497 lines
		
	
	
		
			13 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			497 lines
		
	
	
		
			13 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0-only
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| /*
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|  * Driver for ISSI IS31FL32xx family of I2C LED controllers
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|  *
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|  * Copyright 2015 Allworx Corp.
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|  *
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|  * Datasheets:
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|  *   http://www.issi.com/US/product-analog-fxled-driver.shtml
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|  *   http://www.si-en.com/product.asp?parentid=890
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|  */
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| 
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| #include <linux/device.h>
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| #include <linux/i2c.h>
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| #include <linux/kernel.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/of_device.h>
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| 
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| /* Used to indicate a device has no such register */
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| #define IS31FL32XX_REG_NONE 0xFF
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| 
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| /* Software Shutdown bit in Shutdown Register */
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| #define IS31FL32XX_SHUTDOWN_SSD_ENABLE  0
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| #define IS31FL32XX_SHUTDOWN_SSD_DISABLE BIT(0)
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| 
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| /* IS31FL3216 has a number of unique registers */
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| #define IS31FL3216_CONFIG_REG 0x00
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| #define IS31FL3216_LIGHTING_EFFECT_REG 0x03
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| #define IS31FL3216_CHANNEL_CONFIG_REG 0x04
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| 
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| /* Software Shutdown bit in 3216 Config Register */
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| #define IS31FL3216_CONFIG_SSD_ENABLE  BIT(7)
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| #define IS31FL3216_CONFIG_SSD_DISABLE 0
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| 
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| struct is31fl32xx_priv;
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| struct is31fl32xx_led_data {
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| 	struct led_classdev cdev;
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| 	u8 channel; /* 1-based, max priv->cdef->channels */
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| 	struct is31fl32xx_priv *priv;
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| };
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| 
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| struct is31fl32xx_priv {
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| 	const struct is31fl32xx_chipdef *cdef;
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| 	struct i2c_client *client;
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| 	unsigned int num_leds;
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| 	struct is31fl32xx_led_data leds[];
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| };
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| 
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| /**
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|  * struct is31fl32xx_chipdef - chip-specific attributes
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|  * @channels            : Number of LED channels
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|  * @shutdown_reg        : address of Shutdown register (optional)
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|  * @pwm_update_reg      : address of PWM Update register
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|  * @global_control_reg  : address of Global Control register (optional)
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|  * @reset_reg           : address of Reset register (optional)
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|  * @pwm_register_base   : address of first PWM register
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|  * @pwm_registers_reversed: : true if PWM registers count down instead of up
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|  * @led_control_register_base : address of first LED control register (optional)
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|  * @enable_bits_per_led_control_register: number of LEDs enable bits in each
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|  * @reset_func          : pointer to reset function
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|  * @sw_shutdown_func    : pointer to software shutdown function
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|  *
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|  * For all optional register addresses, the sentinel value %IS31FL32XX_REG_NONE
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|  * indicates that this chip has no such register.
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|  *
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|  * If non-NULL, @reset_func will be called during probing to set all
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|  * necessary registers to a known initialization state. This is needed
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|  * for chips that do not have a @reset_reg.
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|  *
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|  * @enable_bits_per_led_control_register must be >=1 if
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|  * @led_control_register_base != %IS31FL32XX_REG_NONE.
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|  */
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| struct is31fl32xx_chipdef {
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| 	u8	channels;
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| 	u8	shutdown_reg;
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| 	u8	pwm_update_reg;
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| 	u8	global_control_reg;
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| 	u8	reset_reg;
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| 	u8	pwm_register_base;
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| 	bool	pwm_registers_reversed;
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| 	u8	led_control_register_base;
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| 	u8	enable_bits_per_led_control_register;
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| 	int (*reset_func)(struct is31fl32xx_priv *priv);
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| 	int (*sw_shutdown_func)(struct is31fl32xx_priv *priv, bool enable);
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| };
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| 
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| static const struct is31fl32xx_chipdef is31fl3236_cdef = {
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| 	.channels				= 36,
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| 	.shutdown_reg				= 0x00,
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| 	.pwm_update_reg				= 0x25,
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| 	.global_control_reg			= 0x4a,
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| 	.reset_reg				= 0x4f,
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| 	.pwm_register_base			= 0x01,
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| 	.led_control_register_base		= 0x26,
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| 	.enable_bits_per_led_control_register	= 1,
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| };
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| 
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| static const struct is31fl32xx_chipdef is31fl3235_cdef = {
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| 	.channels				= 28,
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| 	.shutdown_reg				= 0x00,
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| 	.pwm_update_reg				= 0x25,
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| 	.global_control_reg			= 0x4a,
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| 	.reset_reg				= 0x4f,
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| 	.pwm_register_base			= 0x05,
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| 	.led_control_register_base		= 0x2a,
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| 	.enable_bits_per_led_control_register	= 1,
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| };
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| 
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| static const struct is31fl32xx_chipdef is31fl3218_cdef = {
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| 	.channels				= 18,
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| 	.shutdown_reg				= 0x00,
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| 	.pwm_update_reg				= 0x16,
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| 	.global_control_reg			= IS31FL32XX_REG_NONE,
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| 	.reset_reg				= 0x17,
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| 	.pwm_register_base			= 0x01,
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| 	.led_control_register_base		= 0x13,
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| 	.enable_bits_per_led_control_register	= 6,
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| };
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| 
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| static int is31fl3216_reset(struct is31fl32xx_priv *priv);
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| static int is31fl3216_software_shutdown(struct is31fl32xx_priv *priv,
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| 					bool enable);
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| static const struct is31fl32xx_chipdef is31fl3216_cdef = {
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| 	.channels				= 16,
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| 	.shutdown_reg				= IS31FL32XX_REG_NONE,
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| 	.pwm_update_reg				= 0xB0,
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| 	.global_control_reg			= IS31FL32XX_REG_NONE,
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| 	.reset_reg				= IS31FL32XX_REG_NONE,
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| 	.pwm_register_base			= 0x10,
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| 	.pwm_registers_reversed			= true,
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| 	.led_control_register_base		= 0x01,
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| 	.enable_bits_per_led_control_register	= 8,
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| 	.reset_func				= is31fl3216_reset,
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| 	.sw_shutdown_func			= is31fl3216_software_shutdown,
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| };
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| 
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| static int is31fl32xx_write(struct is31fl32xx_priv *priv, u8 reg, u8 val)
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| {
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| 	int ret;
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| 
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| 	dev_dbg(&priv->client->dev, "writing register 0x%02X=0x%02X", reg, val);
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| 
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| 	ret =  i2c_smbus_write_byte_data(priv->client, reg, val);
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| 	if (ret) {
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| 		dev_err(&priv->client->dev,
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| 			"register write to 0x%02X failed (error %d)",
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| 			reg, ret);
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| 	}
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| 	return ret;
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| }
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| 
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| /*
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|  * Custom reset function for IS31FL3216 because it does not have a RESET
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|  * register the way that the other IS31FL32xx chips do. We don't bother
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|  * writing the GPIO and animation registers, because the registers we
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|  * do write ensure those will have no effect.
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|  */
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| static int is31fl3216_reset(struct is31fl32xx_priv *priv)
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| {
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| 	unsigned int i;
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| 	int ret;
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| 
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| 	ret = is31fl32xx_write(priv, IS31FL3216_CONFIG_REG,
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| 			       IS31FL3216_CONFIG_SSD_ENABLE);
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| 	if (ret)
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| 		return ret;
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| 	for (i = 0; i < priv->cdef->channels; i++) {
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| 		ret = is31fl32xx_write(priv, priv->cdef->pwm_register_base+i,
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| 				       0x00);
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| 		if (ret)
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| 			return ret;
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| 	}
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| 	ret = is31fl32xx_write(priv, priv->cdef->pwm_update_reg, 0);
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| 	if (ret)
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| 		return ret;
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| 	ret = is31fl32xx_write(priv, IS31FL3216_LIGHTING_EFFECT_REG, 0x00);
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| 	if (ret)
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| 		return ret;
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| 	ret = is31fl32xx_write(priv, IS31FL3216_CHANNEL_CONFIG_REG, 0x00);
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| 	if (ret)
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| 		return ret;
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| 
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| 	return 0;
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| }
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| 
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| /*
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|  * Custom Software-Shutdown function for IS31FL3216 because it does not have
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|  * a SHUTDOWN register the way that the other IS31FL32xx chips do.
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|  * We don't bother doing a read/modify/write on the CONFIG register because
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|  * we only ever use a value of '0' for the other fields in that register.
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|  */
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| static int is31fl3216_software_shutdown(struct is31fl32xx_priv *priv,
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| 					bool enable)
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| {
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| 	u8 value = enable ? IS31FL3216_CONFIG_SSD_ENABLE :
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| 			    IS31FL3216_CONFIG_SSD_DISABLE;
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| 
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| 	return is31fl32xx_write(priv, IS31FL3216_CONFIG_REG, value);
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| }
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| 
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| /*
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|  * NOTE: A mutex is not needed in this function because:
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|  * - All referenced data is read-only after probe()
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|  * - The I2C core has a mutex on to protect the bus
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|  * - There are no read/modify/write operations
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|  * - Intervening operations between the write of the PWM register
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|  *   and the Update register are harmless.
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|  *
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|  * Example:
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|  *	PWM_REG_1 write 16
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|  *	UPDATE_REG write 0
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|  *	PWM_REG_2 write 128
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|  *	UPDATE_REG write 0
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|  *   vs:
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|  *	PWM_REG_1 write 16
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|  *	PWM_REG_2 write 128
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|  *	UPDATE_REG write 0
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|  *	UPDATE_REG write 0
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|  * are equivalent. Poking the Update register merely applies all PWM
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|  * register writes up to that point.
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|  */
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| static int is31fl32xx_brightness_set(struct led_classdev *led_cdev,
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| 				     enum led_brightness brightness)
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| {
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| 	const struct is31fl32xx_led_data *led_data =
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| 		container_of(led_cdev, struct is31fl32xx_led_data, cdev);
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| 	const struct is31fl32xx_chipdef *cdef = led_data->priv->cdef;
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| 	u8 pwm_register_offset;
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| 	int ret;
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| 
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| 	dev_dbg(led_cdev->dev, "%s: %d\n", __func__, brightness);
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| 
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| 	/* NOTE: led_data->channel is 1-based */
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| 	if (cdef->pwm_registers_reversed)
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| 		pwm_register_offset = cdef->channels - led_data->channel;
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| 	else
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| 		pwm_register_offset = led_data->channel - 1;
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| 
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| 	ret = is31fl32xx_write(led_data->priv,
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| 			       cdef->pwm_register_base + pwm_register_offset,
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| 			       brightness);
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| 	if (ret)
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| 		return ret;
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| 
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| 	return is31fl32xx_write(led_data->priv, cdef->pwm_update_reg, 0);
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| }
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| 
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| static int is31fl32xx_reset_regs(struct is31fl32xx_priv *priv)
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| {
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| 	const struct is31fl32xx_chipdef *cdef = priv->cdef;
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| 	int ret;
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| 
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| 	if (cdef->reset_reg != IS31FL32XX_REG_NONE) {
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| 		ret = is31fl32xx_write(priv, cdef->reset_reg, 0);
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| 		if (ret)
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| 			return ret;
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| 	}
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| 
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| 	if (cdef->reset_func)
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| 		return cdef->reset_func(priv);
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| 
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| 	return 0;
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| }
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| 
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| static int is31fl32xx_software_shutdown(struct is31fl32xx_priv *priv,
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| 					bool enable)
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| {
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| 	const struct is31fl32xx_chipdef *cdef = priv->cdef;
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| 	int ret;
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| 
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| 	if (cdef->shutdown_reg != IS31FL32XX_REG_NONE) {
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| 		u8 value = enable ? IS31FL32XX_SHUTDOWN_SSD_ENABLE :
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| 				    IS31FL32XX_SHUTDOWN_SSD_DISABLE;
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| 		ret = is31fl32xx_write(priv, cdef->shutdown_reg, value);
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| 		if (ret)
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| 			return ret;
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| 	}
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| 
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| 	if (cdef->sw_shutdown_func)
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| 		return cdef->sw_shutdown_func(priv, enable);
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| 
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| 	return 0;
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| }
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| 
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| static int is31fl32xx_init_regs(struct is31fl32xx_priv *priv)
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| {
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| 	const struct is31fl32xx_chipdef *cdef = priv->cdef;
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| 	int ret;
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| 
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| 	ret = is31fl32xx_reset_regs(priv);
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| 	if (ret)
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| 		return ret;
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| 
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| 	/*
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| 	 * Set enable bit for all channels.
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| 	 * We will control state with PWM registers alone.
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| 	 */
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| 	if (cdef->led_control_register_base != IS31FL32XX_REG_NONE) {
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| 		u8 value =
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| 		    GENMASK(cdef->enable_bits_per_led_control_register-1, 0);
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| 		u8 num_regs = cdef->channels /
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| 				cdef->enable_bits_per_led_control_register;
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| 		int i;
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| 
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| 		for (i = 0; i < num_regs; i++) {
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| 			ret = is31fl32xx_write(priv,
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| 					       cdef->led_control_register_base+i,
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| 					       value);
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| 			if (ret)
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| 				return ret;
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| 		}
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| 	}
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| 
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| 	ret = is31fl32xx_software_shutdown(priv, false);
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| 	if (ret)
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| 		return ret;
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| 
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| 	if (cdef->global_control_reg != IS31FL32XX_REG_NONE) {
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| 		ret = is31fl32xx_write(priv, cdef->global_control_reg, 0x00);
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| 		if (ret)
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| 			return ret;
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| 	}
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| 
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| 	return 0;
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| }
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| 
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| static int is31fl32xx_parse_child_dt(const struct device *dev,
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| 				     const struct device_node *child,
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| 				     struct is31fl32xx_led_data *led_data)
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| {
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| 	struct led_classdev *cdev = &led_data->cdev;
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| 	int ret = 0;
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| 	u32 reg;
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| 
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| 	ret = of_property_read_u32(child, "reg", ®);
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| 	if (ret || reg < 1 || reg > led_data->priv->cdef->channels) {
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| 		dev_err(dev,
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| 			"Child node %pOF does not have a valid reg property\n",
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| 			child);
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| 		return -EINVAL;
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| 	}
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| 	led_data->channel = reg;
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| 
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| 	cdev->brightness_set_blocking = is31fl32xx_brightness_set;
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| 
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| 	return 0;
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| }
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| 
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| static struct is31fl32xx_led_data *is31fl32xx_find_led_data(
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| 					struct is31fl32xx_priv *priv,
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| 					u8 channel)
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| {
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| 	size_t i;
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| 
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| 	for (i = 0; i < priv->num_leds; i++) {
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| 		if (priv->leds[i].channel == channel)
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| 			return &priv->leds[i];
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| 	}
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| 
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| 	return NULL;
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| }
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| 
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| static int is31fl32xx_parse_dt(struct device *dev,
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| 			       struct is31fl32xx_priv *priv)
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| {
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| 	struct device_node *child;
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| 	int ret = 0;
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| 
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| 	for_each_available_child_of_node(dev_of_node(dev), child) {
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| 		struct led_init_data init_data = {};
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| 		struct is31fl32xx_led_data *led_data =
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| 			&priv->leds[priv->num_leds];
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| 		const struct is31fl32xx_led_data *other_led_data;
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| 
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| 		led_data->priv = priv;
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| 
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| 		ret = is31fl32xx_parse_child_dt(dev, child, led_data);
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| 		if (ret)
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| 			goto err;
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| 
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| 		/* Detect if channel is already in use by another child */
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| 		other_led_data = is31fl32xx_find_led_data(priv,
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| 							  led_data->channel);
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| 		if (other_led_data) {
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| 			dev_err(dev,
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| 				"Node %pOF 'reg' conflicts with another LED\n",
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| 				child);
 | |
| 			goto err;
 | |
| 		}
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| 
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| 		init_data.fwnode = of_fwnode_handle(child);
 | |
| 
 | |
| 		ret = devm_led_classdev_register_ext(dev, &led_data->cdev,
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| 						     &init_data);
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| 		if (ret) {
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| 			dev_err(dev, "Failed to register LED for %pOF: %d\n",
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| 				child, ret);
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| 			goto err;
 | |
| 		}
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| 
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| 		priv->num_leds++;
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| 	}
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| 
 | |
| 	return 0;
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| 
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| err:
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| 	of_node_put(child);
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| 	return ret;
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| }
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| 
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| static const struct of_device_id of_is31fl32xx_match[] = {
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| 	{ .compatible = "issi,is31fl3236", .data = &is31fl3236_cdef, },
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| 	{ .compatible = "issi,is31fl3235", .data = &is31fl3235_cdef, },
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| 	{ .compatible = "issi,is31fl3218", .data = &is31fl3218_cdef, },
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| 	{ .compatible = "si-en,sn3218",    .data = &is31fl3218_cdef, },
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| 	{ .compatible = "issi,is31fl3216", .data = &is31fl3216_cdef, },
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| 	{ .compatible = "si-en,sn3216",    .data = &is31fl3216_cdef, },
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| 	{},
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| };
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| 
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| MODULE_DEVICE_TABLE(of, of_is31fl32xx_match);
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| 
 | |
| static int is31fl32xx_probe(struct i2c_client *client,
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| 			    const struct i2c_device_id *id)
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| {
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| 	const struct is31fl32xx_chipdef *cdef;
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| 	struct device *dev = &client->dev;
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| 	struct is31fl32xx_priv *priv;
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| 	int count;
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| 	int ret = 0;
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| 
 | |
| 	cdef = device_get_match_data(dev);
 | |
| 
 | |
| 	count = of_get_available_child_count(dev_of_node(dev));
 | |
| 	if (!count)
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| 		return -EINVAL;
 | |
| 
 | |
| 	priv = devm_kzalloc(dev, struct_size(priv, leds, count),
 | |
| 			    GFP_KERNEL);
 | |
| 	if (!priv)
 | |
| 		return -ENOMEM;
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| 
 | |
| 	priv->client = client;
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| 	priv->cdef = cdef;
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| 	i2c_set_clientdata(client, priv);
 | |
| 
 | |
| 	ret = is31fl32xx_init_regs(priv);
 | |
| 	if (ret)
 | |
| 		return ret;
 | |
| 
 | |
| 	ret = is31fl32xx_parse_dt(dev, priv);
 | |
| 	if (ret)
 | |
| 		return ret;
 | |
| 
 | |
| 	return 0;
 | |
| }
 | |
| 
 | |
| static int is31fl32xx_remove(struct i2c_client *client)
 | |
| {
 | |
| 	struct is31fl32xx_priv *priv = i2c_get_clientdata(client);
 | |
| 
 | |
| 	return is31fl32xx_reset_regs(priv);
 | |
| }
 | |
| 
 | |
| /*
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|  * i2c-core (and modalias) requires that id_table be properly filled,
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|  * even though it is not used for DeviceTree based instantiation.
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|  */
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| static const struct i2c_device_id is31fl32xx_id[] = {
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| 	{ "is31fl3236" },
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| 	{ "is31fl3235" },
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| 	{ "is31fl3218" },
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| 	{ "sn3218" },
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| 	{ "is31fl3216" },
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| 	{ "sn3216" },
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| 	{},
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| };
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| 
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| MODULE_DEVICE_TABLE(i2c, is31fl32xx_id);
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| 
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| static struct i2c_driver is31fl32xx_driver = {
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| 	.driver = {
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| 		.name	= "is31fl32xx",
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| 		.of_match_table = of_is31fl32xx_match,
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| 	},
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| 	.probe		= is31fl32xx_probe,
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| 	.remove		= is31fl32xx_remove,
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| 	.id_table	= is31fl32xx_id,
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| };
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| 
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| module_i2c_driver(is31fl32xx_driver);
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| 
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| MODULE_AUTHOR("David Rivshin <drivshin@allworx.com>");
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| MODULE_DESCRIPTION("ISSI IS31FL32xx LED driver");
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| MODULE_LICENSE("GPL v2");
 |