arm: mvebu: Use dw-apb-uart instead of ns16650 as UART driver

The UART controller used in the Armada 370 and Armada XP SoCs is the
Synopsys DesignWare 8250 (aka Synopsys DesignWare ABP UART). The
improper use of the ns16550 can lead to a kernel oops during boot if
a character is sent to the UART before the initialization of the
driver. The DW APB has an extra interrupt that gets raised when
writing to the LCR when busy. This explains why we need to use
dw-apb-uart driver to handle this.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

diff --git a/arch/arm/boot/dts/armada-370-xp.dtsi b/arch/arm/boot/dts/armada-370-xp.dtsi
index cf6c48a..4c0abe8 100644 (file)
--- a/arch/arm/boot/dts/armada-370-xp.dtsi
+++ b/arch/arm/boot/dts/armada-370-xp.dtsi
@@ -50,17 +50,19 @@
                ranges;
 
                serial@d0012000 {
-                               compatible = "ns16550";
+                               compatible = "snps,dw-apb-uart";
                                reg = <0xd0012000 0x100>;
                                reg-shift = <2>;
                                interrupts = <41>;
+                               reg-io-width = <4>;
                                status = "disabled";
                };
                serial@d0012100 {
-                               compatible = "ns16550";
+                               compatible = "snps,dw-apb-uart";
                                reg = <0xd0012100 0x100>;
                                reg-shift = <2>;
                                interrupts = <42>;
+                               reg-io-width = <4>;
                                status = "disabled";
                };
 

diff --git a/arch/arm/boot/dts/armada-xp.dtsi b/arch/arm/boot/dts/armada-xp.dtsi
index 367aa3f..8a85ffe 100644 (file)
--- a/arch/arm/boot/dts/armada-xp.dtsi
+++ b/arch/arm/boot/dts/armada-xp.dtsi
@@ -42,17 +42,19 @@
 
        soc {
                serial@d0012200 {
-                               compatible = "ns16550";
+                               compatible = "snps,dw-apb-uart";
                                reg = <0xd0012200 0x100>;
                                reg-shift = <2>;
                                interrupts = <43>;
+                               reg-io-width = <4>;
                                status = "disabled";
                };
                serial@d0012300 {
-                               compatible = "ns16550";
+                               compatible = "snps,dw-apb-uart";
                                reg = <0xd0012300 0x100>;
                                reg-shift = <2>;
                                interrupts = <44>;
+                               reg-io-width = <4>;
                                status = "disabled";
                };
 

diff --git a/arch/arm/configs/mvebu_defconfig b/arch/arm/configs/mvebu_defconfig
index a702fb3..b5bc96c 100644 (file)
--- a/arch/arm/configs/mvebu_defconfig
+++ b/arch/arm/configs/mvebu_defconfig
@@ -33,9 +33,7 @@ CONFIG_MVNETA=y
 CONFIG_MARVELL_PHY=y
 CONFIG_SERIAL_8250=y
 CONFIG_SERIAL_8250_CONSOLE=y
-CONFIG_SERIAL_OF_PLATFORM=y
-CONFIG_I2C=y
-CONFIG_I2C_MV64XXX=y
+CONFIG_SERIAL_8250_DW=y
 CONFIG_GPIOLIB=y
 CONFIG_GPIO_SYSFS=y
 # CONFIG_USB_SUPPORT is not set