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_MODE2_OUTDRV	0x04	/* Open-drain or totem pole */
 43#define PCA963X_MODE2_INVRT	0x10	/* Normal or inverted direction */
 44#define PCA963X_MODE2_DMBLNK	0x20	/* Enable blinking */
 45
 46#define PCA963X_MODE1		0x00
 47#define PCA963X_MODE2		0x01
 48#define PCA963X_PWM_BASE	0x02
 49
 50enum pca963x_type {
 51	pca9633,
 52	pca9634,
 53	pca9635,
 54};
 55
 56struct pca963x_chipdef {
 57	u8			grppwm;
 58	u8			grpfreq;
 59	u8			ledout_base;
 60	int			n_leds;
 61	unsigned int		scaling;
 62};
 63
 64static struct pca963x_chipdef pca963x_chipdefs[] = {
 65	[pca9633] = {
 66		.grppwm		= 0x6,
 67		.grpfreq	= 0x7,
 68		.ledout_base	= 0x8,
 69		.n_leds		= 4,
 70	},
 71	[pca9634] = {
 72		.grppwm		= 0xa,
 73		.grpfreq	= 0xb,
 74		.ledout_base	= 0xc,
 75		.n_leds		= 8,
 76	},
 77	[pca9635] = {
 78		.grppwm		= 0x12,
 79		.grpfreq	= 0x13,
 80		.ledout_base	= 0x14,
 81		.n_leds		= 16,
 82	},
 83};
 84
 85/* Total blink period in milliseconds */
 86#define PCA963X_BLINK_PERIOD_MIN	42
 87#define PCA963X_BLINK_PERIOD_MAX	10667
 88
 89static const struct i2c_device_id pca963x_id[] = {
 90	{ "pca9632", pca9633 },
 91	{ "pca9633", pca9633 },
 92	{ "pca9634", pca9634 },
 93	{ "pca9635", pca9635 },
 94	{ }
 95};
 96MODULE_DEVICE_TABLE(i2c, pca963x_id);
 97
 98struct pca963x;
 99
100struct pca963x_led {
101	struct pca963x *chip;
102	struct led_classdev led_cdev;
103	int led_num; /* 0 .. 15 potentially */
104	u8 gdc;
105	u8 gfrq;
106};
107
108struct pca963x {
109	struct pca963x_chipdef *chipdef;
110	struct mutex mutex;
111	struct i2c_client *client;
112	unsigned long leds_on;
113	struct pca963x_led leds[];
114};
115
116static int pca963x_brightness(struct pca963x_led *led,
117			      enum led_brightness brightness)
118{
119	struct i2c_client *client = led->chip->client;
120	struct pca963x_chipdef *chipdef = led->chip->chipdef;
121	u8 ledout_addr, ledout, mask, val;
122	int shift;
123	int ret;
124
125	ledout_addr = chipdef->ledout_base + (led->led_num / 4);
126	shift = 2 * (led->led_num % 4);
127	mask = 0x3 << shift;
128	ledout = i2c_smbus_read_byte_data(client, ledout_addr);
129
130	switch (brightness) {
131	case LED_FULL:
132		val = (ledout & ~mask) | (PCA963X_LED_ON << shift);
133		ret = i2c_smbus_write_byte_data(client, ledout_addr, val);
134		break;
135	case LED_OFF:
136		val = ledout & ~mask;
137		ret = i2c_smbus_write_byte_data(client, ledout_addr, val);
138		break;
139	default:
140		ret = i2c_smbus_write_byte_data(client,
141						PCA963X_PWM_BASE +
142						led->led_num,
143						brightness);
144		if (ret < 0)
145			return ret;
146
147		val = (ledout & ~mask) | (PCA963X_LED_PWM << shift);
148		ret = i2c_smbus_write_byte_data(client, ledout_addr, val);
149		break;
150	}
151
152	return ret;
153}
154
155static void pca963x_blink(struct pca963x_led *led)
156{
157	struct i2c_client *client = led->chip->client;
158	struct pca963x_chipdef *chipdef = led->chip->chipdef;
159	u8 ledout_addr, ledout, mask, val, mode2;
160	int shift;
161
162	ledout_addr = chipdef->ledout_base + (led->led_num / 4);
163	shift = 2 * (led->led_num % 4);
164	mask = 0x3 << shift;
165	mode2 = i2c_smbus_read_byte_data(client, PCA963X_MODE2);
166
167	i2c_smbus_write_byte_data(client, chipdef->grppwm, led->gdc);
168
169	i2c_smbus_write_byte_data(client, chipdef->grpfreq, led->gfrq);
170
171	if (!(mode2 & PCA963X_MODE2_DMBLNK))
172		i2c_smbus_write_byte_data(client, PCA963X_MODE2,
173					  mode2 | PCA963X_MODE2_DMBLNK);
174
175	mutex_lock(&led->chip->mutex);
176
177	ledout = i2c_smbus_read_byte_data(client, ledout_addr);
178	if ((ledout & mask) != (PCA963X_LED_GRP_PWM << shift)) {
179		val = (ledout & ~mask) | (PCA963X_LED_GRP_PWM << shift);
180		i2c_smbus_write_byte_data(client, ledout_addr, val);
181	}
182
183	mutex_unlock(&led->chip->mutex);
184}
185
186static int pca963x_power_state(struct pca963x_led *led)
187{
188	struct i2c_client *client = led->chip->client;
189	unsigned long *leds_on = &led->chip->leds_on;
190	unsigned long cached_leds = *leds_on;
191
192	if (led->led_cdev.brightness)
193		set_bit(led->led_num, leds_on);
194	else
195		clear_bit(led->led_num, leds_on);
196
197	if (!(*leds_on) != !cached_leds)
198		return i2c_smbus_write_byte_data(client, PCA963X_MODE1,
199						 *leds_on ? 0 : BIT(4));
200
201	return 0;
202}
203
204static int pca963x_led_set(struct led_classdev *led_cdev,
205			   enum led_brightness value)
206{
207	struct pca963x_led *led;
208	int ret;
209
210	led = container_of(led_cdev, struct pca963x_led, led_cdev);
211
212	mutex_lock(&led->chip->mutex);
213
214	ret = pca963x_brightness(led, value);
215	if (ret < 0)
216		goto unlock;
217	ret = pca963x_power_state(led);
218
219unlock:
220	mutex_unlock(&led->chip->mutex);
221	return ret;
222}
223
224static unsigned int pca963x_period_scale(struct pca963x_led *led,
225					 unsigned int val)
226{
227	unsigned int scaling = led->chip->chipdef->scaling;
228
229	return scaling ? DIV_ROUND_CLOSEST(val * scaling, 1000) : val;
230}
231
232static int pca963x_blink_set(struct led_classdev *led_cdev,
233			     unsigned long *delay_on, unsigned long *delay_off)
234{
235	unsigned long time_on, time_off, period;
236	struct pca963x_led *led;
237	u8 gdc, gfrq;
238
239	led = container_of(led_cdev, struct pca963x_led, led_cdev);
240
241	time_on = *delay_on;
242	time_off = *delay_off;
243
244	/* If both zero, pick reasonable defaults of 500ms each */
245	if (!time_on && !time_off) {
246		time_on = 500;
247		time_off = 500;
248	}
249
250	period = pca963x_period_scale(led, time_on + time_off);
251
252	/* If period not supported by hardware, default to someting sane. */
253	if ((period < PCA963X_BLINK_PERIOD_MIN) ||
254	    (period > PCA963X_BLINK_PERIOD_MAX)) {
255		time_on = 500;
256		time_off = 500;
257		period = pca963x_period_scale(led, 1000);
258	}
259
260	/*
261	 * From manual: duty cycle = (GDC / 256) ->
262	 *	(time_on / period) = (GDC / 256) ->
263	 *		GDC = ((time_on * 256) / period)
264	 */
265	gdc = (pca963x_period_scale(led, time_on) * 256) / period;
266
267	/*
268	 * From manual: period = ((GFRQ + 1) / 24) in seconds.
269	 * So, period (in ms) = (((GFRQ + 1) / 24) * 1000) ->
270	 *		GFRQ = ((period * 24 / 1000) - 1)
271	 */
272	gfrq = (period * 24 / 1000) - 1;
273
274	led->gdc = gdc;
275	led->gfrq = gfrq;
276
277	pca963x_blink(led);
278
279	*delay_on = time_on;
280	*delay_off = time_off;
281
282	return 0;
283}
284
285static int pca963x_register_leds(struct i2c_client *client,
286				 struct pca963x *chip)
287{
288	struct pca963x_chipdef *chipdef = chip->chipdef;
289	struct pca963x_led *led = chip->leds;
290	struct device *dev = &client->dev;
291	struct fwnode_handle *child;
292	bool hw_blink;
293	s32 mode2;
294	u32 reg;
295	int ret;
296
297	if (device_property_read_u32(dev, "nxp,period-scale",
298				     &chipdef->scaling))
299		chipdef->scaling = 1000;
300
301	hw_blink = device_property_read_bool(dev, "nxp,hw-blink");
302
303	mode2 = i2c_smbus_read_byte_data(client, PCA963X_MODE2);
304	if (mode2 < 0)
305		return mode2;
306
307	/* default to open-drain unless totem pole (push-pull) is specified */
308	if (device_property_read_bool(dev, "nxp,totem-pole"))
309		mode2 |= PCA963X_MODE2_OUTDRV;
310	else
311		mode2 &= ~PCA963X_MODE2_OUTDRV;
312
313	/* default to non-inverted output, unless inverted is specified */
314	if (device_property_read_bool(dev, "nxp,inverted-out"))
315		mode2 |= PCA963X_MODE2_INVRT;
316	else
317		mode2 &= ~PCA963X_MODE2_INVRT;
318
319	ret = i2c_smbus_write_byte_data(client, PCA963X_MODE2, mode2);
320	if (ret < 0)
321		return ret;
322
323	device_for_each_child_node(dev, child) {
324		struct led_init_data init_data = {};
325		char default_label[32];
326
327		ret = fwnode_property_read_u32(child, "reg", &reg);
328		if (ret || reg >= chipdef->n_leds) {
329			dev_err(dev, "Invalid 'reg' property for node %pfw\n",
330				child);
331			ret = -EINVAL;
332			goto err;
333		}
334
335		led->led_num = reg;
336		led->chip = chip;
337		led->led_cdev.brightness_set_blocking = pca963x_led_set;
338		if (hw_blink)
339			led->led_cdev.blink_set = pca963x_blink_set;
340
341		init_data.fwnode = child;
342		/* for backwards compatibility */
343		init_data.devicename = "pca963x";
344		snprintf(default_label, sizeof(default_label), "%d:%.2x:%u",
345			 client->adapter->nr, client->addr, reg);
346		init_data.default_label = default_label;
347
348		ret = devm_led_classdev_register_ext(dev, &led->led_cdev,
349						     &init_data);
350		if (ret) {
351			dev_err(dev, "Failed to register LED for node %pfw\n",
352				child);
353			goto err;
354		}
355
356		++led;
357	}
358
359	return 0;
360err:
361	fwnode_handle_put(child);
362	return ret;
363}
364
365static const struct of_device_id of_pca963x_match[] = {
366	{ .compatible = "nxp,pca9632", },
367	{ .compatible = "nxp,pca9633", },
368	{ .compatible = "nxp,pca9634", },
369	{ .compatible = "nxp,pca9635", },
370	{},
371};
372MODULE_DEVICE_TABLE(of, of_pca963x_match);
373
374static int pca963x_probe(struct i2c_client *client,
375			 const struct i2c_device_id *id)
376{
377	struct device *dev = &client->dev;
378	struct pca963x_chipdef *chipdef;
379	struct pca963x *chip;
380	int i, count;
381
382	chipdef = &pca963x_chipdefs[id->driver_data];
383
384	count = device_get_child_node_count(dev);
385	if (!count || count > chipdef->n_leds) {
386		dev_err(dev, "Node %pfw must define between 1 and %d LEDs\n",
387			dev_fwnode(dev), chipdef->n_leds);
388		return -EINVAL;
389	}
390
391	chip = devm_kzalloc(dev, struct_size(chip, leds, count), GFP_KERNEL);
392	if (!chip)
393		return -ENOMEM;
394
395	i2c_set_clientdata(client, chip);
396
397	mutex_init(&chip->mutex);
398	chip->chipdef = chipdef;
399	chip->client = client;
400
401	/* Turn off LEDs by default*/
402	for (i = 0; i < chipdef->n_leds / 4; i++)
403		i2c_smbus_write_byte_data(client, chipdef->ledout_base + i, 0x00);
404
405	/* Disable LED all-call address, and power down initially */
406	i2c_smbus_write_byte_data(client, PCA963X_MODE1, BIT(4));
407
408	return pca963x_register_leds(client, chip);
409}
410
411static struct i2c_driver pca963x_driver = {
412	.driver = {
413		.name	= "leds-pca963x",
414		.of_match_table = of_pca963x_match,
415	},
416	.probe	= pca963x_probe,
417	.id_table = pca963x_id,
418};
419
420module_i2c_driver(pca963x_driver);
421
422MODULE_AUTHOR("Peter Meerwald <p.meerwald@bct-electronic.com>");
423MODULE_DESCRIPTION("PCA963X LED driver");
424MODULE_LICENSE("GPL v2");