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1/*
2 * Driver for BCM6328 memory-mapped LEDs, based on leds-syscon.c
3 *
4 * Copyright 2015 Álvaro Fernández Rojas <noltari@gmail.com>
5 * Copyright 2015 Jonas Gorski <jogo@openwrt.org>
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the
9 * Free Software Foundation; either version 2 of the License, or (at your
10 * option) any later version.
11 */
12#include <linux/io.h>
13#include <linux/leds.h>
14#include <linux/module.h>
15#include <linux/of.h>
16#include <linux/platform_device.h>
17#include <linux/spinlock.h>
18
19#define BCM6328_REG_INIT 0x00
20#define BCM6328_REG_MODE_HI 0x04
21#define BCM6328_REG_MODE_LO 0x08
22#define BCM6328_REG_HWDIS 0x0c
23#define BCM6328_REG_STROBE 0x10
24#define BCM6328_REG_LNKACTSEL_HI 0x14
25#define BCM6328_REG_LNKACTSEL_LO 0x18
26#define BCM6328_REG_RBACK 0x1c
27#define BCM6328_REG_SERMUX 0x20
28
29#define BCM6328_LED_MAX_COUNT 24
30#define BCM6328_LED_DEF_DELAY 500
31#define BCM6328_LED_INTERVAL_MS 20
32
33#define BCM6328_LED_INTV_MASK 0x3f
34#define BCM6328_LED_FAST_INTV_SHIFT 6
35#define BCM6328_LED_FAST_INTV_MASK (BCM6328_LED_INTV_MASK << \
36 BCM6328_LED_FAST_INTV_SHIFT)
37#define BCM6328_SERIAL_LED_EN BIT(12)
38#define BCM6328_SERIAL_LED_MUX BIT(13)
39#define BCM6328_SERIAL_LED_CLK_NPOL BIT(14)
40#define BCM6328_SERIAL_LED_DATA_PPOL BIT(15)
41#define BCM6328_SERIAL_LED_SHIFT_DIR BIT(16)
42#define BCM6328_LED_SHIFT_TEST BIT(30)
43#define BCM6328_LED_TEST BIT(31)
44#define BCM6328_INIT_MASK (BCM6328_SERIAL_LED_EN | \
45 BCM6328_SERIAL_LED_MUX | \
46 BCM6328_SERIAL_LED_CLK_NPOL | \
47 BCM6328_SERIAL_LED_DATA_PPOL | \
48 BCM6328_SERIAL_LED_SHIFT_DIR)
49
50#define BCM6328_LED_MODE_MASK 3
51#define BCM6328_LED_MODE_ON 0
52#define BCM6328_LED_MODE_FAST 1
53#define BCM6328_LED_MODE_BLINK 2
54#define BCM6328_LED_MODE_OFF 3
55#define BCM6328_LED_SHIFT(X) ((X) << 1)
56
57/**
58 * struct bcm6328_led - state container for bcm6328 based LEDs
59 * @cdev: LED class device for this LED
60 * @mem: memory resource
61 * @lock: memory lock
62 * @pin: LED pin number
63 * @blink_leds: blinking LEDs
64 * @blink_delay: blinking delay
65 * @active_low: LED is active low
66 */
67struct bcm6328_led {
68 struct led_classdev cdev;
69 void __iomem *mem;
70 spinlock_t *lock;
71 unsigned long pin;
72 unsigned long *blink_leds;
73 unsigned long *blink_delay;
74 bool active_low;
75};
76
77static void bcm6328_led_write(void __iomem *reg, unsigned long data)
78{
79#ifdef CONFIG_CPU_BIG_ENDIAN
80 iowrite32be(data, reg);
81#else
82 writel(data, reg);
83#endif
84}
85
86static unsigned long bcm6328_led_read(void __iomem *reg)
87{
88#ifdef CONFIG_CPU_BIG_ENDIAN
89 return ioread32be(reg);
90#else
91 return readl(reg);
92#endif
93}
94
95/**
96 * LEDMode 64 bits / 24 LEDs
97 * bits [31:0] -> LEDs 8-23
98 * bits [47:32] -> LEDs 0-7
99 * bits [63:48] -> unused
100 */
101static unsigned long bcm6328_pin2shift(unsigned long pin)
102{
103 if (pin < 8)
104 return pin + 16; /* LEDs 0-7 (bits 47:32) */
105 else
106 return pin - 8; /* LEDs 8-23 (bits 31:0) */
107}
108
109static void bcm6328_led_mode(struct bcm6328_led *led, unsigned long value)
110{
111 void __iomem *mode;
112 unsigned long val, shift;
113
114 shift = bcm6328_pin2shift(led->pin);
115 if (shift / 16)
116 mode = led->mem + BCM6328_REG_MODE_HI;
117 else
118 mode = led->mem + BCM6328_REG_MODE_LO;
119
120 val = bcm6328_led_read(mode);
121 val &= ~(BCM6328_LED_MODE_MASK << BCM6328_LED_SHIFT(shift % 16));
122 val |= (value << BCM6328_LED_SHIFT(shift % 16));
123 bcm6328_led_write(mode, val);
124}
125
126static void bcm6328_led_set(struct led_classdev *led_cdev,
127 enum led_brightness value)
128{
129 struct bcm6328_led *led =
130 container_of(led_cdev, struct bcm6328_led, cdev);
131 unsigned long flags;
132
133 spin_lock_irqsave(led->lock, flags);
134 *(led->blink_leds) &= ~BIT(led->pin);
135 if ((led->active_low && value == LED_OFF) ||
136 (!led->active_low && value != LED_OFF))
137 bcm6328_led_mode(led, BCM6328_LED_MODE_ON);
138 else
139 bcm6328_led_mode(led, BCM6328_LED_MODE_OFF);
140 spin_unlock_irqrestore(led->lock, flags);
141}
142
143static unsigned long bcm6328_blink_delay(unsigned long delay)
144{
145 unsigned long bcm6328_delay;
146
147 bcm6328_delay = delay + BCM6328_LED_INTERVAL_MS / 2;
148 bcm6328_delay = bcm6328_delay / BCM6328_LED_INTERVAL_MS;
149 if (bcm6328_delay == 0)
150 bcm6328_delay = 1;
151
152 return bcm6328_delay;
153}
154
155static int bcm6328_blink_set(struct led_classdev *led_cdev,
156 unsigned long *delay_on, unsigned long *delay_off)
157{
158 struct bcm6328_led *led =
159 container_of(led_cdev, struct bcm6328_led, cdev);
160 unsigned long delay, flags;
161 int rc;
162
163 if (!*delay_on)
164 *delay_on = BCM6328_LED_DEF_DELAY;
165 if (!*delay_off)
166 *delay_off = BCM6328_LED_DEF_DELAY;
167
168 delay = bcm6328_blink_delay(*delay_on);
169 if (delay != bcm6328_blink_delay(*delay_off)) {
170 dev_dbg(led_cdev->dev,
171 "fallback to soft blinking (delay_on != delay_off)\n");
172 return -EINVAL;
173 }
174
175 if (delay > BCM6328_LED_INTV_MASK) {
176 dev_dbg(led_cdev->dev,
177 "fallback to soft blinking (delay > %ums)\n",
178 BCM6328_LED_INTV_MASK * BCM6328_LED_INTERVAL_MS);
179 return -EINVAL;
180 }
181
182 spin_lock_irqsave(led->lock, flags);
183 if (*(led->blink_leds) == 0 ||
184 *(led->blink_leds) == BIT(led->pin) ||
185 *(led->blink_delay) == delay) {
186 unsigned long val;
187
188 *(led->blink_leds) |= BIT(led->pin);
189 *(led->blink_delay) = delay;
190
191 val = bcm6328_led_read(led->mem + BCM6328_REG_INIT);
192 val &= ~BCM6328_LED_FAST_INTV_MASK;
193 val |= (delay << BCM6328_LED_FAST_INTV_SHIFT);
194 bcm6328_led_write(led->mem + BCM6328_REG_INIT, val);
195
196 bcm6328_led_mode(led, BCM6328_LED_MODE_BLINK);
197 rc = 0;
198 } else {
199 dev_dbg(led_cdev->dev,
200 "fallback to soft blinking (delay already set)\n");
201 rc = -EINVAL;
202 }
203 spin_unlock_irqrestore(led->lock, flags);
204
205 return rc;
206}
207
208static int bcm6328_hwled(struct device *dev, struct device_node *nc, u32 reg,
209 void __iomem *mem, spinlock_t *lock)
210{
211 int i, cnt;
212 unsigned long flags, val;
213
214 spin_lock_irqsave(lock, flags);
215 val = bcm6328_led_read(mem + BCM6328_REG_HWDIS);
216 val &= ~BIT(reg);
217 bcm6328_led_write(mem + BCM6328_REG_HWDIS, val);
218 spin_unlock_irqrestore(lock, flags);
219
220 /* Only LEDs 0-7 can be activity/link controlled */
221 if (reg >= 8)
222 return 0;
223
224 cnt = of_property_count_elems_of_size(nc, "brcm,link-signal-sources",
225 sizeof(u32));
226 for (i = 0; i < cnt; i++) {
227 u32 sel;
228 void __iomem *addr;
229
230 if (reg < 4)
231 addr = mem + BCM6328_REG_LNKACTSEL_LO;
232 else
233 addr = mem + BCM6328_REG_LNKACTSEL_HI;
234
235 of_property_read_u32_index(nc, "brcm,link-signal-sources", i,
236 &sel);
237
238 if (reg / 4 != sel / 4) {
239 dev_warn(dev, "invalid link signal source\n");
240 continue;
241 }
242
243 spin_lock_irqsave(lock, flags);
244 val = bcm6328_led_read(addr);
245 val |= (BIT(reg) << (((sel % 4) * 4) + 16));
246 bcm6328_led_write(addr, val);
247 spin_unlock_irqrestore(lock, flags);
248 }
249
250 cnt = of_property_count_elems_of_size(nc,
251 "brcm,activity-signal-sources",
252 sizeof(u32));
253 for (i = 0; i < cnt; i++) {
254 u32 sel;
255 void __iomem *addr;
256
257 if (reg < 4)
258 addr = mem + BCM6328_REG_LNKACTSEL_LO;
259 else
260 addr = mem + BCM6328_REG_LNKACTSEL_HI;
261
262 of_property_read_u32_index(nc, "brcm,activity-signal-sources",
263 i, &sel);
264
265 if (reg / 4 != sel / 4) {
266 dev_warn(dev, "invalid activity signal source\n");
267 continue;
268 }
269
270 spin_lock_irqsave(lock, flags);
271 val = bcm6328_led_read(addr);
272 val |= (BIT(reg) << ((sel % 4) * 4));
273 bcm6328_led_write(addr, val);
274 spin_unlock_irqrestore(lock, flags);
275 }
276
277 return 0;
278}
279
280static int bcm6328_led(struct device *dev, struct device_node *nc, u32 reg,
281 void __iomem *mem, spinlock_t *lock,
282 unsigned long *blink_leds, unsigned long *blink_delay)
283{
284 struct bcm6328_led *led;
285 const char *state;
286 int rc;
287
288 led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);
289 if (!led)
290 return -ENOMEM;
291
292 led->pin = reg;
293 led->mem = mem;
294 led->lock = lock;
295 led->blink_leds = blink_leds;
296 led->blink_delay = blink_delay;
297
298 if (of_property_read_bool(nc, "active-low"))
299 led->active_low = true;
300
301 led->cdev.name = of_get_property(nc, "label", NULL) ? : nc->name;
302 led->cdev.default_trigger = of_get_property(nc,
303 "linux,default-trigger",
304 NULL);
305
306 if (!of_property_read_string(nc, "default-state", &state)) {
307 if (!strcmp(state, "on")) {
308 led->cdev.brightness = LED_FULL;
309 } else if (!strcmp(state, "keep")) {
310 void __iomem *mode;
311 unsigned long val, shift;
312
313 shift = bcm6328_pin2shift(led->pin);
314 if (shift / 16)
315 mode = mem + BCM6328_REG_MODE_HI;
316 else
317 mode = mem + BCM6328_REG_MODE_LO;
318
319 val = bcm6328_led_read(mode) >>
320 BCM6328_LED_SHIFT(shift % 16);
321 val &= BCM6328_LED_MODE_MASK;
322 if ((led->active_low && val == BCM6328_LED_MODE_OFF) ||
323 (!led->active_low && val == BCM6328_LED_MODE_ON))
324 led->cdev.brightness = LED_FULL;
325 else
326 led->cdev.brightness = LED_OFF;
327 } else {
328 led->cdev.brightness = LED_OFF;
329 }
330 } else {
331 led->cdev.brightness = LED_OFF;
332 }
333
334 bcm6328_led_set(&led->cdev, led->cdev.brightness);
335
336 led->cdev.brightness_set = bcm6328_led_set;
337 led->cdev.blink_set = bcm6328_blink_set;
338
339 rc = led_classdev_register(dev, &led->cdev);
340 if (rc < 0)
341 return rc;
342
343 dev_dbg(dev, "registered LED %s\n", led->cdev.name);
344
345 return 0;
346}
347
348static int bcm6328_leds_probe(struct platform_device *pdev)
349{
350 struct device *dev = &pdev->dev;
351 struct device_node *np = pdev->dev.of_node;
352 struct device_node *child;
353 struct resource *mem_r;
354 void __iomem *mem;
355 spinlock_t *lock; /* memory lock */
356 unsigned long val, *blink_leds, *blink_delay;
357
358 mem_r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
359 if (!mem_r)
360 return -EINVAL;
361
362 mem = devm_ioremap_resource(dev, mem_r);
363 if (IS_ERR(mem))
364 return PTR_ERR(mem);
365
366 lock = devm_kzalloc(dev, sizeof(*lock), GFP_KERNEL);
367 if (!lock)
368 return -ENOMEM;
369
370 blink_leds = devm_kzalloc(dev, sizeof(*blink_leds), GFP_KERNEL);
371 if (!blink_leds)
372 return -ENOMEM;
373
374 blink_delay = devm_kzalloc(dev, sizeof(*blink_delay), GFP_KERNEL);
375 if (!blink_delay)
376 return -ENOMEM;
377
378 spin_lock_init(lock);
379
380 bcm6328_led_write(mem + BCM6328_REG_HWDIS, ~0);
381 bcm6328_led_write(mem + BCM6328_REG_LNKACTSEL_HI, 0);
382 bcm6328_led_write(mem + BCM6328_REG_LNKACTSEL_LO, 0);
383
384 val = bcm6328_led_read(mem + BCM6328_REG_INIT);
385 val &= ~(BCM6328_INIT_MASK);
386 if (of_property_read_bool(np, "brcm,serial-leds"))
387 val |= BCM6328_SERIAL_LED_EN;
388 if (of_property_read_bool(np, "brcm,serial-mux"))
389 val |= BCM6328_SERIAL_LED_MUX;
390 if (of_property_read_bool(np, "brcm,serial-clk-low"))
391 val |= BCM6328_SERIAL_LED_CLK_NPOL;
392 if (!of_property_read_bool(np, "brcm,serial-dat-low"))
393 val |= BCM6328_SERIAL_LED_DATA_PPOL;
394 if (!of_property_read_bool(np, "brcm,serial-shift-inv"))
395 val |= BCM6328_SERIAL_LED_SHIFT_DIR;
396 bcm6328_led_write(mem + BCM6328_REG_INIT, val);
397
398 for_each_available_child_of_node(np, child) {
399 int rc;
400 u32 reg;
401
402 if (of_property_read_u32(child, "reg", ®))
403 continue;
404
405 if (reg >= BCM6328_LED_MAX_COUNT) {
406 dev_err(dev, "invalid LED (%u >= %d)\n", reg,
407 BCM6328_LED_MAX_COUNT);
408 continue;
409 }
410
411 if (of_property_read_bool(child, "brcm,hardware-controlled"))
412 rc = bcm6328_hwled(dev, child, reg, mem, lock);
413 else
414 rc = bcm6328_led(dev, child, reg, mem, lock,
415 blink_leds, blink_delay);
416
417 if (rc < 0) {
418 of_node_put(child);
419 return rc;
420 }
421 }
422
423 return 0;
424}
425
426static const struct of_device_id bcm6328_leds_of_match[] = {
427 { .compatible = "brcm,bcm6328-leds", },
428 { },
429};
430MODULE_DEVICE_TABLE(of, bcm6328_leds_of_match);
431
432static struct platform_driver bcm6328_leds_driver = {
433 .probe = bcm6328_leds_probe,
434 .driver = {
435 .name = "leds-bcm6328",
436 .of_match_table = bcm6328_leds_of_match,
437 },
438};
439
440module_platform_driver(bcm6328_leds_driver);
441
442MODULE_AUTHOR("Álvaro Fernández Rojas <noltari@gmail.com>");
443MODULE_AUTHOR("Jonas Gorski <jogo@openwrt.org>");
444MODULE_DESCRIPTION("LED driver for BCM6328 controllers");
445MODULE_LICENSE("GPL v2");
446MODULE_ALIAS("platform:leds-bcm6328");