linux-stable/include/linux/wwan.h
M Chetan Kumar 76f05d8862 net: wwan: debugfs obtained dev reference not dropped
WWAN driver call's wwan_get_debugfs_dir() to obtain
WWAN debugfs dir entry. As part of this procedure it
returns a reference to a found device.

Since there is no debugfs interface available at WWAN
subsystem, it is not possible to drop dev reference post
debugfs use. This leads to side effects like post wwan
driver load and reload the wwan instance gets increment
from wwanX to wwanX+1.

A new debugfs interface is added in wwan subsystem so that
wwan driver can drop the obtained dev reference post debugfs
use.

void wwan_put_debugfs_dir(struct dentry *dir)

Signed-off-by: M Chetan Kumar <m.chetan.kumar@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-02-14 14:09:59 +00:00

186 lines
5.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/* Copyright (c) 2021, Linaro Ltd <loic.poulain@linaro.org> */
#ifndef __WWAN_H
#define __WWAN_H
#include <linux/poll.h>
#include <linux/netdevice.h>
#include <linux/types.h>
/**
* enum wwan_port_type - WWAN port types
* @WWAN_PORT_AT: AT commands
* @WWAN_PORT_MBIM: Mobile Broadband Interface Model control
* @WWAN_PORT_QMI: Qcom modem/MSM interface for modem control
* @WWAN_PORT_QCDM: Qcom Modem diagnostic interface
* @WWAN_PORT_FIREHOSE: XML based command protocol
*
* @WWAN_PORT_MAX: Highest supported port types
* @WWAN_PORT_UNKNOWN: Special value to indicate an unknown port type
* @__WWAN_PORT_MAX: Internal use
*/
enum wwan_port_type {
WWAN_PORT_AT,
WWAN_PORT_MBIM,
WWAN_PORT_QMI,
WWAN_PORT_QCDM,
WWAN_PORT_FIREHOSE,
/* Add new port types above this line */
__WWAN_PORT_MAX,
WWAN_PORT_MAX = __WWAN_PORT_MAX - 1,
WWAN_PORT_UNKNOWN,
};
struct device;
struct file;
struct netlink_ext_ack;
struct sk_buff;
struct wwan_port;
/** struct wwan_port_ops - The WWAN port operations
* @start: The routine for starting the WWAN port device.
* @stop: The routine for stopping the WWAN port device.
* @tx: Non-blocking routine that sends WWAN port protocol data to the device.
* @tx_blocking: Optional blocking routine that sends WWAN port protocol data
* to the device.
* @tx_poll: Optional routine that sets additional TX poll flags.
*
* The wwan_port_ops structure contains a list of low-level operations
* that control a WWAN port device. All functions are mandatory unless specified.
*/
struct wwan_port_ops {
int (*start)(struct wwan_port *port);
void (*stop)(struct wwan_port *port);
int (*tx)(struct wwan_port *port, struct sk_buff *skb);
/* Optional operations */
int (*tx_blocking)(struct wwan_port *port, struct sk_buff *skb);
__poll_t (*tx_poll)(struct wwan_port *port, struct file *filp,
poll_table *wait);
};
/**
* wwan_create_port - Add a new WWAN port
* @parent: Device to use as parent and shared by all WWAN ports
* @type: WWAN port type
* @ops: WWAN port operations
* @drvdata: Pointer to caller driver data
*
* Allocate and register a new WWAN port. The port will be automatically exposed
* to user as a character device and attached to the right virtual WWAN device,
* based on the parent pointer. The parent pointer is the device shared by all
* components of a same WWAN modem (e.g. USB dev, PCI dev, MHI controller...).
*
* drvdata will be placed in the WWAN port device driver data and can be
* retrieved with wwan_port_get_drvdata().
*
* This function must be balanced with a call to wwan_remove_port().
*
* Returns a valid pointer to wwan_port on success or PTR_ERR on failure
*/
struct wwan_port *wwan_create_port(struct device *parent,
enum wwan_port_type type,
const struct wwan_port_ops *ops,
void *drvdata);
/**
* wwan_remove_port - Remove a WWAN port
* @port: WWAN port to remove
*
* Remove a previously created port.
*/
void wwan_remove_port(struct wwan_port *port);
/**
* wwan_port_rx - Receive data from the WWAN port
* @port: WWAN port for which data is received
* @skb: Pointer to the rx buffer
*
* A port driver calls this function upon data reception (MBIM, AT...).
*/
void wwan_port_rx(struct wwan_port *port, struct sk_buff *skb);
/**
* wwan_port_txoff - Stop TX on WWAN port
* @port: WWAN port for which TX must be stopped
*
* Used for TX flow control, a port driver calls this function to indicate TX
* is temporary unavailable (e.g. due to ring buffer fullness).
*/
void wwan_port_txoff(struct wwan_port *port);
/**
* wwan_port_txon - Restart TX on WWAN port
* @port: WWAN port for which TX must be restarted
*
* Used for TX flow control, a port driver calls this function to indicate TX
* is available again.
*/
void wwan_port_txon(struct wwan_port *port);
/**
* wwan_port_get_drvdata - Retrieve driver data from a WWAN port
* @port: Related WWAN port
*/
void *wwan_port_get_drvdata(struct wwan_port *port);
/**
* struct wwan_netdev_priv - WWAN core network device private data
* @link_id: WWAN device data link id
* @drv_priv: driver private data area, size is determined in &wwan_ops
*/
struct wwan_netdev_priv {
u32 link_id;
/* must be last */
u8 drv_priv[] __aligned(sizeof(void *));
};
static inline void *wwan_netdev_drvpriv(struct net_device *dev)
{
return ((struct wwan_netdev_priv *)netdev_priv(dev))->drv_priv;
}
/*
* Used to indicate that the WWAN core should not create a default network
* link.
*/
#define WWAN_NO_DEFAULT_LINK U32_MAX
/**
* struct wwan_ops - WWAN device ops
* @priv_size: size of private netdev data area
* @setup: set up a new netdev
* @newlink: register the new netdev
* @dellink: remove the given netdev
*/
struct wwan_ops {
unsigned int priv_size;
void (*setup)(struct net_device *dev);
int (*newlink)(void *ctxt, struct net_device *dev,
u32 if_id, struct netlink_ext_ack *extack);
void (*dellink)(void *ctxt, struct net_device *dev,
struct list_head *head);
};
int wwan_register_ops(struct device *parent, const struct wwan_ops *ops,
void *ctxt, u32 def_link_id);
void wwan_unregister_ops(struct device *parent);
#ifdef CONFIG_WWAN_DEBUGFS
struct dentry *wwan_get_debugfs_dir(struct device *parent);
void wwan_put_debugfs_dir(struct dentry *dir);
#else
static inline struct dentry *wwan_get_debugfs_dir(struct device *parent)
{
return ERR_PTR(-ENODEV);
}
static inline void wwan_put_debugfs_dir(struct dentry *dir) {}
#endif
#endif /* __WWAN_H */