size_t i2c::command(uint8_t slaveaddr,
uint8_t cmd,
const uint8_t* data_addr,
size_t data_size)
{
reset_txfer_done();
set_slave_address(slaveaddr);
set_data_len(1 + data_size);
initiate_write();
write_byte(cmd);
size_t bytes_sent=1;
while (data_size>0)
{
if (write_byte(*data_addr))
{
data_addr++;
data_size--;
bytes_sent++;
}
// TODO check for error conditions
}
wait_for_done();
clear_fifo();
return bytes_sent;
}
/* read up to KFUSE_DATA_SZ bytes into dest.
* always starts at the first kfuse.
*/
int tegra_kfuse_read(void *dest, size_t len)
{
u32 v;
unsigned cnt;
if (len > KFUSE_DATA_SZ)
return -EINVAL;
tegra_kfuse_writel(KFUSE_KEYADDR_AUTOINC, KFUSE_KEYADDR);
wait_for_done();
if ((tegra_kfuse_readl(KFUSE_STATE) & KFUSE_STATE_CRCPASS) == 0) {
pr_err("kfuse: crc failed\n");
return -EIO;
}
for (cnt = 0; cnt < len; cnt += 4) {
v = tegra_kfuse_readl(KFUSE_KEYS);
memcpy(dest + cnt, &v, sizeof v);
}
return 0;
}