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The official Mbed 2 C/C++ SDK provides the software platform and libraries to build your applications.

Last commit 20 Feb 2019 by mbed official

targets/hal/TARGET_Silicon_Labs/TARGET_EFM32/dma_api.c@525:c320967f86b9, 2015-04-28 (annotated)

Committer:
mbed_official
Date:
Tue Apr 28 11:45:12 2015 +0100
Revision:
525:c320967f86b9
Child:
548:1abac31e188e
Synchronized with git revision 299385b8331142b9dc524da7a986536f60b14553



Full URL: https://github.com/mbedmicro/mbed/commit/299385b8331142b9dc524da7a986536f60b14553/



Add in Silicon Labs targets with asynchronous API support

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbed_official 525:c320967f86b9 1 /* mbed Microcontroller Library
mbed_official 525:c320967f86b9 2 * Copyright (c) 2006-2013 ARM Limited
mbed_official 525:c320967f86b9 3 *
mbed_official 525:c320967f86b9 4 * Licensed under the Apache License, Version 2.0 (the "License");
mbed_official 525:c320967f86b9 5 * you may not use this file except in compliance with the License.
mbed_official 525:c320967f86b9 6 * You may obtain a copy of the License at
mbed_official 525:c320967f86b9 7 *
mbed_official 525:c320967f86b9 8 * http://www.apache.org/licenses/LICENSE-2.0
mbed_official 525:c320967f86b9 9 *
mbed_official 525:c320967f86b9 10 * Unless required by applicable law or agreed to in writing, software
mbed_official 525:c320967f86b9 11 * distributed under the License is distributed on an "AS IS" BASIS,
mbed_official 525:c320967f86b9 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
mbed_official 525:c320967f86b9 13 * See the License for the specific language governing permissions and
mbed_official 525:c320967f86b9 14 * limitations under the License.
mbed_official 525:c320967f86b9 15 */
mbed_official 525:c320967f86b9 16
mbed_official 525:c320967f86b9 17 #include <stdint.h>
mbed_official 525:c320967f86b9 18 #include "dma_api_HAL.h"
mbed_official 525:c320967f86b9 19 #include "em_dma.h"
mbed_official 525:c320967f86b9 20 #include "em_cmu.h"
mbed_official 525:c320967f86b9 21
mbed_official 525:c320967f86b9 22 /** DMA control block array, requires proper alignment. */
mbed_official 525:c320967f86b9 23 #if defined (__ICCARM__)
mbed_official 525:c320967f86b9 24 #pragma data_alignment=DMACTRL_ALIGNMENT
mbed_official 525:c320967f86b9 25 DMA_DESCRIPTOR_TypeDef dmaControlBlock[DMACTRL_CH_CNT * 2];
mbed_official 525:c320967f86b9 26
mbed_official 525:c320967f86b9 27 #elif defined (__CC_ARM)
mbed_official 525:c320967f86b9 28 DMA_DESCRIPTOR_TypeDef dmaControlBlock[DMACTRL_CH_CNT * 2] __attribute__ ((aligned(DMACTRL_ALIGNMENT)));
mbed_official 525:c320967f86b9 29
mbed_official 525:c320967f86b9 30 #elif defined (__GNUC__)
mbed_official 525:c320967f86b9 31 DMA_DESCRIPTOR_TypeDef dmaControlBlock[DMACTRL_CH_CNT * 2] __attribute__ ((aligned(DMACTRL_ALIGNMENT), section("dma")));
mbed_official 525:c320967f86b9 32
mbed_official 525:c320967f86b9 33 #else
mbed_official 525:c320967f86b9 34 #error Undefined toolkit, need to define alignment
mbed_official 525:c320967f86b9 35 #endif
mbed_official 525:c320967f86b9 36
mbed_official 525:c320967f86b9 37 uint32_t channels = 0; // Bit vector of taken channels
mbed_official 525:c320967f86b9 38 bool enabled = false;
mbed_official 525:c320967f86b9 39
mbed_official 525:c320967f86b9 40 void dma_init(void)
mbed_official 525:c320967f86b9 41 {
mbed_official 525:c320967f86b9 42 if (enabled) return;
mbed_official 525:c320967f86b9 43 DMA_Init_TypeDef dmaInit;
mbed_official 525:c320967f86b9 44
mbed_official 525:c320967f86b9 45 CMU_ClockEnable(cmuClock_DMA, true);
mbed_official 525:c320967f86b9 46 CMU_ClockEnable(cmuClock_HFPER, true);
mbed_official 525:c320967f86b9 47
mbed_official 525:c320967f86b9 48 /* Configure general DMA issues */
mbed_official 525:c320967f86b9 49 dmaInit.hprot = 0;
mbed_official 525:c320967f86b9 50 dmaInit.controlBlock = dmaControlBlock;
mbed_official 525:c320967f86b9 51 DMA_Init(&dmaInit);
mbed_official 525:c320967f86b9 52 enabled = true;
mbed_official 525:c320967f86b9 53 }
mbed_official 525:c320967f86b9 54
mbed_official 525:c320967f86b9 55 int dma_channel_allocate(uint32_t capabilities)
mbed_official 525:c320967f86b9 56 {
mbed_official 525:c320967f86b9 57 int i;
mbed_official 525:c320967f86b9 58 // Check if 2d copy is required
mbed_official 525:c320967f86b9 59 if (DMA_CAP_2DCOPY & capabilities)
mbed_official 525:c320967f86b9 60 {
mbed_official 525:c320967f86b9 61 if (channels & 1)
mbed_official 525:c320967f86b9 62 {
mbed_official 525:c320967f86b9 63 // Channel already in use
mbed_official 525:c320967f86b9 64 return DMA_ERROR_OUT_OF_CHANNELS;
mbed_official 525:c320967f86b9 65 } else {
mbed_official 525:c320967f86b9 66 channels |= 1 << 0;
mbed_official 525:c320967f86b9 67 return 0;
mbed_official 525:c320967f86b9 68 }
mbed_official 525:c320967f86b9 69 }
mbed_official 525:c320967f86b9 70 for (i = 1; i < DMA_CHAN_COUNT; i++)
mbed_official 525:c320967f86b9 71 {
mbed_official 525:c320967f86b9 72 if ((channels & (1 << i)) == 0)
mbed_official 525:c320967f86b9 73 {
mbed_official 525:c320967f86b9 74 // Channel available
mbed_official 525:c320967f86b9 75 channels |= 1 << i;
mbed_official 525:c320967f86b9 76 return i;
mbed_official 525:c320967f86b9 77 }
mbed_official 525:c320967f86b9 78 }
mbed_official 525:c320967f86b9 79 // Check if channel 0 is available
mbed_official 525:c320967f86b9 80 if ((channels & 1 ) == 0) {
mbed_official 525:c320967f86b9 81 channels |= 1 << 0;
mbed_official 525:c320967f86b9 82 return 0;
mbed_official 525:c320967f86b9 83 }
mbed_official 525:c320967f86b9 84 // Couldn't find a channel.
mbed_official 525:c320967f86b9 85 return DMA_ERROR_OUT_OF_CHANNELS;
mbed_official 525:c320967f86b9 86 }
mbed_official 525:c320967f86b9 87
mbed_official 525:c320967f86b9 88 int dma_channel_free(int channelid)
mbed_official 525:c320967f86b9 89 {
mbed_official 525:c320967f86b9 90 channels &= ~(1 << channelid);
mbed_official 525:c320967f86b9 91 return 0;
mbed_official 525:c320967f86b9 92 }
mbed_official 525:c320967f86b9 93