// SPDX-License-Identifier: GPL-2.0 /* Copyright (c) 2013-2018, The Linux Foundation. All rights reserved. * Copyright (C) 2018-2024 Linaro Ltd. */ #include <linux/qrtr.h> #include <linux/string.h> #include <linux/types.h> #include "ipa.h" #include "ipa_mem.h" #include "ipa_modem.h" #include "ipa_qmi_msg.h" /** * DOC: AP/Modem QMI Handshake * * The AP and modem perform a "handshake" at initialization time to ensure * both sides know when everything is ready to begin operating. The AP * driver (this code) uses two QMI handles (endpoints) for this; a client * using a service on the modem, and server to service modem requests (and * to supply an indication message from the AP). Once the handshake is * complete, the AP and modem may begin IPA operation. This occurs * only when the AP IPA driver, modem IPA driver, and IPA microcontroller * are ready. * * The QMI service on the modem expects to receive an INIT_DRIVER request from * the AP, which contains parameters used by the modem during initialization. * The AP sends this request as soon as it is knows the modem side service * is available. The modem responds to this request, and if this response * contains a success result, the AP knows the modem IPA driver is ready. * * The modem is responsible for loading firmware on the IPA microcontroller. * This occurs only during the initial modem boot. The modem sends a * separate DRIVER_INIT_COMPLETE request to the AP to report that the * microcontroller is ready. The AP may assume the microcontroller is * ready and remain so (even if the modem reboots) once it has received * and responded to this request. * * There is one final exchange involved in the handshake. It is required * on the initial modem boot, but optional (but in practice does occur) on * subsequent boots. The modem expects to receive a final INIT_COMPLETE * indication message from the AP when it is about to begin its normal * operation. The AP will only send this message after it has received * and responded to an INDICATION_REGISTER request from the modem. * * So in summary: * - Whenever the AP learns the modem has booted and its IPA QMI service * is available, it sends an INIT_DRIVER request to the modem. The * modem supplies a success response when it is ready to operate. * - On the initial boot, the modem sets up the IPA microcontroller, and * sends a DRIVER_INIT_COMPLETE request to the AP when this is done. * - When the modem is ready to receive an INIT_COMPLETE indication from * the AP, it sends an INDICATION_REGISTER request to the AP. * - On the initial modem boot, everything is ready when: * - AP has received a success response from its INIT_DRIVER request * - AP has responded to a DRIVER_INIT_COMPLETE request * - AP has responded to an INDICATION_REGISTER request from the modem * - AP has sent an INIT_COMPLETE indication to the modem * - On subsequent modem boots, everything is ready when: * - AP has received a success response from its INIT_DRIVER request * - AP has responded to a DRIVER_INIT_COMPLETE request * - The INDICATION_REGISTER request and INIT_COMPLETE indication are * optional for non-initial modem boots, and have no bearing on the * determination of when things are "ready" */ #define IPA_HOST_SERVICE_SVC_ID … #define IPA_HOST_SVC_VERS … #define IPA_HOST_SERVICE_INS_ID … #define IPA_MODEM_SERVICE_SVC_ID … #define IPA_MODEM_SERVICE_INS_ID … #define IPA_MODEM_SVC_VERS … #define QMI_INIT_DRIVER_TIMEOUT … /* Send an INIT_COMPLETE indication message to the modem */ static void ipa_server_init_complete(struct ipa_qmi *ipa_qmi) { … } /* If requested (and not already sent) send the INIT_COMPLETE indication */ static void ipa_qmi_indication(struct ipa_qmi *ipa_qmi) { … } /* Determine whether everything is ready to start normal operation. * We know everything (else) is ready when we know the IPA driver on * the modem is ready, and the microcontroller is ready. * * When the modem boots (or reboots), the handshake sequence starts * with the AP sending the modem an INIT_DRIVER request. Within * that request, the uc_loaded flag will be zero (false) for an * initial boot, non-zero (true) for a subsequent (SSR) boot. */ static void ipa_qmi_ready(struct ipa_qmi *ipa_qmi) { … } /* All QMI clients from the modem node are gone (modem shut down or crashed). */ static void ipa_server_bye(struct qmi_handle *qmi, unsigned int node) { … } static const struct qmi_ops ipa_server_ops = …; /* Callback function to handle an INDICATION_REGISTER request message from the * modem. This informs the AP that the modem is now ready to receive the * INIT_COMPLETE indication message. */ static void ipa_server_indication_register(struct qmi_handle *qmi, struct sockaddr_qrtr *sq, struct qmi_txn *txn, const void *decoded) { … } /* Respond to a DRIVER_INIT_COMPLETE request message from the modem. */ static void ipa_server_driver_init_complete(struct qmi_handle *qmi, struct sockaddr_qrtr *sq, struct qmi_txn *txn, const void *decoded) { … } /* The server handles two request message types sent by the modem. */ static const struct qmi_msg_handler ipa_server_msg_handlers[] = …; /* Handle an INIT_DRIVER response message from the modem. */ static void ipa_client_init_driver(struct qmi_handle *qmi, struct sockaddr_qrtr *sq, struct qmi_txn *txn, const void *decoded) { … } /* The client handles one response message type sent by the modem. */ static const struct qmi_msg_handler ipa_client_msg_handlers[] = …; /* Return a pointer to an init modem driver request structure, which contains * configuration parameters for the modem. The modem may be started multiple * times, but generally these parameters don't change so we can reuse the * request structure once it's initialized. The only exception is the * skip_uc_load field, which will be set only after the microcontroller has * reported it has completed its initialization. */ static const struct ipa_init_modem_driver_req * init_modem_driver_req(struct ipa_qmi *ipa_qmi) { … } /* Send an INIT_DRIVER request to the modem, and wait for it to complete. */ static void ipa_client_init_driver_work(struct work_struct *work) { … } /* The modem server is now available. We will send an INIT_DRIVER request * to the modem, but can't wait for it to complete in this callback thread. * Schedule a worker on the global workqueue to do that for us. */ static int ipa_client_new_server(struct qmi_handle *qmi, struct qmi_service *svc) { … } static const struct qmi_ops ipa_client_ops = …; /* Set up for QMI message exchange */ int ipa_qmi_setup(struct ipa *ipa) { … } /* Tear down IPA QMI handles */ void ipa_qmi_teardown(struct ipa *ipa) { … }
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