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Diff: targets/hal/TARGET_Silicon_Labs/TARGET_EFM32/dma_api.c
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- 0:9b334a45a8ff
- Child:
- 50:a417edff4437
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/targets/hal/TARGET_Silicon_Labs/TARGET_EFM32/dma_api.c Thu Oct 01 15:25:22 2015 +0300 @@ -0,0 +1,103 @@ +/***************************************************************************//** + * @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; +} +