mbed library sources
Dependents: Encrypted my_mbed lklk CyaSSL_DTLS_Cellular ... more
Superseded
This library was superseded by mbed-dev - https://os.mbed.com/users/mbed_official/code/mbed-dev/.
Development branch of the mbed library sources. This library is kept in synch with the latest changes from the mbed SDK and it is not guaranteed to work.
If you are looking for a stable and tested release, please import one of the official mbed library releases:
Import librarymbed
The official Mbed 2 C/C++ SDK provides the software platform and libraries to build your applications.
targets/hal/TARGET_Silicon_Labs/TARGET_EFM32/dma_api.c
- Committer:
- mbed_official
- Date:
- 2015-05-22
- Revision:
- 548:1abac31e188e
- Parent:
- 525:c320967f86b9
- Child:
- 627:4fa1328d9c60
File content as of revision 548:1abac31e188e:
/* mbed Microcontroller Library * Copyright (c) 2006-2013 ARM Limited * * 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. */ #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; }