arm: stm32l0: Add support for stm32l0 soc

Add necessary kconfig and minimal device tree support for
the stm32l072xz variants.

Signed-off-by: Endre Karlson <endre.karlson@gmail.com>

arch/arm/soc/st_stm32/stm32l0/CMakeLists.txt

@@ -0,0 +1,5 @@
+zephyr_include_directories(${ZEPHYR_BASE}/drivers)
+zephyr_sources(
+  soc.c
+  )
+zephyr_sources_ifdef(CONFIG_GPIO soc_gpio.c)

arch/arm/soc/st_stm32/stm32l0/Kconfig.defconfig.series

@@ -0,0 +1,20 @@
+# Kconfig - ST Microelectronics STM32L0 MCU line
+#
+# Copyright (c) 2018 Endre Karlson <endre.karlson@gmail.com>
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+if SOC_SERIES_STM32L0X
+
+source "arch/arm/soc/st_stm32/stm32l0/Kconfig.defconfig.stm32l0*"
+
+config SOC_SERIES
+	default stm32l0
+
+if GPIO_STM32
+
+endif # GPIO_STM32
+
+
+endif # SOC_SERIES_STM32L0X

arch/arm/soc/st_stm32/stm32l0/Kconfig.defconfig.stm32l072xz

@@ -0,0 +1,31 @@
+# Kconfig - ST Microelectronics STM32L072XB MCU
+#
+# Copyright (c) 2018 Endre Karlson <endre.karlson@gmail.com>
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+if SOC_STM32L072XZ
+
+config SOC
+	string
+	default stm32l072xx
+
+config NUM_IRQS
+	int
+	default 32
+
+if GPIO_STM32
+
+config GPIO_STM32_PORTD
+	default y
+
+config GPIO_STM32_PORTE
+	default y
+
+config GPIO_STM32_PORTH
+default y
+
+endif # GPIO_STM32
+
+endif # SOC_STM32L072XZ

arch/arm/soc/st_stm32/stm32l0/Kconfig.series

@@ -0,0 +1,19 @@
+# Kconfig - ST Microelectronics STM32L4 MCU series
+#
+# Copyright (c) 2018 Endre Karlson <endre.karlson@gmail.com>
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+config SOC_SERIES_STM32L0X
+	bool "STM32L0x Series MCU"
+	select CPU_CORTEX_M
+	select CPU_CORTEX_M0PLUS
+	select CPU_CORTEX_M_HAS_VTOR
+	select SOC_FAMILY_STM32
+	select SYS_POWER_LOW_POWER_STATE_SUPPORTED
+	select HAS_STM32CUBE
+	select CPU_HAS_SYSTICK
+	select CLOCK_CONTROL_STM32_CUBE if CLOCK_CONTROL
+	help
+	  Enable support for STM32L0 MCU series

arch/arm/soc/st_stm32/stm32l0/Kconfig.soc

@@ -0,0 +1,15 @@
+# Kconfig - ST Microelectronics STM32L0 MCU line
+#
+# Copyright (c) 2018 Endre Karlson <endre.karlson@gmail.com>
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+choice
+prompt "STM32L0x MCU Selection"
+depends on SOC_SERIES_STM32L0X
+
+config SOC_STM32L072XZ
+	bool "STM32L072XZ"
+
+endchoice

arch/arm/soc/st_stm32/stm32l0/dts.fixup

@@ -0,0 +1,17 @@
+/* SoC level DTS fixup file */
+
+#define CONFIG_NUM_IRQ_PRIO_BITS	        ARM_V6M_NVIC_E000E100_ARM_NUM_IRQ_PRIORITY_BITS
+
+#define CONFIG_UART_STM32_PORT_1_BASE_ADDRESS	ST_STM32_USART_40013800_BASE_ADDRESS
+#define CONFIG_UART_STM32_PORT_1_BAUD_RATE	ST_STM32_USART_40013800_CURRENT_SPEED
+#define CONFIG_UART_STM32_PORT_1_IRQ_PRI	ST_STM32_USART_40013800_IRQ_0_PRIORITY
+#define CONFIG_UART_STM32_PORT_1_NAME		ST_STM32_USART_40013800_LABEL
+#define PORT_1_IRQ				ST_STM32_USART_40013800_IRQ_0
+
+#define CONFIG_UART_STM32_PORT_2_BASE_ADDRESS	ST_STM32_USART_40004400_BASE_ADDRESS
+#define CONFIG_UART_STM32_PORT_2_BAUD_RATE	ST_STM32_USART_40004400_CURRENT_SPEED
+#define CONFIG_UART_STM32_PORT_2_IRQ_PRI	ST_STM32_USART_40004400_IRQ_0_PRIORITY
+#define CONFIG_UART_STM32_PORT_2_NAME		ST_STM32_USART_40004400_LABEL
+#define PORT_2_IRQ				ST_STM32_USART_40004400_IRQ_0
+
+/* End of SoC Level DTS fixup file */

arch/arm/soc/st_stm32/stm32l0/gpio_registers.h

@@ -0,0 +1,54 @@
+/*
+ * Copyright (c) 2018 Endre Karlson <endre.karlson@gmail.com>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef _STM32L0X_GPIO_REGISTERS_H_
+#define _STM32L0X_GPIO_REGISTERS_H_
+
+/**
+ * @brief
+ *
+ * Based on reference manual:
+ *   STM32L0X advanced ARM ® -based 32-bit MCUs
+
+ *
+ * Chapter 9: General-purpose I/Os (GPIO)
+ * Chapter 10: System configuration controller (SYSCFG)
+ */
+
+struct stm32l0x_gpio {
+	u32_t moder;
+	u32_t otyper;
+	u32_t ospeedr;
+	u32_t pupdr;
+	u32_t idr;
+	u32_t odr;
+	u32_t bsrr;
+	u32_t lckr;
+	u32_t afr[2];
+	u32_t brr;
+};
+
+union syscfg_exticr {
+	u32_t val;
+	struct {
+		u16_t exti;
+		u16_t rsvd__16_31;
+	} bit;
+};
+
+struct stm32l0x_syscfg {
+	u32_t cfgr1;
+	u32_t cfgr2;
+	union syscfg_exticr exticr1;
+	union syscfg_exticr exticr2;
+	union syscfg_exticr exticr3;
+	union syscfg_exticr exticr4;
+	u32_t comp1_ctrl;
+	u32_t comp2_ctrl;
+	u32_t cfgr3;
+};
+
+#endif /* _STM32L0X_GPIO_REGISTERS_H_ */

arch/arm/soc/st_stm32/stm32l0/linker.ld

@@ -0,0 +1,9 @@
+/* linker.ld - Linker command/script file */
+
+/*
+ * Copyright (c) 2018 Endre Karlson <endre.karlson@gmail.com>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <arch/arm/cortex_m/scripts/linker.ld>

arch/arm/soc/st_stm32/stm32l0/soc.c

@@ -0,0 +1,65 @@
+/*
+ * Copyright (c) 2018 Endre Karlson <endre.karlson@gmail.com>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * @file
+ * @brief System/hardware module for STM32L0 processor
+ */
+
+#include <kernel.h>
+#include <device.h>
+#include <init.h>
+#include <soc.h>
+#include <arch/cpu.h>
+#include <cortex_m/exc.h>
+#include <linker/linker-defs.h>
+#include <string.h>
+
+
+/**
+ * @brief This function configures the source of stm32cube time base.
+ *        Cube HAL expects a 1ms tick which matches with k_uptime_get_32.
+ *        Tick interrupt priority is not used
+ * @return HAL status
+ */
+uint32_t HAL_GetTick(void)
+{
+	return k_uptime_get_32();
+}
+
+/**
+ * @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 stm32l0_init(struct device *arg)
+{
+	u32_t key;
+
+	ARG_UNUSED(arg);
+
+	key = irq_lock();
+
+	_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 = 2097152;
+
+	return 0;
+}
+
+SYS_INIT(stm32l0_init, PRE_KERNEL_1, 0);

arch/arm/soc/st_stm32/stm32l0/soc.h

@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2018 Endre Karlson <endre.karlson@gmail.com>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * @file SoC configuration macros for the STM32L0 family processors.
+ *
+ * Based on reference manual:
+ *   STM32L0X advanced ARM ® -based 32-bit MCUs
+ *
+ * Chapter 2.2: Memory organization
+ */
+
+
+#ifndef _STM32L0_SOC_H_
+#define _STM32L0_SOC_H_
+
+#define GPIO_REG_SIZE         0x400
+/* base address for where GPIO registers start */
+#define GPIO_PORTS_BASE       (GPIOA_BASE)
+
+#ifndef _ASMLANGUAGE
+
+#include <device.h>
+#include <misc/util.h>
+#include <random/rand32.h>
+
+#include <stm32l0xx.h>
+
+#include "soc_irq.h"
+
+#ifdef CONFIG_SERIAL_HAS_DRIVER
+#include <stm32l0xx_ll_usart.h>
+#endif
+
+#ifdef CONFIG_CLOCK_CONTROL_STM32_CUBE
+#include <stm32l0xx_ll_utils.h>
+#include <stm32l0xx_ll_bus.h>
+#include <stm32l0xx_ll_rcc.h>
+#include <stm32l0xx_ll_system.h>
+#endif /* CONFIG_CLOCK_CONTROL_STM32_CUBE */
+
+#endif /* !_ASMLANGUAGE */
+
+#endif /* _STM32L0_SOC_H_ */

arch/arm/soc/st_stm32/stm32l0/soc_gpio.c

@@ -0,0 +1,144 @@
+/*
+ * Copyright (c) 2018 Endre Karlson <endre.karlson@gmail.com>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * @brief
+ *
+ * Based on reference manual:
+ *   STM32F030x4/x6/x8/xC,
+ *   STM32F070x6/xB advanced ARM ® -based MCUs
+ *
+ * Chapter 9: General-purpose I/Os (GPIO)
+ */
+
+#include <errno.h>
+
+#include <device.h>
+#include "soc.h"
+#include "soc_registers.h"
+#include <gpio.h>
+#include <gpio/gpio_stm32.h>
+
+int stm32_gpio_flags_to_conf(int flags, int *pincfg)
+{
+	int direction = flags & GPIO_DIR_MASK;
+	int pud = flags & GPIO_PUD_MASK;
+
+	if (!pincfg) {
+		return -EINVAL;
+	}
+
+	if (direction == GPIO_DIR_OUT) {
+		*pincfg = STM32_MODER_OUTPUT_MODE;
+	} else {
+		/* pull-{up,down} maybe? */
+		*pincfg = STM32_MODER_INPUT_MODE;
+		if (pud == GPIO_PUD_PULL_UP) {
+			*pincfg = *pincfg | STM32_PUPDR_PULL_UP;
+		} else if (pud == GPIO_PUD_PULL_DOWN) {
+			*pincfg = *pincfg | STM32_PUPDR_PULL_DOWN;
+		} else {
+			/* floating */
+			*pincfg = *pincfg | STM32_PUPDR_NO_PULL;
+		}
+	}
+
+	return 0;
+}
+
+int stm32_gpio_configure(u32_t *base_addr, int pin, int conf, int altf)
+{
+	volatile struct stm32l0x_gpio *gpio =
+		(struct stm32l0x_gpio *)(base_addr);
+	unsigned int mode, otype, ospeed, pupd;
+	unsigned int pin_shift = pin << 1;
+	unsigned int afr_bank = pin / 8;
+	unsigned int afr_shift = (pin % 8) << 2;
+	u32_t scratch;
+
+	mode = (conf >> STM32_MODER_SHIFT) & STM32_MODER_MASK;
+	otype = (conf >> STM32_OTYPER_SHIFT) & STM32_OTYPER_MASK;
+	ospeed = (conf >> STM32_OSPEEDR_SHIFT) & STM32_OSPEEDR_MASK;
+	pupd = (conf >> STM32_PUPDR_SHIFT) & STM32_PUPDR_MASK;
+
+	scratch = gpio->moder & ~(STM32_MODER_MASK << pin_shift);
+	gpio->moder = scratch | (mode << pin_shift);
+
+	scratch = gpio->ospeedr & ~(STM32_OSPEEDR_MASK << pin_shift);
+	gpio->ospeedr = scratch | (ospeed << pin_shift);
+
+	scratch = gpio->otyper & ~(STM32_OTYPER_MASK << pin);
+	gpio->otyper = scratch | (otype << pin);
+
+	scratch = gpio->pupdr & ~(STM32_PUPDR_MASK << pin_shift);
+	gpio->pupdr = scratch | (pupd << pin_shift);
+
+	scratch = gpio->afr[afr_bank] & ~(STM32_AFR_MASK << afr_shift);
+	gpio->afr[afr_bank] = scratch | (altf << afr_shift);
+
+	return 0;
+}
+
+int stm32_gpio_set(u32_t *base, int pin, int value)
+{
+	struct stm32l0x_gpio *gpio = (struct stm32l0x_gpio *)base;
+
+	int pval = 1 << (pin & 0xf);
+
+	if (value) {
+		gpio->odr |= pval;
+	} else {
+		gpio->odr &= ~pval;
+	}
+
+	return 0;
+}
+
+int stm32_gpio_get(u32_t *base, int pin)
+{
+	struct stm32l0x_gpio *gpio = (struct stm32l0x_gpio *)base;
+
+	return (gpio->idr >> pin) & 0x1;
+}
+
+int stm32_gpio_enable_int(int port, int pin)
+{
+	volatile struct stm32l0x_syscfg *syscfg =
+		(struct stm32l0x_syscfg *)SYSCFG_BASE;
+	volatile union syscfg_exticr *exticr;
+
+	/* Enable System Configuration Controller clock. */
+	struct device *clk =
+		device_get_binding(STM32_CLOCK_CONTROL_NAME);
+
+	struct stm32_pclken pclken = {
+		.bus = STM32_CLOCK_BUS_APB2,
+		.enr = LL_APB2_GRP1_PERIPH_SYSCFG
+	};
+
+	clock_control_on(clk, (clock_control_subsys_t *) &pclken);
+
+	int shift = 0;
+
+	if (pin <= 3) {
+		exticr = &syscfg->exticr1;
+	} else if (pin <= 7) {
+		exticr = &syscfg->exticr2;
+	} else if (pin <= 11) {
+		exticr = &syscfg->exticr3;
+	} else if (pin <= 15) {
+		exticr = &syscfg->exticr4;
+	} else {
+		return -EINVAL;
+	}
+
+	shift = 4 * (pin % 4);
+
+	exticr->val &= ~(0xf << shift);
+	exticr->val |= port << shift;
+
+	return 0;
+}

arch/arm/soc/st_stm32/stm32l0/soc_irq.h

@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2018 Endre Karlson <endre.karlson@gmail.com>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * @file Interrupt numbers for STM32L0 family processors.
+ *
+ * Based on reference manual:
+ *   STM32L0X advanced ARM ® -based 32-bit MCUs
+ *
+ * Chapter 11.1.3: Interrupt and exception vectors
+ */
+
+
+#ifndef _STM32L0_SOC_IRQ_H_
+#define _STM32L0_SOC_IRQ_H_
+
+/* FIXME: Remove when use of enum line number in IRQ_CONNECT is
+ * made possible by ZEP-1165.
+ * soc_irq.h, once it is possible, should be removed.
+ */
+
+#define STM32L0_IRQ_WWDG			0
+#define STM32L0_IRQ_PVD         		1
+#define STM32L0_IRQ_RTC				2
+#define STM32L0_IRQ_FLASH			3
+#define STM32L0_IRQ_RCC				4
+#define STM32L0_IRQ_EXTI0_1			5
+#define STM32L0_IRQ_EXTI2_3			6
+#define STM32L0_IRQ_EXTI4_15			7
+#define STM32L0_IRQ_TSC             		8
+#define STM32L0_IRQ_DMA_CH1			9
+#define STM32L0_IRQ_DMA_CH2_3			10
+#define STM32L0_IRQ_DMA_CH4_7			11
+#define STM32L0_IRQ_ADC				12
+#define STM32L0_IRQ_LPTIM1			13
+#define STM32L0_IRQ_USART_4_5   		14
+#define STM32L0_IRQ_TIM2			15
+#define STM32L0_IRQ_TIM3			16
+#define STM32L0_IRQ_TIM6_DAC			17
+#define STM32L0_IRQ_TIM7			18
+/* reserved */
+#define STM32L0_IRQ_TIM21			20
+#define STM32L0_IRQ_I2C3			21
+#define STM32L0_IRQ_TIM22			22
+#define STM32L0_IRQ_I2C1			23
+#define STM32L0_IRQ_I2C2			24
+#define STM32L0_IRQ_SPI1			25
+#define STM32L0_IRQ_SPI2			26
+#define STM32L0_IRQ_USART1			27
+#define STM32L0_IRQ_USART2			28
+#define STM32L0_IRQ_LPUART1_AES_RNG     	29
+#define STM32L0_IRQ_LCD         		30
+#define STM32L0_IRQ_USB				31
+
+#endif	/* _STM32L0_SOC_IRQ_H_ */

arch/arm/soc/st_stm32/stm32l0/soc_registers.h

@@ -0,0 +1,13 @@
+/*
+ * Copyright (c) 2018 Endre Karlson <endre.karlson@gmail.com>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef _STM32L0X_SOC_REGISTERS_H_
+#define _STM32L0X_SOC_REGISTERS_H_
+
+/* include register mapping headers */
+#include "gpio_registers.h"
+
+#endif /* _STM32L0X_SOC_REGISTERS_H_ */