Re: [PATCH 3/7] serial: sh-sci: implement FIFO threshold register setting

[Geert Uytterhoeven]

Hi Uli,

On Fri, Dec 9, 2016 at 1:36 PM, Ulrich Hecht
 wrote:
> Sets the closest match for a desired RX trigger level.
>
> Signed-off-by: Ulrich Hecht 

Reviewed-by: Geert Uytterhoeven 

> index de25db8..844288f 100644
> --- a/drivers/tty/serial/sh-sci.c
> +++ b/drivers/tty/serial/sh-sci.c
> @@ -1103,6 +1103,61 @@ static int sci_handle_breaks(struct uart_port *port)
> return copied;
>  }
>
> +static int scif_set_rtrg(struct uart_port *port, int rx_trig)
> +{

> +   if (port->type == PORT_SCIF) {

> +   } else if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {

> +   } else {
> +   WARN(1, "unknown FIFO configuration");

This cannot happen, right?

> +   return 1;
> +   }

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds

[PATCH 3/7] serial: sh-sci: implement FIFO threshold register setting

[Ulrich Hecht]

Sets the closest match for a desired RX trigger level.

Signed-off-by: Ulrich Hecht 
---
 drivers/tty/serial/sh-sci.c | 55 +
 1 file changed, 55 insertions(+)

diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index de25db8..844288f 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -1103,6 +1103,61 @@ 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;
+   }
+
+   if (port->type == 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;
+   }
+   } else if (port->type == PORT_SCIFA || port->type == 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;
+   }
+   } else {
+   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