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Release 4.14 drivers/video/backlight/max8925_bl.c

/*
 * Backlight driver for Maxim MAX8925
 *
 * Copyright (C) 2009 Marvell International Ltd.
 *      Haojian Zhuang <haojian.zhuang@marvell.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/fb.h>
#include <linux/i2c.h>
#include <linux/backlight.h>
#include <linux/mfd/max8925.h>
#include <linux/slab.h>
#include <linux/module.h>


#define MAX_BRIGHTNESS		(0xff)

#define MIN_BRIGHTNESS		(0)


#define LWX_FREQ(x)		(((x - 601) / 100) & 0x7)


struct max8925_backlight_data {
	
struct max8925_chip	*chip;

	
int	current_brightness;
	
int	reg_mode_cntl;
	
int	reg_cntl;
};


static int max8925_backlight_set(struct backlight_device *bl, int brightness) { struct max8925_backlight_data *data = bl_get_data(bl); struct max8925_chip *chip = data->chip; unsigned char value; int ret; if (brightness > MAX_BRIGHTNESS) value = MAX_BRIGHTNESS; else value = brightness; ret = max8925_reg_write(chip->i2c, data->reg_cntl, value); if (ret < 0) goto out; if (!data->current_brightness && brightness) /* enable WLED output */ ret = max8925_set_bits(chip->i2c, data->reg_mode_cntl, 1, 1); else if (!brightness) /* disable WLED output */ ret = max8925_set_bits(chip->i2c, data->reg_mode_cntl, 1, 0); if (ret < 0) goto out; dev_dbg(chip->dev, "set brightness %d\n", value); data->current_brightness = value; return 0; out: dev_dbg(chip->dev, "set brightness %d failure with return value:%d\n", value, ret); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Haojian Zhuang177100.00%2100.00%
Total177100.00%2100.00%


static int max8925_backlight_update_status(struct backlight_device *bl) { int brightness = bl->props.brightness; if (bl->props.power != FB_BLANK_UNBLANK) brightness = 0; if (bl->props.fb_blank != FB_BLANK_UNBLANK) brightness = 0; if (bl->props.state & BL_CORE_SUSPENDED) brightness = 0; return max8925_backlight_set(bl, brightness); }

Contributors

PersonTokensPropCommitsCommitProp
Haojian Zhuang70100.00%1100.00%
Total70100.00%1100.00%


static int max8925_backlight_get_brightness(struct backlight_device *bl) { struct max8925_backlight_data *data = bl_get_data(bl); struct max8925_chip *chip = data->chip; int ret; ret = max8925_reg_read(chip->i2c, data->reg_cntl); if (ret < 0) return -EINVAL; data->current_brightness = ret; dev_dbg(chip->dev, "get brightness %d\n", data->current_brightness); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Haojian Zhuang78100.00%2100.00%
Total78100.00%2100.00%

static const struct backlight_ops max8925_backlight_ops = { .options = BL_CORE_SUSPENDRESUME, .update_status = max8925_backlight_update_status, .get_brightness = max8925_backlight_get_brightness, };
static void max8925_backlight_dt_init(struct platform_device *pdev) { struct device_node *nproot = pdev->dev.parent->of_node, *np; struct max8925_backlight_pdata *pdata; u32 val; if (!nproot || !IS_ENABLED(CONFIG_OF)) return; pdata = devm_kzalloc(&pdev->dev, sizeof(struct max8925_backlight_pdata), GFP_KERNEL); if (!pdata) return; np = of_find_node_by_name(nproot, "backlight"); if (!np) { dev_err(&pdev->dev, "failed to find backlight node\n"); return; } if (!of_property_read_u32(np, "maxim,max8925-dual-string", &val)) pdata->dual_string = val; pdev->dev.platform_data = pdata; }

Contributors

PersonTokensPropCommitsCommitProp
Qing Xu7156.80%150.00%
Olof Johansson5443.20%150.00%
Total125100.00%2100.00%


static int max8925_backlight_probe(struct platform_device *pdev) { struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent); struct max8925_backlight_pdata *pdata; struct max8925_backlight_data *data; struct backlight_device *bl; struct backlight_properties props; struct resource *res; unsigned char value; int ret = 0; data = devm_kzalloc(&pdev->dev, sizeof(struct max8925_backlight_data), GFP_KERNEL); if (data == NULL) return -ENOMEM; res = platform_get_resource(pdev, IORESOURCE_REG, 0); if (!res) { dev_err(&pdev->dev, "No REG resource for mode control!\n"); return -ENXIO; } data->reg_mode_cntl = res->start; res = platform_get_resource(pdev, IORESOURCE_REG, 1); if (!res) { dev_err(&pdev->dev, "No REG resource for control!\n"); return -ENXIO; } data->reg_cntl = res->start; data->chip = chip; data->current_brightness = 0; memset(&props, 0, sizeof(struct backlight_properties)); props.type = BACKLIGHT_RAW; props.max_brightness = MAX_BRIGHTNESS; bl = devm_backlight_device_register(&pdev->dev, "max8925-backlight", &pdev->dev, data, &max8925_backlight_ops, &props); if (IS_ERR(bl)) { dev_err(&pdev->dev, "failed to register backlight\n"); return PTR_ERR(bl); } bl->props.brightness = MAX_BRIGHTNESS; platform_set_drvdata(pdev, bl); value = 0; if (!pdev->dev.platform_data) max8925_backlight_dt_init(pdev); pdata = pdev->dev.platform_data; if (pdata) { if (pdata->lxw_scl) value |= (1 << 7); if (pdata->lxw_freq) value |= (LWX_FREQ(pdata->lxw_freq) << 4); if (pdata->dual_string) value |= (1 << 1); } ret = max8925_set_bits(chip->i2c, data->reg_mode_cntl, 0xfe, value); if (ret < 0) return ret; backlight_update_status(bl); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Haojian Zhuang31281.68%220.00%
Matthew Garrett338.64%220.00%
Qing Xu133.40%110.00%
Jingoo Han133.40%220.00%
Olof Johansson92.36%110.00%
Mark Brown10.26%110.00%
Julia Lawall10.26%110.00%
Total382100.00%10100.00%

static struct platform_driver max8925_backlight_driver = { .driver = { .name = "max8925-backlight", }, .probe = max8925_backlight_probe, }; module_platform_driver(max8925_backlight_driver); MODULE_DESCRIPTION("Backlight Driver for Maxim MAX8925"); MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:max8925-backlight");

Overall Contributors

PersonTokensPropCommitsCommitProp
Haojian Zhuang76178.94%214.29%
Qing Xu848.71%17.14%
Olof Johansson636.54%17.14%
Matthew Garrett333.42%214.29%
Jingoo Han131.35%214.29%
Tejun Heo30.31%17.14%
Paul Gortmaker30.31%17.14%
Axel Lin10.10%17.14%
Julia Lawall10.10%17.14%
Mark Brown10.10%17.14%
Lionel Debroux10.10%17.14%
Total964100.00%14100.00%
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