[deliverable/linux.git] / drivers / video / backlight / jornada720_bl.c

/*
 *
 * Backlight 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.
 *
 */

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

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

#include <video/s1d13xxxfb.h>

#define BL_MAX_BRIGHT	255
#define BL_DEF_BRIGHT	25

static int jornada_bl_get_brightness(struct backlight_device *bd)
{
	int ret;

	/* check if backlight is on */
	if (!(PPSR & PPC_LDD1))
		return 0;

	jornada_ssp_start();

	/* cmd should return txdummy */
	ret = jornada_ssp_byte(GETBRIGHTNESS);

	if (jornada_ssp_byte(GETBRIGHTNESS) != TXDUMMY) {
		printk(KERN_ERR "bl : get brightness timeout\n");
		jornada_ssp_end();
		return -ETIMEDOUT;
	} else /* exchange txdummy for value */
		ret = jornada_ssp_byte(TXDUMMY);

	jornada_ssp_end();

	return (BL_MAX_BRIGHT - ret);
}

static int jornada_bl_update_status(struct backlight_device *bd)
{
	int ret = 0;

	jornada_ssp_start();

	/* If backlight is off then really turn it off */
	if ((bd->props.power != FB_BLANK_UNBLANK) || (bd->props.fb_blank != FB_BLANK_UNBLANK)) {
		ret = jornada_ssp_byte(BRIGHTNESSOFF);
		if (ret != TXDUMMY) {
			printk(KERN_INFO "bl : brightness off timeout\n");
			/* turn off backlight */
			PPSR &= ~PPC_LDD1;
			PPDR |= PPC_LDD1;
			ret = -ETIMEDOUT;
		}
	} else  /* turn on backlight */
		PPSR |= PPC_LDD1;

		/* send command to our mcu */
		if (jornada_ssp_byte(SETBRIGHTNESS) != TXDUMMY) {
			printk(KERN_INFO "bl : failed to set brightness\n");
			ret = -ETIMEDOUT;
			goto out;
		}

		/* at this point we expect that the mcu has accepted
		   our command and is waiting for our new value
		   please note that maximum brightness is 255,
		   but due to physical layout it is equal to 0, so we simply
		   invert the value (MAX VALUE - NEW VALUE). */
		if (jornada_ssp_byte(BL_MAX_BRIGHT - bd->props.brightness) != TXDUMMY) {
			printk(KERN_ERR "bl : set brightness failed\n");
			ret = -ETIMEDOUT;
		}

		/* If infact we get an TXDUMMY as output we are happy and dont
		   make any further comments about it */
out:
	jornada_ssp_end();

	return ret;
}

static struct backlight_ops jornada_bl_ops = {
	.get_brightness = jornada_bl_get_brightness,
	.update_status = jornada_bl_update_status,
	.options = BL_CORE_SUSPENDRESUME,
};

static int jornada_bl_probe(struct platform_device *pdev)
{
	int ret;
	struct backlight_device *bd;

	bd = backlight_device_register(S1D_DEVICENAME, &pdev->dev, NULL, &jornada_bl_ops);

	if (IS_ERR(bd)) {
		ret = PTR_ERR(bd);
		printk(KERN_ERR "bl : failed to register device, err=%x\n", ret);
		return ret;
	}

	bd->props.power = FB_BLANK_UNBLANK;
	bd->props.brightness = BL_DEF_BRIGHT;
	/* note. make sure max brightness is set otherwise
	   you will get seemingly non-related errors when
	   trying to change brightness */
	bd->props.max_brightness = BL_MAX_BRIGHT;
	jornada_bl_update_status(bd);

	platform_set_drvdata(pdev, bd);
	printk(KERN_INFO "HP Jornada 700 series backlight driver\n");

	return 0;
}

static int jornada_bl_remove(struct platform_device *pdev)
{
	struct backlight_device *bd = platform_get_drvdata(pdev);

	backlight_device_unregister(bd);

	return 0;
}

static struct platform_driver jornada_bl_driver = {
	.probe		= jornada_bl_probe,
	.remove		= jornada_bl_remove,
	.driver	= {
		.name	= "jornada_bl",
	},
};

int __init jornada_bl_init(void)
{
	return platform_driver_register(&jornada_bl_driver);
}

void __exit jornada_bl_exit(void)
{
	platform_driver_unregister(&jornada_bl_driver);
}

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

module_init(jornada_bl_init);
module_exit(jornada_bl_exit);
Commit	Line	Data
13a7b5dc KE	1	/*
	2	*
	3	* Backlight driver for HP Jornada 700 series (710/720/728)
	4	* Copyright (C) 2006-2009 Kristoffer Ericson <kristoffer.ericson@gmail.com>
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public License version
	8	* 2 or any later version as published by the Free Software Foundation.
	9	*
	10	*/
	11
	12	#include <linux/backlight.h>
	13	#include <linux/device.h>
	14	#include <linux/fb.h>
	15	#include <linux/kernel.h>
	16	#include <linux/module.h>
	17	#include <linux/platform_device.h>
	18
	19	#include <mach/jornada720.h>
	20	#include <mach/hardware.h>
	21
	22	#include <video/s1d13xxxfb.h>
	23
	24	#define BL_MAX_BRIGHT 255
	25	#define BL_DEF_BRIGHT 25
	26
	27	static int jornada_bl_get_brightness(struct backlight_device *bd)
	28	{
	29	int ret;
	30
	31	/* check if backlight is on */
	32	if (!(PPSR & PPC_LDD1))
	33	return 0;
	34
	35	jornada_ssp_start();
	36
	37	/* cmd should return txdummy */
	38	ret = jornada_ssp_byte(GETBRIGHTNESS);
	39
	40	if (jornada_ssp_byte(GETBRIGHTNESS) != TXDUMMY) {
	41	printk(KERN_ERR "bl : get brightness timeout\n");
	42	jornada_ssp_end();
	43	return -ETIMEDOUT;
	44	} else /* exchange txdummy for value */
	45	ret = jornada_ssp_byte(TXDUMMY);
	46
	47	jornada_ssp_end();
	48
	49	return (BL_MAX_BRIGHT - ret);
	50	}
	51
	52	static int jornada_bl_update_status(struct backlight_device *bd)
	53	{
	54	int ret = 0;
	55
	56	jornada_ssp_start();
	57
	58	/* If backlight is off then really turn it off */
	59	if ((bd->props.power != FB_BLANK_UNBLANK) \|\| (bd->props.fb_blank != FB_BLANK_UNBLANK)) {
	60	ret = jornada_ssp_byte(BRIGHTNESSOFF);
	61	if (ret != TXDUMMY) {
	62	printk(KERN_INFO "bl : brightness off timeout\n");
	63	/* turn off backlight */
	64	PPSR &= ~PPC_LDD1;
65	PPDR \|= PPC_LDD1;
66	ret = -ETIMEDOUT;
67	}
68	} else /* turn on backlight */
69	PPSR \|= PPC_LDD1;
70
71	/* send command to our mcu */
72	if (jornada_ssp_byte(SETBRIGHTNESS) != TXDUMMY) {
73	printk(KERN_INFO "bl : failed to set brightness\n");
74	ret = -ETIMEDOUT;
b317c833	75	goto out;
13a7b5dc KE	76	}
	77
	78	/* at this point we expect that the mcu has accepted
	79	our command and is waiting for our new value
	80	please note that maximum brightness is 255,
	81	but due to physical layout it is equal to 0, so we simply
	82	invert the value (MAX VALUE - NEW VALUE). */
	83	if (jornada_ssp_byte(BL_MAX_BRIGHT - bd->props.brightness) != TXDUMMY) {
	84	printk(KERN_ERR "bl : set brightness failed\n");
	85	ret = -ETIMEDOUT;
	86	}
	87
	88	/* If infact we get an TXDUMMY as output we are happy and dont
	89	make any further comments about it */
	90	out:
	91	jornada_ssp_end();
	92
	93	return ret;
	94	}
	95
	96	static struct backlight_ops jornada_bl_ops = {
	97	.get_brightness = jornada_bl_get_brightness,
	98	.update_status = jornada_bl_update_status,
	99	.options = BL_CORE_SUSPENDRESUME,
	100	};
	101
	102	static int jornada_bl_probe(struct platform_device *pdev)
	103	{
	104	int ret;
	105	struct backlight_device *bd;
	106
	107	bd = backlight_device_register(S1D_DEVICENAME, &pdev->dev, NULL, &jornada_bl_ops);
	108
	109	if (IS_ERR(bd)) {
	110	ret = PTR_ERR(bd);
	111	printk(KERN_ERR "bl : failed to register device, err=%x\n", ret);
	112	return ret;
	113	}
	114
	115	bd->props.power = FB_BLANK_UNBLANK;
	116	bd->props.brightness = BL_DEF_BRIGHT;
	117	/* note. make sure max brightness is set otherwise
	118	you will get seemingly non-related errors when
	119	trying to change brightness */
	120	bd->props.max_brightness = BL_MAX_BRIGHT;
	121	jornada_bl_update_status(bd);
	122
	123	platform_set_drvdata(pdev, bd);
	124	printk(KERN_INFO "HP Jornada 700 series backlight driver\n");
	125
	126	return 0;
	127	}
	128
	129	static int jornada_bl_remove(struct platform_device *pdev)
	130	{
	131	struct backlight_device *bd = platform_get_drvdata(pdev);
	132
	133	backlight_device_unregister(bd);
	134
	135	return 0;
	136	}
	137
	138	static struct platform_driver jornada_bl_driver = {
	139	.probe = jornada_bl_probe,
140	.remove = jornada_bl_remove,
141	.driver = {
142	.name = "jornada_bl",
143	},
144	};
145
146	int __init jornada_bl_init(void)
147	{
148	return platform_driver_register(&jornada_bl_driver);
149	}
150
151	void __exit jornada_bl_exit(void)
152	{
153	platform_driver_unregister(&jornada_bl_driver);
154	}
155
156	MODULE_AUTHOR("Kristoffer Ericson <kristoffer.ericson>");
157	MODULE_DESCRIPTION("HP Jornada 710/720/728 Backlight driver");
158	MODULE_LICENSE("GPL");
159
160	module_init(jornada_bl_init);
161	module_exit(jornada_bl_exit);