drivers: gpio: stm32: STM32F7 GPIO support

This patch adds GPIO support for STM32F7 family microcontrollers.

Signed-off-by: Yurii Hamann <yurii@hamann.site>

arch/arm/soc/st_stm32/stm32f7/CMakeLists.txt

@@ -2,3 +2,4 @@ zephyr_include_directories(${ZEPHYR_BASE}/drivers)
 zephyr_sources(
   soc.c
   )
+zephyr_sources_ifdef(CONFIG_GPIO soc_gpio.c)

arch/arm/soc/st_stm32/stm32f7/Kconfig.defconfig.series

@@ -12,4 +12,20 @@ gsource "arch/arm/soc/st_stm32/stm32f7/Kconfig.defconfig.stm32f7*"
 config SOC_SERIES
 	default "stm32f7"
 
+if GPIO_STM32
+
+config GPIO_STM32_PORTD
+	default y
+
+config GPIO_STM32_PORTE
+	default y
+
+config GPIO_STM32_PORTH
+	default y
+
+config GPIO_STM32_PORTI
+	default y
+
+endif # GPIO_STM32
+
 endif # SOC_SERIES_STM32F7X

arch/arm/soc/st_stm32/stm32f7/Kconfig.defconfig.stm32f746xg

@@ -11,6 +11,16 @@ config SOC
 	string
 	default "stm32f746xx"
 
+if GPIO_STM32
+
+config GPIO_STM32_PORTJ
+	default y
+
+config GPIO_STM32_PORTK
+	default y
+
+endif # GPIO_STM32
+
 config NUM_IRQS
 	int
 	default 98

arch/arm/soc/st_stm32/stm32f7/gpio_registers.h

@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2018 Yurii Hamann
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef _STM32F7X_GPIO_REGISTERS_H_
+#define _STM32F7X_GPIO_REGISTERS_H_
+
+/**
+ * @brief Driver for GPIO of STM32F7X family processor.
+ *
+ * Based on reference manual:
+ *   RM0385 Reference manual STM32F75xxx and STM32F74xxx
+ *   advanced ARM(r)-based 32-bit MCUs
+ *
+ * Chapter 6: General-purpose I/Os (GPIOs)
+ */
+
+/* 6.4 GPIO registers - each GPIO port controls 16 pins */
+struct stm32f7x_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 rsvd__16_31;
+		u16_t exti;
+	} bit;
+};
+
+/* 7.2 SYSCFG registers */
+struct stm32f7x_syscfg {
+	u32_t memrmp;
+	u32_t pmc;
+	union syscfg_exticr exticr1;
+	union syscfg_exticr exticr2;
+	union syscfg_exticr exticr3;
+	union syscfg_exticr exticr4;
+	u32_t cmpcr;
+};
+
+#endif /* _STM32F7X_GPIO_REGISTERS_H_ */

arch/arm/soc/st_stm32/stm32f7/soc.h

@@ -17,6 +17,10 @@
 #ifndef _STM32F7_SOC_H_
 #define _STM32F7_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>

arch/arm/soc/st_stm32/stm32f7/soc_gpio.c

@@ -0,0 +1,142 @@
+/*
+ * Copyright (c) 2018 Yurii Hamann
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * @brief
+ *
+ * Based on reference manual:
+ *   RM0385 Reference manual STM32F75xxx and STM32F74xxx
+ *   advanced ARM ® -based 32-bit MCUs
+ *
+ * Chapter 6: General-purpose I/Os (GPIOs)
+ */
+
+#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 stm32f7x_gpio *gpio =
+		(struct stm32f7x_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 stm32f7x_gpio *gpio = (struct stm32f7x_gpio *)base;
+
+	if (value) {
+		/* atomic set */
+		gpio->bsrr = (1 << (pin & 0x0f));
+	} else {
+		/* atomic reset */
+		gpio->bsrr = (1 << ((pin & 0x0f) + 0x10));
+	}
+
+	return 0;
+}
+
+int stm32_gpio_get(u32_t *base, int pin)
+{
+	struct stm32f7x_gpio *gpio = (struct stm32f7x_gpio *)base;
+
+	return (gpio->idr >> pin) & 0x1;
+}
+
+int stm32_gpio_enable_int(int port, int pin)
+{
+	volatile struct stm32f7x_syscfg *syscfg =
+		(struct stm32f7x_syscfg *)SYSCFG_BASE;
+	volatile union syscfg_exticr *exticr;
+	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
+	};
+	int shift = 0;
+
+	/* Enable SYSCFG clock */
+	clock_control_on(clk, (clock_control_subsys_t *) &pclken);
+
+	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/stm32f7/soc_registers.h

@@ -9,5 +9,6 @@
 
 /* include register mapping headers */
 #include "flash_registers.h"
+#include "gpio_registers.h"
 
 #endif /* _STM32F7_SOC_REGISTERS_H_ */

drivers/gpio/gpio_stm32.h

@@ -56,6 +56,19 @@
 #define STM32_PERIPH_GPIOI LL_AHB1_GRP1_PERIPH_GPIOI
 #define STM32_PERIPH_GPIOJ LL_AHB1_GRP1_PERIPH_GPIOJ
 #define STM32_PERIPH_GPIOK LL_AHB1_GRP1_PERIPH_GPIOK
+#elif CONFIG_SOC_SERIES_STM32F7X
+#define STM32_CLOCK_BUS_GPIO STM32_CLOCK_BUS_AHB1
+#define STM32_PERIPH_GPIOA LL_AHB1_GRP1_PERIPH_GPIOA
+#define STM32_PERIPH_GPIOB LL_AHB1_GRP1_PERIPH_GPIOB
+#define STM32_PERIPH_GPIOC LL_AHB1_GRP1_PERIPH_GPIOC
+#define STM32_PERIPH_GPIOD LL_AHB1_GRP1_PERIPH_GPIOD
+#define STM32_PERIPH_GPIOE LL_AHB1_GRP1_PERIPH_GPIOE
+#define STM32_PERIPH_GPIOF LL_AHB1_GRP1_PERIPH_GPIOF
+#define STM32_PERIPH_GPIOG LL_AHB1_GRP1_PERIPH_GPIOG
+#define STM32_PERIPH_GPIOH LL_AHB1_GRP1_PERIPH_GPIOH
+#define STM32_PERIPH_GPIOI LL_AHB1_GRP1_PERIPH_GPIOI
+#define STM32_PERIPH_GPIOJ LL_AHB1_GRP1_PERIPH_GPIOJ
+#define STM32_PERIPH_GPIOK LL_AHB1_GRP1_PERIPH_GPIOK
 #elif CONFIG_SOC_SERIES_STM32L0X
 #define STM32_CLOCK_BUS_GPIO STM32_CLOCK_BUS_IOP
 #define STM32_PERIPH_GPIOA LL_IOP_GRP1_PERIPH_GPIOA