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| author | Ahmad Fatoum <a.fatoum@pengutronix.de> | 2022-10-17 09:09:59 +0200 |
|---|---|---|
| committer | Sascha Hauer <s.hauer@pengutronix.de> | 2022-10-27 11:13:29 +0200 |
| commit | 7f8f629c50dce14bb83e7d4e2614bdd518ca3952 (patch) | |
| tree | 0765d66204b46928a11cf584af1a989067afb04c | |
| parent | 594d5d58afcdb717620ca526ab390cef91e8ba21 (diff) | |
| download | barebox-7f8f629c50dce14bb83e7d4e2614bdd518ca3952.tar.gz barebox-7f8f629c50dce14bb83e7d4e2614bdd518ca3952.tar.xz | |
ARM: i.MX7: describe USB serial download boot mode
Due to i.MX7 erratum e10574: "Watchdog: A watchdog timeout or software
trigger will not reset the SOC", we can't do warm reset via imxwd-warm
for BootROM reboot mode as we do on other i.MX SoCs.
What we can do instead though, is use the SoC's reset controller to
toggle the Cortex-A7's reset. This will have us reenter BootROM with
GPR registers intact. Forcing serial download on the i.MX7 now possible
with:
gpr.reboot_mode.next=serial reset -w
Note that the new restart handler is not fit for general purpose.
Depending on boot medium, it may hang, because the BootROM may not
reinitialize the peripheral properly.
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Link: https://lore.barebox.org/20221017071000.1458292-8-a.fatoum@pengutronix.de
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
| -rw-r--r-- | arch/arm/configs/imx_v7_defconfig | 2 | ||||
| -rw-r--r-- | arch/arm/dts/imx7.dtsi | 37 | ||||
| -rw-r--r-- | drivers/power/reset/syscon-reboot.c | 1 |
3 files changed, 40 insertions, 0 deletions
diff --git a/arch/arm/configs/imx_v7_defconfig b/arch/arm/configs/imx_v7_defconfig index d07abe28ae..3cbec267fc 100644 --- a/arch/arm/configs/imx_v7_defconfig +++ b/arch/arm/configs/imx_v7_defconfig @@ -208,6 +208,8 @@ CONFIG_REGULATOR=y CONFIG_REGULATOR_FIXED=y CONFIG_GENERIC_PHY=y CONFIG_USB_NOP_XCEIV=y +CONFIG_SYSCON_REBOOT_MODE=y +CONFIG_POWER_RESET_SYSCON=y CONFIG_FS_EXT4=y CONFIG_FS_TFTP=y CONFIG_FS_TFTP_MAX_WINDOW_SIZE=8 diff --git a/arch/arm/dts/imx7.dtsi b/arch/arm/dts/imx7.dtsi new file mode 100644 index 0000000000..1c67bdc546 --- /dev/null +++ b/arch/arm/dts/imx7.dtsi @@ -0,0 +1,37 @@ +/* SPDX-License-Identifier: GPL-2.0-only OR MIT */ + +#include "imx7d-ddrc.dtsi" + +/ { + aliases { + gpr.reboot_mode = &reboot_mode_gpr; + }; +}; + +&src { + compatible = "fsl,imx7d-src", "syscon", "simple-mfd"; + + reboot_mode_gpr: reboot-mode { + compatible = "barebox,syscon-reboot-mode"; + offset = <0x94>, <0x98>; /* SRC_GPR{9,10} */ + mask = <0xffffffff>, <0x40000000>; + mode-normal = <0>, <0>; + mode-serial = <0x00000010>, <0x40000000>; + }; + + ca7_reset: cortex-a7-reboot { + compatible = "syscon-reboot"; + regmap = <&src>; + offset = <0x4>; + mask = <1>; + value = <1>; + /* This is not fit for use as general purpose reset */ + restart-priority = <5>; + /* + * Can't use imxwd-warm due to errata e10574: + * Watchdog: A watchdog timeout or software trigger will + * not reset the SOC + */ + barebox,restart-warm-bootrom; + }; +}; diff --git a/drivers/power/reset/syscon-reboot.c b/drivers/power/reset/syscon-reboot.c index 2dbb6c1ddc..b6b8db75ca 100644 --- a/drivers/power/reset/syscon-reboot.c +++ b/drivers/power/reset/syscon-reboot.c @@ -71,6 +71,7 @@ static int syscon_reboot_probe(struct device_d *dev) ctx->restart_handler.name = "syscon-reboot"; ctx->restart_handler.restart = syscon_restart_handle; ctx->restart_handler.priority = 192; + ctx->restart_handler.of_node = dev->device_node; err = restart_handler_register(&ctx->restart_handler); if (err) |