/**************************************************************************** * arch/arm/src/sam3u-ek/sam3u_dmac.c * * Copyright (C) 2010 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * 3. Neither the name NuttX nor the names of its contributors may be * used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include #include #include #include #include "up_arch.h" #include "up_internal.h" #include "os_internal.h" #include "chip.h" #include "sam3u_internal.h" #include "sam3u_pmc.h" #include "sam3u_dmac.h" /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ /* Configuration ************************************************************/ /* Condition out the whole file unless DMA is selected in the configuration */ #ifdef CONFIG_SAM3U_DMA /* If AT90SAM3U support is enabled, then OS DMA support should also be enabled */ #ifndef CONFIG_ARCH_DMA # warning "ATSAM3U DMA enabled but CONFIG_ARCH_DMA disabled" #endif /* Check the number of link list descriptors to allocate */ #ifndef CONFIG_SAM3U_NLLDESC # define CONFIG_SAM3U_NLLDESC CONFIG_SAM3U_NDMACHAN #endif #if CONFIG_SAM3U_NLLDESC < CONFIG_SAM3U_NDMACHAN # warning "At least CONFIG_SAM3U_NDMACHAN descriptors must be allocated" # undef CONFIG_SAM3U_NLLDESC # define CONFIG_SAM3U_NLLDESC CONFIG_SAM3U_NDMACHAN #endif /* Register values **********************************************************/ #define DMACHAN_CTRLB_BOTHDSCR \ (DMACHAN_CTRLB_SRCDSCR | DMACHAN_CTRLB_DSTDSCR) /**************************************************************************** * Private Types ****************************************************************************/ /* This structure descibes one DMA channel */ struct sam3u_dma_s { uint8_t chan; /* DMA channel number (0-6) */ bool inuse; /* TRUE: The DMA channel is in use */ uint32_t flags; /* DMA channel flags */ uint32_t base; /* DMA register channel base address */ uint32_t cfg; /* Pre-calculated CFG register for transfer */ dma_callback_t callback; /* Callback invoked when the DMA completes */ void *arg; /* Argument passed to callback function */ struct dma_linklist_s *llhead; /* DMA link list head */ struct dma_linklist_s *lltail; /* DMA link list head */ }; /**************************************************************************** * Private Data ****************************************************************************/ /* These semaphores protect the DMA channel and descriptor tables */ static sem_t g_chsem; static sem_t g_dsem; /* CTRLA field lookups */ static const uint32_t g_srcwidth[3] = { DMACHAN_CTRLA_SRCWIDTH_BYTE, DMACHAN_CTRLA_SRCWIDTH_HWORD, DMACHAN_CTRLA_SRCWIDTH_WORD }; static const uint32_t g_destwidth[3] = { DMACHAN_CTRLA_DSTWIDTH_BYTE, DMACHAN_CTRLA_DSTWIDTH_HWORD, DMACHAN_CTRLA_DSTWIDTH_WORD }; static const uint32_t g_fifocfg[3] = { DMACHAN_CFG_FIFOCFG_LARGEST, DMACHAN_CFG_FIFOCFG_HALF, DMACHAN_CFG_FIFOCFG_SINGLE }; /* This array describes the available link list descriptors */ static struct dma_linklist_s g_linklist[CONFIG_SAM3U_NLLDESC]; /* This array describes the state of each DMA */ static struct sam3u_dma_s g_dma[CONFIG_SAM3U_NDMACHAN] = { #ifdef CONFIG_ARCH_CHIP_AT91SAM3U4E /* the AT91SAM3U4E has four DMA channels. The FIFOs for channels 0-2 are * 8 bytes in size; channel 3 is 32 bytes. */ #if CONFIG_SAM3U_NDMACHAN != 4 # error "Logic here assumes CONFIG_SAM3U_NDMACHAN is 4" #endif { .chan = 0, .flags = DMACH_FLAG_FIFO_8BYTES, .base = SAM3U_DMACHAN0_BASE, }, { .chan = 1, .flags = DMACH_FLAG_FIFO_8BYTES, .base = SAM3U_DMACHAN1_BASE, }, { .chan = 2, .flags = DMACH_FLAG_FIFO_8BYTES, .base = SAM3U_DMACHAN2_BASE, }, { .chan = 3, .flags = (DMACH_FLAG_FIFO_32BYTES | DMACH_FLAG_FLOWCONTROL), .base = SAM3U_DMACHAN3_BASE, } #else # error "Nothing is known about the DMA channels for this device" #endif }; /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: sam3u_takechsem() and sam3u_givechsem() * * Description: * Used to get exclusive access to the DMA channel table * ****************************************************************************/ static void sam3u_takechsem(void) { /* Take the semaphore (perhaps waiting) */ while (sem_wait(&g_chsem) != 0) { /* The only case that an error should occur here is if the wait was * awakened by a signal. */ ASSERT(errno == EINTR); } } static inline void sam3u_givechsem(void) { (void)sem_post(&g_chsem); } /**************************************************************************** * Name: sam3u_takedsem() and sam3u_givedsem() * * Description: * Used to wait for availability of descriptors in the descriptor table. * ****************************************************************************/ static void sam3u_takedsem(void) { /* Take the semaphore (perhaps waiting) */ while (sem_wait(&g_dsem) != 0) { /* The only case that an error should occur here is if the wait was * awakened by a signal. */ ASSERT(errno == EINTR); } } static inline void sam3u_givedsem(void) { (void)sem_post(&g_dsem); } /**************************************************************************** * Name: sam3u_fifosize * * Description: * Decode the FIFO size from the flags * ****************************************************************************/ static unsigned int sam3u_fifosize(uint8_t dmach_flags) { dmach_flags &= DMACH_FLAG_FIFOSIZE_MASK; if (dmach_flags == DMACH_FLAG_FIFO_8BYTES) { return 8; } else /* if (dmach_flags == DMACH_FLAG_FIFO_32BYTES) */ { return 32; } } /**************************************************************************** * Name: sam3u_flowcontrol * * Description: * Decode the FIFO flow control from the flags * ****************************************************************************/ static inline bool sam3u_flowcontrol(uint8_t dmach_flags) { return ((dmach_flags & DMACH_FLAG_FLOWCONTROL) != 0); } /**************************************************************************** * Name: sam3u_fifocfg * * Description: * Decode the FIFO config from the flags * ****************************************************************************/ static inline uint32_t sam3u_fifocfg(struct sam3u_dma_s *dmach) { unsigned int ndx = (dmach->flags & DMACH_FLAG_FIFOCFG_MASK) >> DMACH_FLAG_FIFOCFG_SHIFT; DEBUGASSERT(ndx < 3); return g_fifocfg[ndx]; } /**************************************************************************** * Name: sam3u_txcfg * * Description: * Decode the the flags to get the correct CFG register bit settings for * a transmit (memory to peripheral) transfer. * ****************************************************************************/ static inline uint32_t sam3u_txcfg(struct sam3u_dma_s *dmach) { uint32_t regval; /* Set transfer (memory to peripheral) DMA channel configuration register */ regval = (((dmach->flags & DMACH_FLAG_MEMPID_MASK) >> DMACH_FLAG_MEMPID_SHIFT) << DMACHAN_CFG_SRCPER_SHIFT); regval |= (dmach->flags & DMACH_FLAG_MEMH2SEL) != 0 ? DMACHAN_CFG_SRCH2SEL : 0; regval |= (((dmach->flags & DMACH_FLAG_PERIPHPID_MASK) >> DMACH_FLAG_PERIPHPID_SHIFT) << DMACHAN_CFG_DSTPER_SHIFT); regval |= (dmach->flags & DMACH_FLAG_PERIPHH2SEL) != 0 ? DMACHAN_CFG_DSTH2SEL : 0; regval |= sam3u_fifocfg(dmach); return regval; } /**************************************************************************** * Name: sam3u_rxcfg * * Description: * Decode the the flags to get the correct CFG register bit settings for * a receive (peripheral to memory) transfer. * ****************************************************************************/ static inline uint32_t sam3u_rxcfg(struct sam3u_dma_s *dmach) { uint32_t regval; /* Set received (peripheral to memory) DMA channel config */ regval = (((dmach->flags & DMACH_FLAG_PERIPHPID_MASK) >> DMACH_FLAG_PERIPHPID_SHIFT) << DMACHAN_CFG_SRCPER_SHIFT); regval |= (dmach->flags & DMACH_FLAG_PERIPHH2SEL) != 0 ? DMACHAN_CFG_SRCH2SEL : 0; regval |= (((dmach->flags & DMACH_FLAG_MEMPID_MASK) >> DMACH_FLAG_MEMPID_SHIFT) << DMACHAN_CFG_DSTPER_SHIFT); regval |= (dmach->flags & DMACH_FLAG_MEMH2SEL) != 0 ? DMACHAN_CFG_DSTH2SEL : 0; regval |= sam3u_fifocfg(dmach); return regval; } /**************************************************************************** * Name: sam3u_txctrlabits * * Description: * Decode the the flags to get the correct CTRLA register bit settings for * a transmit (memory to peripheral) transfer. These are only the "fixed" * CTRLA values and need to be updated with the actual transfer size before * being written to CTRLA sam3u_txctrla). * ****************************************************************************/ static inline uint32_t sam3u_txctrlabits(struct sam3u_dma_s *dmach) { uint32_t regval; unsigned int ndx; DEBUGASSERT(dmach); /* Since this is a transmit, the source is described by the memory selections. * Set the source width (memory width). */ ndx = (dmach->flags & DMACH_FLAG_MEMWIDTH_MASK) >> DMACH_FLAG_MEMWIDTH_SHIFT; DEBUGASSERT(ndx < 3); regval = g_srcwidth[ndx]; /* Set the source chuck size (memory chunk size) */ if ((dmach->flags & DMACH_FLAG_MEMCHUNKSIZE) == DMACH_FLAG_MEMCHUNKSIZE_4) { regval |= DMACHAN_CTRLA_SCSIZE_4; } #if 0 /* DMACHAN_CTRLA_SCSIZE_1 is zero */ else { regval |= DMACHAN_CTRLA_SCSIZE_1; } #endif /* Since this is a transmit, the destination is described by the peripheral selections. * Set the destination width (peripheral width). */ ndx = (dmach->flags & DMACH_FLAG_PERIPHWIDTH_MASK) >> DMACH_FLAG_PERIPHWIDTH_SHIFT; DEBUGASSERT(ndx < 3); regval |= g_destwidth[ndx]; /* Set the destination chuck size (peripheral chunk size) */ if ((dmach->flags & DMACH_FLAG_PERIPHCHUNKSIZE) == DMACH_FLAG_PERIPHCHUNKSIZE_4) { regval |= DMACHAN_CTRLA_DCSIZE_4; } #if 0 /* DMACHAN_CTRLA_DCSIZE_1 is zero */ else { regval |= DMACHAN_CTRLA_DCSIZE_1; } #endif return regval; } /**************************************************************************** * Name: sam3u_txctrla * * Description: * Or in the variable CTRLA bits * ****************************************************************************/ static inline uint32_t sam3u_txctrla(struct sam3u_dma_s *dmach, uint32_t dmasize, uint32_t txctrlabits) { /* Set the buffer transfer size field. This is the number of transfers to * be performed, that is, the number of source width transfers to perform. */ /* Adjust the the source transfer size for the source chunk size (memory * chunk size) */ if ((dmach->flags & DMACH_FLAG_MEMCHUNKSIZE) == DMACH_FLAG_MEMCHUNKSIZE_4) { dmasize >>= 2; } DEBUGASSERT(dmasize <= DMACHAN_CTRLA_BTSIZE_MAX); return (txctrlabits & ~DMACHAN_CTRLA_BTSIZE_MASK) | (dmasize << DMACHAN_CTRLA_BTSIZE_SHIFT); } /**************************************************************************** * Name: sam3u_rxctrlabits * * Description: * Decode the the flags to get the correct CTRLA register bit settings for * a read (peripheral to memory) transfer. These are only the "fixed" CTRLA * values and need to be updated with the actual transfer size before being * written to CTRLA sam3u_rxctrla). * ****************************************************************************/ static inline uint32_t sam3u_rxctrlabits(struct sam3u_dma_s *dmach) { uint32_t regval; unsigned int ndx; DEBUGASSERT(dmach); /* Since this is a receive, the source is described by the peripheral * selections. Set the source width (peripheral width). */ ndx = (dmach->flags & DMACH_FLAG_PERIPHWIDTH_MASK) >> DMACH_FLAG_PERIPHWIDTH_SHIFT; DEBUGASSERT(ndx < 3); regval = g_srcwidth[ndx]; /* Set the source chuck size (peripheral chunk size) */ if ((dmach->flags & DMACH_FLAG_PERIPHCHUNKSIZE) == DMACH_FLAG_PERIPHCHUNKSIZE_4) { regval |= DMACHAN_CTRLA_SCSIZE_4; } #if 0 /* DMACHAN_CTRLA_SCSIZE_1 is zero */ else { regval |= DMACHAN_CTRLA_SCSIZE_1; } #endif /* Since this is a receive, the destination is described by the memory selections. * Set the destination width (memory width). */ ndx = (dmach->flags & DMACH_FLAG_MEMWIDTH_MASK) >> DMACH_FLAG_MEMWIDTH_SHIFT; DEBUGASSERT(ndx < 3); regval |= g_destwidth[ndx]; /* Set the destination chuck size (memory chunk size) */ if ((dmach->flags & DMACH_FLAG_MEMCHUNKSIZE) == DMACH_FLAG_MEMCHUNKSIZE_4) { regval |= DMACHAN_CTRLA_DCSIZE_4; } #if 0 /* DMACHAN_CTRLA_DCSIZE_1 is zero */ else { regval |= DMACHAN_CTRLA_DCSIZE_1; } #endif return regval; } /**************************************************************************** * Name: sam3u_rxctrla * * Description: * 'OR' in the variable CTRLA bits * ****************************************************************************/ static inline uint32_t sam3u_rxctrla(struct sam3u_dma_s *dmach, uint32_t dmasize, uint32_t txctrlabits) { /* Set the buffer transfer size field. This is the number of transfers to * be performed, that is, the number of source width transfers to perform. */ /* Adjust the the source transfer size for the source chunk size (peripheral * chunk size) */ if ((dmach->flags & DMACH_FLAG_PERIPHCHUNKSIZE) == DMACH_FLAG_PERIPHCHUNKSIZE_4) { dmasize >>= 2; } DEBUGASSERT(dmasize <= DMACHAN_CTRLA_BTSIZE_MAX); return (txctrlabits & ~DMACHAN_CTRLA_BTSIZE_MASK) | (dmasize << DMACHAN_CTRLA_BTSIZE_SHIFT); } /**************************************************************************** * Name: sam3u_txctrlb * * Description: * Decode the the flags to get the correct CTRLB register bit settings for * a transmit (memory to peripheral) transfer. * ****************************************************************************/ static inline uint32_t sam3u_txctrlb(struct sam3u_dma_s *dmach) { uint32_t regval; /* Assume that we will not be using the link list and disable the source * and destination descriptors. The default will be single transfer mode. */ regval = DMACHAN_CTRLB_BOTHDSCR; /* Select flow control (even if the channel doesn't support it). The * naming convention from TX is memory to peripheral, but that is really be * determined by bits in the DMA flags. */ /* Is the memory source really a peripheral? */ if ((dmach->flags & DMACH_FLAG_MEMISPERIPH) != 0) { /* Yes.. is the peripheral destination also a peripheral? */ if ((dmach->flags & DMACH_FLAG_PERIPHISPERIPH) != 0) { /* Yes.. Use peripheral-to-peripheral flow control */ regval |= DMACHAN_CTRLB_FC_P2P; } else { /* No.. Use peripheral-to-memory flow control */ regval |= DMACHAN_CTRLB_FC_P2M; } } else { /* No, the source is memory. Is the peripheral destination a * peripheral */ if ((dmach->flags & DMACH_FLAG_PERIPHISPERIPH) != 0) { /* Yes.. Use memory-to-peripheral flow control */ regval |= DMACHAN_CTRLB_FC_M2P; } else { /* No.. Use memory-to-memory flow control */ regval |= DMACHAN_CTRLB_FC_M2M; } } /* Select source address incrementing */ if ((dmach->flags & DMACH_FLAG_MEMINCREMENT) == 0) { regval |= DMACHAN_CTRLB_SRCINCR_FIXED; } /* Select destination address incrementing */ if ((dmach->flags & DMACH_FLAG_PERIPHINCREMENT) == 0) { regval |= DMACHAN_CTRLB_DSTINCR_FIXED; } return regval; } /**************************************************************************** * Name: sam3u_rxctrlb * * Description: * Decode the the flags to get the correct CTRLB register bit settings for * a receive (peripheral to memory) transfer. * ****************************************************************************/ static inline uint32_t sam3u_rxctrlb(struct sam3u_dma_s *dmach) { uint32_t regval; /* Assume that we will not be using the link list and disable the source and * destination descriptors. The default will be single transfer mode. */ regval = DMACHAN_CTRLB_BOTHDSCR; /* Select flow control (even if the channel doesn't support it). The * naming convention from RX is peripheral to memory, but that is really be * determined by bits in the DMA flags. */ /* Is the peripheral source really a peripheral? */ if ((dmach->flags & DMACH_FLAG_PERIPHISPERIPH) != 0) { /* Yes.. is the memory destination also a peripheral? */ if ((dmach->flags & DMACH_FLAG_MEMISPERIPH) != 0) { /* Yes.. Use peripheral-to-peripheral flow control */ regval |= DMACHAN_CTRLB_FC_P2P; } else { /* No.. Use peripheral-to-memory flow control */ regval |= DMACHAN_CTRLB_FC_P2M; } } else { /* No, the peripheral source is memory. Is the memory destination * a peripheral */ if ((dmach->flags & DMACH_FLAG_MEMISPERIPH) != 0) { /* Yes.. Use memory-to-peripheral flow control */ regval |= DMACHAN_CTRLB_FC_M2P; } else { /* No.. Use memory-to-memory flow control */ regval |= DMACHAN_CTRLB_FC_M2M; } } /* Select source address incrementing */ if ((dmach->flags & DMACH_FLAG_PERIPHINCREMENT) == 0) { regval |= DMACHAN_CTRLB_SRCINCR_FIXED; } /* Select address incrementing */ if ((dmach->flags & DMACH_FLAG_MEMINCREMENT) == 0) { regval |= DMACHAN_CTRLB_DSTINCR_FIXED; } return regval; } /**************************************************************************** * Name: sam3u_allocdesc * * Description: * Allocate and add one descriptor to the DMA channel's link list. * * NOTE: link list entries are freed by the DMA interrupt handler. However, * since the setting/clearing of the 'in use' indication is atomic, no * special actions need be performed. It would be a good thing to add logic * to handle the case where all of the entries are exhausted and we could * wait for some to be freed by the interrupt handler. * ****************************************************************************/ static struct dma_linklist_s * sam3u_allocdesc(struct sam3u_dma_s *dmach, struct dma_linklist_s *prev, uint32_t src, uint32_t dest, uint32_t ctrla, uint32_t ctrlb) { struct dma_linklist_s *desc = NULL; int i; /* Sanity check -- src == 0 is the indication that the link is unused. * Obviously setting it to zero would break that usage. */ #ifdef CONFIG_DEBUG if (src != 0) #endif { /* Table a descriptor table semaphore count. When we get one, then there * is at least one free descriptor in the table and it is ours. */ sam3u_takedsem(); /* Examine each link list entry to find an available one -- i.e., one * with src == 0. That src field is set to zero by the DMA transfer * complete interrupt handler. The following should be safe because * that is an atomic operation. */ sam3u_takechsem(); for (i = 0; i < CONFIG_SAM3U_NLLDESC; i++) { if (g_linklist[i].src == 0) { /* We have it. Initialize the new link list entry */ desc = &g_linklist[i]; desc->src = src; /* Source address */ desc->dest = dest; /* Destination address */ desc->ctrla = ctrla; /* Control A value */ desc->ctrlb = ctrlb; /* Control B value */ desc->next = 0; /* Next descriptor address */ /* And then hook it at the tail of the link list */ if (!prev) { /* There is no previous link. This is the new head of * the list */ DEBUGASSERT(dmach->llhead == NULL && dmach->lltail == NULL); dmach->llhead = desc; } else { DEBUGASSERT(dmach->llhead != NULL && dmach->lltail == prev); /* When the second link is added to the list, that is the * cue that we are going to do the link list transfer. * * Enable the source and destination descriptor in the link * list entry just before this one. We assume that both * source and destination buffers are non-continuous, but * this should work even if that is not the case. */ prev->ctrlb &= ~DMACHAN_CTRLB_BOTHDSCR; /* Link the previous tail to the new tail */ prev->next = (uint32_t)desc; } /* In any event, this is the new tail of the list. The source * and destination descriptors must be disabled for the last entry * in the link list. */ desc->ctrlb |= DMACHAN_CTRLB_BOTHDSCR; dmach->lltail = desc; break; } } /* Because we hold a count from the counting semaphore, the above * search loop should always be successful. */ sam3u_givechsem(); DEBUGASSERT(desc != NULL); } return desc; } /**************************************************************************** * Name: sam3u_freelinklist * * Description: * Free all descriptors in the DMA channel's link list. * * NOTE: Called from the DMA interrupt handler. * ****************************************************************************/ static void sam3u_freelinklist(struct sam3u_dma_s *dmach) { struct dma_linklist_s *desc; struct dma_linklist_s *next; /* Get the head of the link list and detach the link list from the DMA * channel */ desc = dmach->llhead; dmach->llhead = NULL; dmach->lltail = NULL; /* Reset each descriptor in the link list (thereby freeing them) */ while (desc != NULL) { next = (struct dma_linklist_s *)desc->next; DEBUGASSERT(desc->src != 0); memset(desc, 0, sizeof(struct dma_linklist_s)); sam3u_givedsem(); desc = next; } } /**************************************************************************** * Name: sam3u_txbuffer * * Description: * Configure DMA for transmit of one buffer (memory to peripheral). This * function may be called multiple times to handle large and/or dis- * continuous transfers. * ****************************************************************************/ static int sam3u_txbuffer(struct sam3u_dma_s *dmach, uint32_t paddr, uint32_t maddr, size_t nbytes) { uint32_t regval; uint32_t ctrla; uint32_t ctrlb; /* If we are appending a buffer to a linklist, then re-use the CTRLA/B * values. Otherwise, create them from the properties of the transfer. */ if (dmach->llhead) { regval = dmach->llhead->ctrla; ctrlb = dmach->llhead->ctrlb; } else { regval = sam3u_txctrlabits(dmach); ctrlb = sam3u_txctrlb(dmach); } ctrla = sam3u_txctrla(dmach, regval, nbytes); /* Add the new link list entry */ if (!sam3u_allocdesc(dmach, dmach->lltail, maddr, paddr, ctrla, ctrlb)) { return -ENOMEM; } /* Pre-calculate the transmit CFG register setting (it won't be used until * the DMA is started). */ dmach->cfg = sam3u_txcfg(dmach); return OK; } /**************************************************************************** * Name: sam3u_rxbuffer * * Description: * Configure DMA for receipt of one buffer (peripheral to memory). This * function may be called multiple times to handle large and/or dis- * continuous transfers. * ****************************************************************************/ static int sam3u_rxbuffer(struct sam3u_dma_s *dmach, uint32_t paddr, uint32_t maddr, size_t nbytes) { uint32_t regval; uint32_t ctrla; uint32_t ctrlb; /* If we are appending a buffer to a linklist, then re-use the CTRLA/B * values. Otherwise, create them from the properties of the transfer. */ if (dmach->llhead) { regval = dmach->llhead->ctrla; ctrlb = dmach->llhead->ctrlb; } else { regval = sam3u_rxctrlabits(dmach); ctrlb = sam3u_rxctrlb(dmach); } ctrla = sam3u_rxctrla(dmach, regval, nbytes); /* Add the new link list entry */ if (!sam3u_allocdesc(dmach, dmach->lltail, paddr, maddr, ctrla, ctrlb)) { return -ENOMEM; } /* Pre-calculate the receive CFG register setting (it won't be used until * the DMA is started). */ dmach->cfg = sam3u_rxcfg(dmach); return OK; } /**************************************************************************** * Name: sam3u_single * * Description: * Start a single buffer DMA. * ****************************************************************************/ static inline int sam3u_single(struct sam3u_dma_s *dmach) { struct dma_linklist_s *llhead = dmach->llhead; /* Clear any pending interrupts from any previous DMAC transfer by reading * the interrupt status register. */ (void)getreg32(SAM3U_DMAC_EBCISR); /* Write the starting source address in the SADDR register */ DEBUGASSERT(llhead != NULL && llhead->src != 0); putreg32(llhead->src, dmach->base + SAM3U_DMACHAN_SADDR_OFFSET); /* Write the starting destination address in the DADDR register */ putreg32(llhead->dest, dmach->base + SAM3U_DMACHAN_DADDR_OFFSET); /* Set up the CTRLA register */ putreg32(llhead->ctrla, dmach->base + SAM3U_DMACHAN_CTRLA_OFFSET); /* Set up the CTRLB register */ putreg32(llhead->ctrlb, dmach->base + SAM3U_DMACHAN_CTRLA_OFFSET); /* Both the DST and SRC DSCR bits should be '1' in CTRLB */ DEBUGASSERT((llhead->ctrlb & DMACHAN_CTRLB_BOTHDSCR) == DMACHAN_CTRLB_BOTHDSCR); /* Set up the CFG register */ putreg32(dmach->cfg, dmach->base + SAM3U_DMACHAN_CFG_OFFSET); /* Enable the channel by writing a ‘1’ to the CHER enable bit */ putreg32(DMAC_CHER_ENA(dmach->chan), SAM3U_DMAC_CHER); /* The DMA has been started. Once the transfer completes, hardware sets the * interrupts and disables the channel. We will received buffer complete and * transfer complete interrupts. * * Enable error, buffer complete and transfer complete interrupts. * (Since there is only a single buffer, we don't need the buffer complete * interrupt). */ putreg32(DMAC_EBC_CBTCINTS(dmach->chan), SAM3U_DMAC_EBCIER); return OK; } /**************************************************************************** * Name: sam3u_multiple * * Description: * Start a multiple buffer DMA. * ****************************************************************************/ static inline int sam3u_multiple(struct sam3u_dma_s *dmach) { struct dma_linklist_s *llhead = dmach->llhead; DEBUGASSERT(llhead != NULL && llhead->src != 0); /* Check the first and last CTRLB values */ DEBUGASSERT((llhead->ctrlb & DMACHAN_CTRLB_BOTHDSCR) == 0); DEBUGASSERT((dmach->lltail->ctrlb & DMACHAN_CTRLB_BOTHDSCR) == DMACHAN_CTRLB_BOTHDSCR); /* Clear any pending interrupts from any previous DMAC transfer by reading the * status register */ (void)getreg32(SAM3U_DMAC_EBCISR); /* Set up the initial CTRLB register (to enable descriptors) */ putreg32(llhead->ctrlb, dmach->base + SAM3U_DMACHAN_CTRLA_OFFSET); /* Set up the CTRLB register */ putreg32(llhead->ctrlb, dmach->base + SAM3U_DMACHAN_CTRLA_OFFSET); /* Write the channel configuration information into the CFG register */ putreg32(dmach->cfg, dmach->base + SAM3U_DMACHAN_CFG_OFFSET); /* Program the DSCR register with the pointer to the firstlink list entry. */ putreg32((uint32_t)llhead, dmach->base + SAM3U_DMACHAN_DSCR_OFFSET); /* Finally, enable the channel by writing a ‘1’ to the CHER enable */ putreg32(DMAC_CHER_ENA(dmach->chan), SAM3U_DMAC_CHER); /* As each buffer of data is transferred, the CTRLA register is written back * into the link list entry. The CTRLA contains updated BTSIZE and DONE bits. * Additionally, the CTRLA DONE bit is asserted when the buffer transfer has completed. * * The DMAC transfer continues until the CTRLB register disables the descriptor * (DSCR bits) registers at the final buffer tranfer. * * Enable error, buffer complete and transfer complete interrupts. We * don't really need the buffer complete interrupts, but we will take them * just to handle stall conditions. */ putreg32(DMAC_EBC_CHANINTS(dmach->chan), SAM3U_DMAC_EBCIER); return OK; } /**************************************************************************** * Name: sam3u_dmasterminate * * Description: * Terminate the DMA transfer and disable the DMA channel * ****************************************************************************/ static void sam3u_dmaterminate(struct sam3u_dma_s *dmach, int result) { /* Disable all channel interrupts */ putreg32(DMAC_EBC_CHANINTS(dmach->chan), SAM3U_DMAC_EBCIDR); /* Disable the channel by writing one to the write-only channel disable register */ putreg32(DMAC_CHDR_DIS(dmach->chan), SAM3U_DMAC_CHDR); /* Free the linklist */ sam3u_freelinklist(dmach); /* Perform the DMA complete callback */ if (dmach->callback) { dmach->callback((DMA_HANDLE)dmach, dmach->arg, result); } dmach->callback = NULL; dmach->arg = NULL; } /**************************************************************************** * Name: sam3u_dmainterrupt * * Description: * DMA interrupt handler * ****************************************************************************/ static int sam3u_dmainterrupt(int irq, void *context) { struct sam3u_dma_s *dmach; unsigned int chndx; uint32_t regval; /* Get the DMAC status register value. Ignore all masked interrupt * status bits. */ regval = getreg32(SAM3U_DMAC_EBCISR) & getreg32(SAM3U_DMAC_EBCIMR); /* Check if the any transfer has completed */ if (regval & DMAC_EBC_BTC_MASK) { /* Yes.. Check each bit to see which channel has interrupted */ for (chndx = 0; chndx < CONFIG_SAM3U_NDMACHAN; chndx++) { /* Are any interrupts pending for this channel? */ if ((regval & DMAC_EBC_CHANINTS(chndx)) != 0) { dmach = &g_dma[chndx]; /* Yes.. Did an error occur? */ if ((regval & DMAC_EBC_ERR(chndx)) != 0) { /* Yes... Terminate the transfer with an error? */ sam3u_dmaterminate(dmach, -EIO); } /* Is the transfer complete? */ else if ((regval & DMAC_EBC_CBTC(chndx)) != 0) { /* Yes.. Terminate the transfer with success */ sam3u_dmaterminate(dmach, OK); } /* Otherwise, this must be a Bufffer Transfer Complete (BTC) * interrupt as part of a multiple buffer transfer. */ else /* f ((regval & DMAC_EBC_BTC(chndx)) != 0) */ { /* Write the KEEPON field to clear the STALL states */ putreg32(DMAC_CHER_KEEP(dmach->chan), SAM3U_DMAC_CHER); } } } } return OK; } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: sam3u_dmainitialize * * Description: * Initialize the DMA subsystem * * Returned Value: * None * ****************************************************************************/ void weak_function up_dmainitialize(void) { /* Enable peripheral clock */ putreg32((1 << SAM3U_PID_DMAC), SAM3U_PMC_PCER); /* Disable all DMA interrupts */ putreg32(DMAC_EBC_ALLINTS, SAM3U_DMAC_EBCIDR); /* Disable all DMA channels */ putreg32(DMAC_CHDR_DIS_ALL, SAM3U_DMAC_CHDR); /* Attach DMA interrupt vector */ (void)irq_attach(SAM3U_IRQ_DMAC, sam3u_dmainterrupt); /* Enable the IRQ at the NVIC (still disabled at the DMA controller) */ up_enable_irq(SAM3U_IRQ_DMAC); /* Enable the DMA controller */ putreg32(DMAC_EN_ENABLE, SAM3U_DMAC_EN); /* Initialize semaphores */ sem_init(&g_chsem, 0, 1); sem_init(&g_chsem, 0, CONFIG_SAM3U_NDMACHAN); } /**************************************************************************** * Name: sam3u_dmachannel * * Description: * Allocate a DMA channel. This function sets aside a DMA channel with * the required FIFO size and flow control capabilities (determined by * dma_flags) then gives the caller exclusive access to the DMA channel. * * The naming convention in all of the DMA interfaces is that one side is * the 'peripheral' and the other is 'memory'. Howerver, the interface * could still be used if, for example, both sides were memory although * the naming would be awkward. * * Returned Value: * If a DMA channel if the required FIFO size is available, this function * returns a non-NULL, void* DMA channel handle. NULL is returned on any * failure. * ****************************************************************************/ DMA_HANDLE sam3u_dmachannel(uint32_t dmach_flags) { struct sam3u_dma_s *dmach; unsigned int chndx; /* Get the search parameters */ bool flowcontrol = sam3u_flowcontrol(dmach_flags); unsigned int fifosize = sam3u_fifosize(dmach_flags); /* Search for an available DMA channel with at least the requested FIFO * size. */ dmach = NULL; sam3u_takechsem(); for (chndx = 0; chndx < CONFIG_SAM3U_NDMACHAN; chndx++) { struct sam3u_dma_s *candidate = &g_dma[chndx]; if (!candidate->inuse && (sam3u_fifosize(candidate->flags) >= fifosize) && (!flowcontrol || sam3u_flowcontrol(dmach_flags))) { dmach = candidate; dmach->inuse = true; /* Read the status register to clear any pending interrupts on the * channel */ (void)getreg32(SAM3U_DMAC_EBCISR); /* Disable the channel by writing one to the write-only channel * disable register */ putreg32(DMAC_CHDR_DIS(chndx), SAM3U_DMAC_CHDR); /* See the DMA channel flags, retaining the fifo size and flow * control settings which are inherent properties of the FIFO * and cannot be changed. */ dmach->flags &= (DMACH_FLAG_FLOWCONTROL | DMACH_FLAG_FIFOSIZE_MASK); dmach->flags |= (dmach_flags & ~((DMACH_FLAG_FLOWCONTROL | DMACH_FLAG_FIFOSIZE_MASK))); break; } } sam3u_givechsem(); return (DMA_HANDLE)dmach; } /**************************************************************************** * Name: sam3u_dmafree * * Description: * Release a DMA channel. NOTE: The 'handle' used in this argument must * NEVER be used again until sam3u_dmachannel() is called again to re-gain * a valid handle. * * Returned Value: * None * ****************************************************************************/ void sam3u_dmafree(DMA_HANDLE handle) { struct sam3u_dma_s *dmach = (struct sam3u_dma_s *)handle; /* Mark the channel no longer in use. Clearing the inuse flag is an atomic * operation and so should be safe. */ DEBUGASSERT((dmach != NULL) && (dmach->inuse)); dmach->flags &= (DMACH_FLAG_FLOWCONTROL | DMACH_FLAG_FIFOSIZE_MASK); dmach->inuse = false; /* No longer in use */ } /**************************************************************************** * Name: sam3u_dmatxsetup * * Description: * Configure DMA for transmit of one buffer (memory to peripheral). This * function may be called multiple times to handle large and/or dis- * continuous transfers. Calls to sam3u_dmatxsetup() and sam3u_dmarxsetup() * must not be intermixed on the same transfer, however. * ****************************************************************************/ int sam3u_dmatxsetup(DMA_HANDLE handle, uint32_t paddr, uint32_t maddr, size_t nbytes) { struct sam3u_dma_s *dmach = (struct sam3u_dma_s *)handle; int ret = OK; DEBUGASSERT(dmach && dmach->llhead != NULL && dmach->lltail != 0); /* If this is a large transfer, break it up into smaller buffers */ while (nbytes > DMACHAN_CTRLA_BTSIZE_MAX) { /* Set up the maximum size transfer */ ret = sam3u_txbuffer(dmach, paddr, maddr, DMACHAN_CTRLA_BTSIZE_MAX); if (ret == OK); { /* Decrement the number of bytes left to transfer */ nbytes -= DMACHAN_CTRLA_BTSIZE_MAX; /* Increment the memory & peripheral address (if it is appropriate to * do do). */ if ((dmach->flags & DMACH_FLAG_PERIPHINCREMENT) != 0) { paddr += DMACHAN_CTRLA_BTSIZE_MAX; } if ((dmach->flags & DMACH_FLAG_MEMINCREMENT) != 0) { maddr += DMACHAN_CTRLA_BTSIZE_MAX; } } } /* Then set up the final buffer transfer */ if (ret == OK && nbytes > 0) { ret = sam3u_txbuffer(dmach, paddr, maddr, nbytes); } return ret; } /**************************************************************************** * Name: sam3u_dmarxsetup * * Description: * Configure DMA for receipt of one buffer (peripheral to memory). This * function may be called multiple times to handle large and/or dis- * continuous transfers. Calls to sam3u_dmatxsetup() and sam3u_dmarxsetup() * must not be intermixed on the same transfer, however. * ****************************************************************************/ int sam3u_dmarxsetup(DMA_HANDLE handle, uint32_t paddr, uint32_t maddr, size_t nbytes) { struct sam3u_dma_s *dmach = (struct sam3u_dma_s *)handle; int ret = OK; DEBUGASSERT(dmach && dmach->llhead != NULL && dmach->lltail != 0); /* If this is a large transfer, break it up into smaller buffers */ while (nbytes > DMACHAN_CTRLA_BTSIZE_MAX) { /* Set up the maximum size transfer */ ret = sam3u_rxbuffer(dmach, paddr, maddr, DMACHAN_CTRLA_BTSIZE_MAX); if (ret == OK); { /* Decrement the number of bytes left to transfer */ nbytes -= DMACHAN_CTRLA_BTSIZE_MAX; /* Increment the memory & peripheral address (if it is appropriate to * do do). */ if ((dmach->flags & DMACH_FLAG_PERIPHINCREMENT) != 0) { paddr += DMACHAN_CTRLA_BTSIZE_MAX; } if ((dmach->flags & DMACH_FLAG_MEMINCREMENT) != 0) { maddr += DMACHAN_CTRLA_BTSIZE_MAX; } } } /* Then set up the final buffer transfer */ if (ret == OK && nbytes > 0) { ret = sam3u_rxbuffer(dmach, paddr, maddr, nbytes); } return ret; } /**************************************************************************** * Name: sam3u_dmastart * * Description: * Start the DMA transfer * ****************************************************************************/ int sam3u_dmastart(DMA_HANDLE handle, dma_callback_t callback, void *arg) { struct sam3u_dma_s *dmach = (struct sam3u_dma_s *)handle; int ret = -EINVAL; /* Verify that the DMA has been setup (i.e., at least one entry in the * link list). */ DEBUGASSERT(dmach != NULL); if (dmach->llhead) { /* Save the callback info. This will be invoked whent the DMA commpletes */ dmach->callback = callback; dmach->arg = arg; /* Is this a single block transfer? Or a multiple block tranfer? */ if (dmach->llhead == dmach->lltail) { ret = sam3u_single(dmach); } else { ret = sam3u_multiple(dmach); } } return ret; } /**************************************************************************** * Name: sam3u_dmastop * * Description: * Cancel the DMA. After sam3u_dmastop() is called, the DMA channel is * reset and sam3u_dmasetup() must be called before sam3u_dmastart() can be * called again * ****************************************************************************/ void sam3u_dmastop(DMA_HANDLE handle) { struct sam3u_dma_s *dmach = (struct sam3u_dma_s *)handle; irqstate_t flags; DEBUGASSERT(dmach != NULL); flags = irqsave(); sam3u_dmaterminate(dmach, -EINTR); irqrestore(flags); } /**************************************************************************** * Name: sam3u_dmasample * * Description: * Sample DMA register contents * * Assumptions: * - DMA handle allocated by sam3u_dmachannel() * ****************************************************************************/ #ifdef CONFIG_DEBUG_DMA void sam3u_dmasample(DMA_HANDLE handle, struct sam3u_dmaregs_s *regs) { struct sam3u_dma_s *dmach = (struct sam3u_dma_s *)handle; irqstate_t flags; /* Sample global registers. NOTE: reading EBCISR clears interrupts, but * that should be okay IF interrupts are enabled when this function is * called. But there is a race condition where this instrumentation could * cause lost interrupts. */ flags = irqsave(); regs->gcfg = getreg32(SAM3U_DMAC_GCFG); regs->en = getreg32(SAM3U_DMAC_EN); regs->sreq = getreg32(SAM3U_DMAC_SREQ); regs->creq = getreg32(SAM3U_DMAC_CREQ); regs->last = getreg32(SAM3U_DMAC_LAST); regs->ebcimr = getreg32(SAM3U_DMAC_EBCIMR); regs->ebcisr = getreg32(SAM3U_DMAC_EBCISR); regs->chsr = getreg32(SAM3U_DMAC_CHSR); /* Sample channel registers */ regs->saddr = getreg32(dmach->base + SAM3U_DMACHAN_SADDR_OFFSET); regs->daddr = getreg32(dmach->base + SAM3U_DMACHAN_DADDR_OFFSET); regs->dscr = getreg32(dmach->base + SAM3U_DMACHAN_DSCR_OFFSET); regs->ctrla = getreg32(dmach->base + SAM3U_DMACHAN_CTRLA_OFFSET); regs->ctrlb = getreg32(dmach->base + SAM3U_DMACHAN_CTRLB_OFFSET); regs->cfg = getreg32(dmach->base + SAM3U_DMACHAN_CFG_OFFSET); irqrestore(flags); } #endif /* CONFIG_DEBUG_DMA */ /**************************************************************************** * Name: sam3u_dmadump * * Description: * Dump previously sampled DMA register contents * * Assumptions: * - DMA handle allocated by sam3u_dmachannel() * ****************************************************************************/ #ifdef CONFIG_DEBUG_DMA void sam3u_dmadump(DMA_HANDLE handle, const struct sam3u_dmaregs_s *regs, const char *msg) { struct sam3u_dma_s *dmach = (struct sam3u_dma_s *)handle; dmadbg("%s\n", msg); dmadbg(" DMA Global Registers:\n"); dmadbg(" GCFG[%08x]: %08x\n", SAM3U_DMAC_GCFG, regs->gcfg); dmadbg(" EN[%08x]: %08x\n", SAM3U_DMAC_EN, regs->en); dmadbg(" SREQ[%08x]: %08x\n", SAM3U_DMAC_SREQ, regs->sreq); dmadbg(" CREQ[%08x]: %08x\n", SAM3U_DMAC_CREQ, regs->creq); dmadbg(" LAST[%08x]: %08x\n", SAM3U_DMAC_LAST, regs->last); dmadbg(" EBCIMR[%08x]: %08x\n", SAM3U_DMAC_EBCIMR, regs->ebcimr); dmadbg(" EBCISR[%08x]: %08x\n", SAM3U_DMAC_EBCISR, regs->ebcisr); dmadbg(" CHSR[%08x]: %08x\n", SAM3U_DMAC_CHSR, regs->chsr); dmadbg(" DMA Channel Registers:\n"); dmadbg(" SADDR[%08x]: %08x\n", dmach->base + SAM3U_DMACHAN_SADDR_OFFSET, regs->saddr); dmadbg(" DADDR[%08x]: %08x\n", dmach->base + SAM3U_DMACHAN_DADDR_OFFSET, regs->daddr); dmadbg(" DSCR[%08x]: %08x\n", dmach->base + SAM3U_DMACHAN_DSCR_OFFSET, regs->dscr); dmadbg(" CTRLA[%08x]: %08x\n", dmach->base + SAM3U_DMACHAN_CTRLA_OFFSET, regs->ctrla); dmadbg(" CTRLB[%08x]: %08x\n", dmach->base + SAM3U_DMACHAN_CTRLB_OFFSET, regs->ctrlb); dmadbg(" CFG[%08x]: %08x\n", dmach->base + SAM3U_DMACHAN_CFG_OFFSET, regs->cfg); } #endif /* CONFIG_DEBUG_DMA */ #endif /* CONFIG_SAM3U_DMA */