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

[michael at walle.cc]

Am 2022-08-23 10:47, schrieb Pali Rohár:
> On Tuesday 23 August 2022 10:24:10 michael at walle.cc wrote:
>> Am 2022-08-23 10:17, schrieb michael at walle.cc:
>> > 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().
>> 
>> ..which isn't working because it somehow finds its way to the
>> hosttools. Hum.
> 
> Or you can include it in ds109/ds109.c file.

And maybe other files, too. Mh. Somehow this feels wrong, but as we
cannot include it in the soc.h I don't see another possibility.

-michael