ARM: Add STM32 family machine

STMicrolectronics's STM32 series is a family of Cortex-M
microcontrollers. It is used in various applications, and
proposes a wide range of peripherals.

Tested-by: Chanwoo Choi <[e-mail]>
Signed-off-by: Maxime Coquelin <[e-mail]>
Signed-off-by: Arnd Bergmann <[e-mail]>

Documentation/arm/stm32/overview.txt

···
+			STM32 ARM Linux Overview
+			========================
+
+Introduction
+------------
+
+  The STMicroelectronics family of Cortex-M based MCUs are supported by the
+  'STM32' platform of ARM Linux. Currently only the STM32F429 is supported.
+
+
+Configuration
+-------------
+
+  A generic configuration is provided for STM32 family, and can be used as the
+  default by
+	make stm32_defconfig
+
+Layout
+------
+
+  All the files for multiple machine families are located in the platform code
+  contained in arch/arm/mach-stm32
+
+  There is a generic board board-dt.c in the mach folder which support
+  Flattened Device Tree, which means, it works with any compatible board with
+  Device Trees.
+
+
+Document Author
+---------------
+
+  Maxime Coquelin <[e-mail]>

Documentation/arm/stm32/stm32f429-overview.txt

···
+			STM32F429 Overview
+			==================
+
+  Introduction
+  ------------
+	The STM32F429 is a Cortex-M4 MCU aimed at various applications.
+	It features:
+	- ARM Cortex-M4 up to 180MHz with FPU
+	- 2MB internal Flash Memory
+	- External memory support through FMC controller (PSRAM, SDRAM, NOR, NAND)
+	- I2C, SPI, SAI, CAN, USB OTG, Ethernet controllers
+	- LCD controller & Camera interface
+	- Cryptographic processor
+
+  Resources
+  ---------
+	Datasheet and reference manual are publicly available on ST website:
+	- http://www.st.com/web/en/catalog/mmc/FM141/SC1169/SS1577/LN1806?ecmp=stm32f429-439_pron_pr-ces2014_nov2013
+
+  Document Author
+  ---------------
+	Maxime Coquelin <[e-mail]>

arch/arm/Kconfig

···
 	help
 	  Support for older TI OMAP1 (omap7xx, omap15xx or omap16xx)
 
+config ARCH_STM32
+	bool "STMicrolectronics STM32"
+	depends on !MMU
+	select ARCH_HAS_RESET_CONTROLLER
+	select ARM_NVIC
+	select ARMV7M_SYSTICK
+	select AUTO_ZRELADDR
+	select CLKSRC_OF
+	select COMMON_CLK
+	select CPU_V7M
+	select GENERIC_CLOCKEVENTS
+	select NO_IOPORT_MAP
+	select RESET_CONTROLLER
+	select SPARSE_IRQ
+	select USE_OF
+	help
+	  Support for STMicroelectronics STM32 processors.
+
 endchoice
 
 menu "Multiple platform selection"

arch/arm/Makefile

···
 machine-$(CONFIG_ARCH_SIRF)		+= prima2
 machine-$(CONFIG_ARCH_SOCFPGA)		+= socfpga
 machine-$(CONFIG_ARCH_STI)		+= sti
+machine-$(CONFIG_ARCH_STM32)		+= stm32
 machine-$(CONFIG_ARCH_SUNXI)		+= sunxi
 machine-$(CONFIG_ARCH_TEGRA)		+= tegra
 machine-$(CONFIG_ARCH_U300)		+= u300

arch/arm/mach-stm32/Makefile

···
+obj-y += board-dt.o

arch/arm/mach-stm32/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-stm32/board-dt.c

···
+/*
+ * Copyright (C) Maxime Coquelin 2015
+ * Author:  Maxime Coquelin <[e-mail]>
+ * License terms:  GNU General Public License (GPL), version 2
+ */
+
+#include <linux/kernel.h>
+#include <asm/v7m.h>
+#include <asm/mach/arch.h>
+
+static const char *const stm32_compat[] __initconst = {
+	"st,stm32f429",
+	NULL
+};
+
+DT_MACHINE_START(STM32DT, "STM32 (Device Tree Support)")
+	.dt_compat = stm32_compat,
+	.restart = armv7m_restart,
+MACHINE_END