From patchwork Fri May 3 22:02:17 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gwendal Grignou X-Patchwork-Id: 10929271 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 7B32B912 for ; Fri, 3 May 2019 22:03:11 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6D148287CF for ; Fri, 3 May 2019 22:03:11 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 61588287DB; Fri, 3 May 2019 22:03:11 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 597E5287CF for ; Fri, 3 May 2019 22:03:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726935AbfECWDJ (ORCPT ); Fri, 3 May 2019 18:03:09 -0400 Received: from mail-pl1-f194.google.com ([209.85.214.194]:46915 "EHLO mail-pl1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726604AbfECWDI (ORCPT ); Fri, 3 May 2019 18:03:08 -0400 Received: by mail-pl1-f194.google.com with SMTP id bi2so3298669plb.13 for ; Fri, 03 May 2019 15:03:08 -0700 (PDT) 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=GvWQKN4ldbQtxhC2Mo0V29fBja+ZKnVpKgJauRZWMXc=; b=Sb3qIa/c+z5t+KRSwycp0sHfuZBmeJVIWsbLbDE1cTRbxd6STgm44tjW51Y675C368 dJuQTOfPjLohmWBYgflYxi2FpEi3pUAQhut9WrqyP2QuZZ4TXqtQpgIpuv5+UWKIGYh7 bOG1/BBm4cfSigOEoM2C2qkYWLX/OzGlrTNb4= 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=GvWQKN4ldbQtxhC2Mo0V29fBja+ZKnVpKgJauRZWMXc=; b=B99rWph5tbblLMVDS/XE9ICltC12bZxCtnyBvhTgFlYFswSwxme8Qlk4htguF7tyz4 pyIvWM77wCEtyyy2KOoE8IJTcCJqyIIN7uo81WK7ndguIeYK1Pmp5wtWlFCNlk+TtkZf bTSSILlXA3ZZU/+HjJ2Zbda/dqAE0wQLZJtAqPP7C5GLAgSnuLbnwQzLmdYXrcdlekpM vQvg3gjCsbg8SWEa3pjbUDSj59Ug5MtpRGqJg81sl32XNtV0tnbUF8bO4Qa7STMhMzeW DfNsVGVgEYHz/FZVFTjqnkTnHZ/QZgKTp3ul1p8RL249IM0Eq6f3SWhs8plOZ9E+9OuM VYGA== X-Gm-Message-State: APjAAAWCJ9ZQrKqdDO5yJi6u4kRKYKxIXR33T1SJqSReBRZhqWcjB3Gm gO5RLgSVMHZWqigtIhRpQjmh7g== X-Google-Smtp-Source: APXvYqxv5YQ9QUjYnNZopsONp33NCin2jYenipJ8UTsEYFIN9EDQKqUXVX/ukdjXJemvrSNPAAMIUA== X-Received: by 2002:a17:902:7d90:: with SMTP id a16mr13457675plm.122.1556920986539; Fri, 03 May 2019 15:03:06 -0700 (PDT) Received: from localhost ([2620:15c:202:1:3c8f:512b:3522:dfaf]) by smtp.gmail.com with ESMTPSA id p2sm8513289pfi.73.2019.05.03.15.03.05 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 03 May 2019 15:03:05 -0700 (PDT) From: Gwendal Grignou To: enric.balletbo@collabora.com, bleung@chromium.org, groeck@chromium.org, lee.jones@linaro.org, jic23@kernel.org, broonie@kernel.org, cychiang@chromium.org, tiwai@suse.com Cc: linux-iio@vger.kernel.org, alsa-devel@alsa-project.org, Gwendal Grignou Subject: [PATCH v2 14/30] mfd: cros_ec: Add EC transport protocol v4 Date: Fri, 3 May 2019 15:02:17 -0700 Message-Id: <20190503220233.64546-15-gwendal@chromium.org> X-Mailer: git-send-email 2.21.0.1020.gf2820cf01a-goog In-Reply-To: <20190503220233.64546-1-gwendal@chromium.org> References: <20190503220233.64546-1-gwendal@chromium.org> MIME-Version: 1.0 Sender: linux-iio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Introduce a new transport procotol between EC and host. Acked-by: Enric Balletbo i Serra Signed-off-by: Gwendal Grignou --- include/linux/mfd/cros_ec_commands.h | 143 ++++++++++++++++++++++++++- 1 file changed, 141 insertions(+), 2 deletions(-) diff --git a/include/linux/mfd/cros_ec_commands.h b/include/linux/mfd/cros_ec_commands.h index 29a996832af0..48e753df7e2d 100644 --- a/include/linux/mfd/cros_ec_commands.h +++ b/include/linux/mfd/cros_ec_commands.h @@ -455,7 +455,10 @@ #define EC_LPC_STATUS_BUSY_MASK \ (EC_LPC_STATUS_FROM_HOST | EC_LPC_STATUS_PROCESSING) -/* Host command response codes */ +/* + * Host command response codes (16-bit). Note that response codes should be + * stored in a uint16_t rather than directly in a value of this type. + */ enum ec_status { EC_RES_SUCCESS = 0, EC_RES_INVALID_COMMAND = 1, @@ -471,7 +474,13 @@ enum ec_status { EC_RES_OVERFLOW = 11, /* Table / data overflow */ EC_RES_INVALID_HEADER = 12, /* Header contains invalid data */ EC_RES_REQUEST_TRUNCATED = 13, /* Didn't get the entire request */ - EC_RES_RESPONSE_TOO_BIG = 14 /* Response was too big to handle */ + EC_RES_RESPONSE_TOO_BIG = 14, /* Response was too big to handle */ + EC_RES_BUS_ERROR = 15, /* Communications bus error */ + EC_RES_BUSY = 16, /* Up but too busy. Should retry */ + EC_RES_INVALID_HEADER_VERSION = 17, /* Header version invalid */ + EC_RES_INVALID_HEADER_CRC = 18, /* Header CRC invalid */ + EC_RES_INVALID_DATA_CRC = 19, /* Data CRC invalid */ + EC_RES_DUP_UNAVAILABLE = 20, /* Can't resend response */ }; /* @@ -744,6 +753,136 @@ struct ec_host_response { uint16_t reserved; } __ec_align4; +/*****************************************************************************/ + +/* + * Host command protocol V4. + * + * Packets always start with a request or response header. They are followed + * by data_len bytes of data. If the data_crc_present flag is set, the data + * bytes are followed by a CRC-8 of that data, using using x^8 + x^2 + x + 1 + * polynomial. + * + * Host algorithm when sending a request q: + * + * 101) tries_left=(some value, e.g. 3); + * 102) q.seq_num++ + * 103) q.seq_dup=0 + * 104) Calculate q.header_crc. + * 105) Send request q to EC. + * 106) Wait for response r. Go to 201 if received or 301 if timeout. + * + * 201) If r.struct_version != 4, go to 301. + * 202) If r.header_crc mismatches calculated CRC for r header, go to 301. + * 203) If r.data_crc_present and r.data_crc mismatches, go to 301. + * 204) If r.seq_num != q.seq_num, go to 301. + * 205) If r.seq_dup == q.seq_dup, return success. + * 207) If r.seq_dup == 1, go to 301. + * 208) Return error. + * + * 301) If --tries_left <= 0, return error. + * 302) If q.seq_dup == 1, go to 105. + * 303) q.seq_dup = 1 + * 304) Go to 104. + * + * EC algorithm when receiving a request q. + * EC has response buffer r, error buffer e. + * + * 101) If q.struct_version != 4, set e.result = EC_RES_INVALID_HEADER_VERSION + * and go to 301 + * 102) If q.header_crc mismatches calculated CRC, set e.result = + * EC_RES_INVALID_HEADER_CRC and go to 301 + * 103) If q.data_crc_present, calculate data CRC. If that mismatches the CRC + * byte at the end of the packet, set e.result = EC_RES_INVALID_DATA_CRC + * and go to 301. + * 104) If q.seq_dup == 0, go to 201. + * 105) If q.seq_num != r.seq_num, go to 201. + * 106) If q.seq_dup == r.seq_dup, go to 205, else go to 203. + * + * 201) Process request q into response r. + * 202) r.seq_num = q.seq_num + * 203) r.seq_dup = q.seq_dup + * 204) Calculate r.header_crc + * 205) If r.data_len > 0 and data is no longer available, set e.result = + * EC_RES_DUP_UNAVAILABLE and go to 301. + * 206) Send response r. + * + * 301) e.seq_num = q.seq_num + * 302) e.seq_dup = q.seq_dup + * 303) Calculate e.header_crc. + * 304) Send error response e. + */ + +/* Version 4 request from host */ +struct ec_host_request4 { + /* + * bits 0-3: struct_version: Structure version (=4) + * bit 4: is_response: Is response (=0) + * bits 5-6: seq_num: Sequence number + * bit 7: seq_dup: Sequence duplicate flag + */ + uint8_t fields0; + + /* + * bits 0-4: command_version: Command version + * bits 5-6: Reserved (set 0, ignore on read) + * bit 7: data_crc_present: Is data CRC present after data + */ + uint8_t fields1; + + /* Command code (EC_CMD_*) */ + uint16_t command; + + /* Length of data which follows this header (not including data CRC) */ + uint16_t data_len; + + /* Reserved (set 0, ignore on read) */ + uint8_t reserved; + + /* CRC-8 of above fields, using x^8 + x^2 + x + 1 polynomial */ + uint8_t header_crc; +} __ec_align4; + +/* Version 4 response from EC */ +struct ec_host_response4 { + /* + * bits 0-3: struct_version: Structure version (=4) + * bit 4: is_response: Is response (=1) + * bits 5-6: seq_num: Sequence number + * bit 7: seq_dup: Sequence duplicate flag + */ + uint8_t fields0; + + /* + * bits 0-6: Reserved (set 0, ignore on read) + * bit 7: data_crc_present: Is data CRC present after data + */ + uint8_t fields1; + + /* Result code (EC_RES_*) */ + uint16_t result; + + /* Length of data which follows this header (not including data CRC) */ + uint16_t data_len; + + /* Reserved (set 0, ignore on read) */ + uint8_t reserved; + + /* CRC-8 of above fields, using x^8 + x^2 + x + 1 polynomial */ + uint8_t header_crc; +} __ec_align4; + +/* Fields in fields0 byte */ +#define EC_PACKET4_0_STRUCT_VERSION_MASK 0x0f +#define EC_PACKET4_0_IS_RESPONSE_MASK 0x10 +#define EC_PACKET4_0_SEQ_NUM_SHIFT 5 +#define EC_PACKET4_0_SEQ_NUM_MASK 0x60 +#define EC_PACKET4_0_SEQ_DUP_MASK 0x80 + +/* Fields in fields1 byte */ +#define EC_PACKET4_1_COMMAND_VERSION_MASK 0x1f /* (request only) */ +#define EC_PACKET4_1_DATA_CRC_PRESENT_MASK 0x80 + /*****************************************************************************/ /* * Notes on commands: