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