51 lines
1.6 KiB
C
51 lines
1.6 KiB
C
#include <string.h>
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#include <hardware/dma.h>
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static int dmacopy_channel = -1;
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// TODO: mutex this!
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void __noinline memcpy32(void *dst, void *src, uint32_t size) {
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dma_channel_config c;
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// Nothing to do!
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if(!size) return;
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// Cowardly avoid unaligned transfers, let memcpy() handle them.
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if((size & 0x3) || (((uint32_t)dst) & 0x3) || (((uint32_t)src) & 0x3)) {
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memcpy(dst, src, size);
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return;
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}
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// 32 bit transfers. Both read and write address increment after each
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// transfer (each pointing to a location in src or dst respectively).
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// No DREQ is selected, so the DMA transfers as fast as it can.
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// Get a free channel, panic() if there are none
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if(dmacopy_channel == -1)
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dmacopy_channel = dma_claim_unused_channel(true);
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c = dma_channel_get_default_config(dmacopy_channel);
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channel_config_set_transfer_data_size(&c, DMA_SIZE_32);
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channel_config_set_read_increment(&c, true);
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channel_config_set_write_increment(&c, true);
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dma_channel_configure(dmacopy_channel, &c, dst, src, (size >> 2), true);
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dma_channel_wait_for_finish_blocking(dmacopy_channel);
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dma_channel_abort(dmacopy_channel);
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// Deinit the DMA channel
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c = dma_channel_get_default_config(dmacopy_channel);
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dma_channel_configure(dmacopy_channel, &c, NULL, NULL, 0, false);
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channel_config_set_read_increment(&c, false);
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channel_config_set_write_increment(&c, false);
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}
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void __noinline dmacpy32(void *start, void *end, void *source) {
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uint32_t size = ((uint32_t)end) - ((uint32_t)start);
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memcpy32(start, source, size);
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}
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