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
|
/*
* Driver for Ntrig/Microsoft Touchscreens over SPI
*
* Copyright (c) 2016 Red Hat Inc.
*/
/*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
* Software Foundation; version 2 of the License.
*/
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/input.h>
#include <linux/input/mt.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/spi/spi.h>
#include <linux/acpi.h>
#include <asm/unaligned.h>
#define SURFACE3_PACKET_SIZE 264
#define SURFACE3_REPORT_TOUCH 0xd2
#define SURFACE3_REPORT_PEN 0x16
struct surface3_ts_data {
struct spi_device *spi;
struct gpio_desc *gpiod_rst[2];
struct input_dev *input_dev;
struct input_dev *pen_input_dev;
int pen_tool;
u8 rd_buf[SURFACE3_PACKET_SIZE] ____cacheline_aligned;
};
struct surface3_ts_data_finger {
u8 status;
__le16 tracking_id;
__le16 x;
__le16 cx;
__le16 y;
__le16 cy;
__le16 width;
__le16 height;
u32 padding;
} __packed;
struct surface3_ts_data_pen {
u8 status;
__le16 x;
__le16 y;
__le16 pressure;
u8 padding;
} __packed;
static int surface3_spi_read(struct surface3_ts_data *ts_data)
{
struct spi_device *spi = ts_data->spi;
memset(ts_data->rd_buf, 0, sizeof(ts_data->rd_buf));
return spi_read(spi, ts_data->rd_buf, sizeof(ts_data->rd_buf));
}
static void surface3_spi_report_touch(struct surface3_ts_data *ts_data,
struct surface3_ts_data_finger *finger)
{
int st = finger->status & 0x01;
int slot;
slot = input_mt_get_slot_by_key(ts_data->input_dev,
get_unaligned_le16(&finger->tracking_id));
if (slot < 0)
return;
input_mt_slot(ts_data->input_dev, slot);
input_mt_report_slot_state(ts_data->input_dev, MT_TOOL_FINGER, st);
if (st) {
input_report_abs(ts_data->input_dev,
ABS_MT_POSITION_X,
get_unaligned_le16(&finger->x));
input_report_abs(ts_data->input_dev,
ABS_MT_POSITION_Y,
get_unaligned_le16(&finger->y));
input_report_abs(ts_data->input_dev,
ABS_MT_WIDTH_MAJOR,
get_unaligned_le16(&finger->width));
input_report_abs(ts_data->input_dev,
ABS_MT_WIDTH_MINOR,
get_unaligned_le16(&finger->height));
}
}
static void surface3_spi_process_touch(struct surface3_ts_data *ts_data, u8 *data)
{
u16 timestamp;
unsigned int i;
timestamp = get_unaligned_le16(&data[15]);
for (i = 0; i < 13; i++) {
struct surface3_ts_data_finger *finger;
finger = (struct surface3_ts_data_finger *)&data[17 +
i * sizeof(struct surface3_ts_data_finger)];
/*
* When bit 5 of status is 1, it marks the end of the report:
* - touch present: 0xe7
* - touch released: 0xe4
* - nothing valuable: 0xff
*/
if (finger->status & 0x10)
break;
surface3_spi_report_touch(ts_data, finger);
}
input_mt_sync_frame(ts_data->input_dev);
input_sync(ts_data->input_dev);
}
static void surface3_spi_report_pen(struct surface3_ts_data *ts_data,
struct surface3_ts_data_pen *pen)
{
struct input_dev *dev = ts_data->pen_input_dev;
int st = pen->status;
int prox = st & 0x01;
int rubber = st & 0x18;
int tool = (prox && rubber) ? BTN_TOOL_RUBBER : BTN_TOOL_PEN;
/* fake proximity out to switch tools */
if (ts_data->pen_tool != tool) {
input_report_key(dev, ts_data->pen_tool, 0);
input_sync(dev);
ts_data->pen_tool = tool;
}
input_report_key(dev, BTN_TOUCH, st & 0x12);
input_report_key(dev, ts_data->pen_tool, prox);
if (st) {
input_report_key(dev,
BTN_STYLUS,
st & 0x04);
input_report_abs(dev,
ABS_X,
get_unaligned_le16(&pen->x));
input_report_abs(dev,
ABS_Y,
get_unaligned_le16(&pen->y));
input_report_abs(dev,
ABS_PRESSURE,
get_unaligned_le16(&pen->pressure));
}
}
static void surface3_spi_process_pen(struct surface3_ts_data *ts_data, u8 *data)
{
struct surface3_ts_data_pen *pen;
pen = (struct surface3_ts_data_pen *)&data[15];
surface3_spi_report_pen(ts_data, pen);
input_sync(ts_data->pen_input_dev);
}
static void surface3_spi_process(struct surface3_ts_data *ts_data)
{
static const char header[] = {
0xff, 0xff, 0xff, 0xff, 0xa5, 0x5a, 0xe7, 0x7e, 0x01
};
u8 *data = ts_data->rd_buf;
if (memcmp(header, data, sizeof(header)))
dev_err(&ts_data->spi->dev,
"%s header error: %*ph, ignoring...\n",
__func__, (int)sizeof(header), data);
switch (data[9]) {
case SURFACE3_REPORT_TOUCH:
surface3_spi_process_touch(ts_data, data);
break;
case SURFACE3_REPORT_PEN:
surface3_spi_process_pen(ts_data, data);
break;
default:
dev_err(&ts_data->spi->dev,
"%s unknown packet type: %x, ignoring...\n",
__func__, data[9]);
break;
}
}
static irqreturn_t surface3_spi_irq_handler(int irq, void *dev_id)
{
struct surface3_ts_data *data = dev_id;
if (surface3_spi_read(data))
return IRQ_HANDLED;
dev_dbg(&data->spi->dev, "%s received -> %*ph\n",
__func__, SURFACE3_PACKET_SIZE, data->rd_buf);
surface3_spi_process(data);
return IRQ_HANDLED;
}
static void surface3_spi_power(struct surface3_ts_data *data, bool on)
{
gpiod_set_value(data->gpiod_rst[0], on);
gpiod_set_value(data->gpiod_rst[1], on);
/* let the device settle a little */
msleep(20);
}
/**
* surface3_spi_get_gpio_config - Get GPIO config from ACPI/DT
*
* @ts: surface3_spi_ts_data pointer
*/
static int surface3_spi_get_gpio_config(struct surface3_ts_data *data)
{
int error;
struct device *dev;
struct gpio_desc *gpiod;
int i;
dev = &data->spi->dev;
/* Get the reset lines GPIO pin number */
for (i = 0; i < 2; i++) {
gpiod = devm_gpiod_get_index(dev, NULL, i, GPIOD_OUT_LOW);
if (IS_ERR(gpiod)) {
error = PTR_ERR(gpiod);
if (error != -EPROBE_DEFER)
dev_err(dev,
"Failed to get power GPIO %d: %d\n",
i,
error);
return error;
}
data->gpiod_rst[i] = gpiod;
}
return 0;
}
static int surface3_spi_create_touch_input(struct surface3_ts_data *data)
{
struct input_dev *input;
int error;
input = devm_input_allocate_device(&data->spi->dev);
if (!input)
return -ENOMEM;
data->input_dev = input;
input_set_abs_params(input, ABS_MT_POSITION_X, 0, 9600, 0, 0);
input_abs_set_res(input, ABS_MT_POSITION_X, 40);
input_set_abs_params(input, ABS_MT_POSITION_Y, 0, 7200, 0, 0);
input_abs_set_res(input, ABS_MT_POSITION_Y, 48);
input_set_abs_params(input, ABS_MT_WIDTH_MAJOR, 0, 1024, 0, 0);
input_set_abs_params(input, ABS_MT_WIDTH_MINOR, 0
|