[GitHub/mt8127/android_kernel_alcatel_ttab.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.
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#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) {
		pr_err("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) {
			pr_info("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) {
			pr_info("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) {
			pr_err("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 const 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)
{
	struct backlight_properties props;
	int ret;
	struct backlight_device *bd;

	memset(&props, 0, sizeof(struct backlight_properties));
	props.type = BACKLIGHT_RAW;
	props.max_brightness = BL_MAX_BRIGHT;
	bd = backlight_device_register(S1D_DEVICENAME, &pdev->dev, NULL,
				       &jornada_bl_ops, &props);

	if (IS_ERR(bd)) {
		ret = PTR_ERR(bd);
		pr_err("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
	 */
	jornada_bl_update_status(bd);

	platform_set_drvdata(pdev, bd);
	pr_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",
	},
};

module_platform_driver(jornada_bl_driver);

MODULE_AUTHOR("Kristoffer Ericson <kristoffer.ericson>");
MODULE_DESCRIPTION("HP Jornada 710/720/728 Backlight driver");
MODULE_LICENSE("GPL");
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
20c225cb JH	12	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
20c225cb JH	13
13a7b5dc KE	14	#include <linux/backlight.h>
	15	#include <linux/device.h>
	16	#include <linux/fb.h>
	17	#include <linux/kernel.h>
	18	#include <linux/module.h>
	19	#include <linux/platform_device.h>
	20
	21	#include <mach/jornada720.h>
	22	#include <mach/hardware.h>
	23
	24	#include <video/s1d13xxxfb.h>
	25
	26	#define BL_MAX_BRIGHT 255
	27	#define BL_DEF_BRIGHT 25
	28
	29	static int jornada_bl_get_brightness(struct backlight_device *bd)
	30	{
	31	int ret;
	32
	33	/* check if backlight is on */
	34	if (!(PPSR & PPC_LDD1))
	35	return 0;
	36
	37	jornada_ssp_start();
	38
	39	/* cmd should return txdummy */
	40	ret = jornada_ssp_byte(GETBRIGHTNESS);
	41
	42	if (jornada_ssp_byte(GETBRIGHTNESS) != TXDUMMY) {
20c225cb	43	pr_err("get brightness timeout\n");
13a7b5dc KE	44	jornada_ssp_end();
	45	return -ETIMEDOUT;
	46	} else /* exchange txdummy for value */
	47	ret = jornada_ssp_byte(TXDUMMY);
	48
	49	jornada_ssp_end();
	50
0a75a568	51	return BL_MAX_BRIGHT - ret;
13a7b5dc KE	52	}
	53
	54	static int jornada_bl_update_status(struct backlight_device *bd)
	55	{
	56	int ret = 0;
	57
	58	jornada_ssp_start();
	59
	60	/* If backlight is off then really turn it off */
	61	if ((bd->props.power != FB_BLANK_UNBLANK) \|\| (bd->props.fb_blank != FB_BLANK_UNBLANK)) {
	62	ret = jornada_ssp_byte(BRIGHTNESSOFF);
	63	if (ret != TXDUMMY) {
20c225cb	64	pr_info("brightness off timeout\n");
13a7b5dc KE	65	/* turn off backlight */
	66	PPSR &= ~PPC_LDD1;
	67	PPDR \|= PPC_LDD1;
	68	ret = -ETIMEDOUT;
	69	}
	70	} else /* turn on backlight */
	71	PPSR \|= PPC_LDD1;
	72
	73	/* send command to our mcu */
	74	if (jornada_ssp_byte(SETBRIGHTNESS) != TXDUMMY) {
20c225cb	75	pr_info("failed to set brightness\n");
13a7b5dc	76	ret = -ETIMEDOUT;
b317c833	77	goto out;
13a7b5dc KE	78	}
13a7b5dc KE	79
0a75a568 JH	80	/*
	81	* at this point we expect that the mcu has accepted
	82	* our command and is waiting for our new value
	83	* please note that maximum brightness is 255,
	84	* but due to physical layout it is equal to 0, so we simply
	85	* invert the value (MAX VALUE - NEW VALUE).
	86	*/
	87	if (jornada_ssp_byte(BL_MAX_BRIGHT - bd->props.brightness)
	88	!= TXDUMMY) {
20c225cb	89	pr_err("set brightness failed\n");
13a7b5dc KE	90	ret = -ETIMEDOUT;
	91	}
	92
0a75a568 JH	93	/*
	94	* If infact we get an TXDUMMY as output we are happy and dont
	95	* make any further comments about it
	96	*/
13a7b5dc KE	97	out:
	98	jornada_ssp_end();
	99
	100	return ret;
	101	}
	102
9905a43b	103	static const struct backlight_ops jornada_bl_ops = {
13a7b5dc KE	104	.get_brightness = jornada_bl_get_brightness,
	105	.update_status = jornada_bl_update_status,
	106	.options = BL_CORE_SUSPENDRESUME,
	107	};
	108
	109	static int jornada_bl_probe(struct platform_device *pdev)
	110	{
a19a6ee6	111	struct backlight_properties props;
13a7b5dc KE	112	int ret;
	113	struct backlight_device *bd;
	114
a19a6ee6	115	memset(&props, 0, sizeof(struct backlight_properties));
bb7ca747	116	props.type = BACKLIGHT_RAW;
a19a6ee6 MG	117	props.max_brightness = BL_MAX_BRIGHT;
	118	bd = backlight_device_register(S1D_DEVICENAME, &pdev->dev, NULL,
	119	&jornada_bl_ops, &props);
13a7b5dc KE	120
	121	if (IS_ERR(bd)) {
	122	ret = PTR_ERR(bd);
20c225cb	123	pr_err("failed to register device, err=%x\n", ret);
13a7b5dc KE	124	return ret;
	125	}
	126
	127	bd->props.power = FB_BLANK_UNBLANK;
	128	bd->props.brightness = BL_DEF_BRIGHT;
0a75a568 JH	129	/*
	130	* note. make sure max brightness is set otherwise
	131	* you will get seemingly non-related errors when
	132	* trying to change brightness
	133	*/
13a7b5dc KE	134	jornada_bl_update_status(bd);
	135
	136	platform_set_drvdata(pdev, bd);
20c225cb	137	pr_info("HP Jornada 700 series backlight driver\n");
13a7b5dc KE	138
	139	return 0;
	140	}
	141
	142	static int jornada_bl_remove(struct platform_device *pdev)
	143	{
	144	struct backlight_device *bd = platform_get_drvdata(pdev);
	145
	146	backlight_device_unregister(bd);
	147
	148	return 0;
	149	}
	150
	151	static struct platform_driver jornada_bl_driver = {
	152	.probe = jornada_bl_probe,
	153	.remove = jornada_bl_remove,
	154	.driver = {
	155	.name = "jornada_bl",
	156	},
	157	};
	158
81178e02	159	module_platform_driver(jornada_bl_driver);
13a7b5dc KE	160
	161	MODULE_AUTHOR("Kristoffer Ericson <kristoffer.ericson>");
	162	MODULE_DESCRIPTION("HP Jornada 710/720/728 Backlight driver");
	163	MODULE_LICENSE("GPL");