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;
#ifndef CONFIG_TOUCHSCREEN_AK4183
if (i2c_put_data(address) < 0)
goto address_err;
#endif
__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++;
}
#ifdef CONFIG_TOUCHSCREEN_AK4183
__i2c_send_nack();
#endif
__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_read(int device, unsigned char *buf, int count)
{
int cnt = count;
int timeout = 5;
device &= 0xFF;
i2c_open();
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_READ ) < 0)
goto device_err;
__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();
i2c_close();
return count - cnt;
device_err:
timeout--;
__i2c_send_stop();
goto L_try_again;
L_timeout:
__i2c_send_stop();
logf("Read I2C device 0x%2x failed.", device);
i2c_close();
return -1;
}
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;
}
static int i2c_jz_xfer(struct i2c_adapter *adap, struct i2c_msg *pmsg, int num)
{
int ret, i;
// printk(KERN_INFO "i2c_jz_xfer %d messages\n", num);
dev_dbg(&adap->dev, "jz47xx_xfer: processing %d messages:\n", num);
for (i = 0; i < num; i++, pmsg++) {
unsigned char *tmpbuf = pmsg->buf;
int cnt = (pmsg->flags & I2C_M_TEN) ? -2:-1; // prepare for sending address;
ret = num; // assume ok
dev_dbg(&adap->dev, " #%d: %s %d byte%s %s 0x%02x flags %04x\n", i,
pmsg->flags & I2C_M_RD ? "reading" : "writing",
pmsg->len, pmsg->len > 1 ? "s" : "",
pmsg->flags & I2C_M_RD ? "from" : "to", pmsg->addr,
pmsg->flags);
if (pmsg->flags & (/*I2C_M_TEN|I2C_M_NOSTART|*/I2C_M_REV_DIR_ADDR|/*I2C_M_IGNORE_NAK|*/I2C_M_NO_RD_ACK|I2C_M_RECV_LEN)) {
dev_dbg(&adap->dev, "jz47xx_xfer: flags=%04x not supported\n", pmsg->flags);
return -EINVAL;
}
if (!pmsg->buf)
continue; /* sanity check */
// printk(KERN_INFO "addr=%x flags=%04x\n", pmsg->addr, pmsg->flags);
if (!(pmsg->flags & I2C_M_NOSTART))
__i2c_send_start();
__i2c_send_ack(); // default (only last byte during receive gets nack)
for(; cnt < pmsg->len; cnt++) {
// printk(KERN_INFO "%d (%d)", cnt, pmsg->len);
#if 0
if(cnt == pmsg->len-1 && i == num-1) {
printk(" send stop\n");
__i2c_send_stop(); // last byte of last message
}
#endif
if (cnt >= 0 && pmsg->flags & I2C_M_RD) { // read data
int timeout = TIMEOUT;
while(!__i2c_check_drf() && timeout--) // wait for data to arrive
udelay(10);
if (timeout < 0)
ret = -ETIMEDOUT;
else {
if(cnt == pmsg->len-2)
__i2c_send_nack(); // nack last byte
*tmpbuf++ = __i2c_read(); // read data byte
// printk(" r: %02x\n", tmpbuf[-1]);
__i2c_clear_drf();
}
}
else {
int timeout = TIMEOUT;
if(cnt == -2) { // send first byte of 10-bit address
// printk(" w: %02x\n", ((pmsg->addr >> 7) & 0x06) | ((pmsg->flags & I2C_M_RD) ? (0xf0 | I2C_READ) : (0xf0 | I2C_WRITE)));
__i2c_write(((pmsg->addr >> 7) & 0x06) | ((pmsg->flags & I2C_M_RD) ? (0xf0 | I2C_READ) : (0xf0 | I2C_WRITE)) ); // first 2 bits
}
else if(cnt == -1) { // send 7 bit address or second byte
if ((pmsg->flags & I2C_M_TEN)) {
// printk(" w: %02x\n", pmsg->addr & 0xff);
__i2c_write(pmsg->addr); // final 8 bits
}
else {
// printk(" w: %02x\n", (pmsg->addr << 1) | ((pmsg->flags & I2C_M_RD) ? I2C_READ : I2C_WRITE));
__i2c_write((pmsg->addr << 1) | ((pmsg->flags & I2C_M_RD) ? I2C_READ : I2C_WRITE)); // set data to be written
}
}
else { // send data
// printk(" w: %02x\n", *tmpbuf);
__i2c_write(*tmpbuf++);
}
__i2c_set_drf(); // data is ready flag
while(__i2c_check_drf() && timeout--) // wait until we can push the next byte
udelay(10);
if(cnt == -1 || cnt == pmsg->len-1) { // last byte, wait for end of transission and final ACK
// printk(" wait transmit_ended\n");
timeout = TIMEOUT;
while(!__i2c_transmit_ended() && timeout--)
udelay(10);
}
if (timeout < 0)
ret = -ETIMEDOUT;
else if (!(pmsg->flags & I2C_M_IGNORE_NAK) && !__i2c_received_ack())
ret = -EIO;
}
if(ret < 0)
break;
}
