drivers/platform/x86/toshiba_haps.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Toshiba HDD Active Protection Sensor (HAPS) driver
   4  *
   5  * Copyright (C) 2014 Azael Avalos <coproscefalo@gmail.com>
   6  */
   7
   8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   9
  10 #include <linux/kernel.h>
  11 #include <linux/module.h>
  12 #include <linux/init.h>
  13 #include <linux/types.h>
  14 #include <linux/acpi.h>
  15
  16 MODULE_AUTHOR("Azael Avalos <coproscefalo@gmail.com>");
  17 MODULE_DESCRIPTION("Toshiba HDD Active Protection Sensor");
  18 MODULE_LICENSE("GPL");
  19
  20 struct toshiba_haps_dev {
  21         struct acpi_device *acpi_dev;
  22
  23         int protection_level;
  24 };
  25
  26 static struct toshiba_haps_dev *toshiba_haps;
  27
  28 /* HAPS functions */
  29 static int toshiba_haps_reset_protection(acpi_handle handle)
  30 {
  31         acpi_status status;
  32
  33         status = acpi_evaluate_object(handle, "RSSS", NULL, NULL);
  34         if (ACPI_FAILURE(status)) {
  35                 pr_err("Unable to reset the HDD protection\n");
  36                 return -EIO;
  37         }
  38
  39         return 0;
  40 }
  41
  42 static int toshiba_haps_protection_level(acpi_handle handle, int level)
  43 {
  44         acpi_status status;
  45
  46         status = acpi_execute_simple_method(handle, "PTLV", level);
  47         if (ACPI_FAILURE(status)) {
  48                 pr_err("Error while setting the protection level\n");
  49                 return -EIO;
  50         }
  51
  52         pr_debug("HDD protection level set to: %d\n", level);
  53
  54         return 0;
  55 }
  56
  57 /* sysfs files */
  58 static ssize_t protection_level_show(struct device *dev,
  59                                      struct device_attribute *attr, char *buf)
  60 {
  61         struct toshiba_haps_dev *haps = dev_get_drvdata(dev);
  62
  63         return sprintf(buf, "%i\n", haps->protection_level);
  64 }
  65
  66 static ssize_t protection_level_store(struct device *dev,
  67                                       struct device_attribute *attr,
  68                                       const char *buf, size_t count)
  69 {
  70         struct toshiba_haps_dev *haps = dev_get_drvdata(dev);
  71         int level;
  72         int ret;
  73
  74         ret = kstrtoint(buf, 0, &level);
  75         if (ret)
  76                 return ret;
  77         /*
  78          * Check for supported levels, which can be:
  79          * 0 - Disabled | 1 - Low | 2 - Medium | 3 - High
  80          */
  81         if (level < 0 || level > 3)
  82                 return -EINVAL;
  83
  84         /* Set the sensor level */
  85         ret = toshiba_haps_protection_level(haps->acpi_dev->handle, level);
  86         if (ret != 0)
  87                 return ret;
  88
  89         haps->protection_level = level;
  90
  91         return count;
  92 }
  93 static DEVICE_ATTR_RW(protection_level);
  94
  95 static ssize_t reset_protection_store(struct device *dev,
  96                                       struct device_attribute *attr,
  97                                       const char *buf, size_t count)
  98 {
  99         struct toshiba_haps_dev *haps = dev_get_drvdata(dev);
 100         int reset;
 101         int ret;
 102
 103         ret = kstrtoint(buf, 0, &reset);
 104         if (ret)
 105                 return ret;
 106         /* The only accepted value is 1 */
 107         if (reset != 1)
 108                 return -EINVAL;
 109
 110         /* Reset the protection interface */
 111         ret = toshiba_haps_reset_protection(haps->acpi_dev->handle);
 112         if (ret != 0)
 113                 return ret;
 114
 115         return count;
 116 }
 117 static DEVICE_ATTR_WO(reset_protection);
 118
 119 static struct attribute *haps_attributes[] = {
 120         &dev_attr_protection_level.attr,
 121         &dev_attr_reset_protection.attr,
 122         NULL,
 123 };
 124
 125 static const struct attribute_group haps_attr_group = {
 126         .attrs = haps_attributes,
 127 };
 128
 129 /*
 130  * ACPI stuff
 131  */
 132 static void toshiba_haps_notify(struct acpi_device *device, u32 event)
 133 {
 134         pr_debug("Received event: 0x%x\n", event);
 135
 136         acpi_bus_generate_netlink_event(device->pnp.device_class,
 137                                         dev_name(&device->dev),
 138                                         event, 0);
 139 }
 140
 141 static void toshiba_haps_remove(struct acpi_device *device)
 142 {
 143         sysfs_remove_group(&device->dev.kobj, &haps_attr_group);
 144
 145         if (toshiba_haps)
 146                 toshiba_haps = NULL;
 147 }
 148
 149 /* Helper function */
 150 static int toshiba_haps_available(acpi_handle handle)
 151 {
 152         acpi_status status;
 153         u64 hdd_present;
 154
 155         /*
 156          * A non existent device as well as having (only)
 157          * Solid State Drives can cause the call to fail.
 158          */
 159         status = acpi_evaluate_integer(handle, "_STA", NULL, &hdd_present);
 160         if (ACPI_FAILURE(status)) {
 161                 pr_err("ACPI call to query HDD protection failed\n");
 162                 return 0;
 163         }
 164
 165         if (!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);