From patchwork Mon Jun 27 19:54:53 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Peter Delevoryas X-Patchwork-Id: 1649100 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: bilbo.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=fb.com header.i=@fb.com header.a=rsa-sha256 header.s=facebook header.b=iwFJqd3S; dkim-atps=neutral Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by bilbo.ozlabs.org (Postfix) with ESMTPS id 4LWz5D5D7yz9sGh for ; Tue, 28 Jun 2022 05:56:47 +1000 (AEST) Received: from localhost ([::1]:59074 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1o5uqh-0004LN-Ao for incoming@patchwork.ozlabs.org; Mon, 27 Jun 2022 15:56:43 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:42914) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1o5upR-0004Io-GA for qemu-devel@nongnu.org; Mon, 27 Jun 2022 15:55:25 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:59380 helo=mx0a-00082601.pphosted.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1o5upO-0000Zh-70 for qemu-devel@nongnu.org; Mon, 27 Jun 2022 15:55:25 -0400 Received: from pps.filterd (m0089730.ppops.net [127.0.0.1]) by m0089730.ppops.net (8.17.1.5/8.17.1.5) with ESMTP id 25RJ1QF8015418 for ; Mon, 27 Jun 2022 12:55:20 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-type : content-transfer-encoding; s=facebook; bh=mo+Wpbct7Exgx+EdBxqY+i88RyTpKdpQDWK3TFqkI0o=; b=iwFJqd3SgHI+8SGHpKkBfwl3Z06GzxxBLN/CbmLEoa8aZp2rpnSeGTPho3RdojUeQRC/ +q35LiYX+ZELVo7SFLZYsA7trM9DTW5z/zs/q2ltyHl/mORnK2TIye9hsrH2powYQhIp 3/Jk5Q8YcDd2uYxqnmyOV8HCM1hcDMS8ao4= Received: from mail.thefacebook.com ([163.114.132.120]) by m0089730.ppops.net (PPS) with ESMTPS id 3gwwv756s5-7 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Mon, 27 Jun 2022 12:55:20 -0700 Received: from twshared31479.05.prn5.facebook.com (2620:10d:c085:108::4) by mail.thefacebook.com (2620:10d:c085:11d::4) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.28; Mon, 27 Jun 2022 12:55:17 -0700 Received: by devvm9194.prn0.facebook.com (Postfix, from userid 385188) id B14298D206E1; Mon, 27 Jun 2022 12:55:07 -0700 (PDT) From: Peter Delevoryas To: CC: , , , , , , , , , Klaus Jensen Subject: [PATCH 01/14] hw/i2c: support multiple masters Date: Mon, 27 Jun 2022 12:54:53 -0700 Message-ID: <20220627195506.403715-2-pdel@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220627195506.403715-1-pdel@fb.com> References: <20220627195506.403715-1-pdel@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-GUID: k-QqyTJb0nwwQ7EODBPvGxBH1v1-C9hC X-Proofpoint-ORIG-GUID: k-QqyTJb0nwwQ7EODBPvGxBH1v1-C9hC X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.883,Hydra:6.0.517,FMLib:17.11.122.1 definitions=2022-06-27_06,2022-06-24_01,2022-06-22_01 Received-SPF: pass client-ip=67.231.153.30; envelope-from=prvs=71779173e5=pdel@fb.com; helo=mx0a-00082601.pphosted.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Klaus Jensen Allow slaves to master the bus by registering a bottom halve. If the bus is busy, the bottom half is queued up. When a slave has succesfully mastered the bus, the bottom half is scheduled. Signed-off-by: Klaus Jensen [ clg : - fixed typos in commit log ] Message-Id: <20220601210831.67259-4-its@irrelevant.dk> Signed-off-by: Cédric Le Goater Signed-off-by: Peter Delevoryas --- hw/i2c/core.c | 34 +++++++++++++++++++++++++++++++++- include/hw/i2c/i2c.h | 14 ++++++++++++++ 2 files changed, 47 insertions(+), 1 deletion(-) diff --git a/hw/i2c/core.c b/hw/i2c/core.c index d0cb2d32fa..145dce6078 100644 --- a/hw/i2c/core.c +++ b/hw/i2c/core.c @@ -13,6 +13,7 @@ #include "migration/vmstate.h" #include "qapi/error.h" #include "qemu/module.h" +#include "qemu/main-loop.h" #include "trace.h" #define I2C_BROADCAST 0x00 @@ -62,6 +63,7 @@ I2CBus *i2c_init_bus(DeviceState *parent, const char *name) bus = I2C_BUS(qbus_new(TYPE_I2C_BUS, parent, name)); QLIST_INIT(&bus->current_devs); + QSIMPLEQ_INIT(&bus->pending_masters); vmstate_register(NULL, VMSTATE_INSTANCE_ID_ANY, &vmstate_i2c_bus, bus); return bus; } @@ -74,7 +76,7 @@ void i2c_slave_set_address(I2CSlave *dev, uint8_t address) /* Return nonzero if bus is busy. */ int i2c_bus_busy(I2CBus *bus) { - return !QLIST_EMPTY(&bus->current_devs); + return !QLIST_EMPTY(&bus->current_devs) || bus->bh; } bool i2c_scan_bus(I2CBus *bus, uint8_t address, bool broadcast, @@ -180,6 +182,26 @@ int i2c_start_transfer(I2CBus *bus, uint8_t address, bool is_recv) : I2C_START_SEND); } +void i2c_bus_master(I2CBus *bus, QEMUBH *bh) +{ + if (i2c_bus_busy(bus)) { + I2CPendingMaster *node = g_new(struct I2CPendingMaster, 1); + node->bh = bh; + + QSIMPLEQ_INSERT_TAIL(&bus->pending_masters, node, entry); + + return; + } + + bus->bh = bh; + qemu_bh_schedule(bus->bh); +} + +void i2c_bus_release(I2CBus *bus) +{ + bus->bh = NULL; +} + int i2c_start_recv(I2CBus *bus, uint8_t address) { return i2c_do_start_transfer(bus, address, I2C_START_RECV); @@ -206,6 +228,16 @@ void i2c_end_transfer(I2CBus *bus) g_free(node); } bus->broadcast = false; + + if (!QSIMPLEQ_EMPTY(&bus->pending_masters)) { + I2CPendingMaster *node = QSIMPLEQ_FIRST(&bus->pending_masters); + bus->bh = node->bh; + + QSIMPLEQ_REMOVE_HEAD(&bus->pending_masters, entry); + g_free(node); + + qemu_bh_schedule(bus->bh); + } } int i2c_send(I2CBus *bus, uint8_t data) diff --git a/include/hw/i2c/i2c.h b/include/hw/i2c/i2c.h index 5ca3b708c0..be8bb8b78a 100644 --- a/include/hw/i2c/i2c.h +++ b/include/hw/i2c/i2c.h @@ -69,13 +69,25 @@ struct I2CNode { QLIST_ENTRY(I2CNode) next; }; +typedef struct I2CPendingMaster I2CPendingMaster; + +struct I2CPendingMaster { + QEMUBH *bh; + QSIMPLEQ_ENTRY(I2CPendingMaster) entry; +}; + typedef QLIST_HEAD(I2CNodeList, I2CNode) I2CNodeList; +typedef QSIMPLEQ_HEAD(I2CPendingMasters, I2CPendingMaster) I2CPendingMasters; struct I2CBus { BusState qbus; I2CNodeList current_devs; + I2CPendingMasters pending_masters; uint8_t saved_address; bool broadcast; + + /* Set from slave currently mastering the bus. */ + QEMUBH *bh; }; I2CBus *i2c_init_bus(DeviceState *parent, const char *name); @@ -117,6 +129,8 @@ int i2c_start_send(I2CBus *bus, uint8_t address); void i2c_end_transfer(I2CBus *bus); void i2c_nack(I2CBus *bus); +void i2c_bus_master(I2CBus *bus, QEMUBH *bh); +void i2c_bus_release(I2CBus *bus); int i2c_send(I2CBus *bus, uint8_t data); uint8_t i2c_recv(I2CBus *bus); bool i2c_scan_bus(I2CBus *bus, uint8_t address, bool broadcast,