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authorPali Rohár2022-08-17 21:37:49 +0200
committerStefan Roese2022-08-23 12:38:47 +0200
commitf395cf9cacb1c54f95bce09473e37b8ac2b5517d (patch)
treed8189f05edb628d23eb4bfabf660442583eb2c14 /arch/arm
parent616278bd2c563a6d12a2347ce5cfc3512f77ee42 (diff)
arm: kirkwood: 88f6281: Detect CONFIG_SYS_TCLK from SAR register
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 Update by Stefan 2022-08-23: - Fix compilation error for ds109 Fixes: 8ac303d49f89 ("arm: kirkwood: Do not overwrite CONFIG_SYS_TCLK") Signed-off-by: Pali Rohár <pali@kernel.org> Reviewed-by: Stefan Roese <sr@denx.de>
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/mach-kirkwood/include/mach/kw88f6281.h3
-rw-r--r--arch/arm/mach-kirkwood/include/mach/soc.h2
2 files changed, 4 insertions, 1 deletions
diff --git a/arch/arm/mach-kirkwood/include/mach/kw88f6281.h b/arch/arm/mach-kirkwood/include/mach/kw88f6281.h
index 87406081cf5..f86cd0bb601 100644
--- a/arch/arm/mach-kirkwood/include/mach/kw88f6281.h
+++ b/arch/arm/mach-kirkwood/include/mach/kw88f6281.h
@@ -15,6 +15,7 @@
#define KW_REGS_PHY_BASE KW88F6281_REGS_PHYS_BASE
/* TCLK Core Clock definition */
-#define CONFIG_SYS_TCLK 200000000 /* 200MHz */
+#define CONFIG_SYS_TCLK ((readl(CONFIG_SAR_REG) & BIT(21)) ? \
+ 166666667 : 200000000)
#endif /* _ASM_ARCH_KW88F6281_H */
diff --git a/arch/arm/mach-kirkwood/include/mach/soc.h b/arch/arm/mach-kirkwood/include/mach/soc.h
index 1d7f2828cd3..5f545c6f434 100644
--- a/arch/arm/mach-kirkwood/include/mach/soc.h
+++ b/arch/arm/mach-kirkwood/include/mach/soc.h
@@ -62,6 +62,8 @@
#define MVCPU_WIN_ENABLE KWCPU_WIN_ENABLE
#define MVCPU_WIN_DISABLE KWCPU_WIN_DISABLE
+#define CONFIG_SAR_REG (KW_MPP_BASE + 0x0030)
+
#if defined (CONFIG_KW88F6281)
#include <asm/arch/kw88f6281.h>
#elif defined (CONFIG_KW88F6192)