From patchwork Wed Mar 1 16:56:11 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?C=C3=A9dric_Le_Goater?= X-Patchwork-Id: 13156246 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 64AD8C64ED6 for ; Wed, 1 Mar 2023 16:59:20 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pXPl2-0000g0-B5; Wed, 01 Mar 2023 11:56:48 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pXPl0-0000ee-On; Wed, 01 Mar 2023 11:56:46 -0500 Received: from gandalf.ozlabs.org ([150.107.74.76]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pXPky-0007dT-Lb; Wed, 01 Mar 2023 11:56:46 -0500 Received: from gandalf.ozlabs.org (gandalf.ozlabs.org [150.107.74.76]) by gandalf.ozlabs.org (Postfix) with ESMTP id 4PRgPN3VpJz4xDh; Thu, 2 Mar 2023 03:56:40 +1100 (AEDT) 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 4PRgPL1Z9tz4x5Y; Thu, 2 Mar 2023 03:56:37 +1100 (AEDT) From: =?utf-8?q?C=C3=A9dric_Le_Goater?= To: qemu-arm@nongnu.org, qemu-devel@nongnu.org Cc: Peter Maydell , Joel Stanley , Andrew Jeffery , Klaus Jensen , =?utf-8?q?C=C3=A9dric_Le_Goater?= Subject: [PATCH v2 03/11] hw/misc: add a toy i2c echo device Date: Wed, 1 Mar 2023 17:56:11 +0100 Message-Id: <20230301165619.2171090-4-clg@kaod.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230301165619.2171090-1-clg@kaod.org> References: <20230301165619.2171090-1-clg@kaod.org> MIME-Version: 1.0 Received-SPF: pass client-ip=150.107.74.76; envelope-from=SRS0=znpK=6Z=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=0.25, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 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+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org From: Klaus Jensen Add an example I2C device to demonstrate how a slave may master the bus and send data asynchronously to another slave. The device will echo whatever it is sent to the device identified by the first byte received. Signed-off-by: Klaus Jensen [ clg: integrated fixes : https://lore.kernel.org/qemu-devel/Y3yMKAhOkYGtnkOp@cormorant.local/ ] Message-Id: <20220601210831.67259-7-its@irrelevant.dk> Signed-off-by: Cédric Le Goater --- hw/misc/i2c-echo.c | 156 ++++++++++++++++++++++++++++++++++++++++++++ hw/misc/meson.build | 2 + 2 files changed, 158 insertions(+) create mode 100644 hw/misc/i2c-echo.c diff --git a/hw/misc/i2c-echo.c b/hw/misc/i2c-echo.c new file mode 100644 index 0000000000..5705ab5d73 --- /dev/null +++ b/hw/misc/i2c-echo.c @@ -0,0 +1,156 @@ +#include "qemu/osdep.h" +#include "qemu/timer.h" +#include "qemu/main-loop.h" +#include "block/aio.h" +#include "hw/i2c/i2c.h" + +#define TYPE_I2C_ECHO "i2c-echo" +OBJECT_DECLARE_SIMPLE_TYPE(I2CEchoState, I2C_ECHO) + +enum i2c_echo_state { + I2C_ECHO_STATE_IDLE, + I2C_ECHO_STATE_START_SEND, + I2C_ECHO_STATE_ACK, +}; + +typedef struct I2CEchoState { + I2CSlave parent_obj; + + I2CBus *bus; + + enum i2c_echo_state state; + QEMUBH *bh; + + unsigned int pos; + uint8_t data[3]; +} I2CEchoState; + +static void i2c_echo_bh(void *opaque) +{ + I2CEchoState *state = opaque; + + switch (state->state) { + case I2C_ECHO_STATE_IDLE: + return; + + case I2C_ECHO_STATE_START_SEND: + if (i2c_start_send_async(state->bus, state->data[0])) { + goto release_bus; + } + + state->pos++; + state->state = I2C_ECHO_STATE_ACK; + return; + + case I2C_ECHO_STATE_ACK: + if (state->pos > 2) { + break; + } + + if (i2c_send_async(state->bus, state->data[state->pos++])) { + break; + } + + return; + } + + + i2c_end_transfer(state->bus); +release_bus: + i2c_bus_release(state->bus); + + state->state = I2C_ECHO_STATE_IDLE; +} + +static int i2c_echo_event(I2CSlave *s, enum i2c_event event) +{ + I2CEchoState *state = I2C_ECHO(s); + + switch (event) { + case I2C_START_RECV: + state->pos = 0; + + break; + + case I2C_START_SEND: + state->pos = 0; + + break; + + case I2C_FINISH: + state->pos = 0; + state->state = I2C_ECHO_STATE_START_SEND; + i2c_bus_master(state->bus, state->bh); + + break; + + case I2C_NACK: + break; + + default: + return -1; + } + + return 0; +} + +static uint8_t i2c_echo_recv(I2CSlave *s) +{ + I2CEchoState *state = I2C_ECHO(s); + + if (state->pos > 2) { + return 0xff; + } + + return state->data[state->pos++]; +} + +static int i2c_echo_send(I2CSlave *s, uint8_t data) +{ + I2CEchoState *state = I2C_ECHO(s); + + if (state->pos > 2) { + return -1; + } + + state->data[state->pos++] = data; + + return 0; +} + +static void i2c_echo_realize(DeviceState *dev, Error **errp) +{ + I2CEchoState *state = I2C_ECHO(dev); + BusState *bus = qdev_get_parent_bus(dev); + + state->bus = I2C_BUS(bus); + state->bh = qemu_bh_new(i2c_echo_bh, state); + + return; +} + +static void i2c_echo_class_init(ObjectClass *oc, void *data) +{ + I2CSlaveClass *sc = I2C_SLAVE_CLASS(oc); + DeviceClass *dc = DEVICE_CLASS(oc); + + dc->realize = i2c_echo_realize; + + sc->event = i2c_echo_event; + sc->recv = i2c_echo_recv; + sc->send = i2c_echo_send; +} + +static const TypeInfo i2c_echo = { + .name = TYPE_I2C_ECHO, + .parent = TYPE_I2C_SLAVE, + .instance_size = sizeof(I2CEchoState), + .class_init = i2c_echo_class_init, +}; + +static void register_types(void) +{ + type_register_static(&i2c_echo); +} + +type_init(register_types); diff --git a/hw/misc/meson.build b/hw/misc/meson.build index fe869b98ca..a40245ad44 100644 --- a/hw/misc/meson.build +++ b/hw/misc/meson.build @@ -128,6 +128,8 @@ softmmu_ss.add(when: 'CONFIG_NRF51_SOC', if_true: files('nrf51_rng.c')) softmmu_ss.add(when: 'CONFIG_GRLIB', if_true: files('grlib_ahb_apb_pnp.c')) +softmmu_ss.add(when: 'CONFIG_I2C', if_true: files('i2c-echo.c')) + specific_ss.add(when: 'CONFIG_AVR_POWER', if_true: files('avr_power.c')) specific_ss.add(when: 'CONFIG_MAC_VIA', if_true: files('mac_via.c'))