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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 Álvaro Fernández 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 const char *state;
334 int rc;
335
336 led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);
337 if (!led)
338 return -ENOMEM;
339
340 led->pin = reg;
341 led->mem = mem;
342 led->lock = lock;
343 led->blink_leds = blink_leds;
344 led->blink_delay = blink_delay;
345
346 if (of_property_read_bool(nc, "active-low"))
347 led->active_low = true;
348
349 if (!of_property_read_string(nc, "default-state", &state)) {
350 if (!strcmp(state, "on")) {
351 led->cdev.brightness = LED_FULL;
352 } else if (!strcmp(state, "keep")) {
353 void __iomem *mode;
354 unsigned long val, shift;
355
356 shift = bcm6328_pin2shift(led->pin);
357 if (shift / 16)
358 mode = mem + BCM6328_REG_MODE_HI;
359 else
360 mode = mem + BCM6328_REG_MODE_LO;
361
362 val = bcm6328_led_read(mode) >>
363 BCM6328_LED_SHIFT(shift % 16);
364 val &= BCM6328_LED_MODE_MASK;
365 if ((led->active_low && val == BCM6328_LED_MODE_OFF) ||
366 (!led->active_low && val == BCM6328_LED_MODE_ON))
367 led->cdev.brightness = LED_FULL;
368 else
369 led->cdev.brightness = LED_OFF;
370 } else {
371 led->cdev.brightness = LED_OFF;
372 }
373 } else {
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 init_data.fwnode = of_fwnode_handle(nc);
382
383 rc = devm_led_classdev_register_ext(dev, &led->cdev, &init_data);
384 if (rc < 0)
385 return rc;
386
387 dev_dbg(dev, "registered LED %s\n", led->cdev.name);
388
389 return 0;
390}
391
392static int bcm6328_leds_probe(struct platform_device *pdev)
393{
394 struct device *dev = &pdev->dev;
395 struct device_node *np = dev_of_node(&pdev->dev);
396 struct device_node *child;
397 void __iomem *mem;
398 spinlock_t *lock; /* memory lock */
399 unsigned long val, *blink_leds, *blink_delay;
400
401 mem = devm_platform_ioremap_resource(pdev, 0);
402 if (IS_ERR(mem))
403 return PTR_ERR(mem);
404
405 lock = devm_kzalloc(dev, sizeof(*lock), GFP_KERNEL);
406 if (!lock)
407 return -ENOMEM;
408
409 blink_leds = devm_kcalloc(dev, BCM6328_LED_BLINK_DELAYS,
410 sizeof(*blink_leds), GFP_KERNEL);
411 if (!blink_leds)
412 return -ENOMEM;
413
414 blink_delay = devm_kcalloc(dev, BCM6328_LED_BLINK_DELAYS,
415 sizeof(*blink_delay), GFP_KERNEL);
416 if (!blink_delay)
417 return -ENOMEM;
418
419 spin_lock_init(lock);
420
421 bcm6328_led_write(mem + BCM6328_REG_HWDIS, ~0);
422 bcm6328_led_write(mem + BCM6328_REG_LNKACTSEL_HI, 0);
423 bcm6328_led_write(mem + BCM6328_REG_LNKACTSEL_LO, 0);
424
425 val = bcm6328_led_read(mem + BCM6328_REG_INIT);
426 val &= ~(BCM6328_INIT_MASK);
427 if (of_property_read_bool(np, "brcm,serial-leds"))
428 val |= BCM6328_SERIAL_LED_EN;
429 if (of_property_read_bool(np, "brcm,serial-mux"))
430 val |= BCM6328_SERIAL_LED_MUX;
431 if (of_property_read_bool(np, "brcm,serial-clk-low"))
432 val |= BCM6328_SERIAL_LED_CLK_NPOL;
433 if (!of_property_read_bool(np, "brcm,serial-dat-low"))
434 val |= BCM6328_SERIAL_LED_DATA_PPOL;
435 if (!of_property_read_bool(np, "brcm,serial-shift-inv"))
436 val |= BCM6328_SERIAL_LED_SHIFT_DIR;
437 bcm6328_led_write(mem + BCM6328_REG_INIT, val);
438
439 for_each_available_child_of_node(np, child) {
440 int rc;
441 u32 reg;
442
443 if (of_property_read_u32(child, "reg", ®))
444 continue;
445
446 if (reg >= BCM6328_LED_MAX_COUNT) {
447 dev_err(dev, "invalid LED (%u >= %d)\n", reg,
448 BCM6328_LED_MAX_COUNT);
449 continue;
450 }
451
452 if (of_property_read_bool(child, "brcm,hardware-controlled"))
453 rc = bcm6328_hwled(dev, child, reg, mem, lock);
454 else
455 rc = bcm6328_led(dev, child, reg, mem, lock,
456 blink_leds, blink_delay);
457
458 if (rc < 0) {
459 of_node_put(child);
460 return rc;
461 }
462 }
463
464 return 0;
465}
466
467static const struct of_device_id bcm6328_leds_of_match[] = {
468 { .compatible = "brcm,bcm6328-leds", },
469 { },
470};
471MODULE_DEVICE_TABLE(of, bcm6328_leds_of_match);
472
473static struct platform_driver bcm6328_leds_driver = {
474 .probe = bcm6328_leds_probe,
475 .driver = {
476 .name = "leds-bcm6328",
477 .of_match_table = bcm6328_leds_of_match,
478 },
479};
480
481module_platform_driver(bcm6328_leds_driver);
482
483MODULE_AUTHOR("Álvaro Fernández Rojas <noltari@gmail.com>");
484MODULE_AUTHOR("Jonas Gorski <jogo@openwrt.org>");
485MODULE_DESCRIPTION("LED driver for BCM6328 controllers");
486MODULE_LICENSE("GPL v2");
487MODULE_ALIAS("platform:leds-bcm6328");