1 /*
2  * Intel Wireless WiMAX Connection 2400m
3  * Linux driver model glue for USB device, reset & fw upload
4  *
5  *
6  * Copyright (C) 2007-2008 Intel Corporation <linux-wimax@intel.com>
7  * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
8  * Yanir Lubetkin <yanirx.lubetkin@intel.com>
9  *
10  * This program is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU General Public License version
12  * 2 as published by the Free Software Foundation.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
22  * 02110-1301, USA.
23  *
24  *
25  * See i2400m-usb.h for a general description of this driver.
26  *
27  * This file implements driver model glue, and hook ups for the
28  * generic driver to implement the bus-specific functions (device
29  * communication setup/tear down, firmware upload and resetting).
30  *
31  * ROADMAP
32  *
33  * i2400mu_probe()
34  *   alloc_netdev()...
35  *     i2400mu_netdev_setup()
36  *       i2400mu_init()
37  *       i2400m_netdev_setup()
38  *   i2400m_setup()...
39  *
40  * i2400mu_disconnect
41  *   i2400m_release()
42  *   free_netdev()
43  *
44  * i2400mu_suspend()
45  *   i2400m_cmd_enter_powersave()
46  *   i2400mu_notification_release()
47  *
48  * i2400mu_resume()
49  *   i2400mu_notification_setup()
50  *
51  * i2400mu_bus_dev_start()        Called by i2400m_dev_start() [who is
52  *   i2400mu_tx_setup()           called by i2400m_setup()]
53  *   i2400mu_rx_setup()
54  *   i2400mu_notification_setup()
55  *
56  * i2400mu_bus_dev_stop()         Called by i2400m_dev_stop() [who is
57  *   i2400mu_notification_release()  called by i2400m_release()]
58  *   i2400mu_rx_release()
59  *   i2400mu_tx_release()
60  *
61  * i2400mu_bus_reset()            Called by i2400m_reset
62  *   __i2400mu_reset()
63  *     __i2400mu_send_barker()
64  *   usb_reset_device()
65  */
66 #include "i2400m-usb.h"
67 #include <linux/wimax/i2400m.h>
68 #include <linux/debugfs.h>
69 #include <linux/slab.h>
70 #include <linux/module.h>
71 
72 
73 #define D_SUBMODULE usb
74 #include "usb-debug-levels.h"
75 
76 static char i2400mu_debug_params[128];
77 module_param_string(debug, i2400mu_debug_params, sizeof(i2400mu_debug_params),
78 		    0644);
79 MODULE_PARM_DESC(debug,
80 		 "String of space-separated NAME:VALUE pairs, where NAMEs "
81 		 "are the different debug submodules and VALUE are the "
82 		 "initial debug value to set.");
83 
84 /* Our firmware file name */
85 static const char *i2400mu_bus_fw_names_5x50[] = {
86 #define I2400MU_FW_FILE_NAME_v1_5 "i2400m-fw-usb-1.5.sbcf"
87 	I2400MU_FW_FILE_NAME_v1_5,
88 #define I2400MU_FW_FILE_NAME_v1_4 "i2400m-fw-usb-1.4.sbcf"
89 	I2400MU_FW_FILE_NAME_v1_4,
90 	NULL,
91 };
92 
93 
94 static const char *i2400mu_bus_fw_names_6050[] = {
95 #define I6050U_FW_FILE_NAME_v1_5 "i6050-fw-usb-1.5.sbcf"
96 	I6050U_FW_FILE_NAME_v1_5,
97 	NULL,
98 };
99 
100 
101 static
i2400mu_bus_dev_start(struct i2400m * i2400m)102 int i2400mu_bus_dev_start(struct i2400m *i2400m)
103 {
104 	int result;
105 	struct i2400mu *i2400mu = container_of(i2400m, struct i2400mu, i2400m);
106 	struct device *dev = &i2400mu->usb_iface->dev;
107 
108 	d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
109 	result = i2400mu_tx_setup(i2400mu);
110 	if (result < 0)
111 		goto error_usb_tx_setup;
112 	result = i2400mu_rx_setup(i2400mu);
113 	if (result < 0)
114 		goto error_usb_rx_setup;
115 	result = i2400mu_notification_setup(i2400mu);
116 	if (result < 0)
117 		goto error_notif_setup;
118 	d_fnend(3, dev, "(i2400m %p) = %d\n", i2400m, result);
119 	return result;
120 
121 error_notif_setup:
122 	i2400mu_rx_release(i2400mu);
123 error_usb_rx_setup:
124 	i2400mu_tx_release(i2400mu);
125 error_usb_tx_setup:
126 	d_fnend(3, dev, "(i2400m %p) = void\n", i2400m);
127 	return result;
128 }
129 
130 
131 static
i2400mu_bus_dev_stop(struct i2400m * i2400m)132 void i2400mu_bus_dev_stop(struct i2400m *i2400m)
133 {
134 	struct i2400mu *i2400mu = container_of(i2400m, struct i2400mu, i2400m);
135 	struct device *dev = &i2400mu->usb_iface->dev;
136 
137 	d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
138 	i2400mu_notification_release(i2400mu);
139 	i2400mu_rx_release(i2400mu);
140 	i2400mu_tx_release(i2400mu);
141 	d_fnend(3, dev, "(i2400m %p) = void\n", i2400m);
142 }
143 
144 
145 /*
146  * Sends a barker buffer to the device
147  *
148  * This helper will allocate a kmalloced buffer and use it to transmit
149  * (then free it). Reason for this is that other arches cannot use
150  * stack/vmalloc/text areas for DMA transfers.
151  *
152  * Error recovery here is simpler: anything is considered a hard error
153  * and will move the reset code to use a last-resort bus-based reset.
154  */
155 static
__i2400mu_send_barker(struct i2400mu * i2400mu,const __le32 * barker,size_t barker_size,unsigned endpoint)156 int __i2400mu_send_barker(struct i2400mu *i2400mu,
157 			  const __le32 *barker,
158 			  size_t barker_size,
159 			  unsigned endpoint)
160 {
161 	struct usb_endpoint_descriptor *epd = NULL;
162 	int pipe, actual_len, ret;
163 	struct device *dev = &i2400mu->usb_iface->dev;
164 	void *buffer;
165 	int do_autopm = 1;
166 
167 	ret = usb_autopm_get_interface(i2400mu->usb_iface);
168 	if (ret < 0) {
169 		dev_err(dev, "RESET: can't get autopm: %d\n", ret);
170 		do_autopm = 0;
171 	}
172 	ret = -ENOMEM;
173 	buffer = kmalloc(barker_size, GFP_KERNEL);
174 	if (buffer == NULL)
175 		goto error_kzalloc;
176 	epd = usb_get_epd(i2400mu->usb_iface, endpoint);
177 	pipe = usb_sndbulkpipe(i2400mu->usb_dev, epd->bEndpointAddress);
178 	memcpy(buffer, barker, barker_size);
179 retry:
180 	ret = usb_bulk_msg(i2400mu->usb_dev, pipe, buffer, barker_size,
181 			   &actual_len, 200);
182 	switch (ret) {
183 	case 0:
184 		if (actual_len != barker_size) {	/* Too short? drop it */
185 			dev_err(dev, "E: %s: short write (%d B vs %zu "
186 				"expected)\n",
187 				__func__, actual_len, barker_size);
188 			ret = -EIO;
189 		}
190 		break;
191 	case -EPIPE:
192 		/*
193 		 * Stall -- maybe the device is choking with our
194 		 * requests. Clear it and give it some time. If they
195 		 * happen to often, it might be another symptom, so we
196 		 * reset.
197 		 *
198 		 * No error handling for usb_clear_halt(0; if it
199 		 * works, the retry works; if it fails, this switch
200 		 * does the error handling for us.
201 		 */
202 		if (edc_inc(&i2400mu->urb_edc,
203 			    10 * EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME)) {
204 			dev_err(dev, "E: %s: too many stalls in "
205 				"URB; resetting device\n", __func__);
206 			usb_queue_reset_device(i2400mu->usb_iface);
207 			/* fallthrough */
208 		} else {
209 			usb_clear_halt(i2400mu->usb_dev, pipe);
210 			msleep(10);	/* give the device some time */
211 			goto retry;
212 		}
213 	case -EINVAL:			/* while removing driver */
214 	case -ENODEV:			/* dev disconnect ... */
215 	case -ENOENT:			/* just ignore it */
216 	case -ESHUTDOWN:		/* and exit */
217 	case -ECONNRESET:
218 		ret = -ESHUTDOWN;
219 		break;
220 	default:			/* Some error? */
221 		if (edc_inc(&i2400mu->urb_edc,
222 			    EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME)) {
223 			dev_err(dev, "E: %s: maximum errors in URB "
224 				"exceeded; resetting device\n",
225 				__func__);
226 			usb_queue_reset_device(i2400mu->usb_iface);
227 		} else {
228 			dev_warn(dev, "W: %s: cannot send URB: %d\n",
229 				 __func__, ret);
230 			goto retry;
231 		}
232 	}
233 	kfree(buffer);
234 error_kzalloc:
235 	if (do_autopm)
236 		usb_autopm_put_interface(i2400mu->usb_iface);
237 	return ret;
238 }
239 
240 
241 /*
242  * Reset a device at different levels (warm, cold or bus)
243  *
244  * @i2400m: device descriptor
245  * @reset_type: soft, warm or bus reset (I2400M_RT_WARM/SOFT/BUS)
246  *
247  * Warm and cold resets get a USB reset if they fail.
248  *
249  * Warm reset:
250  *
251  * The device will be fully reset internally, but won't be
252  * disconnected from the USB bus (so no reenumeration will
253  * happen). Firmware upload will be necessary.
254  *
255  * The device will send a reboot barker in the notification endpoint
256  * that will trigger the driver to reinitialize the state
257  * automatically from notif.c:i2400m_notification_grok() into
258  * i2400m_dev_bootstrap_delayed().
259  *
260  * Cold and bus (USB) reset:
261  *
262  * The device will be fully reset internally, disconnected from the
263  * USB bus an a reenumeration will happen. Firmware upload will be
264  * necessary. Thus, we don't do any locking or struct
265  * reinitialization, as we are going to be fully disconnected and
266  * reenumerated.
267  *
268  * Note we need to return -ENODEV if a warm reset was requested and we
269  * had to resort to a bus reset. See i2400m_op_reset(), wimax_reset()
270  * and wimax_dev->op_reset.
271  *
272  * WARNING: no driver state saved/fixed
273  */
274 static
i2400mu_bus_reset(struct i2400m * i2400m,enum i2400m_reset_type rt)275 int i2400mu_bus_reset(struct i2400m *i2400m, enum i2400m_reset_type rt)
276 {
277 	int result;
278 	struct i2400mu *i2400mu =
279 		container_of(i2400m, struct i2400mu, i2400m);
280 	struct device *dev = i2400m_dev(i2400m);
281 	static const __le32 i2400m_WARM_BOOT_BARKER[4] = {
282 		cpu_to_le32(I2400M_WARM_RESET_BARKER),
283 		cpu_to_le32(I2400M_WARM_RESET_BARKER),
284 		cpu_to_le32(I2400M_WARM_RESET_BARKER),
285 		cpu_to_le32(I2400M_WARM_RESET_BARKER),
286 	};
287 	static const __le32 i2400m_COLD_BOOT_BARKER[4] = {
288 		cpu_to_le32(I2400M_COLD_RESET_BARKER),
289 		cpu_to_le32(I2400M_COLD_RESET_BARKER),
290 		cpu_to_le32(I2400M_COLD_RESET_BARKER),
291 		cpu_to_le32(I2400M_COLD_RESET_BARKER),
292 	};
293 
294 	d_fnstart(3, dev, "(i2400m %p rt %u)\n", i2400m, rt);
295 	if (rt == I2400M_RT_WARM)
296 		result = __i2400mu_send_barker(
297 			i2400mu, i2400m_WARM_BOOT_BARKER,
298 			sizeof(i2400m_WARM_BOOT_BARKER),
299 			i2400mu->endpoint_cfg.bulk_out);
300 	else if (rt == I2400M_RT_COLD)
301 		result = __i2400mu_send_barker(
302 			i2400mu, i2400m_COLD_BOOT_BARKER,
303 			sizeof(i2400m_COLD_BOOT_BARKER),
304 			i2400mu->endpoint_cfg.reset_cold);
305 	else if (rt == I2400M_RT_BUS) {
306 		result = usb_reset_device(i2400mu->usb_dev);
307 		switch (result) {
308 		case 0:
309 		case -EINVAL:	/* device is gone */
310 		case -ENODEV:
311 		case -ENOENT:
312 		case -ESHUTDOWN:
313 			result = 0;
314 			break;	/* We assume the device is disconnected */
315 		default:
316 			dev_err(dev, "USB reset failed (%d), giving up!\n",
317 				result);
318 		}
319 	} else {
320 		result = -EINVAL;	/* shut gcc up in certain arches */
321 		BUG();
322 	}
323 	if (result < 0
324 	    && result != -EINVAL	/* device is gone */
325 	    && rt != I2400M_RT_BUS) {
326 		/*
327 		 * Things failed -- resort to lower level reset, that
328 		 * we queue in another context; the reason for this is
329 		 * that the pre and post reset functionality requires
330 		 * the i2400m->init_mutex; RT_WARM and RT_COLD can
331 		 * come from areas where i2400m->init_mutex is taken.
332 		 */
333 		dev_err(dev, "%s reset failed (%d); trying USB reset\n",
334 			rt == I2400M_RT_WARM ? "warm" : "cold", result);
335 		usb_queue_reset_device(i2400mu->usb_iface);
336 		result = -ENODEV;
337 	}
338 	d_fnend(3, dev, "(i2400m %p rt %u) = %d\n", i2400m, rt, result);
339 	return result;
340 }
341 
342 
343 static
i2400mu_netdev_setup(struct net_device * net_dev)344 void i2400mu_netdev_setup(struct net_device *net_dev)
345 {
346 	struct i2400m *i2400m = net_dev_to_i2400m(net_dev);
347 	struct i2400mu *i2400mu = container_of(i2400m, struct i2400mu, i2400m);
348 	i2400mu_init(i2400mu);
349 	i2400m_netdev_setup(net_dev);
350 }
351 
352 
353 /*
354  * Debug levels control; see debug.h
355  */
356 struct d_level D_LEVEL[] = {
357 	D_SUBMODULE_DEFINE(usb),
358 	D_SUBMODULE_DEFINE(fw),
359 	D_SUBMODULE_DEFINE(notif),
360 	D_SUBMODULE_DEFINE(rx),
361 	D_SUBMODULE_DEFINE(tx),
362 };
363 size_t D_LEVEL_SIZE = ARRAY_SIZE(D_LEVEL);
364 
365 
366 #define __debugfs_register(prefix, name, parent)			\
367 do {									\
368 	result = d_level_register_debugfs(prefix, name, parent);	\
369 	if (result < 0)							\
370 		goto error;						\
371 } while (0)
372 
373 
374 static
i2400mu_debugfs_add(struct i2400mu * i2400mu)375 int i2400mu_debugfs_add(struct i2400mu *i2400mu)
376 {
377 	int result;
378 	struct device *dev = &i2400mu->usb_iface->dev;
379 	struct dentry *dentry = i2400mu->i2400m.wimax_dev.debugfs_dentry;
380 	struct dentry *fd;
381 
382 	dentry = debugfs_create_dir("i2400m-usb", dentry);
383 	result = PTR_ERR(dentry);
384 	if (IS_ERR(dentry)) {
385 		if (result == -ENODEV)
386 			result = 0;	/* No debugfs support */
387 		goto error;
388 	}
389 	i2400mu->debugfs_dentry = dentry;
390 	__debugfs_register("dl_", usb, dentry);
391 	__debugfs_register("dl_", fw, dentry);
392 	__debugfs_register("dl_", notif, dentry);
393 	__debugfs_register("dl_", rx, dentry);
394 	__debugfs_register("dl_", tx, dentry);
395 
396 	/* Don't touch these if you don't know what you are doing */
397 	fd = debugfs_create_u8("rx_size_auto_shrink", 0600, dentry,
398 			       &i2400mu->rx_size_auto_shrink);
399 	result = PTR_ERR(fd);
400 	if (IS_ERR(fd) && result != -ENODEV) {
401 		dev_err(dev, "Can't create debugfs entry "
402 			"rx_size_auto_shrink: %d\n", result);
403 		goto error;
404 	}
405 
406 	fd = debugfs_create_size_t("rx_size", 0600, dentry,
407 				   &i2400mu->rx_size);
408 	result = PTR_ERR(fd);
409 	if (IS_ERR(fd) && result != -ENODEV) {
410 		dev_err(dev, "Can't create debugfs entry "
411 			"rx_size: %d\n", result);
412 		goto error;
413 	}
414 
415 	return 0;
416 
417 error:
418 	debugfs_remove_recursive(i2400mu->debugfs_dentry);
419 	return result;
420 }
421 
422 
423 static struct device_type i2400mu_type = {
424 	.name	= "wimax",
425 };
426 
427 /*
428  * Probe a i2400m interface and register it
429  *
430  * @iface:   USB interface to link to
431  * @id:      USB class/subclass/protocol id
432  * @returns: 0 if ok, < 0 errno code on error.
433  *
434  * Alloc a net device, initialize the bus-specific details and then
435  * calls the bus-generic initialization routine. That will register
436  * the wimax and netdev devices, upload the firmware [using
437  * _bus_bm_*()], call _bus_dev_start() to finalize the setup of the
438  * communication with the device and then will start to talk to it to
439  * finnish setting it up.
440  */
441 static
i2400mu_probe(struct usb_interface * iface,const struct usb_device_id * id)442 int i2400mu_probe(struct usb_interface *iface,
443 		  const struct usb_device_id *id)
444 {
445 	int result;
446 	struct net_device *net_dev;
447 	struct device *dev = &iface->dev;
448 	struct i2400m *i2400m;
449 	struct i2400mu *i2400mu;
450 	struct usb_device *usb_dev = interface_to_usbdev(iface);
451 
452 	if (usb_dev->speed != USB_SPEED_HIGH)
453 		dev_err(dev, "device not connected as high speed\n");
454 
455 	/* Allocate instance [calls i2400m_netdev_setup() on it]. */
456 	result = -ENOMEM;
457 	net_dev = alloc_netdev(sizeof(*i2400mu), "wmx%d",
458 			       i2400mu_netdev_setup);
459 	if (net_dev == NULL) {
460 		dev_err(dev, "no memory for network device instance\n");
461 		goto error_alloc_netdev;
462 	}
463 	SET_NETDEV_DEV(net_dev, dev);
464 	SET_NETDEV_DEVTYPE(net_dev, &i2400mu_type);
465 	i2400m = net_dev_to_i2400m(net_dev);
466 	i2400mu = container_of(i2400m, struct i2400mu, i2400m);
467 	i2400m->wimax_dev.net_dev = net_dev;
468 	i2400mu->usb_dev = usb_get_dev(usb_dev);
469 	i2400mu->usb_iface = iface;
470 	usb_set_intfdata(iface, i2400mu);
471 
472 	i2400m->bus_tx_block_size = I2400MU_BLK_SIZE;
473 	/*
474 	 * Room required in the Tx queue for USB message to accommodate
475 	 * a smallest payload while allocating header space is 16 bytes.
476 	 * Adding this room  for the new tx message increases the
477 	 * possibilities of including any payload with size <= 16 bytes.
478 	 */
479 	i2400m->bus_tx_room_min = I2400MU_BLK_SIZE;
480 	i2400m->bus_pl_size_max = I2400MU_PL_SIZE_MAX;
481 	i2400m->bus_setup = NULL;
482 	i2400m->bus_dev_start = i2400mu_bus_dev_start;
483 	i2400m->bus_dev_stop = i2400mu_bus_dev_stop;
484 	i2400m->bus_release = NULL;
485 	i2400m->bus_tx_kick = i2400mu_bus_tx_kick;
486 	i2400m->bus_reset = i2400mu_bus_reset;
487 	i2400m->bus_bm_retries = I2400M_USB_BOOT_RETRIES;
488 	i2400m->bus_bm_cmd_send = i2400mu_bus_bm_cmd_send;
489 	i2400m->bus_bm_wait_for_ack = i2400mu_bus_bm_wait_for_ack;
490 	i2400m->bus_bm_mac_addr_impaired = 0;
491 
492 	switch (id->idProduct) {
493 	case USB_DEVICE_ID_I6050:
494 	case USB_DEVICE_ID_I6050_2:
495 	case USB_DEVICE_ID_I6250:
496 		i2400mu->i6050 = 1;
497 		break;
498 	default:
499 		break;
500 	}
501 
502 	if (i2400mu->i6050) {
503 		i2400m->bus_fw_names = i2400mu_bus_fw_names_6050;
504 		i2400mu->endpoint_cfg.bulk_out = 0;
505 		i2400mu->endpoint_cfg.notification = 3;
506 		i2400mu->endpoint_cfg.reset_cold = 2;
507 		i2400mu->endpoint_cfg.bulk_in = 1;
508 	} else {
509 		i2400m->bus_fw_names = i2400mu_bus_fw_names_5x50;
510 		i2400mu->endpoint_cfg.bulk_out = 0;
511 		i2400mu->endpoint_cfg.notification = 1;
512 		i2400mu->endpoint_cfg.reset_cold = 2;
513 		i2400mu->endpoint_cfg.bulk_in = 3;
514 	}
515 #ifdef CONFIG_PM
516 	iface->needs_remote_wakeup = 1;		/* autosuspend (15s delay) */
517 	device_init_wakeup(dev, 1);
518 	pm_runtime_set_autosuspend_delay(&usb_dev->dev, 15000);
519 	usb_enable_autosuspend(usb_dev);
520 #endif
521 
522 	result = i2400m_setup(i2400m, I2400M_BRI_MAC_REINIT);
523 	if (result < 0) {
524 		dev_err(dev, "cannot setup device: %d\n", result);
525 		goto error_setup;
526 	}
527 	result = i2400mu_debugfs_add(i2400mu);
528 	if (result < 0) {
529 		dev_err(dev, "Can't register i2400mu's debugfs: %d\n", result);
530 		goto error_debugfs_add;
531 	}
532 	return 0;
533 
534 error_debugfs_add:
535 	i2400m_release(i2400m);
536 error_setup:
537 	usb_set_intfdata(iface, NULL);
538 	usb_put_dev(i2400mu->usb_dev);
539 	free_netdev(net_dev);
540 error_alloc_netdev:
541 	return result;
542 }
543 
544 
545 /*
546  * Disconect a i2400m from the system.
547  *
548  * i2400m_stop() has been called before, so al the rx and tx contexts
549  * have been taken down already. Make sure the queue is stopped,
550  * unregister netdev and i2400m, free and kill.
551  */
552 static
i2400mu_disconnect(struct usb_interface * iface)553 void i2400mu_disconnect(struct usb_interface *iface)
554 {
555 	struct i2400mu *i2400mu = usb_get_intfdata(iface);
556 	struct i2400m *i2400m = &i2400mu->i2400m;
557 	struct net_device *net_dev = i2400m->wimax_dev.net_dev;
558 	struct device *dev = &iface->dev;
559 
560 	d_fnstart(3, dev, "(iface %p i2400m %p)\n", iface, i2400m);
561 
562 	debugfs_remove_recursive(i2400mu->debugfs_dentry);
563 	i2400m_release(i2400m);
564 	usb_set_intfdata(iface, NULL);
565 	usb_put_dev(i2400mu->usb_dev);
566 	free_netdev(net_dev);
567 	d_fnend(3, dev, "(iface %p i2400m %p) = void\n", iface, i2400m);
568 }
569 
570 
571 /*
572  * Get the device ready for USB port or system standby and hibernation
573  *
574  * USB port and system standby are handled the same.
575  *
576  * When the system hibernates, the USB device is powered down and then
577  * up, so we don't really have to do much here, as it will be seen as
578  * a reconnect. Still for simplicity we consider this case the same as
579  * suspend, so that the device has a chance to do notify the base
580  * station (if connected).
581  *
582  * So at the end, the three cases require common handling.
583  *
584  * If at the time of this call the device's firmware is not loaded,
585  * nothing has to be done. Note we can be "loose" about not reading
586  * i2400m->updown under i2400m->init_mutex. If it happens to change
587  * inmediately, other parts of the call flow will fail and effectively
588  * catch it.
589  *
590  * If the firmware is loaded, we need to:
591  *
592  *  - tell the device to go into host interface power save mode, wait
593  *    for it to ack
594  *
595  *    This is quite more interesting than it is; we need to execute a
596  *    command, but this time, we don't want the code in usb-{tx,rx}.c
597  *    to call the usb_autopm_get/put_interface() barriers as it'd
598  *    deadlock, so we need to decrement i2400mu->do_autopm, that acts
599  *    as a poor man's semaphore. Ugly, but it works.
600  *
601  *    As well, the device might refuse going to sleep for whichever
602  *    reason. In this case we just fail. For system suspend/hibernate,
603  *    we *can't* fail. We check PMSG_IS_AUTO to see if the
604  *    suspend call comes from the USB stack or from the system and act
605  *    in consequence.
606  *
607  *  - stop the notification endpoint polling
608  */
609 static
i2400mu_suspend(struct usb_interface * iface,pm_message_t pm_msg)610 int i2400mu_suspend(struct usb_interface *iface, pm_message_t pm_msg)
611 {
612 	int result = 0;
613 	struct device *dev = &iface->dev;
614 	struct i2400mu *i2400mu = usb_get_intfdata(iface);
615 	unsigned is_autosuspend = 0;
616 	struct i2400m *i2400m = &i2400mu->i2400m;
617 
618 #ifdef CONFIG_PM
619 	if (PMSG_IS_AUTO(pm_msg))
620 		is_autosuspend = 1;
621 #endif
622 
623 	d_fnstart(3, dev, "(iface %p pm_msg %u)\n", iface, pm_msg.event);
624 	rmb();		/* see i2400m->updown's documentation  */
625 	if (i2400m->updown == 0)
626 		goto no_firmware;
627 	if (i2400m->state == I2400M_SS_DATA_PATH_CONNECTED && is_autosuspend) {
628 		/* ugh -- the device is connected and this suspend
629 		 * request is an autosuspend one (not a system standby
630 		 * / hibernate).
631 		 *
632 		 * The only way the device can go to standby is if the
633 		 * link with the base station is in IDLE mode; that
634 		 * were the case, we'd be in status
635 		 * I2400M_SS_CONNECTED_IDLE. But we are not.
636 		 *
637 		 * If we *tell* him to go power save now, it'll reset
638 		 * as a precautionary measure, so if this is an
639 		 * autosuspend thing, say no and it'll come back
640 		 * later, when the link is IDLE
641 		 */
642 		result = -EBADF;
643 		d_printf(1, dev, "fw up, link up, not-idle, autosuspend: "
644 			 "not entering powersave\n");
645 		goto error_not_now;
646 	}
647 	d_printf(1, dev, "fw up: entering powersave\n");
648 	atomic_dec(&i2400mu->do_autopm);
649 	result = i2400m_cmd_enter_powersave(i2400m);
650 	atomic_inc(&i2400mu->do_autopm);
651 	if (result < 0 && !is_autosuspend) {
652 		/* System suspend, can't fail */
653 		dev_err(dev, "failed to suspend, will reset on resume\n");
654 		result = 0;
655 	}
656 	if (result < 0)
657 		goto error_enter_powersave;
658 	i2400mu_notification_release(i2400mu);
659 	d_printf(1, dev, "powersave requested\n");
660 error_enter_powersave:
661 error_not_now:
662 no_firmware:
663 	d_fnend(3, dev, "(iface %p pm_msg %u) = %d\n",
664 		iface, pm_msg.event, result);
665 	return result;
666 }
667 
668 
669 static
i2400mu_resume(struct usb_interface * iface)670 int i2400mu_resume(struct usb_interface *iface)
671 {
672 	int ret = 0;
673 	struct device *dev = &iface->dev;
674 	struct i2400mu *i2400mu = usb_get_intfdata(iface);
675 	struct i2400m *i2400m = &i2400mu->i2400m;
676 
677 	d_fnstart(3, dev, "(iface %p)\n", iface);
678 	rmb();		/* see i2400m->updown's documentation  */
679 	if (i2400m->updown == 0) {
680 		d_printf(1, dev, "fw was down, no resume neeed\n");
681 		goto out;
682 	}
683 	d_printf(1, dev, "fw was up, resuming\n");
684 	i2400mu_notification_setup(i2400mu);
685 	/* USB has flow control, so we don't need to give it time to
686 	 * come back; otherwise, we'd use something like a get-state
687 	 * command... */
688 out:
689 	d_fnend(3, dev, "(iface %p) = %d\n", iface, ret);
690 	return ret;
691 }
692 
693 
694 static
i2400mu_reset_resume(struct usb_interface * iface)695 int i2400mu_reset_resume(struct usb_interface *iface)
696 {
697 	int result;
698 	struct device *dev = &iface->dev;
699 	struct i2400mu *i2400mu = usb_get_intfdata(iface);
700 	struct i2400m *i2400m = &i2400mu->i2400m;
701 
702 	d_fnstart(3, dev, "(iface %p)\n", iface);
703 	result = i2400m_dev_reset_handle(i2400m, "device reset on resume");
704 	d_fnend(3, dev, "(iface %p) = %d\n", iface, result);
705 	return result < 0 ? result : 0;
706 }
707 
708 
709 /*
710  * Another driver or user space is triggering a reset on the device
711  * which contains the interface passed as an argument. Cease IO and
712  * save any device state you need to restore.
713  *
714  * If you need to allocate memory here, use GFP_NOIO or GFP_ATOMIC, if
715  * you are in atomic context.
716  */
717 static
i2400mu_pre_reset(struct usb_interface * iface)718 int i2400mu_pre_reset(struct usb_interface *iface)
719 {
720 	struct i2400mu *i2400mu = usb_get_intfdata(iface);
721 	return i2400m_pre_reset(&i2400mu->i2400m);
722 }
723 
724 
725 /*
726  * The reset has completed.  Restore any saved device state and begin
727  * using the device again.
728  *
729  * If you need to allocate memory here, use GFP_NOIO or GFP_ATOMIC, if
730  * you are in atomic context.
731  */
732 static
i2400mu_post_reset(struct usb_interface * iface)733 int i2400mu_post_reset(struct usb_interface *iface)
734 {
735 	struct i2400mu *i2400mu = usb_get_intfdata(iface);
736 	return i2400m_post_reset(&i2400mu->i2400m);
737 }
738 
739 
740 static
741 struct usb_device_id i2400mu_id_table[] = {
742 	{ USB_DEVICE(0x8086, USB_DEVICE_ID_I6050) },
743 	{ USB_DEVICE(0x8086, USB_DEVICE_ID_I6050_2) },
744 	{ USB_DEVICE(0x8086, USB_DEVICE_ID_I6250) },
745 	{ USB_DEVICE(0x8086, 0x0181) },
746 	{ USB_DEVICE(0x8086, 0x1403) },
747 	{ USB_DEVICE(0x8086, 0x1405) },
748 	{ USB_DEVICE(0x8086, 0x0180) },
749 	{ USB_DEVICE(0x8086, 0x0182) },
750 	{ USB_DEVICE(0x8086, 0x1406) },
751 	{ USB_DEVICE(0x8086, 0x1403) },
752 	{ },
753 };
754 MODULE_DEVICE_TABLE(usb, i2400mu_id_table);
755 
756 
757 static
758 struct usb_driver i2400mu_driver = {
759 	.name = KBUILD_MODNAME,
760 	.suspend = i2400mu_suspend,
761 	.resume = i2400mu_resume,
762 	.reset_resume = i2400mu_reset_resume,
763 	.probe = i2400mu_probe,
764 	.disconnect = i2400mu_disconnect,
765 	.pre_reset = i2400mu_pre_reset,
766 	.post_reset = i2400mu_post_reset,
767 	.id_table = i2400mu_id_table,
768 	.supports_autosuspend = 1,
769 };
770 
771 static
i2400mu_driver_init(void)772 int __init i2400mu_driver_init(void)
773 {
774 	d_parse_params(D_LEVEL, D_LEVEL_SIZE, i2400mu_debug_params,
775 		       "i2400m_usb.debug");
776 	return usb_register(&i2400mu_driver);
777 }
778 module_init(i2400mu_driver_init);
779 
780 
781 static
i2400mu_driver_exit(void)782 void __exit i2400mu_driver_exit(void)
783 {
784 	usb_deregister(&i2400mu_driver);
785 }
786 module_exit(i2400mu_driver_exit);
787 
788 MODULE_AUTHOR("Intel Corporation <linux-wimax@intel.com>");
789 MODULE_DESCRIPTION("Driver for USB based Intel Wireless WiMAX Connection 2400M "
790 		   "(5x50 & 6050)");
791 MODULE_LICENSE("GPL");
792 MODULE_FIRMWARE(I2400MU_FW_FILE_NAME_v1_5);
793 MODULE_FIRMWARE(I6050U_FW_FILE_NAME_v1_5);
794