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![Stefan Wahren](/assets/img/avatar_default.png)
This patch adds the Ethernet over UART driver for the Qualcomm QCA7000 HomePlug GreenPHY. Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com> Reviewed-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> Signed-off-by: David S. Miller <davem@davemloft.net>
423 lines
10 KiB
C
423 lines
10 KiB
C
/*
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* Copyright (c) 2011, 2012, Qualcomm Atheros Communications Inc.
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* Copyright (c) 2017, I2SE GmbH
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*
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* Permission to use, copy, modify, and/or distribute this software
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* for any purpose with or without fee is hereby granted, provided
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* that the above copyright notice and this permission notice appear
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* in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
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* WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
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* WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
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* THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
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* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
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* LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
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* NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
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* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*/
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/* This module implements the Qualcomm Atheros UART protocol for
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* kernel-based UART device; it is essentially an Ethernet-to-UART
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* serial converter;
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*/
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#include <linux/device.h>
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#include <linux/errno.h>
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#include <linux/etherdevice.h>
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#include <linux/if_arp.h>
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#include <linux/if_ether.h>
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#include <linux/jiffies.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/netdevice.h>
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#include <linux/of.h>
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#include <linux/of_device.h>
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#include <linux/of_net.h>
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#include <linux/sched.h>
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#include <linux/serdev.h>
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#include <linux/skbuff.h>
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#include <linux/types.h>
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#include "qca_7k_common.h"
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#define QCAUART_DRV_VERSION "0.1.0"
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#define QCAUART_DRV_NAME "qcauart"
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#define QCAUART_TX_TIMEOUT (1 * HZ)
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struct qcauart {
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struct net_device *net_dev;
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spinlock_t lock; /* transmit lock */
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struct work_struct tx_work; /* Flushes transmit buffer */
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struct serdev_device *serdev;
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struct qcafrm_handle frm_handle;
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struct sk_buff *rx_skb;
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unsigned char *tx_head; /* pointer to next XMIT byte */
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int tx_left; /* bytes left in XMIT queue */
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unsigned char *tx_buffer;
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};
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static int
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qca_tty_receive(struct serdev_device *serdev, const unsigned char *data,
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size_t count)
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{
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struct qcauart *qca = serdev_device_get_drvdata(serdev);
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struct net_device *netdev = qca->net_dev;
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struct net_device_stats *n_stats = &netdev->stats;
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size_t i;
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if (!qca->rx_skb) {
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qca->rx_skb = netdev_alloc_skb_ip_align(netdev,
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netdev->mtu +
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VLAN_ETH_HLEN);
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if (!qca->rx_skb) {
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n_stats->rx_errors++;
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n_stats->rx_dropped++;
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return 0;
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}
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}
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for (i = 0; i < count; i++) {
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s32 retcode;
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retcode = qcafrm_fsm_decode(&qca->frm_handle,
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qca->rx_skb->data,
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skb_tailroom(qca->rx_skb),
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data[i]);
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switch (retcode) {
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case QCAFRM_GATHER:
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case QCAFRM_NOHEAD:
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break;
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case QCAFRM_NOTAIL:
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netdev_dbg(netdev, "recv: no RX tail\n");
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n_stats->rx_errors++;
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n_stats->rx_dropped++;
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break;
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case QCAFRM_INVLEN:
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netdev_dbg(netdev, "recv: invalid RX length\n");
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n_stats->rx_errors++;
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n_stats->rx_dropped++;
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break;
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default:
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n_stats->rx_packets++;
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n_stats->rx_bytes += retcode;
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skb_put(qca->rx_skb, retcode);
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qca->rx_skb->protocol = eth_type_trans(
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qca->rx_skb, qca->rx_skb->dev);
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qca->rx_skb->ip_summed = CHECKSUM_UNNECESSARY;
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netif_rx_ni(qca->rx_skb);
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qca->rx_skb = netdev_alloc_skb_ip_align(netdev,
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netdev->mtu +
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VLAN_ETH_HLEN);
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if (!qca->rx_skb) {
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netdev_dbg(netdev, "recv: out of RX resources\n");
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n_stats->rx_errors++;
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return i;
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}
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}
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}
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return i;
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}
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/* Write out any remaining transmit buffer. Scheduled when tty is writable */
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static void qcauart_transmit(struct work_struct *work)
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{
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struct qcauart *qca = container_of(work, struct qcauart, tx_work);
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struct net_device_stats *n_stats = &qca->net_dev->stats;
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int written;
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spin_lock_bh(&qca->lock);
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/* First make sure we're connected. */
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if (!netif_running(qca->net_dev)) {
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spin_unlock_bh(&qca->lock);
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return;
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}
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if (qca->tx_left <= 0) {
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/* Now serial buffer is almost free & we can start
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* transmission of another packet
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*/
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n_stats->tx_packets++;
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spin_unlock_bh(&qca->lock);
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netif_wake_queue(qca->net_dev);
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return;
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}
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written = serdev_device_write_buf(qca->serdev, qca->tx_head,
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qca->tx_left);
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if (written > 0) {
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qca->tx_left -= written;
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qca->tx_head += written;
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}
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spin_unlock_bh(&qca->lock);
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}
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/* Called by the driver when there's room for more data.
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* Schedule the transmit.
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*/
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static void qca_tty_wakeup(struct serdev_device *serdev)
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{
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struct qcauart *qca = serdev_device_get_drvdata(serdev);
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schedule_work(&qca->tx_work);
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}
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static struct serdev_device_ops qca_serdev_ops = {
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.receive_buf = qca_tty_receive,
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.write_wakeup = qca_tty_wakeup,
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};
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static int qcauart_netdev_open(struct net_device *dev)
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{
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struct qcauart *qca = netdev_priv(dev);
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netif_start_queue(qca->net_dev);
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return 0;
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}
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static int qcauart_netdev_close(struct net_device *dev)
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{
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struct qcauart *qca = netdev_priv(dev);
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netif_stop_queue(dev);
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flush_work(&qca->tx_work);
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spin_lock_bh(&qca->lock);
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qca->tx_left = 0;
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spin_unlock_bh(&qca->lock);
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return 0;
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}
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static netdev_tx_t
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qcauart_netdev_xmit(struct sk_buff *skb, struct net_device *dev)
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{
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struct net_device_stats *n_stats = &dev->stats;
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struct qcauart *qca = netdev_priv(dev);
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u8 pad_len = 0;
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int written;
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u8 *pos;
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spin_lock(&qca->lock);
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WARN_ON(qca->tx_left);
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if (!netif_running(dev)) {
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spin_unlock(&qca->lock);
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netdev_warn(qca->net_dev, "xmit: iface is down\n");
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goto out;
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}
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pos = qca->tx_buffer;
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if (skb->len < QCAFRM_MIN_LEN)
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pad_len = QCAFRM_MIN_LEN - skb->len;
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pos += qcafrm_create_header(pos, skb->len + pad_len);
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memcpy(pos, skb->data, skb->len);
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pos += skb->len;
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if (pad_len) {
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memset(pos, 0, pad_len);
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pos += pad_len;
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}
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pos += qcafrm_create_footer(pos);
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netif_stop_queue(qca->net_dev);
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written = serdev_device_write_buf(qca->serdev, qca->tx_buffer,
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pos - qca->tx_buffer);
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if (written > 0) {
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qca->tx_left = (pos - qca->tx_buffer) - written;
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qca->tx_head = qca->tx_buffer + written;
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n_stats->tx_bytes += written;
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}
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spin_unlock(&qca->lock);
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netif_trans_update(dev);
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out:
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dev_kfree_skb_any(skb);
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return NETDEV_TX_OK;
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}
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static void qcauart_netdev_tx_timeout(struct net_device *dev)
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{
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struct qcauart *qca = netdev_priv(dev);
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netdev_info(qca->net_dev, "Transmit timeout at %ld, latency %ld\n",
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jiffies, dev_trans_start(dev));
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dev->stats.tx_errors++;
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dev->stats.tx_dropped++;
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}
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static int qcauart_netdev_init(struct net_device *dev)
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{
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struct qcauart *qca = netdev_priv(dev);
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size_t len;
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/* Finish setting up the device info. */
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dev->mtu = QCAFRM_MAX_MTU;
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dev->type = ARPHRD_ETHER;
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len = QCAFRM_HEADER_LEN + QCAFRM_MAX_LEN + QCAFRM_FOOTER_LEN;
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qca->tx_buffer = devm_kmalloc(&qca->serdev->dev, len, GFP_KERNEL);
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if (!qca->tx_buffer)
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return -ENOMEM;
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qca->rx_skb = netdev_alloc_skb_ip_align(qca->net_dev,
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qca->net_dev->mtu +
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VLAN_ETH_HLEN);
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if (!qca->rx_skb)
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return -ENOBUFS;
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return 0;
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}
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static void qcauart_netdev_uninit(struct net_device *dev)
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{
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struct qcauart *qca = netdev_priv(dev);
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if (qca->rx_skb)
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dev_kfree_skb(qca->rx_skb);
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}
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static const struct net_device_ops qcauart_netdev_ops = {
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.ndo_init = qcauart_netdev_init,
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.ndo_uninit = qcauart_netdev_uninit,
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.ndo_open = qcauart_netdev_open,
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.ndo_stop = qcauart_netdev_close,
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.ndo_start_xmit = qcauart_netdev_xmit,
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.ndo_set_mac_address = eth_mac_addr,
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.ndo_tx_timeout = qcauart_netdev_tx_timeout,
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.ndo_validate_addr = eth_validate_addr,
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};
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static void qcauart_netdev_setup(struct net_device *dev)
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{
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dev->netdev_ops = &qcauart_netdev_ops;
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dev->watchdog_timeo = QCAUART_TX_TIMEOUT;
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dev->priv_flags &= ~IFF_TX_SKB_SHARING;
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dev->tx_queue_len = 100;
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/* MTU range: 46 - 1500 */
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dev->min_mtu = QCAFRM_MIN_MTU;
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dev->max_mtu = QCAFRM_MAX_MTU;
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}
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static const struct of_device_id qca_uart_of_match[] = {
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{
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.compatible = "qca,qca7000",
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},
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{}
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};
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MODULE_DEVICE_TABLE(of, qca_uart_of_match);
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static int qca_uart_probe(struct serdev_device *serdev)
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{
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struct net_device *qcauart_dev = alloc_etherdev(sizeof(struct qcauart));
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struct qcauart *qca;
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const char *mac;
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u32 speed = 115200;
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int ret;
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if (!qcauart_dev)
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return -ENOMEM;
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qcauart_netdev_setup(qcauart_dev);
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SET_NETDEV_DEV(qcauart_dev, &serdev->dev);
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qca = netdev_priv(qcauart_dev);
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if (!qca) {
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pr_err("qca_uart: Fail to retrieve private structure\n");
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ret = -ENOMEM;
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goto free;
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}
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qca->net_dev = qcauart_dev;
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qca->serdev = serdev;
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qcafrm_fsm_init_uart(&qca->frm_handle);
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spin_lock_init(&qca->lock);
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INIT_WORK(&qca->tx_work, qcauart_transmit);
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of_property_read_u32(serdev->dev.of_node, "current-speed", &speed);
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mac = of_get_mac_address(serdev->dev.of_node);
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if (mac)
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ether_addr_copy(qca->net_dev->dev_addr, mac);
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if (!is_valid_ether_addr(qca->net_dev->dev_addr)) {
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eth_hw_addr_random(qca->net_dev);
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dev_info(&serdev->dev, "Using random MAC address: %pM\n",
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qca->net_dev->dev_addr);
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}
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netif_carrier_on(qca->net_dev);
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serdev_device_set_drvdata(serdev, qca);
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serdev_device_set_client_ops(serdev, &qca_serdev_ops);
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ret = serdev_device_open(serdev);
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if (ret) {
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dev_err(&serdev->dev, "Unable to open device %s\n",
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qcauart_dev->name);
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goto free;
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}
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speed = serdev_device_set_baudrate(serdev, speed);
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dev_info(&serdev->dev, "Using baudrate: %u\n", speed);
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serdev_device_set_flow_control(serdev, false);
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ret = register_netdev(qcauart_dev);
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if (ret) {
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dev_err(&serdev->dev, "Unable to register net device %s\n",
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qcauart_dev->name);
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serdev_device_close(serdev);
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cancel_work_sync(&qca->tx_work);
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goto free;
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}
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return 0;
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free:
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free_netdev(qcauart_dev);
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return ret;
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}
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static void qca_uart_remove(struct serdev_device *serdev)
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{
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struct qcauart *qca = serdev_device_get_drvdata(serdev);
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unregister_netdev(qca->net_dev);
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/* Flush any pending characters in the driver. */
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serdev_device_close(serdev);
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cancel_work_sync(&qca->tx_work);
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free_netdev(qca->net_dev);
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}
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static struct serdev_device_driver qca_uart_driver = {
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.probe = qca_uart_probe,
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.remove = qca_uart_remove,
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.driver = {
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.name = QCAUART_DRV_NAME,
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.of_match_table = of_match_ptr(qca_uart_of_match),
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},
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};
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module_serdev_device_driver(qca_uart_driver);
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MODULE_DESCRIPTION("Qualcomm Atheros QCA7000 UART Driver");
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MODULE_AUTHOR("Qualcomm Atheros Communications");
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MODULE_AUTHOR("Stefan Wahren <stefan.wahren@i2se.com>");
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MODULE_LICENSE("Dual BSD/GPL");
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MODULE_VERSION(QCAUART_DRV_VERSION);
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