xref: /linux/drivers/input/mouse/trackpoint.c (revision e2683c8868d03382da7e1ce8453b543a043066d1)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Stephen Evanchik <evanchsa@gmail.com>
4  *
5  * Trademarks are the property of their respective owners.
6  */
7 
8 #include <linux/array_size.h>
9 #include <linux/slab.h>
10 #include <linux/delay.h>
11 #include <linux/serio.h>
12 #include <linux/module.h>
13 #include <linux/input.h>
14 #include <linux/libps2.h>
15 #include <linux/proc_fs.h>
16 #include <linux/string.h>
17 #include <linux/uaccess.h>
18 #include "psmouse.h"
19 #include "trackpoint.h"
20 
21 static const char * const trackpoint_variants[] = {
22 	[TP_VARIANT_IBM]		= "IBM",
23 	[TP_VARIANT_ALPS]		= "ALPS",
24 	[TP_VARIANT_ELAN]		= "Elan",
25 	[TP_VARIANT_NXP]		= "NXP",
26 	[TP_VARIANT_JYT_SYNAPTICS]	= "JYT_Synaptics",
27 	[TP_VARIANT_SYNAPTICS]		= "Synaptics",
28 };
29 
30 /*
31  * Power-on Reset: Resets all trackpoint parameters, including RAM values,
32  * to defaults.
33  * Returns zero on success, non-zero on failure.
34  */
35 static int trackpoint_power_on_reset(struct ps2dev *ps2dev)
36 {
37 	u8 param[2] = { TP_POR };
38 	int err;
39 
40 	err = ps2_command(ps2dev, param, MAKE_PS2_CMD(1, 2, TP_COMMAND));
41 	if (err)
42 		return err;
43 
44 	/* Check for success response -- 0xAA00 */
45 	if (param[0] != 0xAA || param[1] != 0x00)
46 		return -ENODEV;
47 
48 	return 0;
49 }
50 
51 /*
52  * Device IO: read, write and toggle bit
53  */
54 static int trackpoint_read(struct ps2dev *ps2dev, u8 loc, u8 *results)
55 {
56 	results[0] = loc;
57 
58 	return ps2_command(ps2dev, results, MAKE_PS2_CMD(1, 1, TP_COMMAND));
59 }
60 
61 static int trackpoint_write(struct ps2dev *ps2dev, u8 loc, u8 val)
62 {
63 	u8 param[3] = { TP_WRITE_MEM, loc, val };
64 
65 	return ps2_command(ps2dev, param, MAKE_PS2_CMD(3, 0, TP_COMMAND));
66 }
67 
68 static int trackpoint_toggle_bit(struct ps2dev *ps2dev, u8 loc, u8 mask)
69 {
70 	u8 param[3] = { TP_TOGGLE, loc, mask };
71 
72 	/* Bad things will happen if the loc param isn't in this range */
73 	if (loc < 0x20 || loc >= 0x2F)
74 		return -EINVAL;
75 
76 	return ps2_command(ps2dev, param, MAKE_PS2_CMD(3, 0, TP_COMMAND));
77 }
78 
79 static int trackpoint_update_bit(struct ps2dev *ps2dev,
80 				 u8 loc, u8 mask, u8 value)
81 {
82 	int retval;
83 	u8 data;
84 
85 	retval = trackpoint_read(ps2dev, loc, &data);
86 	if (retval)
87 		return retval;
88 
89 	if (((data & mask) == mask) != !!value)
90 		retval = trackpoint_toggle_bit(ps2dev, loc, mask);
91 
92 	return retval;
93 }
94 
95 /*
96  * Trackpoint-specific attributes
97  */
98 struct trackpoint_attr_data {
99 	size_t field_offset;
100 	u8 command;
101 	u8 mask;
102 	bool inverted;
103 	u8 power_on_default;
104 };
105 
106 static ssize_t trackpoint_show_int_attr(struct psmouse *psmouse,
107 					void *data, char *buf)
108 {
109 	struct trackpoint_data *tp = psmouse->private;
110 	struct trackpoint_attr_data *attr = data;
111 	u8 value = *(u8 *)((void *)tp + attr->field_offset);
112 
113 	if (attr->inverted)
114 		value = !value;
115 
116 	return sprintf(buf, "%u\n", value);
117 }
118 
119 static ssize_t trackpoint_set_int_attr(struct psmouse *psmouse, void *data,
120 					const char *buf, size_t count)
121 {
122 	struct trackpoint_data *tp = psmouse->private;
123 	struct trackpoint_attr_data *attr = data;
124 	u8 *field = (void *)tp + attr->field_offset;
125 	u8 value;
126 	int err;
127 
128 	err = kstrtou8(buf, 10, &value);
129 	if (err)
130 		return err;
131 
132 	*field = value;
133 	err = trackpoint_write(&psmouse->ps2dev, attr->command, value);
134 
135 	return err ?: count;
136 }
137 
138 #define TRACKPOINT_INT_ATTR(_name, _command, _default)				\
139 	static struct trackpoint_attr_data trackpoint_attr_##_name = {		\
140 		.field_offset = offsetof(struct trackpoint_data, _name),	\
141 		.command = _command,						\
142 		.power_on_default = _default,					\
143 	};									\
144 	PSMOUSE_DEFINE_ATTR(_name, S_IWUSR | S_IRUGO,				\
145 			    &trackpoint_attr_##_name,				\
146 			    trackpoint_show_int_attr, trackpoint_set_int_attr)
147 
148 static ssize_t trackpoint_set_bit_attr(struct psmouse *psmouse, void *data,
149 					const char *buf, size_t count)
150 {
151 	struct trackpoint_data *tp = psmouse->private;
152 	struct trackpoint_attr_data *attr = data;
153 	bool *field = (void *)tp + attr->field_offset;
154 	bool value;
155 	int err;
156 
157 	err = kstrtobool(buf, &value);
158 	if (err)
159 		return err;
160 
161 	if (attr->inverted)
162 		value = !value;
163 
164 	if (*field != value) {
165 		*field = value;
166 		err = trackpoint_toggle_bit(&psmouse->ps2dev,
167 					    attr->command, attr->mask);
168 	}
169 
170 	return err ?: count;
171 }
172 
173 
174 #define TRACKPOINT_BIT_ATTR(_name, _command, _mask, _inv, _default)	\
175 static struct trackpoint_attr_data trackpoint_attr_##_name = {		\
176 	.field_offset		= offsetof(struct trackpoint_data,	\
177 					   _name),			\
178 	.command		= _command,				\
179 	.mask			= _mask,				\
180 	.inverted		= _inv,					\
181 	.power_on_default	= _default,				\
182 	};								\
183 PSMOUSE_DEFINE_ATTR(_name, S_IWUSR | S_IRUGO,				\
184 		    &trackpoint_attr_##_name,				\
185 		    trackpoint_show_int_attr, trackpoint_set_bit_attr)
186 
187 TRACKPOINT_INT_ATTR(sensitivity, TP_SENS, TP_DEF_SENS);
188 TRACKPOINT_INT_ATTR(speed, TP_SPEED, TP_DEF_SPEED);
189 TRACKPOINT_INT_ATTR(inertia, TP_INERTIA, TP_DEF_INERTIA);
190 TRACKPOINT_INT_ATTR(reach, TP_REACH, TP_DEF_REACH);
191 TRACKPOINT_INT_ATTR(draghys, TP_DRAGHYS, TP_DEF_DRAGHYS);
192 TRACKPOINT_INT_ATTR(mindrag, TP_MINDRAG, TP_DEF_MINDRAG);
193 TRACKPOINT_INT_ATTR(thresh, TP_THRESH, TP_DEF_THRESH);
194 TRACKPOINT_INT_ATTR(upthresh, TP_UP_THRESH, TP_DEF_UP_THRESH);
195 TRACKPOINT_INT_ATTR(ztime, TP_Z_TIME, TP_DEF_Z_TIME);
196 TRACKPOINT_INT_ATTR(jenks, TP_JENKS_CURV, TP_DEF_JENKS_CURV);
197 TRACKPOINT_INT_ATTR(drift_time, TP_DRIFT_TIME, TP_DEF_DRIFT_TIME);
198 
199 TRACKPOINT_BIT_ATTR(press_to_select, TP_TOGGLE_PTSON, TP_MASK_PTSON, false,
200 		    TP_DEF_PTSON);
201 TRACKPOINT_BIT_ATTR(skipback, TP_TOGGLE_SKIPBACK, TP_MASK_SKIPBACK, false,
202 		    TP_DEF_SKIPBACK);
203 TRACKPOINT_BIT_ATTR(ext_dev, TP_TOGGLE_EXT_DEV, TP_MASK_EXT_DEV, true,
204 		    TP_DEF_EXT_DEV);
205 
206 static bool trackpoint_is_attr_available(struct psmouse *psmouse,
207 					 struct attribute *attr)
208 {
209 	struct trackpoint_data *tp = psmouse->private;
210 
211 	return tp->variant_id == TP_VARIANT_IBM ||
212 		attr == &psmouse_attr_sensitivity.dattr.attr ||
213 		attr == &psmouse_attr_press_to_select.dattr.attr;
214 }
215 
216 static umode_t trackpoint_is_attr_visible(struct kobject *kobj,
217 					  struct attribute *attr, int n)
218 {
219 	struct device *dev = kobj_to_dev(kobj);
220 	struct serio *serio = to_serio_port(dev);
221 	struct psmouse *psmouse = psmouse_from_serio(serio);
222 
223 	return trackpoint_is_attr_available(psmouse, attr) ? attr->mode : 0;
224 }
225 
226 static struct attribute *trackpoint_attrs[] = {
227 	&psmouse_attr_sensitivity.dattr.attr,
228 	&psmouse_attr_speed.dattr.attr,
229 	&psmouse_attr_inertia.dattr.attr,
230 	&psmouse_attr_reach.dattr.attr,
231 	&psmouse_attr_draghys.dattr.attr,
232 	&psmouse_attr_mindrag.dattr.attr,
233 	&psmouse_attr_thresh.dattr.attr,
234 	&psmouse_attr_upthresh.dattr.attr,
235 	&psmouse_attr_ztime.dattr.attr,
236 	&psmouse_attr_jenks.dattr.attr,
237 	&psmouse_attr_drift_time.dattr.attr,
238 	&psmouse_attr_press_to_select.dattr.attr,
239 	&psmouse_attr_skipback.dattr.attr,
240 	&psmouse_attr_ext_dev.dattr.attr,
241 	NULL
242 };
243 
244 static struct attribute_group trackpoint_attr_group = {
245 	.is_visible	= trackpoint_is_attr_visible,
246 	.attrs		= trackpoint_attrs,
247 };
248 
249 #define TRACKPOINT_UPDATE(_power_on, _psmouse, _tp, _name)		\
250 do {									\
251 	struct trackpoint_attr_data *_attr = &trackpoint_attr_##_name;	\
252 									\
253 	if ((!_power_on || _tp->_name != _attr->power_on_default) &&	\
254 	    trackpoint_is_attr_available(_psmouse,			\
255 				&psmouse_attr_##_name.dattr.attr)) {	\
256 		if (!_attr->mask)					\
257 			trackpoint_write(&_psmouse->ps2dev,		\
258 					 _attr->command, _tp->_name);	\
259 		else							\
260 			trackpoint_update_bit(&_psmouse->ps2dev,	\
261 					_attr->command, _attr->mask,	\
262 					_tp->_name);			\
263 	}								\
264 } while (0)
265 
266 #define TRACKPOINT_SET_POWER_ON_DEFAULT(_tp, _name)			\
267 do {									\
268 	_tp->_name = trackpoint_attr_##_name.power_on_default;		\
269 } while (0)
270 
271 static int trackpoint_start_protocol(struct psmouse *psmouse,
272 				     u8 *variant_id, u8 *firmware_id)
273 {
274 	u8 param[2] = { 0 };
275 	int error;
276 
277 	error = ps2_command(&psmouse->ps2dev,
278 			    param, MAKE_PS2_CMD(0, 2, TP_READ_ID));
279 	if (error)
280 		return error;
281 
282 	switch (param[0]) {
283 	case TP_VARIANT_IBM:
284 	case TP_VARIANT_ALPS:
285 	case TP_VARIANT_ELAN:
286 	case TP_VARIANT_NXP:
287 	case TP_VARIANT_JYT_SYNAPTICS:
288 	case TP_VARIANT_SYNAPTICS:
289 		if (variant_id)
290 			*variant_id = param[0];
291 		if (firmware_id)
292 			*firmware_id = param[1];
293 		return 0;
294 	}
295 
296 	return -ENODEV;
297 }
298 
299 /*
300  * Write parameters to trackpad.
301  * in_power_on_state: Set to true if TP is in default / power-on state (ex. if
302  *		      power-on reset was run). If so, values will only be
303  *		      written to TP if they differ from power-on default.
304  */
305 static int trackpoint_sync(struct psmouse *psmouse, bool in_power_on_state)
306 {
307 	struct trackpoint_data *tp = psmouse->private;
308 
309 	if (!in_power_on_state && tp->variant_id == TP_VARIANT_IBM) {
310 		/*
311 		 * Disable features that may make device unusable
312 		 * with this driver.
313 		 */
314 		trackpoint_update_bit(&psmouse->ps2dev, TP_TOGGLE_TWOHAND,
315 				      TP_MASK_TWOHAND, TP_DEF_TWOHAND);
316 
317 		trackpoint_update_bit(&psmouse->ps2dev, TP_TOGGLE_SOURCE_TAG,
318 				      TP_MASK_SOURCE_TAG, TP_DEF_SOURCE_TAG);
319 
320 		trackpoint_update_bit(&psmouse->ps2dev, TP_TOGGLE_MB,
321 				      TP_MASK_MB, TP_DEF_MB);
322 	}
323 
324 	/*
325 	 * These properties can be changed in this driver. Only
326 	 * configure them if the values are non-default or if the TP is in
327 	 * an unknown state.
328 	 */
329 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, sensitivity);
330 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, inertia);
331 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, speed);
332 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, reach);
333 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, draghys);
334 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, mindrag);
335 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, thresh);
336 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, upthresh);
337 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, ztime);
338 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, jenks);
339 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, drift_time);
340 
341 	/* toggles */
342 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, press_to_select);
343 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, skipback);
344 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, ext_dev);
345 
346 	return 0;
347 }
348 
349 static void trackpoint_defaults(struct trackpoint_data *tp)
350 {
351 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, sensitivity);
352 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, speed);
353 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, reach);
354 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, draghys);
355 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, mindrag);
356 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, thresh);
357 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, upthresh);
358 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, ztime);
359 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, jenks);
360 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, drift_time);
361 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, inertia);
362 
363 	/* toggles */
364 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, press_to_select);
365 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, skipback);
366 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, ext_dev);
367 }
368 
369 static void trackpoint_disconnect(struct psmouse *psmouse)
370 {
371 	device_remove_group(&psmouse->ps2dev.serio->dev,
372 			    &trackpoint_attr_group);
373 
374 	kfree(psmouse->private);
375 	psmouse->private = NULL;
376 }
377 
378 static int trackpoint_reconnect(struct psmouse *psmouse)
379 {
380 	struct trackpoint_data *tp = psmouse->private;
381 	int error;
382 	bool was_reset;
383 
384 	error = trackpoint_start_protocol(psmouse, NULL, NULL);
385 	if (error)
386 		return error;
387 
388 	was_reset = tp->variant_id == TP_VARIANT_IBM &&
389 		    trackpoint_power_on_reset(&psmouse->ps2dev) == 0;
390 
391 	error = trackpoint_sync(psmouse, was_reset);
392 	if (error)
393 		return error;
394 
395 	return 0;
396 }
397 
398 /* List of known incapable device PNP IDs */
399 static const char * const dt_incompatible_devices[] = {
400 	"LEN0304",
401 	"LEN0306",
402 	"LEN0317",
403 	"LEN031A",
404 	"LEN031B",
405 	"LEN031C",
406 	"LEN031D",
407 };
408 
409 /*
410  * Checks if it's a doubletap capable device.
411  * The PNP ID format is "PNP: LEN030d PNP0f13".
412  */
413 static bool trackpoint_is_dt_capable(const char *pnp_id)
414 {
415 	size_t i;
416 
417 	if (!pnp_id)
418 		return false;
419 
420 	/* Must start with "PNP: LEN03" */
421 	if (!strstarts(pnp_id, "PNP: LEN03"))
422 		return false;
423 
424 	/* Ensure enough length before comparing */
425 	if (strlen(pnp_id) < 12)
426 		return false;
427 
428 	/* Check deny-list */
429 	for (i = 0; i < ARRAY_SIZE(dt_incompatible_devices); i++) {
430 		if (!strncmp(pnp_id + 5, dt_incompatible_devices[i], 7))
431 			return false;
432 	}
433 	return true;
434 }
435 
436 int trackpoint_detect(struct psmouse *psmouse, bool set_properties)
437 {
438 	struct ps2dev *ps2dev = &psmouse->ps2dev;
439 	struct trackpoint_data *tp;
440 	u8 variant_id;
441 	u8 firmware_id;
442 	u8 button_info;
443 	int error;
444 
445 	error = trackpoint_start_protocol(psmouse, &variant_id, &firmware_id);
446 	if (error)
447 		return error;
448 
449 	if (!set_properties)
450 		return 0;
451 
452 	tp = kzalloc_obj(*tp);
453 	if (!tp)
454 		return -ENOMEM;
455 
456 	trackpoint_defaults(tp);
457 	tp->variant_id = variant_id;
458 	tp->firmware_id = firmware_id;
459 
460 	psmouse->private = tp;
461 
462 	psmouse->vendor = trackpoint_variants[variant_id];
463 	psmouse->name = "TrackPoint";
464 
465 	psmouse->reconnect = trackpoint_reconnect;
466 	psmouse->disconnect = trackpoint_disconnect;
467 
468 	if (variant_id != TP_VARIANT_IBM) {
469 		/* Newer variants do not support extended button query. */
470 		button_info = 0x33;
471 	} else {
472 		error = trackpoint_read(ps2dev, TP_EXT_BTN, &button_info);
473 		if (error) {
474 			psmouse_warn(psmouse,
475 				     "failed to get extended button data, assuming 3 buttons\n");
476 			button_info = 0x33;
477 		} else if (!button_info) {
478 			psmouse_warn(psmouse,
479 				     "got 0 in extended button data, assuming 3 buttons\n");
480 			button_info = 0x33;
481 		}
482 	}
483 
484 	if ((button_info & 0x0f) >= 3)
485 		input_set_capability(psmouse->dev, EV_KEY, BTN_MIDDLE);
486 
487 	__set_bit(INPUT_PROP_POINTER, psmouse->dev->propbit);
488 	__set_bit(INPUT_PROP_POINTING_STICK, psmouse->dev->propbit);
489 
490 	if (variant_id != TP_VARIANT_IBM ||
491 	    trackpoint_power_on_reset(ps2dev) != 0) {
492 		/*
493 		 * Write defaults to TP if we did not reset the trackpoint.
494 		 */
495 		trackpoint_sync(psmouse, false);
496 	}
497 
498 	error = device_add_group(&ps2dev->serio->dev, &trackpoint_attr_group);
499 	if (error) {
500 		psmouse_err(psmouse,
501 			    "failed to create sysfs attributes, error: %d\n",
502 			    error);
503 		kfree(psmouse->private);
504 		psmouse->private = NULL;
505 		return -1;
506 	}
507 
508 	psmouse_info(psmouse,
509 		     "%s TrackPoint firmware: 0x%02x, buttons: %d/%d\n",
510 		     psmouse->vendor, firmware_id,
511 		     (button_info & 0xf0) >> 4, button_info & 0x0f);
512 
513 	if (trackpoint_is_dt_capable(ps2dev->serio->firmware_id)) {
514 		error = trackpoint_write(ps2dev, TP_DOUBLETAP, TP_DOUBLETAP_ENABLE);
515 		if (error)
516 			psmouse_warn(psmouse, "Failed to enable doubletap: %d\n", error);
517 	}
518 
519 	return 0;
520 }
521 
522