diff --git a/arch/arm/src/lpc17xx/lpc17_gpdma.c b/arch/arm/src/lpc17xx/lpc17_gpdma.c index 6ccc8e4ef5..ee12b1b229 100644 --- a/arch/arm/src/lpc17xx/lpc17_gpdma.c +++ b/arch/arm/src/lpc17xx/lpc17_gpdma.c @@ -70,8 +70,9 @@ struct lpc17_dmach_s { + uint8_t chn; /* The DMA channel number */ bool inuse; /* True: The channel is in use */ - uint8_t chn; /* Channel number */ + bool inprogress; /* True: DMA is in progress on this channel */ dma_callback_t callback; /* DMA completion callback function */ void *arg; /* Argument to pass to the callback function */ }; @@ -102,10 +103,80 @@ static struct lpc17_gpdma_s g_gpdma; * Public Data ****************************************************************************/ +/* If the following value is zero, then there is no DMA in progress. This + * value is needed in the IDLE loop to determine if the IDLE loop should + * go into lower power power consumption modes. According to the LPC17xx + * User Manual: "The DMA controller can continue to work in Sleep mode, and + * has access to the peripheral SRAMs and all peripheral registers. The + * flash memory and the Main SRAM are not available in Sleep mode, they are + * disabled in order to save power." + */ + +volatile uint8_t g_dma_inprogress; + /**************************************************************************** * Private Functions ****************************************************************************/ +/**************************************************************************** + * Name: lpc17_dmainprogress + * + * Description: + * Another DMA has started. Increment the g_dma_inprogress counter. + * + * Returned Value: + * None + * + ****************************************************************************/ + +static void lpc17_dmainprogress(struct lpc17_dmach_s *dmach) +{ + irqstate_t flags; + + /* Increment the DMA in progress counter */ + + flags = irqsave(); + DEBUGASSERT(!dmach->inprogress && g_dma_inprogress < LPC17_NDMACH); + g_dma_inprogress++; + dmach->inprogress = true; + irqrestore(flags); +} + +/**************************************************************************** + * Name: lpc17_dmadone + * + * Description: + * A DMA has completed. Decrement the g_dma_inprogress counter. + * + * This function is called only from lpc17_dmastop which, in turn, will be + * called either by the user directly, by the user indirectly via + * lpc17_dmafree(), or from gpdma_interrupt when the transfer completes. + * + * NOTE: In the first two cases, we must be able to handle the case where + * there is no DMA in progress and gracefully ignore the call. + * + * Returned Value: + * None + * + ****************************************************************************/ + +static void lpc17_dmadone(struct lpc17_dmach_s *dmach) +{ + irqstate_t flags; + + /* Increment the DMA in progress counter */ + + flags = irqsave(); + if (dmach->inprogress) + { + DEBUGASSERT(g_dma_inprogress > 0); + dmach->inprogress = false; + g_dma_inprogress--; + } + + irqrestore(flags); +} + /**************************************************************************** * Name: gpdma_interrupt * @@ -488,6 +559,14 @@ int lpc17_dmastart(DMA_HANDLE handle, dma_callback_t callback, void *arg) dmach->callback = callback; dmach->arg = arg; + /* Increment the count of DMAs in-progress. This count will be + * decremented when lpc17_dmastop() is called, either by the user, + * indirectly via lpc17_dmafree(), or from gpdma_interrupt when the + * transfer completes. + */ + + lpc17_dmainprogress(dmach); + /* Clear any pending DMA interrupts */ chbit = DMACH((uint32_t)dmach->chn); @@ -521,6 +600,10 @@ int lpc17_dmastart(DMA_HANDLE handle, dma_callback_t callback, void *arg) * reset and lpc17_dmasetup() must be called before lpc17_dmastart() can be * called again * + * This function will be called either by the user directly, by the user + * indirectly via lpc17_dmafree(), or from gpdma_interrupt when the + * transfer completes. + * ****************************************************************************/ void lpc17_dmastop(DMA_HANDLE handle) @@ -547,6 +630,10 @@ void lpc17_dmastop(DMA_HANDLE handle) chbit = DMACH((uint32_t)dmach->chn); putreg32(chbit, LPC17_DMA_INTTCCLR); putreg32(chbit, LPC17_DMA_INTERRCLR); + + /* Decrement the count of DMAs in progress */ + + lpc17_dmadone(dmach); } /**************************************************************************** diff --git a/arch/arm/src/lpc17xx/lpc17_gpdma.h b/arch/arm/src/lpc17xx/lpc17_gpdma.h index 43bdb27eac..0136ac105f 100644 --- a/arch/arm/src/lpc17xx/lpc17_gpdma.h +++ b/arch/arm/src/lpc17xx/lpc17_gpdma.h @@ -1,4 +1,4 @@ -/************************************************************************************ +/**************************************************************************** * arch/arm/src/lpc17xx/lpc17_gpdma.h * * Copyright (C) 2010, 2013 Gregory Nutt. All rights reserved. @@ -31,36 +31,37 @@ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * - ************************************************************************************/ + ****************************************************************************/ #ifndef __ARCH_ARM_SRC_LPC17XX_LPC17_GPDMA_H #define __ARCH_ARM_SRC_LPC17XX_LPC17_GPDMA_H -/************************************************************************************ +/**************************************************************************** * Included Files - ************************************************************************************/ + ****************************************************************************/ #include #include "chip/lpc17_gpdma.h" -/************************************************************************************ +/**************************************************************************** * Pre-processor Definitions - ************************************************************************************/ + ****************************************************************************/ -/************************************************************************************ +/**************************************************************************** * Public Types - ************************************************************************************/ + ****************************************************************************/ #ifdef CONFIG_LPC17_GPDMA /* DMA_HANDLE is an opaque reference to an allocated DMA channel */ typedef FAR void *DMA_HANDLE; -/* dma_callback_t a function pointer provided to lpc17_dmastart. This function is - * called at the completion of the DMA transfer. 'arg' is the same 'arg' value - * that was provided when lpc17_dmastart() was called and result indicates the result - * of the transfer: Zero indicates a successful tranfers. On failure, a negated - * errno is returned indicating the general nature of the DMA faiure. +/* dma_callback_t a function pointer provided to lpc17_dmastart. This + * function is called at the completion of the DMA transfer. 'arg' is the + * same 'arg' value that was provided when lpc17_dmastart() was called and + * result indicates the result of the transfer: Zero indicates a successful + * tranfers. On failure, a negated errno is returned indicating the general + * nature of the DMA faiure. */ typedef void (*dma_callback_t)(DMA_HANDLE handle, void *arg, int result); @@ -110,19 +111,34 @@ struct lpc17_dmaregs_s #endif /* CONFIG_DEBUG_DMA */ -/************************************************************************************ +/**************************************************************************** * Public Data - ************************************************************************************/ + ****************************************************************************/ #ifndef __ASSEMBLY__ -#ifdef __cplusplus +#undef EXTERN +#if defined(__cplusplus) +#define EXTERN extern "C" extern "C" { +#else +#define EXTERN extern #endif -/************************************************************************************ +/* If the following value is zero, then there is no DMA in progress. This + * value is needed in the IDLE loop to determine if the IDLE loop should + * go into lower power power consumption modes. According to the LPC17xx + * User Manual: "The DMA controller can continue to work in Sleep mode, and + * has access to the peripheral SRAMs and all peripheral registers. The + * flash memory and the Main SRAM are not available in Sleep mode, they are + * disabled in order to save power." + */ + +EXTERN volatile uint8_t g_dma_inprogress; + +/**************************************************************************** * Public Functions - ************************************************************************************/ + ****************************************************************************/ /**************************************************************************** * Name: up_dmainitialize @@ -244,6 +260,7 @@ void lpc17_dmadump(DMA_HANDLE handle, const struct lpc17_dmaregs_s *regs, # define lpc17_dmadump(handle,regs,msg) #endif +#undef EXTERN #ifdef __cplusplus } #endif diff --git a/arch/arm/src/lpc17xx/lpc17_idle.c b/arch/arm/src/lpc17xx/lpc17_idle.c index 88cd817f71..133847659b 100644 --- a/arch/arm/src/lpc17xx/lpc17_idle.c +++ b/arch/arm/src/lpc17xx/lpc17_idle.c @@ -41,7 +41,9 @@ #include #include + #include "up_internal.h" +#include "lpc17_gpdma.h" /**************************************************************************** * Pre-processor Definitions @@ -94,11 +96,25 @@ void up_idle(void) sched_process_timer(); #else - /* Sleep until an interrupt occurs to save power */ +/* If the g_dma_inprogress is zero, then there is no DMA in progress. This + * value is needed in the IDLE loop to determine if the IDLE loop should + * go into lower power power consumption modes. According to the LPC17xx + * User Manual: "The DMA controller can continue to work in Sleep mode, and + * has access to the peripheral SRAMs and all peripheral registers. The + * flash memory and the Main SRAM are not available in Sleep mode, they are + * disabled in order to save power." + */ - BEGIN_IDLE(); - asm("WFI"); - END_IDLE(); +#ifdef CONFIG_LPC17_GPDMA + if (g_dma_inprogress == 0) +#endif + { + /* Sleep until an interrupt occurs in order to save power */ + + BEGIN_IDLE(); + asm("WFI"); + END_IDLE(); + } #endif }