linux-kernel - RE: [PATCH 1/2] tty: serial: fsl_lpuart: only enable Idle Line Interrupt for non-dma case

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Message-ID: <AS8PR04MB84048B114EACBBCFA729CA3F92019@AS8PR04MB8404.eurprd04.prod.outlook.com>
Date:   Thu, 10 Nov 2022 03:27:30 +0000
From:   Sherry Sun <sherry.sun@....com>
To:     Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>
CC:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Jiri Slaby <jirislaby@...nel.org>,
        linux-serial <linux-serial@...r.kernel.org>,
        LKML <linux-kernel@...r.kernel.org>,
        dl-linux-imx <linux-imx@....com>
Subject: RE: [PATCH 1/2] tty: serial: fsl_lpuart: only enable Idle Line
 Interrupt for non-dma case



> -----Original Message-----
> From: Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>
> Sent: 2022年11月9日 20:02
> To: Sherry Sun <sherry.sun@....com>
> Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>; Jiri Slaby
> <jirislaby@...nel.org>; linux-serial <linux-serial@...r.kernel.org>; LKML
> <linux-kernel@...r.kernel.org>; dl-linux-imx <linux-imx@....com>
> Subject: Re: [PATCH 1/2] tty: serial: fsl_lpuart: only enable Idle Line Interrupt
> for non-dma case
> 
> On Wed, 9 Nov 2022, Sherry Sun wrote:
> 
> > For the lpuart driver, the Idle Line Interrupt Enable now is only
> > needed for the CPU mode, so enable the UARTCTRL_ILIE at the correct
> > place, and clear it when shutdown.
> >
> > Also need to configure the suitable UARTCTRL_IDLECFG, now the value is
> > 0x7, represent 128 idle characters will trigger the Idle Line Interrupt.
> >
> > Signed-off-by: Sherry Sun <sherry.sun@....com>
> > ---
> >  drivers/tty/serial/fsl_lpuart.c | 13 ++++++++-----
> >  1 file changed, 8 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/tty/serial/fsl_lpuart.c
> > b/drivers/tty/serial/fsl_lpuart.c index bd685491eead..f5a0a14fa366
> > 100644
> > --- a/drivers/tty/serial/fsl_lpuart.c
> > +++ b/drivers/tty/serial/fsl_lpuart.c
> > @@ -179,7 +179,7 @@
> >  #define UARTCTRL_SBK		0x00010000
> >  #define UARTCTRL_MA1IE		0x00008000
> >  #define UARTCTRL_MA2IE		0x00004000
> > -#define UARTCTRL_IDLECFG	0x00000100
> > +#define UARTCTRL_IDLECFG_OFF   8
> >  #define UARTCTRL_LOOPS		0x00000080
> >  #define UARTCTRL_DOZEEN		0x00000040
> >  #define UARTCTRL_RSRC		0x00000020
> > @@ -230,6 +230,8 @@
> >  #define GLOBAL_RST_MIN_US	20
> >  #define GLOBAL_RST_MAX_US	40
> >
> > +#define UARTCTRL_IDLECFG	0x7
> > +
> 
> GEN_MASK() to the correct bits directly?
> 
> >  /* Rx DMA timeout in ms, which is used to calculate Rx ring buffer size */
> >  #define DMA_RX_TIMEOUT		(10)
> >
> > @@ -1506,7 +1508,7 @@ static void lpuart32_setup_watermark(struct
> lpuart_port *sport)
> >  	ctrl = lpuart32_read(&sport->port, UARTCTRL);
> >  	ctrl_saved = ctrl;
> >  	ctrl &= ~(UARTCTRL_TIE | UARTCTRL_TCIE | UARTCTRL_TE |
> > -			UARTCTRL_RIE | UARTCTRL_RE);
> > +			UARTCTRL_RIE | UARTCTRL_RE | UARTCTRL_ILIE);
> >  	lpuart32_write(&sport->port, ctrl, UARTCTRL);
> >
> >  	/* enable FIFO mode */
> > @@ -1530,7 +1532,8 @@ static void
> lpuart32_setup_watermark_enable(struct lpuart_port *sport)
> >  	lpuart32_setup_watermark(sport);
> >
> >  	temp = lpuart32_read(&sport->port, UARTCTRL);
> > -	temp |= UARTCTRL_RE | UARTCTRL_TE | UARTCTRL_ILIE;
> > +	temp |= UARTCTRL_RE | UARTCTRL_TE;
> > +	temp |= UARTCTRL_IDLECFG << UARTCTRL_IDLECFG_OFF;
> 
> FIELD_PREP() would probably be more appropriate for this? Then you can
> also drop the shift offset.

Hi Ilpo, thanks, I will try to use FIELD_PREP() and GENMASK().

Best Regards
Sherry


> 
> --
>  i.
> 
> >  	lpuart32_write(&sport->port, temp, UARTCTRL);  }
> >
> > @@ -1669,7 +1672,7 @@ static void lpuart32_configure(struct lpuart_port
> *sport)
> >  	}
> >  	temp = lpuart32_read(&sport->port, UARTCTRL);
> >  	if (!sport->lpuart_dma_rx_use)
> > -		temp |= UARTCTRL_RIE;
> > +		temp |= UARTCTRL_RIE | UARTCTRL_ILIE;
> >  	if (!sport->lpuart_dma_tx_use)
> >  		temp |= UARTCTRL_TIE;
> >  	lpuart32_write(&sport->port, temp, UARTCTRL); @@ -1770,7
> +1773,7 @@
> > static void lpuart32_shutdown(struct uart_port *port)
> >
> >  	/* disable Rx/Tx and interrupts */
> >  	temp = lpuart32_read(port, UARTCTRL);
> > -	temp &= ~(UARTCTRL_TE | UARTCTRL_RE |
> > +	temp &= ~(UARTCTRL_TE | UARTCTRL_RE | UARTCTRL_ILIE |
> >  			UARTCTRL_TIE | UARTCTRL_TCIE | UARTCTRL_RIE);
> >  	lpuart32_write(port, temp, UARTCTRL);
> >
> >