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op-rfkill.c
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1 /*
2  * Linux WiMAX
3  * RF-kill framework integration
4  *
5  *
6  * Copyright (C) 2008 Intel Corporation <[email protected]>
7  * Inaky Perez-Gonzalez <[email protected]>
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License version
11  * 2 as published by the Free Software Foundation.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
21  * 02110-1301, USA.
22  *
23  *
24  * This integrates into the Linux Kernel rfkill susbystem so that the
25  * drivers just have to do the bare minimal work, which is providing a
26  * method to set the software RF-Kill switch and to report changes in
27  * the software and hardware switch status.
28  *
29  * A non-polled generic rfkill device is embedded into the WiMAX
30  * subsystem's representation of a device.
31  *
32  * FIXME: Need polled support? Let drivers provide a poll routine
33  * and hand it to rfkill ops then?
34  *
35  * All device drivers have to do is after wimax_dev_init(), call
36  * wimax_report_rfkill_hw() and wimax_report_rfkill_sw() to update
37  * initial state and then every time it changes. See wimax.h:struct
38  * wimax_dev for more information.
39  *
40  * ROADMAP
41  *
42  * wimax_gnl_doit_rfkill() User space calling wimax_rfkill()
43  * wimax_rfkill() Kernel calling wimax_rfkill()
44  * __wimax_rf_toggle_radio()
45  *
46  * wimax_rfkill_set_radio_block() RF-Kill subsystem calling
47  * __wimax_rf_toggle_radio()
48  *
49  * __wimax_rf_toggle_radio()
50  * wimax_dev->op_rfkill_sw_toggle() Driver backend
51  * __wimax_state_change()
52  *
53  * wimax_report_rfkill_sw() Driver reports state change
54  * __wimax_state_change()
55  *
56  * wimax_report_rfkill_hw() Driver reports state change
57  * __wimax_state_change()
58  *
59  * wimax_rfkill_add() Initialize/shutdown rfkill support
60  * wimax_rfkill_rm() [called by wimax_dev_add/rm()]
61  */
62 
63 #include <net/wimax.h>
64 #include <net/genetlink.h>
65 #include <linux/wimax.h>
66 #include <linux/security.h>
67 #include <linux/rfkill.h>
68 #include <linux/export.h>
69 #include "wimax-internal.h"
70 
71 #define D_SUBMODULE op_rfkill
72 #include "debug-levels.h"
73 
94  enum wimax_rf_state state)
95 {
96  int result;
97  struct device *dev = wimax_dev_to_dev(wimax_dev);
98  enum wimax_st wimax_state;
99 
100  d_fnstart(3, dev, "(wimax_dev %p state %u)\n", wimax_dev, state);
101  BUG_ON(state == WIMAX_RF_QUERY);
102  BUG_ON(state != WIMAX_RF_ON && state != WIMAX_RF_OFF);
103 
104  mutex_lock(&wimax_dev->mutex);
105  result = wimax_dev_is_ready(wimax_dev);
106  if (result < 0)
107  goto error_not_ready;
108 
109  if (state != wimax_dev->rf_hw) {
110  wimax_dev->rf_hw = state;
111  if (wimax_dev->rf_hw == WIMAX_RF_ON &&
112  wimax_dev->rf_sw == WIMAX_RF_ON)
113  wimax_state = WIMAX_ST_READY;
114  else
115  wimax_state = WIMAX_ST_RADIO_OFF;
116 
117  result = rfkill_set_hw_state(wimax_dev->rfkill,
118  state == WIMAX_RF_OFF);
119 
120  __wimax_state_change(wimax_dev, wimax_state);
121  }
122 error_not_ready:
123  mutex_unlock(&wimax_dev->mutex);
124  d_fnend(3, dev, "(wimax_dev %p state %u) = void [%d]\n",
125  wimax_dev, state, result);
126 }
128 
129 
150  enum wimax_rf_state state)
151 {
152  int result;
153  struct device *dev = wimax_dev_to_dev(wimax_dev);
154  enum wimax_st wimax_state;
155 
156  d_fnstart(3, dev, "(wimax_dev %p state %u)\n", wimax_dev, state);
157  BUG_ON(state == WIMAX_RF_QUERY);
158  BUG_ON(state != WIMAX_RF_ON && state != WIMAX_RF_OFF);
159 
160  mutex_lock(&wimax_dev->mutex);
161  result = wimax_dev_is_ready(wimax_dev);
162  if (result < 0)
163  goto error_not_ready;
164 
165  if (state != wimax_dev->rf_sw) {
166  wimax_dev->rf_sw = state;
167  if (wimax_dev->rf_hw == WIMAX_RF_ON &&
168  wimax_dev->rf_sw == WIMAX_RF_ON)
169  wimax_state = WIMAX_ST_READY;
170  else
171  wimax_state = WIMAX_ST_RADIO_OFF;
172  __wimax_state_change(wimax_dev, wimax_state);
173  rfkill_set_sw_state(wimax_dev->rfkill, state == WIMAX_RF_OFF);
174  }
175 error_not_ready:
176  mutex_unlock(&wimax_dev->mutex);
177  d_fnend(3, dev, "(wimax_dev %p state %u) = void [%d]\n",
178  wimax_dev, state, result);
179 }
181 
182 
183 /*
184  * Callback for the RF Kill toggle operation
185  *
186  * This function is called by:
187  *
188  * - The rfkill subsystem when the RF-Kill key is pressed in the
189  * hardware and the driver notifies through
190  * wimax_report_rfkill_hw(). The rfkill subsystem ends up calling back
191  * here so the software RF Kill switch state is changed to reflect
192  * the hardware switch state.
193  *
194  * - When the user sets the state through sysfs' rfkill/state file
195  *
196  * - When the user calls wimax_rfkill().
197  *
198  * This call blocks!
199  *
200  * WARNING! When we call rfkill_unregister(), this will be called with
201  * state 0!
202  *
203  * WARNING: wimax_dev must be locked
204  */
205 static
206 int __wimax_rf_toggle_radio(struct wimax_dev *wimax_dev,
207  enum wimax_rf_state state)
208 {
209  int result = 0;
210  struct device *dev = wimax_dev_to_dev(wimax_dev);
211  enum wimax_st wimax_state;
212 
213  might_sleep();
214  d_fnstart(3, dev, "(wimax_dev %p state %u)\n", wimax_dev, state);
215  if (wimax_dev->rf_sw == state)
216  goto out_no_change;
217  if (wimax_dev->op_rfkill_sw_toggle != NULL)
218  result = wimax_dev->op_rfkill_sw_toggle(wimax_dev, state);
219  else if (state == WIMAX_RF_OFF) /* No op? can't turn off */
220  result = -ENXIO;
221  else /* No op? can turn on */
222  result = 0; /* should never happen tho */
223  if (result >= 0) {
224  result = 0;
225  wimax_dev->rf_sw = state;
226  wimax_state = state == WIMAX_RF_ON ?
228  __wimax_state_change(wimax_dev, wimax_state);
229  }
230 out_no_change:
231  d_fnend(3, dev, "(wimax_dev %p state %u) = %d\n",
232  wimax_dev, state, result);
233  return result;
234 }
235 
236 
237 /*
238  * Translate from rfkill state to wimax state
239  *
240  * NOTE: Special state handling rules here
241  *
242  * Just pretend the call didn't happen if we are in a state where
243  * we know for sure it cannot be handled (WIMAX_ST_DOWN or
244  * __WIMAX_ST_QUIESCING). rfkill() needs it to register and
245  * unregister, as it will run this path.
246  *
247  * NOTE: This call will block until the operation is completed.
248  */
249 static int wimax_rfkill_set_radio_block(void *data, bool blocked)
250 {
251  int result;
252  struct wimax_dev *wimax_dev = data;
253  struct device *dev = wimax_dev_to_dev(wimax_dev);
254  enum wimax_rf_state rf_state;
255 
256  d_fnstart(3, dev, "(wimax_dev %p blocked %u)\n", wimax_dev, blocked);
257  rf_state = WIMAX_RF_ON;
258  if (blocked)
259  rf_state = WIMAX_RF_OFF;
260  mutex_lock(&wimax_dev->mutex);
261  if (wimax_dev->state <= __WIMAX_ST_QUIESCING)
262  result = 0;
263  else
264  result = __wimax_rf_toggle_radio(wimax_dev, rf_state);
265  mutex_unlock(&wimax_dev->mutex);
266  d_fnend(3, dev, "(wimax_dev %p blocked %u) = %d\n",
267  wimax_dev, blocked, result);
268  return result;
269 }
270 
271 static const struct rfkill_ops wimax_rfkill_ops = {
272  .set_block = wimax_rfkill_set_radio_block,
273 };
274 
301 int wimax_rfkill(struct wimax_dev *wimax_dev, enum wimax_rf_state state)
302 {
303  int result;
304  struct device *dev = wimax_dev_to_dev(wimax_dev);
305 
306  d_fnstart(3, dev, "(wimax_dev %p state %u)\n", wimax_dev, state);
307  mutex_lock(&wimax_dev->mutex);
308  result = wimax_dev_is_ready(wimax_dev);
309  if (result < 0) {
310  /* While initializing, < 1.4.3 wimax-tools versions use
311  * this call to check if the device is a valid WiMAX
312  * device; so we allow it to proceed always,
313  * considering the radios are all off. */
314  if (result == -ENOMEDIUM && state == WIMAX_RF_QUERY)
315  result = WIMAX_RF_OFF << 1 | WIMAX_RF_OFF;
316  goto error_not_ready;
317  }
318  switch (state) {
319  case WIMAX_RF_ON:
320  case WIMAX_RF_OFF:
321  result = __wimax_rf_toggle_radio(wimax_dev, state);
322  if (result < 0)
323  goto error;
324  rfkill_set_sw_state(wimax_dev->rfkill, state == WIMAX_RF_OFF);
325  break;
326  case WIMAX_RF_QUERY:
327  break;
328  default:
329  result = -EINVAL;
330  goto error;
331  }
332  result = wimax_dev->rf_sw << 1 | wimax_dev->rf_hw;
333 error:
334 error_not_ready:
335  mutex_unlock(&wimax_dev->mutex);
336  d_fnend(3, dev, "(wimax_dev %p state %u) = %d\n",
337  wimax_dev, state, result);
338  return result;
339 }
341 
342 
343 /*
344  * Register a new WiMAX device's RF Kill support
345  *
346  * WARNING: wimax_dev->mutex must be unlocked
347  */
348 int wimax_rfkill_add(struct wimax_dev *wimax_dev)
349 {
350  int result;
351  struct rfkill *rfkill;
352  struct device *dev = wimax_dev_to_dev(wimax_dev);
353 
354  d_fnstart(3, dev, "(wimax_dev %p)\n", wimax_dev);
355  /* Initialize RF Kill */
356  result = -ENOMEM;
357  rfkill = rfkill_alloc(wimax_dev->name, dev, RFKILL_TYPE_WIMAX,
358  &wimax_rfkill_ops, wimax_dev);
359  if (rfkill == NULL)
360  goto error_rfkill_allocate;
361 
362  d_printf(1, dev, "rfkill %p\n", rfkill);
363 
364  wimax_dev->rfkill = rfkill;
365 
366  rfkill_init_sw_state(rfkill, 1);
367  result = rfkill_register(wimax_dev->rfkill);
368  if (result < 0)
369  goto error_rfkill_register;
370 
371  /* If there is no SW toggle op, SW RFKill is always on */
372  if (wimax_dev->op_rfkill_sw_toggle == NULL)
373  wimax_dev->rf_sw = WIMAX_RF_ON;
374 
375  d_fnend(3, dev, "(wimax_dev %p) = 0\n", wimax_dev);
376  return 0;
377 
378 error_rfkill_register:
379  rfkill_destroy(wimax_dev->rfkill);
380 error_rfkill_allocate:
381  d_fnend(3, dev, "(wimax_dev %p) = %d\n", wimax_dev, result);
382  return result;
383 }
384 
385 
386 /*
387  * Deregister a WiMAX device's RF Kill support
388  *
389  * Ick, we can't call rfkill_free() after rfkill_unregister()...oh
390  * well.
391  *
392  * WARNING: wimax_dev->mutex must be unlocked
393  */
394 void wimax_rfkill_rm(struct wimax_dev *wimax_dev)
395 {
396  struct device *dev = wimax_dev_to_dev(wimax_dev);
397  d_fnstart(3, dev, "(wimax_dev %p)\n", wimax_dev);
398  rfkill_unregister(wimax_dev->rfkill);
399  rfkill_destroy(wimax_dev->rfkill);
400  d_fnend(3, dev, "(wimax_dev %p)\n", wimax_dev);
401 }
402 
403 
404 /*
405  * Exporting to user space over generic netlink
406  *
407  * Parse the rfkill command from user space, return a combination
408  * value that describe the states of the different toggles.
409  *
410  * Only one attribute: the new state requested (on, off or no change,
411  * just query).
412  */
413 
414 static const struct nla_policy wimax_gnl_rfkill_policy[WIMAX_GNL_ATTR_MAX + 1] = {
416  .type = NLA_U32,
417  },
419  .type = NLA_U32 /* enum wimax_rf_state */
420  },
421 };
422 
423 
424 static
425 int wimax_gnl_doit_rfkill(struct sk_buff *skb, struct genl_info *info)
426 {
427  int result, ifindex;
428  struct wimax_dev *wimax_dev;
429  struct device *dev;
431 
432  d_fnstart(3, NULL, "(skb %p info %p)\n", skb, info);
433  result = -ENODEV;
434  if (info->attrs[WIMAX_GNL_RFKILL_IFIDX] == NULL) {
435  printk(KERN_ERR "WIMAX_GNL_OP_RFKILL: can't find IFIDX "
436  "attribute\n");
437  goto error_no_wimax_dev;
438  }
439  ifindex = nla_get_u32(info->attrs[WIMAX_GNL_RFKILL_IFIDX]);
440  wimax_dev = wimax_dev_get_by_genl_info(info, ifindex);
441  if (wimax_dev == NULL)
442  goto error_no_wimax_dev;
443  dev = wimax_dev_to_dev(wimax_dev);
444  result = -EINVAL;
445  if (info->attrs[WIMAX_GNL_RFKILL_STATE] == NULL) {
446  dev_err(dev, "WIMAX_GNL_RFKILL: can't find RFKILL_STATE "
447  "attribute\n");
448  goto error_no_pid;
449  }
450  new_state = nla_get_u32(info->attrs[WIMAX_GNL_RFKILL_STATE]);
451 
452  /* Execute the operation and send the result back to user space */
453  result = wimax_rfkill(wimax_dev, new_state);
454 error_no_pid:
455  dev_put(wimax_dev->net_dev);
456 error_no_wimax_dev:
457  d_fnend(3, NULL, "(skb %p info %p) = %d\n", skb, info, result);
458  return result;
459 }
460 
461 
463  .cmd = WIMAX_GNL_OP_RFKILL,
464  .flags = GENL_ADMIN_PERM,
465  .policy = wimax_gnl_rfkill_policy,
466  .doit = wimax_gnl_doit_rfkill,
467  .dumpit = NULL,
468 };
469