static u8 wait_9bit(struct tc300k_data *data)
{
int i;
int buf;
u8 send_buf = 0;
gpio_direction_input(data->pdata->gpio_sda);
s3c_gpio_setpull(data->pdata->gpio_sda, S3C_GPIO_PULL_NONE);
getsda(data);
ndelay(10);
setscl(data, 1);
ndelay(40);
setscl(data, 0);
ndelay(20);
for (i = 0; i < 8; i++) {
setscl(data, 1);
ndelay(20);
buf = getsda(data);
ndelay(20);
setscl(data, 0);
ndelay(20);
send_buf |= (buf & 0x01) << i;
}
setsda(data, 0);
return send_buf;
}
/* I2C receiving of bytes - does not send an offset byte */
int efx_i2c_recv_bytes(struct efx_i2c_interface *i2c, u8 device_id,
u8 *bytes, unsigned int len)
{
int i;
int rc;
EFX_WARN_ON_PARANOID(getsda(i2c) != 1);
EFX_WARN_ON_PARANOID(getscl(i2c) != 1);
EFX_WARN_ON_PARANOID(len < 1);
/* Select device */
i2c_start(i2c);
/* Read data from device */
rc = i2c_send_byte(i2c, i2c_read_cmd(device_id));
if (rc)
goto out;
for (i = 0; i < (len - 1); i++)
/* Read and acknowledge all but the last byte */
bytes[i] = i2c_recv_byte(i2c, 1);
/* Read last byte with no acknowledgement */
bytes[i] = i2c_recv_byte(i2c, 0);
out:
i2c_stop(i2c);
i2c_release(i2c);
return rc;
}
/* This performs a fast write of one or more consecutive bytes to an
* I2C device. Not all devices support consecutive writes of more
* than one byte; for these devices use efx_i2c_write() instead.
*/
int efx_i2c_fast_write(struct efx_i2c_interface *i2c,
u8 device_id, u8 offset,
const u8 *data, unsigned int len)
{
int i;
int rc;
EFX_WARN_ON_PARANOID(getsda(i2c) != 1);
EFX_WARN_ON_PARANOID(getscl(i2c) != 1);
EFX_WARN_ON_PARANOID(len < 1);
/* Select device and starting offset */
i2c_start(i2c);
rc = i2c_send_byte(i2c, i2c_write_cmd(device_id));
if (rc)
goto out;
rc = i2c_send_byte(i2c, offset);
if (rc)
goto out;
/* Write data to device */
for (i = 0; i < len; i++) {
rc = i2c_send_byte(i2c, data[i]);
if (rc)
goto out;
}
out:
i2c_stop(i2c);
i2c_release(i2c);
return rc;
}
static int i2c_outb(int c)
{
int i;
int ack;
/* assert: scl is low */
for (i = 7; i >= 0; i--) {
if (c & ( 1 << i )) {
sdahi();
} else {
sdalo();
}
if (sclhi() < 0) { /* timed out */
sdahi(); /* we don't want to block the net */
return -ETIMEDOUT;
};
scllo();
}
sdahi();
if (sclhi() < 0) {
return -ETIMEDOUT;
};
/* read ack: SDA should be pulled down by slave */
ack = getsda() == 0; /* ack: sda is pulled low ->success. */
scllo();
if (rtc_debug)
printk(KERN_DEBUG "i2c_outb(0x%02x) -> %s\n",
c, ack ? "ACK": "NAK");
return ack; /* return 1 if device acked */
/* assert: scl is low (sda undef) */
}
static inline void i2c_release(struct efx_i2c_interface *i2c)
{
EFX_WARN_ON_PARANOID(!i2c->scl);
EFX_WARN_ON_PARANOID(!i2c->sda);
/* Devices may time out if operations do not end */
setscl(i2c, 1);
setsda(i2c, 1);
EFX_BUG_ON_PARANOID(getsda(i2c) != 1);
EFX_BUG_ON_PARANOID(getscl(i2c) != 1);
}
static inline int i2c_recv_bit(struct efx_i2c_interface *i2c)
{
int bit;
EFX_WARN_ON_PARANOID(i2c->scl != 0);
EFX_WARN_ON_PARANOID(!i2c->sda);
setscl(i2c, 1);
bit = getsda(i2c);
setscl(i2c, 0);
return bit;
}
static inline int read_bit(struct i2c *base)
{
int bit;
setsda(base, 1); // so that we can read from the OC line...
delay_quarter_clock();
setscl(base, 1);
delay_half_clock();
setscl(base, 0);
bit = getsda(base);
delay_quarter_clock();
// printf("read bit %d\n", bit);
return bit;
}
int efx_i2c_check_presence(struct efx_i2c_interface *i2c, u8 device_id)
{
int rc;
/* If someone is driving the bus low we just give up. */
if (getsda(i2c) == 0 || getscl(i2c) == 0) {
EFX_ERR(i2c->efx, "%s someone is holding the I2C bus low."
" Giving up.\n", __func__);
return -EFAULT;
}
/* Pretend to initiate a device write */
i2c_start(i2c);
rc = i2c_send_byte(i2c, i2c_write_cmd(device_id));
if (rc)
goto out;
out:
i2c_stop(i2c);
i2c_release(i2c);
return rc;
}
static int i2c_inb(int ack)
{
int i;
unsigned int indata = 0;
/* assert: scl is low */
sdahi();
for (i = 0; i < 8; i++) {
if (sclhi() < 0) {
return -ETIMEDOUT;
};
indata *= 2;
if (getsda())
indata |= 0x01;
scllo();
}
if (ack) {
sdalo();
} else {
sdahi();
}
if (sclhi() < 0) {
sdahi();
return -ETIMEDOUT;
}
scllo();
sdahi();
if (rtc_debug)
printk(KERN_DEBUG "i2c_inb() -> 0x%02x\n", indata);
/* assert: scl is low */
return indata & 0xff;
}
