[PATCH 02/22] arm: kirkwood: 88f6281: Detect CONFIG_SYS_TCLK from SAR register

[Pali Rohár]

On Tuesday 23 August 2022 10:17:31 michael at walle.cc wrote:
> Am 2022-08-23 07:02, schrieb Stefan Roese:
> > Hi Michael,
> > 
> > On 17.08.22 21:37, Michael Walle wrote:
> > > From: Pali Rohár <pali at kernel.org>
> > > 
> > > Bit 21 in SAR register specifies if TCLK is running at 166 MHz or
> > > 200 MHz.
> > > This information is undocumented in public Marvell Kirkwood Functional
> > > Specifications [2], but is available in Linux v3.15 kirkwood code [1].
> > > 
> > > Commit 8ac303d49f89 ("arm: kirkwood: Do not overwrite
> > > CONFIG_SYS_TCLK")
> > > broke support for Marvell 88F6281 SoCs because it was expected that
> > > all
> > > those SoCs have TCLK running at 200 MHz as specified in Marvell
> > > 88F6281
> > > Hardware Specifications [3].
> > > 
> > > Fix broken support for 88F6281 by detecting CONFIG_SYS_TCLK from SAR
> > > register, like it was doing Linux v3.15.
> > > 
> > > [1] - https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/arch/arm/mach-kirkwood/common.c?h=v3.15#n542
> > > [2] - https://web.archive.org/web/20130730091033/http://www.marvell.com/embedded-processors/kirkwood/assets/FS_88F6180_9x_6281_OpenSource.pdf
> > > [3] - https://web.archive.org/web/20120620073511/http://www.marvell.com/embedded-processors/kirkwood/assets/HW_88F6281_OpenSource.pdf
> > > 
> > > Fixes: 8ac303d49f89 ("arm: kirkwood: Do not overwrite
> > > CONFIG_SYS_TCLK")
> > > Signed-off-by: Pali Rohár <pali at kernel.org>
> > 
> > I've applied your patch series on master (from yesterday) and see
> > these error(s):
> > 
> > $ make ds109_defconfig
> > $ make -sj
> > ...
> > In file included from ./arch/arm/include/asm/arch/config.h:18,
> >                  from include/configs/mv-common.h:58,
> >                  from include/configs/ds109.h:14,
> >                  from include/config.h:4,
> >                  from include/common.h:16,
> >                  from board/Synology/ds109/ds109.c:8:
> > board/Synology/ds109/ds109.c: In function 'reset_misc':
> > ./arch/arm/include/asm/arch/kw88f6281.h:18:43: warning: implicit
> > declaration of function 'readl' [-Wimplicit-function-declaration]
> >    18 | #define CONFIG_SYS_TCLK
> > ((readl(CONFIG_SAR_REG) & BIT(21)) ? \
> >       |                                           ^~~~~
> > include/configs/mv-common.h:36:41: note: in expansion of macro
> > 'CONFIG_SYS_TCLK'
> >    36 | #define CONFIG_SYS_NS16550_CLK          CONFIG_SYS_TCLK
> >       |                                         ^~~~~~~~~~~~~~~
> > board/Synology/ds109/ds109.c:111:36: note: in expansion of macro
> > 'CONFIG_SYS_NS16550_CLK'
> >   111 |                                    CONFIG_SYS_NS16550_CLK,
> > 9600);
> >       |                                    ^~~~~~~~~~~~~~~~~~~~~~
> > /opt/kernel.org/gcc-11.1.0-nolibc/arm-linux-gnueabi/bin/arm-linux-gnueabi-ld.bfd:
> > board/Synology/ds109/ds109.o: in function `reset_misc':
> > /home/stefan/git/u-boot/u-boot-marvell/board/Synology/ds109/ds109.c:111:
> > undefined reference to `readl'
> > make: *** [Makefile:1823: u-boot] Error 1
> > 
> > Could you please take a look and fix this?
> 
> I guess soc.h should also include <asm/io.h> because now it is
> using that hidden readl().
> 
> Pali?
> 
> -michael

Yes!