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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);
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
99static 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
117static DEVICE_ATTR(protection_level, S_IRUGO | S_IWUSR,
118 protection_level_show, protection_level_store);
119static DEVICE_ATTR(reset_protection, S_IWUSR, NULL, reset_protection_store);
120
121static struct attribute *haps_attributes[] = {
122 &dev_attr_protection_level.attr,
123 &dev_attr_reset_protection.attr,
124 NULL,
125};
126
127static struct attribute_group haps_attr_group = {
128 .attrs = haps_attributes,
129};
130
131/*
132 * ACPI stuff
133 */
134static 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
143static 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 */
154static 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
173static 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
210static 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
223static 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
243static SIMPLE_DEV_PM_OPS(toshiba_haps_pm,
244 toshiba_haps_suspend, toshiba_haps_resume);
245
246static const struct acpi_device_id haps_device_ids[] = {
247 {"TOS620A", 0},
248 {"", 0},
249};
250MODULE_DEVICE_TABLE(acpi, haps_device_ids);
251
252static 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
265module_acpi_driver(toshiba_haps_driver);