Debug config for vs code ide

inc/gpio.h

@@ -9,6 +9,6 @@ int gpio_open(const struct gpio *gpio);
 int gpio_close(const struct gpio *gpio);
 int gpio_read(const struct gpio *gpio, unsigned int *value);
 int gpio_write(const struct gpio *gpio, unsigned int value);
-void gpio_toggle(const struct gpio *gpio);
+int gpio_toggle(const struct gpio *gpio);
 
 #endif

src/gpio.c

@@ -10,7 +10,8 @@ struct ftdi_obj {
     bool is_open;
     unsigned int vendor_id;
     unsigned int product_id;
-    unsigned char bit_mask;
+    unsigned char bit_mask;     /* Mask of used bits */
+    unsigned char status_mask;  /* Mask of current status of used bits */
 };
 
 static struct ftdi_obj ftdi_obj = {
@@ -19,6 +20,7 @@ static struct ftdi_obj ftdi_obj = {
     .vendor_id = 0x0403,
     .product_id = 0x6001,
     .bit_mask = 0,
+    .status_mask = 0,
 };
 
 static int ftdi_open(void)
@@ -38,18 +40,7 @@ static int ftdi_open(void)
         return EXIT_FAILURE;
     }
 
-    return EXIT_SUCCESS;
-}
-
-static int gpio_read_mask(const struct gpio *gpio, unsigned char *mask)
-{
-    int res;
-
-    if(NULL == gpio || NULL == mask) {
-        return EXIT_FAILURE;
-    }
-
-    res = ftdi_read_data(ftdi_obj.ftdi, mask, 1);
+    res = ftdi_read_data(ftdi_obj.ftdi, &(ftdi_obj.status_mask), 1);
     if(res < 0) {
         syslog(LOG_ERR, "unable to readfrom ftdi device: %d (%s)\n", res,
                ftdi_get_error_string(ftdi_obj.ftdi));
@@ -62,9 +53,7 @@ static int gpio_read_mask(const struct gpio *gpio, unsigned char *mask)
 int gpio_open(const struct gpio *gpio)
 {
     int res;
-    unsigned char init_value = 0;
-    bool init_write = false;
-
+    unsigned int init_value = 0;
 
     if(NULL == gpio) {
         syslog(LOG_ERR, "No valid gpio object given.\n");
@@ -76,7 +65,6 @@ int gpio_open(const struct gpio *gpio)
         if(res != EXIT_SUCCESS) {
             return EXIT_FAILURE;
         }
-        init_write = true;
     }
 
     ftdi_obj.bit_mask |= (unsigned char)gpio->pin;
@@ -85,15 +73,21 @@ int gpio_open(const struct gpio *gpio)
     if(res < 0) {
         syslog(LOG_ERR, "unable to set bit bang mode: %d (%s)\n", res,
                ftdi_get_error_string(ftdi_obj.ftdi));
+        ftdi_usb_close(ftdi_obj.ftdi);
+        ftdi_free(ftdi_obj.ftdi);
+        return EXIT_FAILURE;
+    }
+
+    res = gpio_write(gpio, init_value);
+    if(res < 0) {
+        syslog(LOG_ERR, "unable to write to gpio %u (%s)\n", gpio->pin,
+               ftdi_get_error_string(ftdi_obj.ftdi));
+        ftdi_usb_close(ftdi_obj.ftdi);
         ftdi_free(ftdi_obj.ftdi);
         return EXIT_FAILURE;
     }
     ftdi_obj.is_open = true;
 
-    if(init_write) {
-        ftdi_write_data(ftdi_obj.ftdi, &init_value, 1);
-    }
-
     return EXIT_SUCCESS;
 }
 
@@ -103,8 +97,9 @@ int gpio_close(const struct gpio *gpio)
         return EXIT_FAILURE;
     }
 
-    unsigned char pin = (unsigned char)gpio->pin;
-    ftdi_obj.bit_mask &= ~pin;
+    gpio_write(gpio, 0);
+
+    ftdi_obj.bit_mask &= ~(unsigned char)(gpio->pin);
     if(ftdi_obj.bit_mask == 0) {
         ftdi_usb_close(ftdi_obj.ftdi);
         ftdi_free(ftdi_obj.ftdi);
@@ -115,21 +110,11 @@ int gpio_close(const struct gpio *gpio)
 
 int gpio_read(const struct gpio *gpio, unsigned int *value)
 {
-    int res;
-    unsigned char buf;
-
     if(NULL == gpio || NULL == value) {
         return EXIT_FAILURE;
     }
 
-    res = gpio_read_mask(gpio, &buf);
-    if(res != EXIT_SUCCESS) {
-        syslog(LOG_ERR, "unable to readfrom ftdi device: %d (%s)\n", res,
-               ftdi_get_error_string(ftdi_obj.ftdi));
-        return EXIT_FAILURE;
-    }
-
-    if(buf & (unsigned char)(gpio->pin)) {
+    if(ftdi_obj.status_mask & (unsigned char)(gpio->pin)) {
         *value = 1;
     } else {
         *value = 0;
@@ -141,38 +126,48 @@ int gpio_read(const struct gpio *gpio, unsigned int *value)
 int gpio_write(const struct gpio *gpio, unsigned int value)
 {
     int res;
-    unsigned char buf;
+    unsigned char mask;
 
     if(NULL == gpio) {
         return EXIT_FAILURE;
     }
 
-    res = gpio_read_mask(gpio, &buf);
-    if(res != EXIT_SUCCESS) {
-        syslog(LOG_ERR, "write failed for 0x%02x, error %d (%s)\n", buf, res,
-               ftdi_get_error_string(ftdi_obj.ftdi));
-        return EXIT_FAILURE;
-    }
-
-    syslog(LOG_DEBUG, "current state: 0x%02x\n", buf);
     if(value == 0) {
-        buf &= ~(unsigned char)(gpio->pin);
+        mask &= ~(unsigned char)(gpio->pin);
     }
     else {
-        buf |= (unsigned char)(gpio->pin);
+        mask |= (unsigned char)(gpio->pin);
     }
-    syslog(LOG_DEBUG, "new state: 0x%02x\n", buf);
 
-    res = ftdi_write_data(ftdi_obj.ftdi, &buf, 1);
+    res = ftdi_write_data(ftdi_obj.ftdi, &mask, 1);
     if(res < 0) {
         syslog(LOG_ERR, "write failed for 0x%x, error %d (%s)\n", value, res,
                ftdi_get_error_string(ftdi_obj.ftdi));
         return EXIT_FAILURE;
     }
+    ftdi_obj.status_mask = mask;
 
     return EXIT_SUCCESS;
 }
 
-void gpio_toggle(const struct gpio *gpio)
+int gpio_toggle(const struct gpio *gpio)
 {
+    int res;
+    unsigned char mask = ftdi_obj.status_mask;
+
+    if(NULL == gpio) {
+        return EXIT_FAILURE;
+    }
+
+    mask ^= (unsigned char)(gpio->pin);
+
+    res = ftdi_write_data(ftdi_obj.ftdi, &mask, 1);
+    if(res < 0) {
+        syslog(LOG_ERR, "toggle failed, error %d (%s)\n", res,
+               ftdi_get_error_string(ftdi_obj.ftdi));
+        return EXIT_FAILURE;
+    }
+    ftdi_obj.status_mask = mask;
+
+    return EXIT_SUCCESS;
 }

src/main.c

@@ -33,38 +33,19 @@ int main(int argc, char *argv[])
         return res;
     }
 
+    gpio_write(&gpio_1, 1);
+    gpio_write(&gpio_2, 0);
     for(cnt = 0; cnt < 10; cnt++) {
-        value = cnt & 0x01;
-        res = gpio_write(&gpio_1, value);
-        if(cnt % 2) {
-            res |= gpio_write(&gpio_2, value);
-        }
-        if(res != EXIT_SUCCESS) {
-            syslog(LOG_ERR, "Unable to write to gpio\n");
-            gpio_close(&gpio_1);
-            gpio_close(&gpio_2);
-            return res;
-        }
-
-        res = gpio_read(&gpio_1, &value);
-        if(res != EXIT_SUCCESS) {
-            syslog(LOG_ERR, "Unable to read from gpio pin %u\n", gpio_1.pin);
-            gpio_close(&gpio_1);
-            return res;
-        }
-        printf("read 1 value: 0x%02x\n", value);
-        if(cnt % 2) {
-            res = gpio_read(&gpio_2, &value);
-            if(res != EXIT_SUCCESS) {
-                syslog(LOG_ERR, "Unable to read from gpio pin %u\n", gpio_2.pin);
-                gpio_close(&gpio_2);
-                return res;
-            }
-            printf("read 2 value: 0x%02x\n", value);
-        }
+        gpio_toggle(&gpio_1);
+        gpio_toggle(&gpio_2);
+        gpio_read(&gpio_1, &value);
+        printf("Gpio1: %u\n", value);
+        gpio_read(&gpio_2, &value);
+        printf("Gpio2: %u\n", value);
         sleep(1);
     }
     gpio_close(&gpio_1);
+    gpio_close(&gpio_2);
 
     return EXIT_SUCCESS;
 }