drivers/mailbox/mailbox-test.c

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