# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1475448071 -7200
# Node ID b59bce1670f9376f8c9671f384c60651f6302226
# Parent  ca1a8a522be1bfdb76225c0579da3293831d2076
Added a keyboard scanning task.

diff -r ca1a8a522be1 -r b59bce1670f9 stage2/tasks/keyscan.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/stage2/tasks/keyscan.c	Mon Oct 03 00:41:11 2016 +0200
@@ -0,0 +1,58 @@
+/*
+ * Keyboard scanning task.
+ *
+ * Copyright (C) 2016 Paul Boddie <paul@boddie.org.uk>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "board.h"
+#include "tasks.h"
+#include "task_gpio.h"
+
+void keyscan(unsigned short task)
+{
+	int column, row, value;
+
+	while (1)
+	{
+		/* Select each column and read the key states. */
+
+		for (column = 0; column < GPIO_KEYOUT_COUNT; column++)
+		{
+			task_gpio_set_pin(GPIO_KEYOUT_BASE + column);
+			value = 0;
+
+			for (row = 0; row < GPIO_KEYIN_COUNT; row++)
+			{
+				value = (value << 1) | task_gpio_get_pin(GPIO_KEYIN_BASE + row);
+			}
+
+			/* Perform an operation indicating the status. */
+
+			task_gpio_clear_pin(GPIO_KEYOUT_BASE + column);
+		}
+	}
+}
+
+void start_keyscan(unsigned short task)
+{
+	u32 args[] = {task};
+
+	task_gpio_init(task);
+
+	/* Invoke the task. */
+
+	start_task(task, (void (*)()) keyscan, args, 1);
+}
diff -r ca1a8a522be1 -r b59bce1670f9 stage2/tasks/keyscan.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/stage2/tasks/keyscan.h	Mon Oct 03 00:41:11 2016 +0200
@@ -0,0 +1,6 @@
+#ifndef __KEYSCAN_H__
+#define __KEYSCAN_H__
+
+void start_keyscan(unsigned short);
+
+#endif /* __KEYSCAN_H__ */
diff -r ca1a8a522be1 -r b59bce1670f9 stage2/tasks/manifest.c
--- a/stage2/tasks/manifest.c	Mon Oct 03 00:40:57 2016 +0200
+++ b/stage2/tasks/manifest.c	Mon Oct 03 00:41:11 2016 +0200
@@ -19,12 +19,14 @@
 
 #include "manifest.h"
 #include "example.h"
+#include "keyscan.h"
 
 /* A list of task-starting functions accepting their task identifier. */
 
 void (*initial_task_array[])(unsigned short) = {
 	start_plot_pattern,
 	start_plot_pattern,
+	start_keyscan,
 
 	/*
 	Employ a zero terminator, and make sure that max_tasks is not exceeded