Mouse code for the MacroRat
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?
User | Revision | Line number | New 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 | } |