xref: /openbmc/linux/drivers/input/mouse/trackpoint.c (revision 1804569d)
1 /*
2  * Stephen Evanchik <evanchsa@gmail.com>
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms of the GNU General Public License version 2 as published by
6  * the Free Software Foundation.
7  *
8  * Trademarks are the property of their respective owners.
9  */
10 
11 #include <linux/slab.h>
12 #include <linux/delay.h>
13 #include <linux/serio.h>
14 #include <linux/module.h>
15 #include <linux/input.h>
16 #include <linux/libps2.h>
17 #include <linux/proc_fs.h>
18 #include <linux/uaccess.h>
19 #include "psmouse.h"
20 #include "trackpoint.h"
21 
22 static const char * const trackpoint_variants[] = {
23 	[TP_VARIANT_IBM]	= "IBM",
24 	[TP_VARIANT_ALPS]	= "ALPS",
25 	[TP_VARIANT_ELAN]	= "Elan",
26 	[TP_VARIANT_NXP]	= "NXP",
27 };
28 
29 /*
30  * Power-on Reset: Resets all trackpoint parameters, including RAM values,
31  * to defaults.
32  * Returns zero on success, non-zero on failure.
33  */
34 static int trackpoint_power_on_reset(struct ps2dev *ps2dev)
35 {
36 	u8 param[2] = { TP_POR };
37 	int err;
38 
39 	err = ps2_command(ps2dev, param, MAKE_PS2_CMD(1, 2, TP_COMMAND));
40 	if (err)
41 		return err;
42 
43 	/* Check for success response -- 0xAA00 */
44 	if (param[0] != 0xAA || param[1] != 0x00)
45 		return -ENODEV;
46 
47 	return 0;
48 }
49 
50 /*
51  * Device IO: read, write and toggle bit
52  */
53 static int trackpoint_read(struct ps2dev *ps2dev, u8 loc, u8 *results)
54 {
55 	results[0] = loc;
56 
57 	return ps2_command(ps2dev, results, MAKE_PS2_CMD(1, 1, TP_COMMAND));
58 }
59 
60 static int trackpoint_write(struct ps2dev *ps2dev, u8 loc, u8 val)
61 {
62 	u8 param[3] = { TP_WRITE_MEM, loc, val };
63 
64 	return ps2_command(ps2dev, param, MAKE_PS2_CMD(3, 0, TP_COMMAND));
65 }
66 
67 static int trackpoint_toggle_bit(struct ps2dev *ps2dev, u8 loc, u8 mask)
68 {
69 	u8 param[3] = { TP_TOGGLE, loc, mask };
70 
71 	/* Bad things will happen if the loc param isn't in this range */
72 	if (loc < 0x20 || loc >= 0x2F)
73 		return -EINVAL;
74 
75 	return ps2_command(ps2dev, param, MAKE_PS2_CMD(3, 0, TP_COMMAND));
76 }
77 
78 static int trackpoint_update_bit(struct ps2dev *ps2dev,
79 				 u8 loc, u8 mask, u8 value)
80 {
81 	int retval;
82 	u8 data;
83 
84 	retval = trackpoint_read(ps2dev, loc, &data);
85 	if (retval)
86 		return retval;
87 
88 	if (((data & mask) == mask) != !!value)
89 		retval = trackpoint_toggle_bit(ps2dev, loc, mask);
90 
91 	return retval;
92 }
93 
94 /*
95  * Trackpoint-specific attributes
96  */
97 struct trackpoint_attr_data {
98 	size_t field_offset;
99 	u8 command;
100 	u8 mask;
101 	bool inverted;
102 	u8 power_on_default;
103 };
104 
105 static ssize_t trackpoint_show_int_attr(struct psmouse *psmouse,
106 					void *data, char *buf)
107 {
108 	struct trackpoint_data *tp = psmouse->private;
109 	struct trackpoint_attr_data *attr = data;
110 	u8 value = *(u8 *)((void *)tp + attr->field_offset);
111 
112 	if (attr->inverted)
113 		value = !value;
114 
115 	return sprintf(buf, "%u\n", value);
116 }
117 
118 static ssize_t trackpoint_set_int_attr(struct psmouse *psmouse, void *data,
119 					const char *buf, size_t count)
120 {
121 	struct trackpoint_data *tp = psmouse->private;
122 	struct trackpoint_attr_data *attr = data;
123 	u8 *field = (void *)tp + attr->field_offset;
124 	u8 value;
125 	int err;
126 
127 	err = kstrtou8(buf, 10, &value);
128 	if (err)
129 		return err;
130 
131 	*field = value;
132 	err = trackpoint_write(&psmouse->ps2dev, attr->command, value);
133 
134 	return err ?: count;
135 }
136 
137 #define TRACKPOINT_INT_ATTR(_name, _command, _default)				\
138 	static struct trackpoint_attr_data trackpoint_attr_##_name = {		\
139 		.field_offset = offsetof(struct trackpoint_data, _name),	\
140 		.command = _command,						\
141 		.power_on_default = _default,					\
142 	};									\
143 	PSMOUSE_DEFINE_ATTR(_name, S_IWUSR | S_IRUGO,				\
144 			    &trackpoint_attr_##_name,				\
145 			    trackpoint_show_int_attr, trackpoint_set_int_attr)
146 
147 static ssize_t trackpoint_set_bit_attr(struct psmouse *psmouse, void *data,
148 					const char *buf, size_t count)
149 {
150 	struct trackpoint_data *tp = psmouse->private;
151 	struct trackpoint_attr_data *attr = data;
152 	bool *field = (void *)tp + attr->field_offset;
153 	bool value;
154 	int err;
155 
156 	err = kstrtobool(buf, &value);
157 	if (err)
158 		return err;
159 
160 	if (attr->inverted)
161 		value = !value;
162 
163 	if (*field != value) {
164 		*field = value;
165 		err = trackpoint_toggle_bit(&psmouse->ps2dev,
166 					    attr->command, attr->mask);
167 	}
168 
169 	return err ?: count;
170 }
171 
172 
173 #define TRACKPOINT_BIT_ATTR(_name, _command, _mask, _inv, _default)	\
174 static struct trackpoint_attr_data trackpoint_attr_##_name = {		\
175 	.field_offset		= offsetof(struct trackpoint_data,	\
176 					   _name),			\
177 	.command		= _command,				\
178 	.mask			= _mask,				\
179 	.inverted		= _inv,					\
180 	.power_on_default	= _default,				\
181 	};								\
182 PSMOUSE_DEFINE_ATTR(_name, S_IWUSR | S_IRUGO,				\
183 		    &trackpoint_attr_##_name,				\
184 		    trackpoint_show_int_attr, trackpoint_set_bit_attr)
185 
186 TRACKPOINT_INT_ATTR(sensitivity, TP_SENS, TP_DEF_SENS);
187 TRACKPOINT_INT_ATTR(speed, TP_SPEED, TP_DEF_SPEED);
188 TRACKPOINT_INT_ATTR(inertia, TP_INERTIA, TP_DEF_INERTIA);
189 TRACKPOINT_INT_ATTR(reach, TP_REACH, TP_DEF_REACH);
190 TRACKPOINT_INT_ATTR(draghys, TP_DRAGHYS, TP_DEF_DRAGHYS);
191 TRACKPOINT_INT_ATTR(mindrag, TP_MINDRAG, TP_DEF_MINDRAG);
192 TRACKPOINT_INT_ATTR(thresh, TP_THRESH, TP_DEF_THRESH);
193 TRACKPOINT_INT_ATTR(upthresh, TP_UP_THRESH, TP_DEF_UP_THRESH);
194 TRACKPOINT_INT_ATTR(ztime, TP_Z_TIME, TP_DEF_Z_TIME);
195 TRACKPOINT_INT_ATTR(jenks, TP_JENKS_CURV, TP_DEF_JENKS_CURV);
196 TRACKPOINT_INT_ATTR(drift_time, TP_DRIFT_TIME, TP_DEF_DRIFT_TIME);
197 
198 TRACKPOINT_BIT_ATTR(press_to_select, TP_TOGGLE_PTSON, TP_MASK_PTSON, false,
199 		    TP_DEF_PTSON);
200 TRACKPOINT_BIT_ATTR(skipback, TP_TOGGLE_SKIPBACK, TP_MASK_SKIPBACK, false,
201 		    TP_DEF_SKIPBACK);
202 TRACKPOINT_BIT_ATTR(ext_dev, TP_TOGGLE_EXT_DEV, TP_MASK_EXT_DEV, true,
203 		    TP_DEF_EXT_DEV);
204 
205 static bool trackpoint_is_attr_available(struct psmouse *psmouse,
206 					 struct attribute *attr)
207 {
208 	struct trackpoint_data *tp = psmouse->private;
209 
210 	return tp->variant_id == TP_VARIANT_IBM ||
211 		attr == &psmouse_attr_sensitivity.dattr.attr ||
212 		attr == &psmouse_attr_press_to_select.dattr.attr;
213 }
214 
215 static umode_t trackpoint_is_attr_visible(struct kobject *kobj,
216 					  struct attribute *attr, int n)
217 {
218 	struct device *dev = container_of(kobj, struct device, kobj);
219 	struct serio *serio = to_serio_port(dev);
220 	struct psmouse *psmouse = serio_get_drvdata(serio);
221 
222 	return trackpoint_is_attr_available(psmouse, attr) ? attr->mode : 0;
223 }
224 
225 static struct attribute *trackpoint_attrs[] = {
226 	&psmouse_attr_sensitivity.dattr.attr,
227 	&psmouse_attr_speed.dattr.attr,
228 	&psmouse_attr_inertia.dattr.attr,
229 	&psmouse_attr_reach.dattr.attr,
230 	&psmouse_attr_draghys.dattr.attr,
231 	&psmouse_attr_mindrag.dattr.attr,
232 	&psmouse_attr_thresh.dattr.attr,
233 	&psmouse_attr_upthresh.dattr.attr,
234 	&psmouse_attr_ztime.dattr.attr,
235 	&psmouse_attr_jenks.dattr.attr,
236 	&psmouse_attr_drift_time.dattr.attr,
237 	&psmouse_attr_press_to_select.dattr.attr,
238 	&psmouse_attr_skipback.dattr.attr,
239 	&psmouse_attr_ext_dev.dattr.attr,
240 	NULL
241 };
242 
243 static struct attribute_group trackpoint_attr_group = {
244 	.is_visible	= trackpoint_is_attr_visible,
245 	.attrs		= trackpoint_attrs,
246 };
247 
248 #define TRACKPOINT_UPDATE(_power_on, _psmouse, _tp, _name)		\
249 do {									\
250 	struct trackpoint_attr_data *_attr = &trackpoint_attr_##_name;	\
251 									\
252 	if ((!_power_on || _tp->_name != _attr->power_on_default) &&	\
253 	    trackpoint_is_attr_available(_psmouse,			\
254 				&psmouse_attr_##_name.dattr.attr)) {	\
255 		if (!_attr->mask)					\
256 			trackpoint_write(&_psmouse->ps2dev,		\
257 					 _attr->command, _tp->_name);	\
258 		else							\
259 			trackpoint_update_bit(&_psmouse->ps2dev,	\
260 					_attr->command, _attr->mask,	\
261 					_tp->_name);			\
262 	}								\
263 } while (0)
264 
265 #define TRACKPOINT_SET_POWER_ON_DEFAULT(_tp, _name)			\
266 do {									\
267 	_tp->_name = trackpoint_attr_##_name.power_on_default;		\
268 } while (0)
269 
270 static int trackpoint_start_protocol(struct psmouse *psmouse,
271 				     u8 *variant_id, u8 *firmware_id)
272 {
273 	u8 param[2] = { 0 };
274 	int error;
275 
276 	error = ps2_command(&psmouse->ps2dev,
277 			    param, MAKE_PS2_CMD(0, 2, TP_READ_ID));
278 	if (error)
279 		return error;
280 
281 	switch (param[0]) {
282 	case TP_VARIANT_IBM:
283 	case TP_VARIANT_ALPS:
284 	case TP_VARIANT_ELAN:
285 	case TP_VARIANT_NXP:
286 		if (variant_id)
287 			*variant_id = param[0];
288 		if (firmware_id)
289 			*firmware_id = param[1];
290 		return 0;
291 	}
292 
293 	return -ENODEV;
294 }
295 
296 /*
297  * Write parameters to trackpad.
298  * in_power_on_state: Set to true if TP is in default / power-on state (ex. if
299  *		      power-on reset was run). If so, values will only be
300  *		      written to TP if they differ from power-on default.
301  */
302 static int trackpoint_sync(struct psmouse *psmouse, bool in_power_on_state)
303 {
304 	struct trackpoint_data *tp = psmouse->private;
305 
306 	if (!in_power_on_state && tp->variant_id == TP_VARIANT_IBM) {
307 		/*
308 		 * Disable features that may make device unusable
309 		 * with this driver.
310 		 */
311 		trackpoint_update_bit(&psmouse->ps2dev, TP_TOGGLE_TWOHAND,
312 				      TP_MASK_TWOHAND, TP_DEF_TWOHAND);
313 
314 		trackpoint_update_bit(&psmouse->ps2dev, TP_TOGGLE_SOURCE_TAG,
315 				      TP_MASK_SOURCE_TAG, TP_DEF_SOURCE_TAG);
316 
317 		trackpoint_update_bit(&psmouse->ps2dev, TP_TOGGLE_MB,
318 				      TP_MASK_MB, TP_DEF_MB);
319 	}
320 
321 	/*
322 	 * These properties can be changed in this driver. Only
323 	 * configure them if the values are non-default or if the TP is in
324 	 * an unknown state.
325 	 */
326 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, sensitivity);
327 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, inertia);
328 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, speed);
329 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, reach);
330 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, draghys);
331 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, mindrag);
332 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, thresh);
333 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, upthresh);
334 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, ztime);
335 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, jenks);
336 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, drift_time);
337 
338 	/* toggles */
339 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, press_to_select);
340 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, skipback);
341 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, ext_dev);
342 
343 	return 0;
344 }
345 
346 static void trackpoint_defaults(struct trackpoint_data *tp)
347 {
348 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, sensitivity);
349 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, speed);
350 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, reach);
351 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, draghys);
352 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, mindrag);
353 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, thresh);
354 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, upthresh);
355 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, ztime);
356 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, jenks);
357 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, drift_time);
358 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, inertia);
359 
360 	/* toggles */
361 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, press_to_select);
362 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, skipback);
363 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, ext_dev);
364 }
365 
366 static void trackpoint_disconnect(struct psmouse *psmouse)
367 {
368 	device_remove_group(&psmouse->ps2dev.serio->dev,
369 			    &trackpoint_attr_group);
370 
371 	kfree(psmouse->private);
372 	psmouse->private = NULL;
373 }
374 
375 static int trackpoint_reconnect(struct psmouse *psmouse)
376 {
377 	struct trackpoint_data *tp = psmouse->private;
378 	int error;
379 	bool was_reset;
380 
381 	error = trackpoint_start_protocol(psmouse, NULL, NULL);
382 	if (error)
383 		return error;
384 
385 	was_reset = tp->variant_id == TP_VARIANT_IBM &&
386 		    trackpoint_power_on_reset(&psmouse->ps2dev) == 0;
387 
388 	error = trackpoint_sync(psmouse, was_reset);
389 	if (error)
390 		return error;
391 
392 	return 0;
393 }
394 
395 int trackpoint_detect(struct psmouse *psmouse, bool set_properties)
396 {
397 	struct ps2dev *ps2dev = &psmouse->ps2dev;
398 	struct trackpoint_data *tp;
399 	u8 variant_id;
400 	u8 firmware_id;
401 	u8 button_info;
402 	int error;
403 
404 	error = trackpoint_start_protocol(psmouse, &variant_id, &firmware_id);
405 	if (error)
406 		return error;
407 
408 	if (!set_properties)
409 		return 0;
410 
411 	tp = kzalloc(sizeof(*tp), GFP_KERNEL);
412 	if (!tp)
413 		return -ENOMEM;
414 
415 	trackpoint_defaults(tp);
416 	tp->variant_id = variant_id;
417 	tp->firmware_id = firmware_id;
418 
419 	psmouse->private = tp;
420 
421 	psmouse->vendor = trackpoint_variants[variant_id];
422 	psmouse->name = "TrackPoint";
423 
424 	psmouse->reconnect = trackpoint_reconnect;
425 	psmouse->disconnect = trackpoint_disconnect;
426 
427 	if (variant_id != TP_VARIANT_IBM) {
428 		/* Newer variants do not support extended button query. */
429 		button_info = 0x33;
430 	} else {
431 		error = trackpoint_read(ps2dev, TP_EXT_BTN, &button_info);
432 		if (error) {
433 			psmouse_warn(psmouse,
434 				     "failed to get extended button data, assuming 3 buttons\n");
435 			button_info = 0x33;
436 		} else if (!button_info) {
437 			psmouse_warn(psmouse,
438 				     "got 0 in extended button data, assuming 3 buttons\n");
439 			button_info = 0x33;
440 		}
441 	}
442 
443 	if ((button_info & 0x0f) >= 3)
444 		input_set_capability(psmouse->dev, EV_KEY, BTN_MIDDLE);
445 
446 	__set_bit(INPUT_PROP_POINTER, psmouse->dev->propbit);
447 	__set_bit(INPUT_PROP_POINTING_STICK, psmouse->dev->propbit);
448 
449 	if (variant_id != TP_VARIANT_IBM ||
450 	    trackpoint_power_on_reset(ps2dev) != 0) {
451 		/*
452 		 * Write defaults to TP if we did not reset the trackpoint.
453 		 */
454 		trackpoint_sync(psmouse, false);
455 	}
456 
457 	error = device_add_group(&ps2dev->serio->dev, &trackpoint_attr_group);
458 	if (error) {
459 		psmouse_err(psmouse,
460 			    "failed to create sysfs attributes, error: %d\n",
461 			    error);
462 		kfree(psmouse->private);
463 		psmouse->private = NULL;
464 		return -1;
465 	}
466 
467 	psmouse_info(psmouse,
468 		     "%s TrackPoint firmware: 0x%02x, buttons: %d/%d\n",
469 		     psmouse->vendor, firmware_id,
470 		     (button_info & 0xf0) >> 4, button_info & 0x0f);
471 
472 	return 0;
473 }
474 
475