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![Matthew Garrett](/assets/img/avatar_default.png)
There may be multiple ways of controlling the backlight on a given machine. Allow drivers to expose the type of interface they are providing, making it possible for userspace to make appropriate policy decisions. Signed-off-by: Matthew Garrett <mjg@redhat.com> Cc: Richard Purdie <rpurdie@rpsys.net> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: David Airlie <airlied@linux.ie> Cc: Alex Deucher <alexdeucher@gmail.com> Cc: Ben Skeggs <bskeggs@redhat.com> Cc: Zhang Rui <rui.zhang@intel.com> Cc: Len Brown <lenb@kernel.org> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
205 lines
5.2 KiB
C
205 lines
5.2 KiB
C
/*
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* Backlight driver for Maxim MAX8925
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*
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* Copyright (C) 2009 Marvell International Ltd.
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* Haojian Zhuang <haojian.zhuang@marvell.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/platform_device.h>
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#include <linux/fb.h>
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#include <linux/i2c.h>
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#include <linux/backlight.h>
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#include <linux/mfd/max8925.h>
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#include <linux/slab.h>
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#define MAX_BRIGHTNESS (0xff)
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#define MIN_BRIGHTNESS (0)
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#define LWX_FREQ(x) (((x - 601) / 100) & 0x7)
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struct max8925_backlight_data {
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struct max8925_chip *chip;
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int current_brightness;
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};
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static int max8925_backlight_set(struct backlight_device *bl, int brightness)
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{
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struct max8925_backlight_data *data = bl_get_data(bl);
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struct max8925_chip *chip = data->chip;
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unsigned char value;
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int ret;
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if (brightness > MAX_BRIGHTNESS)
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value = MAX_BRIGHTNESS;
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else
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value = brightness;
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ret = max8925_reg_write(chip->i2c, MAX8925_WLED_CNTL, value);
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if (ret < 0)
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goto out;
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if (!data->current_brightness && brightness)
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/* enable WLED output */
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ret = max8925_set_bits(chip->i2c, MAX8925_WLED_MODE_CNTL, 1, 1);
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else if (!brightness)
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/* disable WLED output */
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ret = max8925_set_bits(chip->i2c, MAX8925_WLED_MODE_CNTL, 1, 0);
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if (ret < 0)
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goto out;
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dev_dbg(chip->dev, "set brightness %d\n", value);
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data->current_brightness = value;
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return 0;
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out:
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dev_dbg(chip->dev, "set brightness %d failure with return value:%d\n",
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value, ret);
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return ret;
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}
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static int max8925_backlight_update_status(struct backlight_device *bl)
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{
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int brightness = bl->props.brightness;
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if (bl->props.power != FB_BLANK_UNBLANK)
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brightness = 0;
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if (bl->props.fb_blank != FB_BLANK_UNBLANK)
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brightness = 0;
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if (bl->props.state & BL_CORE_SUSPENDED)
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brightness = 0;
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return max8925_backlight_set(bl, brightness);
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}
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static int max8925_backlight_get_brightness(struct backlight_device *bl)
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{
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struct max8925_backlight_data *data = bl_get_data(bl);
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struct max8925_chip *chip = data->chip;
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int ret;
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ret = max8925_reg_read(chip->i2c, MAX8925_WLED_CNTL);
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if (ret < 0)
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return -EINVAL;
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data->current_brightness = ret;
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dev_dbg(chip->dev, "get brightness %d\n", data->current_brightness);
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return ret;
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}
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static const struct backlight_ops max8925_backlight_ops = {
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.options = BL_CORE_SUSPENDRESUME,
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.update_status = max8925_backlight_update_status,
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.get_brightness = max8925_backlight_get_brightness,
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};
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static int __devinit max8925_backlight_probe(struct platform_device *pdev)
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{
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struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
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struct max8925_platform_data *max8925_pdata;
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struct max8925_backlight_pdata *pdata = NULL;
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struct max8925_backlight_data *data;
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struct backlight_device *bl;
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struct backlight_properties props;
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struct resource *res;
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char name[MAX8925_NAME_SIZE];
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unsigned char value;
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int ret;
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res = platform_get_resource(pdev, IORESOURCE_IO, 0);
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if (res == NULL) {
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dev_err(&pdev->dev, "No I/O resource!\n");
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return -EINVAL;
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}
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if (pdev->dev.parent->platform_data) {
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max8925_pdata = pdev->dev.parent->platform_data;
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pdata = max8925_pdata->backlight;
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}
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if (!pdata) {
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dev_err(&pdev->dev, "platform data isn't assigned to "
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"backlight\n");
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return -EINVAL;
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}
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data = kzalloc(sizeof(struct max8925_backlight_data), GFP_KERNEL);
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if (data == NULL)
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return -ENOMEM;
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strncpy(name, res->name, MAX8925_NAME_SIZE);
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data->chip = chip;
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data->current_brightness = 0;
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memset(&props, 0, sizeof(struct backlight_properties));
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props.type = BACKLIGHT_RAW;
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props.max_brightness = MAX_BRIGHTNESS;
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bl = backlight_device_register(name, &pdev->dev, data,
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&max8925_backlight_ops, &props);
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if (IS_ERR(bl)) {
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dev_err(&pdev->dev, "failed to register backlight\n");
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kfree(data);
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return PTR_ERR(bl);
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}
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bl->props.brightness = MAX_BRIGHTNESS;
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platform_set_drvdata(pdev, bl);
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value = 0;
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if (pdata->lxw_scl)
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value |= (1 << 7);
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if (pdata->lxw_freq)
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value |= (LWX_FREQ(pdata->lxw_freq) << 4);
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if (pdata->dual_string)
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value |= (1 << 1);
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ret = max8925_set_bits(chip->i2c, MAX8925_WLED_MODE_CNTL, 0xfe, value);
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if (ret < 0)
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goto out;
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backlight_update_status(bl);
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return 0;
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out:
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backlight_device_unregister(bl);
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kfree(data);
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return ret;
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}
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static int __devexit max8925_backlight_remove(struct platform_device *pdev)
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{
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struct backlight_device *bl = platform_get_drvdata(pdev);
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struct max8925_backlight_data *data = bl_get_data(bl);
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backlight_device_unregister(bl);
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kfree(data);
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return 0;
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}
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static struct platform_driver max8925_backlight_driver = {
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.driver = {
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.name = "max8925-backlight",
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.owner = THIS_MODULE,
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},
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.probe = max8925_backlight_probe,
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.remove = __devexit_p(max8925_backlight_remove),
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};
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static int __init max8925_backlight_init(void)
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{
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return platform_driver_register(&max8925_backlight_driver);
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}
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module_init(max8925_backlight_init);
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static void __exit max8925_backlight_exit(void)
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{
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platform_driver_unregister(&max8925_backlight_driver);
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};
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module_exit(max8925_backlight_exit);
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MODULE_DESCRIPTION("Backlight Driver for Maxim MAX8925");
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MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:max8925-backlight");
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