MacroRat / MouseCode

Mouse code for the MacroRat

Dependencies:   ITG3200 QEI

mbed-dev/targets/TARGET_Atmel/TARGET_SAM_CortexM0P/sercom_dma.c@18:6a4db94011d3, 2017-05-14 (annotated)

Committer:
sahilmgandhi
Date:
Sun May 14 23:18:57 2017 +0000
Revision:
18:6a4db94011d3
Publishing again

Who changed what in which revision?

UserRevisionLine numberNew contents of line
sahilmgandhi 18:6a4db94011d3 1 /* mbed Microcontroller Library
sahilmgandhi 18:6a4db94011d3 2 * Copyright (c) 2006-2015 ARM Limited
sahilmgandhi 18:6a4db94011d3 3 *
sahilmgandhi 18:6a4db94011d3 4 * Licensed under the Apache License, Version 2.0 (the "License");
sahilmgandhi 18:6a4db94011d3 5 * you may not use this file except in compliance with the License.
sahilmgandhi 18:6a4db94011d3 6 * You may obtain a copy of the License at
sahilmgandhi 18:6a4db94011d3 7 *
sahilmgandhi 18:6a4db94011d3 8 * http://www.apache.org/licenses/LICENSE-2.0
sahilmgandhi 18:6a4db94011d3 9 *
sahilmgandhi 18:6a4db94011d3 10 * Unless required by applicable law or agreed to in writing, software
sahilmgandhi 18:6a4db94011d3 11 * distributed under the License is distributed on an "AS IS" BASIS,
sahilmgandhi 18:6a4db94011d3 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
sahilmgandhi 18:6a4db94011d3 13 * See the License for the specific language governing permissions and
sahilmgandhi 18:6a4db94011d3 14 * limitations under the License.
sahilmgandhi 18:6a4db94011d3 15 */
sahilmgandhi 18:6a4db94011d3 16 #include "mbed_assert.h"
sahilmgandhi 18:6a4db94011d3 17
sahilmgandhi 18:6a4db94011d3 18 #include "cmsis.h"
sahilmgandhi 18:6a4db94011d3 19 #include "sercom.h"
sahilmgandhi 18:6a4db94011d3 20 #include "dma_api.h"
sahilmgandhi 18:6a4db94011d3 21 #include "dma_api_HAL.h"
sahilmgandhi 18:6a4db94011d3 22 #include "sercom_dma.h"
sahilmgandhi 18:6a4db94011d3 23
sahilmgandhi 18:6a4db94011d3 24 static struct sercom_dma sercom_channels[SERCOM_INST_NUM] = {{0}};
sahilmgandhi 18:6a4db94011d3 25
sahilmgandhi 18:6a4db94011d3 26 /** Allocate a channel for TX
sahilmgandhi 18:6a4db94011d3 27 *
sahilmgandhi 18:6a4db94011d3 28 * @param[in] sercom_index index of sercom instance
sahilmgandhi 18:6a4db94011d3 29 * @param[out] tx_id pointer to channel id
sahilmgandhi 18:6a4db94011d3 30 * @return allocated channel id
sahilmgandhi 18:6a4db94011d3 31 */
sahilmgandhi 18:6a4db94011d3 32 uint8_t sercom_setup_tx_channel(uint8_t sercom_index, uint8_t *tx_id)
sahilmgandhi 18:6a4db94011d3 33 {
sahilmgandhi 18:6a4db94011d3 34 if (sercom_channels[sercom_index].tx_status & DMA_ALLOCATED) {
sahilmgandhi 18:6a4db94011d3 35 *tx_id = sercom_channels[sercom_index].tx_channel_id;
sahilmgandhi 18:6a4db94011d3 36 } else {
sahilmgandhi 18:6a4db94011d3 37 /* Try to allocate a channel */
sahilmgandhi 18:6a4db94011d3 38 sercom_channels[sercom_index].tx_channel_id = dma_channel_allocate(DMA_CAP_NONE);
sahilmgandhi 18:6a4db94011d3 39 if (sercom_channels[sercom_index].tx_channel_id != (uint8_t)DMA_ERROR_OUT_OF_CHANNELS) {
sahilmgandhi 18:6a4db94011d3 40 *tx_id = sercom_channels[sercom_index].tx_channel_id;
sahilmgandhi 18:6a4db94011d3 41 sercom_channels[sercom_index].tx_status = DMA_ALLOCATED;
sahilmgandhi 18:6a4db94011d3 42 } else {
sahilmgandhi 18:6a4db94011d3 43 /* Couldn't find a channel */
sahilmgandhi 18:6a4db94011d3 44 return (uint8_t)DMA_ERROR_OUT_OF_CHANNELS;
sahilmgandhi 18:6a4db94011d3 45 }
sahilmgandhi 18:6a4db94011d3 46 }
sahilmgandhi 18:6a4db94011d3 47 return *tx_id;
sahilmgandhi 18:6a4db94011d3 48 }
sahilmgandhi 18:6a4db94011d3 49
sahilmgandhi 18:6a4db94011d3 50 /** Allocate a channel for RX
sahilmgandhi 18:6a4db94011d3 51 *
sahilmgandhi 18:6a4db94011d3 52 * @param[in] sercom_index index of sercom instance
sahilmgandhi 18:6a4db94011d3 53 * @param[out] rx_id pointer to channel id
sahilmgandhi 18:6a4db94011d3 54 * @return allocated channel id
sahilmgandhi 18:6a4db94011d3 55 */
sahilmgandhi 18:6a4db94011d3 56 uint8_t sercom_setup_rx_channel(uint8_t sercom_index, uint8_t *rx_id)
sahilmgandhi 18:6a4db94011d3 57 {
sahilmgandhi 18:6a4db94011d3 58 if (sercom_channels[sercom_index].rx_status & DMA_ALLOCATED) {
sahilmgandhi 18:6a4db94011d3 59 *rx_id = sercom_channels[sercom_index].rx_channel_id;
sahilmgandhi 18:6a4db94011d3 60 } else {
sahilmgandhi 18:6a4db94011d3 61 /* Try to allocate a channel */
sahilmgandhi 18:6a4db94011d3 62 sercom_channels[sercom_index].rx_channel_id = dma_channel_allocate(DMA_CAP_NONE);
sahilmgandhi 18:6a4db94011d3 63 if (sercom_channels[sercom_index].rx_channel_id != (uint8_t)DMA_ERROR_OUT_OF_CHANNELS) {
sahilmgandhi 18:6a4db94011d3 64 *rx_id = sercom_channels[sercom_index].rx_channel_id;
sahilmgandhi 18:6a4db94011d3 65 sercom_channels[sercom_index].rx_status = DMA_ALLOCATED;
sahilmgandhi 18:6a4db94011d3 66 } else {
sahilmgandhi 18:6a4db94011d3 67 /* Couldn't find a channel */
sahilmgandhi 18:6a4db94011d3 68 return (uint8_t)DMA_ERROR_OUT_OF_CHANNELS;
sahilmgandhi 18:6a4db94011d3 69 }
sahilmgandhi 18:6a4db94011d3 70 }
sahilmgandhi 18:6a4db94011d3 71 return *rx_id;
sahilmgandhi 18:6a4db94011d3 72 }
sahilmgandhi 18:6a4db94011d3 73
sahilmgandhi 18:6a4db94011d3 74 /** Release DMA channels if allocated
sahilmgandhi 18:6a4db94011d3 75 *
sahilmgandhi 18:6a4db94011d3 76 * @param[in] sercom_index index of sercom instance
sahilmgandhi 18:6a4db94011d3 77 * @return void
sahilmgandhi 18:6a4db94011d3 78 */
sahilmgandhi 18:6a4db94011d3 79 void sercom_release_channel(uint8_t sercom_index)
sahilmgandhi 18:6a4db94011d3 80 {
sahilmgandhi 18:6a4db94011d3 81 if (sercom_channels[sercom_index].rx_status & DMA_ALLOCATED) {
sahilmgandhi 18:6a4db94011d3 82 if (0 == dma_channel_free(sercom_channels[sercom_index].rx_channel_id)) {
sahilmgandhi 18:6a4db94011d3 83 sercom_channels[sercom_index].rx_status = DMA_NOT_USED;
sahilmgandhi 18:6a4db94011d3 84 }
sahilmgandhi 18:6a4db94011d3 85 }
sahilmgandhi 18:6a4db94011d3 86 if (sercom_channels[sercom_index].tx_status & DMA_ALLOCATED) {
sahilmgandhi 18:6a4db94011d3 87 if (0 == dma_channel_free(sercom_channels[sercom_index].tx_channel_id)) {
sahilmgandhi 18:6a4db94011d3 88 sercom_channels[sercom_index].tx_status = DMA_NOT_USED;
sahilmgandhi 18:6a4db94011d3 89 }
sahilmgandhi 18:6a4db94011d3 90 }
sahilmgandhi 18:6a4db94011d3 91 }