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i2c: iproc: handle rx fifo full interrupt

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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@broadcom.com>
Acked-by: Ray Jui <ray.jui@broadcom.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
This commit is contained in:
Rayagonda Kokatanur 2020-11-02 09:24:33 +05:30 committed by Wolfram Sang
parent e21d797787
commit 4d658451c9
1 changed files with 17 additions and 4 deletions
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21
drivers/i2c/busses/i2c-bcm-iproc.c
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@ -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)) {