1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Driver for BCM6328 memory-mapped LEDs, based on leds-syscon.c
5 * Copyright 2015 Álvaro Fernández Rojas <noltari@gmail.com>
6 * Copyright 2015 Jonas Gorski <jogo@openwrt.org>
9 #include <linux/leds.h>
10 #include <linux/module.h>
12 #include <linux/platform_device.h>
13 #include <linux/spinlock.h>
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
25 #define BCM6328_LED_MAX_COUNT 24
26 #define BCM6328_LED_DEF_DELAY 500
27 #define BCM6328_LED_INTERVAL_MS 20
29 #define BCM6328_LED_INTV_MASK 0x3f
30 #define BCM6328_LED_FAST_INTV_SHIFT 6
31 #define BCM6328_LED_FAST_INTV_MASK (BCM6328_LED_INTV_MASK << \
32 BCM6328_LED_FAST_INTV_SHIFT)
33 #define BCM6328_SERIAL_LED_EN BIT(12)
34 #define BCM6328_SERIAL_LED_MUX BIT(13)
35 #define BCM6328_SERIAL_LED_CLK_NPOL BIT(14)
36 #define BCM6328_SERIAL_LED_DATA_PPOL BIT(15)
37 #define BCM6328_SERIAL_LED_SHIFT_DIR BIT(16)
38 #define BCM6328_LED_SHIFT_TEST BIT(30)
39 #define BCM6328_LED_TEST BIT(31)
40 #define BCM6328_INIT_MASK (BCM6328_SERIAL_LED_EN | \
41 BCM6328_SERIAL_LED_MUX | \
42 BCM6328_SERIAL_LED_CLK_NPOL | \
43 BCM6328_SERIAL_LED_DATA_PPOL | \
44 BCM6328_SERIAL_LED_SHIFT_DIR)
46 #define BCM6328_LED_MODE_MASK 3
47 #define BCM6328_LED_MODE_ON 0
48 #define BCM6328_LED_MODE_FAST 1
49 #define BCM6328_LED_MODE_BLINK 2
50 #define BCM6328_LED_MODE_OFF 3
51 #define BCM6328_LED_SHIFT(X) ((X) << 1)
54 * struct bcm6328_led - state container for bcm6328 based LEDs
55 * @cdev: LED class device for this LED
56 * @mem: memory resource
58 * @pin: LED pin number
59 * @blink_leds: blinking LEDs
60 * @blink_delay: blinking delay
61 * @active_low: LED is active low
64 struct led_classdev cdev;
68 unsigned long *blink_leds;
69 unsigned long *blink_delay;
73 static void bcm6328_led_write(void __iomem *reg, unsigned long data)
75 #ifdef CONFIG_CPU_BIG_ENDIAN
76 iowrite32be(data, reg);
82 static unsigned long bcm6328_led_read(void __iomem *reg)
84 #ifdef CONFIG_CPU_BIG_ENDIAN
85 return ioread32be(reg);
92 * LEDMode 64 bits / 24 LEDs
93 * bits [31:0] -> LEDs 8-23
94 * bits [47:32] -> LEDs 0-7
95 * bits [63:48] -> unused
97 static unsigned long bcm6328_pin2shift(unsigned long pin)
100 return pin + 16; /* LEDs 0-7 (bits 47:32) */
102 return pin - 8; /* LEDs 8-23 (bits 31:0) */
105 static void bcm6328_led_mode(struct bcm6328_led *led, unsigned long value)
108 unsigned long val, shift;
110 shift = bcm6328_pin2shift(led->pin);
112 mode = led->mem + BCM6328_REG_MODE_HI;
114 mode = led->mem + BCM6328_REG_MODE_LO;
116 val = bcm6328_led_read(mode);
117 val &= ~(BCM6328_LED_MODE_MASK << BCM6328_LED_SHIFT(shift % 16));
118 val |= (value << BCM6328_LED_SHIFT(shift % 16));
119 bcm6328_led_write(mode, val);
122 static void bcm6328_led_set(struct led_classdev *led_cdev,
123 enum led_brightness value)
125 struct bcm6328_led *led =
126 container_of(led_cdev, struct bcm6328_led, cdev);
129 spin_lock_irqsave(led->lock, flags);
130 *(led->blink_leds) &= ~BIT(led->pin);
131 if ((led->active_low && value == LED_OFF) ||
132 (!led->active_low && value != LED_OFF))
133 bcm6328_led_mode(led, BCM6328_LED_MODE_ON);
135 bcm6328_led_mode(led, BCM6328_LED_MODE_OFF);
136 spin_unlock_irqrestore(led->lock, flags);
139 static unsigned long bcm6328_blink_delay(unsigned long delay)
141 unsigned long bcm6328_delay;
143 bcm6328_delay = delay + BCM6328_LED_INTERVAL_MS / 2;
144 bcm6328_delay = bcm6328_delay / BCM6328_LED_INTERVAL_MS;
145 if (bcm6328_delay == 0)
148 return bcm6328_delay;
151 static int bcm6328_blink_set(struct led_classdev *led_cdev,
152 unsigned long *delay_on, unsigned long *delay_off)
154 struct bcm6328_led *led =
155 container_of(led_cdev, struct bcm6328_led, cdev);
156 unsigned long delay, flags;
160 *delay_on = BCM6328_LED_DEF_DELAY;
162 *delay_off = BCM6328_LED_DEF_DELAY;
164 delay = bcm6328_blink_delay(*delay_on);
165 if (delay != bcm6328_blink_delay(*delay_off)) {
166 dev_dbg(led_cdev->dev,
167 "fallback to soft blinking (delay_on != delay_off)\n");
171 if (delay > BCM6328_LED_INTV_MASK) {
172 dev_dbg(led_cdev->dev,
173 "fallback to soft blinking (delay > %ums)\n",
174 BCM6328_LED_INTV_MASK * BCM6328_LED_INTERVAL_MS);
178 spin_lock_irqsave(led->lock, flags);
179 if (*(led->blink_leds) == 0 ||
180 *(led->blink_leds) == BIT(led->pin) ||
181 *(led->blink_delay) == delay) {
184 *(led->blink_leds) |= BIT(led->pin);
185 *(led->blink_delay) = delay;
187 val = bcm6328_led_read(led->mem + BCM6328_REG_INIT);
188 val &= ~BCM6328_LED_FAST_INTV_MASK;
189 val |= (delay << BCM6328_LED_FAST_INTV_SHIFT);
190 bcm6328_led_write(led->mem + BCM6328_REG_INIT, val);
192 bcm6328_led_mode(led, BCM6328_LED_MODE_BLINK);
195 dev_dbg(led_cdev->dev,
196 "fallback to soft blinking (delay already set)\n");
199 spin_unlock_irqrestore(led->lock, flags);
204 static int bcm6328_hwled(struct device *dev, struct device_node *nc, u32 reg,
205 void __iomem *mem, spinlock_t *lock)
208 unsigned long flags, val;
210 spin_lock_irqsave(lock, flags);
211 val = bcm6328_led_read(mem + BCM6328_REG_HWDIS);
213 bcm6328_led_write(mem + BCM6328_REG_HWDIS, val);
214 spin_unlock_irqrestore(lock, flags);
216 /* Only LEDs 0-7 can be activity/link controlled */
220 cnt = of_property_count_elems_of_size(nc, "brcm,link-signal-sources",
222 for (i = 0; i < cnt; i++) {
227 addr = mem + BCM6328_REG_LNKACTSEL_LO;
229 addr = mem + BCM6328_REG_LNKACTSEL_HI;
231 of_property_read_u32_index(nc, "brcm,link-signal-sources", i,
234 if (reg / 4 != sel / 4) {
235 dev_warn(dev, "invalid link signal source\n");
239 spin_lock_irqsave(lock, flags);
240 val = bcm6328_led_read(addr);
241 val |= (BIT(reg % 4) << (((sel % 4) * 4) + 16));
242 bcm6328_led_write(addr, val);
243 spin_unlock_irqrestore(lock, flags);
246 cnt = of_property_count_elems_of_size(nc,
247 "brcm,activity-signal-sources",
249 for (i = 0; i < cnt; i++) {
254 addr = mem + BCM6328_REG_LNKACTSEL_LO;
256 addr = mem + BCM6328_REG_LNKACTSEL_HI;
258 of_property_read_u32_index(nc, "brcm,activity-signal-sources",
261 if (reg / 4 != sel / 4) {
262 dev_warn(dev, "invalid activity signal source\n");
266 spin_lock_irqsave(lock, flags);
267 val = bcm6328_led_read(addr);
268 val |= (BIT(reg % 4) << ((sel % 4) * 4));
269 bcm6328_led_write(addr, val);
270 spin_unlock_irqrestore(lock, flags);
276 static int bcm6328_led(struct device *dev, struct device_node *nc, u32 reg,
277 void __iomem *mem, spinlock_t *lock,
278 unsigned long *blink_leds, unsigned long *blink_delay)
280 struct bcm6328_led *led;
284 led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);
291 led->blink_leds = blink_leds;
292 led->blink_delay = blink_delay;
294 if (of_property_read_bool(nc, "active-low"))
295 led->active_low = true;
297 led->cdev.name = of_get_property(nc, "label", NULL) ? : nc->name;
298 led->cdev.default_trigger = of_get_property(nc,
299 "linux,default-trigger",
302 if (!of_property_read_string(nc, "default-state", &state)) {
303 if (!strcmp(state, "on")) {
304 led->cdev.brightness = LED_FULL;
305 } else if (!strcmp(state, "keep")) {
307 unsigned long val, shift;
309 shift = bcm6328_pin2shift(led->pin);
311 mode = mem + BCM6328_REG_MODE_HI;
313 mode = mem + BCM6328_REG_MODE_LO;
315 val = bcm6328_led_read(mode) >>
316 BCM6328_LED_SHIFT(shift % 16);
317 val &= BCM6328_LED_MODE_MASK;
318 if ((led->active_low && val == BCM6328_LED_MODE_OFF) ||
319 (!led->active_low && val == BCM6328_LED_MODE_ON))
320 led->cdev.brightness = LED_FULL;
322 led->cdev.brightness = LED_OFF;
324 led->cdev.brightness = LED_OFF;
327 led->cdev.brightness = LED_OFF;
330 bcm6328_led_set(&led->cdev, led->cdev.brightness);
332 led->cdev.brightness_set = bcm6328_led_set;
333 led->cdev.blink_set = bcm6328_blink_set;
335 rc = led_classdev_register(dev, &led->cdev);
339 dev_dbg(dev, "registered LED %s\n", led->cdev.name);
344 static int bcm6328_leds_probe(struct platform_device *pdev)
346 struct device *dev = &pdev->dev;
347 struct device_node *np = pdev->dev.of_node;
348 struct device_node *child;
350 spinlock_t *lock; /* memory lock */
351 unsigned long val, *blink_leds, *blink_delay;
353 mem = devm_platform_ioremap_resource(pdev, 0);
357 lock = devm_kzalloc(dev, sizeof(*lock), GFP_KERNEL);
361 blink_leds = devm_kzalloc(dev, sizeof(*blink_leds), GFP_KERNEL);
365 blink_delay = devm_kzalloc(dev, sizeof(*blink_delay), GFP_KERNEL);
369 spin_lock_init(lock);
371 bcm6328_led_write(mem + BCM6328_REG_HWDIS, ~0);
372 bcm6328_led_write(mem + BCM6328_REG_LNKACTSEL_HI, 0);
373 bcm6328_led_write(mem + BCM6328_REG_LNKACTSEL_LO, 0);
375 val = bcm6328_led_read(mem + BCM6328_REG_INIT);
376 val &= ~(BCM6328_INIT_MASK);
377 if (of_property_read_bool(np, "brcm,serial-leds"))
378 val |= BCM6328_SERIAL_LED_EN;
379 if (of_property_read_bool(np, "brcm,serial-mux"))
380 val |= BCM6328_SERIAL_LED_MUX;
381 if (of_property_read_bool(np, "brcm,serial-clk-low"))
382 val |= BCM6328_SERIAL_LED_CLK_NPOL;
383 if (!of_property_read_bool(np, "brcm,serial-dat-low"))
384 val |= BCM6328_SERIAL_LED_DATA_PPOL;
385 if (!of_property_read_bool(np, "brcm,serial-shift-inv"))
386 val |= BCM6328_SERIAL_LED_SHIFT_DIR;
387 bcm6328_led_write(mem + BCM6328_REG_INIT, val);
389 for_each_available_child_of_node(np, child) {
393 if (of_property_read_u32(child, "reg", ®))
396 if (reg >= BCM6328_LED_MAX_COUNT) {
397 dev_err(dev, "invalid LED (%u >= %d)\n", reg,
398 BCM6328_LED_MAX_COUNT);
402 if (of_property_read_bool(child, "brcm,hardware-controlled"))
403 rc = bcm6328_hwled(dev, child, reg, mem, lock);
405 rc = bcm6328_led(dev, child, reg, mem, lock,
406 blink_leds, blink_delay);
417 static const struct of_device_id bcm6328_leds_of_match[] = {
418 { .compatible = "brcm,bcm6328-leds", },
421 MODULE_DEVICE_TABLE(of, bcm6328_leds_of_match);
423 static struct platform_driver bcm6328_leds_driver = {
424 .probe = bcm6328_leds_probe,
426 .name = "leds-bcm6328",
427 .of_match_table = bcm6328_leds_of_match,
431 module_platform_driver(bcm6328_leds_driver);
433 MODULE_AUTHOR("Álvaro Fernández Rojas <noltari@gmail.com>");
434 MODULE_AUTHOR("Jonas Gorski <jogo@openwrt.org>");
435 MODULE_DESCRIPTION("LED driver for BCM6328 controllers");
436 MODULE_LICENSE("GPL v2");
437 MODULE_ALIAS("platform:leds-bcm6328");