VF610 broken by pinctrl: freescale: imx: allow mux_reg offset zero

[Alonso Adrian]

Hi Adrew,

> -----Original Message-----
> From: Andrew Lunn [mailto:andrew at lunn.ch]
> Sent: Saturday, November 14, 2015 8:44 PM
> To: Alonso Lazcano Adrian-B38018 <aalonso at freescale.com>
> Cc: Linus Walleij <linus.walleij at linaro.org>; Shawn Guo
> <shawnguo at kernel.org>; stefan at agner.ch; linux ARM <linux-arm-
> kernel at lists.infradead.org>
> Subject: VF610 broken by pinctrl: freescale: imx: allow mux_reg offset zero
> 
> Hi Adrian
> 
> Your patch
> 
> commit e7b37a522aa92da5f47106aa07b6c1fc58bfd922
> Author: Adrian Alonso <aalonso at freescale.com>
> Date:   Fri Sep 25 16:05:59 2015 -0500
> 
>     pinctrl: freescale: imx: allow mux_reg offset zero
> 
>     Allow mux_reg offset zero to be a valid pin_id, on imx7d
>     mux_conf reg offset is zero for iomuxc-lspr controller
> 
> has broken VF610.
> 
> It looks like you partially reverted
> 
> commit 3dac1918a4912cea9375e76cb3916b751cef22db
> Author: Stefan Agner <stefan at agner.ch>
> Date:   Sat Sep 6 18:25:04 2014 +0200
> 
>     pinctrl: imx: detect uninitialized pins
> 
>     The pinctrl driver initialized the register offsets for the pins
>     with 0. On Vybrid an offset of 0 is a valid offset for the pinctrl
>     mux register. So far, this was solved using the ZERO_OFFSET_VALID
>     flag which allowed offsets of 0. However, this does not allow to
>     verify whether a pins struct imx_pmx_func was initialized or not.
> 
>     Use signed offset values for register offsets and initialize those
>     with -1 in order to detect uninitialized offset values reliable.
> 
> and in the process you have broken VF610, which also uses offset 0.
> 
> What i don't yet understand is why you needed to make this change. If
> VF610 can already use mux_reg, why cannot imx7d?
[Adrian] iMX7D has two iomuxc controllers where mux_reg id's overlap for each controller
So mux_reg offset can't be used to resolve the corresponding pad_id;
> 
> Anyway, it looks like -rc1 is going to be broken on VF610 for some boards,
> because this pin is the Ethernet clock input/output. Please can you get it fixed
> for -rc2?
> 
[Adrian] Sure let me take a look at this.
> Thanks
> 	Andrew