arm64: dts: qcom: sa8540p-ride: enable rtc

SA8540P-ride is one of the Qualcomm platforms that does not have access
to UEFI runtime services and on which the RTC registers are read-only,
as described in:
https://lore.kernel.org/all/20230202155448.6715-1-johan+linaro@kernel.org/

Reserve four bytes in one of the PMIC registers to hold the RTC offset
the same way as it was done for sc8280xp-crd which has similar
limitations:
    commit e67b45582c5e ("arm64: dts: qcom: sc8280xp-crd: enable rtc")

On SA8540P-ride, the register bank SDAM6 of the first PMIC is not
writable. Following recommendations provided during the review, use
SDAM2 from the second PMIC at offset 0xa0 instead.

Reviewed-by: Caleb Connolly <caleb.connolly@linaro.org>
Signed-off-by: Eric Chanudet <echanude@redhat.com>
Link: https://lore.kernel.org/r/20230809203506.1833205-1-echanude@redhat.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

diff --git a/arch/arm64/boot/dts/qcom/sa8540p-pmics.dtsi b/arch/arm64/boot/dts/qcom/sa8540p-pmics.dtsi
index 1221be8..a1fbb47 100644 (file)
--- a/arch/arm64/boot/dts/qcom/sa8540p-pmics.dtsi
+++ b/arch/arm64/boot/dts/qcom/sa8540p-pmics.dtsi
@@ -14,7 +14,7 @@
                #address-cells = <1>;
                #size-cells = <0>;
 
-               rtc@6000 {
+               pmm8540a_rtc: rtc@6000 {
                        compatible = "qcom,pm8941-rtc";
                        reg = <0x6000>, <0x6100>;
                        reg-names = "rtc", "alarm";
@@ -39,6 +39,15 @@
                #address-cells = <1>;
                #size-cells = <0>;
 
+               pmm8540c_sdam_2: nvram@b110 {
+                       compatible = "qcom,spmi-sdam";
+                       reg = <0xb110>;
+                       #address-cells = <1>;
+                       #size-cells = <1>;
+                       ranges = <0 0xb110 0xb0>;
+                       status = "disabled";
+               };
+
                pmm8540c_gpios: gpio@c000 {
                        compatible = "qcom,pm8150-gpio", "qcom,spmi-gpio";
                        reg = <0xc000>;

diff --git a/arch/arm64/boot/dts/qcom/sa8540p-ride.dts b/arch/arm64/boot/dts/qcom/sa8540p-ride.dts
index 5a26974..b04f72e 100644 (file)
--- a/arch/arm64/boot/dts/qcom/sa8540p-ride.dts
+++ b/arch/arm64/boot/dts/qcom/sa8540p-ride.dts
@@ -407,6 +407,21 @@
        status = "okay";
 };
 
+&pmm8540a_rtc {
+       nvmem-cells = <&rtc_offset>;
+       nvmem-cell-names = "offset";
+
+       status = "okay";
+};
+
+&pmm8540c_sdam_2 {
+       status = "okay";
+
+       rtc_offset: rtc-offset@a0 {
+               reg = <0xa0 0x4>;
+       };
+};
+
 &qup0 {
        status = "okay";
 };