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 */
toshiba_haps_reset_protection(acpi_handle handle)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
toshiba_haps_protection_level(acpi_handle handle,int level)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 */
protection_level_show(struct device * dev,struct device_attribute * attr,char * buf)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
protection_level_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)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
reset_protection_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)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 */
toshiba_haps_notify(struct acpi_device * device,u32 event)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
toshiba_haps_remove(struct acpi_device * device)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 */
toshiba_haps_available(acpi_handle handle)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
toshiba_haps_add(struct acpi_device * acpi_dev)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
toshiba_haps_suspend(struct device * device)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
toshiba_haps_resume(struct device * device)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 .ids = haps_device_ids,
255 .flags = ACPI_DRIVER_ALL_NOTIFY_EVENTS,
256 .ops = {
257 .add = toshiba_haps_add,
258 .remove = toshiba_haps_remove,
259 .notify = toshiba_haps_notify,
260 },
261 .drv.pm = &toshiba_haps_pm,
262 };
263
264 module_acpi_driver(toshiba_haps_driver);
265