[PATCH] serial/amba-pl011: move custom pin control to driver

[viresh kumar]

On Wed, May 23, 2012 at 8:18 PM, Linus Walleij
<linus.walleij at stericsson.com> wrote:
> From: Linus Walleij <linus.walleij at linaro.org>
>
> We had a boot regression in Ux500 in the merge window because
> two orthogonal pin control schemes for the PL011 were merged
> at the same time:
>
> - One using the .init() and .exit() hooks into the platform
>  for Ux500 putting the pins into default vs sleep state
>  respectively as the port was started/stopped.
>  commit a09806607fd20bed2f8c41fe22793386790a14aa
>  "ARM: ux500: switch to using pinctrl for uart0"
>
> - One hogging the default setting at PL011 probe()
>  commit 258e055111d3cde2607e0d04eb91da2f7a59b591
>  "serial: amba-pl011: adopt pinctrl support"
>
> To get a solution that works for both let's scrap the stuff
> in the platform callbacks, instead have the driver itself
> select default and sleep states when the port is
> started/stopped. Hopefully this works for all clients.
> Platform callbacks are bad for device tree migration anyway,
> so this rids us of another problem in Ux500.
>
> Cc: linux-serial at vger.kernel.org
> Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
> Cc: Shawn Guo <shawn.guo at linaro.org>
> Cc: Russell King <rmk+kernel at arm.linux.org.uk>
> Reported-by: Lee Jones <lee.jones at linaro.org>
> Signed-off-by: Linus Walleij <linus.walleij at linaro.org>
> ---
>  arch/arm/mach-ux500/board-mop500.c |   54 +-----------------------------------
>  drivers/tty/serial/amba-pl011.c    |   45 +++++++++++++++++++++++++++---
>  2 files changed, 42 insertions(+), 57 deletions(-)

> diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
> @@ -1869,11 +1897,20 @@ static int pl011_probe(struct amba_device *dev, const struct amba_id *id)
>                goto free;
>        }
>
> -       pinctrl = devm_pinctrl_get_select_default(&dev->dev);
> -       if (IS_ERR(pinctrl)) {
> -               ret = PTR_ERR(pinctrl);
> +       uap->pinctrl = devm_pinctrl_get(&dev->dev);
> +       if (IS_ERR(uap->pinctrl)) {
> +               ret = PTR_ERR(uap->pinctrl);
>                goto unmap;
>        }

Hi Linus,

People testing SPEAr with v3.5-rc1 saw that serial devices don't show
up during boot and they
actually return with error from this point, after Shawn's last patch.
That will still happen with
this patch i believe.

What is expected from Platforms to handle this? AFAICR, we haven't
done anything special
to bind a pinctrl node to a struct dev for uart.

--
Viresh