xref: /openbmc/linux/drivers/input/mouse/trackpoint.c (revision f87deada)
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 results[2];
37 	int tries = 0;
38 
39 	/* Issue POR command, and repeat up to once if 0xFC00 received */
40 	do {
41 		if (ps2_command(ps2dev, NULL, MAKE_PS2_CMD(0, 0, TP_COMMAND)) ||
42 		    ps2_command(ps2dev, results, MAKE_PS2_CMD(0, 2, TP_POR)))
43 			return -1;
44 	} while (results[0] == 0xFC && results[1] == 0x00 && ++tries < 2);
45 
46 	/* Check for success response -- 0xAA00 */
47 	if (results[0] != 0xAA || results[1] != 0x00)
48 		return -ENODEV;
49 
50 	return 0;
51 }
52 
53 /*
54  * Device IO: read, write and toggle bit
55  */
56 static int trackpoint_read(struct ps2dev *ps2dev, u8 loc, u8 *results)
57 {
58 	if (ps2_command(ps2dev, NULL, MAKE_PS2_CMD(0, 0, TP_COMMAND)) ||
59 	    ps2_command(ps2dev, results, MAKE_PS2_CMD(0, 1, loc))) {
60 		return -1;
61 	}
62 
63 	return 0;
64 }
65 
66 static int trackpoint_write(struct ps2dev *ps2dev, u8 loc, u8 val)
67 {
68 	if (ps2_command(ps2dev, NULL, MAKE_PS2_CMD(0, 0, TP_COMMAND)) ||
69 	    ps2_command(ps2dev, NULL, MAKE_PS2_CMD(0, 0, TP_WRITE_MEM)) ||
70 	    ps2_command(ps2dev, NULL, MAKE_PS2_CMD(0, 0, loc)) ||
71 	    ps2_command(ps2dev, NULL, MAKE_PS2_CMD(0, 0, val))) {
72 		return -1;
73 	}
74 
75 	return 0;
76 }
77 
78 static int trackpoint_toggle_bit(struct ps2dev *ps2dev, u8 loc, u8 mask)
79 {
80 	/* Bad things will happen if the loc param isn't in this range */
81 	if (loc < 0x20 || loc >= 0x2F)
82 		return -1;
83 
84 	if (ps2_command(ps2dev, NULL, MAKE_PS2_CMD(0, 0, TP_COMMAND)) ||
85 	    ps2_command(ps2dev, NULL, MAKE_PS2_CMD(0, 0, TP_TOGGLE)) ||
86 	    ps2_command(ps2dev, NULL, MAKE_PS2_CMD(0, 0, loc)) ||
87 	    ps2_command(ps2dev, NULL, MAKE_PS2_CMD(0, 0, mask))) {
88 		return -1;
89 	}
90 
91 	return 0;
92 }
93 
94 static int trackpoint_update_bit(struct ps2dev *ps2dev,
95 				 u8 loc, u8 mask, u8 value)
96 {
97 	int retval = 0;
98 	u8 data;
99 
100 	trackpoint_read(ps2dev, loc, &data);
101 	if (((data & mask) == mask) != !!value)
102 		retval = trackpoint_toggle_bit(ps2dev, loc, mask);
103 
104 	return retval;
105 }
106 
107 /*
108  * Trackpoint-specific attributes
109  */
110 struct trackpoint_attr_data {
111 	size_t field_offset;
112 	u8 command;
113 	u8 mask;
114 	bool inverted;
115 	u8 power_on_default;
116 };
117 
118 static ssize_t trackpoint_show_int_attr(struct psmouse *psmouse,
119 					void *data, char *buf)
120 {
121 	struct trackpoint_data *tp = psmouse->private;
122 	struct trackpoint_attr_data *attr = data;
123 	u8 value = *(u8 *)((void *)tp + attr->field_offset);
124 
125 	if (attr->inverted)
126 		value = !value;
127 
128 	return sprintf(buf, "%u\n", value);
129 }
130 
131 static ssize_t trackpoint_set_int_attr(struct psmouse *psmouse, void *data,
132 					const char *buf, size_t count)
133 {
134 	struct trackpoint_data *tp = psmouse->private;
135 	struct trackpoint_attr_data *attr = data;
136 	u8 *field = (void *)tp + attr->field_offset;
137 	u8 value;
138 	int err;
139 
140 	err = kstrtou8(buf, 10, &value);
141 	if (err)
142 		return err;
143 
144 	*field = value;
145 	trackpoint_write(&psmouse->ps2dev, attr->command, value);
146 
147 	return count;
148 }
149 
150 #define TRACKPOINT_INT_ATTR(_name, _command, _default)				\
151 	static struct trackpoint_attr_data trackpoint_attr_##_name = {		\
152 		.field_offset = offsetof(struct trackpoint_data, _name),	\
153 		.command = _command,						\
154 		.power_on_default = _default,					\
155 	};									\
156 	PSMOUSE_DEFINE_ATTR(_name, S_IWUSR | S_IRUGO,				\
157 			    &trackpoint_attr_##_name,				\
158 			    trackpoint_show_int_attr, trackpoint_set_int_attr)
159 
160 static ssize_t trackpoint_set_bit_attr(struct psmouse *psmouse, void *data,
161 					const char *buf, size_t count)
162 {
163 	struct trackpoint_data *tp = psmouse->private;
164 	struct trackpoint_attr_data *attr = data;
165 	bool *field = (void *)tp + attr->field_offset;
166 	bool value;
167 	int err;
168 
169 	err = kstrtobool(buf, &value);
170 	if (err)
171 		return err;
172 
173 	if (attr->inverted)
174 		value = !value;
175 
176 	if (*field != value) {
177 		*field = value;
178 		trackpoint_toggle_bit(&psmouse->ps2dev, attr->command, attr->mask);
179 	}
180 
181 	return count;
182 }
183 
184 
185 #define TRACKPOINT_BIT_ATTR(_name, _command, _mask, _inv, _default)	\
186 static struct trackpoint_attr_data trackpoint_attr_##_name = {		\
187 	.field_offset		= offsetof(struct trackpoint_data,	\
188 					   _name),			\
189 	.command		= _command,				\
190 	.mask			= _mask,				\
191 	.inverted		= _inv,					\
192 	.power_on_default	= _default,				\
193 	};								\
194 PSMOUSE_DEFINE_ATTR(_name, S_IWUSR | S_IRUGO,				\
195 		    &trackpoint_attr_##_name,				\
196 		    trackpoint_show_int_attr, trackpoint_set_bit_attr)
197 
198 TRACKPOINT_INT_ATTR(sensitivity, TP_SENS, TP_DEF_SENS);
199 TRACKPOINT_INT_ATTR(speed, TP_SPEED, TP_DEF_SPEED);
200 TRACKPOINT_INT_ATTR(inertia, TP_INERTIA, TP_DEF_INERTIA);
201 TRACKPOINT_INT_ATTR(reach, TP_REACH, TP_DEF_REACH);
202 TRACKPOINT_INT_ATTR(draghys, TP_DRAGHYS, TP_DEF_DRAGHYS);
203 TRACKPOINT_INT_ATTR(mindrag, TP_MINDRAG, TP_DEF_MINDRAG);
204 TRACKPOINT_INT_ATTR(thresh, TP_THRESH, TP_DEF_THRESH);
205 TRACKPOINT_INT_ATTR(upthresh, TP_UP_THRESH, TP_DEF_UP_THRESH);
206 TRACKPOINT_INT_ATTR(ztime, TP_Z_TIME, TP_DEF_Z_TIME);
207 TRACKPOINT_INT_ATTR(jenks, TP_JENKS_CURV, TP_DEF_JENKS_CURV);
208 TRACKPOINT_INT_ATTR(drift_time, TP_DRIFT_TIME, TP_DEF_DRIFT_TIME);
209 
210 TRACKPOINT_BIT_ATTR(press_to_select, TP_TOGGLE_PTSON, TP_MASK_PTSON, false,
211 		    TP_DEF_PTSON);
212 TRACKPOINT_BIT_ATTR(skipback, TP_TOGGLE_SKIPBACK, TP_MASK_SKIPBACK, false,
213 		    TP_DEF_SKIPBACK);
214 TRACKPOINT_BIT_ATTR(ext_dev, TP_TOGGLE_EXT_DEV, TP_MASK_EXT_DEV, true,
215 		    TP_DEF_EXT_DEV);
216 
217 static bool trackpoint_is_attr_available(struct psmouse *psmouse,
218 					 struct attribute *attr)
219 {
220 	struct trackpoint_data *tp = psmouse->private;
221 
222 	return tp->variant_id == TP_VARIANT_IBM ||
223 		attr == &psmouse_attr_sensitivity.dattr.attr ||
224 		attr == &psmouse_attr_press_to_select.dattr.attr;
225 }
226 
227 static umode_t trackpoint_is_attr_visible(struct kobject *kobj,
228 					  struct attribute *attr, int n)
229 {
230 	struct device *dev = container_of(kobj, struct device, kobj);
231 	struct serio *serio = to_serio_port(dev);
232 	struct psmouse *psmouse = serio_get_drvdata(serio);
233 
234 	return trackpoint_is_attr_available(psmouse, attr) ? attr->mode : 0;
235 }
236 
237 static struct attribute *trackpoint_attrs[] = {
238 	&psmouse_attr_sensitivity.dattr.attr,
239 	&psmouse_attr_speed.dattr.attr,
240 	&psmouse_attr_inertia.dattr.attr,
241 	&psmouse_attr_reach.dattr.attr,
242 	&psmouse_attr_draghys.dattr.attr,
243 	&psmouse_attr_mindrag.dattr.attr,
244 	&psmouse_attr_thresh.dattr.attr,
245 	&psmouse_attr_upthresh.dattr.attr,
246 	&psmouse_attr_ztime.dattr.attr,
247 	&psmouse_attr_jenks.dattr.attr,
248 	&psmouse_attr_drift_time.dattr.attr,
249 	&psmouse_attr_press_to_select.dattr.attr,
250 	&psmouse_attr_skipback.dattr.attr,
251 	&psmouse_attr_ext_dev.dattr.attr,
252 	NULL
253 };
254 
255 static struct attribute_group trackpoint_attr_group = {
256 	.is_visible	= trackpoint_is_attr_visible,
257 	.attrs		= trackpoint_attrs,
258 };
259 
260 #define TRACKPOINT_UPDATE(_power_on, _psmouse, _tp, _name)		\
261 do {									\
262 	struct trackpoint_attr_data *_attr = &trackpoint_attr_##_name;	\
263 									\
264 	if ((!_power_on || _tp->_name != _attr->power_on_default) &&	\
265 	    trackpoint_is_attr_available(_psmouse,			\
266 				&psmouse_attr_##_name.dattr.attr)) {	\
267 		if (!_attr->mask)					\
268 			trackpoint_write(&_psmouse->ps2dev,		\
269 					 _attr->command, _tp->_name);	\
270 		else							\
271 			trackpoint_update_bit(&_psmouse->ps2dev,	\
272 					_attr->command, _attr->mask,	\
273 					_tp->_name);			\
274 	}								\
275 } while (0)
276 
277 #define TRACKPOINT_SET_POWER_ON_DEFAULT(_tp, _name)			\
278 do {									\
279 	_tp->_name = trackpoint_attr_##_name.power_on_default;		\
280 } while (0)
281 
282 static int trackpoint_start_protocol(struct psmouse *psmouse,
283 				     u8 *variant_id, u8 *firmware_id)
284 {
285 	u8 param[2] = { 0 };
286 	int error;
287 
288 	error = ps2_command(&psmouse->ps2dev,
289 			    param, MAKE_PS2_CMD(0, 2, TP_READ_ID));
290 	if (error)
291 		return error;
292 
293 	switch (param[0]) {
294 	case TP_VARIANT_IBM:
295 	case TP_VARIANT_ALPS:
296 	case TP_VARIANT_ELAN:
297 	case TP_VARIANT_NXP:
298 		if (variant_id)
299 			*variant_id = param[0];
300 		if (firmware_id)
301 			*firmware_id = param[1];
302 		return 0;
303 	}
304 
305 	return -ENODEV;
306 }
307 
308 /*
309  * Write parameters to trackpad.
310  * in_power_on_state: Set to true if TP is in default / power-on state (ex. if
311  *		      power-on reset was run). If so, values will only be
312  *		      written to TP if they differ from power-on default.
313  */
314 static int trackpoint_sync(struct psmouse *psmouse, bool in_power_on_state)
315 {
316 	struct trackpoint_data *tp = psmouse->private;
317 
318 	if (!in_power_on_state && tp->variant_id == TP_VARIANT_IBM) {
319 		/*
320 		 * Disable features that may make device unusable
321 		 * with this driver.
322 		 */
323 		trackpoint_update_bit(&psmouse->ps2dev, TP_TOGGLE_TWOHAND,
324 				      TP_MASK_TWOHAND, TP_DEF_TWOHAND);
325 
326 		trackpoint_update_bit(&psmouse->ps2dev, TP_TOGGLE_SOURCE_TAG,
327 				      TP_MASK_SOURCE_TAG, TP_DEF_SOURCE_TAG);
328 
329 		trackpoint_update_bit(&psmouse->ps2dev, TP_TOGGLE_MB,
330 				      TP_MASK_MB, TP_DEF_MB);
331 	}
332 
333 	/*
334 	 * These properties can be changed in this driver. Only
335 	 * configure them if the values are non-default or if the TP is in
336 	 * an unknown state.
337 	 */
338 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, sensitivity);
339 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, inertia);
340 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, speed);
341 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, reach);
342 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, draghys);
343 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, mindrag);
344 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, thresh);
345 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, upthresh);
346 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, ztime);
347 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, jenks);
348 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, drift_time);
349 
350 	/* toggles */
351 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, press_to_select);
352 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, skipback);
353 	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, ext_dev);
354 
355 	return 0;
356 }
357 
358 static void trackpoint_defaults(struct trackpoint_data *tp)
359 {
360 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, sensitivity);
361 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, speed);
362 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, reach);
363 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, draghys);
364 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, mindrag);
365 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, thresh);
366 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, upthresh);
367 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, ztime);
368 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, jenks);
369 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, drift_time);
370 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, inertia);
371 
372 	/* toggles */
373 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, press_to_select);
374 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, skipback);
375 	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, ext_dev);
376 }
377 
378 static void trackpoint_disconnect(struct psmouse *psmouse)
379 {
380 	device_remove_group(&psmouse->ps2dev.serio->dev,
381 			    &trackpoint_attr_group);
382 
383 	kfree(psmouse->private);
384 	psmouse->private = NULL;
385 }
386 
387 static int trackpoint_reconnect(struct psmouse *psmouse)
388 {
389 	struct trackpoint_data *tp = psmouse->private;
390 	int error;
391 	bool was_reset;
392 
393 	error = trackpoint_start_protocol(psmouse, NULL, NULL);
394 	if (error)
395 		return error;
396 
397 	was_reset = tp->variant_id == TP_VARIANT_IBM &&
398 		    trackpoint_power_on_reset(&psmouse->ps2dev) == 0;
399 
400 	error = trackpoint_sync(psmouse, was_reset);
401 	if (error)
402 		return error;
403 
404 	return 0;
405 }
406 
407 int trackpoint_detect(struct psmouse *psmouse, bool set_properties)
408 {
409 	struct ps2dev *ps2dev = &psmouse->ps2dev;
410 	struct trackpoint_data *tp;
411 	u8 variant_id;
412 	u8 firmware_id;
413 	u8 button_info;
414 	int error;
415 
416 	error = trackpoint_start_protocol(psmouse, &variant_id, &firmware_id);
417 	if (error)
418 		return error;
419 
420 	if (!set_properties)
421 		return 0;
422 
423 	tp = kzalloc(sizeof(*tp), GFP_KERNEL);
424 	if (!tp)
425 		return -ENOMEM;
426 
427 	trackpoint_defaults(tp);
428 	tp->variant_id = variant_id;
429 	tp->firmware_id = firmware_id;
430 
431 	psmouse->private = tp;
432 
433 	psmouse->vendor = trackpoint_variants[variant_id];
434 	psmouse->name = "TrackPoint";
435 
436 	psmouse->reconnect = trackpoint_reconnect;
437 	psmouse->disconnect = trackpoint_disconnect;
438 
439 	if (variant_id != TP_VARIANT_IBM) {
440 		/* Newer variants do not support extended button query. */
441 		button_info = 0x33;
442 	} else {
443 		error = trackpoint_read(ps2dev, TP_EXT_BTN, &button_info);
444 		if (error) {
445 			psmouse_warn(psmouse,
446 				     "failed to get extended button data, assuming 3 buttons\n");
447 			button_info = 0x33;
448 		} else if (!button_info) {
449 			psmouse_warn(psmouse,
450 				     "got 0 in extended button data, assuming 3 buttons\n");
451 			button_info = 0x33;
452 		}
453 	}
454 
455 	if ((button_info & 0x0f) >= 3)
456 		input_set_capability(psmouse->dev, EV_KEY, BTN_MIDDLE);
457 
458 	__set_bit(INPUT_PROP_POINTER, psmouse->dev->propbit);
459 	__set_bit(INPUT_PROP_POINTING_STICK, psmouse->dev->propbit);
460 
461 	if (variant_id != TP_VARIANT_IBM ||
462 	    trackpoint_power_on_reset(ps2dev) != 0) {
463 		/*
464 		 * Write defaults to TP if we did not reset the trackpoint.
465 		 */
466 		trackpoint_sync(psmouse, false);
467 	}
468 
469 	error = device_add_group(&ps2dev->serio->dev, &trackpoint_attr_group);
470 	if (error) {
471 		psmouse_err(psmouse,
472 			    "failed to create sysfs attributes, error: %d\n",
473 			    error);
474 		kfree(psmouse->private);
475 		psmouse->private = NULL;
476 		return -1;
477 	}
478 
479 	psmouse_info(psmouse,
480 		     "%s TrackPoint firmware: 0x%02x, buttons: %d/%d\n",
481 		     psmouse->vendor, firmware_id,
482 		     (button_info & 0xf0) >> 4, button_info & 0x0f);
483 
484 	return 0;
485 }
486 
487