serial: sh-sci: implement FIFO threshold register setting

Sets the closest match for a desired RX trigger level.

Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Ulrich Hecht 2017-02-02 18:10:16 +01:00 committed by Greg Kroah-Hartman
parent 88641c79c5
commit a380ed461f

View File

@ -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)
{