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| author | Ulrich Hecht <ulrich.hecht+renesas@gmail.com> | 2017-02-02 18:10:16 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-02-03 10:14:10 +0100 |
| commit | a380ed461f66d1b843cf13380a43a5fe790b8430 (patch) | |
| tree | dffe7f72b8aace9385cfb922a05d5f4f157b5456 /drivers/tty/serial/sh-sci.c | |
| parent | 88641c79c501735efe3b638ccad57ec077ed47f7 (diff) | |
| download | linux-a380ed461f66d1b843cf13380a43a5fe790b8430.tar.gz linux-a380ed461f66d1b843cf13380a43a5fe790b8430.tar.bz2 linux-a380ed461f66d1b843cf13380a43a5fe790b8430.zip | |
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>
Diffstat (limited to 'drivers/tty/serial/sh-sci.c')
| -rw-r--r-- | drivers/tty/serial/sh-sci.c | 59 |
1 files changed, 59 insertions, 0 deletions
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) { |