Diff: flash/flash_erase.c

Revision:

0:0a841b89d614

diff -r 000000000000 -r 0a841b89d614 flash/flash_erase.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/flash/flash_erase.c	Mon Oct 11 10:34:55 2010 +0000
@@ -0,0 +1,141 @@
+/****************************************************************************
+ *    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 "flash.h"
+#include "ssp0.h"
+#include "dma.h"
+#include "gpio.h"
+#include "rit.h"
+#include "user.h"
+#include "utils.h"
+#include "debug.h"
+
+/* Flags to show what state we are in. */
+bool sector_erase_in_progress = false;
+extern bool page_write_in_progress;
+
+bool flash_sector_erase_in_progress(void) {
+    return sector_erase_in_progress;
+}
+
+/** flash_erase_sector
+ */
+int flash_erase_sector(int sector) {
+
+    /* If a sector erase is in progress already
+       we return zero rather than wait (block)
+       because an erase can take so long to complete
+       we don't want to hang around waiting. Let the
+       caller reschedule it sometime later. */
+    if (sector_erase_in_progress) {
+        return 0;
+    }
+
+    /* Request use of SSP0. */
+    while(!SSP0_request()) WHILE_WAITING_DO_PROCESS_FUNCTIONS;
+    
+    sector_erase_in_progress = true;
+    
+    FLASH_CS_ASSERT;
+    FLASH_SHORT_COMMAND(FLASH_WREN);
+    FLASH_CS_DEASSERT;
+    
+    SSP0_FLUSH_RX_FIFO;
+    
+    /* Wait until the flash device has the WEL bit on. */
+    while ((LPC_SSP0->DR & 0x2) == 0) {            
+        FLASH_CS_ASSERT;
+        FLASH_SHORT_COMMAND(FLASH_RDSR);
+        SSP0_FLUSH_RX_FIFO;
+        SSP0_WRITE_BYTE(0);
+        while (SSP0_IS_BUSY);
+        FLASH_CS_DEASSERT;
+    }
+
+    SSP0_FLUSH_RX_FIFO;
+    
+    FLASH_CS_ASSERT;
+    FLASH_LONG_COMMAND(FLASH_SE, sector);
+    FLASH_CS_DEASSERT;
+    
+    /* Note, a sector erase takes much longer than
+       a page write (typical 600ms by the datasheet)
+       so there's no point making the first timeout
+       very short and producing a lot of uneeded 
+       interrupts. So we set the first timeout to
+       be 600 and then it'll switch to a much shorter
+       time in the ISR. */
+    rit_timer_set_counter(FLASH_WRITE_CB, 600);
+    return 1;
+}
+
+/** flash_erase_bulk
+ */
+int flash_erase_bulk(void) {
+
+    /* If a sector erase is in progress already
+       we return zero rather than wait (block)
+       because an erase can take so long to complete
+       we don't want to hang around waiting. Let the
+       caller reschedule it sometime later. */
+   
+    if (sector_erase_in_progress || page_write_in_progress) {
+        return 0;
+    }
+
+    /* Request use of SSP0. */
+    while(!SSP0_request()) WHILE_WAITING_DO_PROCESS_FUNCTIONS;
+    
+    sector_erase_in_progress = true;
+    
+    FLASH_CS_ASSERT;
+    FLASH_SHORT_COMMAND(FLASH_WREN);
+    FLASH_CS_DEASSERT;
+    
+    SSP0_FLUSH_RX_FIFO;
+    
+    /* Wait until the flash device has the WEL bit on. */
+    while ((LPC_SSP0->DR & 0x2) == 0) {            
+        FLASH_CS_ASSERT;
+        FLASH_SHORT_COMMAND(FLASH_RDSR);
+        SSP0_FLUSH_RX_FIFO;
+        SSP0_WRITE_BYTE(0);
+        while (SSP0_IS_BUSY);
+        FLASH_CS_DEASSERT;
+    }
+
+    FLASH_CS_ASSERT;
+    FLASH_SHORT_COMMAND(FLASH_BE);
+    FLASH_CS_DEASSERT;
+    
+    /* Note, a bulk erase takes much longer than
+       a page write (typical 8s by the datasheet)
+       so there's no point making the first timeout
+       very short and producing a lot of uneeded 
+       interrupts. So we set the first timeout to
+       be 8000 and then it'll switch to a much shorter
+       time in the ISR. */
+    rit_timer_set_counter(FLASH_WRITE_CB, 8000);
+    return 1;
+}
+