diff options
Diffstat (limited to 'nuttx/arch/arm/src/lpc17xx/lpc17_gpdma.c')
| -rw-r--r-- | nuttx/arch/arm/src/lpc17xx/lpc17_gpdma.c | 164 |
1 files changed, 162 insertions, 2 deletions
diff --git a/nuttx/arch/arm/src/lpc17xx/lpc17_gpdma.c b/nuttx/arch/arm/src/lpc17xx/lpc17_gpdma.c index 87ea30afb..696309b5f 100644 --- a/nuttx/arch/arm/src/lpc17xx/lpc17_gpdma.c +++ b/nuttx/arch/arm/src/lpc17xx/lpc17_gpdma.c @@ -42,7 +42,9 @@ #include <sys/types.h> #include <stdint.h> #include <stdbool.h> +#include <semaphore.h> #include <errno.h> +#include <assert.h> #include <debug.h> #include <nuttx/arch.h> @@ -82,6 +84,25 @@ /**************************************************************************** * Private Types ****************************************************************************/ +/* This structure represents the state of one DMA channel */ + +struct lpc17_dmach_s +{ + bool inuse; /* True: The channel is in use */ + dma_callback_t callback; /* DMA completion callback function */ + void *arg; /* Argument to pass to the callback function */ +}; + +/* This structure represents the state of the LPC17 DMA block */ + +struct lpc17_gpdma_s +{ + sem_t exclsem; /* For exclusive access to the DMA channel list */ + + /* This is the state of each DMA channel */ + + struct lpc17_dmach_s dmach[LPC17_NDMACH]; +}; /**************************************************************************** * Private Function Prototypes @@ -90,6 +111,9 @@ /**************************************************************************** * Private Data ****************************************************************************/ +/* The state of the LPC17 DMA block */ + +static struct lpc17_gpdma_s g_gpdma; /**************************************************************************** * Public Data @@ -116,6 +140,75 @@ void lpc17_dmainitilaize(void) { + uint32_t regval; + int i; + + /* Enable clocking to the GPDMA block */ + + regval = getreg32(LPC17_SYSCON_PCONP); + regval |= SYSCON_PCONP_PCGPDMA; + putreg32(regval, LPC17_SYSCON_PCONP); + + /* Reset all channel configurations */ + + for (i = 0; i < LPC17_NDMACH; i++) + { + putreg32(0, LPC17_DMACH_CONFIG(i)); + } + + /* Clear all DMA interrupts */ + + putreg32(DMACH_ALL, LPC17_DMA_INTTCCLR); + putreg32(DMACH_ALL, LPC17_DMA_INTERRCLR); + + /* Initialize the DMA state structure */ + + sem_init(&g_gpdma.exclsem, 0, 1); +} + +/**************************************************************************** + * Name: lpc17_dmaconfigure + * + * Description: + * Configure a DMA request. Each DMA request may have two different DMA + * request sources. This associates one of the sources with a DMA request. + * + * Returned Value: + * None + * + ****************************************************************************/ + +void lpc17_dmaconfigure(uint8_t dmarequest, bool alternate) +{ + uint32_t regval; + + DEBUGASSERT(dmarequest < LPC17_NDMAREQ); + +#ifdef LPC176x + /* For the LPC176x family, only request numbers 8-15 have DMASEL bits */ + + if (dmarequest < 8) + { + return; + } + + dmarequest -= 8; +#endif + + /* Set or clear the DMASEL bit corresponding to the request number */ + + regval = getreg32(LPC17_SYSCON_DMAREQSEL); + + if (alternate) + { + regval |= (1 << dmarequest); + } + else + { + regval &= ~(1 << dmarequest); + } + + putreg32(regval, LPC17_SYSCON_DMAREQSEL); } /**************************************************************************** @@ -134,7 +227,37 @@ void lpc17_dmainitilaize(void) DMA_HANDLE lpc17_dmachannel(void) { - return NULL; + struct lpc17_dmach_s *dmach = NULL; + int ret; + int i; + + /* Get exclusive access to the GPDMA state structure */ + + do + { + ret = sem_wait(&g_gpdma.exclsem); + DEBUGASSERT(ret == 0 || errno == EINTR); + } + while (ret < 0); + + /* Find an available DMA channel */ + + for (i = 0; i < LPC17_NDMACH; i++) + { + if (!g_gpdma.dmach[i].inuse) + { + /* Found one! */ + + dmach = &g_gpdma.dmach[i]; + g_gpdma.dmach[i].inuse = true; + break; + } + } + + /* Return what we found (or not) */ + + sem_post(&g_gpdma.exclsem); + return (DMA_HANDLE)dmach; } /**************************************************************************** @@ -152,6 +275,15 @@ DMA_HANDLE lpc17_dmachannel(void) void lpc17_dmafree(DMA_HANDLE handle) { + struct lpc17_dmach_s *dmach = (DMA_HANDLE)handle; + + DEBUGASSERT(dmach && dmach->inuse); + + /* Mark the channel available. This is an atomic operation and needs no + * special protection. + */ + + dmach->inuse = false; } /**************************************************************************** @@ -163,8 +295,13 @@ void lpc17_dmafree(DMA_HANDLE handle) ****************************************************************************/ int lpc17_dmasetup(DMA_HANDLE handle, uint32_t control, uint32_t config, - uint32_t srcaddr, uint32_t destaddr, size_t nbytes) + uint32_t srcaddr, uint32_t destaddr, size_t nxfrs) { + struct lpc17_dmach_s *dmach = (DMA_HANDLE)handle; + + DEBUGASSERT(dmach && dmach->inuse); +#warning "Missing logic" + return -ENOSYS; } @@ -178,6 +315,17 @@ int lpc17_dmasetup(DMA_HANDLE handle, uint32_t control, uint32_t config, int lpc17_dmastart(DMA_HANDLE handle, dma_callback_t callback, void *arg) { + struct lpc17_dmach_s *dmach = (DMA_HANDLE)handle; + + DEBUGASSERT(dmach && dmach->inuse && callback); + + /* Save the callback information */ + + dmach->callback = callback; + dmach->arg = arg; + + /* Start the DMA */ +#warning "Missing logic" return -ENOSYS; } @@ -193,6 +341,10 @@ int lpc17_dmastart(DMA_HANDLE handle, dma_callback_t callback, void *arg) void lpc17_dmastop(DMA_HANDLE handle) { + struct lpc17_dmach_s *dmach = (DMA_HANDLE)handle; + + DEBUGASSERT(dmach && dmach->inuse); +#warning "Missing logic" } /**************************************************************************** @@ -206,6 +358,10 @@ void lpc17_dmastop(DMA_HANDLE handle) #ifdef CONFIG_DEBUG_DMA void lpc17_dmasample(DMA_HANDLE handle, struct lpc17_dmaregs_s *regs) { + struct lpc17_dmach_s *dmach = (DMA_HANDLE)handle; + + DEBUGASSERT(dmach && dmach->inuse); +#warning "Missing logic" } #endif /* CONFIG_DEBUG_DMA */ @@ -220,6 +376,10 @@ void lpc17_dmasample(DMA_HANDLE handle, struct lpc17_dmaregs_s *regs) #ifdef CONFIG_DEBUG_DMA void lpc17_dmadump(DMA_HANDLE handle, const struct lpc17_dmaregs_s *regs, const char *msg) { + struct lpc17_dmach_s *dmach = (DMA_HANDLE)handle; + + DEBUGASSERT(dmach && dmach->inuse); +#warning "Missing logic" } #endif /* CONFIG_DEBUG_DMA */ |