From nobody Fri Apr 4 17:34:32 2025 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1656591738586690.934260843789; Thu, 30 Jun 2022 05:22:18 -0700 (PDT) Received: from localhost ([::1]:49628 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1o6tBZ-000740-5X for importer@patchew.org; Thu, 30 Jun 2022 08:22:17 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:34596) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1o6sIV-0000q9-Ih; Thu, 30 Jun 2022 07:25:23 -0400 Received: from gandalf.ozlabs.org ([150.107.74.76]:59425) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1o6sIT-0002Sx-Fk; Thu, 30 Jun 2022 07:25:23 -0400 Received: from gandalf.ozlabs.org (gandalf.ozlabs.org [150.107.74.76]) by gandalf.ozlabs.org (Postfix) with ESMTP id 4LYbbh2jfZz4xXF; Thu, 30 Jun 2022 21:25:20 +1000 (AEST) Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 4LYbbf0K16z4xD5; Thu, 30 Jun 2022 21:25:17 +1000 (AEST) From: =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= To: qemu-arm@nongnu.org, qemu-devel@nongnu.org Cc: Peter Maydell , Richard Henderson , Klaus Jensen , =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= Subject: [PULL 23/27] hw/i2c: support multiple masters Date: Thu, 30 Jun 2022 13:24:07 +0200 Message-Id: <20220630112411.1474431-24-clg@kaod.org> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20220630112411.1474431-1-clg@kaod.org> References: <20220630112411.1474431-1-clg@kaod.org> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=150.107.74.76; envelope-from=SRS0=N4Bw=XF=kaod.org=clg@ozlabs.org; helo=gandalf.ozlabs.org X-Spam_score_int: -16 X-Spam_score: -1.7 X-Spam_bar: - X-Spam_report: (-1.7 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.249, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=no 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+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZM-MESSAGEID: 1656591740822100001 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: C=C3=A9dric Le Goater Message-Id: <20220630045133.32251-5-me@pjd.dev> Signed-off-by: C=C3=A9dric Le Goater --- include/hw/i2c/i2c.h | 14 ++++++++++++++ hw/i2c/core.c | 34 +++++++++++++++++++++++++++++++++- 2 files changed, 47 insertions(+), 1 deletion(-) diff --git a/include/hw/i2c/i2c.h b/include/hw/i2c/i2c.h index 5ca3b708c0be..be8bb8b78a60 100644 --- a/include/hw/i2c/i2c.h +++ b/include/hw/i2c/i2c.h @@ -69,13 +69,25 @@ struct I2CNode { QLIST_ENTRY(I2CNode) next; }; =20 +typedef struct I2CPendingMaster I2CPendingMaster; + +struct I2CPendingMaster { + QEMUBH *bh; + QSIMPLEQ_ENTRY(I2CPendingMaster) entry; +}; + typedef QLIST_HEAD(I2CNodeList, I2CNode) I2CNodeList; +typedef QSIMPLEQ_HEAD(I2CPendingMasters, I2CPendingMaster) I2CPendingMaste= rs; =20 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; }; =20 I2CBus *i2c_init_bus(DeviceState *parent, const char *name); @@ -117,6 +129,8 @@ int i2c_start_send(I2CBus *bus, uint8_t address); =20 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, diff --git a/hw/i2c/core.c b/hw/i2c/core.c index d0cb2d32fa44..145dce60782a 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" =20 #define I2C_BROADCAST 0x00 @@ -62,6 +63,7 @@ I2CBus *i2c_init_bus(DeviceState *parent, const char *nam= e) =20 bus =3D 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; } =20 bool i2c_scan_bus(I2CBus *bus, uint8_t address, bool broadcast, @@ -180,6 +182,26 @@ int i2c_start_transfer(I2CBus *bus, uint8_t address, b= ool is_recv) : I2C_START_SEND); } =20 +void i2c_bus_master(I2CBus *bus, QEMUBH *bh) +{ + if (i2c_bus_busy(bus)) { + I2CPendingMaster *node =3D g_new(struct I2CPendingMaster, 1); + node->bh =3D bh; + + QSIMPLEQ_INSERT_TAIL(&bus->pending_masters, node, entry); + + return; + } + + bus->bh =3D bh; + qemu_bh_schedule(bus->bh); +} + +void i2c_bus_release(I2CBus *bus) +{ + bus->bh =3D 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 =3D false; + + if (!QSIMPLEQ_EMPTY(&bus->pending_masters)) { + I2CPendingMaster *node =3D QSIMPLEQ_FIRST(&bus->pending_masters); + bus->bh =3D node->bh; + + QSIMPLEQ_REMOVE_HEAD(&bus->pending_masters, entry); + g_free(node); + + qemu_bh_schedule(bus->bh); + } } =20 int i2c_send(I2CBus *bus, uint8_t data) --=20 2.35.3