drivers/base/test/test_async_driver_probe.c

   1 /*
   2  * Copyright (C) 2014 Google, Inc.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  */
  13
  14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  15
  16 #include <linux/delay.h>
  17 #include <linux/init.h>
  18 #include <linux/hrtimer.h>
  19 #include <linux/module.h>
  20 #include <linux/platform_device.h>
  21 #include <linux/time.h>
  22
  23 #define TEST_PROBE_DELAY        (5 * 1000)      /* 5 sec */
  24 #define TEST_PROBE_THRESHOLD    (TEST_PROBE_DELAY / 2)
  25
  26 static int test_probe(struct platform_device *pdev)
  27 {
  28         dev_info(&pdev->dev, "sleeping for %d msecs in probe\n",
  29                  TEST_PROBE_DELAY);
  30         msleep(TEST_PROBE_DELAY);
  31         dev_info(&pdev->dev, "done sleeping\n");
  32
  33         return 0;
  34 }
  35
  36 static struct platform_driver async_driver = {
  37         .driver = {
  38                 .name = "test_async_driver",
  39                 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
  40         },
  41         .probe = test_probe,
  42 };
  43
  44 static struct platform_driver sync_driver = {
  45         .driver = {
  46                 .name = "test_sync_driver",
  47                 .probe_type = PROBE_FORCE_SYNCHRONOUS,
  48         },
  49         .probe = test_probe,
  50 };
  51
  52 static struct platform_device *async_dev_1, *async_dev_2;
  53 static struct platform_device *sync_dev_1;
  54
  55 static int __init test_async_probe_init(void)
  56 {
  57         ktime_t calltime, delta;
  58         unsigned long long duration;
  59         int error;
  60
  61         pr_info("registering first asynchronous device...\n");
  62
  63         async_dev_1 = platform_device_register_simple("test_async_driver", 1,
  64                                                       NULL, 0);
  65         if (IS_ERR(async_dev_1)) {
  66                 error = PTR_ERR(async_dev_1);
  67                 pr_err("failed to create async_dev_1: %d", error);
  68                 return error;
  69         }
  70
  71         pr_info("registering asynchronous driver...\n");
  72         calltime = ktime_get();
  73         error = platform_driver_register(&async_driver);
  74         if (error) {
  75                 pr_err("Failed to register async_driver: %d\n", error);
  76                 goto err_unregister_async_dev_1;
  77         }
  78
  79         delta = ktime_sub(ktime_get(), calltime);
  80         duration = (unsigned long long) ktime_to_ms(delta);
  81         pr_info("registration took %lld msecs\n", duration);
  82         if (duration > TEST_PROBE_THRESHOLD) {
  83                 pr_err("test failed: probe took too long\n");
  84                 error = -ETIMEDOUT;
  85                 goto err_unregister_async_driver;
  86         }
  87
  88         pr_info("registering second asynchronous device...\n");
  89         calltime = ktime_get();
  90         async_dev_2 = platform_device_register_simple("test_async_driver", 2,
  91                                                       NULL, 0);
  92         if (IS_ERR(async_dev_2)) {
  93                 error = PTR_ERR(async_dev_2);
  94                 pr_err("failed to create async_dev_2: %d", error);
  95                 goto err_unregister_async_driver;
  96         }
  97
  98         delta = ktime_sub(ktime_get(), calltime);
  99         duration = (unsigned long long) ktime_to_ms(delta);
 100         pr_info("registration took %lld msecs\n", duration);
 101         if (duration > TEST_PROBE_THRESHOLD) {
 102                 pr_err("test failed: probe took too long\n");
 103                 error = -ETIMEDOUT;
 104                 goto err_unregister_async_dev_2;
 105         }
 106
 107         pr_info("registering synchronous driver...\n");
 108
 109         error = platform_driver_register(&sync_driver);
 110         if (error) {
 111                 pr_err("Failed to register async_driver: %d\n", error);
 112                 goto err_unregister_async_dev_2;
 113         }
 114
 115         pr_info("registering synchronous device...\n");
 116         calltime = ktime_get();
 117         sync_dev_1 = platform_device_register_simple("test_sync_driver", 1,
 118                                                      NULL, 0);
 119         if (IS_ERR(sync_dev_1)) {
 120                 error = PTR_ERR(sync_dev_1);
 121                 pr_err("failed to create sync_dev_1: %d", error);
 122                 goto err_unregister_sync_driver;
 123         }
 124
 125         delta = ktime_sub(ktime_get(), calltime);
 126         duration = (unsigned long long) ktime_to_ms(delta);
 127         pr_info("registration took %lld msecs\n", duration);
 128         if (duration < TEST_PROBE_THRESHOLD) {
 129                 pr_err("test failed: probe was too quick\n");
 130                 error = -ETIMEDOUT;
 131                 goto err_unregister_sync_dev_1;
 132         }
 133
 134         pr_info("completed successfully");
 135
 136         return 0;
 137
 138 err_unregister_sync_dev_1:
 139         platform_device_unregister(sync_dev_1);
 140
 141 err_unregister_sync_driver:
 142         platform_driver_unregister(&sync_driver);
 143
 144 err_unregister_async_dev_2:
 145         platform_device_unregister(async_dev_2);
 146
 147 err_unregister_async_driver:
 148         platform_driver_unregister(&async_driver);
 149
 150 err_unregister_async_dev_1:
 151         platform_device_unregister(async_dev_1);
 152
 153         return error;
 154 }
 155 module_init(test_async_probe_init);
 156
 157 static void __exit test_async_probe_exit(void)
 158 {
 159         platform_driver_unregister(&async_driver);
 160         platform_driver_unregister(&sync_driver);
 161         platform_device_unregister(async_dev_1);
 162         platform_device_unregister(async_dev_2);
 163         platform_device_unregister(sync_dev_1);
 164 }
 165 module_exit(test_async_probe_exit);
 166
 167 MODULE_DESCRIPTION("Test module for asynchronous driver probing");
 168 MODULE_AUTHOR("Dmitry Torokhov <dtor@chromium.org>");
 169 MODULE_LICENSE("GPL");