summaryrefslogtreecommitdiff
path: root/drivers/leds/leds-turris-omnia.c
blob: b443f8c989fa354d46210af463360d734f959461 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
// SPDX-License-Identifier: GPL-2.0
/*
 * CZ.NIC's Turris Omnia LEDs driver
 *
 * 2020, 2023 by Marek Behún <kabel@kernel.org>
 */

#include <linux/i2c.h>
#include <linux/led-class-multicolor.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include "leds.h"

#define OMNIA_BOARD_LEDS	12
#define OMNIA_LED_NUM_CHANNELS	3

/* MCU controller commands at I2C address 0x2a */
#define OMNIA_MCU_I2C_ADDR		0x2a

#define CMD_GET_STATUS_WORD		0x01
#define STS_FEATURES_SUPPORTED		BIT(2)

#define CMD_GET_FEATURES		0x10
#define FEAT_LED_GAMMA_CORRECTION	BIT(5)

/* LED controller commands at I2C address 0x2b */
#define CMD_LED_MODE			0x03
#define CMD_LED_MODE_LED(l)		((l) & 0x0f)
#define CMD_LED_MODE_USER		0x10

#define CMD_LED_STATE			0x04
#define CMD_LED_STATE_LED(l)		((l) & 0x0f)
#define CMD_LED_STATE_ON		0x10

#define CMD_LED_COLOR			0x05
#define CMD_LED_SET_BRIGHTNESS		0x07
#define CMD_LED_GET_BRIGHTNESS		0x08

#define CMD_SET_GAMMA_CORRECTION	0x30
#define CMD_GET_GAMMA_CORRECTION	0x31

struct omnia_led {
	struct led_classdev_mc mc_cdev;
	struct mc_subled subled_info[OMNIA_LED_NUM_CHANNELS];
	u8 cached_channels[OMNIA_LED_NUM_CHANNELS];
	bool on, hwtrig;
	int reg;
};

#define to_omnia_led(l)		container_of(l, struct omnia_led, mc_cdev)

struct omnia_leds {
	struct i2c_client *client;
	struct mutex lock;
	bool has_gamma_correction;
	struct omnia_led leds[];
};

static int omnia_cmd_write_u8(const struct i2c_client *client, u8 cmd, u8 val)
{
	u8 buf[2] = { cmd, val };
	int ret;

	ret = i2c_master_send(client, buf, sizeof(buf));

	return ret < 0 ? ret : 0;
}

static int omnia_cmd_read_raw(struct i2c_adapter *adapter, u8 addr, u8 cmd,
			      void *reply, size_t len)
{
	struct i2c_msg msgs[2];
	int ret;

	msgs[0].addr = addr;
	msgs[0].flags = 0;
	msgs[0].len = 1;
	msgs[0].buf = &cmd;
	msgs[1].addr = addr;
	msgs[1].flags = I2C_M_RD;
	msgs[1].len = len;
	msgs[1].buf = reply;

	ret = i2c_transfer(adapter, msgs, ARRAY_SIZE(msgs));
	if (likely(ret == ARRAY_SIZE(msgs)))
		return 0;
	else if (ret < 0)
		return ret;
	else
		return -EIO;
}

static int omnia_cmd_read_u8(const struct i2c_client *client, u8 cmd)
{
	u8 reply;
	int err;

	err = omnia_cmd_read_raw(client->adapter, client->addr, cmd, &reply, 1);
	if (err)
		return err;

	return reply;
}

static int omnia_led_send_color_cmd(const struct i2c_client *client,
				    struct omnia_led *led)
{
	char cmd[5];
	int ret;

	cmd[0] = CMD_LED_COLOR;
	cmd[1] = led->reg;
	cmd[2] = led->subled_info[0].brightness;
	cmd[3] = led->subled_info[1].brightness;
	cmd[4] = led->subled_info[2].brightness;

	/* Send the color change command */
	ret = i2c_master_send(client, cmd, 5);
	if (ret < 0)
		return ret;

	/* Cache the RGB channel brightnesses */
	for (int i = 0; i < OMNIA_LED_NUM_CHANNELS; ++i)
		led->cached_channels[i] = led->subled_info[i].brightness;

	return 0;
}

/* Determine if the computed RGB channels are different from the cached ones */
static bool omnia_led_channels_changed(struct omnia_led *led)
{
	for (int i = 0; i < OMNIA_LED_NUM_CHANNELS; ++i)
		if (led->subled_info[i].brightness != led->cached_channels[i])
			return true;

	return false;
}

static int omnia_led_brightness_set_blocking(struct led_classdev *cdev,
					     enum led_brightness brightness)
{
	struct led_classdev_mc *mc_cdev = lcdev_to_mccdev(cdev);
	struct omnia_leds *leds = dev_get_drvdata(cdev->dev->parent);
	struct omnia_led *led = to_omnia_led(mc_cdev);
	int err = 0;

	mutex_lock(&leds->lock);

	/*
	 * Only recalculate RGB brightnesses from intensities if brightness is
	 * non-zero (if it is zero and the LED is in HW blinking mode, we use
	 * max_brightness as brightness). Otherwise we won't be using them and
	 * we can save ourselves some software divisions (Omnia's CPU does not
	 * implement the division instruction).
	 */
	if (brightness || led->hwtrig) {
		led_mc_calc_color_components(mc_cdev, brightness ?:
						      cdev->max_brightness);

		/*
		 * Send color command only if brightness is non-zero and the RGB
		 * channel brightnesses changed.
		 */
		if (omnia_led_channels_changed(led))
			err = omnia_led_send_color_cmd(leds->client, led);
	}

	/*
	 * Send on/off state change only if (bool)brightness changed and the LED
	 * is not being blinked by HW.
	 */
	if (!err && !led->hwtrig && !brightness != !led->on) {
		u8 state = CMD_LED_STATE_LED(led->reg);

		if (brightness)
			state |= CMD_LED_STATE_ON;

		err = omnia_cmd_write_u8(leds->client, CMD_LED_STATE, state);
		if (!err)
			led->on = !!brightness;
	}

	mutex_unlock(&leds->lock);

	return err;
}

static struct led_hw_trigger_type omnia_hw_trigger_type;

static int omnia_hwtrig_activate(struct led_classdev *cdev)
{
	struct led_classdev_mc *mc_cdev = lcdev_to_mccdev(cdev);
	struct omnia_leds *leds = dev_get_drvdata(cdev->dev->parent);
	struct omnia_led *led = to_omnia_led(mc_cdev);
	int err = 0;

	mutex_lock(&leds->lock);

	if (!led->on) {
		/*
		 * If the LED is off (brightness was set to 0), the last
		 * configured color was not necessarily sent to the MCU.
		 * Recompute with max_brightness and send if needed.
		 */
		led_mc_calc_color_components(mc_cdev, cdev->max_brightness);

		if (omnia_led_channels_changed(led))
			err = omnia_led_send_color_cmd(leds->client, led);
	}

	if (!err) {
		/* Put the LED into MCU controlled mode */
		err = omnia_cmd_write_u8(leds->client, CMD_LED_MODE,
					 CMD_LED_MODE_LED(led->reg));
		if (!err)
			led->hwtrig = true;
	}

	mutex_unlock(&leds->lock);

	return err;
}

static void omnia_hwtrig_deactivate(struct led_classdev *cdev)
{
	struct omnia_leds *leds = dev_get_drvdata(cdev->dev->parent);
	struct omnia_led *led = to_omnia_led(lcdev_to_mccdev(cdev));
	int err;

	mutex_lock(&leds->lock);

	led->hwtrig = false;

	/* Put the LED into software mode */
	err = omnia_cmd_write_u8(leds->client, CMD_LED_MODE,
				 CMD_LED_MODE_LED(led->reg) |
				 CMD_LED_MODE_USER);

	mutex_unlock(&leds->lock);

	if (err)
		dev_err(cdev->dev, "Cannot put LED to software mode: %i\n",
			err);
}

static struct led_trigger omnia_hw_trigger = {
	.name		= "omnia-mcu",
	.activate	= omnia_hwtrig_activate,
	.deactivate	= omnia_hwtrig_deactivate,
	.trigger_type	= &omnia_hw_trigger_type,
};

static int omnia_led_register(struct i2c_client *client, struct omnia_led *led,
			      struct device_node *np)
{
	struct led_init_data init_data = {};
	struct device *dev = &client->dev;
	struct led_classdev *cdev;
	int ret, color;

	ret = of_property_read_u32(np, "reg", &led->reg);
	if (ret || led->reg >= OMNIA_BOARD_LEDS) {
		dev_warn(dev,
			 "Node %pOF: must contain 'reg' property with values between 0 and %i\n",
			 np, OMNIA_BOARD_LEDS - 1);
		return 0;
	}

	ret = of_property_read_u32(np, "color", &color);
	if (ret || color != LED_COLOR_ID_RGB) {
		dev_warn(dev,
			 "Node %pOF: must contain 'color' property with value LED_COLOR_ID_RGB\n",
			 np);
		return 0;
	}

	led->subled_info[0].color_index = LED_COLOR_ID_RED;
	led->subled_info[1].color_index = LED_COLOR_ID_GREEN;
	led->subled_info[2].color_index = LED_COLOR_ID_BLUE;

	/* Initial color is white */
	for (int i = 0; i < OMNIA_LED_NUM_CHANNELS; ++i) {
		led->subled_info[i].intensity = 255;
		led->subled_info[i].brightness = 255;
		led->subled_info[i].channel = i;
	}

	led->mc_cdev.subled_info = led->subled_info;
	led->mc_cdev.num_colors = OMNIA_LED_NUM_CHANNELS;

	init_data.fwnode = &np->fwnode;

	cdev = &led->mc_cdev.led_cdev;
	cdev->max_brightness = 255;
	cdev->brightness_set_blocking = omnia_led_brightness_set_blocking;
	cdev->trigger_type = &omnia_hw_trigger_type;
	/*
	 * Use the omnia-mcu trigger as the default trigger. It may be rewritten
	 * by LED class from the linux,default-trigger property.
	 */
	cdev->default_trigger = omnia_hw_trigger.name;

	/* put the LED into software mode */
	ret = omnia_cmd_write_u8(client, CMD_LED_MODE,
				 CMD_LED_MODE_LED(led->reg) |
				 CMD_LED_MODE_USER);
	if (ret) {
		dev_err(dev, "Cannot set LED %pOF to software mode: %i\n", np,
			ret);
		return ret;
	}

	/* disable the LED */
	ret = omnia_cmd_write_u8(client, CMD_LED_STATE,
				 CMD_LED_STATE_LED(led->reg));
	if (ret) {
		dev_err(dev, "Cannot set LED %pOF brightness: %i\n", np, ret);
		return ret;
	}

	/* Set initial color and cache it */
	ret = omnia_led_send_color_cmd(client, led);
	if (ret < 0) {
		dev_err(dev, "Cannot set LED %pOF initial color: %i\n", np,
			ret);
		return ret;
	}

	ret = devm_led_classdev_multicolor_register_ext(dev, &led->mc_cdev,
							&init_data);
	if (ret < 0) {
		dev_err(dev, "Cannot register LED %pOF: %i\n", np, ret);
		return ret;
	}

	return 1;
}

/*
 * On the front panel of the Turris Omnia router there is also a button which
 * can be used to control the intensity of all the LEDs at once, so that if they
 * are too bright, user can dim them.
 * The microcontroller cycles between 8 levels of this global brightness (from
 * 100% to 0%), but this setting can have any integer value between 0 and 100.
 * It is therefore convenient to be able to change this setting from software.
 * We expose this setting via a sysfs attribute file called "brightness". This
 * file lives in the device directory of the LED controller, not an individual
 * LED, so it should not confuse users.
 */
static ssize_t brightness_show(struct device *dev, struct device_attribute *a,
			       char *buf)
{
	struct i2c_client *client = to_i2c_client(dev);
	int ret;

	ret = omnia_cmd_read_u8(client, CMD_LED_GET_BRIGHTNESS);

	if (ret < 0)
		return ret;

	return sysfs_emit(buf, "%d\n", ret);
}

static ssize_t brightness_store(struct device *dev, struct device_attribute *a,
				const char *buf, size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	unsigned long brightness;
	int err;

	if (kstrtoul(buf, 10, &brightness))
		return -EINVAL;

	if (brightness > 100)
		return -EINVAL;

	err = omnia_cmd_write_u8(client, CMD_LED_SET_BRIGHTNESS, brightness);

	return err ?: count;
}
static DEVICE_ATTR_RW(brightness);

static ssize_t gamma_correction_show(struct device *dev,
				     struct device_attribute *a, char *buf)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct omnia_leds *leds = i2c_get_clientdata(client);
	int ret;

	if (leds->has_gamma_correction) {
		ret = omnia_cmd_read_u8(client, CMD_GET_GAMMA_CORRECTION);
		if (ret < 0)
			return ret;
	} else {
		ret = 0;
	}

	return sysfs_emit(buf, "%d\n", !!ret);
}

static ssize_t gamma_correction_store(struct device *dev,
				      struct device_attribute *a,
				      const char *buf, size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct omnia_leds *leds = i2c_get_clientdata(client);
	bool val;
	int err;

	if (!leds->has_gamma_correction)
		return -EOPNOTSUPP;

	if (kstrtobool(buf, &val) < 0)
		return -EINVAL;

	err = omnia_cmd_write_u8(client, CMD_SET_GAMMA_CORRECTION, val);

	return err ?: count;
}
static DEVICE_ATTR_RW(gamma_correction);

static struct attribute *omnia_led_controller_attrs[] = {
	&dev_attr_brightness.attr,
	&dev_attr_gamma_correction.attr,
	NULL,
};
ATTRIBUTE_GROUPS(omnia_led_controller);

static int omnia_mcu_get_features(const struct i2c_client *client)
{
	u16 reply;
	int err;

	err = omnia_cmd_read_raw(client->adapter, OMNIA_MCU_I2C_ADDR,
				 CMD_GET_STATUS_WORD, &reply, sizeof(reply));
	if (err)
		return err;

	/* Check whether MCU firmware supports the CMD_GET_FEAUTRES command */
	if (!(le16_to_cpu(reply) & STS_FEATURES_SUPPORTED))
		return 0;

	err = omnia_cmd_read_raw(client->adapter, OMNIA_MCU_I2C_ADDR,
				 CMD_GET_FEATURES, &reply, sizeof(reply));
	if (err)
		return err;

	return le16_to_cpu(reply);
}

static int omnia_leds_probe(struct i2c_client *client)
{
	struct device *dev = &client->dev;
	struct device_node *np = dev_of_node(dev), *child;
	struct omnia_leds *leds;
	struct omnia_led *led;
	int ret, count;

	count = of_get_available_child_count(np);
	if (!count) {
		dev_err(dev, "LEDs are not defined in device tree!\n");
		return -ENODEV;
	} else if (count > OMNIA_BOARD_LEDS) {
		dev_err(dev, "Too many LEDs defined in device tree!\n");
		return -EINVAL;
	}

	leds = devm_kzalloc(dev, struct_size(leds, leds, count), GFP_KERNEL);
	if (!leds)
		return -ENOMEM;

	leds->client = client;
	i2c_set_clientdata(client, leds);

	ret = omnia_mcu_get_features(client);
	if (ret < 0) {
		dev_err(dev, "Cannot determine MCU supported features: %d\n",
			ret);
		return ret;
	}

	leds->has_gamma_correction = ret & FEAT_LED_GAMMA_CORRECTION;
	if (!leds->has_gamma_correction) {
		dev_info(dev,
			 "Your board's MCU firmware does not support the LED gamma correction feature.\n");
		dev_info(dev,
			 "Consider upgrading MCU firmware with the omnia-mcutool utility.\n");
	}

	mutex_init(&leds->lock);

	ret = devm_led_trigger_register(dev, &omnia_hw_trigger);
	if (ret < 0) {
		dev_err(dev, "Cannot register private LED trigger: %d\n", ret);
		return ret;
	}

	led = &leds->leds[0];
	for_each_available_child_of_node(np, child) {
		ret = omnia_led_register(client, led, child);
		if (ret < 0) {
			of_node_put(child);
			return ret;
		}

		led += ret;
	}

	return 0;
}

static void omnia_leds_remove(struct i2c_client *client)
{
	u8 buf[5];

	/* put all LEDs into default (HW triggered) mode */
	omnia_cmd_write_u8(client, CMD_LED_MODE,
			   CMD_LED_MODE_LED(OMNIA_BOARD_LEDS));

	/* set all LEDs color to [255, 255, 255] */
	buf[0] = CMD_LED_COLOR;
	buf[1] = OMNIA_BOARD_LEDS;
	buf[2] = 255;
	buf[3] = 255;
	buf[4] = 255;

	i2c_master_send(client, buf, 5);
}

static const struct of_device_id of_omnia_leds_match[] = {
	{ .compatible = "cznic,turris-omnia-leds", },
	{},
};

static const struct i2c_device_id omnia_id[] = {
	{ "omnia", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, omnia_id);

static struct i2c_driver omnia_leds_driver = {
	.probe		= omnia_leds_probe,
	.remove		= omnia_leds_remove,
	.id_table	= omnia_id,
	.driver		= {
		.name	= "leds-turris-omnia",
		.of_match_table = of_omnia_leds_match,
		.dev_groups = omnia_led_controller_groups,
	},
};

module_i2c_driver(omnia_leds_driver);

MODULE_AUTHOR("Marek Behun <kabel@kernel.org>");
MODULE_DESCRIPTION("CZ.NIC's Turris Omnia LEDs");
MODULE_LICENSE("GPL v2");