From a380ed461f66d1b843cf13380a43a5fe790b8430 Mon Sep 17 00:00:00 2001 From: Ulrich Hecht Date: Thu, 2 Feb 2017 18:10:16 +0100 Subject: serial: sh-sci: implement FIFO threshold register setting Sets the closest match for a desired RX trigger level. Signed-off-by: Ulrich Hecht Reviewed-by: Geert Uytterhoeven Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/sh-sci.c | 59 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 59 insertions(+) (limited to 'drivers/tty/serial/sh-sci.c') diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 5044a5e5d340..050d028cf2a1 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) { -- cgit v1.2.3