Diff: sdcard/sdcard.c

Revision:

0:0a841b89d614

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sdcard/sdcard.c	Mon Oct 11 10:34:55 2010 +0000
@@ -0,0 +1,126 @@
+/****************************************************************************
+ *    Copyright 2010 Andy Kirkham, Stellar Technologies Ltd
+ *    
+ *    This file is part of the Satellite Observers Workbench (SOWB).
+ *
+ *    SOWB 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.
+ *
+ *    SOWB 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 SOWB.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ *    $Id: main.cpp 5 2010-07-12 20:51:11Z ajk $
+ *    
+ ***************************************************************************/
+ 
+#include "sowb.h"
+#include "user.h"
+#include "debug.h"
+#include "rit.h"
+#include "gps.h"
+#include "gpio.h"
+#include "ff.h"
+
+FATFS MyFileSystem;
+bool card_detected_A;
+bool card_detected_B;
+bool card_mounted;
+bool card_bad;
+uint32_t sdcard_detect_shift_register;
+
+/** sdcard_is_mounted
+ *
+ * Tell the caller if an SD card is mounted.
+ *
+ * @return bool True if a card is mounted, false otherwise.
+ */
+bool sdcard_is_mounted(void) {
+    return card_mounted;
+}
+
+/** sdcard_init()
+ */
+void sdcard_init(void) {
+    DEBUG_INIT_START;
+    card_bad        = false;
+    card_mounted    = false;
+    card_detected_A = false;
+    card_detected_B = false;
+    sdcard_detect_shift_register = 0;
+    rit_timer_set_counter(SDCARD_TIMER_CB, 10);
+    DEBUG_INIT_END;
+}
+
+/** sdcard_process()
+ */             
+void sdcard_process(void) {
+    int retry;
+    int f_return;
+    DIR root_directory;
+    
+    /* card_detected_A is set by the RIT timer callback below which performs
+       a rough debounce of the switch. So, if here we need to do a rising
+       edge detect so we only flag a card insertion once. */
+    if (card_detected_A && !card_detected_B && !card_mounted && !card_bad) {
+        card_detected_B = true;        
+        debug_printf("Card insertion detected.\r\n");
+        /* Have found that some cards require a "kick" to bring them to
+           life. So we retry 3 times to init the card. If after 3 tries
+           it fails we mark the card as "bad". */
+        for(retry = 0; retry < 3; retry++) {
+            KICK_WATCHDOG;
+            f_return = f_mount(0,&MyFileSystem);
+            if (f_return == FR_OK) {
+                f_return = f_opendir(&root_directory, "/");
+                if (f_return == FR_OK) {
+                    card_mounted = true;
+                    debug_printf("SD card mounted.\r\n");
+                    retry = 3; /* Break loop. */
+                }
+            }    
+        }
+        
+        if (!card_mounted) {
+            card_bad = true;
+            debug_printf("Failed to mount SD Card\r\n");
+        }
+    }
+}
+
+/** _sdcard_timer_callback
+ *
+ * RIT timer callback.
+ * @see rit.c
+ */
+void _sdcard_timer_callback(int index) {
+    
+    /* Shift left 1bit... */
+    sdcard_detect_shift_register = sdcard_detect_shift_register << 1;
+    
+    /* And then mask in bit0 position. */
+    if (SDCARD_DETECT != 0) {  
+        sdcard_detect_shift_register |= 1;
+    }
+
+    /* 16 consecutive 1s mean card detected. Rough debouncing of the
+       mechanical "card detect" switch in the SD card holder. */
+    if ((sdcard_detect_shift_register & 0x0000FFFFUL) == 0x0000FFFFUL) { 
+        card_detected_A = true; 
+    }
+    else {
+        card_bad        = false;
+        card_mounted    = false;
+        card_detected_A = false;
+        card_detected_B = false;
+    }
+    
+    /* Restart timer. */
+    rit_timer_set_counter(SDCARD_TIMER_CB, 10);
+}