335 lines
		
	
	
		
			7.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			335 lines
		
	
	
		
			7.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * tps65217_bl.c
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|  *
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|  * TPS65217 backlight driver
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|  *
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|  * Copyright (C) 2012 Matthias Kaehlcke
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|  * Author: Matthias Kaehlcke <matthias@kaehlcke.net>
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|  *
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|  * This program is free software; you can redistribute it and/or
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|  * modify it under the terms of the GNU General Public License as
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|  * published by the Free Software Foundation version 2.
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|  *
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|  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
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|  * kind, whether express or implied; without even the implied warranty
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|  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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|  * GNU General Public License for more details.
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|  */
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| 
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| #include <linux/kernel.h>
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| #include <linux/backlight.h>
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| #include <linux/err.h>
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| #include <linux/fb.h>
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| #include <linux/mfd/tps65217.h>
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| #include <linux/module.h>
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| #include <linux/platform_device.h>
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| #include <linux/slab.h>
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| 
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| struct tps65217_bl {
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| 	struct tps65217 *tps;
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| 	struct device *dev;
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| 	struct backlight_device *bl;
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| 	bool is_enabled;
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| };
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| 
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| static int tps65217_bl_enable(struct tps65217_bl *tps65217_bl)
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| {
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| 	int rc;
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| 
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| 	rc = tps65217_set_bits(tps65217_bl->tps, TPS65217_REG_WLEDCTRL1,
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| 			TPS65217_WLEDCTRL1_ISINK_ENABLE,
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| 			TPS65217_WLEDCTRL1_ISINK_ENABLE, TPS65217_PROTECT_NONE);
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| 	if (rc) {
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| 		dev_err(tps65217_bl->dev,
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| 			"failed to enable backlight: %d\n", rc);
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| 		return rc;
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| 	}
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| 
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| 	tps65217_bl->is_enabled = true;
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| 
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| 	dev_dbg(tps65217_bl->dev, "backlight enabled\n");
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| 
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| 	return 0;
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| }
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| 
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| static int tps65217_bl_disable(struct tps65217_bl *tps65217_bl)
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| {
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| 	int rc;
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| 
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| 	rc = tps65217_clear_bits(tps65217_bl->tps,
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| 				TPS65217_REG_WLEDCTRL1,
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| 				TPS65217_WLEDCTRL1_ISINK_ENABLE,
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| 				TPS65217_PROTECT_NONE);
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| 	if (rc) {
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| 		dev_err(tps65217_bl->dev,
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| 			"failed to disable backlight: %d\n", rc);
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| 		return rc;
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| 	}
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| 
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| 	tps65217_bl->is_enabled = false;
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| 
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| 	dev_dbg(tps65217_bl->dev, "backlight disabled\n");
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| 
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| 	return 0;
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| }
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| 
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| static int tps65217_bl_update_status(struct backlight_device *bl)
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| {
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| 	struct tps65217_bl *tps65217_bl = bl_get_data(bl);
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| 	int rc;
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| 	int brightness = bl->props.brightness;
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| 
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| 	if (bl->props.state & BL_CORE_SUSPENDED)
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| 		brightness = 0;
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| 
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| 	if ((bl->props.power != FB_BLANK_UNBLANK) ||
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| 		(bl->props.fb_blank != FB_BLANK_UNBLANK))
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| 		/* framebuffer in low power mode or blanking active */
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| 		brightness = 0;
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| 
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| 	if (brightness > 0) {
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| 		rc = tps65217_reg_write(tps65217_bl->tps,
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| 					TPS65217_REG_WLEDCTRL2,
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| 					brightness - 1,
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| 					TPS65217_PROTECT_NONE);
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| 		if (rc) {
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| 			dev_err(tps65217_bl->dev,
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| 				"failed to set brightness level: %d\n", rc);
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| 			return rc;
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| 		}
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| 
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| 		dev_dbg(tps65217_bl->dev, "brightness set to %d\n", brightness);
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| 
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| 		if (!tps65217_bl->is_enabled)
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| 			rc = tps65217_bl_enable(tps65217_bl);
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| 	} else {
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| 		rc = tps65217_bl_disable(tps65217_bl);
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| 	}
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| 
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| 	return rc;
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| }
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| 
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| static const struct backlight_ops tps65217_bl_ops = {
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| 	.options	= BL_CORE_SUSPENDRESUME,
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| 	.update_status	= tps65217_bl_update_status,
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| };
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| 
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| static int tps65217_bl_hw_init(struct tps65217_bl *tps65217_bl,
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| 			struct tps65217_bl_pdata *pdata)
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| {
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| 	int rc;
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| 
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| 	rc = tps65217_bl_disable(tps65217_bl);
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| 	if (rc)
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| 		return rc;
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| 
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| 	switch (pdata->isel) {
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| 	case TPS65217_BL_ISET1:
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| 		/* select ISET_1 current level */
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| 		rc = tps65217_clear_bits(tps65217_bl->tps,
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| 					TPS65217_REG_WLEDCTRL1,
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| 					TPS65217_WLEDCTRL1_ISEL,
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| 					TPS65217_PROTECT_NONE);
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| 		if (rc) {
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| 			dev_err(tps65217_bl->dev,
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| 				"failed to select ISET1 current level: %d)\n",
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| 				rc);
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| 			return rc;
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| 		}
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| 
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| 		dev_dbg(tps65217_bl->dev, "selected ISET1 current level\n");
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| 
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| 		break;
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| 
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| 	case TPS65217_BL_ISET2:
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| 		/* select ISET2 current level */
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| 		rc = tps65217_set_bits(tps65217_bl->tps, TPS65217_REG_WLEDCTRL1,
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| 				TPS65217_WLEDCTRL1_ISEL,
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| 				TPS65217_WLEDCTRL1_ISEL, TPS65217_PROTECT_NONE);
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| 		if (rc) {
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| 			dev_err(tps65217_bl->dev,
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| 				"failed to select ISET2 current level: %d\n",
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| 				rc);
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| 			return rc;
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| 		}
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| 
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| 		dev_dbg(tps65217_bl->dev, "selected ISET2 current level\n");
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| 
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| 		break;
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| 
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| 	default:
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| 		dev_err(tps65217_bl->dev,
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| 			"invalid value for current level: %d\n", pdata->isel);
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| 		return -EINVAL;
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| 	}
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| 
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| 	/* set PWM frequency */
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| 	rc = tps65217_set_bits(tps65217_bl->tps,
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| 			TPS65217_REG_WLEDCTRL1,
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| 			TPS65217_WLEDCTRL1_FDIM_MASK,
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| 			pdata->fdim,
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| 			TPS65217_PROTECT_NONE);
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| 	if (rc) {
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| 		dev_err(tps65217_bl->dev,
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| 			"failed to select PWM dimming frequency: %d\n",
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| 			rc);
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| 		return rc;
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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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| #ifdef CONFIG_OF
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| static struct tps65217_bl_pdata *
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| tps65217_bl_parse_dt(struct platform_device *pdev)
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| {
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| 	struct tps65217 *tps = dev_get_drvdata(pdev->dev.parent);
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| 	struct device_node *node;
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| 	struct tps65217_bl_pdata *pdata, *err;
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| 	u32 val;
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| 
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| 	node = of_get_child_by_name(tps->dev->of_node, "backlight");
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| 	if (!node)
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| 		return ERR_PTR(-ENODEV);
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| 
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| 	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
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| 	if (!pdata) {
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| 		err = ERR_PTR(-ENOMEM);
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| 		goto err;
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| 	}
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| 
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| 	pdata->isel = TPS65217_BL_ISET1;
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| 	if (!of_property_read_u32(node, "isel", &val)) {
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| 		if (val < TPS65217_BL_ISET1 ||
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| 			val > TPS65217_BL_ISET2) {
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| 			dev_err(&pdev->dev,
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| 				"invalid 'isel' value in the device tree\n");
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| 			err = ERR_PTR(-EINVAL);
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| 			goto err;
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| 		}
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| 
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| 		pdata->isel = val;
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| 	}
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| 
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| 	pdata->fdim = TPS65217_BL_FDIM_200HZ;
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| 	if (!of_property_read_u32(node, "fdim", &val)) {
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| 		switch (val) {
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| 		case 100:
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| 			pdata->fdim = TPS65217_BL_FDIM_100HZ;
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| 			break;
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| 
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| 		case 200:
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| 			pdata->fdim = TPS65217_BL_FDIM_200HZ;
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| 			break;
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| 
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| 		case 500:
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| 			pdata->fdim = TPS65217_BL_FDIM_500HZ;
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| 			break;
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| 
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| 		case 1000:
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| 			pdata->fdim = TPS65217_BL_FDIM_1000HZ;
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| 			break;
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| 
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| 		default:
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| 			dev_err(&pdev->dev,
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| 				"invalid 'fdim' value in the device tree\n");
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| 			err = ERR_PTR(-EINVAL);
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| 			goto err;
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| 		}
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| 	}
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| 
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| 	if (!of_property_read_u32(node, "default-brightness", &val)) {
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| 		if (val > 100) {
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| 			dev_err(&pdev->dev,
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| 				"invalid 'default-brightness' value in the device tree\n");
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| 			err = ERR_PTR(-EINVAL);
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| 			goto err;
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| 		}
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| 
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| 		pdata->dft_brightness = val;
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| 	}
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| 
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| 	of_node_put(node);
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| 
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| 	return pdata;
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| 
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| err:
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| 	of_node_put(node);
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| 
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| 	return err;
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| }
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| #else
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| static struct tps65217_bl_pdata *
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| tps65217_bl_parse_dt(struct platform_device *pdev)
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| {
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| 	return NULL;
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| }
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| #endif
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| 
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| static int tps65217_bl_probe(struct platform_device *pdev)
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| {
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| 	int rc;
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| 	struct tps65217 *tps = dev_get_drvdata(pdev->dev.parent);
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| 	struct tps65217_bl *tps65217_bl;
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| 	struct tps65217_bl_pdata *pdata;
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| 	struct backlight_properties bl_props;
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| 
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| 	pdata = tps65217_bl_parse_dt(pdev);
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| 	if (IS_ERR(pdata))
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| 		return PTR_ERR(pdata);
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| 
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| 	tps65217_bl = devm_kzalloc(&pdev->dev, sizeof(*tps65217_bl),
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| 				GFP_KERNEL);
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| 	if (tps65217_bl == NULL)
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| 		return -ENOMEM;
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| 
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| 	tps65217_bl->tps = tps;
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| 	tps65217_bl->dev = &pdev->dev;
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| 	tps65217_bl->is_enabled = false;
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| 
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| 	rc = tps65217_bl_hw_init(tps65217_bl, pdata);
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| 	if (rc)
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| 		return rc;
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| 
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| 	memset(&bl_props, 0, sizeof(struct backlight_properties));
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| 	bl_props.type = BACKLIGHT_RAW;
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| 	bl_props.max_brightness = 100;
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| 
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| 	tps65217_bl->bl = devm_backlight_device_register(&pdev->dev, pdev->name,
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| 						tps65217_bl->dev, tps65217_bl,
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| 						&tps65217_bl_ops, &bl_props);
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| 	if (IS_ERR(tps65217_bl->bl)) {
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| 		dev_err(tps65217_bl->dev,
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| 			"registration of backlight device failed: %d\n", rc);
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| 		return PTR_ERR(tps65217_bl->bl);
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| 	}
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| 
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| 	tps65217_bl->bl->props.brightness = pdata->dft_brightness;
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| 	backlight_update_status(tps65217_bl->bl);
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| 	platform_set_drvdata(pdev, tps65217_bl);
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| 
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| 	return 0;
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| }
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| 
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| #ifdef CONFIG_OF
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| static const struct of_device_id tps65217_bl_of_match[] = {
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| 	{ .compatible = "ti,tps65217-bl", },
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| 	{ /* sentinel */ },
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| };
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| MODULE_DEVICE_TABLE(of, tps65217_bl_of_match);
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| #endif
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| 
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| static struct platform_driver tps65217_bl_driver = {
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| 	.probe		= tps65217_bl_probe,
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| 	.driver		= {
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| 		.name	= "tps65217-bl",
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| 		.of_match_table = of_match_ptr(tps65217_bl_of_match),
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| 	},
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| };
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| 
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| module_platform_driver(tps65217_bl_driver);
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| 
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| MODULE_DESCRIPTION("TPS65217 Backlight driver");
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| MODULE_LICENSE("GPL v2");
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| MODULE_AUTHOR("Matthias Kaehlcke <matthias@kaehlcke.net>");
 | 
