1 /*
2  * Intel Wireless WiMAX Connection 2400m
3  * Firmware uploader's USB specifics
4  *
5  *
6  * Copyright (C) 2007-2008 Intel Corporation. All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  *   * Redistributions of source code must retain the above copyright
13  *     notice, this list of conditions and the following disclaimer.
14  *   * Redistributions in binary form must reproduce the above copyright
15  *     notice, this list of conditions and the following disclaimer in
16  *     the documentation and/or other materials provided with the
17  *     distribution.
18  *   * Neither the name of Intel Corporation nor the names of its
19  *     contributors may be used to endorse or promote products derived
20  *     from this software without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
25  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
26  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
27  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
28  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
32  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33  *
34  *
35  * Intel Corporation <linux-wimax@intel.com>
36  * Yanir Lubetkin <yanirx.lubetkin@intel.com>
37  * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
38  *  - Initial implementation
39  *
40  * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
41  *  - bus generic/specific split
42  *
43  * THE PROCEDURE
44  *
45  * See fw.c for the generic description of this procedure.
46  *
47  * This file implements only the USB specifics. It boils down to how
48  * to send a command and waiting for an acknowledgement from the
49  * device.
50  *
51  * This code (and process) is single threaded. It assumes it is the
52  * only thread poking around (guaranteed by fw.c).
53  *
54  * COMMAND EXECUTION
55  *
56  * A write URB is posted with the buffer to the bulk output endpoint.
57  *
58  * ACK RECEPTION
59  *
60  * We just post a URB to the notification endpoint and wait for
61  * data. We repeat until we get all the data we expect (as indicated
62  * by the call from the bus generic code).
63  *
64  * The data is not read from the bulk in endpoint for boot mode.
65  *
66  * ROADMAP
67  *
68  * i2400mu_bus_bm_cmd_send
69  *   i2400m_bm_cmd_prepare...
70  *   i2400mu_tx_bulk_out
71  *
72  * i2400mu_bus_bm_wait_for_ack
73  *   i2400m_notif_submit
74  */
75 #include <linux/usb.h>
76 #include <linux/gfp.h>
77 #include "i2400m-usb.h"
78 
79 
80 #define D_SUBMODULE fw
81 #include "usb-debug-levels.h"
82 
83 
84 /*
85  * Synchronous write to the device
86  *
87  * Takes care of updating EDC counts and thus, handle device errors.
88  */
89 static
i2400mu_tx_bulk_out(struct i2400mu * i2400mu,void * buf,size_t buf_size)90 ssize_t i2400mu_tx_bulk_out(struct i2400mu *i2400mu, void *buf, size_t buf_size)
91 {
92 	int result;
93 	struct device *dev = &i2400mu->usb_iface->dev;
94 	int len;
95 	struct usb_endpoint_descriptor *epd;
96 	int pipe, do_autopm = 1;
97 
98 	result = usb_autopm_get_interface(i2400mu->usb_iface);
99 	if (result < 0) {
100 		dev_err(dev, "BM-CMD: can't get autopm: %d\n", result);
101 		do_autopm = 0;
102 	}
103 	epd = usb_get_epd(i2400mu->usb_iface, i2400mu->endpoint_cfg.bulk_out);
104 	pipe = usb_sndbulkpipe(i2400mu->usb_dev, epd->bEndpointAddress);
105 retry:
106 	result = usb_bulk_msg(i2400mu->usb_dev, pipe, buf, buf_size, &len, 200);
107 	switch (result) {
108 	case 0:
109 		if (len != buf_size) {
110 			dev_err(dev, "BM-CMD: short write (%u B vs %zu "
111 				"expected)\n", len, buf_size);
112 			result = -EIO;
113 			break;
114 		}
115 		result = len;
116 		break;
117 	case -EPIPE:
118 		/*
119 		 * Stall -- maybe the device is choking with our
120 		 * requests. Clear it and give it some time. If they
121 		 * happen to often, it might be another symptom, so we
122 		 * reset.
123 		 *
124 		 * No error handling for usb_clear_halt(0; if it
125 		 * works, the retry works; if it fails, this switch
126 		 * does the error handling for us.
127 		 */
128 		if (edc_inc(&i2400mu->urb_edc,
129 			    10 * EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME)) {
130 			dev_err(dev, "BM-CMD: too many stalls in "
131 				"URB; resetting device\n");
132 			usb_queue_reset_device(i2400mu->usb_iface);
133 			/* fallthrough */
134 		} else {
135 			usb_clear_halt(i2400mu->usb_dev, pipe);
136 			msleep(10);	/* give the device some time */
137 			goto retry;
138 		}
139 	case -EINVAL:			/* while removing driver */
140 	case -ENODEV:			/* dev disconnect ... */
141 	case -ENOENT:			/* just ignore it */
142 	case -ESHUTDOWN:		/* and exit */
143 	case -ECONNRESET:
144 		result = -ESHUTDOWN;
145 		break;
146 	case -ETIMEDOUT:			/* bah... */
147 		break;
148 	default:				/* any other? */
149 		if (edc_inc(&i2400mu->urb_edc,
150 			    EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME)) {
151 				dev_err(dev, "BM-CMD: maximum errors in "
152 					"URB exceeded; resetting device\n");
153 				usb_queue_reset_device(i2400mu->usb_iface);
154 				result = -ENODEV;
155 				break;
156 		}
157 		dev_err(dev, "BM-CMD: URB error %d, retrying\n",
158 			result);
159 		goto retry;
160 	}
161 	if (do_autopm)
162 		usb_autopm_put_interface(i2400mu->usb_iface);
163 	return result;
164 }
165 
166 
167 /*
168  * Send a boot-mode command over the bulk-out pipe
169  *
170  * Command can be a raw command, which requires no preparation (and
171  * which might not even be following the command format). Checks that
172  * the right amount of data was transferred.
173  *
174  * To satisfy USB requirements (no onstack, vmalloc or in data segment
175  * buffers), we copy the command to i2400m->bm_cmd_buf and send it from
176  * there.
177  *
178  * @flags: pass thru from i2400m_bm_cmd()
179  * @return: cmd_size if ok, < 0 errno code on error.
180  */
i2400mu_bus_bm_cmd_send(struct i2400m * i2400m,const struct i2400m_bootrom_header * _cmd,size_t cmd_size,int flags)181 ssize_t i2400mu_bus_bm_cmd_send(struct i2400m *i2400m,
182 				const struct i2400m_bootrom_header *_cmd,
183 				size_t cmd_size, int flags)
184 {
185 	ssize_t result;
186 	struct device *dev = i2400m_dev(i2400m);
187 	struct i2400mu *i2400mu = container_of(i2400m, struct i2400mu, i2400m);
188 	int opcode = _cmd == NULL ? -1 : i2400m_brh_get_opcode(_cmd);
189 	struct i2400m_bootrom_header *cmd;
190 	size_t cmd_size_a = ALIGN(cmd_size, 16);	/* USB restriction */
191 
192 	d_fnstart(8, dev, "(i2400m %p cmd %p size %zu)\n",
193 		  i2400m, _cmd, cmd_size);
194 	result = -E2BIG;
195 	if (cmd_size > I2400M_BM_CMD_BUF_SIZE)
196 		goto error_too_big;
197 	if (_cmd != i2400m->bm_cmd_buf)
198 		memmove(i2400m->bm_cmd_buf, _cmd, cmd_size);
199 	cmd = i2400m->bm_cmd_buf;
200 	if (cmd_size_a > cmd_size)			/* Zero pad space */
201 		memset(i2400m->bm_cmd_buf + cmd_size, 0, cmd_size_a - cmd_size);
202 	if ((flags & I2400M_BM_CMD_RAW) == 0) {
203 		if (WARN_ON(i2400m_brh_get_response_required(cmd) == 0))
204 			dev_warn(dev, "SW BUG: response_required == 0\n");
205 		i2400m_bm_cmd_prepare(cmd);
206 	}
207 	result = i2400mu_tx_bulk_out(i2400mu, i2400m->bm_cmd_buf, cmd_size);
208 	if (result < 0) {
209 		dev_err(dev, "boot-mode cmd %d: cannot send: %zd\n",
210 			opcode, result);
211 		goto error_cmd_send;
212 	}
213 	if (result != cmd_size) {		/* all was transferred? */
214 		dev_err(dev, "boot-mode cmd %d: incomplete transfer "
215 			"(%zu vs %zu submitted)\n",  opcode, result, cmd_size);
216 		result = -EIO;
217 		goto error_cmd_size;
218 	}
219 error_cmd_size:
220 error_cmd_send:
221 error_too_big:
222 	d_fnend(8, dev, "(i2400m %p cmd %p size %zu) = %zd\n",
223 		i2400m, _cmd, cmd_size, result);
224 	return result;
225 }
226 
227 
228 static
__i2400mu_bm_notif_cb(struct urb * urb)229 void __i2400mu_bm_notif_cb(struct urb *urb)
230 {
231 	complete(urb->context);
232 }
233 
234 
235 /*
236  * submit a read to the notification endpoint
237  *
238  * @i2400m: device descriptor
239  * @urb: urb to use
240  * @completion: completion varible to complete when done
241  *
242  * Data is always read to i2400m->bm_ack_buf
243  */
244 static
i2400mu_notif_submit(struct i2400mu * i2400mu,struct urb * urb,struct completion * completion)245 int i2400mu_notif_submit(struct i2400mu *i2400mu, struct urb *urb,
246 			 struct completion *completion)
247 {
248 	struct i2400m *i2400m = &i2400mu->i2400m;
249 	struct usb_endpoint_descriptor *epd;
250 	int pipe;
251 
252 	epd = usb_get_epd(i2400mu->usb_iface,
253 			  i2400mu->endpoint_cfg.notification);
254 	pipe = usb_rcvintpipe(i2400mu->usb_dev, epd->bEndpointAddress);
255 	usb_fill_int_urb(urb, i2400mu->usb_dev, pipe,
256 			 i2400m->bm_ack_buf, I2400M_BM_ACK_BUF_SIZE,
257 			 __i2400mu_bm_notif_cb, completion,
258 			 epd->bInterval);
259 	return usb_submit_urb(urb, GFP_KERNEL);
260 }
261 
262 
263 /*
264  * Read an ack from  the notification endpoint
265  *
266  * @i2400m:
267  * @_ack: pointer to where to store the read data
268  * @ack_size: how many bytes we should read
269  *
270  * Returns: < 0 errno code on error; otherwise, amount of received bytes.
271  *
272  * Submits a notification read, appends the read data to the given ack
273  * buffer and then repeats (until @ack_size bytes have been
274  * received).
275  */
i2400mu_bus_bm_wait_for_ack(struct i2400m * i2400m,struct i2400m_bootrom_header * _ack,size_t ack_size)276 ssize_t i2400mu_bus_bm_wait_for_ack(struct i2400m *i2400m,
277 				    struct i2400m_bootrom_header *_ack,
278 				    size_t ack_size)
279 {
280 	ssize_t result = -ENOMEM;
281 	struct device *dev = i2400m_dev(i2400m);
282 	struct i2400mu *i2400mu = container_of(i2400m, struct i2400mu, i2400m);
283 	struct urb notif_urb;
284 	void *ack = _ack;
285 	size_t offset, len;
286 	long val;
287 	int do_autopm = 1;
288 	DECLARE_COMPLETION_ONSTACK(notif_completion);
289 
290 	d_fnstart(8, dev, "(i2400m %p ack %p size %zu)\n",
291 		  i2400m, ack, ack_size);
292 	BUG_ON(_ack == i2400m->bm_ack_buf);
293 	result = usb_autopm_get_interface(i2400mu->usb_iface);
294 	if (result < 0) {
295 		dev_err(dev, "BM-ACK: can't get autopm: %d\n", (int) result);
296 		do_autopm = 0;
297 	}
298 	usb_init_urb(&notif_urb);	/* ready notifications */
299 	usb_get_urb(&notif_urb);
300 	offset = 0;
301 	while (offset < ack_size) {
302 		init_completion(&notif_completion);
303 		result = i2400mu_notif_submit(i2400mu, &notif_urb,
304 					      &notif_completion);
305 		if (result < 0)
306 			goto error_notif_urb_submit;
307 		val = wait_for_completion_interruptible_timeout(
308 			&notif_completion, HZ);
309 		if (val == 0) {
310 			result = -ETIMEDOUT;
311 			usb_kill_urb(&notif_urb);	/* Timedout */
312 			goto error_notif_wait;
313 		}
314 		if (val == -ERESTARTSYS) {
315 			result = -EINTR;		/* Interrupted */
316 			usb_kill_urb(&notif_urb);
317 			goto error_notif_wait;
318 		}
319 		result = notif_urb.status;		/* How was the ack? */
320 		switch (result) {
321 		case 0:
322 			break;
323 		case -EINVAL:			/* while removing driver */
324 		case -ENODEV:			/* dev disconnect ... */
325 		case -ENOENT:			/* just ignore it */
326 		case -ESHUTDOWN:		/* and exit */
327 		case -ECONNRESET:
328 			result = -ESHUTDOWN;
329 			goto error_dev_gone;
330 		default:				/* any other? */
331 			usb_kill_urb(&notif_urb);	/* Timedout */
332 			if (edc_inc(&i2400mu->urb_edc,
333 				    EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME))
334 				goto error_exceeded;
335 			dev_err(dev, "BM-ACK: URB error %d, "
336 				"retrying\n", notif_urb.status);
337 			continue;	/* retry */
338 		}
339 		if (notif_urb.actual_length == 0) {
340 			d_printf(6, dev, "ZLP received, retrying\n");
341 			continue;
342 		}
343 		/* Got data, append it to the buffer */
344 		len = min(ack_size - offset, (size_t) notif_urb.actual_length);
345 		memcpy(ack + offset, i2400m->bm_ack_buf, len);
346 		offset += len;
347 	}
348 	result = offset;
349 error_notif_urb_submit:
350 error_notif_wait:
351 error_dev_gone:
352 out:
353 	if (do_autopm)
354 		usb_autopm_put_interface(i2400mu->usb_iface);
355 	d_fnend(8, dev, "(i2400m %p ack %p size %zu) = %ld\n",
356 		i2400m, ack, ack_size, (long) result);
357 	return result;
358 
359 error_exceeded:
360 	dev_err(dev, "bm: maximum errors in notification URB exceeded; "
361 		"resetting device\n");
362 	usb_queue_reset_device(i2400mu->usb_iface);
363 	goto out;
364 }
365