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 	.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);
266