The upstream Linux kernel relies on the sunxi_sram driver to bind the system-control nodes as syscon devices. Since U-Boot lacks this SRAM driver, peripheral drivers may fail to resolve the syscon node unless an explicit "syscon" compatible is added into the device tree.
To address this, add a bare UCLASS_SYSCON driver that matches all Allwinner system-control and SRAM controller compatibles listed in the Linux kernel to provide the necessary regmap access to the system controller. Signed-off-by: Junhui Liu <[email protected]> --- arch/arm/mach-sunxi/Kconfig | 7 +++++++ arch/arm/mach-sunxi/Makefile | 1 + arch/arm/mach-sunxi/syscon.c | 28 ++++++++++++++++++++++++++++ 3 files changed, 36 insertions(+) diff --git a/arch/arm/mach-sunxi/Kconfig b/arch/arm/mach-sunxi/Kconfig index ceba96b61a5..e5145bf3885 100644 --- a/arch/arm/mach-sunxi/Kconfig +++ b/arch/arm/mach-sunxi/Kconfig @@ -209,6 +209,13 @@ config SUN6I_PRCM Support for the PRCM (Power/Reset/Clock Management) unit available in A31 SoC. +config SUNXI_SYSCON + bool + select SYSCON + help + Enable syscon driver for Allwinner system controllers, which provides + access to the SRAM/system-control node for drivers. + config AXP_PMIC_BUS bool select DM_PMIC if DM_I2C diff --git a/arch/arm/mach-sunxi/Makefile b/arch/arm/mach-sunxi/Makefile index 9c79b55abf3..ff475d8fff5 100644 --- a/arch/arm/mach-sunxi/Makefile +++ b/arch/arm/mach-sunxi/Makefile @@ -10,6 +10,7 @@ obj-y += board.o obj-y += cpu_info.o obj-y += dram_helpers.o obj-$(CONFIG_SUN6I_PRCM) += prcm.o +obj-$(CONFIG_SUNXI_SYSCON) += syscon.o obj-$(CONFIG_AXP_PMIC_BUS) += pmic_bus.o obj-$(CONFIG_MACH_SUNIV) += clock_sun6i.o obj-$(CONFIG_MACH_SUN4I) += clock_sun4i.o diff --git a/arch/arm/mach-sunxi/syscon.c b/arch/arm/mach-sunxi/syscon.c new file mode 100644 index 00000000000..e27110dfb0d --- /dev/null +++ b/arch/arm/mach-sunxi/syscon.c @@ -0,0 +1,28 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2026 Junhui Liu <[email protected]> + */ + +#include <dm.h> +#include <syscon.h> + +static const struct udevice_id sunxi_syscon_ids[] = { + { .compatible = "allwinner,sun4i-a10-sram-controller" }, + { .compatible = "allwinner,sun4i-a10-system-control" }, + { .compatible = "allwinner,sun5i-a13-system-control" }, + { .compatible = "allwinner,sun8i-a23-system-control" }, + { .compatible = "allwinner,sun8i-h3-system-control" }, + { .compatible = "allwinner,sun20i-d1-system-control" }, + { .compatible = "allwinner,sun50i-a64-sram-controller" }, + { .compatible = "allwinner,sun50i-a64-system-control" }, + { .compatible = "allwinner,sun50i-h5-system-control" }, + { .compatible = "allwinner,sun50i-h616-system-control" }, + { .compatible = "allwinner,sun55i-a523-system-control" }, + { /* sentinel */ }, +}; + +U_BOOT_DRIVER(sunxi_syscon) = { + .name = "sunxi_syscon", + .id = UCLASS_SYSCON, + .of_match = sunxi_syscon_ids, +}; -- 2.54.0
