2 * Driver for BCM6328 memory-mapped LEDs, based on leds-syscon.c
4 * Copyright 2015 Álvaro Fernández Rojas <noltari@gmail.com>
5 * Copyright 2015 Jonas Gorski <jogo@openwrt.org>
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.
13 #include <linux/leds.h>
14 #include <linux/module.h>
16 #include <linux/platform_device.h>
17 #include <linux/spinlock.h>
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
29 #define BCM6328_LED_MAX_COUNT 24
30 #define BCM6328_LED_DEF_DELAY 500
31 #define BCM6328_LED_INTERVAL_MS 20
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)
45 #define BCM6328_LED_MODE_MASK 3
46 #define BCM6328_LED_MODE_OFF 0
47 #define BCM6328_LED_MODE_FAST 1
48 #define BCM6328_LED_MODE_BLINK 2
49 #define BCM6328_LED_MODE_ON 3
50 #define BCM6328_LED_SHIFT(X) ((X) << 1)
53 * struct bcm6328_led - state container for bcm6328 based LEDs
54 * @cdev: LED class device for this LED
55 * @mem: memory resource
57 * @pin: LED pin number
58 * @blink_leds: blinking LEDs
59 * @blink_delay: blinking delay
60 * @active_low: LED is active low
63 struct led_classdev cdev;
67 unsigned long *blink_leds;
68 unsigned long *blink_delay;
72 static void bcm6328_led_write(void __iomem *reg, unsigned long data)
74 iowrite32be(data, reg);
77 static unsigned long bcm6328_led_read(void __iomem *reg)
79 return ioread32be(reg);
83 * LEDMode 64 bits / 24 LEDs
84 * bits [31:0] -> LEDs 8-23
85 * bits [47:32] -> LEDs 0-7
86 * bits [63:48] -> unused
88 static unsigned long bcm6328_pin2shift(unsigned long pin)
91 return pin + 16; /* LEDs 0-7 (bits 47:32) */
93 return pin - 8; /* LEDs 8-23 (bits 31:0) */
96 static void bcm6328_led_mode(struct bcm6328_led *led, unsigned long value)
99 unsigned long val, shift;
101 shift = bcm6328_pin2shift(led->pin);
103 mode = led->mem + BCM6328_REG_MODE_HI;
105 mode = led->mem + BCM6328_REG_MODE_LO;
107 val = bcm6328_led_read(mode);
108 val &= ~(BCM6328_LED_MODE_MASK << BCM6328_LED_SHIFT(shift % 16));
109 val |= (value << BCM6328_LED_SHIFT(shift % 16));
110 bcm6328_led_write(mode, val);
113 static void bcm6328_led_set(struct led_classdev *led_cdev,
114 enum led_brightness value)
116 struct bcm6328_led *led =
117 container_of(led_cdev, struct bcm6328_led, cdev);
120 spin_lock_irqsave(led->lock, flags);
121 *(led->blink_leds) &= ~BIT(led->pin);
122 if ((led->active_low && value == LED_OFF) ||
123 (!led->active_low && value != LED_OFF))
124 bcm6328_led_mode(led, BCM6328_LED_MODE_OFF);
126 bcm6328_led_mode(led, BCM6328_LED_MODE_ON);
127 spin_unlock_irqrestore(led->lock, flags);
130 static int bcm6328_blink_set(struct led_classdev *led_cdev,
131 unsigned long *delay_on, unsigned long *delay_off)
133 struct bcm6328_led *led =
134 container_of(led_cdev, struct bcm6328_led, cdev);
135 unsigned long delay, flags;
138 *delay_on = BCM6328_LED_DEF_DELAY;
140 *delay_off = BCM6328_LED_DEF_DELAY;
142 if (*delay_on != *delay_off) {
143 dev_dbg(led_cdev->dev,
144 "fallback to soft blinking (delay_on != delay_off)\n");
148 delay = *delay_on / BCM6328_LED_INTERVAL_MS;
151 else if (delay > BCM6328_LED_INTV_MASK) {
152 dev_dbg(led_cdev->dev,
153 "fallback to soft blinking (delay > %ums)\n",
154 BCM6328_LED_INTV_MASK * BCM6328_LED_INTERVAL_MS);
158 spin_lock_irqsave(led->lock, flags);
159 if (*(led->blink_leds) == 0 ||
160 *(led->blink_leds) == BIT(led->pin) ||
161 *(led->blink_delay) == delay) {
164 *(led->blink_leds) |= BIT(led->pin);
165 *(led->blink_delay) = delay;
167 val = bcm6328_led_read(led->mem + BCM6328_REG_INIT);
168 val &= ~BCM6328_LED_FAST_INTV_MASK;
169 val |= (delay << BCM6328_LED_FAST_INTV_SHIFT);
170 bcm6328_led_write(led->mem + BCM6328_REG_INIT, val);
172 bcm6328_led_mode(led, BCM6328_LED_MODE_BLINK);
174 spin_unlock_irqrestore(led->lock, flags);
176 spin_unlock_irqrestore(led->lock, flags);
177 dev_dbg(led_cdev->dev,
178 "fallback to soft blinking (delay already set)\n");
185 static int bcm6328_hwled(struct device *dev, struct device_node *nc, u32 reg,
186 void __iomem *mem, spinlock_t *lock)
189 unsigned long flags, val;
191 spin_lock_irqsave(lock, flags);
192 val = bcm6328_led_read(mem + BCM6328_REG_HWDIS);
194 bcm6328_led_write(mem + BCM6328_REG_HWDIS, val);
195 spin_unlock_irqrestore(lock, flags);
197 /* Only LEDs 0-7 can be activity/link controlled */
201 cnt = of_property_count_elems_of_size(nc, "brcm,link-signal-sources",
203 for (i = 0; i < cnt; i++) {
208 addr = mem + BCM6328_REG_LNKACTSEL_LO;
210 addr = mem + BCM6328_REG_LNKACTSEL_HI;
212 of_property_read_u32_index(nc, "brcm,link-signal-sources", i,
215 if (reg / 4 != sel / 4) {
216 dev_warn(dev, "invalid link signal source\n");
220 spin_lock_irqsave(lock, flags);
221 val = bcm6328_led_read(addr);
222 val |= (BIT(reg) << (((sel % 4) * 4) + 16));
223 bcm6328_led_write(addr, val);
224 spin_unlock_irqrestore(lock, flags);
227 cnt = of_property_count_elems_of_size(nc,
228 "brcm,activity-signal-sources",
230 for (i = 0; i < cnt; i++) {
235 addr = mem + BCM6328_REG_LNKACTSEL_LO;
237 addr = mem + BCM6328_REG_LNKACTSEL_HI;
239 of_property_read_u32_index(nc, "brcm,activity-signal-sources",
242 if (reg / 4 != sel / 4) {
243 dev_warn(dev, "invalid activity signal source\n");
247 spin_lock_irqsave(lock, flags);
248 val = bcm6328_led_read(addr);
249 val |= (BIT(reg) << ((sel % 4) * 4));
250 bcm6328_led_write(addr, val);
251 spin_unlock_irqrestore(lock, flags);
257 static int bcm6328_led(struct device *dev, struct device_node *nc, u32 reg,
258 void __iomem *mem, spinlock_t *lock,
259 unsigned long *blink_leds, unsigned long *blink_delay)
261 struct bcm6328_led *led;
266 led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);
273 led->blink_leds = blink_leds;
274 led->blink_delay = blink_delay;
276 if (of_property_read_bool(nc, "active-low"))
277 led->active_low = true;
279 led->cdev.name = of_get_property(nc, "label", NULL) ? : nc->name;
280 led->cdev.default_trigger = of_get_property(nc,
281 "linux,default-trigger",
284 if (!of_property_read_string(nc, "default-state", &state)) {
285 spin_lock_irqsave(lock, flags);
286 if (!strcmp(state, "on")) {
287 led->cdev.brightness = LED_FULL;
288 bcm6328_led_mode(led, BCM6328_LED_MODE_ON);
289 } else if (!strcmp(state, "keep")) {
291 unsigned long val, shift;
293 shift = bcm6328_pin2shift(led->pin);
295 mode = mem + BCM6328_REG_MODE_HI;
297 mode = mem + BCM6328_REG_MODE_LO;
299 val = bcm6328_led_read(mode) >> (shift % 16);
300 val &= BCM6328_LED_MODE_MASK;
301 if (val == BCM6328_LED_MODE_ON)
302 led->cdev.brightness = LED_FULL;
304 led->cdev.brightness = LED_OFF;
305 bcm6328_led_mode(led, BCM6328_LED_MODE_OFF);
308 led->cdev.brightness = LED_OFF;
309 bcm6328_led_mode(led, BCM6328_LED_MODE_OFF);
311 spin_unlock_irqrestore(lock, flags);
314 led->cdev.brightness_set = bcm6328_led_set;
315 led->cdev.blink_set = bcm6328_blink_set;
317 rc = led_classdev_register(dev, &led->cdev);
321 dev_dbg(dev, "registered LED %s\n", led->cdev.name);
326 static int bcm6328_leds_probe(struct platform_device *pdev)
328 struct device *dev = &pdev->dev;
329 struct device_node *np = pdev->dev.of_node;
330 struct device_node *child;
331 struct resource *mem_r;
334 unsigned long val, *blink_leds, *blink_delay;
336 mem_r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
340 mem = devm_ioremap_resource(dev, mem_r);
344 lock = devm_kzalloc(dev, sizeof(*lock), GFP_KERNEL);
348 blink_leds = devm_kzalloc(dev, sizeof(*blink_leds), GFP_KERNEL);
352 blink_delay = devm_kzalloc(dev, sizeof(*blink_delay), GFP_KERNEL);
356 spin_lock_init(lock);
358 bcm6328_led_write(mem + BCM6328_REG_HWDIS, ~0);
359 bcm6328_led_write(mem + BCM6328_REG_LNKACTSEL_HI, 0);
360 bcm6328_led_write(mem + BCM6328_REG_LNKACTSEL_LO, 0);
362 val = bcm6328_led_read(mem + BCM6328_REG_INIT);
363 val &= ~BCM6328_SERIAL_LED_EN;
364 if (of_property_read_bool(np, "brcm,serial-leds"))
365 val |= BCM6328_SERIAL_LED_EN;
366 bcm6328_led_write(mem + BCM6328_REG_INIT, val);
368 for_each_available_child_of_node(np, child) {
372 if (of_property_read_u32(child, "reg", ®))
375 if (reg >= BCM6328_LED_MAX_COUNT) {
376 dev_err(dev, "invalid LED (>= %d)\n",
377 BCM6328_LED_MAX_COUNT);
381 if (of_property_read_bool(child, "brcm,hardware-controlled"))
382 rc = bcm6328_hwled(dev, child, reg, mem, lock);
384 rc = bcm6328_led(dev, child, reg, mem, lock,
385 blink_leds, blink_delay);
394 static const struct of_device_id bcm6328_leds_of_match[] = {
395 { .compatible = "brcm,bcm6328-leds", },
398 MODULE_DEVICE_TABLE(of, bcm6328_leds_of_match);
400 static struct platform_driver bcm6328_leds_driver = {
401 .probe = bcm6328_leds_probe,
403 .name = "leds-bcm6328",
404 .of_match_table = bcm6328_leds_of_match,
408 module_platform_driver(bcm6328_leds_driver);
410 MODULE_AUTHOR("Álvaro Fernández Rojas <noltari@gmail.com>");
411 MODULE_AUTHOR("Jonas Gorski <jogo@openwrt.org>");
412 MODULE_DESCRIPTION("LED driver for BCM6328 controllers");
413 MODULE_LICENSE("GPL v2");
414 MODULE_ALIAS("platform:leds-bcm6328");