[mirror_ubuntu-bionic-kernel.git] / drivers / leds / leds-bcm6358.c

/*
 * Driver for BCM6358 memory-mapped LEDs, based on leds-syscon.c
 *
 * Copyright 2015 Álvaro Fernández Rojas <noltari@gmail.com>
 *
 * 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/delay.h>
#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 BCM6358_REG_MODE		0x0
#define BCM6358_REG_CTRL		0x4

#define BCM6358_SLED_CLKDIV_MASK	3
#define BCM6358_SLED_CLKDIV_1		0
#define BCM6358_SLED_CLKDIV_2		1
#define BCM6358_SLED_CLKDIV_4		2
#define BCM6358_SLED_CLKDIV_8		3

#define BCM6358_SLED_POLARITY		BIT(2)
#define BCM6358_SLED_BUSY		BIT(3)

#define BCM6358_SLED_MAX_COUNT		32
#define BCM6358_SLED_WAIT		100

/**
 * struct bcm6358_led - state container for bcm6358 based LEDs
 * @cdev: LED class device for this LED
 * @mem: memory resource
 * @lock: memory lock
 * @pin: LED pin number
 * @active_low: LED is active low
 */
struct bcm6358_led {
	struct led_classdev cdev;
	void __iomem *mem;
	spinlock_t *lock;
	unsigned long pin;
	bool active_low;
};

static void bcm6358_led_write(void __iomem *reg, unsigned long data)
{
#ifdef CONFIG_CPU_BIG_ENDIAN
	iowrite32be(data, reg);
#else
	writel(data, reg);
#endif
}

static unsigned long bcm6358_led_read(void __iomem *reg)
{
#ifdef CONFIG_CPU_BIG_ENDIAN
	return ioread32be(reg);
#else
	return readl(reg);
#endif
}

static unsigned long bcm6358_led_busy(void __iomem *mem)
{
	unsigned long val;

	while ((val = bcm6358_led_read(mem + BCM6358_REG_CTRL)) &
		BCM6358_SLED_BUSY)
		udelay(BCM6358_SLED_WAIT);

	return val;
}

static void bcm6358_led_mode(struct bcm6358_led *led, unsigned long value)
{
	unsigned long val;

	bcm6358_led_busy(led->mem);

	val = bcm6358_led_read(led->mem + BCM6358_REG_MODE);
	if ((led->active_low && value == LED_OFF) ||
	    (!led->active_low && value != LED_OFF))
		val |= BIT(led->pin);
	else
		val &= ~(BIT(led->pin));
	bcm6358_led_write(led->mem + BCM6358_REG_MODE, val);
}

static void bcm6358_led_set(struct led_classdev *led_cdev,
			    enum led_brightness value)
{
	struct bcm6358_led *led =
		container_of(led_cdev, struct bcm6358_led, cdev);
	unsigned long flags;

	spin_lock_irqsave(led->lock, flags);
	bcm6358_led_mode(led, value);
	spin_unlock_irqrestore(led->lock, flags);
}

static int bcm6358_led(struct device *dev, struct device_node *nc, u32 reg,
		       void __iomem *mem, spinlock_t *lock)
{
	struct bcm6358_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;

	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")) {
			unsigned long val;

			bcm6358_led_busy(led->mem);

			val = bcm6358_led_read(led->mem + BCM6358_REG_MODE);
			val &= BIT(led->pin);
			if ((led->active_low && !val) ||
			    (!led->active_low && val))
				led->cdev.brightness = LED_FULL;
			else
				led->cdev.brightness = LED_OFF;
		} else {
			led->cdev.brightness = LED_OFF;
		}
	} else {
		led->cdev.brightness = LED_OFF;
	}

	bcm6358_led_set(&led->cdev, led->cdev.brightness);

	led->cdev.brightness_set = bcm6358_led_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 bcm6358_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;
	u32 clk_div;

	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;

	spin_lock_init(lock);

	val = bcm6358_led_busy(mem);
	val &= ~(BCM6358_SLED_POLARITY | BCM6358_SLED_CLKDIV_MASK);
	if (of_property_read_bool(np, "brcm,clk-dat-low"))
		val |= BCM6358_SLED_POLARITY;
	of_property_read_u32(np, "brcm,clk-div", &clk_div);
	switch (clk_div) {
	case 8:
		val |= BCM6358_SLED_CLKDIV_8;
		break;
	case 4:
		val |= BCM6358_SLED_CLKDIV_4;
		break;
	case 2:
		val |= BCM6358_SLED_CLKDIV_2;
		break;
	default:
		val |= BCM6358_SLED_CLKDIV_1;
		break;
	}
	bcm6358_led_write(mem + BCM6358_REG_CTRL, val);

	for_each_available_child_of_node(np, child) {
		int rc;
		u32 reg;

		if (of_property_read_u32(child, "reg", &reg))
			continue;

		if (reg >= BCM6358_SLED_MAX_COUNT) {
			dev_err(dev, "invalid LED (%u >= %d)\n", reg,
				BCM6358_SLED_MAX_COUNT);
			continue;
		}

		rc = bcm6358_led(dev, child, reg, mem, lock);
		if (rc < 0) {
			of_node_put(child);
			return rc;
		}
	}

	return 0;
}

static const struct of_device_id bcm6358_leds_of_match[] = {
	{ .compatible = "brcm,bcm6358-leds", },
	{ },
};
MODULE_DEVICE_TABLE(of, bcm6358_leds_of_match);

static struct platform_driver bcm6358_leds_driver = {
	.probe = bcm6358_leds_probe,
	.driver = {
		.name = "leds-bcm6358",
		.of_match_table = bcm6358_leds_of_match,
	},
};

module_platform_driver(bcm6358_leds_driver);

MODULE_AUTHOR("Álvaro Fernández Rojas <noltari@gmail.com>");
MODULE_DESCRIPTION("LED driver for BCM6358 controllers");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:leds-bcm6358");
Commit	Line	Data
589fca16 ÁFR	1	/*
	2	* Driver for BCM6358 memory-mapped LEDs, based on leds-syscon.c
	3	*
	4	* Copyright 2015 Álvaro Fernández Rojas <noltari@gmail.com>
	5	*
	6	* This program is free software; you can redistribute it and/or modify it
	7	* under the terms of the GNU General Public License as published by the
	8	* Free Software Foundation; either version 2 of the License, or (at your
	9	* option) any later version.
	10	*/
	11	#include <linux/delay.h>
	12	#include <linux/io.h>
	13	#include <linux/leds.h>
	14	#include <linux/module.h>
	15	#include <linux/of.h>
	16	#include <linux/platform_device.h>
	17	#include <linux/spinlock.h>
	18
	19	#define BCM6358_REG_MODE 0x0
	20	#define BCM6358_REG_CTRL 0x4
	21
	22	#define BCM6358_SLED_CLKDIV_MASK 3
	23	#define BCM6358_SLED_CLKDIV_1 0
	24	#define BCM6358_SLED_CLKDIV_2 1
	25	#define BCM6358_SLED_CLKDIV_4 2
	26	#define BCM6358_SLED_CLKDIV_8 3
	27
	28	#define BCM6358_SLED_POLARITY BIT(2)
	29	#define BCM6358_SLED_BUSY BIT(3)
	30
	31	#define BCM6358_SLED_MAX_COUNT 32
	32	#define BCM6358_SLED_WAIT 100
	33
	34	/**
	35	* struct bcm6358_led - state container for bcm6358 based LEDs
	36	* @cdev: LED class device for this LED
	37	* @mem: memory resource
	38	* @lock: memory lock
	39	* @pin: LED pin number
	40	* @active_low: LED is active low
	41	*/
	42	struct bcm6358_led {
	43	struct led_classdev cdev;
	44	void __iomem *mem;
	45	spinlock_t *lock;
	46	unsigned long pin;
	47	bool active_low;
	48	};
	49
	50	static void bcm6358_led_write(void __iomem *reg, unsigned long data)
	51	{
4ba113b6	52	#ifdef CONFIG_CPU_BIG_ENDIAN
589fca16	53	iowrite32be(data, reg);
4ba113b6 ÁFR	54	#else
	55	writel(data, reg);
	56	#endif
589fca16 ÁFR	57	}
	58
	59	static unsigned long bcm6358_led_read(void __iomem *reg)
	60	{
4ba113b6	61	#ifdef CONFIG_CPU_BIG_ENDIAN
589fca16	62	return ioread32be(reg);
4ba113b6 ÁFR	63	#else
	64	return readl(reg);
	65	#endif
589fca16 ÁFR	66	}
	67
	68	static unsigned long bcm6358_led_busy(void __iomem *mem)
	69	{
	70	unsigned long val;
	71
	72	while ((val = bcm6358_led_read(mem + BCM6358_REG_CTRL)) &
	73	BCM6358_SLED_BUSY)
	74	udelay(BCM6358_SLED_WAIT);
	75
	76	return val;
	77	}
	78
	79	static void bcm6358_led_mode(struct bcm6358_led *led, unsigned long value)
	80	{
	81	unsigned long val;
	82
	83	bcm6358_led_busy(led->mem);
	84
	85	val = bcm6358_led_read(led->mem + BCM6358_REG_MODE);
	86	if ((led->active_low && value == LED_OFF) \|\|
	87	(!led->active_low && value != LED_OFF))
	88	val \|= BIT(led->pin);
	89	else
	90	val &= ~(BIT(led->pin));
	91	bcm6358_led_write(led->mem + BCM6358_REG_MODE, val);
	92	}
	93
	94	static void bcm6358_led_set(struct led_classdev *led_cdev,
	95	enum led_brightness value)
	96	{
	97	struct bcm6358_led *led =
	98	container_of(led_cdev, struct bcm6358_led, cdev);
	99	unsigned long flags;
	100
	101	spin_lock_irqsave(led->lock, flags);
	102	bcm6358_led_mode(led, value);
	103	spin_unlock_irqrestore(led->lock, flags);
	104	}
	105
	106	static int bcm6358_led(struct device dev, struct device_node nc, u32 reg,
	107	void __iomem mem, spinlock_t lock)
	108	{
	109	struct bcm6358_led *led;
589fca16 ÁFR	110	const char *state;
	111	int rc;
	112
	113	led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);
	114	if (!led)
	115	return -ENOMEM;
	116
	117	led->pin = reg;
	118	led->mem = mem;
	119	led->lock = lock;
	120
	121	if (of_property_read_bool(nc, "active-low"))
	122	led->active_low = true;
	123
	124	led->cdev.name = of_get_property(nc, "label", NULL) ? : nc->name;
	125	led->cdev.default_trigger = of_get_property(nc,
	126	"linux,default-trigger",
	127	NULL);
	128
589fca16 ÁFR	129	if (!of_property_read_string(nc, "default-state", &state)) {
	130	if (!strcmp(state, "on")) {
	131	led->cdev.brightness = LED_FULL;
	132	} else if (!strcmp(state, "keep")) {
	133	unsigned long val;
	134
	135	bcm6358_led_busy(led->mem);
	136
	137	val = bcm6358_led_read(led->mem + BCM6358_REG_MODE);
	138	val &= BIT(led->pin);
	139	if ((led->active_low && !val) \|\|
	140	(!led->active_low && val))
	141	led->cdev.brightness = LED_FULL;
	142	else
	143	led->cdev.brightness = LED_OFF;
	144	} else {
	145	led->cdev.brightness = LED_OFF;
	146	}
	147	} else {
	148	led->cdev.brightness = LED_OFF;
	149	}
589fca16	150
42273caa ÁFR	151	bcm6358_led_set(&led->cdev, led->cdev.brightness);
42273caa ÁFR	152
589fca16 ÁFR	153	led->cdev.brightness_set = bcm6358_led_set;
	154
	155	rc = led_classdev_register(dev, &led->cdev);
	156	if (rc < 0)
	157	return rc;
	158
	159	dev_dbg(dev, "registered LED %s\n", led->cdev.name);
	160
	161	return 0;
	162	}
	163
	164	static int bcm6358_leds_probe(struct platform_device *pdev)
	165	{
	166	struct device *dev = &pdev->dev;
	167	struct device_node *np = pdev->dev.of_node;
	168	struct device_node *child;
	169	struct resource *mem_r;
	170	void __iomem *mem;
	171	spinlock_t lock; / memory lock */
	172	unsigned long val;
	173	u32 clk_div;
	174
	175	mem_r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	176	if (!mem_r)
	177	return -EINVAL;
	178
	179	mem = devm_ioremap_resource(dev, mem_r);
	180	if (IS_ERR(mem))
	181	return PTR_ERR(mem);
	182
	183	lock = devm_kzalloc(dev, sizeof(*lock), GFP_KERNEL);
	184	if (!lock)
	185	return -ENOMEM;
	186
	187	spin_lock_init(lock);
	188
	189	val = bcm6358_led_busy(mem);
	190	val &= ~(BCM6358_SLED_POLARITY \| BCM6358_SLED_CLKDIV_MASK);
	191	if (of_property_read_bool(np, "brcm,clk-dat-low"))
	192	val \|= BCM6358_SLED_POLARITY;
	193	of_property_read_u32(np, "brcm,clk-div", &clk_div);
	194	switch (clk_div) {
	195	case 8:
	196	val \|= BCM6358_SLED_CLKDIV_8;
	197	break;
	198	case 4:
	199	val \|= BCM6358_SLED_CLKDIV_4;
	200	break;
	201	case 2:
	202	val \|= BCM6358_SLED_CLKDIV_2;
	203	break;
	204	default:
	205	val \|= BCM6358_SLED_CLKDIV_1;
	206	break;
	207	}
	208	bcm6358_led_write(mem + BCM6358_REG_CTRL, val);
	209
	210	for_each_available_child_of_node(np, child) {
	211	int rc;
	212	u32 reg;
	213
	214	if (of_property_read_u32(child, "reg", &reg))
	215	continue;
	216
217	if (reg >= BCM6358_SLED_MAX_COUNT) {
218	dev_err(dev, "invalid LED (%u >= %d)\n", reg,
219	BCM6358_SLED_MAX_COUNT);
220	continue;
221	}
222
223	rc = bcm6358_led(dev, child, reg, mem, lock);
4b6ba5e2 JL	224	if (rc < 0) {
4b6ba5e2 JL	225	of_node_put(child);
589fca16	226	return rc;
4b6ba5e2	227	}
589fca16 ÁFR	228	}
	229
	230	return 0;
	231	}
	232
	233	static const struct of_device_id bcm6358_leds_of_match[] = {
	234	{ .compatible = "brcm,bcm6358-leds", },
	235	{ },
	236	};
01736f07	237	MODULE_DEVICE_TABLE(of, bcm6358_leds_of_match);
589fca16 ÁFR	238
	239	static struct platform_driver bcm6358_leds_driver = {
	240	.probe = bcm6358_leds_probe,
	241	.driver = {
	242	.name = "leds-bcm6358",
	243	.of_match_table = bcm6358_leds_of_match,
	244	},
	245	};
	246
	247	module_platform_driver(bcm6358_leds_driver);
	248
	249	MODULE_AUTHOR("Álvaro Fernández Rojas <noltari@gmail.com>");
	250	MODULE_DESCRIPTION("LED driver for BCM6358 controllers");
	251	MODULE_LICENSE("GPL v2");
	252	MODULE_ALIAS("platform:leds-bcm6358");