stm32mp: handle SYSRESET

Add support of sysreset with generic driver "syscon-reboot"
provided by RCC, for U-boot and for SPL.
Signed-off-by: NPatrick Delaunay <patrick.delaunay@st.com>

arch/arm/Kconfig

@@ -1166,6 +1166,7 @@ config ARCH_STM32MP
 	select REGMAP
 	select SUPPORT_SPL
 	select SYSCON
+	select SYSRESET
 	select SYS_THUMB_BUILD
 	help
 	  Support for STM32MP SoC family developed by STMicroelectronics,

arch/arm/dts/stm32mp157-u-boot.dtsi

@@ -72,6 +72,10 @@
 	u-boot,dm-pre-reloc;
 };
 
+&rcc_reboot {
+	u-boot,dm-pre-reloc;
+};
+
 &pinctrl {
 	u-boot,dm-pre-reloc;
 };

arch/arm/dts/stm32mp157.dtsi

@@ -114,6 +114,13 @@
 				#reset-cells = <1>;
 				compatible = "st,stm32mp1-rcc-rst";
 			};
+
+			rcc_reboot: rcc-reboot@50000000 {
+				compatible = "syscon-reboot";
+				regmap = <&rcc>;
+				offset = <0x404>;
+				mask = <0x1>;
+			};
 		};
 
 		pinctrl: pin-controller {

arch/arm/mach-stm32mp/Kconfig

@@ -16,6 +16,7 @@ config SPL
 	select SPL_RESET_SUPPORT
 	select SPL_SERIAL_SUPPORT
 	select SPL_SYSCON
+	select SPL_DRIVERS_MISC_SUPPORT
 	imply SPL_LIBDISK_SUPPORT
 
 config SYS_SOC
@@ -26,6 +27,7 @@ config TARGET_STM32MP1
 	select CPU_V7
 	select PINCTRL_STM32
 	select STM32_RESET
+	select SYSRESET_SYSCON
 	help
 		target STMicroelectronics SOC STM32MP1 family
 		STMicroelectronics MPU with core ARMv7

arch/arm/mach-stm32mp/cpu.c

@@ -269,7 +269,3 @@ int arch_misc_init(void)
 
 	return 0;
 }
-
-void reset_cpu(ulong addr)
-{
-}