ARM: new platform for Energy Micro's EFM32 Cortex-M3 SoCs

There are still some missing parts (e.g. board support, device trees),
but with these bits added on top of this patch I can successfully boot a
EFM32GG-DK3750 board that uses an EFM32GG990F1024.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

arch/arm/Kconfig

@@ -410,6 +410,26 @@ config ARCH_EBSA110
 	  Ethernet interface, two PCMCIA sockets, two serial ports and a
 	  parallel port.
 
+config ARCH_EFM32
+	bool "Energy Micro efm32"
+	depends on !MMU
+	select ARCH_REQUIRE_GPIOLIB
+	select ARM_NVIC
+	# CLKSRC_MMIO is wrong here, but needed until a proper fix is merged,
+	# i.e. CLKSRC_EFM32 selecting CLKSRC_MMIO
+	select CLKSRC_MMIO
+	select CLKSRC_OF
+	select COMMON_CLK
+	select CPU_V7M
+	select GENERIC_CLOCKEVENTS
+	select NO_DMA
+	select NO_IOPORT
+	select SPARSE_IRQ
+	select USE_OF
+	help
+	  Support for Energy Micro's (now Silicon Labs) efm32 Giant Gecko
+	  processors.
+
 config ARCH_EP93XX
 	bool "EP93xx-based"
 	select ARCH_HAS_HOLES_MEMORYMODEL
@@ -1799,7 +1819,7 @@ config FORCE_MAX_ZONEORDER
 	int "Maximum zone order" if ARCH_SHMOBILE
 	range 11 64 if ARCH_SHMOBILE
 	default "12" if SOC_AM33XX
-	default "9" if SA1111
+	default "9" if SA1111 || ARCH_EFM32
 	default "11"
 	help
 	  The kernel memory allocator divides physically contiguous memory

arch/arm/Makefile

@@ -153,6 +153,7 @@ machine-$(CONFIG_ARCH_CNS3XXX)		+= cns3xxx
 machine-$(CONFIG_ARCH_DAVINCI)		+= davinci
 machine-$(CONFIG_ARCH_DOVE)		+= dove
 machine-$(CONFIG_ARCH_EBSA110)		+= ebsa110
+machine-$(CONFIG_ARCH_EFM32)		+= efm32
 machine-$(CONFIG_ARCH_EP93XX)		+= ep93xx
 machine-$(CONFIG_ARCH_EXYNOS)		+= exynos
 machine-$(CONFIG_ARCH_GEMINI)		+= gemini

arch/arm/configs/efm32_defconfig

+CONFIG_HIGH_RES_TIMERS=y
+CONFIG_LOG_BUF_SHIFT=12
+CONFIG_CC_OPTIMIZE_FOR_SIZE=y
+# CONFIG_UID16 is not set
+# CONFIG_BASE_FULL is not set
+# CONFIG_FUTEX is not set
+# CONFIG_EPOLL is not set
+# CONFIG_SIGNALFD is not set
+# CONFIG_EVENTFD is not set
+# CONFIG_AIO is not set
+CONFIG_EMBEDDED=y
+# CONFIG_VM_EVENT_COUNTERS is not set
+# CONFIG_SLUB_DEBUG is not set
+# CONFIG_LBDAF is not set
+# CONFIG_BLK_DEV_BSG is not set
+# CONFIG_IOSCHED_DEADLINE is not set
+# CONFIG_IOSCHED_CFQ is not set
+# CONFIG_MMU is not set
+CONFIG_ARCH_EFM32=y
+# CONFIG_KUSER_HELPERS is not set
+CONFIG_SET_MEM_PARAM=y
+CONFIG_DRAM_BASE=0x88000000
+CONFIG_DRAM_SIZE=0x00400000
+CONFIG_FLASH_MEM_BASE=0x8c000000
+CONFIG_FLASH_SIZE=0x01000000
+CONFIG_PREEMPT=y
+CONFIG_ZBOOT_ROM_TEXT=0x0
+CONFIG_ZBOOT_ROM_BSS=0x0
+CONFIG_XIP_KERNEL=y
+CONFIG_XIP_PHYS_ADDR=0x8c000000
+CONFIG_BINFMT_FLAT=y
+CONFIG_BINFMT_SHARED_FLAT=y
+# CONFIG_COREDUMP is not set
+CONFIG_NET=y
+CONFIG_PACKET=y
+CONFIG_UNIX=y
+CONFIG_INET=y
+# CONFIG_INET_XFRM_MODE_TRANSPORT is not set
+# CONFIG_INET_XFRM_MODE_TUNNEL is not set
+# CONFIG_INET_XFRM_MODE_BEET is not set
+# CONFIG_INET_LRO is not set
+# CONFIG_INET_DIAG is not set
+# CONFIG_IPV6 is not set
+# CONFIG_WIRELESS is not set
+CONFIG_DEVTMPFS=y
+CONFIG_DEVTMPFS_MOUNT=y
+# CONFIG_FW_LOADER is not set
+CONFIG_MTD=y
+CONFIG_MTD_BLOCK_RO=y
+CONFIG_MTD_ROM=y
+CONFIG_MTD_UCLINUX=y
+CONFIG_PROC_DEVICETREE=y
+# CONFIG_BLK_DEV is not set
+CONFIG_NETDEVICES=y
+# CONFIG_NET_VENDOR_ARC is not set
+# CONFIG_NET_CADENCE is not set
+# CONFIG_NET_VENDOR_BROADCOM is not set
+# CONFIG_NET_VENDOR_CIRRUS is not set
+# CONFIG_NET_VENDOR_FARADAY is not set
+# CONFIG_NET_VENDOR_INTEL is not set
+# CONFIG_NET_VENDOR_MARVELL is not set
+CONFIG_KS8851=y
+# CONFIG_NET_VENDOR_MICROCHIP is not set
+# CONFIG_NET_VENDOR_NATSEMI is not set
+# CONFIG_NET_VENDOR_SEEQ is not set
+# CONFIG_NET_VENDOR_SMSC is not set
+# CONFIG_NET_VENDOR_STMICRO is not set
+# CONFIG_NET_VENDOR_VIA is not set
+# CONFIG_NET_VENDOR_WIZNET is not set
+# CONFIG_WLAN is not set
+# CONFIG_INPUT is not set
+# CONFIG_SERIO is not set
+# CONFIG_VT is not set
+# CONFIG_UNIX98_PTYS is not set
+# CONFIG_LEGACY_PTYS is not set
+CONFIG_SERIAL_NONSTANDARD=y
+# CONFIG_DEVKMEM is not set
+CONFIG_SERIAL_EFM32_UART=y
+CONFIG_SERIAL_EFM32_UART_CONSOLE=y
+# CONFIG_HW_RANDOM is not set
+CONFIG_SPI=y
+CONFIG_SPI_EFM32=y
+CONFIG_GPIO_SYSFS=y
+# CONFIG_USB_SUPPORT is not set
+CONFIG_MMC=y
+CONFIG_MMC_SPI=y
+# CONFIG_IOMMU_SUPPORT is not set
+CONFIG_EXT2_FS=y
+# CONFIG_FILE_LOCKING is not set
+# CONFIG_DNOTIFY is not set
+# CONFIG_INOTIFY_USER is not set
+CONFIG_ROMFS_FS=y
+CONFIG_ROMFS_BACKED_BY_MTD=y
+# CONFIG_NETWORK_FILESYSTEMS is not set
+CONFIG_PRINTK_TIME=y
+CONFIG_DEBUG_INFO=y
+# CONFIG_ENABLE_WARN_DEPRECATED is not set
+# CONFIG_ENABLE_MUST_CHECK is not set
+CONFIG_MAGIC_SYSRQ=y
+# CONFIG_SCHED_DEBUG is not set
+# CONFIG_DEBUG_BUGVERBOSE is not set
+# CONFIG_FTRACE is not set

arch/arm/mach-efm32/Makefile

+obj-y += dtmachine.o

arch/arm/mach-efm32/Makefile.boot

+# Empty file waiting for deletion once Makefile.boot isn't needed any more.
+# Patch waits for application at
+# http://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=7889/1 .

arch/arm/mach-efm32/dtmachine.c

+#include <linux/kernel.h>
+
+#include <asm/v7m.h>
+
+#include <asm/mach/arch.h>
+
+static const char *const efm32gg_compat[] __initconst = {
+	"efm32,dk3750",
+	NULL
+};
+
+DT_MACHINE_START(EFM32DT, "EFM32 (Device Tree Support)")
+	.dt_compat = efm32gg_compat,
+	.restart = armv7m_restart,
+MACHINE_END

arch/arm/mach-efm32/include/mach/entry-macro.S

+/*
+ * Empty file waiting for deletion once <mach/entry-macro.S> isn't needed any
+ * more. Patch "ARM: v7-M: drop using mach/entry-macro.S" sitting in next.
+ */

arch/arm/mach-efm32/include/mach/timex.h

+/*
+ * Empty file waiting for deletion once <mach/timex.h> isn't needed any more.
+ */