[PATCH v6 10/12] ARM: vf610: enable Cortex-M4 configuration on Vybrid SoC

From: Stefan Agner
Date: Sat May 09 2015 - 16:41:12 EST


This patch allows to build the Kernel for Vybrid (VF6xx) SoC
when ARMv7-M CPU is selected. The resulting image runs on the
secondary Cortex-M4 core. This core has equally access to all
peripherals as the main Cortex-A5 core. However, there is no
resource control mechanism, hence when both cores are used
simultaneously, orthogonal device tree's are required.

The boot CPU is dependent on the SoC variant. The available
boards use mostly variants where the Cortex-A5 is the primary
and hence the boot CPU. Booting the secondary Cortex-M4 CPU
needs SoC specific registers written. There is no in kernel
support for this right now, a external userspace utility
called "m4boot" can be used to boot the kernel:

m4boot xipImage initramfs.cpio.lzo vf610m4-colibri.dtb

Signed-off-by: Stefan Agner <stefan@xxxxxxxx>
---
Documentation/devicetree/bindings/arm/fsl.txt | 3 +++
arch/arm/Kconfig.debug | 2 +-
arch/arm/mach-imx/Kconfig | 38 +++++++++++++++------------
arch/arm/mach-imx/Makefile.boot | 0
arch/arm/mach-imx/mach-vf610.c | 1 +
5 files changed, 26 insertions(+), 18 deletions(-)
create mode 100644 arch/arm/mach-imx/Makefile.boot

diff --git a/Documentation/devicetree/bindings/arm/fsl.txt b/Documentation/devicetree/bindings/arm/fsl.txt
index a5462b6..2a3ba73 100644
--- a/Documentation/devicetree/bindings/arm/fsl.txt
+++ b/Documentation/devicetree/bindings/arm/fsl.txt
@@ -81,12 +81,15 @@ Freescale Vybrid Platform Device Tree Bindings
For the Vybrid SoC familiy all variants with DDR controller are supported,
which is the VF5xx and VF6xx series. Out of historical reasons, in most
places the kernel uses vf610 to refer to the whole familiy.
+The compatible string "fsl,vf610m4" is used for the secondary Cortex-M4
+core support.

Required root node compatible property (one of them):
- compatible = "fsl,vf500";
- compatible = "fsl,vf510";
- compatible = "fsl,vf600";
- compatible = "fsl,vf610";
+ - compatible = "fsl,vf610m4";

Freescale LS1021A Platform Device Tree Bindings
------------------------------------------------
diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug
index 0c12ffb..cb39834 100644
--- a/arch/arm/Kconfig.debug
+++ b/arch/arm/Kconfig.debug
@@ -1562,7 +1562,7 @@ config UNCOMPRESS_INCLUDE
string
default "debug/uncompress.h" if ARCH_MULTIPLATFORM || ARCH_MSM || \
PLAT_SAMSUNG || ARCH_EFM32 || \
- ARCH_SHMOBILE_LEGACY
+ ARCH_SHMOBILE_LEGACY || SOC_VF610
default "mach/uncompress.h"

config EARLY_PRINTK
diff --git a/arch/arm/mach-imx/Kconfig b/arch/arm/mach-imx/Kconfig
index 3a3d3e9..2e3c458 100644
--- a/arch/arm/mach-imx/Kconfig
+++ b/arch/arm/mach-imx/Kconfig
@@ -1,5 +1,5 @@
menuconfig ARCH_MXC
- bool "Freescale i.MX family" if ARCH_MULTI_V4_V5 || ARCH_MULTI_V6_V7
+ bool "Freescale i.MX family" if ARCH_MULTI_V4_V5 || ARCH_MULTI_V6_V7 || ARM_SINGLE_ARMV7M
select ARCH_REQUIRE_GPIOLIB
select ARM_CPU_SUSPEND if PM
select CLKSRC_MMIO
@@ -496,10 +496,10 @@ config MACH_VPR200

endif

-if ARCH_MULTI_V5
-
comment "Device tree only"

+if ARCH_MULTI_V5
+
config SOC_IMX25
bool "i.MX25 support"
select ARCH_MXC_IOMUX_V3
@@ -512,7 +512,7 @@ endif

if ARCH_MULTI_V7

-comment "Device tree only"
+comment "Cortex-A platforms"

config SOC_IMX5
bool
@@ -582,10 +582,24 @@ config SOC_IMX6SX
help
This enables support for Freescale i.MX6 SoloX processor.

+config SOC_LS1021A
+ bool "Freescale LS1021A support"
+ select ARM_GIC
+ select HAVE_ARM_ARCH_TIMER
+ select PCI_DOMAINS if PCI
+ select ZONE_DMA if ARM_LPAE
+ help
+ This enables support for Freescale LS1021A processor.
+
+endif
+
+comment "Cortex-A/Cortex-M asymmetric multiprocessing platforms"
+
+if ARCH_MULTI_V7 || ARM_SINGLE_ARMV7M
+
config SOC_VF610
bool "Vybrid Family VF610 support"
- select IRQ_DOMAIN_HIERARCHY
- select ARM_GIC
+ select ARM_GIC if ARCH_MULTI_V7
select PINCTRL_VF610
select PL310_ERRATA_769419 if CACHE_L2X0
select SMP_ON_UP if SMP
@@ -599,7 +613,7 @@ choice
default VF_USE_ARM_GLOBAL_TIMER

config VF_USE_ARM_GLOBAL_TIMER
- bool "Use ARM Global Timer"
+ bool "Use ARM Global Timer" if ARCH_MULTI_V7
select ARM_GLOBAL_TIMER
select CLKSRC_ARM_GLOBAL_TIMER_SCHED_CLOCK
help
@@ -613,16 +627,6 @@ choice

endchoice

-config SOC_LS1021A
- bool "Freescale LS1021A support"
- select ARM_GIC
- select HAVE_ARM_ARCH_TIMER
- select PCI_DOMAINS if PCI
- select ZONE_DMA if ARM_LPAE
-
- help
- This enables support for Freescale LS1021A processor.
-
endif

source "arch/arm/mach-imx/devices/Kconfig"
diff --git a/arch/arm/mach-imx/Makefile.boot b/arch/arm/mach-imx/Makefile.boot
new file mode 100644
index 0000000..e69de29
diff --git a/arch/arm/mach-imx/mach-vf610.c b/arch/arm/mach-imx/mach-vf610.c
index 2e7c75b..b20f6c1 100644
--- a/arch/arm/mach-imx/mach-vf610.c
+++ b/arch/arm/mach-imx/mach-vf610.c
@@ -17,6 +17,7 @@ static const char * const vf610_dt_compat[] __initconst = {
"fsl,vf510",
"fsl,vf600",
"fsl,vf610",
+ "fsl,vf610m4",
NULL,
};

--
2.4.0

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