From fcba4be107df5b150251d4569a86dc8ff3e824c0 Mon Sep 17 00:00:00 2001
From: knolax <1339802534.kk@gmail.com>
Date: Wed, 20 Dec 2017 00:36:29 -0500
Subject: reversed the roles of the row and column pins to account for an error
 in the prototype board.

---
 skey.c | 37 +++++++++++++++++++++++++++----------
 1 file changed, 27 insertions(+), 10 deletions(-)

diff --git a/skey.c b/skey.c
index 5038e36..70955f4 100644
--- a/skey.c
+++ b/skey.c
@@ -13,6 +13,23 @@
  */
 #define USE_GPIO 1
 /*
+ * On the prototype model, the diodes were soldered backwards, so that the
+ * negative ends were facing the cpins.
+ * as outputs they seem to opendrain(transistor to high, resistor to low)
+ * this means that the cpins can not pull the rlabels down. we can not
+ * work around this by using the pins as active_low
+ * we now have to use rpins as the output and cpins as the input because
+ * we can only use active_high, and the positive side of the diodes are
+ * facing the rpins. This means we don't have short-circuit since the diodes
+ * are still connected to the cpins. however, when shorting them in
+ * production it seems that the problem is not bad enough to cause the board
+ * to shut down.
+ */
+
+
+
+/*
+ * GPIO pins
  * Unsigned ints containing the BCM pin numbers for the pins used, __initdata
  * helps with the loading and unloading of data in memory
  */
@@ -66,22 +83,22 @@ int skey_update_thread (void *data) {
 			//reads the keyboard
 			int row_index = 0;
 			int column_index = 0;
-			while (column_index < 10) {
+			while (row_index < 3) {
 				//sets the column pin high for reading
-				gpio_set_value(column_pins[column_index], 1);
+				gpio_set_value(row_pins[row_index], 1);
 				//reads with all the rows
-				row_index = 0;
-				while (row_index < 3) {
-					if (gpio_get_value(row_pins[row_index])) {
+				column_index = 0;
+				while (column_index < 10) {
+					if (gpio_get_value(column_pins[column_index])) {
 						printk(KERN_INFO "skey: key pressed at column %d, row %d\n", column_index, row_index);
 					} else {
 						printk(KERN_INFO "skey: key not pressed at column %d, row %d\n", column_index, row_index);
 					}
-					row_index++;
+					column_index++;
 				}
 				//sets the row pin low
-				gpio_set_value(column_pins[column_index], 0);
-				column_index++;
+				gpio_set_value(row_pins[row_index], 0);
+				row_index++;
 			}
 		}
 		//sleep 2000us= 2ms = 0.002 seconds
@@ -111,7 +128,7 @@ static int  __init skey_init (void) {
 				return -EINVAL;
 			}
 			//requests access of the GPIO
-			if (gpio_request_one(column_pins[i], GPIOF_OUT_INIT_LOW ,clabels[i])) {
+			if (gpio_request_one(column_pins[i], GPIOF_IN ,clabels[i])) {
 				printk(KERN_ALERT "skey: column_pins[%d], BCM %d request failed\n", i, column_pins[i]);
 				return -EINVAL;
 			}
@@ -129,7 +146,7 @@ static int  __init skey_init (void) {
 				return -EINVAL;
 			}
 			//requests access of the GPIO
-			if (gpio_request_one(row_pins[j], GPIOF_DIR_IN ,rlabels[j])) {
+			if (gpio_request_one(row_pins[j], GPIOF_DIR_OUT_INIT_LOW ,rlabels[j])) {
 				printk(KERN_ALERT "skey: row_pins[%d], BCM %d request failed\n", j, row_pins[j]);
 				return -EINVAL;
 			}
-- 
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