Re: [PATCH RFC u-boot-mvebu] arm: kirkwood: Move internal registers in arch_very_early_init() function

Hi Pali,

On Sat, Mar 11, 2023 at 2:57 AM Pali Rohár pali@kernel.org wrote:

Same change as was done for mvebu in commit 5bb2c550b11e ("arm: mvebu: Move internal registers in arch_very_early_init() function") but for kirkwood.

Signed-off-by: Pali Rohár pali@kernel.org

Hello! Please test this RFC patch on more Kirkwood boards if there is any issue with it.

I've run a regression test with this patch (Debug UART is not enabled). And everything was OK. No change in behavior.

However, when I turned on Debug UART on the nsa310s (88F6702) board, and ran with kwboot, it froze right away upon starting. Unrelated to this patch, I believe DEBUG_UART has been broken for Kirkwood lately, perhaps sometime late December to present, but I did not have time to track it down. Here is the last thread that I had Debug UART working on the Pogo V4 (88F6192): https://lists.denx.de/pipermail/u-boot/2022-December/502605.html

For reference, here is my local patch to configure the NSA310S, in addition to this patch.

diff --git a/configs/nsa310s_defconfig b/configs/nsa310s_defconfig index 76839e62dd..4bef35d576 100644 --- a/configs/nsa310s_defconfig +++ b/configs/nsa310s_defconfig @@ -15,8 +15,11 @@ CONFIG_ENV_SIZE=0x20000 CONFIG_ENV_OFFSET=0xE0000 CONFIG_DEFAULT_DEVICE_TREE="kirkwood-nsa310s" CONFIG_SYS_PROMPT="NSA310s> " +CONFIG_DEBUG_UART_BASE=0xf1012000 +CONFIG_DEBUG_UART_CLOCK=250000000 CONFIG_IDENT_STRING="\nZyXEL NSA310S/320S 1/2-Bay Power Media Server" CONFIG_SYS_LOAD_ADDR=0x800000 +CONFIG_DEBUG_UART=y CONFIG_DISTRO_DEFAULTS=y CONFIG_BOOTDELAY=3 CONFIG_USE_PREBOOT=y @@ -50,6 +53,7 @@ CONFIG_MTD_RAW_NAND=y CONFIG_PHY_MARVELL=y CONFIG_MVGBE=y CONFIG_MII=y +CONFIG_DEBUG_UART_ANNOUNCE=y CONFIG_USB=y CONFIG_USB_EHCI_HCD=y CONFIG_UBIFS_SILENCE_MSG=y

diff --git a/arch/arm/dts/kirkwood-nsa310s.dts b/arch/arm/dts/kirkwood-nsa310s.dts index 09ee76c2a2..2df45aa6da 100644 --- a/arch/arm/dts/kirkwood-nsa310s.dts +++ b/arch/arm/dts/kirkwood-nsa310s.dts @@ -22,6 +22,10 @@ reg = <0x00000000 0x10000000>; };

+ aliases { + serial0 = &uart0; + }; + chosen { bootargs = "console=ttyS0,115200"; stdout-path = &uart0; @@ -317,3 +321,8 @@ &pcie0 { status = "okay"; }; + +&uart0 { + status = "okay"; + u-boot,dm-pre-reloc; +};

If anybody is available to test this patch with Debug UART enabled, it would be great. I'll wait a few days and if there is no suggestion, I would do a bisect from Dec 19th.

Thanks, Tony

---

arch/arm/mach-kirkwood/Kconfig | 2 ++ arch/arm/mach-kirkwood/Makefile | 1 + arch/arm/mach-kirkwood/cpu.c | 3 --- arch/arm/mach-kirkwood/lowlevel.S | 12 ++++++++++++ 4 files changed, 15 insertions(+), 3 deletions(-) create mode 100644 arch/arm/mach-kirkwood/lowlevel.S

diff --git a/arch/arm/mach-kirkwood/Kconfig b/arch/arm/mach-kirkwood/Kconfig index c8a193dd4cdf..ba39e9ae416e 100644 --- a/arch/arm/mach-kirkwood/Kconfig +++ b/arch/arm/mach-kirkwood/Kconfig @@ -5,9 +5,11 @@ config FEROCEON_88FR131

config KW88F6192 bool

•   select ARCH_VERY_EARLY_INIT
  
  

config KW88F6281 bool

•   select ARCH_VERY_EARLY_INIT
  
  

config SHEEVA_88SV131 bool diff --git a/arch/arm/mach-kirkwood/Makefile b/arch/arm/mach-kirkwood/Makefile index 3b2eef8d5419..0fb5a2326f5f 100644 --- a/arch/arm/mach-kirkwood/Makefile +++ b/arch/arm/mach-kirkwood/Makefile @@ -6,6 +6,7 @@

obj-y = cpu.o obj-y += cache.o +obj-y += lowlevel.o obj-y += mpp.o

# cpu.o and cache.o contain CP15 instructions which cannot be run in diff --git a/arch/arm/mach-kirkwood/cpu.c b/arch/arm/mach-kirkwood/cpu.c index df3e8f11782a..2b493b36c20d 100644 --- a/arch/arm/mach-kirkwood/cpu.c +++ b/arch/arm/mach-kirkwood/cpu.c @@ -189,9 +189,6 @@ int arch_cpu_init(void) struct kwcpu_registers *cpureg = (struct kwcpu_registers *)KW_CPU_REG_BASE;

•   /* Linux expects the internal registers to be at 0xf1000000 */
  

•   writel(KW_REGS_PHY_BASE, KW_OFFSET_REG);
  

•   /* Enable and invalidate L2 cache in write through mode */
    writel(readl(&cpureg->l2_cfg) | 0x18, &cpureg->l2_cfg);
    invalidate_l2_cache();
  

diff --git a/arch/arm/mach-kirkwood/lowlevel.S b/arch/arm/mach-kirkwood/lowlevel.S new file mode 100644 index 000000000000..3b339f97f056 --- /dev/null +++ b/arch/arm/mach-kirkwood/lowlevel.S @@ -0,0 +1,12 @@ +/* SPDX-License-Identifier: GPL-2.0+ */

+#include <config.h> +#include <linux/linkage.h>

+ENTRY(arch_very_early_init)

•   /* Move internal registers from KW_OFFSET_REG to KW_REGS_PHY_BASE */
  

•   ldr     r0, =KW_REGS_PHY_BASE
  

•   ldr     r1, =KW_OFFSET_REG
  

•   str     r0, [r1]
  

•   bx      lr
  

+ENDPROC(arch_very_early_init)

2.20.1