mmc: rtsx_pci: Enable MMC_CAP_ERASE to allow erase/discard/trim requests
[linux/fpc-iii.git] / drivers / platform / x86 / dell-smo8800.c
blob0aec4fd4c48ecf5788792b8052b2c8eea8bd7d8c
1 /*
2 * dell-smo8800.c - Dell Latitude ACPI SMO88XX freefall sensor driver
4 * Copyright (C) 2012 Sonal Santan <sonal.santan@gmail.com>
5 * Copyright (C) 2014 Pali Rohár <pali.rohar@gmail.com>
7 * This is loosely based on lis3lv02d driver.
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.
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.
20 #define DRIVER_NAME "smo8800"
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>
28 struct 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 */
37 static irqreturn_t smo8800_interrupt_quick(int irq, void *data)
39 struct smo8800_device *smo8800 = data;
41 atomic_inc(&smo8800->counter);
42 wake_up_interruptible(&smo8800->misc_wait);
43 return IRQ_WAKE_THREAD;
46 static irqreturn_t smo8800_interrupt_thread(int irq, void *data)
48 struct smo8800_device *smo8800 = data;
50 dev_info(smo8800->dev, "detected free fall\n");
51 return IRQ_HANDLED;
54 static acpi_status smo8800_get_resource(struct acpi_resource *resource,
55 void *context)
57 struct acpi_resource_extended_irq *irq;
59 if (resource->type != ACPI_RESOURCE_TYPE_EXTENDED_IRQ)
60 return AE_OK;
62 irq = &resource->data.extended_irq;
63 if (!irq || !irq->interrupt_count)
64 return AE_OK;
66 *((u32 *)context) = irq->interrupts[0];
67 return AE_CTRL_TERMINATE;
70 static u32 smo8800_get_irq(struct acpi_device *device)
72 u32 irq = 0;
73 acpi_status status;
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;
82 return irq;
85 static ssize_t smo8800_misc_read(struct file *file, char __user *buf,
86 size_t count, loff_t *pos)
88 struct smo8800_device *smo8800 = container_of(file->private_data,
89 struct smo8800_device, miscdev);
91 u32 data = 0;
92 unsigned char byte_data = 0;
93 ssize_t retval = 1;
95 if (count < 1)
96 return -EINVAL;
98 atomic_set(&smo8800->counter, 0);
99 retval = wait_event_interruptible(smo8800->misc_wait,
100 (data = atomic_xchg(&smo8800->counter, 0)));
102 if (retval)
103 return retval;
105 byte_data = 1;
106 retval = 1;
108 if (data < 255)
109 byte_data = data;
110 else
111 byte_data = 255;
113 if (put_user(byte_data, buf))
114 retval = -EFAULT;
116 return retval;
119 static int smo8800_misc_open(struct inode *inode, struct file *file)
121 struct smo8800_device *smo8800 = container_of(file->private_data,
122 struct smo8800_device, miscdev);
124 if (test_and_set_bit(0, &smo8800->misc_opened))
125 return -EBUSY; /* already open */
127 atomic_set(&smo8800->counter, 0);
128 return 0;
131 static int smo8800_misc_release(struct inode *inode, struct file *file)
133 struct smo8800_device *smo8800 = container_of(file->private_data,
134 struct smo8800_device, miscdev);
136 clear_bit(0, &smo8800->misc_opened); /* release the device */
137 return 0;
140 static 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,
147 static int smo8800_add(struct acpi_device *device)
149 int err;
150 struct smo8800_device *smo8800;
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;
158 smo8800->dev = &device->dev;
159 smo8800->miscdev.minor = MISC_DYNAMIC_MINOR;
160 smo8800->miscdev.name = "freefall";
161 smo8800->miscdev.fops = &smo8800_misc_fops;
163 init_waitqueue_head(&smo8800->misc_wait);
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;
171 device->driver_data = smo8800;
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;
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;
191 dev_dbg(&device->dev, "device /dev/freefall registered with IRQ %d\n",
192 smo8800->irq);
193 return 0;
195 error:
196 misc_deregister(&smo8800->miscdev);
197 return err;
200 static int smo8800_remove(struct acpi_device *device)
202 struct smo8800_device *smo8800 = device->driver_data;
204 free_irq(smo8800->irq, smo8800);
205 misc_deregister(&smo8800->miscdev);
206 dev_dbg(&device->dev, "device /dev/freefall unregistered\n");
207 return 0;
210 static 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 },
222 MODULE_DEVICE_TABLE(acpi, smo8800_ids);
224 static 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,
232 .owner = THIS_MODULE,
235 module_acpi_driver(smo8800_driver);
237 MODULE_DESCRIPTION("Dell Latitude freefall driver (ACPI SMO88XX)");
238 MODULE_LICENSE("GPL");
239 MODULE_AUTHOR("Sonal Santan, Pali Rohár");