arm: mediatek: Add more basic features

This patch set adds some minor changes to the Mediatek mt6589 support.

The most important patch enables the arm arch timer for mt6589. As already seen on other vendor SoCs, to enable the arch timer we have to enable a SoC timer. This should be normally done by the bootloader. As up to now no open source bootloader exists for the mt6589, I added the functionality to the init_time function.

Other features are low-level debugging on the mt6589, the addition to the "make dtbs" and multi_v7_defconfig, as well as a small typo in the dtsi file.

The patch set is based on v3.17-rc1

Changes for v2:
- rebased on v3.17-rc1
- add patch for the compatible property of aquaris5
- add patch setting GIC compatible string to new "arm,cortex-a7-gic"
- set ARM arch timer frequency in DTS

---

Matthias Brugger (9):
arm: dts: Build dtb for Mediatek board
arm: multi_v7_defconfig: Enable Mediatek platform
arm: dts: mt6589: Fix typo in GIC unit address
arm: mediatek: Add earlyprintk support for mt6589
arm: dts: mt6589-aquaris5: Add boot argument earlyprintk
arm: mediatek: enable gpt6 on boot up to make arch timer working
arm: dts: mt6589: Add arm arch timer node
arm: dts: mediatek: Add compatible property for aquaris5
arm: dts: mt6589: Change compatible string for GIC

 Documentation/devicetree/bindings/arm/mediatek.txt |    6 +++++
 arch/arm/Kconfig.debug                             |   10 ++++++++
 arch/arm/boot/dts/Makefile                         |    1 +
 arch/arm/boot/dts/mt6589-aquaris5.dts              |    5 ++++
 arch/arm/boot/dts/mt6589.dtsi                      |   17 ++++++++++---
 arch/arm/configs/multi_v7_defconfig                |    1 +
 arch/arm/mach-mediatek/mediatek.c                  |   26 ++++++++++++++++++++
 7 files changed, 62 insertions(+), 4 deletions(-)

1.7.9.5

This allows the "make dtbs" to build the aquaris5 dtb for the Mediatek SoC.

---
 arch/arm/boot/dts/Makefile |    1 +
 1 file changed, 1 insertion(+)

index b8c5cd3..055b20c 100644
@@ -491,6 +491,7 @@ dtb-$(CONFIG_MACH_DOVE) += dove-cm-a510.dtb \
 	dove-d2plug.dtb \
 	dove-d3plug.dtb \
 	dove-dove-db.dtb
+dtb-$(CONFIG_ARCH_MEDIATEK) += mt6589-aquaris5.dtb
 
 targets += dtbs dtbs_install
 targets += $(dtb-y)

1.7.9.5

Enable Mediatek platform support for multi_v7_defconfig.

---
 arch/arm/configs/multi_v7_defconfig |    1 +
 1 file changed, 1 insertion(+)

index 5fb95fb..4c08101 100644
@@ -42,6 +42,7 @@ CONFIG_SOC_AM33XX=y
 CONFIG_SOC_AM43XX=y
 CONFIG_SOC_DRA7XX=y
 CONFIG_ARCH_QCOM=y
+CONFIG_ARCH_MEDIATEK=y
 CONFIG_ARCH_MSM8X60=y
 CONFIG_ARCH_MSM8960=y
 CONFIG_ARCH_MSM8974=y

1.7.9.5

This changes the unit address of the gic node to it's first register area.

---
 arch/arm/boot/dts/mt6589.dtsi |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index d0297a0..742c9bd 100644
@@ -81,7 +81,7 @@
 			clock-names = "system-clk", "rtc-clk";
 		};
 
-		gic: interrupt-controller at 10212000 {
+		gic: interrupt-controller at 10211000 {
 			compatible = "arm,cortex-a15-gic";
 			interrupt-controller;
 			#interrupt-cells = <3>;

1.7.9.5

Enable low-level debug for Mediatek mt6589 SoC on UART0.

---
 arch/arm/Kconfig.debug |   10 ++++++++++
 1 file changed, 10 insertions(+)

index b11ad54..cfdd1c0 100644
@@ -834,6 +834,14 @@ choice
 		  Say Y here if you want kernel low-level debugging support
 		  on Ux500 based platforms.
 
+	config DEBUG_MT6589_UART0
+		bool "Mediatek mt6589 UART0"
+		depends on ARCH_MEDIATEK
+		select DEBUG_UART_8250
+		help
+		  Say Y here if you want kernel low-level debugging support
+		  for Mediatek mt6589 based platforms on UART0.
+
 	config DEBUG_VEXPRESS_UART0_DETECT
 		bool "Autodetect UART0 on Versatile Express Cortex-A core tiles"
 		depends on ARCH_VEXPRESS && CPU_CP15_MMU

@@ -1075,6 +1083,7 @@ config DEBUG_UART_PHYS
 	default 0x10126000 if DEBUG_RK3X_UART1
 	default 0x101f1000 if ARCH_VERSATILE
 	default 0x101fb000 if DEBUG_NOMADIK_UART
+	default 0x11006000 if DEBUG_MT6589_UART0
 	default 0x16000000 if ARCH_INTEGRATOR
 	default 0x18000300 if DEBUG_BCM_5301X
 	default 0x1c090000 if DEBUG_VEXPRESS_UART0_RS1

@@ -1137,6 +1146,7 @@ config DEBUG_UART_VIRT
 	default 0xf01fb000 if DEBUG_NOMADIK_UART
 	default 0xf0201000 if DEBUG_BCM2835
 	default 0xf1000300 if DEBUG_BCM_5301X
+	default 0xf1006000 if DEBUG_MT6589_UART0
 	default 0xf11f1000 if ARCH_VERSATILE
 	default 0xf1600000 if ARCH_INTEGRATOR
 	default 0xf1c28000 if DEBUG_SUNXI_UART0

1.7.9.5

Add boot argument for earlyprintk to the aquaris5 device tree file.

---
 arch/arm/boot/dts/mt6589-aquaris5.dts |    4 ++++
 1 file changed, 4 insertions(+)

index 443b446..74cb1ba 100644
@@ -19,6 +19,10 @@
 / {
 	model = "bq Aquaris5";
 
+	chosen {
+		bootargs = "earlyprintk";
+	};
+
 	memory {
 		reg = <0x80000000 0x40000000>;
 	};

1.7.9.5

We enable GTP6 which ungates the arch timer clock. Apart we write the frequency with which the timer is running in the CNTFREQ register. In the future this should be done in the bootloader.

---
 arch/arm/mach-mediatek/mediatek.c |   26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

index f2acf07..2989f18 100644
@@ -16,6 +16,31 @@
  */
 #include <linux/init.h>
 #include <asm/mach/arch.h>
+#include <linux/of.h>
+#include <linux/clk-provider.h>
+#include <linux/clocksource.h>
+
+#define TIMER_CTRL_OP_FREERUN	0x30
+#define TIMER_CTRL_ENABLE	0x01
+
+#define GPT6_CON_MT65xx 0x10008060
+
+static void __init mediatek_timer_init(void)
+{
+	static void __iomem *gpt_base;
+
+	if (of_machine_is_compatible("mediatek,mt6589")) {
+		/* turn on GPT6 which ungates arch timer clocks */
+		gpt_base = ioremap(GPT6_CON_MT65xx, 0x04);
+	}
+
+	/* enabel clock and set to free-run */
+	if (gpt_base)
+		writel(TIMER_CTRL_OP_FREERUN | TIMER_CTRL_ENABLE, gpt_base);
+
+	of_clk_init(NULL);
+	clocksource_of_init();
+};
 
 static const char * const mediatek_board_dt_compat[] = {
 	"mediatek,mt6589",

@@ -24,4 +49,5 @@ static const char * const mediatek_board_dt_compat[] = {
 
 DT_MACHINE_START(MEDIATEK_DT, "Mediatek Cortex-A7 (Device Tree)")
 	.dt_compat	= mediatek_board_dt_compat,
+	.init_time	= mediatek_timer_init,
 MACHINE_END

1.7.9.5

Hi Matthias,

We don't seem to set CNTFRQ below. Does it happen to have a consistent value on current versions of the bootloader?

Do we know how far in the future that's likely to be?

What's the plan for this code when such a bootloader becomes available?

Thanks,
Mark.

2014-08-18 17:45 GMT+02:00 Mark Rutland <[email protected]>:

Oh sorry, my fault. In v2 I moved the frequency to the dts, as this will make the driver write CNTFRQ.
I forgot to update the commit message.

AFAIK no one right now is working on an open source bootloader for the mediatek devices.
So I think we won't see an open source bootloader in a reasonable time.

I think when a bootloader becomes available, this code should be removed. I know that this will lead to a not working ARM arch timer in devices which don't migrate to the new bootloader, but I think it's not too critical. Apart from the ARM arch timer, the devices have the mediatek global porpose timer (drivers/clocksource/mtk_timer.c), which implement a clock source and a clock event timer. So the system won't hang.

Cheers,
Matthias

motzblog.wordpress.com

The arch timer driver does not write CNTFRQ as this can only be done from the secure side. It simply uses the value provided internally. This isn't sufficient for virtualization guests (which need to have CNTFRQ programmed correctly).

For the moment as we're not booting at Hyp that's not necessarily a big problem, but it is a shame.

Ok. :(

I fear that's never going to happen, either because such a bootloader never becomes available or because there will be hold-outs sticking to the old loader.

If that's not critical, why not for the moment use the global timer?

Thanks,
Mark.

This patch adds the device tree node for the arm architecture timer.

---
 arch/arm/boot/dts/mt6589.dtsi |   13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

index 742c9bd..fb922a6 100644
@@ -73,14 +73,23 @@
 		compatible = "simple-bus";
 		ranges;
 
-		timer: timer at 10008000 {
+		timer1: timer at 10008000 {
 			compatible = "mediatek,mt6577-timer";
-			reg = <0x10008000 0x80>;
+			reg = <0x10008000 0x60>;
 			interrupts = <GIC_SPI 113 IRQ_TYPE_EDGE_RISING>;
 			clocks = <&system_clk>, <&rtc_clk>;
 			clock-names = "system-clk", "rtc-clk";
 		};
 
+		timer2: timer {
+			compatible = "arm,armv7-timer";
+			interrupts = <GIC_PPI 13 (GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_LEVEL_LOW)>,
+				     <GIC_PPI 14 (GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_LEVEL_LOW)>,
+				     <GIC_PPI 11 (GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_LEVEL_LOW)>,
+				     <GIC_PPI 10 (GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_LEVEL_LOW)>;
+			clock-frequency = <13000000>;
+		};
+
 		gic: interrupt-controller at 10211000 {
 			compatible = "arm,cortex-a15-gic";
 			interrupt-controller;

1.7.9.5

Add the missing 'compatible' property to device tree root node of

- mt6589-aquaris5.dts

and document the new values.

---
 Documentation/devicetree/bindings/arm/mediatek.txt |    6 ++++++
 arch/arm/boot/dts/mt6589-aquaris5.dts              |    1 +
 2 files changed, 7 insertions(+)

index d6ac71f..fa25226 100644
@@ -6,3 +6,9 @@ Required root node property:
 
 compatible: must contain "mediatek,mt6589"
 
+
+Supported boards:
+
+- bq Aquaris5 smart phone:
+    Required root node properties:
+      - compatible = "mundoreader,bq-aquaris5", "mediatek,mt6589";

index 74cb1ba..0da0470 100644
@@ -18,6 +18,7 @@
 
 / {
 	model = "bq Aquaris5";
+	compatible = "mundoreader,bq-aquaris5", "mediatek,mt6589";
 
 	chosen {
 		bootargs = "earlyprintk";

1.7.9.5

This patch changes the compatible string of the GIC to the new "arm,cortex-a7-gic" which does reflect the actual hardware.

---
 arch/arm/boot/dts/mt6589.dtsi |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index fb922a6..2534ba5 100644
@@ -91,7 +91,7 @@
 		};
 
 		gic: interrupt-controller at 10211000 {
-			compatible = "arm,cortex-a15-gic";
+			compatible = "arm,cortex-a7-gic";
 			interrupt-controller;
 			#interrupt-cells = <3>;
 			reg = <0x10211000 0x1000>,

1.7.9.5