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