xref: /linux/drivers/leds/leds-pca955x.c (revision 0227b49b50276657243e54f5609e65c4f0eaaf4d)
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 
65 #define PCA955X_BLINK_DEFAULT_MS	1000
66 
67 enum pca955x_type {
68 	pca9550,
69 	pca9551,
70 	pca9552,
71 	ibm_pca9552,
72 	pca9553,
73 };
74 
75 struct pca955x_chipdef {
76 	u8			bits;
77 	u8			slv_addr;	/* 7-bit slave address mask */
78 	int			slv_addr_shift;	/* Number of bits to ignore */
79 	int			blink_div;	/* PSC divider */
80 };
81 
82 static const struct pca955x_chipdef pca955x_chipdefs[] = {
83 	[pca9550] = {
84 		.bits		= 2,
85 		.slv_addr	= /* 110000x */ 0x60,
86 		.slv_addr_shift	= 1,
87 		.blink_div	= 44,
88 	},
89 	[pca9551] = {
90 		.bits		= 8,
91 		.slv_addr	= /* 1100xxx */ 0x60,
92 		.slv_addr_shift	= 3,
93 		.blink_div	= 38,
94 	},
95 	[pca9552] = {
96 		.bits		= 16,
97 		.slv_addr	= /* 1100xxx */ 0x60,
98 		.slv_addr_shift	= 3,
99 		.blink_div	= 44,
100 	},
101 	[ibm_pca9552] = {
102 		.bits		= 16,
103 		.slv_addr	= /* 0110xxx */ 0x30,
104 		.slv_addr_shift	= 3,
105 		.blink_div	= 44,
106 	},
107 	[pca9553] = {
108 		.bits		= 4,
109 		.slv_addr	= /* 110001x */ 0x62,
110 		.slv_addr_shift	= 1,
111 		.blink_div	= 44,
112 	},
113 };
114 
115 struct pca955x {
116 	struct mutex lock;
117 	struct pca955x_led *leds;
118 	const struct pca955x_chipdef	*chipdef;
119 	struct i2c_client	*client;
120 	unsigned long active_blink;
121 	unsigned long active_pins;
122 	unsigned long blink_period;
123 #ifdef CONFIG_LEDS_PCA955X_GPIO
124 	struct gpio_chip gpio;
125 #endif
126 };
127 
128 struct pca955x_led {
129 	struct pca955x	*pca955x;
130 	struct led_classdev	led_cdev;
131 	int			led_num;	/* 0 .. 15 potentially */
132 	u32			type;
133 	enum led_default_state	default_state;
134 	struct fwnode_handle	*fwnode;
135 };
136 
137 #define led_to_pca955x(l)	container_of(l, struct pca955x_led, led_cdev)
138 
139 struct pca955x_platform_data {
140 	struct pca955x_led	*leds;
141 	int			num_leds;
142 };
143 
144 /* 8 bits per input register */
pca955x_num_input_regs(u8 bits)145 static inline u8 pca955x_num_input_regs(u8 bits)
146 {
147 	return (bits + 7) / 8;
148 }
149 
150 /* 4 bits per LED selector register */
pca955x_num_led_regs(u8 bits)151 static inline u8 pca955x_num_led_regs(u8 bits)
152 {
153 	return (bits + 3)  / 4;
154 }
155 
156 /*
157  * Return an LED selector register value based on an existing one, with
158  * the appropriate 2-bit state value set for the given LED number (0-3).
159  */
pca955x_ledsel(u8 oldval,int led_num,int state)160 static inline u8 pca955x_ledsel(u8 oldval, int led_num, int state)
161 {
162 	return (oldval & (~(0x3 << (led_num << 1)))) |
163 		((state & 0x3) << (led_num << 1));
164 }
165 
pca955x_ledstate(u8 ls,int led_num)166 static inline int pca955x_ledstate(u8 ls, int led_num)
167 {
168 	return (ls >> (led_num << 1)) & 0x3;
169 }
170 
171 /*
172  * Write to frequency prescaler register, used to program the
173  * period of the PWM output.  period = (PSCx + 1) / coeff
174  * Where for pca9551 chips coeff = 38 and for all other chips coeff = 44
175  */
pca955x_write_psc(struct pca955x * pca955x,int n,u8 val)176 static int pca955x_write_psc(struct pca955x *pca955x, int n, u8 val)
177 {
178 	u8 cmd = pca955x_num_input_regs(pca955x->chipdef->bits) + (2 * n);
179 	int ret;
180 
181 	ret = i2c_smbus_write_byte_data(pca955x->client, cmd, val);
182 	if (ret < 0)
183 		dev_err(&pca955x->client->dev, "%s: reg 0x%x, val 0x%x, err %d\n", __func__, n,
184 			val, ret);
185 	return ret;
186 }
187 
188 /*
189  * Write to PWM register, which determines the duty cycle of the
190  * output.  LED is OFF when the count is less than the value of this
191  * register, and ON when it is greater.  If PWMx == 0, LED is always OFF.
192  *
193  * Duty cycle is (256 - PWMx) / 256
194  */
pca955x_write_pwm(struct pca955x * pca955x,int n,u8 val)195 static int pca955x_write_pwm(struct pca955x *pca955x, int n, u8 val)
196 {
197 	u8 cmd = pca955x_num_input_regs(pca955x->chipdef->bits) + 1 + (2 * n);
198 	int ret;
199 
200 	ret = i2c_smbus_write_byte_data(pca955x->client, cmd, val);
201 	if (ret < 0)
202 		dev_err(&pca955x->client->dev, "%s: reg 0x%x, val 0x%x, err %d\n", __func__, n,
203 			val, ret);
204 	return ret;
205 }
206 
207 /*
208  * Write to LED selector register, which determines the source that
209  * drives the LED output.
210  */
pca955x_write_ls(struct pca955x * pca955x,int n,u8 val)211 static int pca955x_write_ls(struct pca955x *pca955x, int n, u8 val)
212 {
213 	u8 cmd = pca955x_num_input_regs(pca955x->chipdef->bits) + 4 + n;
214 	int ret;
215 
216 	ret = i2c_smbus_write_byte_data(pca955x->client, cmd, val);
217 	if (ret < 0)
218 		dev_err(&pca955x->client->dev, "%s: reg 0x%x, val 0x%x, err %d\n", __func__, n,
219 			val, ret);
220 	return ret;
221 }
222 
223 /*
224  * Read the LED selector register, which determines the source that
225  * drives the LED output.
226  */
pca955x_read_ls(struct pca955x * pca955x,int n,u8 * val)227 static int pca955x_read_ls(struct pca955x *pca955x, int n, u8 *val)
228 {
229 	u8 cmd = pca955x_num_input_regs(pca955x->chipdef->bits) + 4 + n;
230 	int ret;
231 
232 	ret = i2c_smbus_read_byte_data(pca955x->client, cmd);
233 	if (ret < 0) {
234 		dev_err(&pca955x->client->dev, "%s: reg 0x%x, err %d\n", __func__, n, ret);
235 		return ret;
236 	}
237 	*val = (u8)ret;
238 	return 0;
239 }
240 
pca955x_read_pwm(struct pca955x * pca955x,int n,u8 * val)241 static int pca955x_read_pwm(struct pca955x *pca955x, int n, u8 *val)
242 {
243 	u8 cmd = pca955x_num_input_regs(pca955x->chipdef->bits) + 1 + (2 * n);
244 	int ret;
245 
246 	ret = i2c_smbus_read_byte_data(pca955x->client, cmd);
247 	if (ret < 0) {
248 		dev_err(&pca955x->client->dev, "%s: reg 0x%x, err %d\n", __func__, n, ret);
249 		return ret;
250 	}
251 	*val = (u8)ret;
252 	return 0;
253 }
254 
pca955x_read_psc(struct pca955x * pca955x,int n,u8 * val)255 static int pca955x_read_psc(struct pca955x *pca955x, int n, u8 *val)
256 {
257 	int ret;
258 	u8 cmd;
259 
260 	cmd = pca955x_num_input_regs(pca955x->chipdef->bits) + (2 * n);
261 	ret = i2c_smbus_read_byte_data(pca955x->client, cmd);
262 	if (ret < 0) {
263 		dev_err(&pca955x->client->dev, "%s: reg 0x%x, err %d\n", __func__, n, ret);
264 		return ret;
265 	}
266 	*val = (u8)ret;
267 	return 0;
268 }
269 
pca955x_led_get(struct led_classdev * led_cdev)270 static enum led_brightness pca955x_led_get(struct led_classdev *led_cdev)
271 {
272 	struct pca955x_led *pca955x_led = led_to_pca955x(led_cdev);
273 	struct pca955x *pca955x = pca955x_led->pca955x;
274 	u8 ls, pwm;
275 	int ret;
276 
277 	ret = pca955x_read_ls(pca955x, pca955x_led->led_num / 4, &ls);
278 	if (ret)
279 		return ret;
280 
281 	switch (pca955x_ledstate(ls, pca955x_led->led_num % 4)) {
282 	case PCA955X_LS_LED_ON:
283 	case PCA955X_LS_BLINK0:
284 		ret = LED_FULL;
285 		break;
286 	case PCA955X_LS_LED_OFF:
287 		ret = LED_OFF;
288 		break;
289 	case PCA955X_LS_BLINK1:
290 		ret = pca955x_read_pwm(pca955x, 1, &pwm);
291 		if (ret)
292 			return ret;
293 		ret = 255 - pwm;
294 		break;
295 	}
296 
297 	return ret;
298 }
299 
pca955x_led_set(struct led_classdev * led_cdev,enum led_brightness value)300 static int pca955x_led_set(struct led_classdev *led_cdev,
301 			    enum led_brightness value)
302 {
303 	struct pca955x_led *pca955x_led = led_to_pca955x(led_cdev);
304 	struct pca955x *pca955x = pca955x_led->pca955x;
305 	int reg = pca955x_led->led_num / 4;
306 	int bit = pca955x_led->led_num % 4;
307 	u8 ls;
308 	int ret;
309 
310 	mutex_lock(&pca955x->lock);
311 
312 	ret = pca955x_read_ls(pca955x, reg, &ls);
313 	if (ret)
314 		goto out;
315 
316 	if (test_bit(pca955x_led->led_num, &pca955x->active_blink)) {
317 		if (value == LED_OFF) {
318 			clear_bit(pca955x_led->led_num, &pca955x->active_blink);
319 			ls = pca955x_ledsel(ls, bit, PCA955X_LS_LED_OFF);
320 		} else {
321 			/* No variable brightness for blinking LEDs */
322 			goto out;
323 		}
324 	} else {
325 		switch (value) {
326 		case LED_FULL:
327 			ls = pca955x_ledsel(ls, bit, PCA955X_LS_LED_ON);
328 			break;
329 		case LED_OFF:
330 			ls = pca955x_ledsel(ls, bit, PCA955X_LS_LED_OFF);
331 			break;
332 		default:
333 			/*
334 			 * Use PWM1 for all other values. This has the unwanted
335 			 * side effect of making all LEDs on the chip share the
336 			 * same brightness level if set to a value other than
337 			 * OFF or FULL. But, this is probably better than just
338 			 * turning off for all other values.
339 			 */
340 			ret = pca955x_write_pwm(pca955x, 1, 255 - value);
341 			if (ret)
342 				goto out;
343 			ls = pca955x_ledsel(ls, bit, PCA955X_LS_BLINK1);
344 			break;
345 		}
346 	}
347 
348 	ret = pca955x_write_ls(pca955x, reg, ls);
349 
350 out:
351 	mutex_unlock(&pca955x->lock);
352 
353 	return ret;
354 }
355 
pca955x_period_to_psc(struct pca955x * pca955x,unsigned long period)356 static u8 pca955x_period_to_psc(struct pca955x *pca955x, unsigned long period)
357 {
358 	/* psc register value = (blink period * coeff) - 1 */
359 	period *= pca955x->chipdef->blink_div;
360 	period /= MSEC_PER_SEC;
361 	period -= 1;
362 
363 	return period;
364 }
365 
pca955x_psc_to_period(struct pca955x * pca955x,u8 psc)366 static unsigned long pca955x_psc_to_period(struct pca955x *pca955x, u8 psc)
367 {
368 	unsigned long period = psc;
369 
370 	/* blink period = (psc register value + 1) / coeff */
371 	period += 1;
372 	period *= MSEC_PER_SEC;
373 	period /= pca955x->chipdef->blink_div;
374 
375 	return period;
376 }
377 
pca955x_led_blink(struct led_classdev * led_cdev,unsigned long * delay_on,unsigned long * delay_off)378 static int pca955x_led_blink(struct led_classdev *led_cdev,
379 			     unsigned long *delay_on, unsigned long *delay_off)
380 {
381 	struct pca955x_led *pca955x_led = led_to_pca955x(led_cdev);
382 	struct pca955x *pca955x = pca955x_led->pca955x;
383 	unsigned long period = *delay_on + *delay_off;
384 	int ret = 0;
385 
386 	mutex_lock(&pca955x->lock);
387 
388 	if (period) {
389 		if (*delay_on != *delay_off) {
390 			ret = -EINVAL;
391 			goto out;
392 		}
393 
394 		if (period < pca955x_psc_to_period(pca955x, 0) ||
395 		    period > pca955x_psc_to_period(pca955x, 0xff)) {
396 			ret = -EINVAL;
397 			goto out;
398 		}
399 	} else {
400 		period = pca955x->active_blink ? pca955x->blink_period :
401 			PCA955X_BLINK_DEFAULT_MS;
402 	}
403 
404 	if (!pca955x->active_blink ||
405 	    pca955x->active_blink == BIT(pca955x_led->led_num) ||
406 	    pca955x->blink_period == period) {
407 		u8 psc = pca955x_period_to_psc(pca955x, period);
408 
409 		if (!test_and_set_bit(pca955x_led->led_num,
410 				      &pca955x->active_blink)) {
411 			u8 ls;
412 			int reg = pca955x_led->led_num / 4;
413 			int bit = pca955x_led->led_num % 4;
414 
415 			ret = pca955x_read_ls(pca955x, reg, &ls);
416 			if (ret)
417 				goto out;
418 
419 			ls = pca955x_ledsel(ls, bit, PCA955X_LS_BLINK0);
420 			ret = pca955x_write_ls(pca955x, reg, ls);
421 			if (ret)
422 				goto out;
423 
424 			/*
425 			 * Force 50% duty cycle to maintain the specified
426 			 * blink rate.
427 			 */
428 			ret = pca955x_write_pwm(pca955x, 0, 128);
429 			if (ret)
430 				goto out;
431 		}
432 
433 		if (pca955x->blink_period != period) {
434 			pca955x->blink_period = period;
435 			ret = pca955x_write_psc(pca955x, 0, psc);
436 			if (ret)
437 				goto out;
438 		}
439 
440 		period = pca955x_psc_to_period(pca955x, psc);
441 		period /= 2;
442 		*delay_on = period;
443 		*delay_off = period;
444 	} else {
445 		ret = -EBUSY;
446 	}
447 
448 out:
449 	mutex_unlock(&pca955x->lock);
450 
451 	return ret;
452 }
453 
454 #ifdef CONFIG_LEDS_PCA955X_GPIO
455 /*
456  * Read the INPUT register, which contains the state of LEDs.
457  */
pca955x_read_input(struct i2c_client * client,int n,u8 * val)458 static int pca955x_read_input(struct i2c_client *client, int n, u8 *val)
459 {
460 	int ret = i2c_smbus_read_byte_data(client, n);
461 
462 	if (ret < 0) {
463 		dev_err(&client->dev, "%s: reg 0x%x, err %d\n",
464 			__func__, n, ret);
465 		return ret;
466 	}
467 	*val = (u8)ret;
468 	return 0;
469 
470 }
471 
pca955x_gpio_request_pin(struct gpio_chip * gc,unsigned int offset)472 static int pca955x_gpio_request_pin(struct gpio_chip *gc, unsigned int offset)
473 {
474 	struct pca955x *pca955x = gpiochip_get_data(gc);
475 
476 	return test_and_set_bit(offset, &pca955x->active_pins) ? -EBUSY : 0;
477 }
478 
pca955x_gpio_free_pin(struct gpio_chip * gc,unsigned int offset)479 static void pca955x_gpio_free_pin(struct gpio_chip *gc, unsigned int offset)
480 {
481 	struct pca955x *pca955x = gpiochip_get_data(gc);
482 
483 	clear_bit(offset, &pca955x->active_pins);
484 }
485 
pca955x_set_value(struct gpio_chip * gc,unsigned int offset,int val)486 static int pca955x_set_value(struct gpio_chip *gc, unsigned int offset,
487 			     int val)
488 {
489 	struct pca955x *pca955x = gpiochip_get_data(gc);
490 	struct pca955x_led *led = &pca955x->leds[offset];
491 
492 	if (val)
493 		return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_HIGH);
494 
495 	return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_LOW);
496 }
497 
pca955x_gpio_set_value(struct gpio_chip * gc,unsigned int offset,int val)498 static int pca955x_gpio_set_value(struct gpio_chip *gc, unsigned int offset,
499 				  int val)
500 {
501 	return pca955x_set_value(gc, offset, val);
502 }
503 
pca955x_gpio_get_value(struct gpio_chip * gc,unsigned int offset)504 static int pca955x_gpio_get_value(struct gpio_chip *gc, unsigned int offset)
505 {
506 	struct pca955x *pca955x = gpiochip_get_data(gc);
507 	struct pca955x_led *led = &pca955x->leds[offset];
508 	u8 reg = 0;
509 
510 	/* There is nothing we can do about errors */
511 	pca955x_read_input(pca955x->client, led->led_num / 8, &reg);
512 
513 	return !!(reg & (1 << (led->led_num % 8)));
514 }
515 
pca955x_gpio_direction_input(struct gpio_chip * gc,unsigned int offset)516 static int pca955x_gpio_direction_input(struct gpio_chip *gc,
517 					unsigned int offset)
518 {
519 	struct pca955x *pca955x = gpiochip_get_data(gc);
520 	struct pca955x_led *led = &pca955x->leds[offset];
521 
522 	/* To use as input ensure pin is not driven. */
523 	return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_INPUT);
524 }
525 
pca955x_gpio_direction_output(struct gpio_chip * gc,unsigned int offset,int val)526 static int pca955x_gpio_direction_output(struct gpio_chip *gc,
527 					 unsigned int offset, int val)
528 {
529 	return pca955x_set_value(gc, offset, val);
530 }
531 #endif /* CONFIG_LEDS_PCA955X_GPIO */
532 
533 static struct pca955x_platform_data *
pca955x_get_pdata(struct i2c_client * client,const struct pca955x_chipdef * chip)534 pca955x_get_pdata(struct i2c_client *client, const struct pca955x_chipdef *chip)
535 {
536 	struct pca955x_platform_data *pdata;
537 	struct pca955x_led *led;
538 	struct fwnode_handle *child;
539 	int count;
540 
541 	count = device_get_child_node_count(&client->dev);
542 	if (count > chip->bits)
543 		return ERR_PTR(-ENODEV);
544 
545 	pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL);
546 	if (!pdata)
547 		return ERR_PTR(-ENOMEM);
548 
549 	pdata->leds = devm_kcalloc(&client->dev,
550 				   chip->bits, sizeof(struct pca955x_led),
551 				   GFP_KERNEL);
552 	if (!pdata->leds)
553 		return ERR_PTR(-ENOMEM);
554 
555 	device_for_each_child_node(&client->dev, child) {
556 		u32 reg;
557 		int res;
558 
559 		res = fwnode_property_read_u32(child, "reg", &reg);
560 		if ((res != 0) || (reg >= chip->bits))
561 			continue;
562 
563 		led = &pdata->leds[reg];
564 		led->type = PCA955X_TYPE_LED;
565 		led->fwnode = child;
566 		led->default_state = led_init_default_state_get(child);
567 
568 		fwnode_property_read_u32(child, "type", &led->type);
569 	}
570 
571 	pdata->num_leds = chip->bits;
572 
573 	return pdata;
574 }
575 
pca955x_probe(struct i2c_client * client)576 static int pca955x_probe(struct i2c_client *client)
577 {
578 	struct pca955x *pca955x;
579 	struct pca955x_led *pca955x_led;
580 	const struct pca955x_chipdef *chip;
581 	struct led_classdev *led;
582 	struct led_init_data init_data;
583 	struct i2c_adapter *adapter;
584 	u8 i, nls, psc0;
585 	u8 ls1[4];
586 	u8 ls2[4];
587 	struct pca955x_platform_data *pdata;
588 	bool keep_psc0 = false;
589 	bool set_default_label = false;
590 	char default_label[4];
591 	int bit, err, reg;
592 
593 	chip = i2c_get_match_data(client);
594 	if (!chip)
595 		return dev_err_probe(&client->dev, -ENODEV, "unknown chip\n");
596 
597 	adapter = client->adapter;
598 	pdata = dev_get_platdata(&client->dev);
599 	if (!pdata) {
600 		pdata =	pca955x_get_pdata(client, chip);
601 		if (IS_ERR(pdata))
602 			return PTR_ERR(pdata);
603 	}
604 
605 	/* Make sure the slave address / chip type combo given is possible */
606 	if ((client->addr & ~((1 << chip->slv_addr_shift) - 1)) !=
607 	    chip->slv_addr) {
608 		dev_err(&client->dev, "invalid slave address %02x\n",
609 			client->addr);
610 		return -ENODEV;
611 	}
612 
613 	dev_info(&client->dev, "Using %s %u-bit LED driver at slave address 0x%02x\n",
614 		 client->name, chip->bits, client->addr);
615 
616 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
617 		return -EIO;
618 
619 	if (pdata->num_leds != chip->bits) {
620 		dev_err(&client->dev,
621 			"board info claims %d LEDs on a %u-bit chip\n",
622 			pdata->num_leds, chip->bits);
623 		return -ENODEV;
624 	}
625 
626 	pca955x = devm_kzalloc(&client->dev, sizeof(*pca955x), GFP_KERNEL);
627 	if (!pca955x)
628 		return -ENOMEM;
629 
630 	pca955x->leds = devm_kcalloc(&client->dev, chip->bits,
631 				     sizeof(*pca955x_led), GFP_KERNEL);
632 	if (!pca955x->leds)
633 		return -ENOMEM;
634 
635 	i2c_set_clientdata(client, pca955x);
636 
637 	mutex_init(&pca955x->lock);
638 	pca955x->client = client;
639 	pca955x->chipdef = chip;
640 	pca955x->blink_period = PCA955X_BLINK_DEFAULT_MS;
641 
642 	init_data.devname_mandatory = false;
643 	init_data.devicename = "pca955x";
644 
645 	nls = pca955x_num_led_regs(chip->bits);
646 	/* Use auto-increment feature to read all the LED selectors at once. */
647 	err = i2c_smbus_read_i2c_block_data(client,
648 					    0x10 | (pca955x_num_input_regs(chip->bits) + 4), nls,
649 					    ls1);
650 	if (err < 0)
651 		return err;
652 
653 	for (i = 0; i < nls; i++)
654 		ls2[i] = ls1[i];
655 
656 	for (i = 0; i < chip->bits; i++) {
657 		pca955x_led = &pca955x->leds[i];
658 		pca955x_led->led_num = i;
659 		pca955x_led->pca955x = pca955x;
660 		pca955x_led->type = pdata->leds[i].type;
661 
662 		switch (pca955x_led->type) {
663 		case PCA955X_TYPE_NONE:
664 		case PCA955X_TYPE_GPIO:
665 			break;
666 		case PCA955X_TYPE_LED:
667 			bit = i % 4;
668 			reg = i / 4;
669 			led = &pca955x_led->led_cdev;
670 			led->brightness_set_blocking = pca955x_led_set;
671 			led->brightness_get = pca955x_led_get;
672 			led->blink_set = pca955x_led_blink;
673 
674 			if (pdata->leds[i].default_state == LEDS_DEFSTATE_OFF)
675 				ls2[reg] = pca955x_ledsel(ls2[reg], bit, PCA955X_LS_LED_OFF);
676 			else if (pdata->leds[i].default_state == LEDS_DEFSTATE_ON)
677 				ls2[reg] = pca955x_ledsel(ls2[reg], bit, PCA955X_LS_LED_ON);
678 			else if (pca955x_ledstate(ls2[reg], bit) == PCA955X_LS_BLINK0) {
679 				keep_psc0 = true;
680 				set_bit(i, &pca955x->active_blink);
681 			}
682 
683 			init_data.fwnode = pdata->leds[i].fwnode;
684 
685 			if (is_of_node(init_data.fwnode)) {
686 				if (to_of_node(init_data.fwnode)->name[0] ==
687 				    '\0')
688 					set_default_label = true;
689 				else
690 					set_default_label = false;
691 			} else {
692 				set_default_label = true;
693 			}
694 
695 			if (set_default_label) {
696 				snprintf(default_label, sizeof(default_label), "%hhu", i);
697 				init_data.default_label = default_label;
698 			} else {
699 				init_data.default_label = NULL;
700 			}
701 
702 			err = devm_led_classdev_register_ext(&client->dev, led,
703 							     &init_data);
704 			if (err)
705 				return err;
706 
707 			set_bit(i, &pca955x->active_pins);
708 		}
709 	}
710 
711 	for (i = 0; i < nls; i++) {
712 		if (ls1[i] != ls2[i]) {
713 			err = pca955x_write_ls(pca955x, i, ls2[i]);
714 			if (err)
715 				return err;
716 		}
717 	}
718 
719 	if (keep_psc0) {
720 		err = pca955x_read_psc(pca955x, 0, &psc0);
721 	} else {
722 		psc0 = pca955x_period_to_psc(pca955x, pca955x->blink_period);
723 		err = pca955x_write_psc(pca955x, 0, psc0);
724 	}
725 
726 	if (err)
727 		return err;
728 
729 	pca955x->blink_period = pca955x_psc_to_period(pca955x, psc0);
730 
731 	/* Set PWM1 to fast frequency so we do not see flashing */
732 	err = pca955x_write_psc(pca955x, 1, 0);
733 	if (err)
734 		return err;
735 
736 #ifdef CONFIG_LEDS_PCA955X_GPIO
737 	pca955x->gpio.label = "gpio-pca955x";
738 	pca955x->gpio.direction_input = pca955x_gpio_direction_input;
739 	pca955x->gpio.direction_output = pca955x_gpio_direction_output;
740 	pca955x->gpio.set = pca955x_gpio_set_value;
741 	pca955x->gpio.get = pca955x_gpio_get_value;
742 	pca955x->gpio.request = pca955x_gpio_request_pin;
743 	pca955x->gpio.free = pca955x_gpio_free_pin;
744 	pca955x->gpio.can_sleep = 1;
745 	pca955x->gpio.base = -1;
746 	pca955x->gpio.ngpio = chip->bits;
747 	pca955x->gpio.parent = &client->dev;
748 	pca955x->gpio.owner = THIS_MODULE;
749 
750 	err = devm_gpiochip_add_data(&client->dev, &pca955x->gpio,
751 				     pca955x);
752 	if (err) {
753 		/* Use data->gpio.dev as a flag for freeing gpiochip */
754 		pca955x->gpio.parent = NULL;
755 		dev_warn(&client->dev, "could not add gpiochip\n");
756 		return err;
757 	}
758 	dev_info(&client->dev, "gpios %i...%i\n",
759 		 pca955x->gpio.base, pca955x->gpio.base +
760 		 pca955x->gpio.ngpio - 1);
761 #endif
762 
763 	return 0;
764 }
765 
766 static const struct i2c_device_id pca955x_id[] = {
767 	{ "pca9550", (kernel_ulong_t)&pca955x_chipdefs[pca9550] },
768 	{ "pca9551", (kernel_ulong_t)&pca955x_chipdefs[pca9551] },
769 	{ "pca9552", (kernel_ulong_t)&pca955x_chipdefs[pca9552] },
770 	{ "ibm-pca9552", (kernel_ulong_t)&pca955x_chipdefs[ibm_pca9552] },
771 	{ "pca9553", (kernel_ulong_t)&pca955x_chipdefs[pca9553] },
772 	{}
773 };
774 MODULE_DEVICE_TABLE(i2c, pca955x_id);
775 
776 static const struct of_device_id of_pca955x_match[] = {
777 	{ .compatible = "nxp,pca9550", .data = &pca955x_chipdefs[pca9550] },
778 	{ .compatible = "nxp,pca9551", .data = &pca955x_chipdefs[pca9551] },
779 	{ .compatible = "nxp,pca9552", .data = &pca955x_chipdefs[pca9552] },
780 	{ .compatible = "ibm,pca9552", .data = &pca955x_chipdefs[ibm_pca9552] },
781 	{ .compatible = "nxp,pca9553", .data = &pca955x_chipdefs[pca9553] },
782 	{}
783 };
784 MODULE_DEVICE_TABLE(of, of_pca955x_match);
785 
786 static struct i2c_driver pca955x_driver = {
787 	.driver = {
788 		.name	= "leds-pca955x",
789 		.of_match_table = of_pca955x_match,
790 	},
791 	.probe = pca955x_probe,
792 	.id_table = pca955x_id,
793 };
794 
795 module_i2c_driver(pca955x_driver);
796 
797 MODULE_AUTHOR("Nate Case <ncase@xes-inc.com>");
798 MODULE_DESCRIPTION("PCA955x LED driver");
799 MODULE_LICENSE("GPL v2");
800