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targets/hal/TARGET_Silicon_Labs/TARGET_EFM32/dma_api.c
- Committer:
- bogdanm
- Date:
- 2015-10-01
- Revision:
- 0:9b334a45a8ff
- Child:
- 50:a417edff4437
File content as of revision 0:9b334a45a8ff:
/***************************************************************************//** * @file dma_api.c ******************************************************************************* * @section License * <b>(C) Copyright 2015 Silicon Labs, http://www.silabs.com</b> ******************************************************************************* * * Permission is granted to anyone to use this software for any purpose, * including commercial applications, and to alter it and redistribute it * freely, subject to the following restrictions: * * 1. The origin of this software must not be misrepresented; you must not * claim that you wrote the original software. * 2. Altered source versions must be plainly marked as such, and must not be * misrepresented as being the original software. * 3. This notice may not be removed or altered from any source distribution. * * DISCLAIMER OF WARRANTY/LIMITATION OF REMEDIES: Silicon Labs has no * obligation to support this Software. Silicon Labs is providing the * Software "AS IS", with no express or implied warranties of any kind, * including, but not limited to, any implied warranties of merchantability * or fitness for any particular purpose or warranties against infringement * of any proprietary rights of a third party. * * Silicon Labs will not be liable for any consequential, incidental, or * special damages, or any other relief, or for any claim by any third party, * arising from your use of this Software. * ******************************************************************************/ #include <stdint.h> #include "dma_api_HAL.h" #include "em_dma.h" #include "em_cmu.h" /** DMA control block array, requires proper alignment. */ #if defined (__ICCARM__) #pragma data_alignment=DMACTRL_ALIGNMENT DMA_DESCRIPTOR_TypeDef dmaControlBlock[DMACTRL_CH_CNT * 2]; #elif defined (__CC_ARM) DMA_DESCRIPTOR_TypeDef dmaControlBlock[DMACTRL_CH_CNT * 2] __attribute__ ((aligned(DMACTRL_ALIGNMENT))); #elif defined (__GNUC__) DMA_DESCRIPTOR_TypeDef dmaControlBlock[DMACTRL_CH_CNT * 2] __attribute__ ((aligned(DMACTRL_ALIGNMENT), section("dma"))); #else #error Undefined toolkit, need to define alignment #endif uint32_t channels = 0; // Bit vector of taken channels bool enabled = false; void dma_init(void) { if (enabled) return; DMA_Init_TypeDef dmaInit; CMU_ClockEnable(cmuClock_DMA, true); CMU_ClockEnable(cmuClock_HFPER, true); /* Configure general DMA issues */ dmaInit.hprot = 0; dmaInit.controlBlock = dmaControlBlock; DMA_Init(&dmaInit); enabled = true; } int dma_channel_allocate(uint32_t capabilities) { int i; // Check if 2d copy is required if (DMA_CAP_2DCOPY & capabilities) { if (channels & 1) { // Channel already in use return DMA_ERROR_OUT_OF_CHANNELS; } else { channels |= 1 << 0; return 0; } } for (i = 1; i < DMA_CHAN_COUNT; i++) { if ((channels & (1 << i)) == 0) { // Channel available channels |= 1 << i; return i; } } // Check if channel 0 is available if ((channels & 1 ) == 0) { channels |= 1 << 0; return 0; } // Couldn't find a channel. return DMA_ERROR_OUT_OF_CHANNELS; } int dma_channel_free(int channelid) { channels &= ~(1 << channelid); return 0; }