Add a new RTC driver for recent mvebu SoCs

Hi,

The Marvell Armada 38x SoCs contains an RTC which differs from the RTC used in the other mvebu SoCs until now. This third version of the patch set adds support for this new IP and enable it in the Device Tree of the Armada 38x SoC.

Thanks,

Gr??gory

Changelog
v2 -> v3:

- Fixed the reg-names description in the dt binding documentation
- Used the delayed version of the writel in everyplace.

v1 -> v2:

- Used reg-names to identify the registers in the device tree
- Changed the space into tab in the MAINTAINERS file
- Emphasized that the 5s wait was only needed between two consecutive writes
- Reduced the wait in the set_time function, 100ms were enough
- If no interrupt was available, then disable the alarm related functions
- Fixed the critical sections
- Updated the mvebu_v7_defconfig by enabling the new RTC support

Gregory CLEMENT (5):
rtc: armada38x: Add the device tree binding documentation drivers/rtc/rtc-armada38x: Add a new RTC driver for recent mvebu SoCs
MAINTAINERS: Add the RTC driver for the Armada38x
ARM: mvebu: add Device Tree description of RTC on Armada 38x
ARM: mvebu: enable Armada 38x RTC driver in mvebu_v7_defconfig

 .../devicetree/bindings/rtc/armada-380-rtc.txt     |  22 ++
 MAINTAINERS                                        |   1 +
 arch/arm/boot/dts/armada-38x.dtsi                  |   7 +
 arch/arm/configs/mvebu_v7_defconfig                |   1 +
 drivers/rtc/Kconfig                                |  10 +
 drivers/rtc/Makefile                               |   1 +
 drivers/rtc/rtc-armada38x.c                        | 319 +++++++++++++++++++++
 7 files changed, 361 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/rtc/armada-380-rtc.txt
 create mode 100644 drivers/rtc/rtc-armada38x.c

1.9.1

The Armada 38x SoCs come with a new RTC which differs from the one used in the other mvebu SoCs until now. This patch describes the binding of this RTC.

---
 .../devicetree/bindings/rtc/armada-380-rtc.txt     | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/rtc/armada-380-rtc.txt

new file mode 100644
index 000000000000..e6fe29bda608
@@ -0,0 +1,22 @@
+* Real Time Clock of the Armada 38x SoCs
+
+RTC controller for the Armada 38x SoCs
+
+Required properties:
+- compatible : Should be "marvell,armada-380-rtc"
+- reg: physical base address of the controller and length of memory
+  mapped region, associated to the reg-name "rtc". The other entry is
+  related to the interrupt control from the SoC, associated to the
+  reg-name "soc-int".
+- reg-names: names of the mapped memory regions listed in reg property
+    in the same order: "rtc" and "soc-int".
+- interrupts: IRQ line for the RTC.
+
+Example:
+
+rtc at a3800 {
+	compatible = "marvell,armada-380-rtc";
+	reg = <0xa3800 0x20>, <0x184a0 0x0c>;
+	reg-names = "rtc", "soc-int";
+	interrupts = <GIC_SPI 21 IRQ_TYPE_LEVEL_HIGH>;
+};

1.9.1

OK

I don't have much information about it but for sure it is not part of the interrupt controller. It is a range of 3 registers related to the RTC, 2 of them are not documented and the third one is related to the interrupt management of the RTC. That's why I named this range soc-int(errupt), but it would more accurate to name it rtc-soc

Gr?gory

Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com

The new mvebu SoCs come with a new RTC driver. This patch adds the support for this new IP which is currently found in the Armada 38x SoCs.

This RTC provides two alarms, but only the first one is used in the driver. The RTC also allows using periodic interrupts.

---
 drivers/rtc/Kconfig         |  10 ++
 drivers/rtc/Makefile        |   1 +
 drivers/rtc/rtc-armada38x.c | 319 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 330 insertions(+)
 create mode 100644 drivers/rtc/rtc-armada38x.c

index f15cddfeb897..de42ebd4b626 100644
@@ -1269,6 +1269,16 @@ config RTC_DRV_MV
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-mv.
 
+config RTC_DRV_ARMADA38X
+	tristate "Armada 38x Marvell SoC RTC"
+	depends on ARCH_MVEBU
+	help
+	  If you say yes here you will get support for the in-chip RTC
+	  that can be found in the Armada 38x Marvell's SoC device
+
+	  This driver can also be built as a module. If so, the module
+	  will be called armada38x-rtc.
+
 config RTC_DRV_PS3
 	tristate "PS3 RTC"
 	depends on PPC_PS3

index c8ef3e1e6ccd..03fe5629c464 100644
@@ -24,6 +24,7 @@ obj-$(CONFIG_RTC_DRV_88PM860X)  += rtc-88pm860x.o
 obj-$(CONFIG_RTC_DRV_88PM80X)	+= rtc-88pm80x.o
 obj-$(CONFIG_RTC_DRV_AB3100)	+= rtc-ab3100.o
 obj-$(CONFIG_RTC_DRV_AB8500)	+= rtc-ab8500.o
+obj-$(CONFIG_RTC_DRV_ARMADA38X)	+= rtc-armada38x.o
 obj-$(CONFIG_RTC_DRV_AS3722)	+= rtc-as3722.o
 obj-$(CONFIG_RTC_DRV_AT32AP700X)+= rtc-at32ap700x.o
 obj-$(CONFIG_RTC_DRV_AT91RM9200)+= rtc-at91rm9200.o

1.9.1

Put it in the mvebu entry.

---
 MAINTAINERS | 1 +
 1 file changed, 1 insertion(+)

index ddb9ac8d32b3..393f158a64e8 100644
@@ -1157,6 +1157,7 @@ M:	Sebastian Hesselbarth <[email protected]>
 L:	linux-arm-kernel at lists.infradead.org (moderated for non-subscribers)
 S:	Maintained
 F:	arch/arm/mach-mvebu/
+F:	drivers/rtc/armada38x-rtc
 
 ARM/Marvell Berlin SoC support
 M:	Sebastian Hesselbarth <[email protected]>

1.9.1

The Marvell Armada 38x SoCs contains an RTC which differs from the RTC used in the other mvebu SoCs until now. This commit adds the Device Tree description of this interface at the SoC level.

---
 arch/arm/boot/dts/armada-38x.dtsi | 7 +++++++
 1 file changed, 7 insertions(+)

index 04fe80d101f8..36c1d35873dd 100644
@@ -466,6 +466,13 @@
 				clocks = <&gateclk 4>;
 			};
 
+			rtc at a3800 {
+				compatible = "marvell,armada-380-rtc";
+				reg = <0xa3800 0x20>, <0x184a0 0x0c>;
+				reg-names = "rtc", "soc-int";
+				interrupts = <GIC_SPI 21 IRQ_TYPE_LEVEL_HIGH>;
+			};
+
 			sata at a8000 {
 				compatible = "marvell,armada-380-ahci";
 				reg = <0xa8000 0x2000>;

1.9.1

Now that the Armada 38x RTC driver has been pushed, let's enable it in mvebu_v7_defconfig.

---
 arch/arm/configs/mvebu_v7_defconfig | 1 +
 1 file changed, 1 insertion(+)

index 627accea72fb..2400b9f52403 100644
@@ -112,6 +112,7 @@ CONFIG_LEDS_TRIGGER_HEARTBEAT=y
 CONFIG_RTC_CLASS=y
 CONFIG_RTC_DRV_S35390A=y
 CONFIG_RTC_DRV_MV=y
+CONFIG_RTC_DRV_ARMADA38X=y
 CONFIG_DMADEVICES=y
 CONFIG_MV_XOR=y
 # CONFIG_IOMMU_SUPPORT is not set

1.9.1