diff options
Diffstat (limited to 'drivers/leds/leds-bcm6328.c')
| -rw-r--r-- | drivers/leds/leds-bcm6328.c | 487 |
1 files changed, 487 insertions, 0 deletions
diff --git a/drivers/leds/leds-bcm6328.c b/drivers/leds/leds-bcm6328.c new file mode 100644 index 000000000..2d4d87957 --- /dev/null +++ b/drivers/leds/leds-bcm6328.c @@ -0,0 +1,487 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * 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> + */ +#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_BLINK_DELAYS 2 +#define BCM6328_LED_BLINK_MS 20 + +#define BCM6328_LED_BLINK_MASK 0x3f +#define BCM6328_LED_BLINK1_SHIFT 0 +#define BCM6328_LED_BLINK1_MASK (BCM6328_LED_BLINK_MASK << \ + BCM6328_LED_BLINK1_SHIFT) +#define BCM6328_LED_BLINK2_SHIFT 6 +#define BCM6328_LED_BLINK2_MASK (BCM6328_LED_BLINK_MASK << \ + BCM6328_LED_BLINK2_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_BLINK1 1 +#define BCM6328_LED_MODE_BLINK2 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); + + /* Remove LED from cached HW blinking intervals */ + led->blink_leds[0] &= ~BIT(led->pin); + led->blink_leds[1] &= ~BIT(led->pin); + + /* Set LED on/off */ + 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_BLINK_MS / 2; + bcm6328_delay = bcm6328_delay / BCM6328_LED_BLINK_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_BLINK_MASK) { + dev_dbg(led_cdev->dev, + "fallback to soft blinking (delay > %ums)\n", + BCM6328_LED_BLINK_MASK * BCM6328_LED_BLINK_MS); + return -EINVAL; + } + + spin_lock_irqsave(led->lock, flags); + /* + * Check if any of the two configurable HW blinking intervals is + * available: + * 1. No LEDs assigned to the HW blinking interval. + * 2. Only this LED is assigned to the HW blinking interval. + * 3. LEDs with the same delay assigned. + */ + if (led->blink_leds[0] == 0 || + led->blink_leds[0] == BIT(led->pin) || + led->blink_delay[0] == delay) { + unsigned long val; + + /* Add LED to the first HW blinking interval cache */ + led->blink_leds[0] |= BIT(led->pin); + + /* Remove LED from the second HW blinking interval cache */ + led->blink_leds[1] &= ~BIT(led->pin); + + /* Cache first HW blinking interval delay */ + led->blink_delay[0] = delay; + + /* Update the delay for the first HW blinking interval */ + val = bcm6328_led_read(led->mem + BCM6328_REG_INIT); + val &= ~BCM6328_LED_BLINK1_MASK; + val |= (delay << BCM6328_LED_BLINK1_SHIFT); + bcm6328_led_write(led->mem + BCM6328_REG_INIT, val); + + /* Set the LED to first HW blinking interval */ + bcm6328_led_mode(led, BCM6328_LED_MODE_BLINK1); + + rc = 0; + } else if (led->blink_leds[1] == 0 || + led->blink_leds[1] == BIT(led->pin) || + led->blink_delay[1] == delay) { + unsigned long val; + + /* Remove LED from the first HW blinking interval */ + led->blink_leds[0] &= ~BIT(led->pin); + + /* Add LED to the second HW blinking interval */ + led->blink_leds[1] |= BIT(led->pin); + + /* Cache second HW blinking interval delay */ + led->blink_delay[1] = delay; + + /* Update the delay for the second HW blinking interval */ + val = bcm6328_led_read(led->mem + BCM6328_REG_INIT); + val &= ~BCM6328_LED_BLINK2_MASK; + val |= (delay << BCM6328_LED_BLINK2_SHIFT); + bcm6328_led_write(led->mem + BCM6328_REG_INIT, val); + + /* Set the LED to second HW blinking interval */ + bcm6328_led_mode(led, BCM6328_LED_MODE_BLINK2); + + 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 % 4) << (((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 % 4) << ((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 led_init_data init_data = {}; + 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; + + 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; + init_data.fwnode = of_fwnode_handle(nc); + + rc = devm_led_classdev_register_ext(dev, &led->cdev, &init_data); + 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 = dev_of_node(&pdev->dev); + struct device_node *child; + void __iomem *mem; + spinlock_t *lock; /* memory lock */ + unsigned long val, *blink_leds, *blink_delay; + + mem = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(mem)) + return PTR_ERR(mem); + + lock = devm_kzalloc(dev, sizeof(*lock), GFP_KERNEL); + if (!lock) + return -ENOMEM; + + blink_leds = devm_kcalloc(dev, BCM6328_LED_BLINK_DELAYS, + sizeof(*blink_leds), GFP_KERNEL); + if (!blink_leds) + return -ENOMEM; + + blink_delay = devm_kcalloc(dev, BCM6328_LED_BLINK_DELAYS, + 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"); |