Add SCIF DMA rx support for RZ/G2L alike SoCs.
RZ/G2L alike SoCs use the same signal for both interrupt and DMA transfer
requests, so we must disable line interrupt while transferring DMA.
We must set FIFO trigger to 1 so that SCIF will request DMA when there is
a character as SCIF DMA request is based on FIFO data full RDF.
Based on a patch in the BSP by Long Luu
<long.luu.ur@xxxxxxxxxxx>
Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
---
v1->v2:
* No change
---
drivers/tty/serial/sh-sci.c | 18 +++++++++++++++---
1 file changed, 15 insertions(+), 3 deletions(-)
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 81797eb722cb..ce3d6af47759 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -1312,9 +1312,13 @@ static void sci_dma_rx_reenable_irq(struct sci_port *s)
/* Direct new serial port interrupts back to CPU */
scr = serial_port_in(port, SCSCR);
- if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
- scr &= ~SCSCR_RDRQE;
+ if (port->type == PORT_SCIFA || port->type == PORT_SCIFB ||
+ is_rz_scif_port(port, s)) {
enable_irq(s->irqs[SCIx_RXI_IRQ]);
+ if (port->type == PORT_SCIF)
+ scif_set_rtrg(port, s->rx_trigger);
+ else
+ scr &= ~SCSCR_RDRQE;
}
serial_port_out(port, SCSCR, scr | SCSCR_RIE);
}
@@ -1735,7 +1739,15 @@ static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
if (sci_dma_rx_submit(s, false) < 0)
goto handle_pio;
- scr &= ~SCSCR_RIE;
+ if (is_rz_scif_port(port, s)) {
+ /* Switch irq from SCIF to DMA */
+ disable_irq_nosync(s->irqs[SCIx_RXI_IRQ]);
+ scif_set_rtrg(port, 1);
+ /* DMA need RIE enable */
+ scr |= SCSCR_RIE;
+ } else {
+ scr &= ~SCSCR_RIE;
+ }
}
serial_port_out(port, SCSCR, scr);
/* Clear current interrupt */
--
2.25.1
