Sets the closest match for a desired RX trigger level.
Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@xxxxxxxxx>
Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
---
drivers/tty/serial/sh-sci.c | 59 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 59 insertions(+)
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 6085839..b89e6f8 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -974,6 +974,65 @@ static int sci_handle_breaks(struct uart_port *port)
return copied;
}
+static int scif_set_rtrg(struct uart_port *port, int rx_trig)
+{
+ unsigned int bits;
+
+ if (rx_trig < 1)
+ rx_trig = 1;
+ if (rx_trig >= port->fifosize)
+ rx_trig = port->fifosize;
+
+ /* HSCIF can be set to an arbitrary level. */
+ if (sci_getreg(port, HSRTRGR)->size) {
+ serial_port_out(port, HSRTRGR, rx_trig);
+ return rx_trig;
+ }
+
+ switch (port->type) {
+ case PORT_SCIF:
+ if (rx_trig < 4) {
+ bits = 0;
+ rx_trig = 1;
+ } else if (rx_trig < 8) {
+ bits = SCFCR_RTRG0;
+ rx_trig = 4;
+ } else if (rx_trig < 14) {
+ bits = SCFCR_RTRG1;
+ rx_trig = 8;
+ } else {
+ bits = SCFCR_RTRG0 | SCFCR_RTRG1;
+ rx_trig = 14;
+ }
+ break;
+ case PORT_SCIFA:
+ case PORT_SCIFB:
+ if (rx_trig < 16) {
+ bits = 0;
+ rx_trig = 1;
+ } else if (rx_trig < 32) {
+ bits = SCFCR_RTRG0;
+ rx_trig = 16;
+ } else if (rx_trig < 48) {
+ bits = SCFCR_RTRG1;
+ rx_trig = 32;
+ } else {
+ bits = SCFCR_RTRG0 | SCFCR_RTRG1;
+ rx_trig = 48;
+ }
+ break;
+ default:
+ WARN(1, "unknown FIFO configuration");
+ return 1;
+ }
+
+ serial_port_out(port, SCFCR,
+ (serial_port_in(port, SCFCR) &
+ ~(SCFCR_RTRG1 | SCFCR_RTRG0)) | bits);
+
+ return rx_trig;
+}
+
#ifdef CONFIG_SERIAL_SH_SCI_DMA
static void sci_dma_tx_complete(void *arg)
{
--
2.7.4
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