drivers/platform/x86/toshiba_haps.c

   1 /*
   2  * Toshiba HDD Active Protection Sensor (HAPS) driver
   3  *
   4  * Copyright (C) 2014 Azael Avalos <coproscefalo@gmail.com>
   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  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  */
  17
  18 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  19
  20 #include <linux/kernel.h>
  21 #include <linux/module.h>
  22 #include <linux/init.h>
  23 #include <linux/types.h>
  24 #include <linux/acpi.h>
  25
  26 MODULE_AUTHOR("Azael Avalos <coproscefalo@gmail.com>");
  27 MODULE_DESCRIPTION("Toshiba HDD Active Protection Sensor");
  28 MODULE_LICENSE("GPL");
  29
  30 struct toshiba_haps_dev {
  31         struct acpi_device *acpi_dev;
  32
  33         int protection_level;
  34 };
  35
  36 static struct toshiba_haps_dev *toshiba_haps;
  37
  38 /* HAPS functions */
  39 static int toshiba_haps_reset_protection(acpi_handle handle)
  40 {
  41         acpi_status status;
  42
  43         status = acpi_evaluate_object(handle, "RSSS", NULL, NULL);
  44         if (ACPI_FAILURE(status)) {
  45                 pr_err("Unable to reset the HDD protection\n");
  46                 return -EIO;
  47         }
  48
  49         return 0;
  50 }
  51
  52 static int toshiba_haps_protection_level(acpi_handle handle, int level)
  53 {
  54         acpi_status status;
  55
  56         status = acpi_execute_simple_method(handle, "PTLV", level);
  57         if (ACPI_FAILURE(status)) {
  58                 pr_err("Error while setting the protection level\n");
  59                 return -EIO;
  60         }
  61
  62         pr_info("HDD protection level set to: %d\n", level);
  63
  64         return 0;
  65 }
  66
  67 /* sysfs files */
  68 static ssize_t protection_level_show(struct device *dev,
  69                                      struct device_attribute *attr, char *buf)
  70 {
  71         struct toshiba_haps_dev *haps = dev_get_drvdata(dev);
  72
  73         return sprintf(buf, "%i\n", haps->protection_level);
  74 }
  75
  76 static ssize_t protection_level_store(struct device *dev,
  77                                       struct device_attribute *attr,
  78                                       const char *buf, size_t count)
  79 {
  80         struct toshiba_haps_dev *haps = dev_get_drvdata(dev);
  81         int level, ret;
  82
  83         if (sscanf(buf, "%d", &level) != 1 || level < 0 || level > 3)
  84                 return -EINVAL;
  85
  86         /* Set the sensor level.
  87          * Acceptable levels are:
  88          * 0 - Disabled | 1 - Low | 2 - Medium | 3 - High
  89          */
  90         ret = toshiba_haps_protection_level(haps->acpi_dev->handle, level);
  91         if (ret != 0)
  92                 return ret;
  93
  94         haps->protection_level = level;
  95
  96         return count;
  97 }
  98
  99 static ssize_t reset_protection_store(struct device *dev,
 100                                       struct device_attribute *attr,
 101                                       const char *buf, size_t count)
 102 {
 103         struct toshiba_haps_dev *haps = dev_get_drvdata(dev);
 104         int reset, ret;
 105
 106         if (sscanf(buf, "%d", &reset) != 1 || reset != 1)
 107                 return -EINVAL;
 108
 109         /* Reset the protection interface */
 110         ret = toshiba_haps_reset_protection(haps->acpi_dev->handle);
 111         if (ret != 0)
 112                 return ret;
 113
 114         return count;
 115 }
 116
 117 static DEVICE_ATTR(protection_level, S_IRUGO | S_IWUSR,
 118                    protection_level_show, protection_level_store);
 119 static DEVICE_ATTR(reset_protection, S_IWUSR, NULL, reset_protection_store);
 120
 121 static struct attribute *haps_attributes[] = {
 122         &dev_attr_protection_level.attr,
 123         &dev_attr_reset_protection.attr,
 124         NULL,
 125 };
 126
 127 static struct attribute_group haps_attr_group = {
 128         .attrs = haps_attributes,
 129 };
 130
 131 /*
 132  * ACPI stuff
 133  */
 134 static void toshiba_haps_notify(struct acpi_device *device, u32 event)
 135 {
 136         pr_info("Received event: 0x%x", event);
 137
 138         acpi_bus_generate_netlink_event(device->pnp.device_class,
 139                                         dev_name(&device->dev),
 140                                         event, 0);
 141 }
 142
 143 static int toshiba_haps_remove(struct acpi_device *device)
 144 {
 145         sysfs_remove_group(&device->dev.kobj, &haps_attr_group);
 146
 147         if (toshiba_haps)
 148                 toshiba_haps = NULL;
 149
 150         return 0;
 151 }
 152
 153 /* Helper function */
 154 static int toshiba_haps_available(acpi_handle handle)
 155 {
 156         acpi_status status;
 157         u64 hdd_present;
 158
 159         /*
 160          * A non existent device as well as having (only)
 161          * Solid State Drives can cause the call to fail.
 162          */
 163         status = acpi_evaluate_integer(handle, "_STA", NULL,
 164                                        &hdd_present);
 165         if (ACPI_FAILURE(status) || !hdd_present) {
 166                 pr_info("HDD protection not available or using SSD\n");
 167                 return 0;
 168         }
 169
 170         return 1;
 171 }
 172
 173 static int toshiba_haps_add(struct acpi_device *acpi_dev)
 174 {
 175         struct toshiba_haps_dev *haps;
 176         int ret;
 177
 178         if (toshiba_haps)
 179                 return -EBUSY;
 180
 181         if (!toshiba_haps_available(acpi_dev->handle))
 182                 return -ENODEV;
 183
 184         pr_info("Toshiba HDD Active Protection Sensor device\n");
 185
 186         haps = kzalloc(sizeof(struct toshiba_haps_dev), GFP_KERNEL);
 187         if (!haps)
 188                 return -ENOMEM;
 189
 190         haps->acpi_dev = acpi_dev;
 191         haps->protection_level = 2;
 192         acpi_dev->driver_data = haps;
 193         dev_set_drvdata(&acpi_dev->dev, haps);
 194
 195         /* Set the protection level, currently at level 2 (Medium) */
 196         ret = toshiba_haps_protection_level(acpi_dev->handle, 2);
 197         if (ret != 0)
 198                 return ret;
 199
 200         ret = sysfs_create_group(&acpi_dev->dev.kobj, &haps_attr_group);
 201         if (ret)
 202                 return ret;
 203
 204         toshiba_haps = haps;
 205
 206         return 0;
 207 }
 208
 209 #ifdef CONFIG_PM_SLEEP
 210 static int toshiba_haps_suspend(struct device *device)
 211 {
 212         struct toshiba_haps_dev *haps;
 213         int ret;
 214
 215         haps = acpi_driver_data(to_acpi_device(device));
 216
 217         /* Deactivate the protection on suspend */
 218         ret = toshiba_haps_protection_level(haps->acpi_dev->handle, 0);
 219
 220         return ret;
 221 }
 222
 223 static int toshiba_haps_resume(struct device *device)
 224 {
 225         struct toshiba_haps_dev *haps;
 226         int ret;
 227
 228         haps = acpi_driver_data(to_acpi_device(device));
 229
 230         /* Set the stored protection level */
 231         ret = toshiba_haps_protection_level(haps->acpi_dev->handle,
 232                                             haps->protection_level);
 233
 234         /* Reset the protection on resume */
 235         ret = toshiba_haps_reset_protection(haps->acpi_dev->handle);
 236         if (ret != 0)
 237                 return ret;
 238
 239         return ret;
 240 }
 241 #endif
 242
 243 static SIMPLE_DEV_PM_OPS(toshiba_haps_pm,
 244                          toshiba_haps_suspend, toshiba_haps_resume);
 245
 246 static const struct acpi_device_id haps_device_ids[] = {
 247         {"TOS620A", 0},
 248         {"", 0},
 249 };
 250 MODULE_DEVICE_TABLE(acpi, haps_device_ids);
 251
 252 static struct acpi_driver toshiba_haps_driver = {
 253         .name = "Toshiba HAPS",
 254         .owner = THIS_MODULE,
 255         .ids = haps_device_ids,
 256         .flags = ACPI_DRIVER_ALL_NOTIFY_EVENTS,
 257         .ops = {
 258                 .add =          toshiba_haps_add,
 259                 .remove =       toshiba_haps_remove,
 260                 .notify =       toshiba_haps_notify,
 261         },
 262         .drv.pm = &toshiba_haps_pm,
 263 };
 264
 265 module_acpi_driver(toshiba_haps_driver);