Add code to handle IS_S_RX_FIFO_FULL_SHIFT interrupt to support
master write request with >= 64 bytes.
Iproc has a slave rx fifo size of 64 bytes.
Rx fifo full interrupt (IS_S_RX_FIFO_FULL_SHIFT) will be generated
when RX fifo becomes full. This can happen if master issues write
request of more than 64 bytes.
Signed-off-by: Rayagonda Kokatanur <rayagonda.kokatanur@xxxxxxxxxxxx>
---
drivers/i2c/busses/i2c-bcm-iproc.c | 21 +++++++++++++++++----
1 file changed, 17 insertions(+), 4 deletions(-)
diff --git a/drivers/i2c/busses/i2c-bcm-iproc.c b/drivers/i2c/busses/i2c-bcm-iproc.c
index 22e04055b447..cceaf69279a9 100644
--- a/drivers/i2c/busses/i2c-bcm-iproc.c
+++ b/drivers/i2c/busses/i2c-bcm-iproc.c
@@ -313,6 +313,8 @@ static void bcm_iproc_i2c_slave_init(
/* Enable interrupt register to indicate a valid byte in receive fifo */
val = BIT(IE_S_RX_EVENT_SHIFT);
+ /* Enable interrupt register to indicate Slave Rx FIFO Full */
+ val |= BIT(IE_S_RX_FIFO_FULL_SHIFT);
/* Enable interrupt register to indicate a Master read transaction */
val |= BIT(IE_S_RD_EVENT_SHIFT);
/* Enable interrupt register for the Slave BUSY command */
@@ -434,9 +436,15 @@ static bool bcm_iproc_i2c_slave_isr(struct bcm_iproc_i2c_dev *iproc_i2c,
* events
* Master-read : both IS_S_RX_EVENT_SHIFT and IS_S_RD_EVENT_SHIFT
* events or only IS_S_RD_EVENT_SHIFT
+ *
+ * iproc has a slave rx fifo size of 64 bytes. Rx fifo full interrupt
+ * (IS_S_RX_FIFO_FULL_SHIFT) will be generated when RX fifo becomes
+ * full. This can happen if Master issues write requests of more than
+ * 64 bytes.
*/
if (status & BIT(IS_S_RX_EVENT_SHIFT) ||
- status & BIT(IS_S_RD_EVENT_SHIFT)) {
+ status & BIT(IS_S_RD_EVENT_SHIFT) ||
+ status & BIT(IS_S_RX_FIFO_FULL_SHIFT)) {
/* disable slave interrupts */
val = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
val &= ~iproc_i2c->slave_int_mask;
@@ -452,9 +460,14 @@ static bool bcm_iproc_i2c_slave_isr(struct bcm_iproc_i2c_dev *iproc_i2c,
/* schedule tasklet to read data later */
tasklet_schedule(&iproc_i2c->slave_rx_tasklet);
- /* clear only IS_S_RX_EVENT_SHIFT interrupt */
- iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET,
- BIT(IS_S_RX_EVENT_SHIFT));
+ /*
+ * clear only IS_S_RX_EVENT_SHIFT and
+ * IS_S_RX_FIFO_FULL_SHIFT interrupt.
+ */
+ val = BIT(IS_S_RX_EVENT_SHIFT);
+ if (status & BIT(IS_S_RX_FIFO_FULL_SHIFT))
+ val |= BIT(IS_S_RX_FIFO_FULL_SHIFT);
+ iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, val);
}
if (status & BIT(IS_S_TX_UNDERRUN_SHIFT)) {
--
2.17.1
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smime.p7s
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