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A little more DMA logic

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git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@2556 42af7a65-404d-4744-a932-0658087f49c3
This commit is contained in:
patacongo 2010-03-27 02:07:51 +00:00
parent b4a3a986cd
commit 785ce264d9
5 changed files with 154 additions and 118 deletions
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2
arch/arm/src/sam3u/chip.h
View File

@ -58,8 +58,6 @@
/* DMA */
# define CONFIG_SAM3U_NDMACHAN 4 /* 4 DMA Channels */
# define CONFIG_SAM3U_DMACHAN8SET 0x07 /* DMA Channels 0-2 have 8-byte FIFOs */
# define CONFIG_SAM3U_DMACHAN32SET 0x08 /* DMA channel 3 has a 32-byte FIFO */
/* Memory card interface */

213
arch/arm/src/sam3u/sam3u_dmac.c
View File

@ -68,44 +68,54 @@
struct sam3u_dma_s
{
uint8_t chan; /* DMA channel number (0-6) */
// uint8_t irq; /* DMA channel IRQ number */
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 */
uint8_t chan; /* DMA channel number (0-6) */
uint8_t fifosize; /* Size of DMA FIFO in btyes */
bool inuse; /* TRUE: The DMA channel is in use */
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 */
volatile uint16_t xfrsize; /* Total transfer size */
};
/****************************************************************************
* Private Data
****************************************************************************/
/* This semaphore protects the DMA channel table */
static sem_t g_dmasem;
/* 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
static struct sam3u_dma_s g_dma[CONFIG_SAM3U_NDMACHAN] =
{
{
.chan = 0,
// .irq = SAM3U_IRQ_DMA1CH1,
.fifosize = 8,
.base = SAM3U_DMACHAN0_BASE,
},
{
.chan = 1,
// .irq = SAM3U_IRQ_DMA1CH2,
.fifosize = 8,
.base = SAM3U_DMACHAN1_BASE,
},
{
.chan = 2,
// .irq = SAM3U_IRQ_DMA1CH3,
.fifosize = 8,
.base = SAM3U_DMACHAN2_BASE,
},
{
.chan = 3,
// .irq = SAM3U_IRQ_DMA1CH4,
.fifosize = 32,
.base = SAM3U_DMACHAN3_BASE,
}
};
@ -122,11 +132,11 @@ static struct sam3u_dma_s g_dma[CONFIG_SAM3U_NDMACHAN] =
*
************************************************************************************/
static void sam3u_dmatake(FAR struct sam3u_dma_s *dmach)
static void sam3u_dmatake(void)
{
/* Take the semaphore (perhaps waiting) */
while (sem_wait(&dmach->sem) != 0)
while (sem_wait(&g_dmasem) != 0)
{
/* The only case that an error should occur here is if the wait was awakened
* by a signal.
@ -136,27 +146,9 @@ static void sam3u_dmatake(FAR struct sam3u_dma_s *dmach)
}
}
static inline void sam3u_dmagive(FAR struct sam3u_dma_s *dmach)
static inline void sam3u_dmagive(void)
{
(void)sem_post(&dmach->sem);
}
/************************************************************************************
* Name: sam3u_dmachandisable
*
* Description:
* Disable the DMA channel
*
************************************************************************************/
static void sam3u_dmachandisable(struct sam3u_dma_s *dmach)
{
/* Disable all interrupts at the DMA controller */
/* Disable the DMA channel */
/* Clear pending channel interrupts */
# warning "Missing logic"
(void)sem_post(&g_dmasem);
}
/************************************************************************************
@ -190,27 +182,30 @@ static int sam3u_dmainterrupt(int irq, void *context)
void weak_function up_dmainitialize(void)
{
struct sam3u_dma_s *dmach;
int chndx;
/* Initialize each DMA channel */
/* Enable peripheral clock */
for (chndx = 0; chndx < CONFIG_SAM3U_NDMACHAN; chndx++)
{
dmach = &g_dma[chndx];
sem_init(&dmach->sem, 0, 1);
putreg32((1 << SAM3U_PID_DMAC), SAM3U_PMC_PCER);
/* Attach DMA interrupt vectors */
/* Disable all DMA interrupts */
// (void)irq_attach(dmach->irq, sam3u_dmainterrupt);
putreg32(DMAC_DBC_ERR_ALLINTS, SAM3U_DMAC_EBCIDR);
/* Disable the DMA channel */
/* Disable all DMA channels */
sam3u_dmachandisable(dmach);
putreg32(DMAC_CHDR_DIS_ALL, SAM3U_DMAC_CHDR);
/* Enable the IRQ at the NVIC (still disabled at the DMA controller) */
/* Attach DMA interrupt vector */
// up_enable_irq(dmach->irq);
}
(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);
}
/****************************************************************************
@ -218,46 +213,56 @@ void weak_function up_dmainitialize(void)
*
* Description:
* Allocate a DMA channel. This function gives the caller mutually
* exclusive access to the DMA channel specified by the 'chndx' argument.
* DMA channels are shared on the SAM3U: Devices sharing the same DMA
* channel cannot do DMA concurrently! See the DMACHAN_* definitions in
* sam3u_dma.h.
*
* If the DMA channel is not available, then sam3u_dmachannel() will wait
* until the holder of the channel relinquishes the channel by calling
* sam3u_dmafree(). WARNING: If you have two devices sharing a DMA
* channel and the code never releases the channel, the sam3u_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.
* sets aside a DMA channel with the required FIFO size and gives the
* caller exclusive access to the DMA channelt.
*
* Returned Value:
* Provided that 'chndx' is valid, this function ALWAYS returns a non-NULL,
* void* DMA channel handle. (If 'chndx' 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.
* 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(int chndx)
DMA_HANDLE sam3u_dmachannel(unsigned int fifosize)
{
struct sam3u_dma_s *dmach = &g_dma[chndx];
struct sam3u_dma_s *dmach;
unsigned int chndx;
uint32_t regval;
DEBUGASSERT(chndx < CONFIG_SAM3U_NDMACHAN);
/* Get exclusive access to the DMA channel -- OR wait until the channel
* is available if it is currently being used by another driver
/* Search for an available DMA channel with at least the requested FIFO
* size.
*/
sam3u_dmatake(dmach);
dmach = NULL;
sam3u_dmatake();
for (chndx = 0; chndx < CONFIG_SAM3U_NDMACHAN; chndx++)
{
struct sam3u_dma_s *candidate = &g_dma[chndx];
if (!candidate->inuse && candidate->fifosize >= fifosize)
{
dmach = candidate;
dmach->inuse = true;
break;
}
}
sam3u_dmagive();
/* The caller now has exclusive use of the DMA channel */
/* Did we get one? */
if (dmach)
{
/* 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);
/* Initilize the transfer size */
dmach->xfrsize = 0;
}
return (DMA_HANDLE)dmach;
}
@ -266,41 +271,51 @@ DMA_HANDLE sam3u_dmachannel(int chndx)
* Name: sam3u_dmafree
*
* Description:
* Release a DMA channel. If another thread is waiting for this DMA channel
* in a call to sam3u_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 sam3u_dmachannel() is
* called again to re-gain access to the channel.
* 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
*
* Assumptions:
* - The caller holds the DMA channel.
* - There is no DMA in progress
*
****************************************************************************/
void sam3u_dmafree(DMA_HANDLE handle)
{
struct sam3u_dma_s *dmach = (struct sam3u_dma_s *)handle;
DEBUGASSERT(handle != NULL);
/* Mark the channel no longer in use. This is an atomic operation and so
* should be safe.
*/
/* Release the channel */
sam3u_dmagive(dmach);
DEBUGASSERT(dmach != NULL);
dmach->inuse = true;
}
/****************************************************************************
* Name: sam3u_dmasetup
* Name: sam3u_dmatxsetup
*
* Description:
* Configure DMA before using
* Configure DMA for transmit (memory to peripheral) before using
*
****************************************************************************/
void sam3u_dmasetup(DMA_HANDLE handle, uint32_t paddr, uint32_t maddr, size_t ntransfers, uint32_t ccr)
void sam3u_dmarxsetup(DMA_HANDLE handle, uint32_t paddr, uint32_t maddr, size_t ntransfers, uint32_t ccr)
{
struct sam3u_dma_s *dmach = (struct sam3u_dma_s *)handle;
uint32_t regval;
# warning "Missing logic"
}
/****************************************************************************
* Name: sam3u_dmarxsetup
*
* Description:
* Configure DMA for receuve (peripheral to memory) before using
*
****************************************************************************/
void sam3u_dmarxsetup(DMA_HANDLE handle, uint32_t paddr, uint32_t maddr, size_t ntransfers, uint32_t ccr)
{
struct sam3u_dma_s *dmach = (struct sam3u_dma_s *)handle;
uint32_t regval;
@ -348,7 +363,11 @@ void sam3u_dmastart(DMA_HANDLE handle, dma_callback_t callback, void *arg, bool
void sam3u_dmastop(DMA_HANDLE handle)
{
struct sam3u_dma_s *dmach = (struct sam3u_dma_s *)handle;
sam3u_dmachandisable(dmach);
/* Disable the channel by writing one to the write-only channel disable register */
DEBUGASSERT(dmach != NULL);
putreg32(DMAC_CHDR_DIS(dmach->chan), SAM3U_DMAC_CHDR);
}
/****************************************************************************
@ -368,7 +387,11 @@ 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 */
/* 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);

2
arch/arm/src/sam3u/sam3u_dmac.h
View File

@ -263,6 +263,7 @@
# define DMAC_EBC_ERR1 (1 << (DMAC_EBC_ERR_SHIFT+1))
# define DMAC_EBC_ERR2 (1 << (DMAC_EBC_ERR_SHIFT+2))
# define DMAC_EBC_ERR3 (1 << (DMAC_EBC_ERR_SHIFT+3))
#define DMAC_DBC_ERR_ALLINTS (0x000f0f0f)
/* DMAC Channel Handler Enable Register */
@ -297,6 +298,7 @@
# define DMAC_CHDR_DIS1 (1 << (DMAC_CHDR_DIS_SHIFT+1))
# define DMAC_CHDR_DIS2 (1 << (DMAC_CHDR_DIS_SHIFT+2))
# define DMAC_CHDR_DIS3 (1 << (DMAC_CHDR_DIS_SHIFT+3))
# define DMAC_CHDR_DIS_ALL DMAC_CHDR_DIS_MASK
#define DMAC_CHDR_RES_SHIFT (8) /* Bits 8-11: Resume trasnfer, restoring context */
#define DMAC_CHDR_RES_MASK (15 << DMAC_CHDR_RES_SHIFT)
# define DMAC_CHDR_RES(n) (1 << (DMAC_CHDR_RES_SHIFT+(n)))

12
arch/arm/src/sam3u/sam3u_hsmci.c
View File

@ -2346,8 +2346,8 @@ static int sam3u_dmarecvsetup(FAR struct sdio_dev_s *dev, FAR uint8_t *buffer,
sam3u_enablexfrints(priv, HSMCI_DMARECV_INTS);
putreg32(1, HSMCI_DCTRL_DMAEN_BB);
sam3u_dmasetup(priv->dma, SAM3U_HSMCI_FIFO, (uint32_t)buffer,
(buflen + 3) >> 2, HSMCI_RXDMA32_CONFIG);
sam3u_dmarxsetup(priv->dma, SAM3U_HSMCI_FIFO, (uint32_t)buffer,
(buflen + 3) >> 2, HSMCI_RXDMA32_CONFIG);
/* Start the DMA */
@ -2412,8 +2412,8 @@ static int sam3u_dmasendsetup(FAR struct sdio_dev_s *dev,
/* Configure the TX DMA */
sam3u_dmasetup(priv->dma, SAM3U_HSMCI_FIFO, (uint32_t)buffer,
(buflen + 3) >> 2, HSMCI_TXDMA32_CONFIG);
sam3u_dmatxsetup(priv->dma, SAM3U_HSMCI_FIFO, (uint32_t)buffer,
(buflen + 3) >> 2, HSMCI_TXDMA32_CONFIG);
sam3u_sample(priv, SAMPLENDX_BEFORE_ENABLE);
putreg32(1, HSMCI_DCTRL_DMAEN_BB);
@ -2543,9 +2543,9 @@ FAR struct sdio_dev_s *sdio_initialize(int slotno)
priv->waitwdog = wd_create();
DEBUGASSERT(priv->waitwdog);
/* Allocate a DMA channel */
/* Allocate a DMA channel. A FIFO size of 8 is sufficient. */
priv->dma = sam3u_dmachannel();
priv->dma = sam3u_dmachannel(8);
DEBUGASSERT(priv->dma);
/* Configure GPIOs for 4-bit, wide-bus operation. NOTE: (1) the chip is capable of

43
arch/arm/src/sam3u/sam3u_internal.h
View File

@ -461,41 +461,39 @@ EXTERN void sam3u_gpioirqdisable(int irq);
* Name: sam3u_dmachannel
*
* Description:
* Allocate a DMA channel. This function sets aside a DMA channel and
* gives the caller mutually exclusive access to the DMA channel.
* Allocate a DMA channel. This function gives the caller mutually
* sets aside a DMA channel with the required FIFO size and gives the
* caller exclusive access to the DMA channelt.
*
* Returned Value:
* One success, this function ALWAYS will return a non-NULL, DMA channel
* handle.
* 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.
*
****************************************************************************/
EXTERN DMA_HANDLE sam3u_dmachannel(void);
EXTERN DMA_HANDLE sam3u_dmachannel(unsigned int fifosize);
/****************************************************************************
* 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-allocate the channel.
* NEVER be used again until sam3u_dmachannel() is called again to re-gain
* a valid handle.
*
* Returned Value:
* None
*
* Assumptions:
* - The caller holds the DMA channel.
* - There is no DMA in progress
*
****************************************************************************/
EXTERN void sam3u_dmafree(DMA_HANDLE handle);
/****************************************************************************
* Name: sam3u_dmasetup
* Name: sam3u_dmatxsetup
*
* Description:
* Configure DMA before using
* Configure DMA for transmit (memory to periphal) before using
*
* Assumptions:
* - DMA handle allocated by sam3u_dmachannel()
@ -503,8 +501,23 @@ EXTERN void sam3u_dmafree(DMA_HANDLE handle);
*
****************************************************************************/
EXTERN void sam3u_dmasetup(DMA_HANDLE handle, uint32_t paddr, uint32_t maddr,
size_t ntransfers, uint32_t ccr);
EXTERN void sam3u_dmatxsetup(DMA_HANDLE handle, uint32_t paddr, uint32_t maddr,
size_t ntransfers, uint32_t ccr);
/****************************************************************************
* Name: sam3u_dmarxsetup
*
* Description:
* Configure DMA for receive (peripheral to memory) before using
*
* Assumptions:
* - DMA handle allocated by sam3u_dmachannel()
* - No DMA in progress
*
****************************************************************************/
EXTERN void sam3u_dmarxsetup(DMA_HANDLE handle, uint32_t paddr, uint32_t maddr,
size_t ntransfers, uint32_t ccr);
/****************************************************************************
* Name: sam3u_dmastart