Duy Truong | 790f06d | 2013-02-13 16:38:12 -0800 | [diff] [blame] | 1 | /* Copyright (c) 2008-2010, The Linux Foundation. All rights reserved. |
Niranjana Vishwanathapura | 73210a1 | 2011-03-23 16:42:55 -0700 | [diff] [blame] | 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 | * |
Niranjana Vishwanathapura | 73210a1 | 2011-03-23 16:42:55 -0700 | [diff] [blame] | 12 | */ |
| 13 | /* |
| 14 | * SMD Packet Driver -- Provides userspace interface to SMD packet ports. |
| 15 | */ |
| 16 | |
| 17 | #include <linux/slab.h> |
| 18 | #include <linux/cdev.h> |
| 19 | #include <linux/module.h> |
| 20 | #include <linux/fs.h> |
| 21 | #include <linux/device.h> |
| 22 | #include <linux/sched.h> |
| 23 | #include <linux/mutex.h> |
| 24 | #include <linux/delay.h> |
| 25 | #include <linux/uaccess.h> |
| 26 | #include <linux/workqueue.h> |
| 27 | #include <linux/poll.h> |
| 28 | |
| 29 | #include <mach/msm_smd.h> |
| 30 | |
| 31 | #define NUM_SMD_PKT_PORTS 9 |
| 32 | #define DEVICE_NAME "smdpkt" |
| 33 | #define MAX_BUF_SIZE 2048 |
| 34 | |
| 35 | struct smd_pkt_dev { |
| 36 | struct cdev cdev; |
| 37 | struct device *devicep; |
| 38 | |
| 39 | struct smd_channel *ch; |
| 40 | int open_count; |
| 41 | struct mutex ch_lock; |
| 42 | struct mutex rx_lock; |
| 43 | struct mutex tx_lock; |
| 44 | wait_queue_head_t ch_read_wait_queue; |
| 45 | wait_queue_head_t ch_opened_wait_queue; |
| 46 | |
| 47 | int i; |
| 48 | |
| 49 | unsigned char tx_buf[MAX_BUF_SIZE]; |
| 50 | unsigned char rx_buf[MAX_BUF_SIZE]; |
| 51 | int remote_open; |
| 52 | |
| 53 | } *smd_pkt_devp[NUM_SMD_PKT_PORTS]; |
| 54 | |
| 55 | struct class *smd_pkt_classp; |
| 56 | static dev_t smd_pkt_number; |
| 57 | |
| 58 | static int msm_smd_pkt_debug_enable; |
| 59 | module_param_named(debug_enable, msm_smd_pkt_debug_enable, |
| 60 | int, S_IRUGO | S_IWUSR | S_IWGRP); |
| 61 | |
| 62 | #ifdef DEBUG |
| 63 | #define D_DUMP_BUFFER(prestr, cnt, buf) do { \ |
| 64 | int i; \ |
| 65 | if (msm_smd_pkt_debug_enable) { \ |
| 66 | pr_debug("%s", prestr); \ |
| 67 | for (i = 0; i < cnt; i++) \ |
| 68 | pr_debug("%.2x", buf[i]); \ |
| 69 | pr_debug("\n"); \ |
| 70 | } \ |
| 71 | } while (0) |
| 72 | #else |
| 73 | #define D_DUMP_BUFFER(prestr, cnt, buf) do {} while (0) |
| 74 | #endif |
| 75 | |
| 76 | #ifdef DEBUG |
| 77 | #define DBG(x...) do { \ |
| 78 | if (msm_smd_pkt_debug_enable) \ |
| 79 | pr_debug(x); \ |
| 80 | } while (0) |
| 81 | #else |
| 82 | #define DBG(x...) do {} while (0) |
| 83 | #endif |
| 84 | |
| 85 | static void check_and_wakeup_reader(struct smd_pkt_dev *smd_pkt_devp) |
| 86 | { |
| 87 | int sz; |
| 88 | |
| 89 | if (!smd_pkt_devp || !smd_pkt_devp->ch) |
| 90 | return; |
| 91 | |
| 92 | sz = smd_cur_packet_size(smd_pkt_devp->ch); |
| 93 | if (sz == 0) { |
| 94 | DBG("no packet\n"); |
| 95 | return; |
| 96 | } |
| 97 | if (sz > smd_read_avail(smd_pkt_devp->ch)) { |
| 98 | DBG("incomplete packet\n"); |
| 99 | return; |
| 100 | } |
| 101 | |
| 102 | DBG("waking up reader\n"); |
| 103 | wake_up_interruptible(&smd_pkt_devp->ch_read_wait_queue); |
| 104 | } |
| 105 | |
| 106 | static int smd_pkt_read(struct file *file, char __user *buf, |
| 107 | size_t count, loff_t *ppos) |
| 108 | { |
| 109 | int r, bytes_read; |
| 110 | struct smd_pkt_dev *smd_pkt_devp; |
| 111 | struct smd_channel *chl; |
| 112 | |
| 113 | DBG("read %d bytes\n", count); |
| 114 | if (count > MAX_BUF_SIZE) |
| 115 | return -EINVAL; |
| 116 | |
| 117 | smd_pkt_devp = file->private_data; |
| 118 | if (!smd_pkt_devp || !smd_pkt_devp->ch) |
| 119 | return -EINVAL; |
| 120 | |
| 121 | chl = smd_pkt_devp->ch; |
| 122 | wait_for_packet: |
| 123 | r = wait_event_interruptible(smd_pkt_devp->ch_read_wait_queue, |
| 124 | (smd_cur_packet_size(chl) > 0 && |
| 125 | smd_read_avail(chl) >= |
| 126 | smd_cur_packet_size(chl))); |
| 127 | |
| 128 | if (r < 0) { |
| 129 | if (r != -ERESTARTSYS) |
| 130 | pr_err("wait returned %d\n", r); |
| 131 | return r; |
| 132 | } |
| 133 | |
| 134 | mutex_lock(&smd_pkt_devp->rx_lock); |
| 135 | |
| 136 | bytes_read = smd_cur_packet_size(smd_pkt_devp->ch); |
| 137 | if (bytes_read == 0 || |
| 138 | bytes_read < smd_read_avail(smd_pkt_devp->ch)) { |
| 139 | mutex_unlock(&smd_pkt_devp->rx_lock); |
| 140 | DBG("Nothing to read\n"); |
| 141 | goto wait_for_packet; |
| 142 | } |
| 143 | |
| 144 | if (bytes_read > count) { |
| 145 | mutex_unlock(&smd_pkt_devp->rx_lock); |
| 146 | pr_info("packet size %d > buffer size %d", bytes_read, count); |
| 147 | return -EINVAL; |
| 148 | } |
| 149 | |
| 150 | r = smd_read(smd_pkt_devp->ch, smd_pkt_devp->rx_buf, bytes_read); |
| 151 | if (r != bytes_read) { |
| 152 | mutex_unlock(&smd_pkt_devp->rx_lock); |
| 153 | pr_err("smd_read failed to read %d bytes: %d\n", bytes_read, r); |
| 154 | return -EIO; |
| 155 | } |
| 156 | |
| 157 | D_DUMP_BUFFER("read: ", bytes_read, smd_pkt_devp->rx_buf); |
| 158 | r = copy_to_user(buf, smd_pkt_devp->rx_buf, bytes_read); |
| 159 | mutex_unlock(&smd_pkt_devp->rx_lock); |
| 160 | if (r) { |
| 161 | pr_err("copy_to_user failed %d\n", r); |
| 162 | return -EFAULT; |
| 163 | } |
| 164 | |
| 165 | DBG("read complete %d bytes\n", bytes_read); |
| 166 | check_and_wakeup_reader(smd_pkt_devp); |
| 167 | |
| 168 | return bytes_read; |
| 169 | } |
| 170 | |
| 171 | static int smd_pkt_write(struct file *file, const char __user *buf, |
| 172 | size_t count, loff_t *ppos) |
| 173 | { |
| 174 | int r; |
| 175 | struct smd_pkt_dev *smd_pkt_devp; |
| 176 | |
| 177 | if (count > MAX_BUF_SIZE) |
| 178 | return -EINVAL; |
| 179 | |
| 180 | DBG("writting %d bytes\n", count); |
| 181 | |
| 182 | smd_pkt_devp = file->private_data; |
| 183 | if (!smd_pkt_devp || !smd_pkt_devp->ch) |
| 184 | return -EINVAL; |
| 185 | |
| 186 | mutex_lock(&smd_pkt_devp->tx_lock); |
| 187 | if (smd_write_avail(smd_pkt_devp->ch) < count) { |
| 188 | mutex_unlock(&smd_pkt_devp->tx_lock); |
| 189 | DBG("Not enough space to write\n"); |
| 190 | return -ENOMEM; |
| 191 | } |
| 192 | |
| 193 | D_DUMP_BUFFER("write: ", count, buf); |
| 194 | r = copy_from_user(smd_pkt_devp->tx_buf, buf, count); |
| 195 | if (r) { |
| 196 | mutex_unlock(&smd_pkt_devp->tx_lock); |
| 197 | pr_err("copy_from_user failed %d\n", r); |
| 198 | return -EFAULT; |
| 199 | } |
| 200 | |
| 201 | r = smd_write(smd_pkt_devp->ch, smd_pkt_devp->tx_buf, count); |
| 202 | if (r != count) { |
| 203 | mutex_unlock(&smd_pkt_devp->tx_lock); |
| 204 | pr_err("smd_write failed to write %d bytes: %d.\n", count, r); |
| 205 | return -EIO; |
| 206 | } |
| 207 | mutex_unlock(&smd_pkt_devp->tx_lock); |
| 208 | |
| 209 | DBG("wrote %d bytes\n", count); |
| 210 | return count; |
| 211 | } |
| 212 | |
| 213 | static unsigned int smd_pkt_poll(struct file *file, poll_table *wait) |
| 214 | { |
| 215 | struct smd_pkt_dev *smd_pkt_devp; |
| 216 | unsigned int mask = 0; |
| 217 | |
| 218 | smd_pkt_devp = file->private_data; |
| 219 | if (!smd_pkt_devp) |
| 220 | return POLLERR; |
| 221 | |
| 222 | DBG("poll waiting\n"); |
| 223 | poll_wait(file, &smd_pkt_devp->ch_read_wait_queue, wait); |
| 224 | if (smd_read_avail(smd_pkt_devp->ch)) |
| 225 | mask |= POLLIN | POLLRDNORM; |
| 226 | |
| 227 | DBG("poll return\n"); |
| 228 | return mask; |
| 229 | } |
| 230 | |
| 231 | static void smd_pkt_ch_notify(void *priv, unsigned event) |
| 232 | { |
| 233 | struct smd_pkt_dev *smd_pkt_devp = priv; |
| 234 | |
| 235 | if (smd_pkt_devp->ch == 0) |
| 236 | return; |
| 237 | |
| 238 | switch (event) { |
| 239 | case SMD_EVENT_DATA: |
| 240 | DBG("data\n"); |
| 241 | check_and_wakeup_reader(smd_pkt_devp); |
| 242 | break; |
| 243 | |
| 244 | case SMD_EVENT_OPEN: |
| 245 | DBG("remote open\n"); |
| 246 | smd_pkt_devp->remote_open = 1; |
| 247 | wake_up_interruptible(&smd_pkt_devp->ch_opened_wait_queue); |
| 248 | break; |
| 249 | |
| 250 | case SMD_EVENT_CLOSE: |
| 251 | smd_pkt_devp->remote_open = 0; |
| 252 | pr_info("remote closed\n"); |
| 253 | break; |
| 254 | |
| 255 | default: |
| 256 | pr_err("unknown event %d\n", event); |
| 257 | break; |
| 258 | } |
| 259 | } |
| 260 | |
| 261 | static char *smd_pkt_dev_name[] = { |
| 262 | "smdcntl0", |
| 263 | "smdcntl1", |
| 264 | "smdcntl2", |
| 265 | "smdcntl3", |
| 266 | "smdcntl4", |
| 267 | "smdcntl5", |
| 268 | "smdcntl6", |
| 269 | "smdcntl7", |
| 270 | "smd22", |
| 271 | }; |
| 272 | |
| 273 | static char *smd_ch_name[] = { |
| 274 | "DATA5_CNTL", |
| 275 | "DATA6_CNTL", |
| 276 | "DATA7_CNTL", |
| 277 | "DATA8_CNTL", |
| 278 | "DATA9_CNTL", |
| 279 | "DATA12_CNTL", |
| 280 | "DATA13_CNTL", |
| 281 | "DATA14_CNTL", |
| 282 | "DATA22", |
| 283 | }; |
| 284 | |
| 285 | static int smd_pkt_open(struct inode *inode, struct file *file) |
| 286 | { |
| 287 | int r = 0; |
| 288 | struct smd_pkt_dev *smd_pkt_devp; |
| 289 | |
| 290 | smd_pkt_devp = container_of(inode->i_cdev, struct smd_pkt_dev, cdev); |
| 291 | if (!smd_pkt_devp) |
| 292 | return -EINVAL; |
| 293 | |
| 294 | file->private_data = smd_pkt_devp; |
| 295 | |
| 296 | mutex_lock(&smd_pkt_devp->ch_lock); |
| 297 | if (smd_pkt_devp->open_count == 0) { |
| 298 | r = smd_open(smd_ch_name[smd_pkt_devp->i], |
| 299 | &smd_pkt_devp->ch, smd_pkt_devp, |
| 300 | smd_pkt_ch_notify); |
| 301 | if (r < 0) { |
| 302 | pr_err("smd_open failed for %s, %d\n", |
| 303 | smd_ch_name[smd_pkt_devp->i], r); |
| 304 | goto out; |
| 305 | } |
| 306 | |
| 307 | r = wait_event_interruptible_timeout( |
| 308 | smd_pkt_devp->ch_opened_wait_queue, |
| 309 | smd_pkt_devp->remote_open, |
| 310 | msecs_to_jiffies(2 * HZ)); |
| 311 | if (r == 0) |
| 312 | r = -ETIMEDOUT; |
| 313 | |
| 314 | if (r < 0) { |
| 315 | pr_err("wait returned %d\n", r); |
| 316 | smd_close(smd_pkt_devp->ch); |
| 317 | smd_pkt_devp->ch = 0; |
| 318 | } else { |
| 319 | smd_pkt_devp->open_count++; |
| 320 | r = 0; |
| 321 | } |
| 322 | } |
| 323 | out: |
| 324 | mutex_unlock(&smd_pkt_devp->ch_lock); |
| 325 | return r; |
| 326 | } |
| 327 | |
| 328 | static int smd_pkt_release(struct inode *inode, struct file *file) |
| 329 | { |
| 330 | int r = 0; |
| 331 | struct smd_pkt_dev *smd_pkt_devp = file->private_data; |
| 332 | |
| 333 | if (!smd_pkt_devp) |
| 334 | return -EINVAL; |
| 335 | |
| 336 | mutex_lock(&smd_pkt_devp->ch_lock); |
| 337 | if (--smd_pkt_devp->open_count == 0) { |
| 338 | r = smd_close(smd_pkt_devp->ch); |
| 339 | smd_pkt_devp->ch = 0; |
| 340 | } |
| 341 | mutex_unlock(&smd_pkt_devp->ch_lock); |
| 342 | |
| 343 | return r; |
| 344 | } |
| 345 | |
| 346 | static const struct file_operations smd_pkt_fops = { |
| 347 | .owner = THIS_MODULE, |
| 348 | .open = smd_pkt_open, |
| 349 | .release = smd_pkt_release, |
| 350 | .read = smd_pkt_read, |
| 351 | .write = smd_pkt_write, |
| 352 | .poll = smd_pkt_poll, |
| 353 | }; |
| 354 | |
| 355 | static int __init smd_pkt_init(void) |
| 356 | { |
| 357 | int i; |
| 358 | int r; |
| 359 | |
| 360 | r = alloc_chrdev_region(&smd_pkt_number, 0, |
| 361 | NUM_SMD_PKT_PORTS, DEVICE_NAME); |
| 362 | if (r) { |
| 363 | pr_err("alloc_chrdev_region() failed %d\n", r); |
| 364 | return r; |
| 365 | } |
| 366 | |
| 367 | smd_pkt_classp = class_create(THIS_MODULE, DEVICE_NAME); |
| 368 | if (IS_ERR(smd_pkt_classp)) { |
| 369 | r = PTR_ERR(smd_pkt_classp); |
| 370 | pr_err("class_create() failed %d\n", r); |
| 371 | goto unreg_chardev; |
| 372 | } |
| 373 | |
| 374 | for (i = 0; i < NUM_SMD_PKT_PORTS; ++i) { |
| 375 | smd_pkt_devp[i] = kzalloc(sizeof(struct smd_pkt_dev), |
| 376 | GFP_KERNEL); |
Thomas Meyer | 7e8aa04 | 2011-08-25 15:59:09 -0700 | [diff] [blame] | 377 | if (!smd_pkt_devp[i]) { |
| 378 | pr_err("kmalloc() failed\n"); |
Niranjana Vishwanathapura | 73210a1 | 2011-03-23 16:42:55 -0700 | [diff] [blame] | 379 | goto clean_cdevs; |
| 380 | } |
| 381 | |
| 382 | smd_pkt_devp[i]->i = i; |
| 383 | |
| 384 | init_waitqueue_head(&smd_pkt_devp[i]->ch_read_wait_queue); |
| 385 | smd_pkt_devp[i]->remote_open = 0; |
| 386 | init_waitqueue_head(&smd_pkt_devp[i]->ch_opened_wait_queue); |
| 387 | |
| 388 | mutex_init(&smd_pkt_devp[i]->ch_lock); |
| 389 | mutex_init(&smd_pkt_devp[i]->rx_lock); |
| 390 | mutex_init(&smd_pkt_devp[i]->tx_lock); |
| 391 | |
| 392 | cdev_init(&smd_pkt_devp[i]->cdev, &smd_pkt_fops); |
| 393 | smd_pkt_devp[i]->cdev.owner = THIS_MODULE; |
| 394 | |
| 395 | r = cdev_add(&smd_pkt_devp[i]->cdev, |
| 396 | (smd_pkt_number + i), 1); |
| 397 | if (r) { |
| 398 | pr_err("cdev_add() failed %d\n", r); |
| 399 | kfree(smd_pkt_devp[i]); |
| 400 | goto clean_cdevs; |
| 401 | } |
| 402 | |
| 403 | smd_pkt_devp[i]->devicep = |
| 404 | device_create(smd_pkt_classp, NULL, |
| 405 | (smd_pkt_number + i), NULL, |
| 406 | smd_pkt_dev_name[i]); |
| 407 | if (IS_ERR(smd_pkt_devp[i]->devicep)) { |
| 408 | r = PTR_ERR(smd_pkt_devp[i]->devicep); |
| 409 | pr_err("device_create() failed %d\n", r); |
| 410 | cdev_del(&smd_pkt_devp[i]->cdev); |
| 411 | kfree(smd_pkt_devp[i]); |
| 412 | goto clean_cdevs; |
| 413 | } |
| 414 | |
| 415 | } |
| 416 | |
| 417 | pr_info("SMD Packet Port Driver Initialized.\n"); |
| 418 | return 0; |
| 419 | |
| 420 | clean_cdevs: |
| 421 | if (i > 0) { |
| 422 | while (--i >= 0) { |
| 423 | mutex_destroy(&smd_pkt_devp[i]->ch_lock); |
| 424 | mutex_destroy(&smd_pkt_devp[i]->rx_lock); |
| 425 | mutex_destroy(&smd_pkt_devp[i]->tx_lock); |
| 426 | cdev_del(&smd_pkt_devp[i]->cdev); |
| 427 | kfree(smd_pkt_devp[i]); |
| 428 | device_destroy(smd_pkt_classp, |
| 429 | MKDEV(MAJOR(smd_pkt_number), i)); |
| 430 | } |
| 431 | } |
| 432 | |
| 433 | class_destroy(smd_pkt_classp); |
| 434 | unreg_chardev: |
| 435 | unregister_chrdev_region(MAJOR(smd_pkt_number), NUM_SMD_PKT_PORTS); |
| 436 | return r; |
| 437 | } |
| 438 | module_init(smd_pkt_init); |
| 439 | |
| 440 | static void __exit smd_pkt_cleanup(void) |
| 441 | { |
| 442 | int i; |
| 443 | |
| 444 | for (i = 0; i < NUM_SMD_PKT_PORTS; ++i) { |
| 445 | mutex_destroy(&smd_pkt_devp[i]->ch_lock); |
| 446 | mutex_destroy(&smd_pkt_devp[i]->rx_lock); |
| 447 | mutex_destroy(&smd_pkt_devp[i]->tx_lock); |
| 448 | cdev_del(&smd_pkt_devp[i]->cdev); |
| 449 | kfree(smd_pkt_devp[i]); |
| 450 | device_destroy(smd_pkt_classp, |
| 451 | MKDEV(MAJOR(smd_pkt_number), i)); |
| 452 | } |
| 453 | |
| 454 | class_destroy(smd_pkt_classp); |
| 455 | unregister_chrdev_region(MAJOR(smd_pkt_number), NUM_SMD_PKT_PORTS); |
| 456 | } |
| 457 | module_exit(smd_pkt_cleanup); |
| 458 | |
| 459 | MODULE_DESCRIPTION("MSM Shared Memory Packet Port"); |
| 460 | MODULE_LICENSE("GPL v2"); |