", name);
406
407 pdata->leds[reg].type = PCA955X_TYPE_LED;
408 fwnode_property_read_u32(child, "type", &pdata->leds[reg].type);
409 fwnode_property_read_string(child, "linux,default-trigger",
410 &pdata->leds[reg].default_trigger);
411 }
412
413 pdata->num_leds = chip->bits;
414
415 return pdata;
416}
417
418static const struct of_device_id of_pca955x_match[] = {
419 { .compatible = "nxp,pca9550", .data = (void *)pca9550 },
420 { .compatible = "nxp,pca9551", .data = (void *)pca9551 },
421 { .compatible = "nxp,pca9552", .data = (void *)pca9552 },
422 { .compatible = "ibm,pca9552", .data = (void *)ibm_pca9552 },
423 { .compatible = "nxp,pca9553", .data = (void *)pca9553 },
424 {},
425};
426MODULE_DEVICE_TABLE(of, of_pca955x_match);
427
428static int pca955x_probe(struct i2c_client *client,
429 const struct i2c_device_id *id)
430{
431 struct pca955x *pca955x;
432 struct pca955x_led *pca955x_led;
433 struct pca955x_chipdef *chip;
434 struct i2c_adapter *adapter;
435 int i, err;
436 struct pca955x_platform_data *pdata;
437 int ngpios = 0;
438
439 chip = &pca955x_chipdefs[id->driver_data];
440 adapter = client->adapter;
441 pdata = dev_get_platdata(&client->dev);
442 if (!pdata) {
443 pdata = pca955x_get_pdata(client, chip);
444 if (IS_ERR(pdata))
445 return PTR_ERR(pdata);
446 }
447
448 /* Make sure the slave address / chip type combo given is possible */
449 if ((client->addr & ~((1 << chip->slv_addr_shift) - 1)) !=
450 chip->slv_addr) {
451 dev_err(&client->dev, "invalid slave address %02x\n",
452 client->addr);
453 return -ENODEV;
454 }
455
456 dev_info(&client->dev, "leds-pca955x: Using %s %d-bit LED driver at "
457 "slave address 0x%02x\n",
458 client->name, chip->bits, client->addr);
459
460 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
461 return -EIO;
462
463 if (pdata->num_leds != chip->bits) {
464 dev_err(&client->dev,
465 "board info claims %d LEDs on a %d-bit chip\n",
466 pdata->num_leds, chip->bits);
467 return -ENODEV;
468 }
469
470 pca955x = devm_kzalloc(&client->dev, sizeof(*pca955x), GFP_KERNEL);
471 if (!pca955x)
472 return -ENOMEM;
473
474 pca955x->leds = devm_kcalloc(&client->dev,
475 chip->bits, sizeof(*pca955x_led), GFP_KERNEL);
476 if (!pca955x->leds)
477 return -ENOMEM;
478
479 i2c_set_clientdata(client, pca955x);
480
481 mutex_init(&pca955x->lock);
482 pca955x->client = client;
483 pca955x->chipdef = chip;
484
485 for (i = 0; i < chip->bits; i++) {
486 pca955x_led = &pca955x->leds[i];
487 pca955x_led->led_num = i;
488 pca955x_led->pca955x = pca955x;
489 pca955x_led->type = pdata->leds[i].type;
490
491 switch (pca955x_led->type) {
492 case PCA955X_TYPE_NONE:
493 break;
494 case PCA955X_TYPE_GPIO:
495 ngpios++;
496 break;
497 case PCA955X_TYPE_LED:
498 /*
499 * Platform data can specify LED names and
500 * default triggers
501 */
502 if (pdata->leds[i].name[0] == '\0')
503 snprintf(pdata->leds[i].name,
504 sizeof(pdata->leds[i].name), "%d", i);
505
506 snprintf(pca955x_led->name,
507 sizeof(pca955x_led->name), "pca955x:%s",
508 pdata->leds[i].name);
509
510 if (pdata->leds[i].default_trigger)
511 pca955x_led->led_cdev.default_trigger =
512 pdata->leds[i].default_trigger;
513
514 pca955x_led->led_cdev.name = pca955x_led->name;
515 pca955x_led->led_cdev.brightness_set_blocking =
516 pca955x_led_set;
517
518 err = devm_led_classdev_register(&client->dev,
519 &pca955x_led->led_cdev);
520 if (err)
521 return err;
522
523 /* Turn off LED */
524 err = pca955x_led_set(&pca955x_led->led_cdev, LED_OFF);
525 if (err)
526 return err;
527 }
528 }
529
530 /* PWM0 is used for half brightness or 50% duty cycle */
531 err = pca955x_write_pwm(client, 0, 255 - LED_HALF);
532 if (err)
533 return err;
534
535 /* PWM1 is used for variable brightness, default to OFF */
536 err = pca955x_write_pwm(client, 1, 0);
537 if (err)
538 return err;
539
540 /* Set to fast frequency so we do not see flashing */
541 err = pca955x_write_psc(client, 0, 0);
542 if (err)
543 return err;
544 err = pca955x_write_psc(client, 1, 0);
545 if (err)
546 return err;
547
548#ifdef CONFIG_LEDS_PCA955X_GPIO
549 if (ngpios) {
550 pca955x->gpio.label = "gpio-pca955x";
551 pca955x->gpio.direction_input = pca955x_gpio_direction_input;
552 pca955x->gpio.direction_output = pca955x_gpio_direction_output;
553 pca955x->gpio.set = pca955x_gpio_set_value;
554 pca955x->gpio.get = pca955x_gpio_get_value;
555 pca955x->gpio.request = pca955x_gpio_request_pin;
556 pca955x->gpio.can_sleep = 1;
557 pca955x->gpio.base = -1;
558 pca955x->gpio.ngpio = ngpios;
559 pca955x->gpio.parent = &client->dev;
560 pca955x->gpio.owner = THIS_MODULE;
561
562 err = devm_gpiochip_add_data(&client->dev, &pca955x->gpio,
563 pca955x);
564 if (err) {
565 /* Use data->gpio.dev as a flag for freeing gpiochip */
566 pca955x->gpio.parent = NULL;
567 dev_warn(&client->dev, "could not add gpiochip\n");
568 return err;
569 }
570 dev_info(&client->dev, "gpios %i...%i\n",
571 pca955x->gpio.base, pca955x->gpio.base +
572 pca955x->gpio.ngpio - 1);
573 }
574#endif
575
576 return 0;
577}
578
579static struct i2c_driver pca955x_driver = {
580 .driver = {
581 .name = "leds-pca955x",
582 .of_match_table = of_pca955x_match,
583 },
584 .probe = pca955x_probe,
585 .id_table = pca955x_id,
586};
587
588module_i2c_driver(pca955x_driver);
589
590MODULE_AUTHOR("Nate Case <ncase@xes-inc.com>");
591MODULE_DESCRIPTION("PCA955x LED driver");
592MODULE_LICENSE("GPL v2");