/* * Driver for BCM6328 memory-mapped LEDs, based on leds-syscon.c * * Copyright 2015 Álvaro Fernández Rojas <noltari@gmail.com> * Copyright 2015 Jonas Gorski <jogo@openwrt.org> * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the * Free Software Foundation; either version 2 of the License, or (at your * option) any later version. */ #include <linux/io.h> #include <linux/leds.h> #include <linux/module.h> #include <linux/of.h> #include <linux/platform_device.h> #include <linux/spinlock.h> #define BCM6328_REG_INIT 0x00 #define BCM6328_REG_MODE_HI 0x04 #define BCM6328_REG_MODE_LO 0x08 #define BCM6328_REG_HWDIS 0x0c #define BCM6328_REG_STROBE 0x10 #define BCM6328_REG_LNKACTSEL_HI 0x14 #define BCM6328_REG_LNKACTSEL_LO 0x18 #define BCM6328_REG_RBACK 0x1c #define BCM6328_REG_SERMUX 0x20 #define BCM6328_LED_MAX_COUNT 24 #define BCM6328_LED_DEF_DELAY 500 #define BCM6328_LED_INTERVAL_MS 20 #define BCM6328_LED_INTV_MASK 0x3f #define BCM6328_LED_FAST_INTV_SHIFT 6 #define BCM6328_LED_FAST_INTV_MASK (BCM6328_LED_INTV_MASK << \ BCM6328_LED_FAST_INTV_SHIFT) #define BCM6328_SERIAL_LED_EN BIT(12) #define BCM6328_SERIAL_LED_MUX BIT(13) #define BCM6328_SERIAL_LED_CLK_NPOL BIT(14) #define BCM6328_SERIAL_LED_DATA_PPOL BIT(15) #define BCM6328_SERIAL_LED_SHIFT_DIR BIT(16) #define BCM6328_LED_SHIFT_TEST BIT(30) #define BCM6328_LED_TEST BIT(31) #define BCM6328_INIT_MASK (BCM6328_SERIAL_LED_EN | \ BCM6328_SERIAL_LED_MUX | \ BCM6328_SERIAL_LED_CLK_NPOL | \ BCM6328_SERIAL_LED_DATA_PPOL | \ BCM6328_SERIAL_LED_SHIFT_DIR) #define BCM6328_LED_MODE_MASK 3 #define BCM6328_LED_MODE_ON 0 #define BCM6328_LED_MODE_FAST 1 #define BCM6328_LED_MODE_BLINK 2 #define BCM6328_LED_MODE_OFF 3 #define BCM6328_LED_SHIFT(X) ((X) << 1) /** * struct bcm6328_led - state container for bcm6328 based LEDs * @cdev: LED class device for this LED * @mem: memory resource * @lock: memory lock * @pin: LED pin number * @blink_leds: blinking LEDs * @blink_delay: blinking delay * @active_low: LED is active low */ struct bcm6328_led { struct led_classdev cdev; void __iomem *mem; spinlock_t *lock; unsigned long pin; unsigned long *blink_leds; unsigned long *blink_delay; bool active_low; }; static void bcm6328_led_write(void __iomem *reg, unsigned long data) { #ifdef CONFIG_CPU_BIG_ENDIAN iowrite32be(data, reg); #else writel(data, reg); #endif } static unsigned long bcm6328_led_read(void __iomem *reg) { #ifdef CONFIG_CPU_BIG_ENDIAN return ioread32be(reg); #else return readl(reg); #endif } /** * LEDMode 64 bits / 24 LEDs * bits [31:0] -> LEDs 8-23 * bits [47:32] -> LEDs 0-7 * bits [63:48] -> unused */ static unsigned long bcm6328_pin2shift(unsigned long pin) { if (pin < 8) return pin + 16; /* LEDs 0-7 (bits 47:32) */ else return pin - 8; /* LEDs 8-23 (bits 31:0) */ } static void bcm6328_led_mode(struct bcm6328_led *led, unsigned long value) { void __iomem *mode; unsigned long val, shift; shift = bcm6328_pin2shift(led->pin); if (shift / 16) mode = led->mem + BCM6328_REG_MODE_HI; else mode = led->mem + BCM6328_REG_MODE_LO; val = bcm6328_led_read(mode); val &= ~(BCM6328_LED_MODE_MASK << BCM6328_LED_SHIFT(shift % 16)); val |= (value << BCM6328_LED_SHIFT(shift % 16)); bcm6328_led_write(mode, val); } static void bcm6328_led_set(struct led_classdev *led_cdev, enum led_brightness value) { struct bcm6328_led *led = container_of(led_cdev, struct bcm6328_led, cdev); unsigned long flags; spin_lock_irqsave(led->lock, flags); *(led->blink_leds) &= ~BIT(led->pin); if ((led->active_low && value == LED_OFF) || (!led->active_low && value != LED_OFF)) bcm6328_led_mode(led, BCM6328_LED_MODE_ON); else bcm6328_led_mode(led, BCM6328_LED_MODE_OFF); spin_unlock_irqrestore(led->lock, flags); } static unsigned long bcm6328_blink_delay(unsigned long delay) { unsigned long bcm6328_delay; bcm6328_delay = delay + BCM6328_LED_INTERVAL_MS / 2; bcm6328_delay = bcm6328_delay / BCM6328_LED_INTERVAL_MS; if (bcm6328_delay == 0) bcm6328_delay = 1; return bcm6328_delay; } static int bcm6328_blink_set(struct led_classdev *led_cdev, unsigned long *delay_on, unsigned long *delay_off) { struct bcm6328_led *led = container_of(led_cdev, struct bcm6328_led, cdev); unsigned long delay, flags; int rc; if (!*delay_on) *delay_on = BCM6328_LED_DEF_DELAY; if (!*delay_off) *delay_off = BCM6328_LED_DEF_DELAY; delay = bcm6328_blink_delay(*delay_on); if (delay != bcm6328_blink_delay(*delay_off)) { dev_dbg(led_cdev->dev, "fallback to soft blinking (delay_on != delay_off)\n"); return -EINVAL; } if (delay > BCM6328_LED_INTV_MASK) { dev_dbg(led_cdev->dev, "fallback to soft blinking (delay > %ums)\n", BCM6328_LED_INTV_MASK * BCM6328_LED_INTERVAL_MS); return -EINVAL; } spin_lock_irqsave(led->lock, flags); if (*(led->blink_leds) == 0 || *(led->blink_leds) == BIT(led->pin) || *(led->blink_delay) == delay) { unsigned long val; *(led->blink_leds) |= BIT(led->pin); *(led->blink_delay) = delay; val = bcm6328_led_read(led->mem + BCM6328_REG_INIT); val &= ~BCM6328_LED_FAST_INTV_MASK; val |= (delay << BCM6328_LED_FAST_INTV_SHIFT); bcm6328_led_write(led->mem + BCM6328_REG_INIT, val); bcm6328_led_mode(led, BCM6328_LED_MODE_BLINK); rc = 0; } else { dev_dbg(led_cdev->dev, "fallback to soft blinking (delay already set)\n"); rc = -EINVAL; } spin_unlock_irqrestore(led->lock, flags); return rc; } static int bcm6328_hwled(struct device *dev, struct device_node *nc, u32 reg, void __iomem *mem, spinlock_t *lock) { int i, cnt; unsigned long flags, val; spin_lock_irqsave(lock, flags); val = bcm6328_led_read(mem + BCM6328_REG_HWDIS); val &= ~BIT(reg); bcm6328_led_write(mem + BCM6328_REG_HWDIS, val); spin_unlock_irqrestore(lock, flags); /* Only LEDs 0-7 can be activity/link controlled */ if (reg >= 8) return 0; cnt = of_property_count_elems_of_size(nc, "brcm,link-signal-sources", sizeof(u32)); for (i = 0; i < cnt; i++) { u32 sel; void __iomem *addr; if (reg < 4) addr = mem + BCM6328_REG_LNKACTSEL_LO; else addr = mem + BCM6328_REG_LNKACTSEL_HI; of_property_read_u32_index(nc, "brcm,link-signal-sources", i, &sel); if (reg / 4 != sel / 4) { dev_warn(dev, "invalid link signal source\n"); continue; } spin_lock_irqsave(lock, flags); val = bcm6328_led_read(addr); val |= (BIT(reg) << (((sel % 4) * 4) + 16)); bcm6328_led_write(addr, val); spin_unlock_irqrestore(lock, flags); } cnt = of_property_count_elems_of_size(nc, "brcm,activity-signal-sources", sizeof(u32)); for (i = 0; i < cnt; i++) { u32 sel; void __iomem *addr; if (reg < 4) addr = mem + BCM6328_REG_LNKACTSEL_LO; else addr = mem + BCM6328_REG_LNKACTSEL_HI; of_property_read_u32_index(nc, "brcm,activity-signal-sources", i, &sel); if (reg / 4 != sel / 4) { dev_warn(dev, "invalid activity signal source\n"); continue; } spin_lock_irqsave(lock, flags); val = bcm6328_led_read(addr); val |= (BIT(reg) << ((sel % 4) * 4)); bcm6328_led_write(addr, val); spin_unlock_irqrestore(lock, flags); } return 0; } static int bcm6328_led(struct device *dev, struct device_node *nc, u32 reg, void __iomem *mem, spinlock_t *lock, unsigned long *blink_leds, unsigned long *blink_delay) { struct bcm6328_led *led; const char *state; int rc; led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL); if (!led) return -ENOMEM; led->pin = reg; led->mem = mem; led->lock = lock; led->blink_leds = blink_leds; led->blink_delay = blink_delay; if (of_property_read_bool(nc, "active-low")) led->active_low = true; led->cdev.name = of_get_property(nc, "label", NULL) ? : nc->name; led->cdev.default_trigger = of_get_property(nc, "linux,default-trigger", NULL); if (!of_property_read_string(nc, "default-state", &state)) { if (!strcmp(state, "on")) { led->cdev.brightness = LED_FULL; } else if (!strcmp(state, "keep")) { void __iomem *mode; unsigned long val, shift; shift = bcm6328_pin2shift(led->pin); if (shift / 16) mode = mem + BCM6328_REG_MODE_HI; else mode = mem + BCM6328_REG_MODE_LO; val = bcm6328_led_read(mode) >> BCM6328_LED_SHIFT(shift % 16); val &= BCM6328_LED_MODE_MASK; if ((led->active_low && val == BCM6328_LED_MODE_OFF) || (!led->active_low && val == BCM6328_LED_MODE_ON)) led->cdev.brightness = LED_FULL; else led->cdev.brightness = LED_OFF; } else { led->cdev.brightness = LED_OFF; } } else { led->cdev.brightness = LED_OFF; } bcm6328_led_set(&led->cdev, led->cdev.brightness); led->cdev.brightness_set = bcm6328_led_set; led->cdev.blink_set = bcm6328_blink_set; rc = led_classdev_register(dev, &led->cdev); if (rc < 0) return rc; dev_dbg(dev, "registered LED %s\n", led->cdev.name); return 0; } static int bcm6328_leds_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct device_node *np = pdev->dev.of_node; struct device_node *child; struct resource *mem_r; void __iomem *mem; spinlock_t *lock; /* memory lock */ unsigned long val, *blink_leds, *blink_delay; mem_r = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!mem_r) return -EINVAL; mem = devm_ioremap_resource(dev, mem_r); if (IS_ERR(mem)) return PTR_ERR(mem); lock = devm_kzalloc(dev, sizeof(*lock), GFP_KERNEL); if (!lock) return -ENOMEM; blink_leds = devm_kzalloc(dev, sizeof(*blink_leds), GFP_KERNEL); if (!blink_leds) return -ENOMEM; blink_delay = devm_kzalloc(dev, sizeof(*blink_delay), GFP_KERNEL); if (!blink_delay) return -ENOMEM; spin_lock_init(lock); bcm6328_led_write(mem + BCM6328_REG_HWDIS, ~0); bcm6328_led_write(mem + BCM6328_REG_LNKACTSEL_HI, 0); bcm6328_led_write(mem + BCM6328_REG_LNKACTSEL_LO, 0); val = bcm6328_led_read(mem + BCM6328_REG_INIT); val &= ~(BCM6328_INIT_MASK); if (of_property_read_bool(np, "brcm,serial-leds")) val |= BCM6328_SERIAL_LED_EN; if (of_property_read_bool(np, "brcm,serial-mux")) val |= BCM6328_SERIAL_LED_MUX; if (of_property_read_bool(np, "brcm,serial-clk-low")) val |= BCM6328_SERIAL_LED_CLK_NPOL; if (!of_property_read_bool(np, "brcm,serial-dat-low")) val |= BCM6328_SERIAL_LED_DATA_PPOL; if (!of_property_read_bool(np, "brcm,serial-shift-inv")) val |= BCM6328_SERIAL_LED_SHIFT_DIR; bcm6328_led_write(mem + BCM6328_REG_INIT, val); for_each_available_child_of_node(np, child) { int rc; u32 reg; if (of_property_read_u32(child, "reg", ®)) continue; if (reg >= BCM6328_LED_MAX_COUNT) { dev_err(dev, "invalid LED (%u >= %d)\n", reg, BCM6328_LED_MAX_COUNT); continue; } if (of_property_read_bool(child, "brcm,hardware-controlled")) rc = bcm6328_hwled(dev, child, reg, mem, lock); else rc = bcm6328_led(dev, child, reg, mem, lock, blink_leds, blink_delay); if (rc < 0) { of_node_put(child); return rc; } } return 0; } static const struct of_device_id bcm6328_leds_of_match[] = { { .compatible = "brcm,bcm6328-leds", }, { }, }; MODULE_DEVICE_TABLE(of, bcm6328_leds_of_match); static struct platform_driver bcm6328_leds_driver = { .probe = bcm6328_leds_probe, .driver = { .name = "leds-bcm6328", .of_match_table = bcm6328_leds_of_match, }, }; module_platform_driver(bcm6328_leds_driver); MODULE_AUTHOR("Álvaro Fernández Rojas <noltari@gmail.com>"); MODULE_AUTHOR("Jonas Gorski <jogo@openwrt.org>"); MODULE_DESCRIPTION("LED driver for BCM6328 controllers"); MODULE_LICENSE("GPL v2"); MODULE_ALIAS("platform:leds-bcm6328");