Subject: [PATCH] [media] staging: allow omap4iss to be modular

From: [email-masked] (Tony Lindgren)
Date: Wed, 11 Jun 2014 07:47:54 -0700

* Arnd Bergmann <[email-masked]> [140611 07:37]:
> The OMAP4 camera support depends on I2C and VIDEO_V4L2, both
> of which can be loadable modules. This causes build failures
> if we want the camera driver to be built-in.

That's good news, but let's not fix it this way.
 
> This can be solved by turning the option into "tristate",
> which unfortunately causes another problem, because the
> driver incorrectly calls a platform-internal interface
> for omap4_ctrl_pad_readl/omap4_ctrl_pad_writel.
> To work around that, we can export those symbols, but
> that isn't really the correct solution, as we should not
> have dependencies on platform code this way.
> 
> Signed-off-by: Arnd Bergmann <[email-masked]>
> ---
> This is one of just two patches we currently need to get
> 'make allmodconfig' to build again on ARM.
> 
> diff --git a/arch/arm/mach-omap2/control.c b/arch/arm/mach-omap2/control.c
> index 751f354..05d2d98 100644
> --- a/arch/arm/mach-omap2/control.c
> +++ b/arch/arm/mach-omap2/control.c
> @@ -190,11 +190,13 @@ u32 omap4_ctrl_pad_readl(u16 offset)
>  {
>  	return readl_relaxed(OMAP4_CTRL_PAD_REGADDR(offset));
>  }
> +EXPORT_SYMBOL_GPL(omap4_ctrl_pad_readl);
>  
>  void omap4_ctrl_pad_writel(u32 val, u16 offset)
>  {
>  	writel_relaxed(val, OMAP4_CTRL_PAD_REGADDR(offset));
>  }
> +EXPORT_SYMBOL_GPL(omap4_ctrl_pad_writel);
>  
>  #ifdef CONFIG_ARCH_OMAP3

Exporting these will likely cause immediate misuse in other
drivers all over the place.

These should just use either pinctrl-single.c instead for muxing.
Or if they are not mux registers, we do have the syscon mapping
available in omap4.dtsi that pbias-regulator.c is already using.

Laurent, got any better ideas?

Regards,

Tony