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Diffstat (limited to 'os/hal/platforms/LPC17xx/lpc17xx_dma.c')
| -rw-r--r-- | os/hal/platforms/LPC17xx/lpc17xx_dma.c | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/os/hal/platforms/LPC17xx/lpc17xx_dma.c b/os/hal/platforms/LPC17xx/lpc17xx_dma.c new file mode 100644 index 000000000..b4ae57d31 --- /dev/null +++ b/os/hal/platforms/LPC17xx/lpc17xx_dma.c @@ -0,0 +1,205 @@ +/* + ChibiOS/RT - Copyright (C) 2006-2013 Giovanni Di Sirio + LPC17xx DMA driver - Copyright (C) 2013 Marcin Jokel + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +*/ + +/** + * @file LPC17xx/LPC17xx_dma.c + * @brief DMA driver code. + * + * @addtogroup LPC17xx_DMA + * @details DMA sharing helper driver. In the LPC17xx the DMA streams are a + * shared resource, this driver allows to allocate and free DMA + * streams at runtime in order to allow all the other device + * drivers to coordinate the access to the resource. + * @note The DMA ISR handlers are all declared into this module because + * sharing, the various device drivers can associate a callback to + * ISRs when allocating streams. + * @{ + */ + +#include "ch.h" +#include "hal.h" + +/* The following macro is only defined if some driver requiring DMA services + has been enabled.*/ +#if defined(LPC17xx_DMA_REQUIRED) || defined(__DOXYGEN__) + +/*===========================================================================*/ +/* Driver local definitions. */ +/*===========================================================================*/ + + +/*===========================================================================*/ +/* Driver exported variables. */ +/*===========================================================================*/ + + LPC_GPDMACH_TypeDef * \ + _lpc17xx_dma_channel_config_t[LPC17xx_DMA_CHANNELS] = { + LPC_GPDMACH0, LPC_GPDMACH1, LPC_GPDMACH2, LPC_GPDMACH3, LPC_GPDMACH4, + LPC_GPDMACH5, LPC_GPDMACH6, LPC_GPDMACH7 }; + +/*===========================================================================*/ +/* Driver local variables and types. */ +/*===========================================================================*/ + + +/*===========================================================================*/ +/* Driver local functions. */ +/*===========================================================================*/ + +/** + * @brief DMA ISR redirector type. + */ +typedef struct { + lpc17xx_dmaisr_t dma_func; /**< @brief DMA callback function. */ + void *dma_param; /**< @brief DMA callback parameter. */ +} dma_isr_redir_t; + +/** + * @brief Mask of the allocated streams. + */ +static uint32_t dma_streams_mask; + +/** + * @brief DMA IRQ redirectors. + */ +static dma_isr_redir_t dma_isr_redir[LPC17xx_DMA_CHANNELS]; + +/*===========================================================================*/ +/* Driver interrupt handlers. */ +/*===========================================================================*/ + +/** + * @brief DMA interrupt handler. + * + * @isr + */ +CH_IRQ_HANDLER(VectorA8) { + uint32_t irq_status; + uint32_t err_status; + uint8_t i; + + CH_IRQ_PROLOGUE(); + + irq_status = LPC_GPDMA->IntTCStat; + LPC_GPDMA->IntTCClear = irq_status; /* Clear DMA interrupt flag */ + err_status = LPC_GPDMA->IntErrStat; + LPC_GPDMA->IntErrClr = err_status; /* Clear DMA error flag if any*/ + + for (i = 0; i < LPC17xx_DMA_CHANNELS; i++) { + if (irq_status & (1UL << i)) { + if (dma_isr_redir[i].dma_func) + dma_isr_redir[i].dma_func(dma_isr_redir[i].dma_param, err_status); + } + } + + + CH_IRQ_EPILOGUE(); +} + +/*===========================================================================*/ +/* Driver exported functions. */ +/*===========================================================================*/ + +/** + * @brief LPC17xx DMA initialization. + * + * @init + */ +void dmaInit(void) { + uint8_t i; + + LPC_SC->PCONP |= (1UL << 29); /* Enable DMA power */ + + /* Disable all channels */ + for (i = 0; i < LPC17xx_DMA_CHANNELS; i++) + _lpc17xx_dma_channel_config_t[i]->CConfig = 0; + + LPC_GPDMA->IntTCClear = 0xFF; + LPC_GPDMA->IntErrClr = 0xFF; + + LPC_GPDMA->Config = DMACCONFIG_E; /* Enable DMA Controller */ + while((LPC_GPDMA->Config & DMACCONFIG_E) != 0x01) + ; + + nvicEnableVector(DMA_IRQn, CORTEX_PRIORITY_MASK(LPC17xx_DMA_IRQ_PRIORITY)); +} + +/** + * @brief Allocates a DMA channel. + * @details The channel is allocated. + * @pre The channel must not be already in use or an error is returned. + * @post The channel is allocated and the default ISR handler redirected + * to the specified function. + * @post The channel must be freed using @p dmaChannelRelease() before it can + * be reused with another peripheral. + * @note This function can be invoked in both ISR or thread context. + * + * @param[in] dmach DMA channel number + * @param[in] func handling function pointer, can be @p NULL + * @param[in] param a parameter to be passed to the handling function + * @return The operation status. + * @retval FALSE no error, stream taken. + * @retval TRUE error, stream already taken. + * + * @special + */ +bool_t dmaChannelAllocate(lpc17xx_dma_channel_t dmach, + lpc17xx_dmaisr_t func, + void *param) { + uint32_t channel; + channel = (1UL << dmach); + + /* Checks if the channel is already taken.*/ + if ((dma_streams_mask & channel) != 0) + return TRUE; + + /* Marks the stream as allocated.*/ + dma_isr_redir[dmach].dma_func = func; + dma_isr_redir[dmach].dma_param = param; + dma_streams_mask |= channel; + + return FALSE; +} + +/** + * @brief Releases a DMA channel. + * @details The channel is freed. + * Trying to release a unallocated channel is an illegal operation + * and is trapped if assertions are enabled. + * @pre The channel must have been allocated using @p dmaChannelAllocate(). + * @post The channel is again available. + * @note This function can be invoked in both ISR or thread context. + * + * @param[in] dmach DMA channel number + * + * @special + */ +void dmaChannelRelease(lpc17xx_dma_channel_t dmach) { + + uint32_t channel; + channel = (1UL << dmach); + + /* Check if the streams is not taken.*/ + chDbgAssert((dma_streams_mask & channel) != 0, + "dmaStreamRelease(), #1", "not allocated"); + + dma_streams_mask &= ~channel; /* Marks the stream as not allocated.*/ +} + +#endif /* LPC17xx_DMA_REQUIRED */ + +/** @} */ |