- 根目录:
- drivers
- staging
- media
- go7007
- go7007-i2c.c
/*
* Copyright (C) 2005-2006 Micronas USA Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License (Version 2) as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/list.h>
#include <linux/unistd.h>
#include <linux/time.h>
#include <linux/device.h>
#include <linux/i2c.h>
#include <linux/mutex.h>
#include <linux/uaccess.h>
#include "go7007-priv.h"
#include "wis-i2c.h"
/********************* Driver for on-board I2C adapter *********************/
/* #define GO7007_I2C_DEBUG */
#define SPI_I2C_ADDR_BASE 0x1400
#define STATUS_REG_ADDR (SPI_I2C_ADDR_BASE + 0x2)
#define I2C_CTRL_REG_ADDR (SPI_I2C_ADDR_BASE + 0x6)
#define I2C_DEV_UP_ADDR_REG_ADDR (SPI_I2C_ADDR_BASE + 0x7)
#define I2C_LO_ADDR_REG_ADDR (SPI_I2C_ADDR_BASE + 0x8)
#define I2C_DATA_REG_ADDR (SPI_I2C_ADDR_BASE + 0x9)
#define I2C_CLKFREQ_REG_ADDR (SPI_I2C_ADDR_BASE + 0xa)
#define I2C_STATE_MASK 0x0007
#define I2C_READ_READY_MASK 0x0008
/* There is only one I2C port on the TW2804 that feeds all four GO7007 VIPs
* on the Adlink PCI-MPG24, so access is shared between all of them. */
static DEFINE_MUTEX(adlink_mpg24_i2c_lock);
static int go7007_i2c_xfer(struct go7007 *go, u16 addr, int read,
u16 command, int flags, u8 *data)
{
int i, ret = -1;
u16 val;
if (go->status == STATUS_SHUTDOWN)
return -1;
#ifdef GO7007_I2C_DEBUG
if (read)
printk(KERN_DEBUG "go7007-i2c: reading 0x%02x on 0x%02x\n",
command, addr);
else
printk(KERN_DEBUG
"go7007-i2c: writing 0x%02x to 0x%02x on 0x%02x\n",
*data, command, addr);
#endif
mutex_lock(&go->hw_lock);
if (go->board_id == GO7007_BOARDID_ADLINK_MPG24) {
/* Bridge the I2C port on this GO7007 to the shared bus */
mutex_lock(&adlink_mpg24_i2c_lock);
go7007_write_addr(go, 0x3c82, 0x0020);
}
/* Wait for I2C adapter to be ready */
for (i = 0; i < 10; ++i) {
if (go7007_read_addr(go, STATUS_REG_ADDR, &val) < 0)
goto i2c_done;
if (!(val & I2C_STATE_MASK))
break;
msleep(100);
}
if (i == 10) {
printk(KERN_ERR "go7007-i2c: I2C adapter is hung\n");
goto i2c_done;
}
/* Set target register (command) */
go7007_write_addr(go, I2C_CTRL_REG_ADDR, flags);
go7007_write_addr(go, I2C_LO_ADDR_REG_ADDR, command);
/* If we're writing, send the data and target address and we're done */
if (!read) {
go7007_write_addr(go, I2C_DATA_REG_ADDR, *data);
go7007_write_addr(go, I2C_DEV_UP_ADDR_REG_ADDR,
(addr << 9) | (command >> 8));
ret = 0;
goto i2c_done;
}
/* Otherwise, we're reading. First clear i2c_rx_data_rdy. */
if (go7007_read_addr(go, I2C_DATA_REG_ADDR, &val) < 0)
goto i2c_done;
/* Send the target address plus read flag */
go7007_write_addr(go, I2C_DEV_UP_ADDR_REG_ADDR,
(addr << 9) | 0x0100 | (command >> 8));
/* Wait for i2c_rx_data_rdy */
for (i = 0; i < 10; ++i) {
if (go7007_read_addr(go, STATUS_REG_ADDR, &val) < 0)
goto i2c_done;
if (val & I2C_READ_READY_MASK)
break;
msleep(100);
}
if (i == 10) {
printk(KERN_ERR "go7007-i2c: I2C adapter is hung\n");
goto i2c_done;
}
/* Retrieve the read byte */
if (go7007_read_addr(go, I2C_DATA_REG_ADDR, &val) < 0)
goto i2c_done;
*data = val;
ret = 0;
i2c_done:
if (go->board_id == GO7007_BOARDID_ADLINK_MPG24) {
/* Isolate the I2C port on this GO7007 from the shared bus */
go7007_write_addr(go, 0x3c82, 0x0000);
mutex_unlock(&adlink_mpg24_i2c_lock);
}
mutex_unlock(&go->hw_lock);
return ret;
}
static int go7007_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
unsigned short flags, char read_write,
u8 command, int size, union i2c_smbus_data *data)
{
struct go7007 *go = i2c_get_adapdata(adapter);
if (size != I2C_SMBUS_BYTE_DATA)
return -1;
return go7007_i2c_xfer(go, addr, read_write == I2C_SMBUS_READ, command,
flags & I2C_CLIENT_SCCB ? 0x10 : 0x00, &data->byte);
}
/* VERY LIMITED I2C master xfer function -- only needed because the
* SMBus functions only support 8-bit commands and the SAA7135 uses
* 16-bit commands. The I2C interface on the GO7007, as limited as
* it is, does support this mode. */
static int go7007_i2c_master_xfer(struct i2c_adapter *adapter,
struct i2c_msg msgs[], int num)
{
struct go7007 *go = i2c_get_adapdata(adapter);
int i;
for (i = 0; i < num; ++i) {
/* We can only do two things here -- write three bytes, or
* write two bytes and read one byte. */
if (msgs[i].len == 2) {
if (i + 1 == num || msgs[i].addr != msgs[i + 1].addr ||
(msgs[i].flags & I2C_M_RD) ||
!(msgs[i + 1].flags & I2C_M_RD) ||
msgs[i + 1].len != 1)
return -1;
if (go7007_i2c_xfer(go, msgs[i].addr, 1,
(msgs[i].buf[0] << 8) | msgs[i].buf[1],
0x01, &msgs[i + 1].buf[0]) < 0)
return -1;
++i;
} else if (msgs[i].len == 3) {
if (msgs[i].flags & I2C_M_RD)
return -1;
if (msgs[i].len != 3)
return -1;
if (go7007_i2c_xfer(go, msgs[i].addr, 0,
(msgs[i].buf[0] << 8) | msgs[i].buf[1],
0x01, &msgs[i].buf[2]) < 0)
return -1;
} else
return -1;
}
return 0;
}
static u32 go7007_functionality(struct i2c_adapter *adapter)
{
return I2C_FUNC_SMBUS_BYTE_DATA;
}
static struct i2c_algorithm go7007_algo = {
.smbus_xfer = go7007_smbus_xfer,
.master_xfer = go7007_i2c_master_xfer,
.functionality = go7007_functionality,
};
static struct i2c_adapter go7007_adap_templ = {
.owner = THIS_MODULE,
.name = "WIS GO7007SB",
.algo = &go7007_algo,
};
int go7007_i2c_init(struct go7007 *go)
{
memcpy(&go->i2c_adapter, &go7007_adap_templ,
sizeof(go7007_adap_templ));
go->i2c_adapter.dev.parent = go->dev;
i2c_set_adapdata(&go->i2c_adapter, go);
if (i2c_add_adapter(&go->i2c_adapter) < 0) {
printk(KERN_ERR
"go7007-i2c: error: i2c_add_adapter failed\n");
return -1;
}
return 0;
}