rtt/rtt.c

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// SPDX-License-Identifier: GPL-2.0-or-later
 
/*
 * Copyright (C) 2016-2020 by Marc Schink <dev@zapb.de>
 */
 
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
 
#include <stdint.h>
#include <stdbool.h>
#include <string.h>
 
#include <helper/log.h>
#include <helper/list.h>
#include <target/target.h>
#include <target/rtt.h>
 
#include "rtt.h"
 
static struct {
    struct rtt_source source;
    struct rtt_control ctrl;
    struct target *target;
    target_addr_t addr;
    size_t size;
    char id[RTT_CB_MAX_ID_LENGTH];
    bool configured;
    bool started;
    bool changed;
    bool found_cb;
 
    struct rtt_sink_list **sink_list;
    size_t sink_list_length;
 
    unsigned int polling_interval;
} rtt;
 
int rtt_init(void)
{
    rtt.sink_list_length = 1;
    rtt.sink_list = calloc(rtt.sink_list_length,
        sizeof(struct rtt_sink_list *));
 
    if (!rtt.sink_list)
        return ERROR_FAIL;
 
    rtt.sink_list[0] = NULL;
    rtt.started = false;
 
    rtt.polling_interval = 100;
 
    return ERROR_OK;
}
 
int rtt_exit(void)
{
    free(rtt.sink_list);
 
    return ERROR_OK;
}
 
static int read_channel_callback(void *user_data)
{
    int ret;
 
    ret = rtt.source.read(rtt.target, &rtt.ctrl, rtt.sink_list,
        rtt.sink_list_length, NULL);
 
    if (ret != ERROR_OK) {
        target_unregister_timer_callback(&read_channel_callback, NULL);
        rtt.source.stop(rtt.target, NULL);
        return ret;
    }
 
    return ERROR_OK;
}
 
int rtt_setup(target_addr_t address, size_t size, const char *id)
{
    size_t id_length = strlen(id);
 
    if (!id_length || id_length >= RTT_CB_MAX_ID_LENGTH) {
        LOG_ERROR("rtt: Invalid control block ID");
        return ERROR_COMMAND_ARGUMENT_INVALID;
    }
 
    rtt.addr = address;
    rtt.size = size;
    strncpy(rtt.id, id, id_length + 1);
    rtt.changed = true;
    rtt.configured = true;
 
    return ERROR_OK;
}
 
int rtt_register_source(const struct rtt_source source,
        struct target *target)
{
    if (!source.find_cb || !source.read_cb || !source.read_channel_info)
        return ERROR_FAIL;
 
    if (!source.start || !source.stop)
        return ERROR_FAIL;
 
    if (!source.read || !source.write)
        return ERROR_FAIL;
 
    rtt.source = source;
    rtt.target = target;
 
    return ERROR_OK;
}
 
int rtt_start(void)
{
    int ret;
    target_addr_t addr = rtt.addr;
 
    if (rtt.started)
        return ERROR_OK;
 
    if (!rtt.found_cb || rtt.changed) {
        rtt.source.find_cb(rtt.target, &addr, rtt.size, rtt.id,
            &rtt.found_cb, NULL);
 
        rtt.changed = false;
 
        if (rtt.found_cb) {
            LOG_INFO("rtt: Control block found at 0x%" TARGET_PRIxADDR,
                addr);
            rtt.ctrl.address = addr;
        } else {
            LOG_INFO("rtt: No control block found");
            return ERROR_OK;
        }
    }
 
    ret = rtt.source.read_cb(rtt.target, rtt.ctrl.address, &rtt.ctrl, NULL);
 
    if (ret != ERROR_OK)
        return ret;
 
    ret = rtt.source.start(rtt.target, &rtt.ctrl, NULL);
 
    if (ret != ERROR_OK)
        return ret;
 
    target_register_timer_callback(&read_channel_callback,
        rtt.polling_interval, 1, NULL);
    rtt.started = true;
 
    return ERROR_OK;
}
 
int rtt_stop(void)
{
    int ret;
 
    if (!rtt.configured) {
        LOG_ERROR("rtt: Not configured");
        return ERROR_FAIL;
    }
 
    target_unregister_timer_callback(&read_channel_callback, NULL);
    rtt.started = false;
 
    ret = rtt.source.stop(rtt.target, NULL);
 
    if (ret != ERROR_OK)
        return ret;
 
    return ERROR_OK;
}
 
static int adjust_sink_list(size_t length)
{
    struct rtt_sink_list **tmp;
 
    if (length <= rtt.sink_list_length)
        return ERROR_OK;
 
    tmp = realloc(rtt.sink_list, sizeof(struct rtt_sink_list *) * length);
 
    if (!tmp)
        return ERROR_FAIL;
 
    for (size_t i = rtt.sink_list_length; i < length; i++)
        tmp[i] = NULL;
 
    rtt.sink_list = tmp;
    rtt.sink_list_length = length;
 
    return ERROR_OK;
}
 
int rtt_register_sink(unsigned int channel_index, rtt_sink_read read,
        void *user_data)
{
    struct rtt_sink_list *tmp;
 
    if (channel_index >= rtt.sink_list_length) {
        if (adjust_sink_list(channel_index + 1) != ERROR_OK)
            return ERROR_FAIL;
    }
 
    LOG_DEBUG("rtt: Registering sink for channel %u", channel_index);
 
    tmp = malloc(sizeof(struct rtt_sink_list));
 
    if (!tmp)
        return ERROR_FAIL;
 
    tmp->read = read;
    tmp->user_data = user_data;
    tmp->next = rtt.sink_list[channel_index];
 
    rtt.sink_list[channel_index] = tmp;
 
    return ERROR_OK;
}
 
int rtt_unregister_sink(unsigned int channel_index, rtt_sink_read read,
        void *user_data)
{
    struct rtt_sink_list *prev_sink;
 
    LOG_DEBUG("rtt: Unregistering sink for channel %u", channel_index);
 
    if (channel_index >= rtt.sink_list_length)
        return ERROR_FAIL;
 
    prev_sink = rtt.sink_list[channel_index];
 
    for (struct rtt_sink_list *sink = rtt.sink_list[channel_index]; sink;
            prev_sink = sink, sink = sink->next) {
        if (sink->read == read && sink->user_data == user_data) {
 
            if (sink == rtt.sink_list[channel_index])
                rtt.sink_list[channel_index] = sink->next;
            else
                prev_sink->next = sink->next;
 
            free(sink);
 
            return ERROR_OK;
        }
    }
 
    return ERROR_OK;
}
 
int rtt_get_polling_interval(unsigned int *interval)
{
    if (!interval)
        return ERROR_FAIL;
 
    *interval = rtt.polling_interval;
 
    return ERROR_OK;
}
 
int rtt_set_polling_interval(unsigned int interval)
{
    if (!interval)
        return ERROR_FAIL;
 
    if (rtt.polling_interval != interval) {
        target_unregister_timer_callback(&read_channel_callback, NULL);
        target_register_timer_callback(&read_channel_callback, interval, 1,
            NULL);
    }
 
    rtt.polling_interval = interval;
 
    return ERROR_OK;
}
 
int rtt_write_channel(unsigned int channel_index, const uint8_t *buffer,
        size_t *length)
{
    if (channel_index >= rtt.ctrl.num_up_channels) {
        LOG_WARNING("rtt: Down-channel %u is not available", channel_index);
        return ERROR_OK;
    }
 
    return rtt.source.write(rtt.target, &rtt.ctrl, channel_index, buffer,
        length, NULL);
}
 
bool rtt_configured(void)
{
    return rtt.configured;
}
 
bool rtt_found_cb(void)
{
    return rtt.found_cb;
}
 
const struct rtt_control *rtt_get_control(void)
{
    return &rtt.ctrl;
}
 
int rtt_read_channel_info(unsigned int channel_index,
    enum rtt_channel_type type, struct rtt_channel_info *info)
{
    return rtt.source.read_channel_info(rtt.target, &rtt.ctrl,
        channel_index, type, info, NULL);
}