1 files changed, 129 insertions, 29 deletions

diff --git a/libmaple/gpio.c b/libmaple/gpio.c
index 71e5230..18b856b 100644
--- a/libmaple/gpio.c
+++ b/libmaple/gpio.c
@@ -26,44 +26,144 @@
  * @brief GPIO initialization routine
  */
 
-#include "libmaple.h"
-#include "rcc.h"
 #include "gpio.h"
+#include "rcc.h"
+
+/*
+ * GPIO devices
+ */
+
+gpio_dev gpioa = {
+    .regs   = GPIOA_BASE,
+    .clk_id = RCC_GPIOA
+};
+gpio_dev* const GPIOA = &gpioa;
+
+gpio_dev gpiob = {
+    .regs   = GPIOB_BASE,
+    .clk_id = RCC_GPIOB
+};
+gpio_dev* const GPIOB = &gpiob;
+
+gpio_dev gpioc = {
+    .regs   = GPIOC_BASE,
+    .clk_id = RCC_GPIOC
+};
+gpio_dev* const GPIOC = &gpioc;
+
+gpio_dev gpiod = {
+    .regs   = GPIOD_BASE,
+    .clk_id = RCC_GPIOD
+};
+gpio_dev* const GPIOD = &gpiod;
+
+#ifdef STM32_HIGH_DENSITY
+gpio_dev gpioe = {
+    .regs   = GPIOE_BASE,
+    .clk_id = RCC_GPIOE
+};
+gpio_dev* const GPIOE = &gpioe;
+
+gpio_dev gpiof = {
+    .regs   = GPIOF_BASE,
+    .clk_id = RCC_GPIOF
+};
+gpio_dev* const GPIOF = &gpiof;
 
-void gpio_init(void) {
-    rcc_clk_enable(RCC_GPIOA);
-    rcc_clk_enable(RCC_GPIOB);
-    rcc_clk_enable(RCC_GPIOC);
-#if NR_GPIO_PORTS >= 4          /* Maple, but not Maple Mini */
-    rcc_clk_enable(RCC_GPIOD);
-#elif NR_GPIO_PORTS >= 7        /* Maple Native (high density only) */
-    rcc_clk_enable(RCC_GPIOE);
-    rcc_clk_enable(RCC_GPIOF);
-    rcc_clk_enable(RCC_GPIOG);
+gpio_dev gpiog = {
+    .regs   = GPIOG_BASE,
+    .clk_id = RCC_GPIOG
+};
+gpio_dev* const GPIOG = &gpiog;
 #endif
-    rcc_clk_enable(RCC_AFIO);
+
+/*
+ * GPIO convenience routines
+ */
+
+/**
+ * Initialize a GPIO device.
+ *
+ * Enables the clock for and resets the given device.
+ *
+ * @param dev GPIO device to initialize.
+ */
+void gpio_init(gpio_dev *dev) {
+    rcc_clk_enable(dev->clk_id);
+    rcc_reset_dev(dev->clk_id);
 }
 
-void gpio_set_mode(GPIO_Port* port, uint8 gpio_pin, GPIOPinMode mode) {
-    uint32 tmp;
-    uint32 shift = POS(gpio_pin % 8);
-    GPIOReg CR;
+/**
+ * Initialize and reset all available GPIO devices.
+ */
+void gpio_init_all(void) {
+    gpio_init(GPIOA);
+    gpio_init(GPIOB);
+    gpio_init(GPIOC);
+    gpio_init(GPIOD);
+#ifdef STM32_HIGH_DENSITY
+    gpio_init(GPIOE);
+    gpio_init(GPIOF);
+    gpio_init(GPIOG);
+#endif
+}
 
-    ASSERT(port);
-    ASSERT(gpio_pin < 16);
+/**
+ * Set the mode of a GPIO pin.
+ *
+ * @param dev GPIO device.
+ * @param pin Pin on the device whose mode to set, 0--15.
+ * @param mode General purpose or alternate function mode to set the pin to.
+ * @see gpio_pin_mode
+ */
+void gpio_set_mode(gpio_dev *dev, uint8 pin, gpio_pin_mode mode) {
+    gpio_reg_map *regs = dev->regs;
+    __io uint32 *cr = &regs->CRL + (pin >> 3);
+    uint32 shift = (pin & 0x7) * 4;
+    uint32 tmp = *cr;
+
+    tmp &= ~(0xF << shift);
+    tmp |= (mode == GPIO_INPUT_PU ? GPIO_INPUT_PD : mode) << shift;
+    *cr = tmp;
 
-    if (mode == GPIO_MODE_INPUT_PU) {
-        port->ODR |= BIT(gpio_pin);
-        mode = CNF_INPUT_PD;
-    } else if (mode == GPIO_MODE_INPUT_PD) {
-        port->ODR &= ~BIT(gpio_pin);
+    if (mode == GPIO_INPUT_PD) {
+        regs->ODR &= ~BIT(pin);
+    } else if (mode == GPIO_INPUT_PU) {
+        regs->ODR |= BIT(pin);
     }
+}
+
+/*
+ * AFIO
+ */
 
-    CR = (gpio_pin < 8) ? &(port->CRL) : &(port->CRH);
+/**
+ * Initialize the AFIO clock, and reset the AFIO registers.
+ */
+void afio_init(void) {
+    rcc_clk_enable(RCC_AFIO);
+    rcc_reset_dev(RCC_AFIO);
+}
 
-    tmp = *CR;
-    tmp &= POS_MASK(shift);
-    tmp |= mode << shift;
+#define AFIO_EXTI_SEL_MASK 0xF
+
+/**
+ * Select a source input for an external interrupt.
+ *
+ * @param exti      External interrupt.  One of: AFIO_EXTI_0,
+ *                  AFIO_EXTI_1, ..., AFIO_EXTI_15.
+ * @param gpio_port Port which contains pin to use as source input.
+ *                  One of: AFIO_EXTI_PA, AFIO_EXTI_PB, AFIO_EXTI_PC,
+ *                  AFIO_EXTI_PD, and, on high density devices,
+ *                  AFIO_EXTI_PE, AFIO_EXTI_PF, AFIO_EXTI_PG.
+ * @see exti_port
+ */
+void afio_exti_select(afio_exti_num exti, afio_exti_port gpio_port) {
+    __io uint32 *exti_cr = &AFIO_BASE->EXTICR1 + exti / 4;
+    uint32 shift = 4 * (exti % 4);
+    uint32 cr = *exti_cr;
 
-    *CR = tmp;
+    cr &= ~(AFIO_EXTI_SEL_MASK << shift);
+    cr |= gpio_port << shift;
+    *exti_cr = cr;
 }