static irqreturn_t sh_mobile_i2c_isr(int irq, void *dev_id)
{
struct platform_device *dev = dev_id;
struct sh_mobile_i2c_data *pd = platform_get_drvdata(dev);
unsigned char sr;
int wakeup;
sr = ioread8(ICSR(pd));
pd->sr |= sr; /* remember state */
dev_dbg(pd->dev, "i2c_isr 0x%02x 0x%02x %s %d %d!\n", sr, pd->sr,
(pd->msg->flags & I2C_M_RD) ? "read" : "write",
pd->pos, pd->msg->len);
if (sr & (ICSR_AL | ICSR_TACK)) {
/* don't interrupt transaction - continue to issue stop */
iowrite8(sr & ~(ICSR_AL | ICSR_TACK), ICSR(pd));
wakeup = 0;
} else if (pd->msg->flags & I2C_M_RD)
wakeup = sh_mobile_i2c_isr_rx(pd);
else
wakeup = sh_mobile_i2c_isr_tx(pd);
if (sr & ICSR_WAIT) /* TODO: add delay here to support slow acks */
iowrite8(sr & ~ICSR_WAIT, ICSR(pd));
if (wakeup) {
pd->sr |= SW_DONE;
wake_up(&pd->wait);
}
return IRQ_HANDLED;
}
static void deactivate_ch(struct sh_mobile_i2c_data *pd)
{
/* Clear/disable interrupts */
iowrite8(0, ICSR(pd));
iowrite8(0, ICIC(pd));
/* Disable channel */
iowrite8(ioread8(ICCR(pd)) & ~ICCR_ICE, ICCR(pd));
/* Disable clock */
clk_disable(pd->clk);
}
static void deactivate_ch(struct sh_mobile_i2c_data *pd)
{
/* Clear/disable interrupts */
iowrite8(0, ICSR(pd));
iowrite8(0, ICIC(pd));
/* Disable channel */
iowrite8(ioread8(ICCR(pd)) & ~ICCR_ICE, ICCR(pd));
/* Disable clock and mark device as idle */
clk_disable(pd->clk);
pm_runtime_put_sync(pd->dev);
}
static int sh_mobile_i2c_xfer(struct i2c_adapter *adapter,
struct i2c_msg *msgs,
int num)
{
struct sh_mobile_i2c_data *pd = i2c_get_adapdata(adapter);
struct i2c_msg *msg;
int err = 0;
u_int8_t val;
int i, k, retry_count;
activate_ch(pd);
/* Process all messages */
for (i = 0; i < num; i++) {
msg = &msgs[i];
err = start_ch(pd, msg);
if (err)
break;
i2c_op(pd, OP_START, 0);
/* The interrupt handler takes care of the rest... */
k = wait_event_timeout(pd->wait,
pd->sr & (ICSR_TACK | SW_DONE),
5 * HZ);
if (!k)
dev_err(pd->dev, "Transfer request timed out\n");
retry_count = 1000;
again:
val = ioread8(ICSR(pd));
dev_dbg(pd->dev, "val 0x%02x pd->sr 0x%02x\n", val, pd->sr);
/* the interrupt handler may wake us up before the
* transfer is finished, so poll the hardware
* until we're done.
*/
if (val & ICSR_BUSY) {
udelay(10);
if (retry_count--)
goto again;
err = -EIO;
dev_err(pd->dev, "Polling timed out\n");
break;
}
/* handle missing acknowledge and arbitration lost */
if ((val | pd->sr) & (ICSR_TACK | ICSR_AL)) {
err = -EIO;
break;
}
}
deactivate_ch(pd);
if (!err)
err = num;
return err;
}