Johannes Stratmann / mbed-dev

added prescaler for 16 bit pwm in LPC1347 target

Fork of mbed-dev by mbed official

targets/hal/TARGET_Silicon_Labs/TARGET_EFM32/dma_api.c@0:9b334a45a8ff, 2015-10-01 (annotated)

Committer:
bogdanm
Date:
Thu Oct 01 15:25:22 2015 +0300
Revision:
0:9b334a45a8ff
Child:
50:a417edff4437
Initial commit on mbed-dev



Replaces mbed-src (now inactive)

Who changed what in which revision?

UserRevisionLine numberNew contents of line
bogdanm 0:9b334a45a8ff 1 /***************************************************************************//**
bogdanm 0:9b334a45a8ff 2 * @file dma_api.c
bogdanm 0:9b334a45a8ff 3 *******************************************************************************
bogdanm 0:9b334a45a8ff 4 * @section License
bogdanm 0:9b334a45a8ff 5 * <b>(C) Copyright 2015 Silicon Labs, http://www.silabs.com</b>
bogdanm 0:9b334a45a8ff 6 *******************************************************************************
bogdanm 0:9b334a45a8ff 7 *
bogdanm 0:9b334a45a8ff 8 * Permission is granted to anyone to use this software for any purpose,
bogdanm 0:9b334a45a8ff 9 * including commercial applications, and to alter it and redistribute it
bogdanm 0:9b334a45a8ff 10 * freely, subject to the following restrictions:
bogdanm 0:9b334a45a8ff 11 *
bogdanm 0:9b334a45a8ff 12 * 1. The origin of this software must not be misrepresented; you must not
bogdanm 0:9b334a45a8ff 13 * claim that you wrote the original software.
bogdanm 0:9b334a45a8ff 14 * 2. Altered source versions must be plainly marked as such, and must not be
bogdanm 0:9b334a45a8ff 15 * misrepresented as being the original software.
bogdanm 0:9b334a45a8ff 16 * 3. This notice may not be removed or altered from any source distribution.
bogdanm 0:9b334a45a8ff 17 *
bogdanm 0:9b334a45a8ff 18 * DISCLAIMER OF WARRANTY/LIMITATION OF REMEDIES: Silicon Labs has no
bogdanm 0:9b334a45a8ff 19 * obligation to support this Software. Silicon Labs is providing the
bogdanm 0:9b334a45a8ff 20 * Software "AS IS", with no express or implied warranties of any kind,
bogdanm 0:9b334a45a8ff 21 * including, but not limited to, any implied warranties of merchantability
bogdanm 0:9b334a45a8ff 22 * or fitness for any particular purpose or warranties against infringement
bogdanm 0:9b334a45a8ff 23 * of any proprietary rights of a third party.
bogdanm 0:9b334a45a8ff 24 *
bogdanm 0:9b334a45a8ff 25 * Silicon Labs will not be liable for any consequential, incidental, or
bogdanm 0:9b334a45a8ff 26 * special damages, or any other relief, or for any claim by any third party,
bogdanm 0:9b334a45a8ff 27 * arising from your use of this Software.
bogdanm 0:9b334a45a8ff 28 *
bogdanm 0:9b334a45a8ff 29 ******************************************************************************/
bogdanm 0:9b334a45a8ff 30
bogdanm 0:9b334a45a8ff 31 #include <stdint.h>
bogdanm 0:9b334a45a8ff 32 #include "dma_api_HAL.h"
bogdanm 0:9b334a45a8ff 33 #include "em_dma.h"
bogdanm 0:9b334a45a8ff 34 #include "em_cmu.h"
bogdanm 0:9b334a45a8ff 35
bogdanm 0:9b334a45a8ff 36 /** DMA control block array, requires proper alignment. */
bogdanm 0:9b334a45a8ff 37 #if defined (__ICCARM__)
bogdanm 0:9b334a45a8ff 38 #pragma data_alignment=DMACTRL_ALIGNMENT
bogdanm 0:9b334a45a8ff 39 DMA_DESCRIPTOR_TypeDef dmaControlBlock[DMACTRL_CH_CNT * 2];
bogdanm 0:9b334a45a8ff 40
bogdanm 0:9b334a45a8ff 41 #elif defined (__CC_ARM)
bogdanm 0:9b334a45a8ff 42 DMA_DESCRIPTOR_TypeDef dmaControlBlock[DMACTRL_CH_CNT * 2] __attribute__ ((aligned(DMACTRL_ALIGNMENT)));
bogdanm 0:9b334a45a8ff 43
bogdanm 0:9b334a45a8ff 44 #elif defined (__GNUC__)
bogdanm 0:9b334a45a8ff 45 DMA_DESCRIPTOR_TypeDef dmaControlBlock[DMACTRL_CH_CNT * 2] __attribute__ ((aligned(DMACTRL_ALIGNMENT), section("dma")));
bogdanm 0:9b334a45a8ff 46
bogdanm 0:9b334a45a8ff 47 #else
bogdanm 0:9b334a45a8ff 48 #error Undefined toolkit, need to define alignment
bogdanm 0:9b334a45a8ff 49 #endif
bogdanm 0:9b334a45a8ff 50
bogdanm 0:9b334a45a8ff 51 uint32_t channels = 0; // Bit vector of taken channels
bogdanm 0:9b334a45a8ff 52 bool enabled = false;
bogdanm 0:9b334a45a8ff 53
bogdanm 0:9b334a45a8ff 54 void dma_init(void)
bogdanm 0:9b334a45a8ff 55 {
bogdanm 0:9b334a45a8ff 56 if (enabled) return;
bogdanm 0:9b334a45a8ff 57 DMA_Init_TypeDef dmaInit;
bogdanm 0:9b334a45a8ff 58
bogdanm 0:9b334a45a8ff 59 CMU_ClockEnable(cmuClock_DMA, true);
bogdanm 0:9b334a45a8ff 60 CMU_ClockEnable(cmuClock_HFPER, true);
bogdanm 0:9b334a45a8ff 61
bogdanm 0:9b334a45a8ff 62 /* Configure general DMA issues */
bogdanm 0:9b334a45a8ff 63 dmaInit.hprot = 0;
bogdanm 0:9b334a45a8ff 64 dmaInit.controlBlock = dmaControlBlock;
bogdanm 0:9b334a45a8ff 65 DMA_Init(&dmaInit);
bogdanm 0:9b334a45a8ff 66 enabled = true;
bogdanm 0:9b334a45a8ff 67 }
bogdanm 0:9b334a45a8ff 68
bogdanm 0:9b334a45a8ff 69 int dma_channel_allocate(uint32_t capabilities)
bogdanm 0:9b334a45a8ff 70 {
bogdanm 0:9b334a45a8ff 71 int i;
bogdanm 0:9b334a45a8ff 72 // Check if 2d copy is required
bogdanm 0:9b334a45a8ff 73 if (DMA_CAP_2DCOPY & capabilities) {
bogdanm 0:9b334a45a8ff 74 if (channels & 1) {
bogdanm 0:9b334a45a8ff 75 // Channel already in use
bogdanm 0:9b334a45a8ff 76 return DMA_ERROR_OUT_OF_CHANNELS;
bogdanm 0:9b334a45a8ff 77 } else {
bogdanm 0:9b334a45a8ff 78 channels |= 1 << 0;
bogdanm 0:9b334a45a8ff 79 return 0;
bogdanm 0:9b334a45a8ff 80 }
bogdanm 0:9b334a45a8ff 81 }
bogdanm 0:9b334a45a8ff 82 for (i = 1; i < DMA_CHAN_COUNT; i++) {
bogdanm 0:9b334a45a8ff 83 if ((channels & (1 << i)) == 0) {
bogdanm 0:9b334a45a8ff 84 // Channel available
bogdanm 0:9b334a45a8ff 85 channels |= 1 << i;
bogdanm 0:9b334a45a8ff 86 return i;
bogdanm 0:9b334a45a8ff 87 }
bogdanm 0:9b334a45a8ff 88 }
bogdanm 0:9b334a45a8ff 89 // Check if channel 0 is available
bogdanm 0:9b334a45a8ff 90 if ((channels & 1 ) == 0) {
bogdanm 0:9b334a45a8ff 91 channels |= 1 << 0;
bogdanm 0:9b334a45a8ff 92 return 0;
bogdanm 0:9b334a45a8ff 93 }
bogdanm 0:9b334a45a8ff 94 // Couldn't find a channel.
bogdanm 0:9b334a45a8ff 95 return DMA_ERROR_OUT_OF_CHANNELS;
bogdanm 0:9b334a45a8ff 96 }
bogdanm 0:9b334a45a8ff 97
bogdanm 0:9b334a45a8ff 98 int dma_channel_free(int channelid)
bogdanm 0:9b334a45a8ff 99 {
bogdanm 0:9b334a45a8ff 100 channels &= ~(1 << channelid);
bogdanm 0:9b334a45a8ff 101 return 0;
bogdanm 0:9b334a45a8ff 102 }
bogdanm 0:9b334a45a8ff 103