Implements atomic transfers to fix reboot/shutdown on r8a7790 Lager and
similar boards.
Signed-off-by: Ulrich Hecht <uli+renesas@xxxxxxxx>
---
drivers/i2c/busses/i2c-sh_mobile.c | 100 +++++++++++++++++++++++++++----------
1 file changed, 74 insertions(+), 26 deletions(-)
diff --git a/drivers/i2c/busses/i2c-sh_mobile.c b/drivers/i2c/busses/i2c-sh_mobile.c
index d83ca40..e8436f4 100644
--- a/drivers/i2c/busses/i2c-sh_mobile.c
+++ b/drivers/i2c/busses/i2c-sh_mobile.c
@@ -129,6 +129,7 @@ struct sh_mobile_i2c_data {
int sr;
bool send_stop;
bool stop_after_dma;
+ bool atomic_xfer;
struct resource *res;
struct dma_chan *dma_tx;
@@ -330,13 +331,15 @@ static unsigned char i2c_op(struct sh_mobile_i2c_data *pd, enum sh_mobile_i2c_op
ret = iic_rd(pd, ICDR);
break;
case OP_RX_STOP: /* enable DTE interrupt, issue stop */
- iic_wr(pd, ICIC,
- ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
+ if (!pd->atomic_xfer)
+ iic_wr(pd, ICIC,
+ ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
iic_wr(pd, ICCR, ICCR_ICE | ICCR_RACK);
break;
case OP_RX_STOP_DATA: /* enable DTE interrupt, read data, issue stop */
- iic_wr(pd, ICIC,
- ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
+ if (!pd->atomic_xfer)
+ iic_wr(pd, ICIC,
+ ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
ret = iic_rd(pd, ICDR);
iic_wr(pd, ICCR, ICCR_ICE | ICCR_RACK);
break;
@@ -366,7 +369,7 @@ static int sh_mobile_i2c_isr_tx(struct sh_mobile_i2c_data *pd)
static int sh_mobile_i2c_isr_rx(struct sh_mobile_i2c_data *pd)
{
- unsigned char data;
+ unsigned char data = 0;
int real_pos;
/* switch from TX (address) to RX (data) adds two interrupts */
@@ -432,7 +435,8 @@ static irqreturn_t sh_mobile_i2c_isr(int irq, void *dev_id)
if (wakeup) {
pd->sr |= SW_DONE;
- wake_up(&pd->wait);
+ if (!pd->atomic_xfer)
+ wake_up(&pd->wait);
}
/* defeat write posting to avoid spurious WAIT interrupts */
@@ -584,12 +588,14 @@ static void start_ch(struct sh_mobile_i2c_data *pd, struct i2c_msg *usr_msg,
pd->pos = -1;
pd->sr = 0;
- pd->dma_buf = i2c_get_dma_safe_msg_buf(pd->msg, 8);
- if (pd->dma_buf)
- sh_mobile_i2c_xfer_dma(pd);
-
- /* Enable all interrupts to begin with */
- iic_wr(pd, ICIC, ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
+ if (!pd->atomic_xfer) {
+ pd->dma_buf = i2c_get_dma_safe_msg_buf(pd->msg, 8);
+ if (pd->dma_buf)
+ sh_mobile_i2c_xfer_dma(pd);
+ /* Enable all interrupts to begin with */
+ iic_wr(pd, ICIC,
+ ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
+ }
}
static int poll_dte(struct sh_mobile_i2c_data *pd)
@@ -640,18 +646,16 @@ static int poll_busy(struct sh_mobile_i2c_data *pd)
return i ? 0 : -ETIMEDOUT;
}
-static int sh_mobile_i2c_xfer(struct i2c_adapter *adapter,
- struct i2c_msg *msgs,
- int num)
+static int xfer(struct sh_mobile_i2c_data *pd, struct i2c_msg *msgs, int num)
{
- struct sh_mobile_i2c_data *pd = i2c_get_adapdata(adapter);
struct i2c_msg *msg;
int err = 0;
int i;
long timeout;
/* Wake up device and enable clock */
- pm_runtime_get_sync(pd->dev);
+ if (!pd->atomic_xfer)
+ pm_runtime_get_sync(pd->dev);
/* Process all messages */
for (i = 0; i < num; i++) {
@@ -665,13 +669,35 @@ static int sh_mobile_i2c_xfer(struct i2c_adapter *adapter,
if (do_start)
i2c_op(pd, OP_START);
- /* The interrupt handler takes care of the rest... */
- timeout = wait_event_timeout(pd->wait,
- pd->sr & (ICSR_TACK | SW_DONE),
- adapter->timeout);
+ if (pd->atomic_xfer) {
+ unsigned long j = jiffies + pd->adap.timeout;
+
+ timeout = 1;
+ while (!time_after(jiffies, j) &&
+ !(pd->sr & (ICSR_TACK | SW_DONE))) {
+ unsigned char sr = iic_rd(pd, ICSR);
+
+ if (sr & (ICSR_AL | ICSR_TACK |
+ ICSR_WAIT | ICSR_DTE)) {
+ sh_mobile_i2c_isr(0, pd);
+ udelay(150);
+ } else
+ cpu_relax();
+ }
+
+ if (time_after(jiffies, j))
+ timeout = 0;
+ } else {
+ /* The interrupt handler takes care of the rest... */
+ timeout = wait_event_timeout(pd->wait,
+ pd->sr & (ICSR_TACK | SW_DONE),
+ pd->adap.timeout);
- /* 'stop_after_dma' tells if DMA transfer was complete */
- i2c_put_dma_safe_msg_buf(pd->dma_buf, pd->msg, pd->stop_after_dma);
+ /* 'stop_after_dma' tells if DMA xfer was complete */
+ i2c_put_dma_safe_msg_buf(pd->dma_buf, pd->msg,
+ pd->stop_after_dma);
+
+ }
if (!timeout) {
dev_err(pd->dev, "Transfer request timed out\n");
@@ -694,19 +720,41 @@ static int sh_mobile_i2c_xfer(struct i2c_adapter *adapter,
iic_wr(pd, ICCR, ICCR_SCP);
/* Disable clock and mark device as idle */
- pm_runtime_put_sync(pd->dev);
+ if (!pd->atomic_xfer)
+ pm_runtime_put_sync(pd->dev);
return err ?: num;
}
+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);
+
+ pd->atomic_xfer = false;
+ return xfer(pd, msgs, num);
+}
+
+static int sh_mobile_i2c_xfer_atomic(struct i2c_adapter *adapter,
+ struct i2c_msg *msgs,
+ int num)
+{
+ struct sh_mobile_i2c_data *pd = i2c_get_adapdata(adapter);
+
+ pd->atomic_xfer = true;
+ return xfer(pd, msgs, num);
+}
+
static u32 sh_mobile_i2c_func(struct i2c_adapter *adapter)
{
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_PROTOCOL_MANGLING;
}
static const struct i2c_algorithm sh_mobile_i2c_algorithm = {
- .functionality = sh_mobile_i2c_func,
- .master_xfer = sh_mobile_i2c_xfer,
+ .functionality = sh_mobile_i2c_func,
+ .master_xfer = sh_mobile_i2c_xfer,
+ .master_xfer_atomic = sh_mobile_i2c_xfer_atomic,
};
static const struct i2c_adapter_quirks sh_mobile_i2c_quirks = {
--
2.7.4
