1
0
mirror of git://projects.qi-hardware.com/openwrt-xburst.git synced 2024-12-12 05:12:49 +02:00
openwrt-xburst/target/linux/xburst/files-2.6.27/arch/mips/jz4750d/i2c.c
Mirko Vogt dc3d3f1c49 yet another patchset - 2.6.27
it's basically also provided by ingenic and nativly based on 2.6.27,
adjusted to fit into the OpenWrt-environment
2009-10-28 03:13:11 +08:00

386 lines
7.7 KiB
C
Executable File

/*
* linux/arch/mips/jz4750d/i2c.c
*
* Jz4750D I2C routines.
*
* Copyright (C) 2005,2006 Ingenic Semiconductor Inc.
* Author: <lhhuang@ingenic.cn>
*
* This program is free software; you can distribute 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 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/types.h>
#include <linux/delay.h>
#include <asm/uaccess.h>
#include <asm/addrspace.h>
#include <asm/jzsoc.h>
/* I2C protocol */
#define I2C_READ 1
#define I2C_WRITE 0
#define TIMEOUT 1000
/*
* I2C bus protocol basic routines
*/
static int i2c_put_data(unsigned char data)
{
unsigned int timeout = TIMEOUT*10;
__i2c_write(data);
__i2c_set_drf();
while (__i2c_check_drf() != 0);
while (!__i2c_transmit_ended());
while (!__i2c_received_ack() && timeout)
timeout--;
if (timeout)
return 0;
else
return -ETIMEDOUT;
}
static int i2c_put_data_nack(unsigned char data)
{
unsigned int timeout = TIMEOUT*10;
__i2c_write(data);
__i2c_set_drf();
while (__i2c_check_drf() != 0);
while (!__i2c_transmit_ended());
while (timeout--);
return 0;
}
static int i2c_get_data(unsigned char *data, int ack)
{
int timeout = TIMEOUT*10;
if (!ack)
__i2c_send_nack();
else
__i2c_send_ack();
while (__i2c_check_drf() == 0 && timeout)
timeout--;
if (timeout) {
if (!ack)
__i2c_send_stop();
*data = __i2c_read();
__i2c_clear_drf();
return 0;
} else
return -ETIMEDOUT;
}
/*
* I2C interface
*/
void i2c_open(void)
{
__i2c_set_clk(jz_clocks.extalclk, 10000); /* default 10 KHz */
__i2c_enable();
}
void i2c_close(void)
{
udelay(300); /* wait for STOP goes over. */
__i2c_disable();
}
void i2c_setclk(unsigned int i2cclk)
{
__i2c_set_clk(jz_clocks.extalclk, i2cclk);
}
int i2c_lseek(unsigned char device, unsigned char offset)
{
__i2c_send_nack(); /* Master does not send ACK, slave sends it */
__i2c_send_start();
if (i2c_put_data( (device << 1) | I2C_WRITE ) < 0)
goto device_err;
if (i2c_put_data(offset) < 0)
goto address_err;
return 0;
device_err:
printk(KERN_DEBUG "No I2C device (0x%02x) installed.\n", device);
__i2c_send_stop();
return -ENODEV;
address_err:
printk(KERN_DEBUG "No I2C device (0x%02x) response.\n", device);
__i2c_send_stop();
return -EREMOTEIO;
}
int i2c_read(unsigned char device, unsigned char *buf,
unsigned char address, int count)
{
int cnt = count;
int timeout = 5;
L_try_again:
if (timeout < 0)
goto L_timeout;
__i2c_send_nack(); /* Master does not send ACK, slave sends it */
__i2c_send_start();
if (i2c_put_data( (device << 1) | I2C_WRITE ) < 0)
goto device_werr;
if (i2c_put_data(address) < 0)
goto address_err;
__i2c_send_start();
if (i2c_put_data( (device << 1) | I2C_READ ) < 0)
goto device_rerr;
__i2c_send_ack(); /* Master sends ACK for continue reading */
while (cnt) {
if (cnt == 1) {
if (i2c_get_data(buf, 0) < 0)
break;
} else {
if (i2c_get_data(buf, 1) < 0)
break;
}
cnt--;
buf++;
}
__i2c_send_stop();
return count - cnt;
device_rerr:
device_werr:
address_err:
timeout --;
__i2c_send_stop();
goto L_try_again;
L_timeout:
__i2c_send_stop();
printk("Read I2C device 0x%2x failed.\n", device);
return -ENODEV;
}
int i2c_write(unsigned char device, unsigned char *buf,
unsigned char address, int count)
{
int cnt = count;
int cnt_in_pg;
int timeout = 5;
unsigned char *tmpbuf;
unsigned char tmpaddr;
__i2c_send_nack(); /* Master does not send ACK, slave sends it */
W_try_again:
if (timeout < 0)
goto W_timeout;
cnt = count;
tmpbuf = (unsigned char *)buf;
tmpaddr = address;
start_write_page:
cnt_in_pg = 0;
__i2c_send_start();
if (i2c_put_data( (device << 1) | I2C_WRITE ) < 0)
goto device_err;
#ifdef CONFIG_JZ_TPANEL_ATA2508
if (address == 0xff) {
if (i2c_put_data_nack(tmpaddr) < 0)
goto address_err;
while (cnt) {
if (++cnt_in_pg > 8) {
__i2c_send_stop();
mdelay(1);
tmpaddr += 8;
goto start_write_page;
}
if (i2c_put_data_nack(*tmpbuf) < 0)
break;
cnt--;
tmpbuf++;
}
}
else {
if (i2c_put_data(tmpaddr) < 0)
goto address_err;
while (cnt) {
if (++cnt_in_pg > 8) {
__i2c_send_stop();
mdelay(1);
tmpaddr += 8;
goto start_write_page;
}
if (i2c_put_data(*tmpbuf) < 0)
break;
cnt--;
tmpbuf++;
}
}
#else
if (i2c_put_data(tmpaddr) < 0)
goto address_err;
while (cnt) {
if (++cnt_in_pg > 8) {
__i2c_send_stop();
mdelay(1);
tmpaddr += 8;
goto start_write_page;
}
if (i2c_put_data(*tmpbuf) < 0)
break;
cnt--;
tmpbuf++;
}
#endif
__i2c_send_stop();
return count - cnt;
device_err:
address_err:
timeout--;
__i2c_send_stop();
goto W_try_again;
W_timeout:
printk(KERN_DEBUG "Write I2C device 0x%2x failed.\n", device);
__i2c_send_stop();
return -ENODEV;
}
int i2c_read_16(unsigned char device, unsigned char *buf,
unsigned short address, int count)
{
int cnt = count;
int timeout = 5;
unsigned char tmpaddrh, tmpaddrl;
tmpaddrh = (unsigned char)((address >> 8) & 0xff);
tmpaddrl = (unsigned char)(address & 0xff);
L_try_again:
if (timeout < 0)
goto L_timeout;
__i2c_send_nack(); /* Master does not send ACK, slave sends it */
__i2c_send_start();
if (i2c_put_data( (device << 1) | I2C_WRITE ) < 0)
goto device_werr;
if (i2c_put_data_nack(tmpaddrh) < 0)
goto address_err;
if (i2c_put_data(tmpaddrl) < 0)
goto address_err;
__i2c_send_start();
if (i2c_put_data( (device << 1) | I2C_READ ) < 0)
goto device_rerr;
__i2c_send_ack(); /* Master sends ACK for continue reading */
while (cnt) {
if (cnt == 1) {
if (i2c_get_data(buf, 0) < 0)
break;
} else {
if (i2c_get_data(buf, 1) < 0)
break;
}
cnt--;
buf++;
}
__i2c_send_stop();
return count - cnt;
device_rerr:
device_werr:
address_err:
timeout --;
__i2c_send_stop();
goto L_try_again;
L_timeout:
__i2c_send_stop();
printk("Read I2C device 0x%2x failed.\n", device);
return -ENODEV;
}
int i2c_write_16(unsigned char device, unsigned char *buf,
unsigned short address, int count)
{
int cnt = count;
int cnt_in_pg;
int timeout = 5;
unsigned char *tmpbuf;
unsigned char tmpaddrh, tmpaddrl;
__i2c_send_nack(); /* Master does not send ACK, slave sends it */
W_try_again:
if (timeout < 0)
goto W_timeout;
cnt = count;
tmpbuf = (unsigned char *)buf;
tmpaddrh = (unsigned char)((address >> 8) & 0xff);
tmpaddrl = (unsigned char)(address & 0xff);
start_write_page:
cnt_in_pg = 0;
__i2c_send_start();
if (i2c_put_data( (device << 1) | I2C_WRITE ) < 0)
goto device_err;
if (i2c_put_data_nack(tmpaddrh) < 0)
goto address_err;
if (i2c_put_data(tmpaddrl) < 0)
goto address_err;
while (cnt) {
if (++cnt_in_pg > 8) {
__i2c_send_stop();
mdelay(1);
tmpaddrh += 8;
goto start_write_page;
}
if (i2c_put_data(*tmpbuf) < 0)
break;
cnt--;
tmpbuf++;
}
__i2c_send_stop();
return count - cnt;
device_err:
printk("1:Write I2C device 0x%2x failed.\n", device);
address_err:
printk("2:Write I2C address 0x%2x failed.\n", address);
timeout--;
__i2c_send_stop();
goto W_try_again;
W_timeout:
printk("3:Write I2C device 0x%2x failed.\n", device);
__i2c_send_stop();
return -ENODEV;
}
EXPORT_SYMBOL(i2c_open);
EXPORT_SYMBOL(i2c_close);
EXPORT_SYMBOL(i2c_setclk);
EXPORT_SYMBOL(i2c_read);
EXPORT_SYMBOL(i2c_write);
EXPORT_SYMBOL(i2c_read_16);
EXPORT_SYMBOL(i2c_write_16);