Add DMA support for LINFlexD UART driver

[PATCH 02/13] serial: linflexuart: Clean SLEEP bit in LINCR1 after suspend

Posted by Larisa Grigore 1 month, 2 weeks ago

When coming back from reset, we need to re-initialize LINCR1 register.
SLEEP bit should be cleared, otherwise we can't enter INITM mode.

Fixes: 09864c1cdf5c ("tty: serial: Add linflexuart driver for S32V234")
Signed-off-by: Larisa Grigore <larisa.grigore@oss.nxp.com>
---
 drivers/tty/serial/fsl_linflexuart.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/tty/serial/fsl_linflexuart.c b/drivers/tty/serial/fsl_linflexuart.c
index 5a410e2d56ac..016011fd8760 100644
--- a/drivers/tty/serial/fsl_linflexuart.c
+++ b/drivers/tty/serial/fsl_linflexuart.c
@@ -413,8 +413,7 @@ linflex_set_termios(struct uart_port *port, struct ktermios *termios,
 	old_cr = cr;
 
 	/* Enter initialization mode by setting INIT bit */
-	cr1 = readl(port->membase + LINCR1);
-	cr1 |= LINFLEXD_LINCR1_INIT;
+	cr1 = LINFLEXD_LINCR1_INIT | LINFLEXD_LINCR1_MME;
 	writel(cr1, port->membase + LINCR1);
 
 	/* wait for init mode entry */
-- 
2.47.0

Re: [PATCH 02/13] serial: linflexuart: Clean SLEEP bit in LINCR1 after suspend

Posted by Frank Li 1 month, 2 weeks ago

On Mon, Feb 16, 2026 at 04:01:54PM +0100, Larisa Grigore wrote:
> When coming back from reset, we need to re-initialize LINCR1 register.
> SLEEP bit should be cleared, otherwise we can't enter INITM mode.

serial: linflexuart: Clean SLEEP bit in LINCR1 at linflex_set_termios()

Re-initialize LINCR1 register (Clear the SLEEP bit) at
linflex_set_termios(), otherwise the controller cannot enter INITM mode
after suspend/resume.

Frank
>
> Fixes: 09864c1cdf5c ("tty: serial: Add linflexuart driver for S32V234")
> Signed-off-by: Larisa Grigore <larisa.grigore@oss.nxp.com>
> ---
>  drivers/tty/serial/fsl_linflexuart.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/tty/serial/fsl_linflexuart.c b/drivers/tty/serial/fsl_linflexuart.c
> index 5a410e2d56ac..016011fd8760 100644
> --- a/drivers/tty/serial/fsl_linflexuart.c
> +++ b/drivers/tty/serial/fsl_linflexuart.c
> @@ -413,8 +413,7 @@ linflex_set_termios(struct uart_port *port, struct ktermios *termios,
>  	old_cr = cr;
>
>  	/* Enter initialization mode by setting INIT bit */
> -	cr1 = readl(port->membase + LINCR1);
> -	cr1 |= LINFLEXD_LINCR1_INIT;
> +	cr1 = LINFLEXD_LINCR1_INIT | LINFLEXD_LINCR1_MME;
>  	writel(cr1, port->membase + LINCR1);
>
>  	/* wait for init mode entry */
> --
> 2.47.0
>

Re: [PATCH 02/13] serial: linflexuart: Clean SLEEP bit in LINCR1 after suspend

Posted by Larisa Ileana Grigore 1 month, 1 week ago

On 2/16/2026 10:22 PM, Frank Li wrote:
> On Mon, Feb 16, 2026 at 04:01:54PM +0100, Larisa Grigore wrote:
>> When coming back from reset, we need to re-initialize LINCR1 register.
>> SLEEP bit should be cleared, otherwise we can't enter INITM mode.
> 
> serial: linflexuart: Clean SLEEP bit in LINCR1 at linflex_set_termios()
> 
> Re-initialize LINCR1 register (Clear the SLEEP bit) at
> linflex_set_termios(), otherwise the controller cannot enter INITM mode
> after suspend/resume.
> 
> Frank
>>

Thanks!

>> Fixes: 09864c1cdf5c ("tty: serial: Add linflexuart driver for S32V234")
>> Signed-off-by: Larisa Grigore <larisa.grigore@oss.nxp.com>
>> ---
>>   drivers/tty/serial/fsl_linflexuart.c | 3 +--
>>   1 file changed, 1 insertion(+), 2 deletions(-)
>>
>> diff --git a/drivers/tty/serial/fsl_linflexuart.c b/drivers/tty/serial/fsl_linflexuart.c
>> index 5a410e2d56ac..016011fd8760 100644
>> --- a/drivers/tty/serial/fsl_linflexuart.c
>> +++ b/drivers/tty/serial/fsl_linflexuart.c
>> @@ -413,8 +413,7 @@ linflex_set_termios(struct uart_port *port, struct ktermios *termios,
>>   	old_cr = cr;
>>
>>   	/* Enter initialization mode by setting INIT bit */
>> -	cr1 = readl(port->membase + LINCR1);
>> -	cr1 |= LINFLEXD_LINCR1_INIT;
>> +	cr1 = LINFLEXD_LINCR1_INIT | LINFLEXD_LINCR1_MME;
>>   	writel(cr1, port->membase + LINCR1);
>>
>>   	/* wait for init mode entry */
>> --
>> 2.47.0
>>