1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Support for generic time stamping devices on MII buses.
4  * Copyright (C) 2018 Richard Cochran <richardcochran@gmail.com>
5  */
6 #ifndef _LINUX_MII_TIMESTAMPER_H
7 #define _LINUX_MII_TIMESTAMPER_H
8 
9 #include <linux/device.h>
10 #include <linux/ethtool.h>
11 #include <linux/skbuff.h>
12 
13 struct phy_device;
14 
15 /**
16  * struct mii_timestamper - Callback interface to MII time stamping devices.
17  *
18  * @rxtstamp:	Requests a Rx timestamp for 'skb'.  If the skb is accepted,
19  *		the MII time stamping device promises to deliver it using
20  *		netif_rx() as soon as a timestamp becomes available. One of
21  *		the PTP_CLASS_ values is passed in 'type'.  The function
22  *		must return true if the skb is accepted for delivery.
23  *
24  * @txtstamp:	Requests a Tx timestamp for 'skb'.  The MII time stamping
25  *		device promises to deliver it using skb_complete_tx_timestamp()
26  *		as soon as a timestamp becomes available. One of the PTP_CLASS_
27  *		values is passed in 'type'.
28  *
29  * @hwtstamp:	Handles SIOCSHWTSTAMP ioctl for hardware time stamping.
30  *
31  * @link_state: Allows the device to respond to changes in the link
32  *		state.  The caller invokes this function while holding
33  *		the phy_device mutex.
34  *
35  * @ts_info:	Handles ethtool queries for hardware time stamping.
36  * @device:	Remembers the device to which the instance belongs.
37  *
38  * Drivers for PHY time stamping devices should embed their
39  * mii_timestamper within a private structure, obtaining a reference
40  * to it using container_of().
41  *
42  * Drivers for non-PHY time stamping devices should return a pointer
43  * to a mii_timestamper from the probe_channel() callback of their
44  * mii_timestamping_ctrl interface.
45  */
46 struct mii_timestamper {
47 	bool (*rxtstamp)(struct mii_timestamper *mii_ts,
48 			 struct sk_buff *skb, int type);
49 
50 	void (*txtstamp)(struct mii_timestamper *mii_ts,
51 			 struct sk_buff *skb, int type);
52 
53 	int  (*hwtstamp)(struct mii_timestamper *mii_ts,
54 			 struct ifreq *ifreq);
55 
56 	void (*link_state)(struct mii_timestamper *mii_ts,
57 			   struct phy_device *phydev);
58 
59 	int  (*ts_info)(struct mii_timestamper *mii_ts,
60 			struct ethtool_ts_info *ts_info);
61 
62 	struct device *device;
63 };
64 
65 /**
66  * struct mii_timestamping_ctrl - MII time stamping controller interface.
67  *
68  * @probe_channel:	Callback into the controller driver announcing the
69  *			presence of the 'port' channel.  The 'device' field
70  *			had been passed to register_mii_tstamp_controller().
71  *			The driver must return either a pointer to a valid
72  *			MII timestamper instance or PTR_ERR.
73  *
74  * @release_channel:	Releases an instance obtained via .probe_channel.
75  */
76 struct mii_timestamping_ctrl {
77 	struct mii_timestamper *(*probe_channel)(struct device *device,
78 						 unsigned int port);
79 	void (*release_channel)(struct device *device,
80 				struct mii_timestamper *mii_ts);
81 };
82 
83 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
84 
85 int register_mii_tstamp_controller(struct device *device,
86 				   struct mii_timestamping_ctrl *ctrl);
87 
88 void unregister_mii_tstamp_controller(struct device *device);
89 
90 struct mii_timestamper *register_mii_timestamper(struct device_node *node,
91 						 unsigned int port);
92 
93 void unregister_mii_timestamper(struct mii_timestamper *mii_ts);
94 
95 #else
96 
97 static inline
register_mii_tstamp_controller(struct device * device,struct mii_timestamping_ctrl * ctrl)98 int register_mii_tstamp_controller(struct device *device,
99 				   struct mii_timestamping_ctrl *ctrl)
100 {
101 	return -EOPNOTSUPP;
102 }
103 
unregister_mii_tstamp_controller(struct device * device)104 static inline void unregister_mii_tstamp_controller(struct device *device)
105 {
106 }
107 
108 static inline
register_mii_timestamper(struct device_node * node,unsigned int port)109 struct mii_timestamper *register_mii_timestamper(struct device_node *node,
110 						 unsigned int port)
111 {
112 	return NULL;
113 }
114 
unregister_mii_timestamper(struct mii_timestamper * mii_ts)115 static inline void unregister_mii_timestamper(struct mii_timestamper *mii_ts)
116 {
117 }
118 
119 #endif
120 
121 #endif
122