i.MX7 pinctrl driver writing to non existent registers

[Jean-Christophe PLAGNIOL-VILLARD]

> On Feb 8, 2017, at 5:08 PM, Sascha Hauer <s.hauer at pengutronix.de> wrote:
> 
> Hi All,
> 
> The i.MX7 has two pinmux controllers, the LPSR and the regular one. We
> instantiate a driver for each one. Now the driver assumes that the pins
> are completely configured with one iomux controller, but for the LPSR
> pins this is not true: The MUX_CTL and PAD_CTL registers are indeed
> in the LPSR controller, but the SELECT_INPUT registers for the same
> pin are found in the regular controller.
> 
> The result is that with this pin for example:
> 
> #define MX7D_PAD_GPIO1_IO06__UART5_DCE_RX                         0x0018 0x0048 0x0714 0x3 0x4
> 
> The LPSR controller writes to LPSR_BASE + 0x714 where it should really
> be IOMUX_BASE + 0x714.
> 
> I have no idea how to fix this. We could split the LPSR pins into two
> pins, one for each controller. Another possibility would be to create
> some kind of shortcut from one controller to control the other one. Also
> not nice. Also we could simply do nothing, as long as the bootloader
> configures everything correctly we won't even notice ;)
Always expect a bootloader is wrong and do it properly in the kernel
as if you have 2 bootloader they may do different configuration and as the end
found the problem in the kernel on one board and not the other.

Best Regards,
J.