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1/*
2 * dell-smo8800.c - Dell Latitude ACPI SMO88XX freefall sensor driver
3 *
4 * Copyright (C) 2012 Sonal Santan <sonal.santan@gmail.com>
5 * Copyright (C) 2014 Pali Rohár <pali.rohar@gmail.com>
6 *
7 * This is loosely based on lis3lv02d driver.
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 */
19
20#define DRIVER_NAME "smo8800"
21
22#include <linux/kernel.h>
23#include <linux/module.h>
24#include <linux/acpi.h>
25#include <linux/interrupt.h>
26#include <linux/miscdevice.h>
27
28struct smo8800_device {
29 u32 irq; /* acpi device irq */
30 atomic_t counter; /* count after last read */
31 struct miscdevice miscdev; /* for /dev/freefall */
32 unsigned long misc_opened; /* whether the device is open */
33 wait_queue_head_t misc_wait; /* Wait queue for the misc dev */
34 struct device *dev; /* acpi device */
35};
36
37static irqreturn_t smo8800_interrupt_quick(int irq, void *data)
38{
39 struct smo8800_device *smo8800 = data;
40
41 atomic_inc(&smo8800->counter);
42 wake_up_interruptible(&smo8800->misc_wait);
43 return IRQ_WAKE_THREAD;
44}
45
46static irqreturn_t smo8800_interrupt_thread(int irq, void *data)
47{
48 struct smo8800_device *smo8800 = data;
49
50 dev_info(smo8800->dev, "detected free fall\n");
51 return IRQ_HANDLED;
52}
53
54static acpi_status smo8800_get_resource(struct acpi_resource *resource,
55 void *context)
56{
57 struct acpi_resource_extended_irq *irq;
58
59 if (resource->type != ACPI_RESOURCE_TYPE_EXTENDED_IRQ)
60 return AE_OK;
61
62 irq = &resource->data.extended_irq;
63 if (!irq || !irq->interrupt_count)
64 return AE_OK;
65
66 *((u32 *)context) = irq->interrupts[0];
67 return AE_CTRL_TERMINATE;
68}
69
70static u32 smo8800_get_irq(struct acpi_device *device)
71{
72 u32 irq = 0;
73 acpi_status status;
74
75 status = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
76 smo8800_get_resource, &irq);
77 if (ACPI_FAILURE(status)) {
78 dev_err(&device->dev, "acpi_walk_resources failed\n");
79 return 0;
80 }
81
82 return irq;
83}
84
85static ssize_t smo8800_misc_read(struct file *file, char __user *buf,
86 size_t count, loff_t *pos)
87{
88 struct smo8800_device *smo8800 = container_of(file->private_data,
89 struct smo8800_device, miscdev);
90
91 u32 data = 0;
92 unsigned char byte_data = 0;
93 ssize_t retval = 1;
94
95 if (count < 1)
96 return -EINVAL;
97
98 atomic_set(&smo8800->counter, 0);
99 retval = wait_event_interruptible(smo8800->misc_wait,
100 (data = atomic_xchg(&smo8800->counter, 0)));
101
102 if (retval)
103 return retval;
104
105 byte_data = 1;
106 retval = 1;
107
108 if (data < 255)
109 byte_data = data;
110 else
111 byte_data = 255;
112
113 if (put_user(byte_data, buf))
114 retval = -EFAULT;
115
116 return retval;
117}
118
119static int smo8800_misc_open(struct inode *inode, struct file *file)
120{
121 struct smo8800_device *smo8800 = container_of(file->private_data,
122 struct smo8800_device, miscdev);
123
124 if (test_and_set_bit(0, &smo8800->misc_opened))
125 return -EBUSY; /* already open */
126
127 atomic_set(&smo8800->counter, 0);
128 return 0;
129}
130
131static int smo8800_misc_release(struct inode *inode, struct file *file)
132{
133 struct smo8800_device *smo8800 = container_of(file->private_data,
134 struct smo8800_device, miscdev);
135
136 clear_bit(0, &smo8800->misc_opened); /* release the device */
137 return 0;
138}
139
140static const struct file_operations smo8800_misc_fops = {
141 .owner = THIS_MODULE,
142 .read = smo8800_misc_read,
143 .open = smo8800_misc_open,
144 .release = smo8800_misc_release,
145};
146
147static int smo8800_add(struct acpi_device *device)
148{
149 int err;
150 struct smo8800_device *smo8800;
151
152 smo8800 = devm_kzalloc(&device->dev, sizeof(*smo8800), GFP_KERNEL);
153 if (!smo8800) {
154 dev_err(&device->dev, "failed to allocate device data\n");
155 return -ENOMEM;
156 }
157
158 smo8800->dev = &device->dev;
159 smo8800->miscdev.minor = MISC_DYNAMIC_MINOR;
160 smo8800->miscdev.name = "freefall";
161 smo8800->miscdev.fops = &smo8800_misc_fops;
162
163 init_waitqueue_head(&smo8800->misc_wait);
164
165 err = misc_register(&smo8800->miscdev);
166 if (err) {
167 dev_err(&device->dev, "failed to register misc dev: %d\n", err);
168 return err;
169 }
170
171 device->driver_data = smo8800;
172
173 smo8800->irq = smo8800_get_irq(device);
174 if (!smo8800->irq) {
175 dev_err(&device->dev, "failed to obtain IRQ\n");
176 err = -EINVAL;
177 goto error;
178 }
179
180 err = request_threaded_irq(smo8800->irq, smo8800_interrupt_quick,
181 smo8800_interrupt_thread,
182 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
183 DRIVER_NAME, smo8800);
184 if (err) {
185 dev_err(&device->dev,
186 "failed to request thread for IRQ %d: %d\n",
187 smo8800->irq, err);
188 goto error;
189 }
190
191 dev_dbg(&device->dev, "device /dev/freefall registered with IRQ %d\n",
192 smo8800->irq);
193 return 0;
194
195error:
196 misc_deregister(&smo8800->miscdev);
197 return err;
198}
199
200static int smo8800_remove(struct acpi_device *device)
201{
202 struct smo8800_device *smo8800 = device->driver_data;
203
204 free_irq(smo8800->irq, smo8800);
205 misc_deregister(&smo8800->miscdev);
206 dev_dbg(&device->dev, "device /dev/freefall unregistered\n");
207 return 0;
208}
209
210static const struct acpi_device_id smo8800_ids[] = {
211 { "SMO8800", 0 },
212 { "SMO8801", 0 },
213 { "SMO8810", 0 },
214 { "SMO8811", 0 },
215 { "SMO8820", 0 },
216 { "SMO8821", 0 },
217 { "SMO8830", 0 },
218 { "SMO8831", 0 },
219 { "", 0 },
220};
221
222MODULE_DEVICE_TABLE(acpi, smo8800_ids);
223
224static struct acpi_driver smo8800_driver = {
225 .name = DRIVER_NAME,
226 .class = "Latitude",
227 .ids = smo8800_ids,
228 .ops = {
229 .add = smo8800_add,
230 .remove = smo8800_remove,
231 },
232 .owner = THIS_MODULE,
233};
234
235module_acpi_driver(smo8800_driver);
236
237MODULE_DESCRIPTION("Dell Latitude freefall driver (ACPI SMO88XX)");
238MODULE_LICENSE("GPL");
239MODULE_AUTHOR("Sonal Santan, Pali Rohár");
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * dell-smo8800.c - Dell Latitude ACPI SMO88XX freefall sensor driver
4 *
5 * Copyright (C) 2012 Sonal Santan <sonal.santan@gmail.com>
6 * Copyright (C) 2014 Pali Rohár <pali.rohar@gmail.com>
7 *
8 * This is loosely based on lis3lv02d driver.
9 */
10
11#define DRIVER_NAME "smo8800"
12
13#include <linux/kernel.h>
14#include <linux/module.h>
15#include <linux/acpi.h>
16#include <linux/interrupt.h>
17#include <linux/miscdevice.h>
18#include <linux/uaccess.h>
19
20struct smo8800_device {
21 u32 irq; /* acpi device irq */
22 atomic_t counter; /* count after last read */
23 struct miscdevice miscdev; /* for /dev/freefall */
24 unsigned long misc_opened; /* whether the device is open */
25 wait_queue_head_t misc_wait; /* Wait queue for the misc dev */
26 struct device *dev; /* acpi device */
27};
28
29static irqreturn_t smo8800_interrupt_quick(int irq, void *data)
30{
31 struct smo8800_device *smo8800 = data;
32
33 atomic_inc(&smo8800->counter);
34 wake_up_interruptible(&smo8800->misc_wait);
35 return IRQ_WAKE_THREAD;
36}
37
38static irqreturn_t smo8800_interrupt_thread(int irq, void *data)
39{
40 struct smo8800_device *smo8800 = data;
41
42 dev_info(smo8800->dev, "detected free fall\n");
43 return IRQ_HANDLED;
44}
45
46static acpi_status smo8800_get_resource(struct acpi_resource *resource,
47 void *context)
48{
49 struct acpi_resource_extended_irq *irq;
50
51 if (resource->type != ACPI_RESOURCE_TYPE_EXTENDED_IRQ)
52 return AE_OK;
53
54 irq = &resource->data.extended_irq;
55 if (!irq || !irq->interrupt_count)
56 return AE_OK;
57
58 *((u32 *)context) = irq->interrupts[0];
59 return AE_CTRL_TERMINATE;
60}
61
62static u32 smo8800_get_irq(struct acpi_device *device)
63{
64 u32 irq = 0;
65 acpi_status status;
66
67 status = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
68 smo8800_get_resource, &irq);
69 if (ACPI_FAILURE(status)) {
70 dev_err(&device->dev, "acpi_walk_resources failed\n");
71 return 0;
72 }
73
74 return irq;
75}
76
77static ssize_t smo8800_misc_read(struct file *file, char __user *buf,
78 size_t count, loff_t *pos)
79{
80 struct smo8800_device *smo8800 = container_of(file->private_data,
81 struct smo8800_device, miscdev);
82
83 u32 data = 0;
84 unsigned char byte_data;
85 ssize_t retval = 1;
86
87 if (count < 1)
88 return -EINVAL;
89
90 atomic_set(&smo8800->counter, 0);
91 retval = wait_event_interruptible(smo8800->misc_wait,
92 (data = atomic_xchg(&smo8800->counter, 0)));
93
94 if (retval)
95 return retval;
96
97 retval = 1;
98
99 if (data < 255)
100 byte_data = data;
101 else
102 byte_data = 255;
103
104 if (put_user(byte_data, buf))
105 retval = -EFAULT;
106
107 return retval;
108}
109
110static int smo8800_misc_open(struct inode *inode, struct file *file)
111{
112 struct smo8800_device *smo8800 = container_of(file->private_data,
113 struct smo8800_device, miscdev);
114
115 if (test_and_set_bit(0, &smo8800->misc_opened))
116 return -EBUSY; /* already open */
117
118 atomic_set(&smo8800->counter, 0);
119 return 0;
120}
121
122static int smo8800_misc_release(struct inode *inode, struct file *file)
123{
124 struct smo8800_device *smo8800 = container_of(file->private_data,
125 struct smo8800_device, miscdev);
126
127 clear_bit(0, &smo8800->misc_opened); /* release the device */
128 return 0;
129}
130
131static const struct file_operations smo8800_misc_fops = {
132 .owner = THIS_MODULE,
133 .read = smo8800_misc_read,
134 .open = smo8800_misc_open,
135 .release = smo8800_misc_release,
136};
137
138static int smo8800_add(struct acpi_device *device)
139{
140 int err;
141 struct smo8800_device *smo8800;
142
143 smo8800 = devm_kzalloc(&device->dev, sizeof(*smo8800), GFP_KERNEL);
144 if (!smo8800) {
145 dev_err(&device->dev, "failed to allocate device data\n");
146 return -ENOMEM;
147 }
148
149 smo8800->dev = &device->dev;
150 smo8800->miscdev.minor = MISC_DYNAMIC_MINOR;
151 smo8800->miscdev.name = "freefall";
152 smo8800->miscdev.fops = &smo8800_misc_fops;
153
154 init_waitqueue_head(&smo8800->misc_wait);
155
156 err = misc_register(&smo8800->miscdev);
157 if (err) {
158 dev_err(&device->dev, "failed to register misc dev: %d\n", err);
159 return err;
160 }
161
162 device->driver_data = smo8800;
163
164 smo8800->irq = smo8800_get_irq(device);
165 if (!smo8800->irq) {
166 dev_err(&device->dev, "failed to obtain IRQ\n");
167 err = -EINVAL;
168 goto error;
169 }
170
171 err = request_threaded_irq(smo8800->irq, smo8800_interrupt_quick,
172 smo8800_interrupt_thread,
173 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
174 DRIVER_NAME, smo8800);
175 if (err) {
176 dev_err(&device->dev,
177 "failed to request thread for IRQ %d: %d\n",
178 smo8800->irq, err);
179 goto error;
180 }
181
182 dev_dbg(&device->dev, "device /dev/freefall registered with IRQ %d\n",
183 smo8800->irq);
184 return 0;
185
186error:
187 misc_deregister(&smo8800->miscdev);
188 return err;
189}
190
191static int smo8800_remove(struct acpi_device *device)
192{
193 struct smo8800_device *smo8800 = device->driver_data;
194
195 free_irq(smo8800->irq, smo8800);
196 misc_deregister(&smo8800->miscdev);
197 dev_dbg(&device->dev, "device /dev/freefall unregistered\n");
198 return 0;
199}
200
201/* NOTE: Keep this list in sync with drivers/i2c/busses/i2c-i801.c */
202static const struct acpi_device_id smo8800_ids[] = {
203 { "SMO8800", 0 },
204 { "SMO8801", 0 },
205 { "SMO8810", 0 },
206 { "SMO8811", 0 },
207 { "SMO8820", 0 },
208 { "SMO8821", 0 },
209 { "SMO8830", 0 },
210 { "SMO8831", 0 },
211 { "", 0 },
212};
213
214MODULE_DEVICE_TABLE(acpi, smo8800_ids);
215
216static struct acpi_driver smo8800_driver = {
217 .name = DRIVER_NAME,
218 .class = "Latitude",
219 .ids = smo8800_ids,
220 .ops = {
221 .add = smo8800_add,
222 .remove = smo8800_remove,
223 },
224 .owner = THIS_MODULE,
225};
226
227module_acpi_driver(smo8800_driver);
228
229MODULE_DESCRIPTION("Dell Latitude freefall driver (ACPI SMO88XX)");
230MODULE_LICENSE("GPL");
231MODULE_AUTHOR("Sonal Santan, Pali Rohár");