[PATCH RFC v2 net-next 8/8] net: qualcomm: add QCA7000 UART driver
From: Stefan Wahren
Date: Mon Sep 26 2016 - 07:09:47 EST
This patch adds the Ethernet over UART driver for the
Qualcomm QCA7000 HomePlug GreenPHY.
Signed-off-by: Stefan Wahren <stefan.wahren@xxxxxxxx>
---
drivers/net/ethernet/qualcomm/Kconfig | 12 +
drivers/net/ethernet/qualcomm/Makefile | 2 +
drivers/net/ethernet/qualcomm/qca_common.h | 6 +
drivers/net/ethernet/qualcomm/qca_uart.c | 447 +++++++++++++++++++++++++++++
include/uapi/linux/tty.h | 1 +
5 files changed, 468 insertions(+)
create mode 100644 drivers/net/ethernet/qualcomm/qca_uart.c
diff --git a/drivers/net/ethernet/qualcomm/Kconfig b/drivers/net/ethernet/qualcomm/Kconfig
index 0d33728..0ede46e 100644
--- a/drivers/net/ethernet/qualcomm/Kconfig
+++ b/drivers/net/ethernet/qualcomm/Kconfig
@@ -30,6 +30,18 @@ config QCA7000_SPI
To compile this driver as a module, choose M here. The module
will be called qcaspi.
+config QCA7000_UART
+ tristate "Qualcomm Atheros QCA7000 UART support"
+ select QCA7000
+ depends on TTY
+ ---help---
+ This UART protocol driver supports the Qualcomm Atheros QCA7000.
+ The driver implements the tty line discipline N_QCA7K and supports
+ only one netdevice.
+
+ To compile this driver as a module, choose M here. The module
+ will be called qcauart.
+
config QCOM_EMAC
tristate "Qualcomm Technologies, Inc. EMAC Gigabit Ethernet support"
select CRC32
diff --git a/drivers/net/ethernet/qualcomm/Makefile b/drivers/net/ethernet/qualcomm/Makefile
index 00d8729..8847db7 100644
--- a/drivers/net/ethernet/qualcomm/Makefile
+++ b/drivers/net/ethernet/qualcomm/Makefile
@@ -5,5 +5,7 @@
obj-$(CONFIG_QCA7000) += qca_common.o
obj-$(CONFIG_QCA7000_SPI) += qcaspi.o
qcaspi-objs := qca_7k.o qca_debug.o qca_spi.o
+obj-$(CONFIG_QCA7000_UART) += qcauart.o
+qcauart-objs := qca_uart.o
obj-y += emac/
diff --git a/drivers/net/ethernet/qualcomm/qca_common.h b/drivers/net/ethernet/qualcomm/qca_common.h
index c93cfdf07..bc38689 100644
--- a/drivers/net/ethernet/qualcomm/qca_common.h
+++ b/drivers/net/ethernet/qualcomm/qca_common.h
@@ -123,6 +123,12 @@ static inline void qcafrm_fsm_init_spi(struct qcafrm_handle *handle)
handle->state = handle->init;
}
+static inline void qcafrm_fsm_init_uart(struct qcafrm_handle *handle)
+{
+ handle->init = QCAFRM_WAIT_AA1;
+ handle->state = handle->init;
+}
+
/* Gather received bytes and try to extract a full Ethernet frame
* by following a simple state machine.
*
diff --git a/drivers/net/ethernet/qualcomm/qca_uart.c b/drivers/net/ethernet/qualcomm/qca_uart.c
new file mode 100644
index 0000000..0a8dd6d
--- /dev/null
+++ b/drivers/net/ethernet/qualcomm/qca_uart.c
@@ -0,0 +1,447 @@
+/*
+ * Copyright (c) 2011, 2012, Qualcomm Atheros Communications Inc.
+ * Copyright (c) 2016, I2SE GmbH
+ *
+ * Permission to use, copy, modify, and/or distribute this software
+ * for any purpose with or without fee is hereby granted, provided
+ * that the above copyright notice and this permission notice appear
+ * in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
+ * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
+ * THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
+ * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/* This module implements the Qualcomm Atheros UART protocol for
+ * kernel-based UART device; it is essentially an Ethernet-to-UART
+ * serial converter;
+ */
+
+#include <linux/errno.h>
+#include <linux/etherdevice.h>
+#include <linux/if_arp.h>
+#include <linux/if_ether.h>
+#include <linux/init.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/netdevice.h>
+#include <linux/sched.h>
+#include <linux/skbuff.h>
+#include <linux/tty.h>
+#include <linux/types.h>
+
+#include "qca_common.h"
+
+#define QCAUART_DRV_VERSION "0.0.6"
+#define QCAUART_DRV_NAME "qcauart"
+#define QCAUART_TX_TIMEOUT (1 * HZ)
+
+struct qcauart {
+ struct net_device *net_dev;
+ spinlock_t lock; /* transmit lock */
+ struct work_struct tx_work; /* Flushes transmit buffer */
+
+ struct tty_struct *tty;
+
+ unsigned char xbuff[QCAFRM_ETHMAXMTU]; /* transmitter buffer */
+ unsigned char *xhead; /* pointer to next XMIT byte */
+ int xleft; /* bytes left in XMIT queue */
+
+ struct qcafrm_handle frm_handle;
+
+ struct sk_buff *rx_skb;
+};
+
+static struct net_device *qcauart_dev;
+
+void
+qca_tty_receive(struct tty_struct *tty, const unsigned char *cp, char *fp,
+ int count)
+{
+ struct qcauart *qca = tty->disc_data;
+ struct net_device_stats *n_stats = &qca->net_dev->stats;
+ int dropped = 0;
+
+ if (!qca->rx_skb) {
+ qca->rx_skb = netdev_alloc_skb(qca->net_dev, qca->net_dev->mtu +
+ VLAN_ETH_HLEN);
+ if (!qca->rx_skb) {
+ n_stats->rx_errors++;
+ n_stats->rx_dropped++;
+ return;
+ }
+ }
+
+ while (count--) {
+ s32 retcode;
+
+ if (fp && *fp++) {
+ n_stats->rx_errors++;
+ cp++;
+ dropped++;
+ continue;
+ }
+
+ retcode = qcafrm_fsm_decode(&qca->frm_handle,
+ qca->rx_skb->data,
+ skb_tailroom(qca->rx_skb),
+ *cp);
+
+ cp++;
+ switch (retcode) {
+ case QCAFRM_GATHER:
+ case QCAFRM_NOHEAD:
+ break;
+ case QCAFRM_NOTAIL:
+ netdev_dbg(qca->net_dev, "recv: no RX tail\n");
+ n_stats->rx_errors++;
+ n_stats->rx_dropped++;
+ break;
+ case QCAFRM_INVLEN:
+ netdev_dbg(qca->net_dev, "recv: invalid RX length\n");
+ n_stats->rx_errors++;
+ n_stats->rx_dropped++;
+ break;
+ default:
+ qca->rx_skb->dev = qca->net_dev;
+ n_stats->rx_packets++;
+ n_stats->rx_bytes += retcode;
+ skb_put(qca->rx_skb, retcode);
+ qca->rx_skb->protocol = eth_type_trans(
+ qca->rx_skb, qca->rx_skb->dev);
+ qca->rx_skb->ip_summed = CHECKSUM_UNNECESSARY;
+ netif_rx_ni(qca->rx_skb);
+ qca->rx_skb = netdev_alloc_skb(qca->net_dev,
+ qca->net_dev->mtu +
+ VLAN_ETH_HLEN);
+ if (!qca->rx_skb) {
+ netdev_dbg(qca->net_dev, "recv: out of RX resources\n");
+ n_stats->rx_errors++;
+ break;
+ }
+ }
+ }
+
+ if (dropped)
+ dev_dbg_ratelimited(&qca->net_dev->dev, "recv: invalid %d bytes\n",
+ dropped);
+}
+
+/* Write out any remaining transmit buffer. Scheduled when tty is writable */
+static void qcauart_transmit(struct work_struct *work)
+{
+ struct qcauart *qca = container_of(work, struct qcauart, tx_work);
+ struct net_device_stats *n_stats = &qca->net_dev->stats;
+ int written;
+
+ spin_lock_bh(&qca->lock);
+ /* First make sure we're connected. */
+ if (!qca->tty || !netif_running(qca->net_dev)) {
+ spin_unlock_bh(&qca->lock);
+ return;
+ }
+
+ if (qca->xleft <= 0) {
+ /* Now serial buffer is almost free & we can start
+ * transmission of another packet
+ */
+ n_stats->tx_packets++;
+ clear_bit(TTY_DO_WRITE_WAKEUP, &qca->tty->flags);
+ spin_unlock_bh(&qca->lock);
+ netif_wake_queue(qca->net_dev);
+ return;
+ }
+
+ written = qca->tty->ops->write(qca->tty, qca->xhead, qca->xleft);
+ qca->xleft -= written;
+ qca->xhead += written;
+ spin_unlock_bh(&qca->lock);
+}
+
+/* Called by the driver when there's room for more data.
+ * Schedule the transmit.
+ */
+static void qca_tty_wakeup(struct tty_struct *tty)
+{
+ struct qcauart *qca = tty->disc_data;
+
+ schedule_work(&qca->tx_work);
+}
+
+int
+qca_tty_open(struct tty_struct *tty)
+{
+ struct qcauart *qca;
+
+ if (!capable(CAP_NET_ADMIN))
+ return -EPERM;
+
+ if (!tty->ops->write)
+ return -EOPNOTSUPP;
+
+ if (tty->disc_data)
+ return -EEXIST;
+
+ qca = netdev_priv(qcauart_dev);
+ qca->tty = tty;
+ tty->disc_data = qca;
+ tty->receive_room = 4096;
+ netif_carrier_on(qca->net_dev);
+
+ return 0;
+}
+
+void
+qca_tty_close(struct tty_struct *tty)
+{
+ struct qcauart *qca = (void *)tty->disc_data;
+
+ if (!qca)
+ return;
+
+ netif_carrier_off(qca->net_dev);
+ qca->tty = NULL;
+
+ /* Detach from the tty */
+ tty->disc_data = NULL;
+}
+
+static struct tty_ldisc_ops qca_ldisc = {
+ .owner = THIS_MODULE,
+ .magic = TTY_LDISC_MAGIC,
+ .name = "qca",
+ .open = qca_tty_open,
+ .close = qca_tty_close,
+ .ioctl = n_tty_ioctl_helper,
+ .receive_buf = qca_tty_receive,
+ .write_wakeup = qca_tty_wakeup,
+};
+
+int
+qcauart_netdev_open(struct net_device *dev)
+{
+ struct qcauart *qca = netdev_priv(dev);
+
+ qcafrm_fsm_init_uart(&qca->frm_handle);
+ netif_start_queue(qca->net_dev);
+
+ return 0;
+}
+
+int
+qcauart_netdev_close(struct net_device *dev)
+{
+ struct qcauart *qca = netdev_priv(dev);
+
+ spin_lock_bh(&qca->lock);
+ if (qca->tty) {
+ /* TTY discipline is running. */
+ clear_bit(TTY_DO_WRITE_WAKEUP, &qca->tty->flags);
+ }
+ netif_stop_queue(dev);
+ qca->xleft = 0;
+ spin_unlock_bh(&qca->lock);
+
+ return 0;
+}
+
+netdev_tx_t
+qcauart_netdev_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ struct qcauart *qca = netdev_priv(dev);
+ struct net_device_stats *n_stats = &dev->stats;
+ u8 *pos;
+ u8 pad_len = 0;
+ int written;
+
+ spin_lock(&qca->lock);
+
+ if (!netif_running(dev)) {
+ spin_unlock(&qca->lock);
+ netdev_warn(qca->net_dev, "xmit: iface is down\n");
+ goto out;
+ }
+ if (!qca->tty) {
+ spin_unlock(&qca->lock);
+ goto out;
+ }
+
+ pos = qca->xbuff;
+
+ if (skb->len < QCAFRM_ETHMINLEN)
+ pad_len = QCAFRM_ETHMINLEN - skb->len;
+
+ pos += qcafrm_create_header(pos, skb->len + pad_len);
+
+ memcpy(pos, skb->data, skb->len);
+ pos += skb->len;
+
+ if (pad_len) {
+ memset(pos, 0, pad_len);
+ pos += pad_len;
+ }
+
+ pos += qcafrm_create_footer(pos);
+
+ netif_stop_queue(qca->net_dev);
+
+ set_bit(TTY_DO_WRITE_WAKEUP, &qca->tty->flags);
+ written = qca->tty->ops->write(qca->tty, qca->xbuff, pos - qca->xbuff);
+ qca->xleft = (pos - qca->xbuff) - written;
+ qca->xhead = qca->xbuff + written;
+ n_stats->tx_bytes += written;
+ spin_unlock(&qca->lock);
+
+ netif_trans_update(dev);
+out:
+ kfree_skb(skb);
+ return NETDEV_TX_OK;
+}
+
+void
+qcauart_netdev_tx_timeout(struct net_device *dev)
+{
+ struct qcauart *qca = netdev_priv(dev);
+
+ netdev_info(qca->net_dev, "Transmit timeout at %ld, latency %ld\n",
+ jiffies, dev_trans_start(dev));
+ dev->stats.tx_errors++;
+ dev->stats.tx_dropped++;
+
+ clear_bit(TTY_DO_WRITE_WAKEUP, &qca->tty->flags);
+}
+
+static int
+qcauart_netdev_init(struct net_device *dev)
+{
+ struct qcauart *qca = netdev_priv(dev);
+
+ /* Finish setting up the device info. */
+ dev->mtu = QCAFRM_ETHMAXMTU;
+ dev->type = ARPHRD_ETHER;
+
+ qca->rx_skb = netdev_alloc_skb(qca->net_dev,
+ qca->net_dev->mtu + VLAN_ETH_HLEN);
+ if (!qca->rx_skb)
+ return -ENOMEM;
+
+ return 0;
+}
+
+static void
+qcauart_netdev_uninit(struct net_device *dev)
+{
+ struct qcauart *qca = netdev_priv(dev);
+
+ if (qca->rx_skb)
+ dev_kfree_skb(qca->rx_skb);
+}
+
+static const struct net_device_ops qcauart_netdev_ops = {
+ .ndo_init = qcauart_netdev_init,
+ .ndo_uninit = qcauart_netdev_uninit,
+ .ndo_open = qcauart_netdev_open,
+ .ndo_stop = qcauart_netdev_close,
+ .ndo_start_xmit = qcauart_netdev_xmit,
+ .ndo_change_mtu = qcacmn_netdev_change_mtu,
+ .ndo_set_mac_address = eth_mac_addr,
+ .ndo_tx_timeout = qcauart_netdev_tx_timeout,
+ .ndo_validate_addr = eth_validate_addr,
+};
+
+static void
+qcauart_netdev_setup(struct net_device *dev)
+{
+ struct qcauart *qca;
+
+ dev->netdev_ops = &qcauart_netdev_ops;
+ dev->watchdog_timeo = QCAUART_TX_TIMEOUT;
+ dev->priv_flags &= ~IFF_TX_SKB_SHARING;
+ dev->tx_queue_len = 100;
+
+ qca = netdev_priv(dev);
+ memset(qca, 0, sizeof(struct qcauart));
+}
+
+static int __init qcauart_mod_init(void)
+{
+ struct qcauart *qca;
+ int ret;
+
+ ret = tty_register_ldisc(N_QCA7K, &qca_ldisc);
+ if (ret) {
+ pr_err("qca_uart: Can't register line discipline (ret %d)\n",
+ ret);
+ return ret;
+ }
+
+ qcauart_dev = alloc_etherdev(sizeof(struct qcauart));
+ if (!qcauart_dev)
+ return -ENOMEM;
+
+ qcauart_netdev_setup(qcauart_dev);
+
+ qca = netdev_priv(qcauart_dev);
+ if (!qca) {
+ pr_err("qca_uart: Fail to retrieve private structure\n");
+ free_netdev(qcauart_dev);
+ return -ENOMEM;
+ }
+ qca->net_dev = qcauart_dev;
+ spin_lock_init(&qca->lock);
+ INIT_WORK(&qca->tx_work, qcauart_transmit);
+
+ eth_hw_addr_random(qca->net_dev);
+ pr_info("qca_uart: ver=%s, using random MAC address: %pM\n",
+ QCAUART_DRV_VERSION, qca->net_dev->dev_addr);
+
+ netif_carrier_off(qca->net_dev);
+
+ if (register_netdev(qcauart_dev)) {
+ pr_err("qca_uart: Unable to register net device %s\n",
+ qcauart_dev->name);
+ free_netdev(qcauart_dev);
+ return -EFAULT;
+ }
+
+ return 0;
+}
+
+static void __exit qcauart_mod_exit(void)
+{
+ struct qcauart *qca;
+ int ret;
+
+ qca = netdev_priv(qcauart_dev);
+ spin_lock_bh(&qca->lock);
+ if (qca->tty)
+ tty_hangup(qca->tty);
+ spin_unlock_bh(&qca->lock);
+
+ unregister_netdev(qcauart_dev);
+
+ free_netdev(qcauart_dev);
+ qcauart_dev = NULL;
+
+ ret = tty_unregister_ldisc(N_QCA7K);
+ if (ret)
+ pr_err("qca_uart: can't unregister line discipline (ret %d)\n",
+ ret);
+}
+
+module_init(qcauart_mod_init);
+module_exit(qcauart_mod_exit);
+
+MODULE_DESCRIPTION("Qualcomm Atheros UART Driver");
+MODULE_AUTHOR("Qualcomm Atheros Communications");
+MODULE_AUTHOR("Stefan Wahren <stefan.wahren@xxxxxxxx>");
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_VERSION(QCAUART_DRV_VERSION);
+MODULE_ALIAS_LDISC(N_QCA7K);
diff --git a/include/uapi/linux/tty.h b/include/uapi/linux/tty.h
index 01c4410..53c2760 100644
--- a/include/uapi/linux/tty.h
+++ b/include/uapi/linux/tty.h
@@ -35,5 +35,6 @@
#define N_TRACESINK 23 /* Trace data routing for MIPI P1149.7 */
#define N_TRACEROUTER 24 /* Trace data routing for MIPI P1149.7 */
#define N_NCI 25 /* NFC NCI UART */
+#define N_QCA7K 26 /* Qualcomm QCA7000 Ethernet to UART */
#endif /* _UAPI_LINUX_TTY_H */
--
2.1.4