| Message ID | 20230130064449.9564-1-sherry.sun@nxp.com |
|---|---|
| Headers | show |
| Series | tty: serial: fsl_lpuart: improve RXWATER setting and add imx8ulp support | expand |
> -----Original Message----- > From: Alexander Stein <alexander.stein@ew.tq-group.com> > Sent: 2023年2月2日 15:14 > To: Sherry Sun <sherry.sun@nxp.com> > Cc: gregkh@linuxfoundation.org; jirislaby@kernel.org; linux- > serial@vger.kernel.org; linux-kernel@vger.kernel.org; dl-linux-imx <linux- > imx@nxp.com> > Subject: Re: [PATCH 5/6] tty: serial: fsl_lpuart: set RTS watermark for lpuart > > Am Montag, 30. Januar 2023, 07:44:48 CET schrieb Sherry Sun: > > Add RTS watermark support for LPUART. The RX RTS_B output negates > when > > the number of empty words in the receive FIFO is greater or equal to > > RTSWATER. Here set the RTSWATER to half of the rxfifo_size. > > > > Signed-off-by: Sherry Sun <sherry.sun@nxp.com> > > --- > > drivers/tty/serial/fsl_lpuart.c | 8 ++++++++ > > 1 file changed, 8 insertions(+) > > > > diff --git a/drivers/tty/serial/fsl_lpuart.c > > b/drivers/tty/serial/fsl_lpuart.c index 2789749d3d0d..c35e49a09bcc > > 100644 > > --- a/drivers/tty/serial/fsl_lpuart.c > > +++ b/drivers/tty/serial/fsl_lpuart.c > > @@ -201,6 +201,7 @@ > > #define UARTDATA_MASK 0x3ff > > > > #define UARTMODIR_IREN 0x00020000 > > +#define UARTMODIR_RTSWATER GENMASK(10, 8) > > #define UARTMODIR_TXCTSSRC 0x00000020 > > #define UARTMODIR_TXCTSC 0x00000010 > > #define UARTMODIR_RXRTSE 0x00000008 > > @@ -1573,6 +1574,13 @@ static void lpuart32_setup_watermark(struct > > lpuart_port *sport) (0x0 << UARTWATER_TXWATER_OFF); > > lpuart32_write(&sport->port, val, UARTWATER); > > > > + /* set RTS watermark */ > > + if (!uart_console(&sport->port)) { > > + val = lpuart32_read(&sport->port, UARTMODIR); > > + val |= FIELD_PREP(UARTMODIR_RTSWATER, sport- > >rxfifo_size > >> 1); > > + lpuart32_write(&sport->port, val, UARTMODIR); > > On LS1021A these bits are reserved (please refer to QorIQ LS1021A Reference > manual Rev 3.1 02/2020 section 27.3.6). Is it okay to write to them? > Hi Alexander, I checked the LS1021A RM, writing the reserved register bits have no impact, so it is okay here. Also, nxp local linux repo add this patch for a long time, all imx and layerscape boards work well with this patch. Best Regards Sherry
This patch set improves RXWATER setting for lpuart, also adds support for imx8ulp which has different rx_watermark value with imx7ulp. Sherry Sun (6): tty: serial: fsl_lpuart: make rx_watermark configurable for different platforms tty: serial: fsl_lpuart: set receive watermark for imx8qxp platform tty: serial: fsl_lpuart: Fix the wrong RXWATER setting for rx dma case tty: serial: fsl_lpuart: Enable Receiver Idle Empty function for LPUART tty: serial: fsl_lpuart: set RTS watermark for lpuart tty: serial: fsl_lpuart: add imx8ulp support drivers/tty/serial/fsl_lpuart.c | 50 +++++++++++++++++++++++++++------ 1 file changed, 41 insertions(+), 9 deletions(-)