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/io.h>
  15 #include <linux/kernel.h>
  16 #include <linux/mailbox_client.h>
  17 #include <linux/module.h>
  18 #include <linux/of.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/slab.h>
  21 #include <linux/uaccess.h>
  22
  23 #define MBOX_MAX_SIG_LEN        8
  24 #define MBOX_MAX_MSG_LEN        128
  25 #define MBOX_BYTES_PER_LINE     16
  26 #define MBOX_HEXDUMP_LINE_LEN   ((MBOX_BYTES_PER_LINE * 4) + 2)
  27 #define MBOX_HEXDUMP_MAX_LEN    (MBOX_HEXDUMP_LINE_LEN *                \
  28                                  (MBOX_MAX_MSG_LEN / MBOX_BYTES_PER_LINE))
  29
  30 static struct dentry *root_debugfs_dir;
  31
  32 struct mbox_test_device {
  33         struct device           *dev;
  34         void __iomem            *tx_mmio;
  35         void __iomem            *rx_mmio;
  36         struct mbox_chan        *tx_channel;
  37         struct mbox_chan        *rx_channel;
  38         char                    *rx_buffer;
  39         char                    *signal;
  40         char                    *message;
  41         spinlock_t              lock;
  42 };
  43
  44 static ssize_t mbox_test_signal_write(struct file *filp,
  45                                        const char __user *userbuf,
  46                                        size_t count, loff_t *ppos)
  47 {
  48         struct mbox_test_device *tdev = filp->private_data;
  49
  50         if (!tdev->tx_channel) {
  51                 dev_err(tdev->dev, "Channel cannot do Tx\n");
  52                 return -EINVAL;
  53         }
  54
  55         if (count > MBOX_MAX_SIG_LEN) {
  56                 dev_err(tdev->dev,
  57                         "Signal length %zd greater than max allowed %d\n",
  58                         count, MBOX_MAX_SIG_LEN);
  59                 return -EINVAL;
  60         }
  61
  62         /* Only allocate memory if we need to */
  63         if (!tdev->signal) {
  64                 tdev->signal = kzalloc(MBOX_MAX_SIG_LEN, GFP_KERNEL);
  65                 if (!tdev->signal)
  66                         return -ENOMEM;
  67         }
  68
  69         if (copy_from_user(tdev->signal, userbuf, count)) {
  70                 kfree(tdev->signal);
  71                 tdev->signal = NULL;
  72                 return -EFAULT;
  73         }
  74
  75         return count;
  76 }
  77
  78 static const struct file_operations mbox_test_signal_ops = {
  79         .write  = mbox_test_signal_write,
  80         .open   = simple_open,
  81         .llseek = generic_file_llseek,
  82 };
  83
  84 static ssize_t mbox_test_message_write(struct file *filp,
  85                                        const char __user *userbuf,
  86                                        size_t count, loff_t *ppos)
  87 {
  88         struct mbox_test_device *tdev = filp->private_data;
  89         void *data;
  90         int ret;
  91
  92         if (!tdev->tx_channel) {
  93                 dev_err(tdev->dev, "Channel cannot do Tx\n");
  94                 return -EINVAL;
  95         }
  96
  97         if (count > MBOX_MAX_MSG_LEN) {
  98                 dev_err(tdev->dev,
  99                         "Message length %zd greater than max allowed %d\n",
 100                         count, MBOX_MAX_MSG_LEN);
 101                 return -EINVAL;
 102         }
 103
 104         tdev->message = kzalloc(MBOX_MAX_MSG_LEN, GFP_KERNEL);
 105         if (!tdev->message)
 106                 return -ENOMEM;
 107
 108         ret = copy_from_user(tdev->message, userbuf, count);
 109         if (ret) {
 110                 ret = -EFAULT;
 111                 goto out;
 112         }
 113
 114         /*
 115          * A separate signal is only of use if there is
 116          * MMIO to subsequently pass the message through
 117          */
 118         if (tdev->tx_mmio && tdev->signal) {
 119                 print_hex_dump_bytes("Client: Sending: Signal: ", DUMP_PREFIX_ADDRESS,
 120                                      tdev->signal, MBOX_MAX_SIG_LEN);
 121
 122                 data = tdev->signal;
 123         } else
 124                 data = tdev->message;
 125
 126         print_hex_dump_bytes("Client: Sending: Message: ", DUMP_PREFIX_ADDRESS,
 127                              tdev->message, MBOX_MAX_MSG_LEN);
 128
 129         ret = mbox_send_message(tdev->tx_channel, data);
 130         if (ret < 0)
 131                 dev_err(tdev->dev, "Failed to send message via mailbox\n");
 132
 133 out:
 134         kfree(tdev->signal);
 135         kfree(tdev->message);
 136         tdev->signal = NULL;
 137
 138         return ret < 0 ? ret : count;
 139 }
 140
 141 static ssize_t mbox_test_message_read(struct file *filp, char __user *userbuf,
 142                                       size_t count, loff_t *ppos)
 143 {
 144         struct mbox_test_device *tdev = filp->private_data;
 145         unsigned long flags;
 146         char *touser, *ptr;
 147         int l = 0;
 148         int ret;
 149
 150         touser = kzalloc(MBOX_HEXDUMP_MAX_LEN + 1, GFP_KERNEL);
 151         if (!touser)
 152                 return -ENOMEM;
 153
 154         if (!tdev->rx_channel) {
 155                 ret = snprintf(touser, 20, "<NO RX CAPABILITY>\n");
 156                 ret = simple_read_from_buffer(userbuf, count, ppos,
 157                                               touser, ret);
 158                 goto out;
 159         }
 160
 161         if (tdev->rx_buffer[0] == '\0') {
 162                 ret = snprintf(touser, 9, "<EMPTY>\n");
 163                 ret = simple_read_from_buffer(userbuf, count, ppos,
 164                                               touser, ret);
 165                 goto out;
 166         }
 167
 168         spin_lock_irqsave(&tdev->lock, flags);
 169
 170         ptr = tdev->rx_buffer;
 171         while (l < MBOX_HEXDUMP_MAX_LEN) {
 172                 hex_dump_to_buffer(ptr,
 173                                    MBOX_BYTES_PER_LINE,
 174                                    MBOX_BYTES_PER_LINE, 1, touser + l,
 175                                    MBOX_HEXDUMP_LINE_LEN, true);
 176
 177                 ptr += MBOX_BYTES_PER_LINE;
 178                 l += MBOX_HEXDUMP_LINE_LEN;
 179                 *(touser + (l - 1)) = '\n';
 180         }
 181         *(touser + l) = '\0';
 182
 183         memset(tdev->rx_buffer, 0, MBOX_MAX_MSG_LEN);
 184
 185         spin_unlock_irqrestore(&tdev->lock, flags);
 186
 187         ret = simple_read_from_buffer(userbuf, count, ppos, touser, MBOX_HEXDUMP_MAX_LEN);
 188 out:
 189         kfree(touser);
 190         return ret;
 191 }
 192
 193 static const struct file_operations mbox_test_message_ops = {
 194         .write  = mbox_test_message_write,
 195         .read   = mbox_test_message_read,
 196         .open   = simple_open,
 197         .llseek = generic_file_llseek,
 198 };
 199
 200 static int mbox_test_add_debugfs(struct platform_device *pdev,
 201                                  struct mbox_test_device *tdev)
 202 {
 203         if (!debugfs_initialized())
 204                 return 0;
 205
 206         root_debugfs_dir = debugfs_create_dir("mailbox", NULL);
 207         if (!root_debugfs_dir) {
 208                 dev_err(&pdev->dev, "Failed to create Mailbox debugfs\n");
 209                 return -EINVAL;
 210         }
 211
 212         debugfs_create_file("message", 0600, root_debugfs_dir,
 213                             tdev, &mbox_test_message_ops);
 214
 215         debugfs_create_file("signal", 0200, root_debugfs_dir,
 216                             tdev, &mbox_test_signal_ops);
 217
 218         return 0;
 219 }
 220
 221 static void mbox_test_receive_message(struct mbox_client *client, void *message)
 222 {
 223         struct mbox_test_device *tdev = dev_get_drvdata(client->dev);
 224         unsigned long flags;
 225
 226         spin_lock_irqsave(&tdev->lock, flags);
 227         if (tdev->rx_mmio) {
 228                 memcpy_fromio(tdev->rx_buffer, tdev->rx_mmio, MBOX_MAX_MSG_LEN);
 229                 print_hex_dump_bytes("Client: Received [MMIO]: ", DUMP_PREFIX_ADDRESS,
 230                                      tdev->rx_buffer, MBOX_MAX_MSG_LEN);
 231         } else if (message) {
 232                 print_hex_dump_bytes("Client: Received [API]: ", DUMP_PREFIX_ADDRESS,
 233                                      message, MBOX_MAX_MSG_LEN);
 234                 memcpy(tdev->rx_buffer, message, MBOX_MAX_MSG_LEN);
 235         }
 236         spin_unlock_irqrestore(&tdev->lock, flags);
 237 }
 238
 239 static void mbox_test_prepare_message(struct mbox_client *client, void *message)
 240 {
 241         struct mbox_test_device *tdev = dev_get_drvdata(client->dev);
 242
 243         if (tdev->tx_mmio) {
 244                 if (tdev->signal)
 245                         memcpy_toio(tdev->tx_mmio, tdev->message, MBOX_MAX_MSG_LEN);
 246                 else
 247                         memcpy_toio(tdev->tx_mmio, message, MBOX_MAX_MSG_LEN);
 248         }
 249 }
 250
 251 static void mbox_test_message_sent(struct mbox_client *client,
 252                                    void *message, int r)
 253 {
 254         if (r)
 255                 dev_warn(client->dev,
 256                          "Client: Message could not be sent: %d\n", r);
 257         else
 258                 dev_info(client->dev,
 259                          "Client: Message sent\n");
 260 }
 261
 262 static struct mbox_chan *
 263 mbox_test_request_channel(struct platform_device *pdev, const char *name)
 264 {
 265         struct mbox_client *client;
 266         struct mbox_chan *channel;
 267
 268         client = devm_kzalloc(&pdev->dev, sizeof(*client), GFP_KERNEL);
 269         if (!client)
 270                 return ERR_PTR(-ENOMEM);
 271
 272         client->dev             = &pdev->dev;
 273         client->rx_callback     = mbox_test_receive_message;
 274         client->tx_prepare      = mbox_test_prepare_message;
 275         client->tx_done         = mbox_test_message_sent;
 276         client->tx_block        = true;
 277         client->knows_txdone    = false;
 278         client->tx_tout         = 500;
 279
 280         channel = mbox_request_channel_byname(client, name);
 281         if (IS_ERR(channel)) {
 282                 dev_warn(&pdev->dev, "Failed to request %s channel\n", name);
 283                 return NULL;
 284         }
 285
 286         return channel;
 287 }
 288
 289 static int mbox_test_probe(struct platform_device *pdev)
 290 {
 291         struct mbox_test_device *tdev;
 292         struct resource *res;
 293         int ret;
 294
 295         tdev = devm_kzalloc(&pdev->dev, sizeof(*tdev), GFP_KERNEL);
 296         if (!tdev)
 297                 return -ENOMEM;
 298
 299         /* It's okay for MMIO to be NULL */
 300         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 301         tdev->tx_mmio = devm_ioremap_resource(&pdev->dev, res);
 302         if (IS_ERR(tdev->tx_mmio))
 303                 tdev->tx_mmio = NULL;
 304
 305         /* If specified, second reg entry is Rx MMIO */
 306         res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 307         tdev->rx_mmio = devm_ioremap_resource(&pdev->dev, res);
 308         if (IS_ERR(tdev->rx_mmio))
 309                 tdev->rx_mmio = tdev->tx_mmio;
 310
 311         tdev->tx_channel = mbox_test_request_channel(pdev, "tx");
 312         tdev->rx_channel = mbox_test_request_channel(pdev, "rx");
 313
 314         if (!tdev->tx_channel && !tdev->rx_channel)
 315                 return -EPROBE_DEFER;
 316
 317         /* If Rx is not specified but has Rx MMIO, then Rx = Tx */
 318         if (!tdev->rx_channel && (tdev->rx_mmio != tdev->tx_mmio))
 319                 tdev->rx_channel = tdev->tx_channel;
 320
 321         tdev->dev = &pdev->dev;
 322         platform_set_drvdata(pdev, tdev);
 323
 324         spin_lock_init(&tdev->lock);
 325
 326         if (tdev->rx_channel) {
 327                 tdev->rx_buffer = devm_kzalloc(&pdev->dev,
 328                                                MBOX_MAX_MSG_LEN, GFP_KERNEL);
 329                 if (!tdev->rx_buffer)
 330                         return -ENOMEM;
 331         }
 332
 333         ret = mbox_test_add_debugfs(pdev, tdev);
 334         if (ret)
 335                 return ret;
 336
 337         dev_info(&pdev->dev, "Successfully registered\n");
 338
 339         return 0;
 340 }
 341
 342 static int mbox_test_remove(struct platform_device *pdev)
 343 {
 344         struct mbox_test_device *tdev = platform_get_drvdata(pdev);
 345
 346         debugfs_remove_recursive(root_debugfs_dir);
 347
 348         if (tdev->tx_channel)
 349                 mbox_free_channel(tdev->tx_channel);
 350         if (tdev->rx_channel)
 351                 mbox_free_channel(tdev->rx_channel);
 352
 353         return 0;
 354 }
 355
 356 static const struct of_device_id mbox_test_match[] = {
 357         { .compatible = "mailbox-test" },
 358         {},
 359 };
 360
 361 static struct platform_driver mbox_test_driver = {
 362         .driver = {
 363                 .name = "mailbox_test",
 364                 .of_match_table = mbox_test_match,
 365         },
 366         .probe  = mbox_test_probe,
 367         .remove = mbox_test_remove,
 368 };
 369 module_platform_driver(mbox_test_driver);
 370
 371 MODULE_DESCRIPTION("Generic Mailbox Testing Facility");
 372 MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org");
 373 MODULE_LICENSE("GPL v2");