drivers/leds/leds-bcm6328.c - kernel/common - Git at Google

 /*
  * Driver for BCM6328 memory-mapped LEDs, based on leds-syscon.c
  *
  * Copyright 2015 Álvaro Fernández Rojas <[email protected]>
  * Copyright 2015 Jonas Gorski <[email protected]>
  *
  * 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 % 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 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", &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 <[email protected]>");
 MODULE_AUTHOR("Jonas Gorski <[email protected]>");
 MODULE_DESCRIPTION("LED driver for BCM6328 controllers");
 MODULE_LICENSE("GPL v2");
 MODULE_ALIAS("platform:leds-bcm6328");
	/*
	* Driver for BCM6328 memory-mapped LEDs, based on leds-syscon.c
	*
	* Copyright 2015 Álvaro Fernández Rojas <[email protected]>
	* Copyright 2015 Jonas Gorski <[email protected]>
	*
	* 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 % 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 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", &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 <[email protected]>");
	MODULE_AUTHOR("Jonas Gorski <[email protected]>");
	MODULE_DESCRIPTION("LED driver for BCM6328 controllers");
	MODULE_LICENSE("GPL v2");
	MODULE_ALIAS("platform:leds-bcm6328");