Phonet: USB CDC Phonet function for gadget framework

This implements the Nokia vendor-specific communication device class
function to exchange Phonet messages over USB. This function is already
found in the "PC suite" USB profile of (non-Linux) Nokia handsets.

Signed-off-by: Rémi Denis-Courmont <remi.denis-courmont@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 642 insertions, 0 deletions

diff --git a/drivers/usb/gadget/f_phonet.c b/drivers/usb/gadget/f_phonet.c
new file mode 100644
index 000000000000..d8fc9b32fe36
--- /dev/null
+++ b/drivers/usb/gadget/f_phonet.c
@@ -0,0 +1,621 @@
+/*
+ * f_phonet.c -- USB CDC Phonet function
+ *
+ * Copyright (C) 2007-2008 Nokia Corporation. All rights reserved.
+ *
+ * Author: Rémi Denis-Courmont
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+#include <linux/kernel.h>
+#include <linux/device.h>
+
+#include <linux/netdevice.h>
+#include <linux/if_ether.h>
+#include <linux/if_phonet.h>
+#include <linux/if_arp.h>
+
+#include <linux/usb/ch9.h>
+#include <linux/usb/cdc.h>
+#include <linux/usb/composite.h>
+
+#include "u_phonet.h"
+
+#define PN_MEDIA_USB    0x1B
+
+/*-------------------------------------------------------------------------*/
+
+struct phonet_port {
+        struct f_phonet                 *usb;
+        spinlock_t                      lock;
+};
+
+struct f_phonet {
+        struct usb_function             function;
+        struct net_device               *dev;
+        struct usb_ep                   *in_ep, *out_ep;
+
+        struct usb_request              *in_req;
+        struct usb_request              *out_reqv[0];
+};
+
+static int phonet_rxq_size = 2;
+
+static inline struct f_phonet *func_to_pn(struct usb_function *f)
+{
+        return container_of(f, struct f_phonet, function);
+}
+
+/*-------------------------------------------------------------------------*/
+
+#define USB_CDC_SUBCLASS_PHONET 0xfe
+#define USB_CDC_PHONET_TYPE     0xab
+
+static struct usb_interface_descriptor
+pn_control_intf_desc = {
+        .bLength =              sizeof pn_control_intf_desc,
+        .bDescriptorType =      USB_DT_INTERFACE,
+
+        /* .bInterfaceNumber =  DYNAMIC, */
+        .bInterfaceClass =      USB_CLASS_COMM,
+        .bInterfaceSubClass =   USB_CDC_SUBCLASS_PHONET,
+};
+
+static const struct usb_cdc_header_desc
+pn_header_desc = {
+        .bLength =              sizeof pn_header_desc,
+        .bDescriptorType =      USB_DT_CS_INTERFACE,
+        .bDescriptorSubType =   USB_CDC_HEADER_TYPE,
+        .bcdCDC =               __constant_cpu_to_le16(0x0110),
+};
+
+static const struct usb_cdc_header_desc
+pn_phonet_desc = {
+        .bLength =              sizeof pn_phonet_desc,
+        .bDescriptorType =      USB_DT_CS_INTERFACE,
+        .bDescriptorSubType =   USB_CDC_PHONET_TYPE,
+        .bcdCDC =               __constant_cpu_to_le16(0x1505), /* ??? */
+};
+
+static struct usb_cdc_union_desc
+pn_union_desc = {
+        .bLength =              sizeof pn_union_desc,
+        .bDescriptorType =      USB_DT_CS_INTERFACE,
+        .bDescriptorSubType =   USB_CDC_UNION_TYPE,
+
+        /* .bMasterInterface0 = DYNAMIC, */
+        /* .bSlaveInterface0 =  DYNAMIC, */
+};
+
+static struct usb_interface_descriptor
+pn_data_nop_intf_desc = {
+        .bLength =              sizeof pn_data_nop_intf_desc,
+        .bDescriptorType =      USB_DT_INTERFACE,
+
+        /* .bInterfaceNumber =  DYNAMIC, */
+        .bAlternateSetting =    0,
+        .bNumEndpoints =        0,
+        .bInterfaceClass =      USB_CLASS_CDC_DATA,
+};
+
+static struct usb_interface_descriptor
+pn_data_intf_desc = {
+        .bLength =              sizeof pn_data_intf_desc,
+        .bDescriptorType =      USB_DT_INTERFACE,
+
+        /* .bInterfaceNumber =  DYNAMIC, */
+        .bAlternateSetting =    1,
+        .bNumEndpoints =        2,
+        .bInterfaceClass =      USB_CLASS_CDC_DATA,
+};
+
+static struct usb_endpoint_descriptor
+pn_fs_sink_desc = {
+        .bLength =              USB_DT_ENDPOINT_SIZE,
+        .bDescriptorType =      USB_DT_ENDPOINT,
+
+        .bEndpointAddress =     USB_DIR_OUT,
+        .bmAttributes =         USB_ENDPOINT_XFER_BULK,
+};
+
+static struct usb_endpoint_descriptor
+pn_hs_sink_desc = {
+        .bLength =              USB_DT_ENDPOINT_SIZE,
+        .bDescriptorType =      USB_DT_ENDPOINT,
+
+        .bEndpointAddress =     USB_DIR_OUT,
+        .bmAttributes =         USB_ENDPOINT_XFER_BULK,
+        .wMaxPacketSize =       __constant_cpu_to_le16(512),
+};
+
+static struct usb_endpoint_descriptor
+pn_fs_source_desc = {
+        .bLength =              USB_DT_ENDPOINT_SIZE,
+        .bDescriptorType =      USB_DT_ENDPOINT,
+
+        .bEndpointAddress =     USB_DIR_IN,
+        .bmAttributes =         USB_ENDPOINT_XFER_BULK,
+};
+
+static struct usb_endpoint_descriptor
+pn_hs_source_desc = {
+        .bLength =              USB_DT_ENDPOINT_SIZE,
+        .bDescriptorType =      USB_DT_ENDPOINT,
+
+        .bEndpointAddress =     USB_DIR_IN,
+        .bmAttributes =         USB_ENDPOINT_XFER_BULK,
+        .wMaxPacketSize =       __constant_cpu_to_le16(512),
+};
+
+static struct usb_descriptor_header *fs_pn_function[] = {
+        (struct usb_descriptor_header *) &pn_control_intf_desc,
+        (struct usb_descriptor_header *) &pn_header_desc,
+        (struct usb_descriptor_header *) &pn_phonet_desc,
+        (struct usb_descriptor_header *) &pn_union_desc,
+        (struct usb_descriptor_header *) &pn_data_nop_intf_desc,
+        (struct usb_descriptor_header *) &pn_data_intf_desc,
+        (struct usb_descriptor_header *) &pn_fs_sink_desc,
+        (struct usb_descriptor_header *) &pn_fs_source_desc,
+        NULL,
+};
+
+static struct usb_descriptor_header *hs_pn_function[] = {
+        (struct usb_descriptor_header *) &pn_control_intf_desc,
+        (struct usb_descriptor_header *) &pn_header_desc,
+        (struct usb_descriptor_header *) &pn_phonet_desc,
+        (struct usb_descriptor_header *) &pn_union_desc,
+        (struct usb_descriptor_header *) &pn_data_nop_intf_desc,
+        (struct usb_descriptor_header *) &pn_data_intf_desc,
+        (struct usb_descriptor_header *) &pn_hs_sink_desc,
+        (struct usb_descriptor_header *) &pn_hs_source_desc,
+        NULL,
+};
+
+/*-------------------------------------------------------------------------*/
+
+static int pn_net_open(struct net_device *dev)
+{
+        if (netif_carrier_ok(dev))
+                netif_wake_queue(dev);
+        return 0;
+}
+
+static int pn_net_close(struct net_device *dev)
+{
+        netif_stop_queue(dev);
+        return 0;
+}
+
+static void pn_tx_complete(struct usb_ep *ep, struct usb_request *req)
+{
+        struct f_phonet *fp = ep->driver_data;
+        struct net_device *dev = fp->dev;
+        struct sk_buff *skb = req->context;
+
+        switch (req->status) {
+        case 0:
+                dev->stats.tx_packets++;
+                dev->stats.tx_bytes += skb->len;
+                break;
+
+        case -ESHUTDOWN: /* disconnected */
+        case -ECONNRESET: /* disabled */
+                dev->stats.tx_aborted_errors++;
+        default:
+                dev->stats.tx_errors++;
+        }
+
+        dev_kfree_skb_any(skb);
+        if (netif_carrier_ok(dev))
+                netif_wake_queue(dev);
+}
+
+static int pn_net_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+        struct phonet_port *port = netdev_priv(dev);
+        struct f_phonet *fp;
+        struct usb_request *req;
+        unsigned long flags;
+
+        if (skb->protocol != htons(ETH_P_PHONET))
+                goto out;
+
+        spin_lock_irqsave(&port->lock, flags);
+        fp = port->usb;
+        if (unlikely(!fp)) /* race with carrier loss */
+                goto out_unlock;
+
+        req = fp->in_req;
+        req->buf = skb->data;
+        req->length = skb->len;
+        req->complete = pn_tx_complete;
+        req->zero = 1;
+        req->context = skb;
+
+        if (unlikely(usb_ep_queue(fp->in_ep, req, GFP_ATOMIC)))
+                goto out_unlock;
+
+        netif_stop_queue(dev);
+        skb = NULL;
+
+out_unlock:
+        spin_unlock_irqrestore(&port->lock, flags);
+out:
+        if (unlikely(skb)) {
+                dev_kfree_skb_any(skb);
+                dev->stats.tx_dropped++;
+        }
+        return 0;
+}
+
+static int pn_net_mtu(struct net_device *dev, int new_mtu)
+{
+        struct phonet_port *port = netdev_priv(dev);
+        unsigned long flags;
+        int err = -EBUSY;
+
+        if ((new_mtu < PHONET_MIN_MTU) || (new_mtu > PHONET_MAX_MTU))
+                return -EINVAL;
+
+        spin_lock_irqsave(&port->lock, flags);
+        if (!netif_carrier_ok(dev)) {
+                dev->mtu = new_mtu;
+                err = 0;
+        }
+        spin_unlock_irqrestore(&port->lock, flags);
+        return err;
+}
+
+static void pn_net_setup(struct net_device *dev)
+{
+        dev->features           = 0;
+        dev->type               = ARPHRD_PHONET;
+        dev->flags              = IFF_POINTOPOINT | IFF_NOARP;
+        dev->mtu                = PHONET_DEV_MTU;
+        dev->hard_header_len    = 1;
+        dev->dev_addr[0]        = PN_MEDIA_USB;
+        dev->addr_len           = 1;
+        dev->tx_queue_len       = 1;
+
+        dev->destructor         = free_netdev;
+        dev->header_ops         = &phonet_header_ops;
+        dev->open               = pn_net_open;
+        dev->stop               = pn_net_close;
+        dev->hard_start_xmit    = pn_net_xmit; /* mandatory */
+        dev->change_mtu         = pn_net_mtu;
+}
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ * Queue buffer for data from the host
+ */
+static int
+pn_rx_submit(struct f_phonet *fp, struct usb_request *req, gfp_t gfp_flags)
+{
+        struct sk_buff *skb;
+        const size_t size = fp->dev->mtu;
+        int err;
+
+        skb = alloc_skb(size, gfp_flags);
+        if (!skb)
+                return -ENOMEM;
+
+        req->buf = skb->data;
+        req->length = size;
+        req->context = skb;
+
+        err = usb_ep_queue(fp->out_ep, req, gfp_flags);
+        if (unlikely(err))
+                dev_kfree_skb_any(skb);
+        return err;
+}
+
+static void pn_rx_complete(struct usb_ep *ep, struct usb_request *req)
+{
+        struct f_phonet *fp = ep->driver_data;
+        struct net_device *dev = fp->dev;
+        struct sk_buff *skb = req->context;
+        int status = req->status;
+
+        switch (status) {
+        case 0:
+                if (unlikely(!netif_running(dev)))
+                        break;
+                if (unlikely(req->actual < 1))
+                        break;
+                skb_put(skb, req->actual);
+                skb->protocol = htons(ETH_P_PHONET);
+                skb_reset_mac_header(skb);
+                __skb_pull(skb, 1);
+                skb->dev = dev;
+                dev->stats.rx_packets++;
+                dev->stats.rx_bytes += skb->len;
+
+                netif_rx(skb);
+                skb = NULL;
+                break;
+
+        /* Do not resubmit in these cases: */
+        case -ESHUTDOWN: /* disconnect */
+        case -ECONNABORTED: /* hw reset */
+        case -ECONNRESET: /* dequeued (unlink or netif down) */
+                req = NULL;
+                break;
+
+        /* Do resubmit in these cases: */
+        case -EOVERFLOW: /* request buffer overflow */
+                dev->stats.rx_over_errors++;
+        default:
+                dev->stats.rx_errors++;
+                break;
+        }
+
+        if (skb)
+                dev_kfree_skb_any(skb);
+        if (req)
+                pn_rx_submit(fp, req, GFP_ATOMIC);
+}
+
+/*-------------------------------------------------------------------------*/
+
+static void __pn_reset(struct usb_function *f)
+{
+        struct f_phonet *fp = func_to_pn(f);
+        struct net_device *dev = fp->dev;
+        struct phonet_port *port = netdev_priv(dev);
+
+        netif_carrier_off(dev);
+        netif_stop_queue(dev);
+        port->usb = NULL;
+
+        usb_ep_disable(fp->out_ep);
+        usb_ep_disable(fp->in_ep);
+}
+
+static int pn_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
+{
+        struct f_phonet *fp = func_to_pn(f);
+        struct usb_gadget *gadget = fp->function.config->cdev->gadget;
+
+        if (intf == pn_control_intf_desc.bInterfaceNumber)
+                /* control interface, no altsetting */
+                return (alt > 0) ? -EINVAL : 0;
+
+        if (intf == pn_data_intf_desc.bInterfaceNumber) {
+                struct net_device *dev = fp->dev;
+                struct phonet_port *port = netdev_priv(dev);
+
+                /* data intf (0: inactive, 1: active) */
+                if (alt > 1)
+                        return -EINVAL;
+
+                spin_lock(&port->lock);
+                __pn_reset(f);
+                if (alt == 1) {
+                        struct usb_endpoint_descriptor *out, *in;
+                        int i;
+
+                        out = ep_choose(gadget,
+                                        &pn_hs_sink_desc,
+                                        &pn_fs_sink_desc);
+                        in = ep_choose(gadget,
+                                        &pn_hs_source_desc,
+                                        &pn_fs_source_desc);
+                        usb_ep_enable(fp->out_ep, out);
+                        usb_ep_enable(fp->in_ep, in);
+
+                        port->usb = fp;
+                        fp->out_ep->driver_data = fp;
+                        fp->in_ep->driver_data = fp;
+
+                        netif_carrier_on(dev);
+                        if (netif_running(dev))
+                                netif_wake_queue(dev);
+                        for (i = 0; i < phonet_rxq_size; i++)
+                                pn_rx_submit(fp, fp->out_reqv[i], GFP_ATOMIC);
+                }
+                spin_unlock(&port->lock);
+                return 0;
+        }
+
+        return -EINVAL;
+}
+
+static int pn_get_alt(struct usb_function *f, unsigned intf)
+{
+        struct f_phonet *fp = func_to_pn(f);
+
+        if (intf == pn_control_intf_desc.bInterfaceNumber)
+                return 0;
+
+        if (intf == pn_data_intf_desc.bInterfaceNumber) {
+                struct phonet_port *port = netdev_priv(fp->dev);
+                u8 alt;
+
+                spin_lock(&port->lock);
+                alt = port->usb != NULL;
+                spin_unlock(&port->lock);
+                return alt;
+        }
+
+        return -EINVAL;
+}
+
+static void pn_disconnect(struct usb_function *f)
+{
+        struct f_phonet *fp = func_to_pn(f);
+        struct phonet_port *port = netdev_priv(fp->dev);
+        unsigned long flags;
+
+        /* remain disabled until set_alt */
+        spin_lock_irqsave(&port->lock, flags);
+        __pn_reset(f);
+        spin_unlock_irqrestore(&port->lock, flags);
+}
+
+/*-------------------------------------------------------------------------*/
+
+static __init
+int pn_bind(struct usb_configuration *c, struct usb_function *f)
+{
+        struct usb_composite_dev *cdev = c->cdev;
+        struct usb_gadget *gadget = cdev->gadget;
+        struct f_phonet *fp = func_to_pn(f);
+        struct usb_ep *ep;
+        int status, i;
+
+        /* Reserve interface IDs */
+        status = usb_interface_id(c, f);
+        if (status < 0)
+                goto err;
+        pn_control_intf_desc.bInterfaceNumber = status;
+        pn_union_desc.bMasterInterface0 = status;
+
+        status = usb_interface_id(c, f);
+        if (status < 0)
+                goto err;
+        pn_data_nop_intf_desc.bInterfaceNumber = status;
+        pn_data_intf_desc.bInterfaceNumber = status;
+        pn_union_desc.bSlaveInterface0 = status;
+
+        /* Reserve endpoints */
+        status = -ENODEV;
+        ep = usb_ep_autoconfig(gadget, &pn_fs_sink_desc);
+        if (!ep)
+                goto err;
+        fp->out_ep = ep;
+        ep->driver_data = fp; /* Claim */
+
+        ep = usb_ep_autoconfig(gadget, &pn_fs_source_desc);
+        if (!ep)
+                goto err;
+        fp->in_ep = ep;
+        ep->driver_data = fp; /* Claim */
+
+        pn_hs_sink_desc.bEndpointAddress =
+                pn_fs_sink_desc.bEndpointAddress;
+        pn_hs_source_desc.bEndpointAddress =
+                pn_fs_source_desc.bEndpointAddress;
+
+        /* Do not try to bind Phonet twice... */
+        fp->function.descriptors = fs_pn_function;
+        fp->function.hs_descriptors = hs_pn_function;
+
+        /* Incoming USB requests */
+        status = -ENOMEM;
+        for (i = 0; i < phonet_rxq_size; i++) {
+                struct usb_request *req;
+
+                req = usb_ep_alloc_request(fp->out_ep, GFP_KERNEL);
+                if (!req)
+                        goto err;
+
+                req->complete = pn_rx_complete;
+                fp->out_reqv[i] = req;
+        }
+
+        /* Outgoing USB requests */
+        fp->in_req = usb_ep_alloc_request(fp->in_ep, GFP_KERNEL);
+        if (!fp->in_req)
+                goto err;
+
+        INFO(cdev, "USB CDC Phonet function\n");
+        INFO(cdev, "using %s, OUT %s, IN %s\n", cdev->gadget->name,
+                fp->out_ep->name, fp->in_ep->name);
+        return 0;
+
+err:
+        if (fp->out_ep)
+                fp->out_ep->driver_data = NULL;
+        if (fp->in_ep)
+                fp->in_ep->driver_data = NULL;
+        ERROR(cdev, "USB CDC Phonet: cannot autoconfigure\n");
+        return status;
+}
+
+static void
+pn_unbind(struct usb_configuration *c, struct usb_function *f)
+{
+        struct f_phonet *fp = func_to_pn(f);
+        int i;
+
+        /* We are already disconnected */
+        if (fp->in_req)
+                usb_ep_free_request(fp->in_ep, fp->in_req);
+        for (i = 0; i < phonet_rxq_size; i++)
+                if (fp->out_reqv[i])
+                        usb_ep_free_request(fp->out_ep, fp->out_reqv[i]);
+
+        kfree(fp);
+}
+
+/*-------------------------------------------------------------------------*/
+
+static struct net_device *dev;
+
+int __init phonet_bind_config(struct usb_configuration *c)
+{
+        struct f_phonet *fp;
+        int err;
+
+        fp = kzalloc(sizeof(*fp), GFP_KERNEL);
+        if (!fp)
+                return -ENOMEM;
+
+        fp->dev = dev;
+        fp->function.name = "phonet";
+        fp->function.bind = pn_bind;
+        fp->function.unbind = pn_unbind;
+        fp->function.set_alt = pn_set_alt;
+        fp->function.get_alt = pn_get_alt;
+        fp->function.disable = pn_disconnect;
+
+        err = usb_add_function(c, &fp->function);
+        if (err)
+                kfree(fp);
+        return err;
+}
+
+int __init gphonet_setup(struct usb_gadget *gadget)
+{
+        struct phonet_port *port;
+        int err;
+
+        /* Create net device */
+        BUG_ON(dev);
+        dev = alloc_netdev(sizeof(*port)
+                + (phonet_rxq_size * sizeof(struct usb_request *)),
+                                "upnlink%d", pn_net_setup);
+        if (!dev)
+                return -ENOMEM;
+
+        port = netdev_priv(dev);
+        spin_lock_init(&port->lock);
+        netif_carrier_off(dev);
+        netif_stop_queue(dev);
+        SET_NETDEV_DEV(dev, &gadget->dev);
+
+        err = register_netdev(dev);
+        if (err)
+                free_netdev(dev);
+        return err;
+}
+
+void gphonet_cleanup(void)
+{
+        unregister_netdev(dev);
+}
diff --git a/drivers/usb/gadget/u_phonet.h b/drivers/usb/gadget/u_phonet.h
new file mode 100644
index 000000000000..09a75259b6cd
--- /dev/null
+++ b/drivers/usb/gadget/u_phonet.h
@@ -0,0 +1,21 @@
+/*
+ * u_phonet.h - interface to Phonet
+ *
+ * Copyright (C) 2007-2008 by Nokia Corporation
+ *
+ * This software is distributed under the terms of the GNU General
+ * Public License ("GPL") as published by the Free Software Foundation,
+ * either version 2 of that License or (at your option) any later version.
+ */
+
+#ifndef __U_PHONET_H
+#define __U_PHONET_H
+
+#include <linux/usb/composite.h>
+#include <linux/usb/cdc.h>
+
+int gphonet_setup(struct usb_gadget *gadget);
+int phonet_bind_config(struct usb_configuration *c);
+void gphonet_cleanup(void);
+
+#endif /* __U_PHONET_H */