[stm32f0xx] Add external interrupt driver.

platform/stm32f0xx/exti.c

@@ -0,0 +1,182 @@
+/*
+ * Copyright (c) 2017 The Fuchsia Authors.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <platform/exti.h>
+
+#include <arch/arm/cm.h>
+#include <assert.h>
+#include <compiler.h>
+#include <platform/rcc.h>
+#include <stdint.h>
+
+bool __WEAK stm32_exti0_irq(void) {
+    return false;
+}
+
+bool __WEAK stm32_exti1_irq(void) {
+    return false;
+}
+
+bool __WEAK stm32_exti2_irq(void) {
+    return false;
+}
+
+bool __WEAK stm32_exti3_irq(void) {
+    return false;
+}
+
+bool __WEAK stm32_exti4_irq(void) {
+    return false;
+}
+
+bool __WEAK stm32_exti5_irq(void) {
+    return false;
+}
+
+bool __WEAK stm32_exti6_irq(void) {
+    return false;
+}
+
+bool __WEAK stm32_exti7_irq(void) {
+    return false;
+}
+
+bool __WEAK stm32_exti8_irq(void) {
+    return false;
+}
+
+bool __WEAK stm32_exti9_irq(void) {
+    return false;
+}
+
+bool __WEAK stm32_exti10_irq(void) {
+    return false;
+}
+
+bool __WEAK stm32_exti11_irq(void) {
+    return false;
+}
+
+bool __WEAK stm32_exti12_irq(void) {
+    return false;
+}
+
+bool __WEAK stm32_exti13_irq(void) {
+    return false;
+}
+
+bool __WEAK stm32_exti14_irq(void) {
+    return false;
+}
+
+bool __WEAK stm32_exti15_irq(void) {
+    return false;
+}
+
+#define STM32_DISPATCH_EXTI(pr, irq, resched) do { \
+    if ((pr) & (1 << (irq))) { \
+        resched |= stm32_exti ## irq ## _irq(); \
+    } \
+ } while(0)
+
+void stm32_EXTI0_1_IRQ(void) {
+    arm_cm_irq_entry();
+
+    uint32_t pr = EXTI->PR & 0x3;
+    EXTI->PR = pr;
+
+    bool resched = false;
+    STM32_DISPATCH_EXTI(pr, 0, resched);
+    STM32_DISPATCH_EXTI(pr, 1, resched);
+
+    arm_cm_irq_exit(resched);
+}
+
+void stm32_EXTI2_3_IRQ(void) {
+    arm_cm_irq_entry();
+
+    uint32_t pr = EXTI->PR & (0x3 << 2);
+    EXTI->PR = pr;
+
+    bool resched = false;
+    STM32_DISPATCH_EXTI(pr, 2, resched);
+    STM32_DISPATCH_EXTI(pr, 3, resched);
+
+    arm_cm_irq_exit(resched);
+}
+
+void stm32_EXTI4_15_IRQ(void) {
+    arm_cm_irq_entry();
+
+    uint32_t pr = EXTI->PR & ~0xfU;
+    EXTI->PR = pr;
+
+    bool resched = false;
+    STM32_DISPATCH_EXTI(pr, 4, resched);
+    STM32_DISPATCH_EXTI(pr, 5, resched);
+    STM32_DISPATCH_EXTI(pr, 6, resched);
+    STM32_DISPATCH_EXTI(pr, 7, resched);
+    STM32_DISPATCH_EXTI(pr, 8, resched);
+    STM32_DISPATCH_EXTI(pr, 9, resched);
+    STM32_DISPATCH_EXTI(pr, 10, resched);
+    STM32_DISPATCH_EXTI(pr, 11, resched);
+    STM32_DISPATCH_EXTI(pr, 12, resched);
+    STM32_DISPATCH_EXTI(pr, 13, resched);
+    STM32_DISPATCH_EXTI(pr, 14, resched);
+    STM32_DISPATCH_EXTI(pr, 15, resched);
+
+    arm_cm_irq_exit(resched);
+}
+
+#undef STM32_DISPATCH_EXTI
+
+void stm32_setup_ext_interrupt(int interrupt, stm32_ext_interrupt_port_t port,
+                               bool rising_edge, bool falling_edge) {
+    assert(0 <= interrupt && interrupt <= 15);
+
+    uint32_t cfg = SYSCFG->EXTICR[interrupt >> 4];
+    cfg &= SYSCFG_EXTICR1_EXTI0 << (interrupt & 0x3);
+    cfg |= port << (interrupt & 0x3);
+
+    EXTI->IMR |= 1 << interrupt;
+
+    if (rising_edge) {
+        EXTI->RTSR |= 1 << interrupt;
+    } else {
+        EXTI->RTSR &= ~(1 << interrupt);
+    }
+
+    if (falling_edge) {
+        EXTI->FTSR |= 1 << interrupt;
+    } else {
+        EXTI->FTSR &= ~(1 << interrupt);
+    }
+
+    if (0 <= interrupt && interrupt <= 1) {
+        NVIC_EnableIRQ(EXTI0_1_IRQn);
+    } else if (2 <= interrupt && interrupt <= 3) {
+        NVIC_EnableIRQ(EXTI2_3_IRQn);
+    } else if (4 <= interrupt && interrupt <= 15) {
+        NVIC_EnableIRQ(EXTI4_15_IRQn);
+    }
+}

platform/stm32f0xx/include/platform/exti.h

@@ -0,0 +1,38 @@
+#ifndef __PLATFORM_STM32_EXTI_H
+#define __PLATFORM_STM32_EXTI_H
+
+#include <stdbool.h>
+#include <stm32f0xx.h>
+
+typedef enum {
+    EXT_INTERRUPT_PORT_A = SYSCFG_EXTICR1_EXTI0_PA,
+    EXT_INTERRUPT_PORT_B = SYSCFG_EXTICR1_EXTI0_PB,
+    EXT_INTERRUPT_PORT_C = SYSCFG_EXTICR1_EXTI0_PC,
+    EXT_INTERRUPT_PORT_D = SYSCFG_EXTICR1_EXTI0_PD,
+    EXT_INTERRUPT_PORT_E = SYSCFG_EXTICR1_EXTI0_PE,
+    EXT_INTERRUPT_PORT_F = SYSCFG_EXTICR1_EXTI0_PF,
+} stm32_ext_interrupt_port_t;
+
+void stm32_setup_ext_interrupt(int interrupt, stm32_ext_interrupt_port_t port,
+                               bool rising_edge, bool falling_edge);
+
+// Define these in your target code to override the weak, no-op default
+// handlers.  These should return true if lk should reschedule after handling.
+bool stm32_exti0_irq(void);
+bool stm32_exti1_irq(void);
+bool stm32_exti2_irq(void);
+bool stm32_exti3_irq(void);
+bool stm32_exti4_irq(void);
+bool stm32_exti5_irq(void);
+bool stm32_exti6_irq(void);
+bool stm32_exti7_irq(void);
+bool stm32_exti8_irq(void);
+bool stm32_exti9_irq(void);
+bool stm32_exti10_irq(void);
+bool stm32_exti11_irq(void);
+bool stm32_exti12_irq(void);
+bool stm32_exti13_irq(void);
+bool stm32_exti14_irq(void);
+bool stm32_exti15_irq(void);
+
+#endif  // __PLATFORM_STM32_EXTI_H

platform/stm32f0xx/rules.mk

@@ -29,6 +29,7 @@ MODULE_SRCS += \
 	$(LOCAL_DIR)/can.c \
 	$(LOCAL_DIR)/debug.c \
 	$(LOCAL_DIR)/dma.c \
+	$(LOCAL_DIR)/exti.c \
 	$(LOCAL_DIR)/gpio.c \
 	$(LOCAL_DIR)/init.c \
 	$(LOCAL_DIR)/i2c.c \