[PATCH v2 3/5] pinctrl: renesas: r8a77965: Add R8A774B1 PFC support

[Biju Das]

Hi Marek,

> Subject: Re: [PATCH v2 3/5] pinctrl: renesas: r8a77965: Add R8A774B1 PFC
> support
> 
> On 10/14/20 1:29 PM, Biju Das wrote:
> 
> Hi,
> 
> [...]
> 
> >>>> Check with the linux maintainers please, surely there should be
> >>>> some way to separate the extras in a way that's not too hard to
> >>>> maintain, and thus reduce the resulting binary size. For U-Boot,
> >>>> that is quite important already, I think the TFA can only load 1 MiB
> binary in total.
> >>>
> >>> I agree for bootloader size is important. So I will add macros as
> >>> per your
> >> suggestion (we don't need to look into linux for this).
> >>
> >> The PFC tables and clock tables are the same between U-Boot and
> >> Linux, so if you only change them in U-Boot, it will make it hard to
> >> synchronize the tables later with Linux again. Please fix this in Linux and
> synchronize to U-Boot.
> >
> > I have posted a patch for optimizing pin control size for RZ/G2N in
> > Linux [1]
> >
> > [1]
> > https://patchwork.kernel.org/project/linux-renesas-soc/patch/202010141
> > 10238.9600-1-biju.das.jz at bp.renesas.com/
> >
> > This approach will save ~ 6KB=(3x 2KB/SoC) of memory on RZ/G2[HMN] u-
> boot with multi dtb support.
> >
> > 1) By compiling out Automotive parts
> > $ size drivers/pinctrl/renesas/pfc-r8a77965.o
> >    text	   data	    bss	    dec	    hex	filename
> >   46141	      0	      0	  46141	   b43d	drivers/pinctrl/renesas/pfc-
> r8a77965.o
> >
> > 2) without patch
> > $ size drivers/pinctrl/renesas/pfc-r8a77965.o
> >    text	   data	    bss	    dec	    hex	filename
> >   48191	      0	      0	  48191	   bc3f	drivers/pinctrl/renesas/pfc-
> r8a77965.o
> 
> Have a look at the size of the image of rcar3_salvator-x_defconfig , it is just a
> few kiB short of 1MiB , which is the hard limit. Any size reduction helps.

Yes I agree, we need to look into size reduction for Salvator-XS. But currently there is no issue. See the details below.

Case 1) R Car Salvator-XS u-boot size (u-boot-sh/master):

$ ls -al u-boot.bin
-rw-r--r-- 1 biju biju 1025067 Oct 17 12:47 u-boot.bin --> 0xFA42B (23 Kbytes to reach 1MB)

$ size u-boot
   text	   data	    bss	    dec	    hex	filename
 942180	  36208	  71632	1050020	 1005a4	u-boot

$ size drivers/pinctrl/renesas/*.o
   text	   data	    bss	    dec	    hex	filename
 151332	    288	      1	 151621	  25045	drivers/pinctrl/renesas/built-in.o
   3811	    288	      1	   4100	   1004	drivers/pinctrl/renesas/pfc.o
  48123	      0	      0	  48123	   bbfb	drivers/pinctrl/renesas/pfc-r8a7795.o
  47939	      0	      0	  47939	   bb43	drivers/pinctrl/renesas/pfc-r8a77965.o
  47751	      0	      0	  47751	   ba87	drivers/pinctrl/renesas/pfc-r8a7796.o

Case 2) R Car Salvator-X u-boot size after adding RZ/G2[HMN] pin control support

$ ls -al u-boot.bin
-rw-r--r-- 1 biju biju 1027107 Oct 17 12:59 u-boot.bin --> 0xFAC23 (21 Kbytes to reach 1 MB)

$ size u-boot
   text	   data	    bss	    dec	    hex	filename
 944224	  36208	  71632	1052064	 100da0	u-boot

$ size drivers/pinctrl/renesas/*.o
   text	   data	    bss	    dec	    hex	filename
 151868	    288	      1	 152157	  2525d	drivers/pinctrl/renesas/built-in.o
   3811	    288	      1	   4100	   1004	drivers/pinctrl/renesas/pfc.o
  48375	      0	      0	  48375	   bcf7	drivers/pinctrl/renesas/pfc-r8a7795.o
  48191	      0	      0	  48191	   bc3f	drivers/pinctrl/renesas/pfc-r8a77965.o
  47751	      0	      0	  47751	   ba87	drivers/pinctrl/renesas/pfc-r8a7796.o


Regards,
Biju