From patchwork Thu Jan 4 13:01:29 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Harald Mommer X-Patchwork-Id: 13511106 Received: from refb02.tmes.trendmicro.eu (refb02.tmes.trendmicro.eu [18.185.115.58]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 023FB22304 for ; Thu, 4 Jan 2024 13:13:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=opensynergy.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=opensynergy.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=opensynergy.com header.i=@opensynergy.com header.b="WUxYwK/i" Received: from 104.47.7.168_.trendmicro.com (unknown [172.21.19.202]) by refb02.tmes.trendmicro.eu (Postfix) with ESMTPS id 48C0E10A3EB94 for ; Thu, 4 Jan 2024 13:01:56 +0000 (UTC) Received: from 104.47.7.168_.trendmicro.com (unknown [172.21.176.220]) by repost01.tmes.trendmicro.eu (Postfix) with SMTP id 215B1100017A6; Thu, 4 Jan 2024 13:01:49 +0000 (UTC) X-TM-MAIL-RECEIVED-TIME: 1704373308.670000 X-TM-MAIL-UUID: d07ada51-4d3a-476c-a830-014f30aa25a4 Received: from DEU01-BE0-obe.outbound.protection.outlook.com (unknown [104.47.7.168]) by repre01.tmes.trendmicro.eu (Trend Micro Email Security) with ESMTPS id A3CE010047C38; Thu, 4 Jan 2024 13:01:48 +0000 (UTC) ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=Ymh/UGRCUzqE4kwA1LNRD3V76rrU0q5JmXDQmICtgagGd0Sx+6VKeX2wQT3Bgmy4M5W5lmPNCv/wjBtmpdkE76CNQWzu11JKah5qaxWsvyIcK6bXXGzZKOGDURMEtwPc7H5vJRvVf2b9mXD6F9urkxlBkUMqy+QagjyE75Uw2CCsIn0ccSKPpW/iWCs/pFGZQIX6wCpqAMZar4rS07+XnVKqbs5xmawIX/F3btB3t4T02sxH4HmpJAhpcue4qVxfIXlyozSrZeQArwI2nRB4O59Xq8onQeBRxkjAEz19GsZ29UcdY64yvRYn9YJgu7kcYNg6dOpEWq+PIgukrt63rA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=A44VEZYTspkX2zfu6+lQI056JfCNUZlrpQHGpBI4xJ0=; b=c2tAnvbo1XUcD3oFt0xNKMnL86OEcaZGEvzarswmJrM6rhjpCkzdc1VVfUUpe5aYCkzGaR+u6mnESUH61TNsm9olAYfxcNTJqcJ0LPIM1wey1VxiuvwRO2nRibNNx2qToTsJFEtFJth71eKPKaKO8+MlCLog3lGNFy0LLejk4aeLZodl0ChVIZbKjYzJQIg7R23+oWeJ8wmuHbPOCebSGBZ6NxxtQOhxPj7bfDQKliHA3vELRoiWCmxtUutRaAbcN/34pIL5UzgrnOPyDmQC793LLAVwX/6o5v98ty0E6+Pq9EUBZCmZgCugUex/Sa0Gf6KydNNnTGvLHGO/kzJzEQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 217.66.60.4) smtp.rcpttodomain=kernel.org smtp.mailfrom=opensynergy.com; dmarc=pass (p=reject sp=reject pct=100) action=none header.from=opensynergy.com; dkim=none (message not signed); arc=none (0) X-MS-Exchange-Authentication-Results: spf=pass (sender IP is 217.66.60.4) smtp.mailfrom=opensynergy.com; dkim=none (message not signed) header.d=none;dmarc=pass action=none header.from=opensynergy.com; Received-SPF: Pass (protection.outlook.com: domain of opensynergy.com designates 217.66.60.4 as permitted sender) receiver=protection.outlook.com; client-ip=217.66.60.4; helo=SR-MAIL-03.open-synergy.com; pr=C From: Harald Mommer To: virtio-dev@lists.oasis-open.org, Haixu Cui , Mark Brown , Viresh Kumar , linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org Cc: quic_ztu@quicinc.com, Matti Moell , Mikhail Golubev , Harald Mommer , Harald Mommer Subject: [RFC PATCH v2 3/3] SPI: Add virtio SPI driver (V10 draft specification). Date: Thu, 4 Jan 2024 14:01:29 +0100 Message-Id: <20240104130129.17823-4-Harald.Mommer@opensynergy.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20240104130129.17823-1-Harald.Mommer@opensynergy.com> References: <20240104130129.17823-1-Harald.Mommer@opensynergy.com> Precedence: bulk X-Mailing-List: linux-spi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: AM6EUR05FT045:EE_|BEVP281MB3715:EE_ X-MS-Office365-Filtering-Correlation-Id: cc19ef64-7e23-465f-f96a-08dc0d254da0 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: /30CiHNXvXztxycjhydjkpx5UZ8qOlch8nK8rOV6YNGDH4fZo2VFuA27X+c6NuH0C6Vt19OkrKUvtFXGO9oY12mx4iddHFIgDEe6o5GH1SGLWLsJKC11X2m0NuLgw6vElZQLS2Zjdmp7dFP+IrzxeUZUlw1Qwb3wZPwls0aCQZNAWRqvwmfbFgPhknqnrzGOyklA54mTh9mnjkEQsrhQaTqpQHvLnM4WeIolB4Xs8mUJ98jqSO9CB0g1vm9u8c88qo157k7fAoFV3pkrHn94YpHhDfd+jRhetbixvFIcA1v7Ijbf3sv/U8QvcV6icbt+tdZTr+XfIqCbtLbzFjfDWj01Zhh273PMmwEPDKA3rJj3l44zZByzqiYQNYlspuhNwCnhcgqtbPUd3fdlytmmwo2vebLvyIJpJ4IxrZtnI1evdLNhWzP0H0BzCs5ZFTPjNY/bE4TtfkvVu7OyGMm3Yv5XH1vuzrEgUAdQZ/O85S6iQMiBeZFLW1dkOMmiCz5Ga/g1OlR4N52BN3TXQDmnHRMqZedNX7nLFZWiFB1+Qj6woWY+umAIx9u7QXSuq1gpc+i+G4j5SYmUvnRUistgpxIhG4HhVCdnpeZafs+8DL9yvIIILfnMn23aCKDai7i9DbydQYXVfwy7Ixwum4OmQivr+x9amC9TTxZ6btYo3X6hxC8IIItJoHAxwVmJ+DQGXzE6o37bntl7A62XLALY5QHhUHGolXjSCUL4KmdNc2QNjsIoDiqVLMoUlz4soBVU1mTKuVsFf8OYS20M+FbEVAIjbxSpXDaIeVo4G8yXFfs= X-Forefront-Antispam-Report: CIP:217.66.60.4;CTRY:DE;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:SR-MAIL-03.open-synergy.com;PTR:InfoDomainNonexistent;CAT:NONE;SFS:(13230031)(39840400004)(396003)(136003)(376002)(346002)(230922051799003)(82310400011)(451199024)(1800799012)(186009)(64100799003)(36840700001)(46966006)(81166007)(41300700001)(86362001)(8936002)(336012)(316002)(110136005)(8676002)(54906003)(4326008)(40480700001)(42186006)(36756003)(83380400001)(1076003)(26005)(70206006)(70586007)(2616005)(107886003)(30864003)(5660300002)(478600001)(47076005)(2906002)(36860700001)(36900700001);DIR:OUT;SFP:1102; X-OriginatorOrg: opensynergy.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 04 Jan 2024 13:01:44.6332 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: cc19ef64-7e23-465f-f96a-08dc0d254da0 X-MS-Exchange-CrossTenant-Id: 800fae25-9b1b-4edc-993d-c939c4e84a64 X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=800fae25-9b1b-4edc-993d-c939c4e84a64;Ip=[217.66.60.4];Helo=[SR-MAIL-03.open-synergy.com] X-MS-Exchange-CrossTenant-AuthSource: AM6EUR05FT045.eop-eur05.prod.protection.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: BEVP281MB3715 X-TM-AS-ERS: 104.47.7.168-0.0.0.0 X-TMASE-Version: StarCloud-1.3-9.1.1015-28098.007 X-TMASE-Result: 10--16.504500-4.000000 X-TMASE-MatchedRID: Ta8H+ip/h8EAsgl6PZgqJFmcWIT2GKzJgz5VmKZ8x87hCm8am+SP54vP iBq/iW91MpPx8OFzfY26s9an5hGqZUnvjwEYgMmSaHBj3sgbnZB35i8rRu5NquqKwADS/wqWjhj VY8VBNu5bcyDokSMBC+UhQfnTDSSQgEjtxrCIZOl4lyF1lyvUrR4s1tXUFaIffkpOuA8PICy6dX aAYUzGlk2LrJWi3XXEYRSBtQ0oAuFVW+1kgSdrJYWEan0Y08Ot1S6yX8lVpE2JTckzLq0IkhOXf +aEEQhS1kAespA2irnFzbrhCIZiOV8W+1KJQAZLWyx0lCurExrDluc4BYfva4ndKaJ31Y39qFty 1HMHrV4t/kwYYmhI5mlB232a7BNLhH6kN1B9m4YnDrpxCH9Hl4ld6gdpSPEDH7tJno0Yum2/G7t ir40c1bPrLGr+YLzgGkDebuxZrqWxkyWC0qYf8OBHyXZCGbHqfq7xWexVq1yyBw15H24MRz/m+V kiqierl1NYlxxvWUwtgEZJUHc75WBnDtEasdEgiL+RrlWsewopSViUCNYhMOK9fjqiORFcAZjsJ 4RGp+vg4EHeQQT63IIqHp23KYvDBYIaQ0ASMyrHfnPG7+BDZvpS9zfbt9q/ayl06EhYQmZPQFFk 0j5jBsA2iDfbpfy+AVpeDm8nJoLwnQHFZbUP3moEkqixPwVYFrTss38C/MZaOxpgjiWHdQKmARN 5PTKc X-TMASE-XGENCLOUD: b94543a8-9db5-44a4-903f-59606b8ffb10-0-0-200-0 X-TM-Deliver-Signature: 30F28E0FD44B0B4F98844915428E4B1C X-TM-Addin-Auth: CO9yovLtc88pPad4n+QqDxlIjK5FObMliXc+ifrZ+qhWp83xqFRdtQnFqGO 1zI3kAS673zuO/lISHY7goF8cyrpYLYUx6NqiNSQ/+T01wiJ+QeJQQNpqnUkb7OSkU0rjGnT2D1 IlELA2+ObKAZo5MKtCshfSI82N6/YlfE/Yn7LdfQkjy6AmZbXUmWvZic/7Lj2ACMFBghivoff3h 06aArSjdd1gKAdMD3VHDIwf8E7O1ZbkcwP+mgcw8LRvd+4fZBTVIzxWWTOtkDT0ku/T2QG9SkjC Lg+327NYNYD7jQg=.JG2A3hNSm60a/+wDRhUJo5Ba0e86wfkYvR0T1cRT8DGVg3oxsNSDLTZLau 33OJOvo6It9rcxWjaAbNqFpqGbqr5lSBLBB1yInwpdLM3GrvbuxfGkqqOSyL6BXWxNXV2H/xNha JrdBnf+iC8yWYViZT0UgcEb/gYoWgB5F8bUor2CzOh31uvomy3aCl0m0/38J7KU9T3af+wuLFH7 DRus4Ael13pHj9/6wQo7AG6r9lorAtV4WX99wkhK9R3acvbAD4E6rcf/Z/2eCmlGw3hTaB5MeRF zGfB473K5thAlDvDfWGMvgETMOdfqkhbhJfUxQDEhCX7ugCu708HRX6kgbA== X-TM-Addin-ProductCode: EMS DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=opensynergy.com; s=TM-DKIM-20210503141657; t=1704373308; bh=vWrXFOLO2Qy0YjZHKJ1cFRl1tGLQHZRjXF4n+dkhQSA=; l=14341; h=From:To:Date; b=WUxYwK/iIh2NVW9W+6vd0e5juR88oLcJYD+QP/nr9utbDQHe+yAUSMfNYBtTJ+Pcx +0Ca2IaV7qM/fxBvl33CFuP/1wQJBOyhH0GZsds6+kEnc2RLxRZ8TXtTAqAa4bal5D QtJbNOvBujGKA3vb8Q9jZmH2YHwllApqp8Ozqo6CjmdevvK5waID5w/cyhM8MPuVkD CqkuwaU/y8xKouGQMYXezifCGvAXof7pcc7mWXElhcCeyaeJAZssikEdqr5ccOlAjW dHioRjHuuQi5vONnj2OmRSd63rrM9MPMopLkouVZW1LMF7uukmtQE8N8946lzztmLw NG4WBYs5RcKrQ== From: Harald Mommer This is the virtio SPI Linux kernel driver compliant to the "PATCH v10" draft virtio SPI specification. Signed-off-by: Harald Mommer --- drivers/spi/Kconfig | 11 + drivers/spi/Makefile | 1 + drivers/spi/spi-virtio.c | 430 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 442 insertions(+) create mode 100644 drivers/spi/spi-virtio.c diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index ddae0fde798e..f4f617c79ad7 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -1125,6 +1125,17 @@ config SPI_UNIPHIER If your SoC supports SCSSI, say Y here. +config SPI_VIRTIO + tristate "Virtio SPI SPI Controller" + depends on VIRTIO + help + This enables the Virtio SPI driver. + + Virtio SPI is an SPI driver for virtual machines using Virtio. + + If your Linux is a virtual machine using Virtio, say Y here. + If unsure, say N. + config SPI_XCOMM tristate "Analog Devices AD-FMCOMMS1-EBZ SPI-I2C-bridge driver" depends on I2C diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile index 4ff8d725ba5e..ff2243e44e00 100644 --- a/drivers/spi/Makefile +++ b/drivers/spi/Makefile @@ -146,6 +146,7 @@ spi-thunderx-objs := spi-cavium.o spi-cavium-thunderx.o obj-$(CONFIG_SPI_THUNDERX) += spi-thunderx.o obj-$(CONFIG_SPI_TOPCLIFF_PCH) += spi-topcliff-pch.o obj-$(CONFIG_SPI_UNIPHIER) += spi-uniphier.o +obj-$(CONFIG_SPI_VIRTIO) += spi-virtio.o obj-$(CONFIG_SPI_XCOMM) += spi-xcomm.o obj-$(CONFIG_SPI_XILINX) += spi-xilinx.o obj-$(CONFIG_SPI_XLP) += spi-xlp.o diff --git a/drivers/spi/spi-virtio.c b/drivers/spi/spi-virtio.c new file mode 100644 index 000000000000..39eb38184793 --- /dev/null +++ b/drivers/spi/spi-virtio.c @@ -0,0 +1,430 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * SPI bus driver for the Virtio SPI controller + * Copyright (C) 2023 OpenSynergy GmbH + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* virtio_spi private data structure */ +struct virtio_spi_priv { + /* The virtio device we're associated with */ + struct virtio_device *vdev; + /* Pointer to the virtqueue */ + struct virtqueue *vq; + /* Copy of config space mode_func_supported */ + u32 mode_func_supported; + /* Copy of config space max_freq_hz */ + u32 max_freq_hz; +}; + +struct virtio_spi_req { + struct completion completion; + struct spi_transfer_head transfer_head ____cacheline_aligned; + const uint8_t *tx_buf ____cacheline_aligned; + uint8_t *rx_buf ____cacheline_aligned; + struct spi_transfer_result result ____cacheline_aligned; +}; + +static struct spi_board_info board_info = { + .modalias = "spi-virtio", +}; + +static void virtio_spi_msg_done(struct virtqueue *vq) +{ + struct virtio_spi_req *req; + unsigned int len; + + while ((req = virtqueue_get_buf(vq, &len))) + complete(&req->completion); +} + +static int virtio_spi_one_transfer(struct virtio_spi_req *spi_req, + struct spi_controller *ctrl, + struct spi_message *msg, + struct spi_transfer *xfer) +{ + struct virtio_spi_priv *priv = spi_controller_get_devdata(ctrl); + struct device *dev = &priv->vdev->dev; + struct spi_device *spi = msg->spi; + struct spi_transfer_head *th; + struct scatterlist sg_out_head, sg_out_payload; + struct scatterlist sg_in_result, sg_in_payload; + struct scatterlist *sgs[4]; + unsigned int outcnt = 0u; + unsigned int incnt = 0u; + int ret; + + th = &spi_req->transfer_head; + + /* Fill struct spi_transfer_head */ + th->chip_select_id = spi_get_chipselect(spi, 0); + th->bits_per_word = spi->bits_per_word; + /* + * Got comment: "The virtio spec for cs_change is *not* what the Linux + * cs_change field does, this will not do the right thing." + * TODO: Understand/discuss this, still unclear what may be wrong here + */ + th->cs_change = xfer->cs_change; + th->tx_nbits = xfer->tx_nbits; + th->rx_nbits = xfer->rx_nbits; + th->reserved[0] = 0; + th->reserved[1] = 0; + th->reserved[2] = 0; + + BUILD_BUG_ON(VIRTIO_SPI_CPHA != SPI_CPHA); + BUILD_BUG_ON(VIRTIO_SPI_CPOL != SPI_CPOL); + BUILD_BUG_ON(VIRTIO_SPI_CS_HIGH != SPI_CS_HIGH); + BUILD_BUG_ON(VIRTIO_SPI_MODE_LSB_FIRST != SPI_LSB_FIRST); + + th->mode = cpu_to_le32(spi->mode & (SPI_LSB_FIRST | SPI_CS_HIGH | + SPI_CPOL | SPI_CPHA)); + if ((spi->mode & SPI_LOOP) != 0) + th->mode |= cpu_to_le32(VIRTIO_SPI_MODE_LOOP); + + th->freq = cpu_to_le32(xfer->speed_hz); + + ret = spi_delay_to_ns(&xfer->word_delay, xfer); + if (ret < 0) { + dev_warn(dev, "Cannot convert word_delay\n"); + goto msg_done; + } + th->word_delay_ns = cpu_to_le32((u32)ret); + + ret = spi_delay_to_ns(&xfer->delay, xfer); + if (ret < 0) { + dev_warn(dev, "Cannot convert delay\n"); + goto msg_done; + } + th->cs_setup_ns = cpu_to_le32((u32)ret); + th->cs_delay_hold_ns = cpu_to_le32((u32)ret); + + /* This is the "off" time when CS has to be deasserted for a moment */ + ret = spi_delay_to_ns(&xfer->cs_change_delay, xfer); + if (ret < 0) { + dev_warn(dev, "Cannot convert cs_change_delay\n"); + goto msg_done; + } + th->cs_change_delay_inactive_ns = cpu_to_le32((u32)ret); + + /* Set buffers */ + spi_req->tx_buf = xfer->tx_buf; + spi_req->rx_buf = xfer->rx_buf; + + /* Prepare sending of virtio message */ + init_completion(&spi_req->completion); + + sg_init_one(&sg_out_head, &spi_req->transfer_head, + sizeof(struct spi_transfer_head)); + sgs[outcnt] = &sg_out_head; + outcnt++; + + if (spi_req->tx_buf) { + sg_init_one(&sg_out_payload, spi_req->tx_buf, xfer->len); + sgs[outcnt] = &sg_out_payload; + outcnt++; + } + + if (spi_req->rx_buf) { + sg_init_one(&sg_in_payload, spi_req->rx_buf, xfer->len); + sgs[outcnt + incnt] = &sg_in_payload; + incnt++; + } + + sg_init_one(&sg_in_result, &spi_req->result, + sizeof(struct spi_transfer_result)); + sgs[outcnt + incnt] = &sg_in_result; + incnt++; + + ret = virtqueue_add_sgs(priv->vq, sgs, outcnt, incnt, spi_req, + GFP_KERNEL); + +msg_done: + if (ret) + msg->status = ret; + + return ret; +} + +static int virtio_spi_transfer_one_message(struct spi_controller *ctrl, + struct spi_message *msg) +{ + struct virtio_spi_priv *priv = spi_controller_get_devdata(ctrl); + struct virtio_spi_req *spi_req; + struct spi_transfer *xfer; + int ret = 0; + + spi_req = kzalloc(sizeof(*spi_req), GFP_KERNEL); + if (!spi_req) { + ret = -ENOMEM; + goto no_mem; + } + + /* + * Simple implementation: Process message by message and wait for each + * message to be completed by the device side. + */ + list_for_each_entry(xfer, &msg->transfers, transfer_list) { + ret = virtio_spi_one_transfer(spi_req, ctrl, msg, xfer); + if (ret) + goto msg_done; + + virtqueue_kick(priv->vq); + + wait_for_completion(&spi_req->completion); + + /* Read result from message */ + ret = (int)spi_req->result.result; + if (ret) + goto msg_done; + } + +msg_done: + kfree(spi_req); +no_mem: + msg->status = ret; + spi_finalize_current_message(ctrl); + + return ret; +} + +static void virtio_spi_read_config(struct virtio_device *vdev) +{ + struct spi_controller *ctrl = dev_get_drvdata(&vdev->dev); + struct virtio_spi_priv *priv = vdev->priv; + u8 cs_max_number; + u8 tx_nbits_supported; + u8 rx_nbits_supported; + + cs_max_number = virtio_cread8(vdev, offsetof(struct virtio_spi_config, + cs_max_number)); + ctrl->num_chipselect = cs_max_number; + + /* Set the mode bits which are understood by this driver */ + priv->mode_func_supported = + virtio_cread32(vdev, offsetof(struct virtio_spi_config, + mode_func_supported)); + ctrl->mode_bits = priv->mode_func_supported & + (VIRTIO_SPI_CS_HIGH | VIRTIO_SPI_MODE_LSB_FIRST); + if ((priv->mode_func_supported & VIRTIO_SPI_MF_SUPPORT_CPHA_1) != 0) + ctrl->mode_bits |= VIRTIO_SPI_CPHA; + if ((priv->mode_func_supported & VIRTIO_SPI_MF_SUPPORT_CPOL_1) != 0) + ctrl->mode_bits |= VIRTIO_SPI_CPOL; + if ((priv->mode_func_supported & VIRTIO_SPI_MF_SUPPORT_LSB_FIRST) != 0) + ctrl->mode_bits |= SPI_LSB_FIRST; + if ((priv->mode_func_supported & VIRTIO_SPI_MF_SUPPORT_LOOPBACK) != 0) + ctrl->mode_bits |= SPI_LOOP; + tx_nbits_supported = + virtio_cread8(vdev, offsetof(struct virtio_spi_config, + tx_nbits_supported)); + if ((tx_nbits_supported & VIRTIO_SPI_RX_TX_SUPPORT_DUAL) != 0) + ctrl->mode_bits |= SPI_TX_DUAL; + if ((tx_nbits_supported & VIRTIO_SPI_RX_TX_SUPPORT_QUAD) != 0) + ctrl->mode_bits |= SPI_TX_QUAD; + if ((tx_nbits_supported & VIRTIO_SPI_RX_TX_SUPPORT_OCTAL) != 0) + ctrl->mode_bits |= SPI_TX_OCTAL; + rx_nbits_supported = + virtio_cread8(vdev, offsetof(struct virtio_spi_config, + rx_nbits_supported)); + if ((rx_nbits_supported & VIRTIO_SPI_RX_TX_SUPPORT_DUAL) != 0) + ctrl->mode_bits |= SPI_RX_DUAL; + if ((rx_nbits_supported & VIRTIO_SPI_RX_TX_SUPPORT_QUAD) != 0) + ctrl->mode_bits |= SPI_RX_QUAD; + if ((rx_nbits_supported & VIRTIO_SPI_RX_TX_SUPPORT_OCTAL) != 0) + ctrl->mode_bits |= SPI_RX_OCTAL; + + ctrl->bits_per_word_mask = + virtio_cread32(vdev, offsetof(struct virtio_spi_config, + bits_per_word_mask)); + + priv->max_freq_hz = + virtio_cread32(vdev, offsetof(struct virtio_spi_config, + max_freq_hz)); +} + +static int virtio_spi_find_vqs(struct virtio_spi_priv *priv) +{ + struct virtqueue *vq; + + vq = virtio_find_single_vq(priv->vdev, virtio_spi_msg_done, "spi-rq"); + if (IS_ERR(vq)) + return (int)PTR_ERR(vq); + priv->vq = vq; + return 0; +} + +/* Function must not be called before virtio_spi_find_vqs() has been run */ +static void virtio_spi_del_vq(struct virtio_device *vdev) +{ + virtio_reset_device(vdev); + vdev->config->del_vqs(vdev); +} + +static int virtio_spi_validate(struct virtio_device *vdev) +{ + /* + * SPI needs always access to the config space. + * Check that the driver can access the config space + */ + if (!vdev->config->get) { + dev_err(&vdev->dev, "%s failure: config access disabled\n", + __func__); + return -EINVAL; + } + + if (!virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) { + dev_err(&vdev->dev, + "device does not comply with spec version 1.x\n"); + return -EINVAL; + } + + return 0; +} + +static int virtio_spi_probe(struct virtio_device *vdev) +{ + struct device_node *np = vdev->dev.parent->of_node; + struct virtio_spi_priv *priv; + struct spi_controller *ctrl; + int err; + u32 bus_num; + u16 csi; + + ctrl = devm_spi_alloc_host(&vdev->dev, sizeof(*priv)); + if (!ctrl) { + dev_err(&vdev->dev, "Kernel memory exhausted in %s()\n", + __func__); + err = -ENOMEM; + goto err_return; + } + + priv = spi_controller_get_devdata(ctrl); + priv->vdev = vdev; + vdev->priv = priv; + dev_set_drvdata(&vdev->dev, ctrl); + + err = of_property_read_u32(np, "spi,bus-num", &bus_num); + if (!err && bus_num <= S16_MAX) + ctrl->bus_num = (s16)bus_num; + + virtio_spi_read_config(vdev); + + /* Method to transfer a single SPI message */ + ctrl->transfer_one_message = virtio_spi_transfer_one_message; + + /* Initialize virtqueues */ + err = virtio_spi_find_vqs(priv); + if (err) { + dev_err(&vdev->dev, "Cannot setup virtqueues\n"); + goto err_return; + } + + err = spi_register_controller(ctrl); + if (err) { + dev_err(&vdev->dev, "Cannot register controller\n"); + goto err_return; + } + + board_info.max_speed_hz = priv->max_freq_hz; + /* spi_new_device() currently does not use bus_num but better set it */ + board_info.bus_num = (u16)ctrl->bus_num; + + /* Add chip selects to controller */ + for (csi = 0; csi < ctrl->num_chipselect; csi++) { + dev_dbg(&vdev->dev, "Setting up CS=%u\n", csi); + board_info.chip_select = csi; + /* TODO: Discuss setting of board_info.mode */ + if (!(priv->mode_func_supported & VIRTIO_SPI_CS_HIGH)) + board_info.mode = SPI_MODE_0; + else + board_info.mode = SPI_MODE_0 | SPI_CS_HIGH; + if (!spi_new_device(ctrl, &board_info)) { + dev_err(&vdev->dev, "Cannot setup device %u\n", csi); + err = -ENODEV; + goto err_return; + } + } + + return 0; + +err_return: + return err; +} + +static void virtio_spi_remove(struct virtio_device *vdev) +{ + struct spi_controller *ctrl = dev_get_drvdata(&vdev->dev); + + spi_unregister_controller(ctrl); + virtio_spi_del_vq(vdev); +} + +static int virtio_spi_freeze(struct virtio_device *vdev) +{ + struct device *dev = &vdev->dev; + struct spi_controller *ctrl = dev_get_drvdata(dev); + int ret; + + /* Stop the queue running */ + ret = spi_controller_suspend(ctrl); + if (ret) { + dev_warn(dev, "cannot suspend controller (%d)\n", ret); + return ret; + } + + virtio_spi_del_vq(vdev); + return 0; +} + +static int virtio_spi_restore(struct virtio_device *vdev) +{ + struct device *dev = &vdev->dev; + struct spi_controller *ctrl = dev_get_drvdata(dev); + int ret; + + ret = virtio_spi_find_vqs(vdev->priv); + if (ret) { + dev_err(dev, "problem starting vqueue (%d)\n", ret); + return ret; + } + + ret = spi_controller_resume(ctrl); + if (ret) + dev_err(dev, "problem resuming controller (%d)\n", ret); + + return ret; +} + +static struct virtio_device_id virtio_spi_id_table[] = { + { VIRTIO_ID_SPI, VIRTIO_DEV_ANY_ID }, + { 0 }, +}; + +static struct virtio_driver virtio_spi_driver = { + .driver.name = KBUILD_MODNAME, + .driver.owner = THIS_MODULE, + .id_table = virtio_spi_id_table, + .validate = virtio_spi_validate, + .probe = virtio_spi_probe, + .remove = virtio_spi_remove, + .freeze = pm_sleep_ptr(virtio_spi_freeze), + .restore = pm_sleep_ptr(virtio_spi_restore), +}; + +module_virtio_driver(virtio_spi_driver); +MODULE_DEVICE_TABLE(virtio, virtio_spi_id_table); + +MODULE_AUTHOR("OpenSynergy GmbH"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Virtio SPI bus driver");