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Azael Avalos23d0ba02014-08-14 09:55:38 -06001/*
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
26MODULE_AUTHOR("Azael Avalos <coproscefalo@gmail.com>");
27MODULE_DESCRIPTION("Toshiba HDD Active Protection Sensor");
28MODULE_LICENSE("GPL");
29
30struct toshiba_haps_dev {
31 struct acpi_device *acpi_dev;
32
33 int protection_level;
34};
35
36static struct toshiba_haps_dev *toshiba_haps;
37
38/* HAPS functions */
39static 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
52static 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 */
68static 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
76static 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);
Azael Avalosa8820032015-02-26 10:58:30 -070081 int level;
82 int ret;
Azael Avalos23d0ba02014-08-14 09:55:38 -060083
Azael Avalosa8820032015-02-26 10:58:30 -070084 ret = kstrtoint(buf, 0, &level);
85 if (ret)
86 return ret;
87 /*
88 * Check for supported levels, which can be:
Azael Avalos23d0ba02014-08-14 09:55:38 -060089 * 0 - Disabled | 1 - Low | 2 - Medium | 3 - High
90 */
Azael Avalosa8820032015-02-26 10:58:30 -070091 if (level < 0 || level > 3)
92 return -EINVAL;
93
94 /* Set the sensor level */
Azael Avalos23d0ba02014-08-14 09:55:38 -060095 ret = toshiba_haps_protection_level(haps->acpi_dev->handle, level);
96 if (ret != 0)
97 return ret;
98
99 haps->protection_level = level;
100
101 return count;
102}
Azael Avalos7dd62c02015-02-26 10:58:31 -0700103static DEVICE_ATTR_RW(protection_level);
Azael Avalos23d0ba02014-08-14 09:55:38 -0600104
105static ssize_t reset_protection_store(struct device *dev,
106 struct device_attribute *attr,
107 const char *buf, size_t count)
108{
109 struct toshiba_haps_dev *haps = dev_get_drvdata(dev);
Azael Avalosa8820032015-02-26 10:58:30 -0700110 int reset;
111 int ret;
Azael Avalos23d0ba02014-08-14 09:55:38 -0600112
Azael Avalosa8820032015-02-26 10:58:30 -0700113 ret = kstrtoint(buf, 0, &reset);
114 if (ret)
115 return ret;
116 /* The only accepted value is 1 */
117 if (reset != 1)
Azael Avalos23d0ba02014-08-14 09:55:38 -0600118 return -EINVAL;
119
120 /* Reset the protection interface */
121 ret = toshiba_haps_reset_protection(haps->acpi_dev->handle);
122 if (ret != 0)
123 return ret;
124
125 return count;
126}
Azael Avalos7dd62c02015-02-26 10:58:31 -0700127static DEVICE_ATTR_WO(reset_protection);
Azael Avalos23d0ba02014-08-14 09:55:38 -0600128
129static struct attribute *haps_attributes[] = {
130 &dev_attr_protection_level.attr,
131 &dev_attr_reset_protection.attr,
132 NULL,
133};
134
135static struct attribute_group haps_attr_group = {
136 .attrs = haps_attributes,
137};
138
139/*
140 * ACPI stuff
141 */
142static void toshiba_haps_notify(struct acpi_device *device, u32 event)
143{
144 pr_info("Received event: 0x%x", event);
145
146 acpi_bus_generate_netlink_event(device->pnp.device_class,
147 dev_name(&device->dev),
148 event, 0);
149}
150
151static int toshiba_haps_remove(struct acpi_device *device)
152{
153 sysfs_remove_group(&device->dev.kobj, &haps_attr_group);
154
155 if (toshiba_haps)
156 toshiba_haps = NULL;
157
158 return 0;
159}
160
161/* Helper function */
162static int toshiba_haps_available(acpi_handle handle)
163{
164 acpi_status status;
165 u64 hdd_present;
166
167 /*
168 * A non existent device as well as having (only)
169 * Solid State Drives can cause the call to fail.
170 */
171 status = acpi_evaluate_integer(handle, "_STA", NULL,
172 &hdd_present);
173 if (ACPI_FAILURE(status) || !hdd_present) {
174 pr_info("HDD protection not available or using SSD\n");
175 return 0;
176 }
177
178 return 1;
179}
180
181static int toshiba_haps_add(struct acpi_device *acpi_dev)
182{
183 struct toshiba_haps_dev *haps;
184 int ret;
185
186 if (toshiba_haps)
187 return -EBUSY;
188
189 if (!toshiba_haps_available(acpi_dev->handle))
190 return -ENODEV;
191
192 pr_info("Toshiba HDD Active Protection Sensor device\n");
193
194 haps = kzalloc(sizeof(struct toshiba_haps_dev), GFP_KERNEL);
195 if (!haps)
196 return -ENOMEM;
197
198 haps->acpi_dev = acpi_dev;
199 haps->protection_level = 2;
200 acpi_dev->driver_data = haps;
201 dev_set_drvdata(&acpi_dev->dev, haps);
202
203 /* Set the protection level, currently at level 2 (Medium) */
204 ret = toshiba_haps_protection_level(acpi_dev->handle, 2);
205 if (ret != 0)
206 return ret;
207
208 ret = sysfs_create_group(&acpi_dev->dev.kobj, &haps_attr_group);
209 if (ret)
210 return ret;
211
212 toshiba_haps = haps;
213
214 return 0;
215}
216
217#ifdef CONFIG_PM_SLEEP
218static int toshiba_haps_suspend(struct device *device)
219{
220 struct toshiba_haps_dev *haps;
221 int ret;
222
223 haps = acpi_driver_data(to_acpi_device(device));
224
225 /* Deactivate the protection on suspend */
226 ret = toshiba_haps_protection_level(haps->acpi_dev->handle, 0);
227
228 return ret;
229}
230
231static int toshiba_haps_resume(struct device *device)
232{
233 struct toshiba_haps_dev *haps;
234 int ret;
235
236 haps = acpi_driver_data(to_acpi_device(device));
237
238 /* Set the stored protection level */
239 ret = toshiba_haps_protection_level(haps->acpi_dev->handle,
240 haps->protection_level);
241
242 /* Reset the protection on resume */
243 ret = toshiba_haps_reset_protection(haps->acpi_dev->handle);
244 if (ret != 0)
245 return ret;
246
247 return ret;
248}
249#endif
250
251static SIMPLE_DEV_PM_OPS(toshiba_haps_pm,
252 toshiba_haps_suspend, toshiba_haps_resume);
253
254static const struct acpi_device_id haps_device_ids[] = {
255 {"TOS620A", 0},
256 {"", 0},
257};
258MODULE_DEVICE_TABLE(acpi, haps_device_ids);
259
260static struct acpi_driver toshiba_haps_driver = {
261 .name = "Toshiba HAPS",
262 .owner = THIS_MODULE,
263 .ids = haps_device_ids,
264 .flags = ACPI_DRIVER_ALL_NOTIFY_EVENTS,
265 .ops = {
266 .add = toshiba_haps_add,
267 .remove = toshiba_haps_remove,
268 .notify = toshiba_haps_notify,
269 },
270 .drv.pm = &toshiba_haps_pm,
271};
272
273module_acpi_driver(toshiba_haps_driver);