1 /*
2 * Intel Wireless WiMAX Connection 2400m
3 * USB-specific i2400m driver definitions
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 * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
37 * Yanir Lubetkin <yanirx.lubetkin@intel.com>
38 * - Initial implementation
39 *
40 *
41 * This driver implements the bus-specific part of the i2400m for
42 * USB. Check i2400m.h for a generic driver description.
43 *
44 * ARCHITECTURE
45 *
46 * This driver listens to notifications sent from the notification
47 * endpoint (in usb-notif.c); when data is ready to read, the code in
48 * there schedules a read from the device (usb-rx.c) and then passes
49 * the data to the generic RX code (rx.c).
50 *
51 * When the generic driver needs to send data (network or control), it
52 * queues up in the TX FIFO (tx.c) and that will notify the driver
53 * through the i2400m->bus_tx_kick() callback
54 * (usb-tx.c:i2400mu_bus_tx_kick) which will send the items in the
55 * FIFO queue.
56 *
57 * This driver, as well, implements the USB-specific ops for the generic
58 * driver to be able to setup/teardown communication with the device
59 * [i2400m_bus_dev_start() and i2400m_bus_dev_stop()], reseting the
60 * device [i2400m_bus_reset()] and performing firmware upload
61 * [i2400m_bus_bm_cmd() and i2400_bus_bm_wait_for_ack()].
62 */
63
64 #ifndef __I2400M_USB_H__
65 #define __I2400M_USB_H__
66
67 #include "i2400m.h"
68 #include <linux/kthread.h>
69
70
71 /*
72 * Error Density Count: cheapo error density (over time) counter
73 *
74 * Originally by Reinette Chatre <reinette.chatre@intel.com>
75 *
76 * Embed an 'struct edc' somewhere. Each time there is a soft or
77 * retryable error, call edc_inc() and check if the error top
78 * watermark has been reached.
79 */
80 enum {
81 EDC_MAX_ERRORS = 10,
82 EDC_ERROR_TIMEFRAME = HZ,
83 };
84
85 /* error density counter */
86 struct edc {
87 unsigned long timestart;
88 u16 errorcount;
89 };
90
91 struct i2400m_endpoint_cfg {
92 unsigned char bulk_out;
93 unsigned char notification;
94 unsigned char reset_cold;
95 unsigned char bulk_in;
96 };
97
edc_init(struct edc * edc)98 static inline void edc_init(struct edc *edc)
99 {
100 edc->timestart = jiffies;
101 }
102
103 /**
104 * edc_inc - report a soft error and check if we are over the watermark
105 *
106 * @edc: pointer to error density counter.
107 * @max_err: maximum number of errors we can accept over the timeframe
108 * @timeframe: length of the timeframe (in jiffies).
109 *
110 * Returns: !0 1 if maximum acceptable errors per timeframe has been
111 * exceeded. 0 otherwise.
112 *
113 * This is way to determine if the number of acceptable errors per time
114 * period has been exceeded. It is not accurate as there are cases in which
115 * this scheme will not work, for example if there are periodic occurrences
116 * of errors that straddle updates to the start time. This scheme is
117 * sufficient for our usage.
118 *
119 * To use, embed a 'struct edc' somewhere, initialize it with
120 * edc_init() and when an error hits:
121 *
122 * if (do_something_fails_with_a_soft_error) {
123 * if (edc_inc(&my->edc, MAX_ERRORS, MAX_TIMEFRAME))
124 * Ops, hard error, do something about it
125 * else
126 * Retry or ignore, depending on whatever
127 * }
128 */
edc_inc(struct edc * edc,u16 max_err,u16 timeframe)129 static inline int edc_inc(struct edc *edc, u16 max_err, u16 timeframe)
130 {
131 unsigned long now;
132
133 now = jiffies;
134 if (now - edc->timestart > timeframe) {
135 edc->errorcount = 1;
136 edc->timestart = now;
137 } else if (++edc->errorcount > max_err) {
138 edc->errorcount = 0;
139 edc->timestart = now;
140 return 1;
141 }
142 return 0;
143 }
144
145 /* Host-Device interface for USB */
146 enum {
147 I2400M_USB_BOOT_RETRIES = 3,
148 I2400MU_MAX_NOTIFICATION_LEN = 256,
149 I2400MU_BLK_SIZE = 16,
150 I2400MU_PL_SIZE_MAX = 0x3EFF,
151
152 /* Device IDs */
153 USB_DEVICE_ID_I6050 = 0x0186,
154 USB_DEVICE_ID_I6050_2 = 0x0188,
155 USB_DEVICE_ID_I6250 = 0x0187,
156 };
157
158
159 /**
160 * struct i2400mu - descriptor for a USB connected i2400m
161 *
162 * @i2400m: bus-generic i2400m implementation; has to be first (see
163 * it's documentation in i2400m.h).
164 *
165 * @usb_dev: pointer to our USB device
166 *
167 * @usb_iface: pointer to our USB interface
168 *
169 * @urb_edc: error density counter; used to keep a density-on-time tab
170 * on how many soft (retryable or ignorable) errors we get. If we
171 * go over the threshold, we consider the bus transport is failing
172 * too much and reset.
173 *
174 * @notif_urb: URB for receiving notifications from the device.
175 *
176 * @tx_kthread: thread we use for data TX. We use a thread because in
177 * order to do deep power saving and put the device to sleep, we
178 * need to call usb_autopm_*() [blocking functions].
179 *
180 * @tx_wq: waitqueue for the TX kthread to sleep when there is no data
181 * to be sent; when more data is available, it is woken up by
182 * i2400mu_bus_tx_kick().
183 *
184 * @rx_kthread: thread we use for data RX. We use a thread because in
185 * order to do deep power saving and put the device to sleep, we
186 * need to call usb_autopm_*() [blocking functions].
187 *
188 * @rx_wq: waitqueue for the RX kthread to sleep when there is no data
189 * to receive. When data is available, it is woken up by
190 * usb-notif.c:i2400mu_notification_grok().
191 *
192 * @rx_pending_count: number of rx-data-ready notifications that were
193 * still not handled by the RX kthread.
194 *
195 * @rx_size: current RX buffer size that is being used.
196 *
197 * @rx_size_acc: accumulator of the sizes of the previous read
198 * transactions.
199 *
200 * @rx_size_cnt: number of read transactions accumulated in
201 * @rx_size_acc.
202 *
203 * @do_autopm: disable(0)/enable(>0) calling the
204 * usb_autopm_get/put_interface() barriers when executing
205 * commands. See doc in i2400mu_suspend() for more information.
206 *
207 * @rx_size_auto_shrink: if true, the rx_size is shrunk
208 * automatically based on the average size of the received
209 * transactions. This allows the receive code to allocate smaller
210 * chunks of memory and thus reduce pressure on the memory
211 * allocator by not wasting so much space. By default it is
212 * enabled.
213 *
214 * @debugfs_dentry: hookup for debugfs files.
215 * These have to be in a separate directory, a child of
216 * (wimax_dev->debugfs_dentry) so they can be removed when the
217 * module unloads, as we don't keep each dentry.
218 */
219 struct i2400mu {
220 struct i2400m i2400m; /* FIRST! See doc */
221
222 struct usb_device *usb_dev;
223 struct usb_interface *usb_iface;
224 struct edc urb_edc; /* Error density counter */
225 struct i2400m_endpoint_cfg endpoint_cfg;
226
227 struct urb *notif_urb;
228 struct task_struct *tx_kthread;
229 wait_queue_head_t tx_wq;
230
231 struct task_struct *rx_kthread;
232 wait_queue_head_t rx_wq;
233 atomic_t rx_pending_count;
234 size_t rx_size, rx_size_acc, rx_size_cnt;
235 atomic_t do_autopm;
236 u8 rx_size_auto_shrink;
237
238 struct dentry *debugfs_dentry;
239 unsigned i6050:1; /* 1 if this is a 6050 based SKU */
240 };
241
242
243 static inline
i2400mu_init(struct i2400mu * i2400mu)244 void i2400mu_init(struct i2400mu *i2400mu)
245 {
246 i2400m_init(&i2400mu->i2400m);
247 edc_init(&i2400mu->urb_edc);
248 init_waitqueue_head(&i2400mu->tx_wq);
249 atomic_set(&i2400mu->rx_pending_count, 0);
250 init_waitqueue_head(&i2400mu->rx_wq);
251 i2400mu->rx_size = PAGE_SIZE - sizeof(struct skb_shared_info);
252 atomic_set(&i2400mu->do_autopm, 1);
253 i2400mu->rx_size_auto_shrink = 1;
254 }
255
256 extern int i2400mu_notification_setup(struct i2400mu *);
257 extern void i2400mu_notification_release(struct i2400mu *);
258
259 extern int i2400mu_rx_setup(struct i2400mu *);
260 extern void i2400mu_rx_release(struct i2400mu *);
261 extern void i2400mu_rx_kick(struct i2400mu *);
262
263 extern int i2400mu_tx_setup(struct i2400mu *);
264 extern void i2400mu_tx_release(struct i2400mu *);
265 extern void i2400mu_bus_tx_kick(struct i2400m *);
266
267 extern ssize_t i2400mu_bus_bm_cmd_send(struct i2400m *,
268 const struct i2400m_bootrom_header *,
269 size_t, int);
270 extern ssize_t i2400mu_bus_bm_wait_for_ack(struct i2400m *,
271 struct i2400m_bootrom_header *,
272 size_t);
273 #endif /* #ifndef __I2400M_USB_H__ */
274