Johannes Stratmann / mbed-dev

added prescaler for 16 bit pwm in LPC1347 target

Fork of mbed-dev by mbed official

targets/hal/TARGET_Atmel/TARGET_SAM_CortexM0P/sercom_dma.c@147:ba84b7dc41a7, 2016-09-10 (annotated)

Committer:
JojoS
Date:
Sat Sep 10 15:32:04 2016 +0000
Revision:
147:ba84b7dc41a7
Parent:
64:41a834223ea3 
added prescaler for 16 bit timers (solution as in LPC11xx), default prescaler 31 for max 28 ms period time

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbed_official 15:a81a8d6c1dfe 1 /* mbed Microcontroller Library
mbed_official 15:a81a8d6c1dfe 2 * Copyright (c) 2006-2015 ARM Limited
mbed_official 15:a81a8d6c1dfe 3 *
mbed_official 15:a81a8d6c1dfe 4 * Licensed under the Apache License, Version 2.0 (the "License");
mbed_official 15:a81a8d6c1dfe 5 * you may not use this file except in compliance with the License.
mbed_official 15:a81a8d6c1dfe 6 * You may obtain a copy of the License at
mbed_official 15:a81a8d6c1dfe 7 *
mbed_official 15:a81a8d6c1dfe 8 * http://www.apache.org/licenses/LICENSE-2.0
mbed_official 15:a81a8d6c1dfe 9 *
mbed_official 15:a81a8d6c1dfe 10 * Unless required by applicable law or agreed to in writing, software
mbed_official 15:a81a8d6c1dfe 11 * distributed under the License is distributed on an "AS IS" BASIS,
mbed_official 15:a81a8d6c1dfe 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
mbed_official 15:a81a8d6c1dfe 13 * See the License for the specific language governing permissions and
mbed_official 15:a81a8d6c1dfe 14 * limitations under the License.
mbed_official 15:a81a8d6c1dfe 15 */
mbed_official 15:a81a8d6c1dfe 16 #include "mbed_assert.h"
mbed_official 15:a81a8d6c1dfe 17
mbed_official 15:a81a8d6c1dfe 18 #include "cmsis.h"
mbed_official 15:a81a8d6c1dfe 19 #include "sercom.h"
mbed_official 15:a81a8d6c1dfe 20 #include "dma_api.h"
mbed_official 15:a81a8d6c1dfe 21 #include "dma_api_HAL.h"
mbed_official 15:a81a8d6c1dfe 22 #include "sercom_dma.h"
mbed_official 15:a81a8d6c1dfe 23
mbed_official 15:a81a8d6c1dfe 24 static struct sercom_dma sercom_channels[SERCOM_INST_NUM] = {{0}};
mbed_official 15:a81a8d6c1dfe 25
mbed_official 15:a81a8d6c1dfe 26 /** Allocate a channel for TX
mbed_official 15:a81a8d6c1dfe 27 *
mbed_official 15:a81a8d6c1dfe 28 * @param[in] sercom_index index of sercom instance
mbed_official 15:a81a8d6c1dfe 29 * @param[out] tx_id pointer to channel id
mbed_official 15:a81a8d6c1dfe 30 * @return allocated channel id
mbed_official 15:a81a8d6c1dfe 31 */
mbed_official 15:a81a8d6c1dfe 32 uint8_t sercom_setup_tx_channel(uint8_t sercom_index, uint8_t *tx_id)
mbed_official 15:a81a8d6c1dfe 33 {
mbed_official 15:a81a8d6c1dfe 34 if (sercom_channels[sercom_index].tx_status & DMA_ALLOCATED) {
mbed_official 15:a81a8d6c1dfe 35 *tx_id = sercom_channels[sercom_index].tx_channel_id;
mbed_official 15:a81a8d6c1dfe 36 } else {
mbed_official 15:a81a8d6c1dfe 37 /* Try to allocate a channel */
mbed_official 15:a81a8d6c1dfe 38 sercom_channels[sercom_index].tx_channel_id = dma_channel_allocate(DMA_CAP_NONE);
mbed_official 15:a81a8d6c1dfe 39 if (sercom_channels[sercom_index].tx_channel_id != (uint8_t)DMA_ERROR_OUT_OF_CHANNELS) {
mbed_official 15:a81a8d6c1dfe 40 *tx_id = sercom_channels[sercom_index].tx_channel_id;
mbed_official 15:a81a8d6c1dfe 41 sercom_channels[sercom_index].tx_status = DMA_ALLOCATED;
mbed_official 15:a81a8d6c1dfe 42 } else {
mbed_official 15:a81a8d6c1dfe 43 /* Couldn't find a channel */
mbed_official 64:41a834223ea3 44 return (uint8_t)DMA_ERROR_OUT_OF_CHANNELS;
mbed_official 15:a81a8d6c1dfe 45 }
mbed_official 15:a81a8d6c1dfe 46 }
mbed_official 15:a81a8d6c1dfe 47 return *tx_id;
mbed_official 15:a81a8d6c1dfe 48 }
mbed_official 15:a81a8d6c1dfe 49
mbed_official 15:a81a8d6c1dfe 50 /** Allocate a channel for RX
mbed_official 15:a81a8d6c1dfe 51 *
mbed_official 15:a81a8d6c1dfe 52 * @param[in] sercom_index index of sercom instance
mbed_official 15:a81a8d6c1dfe 53 * @param[out] rx_id pointer to channel id
mbed_official 15:a81a8d6c1dfe 54 * @return allocated channel id
mbed_official 15:a81a8d6c1dfe 55 */
mbed_official 15:a81a8d6c1dfe 56 uint8_t sercom_setup_rx_channel(uint8_t sercom_index, uint8_t *rx_id)
mbed_official 15:a81a8d6c1dfe 57 {
mbed_official 15:a81a8d6c1dfe 58 if (sercom_channels[sercom_index].rx_status & DMA_ALLOCATED) {
mbed_official 15:a81a8d6c1dfe 59 *rx_id = sercom_channels[sercom_index].rx_channel_id;
mbed_official 15:a81a8d6c1dfe 60 } else {
mbed_official 15:a81a8d6c1dfe 61 /* Try to allocate a channel */
mbed_official 15:a81a8d6c1dfe 62 sercom_channels[sercom_index].rx_channel_id = dma_channel_allocate(DMA_CAP_NONE);
mbed_official 15:a81a8d6c1dfe 63 if (sercom_channels[sercom_index].rx_channel_id != (uint8_t)DMA_ERROR_OUT_OF_CHANNELS) {
mbed_official 15:a81a8d6c1dfe 64 *rx_id = sercom_channels[sercom_index].rx_channel_id;
mbed_official 15:a81a8d6c1dfe 65 sercom_channels[sercom_index].rx_status = DMA_ALLOCATED;
mbed_official 15:a81a8d6c1dfe 66 } else {
mbed_official 15:a81a8d6c1dfe 67 /* Couldn't find a channel */
mbed_official 64:41a834223ea3 68 return (uint8_t)DMA_ERROR_OUT_OF_CHANNELS;
mbed_official 15:a81a8d6c1dfe 69 }
mbed_official 15:a81a8d6c1dfe 70 }
mbed_official 15:a81a8d6c1dfe 71 return *rx_id;
mbed_official 15:a81a8d6c1dfe 72 }
mbed_official 15:a81a8d6c1dfe 73
mbed_official 15:a81a8d6c1dfe 74 /** Release DMA channels if allocated
mbed_official 15:a81a8d6c1dfe 75 *
mbed_official 15:a81a8d6c1dfe 76 * @param[in] sercom_index index of sercom instance
mbed_official 15:a81a8d6c1dfe 77 * @return void
mbed_official 15:a81a8d6c1dfe 78 */
mbed_official 15:a81a8d6c1dfe 79 void sercom_release_channel(uint8_t sercom_index)
mbed_official 15:a81a8d6c1dfe 80 {
mbed_official 15:a81a8d6c1dfe 81 if (sercom_channels[sercom_index].rx_status & DMA_ALLOCATED) {
mbed_official 15:a81a8d6c1dfe 82 if (0 == dma_channel_free(sercom_channels[sercom_index].rx_channel_id)) {
mbed_official 15:a81a8d6c1dfe 83 sercom_channels[sercom_index].rx_status = DMA_NOT_USED;
mbed_official 15:a81a8d6c1dfe 84 }
mbed_official 15:a81a8d6c1dfe 85 }
mbed_official 15:a81a8d6c1dfe 86 if (sercom_channels[sercom_index].tx_status & DMA_ALLOCATED) {
mbed_official 15:a81a8d6c1dfe 87 if (0 == dma_channel_free(sercom_channels[sercom_index].tx_channel_id)) {
mbed_official 15:a81a8d6c1dfe 88 sercom_channels[sercom_index].tx_status = DMA_NOT_USED;
mbed_official 15:a81a8d6c1dfe 89 }
mbed_official 15:a81a8d6c1dfe 90 }
mbed_official 15:a81a8d6c1dfe 91 }