mbed-os/hal/mbed_itm_api.c

135 lines
3.7 KiB
C

/* mbed Microcontroller Library
* Copyright (c) 2017 ARM Limited
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#if DEVICE_ITM
#include "hal/itm_api.h"
#include "cmsis.h"
#include <stdbool.h>
#ifndef ITM_STIM_FIFOREADY_Msk
#define ITM_STIM_FIFOREADY_Msk 1
#endif
#define ITM_ENABLE_WRITE 0xC5ACCE55
#define SWO_NRZ 0x02
#define SWO_STIMULUS_PORT 0x01
void mbed_itm_init(void)
{
static bool do_init = true;
if (do_init) {
do_init = false;
itm_init();
/* Enable write access to ITM registers. */
ITM->LAR = ITM_ENABLE_WRITE;
/* Trace Port Interface Selected Pin Protocol Register. */
TPI->SPPR = (SWO_NRZ << TPI_SPPR_TXMODE_Pos);
/* Trace Port Interface Formatter and Flush Control Register */
TPI->FFCR = (1 << TPI_FFCR_TrigIn_Pos);
/* Data Watchpoint and Trace Control Register */
DWT->CTRL = (1 << DWT_CTRL_CYCTAP_Pos) |
(0xF << DWT_CTRL_POSTINIT_Pos) |
(0xF << DWT_CTRL_POSTPRESET_Pos) |
(1 << DWT_CTRL_CYCCNTENA_Pos);
/* Trace Privilege Register.
* Disable access to trace channel configuration from non-privileged mode.
*/
ITM->TPR = 0x0;
/* Trace Control Register */
ITM->TCR = (1 << ITM_TCR_TraceBusID_Pos) |
(1 << ITM_TCR_DWTENA_Pos) |
(1 << ITM_TCR_SYNCENA_Pos) |
(1 << ITM_TCR_ITMENA_Pos);
/* Trace Enable Register */
ITM->TER = SWO_STIMULUS_PORT;
}
}
static void itm_out8(uint32_t port, uint8_t data)
{
/* Wait until port is available */
while ((ITM->PORT[port].u32 & ITM_STIM_FIFOREADY_Msk) == 0) {
__NOP();
}
/* write data to port */
ITM->PORT[port].u8 = data;
}
static void itm_out32(uint32_t port, uint32_t data)
{
/* Wait until port is available */
while ((ITM->PORT[port].u32 & ITM_STIM_FIFOREADY_Msk) == 0) {
__NOP();
}
/* write data to port */
ITM->PORT[port].u32 = data;
}
uint32_t mbed_itm_send(uint32_t port, uint32_t data)
{
/* Check if ITM and port is enabled */
if (((ITM->TCR & ITM_TCR_ITMENA_Msk) != 0UL) && /* ITM enabled */
((ITM->TER & (1UL << port)) != 0UL)) { /* ITM Port enabled */
itm_out32(port, data);
}
return data;
}
void mbed_itm_send_block(uint32_t port, const void *data, size_t len)
{
const char *ptr = data;
/* Check if ITM and port is enabled */
if (((ITM->TCR & ITM_TCR_ITMENA_Msk) != 0UL) && /* ITM enabled */
((ITM->TER & (1UL << port)) != 0UL)) { /* ITM Port enabled */
/* Output single byte at a time until data is aligned */
while ((((uintptr_t) ptr) & 3) && len != 0) {
itm_out8(port, *ptr++);
len--;
}
/* Output bulk of data one word at a time */
while (len >= 4) {
itm_out32(port, *(const uint32_t *) ptr);
ptr += 4;
len -= 4;
}
/* Output any trailing bytes */
while (len != 0) {
itm_out8(port, *ptr++);
len--;
}
}
}
#endif // DEVICE_ITM