diff options
Diffstat (limited to 'kernel/drivers/leds/leds-bcm6328.c')
-rw-r--r-- | kernel/drivers/leds/leds-bcm6328.c | 435 |
1 files changed, 435 insertions, 0 deletions
diff --git a/kernel/drivers/leds/leds-bcm6328.c b/kernel/drivers/leds/leds-bcm6328.c new file mode 100644 index 000000000..c7ea5c626 --- /dev/null +++ b/kernel/drivers/leds/leds-bcm6328.c @@ -0,0 +1,435 @@ +/* + * 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_OFF 0 +#define BCM6328_LED_MODE_FAST 1 +#define BCM6328_LED_MODE_BLINK 2 +#define BCM6328_LED_MODE_ON 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) +{ + iowrite32be(data, reg); +} + +static unsigned long bcm6328_led_read(void __iomem *reg) +{ + return ioread32be(reg); +} + +/** + * 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_OFF); + else + bcm6328_led_mode(led, BCM6328_LED_MODE_ON); + spin_unlock_irqrestore(led->lock, flags); +} + +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; + + if (!*delay_on) + *delay_on = BCM6328_LED_DEF_DELAY; + if (!*delay_off) + *delay_off = BCM6328_LED_DEF_DELAY; + + if (*delay_on != *delay_off) { + dev_dbg(led_cdev->dev, + "fallback to soft blinking (delay_on != delay_off)\n"); + return -EINVAL; + } + + delay = *delay_on / BCM6328_LED_INTERVAL_MS; + if (delay == 0) + delay = 1; + else 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); + + spin_unlock_irqrestore(led->lock, flags); + } else { + spin_unlock_irqrestore(led->lock, flags); + dev_dbg(led_cdev->dev, + "fallback to soft blinking (delay already set)\n"); + return -EINVAL; + } + + return 0; +} + +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; + unsigned long flags; + 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); + + spin_lock_irqsave(lock, flags); + 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_ON) || + (!led->active_low && val == BCM6328_LED_MODE_OFF)) + led->cdev.brightness = LED_FULL; + else + led->cdev.brightness = LED_OFF; + } else { + led->cdev.brightness = LED_OFF; + } + } else { + led->cdev.brightness = LED_OFF; + } + + if ((led->active_low && led->cdev.brightness == LED_FULL) || + (!led->active_low && led->cdev.brightness == LED_OFF)) + bcm6328_led_mode(led, BCM6328_LED_MODE_ON); + else + bcm6328_led_mode(led, BCM6328_LED_MODE_OFF); + spin_unlock_irqrestore(lock, flags); + + 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; + 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"); |