cpu/stm32f0: some minor fixes to GPIO driver

- fixed indention on some places
- s/gpio_config/isr_ctx/
- use BRR reg for clearing pin

cpu/stm32f0/include/periph_cpu.h

@@ -42,14 +42,13 @@ typedef uint32_t gpio_t;
 /**
  * @brief   Define a CPU specific GPIO pin generator macro
  */
-#define GPIO_PIN(x, y)          ((GPIOA_BASE + (x << 10)) | y)
+#define GPIO_PIN(x, y)      ((GPIOA_BASE + (x << 10)) | y)
 
 /**
  * @brief   Override flank configuration values
  * @{
  */
-#define HAVE_GPIO_FLANK_T\
-
+#define HAVE_GPIO_FLANK_T
 typedef enum {
     GPIO_RISING = 1,        /**< emit interrupt on rising flank */
     GPIO_FALLING = 2,       /**< emit interrupt on falling flank */
@@ -76,10 +75,6 @@ typedef enum {
     GPIO_AF1,               /**< use alternate function 1 */
     GPIO_AF2,               /**< use alternate function 2 */
     GPIO_AF3,               /**< use alternate function 3 */
-    GPIO_AF4,               /**< use alternate function 4 */
-    GPIO_AF5,               /**< use alternate function 5 */
-    GPIO_AF6,               /**< use alternate function 6 */
-    GPIO_AF7,               /**< use alternate function 7 */
 } gpio_af_t;
 
 /**

cpu/stm32f0/periph/gpio.c

@@ -32,7 +32,7 @@
 /**
  * @brief   Allocate memory for one callback and argument per EXTI channel
  */
-static gpio_isr_ctx_t gpio_config[EXTI_NUMOF];
+static gpio_isr_ctx_t isr_ctx[EXTI_NUMOF];
 
 /**
  * @brief   Extract the port base address from the given pin identifier
@@ -91,8 +91,8 @@ int gpio_init_int(gpio_t pin, gpio_pp_t pullup, gpio_flank_t flank, gpio_cb_t cb
     int port_num = _port_num(pin);
 
     /* set callback */
-    gpio_config[pin_num].cb = cb;
-    gpio_config[pin_num].arg = arg;
+    isr_ctx[pin_num].cb = cb;
+    isr_ctx[pin_num].arg = arg;
 
     /* enable clock of the SYSCFG module for EXTI configuration */
     RCC->APB2ENR |= RCC_APB2ENR_SYSCFGCOMPEN;
@@ -152,13 +152,11 @@ void gpio_irq_disable(gpio_t pin)
 
 int gpio_read(gpio_t pin)
 {
-    GPIO_TypeDef *port = _port(pin);
-    uint32_t pin_num = _pin_num(pin);
-
-    if (port->MODER & (1 << (pin_num * 2))) {   /* if configured as output */
-        return port->ODR & (1 << pin_num);      /* read output data reg */
-    } else {
-        return port->IDR & (1 << pin_num);      /* else read input data reg */
+    if (_port(pin)->MODER & (0x3 << (_pin_num(pin) * 2))) {
+        return _port(pin)->ODR & (1 << _pin_num(pin));
+    }
+    else {
+        return _port(pin)->IDR & (1 << _pin_num(pin));
     }
 }
 
@@ -169,24 +167,24 @@ void gpio_set(gpio_t pin)
 
 void gpio_clear(gpio_t pin)
 {
-    _port(pin)->BSRR = ((1 << _pin_num(pin)) << 16);
+    _port(pin)->BRR = (1 << _pin_num(pin));
 }
 
 void gpio_toggle(gpio_t pin)
 {
     if (gpio_read(pin)) {
-    _port(pin)->BSRR = ((1 << _pin_num(pin))<< 16);
+        _port(pin)->BRR = (1 << _pin_num(pin));
     } else {
-    _port(pin)->BSRR = (1 << _pin_num(pin));
+        _port(pin)->BSRR = (1 << _pin_num(pin));
     }
 }
 
 void gpio_write(gpio_t pin, int value)
 {
     if (value) {
-    _port(pin)->BSRR = (1 << _pin_num(pin));
+        _port(pin)->BSRR = (1 << _pin_num(pin));
     } else {
-    _port(pin)->BSRR = ((1 << _pin_num(pin)) << 16);
+        _port(pin)->BRR = (1 << _pin_num(pin));
     }
 }
 
@@ -195,7 +193,7 @@ void isr_exti(void)
     for (size_t i = 0; i < EXTI_NUMOF; i++) {
         if (EXTI->PR & (1 << i)) {
             EXTI->PR = (1 << i);        /* clear by writing a 1 */
-            gpio_config[i].cb(gpio_config[i].arg);
+            isr_ctx[i].cb(isr_ctx[i].arg);
         }
     }
     if (sched_context_switch_request) {

cpu/stm32f0/vectors.c

@@ -93,9 +93,9 @@ ISR_VECTORS const void *interrupt_vector[] = {
     (void*) isr_rtc,                /* real time clock */
     (void*) isr_flash,              /* flash memory controller */
     (void*) isr_rcc,                /* reset and clock control */
-    (void*) isr_exti,            /* external interrupt lines 0 and 1 */
-    (void*) isr_exti,            /* external interrupt lines 2 and 3 */
-    (void*) isr_exti,            /* external interrupt lines 4 and 15 */
+    (void*) isr_exti,               /* external interrupt lines 0 and 1 */
+    (void*) isr_exti,               /* external interrupt lines 2 and 3 */
+    (void*) isr_exti,               /* external interrupt lines 4 to 15 */
     (void*) isr_ts,                 /* touch sensing input*/
     (void*) isr_dma1_ch1,           /* direct memory access controller 1, channel 1*/
     (void*) isr_dma1_ch2_3,         /* direct memory access controller 1, channel 2 and 3*/