From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7D710C5AE5E for ; Sat, 19 Jan 2019 00:15:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 392BA2086A for ; Sat, 19 Jan 2019 00:15:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="nXWEc1R0" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730342AbfASAOj (ORCPT ); Fri, 18 Jan 2019 19:14:39 -0500 Received: from mail-it1-f194.google.com ([209.85.166.194]:53927 "EHLO mail-it1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730240AbfASAOg (ORCPT ); Fri, 18 Jan 2019 19:14:36 -0500 Received: by mail-it1-f194.google.com with SMTP id g85so9254145ita.3 for ; Fri, 18 Jan 2019 16:14:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=S8B2UCvQd7gRR64mddN1rS5cY92pXhXBggqbXefoupA=; b=nXWEc1R0suVeF7Fg8y8p7soZQvolJFuL72dE9GoyyqEkfF0fYhM6vrTtPD/Fz2b2iB TYl7tZ4qgXeM0fH4jKH+vbxnG+sUTXwXfgcT38Z8flm0ukbpLQeebeuLYIUguicF3+rd E0mioJJ8OsB1/BluwA+bSoj+eLgHPKKEOV5Gg= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=S8B2UCvQd7gRR64mddN1rS5cY92pXhXBggqbXefoupA=; b=Xl/kCZpKlhSHfYrEKp8kVhg+H+/0FUgi7SIvqlMXbtIyv1UgcHkJMw1WJFvHcVU3U5 4WgYHNwYN7KGl40bUoHd9HUPhDrVRYndFAxqqXxmChUBEFCs3bY43KMkMzbWMa/eyMbC SpZ4BsbhtebnmLBK9xF2s3DabdzgFKgQpvlQWP4GS+zJsQZVNo36cCXHdWr0HhyU8iRb i/850s3OCLpcPgWKlNhwiWIp2crsDbaAJHxMKPrChmeUjEjF8tjKNIw4WKSM/2ItMxDU +nooQwFvStLOuyQYbsZG8FX/AuZompUFryVuCYjp3SUAVsls3FFy7bLn5n7wVHGt6t1A tG2g== X-Gm-Message-State: AJcUukfqKwLmym9AyE7w2tJ8RTLxRkY7Xbv76zxHSgGZsLghMUXzXJnw iXq7+2iko2EB6kBNGFmJZkXF6SuQtQQ= X-Google-Smtp-Source: ALg8bN7KXyNlSlcEIM5TM7k+ZDAEdOSh5Qmi+PZZvE1cooRDTCeNRhEaFNkvbuhFjxcCQc7YOGeRfQ== X-Received: by 2002:a05:660c:684:: with SMTP id n4mr10501343itk.64.1547856873874; Fri, 18 Jan 2019 16:14:33 -0800 (PST) Received: from ncrews2.bld.corp.google.com ([2620:15c:183:200:8140:8e3f:aea5:bcdf]) by smtp.gmail.com with ESMTPSA id e22sm2382062iod.47.2019.01.18.16.14.32 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 18 Jan 2019 16:14:33 -0800 (PST) From: Nick Crews To: linux-kernel@vger.kernel.org Cc: groeck@chromium.org, sjg@chromium.org, djkurtz@google.com, dlaurie@chromium.org, Duncan Laurie , Nick Crews , Nick Crews , Enric Balletbo i Serra , Benson Leung Subject: [PATCH v3 3/9] platform/chrome: Add support for raw commands in debugfs Date: Fri, 18 Jan 2019 17:14:16 -0700 Message-Id: <20190119001422.48186-4-ncrews@chromium.org> X-Mailer: git-send-email 2.20.1.321.g9e740568ce-goog In-Reply-To: <20190119001422.48186-1-ncrews@chromium.org> References: <20190119001422.48186-1-ncrews@chromium.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Duncan Laurie Add a debugfs attribute that allows sending raw commands to the EC. This is useful for development and debug but should not be enabled in a production environment. Turn the keyboard global mic mute led on > echo 00 f2 01 76 06 00 00 01 01 > /sys/kernel/debug/wilco_ec/raw Turn the keyboard global mic mute led off > echo 00 f2 01 76 06 00 00 01 00 > /sys/kernel/debug/wilco_ec/raw Get the EC firmware build date First send the request command > echo 00 f0 38 00 03 00 > raw Then read the result. "12/21/18" is in the middle of the response > cat raw 00 31 32 2f 32 31 2f 31 38 00 00 0f 01 00 01 00 .12/21/18....... Signed-off-by: Duncan Laurie Signed-off-by: Nick Crews --- Changes in v3: - Move the attribute to the debugfs system - Move the implementation to debugfs.c - Improve the raw hex parsing - Encapsulate global variables in one object - Add safety check when passing less than 3 bytes - Move documentation to debugfs-wilco-ec Changes in v2: - Add sysfs documentation - rm duplicate EC_MAILBOX_DATA_SIZE defs - Make docstrings follow kernel style - Fix tags in commit msg - Move Kconfig to subdirectory - Reading raw now includes ASCII translation Documentation/ABI/testing/debugfs-wilco-ec | 23 +++ drivers/platform/chrome/wilco_ec/Kconfig | 9 + drivers/platform/chrome/wilco_ec/Makefile | 2 +- drivers/platform/chrome/wilco_ec/core.c | 17 ++ drivers/platform/chrome/wilco_ec/debugfs.c | 218 +++++++++++++++++++++ include/linux/platform_data/wilco-ec.h | 3 + 6 files changed, 271 insertions(+), 1 deletion(-) create mode 100644 Documentation/ABI/testing/debugfs-wilco-ec create mode 100644 drivers/platform/chrome/wilco_ec/debugfs.c diff --git a/Documentation/ABI/testing/debugfs-wilco-ec b/Documentation/ABI/testing/debugfs-wilco-ec new file mode 100644 index 000000000000..90bc3fe08dff --- /dev/null +++ b/Documentation/ABI/testing/debugfs-wilco-ec @@ -0,0 +1,23 @@ +What: /sys/kernel/debug/wilco_ec/raw +Date: January 2019 +KernelVersion: 4.19 +Description: + Write and read raw mailbox commands to the EC. + + For writing: + Bytes 0-1 indicate the message type: + 00 F0 = Execute Legacy Command + 00 F2 = Read/Write NVRAM Property + Byte 2 provides the command code + Bytes 3+ consist of the data passed in the request + + Example: + // Request EC info type 3 (EC firmware build date) + $ echo 00 f0 38 00 03 00 > raw + // View the result. The decoded ASCII result "12/21/18" is + // included after the raw hex. + $ cat raw + 00 31 32 2f 32 31 2f 31 38 00 38 00 01 00 2f 00 .12/21/18.8... + + At least three bytes are required, for the msg type and command, + with additional bytes optional for additional data. diff --git a/drivers/platform/chrome/wilco_ec/Kconfig b/drivers/platform/chrome/wilco_ec/Kconfig index f8e6c9e8c5cd..0bd84c98b79b 100644 --- a/drivers/platform/chrome/wilco_ec/Kconfig +++ b/drivers/platform/chrome/wilco_ec/Kconfig @@ -21,4 +21,13 @@ config WILCO_EC To compile this driver as a module, choose M here: the module will be called wilco_ec. +config WILCO_EC_SYSFS_RAW + bool "Enable raw access to EC via sysfs" + depends on WILCO_EC + help + If you say Y here, you get support for sending raw commands to + the Wilco EC via sysfs. These commands do not do any byte + manipulation and allow for testing arbitrary commands. This + interface is intended for debug only and is disabled by default. + endif # WILCO_EC_PLATFORM diff --git a/drivers/platform/chrome/wilco_ec/Makefile b/drivers/platform/chrome/wilco_ec/Makefile index 03b32301dc61..86d0457d85ea 100644 --- a/drivers/platform/chrome/wilco_ec/Makefile +++ b/drivers/platform/chrome/wilco_ec/Makefile @@ -1,4 +1,4 @@ # SPDX-License-Identifier: GPL-2.0 -wilco_ec-objs := core.o mailbox.o +wilco_ec-objs := core.o mailbox.o debugfs.o obj-$(CONFIG_WILCO_EC) += wilco_ec.o diff --git a/drivers/platform/chrome/wilco_ec/core.c b/drivers/platform/chrome/wilco_ec/core.c index 13fe21dd235a..749fd6a36057 100644 --- a/drivers/platform/chrome/wilco_ec/core.c +++ b/drivers/platform/chrome/wilco_ec/core.c @@ -34,6 +34,7 @@ static int wilco_ec_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct wilco_ec_device *ec; + int ret; ec = devm_kzalloc(dev, sizeof(*ec), GFP_KERNEL); if (!ec) @@ -61,11 +62,27 @@ static int wilco_ec_probe(struct platform_device *pdev) cros_ec_lpc_mec_init(ec->io_packet->start, ec->io_packet->start + EC_MAILBOX_DATA_SIZE); + /* add debugfs attributes */ + ret = wilco_ec_debugfs_init(ec); + if (ret) { + dev_err(dev, "Failed to create debugfs attributes\n"); + goto destroy_mec; + } + return 0; + +destroy_mec: + cros_ec_lpc_mec_destroy(); + return ret; } static int wilco_ec_remove(struct platform_device *pdev) { + struct wilco_ec_device *ec = platform_get_drvdata(pdev); + + /* remove debugfs attributes */ + wilco_ec_debugfs_remove(ec); + /* Teardown cros_ec interface */ cros_ec_lpc_mec_destroy(); diff --git a/drivers/platform/chrome/wilco_ec/debugfs.c b/drivers/platform/chrome/wilco_ec/debugfs.c new file mode 100644 index 000000000000..46b0bf3fdf39 --- /dev/null +++ b/drivers/platform/chrome/wilco_ec/debugfs.c @@ -0,0 +1,218 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * debugfs attributes for Wilco EC + * + * Copyright 2019 Google LLC + * + * There is only one attribute used for debugging, called raw. + * You can write a hexadecimal sentence to raw, and that series of bytes + * will be sent to the EC. Then, you can read the bytes of response + * by reading from raw. + */ + +#include +#include +#include +#include + +#ifdef CONFIG_WILCO_EC_SYSFS_RAW + +#define FORMATTED_BUFFER_SIZE (EC_MAILBOX_DATA_SIZE_EXTENDED * 4) + +struct wilco_ec_debugfs { + struct wilco_ec_device *ec; + struct dentry *dir; + size_t response_size; + u8 raw_data[EC_MAILBOX_DATA_SIZE_EXTENDED]; + u8 formatted_data[FORMATTED_BUFFER_SIZE]; +}; + +static struct wilco_ec_debugfs *debug_info; + +/** + * parse_hex_sentence() - Convert a ascii hex representation into byte array + * @in: Input buffer of ascii + * @isize: Length of input buffer + * @out: Output buffer + * @osize: Length of output buffer, e.g. max number of bytes to parse + * + * If an individual "word" within the hex sentence is longer than MAX_WORD_SIZE, + * then the sentence is illegal. + * + * Return: Number of bytes parsed, or negative error code on failure + */ +static int parse_hex_sentence(const char *in, int isize, u8 *out, int osize) +{ + int n_parsed = 0; + int word_start = 0; + int word_end; + int word_len; + /* Temp buffer for holding a "word" of chars that represents one byte */ + const static int MAX_WORD_SIZE = 16; + char tmp[MAX_WORD_SIZE+1]; + u8 byte; + + while (word_start < isize && n_parsed < osize) { + /* Find the start of the next word */ + while (word_start < isize && isspace(in[word_start])) + word_start++; + /* reached the end of the input before next word? */ + if (word_start >= isize) + break; + + /* Find the end of this word */ + word_end = word_start; + while (word_end < isize && !isspace(in[word_end])) + word_end++; + + /* Copy to a tmp NULL terminated string */ + word_len = word_end - word_start; + if (word_len > MAX_WORD_SIZE) + return -EINVAL; + memcpy(tmp, in + word_start, word_len); + tmp[word_len] = '\0'; + + /* + * Convert from hex string, place in output. If fails to parse, + * just return -EINVAL because specific error code is only + * relevant for this one word, returning it would be confusing. + */ + if (kstrtou8(tmp, 16, &byte)) + return -EINVAL; + out[n_parsed++] = byte; + + word_start = word_end; + } + return n_parsed; +} + +#define CMDS_AND_DATA_SIZE ((EC_MAILBOX_DATA_SIZE) + 3) + +static ssize_t raw_write(struct file *file, const char __user *user_buf, + size_t count, loff_t *ppos) +{ + char *buf = debug_info->formatted_data; + struct wilco_ec_message msg; + u8 request_data[CMDS_AND_DATA_SIZE]; + ssize_t kcount; + int ret; + + if (count > FORMATTED_BUFFER_SIZE) + return -EINVAL; + + kcount = simple_write_to_buffer(buf, FORMATTED_BUFFER_SIZE, ppos, + user_buf, count); + if (kcount < 0) + return kcount; + + ret = parse_hex_sentence(buf, kcount, request_data, CMDS_AND_DATA_SIZE); + if (ret < 0) + return ret; + /* Need at least three bytes for type and command */ + if (ret < 3) + return -EINVAL; + + /* Clear response data buffer */ + memset(debug_info->raw_data, '\0', EC_MAILBOX_DATA_SIZE_EXTENDED); + + msg.type = request_data[0] << 8 | request_data[1]; + msg.flags = WILCO_EC_FLAG_RAW; + msg.command = request_data[2]; + msg.request_data = ret > 3 ? request_data + 3 : NULL; + msg.request_size = ret - 3; + msg.response_data = debug_info->raw_data; + msg.response_size = EC_MAILBOX_DATA_SIZE; + + /* Telemetry commands use extended response data */ + if (msg.type == WILCO_EC_MSG_TELEMETRY) { + msg.flags |= WILCO_EC_FLAG_EXTENDED_DATA; + msg.response_size = EC_MAILBOX_DATA_SIZE_EXTENDED; + } + + ret = wilco_ec_mailbox(debug_info->ec, &msg); + if (ret < 0) + return ret; + debug_info->response_size = ret; + + return count; +} + +/** + * wilco_ec_raw_show() - Show result from previous call to raw_store() + * @dev: Device representing the EC + * @attr: The attribute in question + * @buf: Output buffer to be filled + * + * Example usage: + * // Call raw_store(), read EC info type 3 (EC firmware build date) + * # echo 00 f0 38 00 03 00 > raw + * // Call this function, view the result. The decoded ASCII result + * // "12/21/18" is included after the raw hex. + * # cat raw + * 00 31 32 2f 32 31 2f 31 38 00 38 00 01 00 2f 00 .12/21/18.8.../. + * + * Return: Number of bytes written to output, negative error code on failure + */ +static ssize_t raw_read(struct file *file, char __user *user_buf, size_t count, + loff_t *ppos) +{ + int fmt_len = 0; + + if (debug_info->response_size) { + fmt_len = hex_dump_to_buffer(debug_info->raw_data, + debug_info->response_size, + 16, 1, debug_info->formatted_data, + FORMATTED_BUFFER_SIZE, true); + /* Only return response the first time it is read */ + debug_info->response_size = 0; + } + + return simple_read_from_buffer(user_buf, count, ppos, + debug_info->formatted_data, fmt_len); +} + +static const struct file_operations fops_raw = { + .owner = THIS_MODULE, + .read = raw_read, + .write = raw_write, + .llseek = no_llseek, +}; + +int wilco_ec_debugfs_init(struct wilco_ec_device *ec) +{ + debug_info = devm_kzalloc(ec->dev, sizeof(*debug_info), GFP_KERNEL); + if (!debug_info) + return -ENOMEM; + debug_info->ec = ec; + + debug_info->dir = debugfs_create_dir("wilco_ec", NULL); + if (!debug_info->dir) + return -ENOMEM; + + if (!debugfs_create_file("raw", 0644, debug_info->dir, + NULL, &fops_raw)) { + debugfs_remove_recursive(debug_info->dir); + return -ENOMEM; + } + + return 0; +} + +void wilco_ec_debugfs_remove(struct wilco_ec_device *ec) +{ + if (debug_info) { + debugfs_remove_recursive(debug_info->dir); + devm_kfree(ec->dev, debug_info); /* needed? */ + } +} + +#else /* CONFIG_WILCO_EC_SYSFS_RAW */ + +int wilco_ec_debugfs_init(struct wilco_ec_device *ec) +{ + return 0; +} + +void wilco_ec_debugfs_remove(struct wilco_ec_device *ec) {} + +#endif /* CONFIG_WILCO_EC_SYSFS_RAW */ diff --git a/include/linux/platform_data/wilco-ec.h b/include/linux/platform_data/wilco-ec.h index 5477b8802f81..3298eabe73bc 100644 --- a/include/linux/platform_data/wilco-ec.h +++ b/include/linux/platform_data/wilco-ec.h @@ -135,4 +135,7 @@ struct wilco_ec_response { */ int wilco_ec_mailbox(struct wilco_ec_device *ec, struct wilco_ec_message *msg); +int wilco_ec_debugfs_init(struct wilco_ec_device *ec); +void wilco_ec_debugfs_remove(struct wilco_ec_device *ec); + #endif /* WILCO_EC_H */ -- 2.20.1.321.g9e740568ce-goog