Merge pull request #12634 from aabadie/pr/drivers/hd44780_fix_sam0

drivers/hd44780: fix potential hardfault during initialization
RIOT-OS · Nov 6, 2019 · 08e1cf2 · 08e1cf2
2 parents 8c181d8 + 62d2994
commit 08e1cf2
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Showing 2 changed files with 5 additions and 11 deletions.
diff --git a/drivers/hd44780/hd44780.c b/drivers/hd44780/hd44780.c
@@ -110,19 +110,13 @@ int hd44780_init(hd44780_t *dev, const hd44780_params_t *params)
         LOG_ERROR("hd44780_init: invalid LCD size!\n");
         return -1;
     }
-    uint8_t count_pins = 0;
-    /* check which pins are used */
-    for (unsigned i = 0; i < HD44780_MAX_PINS; ++i) {
-        if (dev->p.data[i] != GPIO_UNDEF) {
-            ++count_pins;
-        }
-    }
+    dev->flag = 0;
     /* set mode depending on configured pins */
-    if (count_pins < HD44780_MAX_PINS) {
-        dev->flag |= HD44780_4BITMODE;
+    if (dev->p.data[4] != GPIO_UNDEF) {
+        dev->flag |= HD44780_8BITMODE;
     }
     else {
-        dev->flag |= HD44780_8BITMODE;
+        dev->flag |= HD44780_4BITMODE;
     }
     /* set flag for 1 or 2 row mode, 4 rows are 2 rows split half */
     if (dev->p.rows > 1) {

diff --git a/drivers/include/hd44780.h b/drivers/include/hd44780.h
@@ -63,7 +63,7 @@ typedef struct {
     gpio_t rs;                      /**< rs gpio pin */
     gpio_t rw;                      /**< rw gpio pin */
     gpio_t enable;                  /**< enable gpio pin */
-    gpio_t data[8];                 /**< data gpio pins */
+    gpio_t data[HD44780_MAX_PINS];  /**< data gpio pins */
 } hd44780_params_t;
 
 /**