Training courses

Kernel and Embedded Linux

Bootlin training courses

Embedded Linux, kernel,
Yocto Project, Buildroot, real-time,
graphics, boot time, debugging...

Bootlin logo

Elixir Cross Referencer

  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
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Stephen Evanchik <evanchsa@gmail.com>
 *
 * Trademarks are the property of their respective owners.
 */

#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/serio.h>
#include <linux/module.h>
#include <linux/input.h>
#include <linux/libps2.h>
#include <linux/proc_fs.h>
#include <linux/uaccess.h>
#include "psmouse.h"
#include "trackpoint.h"

static const char * const trackpoint_variants[] = {
	[TP_VARIANT_IBM]	= "IBM",
	[TP_VARIANT_ALPS]	= "ALPS",
	[TP_VARIANT_ELAN]	= "Elan",
	[TP_VARIANT_NXP]	= "NXP",
};

/*
 * Power-on Reset: Resets all trackpoint parameters, including RAM values,
 * to defaults.
 * Returns zero on success, non-zero on failure.
 */
static int trackpoint_power_on_reset(struct ps2dev *ps2dev)
{
	u8 param[2] = { TP_POR };
	int err;

	err = ps2_command(ps2dev, param, MAKE_PS2_CMD(1, 2, TP_COMMAND));
	if (err)
		return err;

	/* Check for success response -- 0xAA00 */
	if (param[0] != 0xAA || param[1] != 0x00)
		return -ENODEV;

	return 0;
}

/*
 * Device IO: read, write and toggle bit
 */
static int trackpoint_read(struct ps2dev *ps2dev, u8 loc, u8 *results)
{
	results[0] = loc;

	return ps2_command(ps2dev, results, MAKE_PS2_CMD(1, 1, TP_COMMAND));
}

static int trackpoint_write(struct ps2dev *ps2dev, u8 loc, u8 val)
{
	u8 param[3] = { TP_WRITE_MEM, loc, val };

	return ps2_command(ps2dev, param, MAKE_PS2_CMD(3, 0, TP_COMMAND));
}

static int trackpoint_toggle_bit(struct ps2dev *ps2dev, u8 loc, u8 mask)
{
	u8 param[3] = { TP_TOGGLE, loc, mask };

	/* Bad things will happen if the loc param isn't in this range */
	if (loc < 0x20 || loc >= 0x2F)
		return -EINVAL;

	return ps2_command(ps2dev, param, MAKE_PS2_CMD(3, 0, TP_COMMAND));
}

static int trackpoint_update_bit(struct ps2dev *ps2dev,
				 u8 loc, u8 mask, u8 value)
{
	int retval;
	u8 data;

	retval = trackpoint_read(ps2dev, loc, &data);
	if (retval)
		return retval;

	if (((data & mask) == mask) != !!value)
		retval = trackpoint_toggle_bit(ps2dev, loc, mask);

	return retval;
}

/*
 * Trackpoint-specific attributes
 */
struct trackpoint_attr_data {
	size_t field_offset;
	u8 command;
	u8 mask;
	bool inverted;
	u8 power_on_default;
};

static ssize_t trackpoint_show_int_attr(struct psmouse *psmouse,
					void *data, char *buf)
{
	struct trackpoint_data *tp = psmouse->private;
	struct trackpoint_attr_data *attr = data;
	u8 value = *(u8 *)((void *)tp + attr->field_offset);

	if (attr->inverted)
		value = !value;

	return sprintf(buf, "%u\n", value);
}

static ssize_t trackpoint_set_int_attr(struct psmouse *psmouse, void *data,
					const char *buf, size_t count)
{
	struct trackpoint_data *tp = psmouse->private;
	struct trackpoint_attr_data *attr = data;
	u8 *field = (void *)tp + attr->field_offset;
	u8 value;
	int err;

	err = kstrtou8(buf, 10, &value);
	if (err)
		return err;

	*field = value;
	err = trackpoint_write(&psmouse->ps2dev, attr->command, value);

	return err ?: count;
}

#define TRACKPOINT_INT_ATTR(_name, _command, _default)				\
	static struct trackpoint_attr_data trackpoint_attr_##_name = {		\
		.field_offset = offsetof(struct trackpoint_data, _name),	\
		.command = _command,						\
		.power_on_default = _default,					\
	};									\
	PSMOUSE_DEFINE_ATTR(_name, S_IWUSR | S_IRUGO,				\
			    &trackpoint_attr_##_name,				\
			    trackpoint_show_int_attr, trackpoint_set_int_attr)

static ssize_t trackpoint_set_bit_attr(struct psmouse *psmouse, void *data,
					const char *buf, size_t count)
{
	struct trackpoint_data *tp = psmouse->private;
	struct trackpoint_attr_data *attr = data;
	bool *field = (void *)tp + attr->field_offset;
	bool value;
	int err;

	err = kstrtobool(buf, &value);
	if (err)
		return err;

	if (attr->inverted)
		value = !value;

	if (*field != value) {
		*field = value;
		err = trackpoint_toggle_bit(&psmouse->ps2dev,
					    attr->command, attr->mask);
	}

	return err ?: count;
}


#define TRACKPOINT_BIT_ATTR(_name, _command, _mask, _inv, _default)	\
static struct trackpoint_attr_data trackpoint_attr_##_name = {		\
	.field_offset		= offsetof(struct trackpoint_data,	\
					   _name),			\
	.command		= _command,				\
	.mask			= _mask,				\
	.inverted		= _inv,					\
	.power_on_default	= _default,				\
	};								\
PSMOUSE_DEFINE_ATTR(_name, S_IWUSR | S_IRUGO,				\
		    &trackpoint_attr_##_name,				\
		    trackpoint_show_int_attr, trackpoint_set_bit_attr)

TRACKPOINT_INT_ATTR(sensitivity, TP_SENS, TP_DEF_SENS);
TRACKPOINT_INT_ATTR(speed, TP_SPEED, TP_DEF_SPEED);
TRACKPOINT_INT_ATTR(inertia, TP_INERTIA, TP_DEF_INERTIA);
TRACKPOINT_INT_ATTR(reach, TP_REACH, TP_DEF_REACH);
TRACKPOINT_INT_ATTR(draghys, TP_DRAGHYS, TP_DEF_DRAGHYS);
TRACKPOINT_INT_ATTR(mindrag, TP_MINDRAG, TP_DEF_MINDRAG);
TRACKPOINT_INT_ATTR(thresh, TP_THRESH, TP_DEF_THRESH);
TRACKPOINT_INT_ATTR(upthresh, TP_UP_THRESH, TP_DEF_UP_THRESH);
TRACKPOINT_INT_ATTR(ztime, TP_Z_TIME, TP_DEF_Z_TIME);
TRACKPOINT_INT_ATTR(jenks, TP_JENKS_CURV, TP_DEF_JENKS_CURV);
TRACKPOINT_INT_ATTR(drift_time, TP_DRIFT_TIME, TP_DEF_DRIFT_TIME);

TRACKPOINT_BIT_ATTR(press_to_select, TP_TOGGLE_PTSON, TP_MASK_PTSON, false,
		    TP_DEF_PTSON);
TRACKPOINT_BIT_ATTR(skipback, TP_TOGGLE_SKIPBACK, TP_MASK_SKIPBACK, false,
		    TP_DEF_SKIPBACK);
TRACKPOINT_BIT_ATTR(ext_dev, TP_TOGGLE_EXT_DEV, TP_MASK_EXT_DEV, true,
		    TP_DEF_EXT_DEV);

static bool trackpoint_is_attr_available(struct psmouse *psmouse,
					 struct attribute *attr)
{
	struct trackpoint_data *tp = psmouse->private;

	return tp->variant_id == TP_VARIANT_IBM ||
		attr == &psmouse_attr_sensitivity.dattr.attr ||
		attr == &psmouse_attr_press_to_select.dattr.attr;
}

static umode_t trackpoint_is_attr_visible(struct kobject *kobj,
					  struct attribute *attr, int n)
{
	struct device *dev = container_of(kobj, struct device, kobj);
	struct serio *serio = to_serio_port(dev);
	struct psmouse *psmouse = serio_get_drvdata(serio);

	return trackpoint_is_attr_available(psmouse, attr) ? attr->mode : 0;
}

static struct attribute *trackpoint_attrs[] = {
	&psmouse_attr_sensitivity.dattr.attr,
	&psmouse_attr_speed.dattr.attr,
	&psmouse_attr_inertia.dattr.attr,
	&psmouse_attr_reach.dattr.attr,
	&psmouse_attr_draghys.dattr.attr,
	&psmouse_attr_mindrag.dattr.attr,
	&psmouse_attr_thresh.dattr.attr,
	&psmouse_attr_upthresh.dattr.attr,
	&psmouse_attr_ztime.dattr.attr,
	&psmouse_attr_jenks.dattr.attr,
	&psmouse_attr_drift_time.dattr.attr,
	&psmouse_attr_press_to_select.dattr.attr,
	&psmouse_attr_skipback.dattr.attr,
	&psmouse_attr_ext_dev.dattr.attr,
	NULL
};

static struct attribute_group trackpoint_attr_group = {
	.is_visible	= trackpoint_is_attr_visible,
	.attrs		= trackpoint_attrs,
};

#define TRACKPOINT_UPDATE(_power_on, _psmouse, _tp, _name)		\
do {									\
	struct trackpoint_attr_data *_attr = &trackpoint_attr_##_name;	\
									\
	if ((!_power_on || _tp->_name != _attr->power_on_default) &&	\
	    trackpoint_is_attr_available(_psmouse,			\
				&psmouse_attr_##_name.dattr.attr)) {	\
		if (!_attr->mask)					\
			trackpoint_write(&_psmouse->ps2dev,		\
					 _attr->command, _tp->_name);	\
		else							\
			trackpoint_update_bit(&_psmouse->ps2dev,	\
					_attr->command, _attr->mask,	\
					_tp->_name);			\
	}								\
} while (0)

#define TRACKPOINT_SET_POWER_ON_DEFAULT(_tp, _name)			\
do {									\
	_tp->_name = trackpoint_attr_##_name.power_on_default;		\
} while (0)

static int trackpoint_start_protocol(struct psmouse *psmouse,
				     u8 *variant_id, u8 *firmware_id)
{
	u8 param[2] = { 0 };
	int error;

	error = ps2_command(&psmouse->ps2dev,
			    param, MAKE_PS2_CMD(0, 2, TP_READ_ID));
	if (error)
		return error;

	switch (param[0]) {
	case TP_VARIANT_IBM:
	case TP_VARIANT_ALPS:
	case TP_VARIANT_ELAN:
	case TP_VARIANT_NXP:
		if (variant_id)
			*variant_id = param[0];
		if (firmware_id)
			*firmware_id = param[1];
		return 0;
	}

	return -ENODEV;
}

/*
 * Write parameters to trackpad.
 * in_power_on_state: Set to true if TP is in default / power-on state (ex. if
 *		      power-on reset was run). If so, values will only be
 *		      written to TP if they differ from power-on default.
 */
static int trackpoint_sync(struct psmouse *psmouse, bool in_power_on_state)
{
	struct trackpoint_data *tp = psmouse->private;

	if (!in_power_on_state && tp->variant_id == TP_VARIANT_IBM) {
		/*
		 * Disable features that may make device unusable
		 * with this driver.
		 */
		trackpoint_update_bit(&psmouse->ps2dev, TP_TOGGLE_TWOHAND,
				      TP_MASK_TWOHAND, TP_DEF_TWOHAND);

		trackpoint_update_bit(&psmouse->ps2dev, TP_TOGGLE_SOURCE_TAG,
				      TP_MASK_SOURCE_TAG, TP_DEF_SOURCE_TAG);

		trackpoint_update_bit(&psmouse->ps2dev, TP_TOGGLE_MB,
				      TP_MASK_MB, TP_DEF_MB);
	}

	/*
	 * These properties can be changed in this driver. Only
	 * configure them if the values are non-default or if the TP is in
	 * an unknown state.
	 */
	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, sensitivity);
	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, inertia);
	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, speed);
	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, reach);
	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, draghys);
	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, mindrag);
	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, thresh);
	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, upthresh);
	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, ztime);
	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, jenks);
	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, drift_time);

	/* toggles */
	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, press_to_select);
	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, skipback);
	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, ext_dev);

	return 0;
}

static void trackpoint_defaults(struct trackpoint_data *tp)
{
	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, sensitivity);
	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, speed);
	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, reach);
	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, draghys);
	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, mindrag);
	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, thresh);
	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, upthresh);
	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, ztime);
	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, jenks);
	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, drift_time);
	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, inertia);

	/* toggles */
	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, press_to_select);
	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, skipback);
	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, ext_dev);
}

static void trackpoint_disconnect(struct psmouse *psmouse)
{
	device_remove_group(&psmouse->ps2dev.serio->dev,
			    &trackpoint_attr_group);

	kfree(psmouse->private);
	psmouse->private = NULL;
}

static int trackpoint_reconnect(struct psmouse *psmouse)
{
	struct trackpoint_data *tp = psmouse->private;
	int error;
	bool was_reset;

	error = trackpoint_start_protocol(psmouse, NULL, NULL);
	if (error)
		return error;

	was_reset = tp->variant_id == TP_VARIANT_IBM &&
		    trackpoint_power_on_reset(&psmouse->ps2dev) == 0;

	error = trackpoint_sync(psmouse, was_reset);
	if (error)
		return error;

	return 0;
}

int trackpoint_detect(struct psmouse *psmouse, bool set_properties)
{
	struct ps2dev *ps2dev = &psmouse->ps2dev;
	struct trackpoint_data *tp;
	u8 variant_id;
	u8 firmware_id;
	u8 button_info;
	int error;

	error = trackpoint_start_protocol(psmouse, &variant_id, &firmware_id);
	if (error)
		return error;

	if (!set_properties)
		return 0;

	tp = kzalloc(sizeof(*tp), GFP_KERNEL);
	if (!tp)
		return -ENOMEM;

	trackpoint_defaults(tp);
	tp->variant_id = variant_id;
	tp->firmware_id = firmware_id;

	psmouse->private = tp;

	psmouse->vendor = trackpoint_variants[variant_id];
	psmouse->name = "TrackPoint";

	psmouse->reconnect = trackpoint_reconnect;
	psmouse->disconnect = trackpoint_disconnect;

	if (variant_id != TP_VARIANT_IBM) {
		/* Newer variants do not support extended button query. */
		button_info = 0x33;
	} else {
		error = trackpoint_read(ps2dev, TP_EXT_BTN, &button_info);
		if (error) {
			psmouse_warn(psmouse,
				     "failed to get extended button data, assuming 3 buttons\n");
			button_info = 0x33;
		} else if (!button_info) {
			psmouse_warn(psmouse,
				     "got 0 in extended button data, assuming 3 buttons\n");
			button_info = 0x33;
		}
	}

	if ((button_info & 0x0f) >= 3)
		input_set_capability(psmouse->dev, EV_KEY, BTN_MIDDLE);

	__set_bit(INPUT_PROP_POINTER, psmouse->dev->propbit);
	__set_bit(INPUT_PROP_POINTING_STICK, psmouse->dev->propbit);

	if (variant_id != TP_VARIANT_IBM ||
	    trackpoint_power_on_reset(ps2dev) != 0) {
		/*
		 * Write defaults to TP if we did not reset the trackpoint.
		 */
		trackpoint_sync(psmouse, false);
	}

	error = device_add_group(&ps2dev->serio->dev, &trackpoint_attr_group);
	if (error) {
		psmouse_err(psmouse,
			    "failed to create sysfs attributes, error: %d\n",
			    error);
		kfree(psmouse->private);
		psmouse->private = NULL;
		return -1;
	}

	psmouse_info(psmouse,
		     "%s TrackPoint firmware: 0x%02x, buttons: %d/%d\n",
		     psmouse->vendor, firmware_id,
		     (button_info & 0xf0) >> 4, button_info & 0x0f);

	return 0;
}