From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934680AbcIPOKc (ORCPT ); Fri, 16 Sep 2016 10:10:32 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:51542 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933503AbcIPOKY (ORCPT ); Fri, 16 Sep 2016 10:10:24 -0400 Date: Fri, 16 Sep 2016 16:10:28 +0200 From: Greg KH To: Arnd Bergmann , linux-kernel@vger.kernel.org Cc: Johan Hovold , Rui Miguel Silva , Laurent Pinchart , Sandeep Patil , Matt Porter , John Stultz , Rob Herring , Viresh Kumar , Alex Elder , David Lin , "Bryan O'Donoghue" , Vaibhav Agarwal , Mark Greer Subject: [patch 15/32] greybus: logging driver Message-ID: <20160916141028.GC1252@kroah.com> References: <20160914100949.GA6179@kroah.com> <20160916064058.GA17821@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160916064058.GA17821@kroah.com> User-Agent: Mutt/1.7.0 (2016-08-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This driver implements the Greybus logging protocol. Signed-off-by: Greg Kroah-Hartman --- drivers/greybus/log.c | 132 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 132 insertions(+) --- /dev/null +++ b/drivers/greybus/log.c @@ -0,0 +1,132 @@ +/* + * Greybus driver for the log protocol + * + * Copyright 2016 Google Inc. + * + * Released under the GPLv2 only. + */ +#include +#include +#include +#include +#include + +#include "greybus.h" + +struct gb_log { + struct gb_connection *connection; +}; + +static int gb_log_request_handler(struct gb_operation *op) +{ + struct gb_connection *connection = op->connection; + struct device *dev = &connection->bundle->dev; + struct gb_log_send_log_request *receive; + u16 len; + + if (op->type != GB_LOG_TYPE_SEND_LOG) { + dev_err(dev, "unknown request type 0x%02x\n", op->type); + return -EINVAL; + } + + /* Verify size of payload */ + if (op->request->payload_size < sizeof(*receive)) { + dev_err(dev, "log request too small (%zu < %zu)\n", + op->request->payload_size, sizeof(*receive)); + return -EINVAL; + } + receive = op->request->payload; + len = le16_to_cpu(receive->len); + if (len != (int)(op->request->payload_size - sizeof(*receive))) { + dev_err(dev, "log request wrong size %d vs %d\n", len, + (int)(op->request->payload_size - sizeof(*receive))); + return -EINVAL; + } + if (len == 0) { + dev_err(dev, "log request of 0 bytes?\n"); + return -EINVAL; + } + + if (len > GB_LOG_MAX_LEN) { + dev_err(dev, "log request too big: %d\n", len); + return -EINVAL; + } + + /* Ensure the buffer is 0 terminated */ + receive->msg[len - 1] = '\0'; + + /* Print with dev_dbg() so that it can be easily turned off using + * dynamic debugging (and prevent any DoS) */ + dev_dbg(dev, "%s", receive->msg); + + return 0; +} + +static int gb_log_probe(struct gb_bundle *bundle, + const struct greybus_bundle_id *id) +{ + struct greybus_descriptor_cport *cport_desc; + struct gb_connection *connection; + struct gb_log *log; + int retval; + + if (bundle->num_cports != 1) + return -ENODEV; + + cport_desc = &bundle->cport_desc[0]; + if (cport_desc->protocol_id != GREYBUS_PROTOCOL_LOG) + return -ENODEV; + + log = kzalloc(sizeof(*log), GFP_KERNEL); + if (!log) + return -ENOMEM; + + connection = gb_connection_create(bundle, le16_to_cpu(cport_desc->id), + gb_log_request_handler); + if (IS_ERR(connection)) { + retval = PTR_ERR(connection); + goto error_free; + } + + log->connection = connection; + greybus_set_drvdata(bundle, log); + + retval = gb_connection_enable(connection); + if (retval) + goto error_connection_destroy; + + return 0; + +error_connection_destroy: + gb_connection_destroy(connection); +error_free: + kfree(log); + return retval; +} + +static void gb_log_disconnect(struct gb_bundle *bundle) +{ + struct gb_log *log = greybus_get_drvdata(bundle); + struct gb_connection *connection = log->connection; + + gb_connection_disable(connection); + gb_connection_destroy(connection); + + kfree(log); +} + +static const struct greybus_bundle_id gb_log_id_table[] = { + { GREYBUS_DEVICE_CLASS(GREYBUS_CLASS_LOG) }, + { } +}; +MODULE_DEVICE_TABLE(greybus, gb_log_id_table); + +static struct greybus_driver gb_log_driver = { + .name = "log", + .probe = gb_log_probe, + .disconnect = gb_log_disconnect, + .id_table = gb_log_id_table, +}; +module_greybus_driver(gb_log_driver); + +MODULE_LICENSE("GPL v2");