ARM: dts: stm32: support child mfd cells for the stm32mp1 TAMP syscon

The stm32mp1 TAMP peripheral has 32 backup registers that survive
a warm reset. This makes them suitable for storing a reboot
mode, which the vendor's kernel tree is already doing[0].

The actual syscon-reboot-mode child node can be added by a board.dts or
fixed up by the bootloader. For the child node to be probed, the
compatible needs to include simple-mfd. The binding now specifies this,
so have the SoC dtsi adhere to it.

[0]: https://github.com/STMicroelectronics/linux/commit/2e9bfc29dd

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>

diff --git a/arch/arm/boot/dts/stm32mp151.dtsi b/arch/arm/boot/dts/stm32mp151.dtsi
index a333c633a112873fcf047c115bdf3d0037a7dcb2..3c75abacb374ec3eadb027bd0540e38e180fae26 100644 (file)
--- a/arch/arm/boot/dts/stm32mp151.dtsi
+++ b/arch/arm/boot/dts/stm32mp151.dtsi
@@ -1574,7 +1574,7 @@
                };
 
                tamp: tamp@5c00a000 {
-                       compatible = "st,stm32-tamp", "syscon";
+                       compatible = "st,stm32-tamp", "syscon", "simple-mfd";
                        reg = <0x5c00a000 0x400>;
                };