2 * lis3lv02d.c - ST LIS3LV02DL accelerometer driver
4 * Copyright (C) 2007-2008 Yan Burman
5 * Copyright (C) 2008 Eric Piel
6 * Copyright (C) 2008-2009 Pavel Machek
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.
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.
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
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 <asm/atomic.h>
40 #include "lis3lv02d.h"
42 #define DRIVER_NAME "lis3lv02d"
44 /* joystick device poll interval in milliseconds */
45 #define MDPS_POLL_INTERVAL 50
47 * The sensor can also generate interrupts (DRDY) but it's pretty pointless
48 * because their are generated even if the data do not change. So it's better
49 * to keep the interrupt for the free-fall event. The values are updated at
50 * 40Hz (at the lowest frequency), but as it can be pretty time consuming on
51 * some low processor, we poll the sensor only at 20Hz... enough for the
55 struct lis3lv02d lis3_dev = {
56 .misc_wait = __WAIT_QUEUE_HEAD_INITIALIZER(lis3_dev.misc_wait),
59 EXPORT_SYMBOL_GPL(lis3_dev);
61 static s16 lis3lv02d_read_8(struct lis3lv02d *lis3, int reg)
64 if (lis3->read(lis3, reg, &lo) < 0)
70 static s16 lis3lv02d_read_16(struct lis3lv02d *lis3, int reg)
74 lis3->read(lis3, reg - 1, &lo);
75 lis3->read(lis3, reg, &hi);
76 /* In "12 bit right justified" mode, bit 6, bit 7, bit 8 = bit 5 */
77 return (s16)((hi << 8) | lo);
81 * lis3lv02d_get_axis - For the given axis, give the value converted
82 * @axis: 1,2,3 - can also be negative
83 * @hw_values: raw values returned by the hardware
85 * Returns the converted value.
87 static inline int lis3lv02d_get_axis(s8 axis, int hw_values[3])
90 return hw_values[axis - 1];
92 return -hw_values[-axis - 1];
96 * lis3lv02d_get_xyz - Get X, Y and Z axis values from the accelerometer
97 * @lis3: pointer to the device struct
98 * @x: where to store the X axis value
99 * @y: where to store the Y axis value
100 * @z: where to store the Z axis value
102 * Note that 40Hz input device can eat up about 10% CPU at 800MHZ
104 static void lis3lv02d_get_xyz(struct lis3lv02d *lis3, int *x, int *y, int *z)
108 position[0] = lis3->read_data(lis3, OUTX);
109 position[1] = lis3->read_data(lis3, OUTY);
110 position[2] = lis3->read_data(lis3, OUTZ);
112 *x = lis3lv02d_get_axis(lis3->ac.x, position);
113 *y = lis3lv02d_get_axis(lis3->ac.y, position);
114 *z = lis3lv02d_get_axis(lis3->ac.z, position);
117 void lis3lv02d_poweroff(struct lis3lv02d *lis3)
119 /* disable X,Y,Z axis and power down */
120 lis3->write(lis3, CTRL_REG1, 0x00);
122 EXPORT_SYMBOL_GPL(lis3lv02d_poweroff);
124 void lis3lv02d_poweron(struct lis3lv02d *lis3)
131 * Common configuration
132 * BDU: LSB and MSB values are not updated until both have been read.
133 * So the value read will always be correct.
135 lis3->read(lis3, CTRL_REG2, ®);
137 lis3->write(lis3, CTRL_REG2, reg);
139 EXPORT_SYMBOL_GPL(lis3lv02d_poweron);
142 static irqreturn_t lis302dl_interrupt(int irq, void *dummy)
145 * Be careful: on some HP laptops the bios force DD when on battery and
146 * the lid is closed. This leads to interrupts as soon as a little move
149 atomic_inc(&lis3_dev.count);
151 wake_up_interruptible(&lis3_dev.misc_wait);
152 kill_fasync(&lis3_dev.async_queue, SIGIO, POLL_IN);
156 static int lis3lv02d_misc_open(struct inode *inode, struct file *file)
160 if (test_and_set_bit(0, &lis3_dev.misc_opened))
161 return -EBUSY; /* already open */
163 atomic_set(&lis3_dev.count, 0);
166 * The sensor can generate interrupts for free-fall and direction
167 * detection (distinguishable with FF_WU_SRC and DD_SRC) but to keep
168 * the things simple and _fast_ we activate it only for free-fall, so
169 * no need to read register (very slow with ACPI). For the same reason,
170 * we forbid shared interrupts.
172 * IRQF_TRIGGER_RISING seems pointless on HP laptops because the
173 * io-apic is not configurable (and generates a warning) but I keep it
174 * in case of support for other hardware.
176 ret = request_irq(lis3_dev.irq, lis302dl_interrupt, IRQF_TRIGGER_RISING,
177 DRIVER_NAME, &lis3_dev);
180 clear_bit(0, &lis3_dev.misc_opened);
181 printk(KERN_ERR DRIVER_NAME ": IRQ%d allocation failed\n", lis3_dev.irq);
187 static int lis3lv02d_misc_release(struct inode *inode, struct file *file)
189 fasync_helper(-1, file, 0, &lis3_dev.async_queue);
190 free_irq(lis3_dev.irq, &lis3_dev);
191 clear_bit(0, &lis3_dev.misc_opened); /* release the device */
195 static ssize_t lis3lv02d_misc_read(struct file *file, char __user *buf,
196 size_t count, loff_t *pos)
198 DECLARE_WAITQUEUE(wait, current);
200 unsigned char byte_data;
206 add_wait_queue(&lis3_dev.misc_wait, &wait);
208 set_current_state(TASK_INTERRUPTIBLE);
209 data = atomic_xchg(&lis3_dev.count, 0);
213 if (file->f_flags & O_NONBLOCK) {
218 if (signal_pending(current)) {
219 retval = -ERESTARTSYS;
231 /* make sure we are not going into copy_to_user() with
232 * TASK_INTERRUPTIBLE state */
233 set_current_state(TASK_RUNNING);
234 if (copy_to_user(buf, &byte_data, sizeof(byte_data)))
238 __set_current_state(TASK_RUNNING);
239 remove_wait_queue(&lis3_dev.misc_wait, &wait);
244 static unsigned int lis3lv02d_misc_poll(struct file *file, poll_table *wait)
246 poll_wait(file, &lis3_dev.misc_wait, wait);
247 if (atomic_read(&lis3_dev.count))
248 return POLLIN | POLLRDNORM;
252 static int lis3lv02d_misc_fasync(int fd, struct file *file, int on)
254 return fasync_helper(fd, file, on, &lis3_dev.async_queue);
257 static const struct file_operations lis3lv02d_misc_fops = {
258 .owner = THIS_MODULE,
260 .read = lis3lv02d_misc_read,
261 .open = lis3lv02d_misc_open,
262 .release = lis3lv02d_misc_release,
263 .poll = lis3lv02d_misc_poll,
264 .fasync = lis3lv02d_misc_fasync,
267 static struct miscdevice lis3lv02d_misc_device = {
268 .minor = MISC_DYNAMIC_MINOR,
270 .fops = &lis3lv02d_misc_fops,
274 * lis3lv02d_joystick_kthread - Kthread polling function
275 * @data: unused - here to conform to threadfn prototype
277 static int lis3lv02d_joystick_kthread(void *data)
281 while (!kthread_should_stop()) {
282 lis3lv02d_get_xyz(&lis3_dev, &x, &y, &z);
283 input_report_abs(lis3_dev.idev, ABS_X, x - lis3_dev.xcalib);
284 input_report_abs(lis3_dev.idev, ABS_Y, y - lis3_dev.ycalib);
285 input_report_abs(lis3_dev.idev, ABS_Z, z - lis3_dev.zcalib);
287 input_sync(lis3_dev.idev);
290 msleep_interruptible(MDPS_POLL_INTERVAL);
296 static int lis3lv02d_joystick_open(struct input_dev *input)
298 lis3_dev.kthread = kthread_run(lis3lv02d_joystick_kthread, NULL, "klis3lv02d");
299 if (IS_ERR(lis3_dev.kthread)) {
300 return PTR_ERR(lis3_dev.kthread);
306 static void lis3lv02d_joystick_close(struct input_dev *input)
308 kthread_stop(lis3_dev.kthread);
311 static inline void lis3lv02d_calibrate_joystick(void)
313 lis3lv02d_get_xyz(&lis3_dev,
314 &lis3_dev.xcalib, &lis3_dev.ycalib, &lis3_dev.zcalib);
317 int lis3lv02d_joystick_enable(void)
324 lis3_dev.idev = input_allocate_device();
328 lis3lv02d_calibrate_joystick();
330 lis3_dev.idev->name = "ST LIS3LV02DL Accelerometer";
331 lis3_dev.idev->phys = DRIVER_NAME "/input0";
332 lis3_dev.idev->id.bustype = BUS_HOST;
333 lis3_dev.idev->id.vendor = 0;
334 lis3_dev.idev->dev.parent = &lis3_dev.pdev->dev;
335 lis3_dev.idev->open = lis3lv02d_joystick_open;
336 lis3_dev.idev->close = lis3lv02d_joystick_close;
338 set_bit(EV_ABS, lis3_dev.idev->evbit);
339 input_set_abs_params(lis3_dev.idev, ABS_X, -lis3_dev.mdps_max_val, lis3_dev.mdps_max_val, 3, 3);
340 input_set_abs_params(lis3_dev.idev, ABS_Y, -lis3_dev.mdps_max_val, lis3_dev.mdps_max_val, 3, 3);
341 input_set_abs_params(lis3_dev.idev, ABS_Z, -lis3_dev.mdps_max_val, lis3_dev.mdps_max_val, 3, 3);
343 err = input_register_device(lis3_dev.idev);
345 input_free_device(lis3_dev.idev);
346 lis3_dev.idev = NULL;
351 EXPORT_SYMBOL_GPL(lis3lv02d_joystick_enable);
353 void lis3lv02d_joystick_disable(void)
359 misc_deregister(&lis3lv02d_misc_device);
360 input_unregister_device(lis3_dev.idev);
361 lis3_dev.idev = NULL;
363 EXPORT_SYMBOL_GPL(lis3lv02d_joystick_disable);
366 static ssize_t lis3lv02d_position_show(struct device *dev,
367 struct device_attribute *attr, char *buf)
371 lis3lv02d_get_xyz(&lis3_dev, &x, &y, &z);
372 return sprintf(buf, "(%d,%d,%d)\n", x, y, z);
375 static ssize_t lis3lv02d_calibrate_show(struct device *dev,
376 struct device_attribute *attr, char *buf)
378 return sprintf(buf, "(%d,%d,%d)\n", lis3_dev.xcalib, lis3_dev.ycalib, lis3_dev.zcalib);
381 static ssize_t lis3lv02d_calibrate_store(struct device *dev,
382 struct device_attribute *attr,
383 const char *buf, size_t count)
385 lis3lv02d_calibrate_joystick();
389 /* conversion btw sampling rate and the register values */
390 static int lis3lv02dl_df_val[4] = {40, 160, 640, 2560};
391 static ssize_t lis3lv02d_rate_show(struct device *dev,
392 struct device_attribute *attr, char *buf)
397 lis3_dev.read(&lis3_dev, CTRL_REG1, &ctrl);
398 val = (ctrl & (CTRL1_DF0 | CTRL1_DF1)) >> 4;
399 return sprintf(buf, "%d\n", lis3lv02dl_df_val[val]);
402 static DEVICE_ATTR(position, S_IRUGO, lis3lv02d_position_show, NULL);
403 static DEVICE_ATTR(calibrate, S_IRUGO|S_IWUSR, lis3lv02d_calibrate_show,
404 lis3lv02d_calibrate_store);
405 static DEVICE_ATTR(rate, S_IRUGO, lis3lv02d_rate_show, NULL);
407 static struct attribute *lis3lv02d_attributes[] = {
408 &dev_attr_position.attr,
409 &dev_attr_calibrate.attr,
414 static struct attribute_group lis3lv02d_attribute_group = {
415 .attrs = lis3lv02d_attributes
419 static int lis3lv02d_add_fs(struct lis3lv02d *lis3)
421 lis3->pdev = platform_device_register_simple(DRIVER_NAME, -1, NULL, 0);
422 if (IS_ERR(lis3->pdev))
423 return PTR_ERR(lis3->pdev);
425 return sysfs_create_group(&lis3->pdev->dev.kobj, &lis3lv02d_attribute_group);
428 int lis3lv02d_remove_fs(struct lis3lv02d *lis3)
430 sysfs_remove_group(&lis3->pdev->dev.kobj, &lis3lv02d_attribute_group);
431 platform_device_unregister(lis3->pdev);
434 EXPORT_SYMBOL_GPL(lis3lv02d_remove_fs);
437 * Initialise the accelerometer and the various subsystems.
438 * Should be rather independant of the bus system.
440 int lis3lv02d_init_device(struct lis3lv02d *dev)
442 dev->whoami = lis3lv02d_read_8(dev, WHO_AM_I);
444 switch (dev->whoami) {
446 printk(KERN_INFO DRIVER_NAME ": 2-byte sensor found\n");
447 dev->read_data = lis3lv02d_read_16;
448 dev->mdps_max_val = 2048;
451 printk(KERN_INFO DRIVER_NAME ": 1-byte sensor found\n");
452 dev->read_data = lis3lv02d_read_8;
453 dev->mdps_max_val = 128;
456 printk(KERN_ERR DRIVER_NAME
457 ": unknown sensor type 0x%X\n", dev->whoami);
461 lis3lv02d_add_fs(dev);
462 lis3lv02d_poweron(dev);
464 if (lis3lv02d_joystick_enable())
465 printk(KERN_ERR DRIVER_NAME ": joystick initialization failed\n");
467 /* bail if we did not get an IRQ from the bus layer */
469 printk(KERN_ERR DRIVER_NAME
470 ": No IRQ. Disabling /dev/freefall\n");
474 if (misc_register(&lis3lv02d_misc_device))
475 printk(KERN_ERR DRIVER_NAME ": misc_register failed\n");
479 EXPORT_SYMBOL_GPL(lis3lv02d_init_device);
481 MODULE_DESCRIPTION("ST LIS3LV02Dx three-axis digital accelerometer driver");
482 MODULE_AUTHOR("Yan Burman, Eric Piel, Pavel Machek");
483 MODULE_LICENSE("GPL");