Diff: MODDMA.cpp

Revision:

0:c409efd8df78

Child:

6:40d38be4bb59

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MODDMA.cpp	Tue Nov 23 14:50:39 2010 +0000
@@ -0,0 +1,144 @@
+/*
+    Copyright (c) 2010 Andy Kirkham
+ 
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+ 
+    The above copyright notice and this permission notice shall be included in
+    all copies or substantial portions of the Software.
+ 
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+    THE SOFTWARE.
+*/
+
+#include "MODDMA.h"
+
+namespace AjK {
+
+// Create a "hook" for our ISR to make callbacks. Set by init()
+class MODDMA *moddma_p = (class MODDMA *)NULL;
+
+void
+MODDMA::Enable(CHANNELS ChannelNumber)
+{
+    LPC_GPDMACH_TypeDef *pChannel = (LPC_GPDMACH_TypeDef *)Channel_p( ChannelNumber );
+    pChannel->DMACCConfig |= _E;
+}
+
+bool
+MODDMA::Enabled(CHANNELS ChannelNumber)
+{
+    LPC_GPDMACH_TypeDef *pChannel = (LPC_GPDMACH_TypeDef *)Channel_p( ChannelNumber );
+    return (bool)(pChannel->DMACCConfig & _E);
+}
+
+void
+MODDMA::Disable(CHANNELS ChannelNumber)
+{
+    LPC_GPDMACH_TypeDef *pChannel = (LPC_GPDMACH_TypeDef *)Channel_p( ChannelNumber );
+    pChannel->DMACCConfig &= ~(_E);
+}
+
+bool
+MODDMA::isActive(CHANNELS ChannelNumber)
+{
+    LPC_GPDMACH_TypeDef *pChannel = (LPC_GPDMACH_TypeDef *)Channel_p( ChannelNumber );
+    return (bool)( pChannel->DMACCConfig & CxConfig_A() ) ;
+}
+
+void 
+MODDMA::haltChannel(CHANNELS ChannelNumber)
+{
+    LPC_GPDMACH_TypeDef *pChannel = (LPC_GPDMACH_TypeDef *)Channel_p( ChannelNumber );
+    pChannel->DMACCConfig |= CxConfig_H();
+}
+
+uint32_t oldDMAHandler = 0;
+typedef void (*MODDMA_FN)(void);
+
+extern "C" void MODDMA_IRQHandler(void) {
+    uint32_t channel_mask;
+        
+    if (moddma_p == (class MODDMA *)NULL) {
+        if (oldDMAHandler) {
+            ((MODDMA_FN)oldDMAHandler)();
+            return;
+        }
+        else {
+            error("Interrupt without instance");
+        }
+    }
+    
+    for (int channel_number = 0; channel_number < 8; channel_number++) {
+        channel_mask = (1UL << channel_number);
+        if (LPC_GPDMA->DMACIntStat & channel_mask) {
+            if (LPC_GPDMA->DMACIntTCStat & channel_mask) {
+                if (moddma_p->setups[channel_number] != (MODDMA_Config *)NULL) {
+                    moddma_p->setIrqProcessingChannel((MODDMA::CHANNELS)channel_number);
+                    moddma_p->setIrqType(MODDMA::TcIrq);
+                    moddma_p->setups[channel_number]->isrIntTCStat->call();
+                    moddma_p->isrIntTCStat.call();
+                    // The user callback should clear the IRQ. But if they forget
+                    // then the Mbed will lockup. So, check to see if the IRQ has
+                    // been dismissed, if not, we will dismiss it here.
+                    if (LPC_GPDMA->DMACIntTCStat & channel_mask) {
+                        LPC_GPDMA->DMACIntTCClear = channel_mask;
+                    }
+                    // If the user has left the channel enabled, disable it.
+                    // Not, we don't check Active here as it may block inside
+                    // an ISR, we just shut it down immediately. If the user
+                    // must wait for completion they should implement their
+                    // own ISR.
+                    if (moddma_p->Enabled( (MODDMA::CHANNELS)channel_number )) {
+                        moddma_p->Disable( (MODDMA::CHANNELS)channel_number );
+                    }
+                }            
+            }
+            
+            if (LPC_GPDMA->DMACIntErrStat & channel_mask) {
+                if (moddma_p->setups[channel_number] != (MODDMA_Config *)NULL) {
+                    moddma_p->setIrqProcessingChannel((MODDMA::CHANNELS)channel_number);
+                    moddma_p->setIrqType(MODDMA::ErrIrq);
+                    moddma_p->setups[channel_number]->isrIntErrStat->call();
+                    moddma_p->isrIntErrStat.call();
+                    // The user callback should clear the IRQ. But if they forget
+                    // then the Mbed will lockup. So, check to see if the IRQ has
+                    // been dismissed, if not, we will dismiss it here.
+                    if (LPC_GPDMA->DMACIntErrStat & channel_mask) {
+                        LPC_GPDMA->DMACIntErrClr = channel_mask;
+                    }
+                    // If the user has left the channel enabled, disable it.
+                    // Not, we don't check Active here as it may block inside
+                    // an ISR, we just shut it down immediately. If the user
+                    // must wait for completion they should implement their
+                    // own ISR.
+                    if (moddma_p->Enabled( (MODDMA::CHANNELS)channel_number )) {
+                        moddma_p->Disable( (MODDMA::CHANNELS)channel_number );
+                    }
+                }            
+            }
+        }
+    }
+    
+    /* IRQ should be handled by now, check to make sure. */
+    if (LPC_GPDMA->DMACIntStat) {
+        ((MODDMA_FN)oldDMAHandler)();
+        LPC_GPDMA->DMACIntTCClear = (uint32_t)0xFF; /* If not, clear anyway! */
+    }
+    if (LPC_GPDMA->DMACIntErrStat) {
+        ((MODDMA_FN)oldDMAHandler)();
+        LPC_GPDMA->DMACIntErrClr = (uint32_t)0xFF; /* If not, clear anyway! */
+    }
+}
+
+}; // namespace AjK ends
+