1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /* Copyright (c) 2021, Linaro Ltd <loic.poulain@linaro.org> */
3 
4 #ifndef __WWAN_H
5 #define __WWAN_H
6 
7 #include <linux/poll.h>
8 #include <linux/netdevice.h>
9 #include <linux/types.h>
10 
11 /**
12  * enum wwan_port_type - WWAN port types
13  * @WWAN_PORT_AT: AT commands
14  * @WWAN_PORT_MBIM: Mobile Broadband Interface Model control
15  * @WWAN_PORT_QMI: Qcom modem/MSM interface for modem control
16  * @WWAN_PORT_QCDM: Qcom Modem diagnostic interface
17  * @WWAN_PORT_FIREHOSE: XML based command protocol
18  *
19  * @WWAN_PORT_MAX: Highest supported port types
20  * @WWAN_PORT_UNKNOWN: Special value to indicate an unknown port type
21  * @__WWAN_PORT_MAX: Internal use
22  */
23 enum wwan_port_type {
24 	WWAN_PORT_AT,
25 	WWAN_PORT_MBIM,
26 	WWAN_PORT_QMI,
27 	WWAN_PORT_QCDM,
28 	WWAN_PORT_FIREHOSE,
29 
30 	/* Add new port types above this line */
31 
32 	__WWAN_PORT_MAX,
33 	WWAN_PORT_MAX = __WWAN_PORT_MAX - 1,
34 	WWAN_PORT_UNKNOWN,
35 };
36 
37 struct device;
38 struct file;
39 struct netlink_ext_ack;
40 struct sk_buff;
41 struct wwan_port;
42 
43 /** struct wwan_port_ops - The WWAN port operations
44  * @start: The routine for starting the WWAN port device.
45  * @stop: The routine for stopping the WWAN port device.
46  * @tx: Non-blocking routine that sends WWAN port protocol data to the device.
47  * @tx_blocking: Optional blocking routine that sends WWAN port protocol data
48  *               to the device.
49  * @tx_poll: Optional routine that sets additional TX poll flags.
50  *
51  * The wwan_port_ops structure contains a list of low-level operations
52  * that control a WWAN port device. All functions are mandatory unless specified.
53  */
54 struct wwan_port_ops {
55 	int (*start)(struct wwan_port *port);
56 	void (*stop)(struct wwan_port *port);
57 	int (*tx)(struct wwan_port *port, struct sk_buff *skb);
58 
59 	/* Optional operations */
60 	int (*tx_blocking)(struct wwan_port *port, struct sk_buff *skb);
61 	__poll_t (*tx_poll)(struct wwan_port *port, struct file *filp,
62 			    poll_table *wait);
63 };
64 
65 /**
66  * wwan_create_port - Add a new WWAN port
67  * @parent: Device to use as parent and shared by all WWAN ports
68  * @type: WWAN port type
69  * @ops: WWAN port operations
70  * @drvdata: Pointer to caller driver data
71  *
72  * Allocate and register a new WWAN port. The port will be automatically exposed
73  * to user as a character device and attached to the right virtual WWAN device,
74  * based on the parent pointer. The parent pointer is the device shared by all
75  * components of a same WWAN modem (e.g. USB dev, PCI dev, MHI controller...).
76  *
77  * drvdata will be placed in the WWAN port device driver data and can be
78  * retrieved with wwan_port_get_drvdata().
79  *
80  * This function must be balanced with a call to wwan_remove_port().
81  *
82  * Returns a valid pointer to wwan_port on success or PTR_ERR on failure
83  */
84 struct wwan_port *wwan_create_port(struct device *parent,
85 				   enum wwan_port_type type,
86 				   const struct wwan_port_ops *ops,
87 				   void *drvdata);
88 
89 /**
90  * wwan_remove_port - Remove a WWAN port
91  * @port: WWAN port to remove
92  *
93  * Remove a previously created port.
94  */
95 void wwan_remove_port(struct wwan_port *port);
96 
97 /**
98  * wwan_port_rx - Receive data from the WWAN port
99  * @port: WWAN port for which data is received
100  * @skb: Pointer to the rx buffer
101  *
102  * A port driver calls this function upon data reception (MBIM, AT...).
103  */
104 void wwan_port_rx(struct wwan_port *port, struct sk_buff *skb);
105 
106 /**
107  * wwan_port_txoff - Stop TX on WWAN port
108  * @port: WWAN port for which TX must be stopped
109  *
110  * Used for TX flow control, a port driver calls this function to indicate TX
111  * is temporary unavailable (e.g. due to ring buffer fullness).
112  */
113 void wwan_port_txoff(struct wwan_port *port);
114 
115 
116 /**
117  * wwan_port_txon - Restart TX on WWAN port
118  * @port: WWAN port for which TX must be restarted
119  *
120  * Used for TX flow control, a port driver calls this function to indicate TX
121  * is available again.
122  */
123 void wwan_port_txon(struct wwan_port *port);
124 
125 /**
126  * wwan_port_get_drvdata - Retrieve driver data from a WWAN port
127  * @port: Related WWAN port
128  */
129 void *wwan_port_get_drvdata(struct wwan_port *port);
130 
131 /**
132  * struct wwan_netdev_priv - WWAN core network device private data
133  * @link_id: WWAN device data link id
134  * @drv_priv: driver private data area, size is determined in &wwan_ops
135  */
136 struct wwan_netdev_priv {
137 	u32 link_id;
138 
139 	/* must be last */
140 	u8 drv_priv[] __aligned(sizeof(void *));
141 };
142 
wwan_netdev_drvpriv(struct net_device * dev)143 static inline void *wwan_netdev_drvpriv(struct net_device *dev)
144 {
145 	return ((struct wwan_netdev_priv *)netdev_priv(dev))->drv_priv;
146 }
147 
148 /*
149  * Used to indicate that the WWAN core should not create a default network
150  * link.
151  */
152 #define WWAN_NO_DEFAULT_LINK		U32_MAX
153 
154 /**
155  * struct wwan_ops - WWAN device ops
156  * @priv_size: size of private netdev data area
157  * @setup: set up a new netdev
158  * @newlink: register the new netdev
159  * @dellink: remove the given netdev
160  */
161 struct wwan_ops {
162 	unsigned int priv_size;
163 	void (*setup)(struct net_device *dev);
164 	int (*newlink)(void *ctxt, struct net_device *dev,
165 		       u32 if_id, struct netlink_ext_ack *extack);
166 	void (*dellink)(void *ctxt, struct net_device *dev,
167 			struct list_head *head);
168 };
169 
170 int wwan_register_ops(struct device *parent, const struct wwan_ops *ops,
171 		      void *ctxt, u32 def_link_id);
172 
173 void wwan_unregister_ops(struct device *parent);
174 
175 #ifdef CONFIG_WWAN_DEBUGFS
176 struct dentry *wwan_get_debugfs_dir(struct device *parent);
177 void wwan_put_debugfs_dir(struct dentry *dir);
178 #else
wwan_get_debugfs_dir(struct device * parent)179 static inline struct dentry *wwan_get_debugfs_dir(struct device *parent)
180 {
181 	return ERR_PTR(-ENODEV);
182 }
wwan_put_debugfs_dir(struct dentry * dir)183 static inline void wwan_put_debugfs_dir(struct dentry *dir) {}
184 #endif
185 
186 #endif /* __WWAN_H */
187