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/*
* Copyright 2009 Freescale Semiconductor, Inc. All Rights Reserved.
*/
/*
* The code contained herein is licensed under the GNU General Public
* License. You may obtain a copy of the GNU General Public License
* Version 2 or later at the following locations:
*
* http://www.opensource.org/licenses/gpl-license.html
* http://www.gnu.org/copyleft/gpl.html
*/
/*!
* @defgroup Framebuffer Framebuffer Driver for SDC and ADC.
*/
/*!
* @file mxc_edid.c
*
* @brief MXC EDID tools
*
* @ingroup Framebuffer
*/
/*!
* Include files
*/
#include <linux/fb.h>
#define EDID_LENGTH 128
static u8 edid[EDID_LENGTH];
int read_edid(struct i2c_adapter *adp,
struct fb_var_screeninfo *einfo,
int *dvi)
{
u8 buf0[2] = {0, 0};
int dat = 0;
u16 addr = 0x50;
struct i2c_msg msg[2] = {
{
.addr = addr,
.flags = 0,
.len = 1,
.buf = buf0,
}, {
.addr = addr,
.flags = I2C_M_RD,
.len = EDID_LENGTH,
.buf = edid,
},
};
if (adp == NULL || einfo == NULL)
return -EINVAL;
buf0[0] = 0x00;
memset(&edid, 0, sizeof(edid));
memset(einfo, 0, sizeof(struct fb_var_screeninfo));
dat = i2c_transfer(adp, msg, 2);
/* If 0x50 fails, try 0x37. */
if (edid[1] == 0x00) {
msg[0].addr = msg[1].addr = 0x37;
dat = i2c_transfer(adp, msg, 2);
}
if (edid[1] == 0x00)
return -ENOENT;
*dvi = 0;
if ((edid[20] == 0x80) || (edid[20] == 0x88) || (edid[20] == 0))
*dvi = 1;
dat = fb_parse_edid(edid, einfo);
if (dat)
return -dat;
/* This is valid for version 1.3 of the EDID */
if ((edid[18] == 1) && (edid[19] == 3)) {
einfo->height = edid[21] * 10;
einfo->width = edid[22] * 10;
}
return 0;
}
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