From: Loic Poulain <loic.poulain@linaro.org>
To: oliver@neukum.org
Cc: kuba@kernel.org, davem@davemloft.net, bjorn@mork.no,
netdev@vger.kernel.org, aleksander@aleksander.es,
Loic Poulain <loic.poulain@linaro.org>
Subject: [PATCH net-next v2 2/2] usb: class: cdc-wdm: WWAN framework integration
Date: Tue, 11 May 2021 16:42:23 +0200 [thread overview]
Message-ID: <1620744143-26075-2-git-send-email-loic.poulain@linaro.org> (raw)
In-Reply-To: <1620744143-26075-1-git-send-email-loic.poulain@linaro.org>
The WWAN framework provides a unified way to handle WWAN/modems and its
control port(s). It has initially been introduced to support MHI/PCI
modems, offering the same control protocols as the USB variants such as
MBIM, QMI, AT... The WWAN framework exposes these control protocols as
character devices, similarly to cdc-wdm, but in a bus agnostic fashion.
This change adds registration of the USB modem cdc-wdm control endpoints
to the WWAN framework as standard control ports (wwanXpY...).
Exposing cdc-wdm through WWAN framework normally maintains backward
compatibility, e.g:
$ qmicli --device-open-qmi -d /dev/wwan0p1QMI --dms-get-ids
instead of
$ qmicli --device-open-qmi -d /dev/cdc-wdm0 --dms-get-ids
However, some tools may rely on cdc-wdm driver/device name for device
detection. It is then safer to keep the 'legacy' cdc-wdm character
device to prevent any breakage. This is handled in this change by
API mutual exclusion, only one access method can be used at a time,
either cdc-wdm chardev or WWAN API.
Note that unknown channel types (other than MBIM, AT or MBIM) are not
registered to the WWAN framework.
Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
---
v2: - Fix pm runtime while ongoing transmission
- Use WWAN port type instead of CDC specific ones
- Change port_start ordering
- Handle usb_submit_urb return value
- Fix build issue reported by kernel-test-rebot
drivers/net/usb/cdc_mbim.c | 1 +
drivers/net/usb/huawei_cdc_ncm.c | 1 +
drivers/net/usb/qmi_wwan.c | 3 +-
drivers/usb/class/cdc-wdm.c | 180 ++++++++++++++++++++++++++++++++++++++-
include/linux/usb/cdc-wdm.h | 3 +-
5 files changed, 182 insertions(+), 6 deletions(-)
diff --git a/drivers/net/usb/cdc_mbim.c b/drivers/net/usb/cdc_mbim.c
index 5db6627..42fb750 100644
--- a/drivers/net/usb/cdc_mbim.c
+++ b/drivers/net/usb/cdc_mbim.c
@@ -168,6 +168,7 @@ static int cdc_mbim_bind(struct usbnet *dev, struct usb_interface *intf)
subdriver = usb_cdc_wdm_register(ctx->control,
&dev->status->desc,
le16_to_cpu(ctx->mbim_desc->wMaxControlMessage),
+ WWAN_PORT_MBIM,
cdc_mbim_wdm_manage_power);
if (IS_ERR(subdriver)) {
ret = PTR_ERR(subdriver);
diff --git a/drivers/net/usb/huawei_cdc_ncm.c b/drivers/net/usb/huawei_cdc_ncm.c
index a87f0da..849b773 100644
--- a/drivers/net/usb/huawei_cdc_ncm.c
+++ b/drivers/net/usb/huawei_cdc_ncm.c
@@ -96,6 +96,7 @@ static int huawei_cdc_ncm_bind(struct usbnet *usbnet_dev,
subdriver = usb_cdc_wdm_register(ctx->control,
&usbnet_dev->status->desc,
1024, /* wMaxCommand */
+ WWAN_PORT_AT,
huawei_cdc_ncm_wdm_manage_power);
if (IS_ERR(subdriver)) {
ret = PTR_ERR(subdriver);
diff --git a/drivers/net/usb/qmi_wwan.c b/drivers/net/usb/qmi_wwan.c
index 17a0505..11c898f 100644
--- a/drivers/net/usb/qmi_wwan.c
+++ b/drivers/net/usb/qmi_wwan.c
@@ -724,7 +724,8 @@ static int qmi_wwan_register_subdriver(struct usbnet *dev)
/* register subdriver */
subdriver = usb_cdc_wdm_register(info->control, &dev->status->desc,
- 4096, &qmi_wwan_cdc_wdm_manage_power);
+ 4096, WWAN_PORT_QMI,
+ &qmi_wwan_cdc_wdm_manage_power);
if (IS_ERR(subdriver)) {
dev_err(&info->control->dev, "subdriver registration failed\n");
rv = PTR_ERR(subdriver);
diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c
index 508b1c3..457b00c 100644
--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -21,8 +21,10 @@
#include <linux/uaccess.h>
#include <linux/bitops.h>
#include <linux/poll.h>
+#include <linux/skbuff.h>
#include <linux/usb.h>
#include <linux/usb/cdc.h>
+#include <linux/wwan.h>
#include <asm/byteorder.h>
#include <asm/unaligned.h>
#include <linux/usb/cdc-wdm.h>
@@ -55,6 +57,7 @@ MODULE_DEVICE_TABLE (usb, wdm_ids);
#define WDM_SUSPENDING 8
#define WDM_RESETTING 9
#define WDM_OVERFLOW 10
+#define WDM_WWAN_IN_USE 11
#define WDM_MAX 16
@@ -106,6 +109,9 @@ struct wdm_device {
struct list_head device_list;
int (*manage_power)(struct usb_interface *, int);
+
+ enum wwan_port_type wwanp_type;
+ struct wwan_port *wwanp;
};
static struct usb_driver wdm_driver;
@@ -157,6 +163,8 @@ static void wdm_out_callback(struct urb *urb)
wake_up_all(&desc->wait);
}
+static void wdm_wwan_rx(struct wdm_device *desc, int length);
+
static void wdm_in_callback(struct urb *urb)
{
unsigned long flags;
@@ -192,6 +200,11 @@ static void wdm_in_callback(struct urb *urb)
}
}
+ if (test_bit(WDM_WWAN_IN_USE, &desc->flags)) {
+ wdm_wwan_rx(desc, length);
+ goto out;
+ }
+
/*
* only set a new error if there is no previous error.
* Errors are only cleared during read/open
@@ -226,6 +239,7 @@ static void wdm_in_callback(struct urb *urb)
set_bit(WDM_READ, &desc->flags);
wake_up(&desc->wait);
}
+out:
spin_unlock_irqrestore(&desc->iuspin, flags);
}
@@ -697,6 +711,11 @@ static int wdm_open(struct inode *inode, struct file *file)
goto out;
file->private_data = desc;
+ if (test_bit(WDM_WWAN_IN_USE, &desc->flags)) {
+ rv = -EBUSY;
+ goto out;
+ }
+
rv = usb_autopm_get_interface(desc->intf);
if (rv < 0) {
dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
@@ -792,6 +811,151 @@ static struct usb_class_driver wdm_class = {
.minor_base = WDM_MINOR_BASE,
};
+/* --- WWAN framework integration --- */
+#ifdef CONFIG_WWAN
+static int wdm_wwan_port_start(struct wwan_port *port)
+{
+ struct wdm_device *desc = wwan_port_get_drvdata(port);
+
+ /* The interface is both exposed via the WWAN framework and as a
+ * legacy usbmisc chardev. If chardev is already open, just fail
+ * to prevent concurrent usage. Otherwise, switch to WWAN mode.
+ */
+ mutex_lock(&wdm_mutex);
+ if (desc->count) {
+ mutex_unlock(&wdm_mutex);
+ return -EBUSY;
+ }
+ set_bit(WDM_WWAN_IN_USE, &desc->flags);
+ mutex_unlock(&wdm_mutex);
+
+ desc->manage_power(desc->intf, 1);
+
+ /* tx is allowed */
+ wwan_port_txon(port);
+
+ /* Start getting events */
+ return usb_submit_urb(desc->validity, GFP_KERNEL);
+}
+
+static void wdm_wwan_port_stop(struct wwan_port *port)
+{
+ struct wdm_device *desc = wwan_port_get_drvdata(port);
+
+ /* Stop all transfers and disable WWAN mode */
+ kill_urbs(desc);
+ desc->manage_power(desc->intf, 0);
+ clear_bit(WDM_READ, &desc->flags);
+ clear_bit(WDM_WWAN_IN_USE, &desc->flags);
+}
+
+static void wdm_wwan_port_tx_complete(struct urb *urb)
+{
+ struct sk_buff *skb = urb->context;
+ struct wdm_device *desc = skb_shinfo(skb)->destructor_arg;
+
+ usb_autopm_put_interface(desc->intf);
+ wwan_port_txon(desc->wwanp);
+ kfree_skb(skb);
+}
+
+static int wdm_wwan_port_tx(struct wwan_port *port, struct sk_buff *skb)
+{
+ struct wdm_device *desc = wwan_port_get_drvdata(port);
+ struct usb_interface *intf = desc->intf;
+ struct usb_ctrlrequest *req = desc->orq;
+ int rv;
+
+ rv = usb_autopm_get_interface(intf);
+ if (rv)
+ return rv;
+
+ usb_fill_control_urb(
+ desc->command,
+ interface_to_usbdev(intf),
+ usb_sndctrlpipe(interface_to_usbdev(intf), 0),
+ (unsigned char *)req,
+ skb->data,
+ skb->len,
+ wdm_wwan_port_tx_complete,
+ skb
+ );
+
+ req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
+ req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
+ req->wValue = 0;
+ req->wIndex = desc->inum;
+ req->wLength = cpu_to_le16(skb->len);
+
+ skb_shinfo(skb)->destructor_arg = desc;
+
+ rv = usb_submit_urb(desc->command, GFP_KERNEL);
+ if (rv)
+ usb_autopm_put_interface(intf);
+ else /* One transfer at a time, stop TX until URB completion */
+ wwan_port_txoff(port);
+
+ return rv;
+}
+
+static struct wwan_port_ops wdm_wwan_port_ops = {
+ .start = wdm_wwan_port_start,
+ .stop = wdm_wwan_port_stop,
+ .tx = wdm_wwan_port_tx,
+};
+
+static void wdm_wwan_init(struct wdm_device *desc)
+{
+ struct usb_interface *intf = desc->intf;
+ struct wwan_port *port;
+
+ /* Only register to WWAN core if protocol/type is known */
+ if (desc->wwanp_type == WWAN_PORT_UNKNOWN) {
+ dev_info(&intf->dev, "Unknown control protocol\n");
+ return;
+ }
+
+ port = wwan_create_port(&intf->dev, desc->wwanp_type, &wdm_wwan_port_ops, desc);
+ if (IS_ERR(port)) {
+ dev_err(&intf->dev, "%s: Unable to create WWAN port\n",
+ dev_name(intf->usb_dev));
+ return;
+ }
+
+ desc->wwanp = port;
+}
+
+static void wdm_wwan_deinit(struct wdm_device *desc)
+{
+ if (!desc->wwanp)
+ return;
+
+ wwan_remove_port(desc->wwanp);
+ desc->wwanp = NULL;
+}
+
+static void wdm_wwan_rx(struct wdm_device *desc, int length)
+{
+ struct wwan_port *port = desc->wwanp;
+ struct sk_buff *skb;
+
+ /* Forward data to WWAN port */
+ skb = alloc_skb(length, GFP_ATOMIC);
+ if (!skb)
+ return;
+
+ memcpy(skb_put(skb, length), desc->inbuf, length);
+ wwan_port_rx(port, skb);
+
+ /* inbuf has been copied, it is safe to check for outstanding data */
+ schedule_work(&desc->service_outs_intr);
+}
+#else /* CONFIG_WWAN */
+static void wdm_wwan_init(struct wdm_device *desc) {}
+static void wdm_wwan_deinit(struct wdm_device *desc) {}
+static void wdm_wwan_rx(struct wdm_device *desc, int length) {}
+#endif /* CONFIG_WWAN */
+
/* --- error handling --- */
static void wdm_rxwork(struct work_struct *work)
{
@@ -836,7 +1000,8 @@ static void service_interrupt_work(struct work_struct *work)
/* --- hotplug --- */
static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor *ep,
- u16 bufsize, int (*manage_power)(struct usb_interface *, int))
+ u16 bufsize, enum wwan_port_type type,
+ int (*manage_power)(struct usb_interface *, int))
{
int rv = -ENOMEM;
struct wdm_device *desc;
@@ -853,6 +1018,7 @@ static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor
/* this will be expanded and needed in hardware endianness */
desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
desc->intf = intf;
+ desc->wwanp_type = type;
INIT_WORK(&desc->rxwork, wdm_rxwork);
INIT_WORK(&desc->service_outs_intr, service_interrupt_work);
@@ -933,6 +1099,9 @@ static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor
goto err;
else
dev_info(&intf->dev, "%s: USB WDM device\n", dev_name(intf->usb_dev));
+
+ wdm_wwan_init(desc);
+
out:
return rv;
err:
@@ -977,7 +1146,7 @@ static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
goto err;
ep = &iface->endpoint[0].desc;
- rv = wdm_create(intf, ep, maxcom, &wdm_manage_power);
+ rv = wdm_create(intf, ep, maxcom, WWAN_PORT_UNKNOWN, &wdm_manage_power);
err:
return rv;
@@ -988,6 +1157,7 @@ static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
* @intf: usb interface the subdriver will associate with
* @ep: interrupt endpoint to monitor for notifications
* @bufsize: maximum message size to support for read/write
+ * @type: Type/protocol of the transported data (MBIM, QMI...)
* @manage_power: call-back invoked during open and release to
* manage the device's power
* Create WDM usb class character device and associate it with intf
@@ -1005,12 +1175,12 @@ static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
*/
struct usb_driver *usb_cdc_wdm_register(struct usb_interface *intf,
struct usb_endpoint_descriptor *ep,
- int bufsize,
+ int bufsize, enum wwan_port_type type,
int (*manage_power)(struct usb_interface *, int))
{
int rv;
- rv = wdm_create(intf, ep, bufsize, manage_power);
+ rv = wdm_create(intf, ep, bufsize, type, manage_power);
if (rv < 0)
goto err;
@@ -1029,6 +1199,8 @@ static void wdm_disconnect(struct usb_interface *intf)
desc = wdm_find_device(intf);
mutex_lock(&wdm_mutex);
+ wdm_wwan_deinit(desc);
+
/* the spinlock makes sure no new urbs are generated in the callbacks */
spin_lock_irqsave(&desc->iuspin, flags);
set_bit(WDM_DISCONNECTING, &desc->flags);
diff --git a/include/linux/usb/cdc-wdm.h b/include/linux/usb/cdc-wdm.h
index 9b895f9..9f5a51f 100644
--- a/include/linux/usb/cdc-wdm.h
+++ b/include/linux/usb/cdc-wdm.h
@@ -12,11 +12,12 @@
#ifndef __LINUX_USB_CDC_WDM_H
#define __LINUX_USB_CDC_WDM_H
+#include <linux/wwan.h>
#include <uapi/linux/usb/cdc-wdm.h>
extern struct usb_driver *usb_cdc_wdm_register(struct usb_interface *intf,
struct usb_endpoint_descriptor *ep,
- int bufsize,
+ int bufsize, enum wwan_port_type type,
int (*manage_power)(struct usb_interface *, int));
#endif /* __LINUX_USB_CDC_WDM_H */
--
2.7.4
next prev parent reply other threads:[~2021-05-11 14:33 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-11 14:42 [PATCH net-next v2 1/2] net: wwan: Add unknown port type Loic Poulain
2021-05-11 14:42 ` Loic Poulain [this message]
2021-05-12 7:30 ` [PATCH net-next v2 2/2] usb: class: cdc-wdm: WWAN framework integration Aleksander Morgado
[not found] ` <CAMZdPi_2PdM9+_RQi0hL=eQauXfN3wFJVyHwSWGsfnK2QBaHbw@mail.gmail.com>
2021-05-12 9:04 ` Aleksander Morgado
2021-05-12 11:01 ` Loic Poulain
2021-05-12 11:05 ` Bjørn Mork
2021-05-12 16:34 ` Dan Williams
2021-05-19 9:25 ` Loic Poulain
2021-05-19 9:40 ` Aleksander Morgado
2021-05-11 23:33 ` [PATCH net-next v2 1/2] net: wwan: Add unknown port type patchwork-bot+netdevbpf
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