backlight: Add Cirrus EP93xx backlight driver (08b3924b) · Commits · 戴 / test

drivers/video/backlight/Kconfig

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		@@ -142,6 +142,16 @@ config BACKLIGHT_ATMEL_PWM
		To compile this driver as a module, choose M here: the module will be
		called atmel-pwm-bl.

		config BACKLIGHT_EP93XX
		tristate "Cirrus EP93xx Backlight Driver"
		depends on FB_EP93XX
		help
		If you have a LCD backlight connected to the BRIGHT output of
		the EP93xx, say Y here to enable this driver.

		To compile this driver as a module, choose M here: the module will
		be called ep93xx_bl.

		config BACKLIGHT_GENERIC
		tristate "Generic (aka Sharp Corgi) Backlight Driver"
		default y

drivers/video/backlight/Makefile

+1 −0

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		@@ -14,6 +14,7 @@ obj-$(CONFIG_LCD_TOSA) += tosa_lcd.o

		obj-$(CONFIG_BACKLIGHT_CLASS_DEVICE) += backlight.o
		obj-$(CONFIG_BACKLIGHT_ATMEL_PWM) += atmel-pwm-bl.o
		obj-$(CONFIG_BACKLIGHT_EP93XX) += ep93xx_bl.o
		obj-$(CONFIG_BACKLIGHT_GENERIC) += generic_bl.o
		obj-$(CONFIG_BACKLIGHT_HP700) += jornada720_bl.o
		obj-$(CONFIG_BACKLIGHT_HP680) += hp680_bl.o

drivers/video/backlight/ep93xx_bl.c

0 → 100644

+160 −0

Original line number	Diff line number	Diff line
		/*
		* Driver for the Cirrus EP93xx lcd backlight
		*
		* Copyright (c) 2010 H Hartley Sweeten <hsweeten@visionengravers.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.
		*
		* This driver controls the pulse width modulated brightness control output,
		* BRIGHT, on the Cirrus EP9307, EP9312, and EP9315 processors.
		*/


		#include <linux/platform_device.h>
		#include <linux/io.h>
		#include <linux/fb.h>
		#include <linux/backlight.h>

		#include <mach/hardware.h>

		#define EP93XX_RASTER_REG(x) (EP93XX_RASTER_BASE + (x))
		#define EP93XX_RASTER_BRIGHTNESS EP93XX_RASTER_REG(0x20)

		#define EP93XX_MAX_COUNT 255
		#define EP93XX_MAX_BRIGHT 255
		#define EP93XX_DEF_BRIGHT 128

		struct ep93xxbl {
		void __iomem *mmio;
		int brightness;
		};

		static int ep93xxbl_set(struct backlight_device *bl, int brightness)
		{
		struct ep93xxbl *ep93xxbl = bl_get_data(bl);

		__raw_writel((brightness << 8) \| EP93XX_MAX_COUNT, ep93xxbl->mmio);

		ep93xxbl->brightness = brightness;

		return 0;
		}

		static int ep93xxbl_update_status(struct backlight_device *bl)
		{
		int brightness = bl->props.brightness;

		if (bl->props.power != FB_BLANK_UNBLANK \|\|
		bl->props.fb_blank != FB_BLANK_UNBLANK)
		brightness = 0;

		return ep93xxbl_set(bl, brightness);
		}

		static int ep93xxbl_get_brightness(struct backlight_device *bl)
		{
		struct ep93xxbl *ep93xxbl = bl_get_data(bl);

		return ep93xxbl->brightness;
		}

		static const struct backlight_ops ep93xxbl_ops = {
		.update_status = ep93xxbl_update_status,
		.get_brightness = ep93xxbl_get_brightness,
		};

		static int __init ep93xxbl_probe(struct platform_device *dev)
		{
		struct ep93xxbl *ep93xxbl;
		struct backlight_device *bl;
		struct backlight_properties props;

		ep93xxbl = devm_kzalloc(&dev->dev, sizeof(*ep93xxbl), GFP_KERNEL);
		if (!ep93xxbl)
		return -ENOMEM;

		/*
		* This register is located in the range already ioremap'ed by
		* the framebuffer driver. A MFD driver seems a bit of overkill
		* to handle this so use the static I/O mapping; this address
		* is already virtual.
		*
		* NOTE: No locking is required; the framebuffer does not touch
		* this register.
		*/
		ep93xxbl->mmio = EP93XX_RASTER_BRIGHTNESS;

		memset(&props, 0, sizeof(struct backlight_properties));
		props.max_brightness = EP93XX_MAX_BRIGHT;
		bl = backlight_device_register(dev->name, &dev->dev, ep93xxbl,
		&ep93xxbl_ops, &props);
		if (IS_ERR(bl))
		return PTR_ERR(bl);

		bl->props.brightness = EP93XX_DEF_BRIGHT;

		platform_set_drvdata(dev, bl);

		ep93xxbl_update_status(bl);

		return 0;
		}

		static int ep93xxbl_remove(struct platform_device *dev)
		{
		struct backlight_device *bl = platform_get_drvdata(dev);

		backlight_device_unregister(bl);
		platform_set_drvdata(dev, NULL);
		return 0;
		}

		#ifdef CONFIG_PM
		static int ep93xxbl_suspend(struct platform_device *dev, pm_message_t state)
		{
		struct backlight_device *bl = platform_get_drvdata(dev);

		return ep93xxbl_set(bl, 0);
		}

		static int ep93xxbl_resume(struct platform_device *dev)
		{
		struct backlight_device *bl = platform_get_drvdata(dev);

		backlight_update_status(bl);
		return 0;
		}
		#else
		#define ep93xxbl_suspend NULL
		#define ep93xxbl_resume NULL
		#endif

		static struct platform_driver ep93xxbl_driver = {
		.driver = {
		.name = "ep93xx-bl",
		.owner = THIS_MODULE,
		},
		.probe = ep93xxbl_probe,
		.remove = __devexit_p(ep93xxbl_remove),
		.suspend = ep93xxbl_suspend,
		.resume = ep93xxbl_resume,
		};

		static int __init ep93xxbl_init(void)
		{
		return platform_driver_register(&ep93xxbl_driver);
		}
		module_init(ep93xxbl_init);

		static void __exit ep93xxbl_exit(void)
		{
		platform_driver_unregister(&ep93xxbl_driver);
		}
		module_exit(ep93xxbl_exit);

		MODULE_DESCRIPTION("EP93xx Backlight Driver");
		MODULE_AUTHOR("H Hartley Sweeten <hsweeten@visionengravers.com>");
		MODULE_LICENSE("GPL");
		MODULE_ALIAS("platform:ep93xx-bl");

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