mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-21 08:19:28 +00:00
![Stefani Seibold](/assets/img/avatar_default.png)
These patch fix a longstanding bug in the i810 frame buffer driver. The handling of the i2c bus is wrong: A 1 bit should not written to the i2c, these will be done by switch the i2c to input. Driving an 1 bit active is against the i2c spec. An active driven of a 1 bit will result in very strange error, depending which side is the more powerful one. In my case it depends on the temperature of the Display-Controller-EEprom: With an cold eprom a got the correct EDID datas, with a warm one some of the 1 bits was 0 :-( The same bug is also in the intelfb driver in the file drivers/video/intelfb/intelfb_i2c.c. The functions intelfb_gpio_setscl() and intelfb_gpio_setsda() do drive the 1 bit active to the i2c bus. But since i have no card which is used by the intelfb driver i cannot fix it. Signed-off-by: Stefani Seibold <stefani@seibold.net> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Jean Delvare <khali@linux-fr.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
175 lines
5 KiB
C
175 lines
5 KiB
C
/*-*- linux-c -*-
|
|
* linux/drivers/video/i810-i2c.c -- Intel 810/815 I2C support
|
|
*
|
|
* Copyright (C) 2004 Antonino Daplas<adaplas@pol.net>
|
|
* All Rights Reserved
|
|
*
|
|
* 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/module.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/gfp.h>
|
|
#include <linux/pci.h>
|
|
#include <linux/fb.h>
|
|
#include "i810.h"
|
|
#include "i810_regs.h"
|
|
#include "i810_main.h"
|
|
#include "../edid.h"
|
|
|
|
/* bit locations in the registers */
|
|
#define SCL_DIR_MASK 0x0001
|
|
#define SCL_DIR 0x0002
|
|
#define SCL_VAL_MASK 0x0004
|
|
#define SCL_VAL_OUT 0x0008
|
|
#define SCL_VAL_IN 0x0010
|
|
#define SDA_DIR_MASK 0x0100
|
|
#define SDA_DIR 0x0200
|
|
#define SDA_VAL_MASK 0x0400
|
|
#define SDA_VAL_OUT 0x0800
|
|
#define SDA_VAL_IN 0x1000
|
|
|
|
#define DEBUG /* define this for verbose EDID parsing output */
|
|
|
|
#ifdef DEBUG
|
|
#define DPRINTK(fmt, args...) printk(fmt,## args)
|
|
#else
|
|
#define DPRINTK(fmt, args...)
|
|
#endif
|
|
|
|
static void i810i2c_setscl(void *data, int state)
|
|
{
|
|
struct i810fb_i2c_chan *chan = data;
|
|
struct i810fb_par *par = chan->par;
|
|
u8 __iomem *mmio = par->mmio_start_virtual;
|
|
|
|
if (state)
|
|
i810_writel(mmio, chan->ddc_base, SCL_DIR_MASK | SCL_VAL_MASK);
|
|
else
|
|
i810_writel(mmio, chan->ddc_base, SCL_DIR | SCL_DIR_MASK | SCL_VAL_MASK);
|
|
i810_readl(mmio, chan->ddc_base); /* flush posted write */
|
|
}
|
|
|
|
static void i810i2c_setsda(void *data, int state)
|
|
{
|
|
struct i810fb_i2c_chan *chan = data;
|
|
struct i810fb_par *par = chan->par;
|
|
u8 __iomem *mmio = par->mmio_start_virtual;
|
|
|
|
if (state)
|
|
i810_writel(mmio, chan->ddc_base, SDA_DIR_MASK | SDA_VAL_MASK);
|
|
else
|
|
i810_writel(mmio, chan->ddc_base, SDA_DIR | SDA_DIR_MASK | SDA_VAL_MASK);
|
|
i810_readl(mmio, chan->ddc_base); /* flush posted write */
|
|
}
|
|
|
|
static int i810i2c_getscl(void *data)
|
|
{
|
|
struct i810fb_i2c_chan *chan = data;
|
|
struct i810fb_par *par = chan->par;
|
|
u8 __iomem *mmio = par->mmio_start_virtual;
|
|
|
|
i810_writel(mmio, chan->ddc_base, SCL_DIR_MASK);
|
|
i810_writel(mmio, chan->ddc_base, 0);
|
|
return ((i810_readl(mmio, chan->ddc_base) & SCL_VAL_IN) != 0);
|
|
}
|
|
|
|
static int i810i2c_getsda(void *data)
|
|
{
|
|
struct i810fb_i2c_chan *chan = data;
|
|
struct i810fb_par *par = chan->par;
|
|
u8 __iomem *mmio = par->mmio_start_virtual;
|
|
|
|
i810_writel(mmio, chan->ddc_base, SDA_DIR_MASK);
|
|
i810_writel(mmio, chan->ddc_base, 0);
|
|
return ((i810_readl(mmio, chan->ddc_base) & SDA_VAL_IN) != 0);
|
|
}
|
|
|
|
static int i810_setup_i2c_bus(struct i810fb_i2c_chan *chan, const char *name)
|
|
{
|
|
int rc;
|
|
|
|
strcpy(chan->adapter.name, name);
|
|
chan->adapter.owner = THIS_MODULE;
|
|
chan->adapter.algo_data = &chan->algo;
|
|
chan->adapter.dev.parent = &chan->par->dev->dev;
|
|
chan->algo.setsda = i810i2c_setsda;
|
|
chan->algo.setscl = i810i2c_setscl;
|
|
chan->algo.getsda = i810i2c_getsda;
|
|
chan->algo.getscl = i810i2c_getscl;
|
|
chan->algo.udelay = 10;
|
|
chan->algo.timeout = (HZ/2);
|
|
chan->algo.data = chan;
|
|
|
|
i2c_set_adapdata(&chan->adapter, chan);
|
|
|
|
/* Raise SCL and SDA */
|
|
chan->algo.setsda(chan, 1);
|
|
chan->algo.setscl(chan, 1);
|
|
udelay(20);
|
|
|
|
rc = i2c_bit_add_bus(&chan->adapter);
|
|
|
|
if (rc == 0)
|
|
dev_dbg(&chan->par->dev->dev, "I2C bus %s registered.\n",name);
|
|
else {
|
|
dev_warn(&chan->par->dev->dev, "Failed to register I2C bus "
|
|
"%s.\n", name);
|
|
chan->par = NULL;
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
void i810_create_i2c_busses(struct i810fb_par *par)
|
|
{
|
|
par->chan[0].par = par;
|
|
par->chan[1].par = par;
|
|
par->chan[2].par = par;
|
|
|
|
par->chan[0].ddc_base = GPIOA;
|
|
i810_setup_i2c_bus(&par->chan[0], "I810-DDC");
|
|
par->chan[1].ddc_base = GPIOB;
|
|
i810_setup_i2c_bus(&par->chan[1], "I810-I2C");
|
|
par->chan[2].ddc_base = GPIOC;
|
|
i810_setup_i2c_bus(&par->chan[2], "I810-GPIOC");
|
|
}
|
|
|
|
void i810_delete_i2c_busses(struct i810fb_par *par)
|
|
{
|
|
if (par->chan[0].par)
|
|
i2c_del_adapter(&par->chan[0].adapter);
|
|
par->chan[0].par = NULL;
|
|
|
|
if (par->chan[1].par)
|
|
i2c_del_adapter(&par->chan[1].adapter);
|
|
par->chan[1].par = NULL;
|
|
|
|
if (par->chan[2].par)
|
|
i2c_del_adapter(&par->chan[2].adapter);
|
|
par->chan[2].par = NULL;
|
|
}
|
|
|
|
int i810_probe_i2c_connector(struct fb_info *info, u8 **out_edid, int conn)
|
|
{
|
|
struct i810fb_par *par = info->par;
|
|
u8 *edid = NULL;
|
|
|
|
DPRINTK("i810-i2c: Probe DDC%i Bus\n", conn+1);
|
|
if (conn < par->ddc_num) {
|
|
edid = fb_ddc_read(&par->chan[conn].adapter);
|
|
} else {
|
|
const u8 *e = fb_firmware_edid(info->device);
|
|
|
|
if (e != NULL) {
|
|
DPRINTK("i810-i2c: Getting EDID from BIOS\n");
|
|
edid = kmemdup(e, EDID_LENGTH, GFP_KERNEL);
|
|
}
|
|
}
|
|
|
|
*out_edid = edid;
|
|
|
|
return (edid) ? 0 : 1;
|
|
}
|