stm: Factor out GPIO code to its own file. Add functions to set GPIO mode.

GPIO functions are crude, and need to be replaced with better ones!

stm/Makefile

@@ -51,6 +51,7 @@ SRC_C = \
 	lexerfatfs.c \
 	pyexec.c \
 	led.c \
+	gpio.c \
 	lcd.c \
 	servo.c \
 	flash.c \

stm/gpio.c

+// This is a woefully inadequate set of bindings for GPIO control, and
+// needs to be replaced with something much better.
+
+#include <stdio.h>
+#include <string.h>
+#include <stm32f4xx.h>
+#include <stm32f4xx_rcc.h>
+#include <stm32f4xx_syscfg.h>
+#include <stm32f4xx_gpio.h>
+#include <stm32f4xx_exti.h>
+#include <stm32f4xx_tim.h>
+#include <stm32f4xx_pwr.h>
+#include <stm32f4xx_rtc.h>
+#include <stm32f4xx_usart.h>
+#include <stm32f4xx_rng.h>
+#include <usbd_storage_msd.h>
+#include <stm_misc.h>
+
+#include "nlr.h"
+#include "misc.h"
+#include "mpconfig.h"
+#include "qstr.h"
+#include "misc.h"
+#include "parse.h"
+#include "obj.h"
+#include "compile.h"
+#include "runtime0.h"
+#include "runtime.h"
+#include "systick.h"
+#include "gpio.h"
+
+void parse_pin_name(mp_obj_t name, GPIO_TypeDef **port, uint *pin) {
+    const char *pin_name = mp_obj_str_get_str(name);
+    switch (pin_name[0]) {
+        case 'A': case 'a': *port = GPIOA; break;
+        case 'B': case 'b': *port = GPIOB; break;
+        case 'C': case 'c': *port = GPIOC; break;
+        case 'D': case 'd': *port = GPIOD; break;
+        default: goto pin_error;
+    }
+    *pin = 0;
+    for (const char *s = pin_name + 1; *s; s++) {
+        if (!('0' <= *s && *s <= '9')) {
+            goto pin_error;
+        }
+        *pin = 10 * (*pin) + *s - '0';
+    }
+    if (!(0 <= *pin && *pin <= 15)) {
+        goto pin_error;
+    }
+
+    return;
+
+pin_error:
+    nlr_jump(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "pin %s does not exist", pin_name));
+}
+
+mp_obj_t pyb_gpio(uint n_args, mp_obj_t *args) {
+    //assert(1 <= n_args && n_args <= 2);
+
+    GPIO_TypeDef *port;
+    uint pin;
+    parse_pin_name(args[0], &port, &pin);
+
+    if (n_args == 1) {
+        // get pin
+        if ((port->IDR & (1 << pin)) != (uint32_t)Bit_RESET) {
+            return MP_OBJ_NEW_SMALL_INT(1);
+        } else {
+            return MP_OBJ_NEW_SMALL_INT(0);
+        }
+    } else {
+        // set pin
+        if (rt_is_true(args[1])) {
+            // set pin high
+            port->BSRRL = 1 << pin;
+        } else {
+            // set pin low
+            port->BSRRH = 1 << pin;
+        }
+        return mp_const_none;
+    }
+}
+
+MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(pyb_gpio_obj, 1, 2, pyb_gpio);
+
+mp_obj_t pyb_gpio_input(mp_obj_t arg_port_pin, mp_obj_t arg_mode) {
+    GPIO_TypeDef *port;
+    uint pin;
+    parse_pin_name(arg_port_pin, &port, &pin);
+
+    GPIO_InitTypeDef GPIO_InitStructure;
+    GPIO_InitStructure.GPIO_Pin = 1 << pin;
+    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;
+    GPIO_InitStructure.GPIO_PuPd = mp_obj_get_int(arg_mode);
+    GPIO_Init(port, &GPIO_InitStructure);
+
+    return mp_const_none;
+}
+
+MP_DEFINE_CONST_FUN_OBJ_2(pyb_gpio_input_obj, pyb_gpio_input);
+
+mp_obj_t pyb_gpio_output(mp_obj_t arg_port_pin, mp_obj_t arg_mode) {
+    GPIO_TypeDef *port;
+    uint pin;
+    parse_pin_name(arg_port_pin, &port, &pin);
+
+    GPIO_InitTypeDef GPIO_InitStructure;
+    GPIO_InitStructure.GPIO_Pin = 1 << pin;
+    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
+    GPIO_InitStructure.GPIO_Speed = GPIO_Fast_Speed;
+    GPIO_InitStructure.GPIO_OType = mp_obj_get_int(arg_mode);
+    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
+    GPIO_Init(port, &GPIO_InitStructure);
+
+    return mp_const_none;
+}
+
+MP_DEFINE_CONST_FUN_OBJ_2(pyb_gpio_output_obj, pyb_gpio_output);
+
+void gpio_init(mp_obj_t mod) {
+    rt_store_attr(mod, MP_QSTR_gpio, (mp_obj_t)&pyb_gpio_obj);
+    rt_store_attr(mod, MP_QSTR_gpio_in, (mp_obj_t)&pyb_gpio_input_obj);
+    rt_store_attr(mod, MP_QSTR_gpio_out, (mp_obj_t)&pyb_gpio_output_obj);
+    rt_store_attr(mod, qstr_from_str("PULL_NONE"), MP_OBJ_NEW_SMALL_INT(GPIO_PuPd_NOPULL));
+    rt_store_attr(mod, qstr_from_str("PULL_UP"), MP_OBJ_NEW_SMALL_INT(GPIO_PuPd_UP));
+    rt_store_attr(mod, qstr_from_str("PULL_DOWN"), MP_OBJ_NEW_SMALL_INT(GPIO_PuPd_DOWN));
+    rt_store_attr(mod, qstr_from_str("PUSH_PULL"), MP_OBJ_NEW_SMALL_INT(GPIO_OType_PP));
+    rt_store_attr(mod, qstr_from_str("OPEN_DRAIN"), MP_OBJ_NEW_SMALL_INT(GPIO_OType_OD));
+}

stm/gpio.h

+void gpio_init(mp_obj_t mod);

stm/main.c

@@ -34,6 +34,7 @@
 #include "pendsv.h"
 #include "pyexec.h"
 #include "led.h"
+#include "gpio.h"
 #include "servo.h"
 #include "lcd.h"
 #include "storage.h"
@@ -259,53 +260,6 @@ static mp_obj_t pyb_standby(void) {
     return mp_const_none;
 }
 
-mp_obj_t pyb_gpio(uint n_args, mp_obj_t *args) {
-    //assert(1 <= n_args && n_args <= 2);
-
-    const char *pin_name = mp_obj_str_get_str(args[0]);
-    GPIO_TypeDef *port;
-    switch (pin_name[0]) {
-        case 'A': case 'a': port = GPIOA; break;
-        case 'B': case 'b': port = GPIOB; break;
-        case 'C': case 'c': port = GPIOC; break;
-        default: goto pin_error;
-    }
-    uint pin_num = 0;
-    for (const char *s = pin_name + 1; *s; s++) {
-        if (!('0' <= *s && *s <= '9')) {
-            goto pin_error;
-        }
-        pin_num = 10 * pin_num + *s - '0';
-    }
-    if (!(0 <= pin_num && pin_num <= 15)) {
-        goto pin_error;
-    }
-
-    if (n_args == 1) {
-        // get pin
-        if ((port->IDR & (1 << pin_num)) != (uint32_t)Bit_RESET) {
-            return MP_OBJ_NEW_SMALL_INT(1);
-        } else {
-            return MP_OBJ_NEW_SMALL_INT(0);
-        }
-    } else {
-        // set pin
-        if (rt_is_true(args[1])) {
-            // set pin high
-            port->BSRRL = 1 << pin_num;
-        } else {
-            // set pin low
-            port->BSRRH = 1 << pin_num;
-        }
-        return mp_const_none;
-    }
-
-pin_error:
-    nlr_jump(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "pin %s does not exist", pin_name));
-}
-
-MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(pyb_gpio_obj, 1, 2, pyb_gpio);
-
 mp_obj_t pyb_hid_send_report(mp_obj_t arg) {
     mp_obj_t *items = mp_obj_get_array_fixed_n(arg, 4);
     uint8_t data[4];
@@ -479,11 +433,13 @@ soft_reset:
         rt_store_attr(m, MP_QSTR_Servo, rt_make_function_n(1, pyb_Servo));
 #endif
         rt_store_attr(m, MP_QSTR_I2C, rt_make_function_n(2, pyb_I2C));
-        rt_store_attr(m, MP_QSTR_gpio, (mp_obj_t)&pyb_gpio_obj);
         rt_store_attr(m, MP_QSTR_Usart, rt_make_function_n(2, pyb_Usart));
         rt_store_attr(m, qstr_from_str("ADC_all"), (mp_obj_t)&pyb_ADC_all_obj);
         rt_store_attr(m, MP_QSTR_ADC, (mp_obj_t)&pyb_ADC_obj);
         rt_store_attr(m, qstr_from_str("millis"), rt_make_function_n(0, pyb_millis));
+
+        gpio_init(m);
+
         rt_store_name(MP_QSTR_pyb, m);
 
         rt_store_name(MP_QSTR_open, rt_make_function_n(2, pyb_io_open));

stm/qstrdefsport.h

@@ -26,6 +26,8 @@ Q(Servo)
 Q(SDcard)
 Q(I2C)
 Q(gpio)
+Q(gpio_in)
+Q(gpio_out)
 Q(Usart)
 Q(ADC)
 Q(open)