malta: Use device model & tree for UART

Make use of device model & device tree to probe the UART driver. This is
the initial step in bringing Malta up to date with driver model, and
allows for cleaner handling of the different I/O addresses for different
system controllers by specifying the ISA bus address instead of a
translated memory address.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Reviewed-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>

arch/mips/Kconfig

@@ -23,7 +23,11 @@ config TARGET_QEMU_MIPS
 
 config TARGET_MALTA
 	bool "Support malta"
+	select DM
+	select DM_SERIAL
 	select DYNAMIC_IO_PORT_BASE
+	select OF_CONTROL
+	select OF_ISA_BUS
 	select SUPPORTS_BIG_ENDIAN
 	select SUPPORTS_LITTLE_ENDIAN
 	select SUPPORTS_CPU_MIPS32_R1

arch/mips/dts/Makefile

@@ -4,6 +4,7 @@
 
 dtb-$(CONFIG_TARGET_AP121) += ap121.dtb
 dtb-$(CONFIG_TARGET_AP143) += ap143.dtb
+dtb-$(CONFIG_TARGET_MALTA) += mti,malta.dtb
 dtb-$(CONFIG_TARGET_PIC32MZDASK) += pic32mzda_sk.dtb
 dtb-$(CONFIG_BOARD_TPLINK_WDR4300) += tplink_wdr4300.dtb
 

arch/mips/dts/mti,malta.dts

@@ -0,0 +1,32 @@
+/dts-v1/;
+
+/memreserve/ 0x00000000 0x00001000;	/* Exception vectors */
+/memreserve/ 0x000f0000 0x00010000;	/* PIIX4 ISA memory */
+
+/ {
+	#address-cells = <1>;
+	#size-cells = <1>;
+	compatible = "mti,malta";
+
+	chosen {
+		stdout-path = &uart0;
+	};
+
+	isa@0 {
+		compatible = "isa";
+		#address-cells = <2>;
+		#size-cells = <1>;
+		ranges = <1 0 0 0x1000>;
+
+		uart0: serial@3f8 {
+			compatible = "ns16550a";
+
+			reg = <1 0x3f8 0x40>;
+			reg-shift = <0>;
+
+			clock-frequency = <1843200>;
+
+			u-boot,dm-pre-reloc;
+		};
+	};
+};

configs/malta_defconfig

@@ -1,5 +1,6 @@
 CONFIG_MIPS=y
 CONFIG_TARGET_MALTA=y
+CONFIG_DEFAULT_DEVICE_TREE="mti,malta"
 CONFIG_HUSH_PARSER=y
 CONFIG_SYS_PROMPT="malta # "
 # CONFIG_CMD_LOADB is not set
@@ -9,5 +10,6 @@ CONFIG_SYS_PROMPT="malta # "
 CONFIG_CMD_DHCP=y
 # CONFIG_CMD_NFS is not set
 CONFIG_CMD_PING=y
+CONFIG_OF_EMBED=y
 CONFIG_SYS_NS16550=y
 CONFIG_USE_PRIVATE_LIBGCC=y

configs/maltael_defconfig

@@ -1,6 +1,7 @@
 CONFIG_MIPS=y
 CONFIG_TARGET_MALTA=y
 CONFIG_SYS_LITTLE_ENDIAN=y
+CONFIG_DEFAULT_DEVICE_TREE="mti,malta"
 CONFIG_HUSH_PARSER=y
 CONFIG_SYS_PROMPT="maltael # "
 # CONFIG_CMD_LOADB is not set
@@ -10,5 +11,6 @@ CONFIG_SYS_PROMPT="maltael # "
 CONFIG_CMD_DHCP=y
 # CONFIG_CMD_NFS is not set
 CONFIG_CMD_PING=y
+CONFIG_OF_EMBED=y
 CONFIG_SYS_NS16550=y
 CONFIG_USE_PRIVATE_LIBGCC=y

include/configs/malta.h

@@ -65,13 +65,7 @@
  * Serial driver
  */
 #define CONFIG_BAUDRATE			115200
-
-#define CONFIG_SYS_NS16550_SERIAL
 #define CONFIG_SYS_NS16550_PORT_MAPPED
-#define CONFIG_SYS_NS16550_REG_SIZE	1
-#define CONFIG_SYS_NS16550_CLK		(115200 * 16)
-#define CONFIG_SYS_NS16550_COM1		0x3f8
-#define CONFIG_CONS_INDEX		1
 
 /*
  * Flash configuration