xref: /openbmc/linux/include/linux/wwan.h (revision 36bd28c1)
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  * @WWAN_PORT_XMMRPC: Control protocol for Intel XMM modems
19  *
20  * @WWAN_PORT_MAX: Highest supported port types
21  * @WWAN_PORT_UNKNOWN: Special value to indicate an unknown port type
22  * @__WWAN_PORT_MAX: Internal use
23  */
24 enum wwan_port_type {
25 	WWAN_PORT_AT,
26 	WWAN_PORT_MBIM,
27 	WWAN_PORT_QMI,
28 	WWAN_PORT_QCDM,
29 	WWAN_PORT_FIREHOSE,
30 	WWAN_PORT_XMMRPC,
31 
32 	/* Add new port types above this line */
33 
34 	__WWAN_PORT_MAX,
35 	WWAN_PORT_MAX = __WWAN_PORT_MAX - 1,
36 	WWAN_PORT_UNKNOWN,
37 };
38 
39 struct device;
40 struct file;
41 struct netlink_ext_ack;
42 struct sk_buff;
43 struct wwan_port;
44 
45 /** struct wwan_port_ops - The WWAN port operations
46  * @start: The routine for starting the WWAN port device.
47  * @stop: The routine for stopping the WWAN port device.
48  * @tx: Non-blocking routine that sends WWAN port protocol data to the device.
49  * @tx_blocking: Optional blocking routine that sends WWAN port protocol data
50  *               to the device.
51  * @tx_poll: Optional routine that sets additional TX poll flags.
52  *
53  * The wwan_port_ops structure contains a list of low-level operations
54  * that control a WWAN port device. All functions are mandatory unless specified.
55  */
56 struct wwan_port_ops {
57 	int (*start)(struct wwan_port *port);
58 	void (*stop)(struct wwan_port *port);
59 	int (*tx)(struct wwan_port *port, struct sk_buff *skb);
60 
61 	/* Optional operations */
62 	int (*tx_blocking)(struct wwan_port *port, struct sk_buff *skb);
63 	__poll_t (*tx_poll)(struct wwan_port *port, struct file *filp,
64 			    poll_table *wait);
65 };
66 
67 /** struct wwan_port_caps - The WWAN port capbilities
68  * @frag_len: WWAN port TX fragments length
69  * @headroom_len: WWAN port TX fragments reserved headroom length
70  */
71 struct wwan_port_caps {
72 	size_t frag_len;
73 	unsigned int headroom_len;
74 };
75 
76 /**
77  * wwan_create_port - Add a new WWAN port
78  * @parent: Device to use as parent and shared by all WWAN ports
79  * @type: WWAN port type
80  * @ops: WWAN port operations
81  * @caps: WWAN port capabilities
82  * @drvdata: Pointer to caller driver data
83  *
84  * Allocate and register a new WWAN port. The port will be automatically exposed
85  * to user as a character device and attached to the right virtual WWAN device,
86  * based on the parent pointer. The parent pointer is the device shared by all
87  * components of a same WWAN modem (e.g. USB dev, PCI dev, MHI controller...).
88  *
89  * drvdata will be placed in the WWAN port device driver data and can be
90  * retrieved with wwan_port_get_drvdata().
91  *
92  * This function must be balanced with a call to wwan_remove_port().
93  *
94  * Returns a valid pointer to wwan_port on success or PTR_ERR on failure
95  */
96 struct wwan_port *wwan_create_port(struct device *parent,
97 				   enum wwan_port_type type,
98 				   const struct wwan_port_ops *ops,
99 				   struct wwan_port_caps *caps,
100 				   void *drvdata);
101 
102 /**
103  * wwan_remove_port - Remove a WWAN port
104  * @port: WWAN port to remove
105  *
106  * Remove a previously created port.
107  */
108 void wwan_remove_port(struct wwan_port *port);
109 
110 /**
111  * wwan_port_rx - Receive data from the WWAN port
112  * @port: WWAN port for which data is received
113  * @skb: Pointer to the rx buffer
114  *
115  * A port driver calls this function upon data reception (MBIM, AT...).
116  */
117 void wwan_port_rx(struct wwan_port *port, struct sk_buff *skb);
118 
119 /**
120  * wwan_port_txoff - Stop TX on WWAN port
121  * @port: WWAN port for which TX must be stopped
122  *
123  * Used for TX flow control, a port driver calls this function to indicate TX
124  * is temporary unavailable (e.g. due to ring buffer fullness).
125  */
126 void wwan_port_txoff(struct wwan_port *port);
127 
128 
129 /**
130  * wwan_port_txon - Restart TX on WWAN port
131  * @port: WWAN port for which TX must be restarted
132  *
133  * Used for TX flow control, a port driver calls this function to indicate TX
134  * is available again.
135  */
136 void wwan_port_txon(struct wwan_port *port);
137 
138 /**
139  * wwan_port_get_drvdata - Retrieve driver data from a WWAN port
140  * @port: Related WWAN port
141  */
142 void *wwan_port_get_drvdata(struct wwan_port *port);
143 
144 /**
145  * struct wwan_netdev_priv - WWAN core network device private data
146  * @link_id: WWAN device data link id
147  * @drv_priv: driver private data area, size is determined in &wwan_ops
148  */
149 struct wwan_netdev_priv {
150 	u32 link_id;
151 
152 	/* must be last */
153 	u8 drv_priv[] __aligned(sizeof(void *));
154 };
155 
wwan_netdev_drvpriv(struct net_device * dev)156 static inline void *wwan_netdev_drvpriv(struct net_device *dev)
157 {
158 	return ((struct wwan_netdev_priv *)netdev_priv(dev))->drv_priv;
159 }
160 
161 /*
162  * Used to indicate that the WWAN core should not create a default network
163  * link.
164  */
165 #define WWAN_NO_DEFAULT_LINK		U32_MAX
166 
167 /**
168  * struct wwan_ops - WWAN device ops
169  * @priv_size: size of private netdev data area
170  * @setup: set up a new netdev
171  * @newlink: register the new netdev
172  * @dellink: remove the given netdev
173  */
174 struct wwan_ops {
175 	unsigned int priv_size;
176 	void (*setup)(struct net_device *dev);
177 	int (*newlink)(void *ctxt, struct net_device *dev,
178 		       u32 if_id, struct netlink_ext_ack *extack);
179 	void (*dellink)(void *ctxt, struct net_device *dev,
180 			struct list_head *head);
181 };
182 
183 int wwan_register_ops(struct device *parent, const struct wwan_ops *ops,
184 		      void *ctxt, u32 def_link_id);
185 
186 void wwan_unregister_ops(struct device *parent);
187 
188 #ifdef CONFIG_WWAN_DEBUGFS
189 struct dentry *wwan_get_debugfs_dir(struct device *parent);
190 void wwan_put_debugfs_dir(struct dentry *dir);
191 #else
wwan_get_debugfs_dir(struct device * parent)192 static inline struct dentry *wwan_get_debugfs_dir(struct device *parent)
193 {
194 	return ERR_PTR(-ENODEV);
195 }
wwan_put_debugfs_dir(struct dentry * dir)196 static inline void wwan_put_debugfs_dir(struct dentry *dir) {}
197 #endif
198 
199 #endif /* __WWAN_H */
200