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", event);
135 
136 	acpi_bus_generate_netlink_event(device->pnp.device_class,
137 					dev_name(&device->dev),
138 					event, 0);
139 }
140 
141 static int 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 	return 0;
149 }
150 
151 /* Helper function */
152 static int toshiba_haps_available(acpi_handle handle)
153 {
154 	acpi_status status;
155 	u64 hdd_present;
156 
157 	/*
158 	 * A non existent device as well as having (only)
159 	 * Solid State Drives can cause the call to fail.
160 	 */
161 	status = acpi_evaluate_integer(handle, "_STA", NULL, &hdd_present);
162 	if (ACPI_FAILURE(status)) {
163 		pr_err("ACPI call to query HDD protection failed\n");
164 		return 0;
165 	}
166 
167 	if (!hdd_present) {
168 		pr_info("HDD protection not available or using SSD\n");
169 		return 0;
170 	}
171 
172 	return 1;
173 }
174 
175 static int toshiba_haps_add(struct acpi_device *acpi_dev)
176 {
177 	struct toshiba_haps_dev *haps;
178 	int ret;
179 
180 	if (toshiba_haps)
181 		return -EBUSY;
182 
183 	if (!toshiba_haps_available(acpi_dev->handle))
184 		return -ENODEV;
185 
186 	pr_info("Toshiba HDD Active Protection Sensor device\n");
187 
188 	haps = kzalloc(sizeof(struct toshiba_haps_dev), GFP_KERNEL);
189 	if (!haps)
190 		return -ENOMEM;
191 
192 	haps->acpi_dev = acpi_dev;
193 	haps->protection_level = 2;
194 	acpi_dev->driver_data = haps;
195 	dev_set_drvdata(&acpi_dev->dev, haps);
196 
197 	/* Set the protection level, currently at level 2 (Medium) */
198 	ret = toshiba_haps_protection_level(acpi_dev->handle, 2);
199 	if (ret != 0)
200 		return ret;
201 
202 	ret = sysfs_create_group(&acpi_dev->dev.kobj, &haps_attr_group);
203 	if (ret)
204 		return ret;
205 
206 	toshiba_haps = haps;
207 
208 	return 0;
209 }
210 
211 #ifdef CONFIG_PM_SLEEP
212 static int toshiba_haps_suspend(struct device *device)
213 {
214 	struct toshiba_haps_dev *haps;
215 	int ret;
216 
217 	haps = acpi_driver_data(to_acpi_device(device));
218 
219 	/* Deactivate the protection on suspend */
220 	ret = toshiba_haps_protection_level(haps->acpi_dev->handle, 0);
221 
222 	return ret;
223 }
224 
225 static int toshiba_haps_resume(struct device *device)
226 {
227 	struct toshiba_haps_dev *haps;
228 	int ret;
229 
230 	haps = acpi_driver_data(to_acpi_device(device));
231 
232 	/* Set the stored protection level */
233 	ret = toshiba_haps_protection_level(haps->acpi_dev->handle,
234 					    haps->protection_level);
235 
236 	/* Reset the protection on resume */
237 	ret = toshiba_haps_reset_protection(haps->acpi_dev->handle);
238 	if (ret != 0)
239 		return ret;
240 
241 	return ret;
242 }
243 #endif
244 
245 static SIMPLE_DEV_PM_OPS(toshiba_haps_pm,
246 			 toshiba_haps_suspend, toshiba_haps_resume);
247 
248 static const struct acpi_device_id haps_device_ids[] = {
249 	{"TOS620A", 0},
250 	{"", 0},
251 };
252 MODULE_DEVICE_TABLE(acpi, haps_device_ids);
253 
254 static struct acpi_driver toshiba_haps_driver = {
255 	.name = "Toshiba HAPS",
256 	.owner = THIS_MODULE,
257 	.ids = haps_device_ids,
258 	.flags = ACPI_DRIVER_ALL_NOTIFY_EVENTS,
259 	.ops = {
260 		.add =		toshiba_haps_add,
261 		.remove =	toshiba_haps_remove,
262 		.notify =	toshiba_haps_notify,
263 	},
264 	.drv.pm = &toshiba_haps_pm,
265 };
266 
267 module_acpi_driver(toshiba_haps_driver);
268