aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/hwmon/lis3lv02d.c
blob: cf5afb9a10abbd9af3432dce36249a23edfcab0d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
/*
 *  lis3lv02d.c - ST LIS3LV02DL accelerometer driver
 *
 *  Copyright (C) 2007-2008 Yan Burman
 *  Copyright (C) 2008 Eric Piel
 *  Copyright (C) 2008-2009 Pavel Machek
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/dmi.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/input-polldev.h>
#include <linux/delay.h>
#include <linux/wait.h>
#include <linux/poll.h>
#include <linux/freezer.h>
#include <linux/uaccess.h>
#include <linux/miscdevice.h>
#include <asm/atomic.h>
#include "lis3lv02d.h"

#define DRIVER_NAME     "lis3lv02d"

/* joystick device poll interval in milliseconds */
#define MDPS_POLL_INTERVAL 50
/*
 * The sensor can also generate interrupts (DRDY) but it's pretty pointless
 * because their are generated even if the data do not change. So it's better
 * to keep the interrupt for the free-fall event. The values are updated at
 * 40Hz (at the lowest frequency), but as it can be pretty time consuming on
 * some low processor, we poll the sensor only at 20Hz... enough for the
 * joystick.
 */

struct lis3lv02d lis3_dev = {
	.misc_wait   = __WAIT_QUEUE_HEAD_INITIALIZER(lis3_dev.misc_wait),
};

EXPORT_SYMBOL_GPL(lis3_dev);

static s16 lis3lv02d_read_8(struct lis3lv02d *lis3, int reg)
{
	s8 lo;
	if (lis3->read(lis3, reg, &lo) < 0)
		return 0;

	return lo;
}

static s16 lis3lv02d_read_16(struct lis3lv02d *lis3, int reg)
{
	u8 lo, hi;

	lis3->read(lis3, reg - 1, &lo);
	lis3->read(lis3, reg, &hi);
	/* In "12 bit right justified" mode, bit 6, bit 7, bit 8 = bit 5 */
	return (s16)((hi << 8) | lo);
}

/**
 * lis3lv02d_get_axis - For the given axis, give the value converted
 * @axis:      1,2,3 - can also be negative
 * @hw_values: raw values returned by the hardware
 *
 * Returns the converted value.
 */
static inline int lis3lv02d_get_axis(s8 axis, int hw_values[3])
{
	if (axis > 0)
		return hw_values[axis - 1];
	else
		return -hw_values[-axis - 1];
}

/**
 * lis3lv02d_get_xyz - Get X, Y and Z axis values from the accelerometer
 * @lis3: pointer to the device struct
 * @x:    where to store the X axis value
 * @y:    where to store the Y axis value
 * @z:    where to store the Z axis value
 *
 * Note that 40Hz input device can eat up about 10% CPU at 800MHZ
 */
static void lis3lv02d_get_xyz(struct lis3lv02d *lis3, int *x, int *y, int *z)
{
	int position[3];

	position[0] = lis3->read_data(lis3, OUTX);
	position[1] = lis3->read_data(lis3, OUTY);
	position[2] = lis3->read_data(lis3, OUTZ);

	*x = lis3lv02d_get_axis(lis3->ac.x, position);
	*y = lis3lv02d_get_axis(lis3->ac.y, position);
	*z = lis3lv02d_get_axis(lis3->ac.z, position);
}

void lis3lv02d_poweroff(struct lis3lv02d *lis3)
{
	/* disable X,Y,Z axis and power down */
	lis3->write(lis3, CTRL_REG1, 0x00);
}
EXPORT_SYMBOL_GPL(lis3lv02d_poweroff);

void lis3lv02d_poweron(struct lis3lv02d *lis3)
{
	u8 reg;

	lis3->init(lis3);

	/*
	 * Common configuration
	 * BDU: LSB and MSB values are not updated until both have been read.
	 *      So the value read will always be correct.
	 */
	lis3->read(lis3, CTRL_REG2, &reg);
	reg |= CTRL2_BDU;
	lis3->write(lis3, CTRL_REG2, reg);
}
EXPORT_SYMBOL_GPL(lis3lv02d_poweron);


static irqreturn_t lis302dl_interrupt(int irq, void *dummy)
{
	/*
	 * Be careful: on some HP laptops the bios force DD when on battery and
	 * the lid is closed. This leads to interrupts as soon as a little move
	 * is done.
	 */
	atomic_inc(&lis3_dev.count);

	wake_up_interruptible(&lis3_dev.misc_wait);
	kill_fasync(&lis3_dev.async_queue, SIGIO, POLL_IN);
	return IRQ_HANDLED;
}

static int lis3lv02d_misc_open(struct inode *inode, struct file *file)
{
	int ret;

	if (test_and_set_bit(0, &lis3_dev.misc_opened))
		return -EBUSY; /* already open */

	atomic_set(&lis3_dev.count, 0);

	/*
	 * The sensor can generate interrupts for free-fall and direction
	 * detection (distinguishable with FF_WU_SRC and DD_SRC) but to keep
	 * the things simple and _fast_ we activate it only for free-fall, so
	 * no need to read register (very slow with ACPI). For the same reason,
	 * we forbid shared interrupts.
	 *
	 * IRQF_TRIGGER_RISING seems pointless on HP laptops because the
	 * io-apic is not configurable (and generates a warning) but I keep it
	 * in case of support for other hardware.
	 */
	ret = request_irq(lis3_dev.irq, lis302dl_interrupt, IRQF_TRIGGER_RISING,
			  DRIVER_NAME, &lis3_dev);

	if (ret) {
		clear_bit(0, &lis3_dev.misc_opened);
		printk(KERN_ERR DRIVER_NAME ": IRQ%d allocation failed\n", lis3_dev.irq);
		return -EBUSY;
	}
	return 0;
}

static int lis3lv02d_misc_release(struct inode *inode, struct file *file)
{
	fasync_helper(-1, file, 0, &lis3_dev.async_queue);
	free_irq(lis3_dev.irq, &lis3_dev);
	clear_bit(0, &lis3_dev.misc_opened); /* release the device */
	return 0;
}

static ssize_t lis3lv02d_misc_read(struct file *file, char __user *buf,
				size_t count, loff_t *pos)
{
	DECLARE_WAITQUEUE(wait, current);
	u32 data;
	unsigned char byte_data;
	ssize_t retval = 1;

	if (count < 1)
		return -EINVAL;

	add_wait_queue(&lis3_dev.misc_wait, &wait);
	while (true) {
		set_current_state(TASK_INTERRUPTIBLE);
		data = atomic_xchg(&lis3_dev.count, 0);
		if (data)
			break;

		if (file->f_flags & O_NONBLOCK) {
			retval = -EAGAIN;
			goto out;
		}

		if (signal_pending(current)) {
			retval = -ERESTARTSYS;
			goto out;
		}

		schedule();
	}

	if (data < 255)
		byte_data = data;
	else
		byte_data = 255;

	/* make sure we are not going into copy_to_user() with
	 * TASK_INTERRUPTIBLE state */
	set_current_state(TASK_RUNNING);
	if (copy_to_user(buf, &byte_data, sizeof(byte_data)))
		retval = -EFAULT;

out:
	__set_current_state(TASK_RUNNING);
	remove_wait_queue(&lis3_dev.misc_wait, &wait);

	return retval;
}

static unsigned int lis3lv02d_misc_poll(struct file *file, poll_table *wait)
{
	poll_wait(file, &lis3_dev.misc_wait, wait);
	if (atomic_read(&lis3_dev.count))
		return POLLIN | POLLRDNORM;
	return 0;
}

static int lis3lv02d_misc_fasync(int fd, struct file *file, int on)
{
	return fasync_helper(fd, file, on, &lis3_dev.async_queue);
}

static const struct file_operations lis3lv02d_misc_fops = {
	.owner   = THIS_MODULE,
	.llseek  = no_llseek,
	.read    = lis3lv02d_misc_read,
	.open    = lis3lv02d_misc_open,
	.release = lis3lv02d_misc_release,
	.poll    = lis3lv02d_misc_poll,
	.fasync  = lis3lv02d_misc_fasync,
};

static struct miscdevice lis3lv02d_misc_device = {
	.minor   = MISC_DYNAMIC_MINOR,
	.name    = "freefall",
	.fops    = &lis3lv02d_misc_fops,
};

static void lis3lv02d_joystick_poll(struct input_polled_dev *pidev)
{
	int x, y, z;

	lis3lv02d_get_xyz(&lis3_dev, &x, &y, &z);
	input_report_abs(pidev->input, ABS_X, x - lis3_dev.xcalib);
	input_report_abs(pidev->input, ABS_Y, y - lis3_dev.ycalib);
	input_report_abs(pidev->input, ABS_Z, z - lis3_dev.zcalib);
}


static inline void lis3lv02d_calibrate_joystick(void)
{
	lis3lv02d_get_xyz(&lis3_dev,
		&lis3_dev.xcalib, &lis3_dev.ycalib, &lis3_dev.zcalib);
}

int lis3lv02d_joystick_enable(void)
{
	struct input_dev *input_dev;
	int err;

	if (lis3_dev.idev)
		return -EINVAL;

	lis3_dev.idev = input_allocate_polled_device();
	if (!lis3_dev.idev)
		return -ENOMEM;

	lis3_dev.idev->poll = lis3lv02d_joystick_poll;
	lis3_dev.idev->poll_interval = MDPS_POLL_INTERVAL;
	input_dev = lis3_dev.idev->input;

	lis3lv02d_calibrate_joystick();

	input_dev->name       = "ST LIS3LV02DL Accelerometer";
	input_dev->phys       = DRIVER_NAME "/input0";
	input_dev->id.bustype = BUS_HOST;
	input_dev->id.vendor  = 0;
	input_dev->dev.parent = &lis3_dev.pdev->dev;

	set_bit(EV_ABS, input_dev->evbit);
	input_set_abs_params(input_dev, ABS_X, -lis3_dev.mdps_max_val, lis3_dev.mdps_max_val, 3, 3);
	input_set_abs_params(input_dev, ABS_Y, -lis3_dev.mdps_max_val, lis3_dev.mdps_max_val, 3, 3);
	input_set_abs_params(input_dev, ABS_Z, -lis3_dev.mdps_max_val, lis3_dev.mdps_max_val, 3, 3);

	err = input_register_polled_device(lis3_dev.idev);
	if (err) {
		input_free_polled_device(lis3_dev.idev);
		lis3_dev.idev = NULL;
	}

	return err;
}
EXPORT_SYMBOL_GPL(lis3lv02d_joystick_enable);

void lis3lv02d_joystick_disable(void)
{
	if (!lis3_dev.idev)
		return;

	if (lis3_dev.irq)
		misc_deregister(&lis3lv02d_misc_device);
	input_unregister_polled_device(lis3_dev.idev);
	lis3_dev.idev = NULL;
}
EXPORT_SYMBOL_GPL(lis3lv02d_joystick_disable);

/* Sysfs stuff */
static ssize_t lis3lv02d_position_show(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	int x, y, z;

	lis3lv02d_get_xyz(&lis3_dev, &x, &y, &z);
	return sprintf(buf, "(%d,%d,%d)\n", x, y, z);
}

static ssize_t lis3lv02d_calibrate_show(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	return sprintf(buf, "(%d,%d,%d)\n", lis3_dev.xcalib, lis3_dev.ycalib, lis3_dev.zcalib);
}

static ssize_t lis3lv02d_calibrate_store(struct device *dev,
				struct device_attribute *attr,
				const char *buf, size_t count)
{
	lis3lv02d_calibrate_joystick();
	return count;
}

/* conversion btw sampling rate and the register values */
static int lis3lv02dl_df_val[4] = {40, 160, 640, 2560};
static ssize_t lis3lv02d_rate_show(struct device *dev,
			struct device_attribute *attr, char *buf)
{
	u8 ctrl;
	int val;

	lis3_dev.read(&lis3_dev, CTRL_REG1, &ctrl);
	val = (ctrl & (CTRL1_DF0 | CTRL1_DF1)) >> 4;
	return sprintf(buf, "%d\n", lis3lv02dl_df_val[val]);
}

static DEVICE_ATTR(position, S_IRUGO, lis3lv02d_position_show, NULL);
static DEVICE_ATTR(calibrate, S_IRUGO|S_IWUSR, lis3lv02d_calibrate_show,
	lis3lv02d_calibrate_store);
static DEVICE_ATTR(rate, S_IRUGO, lis3lv02d_rate_show, NULL);

static struct attribute *lis3lv02d_attributes[] = {
	&dev_attr_position.attr,
	&dev_attr_calibrate.attr,
	&dev_attr_rate.attr,
	NULL
};

static struct attribute_group lis3lv02d_attribute_group = {
	.attrs = lis3lv02d_attributes
};


static int lis3lv02d_add_fs(struct lis3lv02d *lis3)
{
	lis3->pdev = platform_device_register_simple(DRIVER_NAME, -1, NULL, 0);
	if (IS_ERR(lis3->pdev))
		return PTR_ERR(lis3->pdev);

	return sysfs_create_group(&lis3->pdev->dev.kobj, &lis3lv02d_attribute_group);
}

int lis3lv02d_remove_fs(struct lis3lv02d *lis3)
{
	sysfs_remove_group(&lis3->pdev->dev.kobj, &lis3lv02d_attribute_group);
	platform_device_unregister(lis3->pdev);
	return 0;
}
EXPORT_SYMBOL_GPL(lis3lv02d_remove_fs);

/*
 * Initialise the accelerometer and the various subsystems.
 * Should be rather independant of the bus system.
 */
int lis3lv02d_init_device(struct lis3lv02d *dev)
{
	dev->whoami = lis3lv02d_read_8(dev, WHO_AM_I);

	switch (dev->whoami) {
	case LIS_DOUBLE_ID:
		printk(KERN_INFO DRIVER_NAME ": 2-byte sensor found\n");
		dev->read_data = lis3lv02d_read_16;
		dev->mdps_max_val = 2048;
		break;
	case LIS_SINGLE_ID:
		printk(KERN_INFO DRIVER_NAME ": 1-byte sensor found\n");
		dev->read_data = lis3lv02d_read_8;
		dev->mdps_max_val = 128;
		break;
	default:
		printk(KERN_ERR DRIVER_NAME
			": unknown sensor type 0x%X\n", dev->whoami);
		return -EINVAL;
	}

	lis3lv02d_add_fs(dev);
	lis3lv02d_poweron(dev);

	if (lis3lv02d_joystick_enable())
		printk(KERN_ERR DRIVER_NAME ": joystick initialization failed\n");

	/* passing in platform specific data is purely optional and only
	 * used by the SPI transport layer at the moment */
	if (dev->pdata) {
		struct lis3lv02d_platform_data *p = dev->pdata;

		if (p->click_flags && (dev->whoami == LIS_SINGLE_ID)) {
			dev->write(dev, CLICK_CFG, p->click_flags);
			dev->write(dev, CLICK_TIMELIMIT, p->click_time_limit);
			dev->write(dev, CLICK_LATENCY, p->click_latency);
			dev->write(dev, CLICK_WINDOW, p->click_window);
			dev->write(dev, CLICK_THSZ, p->click_thresh_z & 0xf);
			dev->write(dev, CLICK_THSY_X,
					(p->click_thresh_x & 0xf) |
					(p->click_thresh_y << 4));
		}

		if (p->wakeup_flags && (dev->whoami == LIS_SINGLE_ID)) {
			dev->write(dev, FF_WU_CFG_1, p->wakeup_flags);
			dev->write(dev, FF_WU_THS_1, p->wakeup_thresh & 0x7f);
			/* default to 2.5ms for now */
			dev->write(dev, FF_WU_DURATION_1, 1);
			/* enable high pass filter for both free-fall units */
			dev->write(dev, CTRL_REG2, HP_FF_WU1 | HP_FF_WU2);
		}

		if (p->irq_cfg)
			dev->write(dev, CTRL_REG3, p->irq_cfg);
	}

	/* bail if we did not get an IRQ from the bus layer */
	if (!dev->irq) {
		printk(KERN_ERR DRIVER_NAME
			": No IRQ. Disabling /dev/freefall\n");
		goto out;
	}

	if (misc_register(&lis3lv02d_misc_device))
		printk(KERN_ERR DRIVER_NAME ": misc_register failed\n");
out:
	return 0;
}
EXPORT_SYMBOL_GPL(lis3lv02d_init_device);

MODULE_DESCRIPTION("ST LIS3LV02Dx three-axis digital accelerometer driver");
MODULE_AUTHOR("Yan Burman, Eric Piel, Pavel Machek");
MODULE_LICENSE("GPL");