308 lines
		
	
	
		
			7.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			308 lines
		
	
	
		
			7.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0-only
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/*
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 * Copyright (C) 2021 Rafał Miłecki <rafal@milecki.pl>
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 */
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#include <linux/delay.h>
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#include <linux/io.h>
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#include <linux/leds.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/pinctrl/consumer.h>
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#include <linux/platform_device.h>
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#include <linux/spinlock.h>
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#define BCM63138_MAX_LEDS				32
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#define BCM63138_MAX_BRIGHTNESS				9
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#define BCM63138_LED_BITS				4				/* how many bits control a single LED */
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#define BCM63138_LED_MASK				((1 << BCM63138_LED_BITS) - 1)	/* 0xf */
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#define BCM63138_LEDS_PER_REG				(32 / BCM63138_LED_BITS)	/* 8 */
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#define BCM63138_GLB_CTRL				0x00
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#define  BCM63138_GLB_CTRL_SERIAL_LED_DATA_PPOL		0x00000002
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#define  BCM63138_GLB_CTRL_SERIAL_LED_EN_POL		0x00000008
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#define BCM63138_MASK					0x04
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#define BCM63138_HW_LED_EN				0x08
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#define BCM63138_SERIAL_LED_SHIFT_SEL			0x0c
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#define BCM63138_FLASH_RATE_CTRL1			0x10
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#define BCM63138_FLASH_RATE_CTRL2			0x14
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#define BCM63138_FLASH_RATE_CTRL3			0x18
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#define BCM63138_FLASH_RATE_CTRL4			0x1c
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#define BCM63138_BRIGHT_CTRL1				0x20
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#define BCM63138_BRIGHT_CTRL2				0x24
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#define BCM63138_BRIGHT_CTRL3				0x28
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#define BCM63138_BRIGHT_CTRL4				0x2c
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#define BCM63138_POWER_LED_CFG				0x30
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#define BCM63138_HW_POLARITY				0xb4
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#define BCM63138_SW_DATA				0xb8
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#define BCM63138_SW_POLARITY				0xbc
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#define BCM63138_PARALLEL_LED_POLARITY			0xc0
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#define BCM63138_SERIAL_LED_POLARITY			0xc4
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#define BCM63138_HW_LED_STATUS				0xc8
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#define BCM63138_FLASH_CTRL_STATUS			0xcc
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#define BCM63138_FLASH_BRT_CTRL				0xd0
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#define BCM63138_FLASH_P_LED_OUT_STATUS			0xd4
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#define BCM63138_FLASH_S_LED_OUT_STATUS			0xd8
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struct bcm63138_leds {
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	struct device *dev;
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	void __iomem *base;
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	spinlock_t lock;
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};
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struct bcm63138_led {
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	struct bcm63138_leds *leds;
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	struct led_classdev cdev;
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	u32 pin;
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	bool active_low;
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};
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/*
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 * I/O access
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 */
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static void bcm63138_leds_write(struct bcm63138_leds *leds, unsigned int reg,
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				u32 data)
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{
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	writel(data, leds->base + reg);
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}
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static unsigned long bcm63138_leds_read(struct bcm63138_leds *leds,
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					unsigned int reg)
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{
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	return readl(leds->base + reg);
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}
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static void bcm63138_leds_update_bits(struct bcm63138_leds *leds,
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				      unsigned int reg, u32 mask, u32 val)
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{
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	WARN_ON(val & ~mask);
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	bcm63138_leds_write(leds, reg, (bcm63138_leds_read(leds, reg) & ~mask) | (val & mask));
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}
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/*
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 * Helpers
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 */
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static void bcm63138_leds_set_flash_rate(struct bcm63138_leds *leds,
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					 struct bcm63138_led *led,
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					 u8 value)
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{
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	int reg_offset = (led->pin >> fls((BCM63138_LEDS_PER_REG - 1))) * 4;
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	int shift = (led->pin & (BCM63138_LEDS_PER_REG - 1)) * BCM63138_LED_BITS;
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	bcm63138_leds_update_bits(leds, BCM63138_FLASH_RATE_CTRL1 + reg_offset,
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				  BCM63138_LED_MASK << shift, value << shift);
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}
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static void bcm63138_leds_set_bright(struct bcm63138_leds *leds,
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				     struct bcm63138_led *led,
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				     u8 value)
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{
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	int reg_offset = (led->pin >> fls((BCM63138_LEDS_PER_REG - 1))) * 4;
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	int shift = (led->pin & (BCM63138_LEDS_PER_REG - 1)) * BCM63138_LED_BITS;
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	bcm63138_leds_update_bits(leds, BCM63138_BRIGHT_CTRL1 + reg_offset,
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				  BCM63138_LED_MASK << shift, value << shift);
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}
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static void bcm63138_leds_enable_led(struct bcm63138_leds *leds,
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				     struct bcm63138_led *led,
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				     enum led_brightness value)
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{
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	u32 bit = BIT(led->pin);
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	bcm63138_leds_update_bits(leds, BCM63138_SW_DATA, bit, value ? bit : 0);
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}
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/*
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 * API callbacks
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 */
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static void bcm63138_leds_brightness_set(struct led_classdev *led_cdev,
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					 enum led_brightness value)
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{
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	struct bcm63138_led *led = container_of(led_cdev, struct bcm63138_led, cdev);
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	struct bcm63138_leds *leds = led->leds;
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	unsigned long flags;
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	spin_lock_irqsave(&leds->lock, flags);
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	bcm63138_leds_enable_led(leds, led, value);
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	if (!value)
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		bcm63138_leds_set_flash_rate(leds, led, 0);
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	else
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		bcm63138_leds_set_bright(leds, led, value);
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	spin_unlock_irqrestore(&leds->lock, flags);
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}
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static int bcm63138_leds_blink_set(struct led_classdev *led_cdev,
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				   unsigned long *delay_on,
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				   unsigned long *delay_off)
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{
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	struct bcm63138_led *led = container_of(led_cdev, struct bcm63138_led, cdev);
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	struct bcm63138_leds *leds = led->leds;
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	unsigned long flags;
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	u8 value;
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	if (!*delay_on && !*delay_off) {
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		*delay_on = 640;
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		*delay_off = 640;
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	}
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	if (*delay_on != *delay_off) {
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		dev_dbg(led_cdev->dev, "Blinking at unequal delays is not supported\n");
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		return -EINVAL;
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	}
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	switch (*delay_on) {
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	case 1152 ... 1408: /* 1280 ms ± 10% */
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		value = 0x7;
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		break;
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	case 576 ... 704: /* 640 ms ± 10% */
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		value = 0x6;
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		break;
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	case 288 ... 352: /* 320 ms ± 10% */
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		value = 0x5;
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		break;
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	case 126 ... 154: /* 140 ms ± 10% */
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		value = 0x4;
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		break;
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	case 59 ... 72: /* 65 ms ± 10% */
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		value = 0x3;
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		break;
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	default:
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		dev_dbg(led_cdev->dev, "Blinking delay value %lu is unsupported\n",
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			*delay_on);
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		return -EINVAL;
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	}
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	spin_lock_irqsave(&leds->lock, flags);
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	bcm63138_leds_enable_led(leds, led, BCM63138_MAX_BRIGHTNESS);
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	bcm63138_leds_set_flash_rate(leds, led, value);
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	spin_unlock_irqrestore(&leds->lock, flags);
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	return 0;
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}
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/*
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 * LED driver
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 */
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static void bcm63138_leds_create_led(struct bcm63138_leds *leds,
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				     struct device_node *np)
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{
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	struct led_init_data init_data = {
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		.fwnode = of_fwnode_handle(np),
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	};
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	struct device *dev = leds->dev;
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	struct bcm63138_led *led;
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	struct pinctrl *pinctrl;
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	u32 bit;
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	int err;
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	led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);
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	if (!led) {
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		dev_err(dev, "Failed to alloc LED\n");
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		return;
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	}
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	led->leds = leds;
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	if (of_property_read_u32(np, "reg", &led->pin)) {
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		dev_err(dev, "Missing \"reg\" property in %pOF\n", np);
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		goto err_free;
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	}
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	if (led->pin >= BCM63138_MAX_LEDS) {
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		dev_err(dev, "Invalid \"reg\" value %d\n", led->pin);
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		goto err_free;
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	}
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	led->active_low = of_property_read_bool(np, "active-low");
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	led->cdev.max_brightness = BCM63138_MAX_BRIGHTNESS;
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	led->cdev.brightness_set = bcm63138_leds_brightness_set;
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	led->cdev.blink_set = bcm63138_leds_blink_set;
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	err = devm_led_classdev_register_ext(dev, &led->cdev, &init_data);
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	if (err) {
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		dev_err(dev, "Failed to register LED %pOF: %d\n", np, err);
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		goto err_free;
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	}
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	pinctrl = devm_pinctrl_get_select_default(led->cdev.dev);
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	if (IS_ERR(pinctrl) && PTR_ERR(pinctrl) != -ENODEV) {
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		dev_warn(led->cdev.dev, "Failed to select %pOF pinctrl: %ld\n",
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			 np, PTR_ERR(pinctrl));
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	}
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	bit = BIT(led->pin);
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	bcm63138_leds_update_bits(leds, BCM63138_PARALLEL_LED_POLARITY, bit,
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				  led->active_low ? 0 : bit);
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	bcm63138_leds_update_bits(leds, BCM63138_HW_LED_EN, bit, 0);
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	bcm63138_leds_set_flash_rate(leds, led, 0);
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	bcm63138_leds_enable_led(leds, led, led->cdev.brightness);
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	return;
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err_free:
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	devm_kfree(dev, led);
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}
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static int bcm63138_leds_probe(struct platform_device *pdev)
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{
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	struct device_node *np = dev_of_node(&pdev->dev);
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	struct device *dev = &pdev->dev;
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	struct bcm63138_leds *leds;
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	struct device_node *child;
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	leds = devm_kzalloc(dev, sizeof(*leds), GFP_KERNEL);
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	if (!leds)
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		return -ENOMEM;
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	leds->dev = dev;
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	leds->base = devm_platform_ioremap_resource(pdev, 0);
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	if (IS_ERR(leds->base))
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		return PTR_ERR(leds->base);
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	spin_lock_init(&leds->lock);
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	bcm63138_leds_write(leds, BCM63138_GLB_CTRL,
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			    BCM63138_GLB_CTRL_SERIAL_LED_DATA_PPOL |
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			    BCM63138_GLB_CTRL_SERIAL_LED_EN_POL);
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	bcm63138_leds_write(leds, BCM63138_HW_LED_EN, 0);
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	bcm63138_leds_write(leds, BCM63138_SERIAL_LED_POLARITY, 0);
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	bcm63138_leds_write(leds, BCM63138_PARALLEL_LED_POLARITY, 0);
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	for_each_available_child_of_node(np, child) {
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		bcm63138_leds_create_led(leds, child);
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	}
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	return 0;
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}
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static const struct of_device_id bcm63138_leds_of_match_table[] = {
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	{ .compatible = "brcm,bcm63138-leds", },
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	{ },
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};
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static struct platform_driver bcm63138_leds_driver = {
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	.probe = bcm63138_leds_probe,
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	.driver = {
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		.name = "leds-bcm63xxx",
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		.of_match_table = bcm63138_leds_of_match_table,
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	},
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};
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module_platform_driver(bcm63138_leds_driver);
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MODULE_AUTHOR("Rafał Miłecki");
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MODULE_LICENSE("GPL");
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MODULE_DEVICE_TABLE(of, bcm63138_leds_of_match_table);
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