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73210a13 NV |
1 | /* Copyright (c) 2008-2010, Code Aurora Forum. All rights reserved. |
2 | * | |
3 | * This program is free software; you can redistribute it and/or modify | |
4 | * it under the terms of the GNU General Public License version 2 and | |
5 | * only version 2 as published by the Free Software Foundation. | |
6 | * | |
7 | * This program is distributed in the hope that it will be useful, | |
8 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
9 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
10 | * GNU General Public License for more details. | |
11 | * | |
12 | * You should have received a copy of the GNU General Public License | |
13 | * along with this program; if not, write to the Free Software | |
14 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA | |
15 | * 02110-1301, USA. | |
16 | * | |
17 | */ | |
18 | /* | |
19 | * SMD Packet Driver -- Provides userspace interface to SMD packet ports. | |
20 | */ | |
21 | ||
22 | #include <linux/slab.h> | |
23 | #include <linux/cdev.h> | |
24 | #include <linux/module.h> | |
25 | #include <linux/fs.h> | |
26 | #include <linux/device.h> | |
27 | #include <linux/sched.h> | |
28 | #include <linux/mutex.h> | |
29 | #include <linux/delay.h> | |
30 | #include <linux/uaccess.h> | |
31 | #include <linux/workqueue.h> | |
32 | #include <linux/poll.h> | |
33 | ||
34 | #include <mach/msm_smd.h> | |
35 | ||
36 | #define NUM_SMD_PKT_PORTS 9 | |
37 | #define DEVICE_NAME "smdpkt" | |
38 | #define MAX_BUF_SIZE 2048 | |
39 | ||
40 | struct smd_pkt_dev { | |
41 | struct cdev cdev; | |
42 | struct device *devicep; | |
43 | ||
44 | struct smd_channel *ch; | |
45 | int open_count; | |
46 | struct mutex ch_lock; | |
47 | struct mutex rx_lock; | |
48 | struct mutex tx_lock; | |
49 | wait_queue_head_t ch_read_wait_queue; | |
50 | wait_queue_head_t ch_opened_wait_queue; | |
51 | ||
52 | int i; | |
53 | ||
54 | unsigned char tx_buf[MAX_BUF_SIZE]; | |
55 | unsigned char rx_buf[MAX_BUF_SIZE]; | |
56 | int remote_open; | |
57 | ||
58 | } *smd_pkt_devp[NUM_SMD_PKT_PORTS]; | |
59 | ||
60 | struct class *smd_pkt_classp; | |
61 | static dev_t smd_pkt_number; | |
62 | ||
63 | static int msm_smd_pkt_debug_enable; | |
64 | module_param_named(debug_enable, msm_smd_pkt_debug_enable, | |
65 | int, S_IRUGO | S_IWUSR | S_IWGRP); | |
66 | ||
67 | #ifdef DEBUG | |
68 | #define D_DUMP_BUFFER(prestr, cnt, buf) do { \ | |
69 | int i; \ | |
70 | if (msm_smd_pkt_debug_enable) { \ | |
71 | pr_debug("%s", prestr); \ | |
72 | for (i = 0; i < cnt; i++) \ | |
73 | pr_debug("%.2x", buf[i]); \ | |
74 | pr_debug("\n"); \ | |
75 | } \ | |
76 | } while (0) | |
77 | #else | |
78 | #define D_DUMP_BUFFER(prestr, cnt, buf) do {} while (0) | |
79 | #endif | |
80 | ||
81 | #ifdef DEBUG | |
82 | #define DBG(x...) do { \ | |
83 | if (msm_smd_pkt_debug_enable) \ | |
84 | pr_debug(x); \ | |
85 | } while (0) | |
86 | #else | |
87 | #define DBG(x...) do {} while (0) | |
88 | #endif | |
89 | ||
90 | static void check_and_wakeup_reader(struct smd_pkt_dev *smd_pkt_devp) | |
91 | { | |
92 | int sz; | |
93 | ||
94 | if (!smd_pkt_devp || !smd_pkt_devp->ch) | |
95 | return; | |
96 | ||
97 | sz = smd_cur_packet_size(smd_pkt_devp->ch); | |
98 | if (sz == 0) { | |
99 | DBG("no packet\n"); | |
100 | return; | |
101 | } | |
102 | if (sz > smd_read_avail(smd_pkt_devp->ch)) { | |
103 | DBG("incomplete packet\n"); | |
104 | return; | |
105 | } | |
106 | ||
107 | DBG("waking up reader\n"); | |
108 | wake_up_interruptible(&smd_pkt_devp->ch_read_wait_queue); | |
109 | } | |
110 | ||
111 | static int smd_pkt_read(struct file *file, char __user *buf, | |
112 | size_t count, loff_t *ppos) | |
113 | { | |
114 | int r, bytes_read; | |
115 | struct smd_pkt_dev *smd_pkt_devp; | |
116 | struct smd_channel *chl; | |
117 | ||
118 | DBG("read %d bytes\n", count); | |
119 | if (count > MAX_BUF_SIZE) | |
120 | return -EINVAL; | |
121 | ||
122 | smd_pkt_devp = file->private_data; | |
123 | if (!smd_pkt_devp || !smd_pkt_devp->ch) | |
124 | return -EINVAL; | |
125 | ||
126 | chl = smd_pkt_devp->ch; | |
127 | wait_for_packet: | |
128 | r = wait_event_interruptible(smd_pkt_devp->ch_read_wait_queue, | |
129 | (smd_cur_packet_size(chl) > 0 && | |
130 | smd_read_avail(chl) >= | |
131 | smd_cur_packet_size(chl))); | |
132 | ||
133 | if (r < 0) { | |
134 | if (r != -ERESTARTSYS) | |
135 | pr_err("wait returned %d\n", r); | |
136 | return r; | |
137 | } | |
138 | ||
139 | mutex_lock(&smd_pkt_devp->rx_lock); | |
140 | ||
141 | bytes_read = smd_cur_packet_size(smd_pkt_devp->ch); | |
142 | if (bytes_read == 0 || | |
143 | bytes_read < smd_read_avail(smd_pkt_devp->ch)) { | |
144 | mutex_unlock(&smd_pkt_devp->rx_lock); | |
145 | DBG("Nothing to read\n"); | |
146 | goto wait_for_packet; | |
147 | } | |
148 | ||
149 | if (bytes_read > count) { | |
150 | mutex_unlock(&smd_pkt_devp->rx_lock); | |
151 | pr_info("packet size %d > buffer size %d", bytes_read, count); | |
152 | return -EINVAL; | |
153 | } | |
154 | ||
155 | r = smd_read(smd_pkt_devp->ch, smd_pkt_devp->rx_buf, bytes_read); | |
156 | if (r != bytes_read) { | |
157 | mutex_unlock(&smd_pkt_devp->rx_lock); | |
158 | pr_err("smd_read failed to read %d bytes: %d\n", bytes_read, r); | |
159 | return -EIO; | |
160 | } | |
161 | ||
162 | D_DUMP_BUFFER("read: ", bytes_read, smd_pkt_devp->rx_buf); | |
163 | r = copy_to_user(buf, smd_pkt_devp->rx_buf, bytes_read); | |
164 | mutex_unlock(&smd_pkt_devp->rx_lock); | |
165 | if (r) { | |
166 | pr_err("copy_to_user failed %d\n", r); | |
167 | return -EFAULT; | |
168 | } | |
169 | ||
170 | DBG("read complete %d bytes\n", bytes_read); | |
171 | check_and_wakeup_reader(smd_pkt_devp); | |
172 | ||
173 | return bytes_read; | |
174 | } | |
175 | ||
176 | static int smd_pkt_write(struct file *file, const char __user *buf, | |
177 | size_t count, loff_t *ppos) | |
178 | { | |
179 | int r; | |
180 | struct smd_pkt_dev *smd_pkt_devp; | |
181 | ||
182 | if (count > MAX_BUF_SIZE) | |
183 | return -EINVAL; | |
184 | ||
77d84ff8 | 185 | DBG("writing %d bytes\n", count); |
73210a13 NV |
186 | |
187 | smd_pkt_devp = file->private_data; | |
188 | if (!smd_pkt_devp || !smd_pkt_devp->ch) | |
189 | return -EINVAL; | |
190 | ||
191 | mutex_lock(&smd_pkt_devp->tx_lock); | |
192 | if (smd_write_avail(smd_pkt_devp->ch) < count) { | |
193 | mutex_unlock(&smd_pkt_devp->tx_lock); | |
194 | DBG("Not enough space to write\n"); | |
195 | return -ENOMEM; | |
196 | } | |
197 | ||
198 | D_DUMP_BUFFER("write: ", count, buf); | |
199 | r = copy_from_user(smd_pkt_devp->tx_buf, buf, count); | |
200 | if (r) { | |
201 | mutex_unlock(&smd_pkt_devp->tx_lock); | |
202 | pr_err("copy_from_user failed %d\n", r); | |
203 | return -EFAULT; | |
204 | } | |
205 | ||
206 | r = smd_write(smd_pkt_devp->ch, smd_pkt_devp->tx_buf, count); | |
207 | if (r != count) { | |
208 | mutex_unlock(&smd_pkt_devp->tx_lock); | |
209 | pr_err("smd_write failed to write %d bytes: %d.\n", count, r); | |
210 | return -EIO; | |
211 | } | |
212 | mutex_unlock(&smd_pkt_devp->tx_lock); | |
213 | ||
214 | DBG("wrote %d bytes\n", count); | |
215 | return count; | |
216 | } | |
217 | ||
218 | static unsigned int smd_pkt_poll(struct file *file, poll_table *wait) | |
219 | { | |
220 | struct smd_pkt_dev *smd_pkt_devp; | |
221 | unsigned int mask = 0; | |
222 | ||
223 | smd_pkt_devp = file->private_data; | |
224 | if (!smd_pkt_devp) | |
225 | return POLLERR; | |
226 | ||
227 | DBG("poll waiting\n"); | |
228 | poll_wait(file, &smd_pkt_devp->ch_read_wait_queue, wait); | |
229 | if (smd_read_avail(smd_pkt_devp->ch)) | |
230 | mask |= POLLIN | POLLRDNORM; | |
231 | ||
232 | DBG("poll return\n"); | |
233 | return mask; | |
234 | } | |
235 | ||
236 | static void smd_pkt_ch_notify(void *priv, unsigned event) | |
237 | { | |
238 | struct smd_pkt_dev *smd_pkt_devp = priv; | |
239 | ||
240 | if (smd_pkt_devp->ch == 0) | |
241 | return; | |
242 | ||
243 | switch (event) { | |
244 | case SMD_EVENT_DATA: | |
245 | DBG("data\n"); | |
246 | check_and_wakeup_reader(smd_pkt_devp); | |
247 | break; | |
248 | ||
249 | case SMD_EVENT_OPEN: | |
250 | DBG("remote open\n"); | |
251 | smd_pkt_devp->remote_open = 1; | |
252 | wake_up_interruptible(&smd_pkt_devp->ch_opened_wait_queue); | |
253 | break; | |
254 | ||
255 | case SMD_EVENT_CLOSE: | |
256 | smd_pkt_devp->remote_open = 0; | |
257 | pr_info("remote closed\n"); | |
258 | break; | |
259 | ||
260 | default: | |
261 | pr_err("unknown event %d\n", event); | |
262 | break; | |
263 | } | |
264 | } | |
265 | ||
266 | static char *smd_pkt_dev_name[] = { | |
267 | "smdcntl0", | |
268 | "smdcntl1", | |
269 | "smdcntl2", | |
270 | "smdcntl3", | |
271 | "smdcntl4", | |
272 | "smdcntl5", | |
273 | "smdcntl6", | |
274 | "smdcntl7", | |
275 | "smd22", | |
276 | }; | |
277 | ||
278 | static char *smd_ch_name[] = { | |
279 | "DATA5_CNTL", | |
280 | "DATA6_CNTL", | |
281 | "DATA7_CNTL", | |
282 | "DATA8_CNTL", | |
283 | "DATA9_CNTL", | |
284 | "DATA12_CNTL", | |
285 | "DATA13_CNTL", | |
286 | "DATA14_CNTL", | |
287 | "DATA22", | |
288 | }; | |
289 | ||
290 | static int smd_pkt_open(struct inode *inode, struct file *file) | |
291 | { | |
292 | int r = 0; | |
293 | struct smd_pkt_dev *smd_pkt_devp; | |
294 | ||
295 | smd_pkt_devp = container_of(inode->i_cdev, struct smd_pkt_dev, cdev); | |
296 | if (!smd_pkt_devp) | |
297 | return -EINVAL; | |
298 | ||
299 | file->private_data = smd_pkt_devp; | |
300 | ||
301 | mutex_lock(&smd_pkt_devp->ch_lock); | |
302 | if (smd_pkt_devp->open_count == 0) { | |
303 | r = smd_open(smd_ch_name[smd_pkt_devp->i], | |
304 | &smd_pkt_devp->ch, smd_pkt_devp, | |
305 | smd_pkt_ch_notify); | |
306 | if (r < 0) { | |
307 | pr_err("smd_open failed for %s, %d\n", | |
308 | smd_ch_name[smd_pkt_devp->i], r); | |
309 | goto out; | |
310 | } | |
311 | ||
312 | r = wait_event_interruptible_timeout( | |
313 | smd_pkt_devp->ch_opened_wait_queue, | |
314 | smd_pkt_devp->remote_open, | |
315 | msecs_to_jiffies(2 * HZ)); | |
316 | if (r == 0) | |
317 | r = -ETIMEDOUT; | |
318 | ||
319 | if (r < 0) { | |
320 | pr_err("wait returned %d\n", r); | |
321 | smd_close(smd_pkt_devp->ch); | |
322 | smd_pkt_devp->ch = 0; | |
323 | } else { | |
324 | smd_pkt_devp->open_count++; | |
325 | r = 0; | |
326 | } | |
327 | } | |
328 | out: | |
329 | mutex_unlock(&smd_pkt_devp->ch_lock); | |
330 | return r; | |
331 | } | |
332 | ||
333 | static int smd_pkt_release(struct inode *inode, struct file *file) | |
334 | { | |
335 | int r = 0; | |
336 | struct smd_pkt_dev *smd_pkt_devp = file->private_data; | |
337 | ||
338 | if (!smd_pkt_devp) | |
339 | return -EINVAL; | |
340 | ||
341 | mutex_lock(&smd_pkt_devp->ch_lock); | |
342 | if (--smd_pkt_devp->open_count == 0) { | |
343 | r = smd_close(smd_pkt_devp->ch); | |
344 | smd_pkt_devp->ch = 0; | |
345 | } | |
346 | mutex_unlock(&smd_pkt_devp->ch_lock); | |
347 | ||
348 | return r; | |
349 | } | |
350 | ||
351 | static const struct file_operations smd_pkt_fops = { | |
352 | .owner = THIS_MODULE, | |
353 | .open = smd_pkt_open, | |
354 | .release = smd_pkt_release, | |
355 | .read = smd_pkt_read, | |
356 | .write = smd_pkt_write, | |
357 | .poll = smd_pkt_poll, | |
358 | }; | |
359 | ||
360 | static int __init smd_pkt_init(void) | |
361 | { | |
362 | int i; | |
363 | int r; | |
364 | ||
365 | r = alloc_chrdev_region(&smd_pkt_number, 0, | |
366 | NUM_SMD_PKT_PORTS, DEVICE_NAME); | |
367 | if (r) { | |
368 | pr_err("alloc_chrdev_region() failed %d\n", r); | |
369 | return r; | |
370 | } | |
371 | ||
372 | smd_pkt_classp = class_create(THIS_MODULE, DEVICE_NAME); | |
373 | if (IS_ERR(smd_pkt_classp)) { | |
374 | r = PTR_ERR(smd_pkt_classp); | |
375 | pr_err("class_create() failed %d\n", r); | |
376 | goto unreg_chardev; | |
377 | } | |
378 | ||
379 | for (i = 0; i < NUM_SMD_PKT_PORTS; ++i) { | |
380 | smd_pkt_devp[i] = kzalloc(sizeof(struct smd_pkt_dev), | |
381 | GFP_KERNEL); | |
7e8aa048 TM |
382 | if (!smd_pkt_devp[i]) { |
383 | pr_err("kmalloc() failed\n"); | |
73210a13 NV |
384 | goto clean_cdevs; |
385 | } | |
386 | ||
387 | smd_pkt_devp[i]->i = i; | |
388 | ||
389 | init_waitqueue_head(&smd_pkt_devp[i]->ch_read_wait_queue); | |
390 | smd_pkt_devp[i]->remote_open = 0; | |
391 | init_waitqueue_head(&smd_pkt_devp[i]->ch_opened_wait_queue); | |
392 | ||
393 | mutex_init(&smd_pkt_devp[i]->ch_lock); | |
394 | mutex_init(&smd_pkt_devp[i]->rx_lock); | |
395 | mutex_init(&smd_pkt_devp[i]->tx_lock); | |
396 | ||
397 | cdev_init(&smd_pkt_devp[i]->cdev, &smd_pkt_fops); | |
398 | smd_pkt_devp[i]->cdev.owner = THIS_MODULE; | |
399 | ||
400 | r = cdev_add(&smd_pkt_devp[i]->cdev, | |
401 | (smd_pkt_number + i), 1); | |
402 | if (r) { | |
403 | pr_err("cdev_add() failed %d\n", r); | |
404 | kfree(smd_pkt_devp[i]); | |
405 | goto clean_cdevs; | |
406 | } | |
407 | ||
408 | smd_pkt_devp[i]->devicep = | |
409 | device_create(smd_pkt_classp, NULL, | |
410 | (smd_pkt_number + i), NULL, | |
411 | smd_pkt_dev_name[i]); | |
412 | if (IS_ERR(smd_pkt_devp[i]->devicep)) { | |
413 | r = PTR_ERR(smd_pkt_devp[i]->devicep); | |
414 | pr_err("device_create() failed %d\n", r); | |
415 | cdev_del(&smd_pkt_devp[i]->cdev); | |
416 | kfree(smd_pkt_devp[i]); | |
417 | goto clean_cdevs; | |
418 | } | |
419 | ||
420 | } | |
421 | ||
422 | pr_info("SMD Packet Port Driver Initialized.\n"); | |
423 | return 0; | |
424 | ||
425 | clean_cdevs: | |
426 | if (i > 0) { | |
427 | while (--i >= 0) { | |
428 | mutex_destroy(&smd_pkt_devp[i]->ch_lock); | |
429 | mutex_destroy(&smd_pkt_devp[i]->rx_lock); | |
430 | mutex_destroy(&smd_pkt_devp[i]->tx_lock); | |
431 | cdev_del(&smd_pkt_devp[i]->cdev); | |
432 | kfree(smd_pkt_devp[i]); | |
433 | device_destroy(smd_pkt_classp, | |
434 | MKDEV(MAJOR(smd_pkt_number), i)); | |
435 | } | |
436 | } | |
437 | ||
438 | class_destroy(smd_pkt_classp); | |
439 | unreg_chardev: | |
440 | unregister_chrdev_region(MAJOR(smd_pkt_number), NUM_SMD_PKT_PORTS); | |
441 | return r; | |
442 | } | |
443 | module_init(smd_pkt_init); | |
444 | ||
445 | static void __exit smd_pkt_cleanup(void) | |
446 | { | |
447 | int i; | |
448 | ||
449 | for (i = 0; i < NUM_SMD_PKT_PORTS; ++i) { | |
450 | mutex_destroy(&smd_pkt_devp[i]->ch_lock); | |
451 | mutex_destroy(&smd_pkt_devp[i]->rx_lock); | |
452 | mutex_destroy(&smd_pkt_devp[i]->tx_lock); | |
453 | cdev_del(&smd_pkt_devp[i]->cdev); | |
454 | kfree(smd_pkt_devp[i]); | |
455 | device_destroy(smd_pkt_classp, | |
456 | MKDEV(MAJOR(smd_pkt_number), i)); | |
457 | } | |
458 | ||
459 | class_destroy(smd_pkt_classp); | |
460 | unregister_chrdev_region(MAJOR(smd_pkt_number), NUM_SMD_PKT_PORTS); | |
461 | } | |
462 | module_exit(smd_pkt_cleanup); | |
463 | ||
464 | MODULE_DESCRIPTION("MSM Shared Memory Packet Port"); | |
465 | MODULE_LICENSE("GPL v2"); |