soc: arm: st_stm32: Add STM32L1 SoC series

Add STM32L1 SoC series support with STM32L15XXB as the target
SoC.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

dts/arm/st/l1/stm32l1.dtsi

@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2019 Linaro Ltd.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <arm/armv7-m.dtsi>
+
+/ {
+	cpus {
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		cpu@0 {
+			device_type = "cpu";
+			compatible = "arm,cortex-m3";
+			reg = <0>;
+		};
+	};
+
+	sram0: memory@20000000 {
+		device_type = "memory";
+		compatible = "mmio-sram";
+	};
+
+	soc {
+		flash-controller@40023c00 {
+			compatible = "st,stm32l1-flash-controller";
+			label = "FLASH_CTRL";
+			reg = <0x40023c00 0x400>;
+			interrupts = <4 0>;
+
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			flash0: flash@8000000 {
+				compatible = "soc-nv-flash";
+				label = "FLASH_STM32";
+
+				write-block-size = <4>;
+			};
+		};
+
+	};
+};
+
+&nvic {
+	arm,num-irq-priority-bits = <4>;
+};

dts/arm/st/l1/stm32l151.dtsi

@@ -0,0 +1,7 @@
+/*
+ * Copyright (c) 2019 Linaro Limited
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <st/l1/stm32l1.dtsi>

dts/arm/st/l1/stm32l151Xb.dtsi

@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2019 Linaro Limited
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <mem.h>
+#include <st/l1/stm32l151.dtsi>
+
+/ {
+	sram0: memory@20000000 {
+		reg = <0x20000000 DT_SIZE_K(16)>;
+	};
+
+	soc {
+		flash-controller@40023c00 {
+			flash0: flash@8000000 {
+				reg = <0x08000000 DT_SIZE_K(128)>;
+			};
+		};
+	};
+};

dts/bindings/flash_controller/st,stm32l1-flash-controller.yaml

@@ -0,0 +1,15 @@
+---
+title: STM32 L1 Flash Controller
+version: 0.1
+
+description: >
+    This binding gives a base representation of the STM32 L1 Flash Controller
+
+inherits:
+    !include flash-controller.yaml
+
+properties:
+    compatible:
+      constraint: "st,stm32l1-flash-controller"
+
+...

soc/arm/st_stm32/stm32l1/CMakeLists.txt

@@ -0,0 +1,4 @@
+zephyr_include_directories(${ZEPHYR_BASE}/drivers)
+zephyr_sources(
+  soc.c
+  )

soc/arm/st_stm32/stm32l1/Kconfig.defconfig.series

@@ -0,0 +1,15 @@
+# Kconfig - ST Microelectronics STM32L1 MCU line
+#
+# Copyright (c) 2019 Linaro Ltd.
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+if SOC_SERIES_STM32L1X
+
+source "soc/arm/st_stm32/stm32l1/Kconfig.defconfig.stm32l1*"
+
+config SOC_SERIES
+	default "stm32l1"
+
+endif # SOC_SERIES_STM32L1X

soc/arm/st_stm32/stm32l1/Kconfig.defconfig.stm32l151xb

@@ -0,0 +1,18 @@
+# Kconfig - ST Microelectronics STM32L151XB MCU
+#
+# Copyright (c) 2019 Linaro Ltd.
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+if SOC_STM32L151XB
+
+config SOC
+	string
+	default "stm32l151xb"
+
+config NUM_IRQS
+	int
+	default 45
+
+endif # SOC_STM32L151XB

soc/arm/st_stm32/stm32l1/Kconfig.series

@@ -0,0 +1,16 @@
+# Kconfig - ST Microelectronics STM32L1 MCU series
+#
+# Copyright (c) 2019 Linaro Ltd.
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+config SOC_SERIES_STM32L1X
+	bool "STM32L1x Series MCU"
+	select CPU_CORTEX_M3
+	select SOC_FAMILY_STM32
+	select HAS_STM32CUBE
+	select CPU_HAS_SYSTICK
+	select CLOCK_CONTROL_STM32_CUBE if CLOCK_CONTROL
+	help
+	  Enable support for STM32L1 MCU series

soc/arm/st_stm32/stm32l1/Kconfig.soc

@@ -0,0 +1,15 @@
+# Kconfig - ST Microelectronics STM32L1 MCU line
+#
+# Copyright (c) 2019 Linaro Ltd.
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+choice
+prompt "STM32L1x MCU Selection"
+depends on SOC_SERIES_STM32L1X
+
+config SOC_STM32L151XB
+	bool "STM32L151XB"
+
+endchoice

soc/arm/st_stm32/stm32l1/dts_fixup.h

@@ -0,0 +1,11 @@
+/*
+ * Copyright (c) 2019 Linaro Ltd.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/* SoC level DTS fixup file */
+
+#define DT_NUM_IRQ_PRIO_BITS	        DT_ARM_V7M_NVIC_E000E100_ARM_NUM_IRQ_PRIORITY_BITS
+
+/* End of SoC Level DTS fixup file */

soc/arm/st_stm32/stm32l1/linker.ld

@@ -0,0 +1,9 @@
+/* linker.ld - Linker command/script file */
+
+/*
+ * Copyright (c) 2019 Linaro Ltd.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <arch/arm/cortex_m/scripts/linker.ld>

soc/arm/st_stm32/stm32l1/soc.c

@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2019 Linaro Ltd.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * @file
+ * @brief System/hardware module for STM32L1 processor
+ */
+
+#include <device.h>
+#include <init.h>
+#include <arch/cpu.h>
+#include <cortex_m/exc.h>
+#include <linker/linker-defs.h>
+#include <string.h>
+
+/**
+ * @brief Perform basic hardware initialization at boot.
+ *
+ * This needs to be run from the very beginning.
+ * So the init priority has to be 0 (zero).
+ *
+ * @return 0
+ */
+static int stm32l1_init(struct device *arg)
+{
+	u32_t key;
+
+	ARG_UNUSED(arg);
+
+	key = irq_lock();
+
+	z_clearfaults();
+
+	/* Install default handler that simply resets the CPU
+	 * if configured in the kernel, NOP otherwise
+	 */
+	NMI_INIT();
+
+	irq_unlock(key);
+
+	/* Update CMSIS SystemCoreClock variable (HCLK) */
+	/* At reset, system core clock is set to 2.1 MHz from MSI */
+	SystemCoreClock = 2097000;
+
+	return 0;
+}
+
+SYS_INIT(stm32l1_init, PRE_KERNEL_1, 0);

soc/arm/st_stm32/stm32l1/soc.h

@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2019 Linaro Ltd.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * @file SoC configuration macros for the STM32L1 family processors.
+ *
+ * Based on reference manual:
+ *   STM32L1X advanced ARM ® -based 32-bit MCUs
+ *
+ * Chapter 2.2: Memory organization
+ */
+
+
+#ifndef _STM32L1_SOC_H_
+#define _STM32L1_SOC_H_
+
+#ifndef _ASMLANGUAGE
+
+#include <stm32l1xx.h>
+
+/* ARM CMSIS definitions must be included before kernel_includes.h.
+ * Therefore, it is essential to include kernel_includes.h after including
+ * core SOC-specific headers.
+ */
+#include <kernel_includes.h>
+
+#include <stm32l1xx_ll_system.h>
+
+#endif /* !_ASMLANGUAGE */
+
+#endif /* _STM32L1_SOC_H_ */

soc/arm/st_stm32/stm32l1/soc_registers.h

@@ -0,0 +1,12 @@
+/*
+ * Copyright (c) 2019 Linaro Ltd.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef _STM32L1X_SOC_REGISTERS_H_
+#define _STM32L1X_SOC_REGISTERS_H_
+
+/* include register mapping headers */
+
+#endif /* _STM32L1X_SOC_REGISTERS_H_ */