1STRUCT WIMAX_DEV(9) Linux Networking STRUCT WIMAX_DEV(9)
2
6 struct_wimax_dev - Generic WiMAX device
7
9 struct wimax_dev {
10 struct net_device * net_dev;
11 struct list_head id_table_node;
12 struct mutex mutex;
13 struct mutex mutex_reset;
14 enum wimax_st state;
15 int (* op_msg_from_user) (struct wimax_dev *wimax_dev,const char *,const void *, size_t,const struct genl_info *info);
16 int (* op_rfkill_sw_toggle) (struct wimax_dev *wimax_dev,enum wimax_rf_state);
17 int (* op_reset) (struct wimax_dev *wimax_dev);
18 struct rfkill * rfkill;
19 unsigned int rf_hw;
20 unsigned int rf_sw;
21 char name[32];
22 struct dentry * debugfs_dentry;
23 };
24
26 net_dev
27 [fill] Pointer to the struct net_device this WiMAX device
28 implements.
29 id_table_node
31 [private] link to the list of wimax devices kept by id-table.c.
32 Protected by it's own spinlock.
33 mutex
35 [private] Serializes all concurrent access and execution of
36 operations.
37 mutex_reset
39 [private] Serializes reset operations. Needs to be a different
40 mutex because as part of the reset operation, the driver has to
41 call back into the stack to do things such as state change, that
42 require wimax_dev->mutex.
43 state
45 [private] Current state of the WiMAX device.
46 op_msg_from_user
48 [fill] Driver-specific operation to handle a raw message from user
49 space to the driver. The driver can send messages to user space
50 using with wimax_msg_to_user.
51 op_rfkill_sw_toggle
53 [fill] Driver-specific operation to act on userspace (or any other
54 agent) requesting the WiMAX device to change the RF Kill software
55 switch (WIMAX_RF_ON or WIMAX_RF_OFF). If such hardware support is
56 not present, it is assumed the radio cannot be switched off and it
57 is always on (and the stack will error out when trying to switch it
58 off). In such case, this function pointer can be left as NULL.
59 op_reset
61 [fill] Driver specific operation to reset the device. This
62 operation should always attempt first a warm reset that does not
63 disconnect the device from the bus and return 0. If that fails, it
64 should resort to some sort of cold or bus reset (even if it implies
65 a bus disconnection and device disappearance). In that case,
66 -ENODEV should be returned to indicate the device is gone. This
67 operation has to be synchronous, and return only when the reset is
68 complete. In case of having had to resort to bus/cold reset
69 implying a device disconnection, the call is allowed to return
70 inmediately.
71 rfkill
73 [private] integration into the RF-Kill infrastructure.
74 rf_hw
76 [private] State of the hardware radio switch (OFF/ON)
77 rf_sw
79 [private] State of the software radio switch (OFF/ON)
80 name[32]
82 [fill] A way to identify this device. We need to register a name
83 with many subsystems (rfkill, workqueue creation, etc). We can't
84 use the network device name as that might change and in some
85 instances we don't know it yet (until we don't call
86 register_netdev). So we generate an unique one using the driver
87 name and device bus id, place it here and use it across the board.
88 Recommended naming: DRIVERNAME-BUSNAME:BUSID (dev->bus->name,
89 dev->bus_id).
90 debugfs_dentry
92 [private] Used to hook up a debugfs entry. This shows up in the
93 debugfs root as wimax\:DEVICENAME.
94
96 wimax_dev->mutex is NOT locked when this op is being called; however,
97 wimax_dev->mutex_reset IS locked to ensure serialization of calls to
98 wimax_reset. See wimax_reset's documentation.
99
101 This structure defines a common interface to access all WiMAX devices
102 from different vendors and provides a common API as well as a free-form
103 device-specific messaging channel.
104
106 1. Embed a struct wimax_dev at *the beginning* the network device
107 structure so that netdev_priv points to it.
108 2. memset it to zero
110 3. Initialize with wimax_dev_init. This will leave the WiMAX device in
112 the __WIMAX_ST_NULL state.
113 4. Fill all the fields marked with [fill]; once called wimax_dev_add,
115 those fields CANNOT be modified.
116 5. Call wimax_dev_add *after* registering the network device. This will
118 leave the WiMAX device in the WIMAX_ST_DOWN state. Protect the driver's
119 net_device->open against succeeding if the wimax device state is lower
120 than WIMAX_ST_DOWN.
121 6. Select when the device is going to be turned on/initialized; for
123 example, it could be initialized on 'ifconfig up' (when the netdev op
124 'open' is called on the driver).
125 When the device is initialized (at `ifconfig up` time, or right after
127 calling wimax_dev_add from _probe, make sure the following steps are
128 taken
129 a. Move the device to WIMAX_ST_UNINITIALIZED. This is needed so some
131 API calls that shouldn't work until the device is ready can be blocked.
132 b. Initialize the device. Make sure to turn the SW radio switch off and
134 move the device to state WIMAX_ST_RADIO_OFF when done. When just
135 initialized, a device should be left in RADIO OFF state until user
136 space devices to turn it on.
137 c. Query the device for the state of the hardware rfkill switch and
139 call wimax_rfkill_report_hw and wimax_rfkill_report_sw as needed. See
140 below.
141 wimax_dev_rm undoes before unregistering the network device. Once
143 wimax_dev_add is called, the driver can get called on the
144 wimax_dev->op_* function pointers
145
147 The stack provides a mutex for each device that will disallow API calls
148 happening concurrently; thus, op calls into the driver through the
149 wimax_dev->op*() function pointers will always be serialized and
150 *never* concurrent.
151 For locking, take wimax_dev->mutex is taken; (most) operations in the
153 API have to check for wimax_dev_is_ready to return 0 before continuing
154 (this is done internally).
155
157 The WiMAX device is reference counted by the associated network device.
158 The only operation that can be used to reference the device is
159 wimax_dev_get_by_genl_info, and the reference it acquires has to be
160 released with dev_put(wimax_dev->net_dev).
161
163 At startup, both HW and SW radio switchess are assumed to be off.
164 At initialization time [after calling wimax_dev_add], have the driver
166 query the device for the status of the software and hardware RF kill
167 switches and call wimax_report_rfkill_hw and wimax_rfkill_report_sw to
168 indicate their state. If any is missing, just call it to indicate it is
169 ON (radio always on).
170 Whenever the driver detects a change in the state of the RF kill
172 switches, it should call wimax_report_rfkill_hw or
173 wimax_report_rfkill_sw to report it to the stack.
174
176Kernel Hackers Manual 3.10 June 2019 STRUCT WIMAX_DEV(9)