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nuttx/arch/arm/src/sam34/sam_dmac.c
Gregory Nutt aed4d0e198 Missed a few *llinfo() to *info() conversions
2016-06-20 16:24:09 -06:00

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/****************************************************************************
* arch/arm/src/sam34/sam_dmac.c
*
* Copyright (C) 2010, 2013-2014, 2016 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* 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 <nuttx/config.h>
#include <stdint.h>
#include <stdbool.h>
#include <string.h>
#include <semaphore.h>
#include <debug.h>
#include <errno.h>
#include <nuttx/irq.h>
#include <nuttx/arch.h>
#include "up_arch.h"
#include "up_internal.h"
#include "sched/sched.h"
#include "chip.h"
#include "sam_dmac.h"
#include "sam_periphclks.h"
#include "chip/sam_pmc.h"
#include "chip/sam_dmac.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Configuration ************************************************************/
/* Condition out the whole file unless DMA is selected in the configuration */
#ifdef CONFIG_SAM34_DMAC0
/* If SAM3/4 support is enabled, then OS DMA support should also be enabled */
#ifndef CONFIG_ARCH_DMA
# warning "SAM3/4 DMA enabled but CONFIG_ARCH_DMA disabled"
#endif
/* Check the number of link list descriptors to allocate */
#ifndef CONFIG_SAM34_NLLDESC
# define CONFIG_SAM34_NLLDESC SAM34_NDMACHAN
#endif
#if CONFIG_SAM34_NLLDESC < SAM34_NDMACHAN
# warning "At least SAM34_NDMACHAN descriptors must be allocated"
# undef CONFIG_SAM34_NLLDESC
# define CONFIG_SAM34_NLLDESC SAM34_NDMACHAN
#endif
/* Register values **********************************************************/
#define DMACHAN_CTRLB_BOTHDSCR \
(DMACHAN_CTRLB_SRCDSCR | DMACHAN_CTRLB_DSTDSCR)
/****************************************************************************
* Private Types
****************************************************************************/
/* This structure describes one DMA channel */
struct sam_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_SAM34_NLLDESC];
/* This array describes the state of each DMA */
static struct sam_dma_s g_dma[SAM34_NDMACHAN] =
{
#if defined(CONFIG_ARCH_CHIP_SAM3U)
/* The SAM3U has four DMA channels. The FIFOs for channels 0-2 are
* 8 bytes in size; channel 3 is 32 bytes.
*/
#if SAM34_NDMACHAN != 4
# error "Logic here assumes SAM34_NDMACHAN is 4"
#endif
{
.chan = 0,
.flags = DMACH_FLAG_FIFO_8BYTES,
.base = SAM_DMACHAN0_BASE,
},
{
.chan = 1,
.flags = DMACH_FLAG_FIFO_8BYTES,
.base = SAM_DMACHAN1_BASE,
},
{
.chan = 2,
.flags = DMACH_FLAG_FIFO_8BYTES,
.base = SAM_DMACHAN2_BASE,
},
{
.chan = 3,
.flags = DMACH_FLAG_FIFO_32BYTES,
.base = SAM_DMACHAN3_BASE,
}
#elif defined(CONFIG_ARCH_CHIP_SAM3X) || defined(CONFIG_ARCH_CHIP_SAM3A)
/* The SAM3A/X have six DMA channels. The FIFOs for channels 0-2 are
* 8 bytes in size; channel 3 is 32 bytes.
*/
#if SAM34_NDMACHAN != 6
# error "Logic here assumes SAM34_NDMACHAN is 6"
#endif
{
.chan = 0,
.flags = DMACH_FLAG_FIFO_8BYTES,
.base = SAM_DMACHAN0_BASE,
},
{
.chan = 1,
.flags = DMACH_FLAG_FIFO_8BYTES,
.base = SAM_DMACHAN1_BASE,
},
{
.chan = 2,
.flags = DMACH_FLAG_FIFO_8BYTES,
.base = SAM_DMACHAN2_BASE,
},
{
.chan = 3,
.flags = DMACH_FLAG_FIFO_32BYTES,
.base = SAM_DMACHAN3_BASE,
}
{
.chan = 4,
.flags = DMACH_FLAG_FIFO_8BYTES,
.base = SAM_DMACHAN4_BASE,
}
{
.chan = 5,
.flags = DMACH_FLAG_FIFO_32BYTES,
.base = SAM_DMACHAN5_BASE,
}
#elif defined(CONFIG_ARCH_CHIP_SAM4E)
/* The SAM4E16E, SAM4E8E, SAM4E16C, and SAM4E8C have four DMA channels.
*
* REVISIT: I have not yet found any documentation for the per-channel
* FIFO depth. Here I am assuming that the FIFO characteristics are
* the same as for the SAM3U.
*/
#if SAM34_NDMACHAN != 4
# error "Logic here assumes SAM34_NDMACHAN is 4"
#endif
{
.chan = 0,
.flags = DMACH_FLAG_FIFO_8BYTES,
.base = SAM_DMACHAN0_BASE,
},
{
.chan = 1,
.flags = DMACH_FLAG_FIFO_8BYTES,
.base = SAM_DMACHAN1_BASE,
},
{
.chan = 2,
.flags = DMACH_FLAG_FIFO_8BYTES,
.base = SAM_DMACHAN2_BASE,
},
{
.chan = 3,
.flags = DMACH_FLAG_FIFO_32BYTES,
.base = SAM_DMACHAN3_BASE,
}
#else
# error "Nothing is known about the DMA channels for this device"
#endif
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: sam_takechsem() and sam_givechsem()
*
* Description:
* Used to get exclusive access to the DMA channel table
*
****************************************************************************/
static void sam_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 sam_givechsem(void)
{
(void)sem_post(&g_chsem);
}
/****************************************************************************
* Name: sam_takedsem() and sam_givedsem()
*
* Description:
* Used to wait for availability of descriptors in the descriptor table.
*
****************************************************************************/
static void sam_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 sam_givedsem(void)
{
(void)sem_post(&g_dsem);
}
/****************************************************************************
* Name: sam_fifosize
*
* Description:
* Decode the FIFO size from the flags
*
****************************************************************************/
static unsigned int sam_fifosize(uint8_t chflags)
{
chflags &= DMACH_FLAG_FIFOSIZE_MASK;
if (chflags == DMACH_FLAG_FIFO_8BYTES)
{
return 8;
}
else /* if (chflags == DMACH_FLAG_FIFO_32BYTES) */
{
return 32;
}
}
/****************************************************************************
* Name: sam_fifocfg
*
* Description:
* Decode the FIFO config from the flags
*
****************************************************************************/
static inline uint32_t sam_fifocfg(struct sam_dma_s *dmach)
{
unsigned int ndx = (dmach->flags & DMACH_FLAG_FIFOCFG_MASK) >> DMACH_FLAG_FIFOCFG_SHIFT;
DEBUGASSERT(ndx < 3);
return g_fifocfg[ndx];
}
/****************************************************************************
* Name: sam_txcfg
*
* Description:
* Decode the flags to get the correct CFG register bit settings for
* a transmit (memory to peripheral) transfer.
*
****************************************************************************/
static inline uint32_t sam_txcfg(struct sam_dma_s *dmach)
{
uint32_t regval;
/* Set transfer (memory to peripheral) DMA channel configuration register */
regval = DMACHAN_CFG_SOD;
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 |= sam_fifocfg(dmach);
return regval;
}
/****************************************************************************
* Name: sam_rxcfg
*
* Description:
* Decode the flags to get the correct CFG register bit settings for
* a receive (peripheral to memory) transfer.
*
****************************************************************************/
static inline uint32_t sam_rxcfg(struct sam_dma_s *dmach)
{
uint32_t regval;
/* Set received (peripheral to memory) DMA channel config */
regval = DMACHAN_CFG_SOD;
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 |= sam_fifocfg(dmach);
return regval;
}
/****************************************************************************
* Name: sam_txctrlabits
*
* Description:
* Decode 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 sam_txctrla).
*
****************************************************************************/
static inline uint32_t
sam_txctrlabits(struct sam_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];
#if defined(CONFIG_ARCH_CHIP_SAM3U) || defined(CONFIG_ARCH_CHIP_SAM3X) || \
defined(CONFIG_ARCH_CHIP_SAM3A)
/* Set the source chunk 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
#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];
#if defined(CONFIG_ARCH_CHIP_SAM3U) || defined(CONFIG_ARCH_CHIP_SAM3X) || \
defined(CONFIG_ARCH_CHIP_SAM3A)
/* Set the destination chunk 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
#endif
return regval;
}
/****************************************************************************
* Name: sam_maxtxtransfer
*
* Description:
* Maximum number of bytes that can be sent in on transfer
*
****************************************************************************/
static size_t sam_maxtxtransfer(struct sam_dma_s *dmach)
{
unsigned int srcwidth;
size_t maxtransfer;
/* Get the maximum transfer size in bytes. BTSIZE is "the number of
* transfers to be performed, that is, for writes it refers to the number
* of source width transfers to perform when DMAC is flow controller. For
* Reads, BTSIZE refers to the number of transfers completed on the Source
* Interface. ..."
*/
srcwidth = (dmach->flags & DMACH_FLAG_MEMWIDTH_MASK)
>> DMACH_FLAG_MEMWIDTH_SHIFT;
switch (srcwidth)
{
default:
case 0: /* 8 bits, 1 byte */
maxtransfer = DMACHAN_CTRLA_BTSIZE_MAX;
break;
case 1: /* 16 bits, 2 bytes */
maxtransfer = 2 * DMACHAN_CTRLA_BTSIZE_MAX;
break;
case 2: /* 32 bits 4 bytes */
maxtransfer = 4 * DMACHAN_CTRLA_BTSIZE_MAX;
break;
}
return maxtransfer;
}
/****************************************************************************
* Name: sam_txctrla
*
* Description:
* Or in the variable CTRLA bits
*
****************************************************************************/
static inline uint32_t sam_txctrla(struct sam_dma_s *dmach,
uint32_t ctrla, uint32_t dmasize)
{
unsigned int srcwidth;
/* 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.
*/
srcwidth = (dmach->flags & DMACH_FLAG_MEMWIDTH_MASK)
>> DMACH_FLAG_MEMWIDTH_SHIFT;
switch (srcwidth)
{
default:
case 0: /* 8 bits, 1 byte */
break;
case 1: /* 16 bits, 2 bytes */
dmasize = (dmasize + 1) >> 1;
break;
case 2: /* 32 bits, 4 bytes */
dmasize = (dmasize + 3) >> 2;
break;
}
DEBUGASSERT(dmasize <= DMACHAN_CTRLA_BTSIZE_MAX);
return (ctrla & ~DMACHAN_CTRLA_BTSIZE_MASK) |
(dmasize << DMACHAN_CTRLA_BTSIZE_SHIFT);
}
/****************************************************************************
* Name: sam_rxctrlabits
*
* Description:
* Decode 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 sam_rxctrla).
*
****************************************************************************/
static inline uint32_t sam_rxctrlabits(struct sam_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];
#if defined(CONFIG_ARCH_CHIP_SAM3U) || defined(CONFIG_ARCH_CHIP_SAM3X) || \
defined(CONFIG_ARCH_CHIP_SAM3A)
/* Set the source chunk 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
#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];
#if defined(CONFIG_ARCH_CHIP_SAM3U) || defined(CONFIG_ARCH_CHIP_SAM3X) || \
defined(CONFIG_ARCH_CHIP_SAM3A)
/* Set the destination chunk 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
#endif
return regval;
}
/****************************************************************************
* Name: sam_maxrxtransfer
*
* Description:
* Maximum number of bytes that can be sent in on transfer
*
****************************************************************************/
static size_t sam_maxrxtransfer(struct sam_dma_s *dmach)
{
unsigned int srcwidth;
size_t maxtransfer;
/* Get the maximum transfer size in bytes. BTSIZE is "the number of
* transfers to be performed, that is, for writes it refers to the number
* of source width transfers to perform when DMAC is flow controller. For
* Reads, BTSIZE refers to the number of transfers completed on the Source
* Interface. ..."
*/
srcwidth = (dmach->flags & DMACH_FLAG_PERIPHWIDTH_MASK)
>> DMACH_FLAG_PERIPHWIDTH_SHIFT;
switch (srcwidth)
{
default:
case 0: /* 8 bits, 1 byte */
maxtransfer = DMACHAN_CTRLA_BTSIZE_MAX;
break;
case 1: /* 16 bits, 2 bytes */
maxtransfer = 2 * DMACHAN_CTRLA_BTSIZE_MAX;
break;
case 2: /* 32 bits, 4 bytes */
maxtransfer = 4 * DMACHAN_CTRLA_BTSIZE_MAX;
break;
}
return maxtransfer;
}
/****************************************************************************
* Name: sam_rxctrla
*
* Description:
* 'OR' in the variable CTRLA bits
*
****************************************************************************/
static inline uint32_t sam_rxctrla(struct sam_dma_s *dmach,
uint32_t ctrla, uint32_t dmasize)
{
unsigned int srcwidth;
/* 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.
*/
srcwidth = (dmach->flags & DMACH_FLAG_PERIPHWIDTH_MASK)
>> DMACH_FLAG_PERIPHWIDTH_SHIFT;
switch (srcwidth)
{
default:
case 0: /* 8 bits, 1 byte */
break;
case 1: /* 16 bits, 2 bytes */
dmasize = (dmasize + 1) >> 1;
break;
case 2: /* 32 bits, 4 bytes */
dmasize = (dmasize + 3) >> 2;
break;
}
DEBUGASSERT(dmasize <= DMACHAN_CTRLA_BTSIZE_MAX);
return (ctrla & ~DMACHAN_CTRLA_BTSIZE_MASK) |
(dmasize << DMACHAN_CTRLA_BTSIZE_SHIFT);
}
/****************************************************************************
* Name: sam_txctrlb
*
* Description:
* Decode the flags to get the correct CTRLB register bit settings for
* a transmit (memory to peripheral) transfer.
*
****************************************************************************/
static inline uint32_t sam_txctrlb(struct sam_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: sam_rxctrlb
*
* Description:
* Decode the flags to get the correct CTRLB register bit settings for
* a receive (peripheral to memory) transfer.
*
****************************************************************************/
static inline uint32_t sam_rxctrlb(struct sam_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: sam_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 *
sam_allocdesc(struct sam_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_FEATURES
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.
*/
sam_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.
*/
sam_takechsem();
for (i = 0; i < CONFIG_SAM34_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.
*/
sam_givechsem();
DEBUGASSERT(desc != NULL);
}
return desc;
}
/****************************************************************************
* Name: sam_freelinklist
*
* Description:
* Free all descriptors in the DMA channel's link list.
*
* NOTE: Called from the DMA interrupt handler.
*
****************************************************************************/
static void sam_freelinklist(struct sam_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));
sam_givedsem();
desc = next;
}
}
/****************************************************************************
* Name: sam_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 sam_txbuffer(struct sam_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 = sam_txctrlabits(dmach);
ctrlb = sam_txctrlb(dmach);
}
ctrla = sam_txctrla(dmach, regval, nbytes);
/* Add the new link list entry */
if (!sam_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 = sam_txcfg(dmach);
return OK;
}
/****************************************************************************
* Name: sam_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 sam_rxbuffer(struct sam_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 = sam_rxctrlabits(dmach);
ctrlb = sam_rxctrlb(dmach);
}
ctrla = sam_rxctrla(dmach, regval, nbytes);
/* Add the new link list entry */
if (!sam_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 = sam_rxcfg(dmach);
return OK;
}
/****************************************************************************
* Name: sam_single
*
* Description:
* Start a single buffer DMA.
*
****************************************************************************/
static inline int sam_single(struct sam_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.
*
* REVISIT: If DMAC interrupts are disabled at the NVIKC, then reading the
* EBCISR register could cause a loss of interrupts!
*/
(void)getreg32(SAM_DMAC_EBCISR);
/* Write the starting source address in the SADDR register */
DEBUGASSERT(llhead != NULL && llhead->src != 0);
putreg32(llhead->src, dmach->base + SAM_DMACHAN_SADDR_OFFSET);
/* Write the starting destination address in the DADDR register */
putreg32(llhead->dest, dmach->base + SAM_DMACHAN_DADDR_OFFSET);
/* Clear the next descriptor address register */
putreg32(0, dmach->base + SAM_DMACHAN_DSCR_OFFSET);
/* Set up the CTRLA register */
putreg32(llhead->ctrla, dmach->base + SAM_DMACHAN_CTRLA_OFFSET);
/* Set up the CTRLB register */
putreg32(llhead->ctrlb, dmach->base + SAM_DMACHAN_CTRLB_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 + SAM_DMACHAN_CFG_OFFSET);
/* Enable the channel by writing a <20>1<EFBFBD> to the CHER enable bit */
putreg32(DMAC_CHER_ENA(dmach->chan), SAM_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), SAM_DMAC_EBCIER);
return OK;
}
/****************************************************************************
* Name: sam_multiple
*
* Description:
* Start a multiple buffer DMA.
*
****************************************************************************/
static inline int sam_multiple(struct sam_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
*
* REVISIT: If DMAC interrupts are disabled at the NVIKC, then reading the
* EBCISR register could cause a loss of interrupts!
*/
(void)getreg32(SAM_DMAC_EBCISR);
/* Set up the initial CTRLA register */
putreg32(llhead->ctrla, dmach->base + SAM_DMACHAN_CTRLA_OFFSET);
/* Set up the CTRLB register (will enable descriptors) */
putreg32(llhead->ctrlb, dmach->base + SAM_DMACHAN_CTRLB_OFFSET);
/* Write the channel configuration information into the CFG register */
putreg32(dmach->cfg, dmach->base + SAM_DMACHAN_CFG_OFFSET);
/* Program the DSCR register with the pointer to the firstlink list entry. */
putreg32((uint32_t)llhead, dmach->base + SAM_DMACHAN_DSCR_OFFSET);
/* Finally, enable the channel by writing a <20>1<EFBFBD> to the CHER enable */
putreg32(DMAC_CHER_ENA(dmach->chan), SAM_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 transfer.
*
* 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), SAM_DMAC_EBCIER);
return OK;
}
/****************************************************************************
* Name: sam_dmaterminate
*
* Description:
* Terminate the DMA transfer and disable the DMA channel
*
****************************************************************************/
static void sam_dmaterminate(struct sam_dma_s *dmach, int result)
{
/* Disable all channel interrupts */
putreg32(DMAC_EBC_CHANINTS(dmach->chan), SAM_DMAC_EBCIDR);
/* Disable the channel by writing one to the write-only channel disable register */
putreg32(DMAC_CHDR_DIS(dmach->chan), SAM_DMAC_CHDR);
/* Free the linklist */
sam_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: sam_dmainterrupt
*
* Description:
* DMA interrupt handler
*
****************************************************************************/
static int sam_dmainterrupt(int irq, void *context)
{
struct sam_dma_s *dmach;
unsigned int chndx;
uint32_t regval;
/* Get the DMAC status register value. Ignore all masked interrupt
* status bits.
*/
regval = getreg32(SAM_DMAC_EBCISR) & getreg32(SAM_DMAC_EBCIMR);
/* Check if the any transfer has completed or any errors have occurred */
if ((regval & DMAC_EBC_ALLINTS) != 0)
{
/* Yes.. Check each bit to see which channel has interrupted */
for (chndx = 0; chndx < SAM34_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? */
sam_dmaterminate(dmach, -EIO);
}
/* Is the transfer complete? */
else if ((regval & DMAC_EBC_CBTC(chndx)) != 0)
{
/* Yes.. Terminate the transfer with success */
sam_dmaterminate(dmach, OK);
}
/* Otherwise, this must be a Buffer Transfer Complete (BTC)
* interrupt as part of a multiple buffer transfer.
*/
else /* if ((regval & DMAC_EBC_BTC(chndx)) != 0) */
{
/* Write the KEEPON field to clear the STALL states */
putreg32(DMAC_CHER_KEEP(dmach->chan), SAM_DMAC_CHER);
}
}
}
}
return OK;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: up_dmainitialize
*
* Description:
* Initialize the DMA subsystem
*
* Returned Value:
* None
*
****************************************************************************/
void weak_function up_dmainitialize(void)
{
dmainfo("Initialize DMAC0\n");
/* Enable peripheral clock */
sam_dmac_enableclk();
/* Disable all DMA interrupts */
putreg32(DMAC_EBC_ALLINTS, SAM_DMAC_EBCIDR);
/* Disable all DMA channels */
putreg32(DMAC_CHDR_DIS_ALL, SAM_DMAC_CHDR);
/* Attach DMA interrupt vector */
(void)irq_attach(SAM_IRQ_DMAC, sam_dmainterrupt);
/* Enable the IRQ at the NVIC (still disabled at the DMA controller) */
up_enable_irq(SAM_IRQ_DMAC);
/* Enable the DMA controller */
putreg32(DMAC_EN_ENABLE, SAM_DMAC_EN);
/* Initialize semaphores */
sem_init(&g_chsem, 0, 1);
sem_init(&g_dsem, 0, CONFIG_SAM34_NLLDESC);
}
/****************************************************************************
* Name: sam_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 sam_dmachannel(uint32_t chflags)
{
struct sam_dma_s *dmach;
unsigned int fifosize;
unsigned int chndx;
/* Get the search parameters */
fifosize = sam_fifosize(chflags);
/* Search for an available DMA channel with at least the requested FIFO
* size.
*/
dmach = NULL;
sam_takechsem();
for (chndx = 0; chndx < SAM34_NDMACHAN; chndx++)
{
struct sam_dma_s *candidate = &g_dma[chndx];
if (!candidate->inuse &&
(sam_fifosize(candidate->flags) >= fifosize))
{
dmach = candidate;
dmach->inuse = true;
/* Read the status register to clear any pending interrupts on the
* channel
*
* REVISIT: If DMAC interrupts are disabled at the NVIKC, then
* reading the EBCISR register could cause a loss of interrupts!
*/
(void)getreg32(SAM_DMAC_EBCISR);
/* Disable the channel by writing one to the write-only channel
* disable register
*/
putreg32(DMAC_CHDR_DIS(chndx), SAM_DMAC_CHDR);
/* Set the DMA channel flags, retaining the fifo size setting
* which is an inherent properties of the FIFO and cannot be
* changed.
*/
dmach->flags &= DMACH_FLAG_FIFOSIZE_MASK;
dmach->flags |= (chflags & ~DMACH_FLAG_FIFOSIZE_MASK);
break;
}
}
sam_givechsem();
dmainfo("chflags: %08x returning dmach: %p\n", (int)chflags, dmach);
return (DMA_HANDLE)dmach;
}
/************************************************************************************
* Name: sam_dmaconfig
*
* Description:
* There are two channel usage models: (1) The channel is allocated and configured
* in one step. This is the typical case where a DMA channel performs a constant
* role. The alternative is (2) where the DMA channel is reconfigured on the fly.
* In this case, the chflags provided to sam_dmachannel are not used and
* sam_dmaconfig() is called before each DMA to configure the DMA channel
* appropriately.
*
* Returned Value:
* None
*
************************************************************************************/
void sam_dmaconfig(DMA_HANDLE handle, uint32_t chflags)
{
struct sam_dma_s *dmach = (struct sam_dma_s *)handle;
/* Set the new DMA channel flags. */
dmainfo("chflags: %08x\n", (int)chflags);
dmach->flags = chflags;
}
/****************************************************************************
* Name: sam_dmafree
*
* Description:
* Release a DMA channel. NOTE: The 'handle' used in this argument must
* NEVER be used again until sam_dmachannel() is called again to re-gain
* a valid handle.
*
* Returned Value:
* None
*
****************************************************************************/
void sam_dmafree(DMA_HANDLE handle)
{
struct sam_dma_s *dmach = (struct sam_dma_s *)handle;
dmainfo("dmach: %p\n", dmach);
DEBUGASSERT((dmach != NULL) && (dmach->inuse));
/* Mark the channel no longer in use. Clearing the inuse flag is an atomic
* operation and so should be safe.
*/
dmach->flags &= DMACH_FLAG_FIFOSIZE_MASK;
dmach->inuse = false; /* No longer in use */
}
/****************************************************************************
* Name: sam_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 sam_dmatxsetup() and sam_dmarxsetup()
* must not be intermixed on the same transfer, however.
*
****************************************************************************/
int sam_dmatxsetup(DMA_HANDLE handle, uint32_t paddr, uint32_t maddr, size_t nbytes)
{
struct sam_dma_s *dmach = (struct sam_dma_s *)handle;
ssize_t remaining = (ssize_t)nbytes;
size_t maxtransfer;
int ret = OK;
dmainfo("dmach: %p paddr: %08x maddr: %08x nbytes: %d\n",
dmach, (int)paddr, (int)maddr, (int)nbytes);
DEBUGASSERT(dmach);
dmainfo("llhead: %p lltail: %p\n", dmach->llhead, dmach->lltail);
/* The maximum transfer size in bytes depends upon the maximum number of
* transfers and the number of bytes per transfer.
*/
maxtransfer = sam_maxtxtransfer(dmach);
/* If this is a large transfer, break it up into smaller buffers */
while (remaining > maxtransfer)
{
/* Set up the maximum size transfer */
ret = sam_txbuffer(dmach, paddr, maddr, maxtransfer);
if (ret == OK)
{
/* Decrement the number of bytes left to transfer */
remaining -= maxtransfer;
/* Increment the memory & peripheral address (if it is appropriate to
* do do).
*/
if ((dmach->flags & DMACH_FLAG_PERIPHINCREMENT) != 0)
{
paddr += maxtransfer;
}
if ((dmach->flags & DMACH_FLAG_MEMINCREMENT) != 0)
{
maddr += maxtransfer;
}
}
}
/* Then set up the final buffer transfer */
if (ret == OK && remaining > 0)
{
ret = sam_txbuffer(dmach, paddr, maddr, remaining);
}
return ret;
}
/****************************************************************************
* Name: sam_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 sam_dmatxsetup() and sam_dmarxsetup()
* must not be intermixed on the same transfer, however.
*
****************************************************************************/
int sam_dmarxsetup(DMA_HANDLE handle, uint32_t paddr, uint32_t maddr, size_t nbytes)
{
struct sam_dma_s *dmach = (struct sam_dma_s *)handle;
ssize_t remaining = (ssize_t)nbytes;
size_t maxtransfer;
int ret = OK;
dmainfo("dmach: %p paddr: %08x maddr: %08x nbytes: %d\n",
dmach, (int)paddr, (int)maddr, (int)nbytes);
DEBUGASSERT(dmach);
dmainfo("llhead: %p lltail: %p\n", dmach->llhead, dmach->lltail);
/* The maximum transfer size in bytes depends upon the maximum number of
* transfers and the number of bytes per transfer.
*/
maxtransfer = sam_maxrxtransfer(dmach);
/* If this is a large transfer, break it up into smaller buffers */
while (remaining > maxtransfer)
{
/* Set up the maximum size transfer */
ret = sam_rxbuffer(dmach, paddr, maddr, maxtransfer);
if (ret == OK)
{
/* Decrement the number of bytes left to transfer */
remaining -= maxtransfer;
/* Increment the memory & peripheral address (if it is appropriate to
* do do).
*/
if ((dmach->flags & DMACH_FLAG_PERIPHINCREMENT) != 0)
{
paddr += maxtransfer;
}
if ((dmach->flags & DMACH_FLAG_MEMINCREMENT) != 0)
{
maddr += maxtransfer;
}
}
}
/* Then set up the final buffer transfer */
if (ret == OK && remaining > 0)
{
ret = sam_rxbuffer(dmach, paddr, maddr, remaining);
}
return ret;
}
/****************************************************************************
* Name: sam_dmastart
*
* Description:
* Start the DMA transfer
*
****************************************************************************/
int sam_dmastart(DMA_HANDLE handle, dma_callback_t callback, void *arg)
{
struct sam_dma_s *dmach = (struct sam_dma_s *)handle;
int ret = -EINVAL;
dmainfo("dmach: %p callback: %p arg: %p\n", dmach, callback, arg);
DEBUGASSERT(dmach != NULL);
/* Verify that the DMA has been setup (i.e., at least one entry in the
* link list).
*/
if (dmach->llhead)
{
/* Save the callback info. This will be invoked when the DMA completes */
dmach->callback = callback;
dmach->arg = arg;
/* Is this a single block transfer? Or a multiple block transfer? */
if (dmach->llhead == dmach->lltail)
{
ret = sam_single(dmach);
}
else
{
ret = sam_multiple(dmach);
}
}
return ret;
}
/****************************************************************************
* Name: sam_dmastop
*
* Description:
* Cancel the DMA. After sam_dmastop() is called, the DMA channel is
* reset and sam_dmarx/txsetup() must be called before sam_dmastart() can be
* called again
*
****************************************************************************/
void sam_dmastop(DMA_HANDLE handle)
{
struct sam_dma_s *dmach = (struct sam_dma_s *)handle;
irqstate_t flags;
dmainfo("dmach: %p\n", dmach);
DEBUGASSERT(dmach != NULL);
flags = enter_critical_section();
sam_dmaterminate(dmach, -EINTR);
leave_critical_section(flags);
}
/****************************************************************************
* Name: sam_dmasample
*
* Description:
* Sample DMA register contents
*
* Assumptions:
* - DMA handle allocated by sam_dmachannel()
*
****************************************************************************/
#ifdef CONFIG_DEBUG_DMA_INFO
void sam_dmasample(DMA_HANDLE handle, struct sam_dmaregs_s *regs)
{
struct sam_dma_s *dmach = (struct sam_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 = enter_critical_section();
regs->gcfg = getreg32(SAM_DMAC_GCFG);
regs->en = getreg32(SAM_DMAC_EN);
regs->sreq = getreg32(SAM_DMAC_SREQ);
regs->creq = getreg32(SAM_DMAC_CREQ);
regs->last = getreg32(SAM_DMAC_LAST);
regs->ebcimr = getreg32(SAM_DMAC_EBCIMR);
regs->chsr = getreg32(SAM_DMAC_CHSR);
/* Sample channel registers */
regs->saddr = getreg32(dmach->base + SAM_DMACHAN_SADDR_OFFSET);
regs->daddr = getreg32(dmach->base + SAM_DMACHAN_DADDR_OFFSET);
regs->dscr = getreg32(dmach->base + SAM_DMACHAN_DSCR_OFFSET);
regs->ctrla = getreg32(dmach->base + SAM_DMACHAN_CTRLA_OFFSET);
regs->ctrlb = getreg32(dmach->base + SAM_DMACHAN_CTRLB_OFFSET);
regs->cfg = getreg32(dmach->base + SAM_DMACHAN_CFG_OFFSET);
leave_critical_section(flags);
}
#endif /* CONFIG_DEBUG_DMA_INFO */
/****************************************************************************
* Name: sam_dmadump
*
* Description:
* Dump previously sampled DMA register contents
*
* Assumptions:
* - DMA handle allocated by sam_dmachannel()
*
****************************************************************************/
#ifdef CONFIG_DEBUG_DMA_INFO
void sam_dmadump(DMA_HANDLE handle, const struct sam_dmaregs_s *regs,
const char *msg)
{
struct sam_dma_s *dmach = (struct sam_dma_s *)handle;
dmainfo("%s\n", msg);
dmainfo(" DMA Global Registers:\n");
dmainfo(" GCFG[%08x]: %08x\n", SAM_DMAC_GCFG, regs->gcfg);
dmainfo(" EN[%08x]: %08x\n", SAM_DMAC_EN, regs->en);
dmainfo(" SREQ[%08x]: %08x\n", SAM_DMAC_SREQ, regs->sreq);
dmainfo(" CREQ[%08x]: %08x\n", SAM_DMAC_CREQ, regs->creq);
dmainfo(" LAST[%08x]: %08x\n", SAM_DMAC_LAST, regs->last);
dmainfo(" EBCIMR[%08x]: %08x\n", SAM_DMAC_EBCIMR, regs->ebcimr);
dmainfo(" CHSR[%08x]: %08x\n", SAM_DMAC_CHSR, regs->chsr);
dmainfo(" DMA Channel Registers:\n");
dmainfo(" SADDR[%08x]: %08x\n", dmach->base + SAM_DMACHAN_SADDR_OFFSET, regs->saddr);
dmainfo(" DADDR[%08x]: %08x\n", dmach->base + SAM_DMACHAN_DADDR_OFFSET, regs->daddr);
dmainfo(" DSCR[%08x]: %08x\n", dmach->base + SAM_DMACHAN_DSCR_OFFSET, regs->dscr);
dmainfo(" CTRLA[%08x]: %08x\n", dmach->base + SAM_DMACHAN_CTRLA_OFFSET, regs->ctrla);
dmainfo(" CTRLB[%08x]: %08x\n", dmach->base + SAM_DMACHAN_CTRLB_OFFSET, regs->ctrlb);
dmainfo(" CFG[%08x]: %08x\n", dmach->base + SAM_DMACHAN_CFG_OFFSET, regs->cfg);
}
#endif /* CONFIG_DEBUG_DMA_INFO */
#endif /* CONFIG_SAM34_DMAC0 */
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