From 4d658451c9d620ab8fb79483bf83d65b14375723 Mon Sep 17 00:00:00 2001 From: Rayagonda Kokatanur Date: Mon, 2 Nov 2020 09:24:33 +0530 Subject: [PATCH] i2c: iproc: handle rx fifo full interrupt 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 Acked-by: Ray Jui Signed-off-by: Wolfram Sang --- 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 22e04055b447b..cceaf69279a94 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)) {