// 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)
  ");
  		return -EINVAL;
  	}

  	if (delay > BCM6328_LED_BLINK_MASK) {

  		dev_dbg(led_cdev->dev,
  			"fallback to soft blinking (delay > %ums)
  ",

  			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)
  ");

  		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
  ");
  			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
  ");
  			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
  ", 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", &reg))
  			continue;
  
  		if (reg >= BCM6328_LED_MAX_COUNT) {

  			dev_err(dev, "invalid LED (%u >= %d)
  ", 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");