// SPDX-License-Identifier: GPL-2.0 // ISHTP interface for ChromeOS Embedded Controller // // Copyright (c) 2019, Intel Corporation. // // ISHTP client driver for talking to the Chrome OS EC firmware running // on Intel Integrated Sensor Hub (ISH) using the ISH Transport protocol // (ISH-TP). #include #include #include #include #include #include #include "cros_ec.h" /* * ISH TX/RX ring buffer pool size * * The AP->ISH messages and corresponding ISH->AP responses are * serialized. We need 1 TX and 1 RX buffer for these. * * The MKBP ISH->AP events are serialized. We need one additional RX * buffer for them. */ #define CROS_ISH_CL_TX_RING_SIZE 8 #define CROS_ISH_CL_RX_RING_SIZE 8 /* ISH CrOS EC Host Commands */ enum cros_ec_ish_channel { CROS_EC_COMMAND = 1, /* AP->ISH message */ CROS_MKBP_EVENT = 2, /* ISH->AP events */ }; /* * ISH firmware timeout for 1 message send failure is 1Hz, and the * firmware will retry 2 times, so 3Hz is used for timeout. */ #define ISHTP_SEND_TIMEOUT (3 * HZ) /* ISH Transport CrOS EC ISH client unique GUID */ static const guid_t cros_ish_guid = GUID_INIT(0x7b7154d0, 0x56f4, 0x4bdc, 0xb0, 0xd8, 0x9e, 0x7c, 0xda, 0xe0, 0xd6, 0xa0); struct header { u8 channel; u8 status; u8 token; u8 reserved; } __packed; struct cros_ish_out_msg { struct header hdr; struct ec_host_request ec_request; } __packed; struct cros_ish_in_msg { struct header hdr; struct ec_host_response ec_response; } __packed; #define IN_MSG_EC_RESPONSE_PREAMBLE \ offsetof(struct cros_ish_in_msg, ec_response) #define OUT_MSG_EC_REQUEST_PREAMBLE \ offsetof(struct cros_ish_out_msg, ec_request) #define cl_data_to_dev(client_data) ishtp_device((client_data)->cl_device) /* * The Read-Write Semaphore is used to prevent message TX or RX while * the ishtp client is being initialized or undergoing reset. * * The readers are the kernel function calls responsible for IA->ISH * and ISH->AP messaging. * * The writers are .reset() and .probe() function. */ static DECLARE_RWSEM(init_lock); /** * struct response_info - Encapsulate firmware response related * information for passing between function ish_send() and * process_recv() callback. * * @data: Copy the data received from firmware here. * @max_size: Max size allocated for the @data buffer. If the received * data exceeds this value, we log an error. * @size: Actual size of data received from firmware. * @error: 0 for success, negative error code for a failure in process_recv(). * @token: Expected token for response that we are waiting on. * @received: Set to true on receiving a valid firmware response to host command * @wait_queue: Wait queue for host to wait for firmware response. */ struct response_info { void *data; size_t max_size; size_t size; int error; u8 token; bool received; wait_queue_head_t wait_queue; }; /** * struct ishtp_cl_data - Encapsulate per ISH TP Client. * * @cros_ish_cl: ISHTP firmware client instance. * @cl_device: ISHTP client device instance. * @response: Response info passing between ish_send() and process_recv(). * @work_ishtp_reset: Work queue reset handling. * @work_ec_evt: Work queue for EC events. * @ec_dev: CrOS EC MFD device. * * This structure is used to store per client data. */ struct ishtp_cl_data { struct ishtp_cl *cros_ish_cl; struct ishtp_cl_device *cl_device; /* * Used for passing firmware response information between * ish_send() and process_recv() callback. */ struct response_info response; struct work_struct work_ishtp_reset; struct work_struct work_ec_evt; struct cros_ec_device *ec_dev; }; /** * ish_evt_handler - ISH to AP event handler * @work: Work struct */ static void ish_evt_handler(struct work_struct *work) { struct ishtp_cl_data *client_data = container_of(work, struct ishtp_cl_data, work_ec_evt); struct cros_ec_device *ec_dev = client_data->ec_dev; bool ec_has_more_events; do { ec_has_more_events = cros_ec_handle_event(ec_dev); } while (ec_has_more_events); } /** * ish_send() - Send message from host to firmware * * @client_data: Client data instance * @out_msg: Message buffer to be sent to firmware * @out_size: Size of out going message * @in_msg: Message buffer where the incoming data is copied. This buffer * is allocated by calling * @in_size: Max size of incoming message * * Return: Number of bytes copied in the in_msg on success, negative * error code on failure. */ static int ish_send(struct ishtp_cl_data *client_data, u8 *out_msg, size_t out_size, u8 *in_msg, size_t in_size) { static u8 next_token; int rv; struct header *out_hdr = (struct header *)out_msg; struct ishtp_cl *cros_ish_cl = client_data->cros_ish_cl; dev_dbg(cl_data_to_dev(client_data), "%s: channel=%02u status=%02u\n", __func__, out_hdr->channel, out_hdr->status); /* Setup for incoming response */ client_data->response.data = in_msg; client_data->response.max_size = in_size; client_data->response.error = 0; client_data->response.token = next_token++; client_data->response.received = false; out_hdr->token = client_data->response.token; rv = ishtp_cl_send(cros_ish_cl, out_msg, out_size); if (rv) { dev_err(cl_data_to_dev(client_data), "ishtp_cl_send error %d\n", rv); return rv; } wait_event_interruptible_timeout(client_data->response.wait_queue, client_data->response.received, ISHTP_SEND_TIMEOUT); if (!client_data->response.received) { dev_err(cl_data_to_dev(client_data), "Timed out for response to host message\n"); return -ETIMEDOUT; } if (client_data->response.error < 0) return client_data->response.error; return client_data->response.size; } /** * process_recv() - Received and parse incoming packet * @cros_ish_cl: Client instance to get stats * @rb_in_proc: Host interface message buffer * @timestamp: Timestamp of when parent callback started * * Parse the incoming packet. If it is a response packet then it will * update per instance flags and wake up the caller waiting to for the * response. If it is an event packet then it will schedule event work. */ static void process_recv(struct ishtp_cl *cros_ish_cl, struct ishtp_cl_rb *rb_in_proc, ktime_t timestamp) { size_t data_len = rb_in_proc->buf_idx; struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl); struct device *dev = cl_data_to_dev(client_data); struct cros_ish_in_msg *in_msg = (struct cros_ish_in_msg *)rb_in_proc->buffer.data; /* Proceed only if reset or init is not in progress */ if (!down_read_trylock(&init_lock)) { /* Free the buffer */ ishtp_cl_io_rb_recycle(rb_in_proc); dev_warn(dev, "Host is not ready to receive incoming messages\n"); return; } /* * All firmware messages contain a header. Check the buffer size * before accessing elements inside. */ if (!rb_in_proc->buffer.data) { dev_warn(dev, "rb_in_proc->buffer.data returned null"); client_data->response.error = -EBADMSG; goto end_error; } if (data_len < sizeof(struct header)) { dev_err(dev, "data size %zu is less than header %zu\n", data_len, sizeof(struct header)); client_data->response.error = -EMSGSIZE; goto end_error; } dev_dbg(dev, "channel=%02u status=%02u\n", in_msg->hdr.channel, in_msg->hdr.status); switch (in_msg->hdr.channel) { case CROS_EC_COMMAND: if (client_data->response.received) { dev_err(dev, "Previous firmware message not yet processed\n"); goto end_error; } if (client_data->response.token != in_msg->hdr.token) { dev_err_ratelimited(dev, "Dropping old response token %d\n", in_msg->hdr.token); goto end_error; } /* Sanity check */ if (!client_data->response.data) { dev_err(dev, "Receiving buffer is null. Should be allocated by calling function\n"); client_data->response.error = -EINVAL; goto error_wake_up; } if (data_len > client_data->response.max_size) { dev_err(dev, "Received buffer size %zu is larger than allocated buffer %zu\n", data_len, client_data->response.max_size); client_data->response.error = -EMSGSIZE; goto error_wake_up; } if (in_msg->hdr.status) { dev_err(dev, "firmware returned status %d\n", in_msg->hdr.status); client_data->response.error = -EIO; goto error_wake_up; } /* Update the actual received buffer size */ client_data->response.size = data_len; /* * Copy the buffer received in firmware response for the * calling thread. */ memcpy(client_data->response.data, rb_in_proc->buffer.data, data_len); error_wake_up: /* Free the buffer since we copied data or didn't need it */ ishtp_cl_io_rb_recycle(rb_in_proc); rb_in_proc = NULL; /* Set flag before waking up the caller */ client_data->response.received = true; /* Wake the calling thread */ wake_up_interruptible(&client_data->response.wait_queue); break; case CROS_MKBP_EVENT: /* Free the buffer. This is just an event without data */ ishtp_cl_io_rb_recycle(rb_in_proc); rb_in_proc = NULL; /* * Set timestamp from beginning of function since we actually * got an incoming MKBP event */ client_data->ec_dev->last_event_time = timestamp; schedule_work(&client_data->work_ec_evt); break; default: dev_err(dev, "Invalid channel=%02d\n", in_msg->hdr.channel); } end_error: /* Free the buffer if we already haven't */ if (rb_in_proc) ishtp_cl_io_rb_recycle(rb_in_proc); up_read(&init_lock); } /** * ish_event_cb() - bus driver callback for incoming message * @cl_device: ISHTP client device for which this message is targeted. * * Remove the packet from the list and process the message by calling * process_recv. */ static void ish_event_cb(struct ishtp_cl_device *cl_device) { struct ishtp_cl_rb *rb_in_proc; struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device); ktime_t timestamp; /* * Take timestamp as close to hardware interrupt as possible for sensor * timestamps. */ timestamp = cros_ec_get_time_ns(); while ((rb_in_proc = ishtp_cl_rx_get_rb(cros_ish_cl)) != NULL) { /* Decide what to do with received data */ process_recv(cros_ish_cl, rb_in_proc, timestamp); } } /** * cros_ish_init() - Init function for ISHTP client * @cros_ish_cl: ISHTP client instance * * This function complete the initializtion of the client. * * Return: 0 for success, negative error code for failure. */ static int cros_ish_init(struct ishtp_cl *cros_ish_cl) { int rv; struct ishtp_device *dev; struct ishtp_fw_client *fw_client; struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl); rv = ishtp_cl_link(cros_ish_cl); if (rv) { dev_err(cl_data_to_dev(client_data), "ishtp_cl_link failed\n"); return rv; } dev = ishtp_get_ishtp_device(cros_ish_cl); /* Connect to firmware client */ ishtp_set_tx_ring_size(cros_ish_cl, CROS_ISH_CL_TX_RING_SIZE); ishtp_set_rx_ring_size(cros_ish_cl, CROS_ISH_CL_RX_RING_SIZE); fw_client = ishtp_fw_cl_get_client(dev, &cros_ish_guid); if (!fw_client) { dev_err(cl_data_to_dev(client_data), "ish client uuid not found\n"); rv = -ENOENT; goto err_cl_unlink; } ishtp_cl_set_fw_client_id(cros_ish_cl, ishtp_get_fw_client_id(fw_client)); ishtp_set_connection_state(cros_ish_cl, ISHTP_CL_CONNECTING); rv = ishtp_cl_connect(cros_ish_cl); if (rv) { dev_err(cl_data_to_dev(client_data), "client connect fail\n"); goto err_cl_unlink; } ishtp_register_event_cb(client_data->cl_device, ish_event_cb); return 0; err_cl_unlink: ishtp_cl_unlink(cros_ish_cl); return rv; } /** * cros_ish_deinit() - Deinit function for ISHTP client * @cros_ish_cl: ISHTP client instance * * Unlink and free cros_ec client */ static void cros_ish_deinit(struct ishtp_cl *cros_ish_cl) { ishtp_set_connection_state(cros_ish_cl, ISHTP_CL_DISCONNECTING); ishtp_cl_disconnect(cros_ish_cl); ishtp_cl_unlink(cros_ish_cl); ishtp_cl_flush_queues(cros_ish_cl); /* Disband and free all Tx and Rx client-level rings */ ishtp_cl_free(cros_ish_cl); } /** * prepare_cros_ec_rx() - Check & prepare receive buffer * @ec_dev: CrOS EC MFD device. * @in_msg: Incoming message buffer * @msg: cros_ec command used to send & receive data * * Return: 0 for success, negative error code for failure. * * Check the received buffer. Convert to cros_ec_command format. */ static int prepare_cros_ec_rx(struct cros_ec_device *ec_dev, const struct cros_ish_in_msg *in_msg, struct cros_ec_command *msg) { u8 sum = 0; int i, rv, offset; /* Check response error code */ msg->result = in_msg->ec_response.result; rv = cros_ec_check_result(ec_dev, msg); if (rv < 0) return rv; if (in_msg->ec_response.data_len > msg->insize) { dev_err(ec_dev->dev, "Packet too long (%d bytes, expected %d)", in_msg->ec_response.data_len, msg->insize); return -ENOSPC; } /* Copy response packet payload and compute checksum */ for (i = 0; i < sizeof(struct ec_host_response); i++) sum += ((u8 *)in_msg)[IN_MSG_EC_RESPONSE_PREAMBLE + i]; offset = sizeof(struct cros_ish_in_msg); for (i = 0; i < in_msg->ec_response.data_len; i++) sum += msg->data[i] = ((u8 *)in_msg)[offset + i]; if (sum) { dev_dbg(ec_dev->dev, "Bad received packet checksum %d\n", sum); return -EBADMSG; } return 0; } static int cros_ec_pkt_xfer_ish(struct cros_ec_device *ec_dev, struct cros_ec_command *msg) { int rv; struct ishtp_cl *cros_ish_cl = ec_dev->priv; struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl); struct device *dev = cl_data_to_dev(client_data); struct cros_ish_in_msg *in_msg = (struct cros_ish_in_msg *)ec_dev->din; struct cros_ish_out_msg *out_msg = (struct cros_ish_out_msg *)ec_dev->dout; size_t in_size = sizeof(struct cros_ish_in_msg) + msg->insize; size_t out_size = sizeof(struct cros_ish_out_msg) + msg->outsize; /* Sanity checks */ if (in_size > ec_dev->din_size) { dev_err(dev, "Incoming payload size %zu is too large for ec_dev->din_size %d\n", in_size, ec_dev->din_size); return -EMSGSIZE; } if (out_size > ec_dev->dout_size) { dev_err(dev, "Outgoing payload size %zu is too large for ec_dev->dout_size %d\n", out_size, ec_dev->dout_size); return -EMSGSIZE; } /* Proceed only if reset-init is not in progress */ if (!down_read_trylock(&init_lock)) { dev_warn(dev, "Host is not ready to send messages to ISH. Try again\n"); return -EAGAIN; } /* Prepare the package to be sent over ISH TP */ out_msg->hdr.channel = CROS_EC_COMMAND; out_msg->hdr.status = 0; ec_dev->dout += OUT_MSG_EC_REQUEST_PREAMBLE; cros_ec_prepare_tx(ec_dev, msg); ec_dev->dout -= OUT_MSG_EC_REQUEST_PREAMBLE; dev_dbg(dev, "out_msg: struct_ver=0x%x checksum=0x%x command=0x%x command_ver=0x%x data_len=0x%x\n", out_msg->ec_request.struct_version, out_msg->ec_request.checksum, out_msg->ec_request.command, out_msg->ec_request.command_version, out_msg->ec_request.data_len); /* Send command to ISH EC firmware and read response */ rv = ish_send(client_data, (u8 *)out_msg, out_size, (u8 *)in_msg, in_size); if (rv < 0) goto end_error; rv = prepare_cros_ec_rx(ec_dev, in_msg, msg); if (rv) goto end_error; rv = in_msg->ec_response.data_len; dev_dbg(dev, "in_msg: struct_ver=0x%x checksum=0x%x result=0x%x data_len=0x%x\n", in_msg->ec_response.struct_version, in_msg->ec_response.checksum, in_msg->ec_response.result, in_msg->ec_response.data_len); end_error: if (msg->command == EC_CMD_REBOOT_EC) msleep(EC_REBOOT_DELAY_MS); up_read(&init_lock); return rv; } static int cros_ec_dev_init(struct ishtp_cl_data *client_data) { struct cros_ec_device *ec_dev; struct device *dev = cl_data_to_dev(client_data); ec_dev = devm_kzalloc(dev, sizeof(*ec_dev), GFP_KERNEL); if (!ec_dev) return -ENOMEM; client_data->ec_dev = ec_dev; dev->driver_data = ec_dev; ec_dev->dev = dev; ec_dev->priv = client_data->cros_ish_cl; ec_dev->cmd_xfer = NULL; ec_dev->pkt_xfer = cros_ec_pkt_xfer_ish; ec_dev->phys_name = dev_name(dev); ec_dev->din_size = sizeof(struct cros_ish_in_msg) + sizeof(struct ec_response_get_protocol_info); ec_dev->dout_size = sizeof(struct cros_ish_out_msg); return cros_ec_register(ec_dev); } static void reset_handler(struct work_struct *work) { int rv; struct device *dev; struct ishtp_cl *cros_ish_cl; struct ishtp_cl_device *cl_device; struct ishtp_cl_data *client_data = container_of(work, struct ishtp_cl_data, work_ishtp_reset); /* Lock for reset to complete */ down_write(&init_lock); cros_ish_cl = client_data->cros_ish_cl; cl_device = client_data->cl_device; /* Unlink, flush queues & start again */ ishtp_cl_unlink(cros_ish_cl); ishtp_cl_flush_queues(cros_ish_cl); ishtp_cl_free(cros_ish_cl); cros_ish_cl = ishtp_cl_allocate(cl_device); if (!cros_ish_cl) { up_write(&init_lock); return; } ishtp_set_drvdata(cl_device, cros_ish_cl); ishtp_set_client_data(cros_ish_cl, client_data); client_data->cros_ish_cl = cros_ish_cl; rv = cros_ish_init(cros_ish_cl); if (rv) { ishtp_cl_free(cros_ish_cl); dev_err(cl_data_to_dev(client_data), "Reset Failed\n"); up_write(&init_lock); return; } /* Refresh ec_dev device pointers */ client_data->ec_dev->priv = client_data->cros_ish_cl; dev = cl_data_to_dev(client_data); dev->driver_data = client_data->ec_dev; dev_info(cl_data_to_dev(client_data), "Chrome EC ISH reset done\n"); up_write(&init_lock); } /** * cros_ec_ishtp_probe() - ISHTP client driver probe callback * @cl_device: ISHTP client device instance * * Return: 0 for success, negative error code for failure. */ static int cros_ec_ishtp_probe(struct ishtp_cl_device *cl_device) { int rv; struct ishtp_cl *cros_ish_cl; struct ishtp_cl_data *client_data = devm_kzalloc(ishtp_device(cl_device), sizeof(*client_data), GFP_KERNEL); if (!client_data) return -ENOMEM; /* Lock for initialization to complete */ down_write(&init_lock); cros_ish_cl = ishtp_cl_allocate(cl_device); if (!cros_ish_cl) { rv = -ENOMEM; goto end_ishtp_cl_alloc_error; } ishtp_set_drvdata(cl_device, cros_ish_cl); ishtp_set_client_data(cros_ish_cl, client_data); client_data->cros_ish_cl = cros_ish_cl; client_data->cl_device = cl_device; init_waitqueue_head(&client_data->response.wait_queue); INIT_WORK(&client_data->work_ishtp_reset, reset_handler); INIT_WORK(&client_data->work_ec_evt, ish_evt_handler); rv = cros_ish_init(cros_ish_cl); if (rv) goto end_ishtp_cl_init_error; ishtp_get_device(cl_device); up_write(&init_lock); /* Register croc_ec_dev mfd */ rv = cros_ec_dev_init(client_data); if (rv) goto end_cros_ec_dev_init_error; return 0; end_cros_ec_dev_init_error: ishtp_set_connection_state(cros_ish_cl, ISHTP_CL_DISCONNECTING); ishtp_cl_disconnect(cros_ish_cl); ishtp_cl_unlink(cros_ish_cl); ishtp_cl_flush_queues(cros_ish_cl); ishtp_put_device(cl_device); end_ishtp_cl_init_error: ishtp_cl_free(cros_ish_cl); end_ishtp_cl_alloc_error: up_write(&init_lock); return rv; } /** * cros_ec_ishtp_remove() - ISHTP client driver remove callback * @cl_device: ISHTP client device instance * * Return: 0 */ static int cros_ec_ishtp_remove(struct ishtp_cl_device *cl_device) { struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device); struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl); cancel_work_sync(&client_data->work_ishtp_reset); cancel_work_sync(&client_data->work_ec_evt); cros_ish_deinit(cros_ish_cl); ishtp_put_device(cl_device); return 0; } /** * cros_ec_ishtp_reset() - ISHTP client driver reset callback * @cl_device: ISHTP client device instance * * Return: 0 */ static int cros_ec_ishtp_reset(struct ishtp_cl_device *cl_device) { struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device); struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl); schedule_work(&client_data->work_ishtp_reset); return 0; } /** * cros_ec_ishtp_suspend() - ISHTP client driver suspend callback * @device: device instance * * Return: 0 for success, negative error code for failure. */ static int __maybe_unused cros_ec_ishtp_suspend(struct device *device) { struct ishtp_cl_device *cl_device = ishtp_dev_to_cl_device(device); struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device); struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl); return cros_ec_suspend(client_data->ec_dev); } /** * cros_ec_ishtp_resume() - ISHTP client driver resume callback * @device: device instance * * Return: 0 for success, negative error code for failure. */ static int __maybe_unused cros_ec_ishtp_resume(struct device *device) { struct ishtp_cl_device *cl_device = ishtp_dev_to_cl_device(device); struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device); struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl); return cros_ec_resume(client_data->ec_dev); } static SIMPLE_DEV_PM_OPS(cros_ec_ishtp_pm_ops, cros_ec_ishtp_suspend, cros_ec_ishtp_resume); static struct ishtp_cl_driver cros_ec_ishtp_driver = { .name = "cros_ec_ishtp", .guid = &cros_ish_guid, .probe = cros_ec_ishtp_probe, .remove = cros_ec_ishtp_remove, .reset = cros_ec_ishtp_reset, .driver = { .pm = &cros_ec_ishtp_pm_ops, }, }; static int __init cros_ec_ishtp_mod_init(void) { return ishtp_cl_driver_register(&cros_ec_ishtp_driver, THIS_MODULE); } static void __exit cros_ec_ishtp_mod_exit(void) { ishtp_cl_driver_unregister(&cros_ec_ishtp_driver); } module_init(cros_ec_ishtp_mod_init); module_exit(cros_ec_ishtp_mod_exit); MODULE_DESCRIPTION("ChromeOS EC ISHTP Client Driver"); MODULE_AUTHOR("Rushikesh S Kadam "); MODULE_LICENSE("GPL v2"); MODULE_ALIAS("ishtp:*");