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kernel-ark/drivers/video/i810/i810-i2c.c
Antonino A. Daplas 5fab851ea1 [PATCH] i810fb: Cleanup I2C code 
- The functions for reading the 1st and 2nd bus are essentially the same,
  except for the register.  Consolidate them all.

- According to Nicolas Boichat, there is an undocumented 3rd i2c bus for
  attaching daughter cards.  Add support for this.

Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07 07:53:52 -08:00

217 lines
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/*-*- 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/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <linux/pci.h>
#include <linux/fb.h>
#include "i810.h"
#include "i810_regs.h"
#include "../edid.h"
#define I810_DDC 0x50
/* 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 = (struct i810fb_i2c_chan *)data;
struct i810fb_par *par = chan->par;
u8 __iomem *mmio = par->mmio_start_virtual;
i810_writel(mmio, chan->ddc_base, (state ? SCL_VAL_OUT : 0) | 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;
i810_writel(mmio, chan->ddc_base, (state ? SDA_VAL_OUT : 0) | 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->adapter.id = I2C_HW_B_I810;
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.mdelay = 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_bit_del_bus(&par->chan[0].adapter);
par->chan[0].par = NULL;
if (par->chan[1].par)
i2c_bit_del_bus(&par->chan[1].adapter);
par->chan[1].par = NULL;
if (par->chan[2].par)
i2c_bit_del_bus(&par->chan[2].adapter);
par->chan[2].par = NULL;
}
static u8 *i810_do_probe_i2c_edid(struct i810fb_i2c_chan *chan)
{
u8 start = 0x0;
struct i2c_msg msgs[] = {
{
.addr = I810_DDC,
.len = 1,
.buf = &start,
}, {
.addr = I810_DDC,
.flags = I2C_M_RD,
.len = EDID_LENGTH,
},
};
u8 *buf;
buf = kmalloc(EDID_LENGTH, GFP_KERNEL);
if (!buf) {
DPRINTK("i810-i2c: Failed to allocate memory\n");
return NULL;
}
msgs[1].buf = buf;
if (i2c_transfer(&chan->adapter, msgs, 2) == 2) {
DPRINTK("i810-i2c: I2C Transfer successful\n");
return buf;
}
DPRINTK("i810-i2c: Unable to read EDID block.\n");
kfree(buf);
return NULL;
}
int i810_probe_i2c_connector(struct fb_info *info, u8 **out_edid, int conn)
{
struct i810fb_par *par = info->par;
u8 *edid = NULL;
int i;
DPRINTK("i810-i2c: Probe DDC%i Bus\n", conn);
if (conn < 4) {
for (i = 0; i < 3; i++) {
/* Do the real work */
edid = i810_do_probe_i2c_edid(&par->chan[conn-1]);
if (edid)
break;
}
} else {
const u8 *e = fb_firmware_edid(info->device);
if (e != NULL) {
DPRINTK("i810-i2c: Getting EDID from BIOS\n");
edid = kmalloc(EDID_LENGTH, GFP_KERNEL);
if (edid)
memcpy(edid, e, EDID_LENGTH);
}
}
if (out_edid)
*out_edid = edid;
return (edid) ? 0 : 1;
}
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