355b200bac
They were getting this implicitly by an include of module.h from device.h -- but we are going to clean that up and break that include chain, so include module.h explicitly now. [ with contributions from Axel Lin <axel.lin@gmail.com> ] Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
119 lines
2.6 KiB
C
119 lines
2.6 KiB
C
/*
|
|
* drivers/video/fb_ddc.c - DDC/EDID read support.
|
|
*
|
|
* Copyright (C) 2006 Dennis Munsie <dmunsie@cecropia.com>
|
|
*
|
|
* This file is subject to the terms and conditions of the GNU General Public
|
|
* License. See the file COPYING in the main directory of this archive
|
|
* for more details.
|
|
*/
|
|
|
|
#include <linux/delay.h>
|
|
#include <linux/device.h>
|
|
#include <linux/module.h>
|
|
#include <linux/fb.h>
|
|
#include <linux/i2c-algo-bit.h>
|
|
#include <linux/slab.h>
|
|
|
|
#include "edid.h"
|
|
|
|
#define DDC_ADDR 0x50
|
|
|
|
static unsigned char *fb_do_probe_ddc_edid(struct i2c_adapter *adapter)
|
|
{
|
|
unsigned char start = 0x0;
|
|
unsigned char *buf = kmalloc(EDID_LENGTH, GFP_KERNEL);
|
|
struct i2c_msg msgs[] = {
|
|
{
|
|
.addr = DDC_ADDR,
|
|
.flags = 0,
|
|
.len = 1,
|
|
.buf = &start,
|
|
}, {
|
|
.addr = DDC_ADDR,
|
|
.flags = I2C_M_RD,
|
|
.len = EDID_LENGTH,
|
|
.buf = buf,
|
|
}
|
|
};
|
|
|
|
if (!buf) {
|
|
dev_warn(&adapter->dev, "unable to allocate memory for EDID "
|
|
"block.\n");
|
|
return NULL;
|
|
}
|
|
|
|
if (i2c_transfer(adapter, msgs, 2) == 2)
|
|
return buf;
|
|
|
|
dev_warn(&adapter->dev, "unable to read EDID block.\n");
|
|
kfree(buf);
|
|
return NULL;
|
|
}
|
|
|
|
unsigned char *fb_ddc_read(struct i2c_adapter *adapter)
|
|
{
|
|
struct i2c_algo_bit_data *algo_data = adapter->algo_data;
|
|
unsigned char *edid = NULL;
|
|
int i, j;
|
|
|
|
algo_data->setscl(algo_data->data, 1);
|
|
|
|
for (i = 0; i < 3; i++) {
|
|
/* For some old monitors we need the
|
|
* following process to initialize/stop DDC
|
|
*/
|
|
algo_data->setsda(algo_data->data, 1);
|
|
msleep(13);
|
|
|
|
algo_data->setscl(algo_data->data, 1);
|
|
for (j = 0; j < 5; j++) {
|
|
msleep(10);
|
|
if (algo_data->getscl(algo_data->data))
|
|
break;
|
|
}
|
|
if (j == 5)
|
|
continue;
|
|
|
|
algo_data->setsda(algo_data->data, 0);
|
|
msleep(15);
|
|
algo_data->setscl(algo_data->data, 0);
|
|
msleep(15);
|
|
algo_data->setsda(algo_data->data, 1);
|
|
msleep(15);
|
|
|
|
/* Do the real work */
|
|
edid = fb_do_probe_ddc_edid(adapter);
|
|
algo_data->setsda(algo_data->data, 0);
|
|
algo_data->setscl(algo_data->data, 0);
|
|
msleep(15);
|
|
|
|
algo_data->setscl(algo_data->data, 1);
|
|
for (j = 0; j < 10; j++) {
|
|
msleep(10);
|
|
if (algo_data->getscl(algo_data->data))
|
|
break;
|
|
}
|
|
|
|
algo_data->setsda(algo_data->data, 1);
|
|
msleep(15);
|
|
algo_data->setscl(algo_data->data, 0);
|
|
algo_data->setsda(algo_data->data, 0);
|
|
if (edid)
|
|
break;
|
|
}
|
|
/* Release the DDC lines when done or the Apple Cinema HD display
|
|
* will switch off
|
|
*/
|
|
algo_data->setsda(algo_data->data, 1);
|
|
algo_data->setscl(algo_data->data, 1);
|
|
|
|
adapter->class |= I2C_CLASS_DDC;
|
|
return edid;
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(fb_ddc_read);
|
|
|
|
MODULE_AUTHOR("Dennis Munsie <dmunsie@cecropia.com>");
|
|
MODULE_DESCRIPTION("DDC/EDID reading support");
|
|
MODULE_LICENSE("GPL");
|