From patchwork Thu Sep 28 07:06:28 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Herve Codina X-Patchwork-Id: 727128 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 alsa0.perex.cz (alsa0.perex.cz [77.48.224.243]) (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 0BF95CE7B04 for ; Thu, 28 Sep 2023 07:12:44 +0000 (UTC) Received: from alsa1.perex.cz (alsa1.perex.cz [207.180.221.201]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by alsa0.perex.cz (Postfix) with ESMTPS id 290CBDF2; Thu, 28 Sep 2023 09:11:53 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz 290CBDF2 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1695885163; bh=LQxm7ZiujO4Y8qquZJowBkIOJ+he/2eTSmJA/WcQD68=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-Id: List-Archive:List-Help:List-Owner:List-Post:List-Subscribe: List-Unsubscribe:From; b=Rxnk7/UIxANTWDMqAhQgKlMxmlkn32JVBqX/B/Xvmt/uY5O6qA1AZ+VzzQb6BzcX+ 40Gnc6YNkDviQoAw+4vzCi4RTIrj//qQvEE24nIJwBUyMahm6tA4GeA59e6cYcHIrW qfEOeYjS9ioPl/AM1URDzXnXwYHLX/wdeK5azAiI= Received: by alsa1.perex.cz (Postfix, from userid 50401) id A29C9F805F7; Thu, 28 Sep 2023 09:09:35 +0200 (CEST) Received: from mailman-core.alsa-project.org (mailman-core.alsa-project.org [10.254.200.10]) by alsa1.perex.cz (Postfix) with ESMTP id 98EC8F805F7; Thu, 28 Sep 2023 09:09:34 +0200 (CEST) Received: by alsa1.perex.cz (Postfix, from userid 50401) id 9263AF80564; Thu, 28 Sep 2023 09:07:49 +0200 (CEST) Received: from relay7-d.mail.gandi.net (relay7-d.mail.gandi.net [IPv6:2001:4b98:dc4:8::227]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by alsa1.perex.cz (Postfix) with ESMTPS id 64356F80290 for ; Thu, 28 Sep 2023 09:07:42 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz 64356F80290 Authentication-Results: alsa1.perex.cz; dkim=pass (2048-bit key, unprotected) header.d=bootlin.com header.i=@bootlin.com header.a=rsa-sha256 header.s=gm1 header.b=RiZJJF2R Received: by mail.gandi.net (Postfix) with ESMTPA id 1FBB02000D; Thu, 28 Sep 2023 07:07:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1695884861; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=k9NqSOYILPZgbeylDC10IPY//ple7zsTiiFeeN2By68=; b=RiZJJF2RCJqVsImc6J6Yr99KuAsMW/9VXvySiaG+c1twRQZHaG5u1bWgkE/fpMZSACJC0b qVt0ev+susJu/d4IrPqaU30MtzK54w9Uz5Ydixb0FqbeLK2D13xl34yXbh05ZHxa4FbQPP wa52qV8VKsVYeGO1ed/XX3JADCeMeexSBmc6v3jRBdU37z0v6rvBDIE9Q4V5BCE6YsI1N2 ytqIs4xcJ+bIOg5aDGHoH4kyjdIeHIMt7l504NQ4ZA+2RoFm4pf70c31RTk/r6ltLeAIfJ V9ope3FLFM5rXf6ynYWET29xzAH+Wx+isQUnAI4Ib41yDPGt9FrcI8yURLRa5g== From: Herve Codina To: Herve Codina , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Andrew Lunn , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Linus Walleij , Qiang Zhao , Li Yang , Liam Girdwood , Mark Brown , Jaroslav Kysela , Takashi Iwai , Shengjiu Wang , Xiubo Li , Fabio Estevam , Nicolin Chen , Christophe Leroy , Randy Dunlap Cc: netdev@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org, linux-arm-kernel@lists.infradead.org, alsa-devel@alsa-project.org, Simon Horman , Christophe JAILLET , Thomas Petazzoni Subject: [PATCH v7 10/30] net: wan: Add support for QMC HDLC Date: Thu, 28 Sep 2023 09:06:28 +0200 Message-ID: <20230928070652.330429-11-herve.codina@bootlin.com> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230928070652.330429-1-herve.codina@bootlin.com> References: <20230928070652.330429-1-herve.codina@bootlin.com> MIME-Version: 1.0 X-GND-Sasl: herve.codina@bootlin.com Message-ID-Hash: 2YVFE2JGP3P6KIAWLXYN6LKCOWYRYZVF X-Message-ID-Hash: 2YVFE2JGP3P6KIAWLXYN6LKCOWYRYZVF X-MailFrom: herve.codina@bootlin.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; header-match-alsa-devel.alsa-project.org-0; header-match-alsa-devel.alsa-project.org-1; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.8 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: The QMC HDLC driver provides support for HDLC using the QMC (QUICC Multichannel Controller) to transfer the HDLC data. Signed-off-by: Herve Codina Reviewed-by: Christophe Leroy --- drivers/net/wan/Kconfig | 12 + drivers/net/wan/Makefile | 1 + drivers/net/wan/fsl_qmc_hdlc.c | 422 +++++++++++++++++++++++++++++++++ 3 files changed, 435 insertions(+) create mode 100644 drivers/net/wan/fsl_qmc_hdlc.c diff --git a/drivers/net/wan/Kconfig b/drivers/net/wan/Kconfig index dcb069dde66b..8de99f4b647b 100644 --- a/drivers/net/wan/Kconfig +++ b/drivers/net/wan/Kconfig @@ -195,6 +195,18 @@ config FARSYNC To compile this driver as a module, choose M here: the module will be called farsync. +config FSL_QMC_HDLC + tristate "Freescale QMC HDLC support" + depends on HDLC + depends on CPM_QMC + help + HDLC support using the Freescale QUICC Multichannel Controller (QMC). + + To compile this driver as a module, choose M here: the + module will be called fsl_qmc_hdlc. + + If unsure, say N. + config FSL_UCC_HDLC tristate "Freescale QUICC Engine HDLC support" depends on HDLC diff --git a/drivers/net/wan/Makefile b/drivers/net/wan/Makefile index 5bec8fae47f8..f338f4830626 100644 --- a/drivers/net/wan/Makefile +++ b/drivers/net/wan/Makefile @@ -23,6 +23,7 @@ obj-$(CONFIG_WANXL) += wanxl.o obj-$(CONFIG_PCI200SYN) += pci200syn.o obj-$(CONFIG_PC300TOO) += pc300too.o obj-$(CONFIG_IXP4XX_HSS) += ixp4xx_hss.o +obj-$(CONFIG_FSL_QMC_HDLC) += fsl_qmc_hdlc.o obj-$(CONFIG_FSL_UCC_HDLC) += fsl_ucc_hdlc.o obj-$(CONFIG_SLIC_DS26522) += slic_ds26522.o diff --git a/drivers/net/wan/fsl_qmc_hdlc.c b/drivers/net/wan/fsl_qmc_hdlc.c new file mode 100644 index 000000000000..15e102547ff2 --- /dev/null +++ b/drivers/net/wan/fsl_qmc_hdlc.c @@ -0,0 +1,422 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Freescale QMC HDLC Device Driver + * + * Copyright 2023 CS GROUP France + * + * Author: Herve Codina + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +struct qmc_hdlc_desc { + struct net_device *netdev; + struct sk_buff *skb; /* NULL if the descriptor is not in use */ + dma_addr_t dma_addr; + size_t dma_size; +}; + +struct qmc_hdlc { + struct device *dev; + struct qmc_chan *qmc_chan; + struct net_device *netdev; + bool is_crc32; + spinlock_t tx_lock; /* Protect tx descriptors */ + struct qmc_hdlc_desc tx_descs[8]; + unsigned int tx_out; + struct qmc_hdlc_desc rx_descs[4]; +}; + +static inline struct qmc_hdlc *netdev_to_qmc_hdlc(struct net_device *netdev) +{ + return dev_to_hdlc(netdev)->priv; +} + +static int qmc_hdlc_recv_queue(struct qmc_hdlc *qmc_hdlc, struct qmc_hdlc_desc *desc, size_t size); + +#define QMC_HDLC_RX_ERROR_FLAGS (QMC_RX_FLAG_HDLC_OVF | \ + QMC_RX_FLAG_HDLC_UNA | \ + QMC_RX_FLAG_HDLC_ABORT | \ + QMC_RX_FLAG_HDLC_CRC) + +static void qmc_hcld_recv_complete(void *context, size_t length, unsigned int flags) +{ + struct qmc_hdlc_desc *desc = context; + struct net_device *netdev = desc->netdev; + struct qmc_hdlc *qmc_hdlc = netdev_to_qmc_hdlc(desc->netdev); + int ret; + + dma_unmap_single(qmc_hdlc->dev, desc->dma_addr, desc->dma_size, DMA_FROM_DEVICE); + + if (flags & QMC_HDLC_RX_ERROR_FLAGS) { + netdev->stats.rx_errors++; + if (flags & QMC_RX_FLAG_HDLC_OVF) /* Data overflow */ + netdev->stats.rx_over_errors++; + if (flags & QMC_RX_FLAG_HDLC_UNA) /* bits received not multiple of 8 */ + netdev->stats.rx_frame_errors++; + if (flags & QMC_RX_FLAG_HDLC_ABORT) /* Received an abort sequence */ + netdev->stats.rx_frame_errors++; + if (flags & QMC_RX_FLAG_HDLC_CRC) /* CRC error */ + netdev->stats.rx_crc_errors++; + kfree_skb(desc->skb); + } else { + netdev->stats.rx_packets++; + netdev->stats.rx_bytes += length; + + skb_put(desc->skb, length); + desc->skb->protocol = hdlc_type_trans(desc->skb, netdev); + netif_rx(desc->skb); + } + + /* Re-queue a transfer using the same descriptor */ + ret = qmc_hdlc_recv_queue(qmc_hdlc, desc, desc->dma_size); + if (ret) { + dev_err(qmc_hdlc->dev, "queue recv desc failed (%d)\n", ret); + netdev->stats.rx_errors++; + } +} + +static int qmc_hdlc_recv_queue(struct qmc_hdlc *qmc_hdlc, struct qmc_hdlc_desc *desc, size_t size) +{ + int ret; + + desc->skb = dev_alloc_skb(size); + if (!desc->skb) + return -ENOMEM; + + desc->dma_size = size; + desc->dma_addr = dma_map_single(qmc_hdlc->dev, desc->skb->data, + desc->dma_size, DMA_FROM_DEVICE); + ret = dma_mapping_error(qmc_hdlc->dev, desc->dma_addr); + if (ret) + goto free_skb; + + ret = qmc_chan_read_submit(qmc_hdlc->qmc_chan, desc->dma_addr, desc->dma_size, + qmc_hcld_recv_complete, desc); + if (ret) + goto dma_unmap; + + return 0; + +dma_unmap: + dma_unmap_single(qmc_hdlc->dev, desc->dma_addr, desc->dma_size, DMA_FROM_DEVICE); +free_skb: + kfree_skb(desc->skb); + desc->skb = NULL; + return ret; +} + +static void qmc_hdlc_xmit_complete(void *context) +{ + struct qmc_hdlc_desc *desc = context; + struct net_device *netdev = desc->netdev; + struct qmc_hdlc *qmc_hdlc = netdev_to_qmc_hdlc(netdev); + struct sk_buff *skb; + unsigned long flags; + + spin_lock_irqsave(&qmc_hdlc->tx_lock, flags); + dma_unmap_single(qmc_hdlc->dev, desc->dma_addr, desc->dma_size, DMA_TO_DEVICE); + skb = desc->skb; + desc->skb = NULL; /* Release the descriptor */ + if (netif_queue_stopped(netdev)) + netif_wake_queue(netdev); + spin_unlock_irqrestore(&qmc_hdlc->tx_lock, flags); + + netdev->stats.tx_packets++; + netdev->stats.tx_bytes += skb->len; + + dev_consume_skb_any(skb); +} + +static int qmc_hdlc_xmit_queue(struct qmc_hdlc *qmc_hdlc, struct qmc_hdlc_desc *desc) +{ + int ret; + + desc->dma_addr = dma_map_single(qmc_hdlc->dev, desc->skb->data, + desc->dma_size, DMA_TO_DEVICE); + ret = dma_mapping_error(qmc_hdlc->dev, desc->dma_addr); + if (ret) { + dev_err(qmc_hdlc->dev, "failed to map skb\n"); + return ret; + } + + ret = qmc_chan_write_submit(qmc_hdlc->qmc_chan, desc->dma_addr, desc->dma_size, + qmc_hdlc_xmit_complete, desc); + if (ret) { + dev_err(qmc_hdlc->dev, "qmc chan write returns %d\n", ret); + dma_unmap_single(qmc_hdlc->dev, desc->dma_addr, desc->dma_size, DMA_TO_DEVICE); + return ret; + } + + return 0; +} + +static netdev_tx_t qmc_hdlc_xmit(struct sk_buff *skb, struct net_device *netdev) +{ + struct qmc_hdlc *qmc_hdlc = netdev_to_qmc_hdlc(netdev); + struct qmc_hdlc_desc *desc; + unsigned long flags; + int ret; + + spin_lock_irqsave(&qmc_hdlc->tx_lock, flags); + desc = &qmc_hdlc->tx_descs[qmc_hdlc->tx_out]; + if (desc->skb) { + /* Should never happen. + * Previous xmit should have already stopped the queue. + */ + netif_stop_queue(netdev); + spin_unlock_irqrestore(&qmc_hdlc->tx_lock, flags); + return NETDEV_TX_BUSY; + } + spin_unlock_irqrestore(&qmc_hdlc->tx_lock, flags); + + desc->netdev = netdev; + desc->dma_size = skb->len; + desc->skb = skb; + ret = qmc_hdlc_xmit_queue(qmc_hdlc, desc); + if (ret) { + desc->skb = NULL; /* Release the descriptor */ + if (ret == -EBUSY) { + netif_stop_queue(netdev); + return NETDEV_TX_BUSY; + } + dev_kfree_skb(skb); + netdev->stats.tx_dropped++; + return NETDEV_TX_OK; + } + + qmc_hdlc->tx_out = (qmc_hdlc->tx_out + 1) % ARRAY_SIZE(qmc_hdlc->tx_descs); + + spin_lock_irqsave(&qmc_hdlc->tx_lock, flags); + if (qmc_hdlc->tx_descs[qmc_hdlc->tx_out].skb) + netif_stop_queue(netdev); + spin_unlock_irqrestore(&qmc_hdlc->tx_lock, flags); + + return NETDEV_TX_OK; +} + +static int qmc_hdlc_open(struct net_device *netdev) +{ + struct qmc_hdlc *qmc_hdlc = netdev_to_qmc_hdlc(netdev); + struct qmc_chan_param chan_param; + struct qmc_hdlc_desc *desc; + int ret; + int i; + + ret = hdlc_open(netdev); + if (ret) + return ret; + + chan_param.mode = QMC_HDLC; + /* HDLC_MAX_MRU + 4 for the CRC + * HDLC_MAX_MRU + 4 + 8 for the CRC and some extraspace needed by the QMC + */ + chan_param.hdlc.max_rx_buf_size = HDLC_MAX_MRU + 4 + 8; + chan_param.hdlc.max_rx_frame_size = HDLC_MAX_MRU + 4; + chan_param.hdlc.is_crc32 = qmc_hdlc->is_crc32; + ret = qmc_chan_set_param(qmc_hdlc->qmc_chan, &chan_param); + if (ret) { + dev_err(qmc_hdlc->dev, "failed to set param (%d)\n", ret); + goto hdlc_close; + } + + /* Queue as many recv descriptors as possible */ + for (i = 0; i < ARRAY_SIZE(qmc_hdlc->rx_descs); i++) { + desc = &qmc_hdlc->rx_descs[i]; + + desc->netdev = netdev; + ret = qmc_hdlc_recv_queue(qmc_hdlc, desc, chan_param.hdlc.max_rx_buf_size); + if (ret) { + if (ret == -EBUSY && i != 0) + break; /* We use all the QMC chan capability */ + goto free_desc; + } + } + + ret = qmc_chan_start(qmc_hdlc->qmc_chan, QMC_CHAN_ALL); + if (ret) { + dev_err(qmc_hdlc->dev, "qmc chan start failed (%d)\n", ret); + goto free_desc; + } + + netif_start_queue(netdev); + + return 0; + +free_desc: + qmc_chan_reset(qmc_hdlc->qmc_chan, QMC_CHAN_ALL); + for (i = 0; i < ARRAY_SIZE(qmc_hdlc->rx_descs); i++) { + desc = &qmc_hdlc->rx_descs[i]; + if (!desc->skb) + continue; + dma_unmap_single(qmc_hdlc->dev, desc->dma_addr, desc->dma_size, + DMA_FROM_DEVICE); + kfree_skb(desc->skb); + desc->skb = NULL; + } +hdlc_close: + hdlc_close(netdev); + return ret; +} + +static int qmc_hdlc_close(struct net_device *netdev) +{ + struct qmc_hdlc *qmc_hdlc = netdev_to_qmc_hdlc(netdev); + struct qmc_hdlc_desc *desc; + int i; + + netif_stop_queue(netdev); + + qmc_chan_stop(qmc_hdlc->qmc_chan, QMC_CHAN_ALL); + qmc_chan_reset(qmc_hdlc->qmc_chan, QMC_CHAN_ALL); + + for (i = 0; i < ARRAY_SIZE(qmc_hdlc->tx_descs); i++) { + desc = &qmc_hdlc->tx_descs[i]; + if (!desc->skb) + continue; + dma_unmap_single(qmc_hdlc->dev, desc->dma_addr, desc->dma_size, + DMA_TO_DEVICE); + kfree_skb(desc->skb); + desc->skb = NULL; + } + + for (i = 0; i < ARRAY_SIZE(qmc_hdlc->rx_descs); i++) { + desc = &qmc_hdlc->rx_descs[i]; + if (!desc->skb) + continue; + dma_unmap_single(qmc_hdlc->dev, desc->dma_addr, desc->dma_size, + DMA_FROM_DEVICE); + kfree_skb(desc->skb); + desc->skb = NULL; + } + + hdlc_close(netdev); + return 0; +} + +static int qmc_hdlc_attach(struct net_device *netdev, unsigned short encoding, + unsigned short parity) +{ + struct qmc_hdlc *qmc_hdlc = netdev_to_qmc_hdlc(netdev); + + if (encoding != ENCODING_NRZ) + return -EINVAL; + + switch (parity) { + case PARITY_CRC16_PR1_CCITT: + qmc_hdlc->is_crc32 = false; + break; + case PARITY_CRC32_PR1_CCITT: + qmc_hdlc->is_crc32 = true; + break; + default: + dev_err(qmc_hdlc->dev, "unsupported parity %u\n", parity); + return -EINVAL; + } + + return 0; +} + +static const struct net_device_ops qmc_hdlc_netdev_ops = { + .ndo_open = qmc_hdlc_open, + .ndo_stop = qmc_hdlc_close, + .ndo_start_xmit = hdlc_start_xmit, + .ndo_siocwandev = hdlc_ioctl, +}; + +static int qmc_hdlc_probe(struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + struct qmc_hdlc *qmc_hdlc; + struct qmc_chan_info info; + hdlc_device *hdlc; + int ret; + + qmc_hdlc = devm_kzalloc(&pdev->dev, sizeof(*qmc_hdlc), GFP_KERNEL); + if (!qmc_hdlc) + return -ENOMEM; + + qmc_hdlc->dev = &pdev->dev; + spin_lock_init(&qmc_hdlc->tx_lock); + + qmc_hdlc->qmc_chan = devm_qmc_chan_get_bychild(qmc_hdlc->dev, np); + if (IS_ERR(qmc_hdlc->qmc_chan)) { + ret = PTR_ERR(qmc_hdlc->qmc_chan); + return dev_err_probe(qmc_hdlc->dev, ret, "get QMC channel failed\n"); + } + + ret = qmc_chan_get_info(qmc_hdlc->qmc_chan, &info); + if (ret) { + dev_err(qmc_hdlc->dev, "get QMC channel info failed %d\n", ret); + return ret; + } + + if (info.mode != QMC_HDLC) { + dev_err(qmc_hdlc->dev, "QMC chan mode %d is not QMC_HDLC\n", + info.mode); + return -EINVAL; + } + + qmc_hdlc->netdev = alloc_hdlcdev(qmc_hdlc); + if (!qmc_hdlc->netdev) { + dev_err(qmc_hdlc->dev, "failed to alloc hdlc dev\n"); + return -ENOMEM; + } + + hdlc = dev_to_hdlc(qmc_hdlc->netdev); + hdlc->attach = qmc_hdlc_attach; + hdlc->xmit = qmc_hdlc_xmit; + SET_NETDEV_DEV(qmc_hdlc->netdev, qmc_hdlc->dev); + qmc_hdlc->netdev->tx_queue_len = ARRAY_SIZE(qmc_hdlc->tx_descs); + qmc_hdlc->netdev->netdev_ops = &qmc_hdlc_netdev_ops; + ret = register_hdlc_device(qmc_hdlc->netdev); + if (ret) { + dev_err(qmc_hdlc->dev, "failed to register hdlc device (%d)\n", ret); + goto free_netdev; + } + + platform_set_drvdata(pdev, qmc_hdlc); + + return 0; + +free_netdev: + free_netdev(qmc_hdlc->netdev); + return ret; +} + +static int qmc_hdlc_remove(struct platform_device *pdev) +{ + struct qmc_hdlc *qmc_hdlc = platform_get_drvdata(pdev); + + unregister_hdlc_device(qmc_hdlc->netdev); + free_netdev(qmc_hdlc->netdev); + + return 0; +} + +static const struct of_device_id qmc_hdlc_id_table[] = { + { .compatible = "fsl,qmc-hdlc" }, + {} /* sentinel */ +}; +MODULE_DEVICE_TABLE(of, qmc_hdlc_driver); + +static struct platform_driver qmc_hdlc_driver = { + .driver = { + .name = "fsl-qmc-hdlc", + .of_match_table = qmc_hdlc_id_table, + }, + .probe = qmc_hdlc_probe, + .remove = qmc_hdlc_remove, +}; +module_platform_driver(qmc_hdlc_driver); + +MODULE_AUTHOR("Herve Codina "); +MODULE_DESCRIPTION("QMC HDLC driver"); +MODULE_LICENSE("GPL");