aboutsummaryrefslogtreecommitdiff
path: root/drivers/leds/leds-bcm6328.c
blob: 2d4d87957a3003ed5cd4b015e8bf92ebbba25945 (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
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Driver for BCM6328 memory-mapped LEDs, based on leds-syscon.c
 *
 * Copyright 2015 Álvaro Fernández Rojas <noltari@gmail.com>
 * Copyright 2015 Jonas Gorski <jogo@openwrt.org>
 */
#include <linux/io.h>
#include <linux/leds.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/spinlock.h>

#define BCM6328_REG_INIT		0x00
#define BCM6328_REG_MODE_HI		0x04
#define BCM6328_REG_MODE_LO		0x08
#define BCM6328_REG_HWDIS		0x0c
#define BCM6328_REG_STROBE		0x10
#define BCM6328_REG_LNKACTSEL_HI	0x14
#define BCM6328_REG_LNKACTSEL_LO	0x18
#define BCM6328_REG_RBACK		0x1c
#define BCM6328_REG_SERMUX		0x20

#define BCM6328_LED_MAX_COUNT		24
#define BCM6328_LED_DEF_DELAY		500

#define BCM6328_LED_BLINK_DELAYS	2
#define BCM6328_LED_BLINK_MS		20

#define BCM6328_LED_BLINK_MASK		0x3f
#define BCM6328_LED_BLINK1_SHIFT	0
#define BCM6328_LED_BLINK1_MASK		(BCM6328_LED_BLINK_MASK << \
					 BCM6328_LED_BLINK1_SHIFT)
#define BCM6328_LED_BLINK2_SHIFT	6
#define BCM6328_LED_BLINK2_MASK		(BCM6328_LED_BLINK_MASK << \
					 BCM6328_LED_BLINK2_SHIFT)
#define BCM6328_SERIAL_LED_EN		BIT(12)
#define BCM6328_SERIAL_LED_MUX		BIT(13)
#define BCM6328_SERIAL_LED_CLK_NPOL	BIT(14)
#define BCM6328_SERIAL_LED_DATA_PPOL	BIT(15)
#define BCM6328_SERIAL_LED_SHIFT_DIR	BIT(16)
#define BCM6328_LED_SHIFT_TEST		BIT(30)
#define BCM6328_LED_TEST		BIT(31)
#define BCM6328_INIT_MASK		(BCM6328_SERIAL_LED_EN | \
					 BCM6328_SERIAL_LED_MUX | \
					 BCM6328_SERIAL_LED_CLK_NPOL | \
					 BCM6328_SERIAL_LED_DATA_PPOL | \
					 BCM6328_SERIAL_LED_SHIFT_DIR)

#define BCM6328_LED_MODE_MASK		3
#define BCM6328_LED_MODE_ON		0
#define BCM6328_LED_MODE_BLINK1		1
#define BCM6328_LED_MODE_BLINK2		2
#define BCM6328_LED_MODE_OFF		3
#define BCM6328_LED_SHIFT(X)		((X) << 1)

/**
 * struct bcm6328_led - state container for bcm6328 based LEDs
 * @cdev: LED class device for this LED
 * @mem: memory resource
 * @lock: memory lock
 * @pin: LED pin number
 * @blink_leds: blinking LEDs
 * @blink_delay: blinking delay
 * @active_low: LED is active low
 */
struct bcm6328_led {
	struct led_classdev cdev;
	void __iomem *mem;
	spinlock_t *lock;
	unsigned long pin;
	unsigned long *blink_leds;
	unsigned long *blink_delay;
	bool active_low;
};

static void bcm6328_led_write(void __iomem *reg, unsigned long data)
{
#ifdef CONFIG_CPU_BIG_ENDIAN
	iowrite32be(data, reg);
#else
	writel(data, reg);
#endif
}

static unsigned long bcm6328_led_read(void __iomem *reg)
{
#ifdef CONFIG_CPU_BIG_ENDIAN
	return ioread32be(reg);
#else
	return readl(reg);
#endif
}

/*
 * LEDMode 64 bits / 24 LEDs
 * bits [31:0] -> LEDs 8-23
 * bits [47:32] -> LEDs 0-7
 * bits [63:48] -> unused
 */
static unsigned long bcm6328_pin2shift(unsigned long pin)
{
	if (pin < 8)
		return pin + 16; /* LEDs 0-7 (bits 47:32) */
	else
		return pin - 8; /* LEDs 8-23 (bits 31:0) */
}

static void bcm6328_led_mode(struct bcm6328_led *led, unsigned long value)
{
	void __iomem *mode;
	unsigned long val, shift;

	shift = bcm6328_pin2shift(led->pin);
	if (shift / 16)
		mode = led->mem + BCM6328_REG_MODE_HI;
	else
		mode = led->mem + BCM6328_REG_MODE_LO;

	val = bcm6328_led_read(mode);
	val &= ~(BCM6328_LED_MODE_MASK << BCM6328_LED_SHIFT(shift % 16));
	val |= (value << BCM6328_LED_SHIFT(shift % 16));
	bcm6328_led_write(mode, val);
}

static void bcm6328_led_set(struct led_classdev *led_cdev,
			    enum led_brightness value)
{
	struct bcm6328_led *led =
		container_of(led_cdev, struct bcm6328_led, cdev);
	unsigned long flags;

	spin_lock_irqsave(led->lock, flags);

	/* Remove LED from cached HW blinking intervals */
	led->blink_leds[0] &= ~BIT(led->pin);
	led->blink_leds[1] &= ~BIT(led->pin);

	/* Set LED on/off */
	if ((led->active_low && value == LED_OFF) ||
	    (!led->active_low && value != LED_OFF))
		bcm6328_led_mode(led, BCM6328_LED_MODE_ON);
	else
		bcm6328_led_mode(led, BCM6328_LED_MODE_OFF);

	spin_unlock_irqrestore(led->lock, flags);
}

static unsigned long bcm6328_blink_delay(unsigned long delay)
{
	unsigned long bcm6328_delay;

	bcm6328_delay = delay + BCM6328_LED_BLINK_MS / 2;
	bcm6328_delay = bcm6328_delay / BCM6328_LED_BLINK_MS;
	if (bcm6328_delay == 0)
		bcm6328_delay = 1;

	return bcm6328_delay;
}

static int bcm6328_blink_set(struct led_classdev *led_cdev,
			     unsigned long *delay_on, unsigned long *delay_off)
{
	struct bcm6328_led *led =
		container_of(led_cdev, struct bcm6328_led, cdev);
	unsigned long delay, flags;
	int rc;

	if (!*delay_on)
		*delay_on = BCM6328_LED_DEF_DELAY;
	if (!*delay_off)
		*delay_off = BCM6328_LED_DEF_DELAY;

	delay = bcm6328_blink_delay(*delay_on);
	if (delay != bcm6328_blink_delay(*delay_off)) {
		dev_dbg(led_cdev->dev,
			"fallback to soft blinking (delay_on != delay_off)\n");
		return -EINVAL;
	}

	if (delay > BCM6328_LED_BLINK_MASK) {
		dev_dbg(led_cdev->dev,
			"fallback to soft blinking (delay > %ums)\n",
			BCM6328_LED_BLINK_MASK * BCM6328_LED_BLINK_MS);
		return -EINVAL;
	}

	spin_lock_irqsave(led->lock, flags);
	/*
	 * Check if any of the two configurable HW blinking intervals is
	 * available:
	 *   1. No LEDs assigned to the HW blinking interval.
	 *   2. Only this LED is assigned to the HW blinking interval.
	 *   3. LEDs with the same delay assigned.
	 */
	if (led->blink_leds[0] == 0 ||
	    led->blink_leds[0] == BIT(led->pin) ||
	    led->blink_delay[0] == delay) {
		unsigned long val;

		/* Add LED to the first HW blinking interval cache */
		led->blink_leds[0] |= BIT(led->pin);

		/* Remove LED from the second HW blinking interval cache */
		led->blink_leds[1] &= ~BIT(led->pin);

		/* Cache first HW blinking interval delay */
		led->blink_delay[0] = delay;

		/* Update the delay for the first HW blinking interval */
		val = bcm6328_led_read(led->mem + BCM6328_REG_INIT);
		val &= ~BCM6328_LED_BLINK1_MASK;
		val |= (delay << BCM6328_LED_BLINK1_SHIFT);
		bcm6328_led_write(led->mem + BCM6328_REG_INIT, val);

		/* Set the LED to first HW blinking interval */
		bcm6328_led_mode(led, BCM6328_LED_MODE_BLINK1);

		rc = 0;
	} else if (led->blink_leds[1] == 0 ||
		   led->blink_leds[1] == BIT(led->pin) ||
		   led->blink_delay[1] == delay) {
		unsigned long val;

		/* Remove LED from the first HW blinking interval */
		led->blink_leds[0] &= ~BIT(led->pin);

		/* Add LED to the second HW blinking interval */
		led->blink_leds[1] |= BIT(led->pin);

		/* Cache second HW blinking interval delay */
		led->blink_delay[1] = delay;

		/* Update the delay for the second HW blinking interval */
		val = bcm6328_led_read(led->mem + BCM6328_REG_INIT);
		val &= ~BCM6328_LED_BLINK2_MASK;
		val |= (delay << BCM6328_LED_BLINK2_SHIFT);
		bcm6328_led_write(led->mem + BCM6328_REG_INIT, val);

		/* Set the LED to second HW blinking interval */
		bcm6328_led_mode(led, BCM6328_LED_MODE_BLINK2);

		rc = 0;
	} else {
		dev_dbg(led_cdev->dev,
			"fallback to soft blinking (delay already set)\n");
		rc = -EINVAL;
	}
	spin_unlock_irqrestore(led->lock, flags);

	return rc;
}

static int bcm6328_hwled(struct device *dev, struct device_node *nc, u32 reg,
			 void __iomem *mem, spinlock_t *lock)
{
	int i, cnt;
	unsigned long flags, val;

	spin_lock_irqsave(lock, flags);
	val = bcm6328_led_read(mem + BCM6328_REG_HWDIS);
	val &= ~BIT(reg);
	bcm6328_led_write(mem + BCM6328_REG_HWDIS, val);
	spin_unlock_irqrestore(lock, flags);

	/* Only LEDs 0-7 can be activity/link controlled */
	if (reg >= 8)
		return 0;

	cnt = of_property_count_elems_of_size(nc, "brcm,link-signal-sources",
					      sizeof(u32));
	for (i = 0; i < cnt; i++) {
		u32 sel;
		void __iomem *addr;

		if (reg < 4)
			addr = mem + BCM6328_REG_LNKACTSEL_LO;
		else
			addr = mem + BCM6328_REG_LNKACTSEL_HI;

		of_property_read_u32_index(nc, "brcm,link-signal-sources", i,
					   &sel);

		if (reg / 4 != sel / 4) {
			dev_warn(dev, "invalid link signal source\n");
			continue;
		}

		spin_lock_irqsave(lock, flags);
		val = bcm6328_led_read(addr);
		val |= (BIT(reg % 4) << (((sel % 4) * 4) + 16));
		bcm6328_led_write(addr, val);
		spin_unlock_irqrestore(lock, flags);
	}

	cnt = of_property_count_elems_of_size(nc,
					      "brcm,activity-signal-sources",
					      sizeof(u32));
	for (i = 0; i < cnt; i++) {
		u32 sel;
		void __iomem *addr;

		if (reg < 4)
			addr = mem + BCM6328_REG_LNKACTSEL_LO;
		else
			addr = mem + BCM6328_REG_LNKACTSEL_HI;

		of_property_read_u32_index(nc, "brcm,activity-signal-sources",
					   i, &sel);

		if (reg / 4 != sel / 4) {
			dev_warn(dev, "invalid activity signal source\n");
			continue;
		}

		spin_lock_irqsave(lock, flags);
		val = bcm6328_led_read(addr);
		val |= (BIT(reg % 4) << ((sel % 4) * 4));
		bcm6328_led_write(addr, val);
		spin_unlock_irqrestore(lock, flags);
	}

	return 0;
}

static int bcm6328_led(struct device *dev, struct device_node *nc, u32 reg,
		       void __iomem *mem, spinlock_t *lock,
		       unsigned long *blink_leds, unsigned long *blink_delay)
{
	struct led_init_data init_data = {};
	struct bcm6328_led *led;
	const char *state;
	int rc;

	led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);
	if (!led)
		return -ENOMEM;

	led->pin = reg;
	led->mem = mem;
	led->lock = lock;
	led->blink_leds = blink_leds;
	led->blink_delay = blink_delay;

	if (of_property_read_bool(nc, "active-low"))
		led->active_low = true;

	if (!of_property_read_string(nc, "default-state", &state)) {
		if (!strcmp(state, "on")) {
			led->cdev.brightness = LED_FULL;
		} else if (!strcmp(state, "keep")) {
			void __iomem *mode;
			unsigned long val, shift;

			shift = bcm6328_pin2shift(led->pin);
			if (shift / 16)
				mode = mem + BCM6328_REG_MODE_HI;
			else
				mode = mem + BCM6328_REG_MODE_LO;

			val = bcm6328_led_read(mode) >>
			      BCM6328_LED_SHIFT(shift % 16);
			val &= BCM6328_LED_MODE_MASK;
			if ((led->active_low && val == BCM6328_LED_MODE_OFF) ||
			    (!led->active_low && val == BCM6328_LED_MODE_ON))
				led->cdev.brightness = LED_FULL;
			else
				led->cdev.brightness = LED_OFF;
		} else {
			led->cdev.brightness = LED_OFF;
		}
	} else {
		led->cdev.brightness = LED_OFF;
	}

	bcm6328_led_set(&led->cdev, led->cdev.brightness);

	led->cdev.brightness_set = bcm6328_led_set;
	led->cdev.blink_set = bcm6328_blink_set;
	init_data.fwnode = of_fwnode_handle(nc);

	rc = devm_led_classdev_register_ext(dev, &led->cdev, &init_data);
	if (rc < 0)
		return rc;

	dev_dbg(dev, "registered LED %s\n", led->cdev.name);

	return 0;
}

static int bcm6328_leds_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct device_node *np = dev_of_node(&pdev->dev);
	struct device_node *child;
	void __iomem *mem;
	spinlock_t *lock; /* memory lock */
	unsigned long val, *blink_leds, *blink_delay;

	mem = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(mem))
		return PTR_ERR(mem);

	lock = devm_kzalloc(dev, sizeof(*lock), GFP_KERNEL);
	if (!lock)
		return -ENOMEM;

	blink_leds = devm_kcalloc(dev, BCM6328_LED_BLINK_DELAYS,
				  sizeof(*blink_leds), GFP_KERNEL);
	if (!blink_leds)
		return -ENOMEM;

	blink_delay = devm_kcalloc(dev, BCM6328_LED_BLINK_DELAYS,
				   sizeof(*blink_delay), GFP_KERNEL);
	if (!blink_delay)
		return -ENOMEM;

	spin_lock_init(lock);

	bcm6328_led_write(mem + BCM6328_REG_HWDIS, ~0);
	bcm6328_led_write(mem + BCM6328_REG_LNKACTSEL_HI, 0);
	bcm6328_led_write(mem + BCM6328_REG_LNKACTSEL_LO, 0);

	val = bcm6328_led_read(mem + BCM6328_REG_INIT);
	val &= ~(BCM6328_INIT_MASK);
	if (of_property_read_bool(np, "brcm,serial-leds"))
		val |= BCM6328_SERIAL_LED_EN;
	if (of_property_read_bool(np, "brcm,serial-mux"))
		val |= BCM6328_SERIAL_LED_MUX;
	if (of_property_read_bool(np, "brcm,serial-clk-low"))
		val |= BCM6328_SERIAL_LED_CLK_NPOL;
	if (!of_property_read_bool(np, "brcm,serial-dat-low"))
		val |= BCM6328_SERIAL_LED_DATA_PPOL;
	if (!of_property_read_bool(np, "brcm,serial-shift-inv"))
		val |= BCM6328_SERIAL_LED_SHIFT_DIR;
	bcm6328_led_write(mem + BCM6328_REG_INIT, val);

	for_each_available_child_of_node(np, child) {
		int rc;
		u32 reg;

		if (of_property_read_u32(child, "reg", &reg))
			continue;

		if (reg >= BCM6328_LED_MAX_COUNT) {
			dev_err(dev, "invalid LED (%u >= %d)\n", reg,
				BCM6328_LED_MAX_COUNT);
			continue;
		}

		if (of_property_read_bool(child, "brcm,hardware-controlled"))
			rc = bcm6328_hwled(dev, child, reg, mem, lock);
		else
			rc = bcm6328_led(dev, child, reg, mem, lock,
					 blink_leds, blink_delay);

		if (rc < 0) {
			of_node_put(child);
			return rc;
		}
	}

	return 0;
}

static const struct of_device_id bcm6328_leds_of_match[] = {
	{ .compatible = "brcm,bcm6328-leds", },
	{ },
};
MODULE_DEVICE_TABLE(of, bcm6328_leds_of_match);

static struct platform_driver bcm6328_leds_driver = {
	.probe = bcm6328_leds_probe,
	.driver = {
		.name = "leds-bcm6328",
		.of_match_table = bcm6328_leds_of_match,
	},
};

module_platform_driver(bcm6328_leds_driver);

MODULE_AUTHOR("Álvaro Fernández Rojas <noltari@gmail.com>");
MODULE_AUTHOR("Jonas Gorski <jogo@openwrt.org>");
MODULE_DESCRIPTION("LED driver for BCM6328 controllers");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:leds-bcm6328");