From patchwork Thu Jun 1 17:10:30 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Peter Maydell X-Patchwork-Id: 100975 Delivered-To: patch@linaro.org Received: by 10.182.202.35 with SMTP id kf3csp864917obc; Thu, 1 Jun 2017 10:30:32 -0700 (PDT) X-Received: by 10.55.69.72 with SMTP id s69mr3191566qka.175.1496338232623; Thu, 01 Jun 2017 10:30:32 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1496338232; cv=none; d=google.com; s=arc-20160816; b=ICaabA/72yEJnlL2PnKmhv+CNN9vQDQacVJXU+Xuk8kyh2LSV4LpshjGBPqEoSZOWj i/esPbMbXmUCkMkHV7vMgSQV/zjW6rmDSYQfHAa9vpmanS4zwfNN/BzMOFYXmH4curKz TPBgMiBkbuCJgNpQRtlAH1IWGtM4m3x3azKDuKNBYGQRRRCmztcUutzzZfNS2go8yH+0 17tDtfRiR+o4XaCNiSkBwN84Qrd6TmN3shRRMyX7oFVkzd8C7B+LdZ/oGxx1FubTYtPb nEtoaRZevf2WZIgctU8/cA1yrj5jQgRSQq1Kjr7sh/uGiCdQ6A760wl/CXYosJO2oe5k 4xSg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=sender:errors-to:list-subscribe:list-help:list-post:list-archive :list-unsubscribe:list-id:precedence:subject :content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:to:from:arc-authentication-results; bh=QbFijTpPk6a+TYPzS7Ej7dgMn2yS6FJoK1L2zQWcvn4=; b=bEupFVDk3PhRej1m8HQzI1XTfmfKvdvDYdWQ+8qUMwLchGNKL5WB9xCxjqM4od+eW4 YYiDpd9m+ydFimfQs0F6Lp87NDbnUEvyL+pLUEdqPNr8E8bqIcLqlzHM19cKAIJxU8lB 3/wAaJpecYWlm+qV4Ahr6rzinhY0h2E+etmQjZf4dZzatT0B+0WkhQ6fVvDZvxuj6S4Z FbmKhRZZPvUf1cp4/us01UU8Lc57hk8bHv0lQwgwbHHGQ/UlaDgkNV1+hBNHlxkvDLDw rRHs3WSnyg4MjwzHGhDVhGCNKID45k4QnLLcJmYPi/wGNQa+mj4n4zT8k/vPsukPjTXb /Jew== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 2001:4830:134:3::11 as permitted sender) smtp.mailfrom=qemu-devel-bounces+patch=linaro.org@nongnu.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=linaro.org Return-Path: Received: from lists.gnu.org (lists.gnu.org. [2001:4830:134:3::11]) by mx.google.com with ESMTPS id 15si6297835qku.15.2017.06.01.10.30.32 for (version=TLS1 cipher=AES128-SHA bits=128/128); Thu, 01 Jun 2017 10:30:32 -0700 (PDT) Received-SPF: pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 2001:4830:134:3::11 as permitted sender) client-ip=2001:4830:134:3::11; Authentication-Results: mx.google.com; spf=pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 2001:4830:134:3::11 as permitted sender) smtp.mailfrom=qemu-devel-bounces+patch=linaro.org@nongnu.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: from localhost ([::1]:45888 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dGTvZ-0002Pj-TC for patch@linaro.org; Thu, 01 Jun 2017 13:30:29 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35346) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dGTcc-0001Af-2D for qemu-devel@nongnu.org; Thu, 01 Jun 2017 13:10:59 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dGTca-0006Fc-Ng for qemu-devel@nongnu.org; Thu, 01 Jun 2017 13:10:53 -0400 Received: from orth.archaic.org.uk ([2001:8b0:1d0::2]:37149) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1dGTca-0006DU-E9 for qemu-devel@nongnu.org; Thu, 01 Jun 2017 13:10:52 -0400 Received: from pm215 by orth.archaic.org.uk with local (Exim 4.84_2) (envelope-from ) id 1dGTcZ-0007UQ-9E for qemu-devel@nongnu.org; Thu, 01 Jun 2017 18:10:51 +0100 From: Peter Maydell To: qemu-devel@nongnu.org Date: Thu, 1 Jun 2017 18:10:30 +0100 Message-Id: <1496337035-30213-23-git-send-email-peter.maydell@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1496337035-30213-1-git-send-email-peter.maydell@linaro.org> References: <1496337035-30213-1-git-send-email-peter.maydell@linaro.org> MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 2001:8b0:1d0::2 Subject: [Qemu-devel] [PULL 22/27] aspeed/i2c: introduce a state machine X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+patch=linaro.org@nongnu.org Sender: "Qemu-devel" From: Cédric Le Goater The Aspeed I2C controller maintains a state machine in the command register, which is mostly used for debug. Let's start adding a few states to handle abnormal STOP commands. Today, the model uses the busy status of the bus as a condition to do so but it is not precise enough. Also remove the ABNORMAL bit for failing TX commands. This is incorrect with respect to the specs. Signed-off-by: Cédric Le Goater Message-id: 1494827476-1487-4-git-send-email-clg@kaod.org Signed-off-by: Peter Maydell --- hw/i2c/aspeed_i2c.c | 36 +++++++++++++++++++++++++++++++++--- 1 file changed, 33 insertions(+), 3 deletions(-) -- 2.7.4 diff --git a/hw/i2c/aspeed_i2c.c b/hw/i2c/aspeed_i2c.c index 67004c6..c762c73 100644 --- a/hw/i2c/aspeed_i2c.c +++ b/hw/i2c/aspeed_i2c.c @@ -169,6 +169,21 @@ static uint64_t aspeed_i2c_bus_read(void *opaque, hwaddr offset, } } +static void aspeed_i2c_set_state(AspeedI2CBus *bus, uint8_t state) +{ + bus->cmd &= ~(I2CD_TX_STATE_MASK << I2CD_TX_STATE_SHIFT); + bus->cmd |= (state & I2CD_TX_STATE_MASK) << I2CD_TX_STATE_SHIFT; +} + +static uint8_t aspeed_i2c_get_state(AspeedI2CBus *bus) +{ + return (bus->cmd >> I2CD_TX_STATE_SHIFT) & I2CD_TX_STATE_MASK; +} + +/* + * The state machine needs some refinement. It is only used to track + * invalid STOP commands for the moment. + */ static void aspeed_i2c_bus_handle_cmd(AspeedI2CBus *bus, uint64_t value) { bus->cmd &= ~0xFFFF; @@ -176,6 +191,11 @@ static void aspeed_i2c_bus_handle_cmd(AspeedI2CBus *bus, uint64_t value) bus->intr_status = 0; if (bus->cmd & I2CD_M_START_CMD) { + uint8_t state = aspeed_i2c_get_state(bus) & I2CD_MACTIVE ? + I2CD_MSTARTR : I2CD_MSTART; + + aspeed_i2c_set_state(bus, state); + if (i2c_start_transfer(bus->bus, extract32(bus->buf, 1, 7), extract32(bus->buf, 0, 1))) { bus->intr_status |= I2CD_INTR_TX_NAK; @@ -191,20 +211,26 @@ static void aspeed_i2c_bus_handle_cmd(AspeedI2CBus *bus, uint64_t value) if (!i2c_bus_busy(bus->bus)) { return; } + aspeed_i2c_set_state(bus, I2CD_MACTIVE); } if (bus->cmd & I2CD_M_TX_CMD) { + aspeed_i2c_set_state(bus, I2CD_MTXD); if (i2c_send(bus->bus, bus->buf)) { - bus->intr_status |= (I2CD_INTR_TX_NAK | I2CD_INTR_ABNORMAL); + bus->intr_status |= (I2CD_INTR_TX_NAK); i2c_end_transfer(bus->bus); } else { bus->intr_status |= I2CD_INTR_TX_ACK; } bus->cmd &= ~I2CD_M_TX_CMD; + aspeed_i2c_set_state(bus, I2CD_MACTIVE); } if (bus->cmd & (I2CD_M_RX_CMD | I2CD_M_S_RX_CMD_LAST)) { - int ret = i2c_recv(bus->bus); + int ret; + + aspeed_i2c_set_state(bus, I2CD_MRXD); + ret = i2c_recv(bus->bus); if (ret < 0) { qemu_log_mask(LOG_GUEST_ERROR, "%s: read failed\n", __func__); ret = 0xff; @@ -216,16 +242,20 @@ static void aspeed_i2c_bus_handle_cmd(AspeedI2CBus *bus, uint64_t value) i2c_nack(bus->bus); } bus->cmd &= ~(I2CD_M_RX_CMD | I2CD_M_S_RX_CMD_LAST); + aspeed_i2c_set_state(bus, I2CD_MACTIVE); } if (bus->cmd & I2CD_M_STOP_CMD) { - if (!i2c_bus_busy(bus->bus)) { + if (!(aspeed_i2c_get_state(bus) & I2CD_MACTIVE)) { + qemu_log_mask(LOG_GUEST_ERROR, "%s: abnormal stop\n", __func__); bus->intr_status |= I2CD_INTR_ABNORMAL; } else { + aspeed_i2c_set_state(bus, I2CD_MSTOP); i2c_end_transfer(bus->bus); bus->intr_status |= I2CD_INTR_NORMAL_STOP; } bus->cmd &= ~I2CD_M_STOP_CMD; + aspeed_i2c_set_state(bus, I2CD_IDLE); } }