On 24.06.21 15:20, Michael Tretter wrote: > On Thu, 24 Jun 2021 12:48:44 +0200, Ahmad Fatoum wrote: >> On 24.06.21 12:23, Michael Tretter wrote: >>> The reset reason is available in the APB register set on the ZynqMP. >>> Read the reset reason and set the reset source accordingly. >>> >>> There might be multiple bits set in the APB register. Use the MSB for >>> determining the actual reset source. >> >> APB is usually the AMBA Advanced Peripheral Bus. Perhaps CRL is the >> actual name of the register and APB just tells that it's mapped there? > > Ack. The data sheet calls it "Clock and Reset control registers for LPD." I > will fix it in v2. > >> >>> >>> Signed-off-by: Michael Tretter <m.tretter@xxxxxxxxxxxxxx> >>> --- >>> arch/arm/mach-zynqmp/Makefile | 1 + >>> arch/arm/mach-zynqmp/include/mach/zynqmp.h | 6 ++ >>> arch/arm/mach-zynqmp/zynqmp.c | 74 ++++++++++++++++++++++ >>> 3 files changed, 81 insertions(+) >>> create mode 100644 arch/arm/mach-zynqmp/include/mach/zynqmp.h >>> create mode 100644 arch/arm/mach-zynqmp/zynqmp.c >>> >>> diff --git a/arch/arm/mach-zynqmp/Makefile b/arch/arm/mach-zynqmp/Makefile >>> index 021efc94afaf..14b8a4e46b87 100644 >>> --- a/arch/arm/mach-zynqmp/Makefile >>> +++ b/arch/arm/mach-zynqmp/Makefile >>> @@ -1,2 +1,3 @@ >>> # SPDX-License-Identifier: GPL-2.0-or-later >>> obj-y += firmware-zynqmp.o >>> +obj-y += zynqmp.o >>> diff --git a/arch/arm/mach-zynqmp/include/mach/zynqmp.h b/arch/arm/mach-zynqmp/include/mach/zynqmp.h >>> new file mode 100644 >>> index 000000000000..f6c05f35a470 >>> --- /dev/null >>> +++ b/arch/arm/mach-zynqmp/include/mach/zynqmp.h >> >> Nitpick: revision.h sounds more self-describing. > > Ok. I thought there might be some more soc specific function instead of > revision specific functions here, but revision.h is fine for me as well. > >> >>> @@ -0,0 +1,6 @@ >>> +#ifndef __MACH_ZYNQMP_H >>> +#define __MACH_ZYNQMP_H >>> + >>> +int zynqmp_soc_revision(void); >>> + >>> +#endif /* __MACH_ZYNQMP_H */ >>> diff --git a/arch/arm/mach-zynqmp/zynqmp.c b/arch/arm/mach-zynqmp/zynqmp.c >>> new file mode 100644 >>> index 000000000000..2b3bd8406ce9 >>> --- /dev/null >>> +++ b/arch/arm/mach-zynqmp/zynqmp.c >>> @@ -0,0 +1,74 @@ >>> +// SPDX-License-Identifier: GPL-2.0-only >>> +/* >>> + * Copyright (C) 2020 Michael Tretter <m.tretter@xxxxxxxxxxxxxx> >>> + */ >>> + >>> +#include <common.h> >>> +#include <init.h> >>> +#include <linux/types.h> >>> +#include <reset_source.h> >>> + >>> +#include <mach/zynqmp.h> >>> + >>> +#define ZYNQMP_CRL_APB_BASE 0xff5e0000 >>> +#define ZYNQMP_CRL_APB_RESET_REASON (ZYNQMP_CRL_APB_BASE + 0x220) >>> + >>> +/* External POR: The PS_POR_B reset signal pin was asserted. */ >>> +#define ZYNQMP_CRL_APB_RESET_REASON_EXTERNAL BIT(0) >>> +/* Internal POR: A system error triggered a POR reset. */ >>> +#define ZYNQMP_CRL_APB_RESET_REASON_INTERNAL BIT(1) >>> +/* Internal system reset; A system error triggered a system reset. */ >>> +#define ZYNQMP_CRL_APB_RESET_REASON_PMU BIT(2) >>> +/* PS-only reset: Write to PMU_GLOBAL.GLOBAL_RESET [PS_ONLY_RST]. */ >>> +#define ZYNQMP_CRL_APB_RESET_REASON_PSONLY BIT(3) >>> +/* External system reset: The PS_SRST_B reset signal pin was asserted. */ >>> +#define ZYNQMP_CRL_APB_RESET_REASON_SRST BIT(4) >>> +/* Software system reset: Write to RESET_CTRL [soft_reset]. */ >>> +#define ZYNQMP_CRL_APB_RESET_REASON_SOFT BIT(5) >>> +/* Software debugger reset: Write to BLOCKONLY_RST [debug_only]. */ >>> +#define ZYNQMP_CRL_APB_RESET_REASON_DEBUG_SYS BIT(6) >>> + >>> +struct zynqmp_reset_reason { >>> + u32 mask; >>> + enum reset_src_type type; >>> +}; >>> + >>> +static const struct zynqmp_reset_reason reset_reasons[] = { >>> + { ZYNQMP_CRL_APB_RESET_REASON_DEBUG_SYS, RESET_UKWN }, >> >> RESET_JTAG? > > I am not sure, if I understand RESET_JTAG correctly. The reference manual says > that it is like a soft reset while preserving the debug logic and originates > in the DAP controller. Is this RESET_JTAG? Yes. DAP may be used with SWD as well, but as far as barebox reset reasons are concerned, every debugger related reset should be RESET_JTAG. > >> >>> + { ZYNQMP_CRL_APB_RESET_REASON_SOFT, RESET_RST }, >>> + { ZYNQMP_CRL_APB_RESET_REASON_SRST, RESET_POR }, >>> + { ZYNQMP_CRL_APB_RESET_REASON_PSONLY, RESET_POR }, >>> + { ZYNQMP_CRL_APB_RESET_REASON_PMU, RESET_POR }, >>> + { ZYNQMP_CRL_APB_RESET_REASON_INTERNAL, RESET_POR }, >>> + { ZYNQMP_CRL_APB_RESET_REASON_EXTERNAL, RESET_POR }, >> >> RESET_EXT? > > This bit is set for a normal POR, too. > >> >>> + { /* sentinel */ } >>> +}; >>> + >>> +static enum reset_src_type zynqmp_get_reset_src(void) >>> +{ >>> + enum reset_src_type type = RESET_UKWN; >>> + unsigned int i; >>> + u32 val; >>> + >>> + val = readl(ZYNQMP_CRL_APB_RESET_REASON); >>> + >>> + for (i = 0; i < ARRAY_SIZE(reset_reasons); i++) { >>> + if (val & reset_reasons[i].mask) { >>> + type = reset_reasons[i].type; >>> + break; >>> + } >>> + } >>> + >>> + pr_info("ZynqMP reset reason %s (ZYNQMP_CRL_APB_RESET_REASON: 0x%08x)\n", >>> + reset_source_to_string(type), val); >>> + >>> + return type; >>> +} >>> + >>> +static int zynqmp_init(void) >>> +{ >>> + reset_source_set(zynqmp_get_reset_src()); >>> + >>> + return 0; >>> +} >>> +postcore_initcall(zynqmp_init); >>> > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox