drivers/mailbox/mailbox-test.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (C) 2015 ST Microelectronics
   4  *
   5  * Author: Lee Jones <lee.jones@linaro.org>
   6  */
   7
   8 #include <linux/debugfs.h>
   9 #include <linux/err.h>
  10 #include <linux/fs.h>
  11 #include <linux/io.h>
  12 #include <linux/kernel.h>
  13 #include <linux/mailbox_client.h>
  14 #include <linux/module.h>
  15 #include <linux/mutex.h>
  16 #include <linux/of.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/poll.h>
  19 #include <linux/slab.h>
  20 #include <linux/spinlock.h>
  21 #include <linux/uaccess.h>
  22 #include <linux/sched/signal.h>
  23
  24 #define MBOX_MAX_SIG_LEN        8
  25 #define MBOX_MAX_MSG_LEN        128
  26 #define MBOX_BYTES_PER_LINE     16
  27 #define MBOX_HEXDUMP_LINE_LEN   ((MBOX_BYTES_PER_LINE * 4) + 2)
  28 #define MBOX_HEXDUMP_MAX_LEN    (MBOX_HEXDUMP_LINE_LEN *                \
  29                                  (MBOX_MAX_MSG_LEN / MBOX_BYTES_PER_LINE))
  30
  31 static bool mbox_data_ready;
  32
  33 struct mbox_test_device {
  34         struct device           *dev;
  35         void __iomem            *tx_mmio;
  36         void __iomem            *rx_mmio;
  37         struct mbox_chan        *tx_channel;
  38         struct mbox_chan        *rx_channel;
  39         char                    *rx_buffer;
  40         char                    *signal;
  41         char                    *message;
  42         spinlock_t              lock;
  43         struct mutex            mutex;
  44         wait_queue_head_t       waitq;
  45         struct fasync_struct    *async_queue;
  46         struct dentry           *root_debugfs_dir;
  47 };
  48
  49 static ssize_t mbox_test_signal_write(struct file *filp,
  50                                        const char __user *userbuf,
  51                                        size_t count, loff_t *ppos)
  52 {
  53         struct mbox_test_device *tdev = filp->private_data;
  54
  55         if (!tdev->tx_channel) {
  56                 dev_err(tdev->dev, "Channel cannot do Tx\n");
  57                 return -EINVAL;
  58         }
  59
  60         if (count > MBOX_MAX_SIG_LEN) {
  61                 dev_err(tdev->dev,
  62                         "Signal length %zd greater than max allowed %d\n",
  63                         count, MBOX_MAX_SIG_LEN);
  64                 return -EINVAL;
  65         }
  66
  67         /* Only allocate memory if we need to */
  68         if (!tdev->signal) {
  69                 tdev->signal = kzalloc(MBOX_MAX_SIG_LEN, GFP_KERNEL);
  70                 if (!tdev->signal)
  71                         return -ENOMEM;
  72         }
  73
  74         if (copy_from_user(tdev->signal, userbuf, count)) {
  75                 kfree(tdev->signal);
  76                 tdev->signal = NULL;
  77                 return -EFAULT;
  78         }
  79
  80         return count;
  81 }
  82
  83 static const struct file_operations mbox_test_signal_ops = {
  84         .write  = mbox_test_signal_write,
  85         .open   = simple_open,
  86         .llseek = generic_file_llseek,
  87 };
  88
  89 static int mbox_test_message_fasync(int fd, struct file *filp, int on)
  90 {
  91         struct mbox_test_device *tdev = filp->private_data;
  92
  93         return fasync_helper(fd, filp, on, &tdev->async_queue);
  94 }
  95
  96 static ssize_t mbox_test_message_write(struct file *filp,
  97                                        const char __user *userbuf,
  98                                        size_t count, loff_t *ppos)
  99 {
 100         struct mbox_test_device *tdev = filp->private_data;
 101         char *message;
 102         void *data;
 103         int ret;
 104
 105         if (!tdev->tx_channel) {
 106                 dev_err(tdev->dev, "Channel cannot do Tx\n");
 107                 return -EINVAL;
 108         }
 109
 110         if (count > MBOX_MAX_MSG_LEN) {
 111                 dev_err(tdev->dev,
 112                         "Message length %zd greater than max allowed %d\n",
 113                         count, MBOX_MAX_MSG_LEN);
 114                 return -EINVAL;
 115         }
 116
 117         message = kzalloc(MBOX_MAX_MSG_LEN, GFP_KERNEL);
 118         if (!message)
 119                 return -ENOMEM;
 120
 121         mutex_lock(&tdev->mutex);
 122
 123         tdev->message = message;
 124         ret = copy_from_user(tdev->message, userbuf, count);
 125         if (ret) {
 126                 ret = -EFAULT;
 127                 goto out;
 128         }
 129
 130         /*
 131          * A separate signal is only of use if there is
 132          * MMIO to subsequently pass the message through
 133          */
 134         if (tdev->tx_mmio && tdev->signal) {
 135                 print_hex_dump_bytes("Client: Sending: Signal: ", DUMP_PREFIX_ADDRESS,
 136                                      tdev->signal, MBOX_MAX_SIG_LEN);
 137
 138                 data = tdev->signal;
 139         } else
 140                 data = tdev->message;
 141
 142         print_hex_dump_bytes("Client: Sending: Message: ", DUMP_PREFIX_ADDRESS,
 143                              tdev->message, MBOX_MAX_MSG_LEN);
 144
 145         ret = mbox_send_message(tdev->tx_channel, data);
 146         if (ret < 0)
 147                 dev_err(tdev->dev, "Failed to send message via mailbox\n");
 148
 149 out:
 150         kfree(tdev->signal);
 151         kfree(tdev->message);
 152         tdev->signal = NULL;
 153
 154         mutex_unlock(&tdev->mutex);
 155
 156         return ret < 0 ? ret : count;
 157 }
 158
 159 static bool mbox_test_message_data_ready(struct mbox_test_device *tdev)
 160 {
 161         bool data_ready;
 162         unsigned long flags;
 163
 164         spin_lock_irqsave(&tdev->lock, flags);
 165         data_ready = mbox_data_ready;
 166         spin_unlock_irqrestore(&tdev->lock, flags);
 167
 168         return data_ready;
 169 }
 170
 171 static ssize_t mbox_test_message_read(struct file *filp, char __user *userbuf,
 172                                       size_t count, loff_t *ppos)
 173 {
 174         struct mbox_test_device *tdev = filp->private_data;
 175         unsigned long flags;
 176         char *touser, *ptr;
 177         int l = 0;
 178         int ret;
 179
 180         DECLARE_WAITQUEUE(wait, current);
 181
 182         touser = kzalloc(MBOX_HEXDUMP_MAX_LEN + 1, GFP_KERNEL);
 183         if (!touser)
 184                 return -ENOMEM;
 185
 186         if (!tdev->rx_channel) {
 187                 ret = snprintf(touser, 20, "<NO RX CAPABILITY>\n");
 188                 ret = simple_read_from_buffer(userbuf, count, ppos,
 189                                               touser, ret);
 190                 goto kfree_err;
 191         }
 192
 193         add_wait_queue(&tdev->waitq, &wait);
 194
 195         do {
 196                 __set_current_state(TASK_INTERRUPTIBLE);
 197
 198                 if (mbox_test_message_data_ready(tdev))
 199                         break;
 200
 201                 if (filp->f_flags & O_NONBLOCK) {
 202                         ret = -EAGAIN;
 203                         goto waitq_err;
 204                 }
 205
 206                 if (signal_pending(current)) {
 207                         ret = -ERESTARTSYS;
 208                         goto waitq_err;
 209                 }
 210                 schedule();
 211
 212         } while (1);
 213
 214         spin_lock_irqsave(&tdev->lock, flags);
 215
 216         ptr = tdev->rx_buffer;
 217         while (l < MBOX_HEXDUMP_MAX_LEN) {
 218                 hex_dump_to_buffer(ptr,
 219                                    MBOX_BYTES_PER_LINE,
 220                                    MBOX_BYTES_PER_LINE, 1, touser + l,
 221                                    MBOX_HEXDUMP_LINE_LEN, true);
 222
 223                 ptr += MBOX_BYTES_PER_LINE;
 224                 l += MBOX_HEXDUMP_LINE_LEN;
 225                 *(touser + (l - 1)) = '\n';
 226         }
 227         *(touser + l) = '\0';
 228
 229         memset(tdev->rx_buffer, 0, MBOX_MAX_MSG_LEN);
 230         mbox_data_ready = false;
 231
 232         spin_unlock_irqrestore(&tdev->lock, flags);
 233
 234         ret = simple_read_from_buffer(userbuf, count, ppos, touser, MBOX_HEXDUMP_MAX_LEN);
 235 waitq_err:
 236         __set_current_state(TASK_RUNNING);
 237         remove_wait_queue(&tdev->waitq, &wait);
 238 kfree_err:
 239         kfree(touser);
 240         return ret;
 241 }
 242
 243 static __poll_t
 244 mbox_test_message_poll(struct file *filp, struct poll_table_struct *wait)
 245 {
 246         struct mbox_test_device *tdev = filp->private_data;
 247
 248         poll_wait(filp, &tdev->waitq, wait);
 249
 250         if (mbox_test_message_data_ready(tdev))
 251                 return EPOLLIN | EPOLLRDNORM;
 252         return 0;
 253 }
 254
 255 static const struct file_operations mbox_test_message_ops = {
 256         .write  = mbox_test_message_write,
 257         .read   = mbox_test_message_read,
 258         .fasync = mbox_test_message_fasync,
 259         .poll   = mbox_test_message_poll,
 260         .open   = simple_open,
 261         .llseek = generic_file_llseek,
 262 };
 263
 264 static int mbox_test_add_debugfs(struct platform_device *pdev,
 265                                  struct mbox_test_device *tdev)
 266 {
 267         if (!debugfs_initialized())
 268                 return 0;
 269
 270         tdev->root_debugfs_dir = debugfs_create_dir(dev_name(&pdev->dev), NULL);
 271         if (!tdev->root_debugfs_dir) {
 272                 dev_err(&pdev->dev, "Failed to create Mailbox debugfs\n");
 273                 return -EINVAL;
 274         }
 275
 276         debugfs_create_file("message", 0600, tdev->root_debugfs_dir,
 277                             tdev, &mbox_test_message_ops);
 278
 279         debugfs_create_file("signal", 0200, tdev->root_debugfs_dir,
 280                             tdev, &mbox_test_signal_ops);
 281
 282         return 0;
 283 }
 284
 285 static void mbox_test_receive_message(struct mbox_client *client, void *message)
 286 {
 287         struct mbox_test_device *tdev = dev_get_drvdata(client->dev);
 288         unsigned long flags;
 289
 290         spin_lock_irqsave(&tdev->lock, flags);
 291         if (tdev->rx_mmio) {
 292                 memcpy_fromio(tdev->rx_buffer, tdev->rx_mmio, MBOX_MAX_MSG_LEN);
 293                 print_hex_dump_bytes("Client: Received [MMIO]: ", DUMP_PREFIX_ADDRESS,
 294                                      tdev->rx_buffer, MBOX_MAX_MSG_LEN);
 295         } else if (message) {
 296                 print_hex_dump_bytes("Client: Received [API]: ", DUMP_PREFIX_ADDRESS,
 297                                      message, MBOX_MAX_MSG_LEN);
 298                 memcpy(tdev->rx_buffer, message, MBOX_MAX_MSG_LEN);
 299         }
 300         mbox_data_ready = true;
 301         spin_unlock_irqrestore(&tdev->lock, flags);
 302
 303         wake_up_interruptible(&tdev->waitq);
 304
 305         kill_fasync(&tdev->async_queue, SIGIO, POLL_IN);
 306 }
 307
 308 static void mbox_test_prepare_message(struct mbox_client *client, void *message)
 309 {
 310         struct mbox_test_device *tdev = dev_get_drvdata(client->dev);
 311
 312         if (tdev->tx_mmio) {
 313                 if (tdev->signal)
 314                         memcpy_toio(tdev->tx_mmio, tdev->message, MBOX_MAX_MSG_LEN);
 315                 else
 316                         memcpy_toio(tdev->tx_mmio, message, MBOX_MAX_MSG_LEN);
 317         }
 318 }
 319
 320 static void mbox_test_message_sent(struct mbox_client *client,
 321                                    void *message, int r)
 322 {
 323         if (r)
 324                 dev_warn(client->dev,
 325                          "Client: Message could not be sent: %d\n", r);
 326         else
 327                 dev_info(client->dev,
 328                          "Client: Message sent\n");
 329 }
 330
 331 static struct mbox_chan *
 332 mbox_test_request_channel(struct platform_device *pdev, const char *name)
 333 {
 334         struct mbox_client *client;
 335         struct mbox_chan *channel;
 336
 337         client = devm_kzalloc(&pdev->dev, sizeof(*client), GFP_KERNEL);
 338         if (!client)
 339                 return ERR_PTR(-ENOMEM);
 340
 341         client->dev             = &pdev->dev;
 342         client->rx_callback     = mbox_test_receive_message;
 343         client->tx_prepare      = mbox_test_prepare_message;
 344         client->tx_done         = mbox_test_message_sent;
 345         client->tx_block        = true;
 346         client->knows_txdone    = false;
 347         client->tx_tout         = 500;
 348
 349         channel = mbox_request_channel_byname(client, name);
 350         if (IS_ERR(channel)) {
 351                 dev_warn(&pdev->dev, "Failed to request %s channel\n", name);
 352                 return NULL;
 353         }
 354
 355         return channel;
 356 }
 357
 358 static int mbox_test_probe(struct platform_device *pdev)
 359 {
 360         struct mbox_test_device *tdev;
 361         struct resource *res;
 362         resource_size_t size;
 363         int ret;
 364
 365         tdev = devm_kzalloc(&pdev->dev, sizeof(*tdev), GFP_KERNEL);
 366         if (!tdev)
 367                 return -ENOMEM;
 368
 369         /* It's okay for MMIO to be NULL */
 370         tdev->tx_mmio = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
 371         if (PTR_ERR(tdev->tx_mmio) == -EBUSY) {
 372                 /* if reserved area in SRAM, try just ioremap */
 373                 size = resource_size(res);
 374                 tdev->tx_mmio = devm_ioremap(&pdev->dev, res->start, size);
 375         } else if (IS_ERR(tdev->tx_mmio)) {
 376                 tdev->tx_mmio = NULL;
 377         }
 378
 379         /* If specified, second reg entry is Rx MMIO */
 380         tdev->rx_mmio = devm_platform_get_and_ioremap_resource(pdev, 1, &res);
 381         if (PTR_ERR(tdev->rx_mmio) == -EBUSY) {
 382                 size = resource_size(res);
 383                 tdev->rx_mmio = devm_ioremap(&pdev->dev, res->start, size);
 384         } else if (IS_ERR(tdev->rx_mmio)) {
 385                 tdev->rx_mmio = tdev->tx_mmio;
 386         }
 387
 388         tdev->tx_channel = mbox_test_request_channel(pdev, "tx");
 389         tdev->rx_channel = mbox_test_request_channel(pdev, "rx");
 390
 391         if (IS_ERR_OR_NULL(tdev->tx_channel) && IS_ERR_OR_NULL(tdev->rx_channel))
 392                 return -EPROBE_DEFER;
 393
 394         /* If Rx is not specified but has Rx MMIO, then Rx = Tx */
 395         if (!tdev->rx_channel && (tdev->rx_mmio != tdev->tx_mmio))
 396                 tdev->rx_channel = tdev->tx_channel;
 397
 398         tdev->dev = &pdev->dev;
 399         platform_set_drvdata(pdev, tdev);
 400
 401         spin_lock_init(&tdev->lock);
 402         mutex_init(&tdev->mutex);
 403
 404         if (tdev->rx_channel) {
 405                 tdev->rx_buffer = devm_kzalloc(&pdev->dev,
 406                                                MBOX_MAX_MSG_LEN, GFP_KERNEL);
 407                 if (!tdev->rx_buffer)
 408                         return -ENOMEM;
 409         }
 410
 411         ret = mbox_test_add_debugfs(pdev, tdev);
 412         if (ret)
 413                 return ret;
 414
 415         init_waitqueue_head(&tdev->waitq);
 416         dev_info(&pdev->dev, "Successfully registered\n");
 417
 418         return 0;
 419 }
 420
 421 static void mbox_test_remove(struct platform_device *pdev)
 422 {
 423         struct mbox_test_device *tdev = platform_get_drvdata(pdev);
 424
 425         debugfs_remove_recursive(tdev->root_debugfs_dir);
 426
 427         if (tdev->tx_channel)
 428                 mbox_free_channel(tdev->tx_channel);
 429         if (tdev->rx_channel)
 430                 mbox_free_channel(tdev->rx_channel);
 431 }
 432
 433 static const struct of_device_id mbox_test_match[] = {
 434         { .compatible = "mailbox-test" },
 435         {},
 436 };
 437 MODULE_DEVICE_TABLE(of, mbox_test_match);
 438
 439 static struct platform_driver mbox_test_driver = {
 440         .driver = {
 441                 .name = "mailbox_test",
 442                 .of_match_table = mbox_test_match,
 443         },
 444         .probe  = mbox_test_probe,
 445         .remove_new = mbox_test_remove,
 446 };
 447 module_platform_driver(mbox_test_driver);
 448
 449 MODULE_DESCRIPTION("Generic Mailbox Testing Facility");
 450 MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org");
 451 MODULE_LICENSE("GPL v2");