xref: /linux/drivers/input/mouse/trackpoint.c (revision 019b383d1132e4051de0d2e43254454b86538cf4)
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/slab.h>
9 #include <linux/delay.h>
10 #include <linux/serio.h>
11 #include <linux/module.h>
12 #include <linux/input.h>
13 #include <linux/libps2.h>
14 #include <linux/proc_fs.h>
15 #include <linux/uaccess.h>
16 #include "psmouse.h"
17 #include "trackpoint.h"
18 
19 static const char * const trackpoint_variants[] = {
20 	[TP_VARIANT_IBM]		= "IBM",
21 	[TP_VARIANT_ALPS]		= "ALPS",
22 	[TP_VARIANT_ELAN]		= "Elan",
23 	[TP_VARIANT_NXP]		= "NXP",
24 	[TP_VARIANT_JYT_SYNAPTICS]	= "JYT_Synaptics",
25 	[TP_VARIANT_SYNAPTICS]		= "Synaptics",
26 };
27 
28 /*
29  * Power-on Reset: Resets all trackpoint parameters, including RAM values,
30  * to defaults.
31  * Returns zero on success, non-zero on failure.
32  */
33 static int trackpoint_power_on_reset(struct ps2dev *ps2dev)
34 {
35 	u8 param[2] = { TP_POR };
36 	int err;
37 
38 	err = ps2_command(ps2dev, param, MAKE_PS2_CMD(1, 2, TP_COMMAND));
39 	if (err)
40 		return err;
41 
42 	/* Check for success response -- 0xAA00 */
43 	if (param[0] != 0xAA || param[1] != 0x00)
44 		return -ENODEV;
45 
46 	return 0;
47 }
48 
49 /*
50  * Device IO: read, write and toggle bit
51  */
52 static int trackpoint_read(struct ps2dev *ps2dev, u8 loc, u8 *results)
53 {
54 	results[0] = loc;
55 
56 	return ps2_command(ps2dev, results, MAKE_PS2_CMD(1, 1, TP_COMMAND));
57 }
58 
59 static int trackpoint_write(struct ps2dev *ps2dev, u8 loc, u8 val)
60 {
61 	u8 param[3] = { TP_WRITE_MEM, loc, val };
62 
63 	return ps2_command(ps2dev, param, MAKE_PS2_CMD(3, 0, TP_COMMAND));
64 }
65 
66 static int trackpoint_toggle_bit(struct ps2dev *ps2dev, u8 loc, u8 mask)
67 {
68 	u8 param[3] = { TP_TOGGLE, loc, mask };
69 
70 	/* Bad things will happen if the loc param isn't in this range */
71 	if (loc < 0x20 || loc >= 0x2F)
72 		return -EINVAL;
73 
74 	return ps2_command(ps2dev, param, MAKE_PS2_CMD(3, 0, TP_COMMAND));
75 }
76 
77 static int trackpoint_update_bit(struct ps2dev *ps2dev,
78 				 u8 loc, u8 mask, u8 value)
79 {
80 	int retval;
81 	u8 data;
82 
83 	retval = trackpoint_read(ps2dev, loc, &data);
84 	if (retval)
85 		return retval;
86 
87 	if (((data & mask) == mask) != !!value)
88 		retval = trackpoint_toggle_bit(ps2dev, loc, mask);
89 
90 	return retval;
91 }
92 
93 /*
94  * Trackpoint-specific attributes
95  */
96 struct trackpoint_attr_data {
97 	size_t field_offset;
98 	u8 command;
99 	u8 mask;
100 	bool inverted;
101 	u8 power_on_default;
102 };
103 
104 static ssize_t trackpoint_show_int_attr(struct psmouse *psmouse,
105 					void *data, char *buf)
106 {
107 	struct trackpoint_data *tp = psmouse->private;
108 	struct trackpoint_attr_data *attr = data;
109 	u8 value = *(u8 *)((void *)tp + attr->field_offset);
110 
111 	if (attr->inverted)
112 		value = !value;
113 
114 	return sprintf(buf, "%u\n", value);
115 }
116 
117 static ssize_t trackpoint_set_int_attr(struct psmouse *psmouse, void *data,
118 					const char *buf, size_t count)
119 {
120 	struct trackpoint_data *tp = psmouse->private;
121 	struct trackpoint_attr_data *attr = data;
122 	u8 *field = (void *)tp + attr->field_offset;
123 	u8 value;
124 	int err;
125 
126 	err = kstrtou8(buf, 10, &value);
127 	if (err)
128 		return err;
129 
130 	*field = value;
131 	err = trackpoint_write(&psmouse->ps2dev, attr->command, value);
132 
133 	return err ?: count;
134 }
135 
136 #define TRACKPOINT_INT_ATTR(_name, _command, _default)				\
137 	static struct trackpoint_attr_data trackpoint_attr_##_name = {		\
138 		.field_offset = offsetof(struct trackpoint_data, _name),	\
139 		.command = _command,						\
140 		.power_on_default = _default,					\
141 	};									\
142 	PSMOUSE_DEFINE_ATTR(_name, S_IWUSR | S_IRUGO,				\
143 			    &trackpoint_attr_##_name,				\
144 			    trackpoint_show_int_attr, trackpoint_set_int_attr)
145 
146 static ssize_t trackpoint_set_bit_attr(struct psmouse *psmouse, void *data,
147 					const char *buf, size_t count)
148 {
149 	struct trackpoint_data *tp = psmouse->private;
150 	struct trackpoint_attr_data *attr = data;
151 	bool *field = (void *)tp + attr->field_offset;
152 	bool value;
153 	int err;
154 
155 	err = kstrtobool(buf, &value);
156 	if (err)
157 		return err;
158 
159 	if (attr->inverted)
160 		value = !value;
161 
162 	if (*field != value) {
163 		*field = value;
164 		err = trackpoint_toggle_bit(&psmouse->ps2dev,
165 					    attr->command, attr->mask);
166 	}
167 
168 	return err ?: count;
169 }
170 
171 
172 #define TRACKPOINT_BIT_ATTR(_name, _command, _mask, _inv, _default)	\
173 static struct trackpoint_attr_data trackpoint_attr_##_name = {		\
174 	.field_offset		= offsetof(struct trackpoint_data,	\
175 					   _name),			\
176 	.command		= _command,				\
177 	.mask			= _mask,				\
178 	.inverted		= _inv,					\
179 	.power_on_default	= _default,				\
180 	};								\
181 PSMOUSE_DEFINE_ATTR(_name, S_IWUSR | S_IRUGO,				\
182 		    &trackpoint_attr_##_name,				\
183 		    trackpoint_show_int_attr, trackpoint_set_bit_attr)
184 
185 TRACKPOINT_INT_ATTR(sensitivity, TP_SENS, TP_DEF_SENS);
186 TRACKPOINT_INT_ATTR(speed, TP_SPEED, TP_DEF_SPEED);
187 TRACKPOINT_INT_ATTR(inertia, TP_INERTIA, TP_DEF_INERTIA);
188 TRACKPOINT_INT_ATTR(reach, TP_REACH, TP_DEF_REACH);
189 TRACKPOINT_INT_ATTR(draghys, TP_DRAGHYS, TP_DEF_DRAGHYS);
190 TRACKPOINT_INT_ATTR(mindrag, TP_MINDRAG, TP_DEF_MINDRAG);
191 TRACKPOINT_INT_ATTR(thresh, TP_THRESH, TP_DEF_THRESH);
192 TRACKPOINT_INT_ATTR(upthresh, TP_UP_THRESH, TP_DEF_UP_THRESH);
193 TRACKPOINT_INT_ATTR(ztime, TP_Z_TIME, TP_DEF_Z_TIME);
194 TRACKPOINT_INT_ATTR(jenks, TP_JENKS_CURV, TP_DEF_JENKS_CURV);
195 TRACKPOINT_INT_ATTR(drift_time, TP_DRIFT_TIME, TP_DEF_DRIFT_TIME);
196 
197 TRACKPOINT_BIT_ATTR(press_to_select, TP_TOGGLE_PTSON, TP_MASK_PTSON, false,
198 		    TP_DEF_PTSON);
199 TRACKPOINT_BIT_ATTR(skipback, TP_TOGGLE_SKIPBACK, TP_MASK_SKIPBACK, false,
200 		    TP_DEF_SKIPBACK);
201 TRACKPOINT_BIT_ATTR(ext_dev, TP_TOGGLE_EXT_DEV, TP_MASK_EXT_DEV, true,
202 		    TP_DEF_EXT_DEV);
203 
204 static bool trackpoint_is_attr_available(struct psmouse *psmouse,
205 					 struct attribute *attr)
206 {
207 	struct trackpoint_data *tp = psmouse->private;
208 
209 	return tp->variant_id == TP_VARIANT_IBM ||
210 		attr == &psmouse_attr_sensitivity.dattr.attr ||
211 		attr == &psmouse_attr_press_to_select.dattr.attr;
212 }
213 
214 static umode_t trackpoint_is_attr_visible(struct kobject *kobj,
215 					  struct attribute *attr, int n)
216 {
217 	struct device *dev = kobj_to_dev(kobj);
218 	struct serio *serio = to_serio_port(dev);
219 	struct psmouse *psmouse = psmouse_from_serio(serio);
220 
221 	return trackpoint_is_attr_available(psmouse, attr) ? attr->mode : 0;
222 }
223 
224 static struct attribute *trackpoint_attrs[] = {
225 	&psmouse_attr_sensitivity.dattr.attr,
226 	&psmouse_attr_speed.dattr.attr,
227 	&psmouse_attr_inertia.dattr.attr,
228 	&psmouse_attr_reach.dattr.attr,
229 	&psmouse_attr_draghys.dattr.attr,
230 	&psmouse_attr_mindrag.dattr.attr,
231 	&psmouse_attr_thresh.dattr.attr,
232 	&psmouse_attr_upthresh.dattr.attr,
233 	&psmouse_attr_ztime.dattr.attr,
234 	&psmouse_attr_jenks.dattr.attr,
235 	&psmouse_attr_drift_time.dattr.attr,
236 	&psmouse_attr_press_to_select.dattr.attr,
237 	&psmouse_attr_skipback.dattr.attr,
238 	&psmouse_attr_ext_dev.dattr.attr,
239 	NULL
240 };
241 
242 static struct attribute_group trackpoint_attr_group = {
243 	.is_visible	= trackpoint_is_attr_visible,
244 	.attrs		= trackpoint_attrs,
245 };
246 
247 #define TRACKPOINT_UPDATE(_power_on, _psmouse, _tp, _name)		\
248 do {									\
249 	struct trackpoint_attr_data *_attr = &trackpoint_attr_##_name;	\
250 									\
251 	if ((!_power_on || _tp->_name != _attr->power_on_default) &&	\
252 	    trackpoint_is_attr_available(_psmouse,			\
253 				&psmouse_attr_##_name.dattr.attr)) {	\
254 		if (!_attr->mask)					\
255 			trackpoint_write(&_psmouse->ps2dev,		\
256 					 _attr->command, _tp->_name);	\
257 		else							\
258 			trackpoint_update_bit(&_psmouse->ps2dev,	\
259 					_attr->command, _attr->mask,	\
260 					_tp->_name);			\
261 	}								\
262 } while (0)
263 
264 #define TRACKPOINT_SET_POWER_ON_DEFAULT(_tp, _name)			\
265 do {									\
266 	_tp->_name = trackpoint_attr_##_name.power_on_default;		\
267 } while (0)
268 
269 static int trackpoint_start_protocol(struct psmouse *psmouse,
270 				     u8 *variant_id, u8 *firmware_id)
271 {
272 	u8 param[2] = { 0 };
273 	int error;
274 
275 	error = ps2_command(&psmouse->ps2dev,
276 			    param, MAKE_PS2_CMD(0, 2, TP_READ_ID));
277 	if (error)
278 		return error;
279 
280 	switch (param[0]) {
281 	case TP_VARIANT_IBM:
282 	case TP_VARIANT_ALPS:
283 	case TP_VARIANT_ELAN:
284 	case TP_VARIANT_NXP:
285 	case TP_VARIANT_JYT_SYNAPTICS:
286 	case TP_VARIANT_SYNAPTICS:
287 		if (variant_id)
288 			*variant_id = param[0];
289 		if (firmware_id)
290 			*firmware_id = param[1];
291 		return 0;
292 	}
293 
294 	return -ENODEV;
295 }
296 
297 /*
298  * Write parameters to trackpad.
299  * in_power_on_state: Set to true if TP is in default / power-on state (ex. if
300  *		      power-on reset was run). If so, values will only be
301  *		      written to TP if they differ from power-on default.
302  */
303 static int trackpoint_sync(struct psmouse *psmouse, bool in_power_on_state)
304 {
305 	struct trackpoint_data *tp = psmouse->private;
306 
307 	if (!in_power_on_state && tp->variant_id == TP_VARIANT_IBM) {
308 		/*
309 		 * Disable features that may make device unusable
310 		 * with this driver.
311 		 */
312 		trackpoint_update_bit(&psmouse->ps2dev, TP_TOGGLE_TWOHAND,
313 				      TP_MASK_TWOHAND, TP_DEF_TWOHAND);
314 
315 		trackpoint_update_bit(&psmouse->ps2dev, TP_TOGGLE_SOURCE_TAG,
316 				      TP_MASK_SOURCE_TAG, TP_DEF_SOURCE_TAG);
317 
318 		trackpoint_update_bit(&psmouse->ps2dev, TP_TOGGLE_MB,
319 				      TP_MASK_MB, TP_DEF_MB);
320 	}
321 
322 	/*
323 	 * These properties can be changed in this driver. Only
324 	 * configure them if the values are non-default or if the TP is in
325 	 * an unknown state.
326 	 */
327 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, sensitivity);
328 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, inertia);
329 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, speed);
330 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, reach);
331 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, draghys);
332 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, mindrag);
333 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, thresh);
334 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, upthresh);
335 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, ztime);
336 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, jenks);
337 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, drift_time);
338 
339 	/* toggles */
340 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, press_to_select);
341 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, skipback);
342 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, ext_dev);
343 
344 	return 0;
345 }
346 
347 static void trackpoint_defaults(struct trackpoint_data *tp)
348 {
349 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, sensitivity);
350 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, speed);
351 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, reach);
352 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, draghys);
353 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, mindrag);
354 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, thresh);
355 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, upthresh);
356 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, ztime);
357 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, jenks);
358 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, drift_time);
359 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, inertia);
360 
361 	/* toggles */
362 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, press_to_select);
363 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, skipback);
364 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, ext_dev);
365 }
366 
367 static void trackpoint_disconnect(struct psmouse *psmouse)
368 {
369 	device_remove_group(&psmouse->ps2dev.serio->dev,
370 			    &trackpoint_attr_group);
371 
372 	kfree(psmouse->private);
373 	psmouse->private = NULL;
374 }
375 
376 static int trackpoint_reconnect(struct psmouse *psmouse)
377 {
378 	struct trackpoint_data *tp = psmouse->private;
379 	int error;
380 	bool was_reset;
381 
382 	error = trackpoint_start_protocol(psmouse, NULL, NULL);
383 	if (error)
384 		return error;
385 
386 	was_reset = tp->variant_id == TP_VARIANT_IBM &&
387 		    trackpoint_power_on_reset(&psmouse->ps2dev) == 0;
388 
389 	error = trackpoint_sync(psmouse, was_reset);
390 	if (error)
391 		return error;
392 
393 	return 0;
394 }
395 
396 int trackpoint_detect(struct psmouse *psmouse, bool set_properties)
397 {
398 	struct ps2dev *ps2dev = &psmouse->ps2dev;
399 	struct trackpoint_data *tp;
400 	u8 variant_id;
401 	u8 firmware_id;
402 	u8 button_info;
403 	int error;
404 
405 	error = trackpoint_start_protocol(psmouse, &variant_id, &firmware_id);
406 	if (error)
407 		return error;
408 
409 	if (!set_properties)
410 		return 0;
411 
412 	tp = kzalloc(sizeof(*tp), GFP_KERNEL);
413 	if (!tp)
414 		return -ENOMEM;
415 
416 	trackpoint_defaults(tp);
417 	tp->variant_id = variant_id;
418 	tp->firmware_id = firmware_id;
419 
420 	psmouse->private = tp;
421 
422 	psmouse->vendor = trackpoint_variants[variant_id];
423 	psmouse->name = "TrackPoint";
424 
425 	psmouse->reconnect = trackpoint_reconnect;
426 	psmouse->disconnect = trackpoint_disconnect;
427 
428 	if (variant_id != TP_VARIANT_IBM) {
429 		/* Newer variants do not support extended button query. */
430 		button_info = 0x33;
431 	} else {
432 		error = trackpoint_read(ps2dev, TP_EXT_BTN, &button_info);
433 		if (error) {
434 			psmouse_warn(psmouse,
435 				     "failed to get extended button data, assuming 3 buttons\n");
436 			button_info = 0x33;
437 		} else if (!button_info) {
438 			psmouse_warn(psmouse,
439 				     "got 0 in extended button data, assuming 3 buttons\n");
440 			button_info = 0x33;
441 		}
442 	}
443 
444 	if ((button_info & 0x0f) >= 3)
445 		input_set_capability(psmouse->dev, EV_KEY, BTN_MIDDLE);
446 
447 	__set_bit(INPUT_PROP_POINTER, psmouse->dev->propbit);
448 	__set_bit(INPUT_PROP_POINTING_STICK, psmouse->dev->propbit);
449 
450 	if (variant_id != TP_VARIANT_IBM ||
451 	    trackpoint_power_on_reset(ps2dev) != 0) {
452 		/*
453 		 * Write defaults to TP if we did not reset the trackpoint.
454 		 */
455 		trackpoint_sync(psmouse, false);
456 	}
457 
458 	error = device_add_group(&ps2dev->serio->dev, &trackpoint_attr_group);
459 	if (error) {
460 		psmouse_err(psmouse,
461 			    "failed to create sysfs attributes, error: %d\n",
462 			    error);
463 		kfree(psmouse->private);
464 		psmouse->private = NULL;
465 		return -1;
466 	}
467 
468 	psmouse_info(psmouse,
469 		     "%s TrackPoint firmware: 0x%02x, buttons: %d/%d\n",
470 		     psmouse->vendor, firmware_id,
471 		     (button_info & 0xf0) >> 4, button_info & 0x0f);
472 
473 	return 0;
474 }
475 
476