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
 137         return ret < 0 ? ret : count;
 138 }
 139
 140 static ssize_t mbox_test_message_read(struct file *filp, char __user *userbuf,
 141                                       size_t count, loff_t *ppos)
 142 {
 143         struct mbox_test_device *tdev = filp->private_data;
 144         unsigned long flags;
 145         char *touser, *ptr;
 146         int l = 0;
 147         int ret;
 148
 149         touser = kzalloc(MBOX_HEXDUMP_MAX_LEN + 1, GFP_KERNEL);
 150         if (!touser)
 151                 return -ENOMEM;
 152
 153         if (!tdev->rx_channel) {
 154                 ret = snprintf(touser, 20, "<NO RX CAPABILITY>\n");
 155                 ret = simple_read_from_buffer(userbuf, count, ppos,
 156                                               touser, ret);
 157                 goto out;
 158         }
 159
 160         if (tdev->rx_buffer[0] == '\0') {
 161                 ret = snprintf(touser, 9, "<EMPTY>\n");
 162                 ret = simple_read_from_buffer(userbuf, count, ppos,
 163                                               touser, ret);
 164                 goto out;
 165         }
 166
 167         spin_lock_irqsave(&tdev->lock, flags);
 168
 169         ptr = tdev->rx_buffer;
 170         while (l < MBOX_HEXDUMP_MAX_LEN) {
 171                 hex_dump_to_buffer(ptr,
 172                                    MBOX_BYTES_PER_LINE,
 173                                    MBOX_BYTES_PER_LINE, 1, touser + l,
 174                                    MBOX_HEXDUMP_LINE_LEN, true);
 175
 176                 ptr += MBOX_BYTES_PER_LINE;
 177                 l += MBOX_HEXDUMP_LINE_LEN;
 178                 *(touser + (l - 1)) = '\n';
 179         }
 180         *(touser + l) = '\0';
 181
 182         memset(tdev->rx_buffer, 0, MBOX_MAX_MSG_LEN);
 183
 184         spin_unlock_irqrestore(&tdev->lock, flags);
 185
 186         ret = simple_read_from_buffer(userbuf, count, ppos, touser, MBOX_HEXDUMP_MAX_LEN);
 187 out:
 188         kfree(touser);
 189         return ret;
 190 }
 191
 192 static const struct file_operations mbox_test_message_ops = {
 193         .write  = mbox_test_message_write,
 194         .read   = mbox_test_message_read,
 195         .open   = simple_open,
 196         .llseek = generic_file_llseek,
 197 };
 198
 199 static int mbox_test_add_debugfs(struct platform_device *pdev,
 200                                  struct mbox_test_device *tdev)
 201 {
 202         if (!debugfs_initialized())
 203                 return 0;
 204
 205         root_debugfs_dir = debugfs_create_dir("mailbox", NULL);
 206         if (!root_debugfs_dir) {
 207                 dev_err(&pdev->dev, "Failed to create Mailbox debugfs\n");
 208                 return -EINVAL;
 209         }
 210
 211         debugfs_create_file("message", 0600, root_debugfs_dir,
 212                             tdev, &mbox_test_message_ops);
 213
 214         debugfs_create_file("signal", 0200, root_debugfs_dir,
 215                             tdev, &mbox_test_signal_ops);
 216
 217         return 0;
 218 }
 219
 220 static void mbox_test_receive_message(struct mbox_client *client, void *message)
 221 {
 222         struct mbox_test_device *tdev = dev_get_drvdata(client->dev);
 223         unsigned long flags;
 224
 225         spin_lock_irqsave(&tdev->lock, flags);
 226         if (tdev->rx_mmio) {
 227                 memcpy_fromio(tdev->rx_buffer, tdev->rx_mmio, MBOX_MAX_MSG_LEN);
 228                 print_hex_dump_bytes("Client: Received [MMIO]: ", DUMP_PREFIX_ADDRESS,
 229                                      tdev->rx_buffer, MBOX_MAX_MSG_LEN);
 230         } else if (message) {
 231                 print_hex_dump_bytes("Client: Received [API]: ", DUMP_PREFIX_ADDRESS,
 232                                      message, MBOX_MAX_MSG_LEN);
 233                 memcpy(tdev->rx_buffer, message, MBOX_MAX_MSG_LEN);
 234         }
 235         spin_unlock_irqrestore(&tdev->lock, flags);
 236 }
 237
 238 static void mbox_test_prepare_message(struct mbox_client *client, void *message)
 239 {
 240         struct mbox_test_device *tdev = dev_get_drvdata(client->dev);
 241
 242         if (tdev->tx_mmio) {
 243                 if (tdev->signal)
 244                         memcpy_toio(tdev->tx_mmio, tdev->message, MBOX_MAX_MSG_LEN);
 245                 else
 246                         memcpy_toio(tdev->tx_mmio, message, MBOX_MAX_MSG_LEN);
 247         }
 248 }
 249
 250 static void mbox_test_message_sent(struct mbox_client *client,
 251                                    void *message, int r)
 252 {
 253         if (r)
 254                 dev_warn(client->dev,
 255                          "Client: Message could not be sent: %d\n", r);
 256         else
 257                 dev_info(client->dev,
 258                          "Client: Message sent\n");
 259 }
 260
 261 static struct mbox_chan *
 262 mbox_test_request_channel(struct platform_device *pdev, const char *name)
 263 {
 264         struct mbox_client *client;
 265         struct mbox_chan *channel;
 266
 267         client = devm_kzalloc(&pdev->dev, sizeof(*client), GFP_KERNEL);
 268         if (!client)
 269                 return ERR_PTR(-ENOMEM);
 270
 271         client->dev             = &pdev->dev;
 272         client->rx_callback     = mbox_test_receive_message;
 273         client->tx_prepare      = mbox_test_prepare_message;
 274         client->tx_done         = mbox_test_message_sent;
 275         client->tx_block        = true;
 276         client->knows_txdone    = false;
 277         client->tx_tout         = 500;
 278
 279         channel = mbox_request_channel_byname(client, name);
 280         if (IS_ERR(channel)) {
 281                 dev_warn(&pdev->dev, "Failed to request %s channel\n", name);
 282                 return NULL;
 283         }
 284
 285         return channel;
 286 }
 287
 288 static int mbox_test_probe(struct platform_device *pdev)
 289 {
 290         struct mbox_test_device *tdev;
 291         struct resource *res;
 292         int ret;
 293
 294         tdev = devm_kzalloc(&pdev->dev, sizeof(*tdev), GFP_KERNEL);
 295         if (!tdev)
 296                 return -ENOMEM;
 297
 298         /* It's okay for MMIO to be NULL */
 299         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 300         tdev->tx_mmio = devm_ioremap_resource(&pdev->dev, res);
 301         if (IS_ERR(tdev->tx_mmio))
 302                 tdev->tx_mmio = NULL;
 303
 304         /* If specified, second reg entry is Rx MMIO */
 305         res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 306         tdev->rx_mmio = devm_ioremap_resource(&pdev->dev, res);
 307         if (IS_ERR(tdev->rx_mmio))
 308                 tdev->rx_mmio = tdev->tx_mmio;
 309
 310         tdev->tx_channel = mbox_test_request_channel(pdev, "tx");
 311         tdev->rx_channel = mbox_test_request_channel(pdev, "rx");
 312
 313         if (!tdev->tx_channel && !tdev->rx_channel)
 314                 return -EPROBE_DEFER;
 315
 316         /* If Rx is not specified but has Rx MMIO, then Rx = Tx */
 317         if (!tdev->rx_channel && (tdev->rx_mmio != tdev->tx_mmio))
 318                 tdev->rx_channel = tdev->tx_channel;
 319
 320         tdev->dev = &pdev->dev;
 321         platform_set_drvdata(pdev, tdev);
 322
 323         spin_lock_init(&tdev->lock);
 324
 325         if (tdev->rx_channel) {
 326                 tdev->rx_buffer = devm_kzalloc(&pdev->dev,
 327                                                MBOX_MAX_MSG_LEN, GFP_KERNEL);
 328                 if (!tdev->rx_buffer)
 329                         return -ENOMEM;
 330         }
 331
 332         ret = mbox_test_add_debugfs(pdev, tdev);
 333         if (ret)
 334                 return ret;
 335
 336         dev_info(&pdev->dev, "Successfully registered\n");
 337
 338         return 0;
 339 }
 340
 341 static int mbox_test_remove(struct platform_device *pdev)
 342 {
 343         struct mbox_test_device *tdev = platform_get_drvdata(pdev);
 344
 345         debugfs_remove_recursive(root_debugfs_dir);
 346
 347         if (tdev->tx_channel)
 348                 mbox_free_channel(tdev->tx_channel);
 349         if (tdev->rx_channel)
 350                 mbox_free_channel(tdev->rx_channel);
 351
 352         return 0;
 353 }
 354
 355 static const struct of_device_id mbox_test_match[] = {
 356         { .compatible = "mailbox-test" },
 357         {},
 358 };
 359
 360 static struct platform_driver mbox_test_driver = {
 361         .driver = {
 362                 .name = "mailbox_test",
 363                 .of_match_table = mbox_test_match,
 364         },
 365         .probe  = mbox_test_probe,
 366         .remove = mbox_test_remove,
 367 };
 368 module_platform_driver(mbox_test_driver);
 369
 370 MODULE_DESCRIPTION("Generic Mailbox Testing Facility");
 371 MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org");
 372 MODULE_LICENSE("GPL v2");