Message-ID: <47A9A944.7090401@tiscali.nl>
Date: Wed, 06 Feb 2008 13:34:12 +0100
From: Roel Kluin <12o3l@tiscali.nl>
User-Agent: Thunderbird 2.0.0.9 (X11/20071031)
MIME-Version: 1.0
To: Kristoffer Ericson <kristoffer.ericson@gmail.com>
CC: Russell King <linux@arm.linux.org.uk>, rpurdie@openedhand.com,
       Linux-arm <linux-arm-kernel@lists.arm.linux.org.uk>,
       linux-main <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH/HP7XX] - Add combined LCD / BL driver for platform HP
 Jornada 7xx handhelds
References: <20080205195331.fa2ca02b.Kristoffer.ericson@gmail.com>
In-Reply-To: <20080205195331.fa2ca02b.Kristoffer.ericson@gmail.com>
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Sender: linux-kernel-owner@vger.kernel.org
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Kristoffer Ericson wrote:
> Greetings,
> 
> Richard I've cleaned up the driver by checking with checkpatch.pl as Russell suggested. I would appreciate it if you could
> look through the patch again and give comments since the patch looks somewhat different.
> 
> I can add patch for Kconfig/Makefile later on but suspect there will be some changes required before that.
> 
> Oh and to answer your question regarding MAX/MIN values of the backlight, 0 = max and 255 = min. So we simply turn it around
> by returning 255 - value. Same thing when we need to set value.
> 
> Best wishes
> Kristoffer Ericson
> 
> diff --git a/drivers/video/backlight/jornada720_bllcd.c b/drivers/video/backlight/jornada720_bllcd.c
> new file mode 100644
> index 0000000..4967b86
> --- /dev/null
> +++ b/drivers/video/backlight/jornada720_bllcd.c
> @@ -0,0 +1,284 @@
> +/*
> + * drivers/video/backlight/jornada720_bllcd.c
> + *
> + * Backlight and LCD Driver for HP Jornada 720
> + * Copyright (C) 2007 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.
> + *
> + */
> +#include <linux/module.h>
> +#include <linux/kernel.h>
> +#include <linux/init.h>
> +#include <linux/backlight.h>
> +#include <linux/lcd.h>
> +#include <linux/delay.h>
> +#include <linux/platform_device.h>
> +#include <linux/fb.h>
> +#include <linux/device.h>
> +#include <asm/hardware.h>
> +#include <asm/arch/jornada720.h>
> +#include <video/s1d13xxxfb.h>
> +
> +MODULE_AUTHOR("Kristoffer Ericson <kristoffer.ericson@gmail.com>");
> +MODULE_DESCRIPTION("HP Jornada 710/720/728 Backlight/LCD Driver");
> +MODULE_LICENSE("GPL");
> +
> +#define JORNADA_LCD_MAX_CONTRAST	0xff
> +#define JORNADA_LCD_DEFAULT_CONTRAST	0x80
> +#define JORNADA_BL_MAX_BRIGHTNESS	0xff
> +#define JORNADA_BL_DEFAULT_BRIGHTNESS	0x19
> +
> +struct jornada_bllcd_device {
> +	struct backlight_device *jorn_backlight_device;
> +	struct lcd_device *jorn_lcd_device;
> +};
> +
> +/*
> + * BACKLIGHT HANDLING ROUTINES
> + */
> +static int jornada_bl_get_brightness(struct backlight_device *dev)
> +{
> +	int ret;
> +
> +	/* check if backlight is on */
> +	if (!(PPSR & PPC_LDD1))
> +		return 255;
return JORNADA_BL_MAX_BRIGHTNESS;

> +
> +	jornada_ssp_start();
> +	if (jornada_ssp_inout(GETBRIGHTNESS) == -ETIMEDOUT) {
> +		printk(KERN_ERR "jornada720_bl: GetBrightness failed\n");
> +		ret = 256;
ret = JORNADA_BL_MAX_BRIGHTNESS + 1;
> +	} else
> +		ret = jornada_ssp_inout(TXDUMMY);
> +
> +	jornada_ssp_end();
> +
> +	/* 0 is max brightness */
> +	return (255 - ret);
return (JORNADA_BL_MAX_BRIGHTNESS - ret);
> +}
> +
> +static int jornada_bl_update_status(struct backlight_device *dev)
> +{
> +	int ret = 0;
> +
> +	jornada_ssp_start();
> +
> +	if (dev->props.power != FB_BLANK_UNBLANK ||
> +		dev->props.fb_blank != FB_BLANK_UNBLANK) {
> +		ret = jornada_ssp_inout(BRIGHTNESSOFF);
> +		if (ret == -ETIMEDOUT)
> +			printk(KERN_ERR "jornada720_bl:
> +				BrightnessOff timeout\n");
> +		else {
> +		/* backlight off */
> +			PPSR &= ~PPC_LDD1;
> +			PPDR |= PPC_LDD1;
> +		}
> +	} else {/* backlight on */
> +			PPSR |= PPC_LDD1;

missing curly bracket

> +
> +	if ((jornada_ssp_inout(SETBRIGHTNESS)) == TXDUMMY) {
> +		/* send brightness value (0 is max, 255 lowest) */
> +		if (jornada_ssp_byte(255 - dev->props.brightness) != -ETIMEDOUT)
> +			ret = (255 - dev->props.brightness);

similarly JORNADA_BL_MAX_BRIGHTNESS in the three lines above

> +	} else
> +		printk(KERN_ERR "jornada720_bl: SetBrightness timeout\n");
> +	}
> +
> +	jornada_ssp_end();
> +
> +	return ret;
> +}
> +
> +/* LCD HANDLING FUNCTIONS
> +   ====================== */
> +static int jornada_lcd_set_contrast(struct lcd_device *pdev, int contrast)
> +{
> +	int ret = 0;
> +
> +	jornada_ssp_start();
> +
> +	ret = jornada_ssp_inout(SETCONTRAST);
> +
> +	if (ret == -ETIMEDOUT)
> +		printk(KERN_INFO "jornada_lcd: failure to set contrast\n");
> +	 else
> +		ret = jornada_ssp_byte(contrast);
> +
> +	jornada_ssp_end();
> +
> +	return ret;
> +}
> +
> +static int jornada_lcd_set_power(struct lcd_device  *pdev, int power)
> +{
> +	if (power != FB_BLANK_UNBLANK) {
> +		/* turn off LCD */
> +		PPSR &= ~PPC_LDD2;
> +		PPDR |= PPC_LDD2;
> +	} else
> +	/* turn on LCD */
> +	PPSR |= PPC_LDD2;

wrong indent

> +
> +	return 0;
> +}
> +
> +static int jornada_lcd_get_power(struct lcd_device *pdev)
> +{
> +	if (PPSR & PPC_LDD2)
> +		return FB_BLANK_UNBLANK;
> +	else
> +		return FB_BLANK_POWERDOWN;
> +}
> +
> +static int jornada_lcd_get_contrast(struct lcd_device *pdev)
> +{
> +	int ret;
> +
> +	/* Don't set contrast on off powerd LCD */
> +	if (jornada_lcd_get_power(pdev) != FB_BLANK_UNBLANK)
> +		return 0;
> +
> +	jornada_ssp_start();
> +
> +	ret = jornada_ssp_inout(GETCONTRAST);
> +	if (ret != -ETIMEDOUT)
> +		ret = jornada_ssp_inout(TXDUMMY);
> +	else {
> +		printk(KERN_INFO "jornada_lcd: getcontrast failed!\n");
> +		ret = 256;

JORNADA_BL_MAX_BRIGHTNESS + 1

> +	}
> +
> +	jornada_ssp_end();
> +
> +	return ret;
> +}
> +
> +static struct backlight_ops jornada_bl_ops = {
> +	.get_brightness = jornada_bl_get_brightness,
> +	.update_status = jornada_bl_update_status,
> +};
> +
> +static struct lcd_ops jornada_lcd_ops = {
> +	.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_bl_probe(struct platform_device *pdev)
> +{
> +	struct jornada_bllcd_device *bllcd;
> +
> +	bllcd = kzalloc(sizeof(*bllcd), GFP_KERNEL);
> +	if (bllcd == NULL)
> +		return -ENOMEM;
> +
> +	/* bl driver - name must match fb driver name */
> +	bllcd->jorn_backlight_device = backlight_device_register(S1D_DEVICENAME,
> +				&pdev->dev, NULL, &jornada_bl_ops);
> +
> +	if (IS_ERR(bllcd->jorn_backlight_device)) {
> +		kfree(bllcd);
> +		return PTR_ERR(bllcd->jorn_backlight_device);
> +	}
> +
> +	/* lcd driver */
> +	bllcd->jorn_lcd_device = lcd_device_register(S1D_DEVICENAME,
> +				&pdev->dev, NULL, &jornada_lcd_ops);
> +	if (IS_ERR(bllcd->jorn_lcd_device)) {
> +		kfree(bllcd);
> +		return PTR_ERR(bllcd->jorn_lcd_device);
> +	}
> +
> +	jornada_lcd_set_contrast(bllcd->jorn_lcd_device,
> +			JORNADA_LCD_DEFAULT_CONTRAST);
> +	jornada_lcd_set_power(bllcd->jorn_lcd_device,
> +			FB_BLANK_UNBLANK);
> +
> +	msleep(100);
> +
> +	bllcd->jorn_backlight_device->props.power
> +		= FB_BLANK_UNBLANK;
> +	bllcd->jorn_backlight_device->props.brightness
> +		= JORNADA_BL_DEFAULT_BRIGHTNESS;
> +	jornada_bl_update_status(bllcd->jorn_backlight_device);
> +
> +	platform_set_drvdata(pdev, bllcd);
> +	printk(KERN_INFO "HP Jornada 7xx Backlight/LCD driver activated\n");
> +
> +	return 0;
> +}
> +
> +static int jornada_bl_remove(struct platform_device *pdev)
> +{
> +	struct jornada_bllcd_device *bllcd = platform_get_drvdata(pdev);
> +
> +	bllcd->jorn_backlight_device->props.power = FB_BLANK_POWERDOWN;
> +	bllcd->jorn_backlight_device->props.brightness = 0;
> +	bllcd->jorn_backlight_device->props.max_brightness = 0;
> +
> +	backlight_device_unregister(bllcd->jorn_backlight_device);
> +	lcd_device_unregister(bllcd->jorn_lcd_device);
> +
> +	return 0;
> +}
> +
> +static int jornada_bl_suspend(struct platform_device *pdev, pm_message_t state)
> +{
> +	struct jornada_bllcd_device *bllcd = platform_get_drvdata(pdev);
> +
> +	bllcd->jorn_backlight_device->props.power = FB_BLANK_POWERDOWN;
> +	bllcd->jorn_backlight_device->props.brightness = 0;
> +	bllcd->jorn_backlight_device->props.max_brightness = 0;
> +	jornada_bl_update_status(bllcd->jorn_backlight_device);
> +
> +	jornada_lcd_set_power(bllcd->jorn_lcd_device, FB_BLANK_POWERDOWN);
> +
> +	return 0;
> +}
> +
> +static int jornada_bl_resume(struct platform_device *pdev)
> +{
> +	struct jornada_bllcd_device *bllcd = platform_get_drvdata(pdev);
> +
> +	bllcd->jorn_backlight_device->props.power
> +		= FB_BLANK_UNBLANK;
> +	bllcd->jorn_backlight_device->props.brightness
> +		= JORNADA_BL_DEFAULT_BRIGHTNESS;
> +	bllcd->jorn_backlight_device->props.max_brightness
> +		= JORNADA_BL_MAX_BRIGHTNESS;
> +	jornada_bl_update_status(bllcd->jorn_backlight_device);
> +
> +	jornada_lcd_set_power(bllcd->jorn_lcd_device, FB_BLANK_UNBLANK);
> +
> +	return 0;
> +}
> +
> +static struct platform_driver jornada_bl_driver = {
> +	.probe	= jornada_bl_probe,
> +	.remove	= jornada_bl_remove,
> +#ifdef CONFIG_PM
> +	.suspend = jornada_bl_suspend,
> +	.resume = jornada_bl_resume,
> +#endif
> +	.driver = {
> +	    .name = "jornada_bl",
> +	},
> +};
> +
> +static int __init jornada_bl_init(void)
> +{
> +	return platform_driver_register(&jornada_bl_driver);
> +}
> +
> +static void __exit jornada_bl_exit(void)
> +{
> +	platform_driver_unregister(&jornada_bl_driver);
> +}
> +
> +module_init(jornada_bl_init);
> +module_exit(jornada_bl_exit);

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