1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright 2011 bct electronic GmbH
  4 * Copyright 2013 Qtechnology/AS
  5 *
  6 * Author: Peter Meerwald <p.meerwald@bct-electronic.com>
  7 * Author: Ricardo Ribalda <ribalda@kernel.org>
  8 *
  9 * Based on leds-pca955x.c
 10 *
 11 * LED driver for the PCA9633 I2C LED driver (7-bit slave address 0x62)
 12 * LED driver for the PCA9634/5 I2C LED driver (7-bit slave address set by hw.)
 13 *
 14 * Note that hardware blinking violates the leds infrastructure driver
 15 * interface since the hardware only supports blinking all LEDs with the
 16 * same delay_on/delay_off rates.  That is, only the LEDs that are set to
 17 * blink will actually blink but all LEDs that are set to blink will blink
 18 * in identical fashion.  The delay_on/delay_off values of the last LED
 19 * that is set to blink will be used for all of the blinking LEDs.
 20 * Hardware blinking is disabled by default but can be enabled by setting
 21 * the 'blink_type' member in the platform_data struct to 'PCA963X_HW_BLINK'
 22 * or by adding the 'nxp,hw-blink' property to the DTS.
 23 */
 24
 25#include <linux/module.h>
 26#include <linux/delay.h>
 27#include <linux/string.h>
 28#include <linux/ctype.h>
 29#include <linux/leds.h>
 30#include <linux/err.h>
 31#include <linux/i2c.h>
 32#include <linux/property.h>
 33#include <linux/slab.h>
 34#include <linux/of.h>
 35
 36/* LED select registers determine the source that drives LED outputs */
 37#define PCA963X_LED_OFF		0x0	/* LED driver off */
 38#define PCA963X_LED_ON		0x1	/* LED driver on */
 39#define PCA963X_LED_PWM		0x2	/* Controlled through PWM */
 40#define PCA963X_LED_GRP_PWM	0x3	/* Controlled through PWM/GRPPWM */
 41
 42#define PCA963X_MODE1_SLEEP	0x04    /* Normal mode or Low Power mode, oscillator off */
 43#define PCA963X_MODE2_OUTDRV	0x04	/* Open-drain or totem pole */
 44#define PCA963X_MODE2_INVRT	0x10	/* Normal or inverted direction */
 45#define PCA963X_MODE2_DMBLNK	0x20	/* Enable blinking */
 46
 47#define PCA963X_MODE1		0x00
 48#define PCA963X_MODE2		0x01
 49#define PCA963X_PWM_BASE	0x02
 50
 51enum pca963x_type {
 52	pca9633,
 53	pca9634,
 54	pca9635,
 55};
 56
 57struct pca963x_chipdef {
 58	u8			grppwm;
 59	u8			grpfreq;
 60	u8			ledout_base;
 61	int			n_leds;
 62	unsigned int		scaling;
 63};
 64
 65static struct pca963x_chipdef pca963x_chipdefs[] = {
 66	[pca9633] = {
 67		.grppwm		= 0x6,
 68		.grpfreq	= 0x7,
 69		.ledout_base	= 0x8,
 70		.n_leds		= 4,
 71	},
 72	[pca9634] = {
 73		.grppwm		= 0xa,
 74		.grpfreq	= 0xb,
 75		.ledout_base	= 0xc,
 76		.n_leds		= 8,
 77	},
 78	[pca9635] = {
 79		.grppwm		= 0x12,
 80		.grpfreq	= 0x13,
 81		.ledout_base	= 0x14,
 82		.n_leds		= 16,
 83	},
 84};
 85
 86/* Total blink period in milliseconds */
 87#define PCA963X_BLINK_PERIOD_MIN	42
 88#define PCA963X_BLINK_PERIOD_MAX	10667
 89
 90static const struct i2c_device_id pca963x_id[] = {
 91	{ "pca9632", pca9633 },
 92	{ "pca9633", pca9633 },
 93	{ "pca9634", pca9634 },
 94	{ "pca9635", pca9635 },
 95	{ }
 96};
 97MODULE_DEVICE_TABLE(i2c, pca963x_id);
 98
 99struct pca963x;
100
101struct pca963x_led {
102	struct pca963x *chip;
103	struct led_classdev led_cdev;
104	int led_num; /* 0 .. 15 potentially */
105	bool blinking;
106	u8 gdc;
107	u8 gfrq;
108};
109
110struct pca963x {
111	struct pca963x_chipdef *chipdef;
112	struct mutex mutex;
113	struct i2c_client *client;
114	unsigned long leds_on;
115	struct pca963x_led leds[];
116};
117
118static int pca963x_brightness(struct pca963x_led *led,
119			      enum led_brightness brightness)
120{
121	struct i2c_client *client = led->chip->client;
122	struct pca963x_chipdef *chipdef = led->chip->chipdef;
123	u8 ledout_addr, ledout, mask, val;
124	int shift;
125	int ret;
126
127	ledout_addr = chipdef->ledout_base + (led->led_num / 4);
128	shift = 2 * (led->led_num % 4);
129	mask = 0x3 << shift;
130	ledout = i2c_smbus_read_byte_data(client, ledout_addr);
131
132	switch (brightness) {
133	case LED_FULL:
134		if (led->blinking) {
135			val = (ledout & ~mask) | (PCA963X_LED_GRP_PWM << shift);
136			ret = i2c_smbus_write_byte_data(client,
137						PCA963X_PWM_BASE +
138						led->led_num,
139						LED_FULL);
140		} else {
141			val = (ledout & ~mask) | (PCA963X_LED_ON << shift);
142		}
143		ret = i2c_smbus_write_byte_data(client, ledout_addr, val);
144		break;
145	case LED_OFF:
146		val = ledout & ~mask;
147		ret = i2c_smbus_write_byte_data(client, ledout_addr, val);
148		led->blinking = false;
149		break;
150	default:
151		ret = i2c_smbus_write_byte_data(client,
152						PCA963X_PWM_BASE +
153						led->led_num,
154						brightness);
155		if (ret < 0)
156			return ret;
157
158		if (led->blinking)
159			val = (ledout & ~mask) | (PCA963X_LED_GRP_PWM << shift);
160		else
161			val = (ledout & ~mask) | (PCA963X_LED_PWM << shift);
162
163		ret = i2c_smbus_write_byte_data(client, ledout_addr, val);
164		break;
165	}
166
167	return ret;
168}
169
170static void pca963x_blink(struct pca963x_led *led)
171{
172	struct i2c_client *client = led->chip->client;
173	struct pca963x_chipdef *chipdef = led->chip->chipdef;
174	u8 ledout_addr, ledout, mask, val, mode2;
175	int shift;
176
177	ledout_addr = chipdef->ledout_base + (led->led_num / 4);
178	shift = 2 * (led->led_num % 4);
179	mask = 0x3 << shift;
180	mode2 = i2c_smbus_read_byte_data(client, PCA963X_MODE2);
181
182	i2c_smbus_write_byte_data(client, chipdef->grppwm, led->gdc);
183
184	i2c_smbus_write_byte_data(client, chipdef->grpfreq, led->gfrq);
185
186	if (!(mode2 & PCA963X_MODE2_DMBLNK))
187		i2c_smbus_write_byte_data(client, PCA963X_MODE2,
188					  mode2 | PCA963X_MODE2_DMBLNK);
189
190	mutex_lock(&led->chip->mutex);
191
192	ledout = i2c_smbus_read_byte_data(client, ledout_addr);
193	if ((ledout & mask) != (PCA963X_LED_GRP_PWM << shift)) {
194		val = (ledout & ~mask) | (PCA963X_LED_GRP_PWM << shift);
195		i2c_smbus_write_byte_data(client, ledout_addr, val);
196	}
197
198	mutex_unlock(&led->chip->mutex);
199	led->blinking = true;
200}
201
202static int pca963x_power_state(struct pca963x_led *led)
203{
204	struct i2c_client *client = led->chip->client;
205	unsigned long *leds_on = &led->chip->leds_on;
206	unsigned long cached_leds = *leds_on;
207
208	if (led->led_cdev.brightness)
209		set_bit(led->led_num, leds_on);
210	else
211		clear_bit(led->led_num, leds_on);
212
213	if (!(*leds_on) != !cached_leds)
214		return i2c_smbus_write_byte_data(client, PCA963X_MODE1,
215						 *leds_on ? 0 : BIT(4));
216
217	return 0;
218}
219
220static int pca963x_led_set(struct led_classdev *led_cdev,
221			   enum led_brightness value)
222{
223	struct pca963x_led *led;
224	int ret;
225
226	led = container_of(led_cdev, struct pca963x_led, led_cdev);
227
228	mutex_lock(&led->chip->mutex);
229
230	ret = pca963x_brightness(led, value);
231	if (ret < 0)
232		goto unlock;
233	ret = pca963x_power_state(led);
234
235unlock:
236	mutex_unlock(&led->chip->mutex);
237	return ret;
238}
239
240static unsigned int pca963x_period_scale(struct pca963x_led *led,
241					 unsigned int val)
242{
243	unsigned int scaling = led->chip->chipdef->scaling;
244
245	return scaling ? DIV_ROUND_CLOSEST(val * scaling, 1000) : val;
246}
247
248static int pca963x_blink_set(struct led_classdev *led_cdev,
249			     unsigned long *delay_on, unsigned long *delay_off)
250{
251	unsigned long time_on, time_off, period;
252	struct pca963x_led *led;
253	u8 gdc, gfrq;
254
255	led = container_of(led_cdev, struct pca963x_led, led_cdev);
256
257	time_on = *delay_on;
258	time_off = *delay_off;
259
260	/* If both zero, pick reasonable defaults of 500ms each */
261	if (!time_on && !time_off) {
262		time_on = 500;
263		time_off = 500;
264	}
265
266	period = pca963x_period_scale(led, time_on + time_off);
267
268	/* If period not supported by hardware, default to someting sane. */
269	if ((period < PCA963X_BLINK_PERIOD_MIN) ||
270	    (period > PCA963X_BLINK_PERIOD_MAX)) {
271		time_on = 500;
272		time_off = 500;
273		period = pca963x_period_scale(led, 1000);
274	}
275
276	/*
277	 * From manual: duty cycle = (GDC / 256) ->
278	 *	(time_on / period) = (GDC / 256) ->
279	 *		GDC = ((time_on * 256) / period)
280	 */
281	gdc = (pca963x_period_scale(led, time_on) * 256) / period;
282
283	/*
284	 * From manual: period = ((GFRQ + 1) / 24) in seconds.
285	 * So, period (in ms) = (((GFRQ + 1) / 24) * 1000) ->
286	 *		GFRQ = ((period * 24 / 1000) - 1)
287	 */
288	gfrq = (period * 24 / 1000) - 1;
289
290	led->gdc = gdc;
291	led->gfrq = gfrq;
292
293	pca963x_blink(led);
294	led->led_cdev.brightness = LED_FULL;
295	pca963x_led_set(led_cdev, LED_FULL);
296
297	*delay_on = time_on;
298	*delay_off = time_off;
299
300	return 0;
301}
302
303static int pca963x_register_leds(struct i2c_client *client,
304				 struct pca963x *chip)
305{
306	struct pca963x_chipdef *chipdef = chip->chipdef;
307	struct pca963x_led *led = chip->leds;
308	struct device *dev = &client->dev;
309	bool hw_blink;
310	s32 mode2;
311	u32 reg;
312	int ret;
313
314	if (device_property_read_u32(dev, "nxp,period-scale",
315				     &chipdef->scaling))
316		chipdef->scaling = 1000;
317
318	hw_blink = device_property_read_bool(dev, "nxp,hw-blink");
319
320	mode2 = i2c_smbus_read_byte_data(client, PCA963X_MODE2);
321	if (mode2 < 0)
322		return mode2;
323
324	/* default to open-drain unless totem pole (push-pull) is specified */
325	if (device_property_read_bool(dev, "nxp,totem-pole"))
326		mode2 |= PCA963X_MODE2_OUTDRV;
327	else
328		mode2 &= ~PCA963X_MODE2_OUTDRV;
329
330	/* default to non-inverted output, unless inverted is specified */
331	if (device_property_read_bool(dev, "nxp,inverted-out"))
332		mode2 |= PCA963X_MODE2_INVRT;
333	else
334		mode2 &= ~PCA963X_MODE2_INVRT;
335
336	ret = i2c_smbus_write_byte_data(client, PCA963X_MODE2, mode2);
337	if (ret < 0)
338		return ret;
339
340	device_for_each_child_node_scoped(dev, child) {
341		struct led_init_data init_data = {};
342		char default_label[32];
343
344		ret = fwnode_property_read_u32(child, "reg", &reg);
345		if (ret || reg >= chipdef->n_leds) {
346			dev_err(dev, "Invalid 'reg' property for node %pfw\n",
347				child);
348			return -EINVAL;
349		}
350
351		led->led_num = reg;
352		led->chip = chip;
353		led->led_cdev.brightness_set_blocking = pca963x_led_set;
354		if (hw_blink)
355			led->led_cdev.blink_set = pca963x_blink_set;
356		led->blinking = false;
357
358		init_data.fwnode = child;
359		/* for backwards compatibility */
360		init_data.devicename = "pca963x";
361		snprintf(default_label, sizeof(default_label), "%d:%.2x:%u",
362			 client->adapter->nr, client->addr, reg);
363		init_data.default_label = default_label;
364
365		ret = devm_led_classdev_register_ext(dev, &led->led_cdev,
366						     &init_data);
367		if (ret) {
368			dev_err(dev, "Failed to register LED for node %pfw\n",
369				child);
370			return ret;
371		}
372
373		++led;
374	}
375
376	return 0;
377}
378
379static int pca963x_suspend(struct device *dev)
380{
381	struct pca963x *chip = dev_get_drvdata(dev);
382	u8 reg;
383
384	reg = i2c_smbus_read_byte_data(chip->client, PCA963X_MODE1);
385	reg = reg | BIT(PCA963X_MODE1_SLEEP);
386	i2c_smbus_write_byte_data(chip->client, PCA963X_MODE1, reg);
387
388	return 0;
389}
390
391static int pca963x_resume(struct device *dev)
392{
393	struct pca963x *chip = dev_get_drvdata(dev);
394	u8 reg;
395
396	reg = i2c_smbus_read_byte_data(chip->client, PCA963X_MODE1);
397	reg = reg & ~BIT(PCA963X_MODE1_SLEEP);
398	i2c_smbus_write_byte_data(chip->client, PCA963X_MODE1, reg);
399
400	return 0;
401}
402
403static DEFINE_SIMPLE_DEV_PM_OPS(pca963x_pm, pca963x_suspend, pca963x_resume);
404
405static const struct of_device_id of_pca963x_match[] = {
406	{ .compatible = "nxp,pca9632", },
407	{ .compatible = "nxp,pca9633", },
408	{ .compatible = "nxp,pca9634", },
409	{ .compatible = "nxp,pca9635", },
410	{},
411};
412MODULE_DEVICE_TABLE(of, of_pca963x_match);
413
414static int pca963x_probe(struct i2c_client *client)
415{
416	const struct i2c_device_id *id = i2c_client_get_device_id(client);
417	struct device *dev = &client->dev;
418	struct pca963x_chipdef *chipdef;
419	struct pca963x *chip;
420	int i, count;
421
422	chipdef = &pca963x_chipdefs[id->driver_data];
423
424	count = device_get_child_node_count(dev);
425	if (!count || count > chipdef->n_leds) {
426		dev_err(dev, "Node %pfw must define between 1 and %d LEDs\n",
427			dev_fwnode(dev), chipdef->n_leds);
428		return -EINVAL;
429	}
430
431	chip = devm_kzalloc(dev, struct_size(chip, leds, count), GFP_KERNEL);
432	if (!chip)
433		return -ENOMEM;
434
435	i2c_set_clientdata(client, chip);
436
437	mutex_init(&chip->mutex);
438	chip->chipdef = chipdef;
439	chip->client = client;
440
441	/* Turn off LEDs by default*/
442	for (i = 0; i < chipdef->n_leds / 4; i++)
443		i2c_smbus_write_byte_data(client, chipdef->ledout_base + i, 0x00);
444
445	/* Disable LED all-call address, and power down initially */
446	i2c_smbus_write_byte_data(client, PCA963X_MODE1, BIT(4));
447
448	return pca963x_register_leds(client, chip);
449}
450
451static struct i2c_driver pca963x_driver = {
452	.driver = {
453		.name	= "leds-pca963x",
454		.of_match_table = of_pca963x_match,
455		.pm = pm_sleep_ptr(&pca963x_pm)
456	},
457	.probe = pca963x_probe,
458	.id_table = pca963x_id,
459};
460
461module_i2c_driver(pca963x_driver);
462
463MODULE_AUTHOR("Peter Meerwald <p.meerwald@bct-electronic.com>");
464MODULE_DESCRIPTION("PCA963X LED driver");
465MODULE_LICENSE("GPL v2");