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-rw-r--r--firmware/main.c59
1 files changed, 27 insertions, 32 deletions
diff --git a/firmware/main.c b/firmware/main.c
index 7f44313..7dd99f0 100644
--- a/firmware/main.c
+++ b/firmware/main.c
@@ -71,6 +71,7 @@ unsigned char framebuffer[BUS_COUNT*BUS_SIZE];
/* Kick off DMA from RAM to SPI interfaces */
void start_dma(void);
unsigned long framebuffer_read(void *data, unsigned long len);
+void ssi_udma_channel_config(unsigned char channel, unsigned char offset);
unsigned char ucControlTable[1024] __attribute__ ((aligned(1024)));
@@ -150,10 +151,18 @@ unsigned long framebuffer_read(void *data, unsigned long len){
}
void start_dma(void){
- ROM_SSIDMAEnable(SSI0_BASE, SSI_DMA_TX);
- ROM_SSIDMAEnable(SSI1_BASE, SSI_DMA_TX);
- ROM_SSIDMAEnable(SSI2_BASE, SSI_DMA_TX);
- ROM_SSIDMAEnable(SSI3_BASE, SSI_DMA_TX);
+}
+
+void ssi_udma_channel_config(unsigned char channel, unsigned char offset){
+ /* Set the USEBURST attribute for the uDMA SSI TX channel. This will force the controller to always use a burst
+ * when transferring data from the TX buffer to the SSI. This is somewhat more effecient bus usage than the default
+ * which allows single or burst transfers. */
+ ROM_uDMAChannelAttributeEnable(channel, UDMA_ATTR_USEBURST);
+ /* Configure the SSI Tx µDMA Channel to transfer from RAM to TX FIFO. The arbitration size is set to 4, which
+ * matches the SSI TX FIFO µDMA trigger threshold. */
+ ROM_uDMAChannelControlSet(channel, UDMA_SIZE_8 | UDMA_SRC_INC_8 | UDMA_DST_INC_NONE | UDMA_ARB_4);
+ ROM_uDMAChannelTransferSet(channel | UDMA_PRI_SELECT, UDMA_MODE_BASIC, framebuffer+BUS_SIZE*offset, (void *)(SSI0_BASE + SSI_O_DR), BUS_SIZE);
+ ROM_uDMAChannelEnable(channel);
}
int main(void){
@@ -231,35 +240,21 @@ int main(void){
ROM_IntEnable(INT_UDMAERR); // Enable µDMA error interrupt
ROM_uDMAEnable();
ROM_uDMAControlBaseSet(ucControlTable);
- //Put the µDMA attributes in a known state. These should already be disabled by default.
- ROM_uDMAChannelAttributeDisable(UDMA_CH11_SSI0TX, UDMA_ATTR_ALTSELECT | UDMA_ATTR_HIGH_PRIORITY | UDMA_ATTR_REQMASK);
- ROM_uDMAChannelAttributeDisable(UDMA_CH11_SSI1TX, UDMA_ATTR_ALTSELECT | UDMA_ATTR_HIGH_PRIORITY | UDMA_ATTR_REQMASK);
- ROM_uDMAChannelAttributeDisable(UDMA_CH13_SSI2TX, UDMA_ATTR_ALTSELECT | UDMA_ATTR_HIGH_PRIORITY | UDMA_ATTR_REQMASK);
- ROM_uDMAChannelAttributeDisable(UDMA_CH15_SSI3TX, UDMA_ATTR_ALTSELECT | UDMA_ATTR_HIGH_PRIORITY | UDMA_ATTR_REQMASK);
- /* Set the USEBURST attribute for the uDMA UART TX channel. This will force the controller to always use a burst
- * when transferring data from the TX buffer to the UART. This is somewhat more effecient bus usage than the
- * default which allows single or burst transfers. */
- ROM_uDMAChannelAttributeEnable(UDMA_CH11_SSI0TX, UDMA_ATTR_USEBURST);
- ROM_uDMAChannelAttributeEnable(UDMA_CH11_SSI1TX, UDMA_ATTR_USEBURST);
- ROM_uDMAChannelAttributeEnable(UDMA_CH13_SSI2TX, UDMA_ATTR_USEBURST);
- ROM_uDMAChannelAttributeEnable(UDMA_CH15_SSI3TX, UDMA_ATTR_USEBURST);
- /* Configure the SSI Tx µDMA Channel to transfer from RAM to TX FIFO. The arbitration size is set to 4, which
- * matches the SSI TX FIFO µDMA trigger threshold. */
- ROM_uDMAChannelControlSet(UDMA_CH11_SSI0TX, UDMA_SIZE_8 | UDMA_SRC_INC_8 | UDMA_DST_INC_NONE | UDMA_ARB_4);
- ROM_uDMAChannelTransferSet(UDMA_CH11_SSI0TX | UDMA_PRI_SELECT, UDMA_MODE_BASIC, framebuffer, (void *)(SSI0_BASE + SSI_O_DR), BUS_SIZE);
- ROM_uDMAChannelEnable(UDMA_CH11_SSI0TX);
-
- ROM_uDMAChannelControlSet(UDMA_CH11_SSI1TX, UDMA_SIZE_8 | UDMA_SRC_INC_8 | UDMA_DST_INC_NONE | UDMA_ARB_4);
- ROM_uDMAChannelTransferSet(UDMA_CH11_SSI1TX | UDMA_PRI_SELECT, UDMA_MODE_BASIC, framebuffer+BUS_SIZE, (void *)(SSI0_BASE + SSI_O_DR), BUS_SIZE);
- ROM_uDMAChannelEnable(UDMA_CH11_SSI1TX);
-
- ROM_uDMAChannelControlSet(UDMA_CH13_SSI2TX, UDMA_SIZE_8 | UDMA_SRC_INC_8 | UDMA_DST_INC_NONE | UDMA_ARB_4);
- ROM_uDMAChannelTransferSet(UDMA_CH13_SSI2TX | UDMA_PRI_SELECT, UDMA_MODE_BASIC, framebuffer+BUS_SIZE*2, (void *)(SSI0_BASE + SSI_O_DR), BUS_SIZE);
- ROM_uDMAChannelEnable(UDMA_CH13_SSI2TX);
+
+ ROM_uDMAChannelAssign(UDMA_CH11_SSI0TX);
+ ROM_uDMAChannelAssign(UDMA_CH25_SSI1TX);
+ ROM_uDMAChannelAssign(UDMA_CH13_SSI2TX);
+ ROM_uDMAChannelAssign(UDMA_CH15_SSI3TX);
+
+ ssi_udma_channel_config(11, 0);
+ ssi_udma_channel_config(25, 1);
+ ssi_udma_channel_config(13, 2);
+ ssi_udma_channel_config(15, 3);
- ROM_uDMAChannelControlSet(UDMA_CH15_SSI3TX, UDMA_SIZE_8 | UDMA_SRC_INC_8 | UDMA_DST_INC_NONE | UDMA_ARB_4);
- ROM_uDMAChannelTransferSet(UDMA_CH15_SSI3TX | UDMA_PRI_SELECT, UDMA_MODE_BASIC, framebuffer+BUS_SIZE*3, (void *)(SSI0_BASE + SSI_O_DR), BUS_SIZE);
- ROM_uDMAChannelEnable(UDMA_CH15_SSI3TX);
+ ROM_SSIDMAEnable(SSI0_BASE, SSI_DMA_TX);
+ ROM_SSIDMAEnable(SSI1_BASE, SSI_DMA_TX);
+ ROM_SSIDMAEnable(SSI2_BASE, SSI_DMA_TX);
+ ROM_SSIDMAEnable(SSI3_BASE, SSI_DMA_TX);
//Enable the SSIs after configuring anything around them.
SSIEnable(SSI0_BASE);