1/*
2 * Driver for Ntrig/Microsoft Touchscreens over SPI
3 *
4 * Copyright (c) 2016 Red Hat Inc.
5 */
6
7/*
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the Free
10 * Software Foundation; version 2 of the License.
11 */
12
13#include <linux/kernel.h>
14
15#include <linux/delay.h>
16#include <linux/gpio/consumer.h>
17#include <linux/input.h>
18#include <linux/input/mt.h>
19#include <linux/interrupt.h>
20#include <linux/module.h>
21#include <linux/slab.h>
22#include <linux/spi/spi.h>
23#include <linux/acpi.h>
24
25#include <asm/unaligned.h>
26
27#define SURFACE3_PACKET_SIZE 264
28
29#define SURFACE3_REPORT_TOUCH 0xd2
30#define SURFACE3_REPORT_PEN 0x16
31
32struct surface3_ts_data {
33 struct spi_device *spi;
34 struct gpio_desc *gpiod_rst[2];
35 struct input_dev *input_dev;
36 struct input_dev *pen_input_dev;
37 int pen_tool;
38
39 u8 rd_buf[SURFACE3_PACKET_SIZE] ____cacheline_aligned;
40};
41
42struct surface3_ts_data_finger {
43 u8 status;
44 __le16 tracking_id;
45 __le16 x;
46 __le16 cx;
47 __le16 y;
48 __le16 cy;
49 __le16 width;
50 __le16 height;
51 u32 padding;
52} __packed;
53
54struct surface3_ts_data_pen {
55 u8 status;
56 __le16 x;
57 __le16 y;
58 __le16 pressure;
59 u8 padding;
60} __packed;
61
62static int surface3_spi_read(struct surface3_ts_data *ts_data)
63{
64 struct spi_device *spi = ts_data->spi;
65
66 memset(ts_data->rd_buf, 0, sizeof(ts_data->rd_buf));
67 return spi_read(spi, ts_data->rd_buf, sizeof(ts_data->rd_buf));
68}
69
70static void surface3_spi_report_touch(struct surface3_ts_data *ts_data,
71 struct surface3_ts_data_finger *finger)
72{
73 int st = finger->status & 0x01;
74 int slot;
75
76 slot = input_mt_get_slot_by_key(ts_data->input_dev,
77 get_unaligned_le16(&finger->tracking_id));
78 if (slot < 0)
79 return;
80
81 input_mt_slot(ts_data->input_dev, slot);
82 input_mt_report_slot_state(ts_data->input_dev, MT_TOOL_FINGER, st);
83 if (st) {
84 input_report_abs(ts_data->input_dev,
85 ABS_MT_POSITION_X,
86 get_unaligned_le16(&finger->x));
87 input_report_abs(ts_data->input_dev,
88 ABS_MT_POSITION_Y,
89 get_unaligned_le16(&finger->y));
90 input_report_abs(ts_data->input_dev,
91 ABS_MT_WIDTH_MAJOR,
92 get_unaligned_le16(&finger->width));
93 input_report_abs(ts_data->input_dev,
94 ABS_MT_WIDTH_MINOR,
95 get_unaligned_le16(&finger->height));
96 }
97}
98
99static void surface3_spi_process_touch(struct surface3_ts_data *ts_data, u8 *data)
100{
101 u16 timestamp;
102 unsigned int i;
103 timestamp = get_unaligned_le16(&data[15]);
104
105 for (i = 0; i < 13; i++) {
106 struct surface3_ts_data_finger *finger;
107
108 finger = (struct surface3_ts_data_finger *)&data[17 +
109 i * sizeof(struct surface3_ts_data_finger)];
110
111 /*
112 * When bit 5 of status is 1, it marks the end of the report:
113 * - touch present: 0xe7
114 * - touch released: 0xe4
115 * - nothing valuable: 0xff
116 */
117 if (finger->status & 0x10)
118 break;
119
120 surface3_spi_report_touch(ts_data, finger);
121 }
122
123 input_mt_sync_frame(ts_data->input_dev);
124 input_sync(ts_data->input_dev);
125}
126
127static void surface3_spi_report_pen(struct surface3_ts_data *ts_data,
128 struct surface3_ts_data_pen *pen)
129{
130 struct input_dev *dev = ts_data->pen_input_dev;
131 int st = pen->status;
132 int prox = st & 0x01;
133 int rubber = st & 0x18;
134 int tool = (prox && rubber) ? BTN_TOOL_RUBBER : BTN_TOOL_PEN;
135
136 /* fake proximity out to switch tools */
137 if (ts_data->pen_tool != tool) {
138 input_report_key(dev, ts_data->pen_tool, 0);
139 input_sync(dev);
140 ts_data->pen_tool = tool;
141 }
142
143 input_report_key(dev, BTN_TOUCH, st & 0x12);
144
145 input_report_key(dev, ts_data->pen_tool, prox);
146
147 if (st) {
148 input_report_key(dev,
149 BTN_STYLUS,
150 st & 0x04);
151
152 input_report_abs(dev,
153 ABS_X,
154 get_unaligned_le16(&pen->x));
155 input_report_abs(dev,
156 ABS_Y,
157 get_unaligned_le16(&pen->y));
158 input_report_abs(dev,
159 ABS_PRESSURE,
160 get_unaligned_le16(&pen->pressure));
161 }
162}
163
164static void surface3_spi_process_pen(struct surface3_ts_data *ts_data, u8 *data)
165{
166 struct surface3_ts_data_pen *pen;
167
168 pen = (struct surface3_ts_data_pen *)&data[15];
169
170 surface3_spi_report_pen(ts_data, pen);
171 input_sync(ts_data->pen_input_dev);
172}
173
174static void surface3_spi_process(struct surface3_ts_data *ts_data)
175{
176 static const char header[] = {
177 0xff, 0xff, 0xff, 0xff, 0xa5, 0x5a, 0xe7, 0x7e, 0x01
178 };
179 u8 *data = ts_data->rd_buf;
180
181 if (memcmp(header, data, sizeof(header)))
182 dev_err(&ts_data->spi->dev,
183 "%s header error: %*ph, ignoring...\n",
184 __func__, (int)sizeof(header), data);
185
186 switch (data[9]) {
187 case SURFACE3_REPORT_TOUCH:
188 surface3_spi_process_touch(ts_data, data);
189 break;
190 case SURFACE3_REPORT_PEN:
191 surface3_spi_process_pen(ts_data, data);
192 break;
193 default:
194 dev_err(&ts_data->spi->dev,
195 "%s unknown packet type: %x, ignoring...\n",
196 __func__, data[9]);
197 break;
198 }
199}
200
201static irqreturn_t surface3_spi_irq_handler(int irq, void *dev_id)
202{
203 struct surface3_ts_data *data = dev_id;
204
205 if (surface3_spi_read(data))
206 return IRQ_HANDLED;
207
208 dev_dbg(&data->spi->dev, "%s received -> %*ph\n",
209 __func__, SURFACE3_PACKET_SIZE, data->rd_buf);
210 surface3_spi_process(data);
211
212 return IRQ_HANDLED;
213}
214
215static void surface3_spi_power(struct surface3_ts_data *data, bool on)
216{
217 gpiod_set_value(data->gpiod_rst[0], on);
218 gpiod_set_value(data->gpiod_rst[1], on);
219 /* let the device settle a little */
220 msleep(20);
221}
222
223/**
224 * surface3_spi_get_gpio_config - Get GPIO config from ACPI/DT
225 *
226 * @ts: surface3_spi_ts_data pointer
227 */
228static int surface3_spi_get_gpio_config(struct surface3_ts_data *data)
229{
230 int error;
231 struct device *dev;
232 struct gpio_desc *gpiod;
233 int i;
234
235 dev = &data->spi->dev;
236
237 /* Get the reset lines GPIO pin number */
238 for (i = 0; i < 2; i++) {
239 gpiod = devm_gpiod_get_index(dev, NULL, i, GPIOD_OUT_LOW);
240 if (IS_ERR(gpiod)) {
241 error = PTR_ERR(gpiod);
242 if (error != -EPROBE_DEFER)
243 dev_err(dev,
244 "Failed to get power GPIO %d: %d\n",
245 i,
246 error);
247 return error;
248 }
249
250 data->gpiod_rst[i] = gpiod;
251 }
252
253 return 0;
254}
255
256static int surface3_spi_create_touch_input(struct surface3_ts_data *data)
257{
258 struct input_dev *input;
259 int error;
260
261 input = devm_input_allocate_device(&data->spi->dev);
262 if (!input)
263 return -ENOMEM;
264
265 data->input_dev = input;
266
267 input_set_abs_params(input, ABS_MT_POSITION_X, 0, 9600, 0, 0);
268 input_abs_set_res(input, ABS_MT_POSITION_X, 40);
269 input_set_abs_params(input, ABS_MT_POSITION_Y, 0, 7200, 0, 0);
270 input_abs_set_res(input, ABS_MT_POSITION_Y, 48);
271 input_set_abs_params(input, ABS_MT_WIDTH_MAJOR, 0, 1024, 0, 0);
272 input_set_abs_params(input, ABS_MT_WIDTH_MINOR, 0, 1024, 0, 0);
273 input_mt_init_slots(input, 10, INPUT_MT_DIRECT);
274
275 input->name = "Surface3 SPI Capacitive TouchScreen";
276 input->phys = "input/ts";
277 input->id.bustype = BUS_SPI;
278 input->id.vendor = 0x045e; /* Microsoft */
279 input->id.product = 0x0001;
280 input->id.version = 0x0000;
281
282 error = input_register_device(input);
283 if (error) {
284 dev_err(&data->spi->dev,
285 "Failed to register input device: %d", error);
286 return error;
287 }
288
289 return 0;
290}
291
292static int surface3_spi_create_pen_input(struct surface3_ts_data *data)
293{
294 struct input_dev *input;
295 int error;
296
297 input = devm_input_allocate_device(&data->spi->dev);
298 if (!input)
299 return -ENOMEM;
300
301 data->pen_input_dev = input;
302 data->pen_tool = BTN_TOOL_PEN;
303
304 __set_bit(INPUT_PROP_DIRECT, input->propbit);
305 __set_bit(INPUT_PROP_POINTER, input->propbit);
306 input_set_abs_params(input, ABS_X, 0, 9600, 0, 0);
307 input_abs_set_res(input, ABS_X, 40);
308 input_set_abs_params(input, ABS_Y, 0, 7200, 0, 0);
309 input_abs_set_res(input, ABS_Y, 48);
310 input_set_abs_params(input, ABS_PRESSURE, 0, 1024, 0, 0);
311 input_set_capability(input, EV_KEY, BTN_TOUCH);
312 input_set_capability(input, EV_KEY, BTN_STYLUS);
313 input_set_capability(input, EV_KEY, BTN_TOOL_PEN);
314 input_set_capability(input, EV_KEY, BTN_TOOL_RUBBER);
315
316 input->name = "Surface3 SPI Pen Input";
317 input->phys = "input/ts";
318 input->id.bustype = BUS_SPI;
319 input->id.vendor = 0x045e; /* Microsoft */
320 input->id.product = 0x0002;
321 input->id.version = 0x0000;
322
323 error = input_register_device(input);
324 if (error) {
325 dev_err(&data->spi->dev,
326 "Failed to register input device: %d", error);
327 return error;
328 }
329
330 return 0;
331}
332
333static int surface3_spi_probe(struct spi_device *spi)
334{
335 struct surface3_ts_data *data;
336 int error;
337
338 /* Set up SPI*/
339 spi->bits_per_word = 8;
340 spi->mode = SPI_MODE_0;
341 error = spi_setup(spi);
342 if (error)
343 return error;
344
345 data = devm_kzalloc(&spi->dev, sizeof(*data), GFP_KERNEL);
346 if (!data)
347 return -ENOMEM;
348
349 data->spi = spi;
350 spi_set_drvdata(spi, data);
351
352 error = surface3_spi_get_gpio_config(data);
353 if (error)
354 return error;
355
356 surface3_spi_power(data, true);
357 surface3_spi_power(data, false);
358 surface3_spi_power(data, true);
359
360 error = surface3_spi_create_touch_input(data);
361 if (error)
362 return error;
363
364 error = surface3_spi_create_pen_input(data);
365 if (error)
366 return error;
367
368 error = devm_request_threaded_irq(&spi->dev, spi->irq,
369 NULL, surface3_spi_irq_handler,
370 IRQF_ONESHOT,
371 "Surface3-irq", data);
372 if (error)
373 return error;
374
375 return 0;
376}
377
378static int __maybe_unused surface3_spi_suspend(struct device *dev)
379{
380 struct spi_device *spi = to_spi_device(dev);
381 struct surface3_ts_data *data = spi_get_drvdata(spi);
382
383 disable_irq(data->spi->irq);
384
385 surface3_spi_power(data, false);
386
387 return 0;
388}
389
390static int __maybe_unused surface3_spi_resume(struct device *dev)
391{
392 struct spi_device *spi = to_spi_device(dev);
393 struct surface3_ts_data *data = spi_get_drvdata(spi);
394
395 surface3_spi_power(data, true);
396
397 enable_irq(data->spi->irq);
398
399 return 0;
400}
401
402static SIMPLE_DEV_PM_OPS(surface3_spi_pm_ops,
403 surface3_spi_suspend,
404 surface3_spi_resume);
405
406#ifdef CONFIG_ACPI
407static const struct acpi_device_id surface3_spi_acpi_match[] = {
408 { "MSHW0037", 0 },
409 { }
410};
411MODULE_DEVICE_TABLE(acpi, surface3_spi_acpi_match);
412#endif
413
414static struct spi_driver surface3_spi_driver = {
415 .driver = {
416 .name = "Surface3-spi",
417 .acpi_match_table = ACPI_PTR(surface3_spi_acpi_match),
418 .pm = &surface3_spi_pm_ops,
419 },
420 .probe = surface3_spi_probe,
421};
422
423module_spi_driver(surface3_spi_driver);
424
425MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
426MODULE_DESCRIPTION("Surface 3 SPI touchscreen driver");
427MODULE_LICENSE("GPL v2");
428