1 /*
2 * lis3lv02d.c - ST LIS3LV02DL accelerometer driver
3 *
4 * Copyright (C) 2007-2008 Yan Burman
5 * Copyright (C) 2008 Eric Piel
6 * Copyright (C) 2008-2009 Pavel Machek
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 */
22
23 #include <linux/kernel.h>
24 #include <linux/init.h>
25 #include <linux/dmi.h>
26 #include <linux/module.h>
27 #include <linux/types.h>
28 #include <linux/platform_device.h>
29 #include <linux/interrupt.h>
30 #include <linux/input.h>
31 #include <linux/kthread.h>
32 #include <linux/semaphore.h>
33 #include <linux/delay.h>
34 #include <linux/wait.h>
35 #include <linux/poll.h>
36 #include <linux/freezer.h>
37 #include <linux/uaccess.h>
38 #include <linux/miscdevice.h>
39 #include <acpi/acpi_drivers.h>
40 #include <asm/atomic.h>
41 #include "lis3lv02d.h"
42
43 #define DRIVER_NAME "lis3lv02d"
44
45 /* joystick device poll interval in milliseconds */
46 #define MDPS_POLL_INTERVAL 50
47 /*
48 * The sensor can also generate interrupts (DRDY) but it's pretty pointless
49 * because their are generated even if the data do not change. So it's better
50 * to keep the interrupt for the free-fall event. The values are updated at
51 * 40Hz (at the lowest frequency), but as it can be pretty time consuming on
52 * some low processor, we poll the sensor only at 20Hz... enough for the
53 * joystick.
54 */
55
56 struct acpi_lis3lv02d adev = {
57 .misc_wait = __WAIT_QUEUE_HEAD_INITIALIZER(adev.misc_wait),
58 };
59
60 EXPORT_SYMBOL_GPL(adev);
61
62 static int lis3lv02d_add_fs(struct acpi_device *device);
63
64 /**
65 * lis3lv02d_get_axis - For the given axis, give the value converted
66 * @axis: 1,2,3 - can also be negative
67 * @hw_values: raw values returned by the hardware
68 *
69 * Returns the converted value.
70 */
lis3lv02d_get_axis(s8 axis,int hw_values[3])71 static inline int lis3lv02d_get_axis(s8 axis, int hw_values[3])
72 {
73 if (axis > 0)
74 return hw_values[axis - 1];
75 else
76 return -hw_values[-axis - 1];
77 }
78
79 /**
80 * lis3lv02d_get_xyz - Get X, Y and Z axis values from the accelerometer
81 * @handle: the handle to the device
82 * @x: where to store the X axis value
83 * @y: where to store the Y axis value
84 * @z: where to store the Z axis value
85 *
86 * Note that 40Hz input device can eat up about 10% CPU at 800MHZ
87 */
lis3lv02d_get_xyz(acpi_handle handle,int * x,int * y,int * z)88 static void lis3lv02d_get_xyz(acpi_handle handle, int *x, int *y, int *z)
89 {
90 int position[3];
91
92 position[0] = adev.read_data(handle, OUTX);
93 position[1] = adev.read_data(handle, OUTY);
94 position[2] = adev.read_data(handle, OUTZ);
95
96 *x = lis3lv02d_get_axis(adev.ac.x, position);
97 *y = lis3lv02d_get_axis(adev.ac.y, position);
98 *z = lis3lv02d_get_axis(adev.ac.z, position);
99 }
100
lis3lv02d_poweroff(acpi_handle handle)101 void lis3lv02d_poweroff(acpi_handle handle)
102 {
103 adev.is_on = 0;
104 }
105 EXPORT_SYMBOL_GPL(lis3lv02d_poweroff);
106
lis3lv02d_poweron(acpi_handle handle)107 void lis3lv02d_poweron(acpi_handle handle)
108 {
109 adev.is_on = 1;
110 adev.init(handle);
111 }
112 EXPORT_SYMBOL_GPL(lis3lv02d_poweron);
113
114 /*
115 * To be called before starting to use the device. It makes sure that the
116 * device will always be on until a call to lis3lv02d_decrease_use(). Not to be
117 * used from interrupt context.
118 */
lis3lv02d_increase_use(struct acpi_lis3lv02d * dev)119 static void lis3lv02d_increase_use(struct acpi_lis3lv02d *dev)
120 {
121 mutex_lock(&dev->lock);
122 dev->usage++;
123 if (dev->usage == 1) {
124 if (!dev->is_on)
125 lis3lv02d_poweron(dev->device->handle);
126 }
127 mutex_unlock(&dev->lock);
128 }
129
130 /*
131 * To be called whenever a usage of the device is stopped.
132 * It will make sure to turn off the device when there is not usage.
133 */
lis3lv02d_decrease_use(struct acpi_lis3lv02d * dev)134 static void lis3lv02d_decrease_use(struct acpi_lis3lv02d *dev)
135 {
136 mutex_lock(&dev->lock);
137 dev->usage--;
138 if (dev->usage == 0)
139 lis3lv02d_poweroff(dev->device->handle);
140 mutex_unlock(&dev->lock);
141 }
142
lis302dl_interrupt(int irq,void * dummy)143 static irqreturn_t lis302dl_interrupt(int irq, void *dummy)
144 {
145 /*
146 * Be careful: on some HP laptops the bios force DD when on battery and
147 * the lid is closed. This leads to interrupts as soon as a little move
148 * is done.
149 */
150 atomic_inc(&adev.count);
151
152 wake_up_interruptible(&adev.misc_wait);
153 kill_fasync(&adev.async_queue, SIGIO, POLL_IN);
154 return IRQ_HANDLED;
155 }
156
lis3lv02d_misc_open(struct inode * inode,struct file * file)157 static int lis3lv02d_misc_open(struct inode *inode, struct file *file)
158 {
159 int ret;
160
161 if (test_and_set_bit(0, &adev.misc_opened))
162 return -EBUSY; /* already open */
163
164 atomic_set(&adev.count, 0);
165
166 /*
167 * The sensor can generate interrupts for free-fall and direction
168 * detection (distinguishable with FF_WU_SRC and DD_SRC) but to keep
169 * the things simple and _fast_ we activate it only for free-fall, so
170 * no need to read register (very slow with ACPI). For the same reason,
171 * we forbid shared interrupts.
172 *
173 * IRQF_TRIGGER_RISING seems pointless on HP laptops because the
174 * io-apic is not configurable (and generates a warning) but I keep it
175 * in case of support for other hardware.
176 */
177 ret = request_irq(adev.irq, lis302dl_interrupt, IRQF_TRIGGER_RISING,
178 DRIVER_NAME, &adev);
179
180 if (ret) {
181 clear_bit(0, &adev.misc_opened);
182 printk(KERN_ERR DRIVER_NAME ": IRQ%d allocation failed\n", adev.irq);
183 return -EBUSY;
184 }
185 lis3lv02d_increase_use(&adev);
186 printk("lis3: registered interrupt %d\n", adev.irq);
187 return 0;
188 }
189
lis3lv02d_misc_release(struct inode * inode,struct file * file)190 static int lis3lv02d_misc_release(struct inode *inode, struct file *file)
191 {
192 fasync_helper(-1, file, 0, &adev.async_queue);
193 lis3lv02d_decrease_use(&adev);
194 free_irq(adev.irq, &adev);
195 clear_bit(0, &adev.misc_opened); /* release the device */
196 return 0;
197 }
198
lis3lv02d_misc_read(struct file * file,char __user * buf,size_t count,loff_t * pos)199 static ssize_t lis3lv02d_misc_read(struct file *file, char __user *buf,
200 size_t count, loff_t *pos)
201 {
202 DECLARE_WAITQUEUE(wait, current);
203 u32 data;
204 unsigned char byte_data;
205 ssize_t retval = 1;
206
207 if (count < 1)
208 return -EINVAL;
209
210 add_wait_queue(&adev.misc_wait, &wait);
211 while (true) {
212 set_current_state(TASK_INTERRUPTIBLE);
213 data = atomic_xchg(&adev.count, 0);
214 if (data)
215 break;
216
217 if (file->f_flags & O_NONBLOCK) {
218 retval = -EAGAIN;
219 goto out;
220 }
221
222 if (signal_pending(current)) {
223 retval = -ERESTARTSYS;
224 goto out;
225 }
226
227 schedule();
228 }
229
230 if (data < 255)
231 byte_data = data;
232 else
233 byte_data = 255;
234
235 /* make sure we are not going into copy_to_user() with
236 * TASK_INTERRUPTIBLE state */
237 set_current_state(TASK_RUNNING);
238 if (copy_to_user(buf, &byte_data, sizeof(byte_data)))
239 retval = -EFAULT;
240
241 out:
242 __set_current_state(TASK_RUNNING);
243 remove_wait_queue(&adev.misc_wait, &wait);
244
245 return retval;
246 }
247
lis3lv02d_misc_poll(struct file * file,poll_table * wait)248 static unsigned int lis3lv02d_misc_poll(struct file *file, poll_table *wait)
249 {
250 poll_wait(file, &adev.misc_wait, wait);
251 if (atomic_read(&adev.count))
252 return POLLIN | POLLRDNORM;
253 return 0;
254 }
255
lis3lv02d_misc_fasync(int fd,struct file * file,int on)256 static int lis3lv02d_misc_fasync(int fd, struct file *file, int on)
257 {
258 return fasync_helper(fd, file, on, &adev.async_queue);
259 }
260
261 static const struct file_operations lis3lv02d_misc_fops = {
262 .owner = THIS_MODULE,
263 .llseek = no_llseek,
264 .read = lis3lv02d_misc_read,
265 .open = lis3lv02d_misc_open,
266 .release = lis3lv02d_misc_release,
267 .poll = lis3lv02d_misc_poll,
268 .fasync = lis3lv02d_misc_fasync,
269 };
270
271 static struct miscdevice lis3lv02d_misc_device = {
272 .minor = MISC_DYNAMIC_MINOR,
273 .name = "freefall",
274 .fops = &lis3lv02d_misc_fops,
275 };
276
277 /**
278 * lis3lv02d_joystick_kthread - Kthread polling function
279 * @data: unused - here to conform to threadfn prototype
280 */
lis3lv02d_joystick_kthread(void * data)281 static int lis3lv02d_joystick_kthread(void *data)
282 {
283 int x, y, z;
284
285 while (!kthread_should_stop()) {
286 lis3lv02d_get_xyz(adev.device->handle, &x, &y, &z);
287 input_report_abs(adev.idev, ABS_X, x - adev.xcalib);
288 input_report_abs(adev.idev, ABS_Y, y - adev.ycalib);
289 input_report_abs(adev.idev, ABS_Z, z - adev.zcalib);
290
291 input_sync(adev.idev);
292
293 try_to_freeze();
294 msleep_interruptible(MDPS_POLL_INTERVAL);
295 }
296
297 return 0;
298 }
299
lis3lv02d_joystick_open(struct input_dev * input)300 static int lis3lv02d_joystick_open(struct input_dev *input)
301 {
302 lis3lv02d_increase_use(&adev);
303 adev.kthread = kthread_run(lis3lv02d_joystick_kthread, NULL, "klis3lv02d");
304 if (IS_ERR(adev.kthread)) {
305 lis3lv02d_decrease_use(&adev);
306 return PTR_ERR(adev.kthread);
307 }
308
309 return 0;
310 }
311
lis3lv02d_joystick_close(struct input_dev * input)312 static void lis3lv02d_joystick_close(struct input_dev *input)
313 {
314 kthread_stop(adev.kthread);
315 lis3lv02d_decrease_use(&adev);
316 }
317
lis3lv02d_calibrate_joystick(void)318 static inline void lis3lv02d_calibrate_joystick(void)
319 {
320 lis3lv02d_get_xyz(adev.device->handle, &adev.xcalib, &adev.ycalib, &adev.zcalib);
321 }
322
lis3lv02d_joystick_enable(void)323 int lis3lv02d_joystick_enable(void)
324 {
325 int err;
326
327 if (adev.idev)
328 return -EINVAL;
329
330 adev.idev = input_allocate_device();
331 if (!adev.idev)
332 return -ENOMEM;
333
334 lis3lv02d_calibrate_joystick();
335
336 adev.idev->name = "ST LIS3LV02DL Accelerometer";
337 adev.idev->phys = DRIVER_NAME "/input0";
338 adev.idev->id.bustype = BUS_HOST;
339 adev.idev->id.vendor = 0;
340 adev.idev->dev.parent = &adev.pdev->dev;
341 adev.idev->open = lis3lv02d_joystick_open;
342 adev.idev->close = lis3lv02d_joystick_close;
343
344 set_bit(EV_ABS, adev.idev->evbit);
345 input_set_abs_params(adev.idev, ABS_X, -adev.mdps_max_val, adev.mdps_max_val, 3, 3);
346 input_set_abs_params(adev.idev, ABS_Y, -adev.mdps_max_val, adev.mdps_max_val, 3, 3);
347 input_set_abs_params(adev.idev, ABS_Z, -adev.mdps_max_val, adev.mdps_max_val, 3, 3);
348
349 err = input_register_device(adev.idev);
350 if (err) {
351 input_free_device(adev.idev);
352 adev.idev = NULL;
353 }
354
355 return err;
356 }
357 EXPORT_SYMBOL_GPL(lis3lv02d_joystick_enable);
358
lis3lv02d_joystick_disable(void)359 void lis3lv02d_joystick_disable(void)
360 {
361 if (!adev.idev)
362 return;
363
364 misc_deregister(&lis3lv02d_misc_device);
365 input_unregister_device(adev.idev);
366 adev.idev = NULL;
367 }
368 EXPORT_SYMBOL_GPL(lis3lv02d_joystick_disable);
369
370 /*
371 * Initialise the accelerometer and the various subsystems.
372 * Should be rather independant of the bus system.
373 */
lis3lv02d_init_device(struct acpi_lis3lv02d * dev)374 int lis3lv02d_init_device(struct acpi_lis3lv02d *dev)
375 {
376 mutex_init(&dev->lock);
377 lis3lv02d_add_fs(dev->device);
378 lis3lv02d_increase_use(dev);
379
380 if (lis3lv02d_joystick_enable())
381 printk(KERN_ERR DRIVER_NAME ": joystick initialization failed\n");
382
383 printk("lis3_init_device: irq %d\n", dev->irq);
384
385 /* if we did not get an IRQ from ACPI - we have nothing more to do */
386 if (!dev->irq) {
387 printk(KERN_ERR DRIVER_NAME
388 ": No IRQ in ACPI. Disabling /dev/freefall\n");
389 goto out;
390 }
391
392 printk("lis3: registering device\n");
393 if (misc_register(&lis3lv02d_misc_device))
394 printk(KERN_ERR DRIVER_NAME ": misc_register failed\n");
395 out:
396 lis3lv02d_decrease_use(dev);
397 return 0;
398 }
399 EXPORT_SYMBOL_GPL(lis3lv02d_init_device);
400
401 /* Sysfs stuff */
lis3lv02d_position_show(struct device * dev,struct device_attribute * attr,char * buf)402 static ssize_t lis3lv02d_position_show(struct device *dev,
403 struct device_attribute *attr, char *buf)
404 {
405 int x, y, z;
406
407 lis3lv02d_increase_use(&adev);
408 lis3lv02d_get_xyz(adev.device->handle, &x, &y, &z);
409 lis3lv02d_decrease_use(&adev);
410 return sprintf(buf, "(%d,%d,%d)\n", x, y, z);
411 }
412
lis3lv02d_calibrate_show(struct device * dev,struct device_attribute * attr,char * buf)413 static ssize_t lis3lv02d_calibrate_show(struct device *dev,
414 struct device_attribute *attr, char *buf)
415 {
416 return sprintf(buf, "(%d,%d,%d)\n", adev.xcalib, adev.ycalib, adev.zcalib);
417 }
418
lis3lv02d_calibrate_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)419 static ssize_t lis3lv02d_calibrate_store(struct device *dev,
420 struct device_attribute *attr,
421 const char *buf, size_t count)
422 {
423 lis3lv02d_increase_use(&adev);
424 lis3lv02d_calibrate_joystick();
425 lis3lv02d_decrease_use(&adev);
426 return count;
427 }
428
429 /* conversion btw sampling rate and the register values */
430 static int lis3lv02dl_df_val[4] = {40, 160, 640, 2560};
lis3lv02d_rate_show(struct device * dev,struct device_attribute * attr,char * buf)431 static ssize_t lis3lv02d_rate_show(struct device *dev,
432 struct device_attribute *attr, char *buf)
433 {
434 u8 ctrl;
435 int val;
436
437 lis3lv02d_increase_use(&adev);
438 adev.read(adev.device->handle, CTRL_REG1, &ctrl);
439 lis3lv02d_decrease_use(&adev);
440 val = (ctrl & (CTRL1_DF0 | CTRL1_DF1)) >> 4;
441 return sprintf(buf, "%d\n", lis3lv02dl_df_val[val]);
442 }
443
444 static DEVICE_ATTR(position, S_IRUGO, lis3lv02d_position_show, NULL);
445 static DEVICE_ATTR(calibrate, S_IRUGO|S_IWUSR, lis3lv02d_calibrate_show,
446 lis3lv02d_calibrate_store);
447 static DEVICE_ATTR(rate, S_IRUGO, lis3lv02d_rate_show, NULL);
448
449 static struct attribute *lis3lv02d_attributes[] = {
450 &dev_attr_position.attr,
451 &dev_attr_calibrate.attr,
452 &dev_attr_rate.attr,
453 NULL
454 };
455
456 static struct attribute_group lis3lv02d_attribute_group = {
457 .attrs = lis3lv02d_attributes
458 };
459
460
lis3lv02d_add_fs(struct acpi_device * device)461 static int lis3lv02d_add_fs(struct acpi_device *device)
462 {
463 adev.pdev = platform_device_register_simple(DRIVER_NAME, -1, NULL, 0);
464 if (IS_ERR(adev.pdev))
465 return PTR_ERR(adev.pdev);
466
467 return sysfs_create_group(&adev.pdev->dev.kobj, &lis3lv02d_attribute_group);
468 }
469
lis3lv02d_remove_fs(void)470 int lis3lv02d_remove_fs(void)
471 {
472 sysfs_remove_group(&adev.pdev->dev.kobj, &lis3lv02d_attribute_group);
473 platform_device_unregister(adev.pdev);
474 return 0;
475 }
476 EXPORT_SYMBOL_GPL(lis3lv02d_remove_fs);
477
478 MODULE_DESCRIPTION("ST LIS3LV02Dx three-axis digital accelerometer driver");
479 MODULE_AUTHOR("Yan Burman, Eric Piel, Pavel Machek");
480 MODULE_LICENSE("GPL");
481
482