leds: add BCM6358 LED driver (589fca16) · Commits · e / devices / android_kernel_teracube_emerald

drivers/leds/Kconfig

+8 −0

Original line number	Diff line number	Diff line
		@@ -58,6 +58,14 @@ config LEDS_BCM6328
		This option enables support for LEDs connected to the BCM6328
		LED HW controller accessed via MMIO registers.

		config LEDS_BCM6358
		tristate "LED Support for Broadcom BCM6358"
		depends on LEDS_CLASS
		depends on OF
		help
		This option enables support for LEDs connected to the BCM6358
		LED HW controller accessed via MMIO registers.

		config LEDS_LM3530
		tristate "LCD Backlight driver for LM3530"
		depends on LEDS_CLASS

drivers/leds/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -9,6 +9,7 @@ obj-$(CONFIG_LEDS_TRIGGERS) += led-triggers.o
		obj-$(CONFIG_LEDS_88PM860X) += leds-88pm860x.o
		obj-$(CONFIG_LEDS_AAT1290) += leds-aat1290.o
		obj-$(CONFIG_LEDS_BCM6328) += leds-bcm6328.o
		obj-$(CONFIG_LEDS_BCM6358) += leds-bcm6358.o
		obj-$(CONFIG_LEDS_BD2802) += leds-bd2802.o
		obj-$(CONFIG_LEDS_LOCOMO) += leds-locomo.o
		obj-$(CONFIG_LEDS_LM3530) += leds-lm3530.o

drivers/leds/leds-bcm6358.c

0 → 100644

+243 −0

Original line number	Diff line number	Diff line
		/*
		* 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)
		{
		iowrite32be(data, reg);
		}

		static unsigned long bcm6358_led_read(void __iomem *reg)
		{
		return ioread32be(reg);
		}

		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;
		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;

		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")) {
		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_mode(led, led->cdev.brightness);
		spin_unlock_irqrestore(lock, flags);

		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)
		return rc;
		}

		return 0;
		}

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

		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");