aspeed: Add basic ast2500-specific drivers and configuration

Clock Driver

This driver is ast2500-specific and is not compatible with earlier
versions of this chip. The differences are not that big, but they are
in somewhat random places, so making it compatible with ast2400 is not
worth the effort at the moment.

SDRAM MC driver

The driver is very ast2500-specific and is completely incompatible
with previous versions of the chip.

The memory controller is very poorly documented by Aspeed in the
datasheet, with any mention of the whole range of registers missing. The
initialization procedure has been basically taken from Aspeed SDK, where
it is implemented in assembly. Here it is rewritten in C, with very limited
understanding of what exactly it is doing.
Reviewed-by: Simon Glass <sjg@chromium.org>

2 files changed, 227 insertions, 0 deletions

diff --git a/arch/arm/dts/ast2500-u-boot.dtsi b/arch/arm/dts/ast2500-u-boot.dtsi
new file mode 100644
index 0000000000..c95a7ba835
--- /dev/null
+++ b/arch/arm/dts/ast2500-u-boot.dtsi
@@ -0,0 +1,53 @@
+#include <dt-bindings/clock/ast2500-scu.h>
+
+#include "ast2500.dtsi"
+
+/ {
+	scu: clock-controller@1e6e2000 {
+		compatible = "aspeed,ast2500-scu";
+		reg = <0x1e6e2000 0x1000>;
+		u-boot,dm-pre-reloc;
+		#clock-cells = <1>;
+		#reset-cells = <1>;
+	};
+
+	sdrammc: sdrammc@1e6e0000 {
+		u-boot,dm-pre-reloc;
+		compatible = "aspeed,ast2500-sdrammc";
+		reg = <0x1e6e0000 0x174
+			0x1e6e0200 0x1d4 >;
+		clocks = <&scu PLL_MPLL>;
+	};
+
+	ahb {
+		u-boot,dm-pre-reloc;
+
+		apb {
+			u-boot,dm-pre-reloc;
+
+			timer: timer@1e782000 {
+				u-boot,dm-pre-reloc;
+			};
+
+			uart1: serial@1e783000 {
+				clocks = <&scu PCLK_UART1>;
+			};
+
+			uart2: serial@1e78d000 {
+				clocks = <&scu PCLK_UART2>;
+			};
+
+			uart3: serial@1e78e000 {
+				clocks = <&scu PCLK_UART3>;
+			};
+
+			uart4: serial@1e78f000 {
+				clocks = <&scu PCLK_UART4>;
+			};
+
+			uart5: serial@1e784000 {
+				clocks = <&scu PCLK_UART5>;
+			};
+		};
+	};
+};
diff --git a/arch/arm/dts/ast2500.dtsi b/arch/arm/dts/ast2500.dtsi
new file mode 100644
index 0000000000..97fac69d11
--- /dev/null
+++ b/arch/arm/dts/ast2500.dtsi
@@ -0,0 +1,174 @@
+/*
+ * This device tree is copied from
+ * https://raw.githubusercontent.com/torvalds/linux/02440622/arch/arm/boot/dts/
+ */
+#include "skeleton.dtsi"
+
+/ {
+	model = "Aspeed BMC";
+	compatible = "aspeed,ast2500";
+	#address-cells = <1>;
+	#size-cells = <1>;
+	interrupt-parent = <&vic>;
+
+	cpus {
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		cpu@0 {
+			compatible = "arm,arm1176jzf-s";
+			device_type = "cpu";
+			reg = <0>;
+		};
+	};
+
+	ahb {
+		compatible = "simple-bus";
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges;
+
+		vic: interrupt-controller@1e6c0080 {
+			compatible = "aspeed,ast2400-vic";
+			interrupt-controller;
+			#interrupt-cells = <1>;
+			valid-sources = <0xfefff7ff 0x0807ffff>;
+			reg = <0x1e6c0080 0x80>;
+		};
+
+		apb {
+			compatible = "simple-bus";
+			#address-cells = <1>;
+			#size-cells = <1>;
+			ranges;
+
+			clk_clkin: clk_clkin@1e6e2070 {
+				#clock-cells = <0>;
+				compatible = "aspeed,g5-clkin-clock";
+				reg = <0x1e6e2070 0x04>;
+			};
+
+			clk_hpll: clk_hpll@1e6e2024 {
+				#clock-cells = <0>;
+				compatible = "aspeed,g5-hpll-clock";
+				reg = <0x1e6e2024 0x4>;
+				clocks = <&clk_clkin>;
+			};
+
+			clk_ahb: clk_ahb@1e6e2070 {
+				#clock-cells = <0>;
+				compatible = "aspeed,g5-ahb-clock";
+				reg = <0x1e6e2070 0x4>;
+				clocks = <&clk_hpll>;
+			};
+
+			clk_apb: clk_apb@1e6e2008 {
+				#clock-cells = <0>;
+				compatible = "aspeed,g5-apb-clock";
+				reg = <0x1e6e2008 0x4>;
+				clocks = <&clk_hpll>;
+			};
+
+			clk_uart: clk_uart@1e6e2008 {
+				#clock-cells = <0>;
+				compatible = "aspeed,uart-clock";
+				reg = <0x1e6e202c 0x4>;
+			};
+
+			sram@1e720000 {
+				compatible = "mmio-sram";
+				reg = <0x1e720000 0x9000>;	// 36K
+			};
+
+			timer: timer@1e782000 {
+				compatible = "aspeed,ast2400-timer";
+				reg = <0x1e782000 0x90>;
+				// The moxart_timer driver registers only one
+				// interrupt and assumes it's for timer 1
+				//interrupts = <16 17 18 35 36 37 38 39>;
+				interrupts = <16>;
+				clocks = <&clk_apb>;
+			};
+
+			wdt1: wdt@1e785000 {
+				compatible = "aspeed,wdt";
+				reg = <0x1e785000 0x1c>;
+				interrupts = <27>;
+			};
+
+			wdt2: wdt@1e785020 {
+				compatible = "aspeed,wdt";
+				reg = <0x1e785020 0x1c>;
+				interrupts = <27>;
+				status = "disabled";
+			};
+
+			wdt3: wdt@1e785040 {
+				compatible = "aspeed,wdt";
+				reg = <0x1e785074 0x1c>;
+				status = "disabled";
+			};
+
+			uart1: serial@1e783000 {
+				compatible = "ns16550a";
+				reg = <0x1e783000 0x1000>;
+				reg-shift = <2>;
+				interrupts = <9>;
+				clocks = <&clk_uart>;
+				no-loopback-test;
+				status = "disabled";
+			};
+
+			uart2: serial@1e78d000 {
+				compatible = "ns16550a";
+				reg = <0x1e78d000 0x1000>;
+				reg-shift = <2>;
+				interrupts = <32>;
+				clocks = <&clk_uart>;
+				no-loopback-test;
+				status = "disabled";
+			};
+
+			uart3: serial@1e78e000 {
+				compatible = "ns16550a";
+				reg = <0x1e78e000 0x1000>;
+				reg-shift = <2>;
+				interrupts = <33>;
+				clocks = <&clk_uart>;
+				no-loopback-test;
+				status = "disabled";
+			};
+
+			uart4: serial@1e78f000 {
+				compatible = "ns16550a";
+				reg = <0x1e78f000 0x1000>;
+				reg-shift = <2>;
+				interrupts = <34>;
+				clocks = <&clk_uart>;
+				no-loopback-test;
+				status = "disabled";
+			};
+
+			uart5: serial@1e784000 {
+				compatible = "ns16550a";
+				reg = <0x1e784000 0x1000>;
+				reg-shift = <2>;
+				interrupts = <10>;
+				clocks = <&clk_uart>;
+				current-speed = <38400>;
+				no-loopback-test;
+				status = "disabled";
+			};
+
+			uart6: serial@1e787000 {
+				compatible = "ns16550a";
+				reg = <0x1e787000 0x1000>;
+				reg-shift = <2>;
+				interrupts = <10>;
+				clocks = <&clk_uart>;
+				no-loopback-test;
+				status = "disabled";
+			};
+		};
+	};
+};