device_parser.c

/*
 * Copyright (c) 2018, Linaro Ltd.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * 3. Neither the name of the copyright holder nor the names of its contributors
 * may be used to endorse or promote products derived from this software without
 * specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */
#include <stdio.h>
#include <stdbool.h>
#include <yaml.h>

#include "device.h"
#include "ftdi-gpio.h"
#include "local-gpio.h"
#include "conmux.h"
#include "console.h"
#include "ppps.h"

#define TOKEN_LENGTH	16384

struct device_parser {
	yaml_parser_t parser;
	yaml_event_t event;
};

static void nextsym(struct device_parser *dp)
{
	if (!yaml_parser_parse(&dp->parser, &dp->event)) {
		fprintf(stderr, "device parser: error %u\n", dp->parser.error);
		exit(1);
	}
}

static int accept(struct device_parser *dp, int type, char *scalar)
{
	if (dp->event.type == type) {
		if (scalar) {
			strncpy(scalar, (char *)dp->event.data.scalar.value, TOKEN_LENGTH - 1);
			scalar[TOKEN_LENGTH - 1] = '\0';
		}

		yaml_event_delete(&dp->event);
		nextsym(dp);
		return true;
	} else {
		return false;
	}
}

static bool expect(struct device_parser *dp, int type, char *scalar)
{
	if (accept(dp, type, scalar)) {
		return true;
	}

	fprintf(stderr, "device parser: expected %d got %u\n", type, dp->event.type);
	exit(1);
}

static void parse_board(struct device_parser *dp)
{
	struct device *dev;
	char value[TOKEN_LENGTH];
	char key[TOKEN_LENGTH];

	dev = calloc(1, sizeof(*dev));

	while (accept(dp, YAML_SCALAR_EVENT, key)) {
		if (!strcmp(key, "users")) {
			dev->users = calloc(1, sizeof(*dev->users));
			list_init(dev->users);

			if (accept(dp, YAML_SCALAR_EVENT, value))
				continue;

			expect(dp, YAML_SEQUENCE_START_EVENT, NULL);

			while (accept(dp, YAML_SCALAR_EVENT, key)) {
				struct device_user *user = calloc(1, sizeof(*user));

				user->username = strdup(key);

				list_add(dev->users, &user->node);
			}

			expect(dp, YAML_SEQUENCE_END_EVENT, NULL);

			continue;
		}
		
		if (!strcmp(key, "boot-stages")) {
			if (accept(dp, YAML_SCALAR_EVENT, value))
				continue;

			expect(dp, YAML_SEQUENCE_START_EVENT, NULL);

			while (accept(dp, YAML_MAPPING_START_EVENT, NULL)) {
				while (accept(dp, YAML_SCALAR_EVENT, key)) {
					enum boot_stage boot_stage_type = BOOT_NONE;

					expect(dp, YAML_SCALAR_EVENT, value);

					if (!strcmp(key, "pyamlboot")) {
						boot_stage_type = BOOT_PYAMLBOOT;
					} else if (!strcmp(key, "dfu")) {
						boot_stage_type = BOOT_DFU;
					} else {
						fprintf(stderr, "device parser: Unknown boot stage '%s'\n", key);
					}

					dev->boot_stages[dev->boot_num_stages] = boot_stage_type;
					dev->boot_stage_options[dev->boot_num_stages] = strdup(value);
					++dev->boot_num_stages;
				}

				expect(dp, YAML_MAPPING_END_EVENT, NULL);
			}
			expect(dp, YAML_SEQUENCE_END_EVENT, NULL);

			continue;
		}

		expect(dp, YAML_SCALAR_EVENT, value);

		if (!strcmp(key, "board")) {
			dev->board = strdup(value);
		} else if (!strcmp(key, "name")) {
			dev->name = strdup(value);
		} else if (!strcmp(key, "conmux")) {
			dev->control_dev = strdup(value);

			dev->open = conmux_open;
			dev->power = conmux_power;
			dev->write = conmux_write;
		} else if (!strcmp(key, "ftdi_gpio")) {
			dev->control_dev = strdup(value);

			dev->open = ftdi_gpio_open;
			dev->power = ftdi_gpio_power;
			dev->usb = ftdi_gpio_usb;
			dev->key = ftdi_gpio_key;
		} else if (!strcmp(key, "local_gpio")) {
			dev->control_dev = strdup(value);

			dev->open = local_gpio_open;
			dev->power = local_gpio_power;
			dev->usb = local_gpio_usb;
			dev->key = local_gpio_key;
		} else if (!strcmp(key, "console")) {
			dev->console_dev = strdup(value);
			dev->write = console_write;
			dev->send_break = console_send_break;
		} else if (!strcmp(key, "voltage")) {
			dev->voltage = strtoul(value, NULL, 10);
		} else if (!strcmp(key, "description")) {
			dev->description = strdup(value);
		} else if (!strcmp(key, "boot_key_timeout")) {
			dev->boot_key_timeout = strtoul(value, NULL, 10);
		} else if (!strcmp(key, "usb_always_on")) {
			dev->usb_always_on = !strcmp(value, "true");
		} else if (!strcmp(key, "ppps_path")) {
			dev->ppps_path = strdup(value);
		} else {
			fprintf(stderr, "device parser: unknown key \"%s\"\n", key);
			exit(1);
		}
	}

	if (!dev->board || !dev->boot_num_stages || !(dev->open || dev->console_dev)) {
		fprintf(stderr, "device parser: insufficiently defined device\n");
		exit(1);
	}

	device_add(dev);
}

int device_parser(const char *path)
{
	struct device_parser dp;
	char key[TOKEN_LENGTH];
	FILE *fh;

	fh = fopen(path, "r");
	if (!fh)
		return -1;

	if(!yaml_parser_initialize(&dp.parser)) {
		fprintf(stderr, "device parser: failed to initialize parser\n");
		return -1;
	}

	yaml_parser_set_input_file(&dp.parser, fh);

	nextsym(&dp);

	expect(&dp, YAML_STREAM_START_EVENT, NULL);

	expect(&dp, YAML_DOCUMENT_START_EVENT, NULL);
	expect(&dp, YAML_MAPPING_START_EVENT, NULL);

	if (accept(&dp, YAML_SCALAR_EVENT, key)) {
		expect(&dp, YAML_SEQUENCE_START_EVENT, NULL);

		while (accept(&dp, YAML_MAPPING_START_EVENT, NULL)) {
			parse_board(&dp);
			expect(&dp, YAML_MAPPING_END_EVENT, NULL);
		}

		expect(&dp, YAML_SEQUENCE_END_EVENT, NULL);
	}

	expect(&dp, YAML_MAPPING_END_EVENT, NULL);
	expect(&dp, YAML_DOCUMENT_END_EVENT, NULL);
	expect(&dp, YAML_STREAM_END_EVENT, NULL);

	yaml_event_delete(&dp.event);
	yaml_parser_delete(&dp.parser);

	fclose(fh);

	return 0;
}