drivers/modem/simcom/sim7080/sim7080.c

/*
 * Copyright (C) 2021 metraTec GmbH
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#define DT_DRV_COMPAT simcom_sim7080

#include <zephyr/logging/log.h>
#include <zephyr/net/offloaded_netdev.h>
LOG_MODULE_REGISTER(modem_simcom_sim7080, CONFIG_MODEM_LOG_LEVEL);

#include <zephyr/drivers/modem/simcom-sim7080.h>
#include "sim7080.h"

struct sim7080_data mdata;
struct modem_context mctx;

static struct k_thread modem_rx_thread;
static struct k_work_q modem_workq;

static K_KERNEL_STACK_DEFINE(modem_rx_stack, CONFIG_MODEM_SIMCOM_SIM7080_RX_STACK_SIZE);
static K_KERNEL_STACK_DEFINE(modem_workq_stack, CONFIG_MODEM_SIMCOM_SIM7080_RX_WORKQ_STACK_SIZE);
NET_BUF_POOL_DEFINE(mdm_recv_pool, MDM_RECV_MAX_BUF, MDM_RECV_BUF_SIZE, 0, NULL);

/* pin settings */
static const struct gpio_dt_spec power_gpio = GPIO_DT_SPEC_INST_GET(0, mdm_power_gpios);

struct modem_context *sim7080_get_mctx(void)
{
	return &mctx;
}

static inline uint32_t hash32(char *str, int len)
{
#define HASH_MULTIPLIER 37
	uint32_t h = 0;
	int i;

	for (i = 0; i < len; ++i) {
		h = (h * HASH_MULTIPLIER) + str[i];
	}

	return h;
}

static inline uint8_t *modem_get_mac(const struct device *dev)
{
	struct sim7080_data *data = dev->data;
	uint32_t hash_value;

	data->mac_addr[0] = 0x00;
	data->mac_addr[1] = 0x10;

	/* use IMEI for mac_addr */
	hash_value = hash32(mdata.mdm_imei, strlen(mdata.mdm_imei));

	UNALIGNED_PUT(hash_value, (uint32_t *)(data->mac_addr + 2));

	return data->mac_addr;
}

static int offload_socket(int family, int type, int proto);

/* Setup the Modem NET Interface. */
static void modem_net_iface_init(struct net_if *iface)
{
	const struct device *dev = net_if_get_device(iface);
	struct sim7080_data *data = dev->data;

	net_if_set_link_addr(iface, modem_get_mac(dev), sizeof(data->mac_addr), NET_LINK_ETHERNET);

	data->netif = iface;

	socket_offload_dns_register(&offload_dns_ops);

	net_if_socket_offload_set(iface, offload_socket);
}

/**
 * Changes the operating state of the sim7080.
 *
 * @param state The new state.
 */
void sim7080_change_state(enum sim7080_state state)
{
	LOG_DBG("Changing state to (%d)", state);
	mdata.state = state;
}

/**
 * Get the current operating state of the sim7080.
 *
 * @return The current state.
 */
enum sim7080_state sim7080_get_state(void)
{
	return mdata.state;
}

static struct offloaded_if_api api_funcs = {
	.iface_api.init = modem_net_iface_init,
};

static bool offload_is_supported(int family, int type, int proto)
{
	if (family != AF_INET &&
	    family != AF_INET6) {
		return false;
	}

	if (type != SOCK_DGRAM &&
	    type != SOCK_STREAM) {
		return false;
	}

	if (proto != IPPROTO_TCP &&
	    proto != IPPROTO_UDP) {
		return false;
	}

	return true;
}

static int offload_socket(int family, int type, int proto)
{
	int ret;

	ret = modem_socket_get(&mdata.socket_config, family, type, proto);
	if (ret < 0) {
		errno = -ret;
		return -1;
	}

	errno = 0;
	return ret;
}

/*
 * Process all messages received from the modem.
 */
static void modem_rx(void *p1, void *p2, void *p3)
{
	ARG_UNUSED(p1);
	ARG_UNUSED(p2);
	ARG_UNUSED(p3);

	while (true) {
		/* Wait for incoming data */
		modem_iface_uart_rx_wait(&mctx.iface, K_FOREVER);

		modem_cmd_handler_process(&mctx.cmd_handler, &mctx.iface);
	}
}

MODEM_CMD_DEFINE(on_cmd_ok)
{
	modem_cmd_handler_set_error(data, 0);
	k_sem_give(&mdata.sem_response);
	return 0;
}

MODEM_CMD_DEFINE(on_cmd_error)
{
	modem_cmd_handler_set_error(data, -EIO);
	k_sem_give(&mdata.sem_response);
	return 0;
}

MODEM_CMD_DEFINE(on_cmd_exterror)
{
	modem_cmd_handler_set_error(data, -EIO);
	k_sem_give(&mdata.sem_response);
	return 0;
}

/*
 * Handles pdp context urc.
 *
 * The urc has the form +APP PDP: <index>,<state>.
 * State can either be ACTIVE for activation or
 * DEACTIVE if disabled.
 */
MODEM_CMD_DEFINE(on_urc_app_pdp)
{
	mdata.pdp_active = strcmp(argv[1], "ACTIVE") == 0;
	LOG_INF("PDP context: %u", mdata.pdp_active);
	k_sem_give(&mdata.sem_response);
	return 0;
}

MODEM_CMD_DEFINE(on_urc_sms)
{
	LOG_INF("SMS: %s", argv[0]);
	return 0;
}

/*
 * Handles socket data notification.
 *
 * The sim modem sends and unsolicited +CADATAIND: <cid>
 * if data can be read from a socket.
 */
MODEM_CMD_DEFINE(on_urc_cadataind)
{
	struct modem_socket *sock;
	int sock_fd;

	sock_fd = atoi(argv[0]);

	sock = modem_socket_from_fd(&mdata.socket_config, sock_fd);
	if (!sock) {
		return 0;
	}

	/* Modem does not tell packet size. Set dummy for receive. */
	modem_socket_packet_size_update(&mdata.socket_config, sock, 1);

	LOG_INF("Data available on socket: %d", sock_fd);
	modem_socket_data_ready(&mdata.socket_config, sock);

	return 0;
}

/*
 * Handles the castate response.
 *
 * +CASTATE: <cid>,<state>
 *
 * Cid is the connection id (socket fd) and
 * state can be:
 *  0 - Closed by remote server or error
 *  1 - Connected to remote server
 *  2 - Listening
 */
MODEM_CMD_DEFINE(on_urc_castate)
{
	struct modem_socket *sock;
	int sockfd, state;

	sockfd = atoi(argv[0]);
	state = atoi(argv[1]);

	sock = modem_socket_from_fd(&mdata.socket_config, sockfd);
	if (!sock) {
		return 0;
	}

	/* Only continue if socket was closed. */
	if (state != 0) {
		return 0;
	}

	LOG_INF("Socket close indication for socket: %d", sockfd);

	sock->is_connected = false;
	LOG_INF("Socket closed: %d", sockfd);

	return 0;
}

/**
 * Handles the ftpget urc.
 *
 * +FTPGET: <mode>,<error>
 *
 * Mode can be 1 for opening a session and
 * reporting that data is available or 2 for
 * reading data. This urc handler will only handle
 * mode 1 because 2 will not occur as urc.
 *
 * Error can be either:
 *  - 1 for data available/opened session.
 *  - 0 If transfer is finished.
 *  - >0 for some error.
 */
MODEM_CMD_DEFINE(on_urc_ftpget)
{
	int error = atoi(argv[0]);

	LOG_INF("+FTPGET: 1,%d", error);

	/* Transfer finished. */
	if (error == 0) {
		mdata.ftp.state = SIM7080_FTP_CONNECTION_STATE_FINISHED;
	} else if (error == 1) {
		mdata.ftp.state = SIM7080_FTP_CONNECTION_STATE_CONNECTED;
	} else {
		mdata.ftp.state = SIM7080_FTP_CONNECTION_STATE_ERROR;
	}

	k_sem_give(&mdata.sem_ftp);

	return 0;
}

/*
 * Read manufacturer identification.
 */
MODEM_CMD_DEFINE(on_cmd_cgmi)
{
	size_t out_len = net_buf_linearize(
		mdata.mdm_manufacturer, sizeof(mdata.mdm_manufacturer) - 1, data->rx_buf, 0, len);
	mdata.mdm_manufacturer[out_len] = '\0';
	LOG_INF("Manufacturer: %s", mdata.mdm_manufacturer);
	return 0;
}

/*
 * Read model identification.
 */
MODEM_CMD_DEFINE(on_cmd_cgmm)
{
	size_t out_len = net_buf_linearize(mdata.mdm_model, sizeof(mdata.mdm_model) - 1,
					   data->rx_buf, 0, len);
	mdata.mdm_model[out_len] = '\0';
	LOG_INF("Model: %s", mdata.mdm_model);
	return 0;
}

/*
 * Read software release.
 *
 * Response will be in format RESPONSE: <revision>.
 */
MODEM_CMD_DEFINE(on_cmd_cgmr)
{
	size_t out_len;
	char *p;

	out_len = net_buf_linearize(mdata.mdm_revision, sizeof(mdata.mdm_revision) - 1,
				    data->rx_buf, 0, len);
	mdata.mdm_revision[out_len] = '\0';

	/* The module prepends a Revision: */
	p = strchr(mdata.mdm_revision, ':');
	if (p) {
		out_len = strlen(p + 1);
		memmove(mdata.mdm_revision, p + 1, out_len + 1);
	}

	LOG_INF("Revision: %s", mdata.mdm_revision);
	return 0;
}

/*
 * Read serial number identification.
 */
MODEM_CMD_DEFINE(on_cmd_cgsn)
{
	size_t out_len =
		net_buf_linearize(mdata.mdm_imei, sizeof(mdata.mdm_imei) - 1, data->rx_buf, 0, len);
	mdata.mdm_imei[out_len] = '\0';
	LOG_INF("IMEI: %s", mdata.mdm_imei);
	return 0;
}

#if defined(CONFIG_MODEM_SIM_NUMBERS)
/*
 * Read international mobile subscriber identity.
 */
MODEM_CMD_DEFINE(on_cmd_cimi)
{
	size_t out_len =
		net_buf_linearize(mdata.mdm_imsi, sizeof(mdata.mdm_imsi) - 1, data->rx_buf, 0, len);
	mdata.mdm_imsi[out_len] = '\0';

	/* Log the received information. */
	LOG_INF("IMSI: %s", mdata.mdm_imsi);
	return 0;
}

/*
 * Read iccid.
 */
MODEM_CMD_DEFINE(on_cmd_ccid)
{
	size_t out_len = net_buf_linearize(mdata.mdm_iccid, sizeof(mdata.mdm_iccid) - 1,
					   data->rx_buf, 0, len);
	mdata.mdm_iccid[out_len] = '\0';

	/* Log the received information. */
	LOG_INF("ICCID: %s", mdata.mdm_iccid);
	return 0;
}
#endif /* defined(CONFIG_MODEM_SIM_NUMBERS) */

/*
 * Parses the non urc C(E)REG and updates registration status.
 */
MODEM_CMD_DEFINE(on_cmd_cereg)
{
	mdata.mdm_registration = atoi(argv[1]);
	LOG_INF("CREG: %u", mdata.mdm_registration);
	return 0;
}

MODEM_CMD_DEFINE(on_cmd_cgatt)
{
	int cgatt = atoi(argv[0]);

	if (cgatt) {
		mdata.status_flags |= SIM7080_STATUS_FLAG_ATTACHED;
	} else {
		mdata.status_flags &= ~SIM7080_STATUS_FLAG_ATTACHED;
	}

	LOG_INF("CGATT: %d", cgatt);
	return 0;
}

/*
 * Handler for RSSI query.
 *
 * +CSQ: <rssi>,<ber>
 *  rssi: 0,-115dBm; 1,-111dBm; 2...30,-110...-54dBm; 31,-52dBm or greater.
 *        99, ukn
 *  ber: Not used.
 */
MODEM_CMD_DEFINE(on_cmd_csq)
{
	int rssi = atoi(argv[0]);

	if (rssi == 0) {
		mdata.mdm_rssi = -115;
	} else if (rssi == 1) {
		mdata.mdm_rssi = -111;
	} else if (rssi > 1 && rssi < 31) {
		mdata.mdm_rssi = -114 + 2 * rssi;
	} else if (rssi == 31) {
		mdata.mdm_rssi = -52;
	} else {
		mdata.mdm_rssi = -1000;
	}

	LOG_INF("RSSI: %d", mdata.mdm_rssi);
	return 0;
}

/*
 * Queries modem RSSI.
 *
 * If a work queue parameter is provided query work will
 * be scheduled. Otherwise rssi is queried once.
 */
static void modem_rssi_query_work(struct k_work *work)
{
	struct modem_cmd cmd[] = { MODEM_CMD("+CSQ: ", on_cmd_csq, 2U, ",") };
	static char *send_cmd = "AT+CSQ";
	int ret;

	ret = modem_cmd_send(&mctx.iface, &mctx.cmd_handler, cmd, ARRAY_SIZE(cmd), send_cmd,
			     &mdata.sem_response, MDM_CMD_TIMEOUT);
	if (ret < 0) {
		LOG_ERR("AT+CSQ ret:%d", ret);
	}

	if (work) {
		k_work_reschedule_for_queue(&modem_workq, &mdata.rssi_query_work,
					    K_SECONDS(RSSI_TIMEOUT_SECS));
	}
}

/*
 * Unlock the tx ready semaphore if '> ' is received.
 */
MODEM_CMD_DIRECT_DEFINE(on_cmd_tx_ready)
{
	k_sem_give(&mdata.sem_tx_ready);
	return len;
}

MODEM_CMD_DIRECT_DEFINE(on_urc_rdy)
{
	LOG_DBG("RDY received");
	mdata.status_flags |= SIM7080_STATUS_FLAG_POWER_ON;
	k_sem_give(&mdata.boot_sem);
	return 0;
}

MODEM_CMD_DIRECT_DEFINE(on_urc_pwr_down)
{
	LOG_DBG("POWER DOWN received");
	mdata.status_flags &= ~SIM7080_STATUS_FLAG_POWER_ON;
	k_sem_give(&mdata.boot_sem);
	return 0;
}

MODEM_CMD_DEFINE(on_urc_cpin)
{
	if (strcmp(argv[0], "READY") == 0) {
		mdata.status_flags |= SIM7080_STATUS_FLAG_CPIN_READY;
	} else {
		mdata.status_flags &= ~SIM7080_STATUS_FLAG_CPIN_READY;
	}

	k_sem_give(&mdata.boot_sem);

	LOG_INF("CPIN: %s", argv[0]);
	return 0;
}

/*
 * Possible responses by the sim7080.
 */
static const struct modem_cmd response_cmds[] = {
	MODEM_CMD("OK", on_cmd_ok, 0U, ""),
	MODEM_CMD("ERROR", on_cmd_error, 0U, ""),
	MODEM_CMD("+CME ERROR: ", on_cmd_exterror, 1U, ""),
	MODEM_CMD_DIRECT(">", on_cmd_tx_ready),
};

/*
 * Possible unsolicited commands.
 */
static const struct modem_cmd unsolicited_cmds[] = {
	MODEM_CMD("+APP PDP: ", on_urc_app_pdp, 2U, ","),
	MODEM_CMD("SMS ", on_urc_sms, 1U, ""),
	MODEM_CMD("+CADATAIND: ", on_urc_cadataind, 1U, ""),
	MODEM_CMD("+CASTATE: ", on_urc_castate, 2U, ","),
	MODEM_CMD("+FTPGET: 1,", on_urc_ftpget, 1U, ""),
	MODEM_CMD("RDY", on_urc_rdy, 0U, ""),
	MODEM_CMD("NORMAL POWER DOWN", on_urc_pwr_down, 0U, ""),
	MODEM_CMD("+CPIN: ", on_urc_cpin, 1U, ","),
};

/*
 * Activates the pdp context
 */
static int modem_pdp_activate(void)
{
	int counter;
	int ret = 0;
#if defined(CONFIG_MODEM_SIMCOM_SIM7080_RAT_GSM)
	const char *buf = "AT+CREG?";
	struct modem_cmd cmds[] = { MODEM_CMD("+CREG: ", on_cmd_cereg, 2U, ",") };
#else
	const char *buf = "AT+CEREG?";
	struct modem_cmd cmds[] = { MODEM_CMD("+CEREG: ", on_cmd_cereg, 2U, ",") };
#endif /* defined(CONFIG_MODEM_SIMCOM_SIM7080_RAT_GSM) */

	struct modem_cmd cgatt_cmd[] = { MODEM_CMD("+CGATT: ", on_cmd_cgatt, 1U, "") };

	counter = 0;
	while (counter++ < MDM_MAX_CGATT_WAITS && (mdata.status_flags & SIM7080_STATUS_FLAG_ATTACHED) == 0) {
		ret = modem_cmd_send(&mctx.iface, &mctx.cmd_handler, cgatt_cmd,
				     ARRAY_SIZE(cgatt_cmd), "AT+CGATT?", &mdata.sem_response,
				     MDM_CMD_TIMEOUT);
		if (ret < 0) {
			LOG_ERR("Failed to query cgatt!!");
			return -1;
		}

		k_sleep(K_SECONDS(1));
	}

	if (counter >= MDM_MAX_CGATT_WAITS) {
		LOG_WRN("Network attach failed!!");
		return -1;
	}

	if ((mdata.status_flags & SIM7080_STATUS_FLAG_CPIN_READY) == 0 ||
		(mdata.status_flags & SIM7080_STATUS_FLAG_ATTACHED) == 0) {
		LOG_ERR("Fatal: Modem is not attached to GPRS network!!");
		return -1;
	}

	LOG_INF("Waiting for network");

	/* Wait until the module is registered to the network.
	 * Registration will be set by urc.
	 */
	counter = 0;
	while (counter++ < MDM_MAX_CEREG_WAITS && mdata.mdm_registration != 1 &&
	       mdata.mdm_registration != 5) {
		ret = modem_cmd_send(&mctx.iface, &mctx.cmd_handler, cmds, ARRAY_SIZE(cmds), buf,
				     &mdata.sem_response, MDM_CMD_TIMEOUT);
		if (ret < 0) {
			LOG_ERR("Failed to query registration!!");
			return -1;
		}

		k_sleep(K_SECONDS(1));
	}

	if (counter >= MDM_MAX_CEREG_WAITS) {
		LOG_WRN("Network registration failed!");
		ret = -1;
		goto error;
	}

	/* Set dual stack mode (IPv4/IPv6) */
	ret = modem_cmd_send(&mctx.iface, &mctx.cmd_handler, NULL, 0, "AT+CNCFG=0,0",
				&mdata.sem_response, MDM_CMD_TIMEOUT);
	if (ret < 0) {
		LOG_ERR("Could not configure pdp context!");
		goto error;
	}

	/*
	 * Now activate the pdp context and wait for confirmation.
	 */
	ret = modem_cmd_send(&mctx.iface, &mctx.cmd_handler, NULL, 0, "AT+CNACT=0,1",
			     &mdata.sem_response, MDM_CMD_TIMEOUT);
	if (ret < 0) {
		LOG_ERR("Could not activate PDP context.");
		goto error;
	}

	ret = k_sem_take(&mdata.sem_response, MDM_PDP_TIMEOUT);
	if (ret < 0 || mdata.pdp_active == false) {
		LOG_ERR("Failed to activate PDP context.");
		ret = -1;
		goto error;
	}

	LOG_INF("Network active.");

error:
	return ret;
}

/*
 * Toggles the modems power pin.
 */
static void modem_pwrkey(void)
{
	LOG_DBG("Pulling PWRKEY");
	/* Power pin should be high for 1.5 seconds. */
	gpio_pin_set_dt(&power_gpio, 1);
	k_sleep(K_MSEC(1500));
	gpio_pin_set_dt(&power_gpio, 0);
}

static int modem_set_baudrate(uint32_t baudrate)
{
	char buf[sizeof("AT+IPR=##########")] = {0};

	int ret = snprintk(buf, sizeof(buf), "AT+IPR=%u", baudrate);
	if (ret < 0) {
		LOG_ERR("Failed to build command");
		goto out;
	}

	ret = modem_cmd_send(&mctx.iface, &mctx.cmd_handler, NULL, 0U, buf, &mdata.sem_response, K_SECONDS(2));
	if (ret != 0) {
		LOG_ERR("Failed to set baudrate");
	}

out:
	return ret;
}

/**
 * Performs the autobaud sequence until modem answers or limit is reached.
 *
 * @return On successful boot 0 is returned. Otherwise <0 is returned.
 */
int modem_autobaud(void)
{
	int counter = 0;
	int ret = -1;

	/*
	 * The sim7080 has a autobaud function.
	 * On startup multiple AT's are sent until
	 * a OK is received.
	 */
	counter = 0;
	while (counter++ <= MDM_MAX_AUTOBAUD) {
		ret = modem_cmd_send(&mctx.iface, &mctx.cmd_handler, NULL, 0U, "AT",
				     &mdata.sem_response, K_MSEC(500));
		if (ret != 0) {
			LOG_DBG("No response to autobaud AT");
			continue;
		}
		break;
	}

	return ret;
}

/**
 * Power on the modem and wait for operational sim card.
 *
 * @param allow_autobaud Allow autobaud functionality.
 * @return 0 on success. Otherwise <0.
 *
 * @note Autobaud is only allowed during driver setup.
 * 		 In any other case a fixed baudrate should be used.
 */
static int modem_boot(bool allow_autobaud)
{
	uint8_t boot_tries = 0;
	int ret = -1;

	/* Reset the status flags */
	mdata.status_flags = 0;

	/* Try boot multiple times in case modem was already on */
	while (boot_tries++ <= MDM_BOOT_TRIES) {

		k_sem_reset(&mdata.boot_sem);

		modem_pwrkey();

		ret = k_sem_take(&mdata.boot_sem, K_SECONDS(5));
		if (ret == 0) {
			if (mdata.status_flags & SIM7080_STATUS_FLAG_POWER_ON) {
				LOG_INF("Modem booted");
				break;
			}

			LOG_INF("Modem turned off");
			k_sleep(K_SECONDS(1));
			continue;
		}

		LOG_WRN("No modem response after pwrkey");

		if (allow_autobaud == false) {
			continue;
		}

		LOG_INF("Trying autobaud");

		ret = modem_autobaud();
		if (ret != 0) {
			LOG_WRN("Autobaud failed");
			continue;
		}

		/* Set baudrate to disable autobaud on next startup */
		ret = modem_set_baudrate(CONFIG_MODEM_SIMCOM_SIM7080_BAUDRATE);
		if (ret != 0) {
			LOG_ERR("Failed to disable echo");
			continue;
		}

		/* Reset modem and wait for ready indication */
		ret = modem_cmd_send(&mctx.iface, &mctx.cmd_handler, NULL, 0U, "AT+CFUN=1,1",
			     &mdata.sem_response, K_MSEC(500));
		if (ret != 0) {
			LOG_ERR("Reset failed");
			break;
		}

		ret = k_sem_take(&mdata.boot_sem, K_SECONDS(5));
		if (ret != 0) {
			LOG_ERR("No RDY received!");
			break;
		}

		if ((mdata.status_flags & SIM7080_STATUS_FLAG_POWER_ON) == 0) {
			LOG_ERR("Modem not powered");
			break;
		}

		break;
	}

	if (ret != 0) {
		LOG_ERR("Modem boot failed!");
		goto out;
	}

	/* Wait for sim card status */
	ret = k_sem_take(&mdata.boot_sem, K_SECONDS(5));
	if (ret != 0) {
		LOG_ERR("Timeout while waiting for sim status");
		goto out;
	}

	if ((mdata.status_flags & SIM7080_STATUS_FLAG_CPIN_READY) == 0) {
		LOG_ERR("Sim card not ready!");
		goto out;
	}

	/* Disable echo on successful boot */
	ret = modem_cmd_send(&mctx.iface, &mctx.cmd_handler, NULL, 0U, "ATE0",
				 &mdata.sem_response, K_MSEC(500));
	if (ret != 0) {
		LOG_ERR("Disabling echo failed");
		goto out;
	}

out:
	return ret;
}

/*
 * Commands to be sent at setup.
 */
static const struct setup_cmd setup_cmds[] = {
	SETUP_CMD("AT+CGMI", "", on_cmd_cgmi, 0U, ""),
	SETUP_CMD("AT+CGMM", "", on_cmd_cgmm, 0U, ""),
	SETUP_CMD("AT+CGMR", "", on_cmd_cgmr, 0U, ""),
	SETUP_CMD("AT+CGSN", "", on_cmd_cgsn, 0U, ""),
#if defined(CONFIG_MODEM_SIM_NUMBERS)
	SETUP_CMD("AT+CIMI", "", on_cmd_cimi, 0U, ""),
	SETUP_CMD("AT+CCID", "", on_cmd_ccid, 0U, ""),
#endif /* defined(CONFIG_MODEM_SIM_NUMBERS) */
};

/*
 * Does the modem setup by starting it and
 * bringing the modem to a PDP active state.
 */
static int modem_setup(void)
{
	int ret = 0;

	k_work_cancel_delayable(&mdata.rssi_query_work);

	ret = modem_boot(true);
	if (ret < 0) {
		LOG_ERR("Booting modem failed!!");
		goto error;
	}

	ret = modem_cmd_handler_setup_cmds(&mctx.iface, &mctx.cmd_handler, setup_cmds,
					   ARRAY_SIZE(setup_cmds), &mdata.sem_response,
					   MDM_REGISTRATION_TIMEOUT);
	if (ret < 0) {
		LOG_ERR("Failed to send init commands!");
		goto error;
	}

	sim7080_change_state(SIM7080_STATE_IDLE);

	/* Wait for acceptable rssi values. */
	modem_rssi_query_work(NULL);
	k_sleep(MDM_WAIT_FOR_RSSI_DELAY);

	int counter = 0;
	while (counter++ < MDM_WAIT_FOR_RSSI_COUNT &&
	       (mdata.mdm_rssi >= 0 || mdata.mdm_rssi <= -1000)) {
		modem_rssi_query_work(NULL);
		k_sleep(MDM_WAIT_FOR_RSSI_DELAY);
	}

	if (mdata.mdm_rssi >= 0 || mdata.mdm_rssi <= -1000) {
		LOG_ERR("Network not reachable!!");
		ret = -ENETUNREACH;
		goto error;
	}

	ret = modem_pdp_activate();
	if (ret < 0) {
		goto error;
	}

	k_work_reschedule_for_queue(&modem_workq, &mdata.rssi_query_work,
				    K_SECONDS(RSSI_TIMEOUT_SECS));

	sim7080_change_state(SIM7080_STATE_NETWORKING);

error:
	return ret;
}

int mdm_sim7080_start_network(void)
{
	sim7080_change_state(SIM7080_STATE_INIT);
	return modem_setup();
}

int mdm_sim7080_power_on(void)
{
	return modem_boot(false);
}

int mdm_sim7080_power_off(void)
{
	int ret = -EALREADY;

	k_work_cancel_delayable(&mdata.rssi_query_work);

	if ((mdata.status_flags & SIM7080_STATUS_FLAG_POWER_ON) == 0) {
		LOG_WRN("Modem already off");
		goto out;
	}

	k_sem_reset(&mdata.boot_sem);

	/* Pull pwrkey to turn off */
	modem_pwrkey();

	/* Wait for power down indication */
	ret = k_sem_take(&mdata.boot_sem, K_SECONDS(5));
	if (ret != 0) {
		LOG_ERR("No power down indication");
		goto out;
	}

	if ((mdata.status_flags & SIM7080_STATUS_FLAG_POWER_ON) != 0) {
		LOG_ERR("Modem not powered down!");
		ret = -1;
		goto out;
	}

	LOG_DBG("Modem turned off");
	mdata.status_flags = 0;
	sim7080_change_state(SIM7080_STATE_OFF);

out:
	return ret;
}

const char *mdm_sim7080_get_manufacturer(void)
{
	return mdata.mdm_manufacturer;
}

const char *mdm_sim7080_get_model(void)
{
	return mdata.mdm_model;
}

const char *mdm_sim7080_get_revision(void)
{
	return mdata.mdm_revision;
}

const char *mdm_sim7080_get_imei(void)
{
	return mdata.mdm_imei;
}

/*
 * Initializes modem handlers and context.
 * After successful init this function calls
 * modem_setup.
 */
static int modem_init(const struct device *dev)
{
	int ret;

	ARG_UNUSED(dev);

	k_sem_init(&mdata.sem_response, 0, 1);
	k_sem_init(&mdata.sem_tx_ready, 0, 1);
	k_sem_init(&mdata.sem_dns, 0, 1);
	k_sem_init(&mdata.sem_ftp, 0, 1);
	k_sem_init(&mdata.boot_sem, 0 ,1);
	k_work_queue_start(&modem_workq, modem_workq_stack,
			   K_KERNEL_STACK_SIZEOF(modem_workq_stack), K_PRIO_COOP(7), NULL);

	/* Assume the modem is not registered to the network. */
	mdata.mdm_registration = 0;
	mdata.status_flags = 0;
	mdata.pdp_active = false;

	mdata.sms_buffer = NULL;
	mdata.sms_buffer_pos = 0;

	/* Socket config. */
	ret = modem_socket_init(&mdata.socket_config, &mdata.sockets[0], ARRAY_SIZE(mdata.sockets),
				MDM_BASE_SOCKET_NUM, true, &offload_socket_fd_op_vtable);
	if (ret < 0) {
		goto error;
	}

	sim7080_change_state(SIM7080_STATE_OFF);

	/* Command handler. */
	const struct modem_cmd_handler_config cmd_handler_config = {
		.match_buf = &mdata.cmd_match_buf[0],
		.match_buf_len = sizeof(mdata.cmd_match_buf),
		.buf_pool = &mdm_recv_pool,
		.alloc_timeout = BUF_ALLOC_TIMEOUT,
		.eol = "\r\n",
		.user_data = NULL,
		.response_cmds = response_cmds,
		.response_cmds_len = ARRAY_SIZE(response_cmds),
		.unsol_cmds = unsolicited_cmds,
		.unsol_cmds_len = ARRAY_SIZE(unsolicited_cmds),
	};

	ret = modem_cmd_handler_init(&mctx.cmd_handler, &mdata.cmd_handler_data,
				     &cmd_handler_config);
	if (ret < 0) {
		goto error;
	}

	/* Uart handler. */
	const struct modem_iface_uart_config uart_config = {
		.rx_rb_buf = &mdata.iface_rb_buf[0],
		.rx_rb_buf_len = sizeof(mdata.iface_rb_buf),
		.dev = MDM_UART_DEV,
		.hw_flow_control = DT_PROP(MDM_UART_NODE, hw_flow_control),
	};

	ret = modem_iface_uart_init(&mctx.iface, &mdata.iface_data, &uart_config);
	if (ret < 0) {
		goto error;
	}

	mdata.current_sock_fd = -1;
	mdata.current_sock_written = 0;

	mdata.ftp.read_buffer = NULL;
	mdata.ftp.nread = 0;
	mdata.ftp.state = SIM7080_FTP_CONNECTION_STATE_INITIAL;

	/* Modem data storage. */
	mctx.data_manufacturer = mdata.mdm_manufacturer;
	mctx.data_model = mdata.mdm_model;
	mctx.data_revision = mdata.mdm_revision;
	mctx.data_imei = mdata.mdm_imei;
#if defined(CONFIG_MODEM_SIM_NUMBERS)
	mctx.data_imsi = mdata.mdm_imsi;
	mctx.data_iccid = mdata.mdm_iccid;
#endif /* #if defined(CONFIG_MODEM_SIM_NUMBERS) */
	mctx.data_rssi = &mdata.mdm_rssi;

	ret = gpio_pin_configure_dt(&power_gpio, GPIO_OUTPUT_LOW);
	if (ret < 0) {
		LOG_ERR("Failed to configure %s pin", "power");
		goto error;
	}

	mctx.driver_data = &mdata;

	ret = modem_context_register(&mctx);
	if (ret < 0) {
		LOG_ERR("Error registering modem context: %d", ret);
		goto error;
	}

	k_thread_create(&modem_rx_thread, modem_rx_stack, K_KERNEL_STACK_SIZEOF(modem_rx_stack),
			modem_rx, NULL, NULL, NULL, K_PRIO_COOP(7), 0, K_NO_WAIT);

	/* Init RSSI query */
	k_work_init_delayable(&mdata.rssi_query_work, modem_rssi_query_work);

	return modem_setup();
error:
	return ret;
}

/* Register device with the networking stack. */
NET_DEVICE_DT_INST_OFFLOAD_DEFINE(0, modem_init, NULL, &mdata, NULL,
				  CONFIG_MODEM_SIMCOM_SIM7080_INIT_PRIORITY, &api_funcs,
				  MDM_MAX_DATA_LENGTH);

NET_SOCKET_OFFLOAD_REGISTER(simcom_sim7080, CONFIG_NET_SOCKETS_OFFLOAD_PRIORITY,
			    AF_UNSPEC, offload_is_supported, offload_socket);