/* ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010, 2011 Giovanni Di Sirio. This file is part of ChibiOS/RT. ChibiOS/RT is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. ChibiOS/RT is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see . */ /** * @file DMAv1/stm32_dma.c * @brief DMA helper driver code. * * @addtogroup STM32_DMA * @details DMA sharing helper driver. In the STM32 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 * IRSs 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(STM32_DMA_REQUIRED) || defined(__DOXYGEN__) /*===========================================================================*/ /* Driver local definitions. */ /*===========================================================================*/ /** * @brief Mask of the DMA1 streams in @p dma_streams_mask. */ #define STM32_DMA1_STREAMS_MASK 0x0000007F /** * @brief Mask of the DMA2 streams in @p dma_streams_mask. */ #define STM32_DMA2_STREAMS_MASK 0x00000F80 /*===========================================================================*/ /* Driver exported variables. */ /*===========================================================================*/ /** * @brief DMA streams descriptors. * @details This table keeps the association between an unique stream * identifier and the involved physical registers. * @note Don't use this array directly, use the appropriate wrapper macros * instead: @p STM32_DMA1_STREAM1, @p STM32_DMA1_STREAM2 etc. */ const stm32_dma_stream_t _stm32_dma_streams[STM32_DMA_STREAMS] = { {0, DMA1, DMA1_Channel1, &DMA1->IFCR, 0}, {1, DMA1, DMA1_Channel2, &DMA1->IFCR, 4}, {2, DMA1, DMA1_Channel3, &DMA1->IFCR, 8}, {3, DMA1, DMA1_Channel4, &DMA1->IFCR, 12}, {4, DMA1, DMA1_Channel5, &DMA1->IFCR, 16}, {5, DMA1, DMA1_Channel6, &DMA1->IFCR, 20}, {6, DMA1, DMA1_Channel7, &DMA1->IFCR, 24}, #if STM32_HAS_DMA2 || defined(__DOXYGEN__) {7, DMA2, DMA2_Channel1, &DMA2->IFCR, 0}, {8, DMA2, DMA2_Channel2, &DMA2->IFCR, 4}, {9, DMA2, DMA2_Channel3, &DMA2->IFCR, 8}, {10, DMA2, DMA2_Channel4, &DMA2->IFCR, 12}, {11, DMA2, DMA2_Channel5, &DMA2->IFCR, 16}, #endif }; /*===========================================================================*/ /* Driver local variables and types. */ /*===========================================================================*/ /** * @brief DMA ISR redirector type. */ typedef struct { stm32_dmaisr_t dma_func; void *dma_param; } 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[STM32_DMA_STREAMS]; /*===========================================================================*/ /* Driver local functions. */ /*===========================================================================*/ /*===========================================================================*/ /* Driver interrupt handlers. */ /*===========================================================================*/ /** * @brief DMA1 stream 1 shared interrupt handler. * * @isr */ CH_IRQ_HANDLER(DMA1_Ch1_IRQHandler) { uint32_t flags; CH_IRQ_PROLOGUE(); flags = (DMA1->ISR >> 0) & STM32_DMA_ISR_MASK; DMA1->IFCR = STM32_DMA_ISR_MASK << 0; if (dma_isr_redir[0].dma_func) dma_isr_redir[0].dma_func(dma_isr_redir[0].dma_param, flags); CH_IRQ_EPILOGUE(); } /*===========================================================================*/ /* Driver exported functions. */ /*===========================================================================*/ /** * @brief STM32 DMA helper initialization. * * @init */ void dmaInit(void) { int i; dma_streams_mask = 0; for (i = 0; i < STM32_DMA_STREAMS; i--) { _stm32_dma_streams[i].channel->CCR = 0; dma_isr_redir[i].dma_func = NULL; } DMA1->IFCR = 0xFFFFFFFF; #if STM32_HAS_DMA2 DMA2->IFCR = 0xFFFFFFFF; #endif } /** * @brief Allocates a DMA stream. * @details The stream is allocated and, if required, the DMA clock enabled. * Trying to allocate a stream already allocated is an illegal * operation and is trapped if assertions are enabled. * @pre The stream must not be already in use. * @post The stream is allocated and the default ISR handler redirected * to the specified function. * @post The stream must be freed using @p dmaRelease() before it can * be reused with another peripheral. * @note This function can be invoked in both ISR or thread context. * * @param[in] dmastp pointer to a stm32_dma_stream_t structure * @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 dmaAllocate(stm32_dma_stream_t *dmastp, stm32_dmaisr_t func, void *param) { chDbgCheck(dmastp != NULL, "dmaAllocate"); /* Checks if the stream is already taken.*/ if ((dma_streams_mask & (1 << dmastp->selfindex)) != 0) return TRUE; /* Marks the stream as allocated.*/ dma_isr_redir[dmastp->selfindex].dma_func = func; dma_isr_redir[dmastp->selfindex].dma_param = param; dma_streams_mask |= (1 << dmastp->selfindex); /* Enabling DMA clocks required by the current streams set.*/ if ((dma_streams_mask & STM32_DMA1_STREAMS_MASK) != 0) RCC->AHBENR |= RCC_AHBENR_DMA1EN; #if STM32_HAS_DMA2 if ((dma_streams_mask & STM32_DMA2_STREAMS_MASK) != 0) RCC->AHBENR |= RCC_AHBENR_DMA2EN; #endif /* Making sure there are no spurious interrupts flags pending.*/ dmaStreamClearInterrupt(dmastp); return FALSE; } /** * @brief Releases a DMA stream. * @details The stream is freed and, if required, the DMA clock disabled. * Trying to release a unallocated stream is an illegal operation * and is trapped if assertions are enabled. * @pre The stream must have been allocated using @p dmaRequest(). * @post The stream is again available. * @note This function can be invoked in both ISR or thread context. * * @param[in] dmastp pointer to a stm32_dma_stream_t structure * * @special */ void dmaRelease(stm32_dma_stream_t *dmastp) { chDbgCheck(dmastp != NULL, "dmaRelease"); /* Check if the streams is not taken.*/ chDbgAssert((dma_streams_mask & (1 << dmastp->selfindex)) != 0, "dmaRelease(), #1", "not allocated"); /* Marks the stream as not allocated.*/ dma_streams_mask &= ~(1 << dmastp->selfindex); /* Shutting down clocks that are no more required, if any.*/ if ((dma_streams_mask & STM32_DMA1_STREAMS_MASK) == 0) RCC->AHBENR &= ~RCC_AHBENR_DMA1EN; #if STM32_HAS_DMA2 if ((dma_streams_mask & STM32_DMA2_STREAMS_MASK) == 0) RCC->AHBENR &= ~RCC_AHBENR_DMA2EN; #endif } #endif /* STM32_DMA_REQUIRED */ /** @} */