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nuttx-bb/nuttx/arch/arm/src/stm32/stm32f20xxx_dma.c

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/****************************************************************************
* arch/arm/src/stm32/stm32f20xxx_dma.c
*
* Copyright (C) 2012 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 <semaphore.h>
#include <debug.h>
#include <errno.h>
#include <nuttx/irq.h>
#include <nuttx/arch.h>
#include <arch/irq.h>
#include "up_arch.h"
#include "up_internal.h"
#include "os_internal.h"
#include "chip.h"
#include "stm32_dma.h"
#include "stm32_internal.h"
/* This file supports only the STM32 F2 family (although it is identical to
* the corresponding F4 file).
*/
#if defined(CONFIG_STM32_STM32F20XX)
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define DMA1_NSTREAMS 8
#if STM32_NDMA > 1
# define DMA2_NSTREAMS 8
# define DMA_NSTREAMS (DMA1_NSTREAMS+DMA2_NSTREAMS)
#else
# define DMA_NSTREAMS DMA1_NSTREAMS
#endif
#ifndef CONFIG_DMA_PRI
# define CONFIG_DMA_PRI NVIC_SYSH_PRIORITY_DEFAULT
#endif
/* Convert the DMA stream base address to the DMA register block address */
#define DMA_BASE(ch) (ch & 0xfffffc00)
/****************************************************************************
* Private Types
****************************************************************************/
/* This structure descibes one DMA channel */
struct stm32_dma_s
{
uint8_t stream; /* DMA stream number (0-7) */
uint8_t irq; /* DMA stream IRQ number */
uint8_t shift; /* ISR/IFCR bit shift value */
uint8_t channel; /* DMA channel number (0-7) */
bool nonstop; /* Stream is configured in a non-stopping mode. */
sem_t sem; /* Used to wait for DMA channel to become available */
uint32_t base; /* DMA register channel base address */
dma_callback_t callback; /* Callback invoked when the DMA completes */
void *arg; /* Argument passed to callback function */
};
/****************************************************************************
* Private Data
****************************************************************************/
/* This array describes the state of each DMA */
static struct stm32_dma_s g_dma[DMA_NSTREAMS] =
{
{
.stream = 0,
.irq = STM32_IRQ_DMA1S0,
.shift = DMA_INT_STREAM0_SHIFT,
.base = STM32_DMA1_BASE + STM32_DMA_OFFSET(0),
},
{
.stream = 1,
.irq = STM32_IRQ_DMA1S1,
.shift = DMA_INT_STREAM1_SHIFT,
.base = STM32_DMA1_BASE + STM32_DMA_OFFSET(1),
},
{
.stream = 2,
.irq = STM32_IRQ_DMA1S2,
.shift = DMA_INT_STREAM2_SHIFT,
.base = STM32_DMA1_BASE + STM32_DMA_OFFSET(2),
},
{
.stream = 3,
.irq = STM32_IRQ_DMA1S3,
.shift = DMA_INT_STREAM3_SHIFT,
.base = STM32_DMA1_BASE + STM32_DMA_OFFSET(4),
},
{
.stream = 4,
.irq = STM32_IRQ_DMA1S4,
.shift = DMA_INT_STREAM4_SHIFT,
.base = STM32_DMA1_BASE + STM32_DMA_OFFSET(4),
},
{
.stream = 5,
.irq = STM32_IRQ_DMA1S5,
.shift = DMA_INT_STREAM5_SHIFT,
.base = STM32_DMA1_BASE + STM32_DMA_OFFSET(5),
},
{
.stream = 6,
.irq = STM32_IRQ_DMA1S6,
.shift = DMA_INT_STREAM6_SHIFT,
.base = STM32_DMA1_BASE + STM32_DMA_OFFSET(6),
},
{
.stream = 7,
.irq = STM32_IRQ_DMA1S7,
.shift = DMA_INT_STREAM7_SHIFT,
.base = STM32_DMA1_BASE + STM32_DMA_OFFSET(7),
},
#if STM32_NDMA > 1
{
.stream = 0,
.irq = STM32_IRQ_DMA2S0,
.shift = DMA_INT_STREAM0_SHIFT,
.base = STM32_DMA2_BASE + STM32_DMA_OFFSET(0),
},
{
.stream = 1,
.irq = STM32_IRQ_DMA2S1,
.shift = DMA_INT_STREAM1_SHIFT,
.base = STM32_DMA2_BASE + STM32_DMA_OFFSET(1),
},
{
.stream = 2,
.irq = STM32_IRQ_DMA2S2,
.shift = DMA_INT_STREAM2_SHIFT,
.base = STM32_DMA2_BASE + STM32_DMA_OFFSET(2),
},
{
.stream = 3,
.irq = STM32_IRQ_DMA2S3,
.shift = DMA_INT_STREAM3_SHIFT,
.base = STM32_DMA2_BASE + STM32_DMA_OFFSET(3),
},
{
.stream = 4,
.irq = STM32_IRQ_DMA2S4,
.base = STM32_DMA2_BASE + STM32_DMA_OFFSET(4),
},
{
.stream = 5,
.irq = STM32_IRQ_DMA2S5,
.shift = DMA_INT_STREAM5_SHIFT,
.base = STM32_DMA2_BASE + STM32_DMA_OFFSET(5),
},
{
.stream = 6,
.irq = STM32_IRQ_DMA2S6,
.shift = DMA_INT_STREAM6_SHIFT,
.base = STM32_DMA2_BASE + STM32_DMA_OFFSET(6),
},
{
.stream = 7,
.irq = STM32_IRQ_DMA2S7,
.shift = DMA_INT_STREAM7_SHIFT,
.base = STM32_DMA2_BASE + STM32_DMA_OFFSET(7),
},
#endif
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* DMA register access functions
****************************************************************************/
/* Get non-channel register from DMA1 or DMA2 */
static inline uint32_t dmabase_getreg(struct stm32_dma_s *dmast, uint32_t offset)
{
return getreg32(DMA_BASE(dmast->base) + offset);
}
/* Write to non-channel register in DMA1 or DMA2 */
static inline void dmabase_putreg(struct stm32_dma_s *dmast, uint32_t offset, uint32_t value)
{
putreg32(value, DMA_BASE(dmast->base) + offset);
}
/* Get channel register from DMA1 or DMA2 */
static inline uint32_t dmast_getreg(struct stm32_dma_s *dmast, uint32_t offset)
{
return getreg32(dmast->base + offset);
}
/* Write to channel register in DMA1 or DMA2 */
static inline void dmast_putreg(struct stm32_dma_s *dmast, uint32_t offset, uint32_t value)
{
putreg32(value, dmast->base + offset);
}
/************************************************************************************
* Name: stm32_dmatake() and stm32_dmagive()
*
* Description:
* Used to get exclusive access to a DMA channel.
*
************************************************************************************/
static void stm32_dmatake(FAR struct stm32_dma_s *dmast)
{
/* Take the semaphore (perhaps waiting) */
while (sem_wait(&dmast->sem) != 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 stm32_dmagive(FAR struct stm32_dma_s *dmast)
{
(void)sem_post(&dmast->sem);
}
/************************************************************************************
* Name: stm32_dmastream
*
* Description:
* Get the g_dma table entry associated with a DMA controller and a stream number
*
************************************************************************************/
static inline FAR struct stm32_dma_s *stm32_dmastream(unsigned int stream,
unsigned int controller)
{
int index;
DEBUGASSERT(stream < DMA_NSTREAMS && controller < STM32_NDMA);
/* Convert the controller + stream based on the fact that there are 8 streams
* per controller.
*/
#if STM32_NDMA > 1
index = controller << 3 | stream;
#else
index = stream;
#endif
/* Then return the stream structure associated with the stream index */
return &g_dma[index];
}
/************************************************************************************
* Name: stm32_dmamap
*
* Description:
* Get the g_dma table entry associated with a bit-encoded DMA selection
*
************************************************************************************/
static inline FAR struct stm32_dma_s *stm32_dmamap(unsigned long dmamap)
{
/* Extract the DMA controller number from the bit encoded value */
unsigned int controller = STM32_DMA_CONTROLLER(dmamap);
/* Extact the stream number from the bit encoded value */
unsigned int stream = STM32_DMA_STREAM(dmamap);
/* Return the table entry associated with the controller + stream */
return stm32_dmastream(stream, controller);
}
/************************************************************************************
* Name: stm32_dmastreamdisable
*
* Description:
* Disable the DMA stream
*
************************************************************************************/
static void stm32_dmastreamdisable(struct stm32_dma_s *dmast)
{
uint32_t regoffset;
uint32_t regval;
/* Disable all interrupts at the DMA controller */
regval = dmast_getreg(dmast, STM32_DMA_SCR_OFFSET);
regval &= ~DMA_SCR_ALLINTS;
/* Disable the DMA stream */
regval &= ~DMA_SCR_EN;
dmast_putreg(dmast, STM32_DMA_SCR_OFFSET, regval);
/* Clear pending stream interrupts by setting bits in the upper or lower IFCR
* register
*/
if (dmast->stream < 4)
{
regoffset = STM32_DMA_LIFCR_OFFSET;
}
else
{
regoffset = STM32_DMA_HIFCR_OFFSET;
}
dmabase_putreg(dmast, regoffset, (DMA_STREAM_MASK << dmast->shift));
}
/************************************************************************************
* Name: stm32_dmainterrupt
*
* Description:
* DMA interrupt handler
*
************************************************************************************/
static int stm32_dmainterrupt(int irq, void *context)
{
struct stm32_dma_s *dmast;
uint32_t status;
uint32_t regoffset = 0;
unsigned int stream = 0;
unsigned int controller = 0;
/* Get the stream and the controller that generated the interrupt */
if (irq >= STM32_IRQ_DMA1S0 && irq <= STM32_IRQ_DMA1S6)
{
stream = irq - STM32_IRQ_DMA1S0;
controller = DMA1;
}
else if (irq == STM32_IRQ_DMA1S7)
{
stream = 7;
controller = DMA1;
}
else
#if STM32_NDMA > 1
if (irq >= STM32_IRQ_DMA2S0 && irq <= STM32_IRQ_DMA2S4)
{
stream = irq - STM32_IRQ_DMA2S0;
controller = DMA2;
}
else if (irq >= STM32_IRQ_DMA2S5 && irq <= STM32_IRQ_DMA2S7)
{
stream = irq - STM32_IRQ_DMA2S5 + 5;
controller = DMA2;
}
else
#endif
{
PANIC(OSERR_INTERNAL);
}
/* Get the stream structure from the stream and controller numbers */
dmast = stm32_dmastream(stream, controller);
/* Select the interrupt status register (either the LISR or HISR)
* based on the stream number that caused the interrupt.
*/
if (stream < 4)
{
regoffset = STM32_DMA_LISR_OFFSET;
}
else
{
regoffset = STM32_DMA_HISR_OFFSET;
}
/* Get the interrupt status for this stream */
status = (dmabase_getreg(dmast, regoffset) >> dmast->shift) & DMA_STREAM_MASK;
/* Clear fetched stream interrupts by setting bits in the upper or lower IFCR
* register
*/
if (stream < 4)
{
regoffset = STM32_DMA_LIFCR_OFFSET;
}
else
{
regoffset = STM32_DMA_HIFCR_OFFSET;
}
dmabase_putreg(dmast, regoffset, (status << dmast->shift));
/* Invoke the callback */
if (dmast->callback)
{
dmast->callback(dmast, status, dmast->arg);
}
return OK;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: stm32_dmainitialize
*
* Description:
* Initialize the DMA subsystem
*
* Returned Value:
* None
*
****************************************************************************/
void weak_function up_dmainitialize(void)
{
struct stm32_dma_s *dmast;
int stream;
/* Initialize each DMA stream */
for (stream = 0; stream < DMA_NSTREAMS; stream++)
{
dmast = &g_dma[stream];
sem_init(&dmast->sem, 0, 1);
/* Attach DMA interrupt vectors */
(void)irq_attach(dmast->irq, stm32_dmainterrupt);
/* Disable the DMA stream */
stm32_dmastreamdisable(dmast);
/* Enable the IRQ at the NVIC (still disabled at the DMA controller) */
up_enable_irq(dmast->irq);
/* Set the interrrupt priority */
up_prioritize_irq(dmast->irq, CONFIG_DMA_PRI);
}
}
/****************************************************************************
* Name: stm32_dmachannel
*
* Description:
* Allocate a DMA channel. This function gives the caller mutually
* exclusive access to the DMA channel specified by the 'dmamap' argument.
* DMA channels are shared on the STM32: Devices sharing the same DMA
* channel cannot do DMA concurrently! See the DMACHAN_* definitions in
* stm32_dma.h.
*
* If the DMA channel is not available, then stm32_dmachannel() will wait
* until the holder of the channel relinquishes the channel by calling
* stm32_dmafree(). WARNING: If you have two devices sharing a DMA
* channel and the code never releases the channel, the stm32_dmachannel
* call for the other will hang forever in this function! Don't let your
* design do that!
*
* Hmm.. I suppose this interface could be extended to make a non-blocking
* version. Feel free to do that if that is what you need.
*
* Input parameter:
* dmamap - Identifies the stream/channel resource. For the STM32 F2, this
* is a bit-encoded value as provided by the the DMAMAP_* definitions
* in chip/stm32f20xxx_dma.h
*
* Returned Value:
* Provided that 'dmamap' is valid, this function ALWAYS returns a non-NULL,
* void* DMA channel handle. (If 'dmamap' is invalid, the function will
* assert if debug is enabled or do something ignorant otherwise).
*
* Assumptions:
* - The caller does not hold he DMA channel.
* - The caller can wait for the DMA channel to be freed if it is no
* available.
*
****************************************************************************/
DMA_HANDLE stm32_dmachannel(unsigned int dmamap)
{
FAR struct stm32_dma_s *dmast;
/* Get the stream index from the bit-encoded channel value */
dmast = stm32_dmamap(dmamap);
DEBUGASSERT(dmast != NULL);
/* Get exclusive access to the DMA channel -- OR wait until the channel
* is available if it is currently being used by another driver
*/
stm32_dmatake(dmast);
/* The caller now has exclusive use of the DMA channel. Assign the
* channel to the stream and return an opaque reference to the stream
* structure.
*/
dmast->channel = STM32_DMA_CHANNEL(dmamap);
return (DMA_HANDLE)dmast;
}
/****************************************************************************
* Name: stm32_dmafree
*
* Description:
* Release a DMA channel. If another thread is waiting for this DMA channel
* in a call to stm32_dmachannel, then this function will re-assign the
* DMA channel to that thread and wake it up. NOTE: The 'handle' used
* in this argument must NEVER be used again until stm32_dmachannel() is
* called again to re-gain access to the channel.
*
* Returned Value:
* None
*
* Assumptions:
* - The caller holds the DMA channel.
* - There is no DMA in progress
*
****************************************************************************/
void stm32_dmafree(DMA_HANDLE handle)
{
struct stm32_dma_s *dmast = (struct stm32_dma_s *)handle;
DEBUGASSERT(handle != NULL);
/* Release the channel */
stm32_dmagive(dmast);
}
/****************************************************************************
* Name: stm32_dmasetup
*
* Description:
* Configure DMA before using
*
****************************************************************************/
void stm32_dmasetup(DMA_HANDLE handle, uint32_t paddr, uint32_t maddr,
size_t ntransfers, uint32_t scr)
{
struct stm32_dma_s *dmast = (struct stm32_dma_s *)handle;
uint32_t regoffset;
uint32_t regval;
dmadbg("paddr: %08x maddr: %08x ntransfers: %d scr: %08x\n",
paddr, maddr, ntransfers, scr);
/* "If the stream is enabled, disable it by resetting the EN bit in the
* DMA_SxCR register, then read this bit in order to confirm that there is no
* ongoing stream operation. Writing this bit to 0 is not immediately
* effective since it is actually written to 0 once all the current transfers
* have finished. When the EN bit is read as 0, this means that the stream is
* ready to be configured. It is therefore necessary to wait for the EN bit
* to be cleared before starting any stream configuration. ..."
*/
while ((dmast_getreg(dmast, STM32_DMA_SCR_OFFSET) & DMA_SCR_EN) != 0);
/* "... All the stream dedicated bits set in the status register (DMA_LISR
* and DMA_HISR) from the previous data block DMA transfer should be cleared
* before the stream can be re-enabled."
*
* Clear pending stream interrupts by setting bits in the upper or lower IFCR
* register
*/
if (dmast->stream < 4)
{
regoffset = STM32_DMA_LIFCR_OFFSET;
}
else
{
regoffset = STM32_DMA_HIFCR_OFFSET;
}
dmabase_putreg(dmast, regoffset, (DMA_STREAM_MASK << dmast->shift));
/* "Set the peripheral register address in the DMA_SPARx register. The data
* will be moved from/to this address to/from the memory after the
* peripheral event.
*/
dmast_putreg(dmast, STM32_DMA_SPAR_OFFSET, paddr);
/* "Set the memory address in the DMA_SM0ARx ... register. The data will be
* written to or read from this memory after the peripheral event."
*
* Note that in double-buffered mode it is explicitly assumed that the second
* buffer immediately follows the first.
*/
dmast_putreg(dmast, STM32_DMA_SM0AR_OFFSET, maddr);
if (scr & DMA_SCR_DBM)
{
dmast_putreg(dmast, STM32_DMA_SM1AR_OFFSET, maddr + ntransfers);
}
/* "Configure the total number of data items to be transferred in the
* DMA_SNDTRx register. After each peripheral event, this value will be
* decremented."
*
* "When the peripheral flow controller is used for a given stream, the value
* written into the DMA_SxNDTR has no effect on the DMA transfer. Actually,
* whatever the value written, it will be forced by hardware to 0xFFFF as soon
* as the stream is enabled..."
*/
dmast_putreg(dmast, STM32_DMA_SNDTR_OFFSET, ntransfers);
/* "Select the DMA channel (request) using CHSEL[2:0] in the DMA_SxCR register."
*
* "Configure the stream priority using the PL[1:0] bits in the DMA_SCRx"
* register."
*/
regval = dmast_getreg(dmast, STM32_DMA_SCR_OFFSET);
regval &= ~(DMA_SCR_PL_MASK|DMA_SCR_CHSEL_MASK);
regval |= scr & DMA_SCR_PL_MASK;
regval |= (uint32_t)dmast->channel << DMA_SCR_CHSEL_SHIFT;
dmast_putreg(dmast, STM32_DMA_SCR_OFFSET, regval);
/* "Configure the FIFO usage (enable or disable, threshold in transmission and
* reception)"
*
* "Caution is required when choosing the FIFO threshold (bits FTH[1:0] of the
* DMA_SxFCR register) and the size of the memory burst (MBURST[1:0] of the
* DMA_SxCR register): The content pointed by the FIFO threshold must exactly
* match to an integer number of memory burst transfers. If this is not in the
* case, a FIFO error (flag FEIFx of the DMA_HISR or DMA_LISR register) will be
* generated when the stream is enabled, then the stream will be automatically
* disabled."
*
* The FIFO is disabled in circular mode when transferring data from a
* peripheral to memory, as in this case it is usually desirable to know that
* every byte from the peripheral is transferred immediately to memory. It is
* not practical to flush the DMA FIFO, as this requires disabling the channel
* which triggers the transfer-complete interrupt.
*
* NOTE: The FEIFx error interrupt is not enabled because the FEIFx seems to
* be reported spuriously causing good transfers to be marked as failures.
*/
regval = dmast_getreg(dmast, STM32_DMA_SFCR_OFFSET);
regval &= ~(DMA_SFCR_FTH_MASK | DMA_SFCR_FS_MASK | DMA_SFCR_FEIE);
if (!((scr & (DMA_SCR_CIRC | DMA_SCR_DIR_MASK)) == (DMA_SCR_CIRC | DMA_SCR_DIR_P2M)))
{
regval |= (DMA_SFCR_FTH_FULL | DMA_SFCR_DMDIS);
}
dmast_putreg(dmast, STM32_DMA_SFCR_OFFSET, regval);
/* "Configure data transfer direction, circular mode, peripheral & memory
* incremented mode, peripheral & memory data size, and interrupt after
* half and/or full transfer in the DMA_CCRx register."
*
* Note: The CT bit is always reset.
*/
regval = dmast_getreg(dmast, STM32_DMA_SCR_OFFSET);
regval &= ~(DMA_SCR_PFCTRL|DMA_SCR_DIR_MASK|DMA_SCR_PINC|DMA_SCR_MINC|
DMA_SCR_PSIZE_MASK|DMA_SCR_MSIZE_MASK|DMA_SCR_PINCOS|
DMA_SCR_CIRC|DMA_SCR_DBM|DMA_SCR_CT|
DMA_SCR_PBURST_MASK|DMA_SCR_MBURST_MASK);
scr &= (DMA_SCR_PFCTRL|DMA_SCR_DIR_MASK|DMA_SCR_PINC|DMA_SCR_MINC|
DMA_SCR_PSIZE_MASK|DMA_SCR_MSIZE_MASK|DMA_SCR_PINCOS|
DMA_SCR_DBM|DMA_SCR_CIRC|
DMA_SCR_PBURST_MASK|DMA_SCR_MBURST_MASK);
regval |= scr;
dmast->nonstop = (scr & (DMA_SCR_DBM|DMA_SCR_CIRC)) != 0;
dmast_putreg(dmast, STM32_DMA_SCR_OFFSET, regval);
}
/****************************************************************************
* Name: stm32_dmastart
*
* Description:
* Start the DMA transfer
*
* Assumptions:
* - DMA handle allocated by stm32_dmachannel()
* - No DMA in progress
*
****************************************************************************/
void stm32_dmastart(DMA_HANDLE handle, dma_callback_t callback, void *arg, bool half)
{
struct stm32_dma_s *dmast = (struct stm32_dma_s *)handle;
uint32_t scr;
DEBUGASSERT(handle != NULL);
/* Save the callback info. This will be invoked whent the DMA commpletes */
dmast->callback = callback;
dmast->arg = arg;
/* Activate the stream by setting the ENABLE bit in the DMA_SCRx register.
* As soon as the stream is enabled, it can serve any DMA request from the
* peripheral connected on the stream.
*/
scr = dmast_getreg(dmast, STM32_DMA_SCR_OFFSET);
scr |= DMA_SCR_EN;
if (!dmast->nonstop)
{
/* Once half of the bytes are transferred, the half-transfer flag (HTIF) is
* set and an interrupt is generated if the Half-Transfer Interrupt Enable
* bit (HTIE) is set. At the end of the transfer, the Transfer Complete Flag
* (TCIF) is set and an interrupt is generated if the Transfer Complete
* Interrupt Enable bit (TCIE) is set.
*/
scr |= (half ? (DMA_SCR_HTIE|DMA_SCR_TEIE) : (DMA_SCR_TCIE|DMA_SCR_TEIE));
}
else
{
/* In nonstop mode, when the transfer completes it immediately resets
* and starts again. The transfer-complete interrupt is thus always
* enabled, and the half-complete interrupt can be used in circular
* mode to determine when the buffer is half-full, or in double-buffered
* mode to determine when one of the two buffers is full.
*/
scr |= (half ? DMA_SCR_HTIE : 0) | DMA_SCR_TCIE | DMA_SCR_TEIE;
}
dmast_putreg(dmast, STM32_DMA_SCR_OFFSET, scr);
}
/****************************************************************************
* Name: stm32_dmastop
*
* Description:
* Cancel the DMA. After stm32_dmastop() is called, the DMA channel is
* reset and stm32_dmasetup() must be called before stm32_dmastart() can be
* called again
*
* Assumptions:
* - DMA handle allocated by stm32_dmachannel()
*
****************************************************************************/
void stm32_dmastop(DMA_HANDLE handle)
{
struct stm32_dma_s *dmast = (struct stm32_dma_s *)handle;
stm32_dmastreamdisable(dmast);
}
/****************************************************************************
* Name: stm32_dmaresidual
*
* Description:
* Read the DMA bytes-remaining register.
*
* Assumptions:
* - DMA handle allocated by stm32_dmachannel()
*
****************************************************************************/
size_t stm32_dmaresidual(DMA_HANDLE handle)
{
struct stm32_dma_s *dmast = (struct stm32_dma_s *)handle;
uint32_t residual;
/* Fetch the count of bytes remaining to be transferred.
*
* If the FIFO is enabled, this count may be inaccurate. ST don't
* appear to document whether this counts the peripheral or the memory
* side of the channel, and they don't make the memory pointer
* available either.
*
* For reception in circular mode the FIFO is disabled in order that
* this value can be useful.
*/
residual = dmast_getreg(dmast, STM32_DMA_SNDTR_OFFSET);
return (size_t)residual;
}
/****************************************************************************
* Name: stm32_dmasample
*
* Description:
* Sample DMA register contents
*
* Assumptions:
* - DMA handle allocated by stm32_dmachannel()
*
****************************************************************************/
#ifdef CONFIG_DEBUG_DMA
void stm32_dmasample(DMA_HANDLE handle, struct stm32_dmaregs_s *regs)
{
struct stm32_dma_s *dmast = (struct stm32_dma_s *)handle;
irqstate_t flags;
flags = irqsave();
regs->lisr = dmabase_getreg(dmast, STM32_DMA_LISR_OFFSET);
regs->hisr = dmabase_getreg(dmast, STM32_DMA_HISR_OFFSET);
regs->scr = dmast_getreg(dmast, STM32_DMA_SCR_OFFSET);
regs->sndtr = dmast_getreg(dmast, STM32_DMA_SNDTR_OFFSET);
regs->spar = dmast_getreg(dmast, STM32_DMA_SPAR_OFFSET);
regs->sm0ar = dmast_getreg(dmast, STM32_DMA_SM0AR_OFFSET);
regs->sm1ar = dmast_getreg(dmast, STM32_DMA_SM1AR_OFFSET);
regs->sfcr = dmast_getreg(dmast, STM32_DMA_SFCR_OFFSET);
irqrestore(flags);
}
#endif
/****************************************************************************
* Name: stm32_dmadump
*
* Description:
* Dump previously sampled DMA register contents
*
* Assumptions:
* - DMA handle allocated by stm32_dmachannel()
*
****************************************************************************/
#ifdef CONFIG_DEBUG_DMA
void stm32_dmadump(DMA_HANDLE handle, const struct stm32_dmaregs_s *regs,
const char *msg)
{
struct stm32_dma_s *dmast = (struct stm32_dma_s *)handle;
uint32_t dmabase = DMA_BASE(dmast->base);
dmadbg("DMA Registers: %s\n", msg);
dmadbg(" LISR[%08x]: %08x\n", dmabase + STM32_DMA_LISR_OFFSET, regs->lisr);
dmadbg(" HISR[%08x]: %08x\n", dmabase + STM32_DMA_HISR_OFFSET, regs->hisr);
dmadbg(" SCR[%08x]: %08x\n", dmast->base + STM32_DMA_SCR_OFFSET, regs->scr);
dmadbg(" SNDTR[%08x]: %08x\n", dmast->base + STM32_DMA_SNDTR_OFFSET, regs->sndtr);
dmadbg(" SPAR[%08x]: %08x\n", dmast->base + STM32_DMA_SPAR_OFFSET, regs->spar);
dmadbg(" SM0AR[%08x]: %08x\n", dmast->base + STM32_DMA_SM0AR_OFFSET, regs->sm0ar);
dmadbg(" SM1AR[%08x]: %08x\n", dmast->base + STM32_DMA_SM1AR_OFFSET, regs->sm1ar);
dmadbg(" SFCR[%08x]: %08x\n", dmast->base + STM32_DMA_SFCR_OFFSET, regs->sfcr);
}
#endif
#endif /* CONFIG_STM32_STM32F20XX */
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