Re: [PATCH 04/16] serial: mvebu-uart: support probe of multiple ports

[Miquel RAYNAL <miquel.raynal@xxxxxxxxxxxxxxxxxx>]

On Fri, 06 Oct 2017 14:23:55 +0200
Gregory CLEMENT <gregory.clement@xxxxxxxxxxxxxxxxxx> wrote:

> Hi Miquel,
>  
>  On ven., oct. 06 2017, Miquel Raynal
> <miquel.raynal@xxxxxxxxxxxxxxxxxx> wrote:
> 
> > From: Allen Yan <yanwei@xxxxxxxxxxx>
> >
> > Until now, the mvebu-uart driver only supported probing a single
> > UART port. However, some platforms have multiple instances of this
> > UART controller, and therefore the driver should support multiple
> > ports.
> >
> > In order to achieve this, we make sure to assign port->line
> > properly, instead of hardcoding it to zero.
> >
> > Signed-off-by: Allen Yan <yanwei@xxxxxxxxxxx>
> > Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxxxxxxxxx>
> > ---
> >  drivers/tty/serial/mvebu-uart.c | 13 +++++++++++--
> >  1 file changed, 11 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/tty/serial/mvebu-uart.c
> > b/drivers/tty/serial/mvebu-uart.c index 7e0a3e9fee15..25b11ede3a97
> > 100644 --- a/drivers/tty/serial/mvebu-uart.c
> > +++ b/drivers/tty/serial/mvebu-uart.c
> > @@ -560,7 +560,16 @@ static int mvebu_uart_probe(struct
> > platform_device *pdev) return -EINVAL;
> >  	}
> >  
> > -	port = &mvebu_uart_ports[0];
> > +	if (pdev->dev.of_node)
> > +		pdev->id = of_alias_get_id(pdev->dev.of_node,
> > "serial");  
> 
> If the id is retrieved using an of_ function, then I think that the
> driver would depend on OF_CONFIG.

Is this okay?

if (pdev->dev.of_node && IS_ENABLED(CONFIG_OF))
        pdev->id = of_alias_get_id(pdev->dev.of_node, "serial");
else
        pdev->id = 0;

BTW, I could not test without CONFIG_OF as it is defined by default in
our case: Selected by: ARM64 [=y]
I don't think there will be a 32-bit SoC with this UART IP?

Thanks,
Miquèl

> 
> Gregory
> 
> 
> > +
> > +	if (pdev->id >= MVEBU_NR_UARTS) {
> > +		dev_err(&pdev->dev, "cannot have more than %d UART
> > ports\n",
> > +			MVEBU_NR_UARTS);
> > +		return -EINVAL;
> > +	}
> > +
> > +	port = &mvebu_uart_ports[pdev->id];
> >  
> >  	spin_lock_init(&port->lock);
> >  
> > @@ -572,7 +581,7 @@ static int mvebu_uart_probe(struct
> > platform_device *pdev) port->fifosize   = 32;
> >  	port->iotype     = UPIO_MEM32;
> >  	port->flags      = UPF_FIXED_PORT;
> > -	port->line       = 0; /* single port: force line number
> > to  0 */
> > +	port->line       = pdev->id;
> >  
> >  	port->irq        = irq->start;
> >  	port->irqflags   = 0;
> > -- 
> > 2.11.0
> >
> >
> > _______________________________________________
> > linux-arm-kernel mailing list
> > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel  
> 



-- 
Miquel Raynal, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
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