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, &reg);
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", &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");
667