linux/drivers/video/backlight/jornada720_lcd.c

/*
 *
 * LCD driver for HP Jornada 700 series (710/720/728)
 * Copyright (C) 2006-2009 Kristoffer Ericson <kristoffer.ericson@gmail.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 or any later version as published by the Free Software Foundation.
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/device.h>
#include <linux/fb.h>
#include <linux/kernel.h>
#include <linux/lcd.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/delay.h>

#include <mach/jornada720.h>
#include <mach/hardware.h>

#include <video/s1d13xxxfb.h>

#define LCD_MAX_CONTRAST	0xff
#define LCD_DEF_CONTRAST	0x80

static int jornada_lcd_get_power(struct lcd_device *dev)
{
	/* LDD2 in PPC = LCD POWER */
	if (PPSR & PPC_LDD2)
		return FB_BLANK_UNBLANK;	/* PW ON */
	else
		return FB_BLANK_POWERDOWN;	/* PW OFF */
}

static int jornada_lcd_get_contrast(struct lcd_device *dev)
{
	int ret;

	if (jornada_lcd_get_power(dev) != FB_BLANK_UNBLANK)
		return 0;

	jornada_ssp_start();

	if (jornada_ssp_byte(GETCONTRAST) != TXDUMMY) {
		pr_err("get contrast failed\n");
		jornada_ssp_end();
		return -ETIMEDOUT;
	} else {
		ret = jornada_ssp_byte(TXDUMMY);
		jornada_ssp_end();
		return ret;
	}
}

static int jornada_lcd_set_contrast(struct lcd_device *dev, int value)
{
	int ret;

	jornada_ssp_start();

	/* start by sending our set contrast cmd to mcu */
	ret = jornada_ssp_byte(SETCONTRAST);

	/* push the new value */
	if (jornada_ssp_byte(value) != TXDUMMY) {
		pr_err("set contrast failed\n");
		jornada_ssp_end();
		return -ETIMEDOUT;
	}

	/* if we get here we can assume everything went well */
	jornada_ssp_end();

	return 0;
}

static int jornada_lcd_set_power(struct lcd_device *dev, int power)
{
	if (power != FB_BLANK_UNBLANK) {
		PPSR &= ~PPC_LDD2;
		PPDR |= PPC_LDD2;
	} else
		PPSR |= PPC_LDD2;

	return 0;
}

static struct lcd_ops jornada_lcd_props = {
	.get_contrast = jornada_lcd_get_contrast,
	.set_contrast = jornada_lcd_set_contrast,
	.get_power = jornada_lcd_get_power,
	.set_power = jornada_lcd_set_power,
};

static int jornada_lcd_probe(struct platform_device *pdev)
{
	struct lcd_device *lcd_device;
	int ret;

	lcd_device = lcd_device_register(S1D_DEVICENAME, &pdev->dev, NULL, &jornada_lcd_props);

	if (IS_ERR(lcd_device)) {
		ret = PTR_ERR(lcd_device);
		pr_err("failed to register device\n");
		return ret;
	}

	platform_set_drvdata(pdev, lcd_device);

	/* lets set our default values */
	jornada_lcd_set_contrast(lcd_device, LCD_DEF_CONTRAST);
	jornada_lcd_set_power(lcd_device, FB_BLANK_UNBLANK);
	/* give it some time to startup */
	msleep(100);

	return 0;
}

static int jornada_lcd_remove(struct platform_device *pdev)
{
	struct lcd_device *lcd_device = platform_get_drvdata(pdev);

	lcd_device_unregister(lcd_device);

	return 0;
}

static struct platform_driver jornada_lcd_driver = {
	.probe	= jornada_lcd_probe,
	.remove	= jornada_lcd_remove,
	.driver	= {
		.name	= "jornada_lcd",
	},
};

module_platform_driver(jornada_lcd_driver);

MODULE_AUTHOR("Kristoffer Ericson <kristoffer.ericson@gmail.com>");
MODULE_DESCRIPTION("HP Jornada 710/720/728 LCD driver");
MODULE_LICENSE("GPL");