1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Driver for BCM6328 memory-mapped LEDs, based on leds-syscon.c
4 *
5 * Copyright 2015 ��lvaro Fern��ndez Rojas <noltari@gmail.com>
6 * Copyright 2015 Jonas Gorski <jogo@openwrt.org>
7 */
8#include <linux/io.h>
9#include <linux/leds.h>
10#include <linux/module.h>
11#include <linux/of.h>
12#include <linux/platform_device.h>
13#include <linux/spinlock.h>
14
15#define BCM6328_REG_INIT		0x00
16#define BCM6328_REG_MODE_HI		0x04
17#define BCM6328_REG_MODE_LO		0x08
18#define BCM6328_REG_HWDIS		0x0c
19#define BCM6328_REG_STROBE		0x10
20#define BCM6328_REG_LNKACTSEL_HI	0x14
21#define BCM6328_REG_LNKACTSEL_LO	0x18
22#define BCM6328_REG_RBACK		0x1c
23#define BCM6328_REG_SERMUX		0x20
24
25#define BCM6328_LED_MAX_COUNT		24
26#define BCM6328_LED_DEF_DELAY		500
27
28#define BCM6328_LED_BLINK_DELAYS	2
29#define BCM6328_LED_BLINK_MS		20
30
31#define BCM6328_LED_BLINK_MASK		0x3f
32#define BCM6328_LED_BLINK1_SHIFT	0
33#define BCM6328_LED_BLINK1_MASK		(BCM6328_LED_BLINK_MASK << \
34					 BCM6328_LED_BLINK1_SHIFT)
35#define BCM6328_LED_BLINK2_SHIFT	6
36#define BCM6328_LED_BLINK2_MASK		(BCM6328_LED_BLINK_MASK << \
37					 BCM6328_LED_BLINK2_SHIFT)
38#define BCM6328_SERIAL_LED_EN		BIT(12)
39#define BCM6328_SERIAL_LED_MUX		BIT(13)
40#define BCM6328_SERIAL_LED_CLK_NPOL	BIT(14)
41#define BCM6328_SERIAL_LED_DATA_PPOL	BIT(15)
42#define BCM6328_SERIAL_LED_SHIFT_DIR	BIT(16)
43#define BCM6328_LED_SHIFT_TEST		BIT(30)
44#define BCM6328_LED_TEST		BIT(31)
45#define BCM6328_INIT_MASK		(BCM6328_SERIAL_LED_EN | \
46					 BCM6328_SERIAL_LED_MUX | \
47					 BCM6328_SERIAL_LED_CLK_NPOL | \
48					 BCM6328_SERIAL_LED_DATA_PPOL | \
49					 BCM6328_SERIAL_LED_SHIFT_DIR)
50
51#define BCM6328_LED_MODE_MASK		3
52#define BCM6328_LED_MODE_ON		0
53#define BCM6328_LED_MODE_BLINK1		1
54#define BCM6328_LED_MODE_BLINK2		2
55#define BCM6328_LED_MODE_OFF		3
56#define BCM6328_LED_SHIFT(X)		((X) << 1)
57
58/**
59 * struct bcm6328_led - state container for bcm6328 based LEDs
60 * @cdev: LED class device for this LED
61 * @mem: memory resource
62 * @lock: memory lock
63 * @pin: LED pin number
64 * @blink_leds: blinking LEDs
65 * @blink_delay: blinking delay
66 * @active_low: LED is active low
67 */
68struct bcm6328_led {
69	struct led_classdev cdev;
70	void __iomem *mem;
71	spinlock_t *lock;
72	unsigned long pin;
73	unsigned long *blink_leds;
74	unsigned long *blink_delay;
75	bool active_low;
76};
77
78static void bcm6328_led_write(void __iomem *reg, unsigned long data)
79{
80#ifdef CONFIG_CPU_BIG_ENDIAN
81	iowrite32be(data, reg);
82#else
83	writel(data, reg);
84#endif
85}
86
87static unsigned long bcm6328_led_read(void __iomem *reg)
88{
89#ifdef CONFIG_CPU_BIG_ENDIAN
90	return ioread32be(reg);
91#else
92	return readl(reg);
93#endif
94}
95
96/*
97 * LEDMode 64 bits / 24 LEDs
98 * bits [31:0] -> LEDs 8-23
99 * bits [47:32] -> LEDs 0-7
100 * bits [63:48] -> unused
101 */
102static unsigned long bcm6328_pin2shift(unsigned long pin)
103{
104	if (pin < 8)
105		return pin + 16; /* LEDs 0-7 (bits 47:32) */
106	else
107		return pin - 8; /* LEDs 8-23 (bits 31:0) */
108}
109
110static void bcm6328_led_mode(struct bcm6328_led *led, unsigned long value)
111{
112	void __iomem *mode;
113	unsigned long val, shift;
114
115	shift = bcm6328_pin2shift(led->pin);
116	if (shift / 16)
117		mode = led->mem + BCM6328_REG_MODE_HI;
118	else
119		mode = led->mem + BCM6328_REG_MODE_LO;
120
121	val = bcm6328_led_read(mode);
122	val &= ~(BCM6328_LED_MODE_MASK << BCM6328_LED_SHIFT(shift % 16));
123	val |= (value << BCM6328_LED_SHIFT(shift % 16));
124	bcm6328_led_write(mode, val);
125}
126
127static void bcm6328_led_set(struct led_classdev *led_cdev,
128			    enum led_brightness value)
129{
130	struct bcm6328_led *led =
131		container_of(led_cdev, struct bcm6328_led, cdev);
132	unsigned long flags;
133
134	spin_lock_irqsave(led->lock, flags);
135
136	/* Remove LED from cached HW blinking intervals */
137	led->blink_leds[0] &= ~BIT(led->pin);
138	led->blink_leds[1] &= ~BIT(led->pin);
139
140	/* Set LED on/off */
141	if ((led->active_low && value == LED_OFF) ||
142	    (!led->active_low && value != LED_OFF))
143		bcm6328_led_mode(led, BCM6328_LED_MODE_ON);
144	else
145		bcm6328_led_mode(led, BCM6328_LED_MODE_OFF);
146
147	spin_unlock_irqrestore(led->lock, flags);
148}
149
150static unsigned long bcm6328_blink_delay(unsigned long delay)
151{
152	unsigned long bcm6328_delay;
153
154	bcm6328_delay = delay + BCM6328_LED_BLINK_MS / 2;
155	bcm6328_delay = bcm6328_delay / BCM6328_LED_BLINK_MS;
156	if (bcm6328_delay == 0)
157		bcm6328_delay = 1;
158
159	return bcm6328_delay;
160}
161
162static int bcm6328_blink_set(struct led_classdev *led_cdev,
163			     unsigned long *delay_on, unsigned long *delay_off)
164{
165	struct bcm6328_led *led =
166		container_of(led_cdev, struct bcm6328_led, cdev);
167	unsigned long delay, flags;
168	int rc;
169
170	if (!*delay_on)
171		*delay_on = BCM6328_LED_DEF_DELAY;
172	if (!*delay_off)
173		*delay_off = BCM6328_LED_DEF_DELAY;
174
175	delay = bcm6328_blink_delay(*delay_on);
176	if (delay != bcm6328_blink_delay(*delay_off)) {
177		dev_dbg(led_cdev->dev,
178			"fallback to soft blinking (delay_on != delay_off)\n");
179		return -EINVAL;
180	}
181
182	if (delay > BCM6328_LED_BLINK_MASK) {
183		dev_dbg(led_cdev->dev,
184			"fallback to soft blinking (delay > %ums)\n",
185			BCM6328_LED_BLINK_MASK * BCM6328_LED_BLINK_MS);
186		return -EINVAL;
187	}
188
189	spin_lock_irqsave(led->lock, flags);
190	/*
191	 * Check if any of the two configurable HW blinking intervals is
192	 * available:
193	 *   1. No LEDs assigned to the HW blinking interval.
194	 *   2. Only this LED is assigned to the HW blinking interval.
195	 *   3. LEDs with the same delay assigned.
196	 */
197	if (led->blink_leds[0] == 0 ||
198	    led->blink_leds[0] == BIT(led->pin) ||
199	    led->blink_delay[0] == delay) {
200		unsigned long val;
201
202		/* Add LED to the first HW blinking interval cache */
203		led->blink_leds[0] |= BIT(led->pin);
204
205		/* Remove LED from the second HW blinking interval cache */
206		led->blink_leds[1] &= ~BIT(led->pin);
207
208		/* Cache first HW blinking interval delay */
209		led->blink_delay[0] = delay;
210
211		/* Update the delay for the first HW blinking interval */
212		val = bcm6328_led_read(led->mem + BCM6328_REG_INIT);
213		val &= ~BCM6328_LED_BLINK1_MASK;
214		val |= (delay << BCM6328_LED_BLINK1_SHIFT);
215		bcm6328_led_write(led->mem + BCM6328_REG_INIT, val);
216
217		/* Set the LED to first HW blinking interval */
218		bcm6328_led_mode(led, BCM6328_LED_MODE_BLINK1);
219
220		rc = 0;
221	} else if (led->blink_leds[1] == 0 ||
222		   led->blink_leds[1] == BIT(led->pin) ||
223		   led->blink_delay[1] == delay) {
224		unsigned long val;
225
226		/* Remove LED from the first HW blinking interval */
227		led->blink_leds[0] &= ~BIT(led->pin);
228
229		/* Add LED to the second HW blinking interval */
230		led->blink_leds[1] |= BIT(led->pin);
231
232		/* Cache second HW blinking interval delay */
233		led->blink_delay[1] = delay;
234
235		/* Update the delay for the second HW blinking interval */
236		val = bcm6328_led_read(led->mem + BCM6328_REG_INIT);
237		val &= ~BCM6328_LED_BLINK2_MASK;
238		val |= (delay << BCM6328_LED_BLINK2_SHIFT);
239		bcm6328_led_write(led->mem + BCM6328_REG_INIT, val);
240
241		/* Set the LED to second HW blinking interval */
242		bcm6328_led_mode(led, BCM6328_LED_MODE_BLINK2);
243
244		rc = 0;
245	} else {
246		dev_dbg(led_cdev->dev,
247			"fallback to soft blinking (delay already set)\n");
248		rc = -EINVAL;
249	}
250	spin_unlock_irqrestore(led->lock, flags);
251
252	return rc;
253}
254
255static int bcm6328_hwled(struct device *dev, struct device_node *nc, u32 reg,
256			 void __iomem *mem, spinlock_t *lock)
257{
258	int i, cnt;
259	unsigned long flags, val;
260
261	spin_lock_irqsave(lock, flags);
262	val = bcm6328_led_read(mem + BCM6328_REG_HWDIS);
263	val &= ~BIT(reg);
264	bcm6328_led_write(mem + BCM6328_REG_HWDIS, val);
265	spin_unlock_irqrestore(lock, flags);
266
267	/* Only LEDs 0-7 can be activity/link controlled */
268	if (reg >= 8)
269		return 0;
270
271	cnt = of_property_count_elems_of_size(nc, "brcm,link-signal-sources",
272					      sizeof(u32));
273	for (i = 0; i < cnt; i++) {
274		u32 sel;
275		void __iomem *addr;
276
277		if (reg < 4)
278			addr = mem + BCM6328_REG_LNKACTSEL_LO;
279		else
280			addr = mem + BCM6328_REG_LNKACTSEL_HI;
281
282		of_property_read_u32_index(nc, "brcm,link-signal-sources", i,
283					   &sel);
284
285		if (reg / 4 != sel / 4) {
286			dev_warn(dev, "invalid link signal source\n");
287			continue;
288		}
289
290		spin_lock_irqsave(lock, flags);
291		val = bcm6328_led_read(addr);
292		val |= (BIT(reg % 4) << (((sel % 4) * 4) + 16));
293		bcm6328_led_write(addr, val);
294		spin_unlock_irqrestore(lock, flags);
295	}
296
297	cnt = of_property_count_elems_of_size(nc,
298					      "brcm,activity-signal-sources",
299					      sizeof(u32));
300	for (i = 0; i < cnt; i++) {
301		u32 sel;
302		void __iomem *addr;
303
304		if (reg < 4)
305			addr = mem + BCM6328_REG_LNKACTSEL_LO;
306		else
307			addr = mem + BCM6328_REG_LNKACTSEL_HI;
308
309		of_property_read_u32_index(nc, "brcm,activity-signal-sources",
310					   i, &sel);
311
312		if (reg / 4 != sel / 4) {
313			dev_warn(dev, "invalid activity signal source\n");
314			continue;
315		}
316
317		spin_lock_irqsave(lock, flags);
318		val = bcm6328_led_read(addr);
319		val |= (BIT(reg % 4) << ((sel % 4) * 4));
320		bcm6328_led_write(addr, val);
321		spin_unlock_irqrestore(lock, flags);
322	}
323
324	return 0;
325}
326
327static int bcm6328_led(struct device *dev, struct device_node *nc, u32 reg,
328		       void __iomem *mem, spinlock_t *lock,
329		       unsigned long *blink_leds, unsigned long *blink_delay)
330{
331	struct led_init_data init_data = {};
332	struct bcm6328_led *led;
333	enum led_default_state state;
334	unsigned long val, shift;
335	void __iomem *mode;
336	int rc;
337
338	led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);
339	if (!led)
340		return -ENOMEM;
341
342	led->pin = reg;
343	led->mem = mem;
344	led->lock = lock;
345	led->blink_leds = blink_leds;
346	led->blink_delay = blink_delay;
347
348	if (of_property_read_bool(nc, "active-low"))
349		led->active_low = true;
350
351	init_data.fwnode = of_fwnode_handle(nc);
352
353	state = led_init_default_state_get(init_data.fwnode);
354	switch (state) {
355	case LEDS_DEFSTATE_ON:
356		led->cdev.brightness = LED_FULL;
357		break;
358	case LEDS_DEFSTATE_KEEP:
359		shift = bcm6328_pin2shift(led->pin);
360		if (shift / 16)
361			mode = mem + BCM6328_REG_MODE_HI;
362		else
363			mode = mem + BCM6328_REG_MODE_LO;
364
365		val = bcm6328_led_read(mode) >> BCM6328_LED_SHIFT(shift % 16);
366		val &= BCM6328_LED_MODE_MASK;
367		if ((led->active_low && val == BCM6328_LED_MODE_OFF) ||
368		    (!led->active_low && val == BCM6328_LED_MODE_ON))
369			led->cdev.brightness = LED_FULL;
370		else
371			led->cdev.brightness = LED_OFF;
372		break;
373	default:
374		led->cdev.brightness = LED_OFF;
375	}
376
377	bcm6328_led_set(&led->cdev, led->cdev.brightness);
378
379	led->cdev.brightness_set = bcm6328_led_set;
380	led->cdev.blink_set = bcm6328_blink_set;
381
382	rc = devm_led_classdev_register_ext(dev, &led->cdev, &init_data);
383	if (rc < 0)
384		return rc;
385
386	dev_dbg(dev, "registered LED %s\n", led->cdev.name);
387
388	return 0;
389}
390
391static int bcm6328_leds_probe(struct platform_device *pdev)
392{
393	struct device *dev = &pdev->dev;
394	struct device_node *np = dev_of_node(&pdev->dev);
395	struct device_node *child;
396	void __iomem *mem;
397	spinlock_t *lock; /* memory lock */
398	unsigned long val, *blink_leds, *blink_delay;
399
400	mem = devm_platform_ioremap_resource(pdev, 0);
401	if (IS_ERR(mem))
402		return PTR_ERR(mem);
403
404	lock = devm_kzalloc(dev, sizeof(*lock), GFP_KERNEL);
405	if (!lock)
406		return -ENOMEM;
407
408	blink_leds = devm_kcalloc(dev, BCM6328_LED_BLINK_DELAYS,
409				  sizeof(*blink_leds), GFP_KERNEL);
410	if (!blink_leds)
411		return -ENOMEM;
412
413	blink_delay = devm_kcalloc(dev, BCM6328_LED_BLINK_DELAYS,
414				   sizeof(*blink_delay), GFP_KERNEL);
415	if (!blink_delay)
416		return -ENOMEM;
417
418	spin_lock_init(lock);
419
420	bcm6328_led_write(mem + BCM6328_REG_HWDIS, ~0);
421	bcm6328_led_write(mem + BCM6328_REG_LNKACTSEL_HI, 0);
422	bcm6328_led_write(mem + BCM6328_REG_LNKACTSEL_LO, 0);
423
424	val = bcm6328_led_read(mem + BCM6328_REG_INIT);
425	val &= ~(BCM6328_INIT_MASK);
426	if (of_property_read_bool(np, "brcm,serial-leds"))
427		val |= BCM6328_SERIAL_LED_EN;
428	if (of_property_read_bool(np, "brcm,serial-mux"))
429		val |= BCM6328_SERIAL_LED_MUX;
430	if (of_property_read_bool(np, "brcm,serial-clk-low"))
431		val |= BCM6328_SERIAL_LED_CLK_NPOL;
432	if (!of_property_read_bool(np, "brcm,serial-dat-low"))
433		val |= BCM6328_SERIAL_LED_DATA_PPOL;
434	if (!of_property_read_bool(np, "brcm,serial-shift-inv"))
435		val |= BCM6328_SERIAL_LED_SHIFT_DIR;
436	bcm6328_led_write(mem + BCM6328_REG_INIT, val);
437
438	for_each_available_child_of_node(np, child) {
439		int rc;
440		u32 reg;
441
442		if (of_property_read_u32(child, "reg", &reg))
443			continue;
444
445		if (reg >= BCM6328_LED_MAX_COUNT) {
446			dev_err(dev, "invalid LED (%u >= %d)\n", reg,
447				BCM6328_LED_MAX_COUNT);
448			continue;
449		}
450
451		if (of_property_read_bool(child, "brcm,hardware-controlled"))
452			rc = bcm6328_hwled(dev, child, reg, mem, lock);
453		else
454			rc = bcm6328_led(dev, child, reg, mem, lock,
455					 blink_leds, blink_delay);
456
457		if (rc < 0) {
458			of_node_put(child);
459			return rc;
460		}
461	}
462
463	return 0;
464}
465
466static const struct of_device_id bcm6328_leds_of_match[] = {
467	{ .compatible = "brcm,bcm6328-leds", },
468	{ },
469};
470MODULE_DEVICE_TABLE(of, bcm6328_leds_of_match);
471
472static struct platform_driver bcm6328_leds_driver = {
473	.probe = bcm6328_leds_probe,
474	.driver = {
475		.name = "leds-bcm6328",
476		.of_match_table = bcm6328_leds_of_match,
477	},
478};
479
480module_platform_driver(bcm6328_leds_driver);
481
482MODULE_AUTHOR("��lvaro Fern��ndez Rojas <noltari@gmail.com>");
483MODULE_AUTHOR("Jonas Gorski <jogo@openwrt.org>");
484MODULE_DESCRIPTION("LED driver for BCM6328 controllers");
485MODULE_LICENSE("GPL v2");
486MODULE_ALIAS("platform:leds-bcm6328");
487