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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Driver for Ntrig/Microsoft Touchscreens over SPI
4 *
5 * Copyright (c) 2016 Red Hat Inc.
6 */
7
8
9#include <linux/kernel.h>
10
11#include <linux/delay.h>
12#include <linux/gpio/consumer.h>
13#include <linux/input.h>
14#include <linux/input/mt.h>
15#include <linux/interrupt.h>
16#include <linux/module.h>
17#include <linux/slab.h>
18#include <linux/spi/spi.h>
19#include <linux/acpi.h>
20
21#include <linux/unaligned.h>
22
23#define SURFACE3_PACKET_SIZE 264
24
25#define SURFACE3_REPORT_TOUCH 0xd2
26#define SURFACE3_REPORT_PEN 0x16
27
28struct surface3_ts_data {
29 struct spi_device *spi;
30 struct gpio_desc *gpiod_rst[2];
31 struct input_dev *input_dev;
32 struct input_dev *pen_input_dev;
33 int pen_tool;
34
35 u8 rd_buf[SURFACE3_PACKET_SIZE] ____cacheline_aligned;
36};
37
38struct surface3_ts_data_finger {
39 u8 status;
40 __le16 tracking_id;
41 __le16 x;
42 __le16 cx;
43 __le16 y;
44 __le16 cy;
45 __le16 width;
46 __le16 height;
47 u32 padding;
48} __packed;
49
50struct surface3_ts_data_pen {
51 u8 status;
52 __le16 x;
53 __le16 y;
54 __le16 pressure;
55 u8 padding;
56} __packed;
57
58static int surface3_spi_read(struct surface3_ts_data *ts_data)
59{
60 struct spi_device *spi = ts_data->spi;
61
62 memset(ts_data->rd_buf, 0, sizeof(ts_data->rd_buf));
63 return spi_read(spi, ts_data->rd_buf, sizeof(ts_data->rd_buf));
64}
65
66static void surface3_spi_report_touch(struct surface3_ts_data *ts_data,
67 struct surface3_ts_data_finger *finger)
68{
69 int st = finger->status & 0x01;
70 int slot;
71
72 slot = input_mt_get_slot_by_key(ts_data->input_dev,
73 get_unaligned_le16(&finger->tracking_id));
74 if (slot < 0)
75 return;
76
77 input_mt_slot(ts_data->input_dev, slot);
78 input_mt_report_slot_state(ts_data->input_dev, MT_TOOL_FINGER, st);
79 if (st) {
80 input_report_abs(ts_data->input_dev,
81 ABS_MT_POSITION_X,
82 get_unaligned_le16(&finger->x));
83 input_report_abs(ts_data->input_dev,
84 ABS_MT_POSITION_Y,
85 get_unaligned_le16(&finger->y));
86 input_report_abs(ts_data->input_dev,
87 ABS_MT_WIDTH_MAJOR,
88 get_unaligned_le16(&finger->width));
89 input_report_abs(ts_data->input_dev,
90 ABS_MT_WIDTH_MINOR,
91 get_unaligned_le16(&finger->height));
92 }
93}
94
95static void surface3_spi_process_touch(struct surface3_ts_data *ts_data, u8 *data)
96{
97 unsigned int i;
98
99 for (i = 0; i < 13; i++) {
100 struct surface3_ts_data_finger *finger;
101
102 finger = (struct surface3_ts_data_finger *)&data[17 +
103 i * sizeof(struct surface3_ts_data_finger)];
104
105 /*
106 * When bit 5 of status is 1, it marks the end of the report:
107 * - touch present: 0xe7
108 * - touch released: 0xe4
109 * - nothing valuable: 0xff
110 */
111 if (finger->status & 0x10)
112 break;
113
114 surface3_spi_report_touch(ts_data, finger);
115 }
116
117 input_mt_sync_frame(ts_data->input_dev);
118 input_sync(ts_data->input_dev);
119}
120
121static void surface3_spi_report_pen(struct surface3_ts_data *ts_data,
122 struct surface3_ts_data_pen *pen)
123{
124 struct input_dev *dev = ts_data->pen_input_dev;
125 int st = pen->status;
126 int prox = st & 0x01;
127 int rubber = st & 0x18;
128 int tool = (prox && rubber) ? BTN_TOOL_RUBBER : BTN_TOOL_PEN;
129
130 /* fake proximity out to switch tools */
131 if (ts_data->pen_tool != tool) {
132 input_report_key(dev, ts_data->pen_tool, 0);
133 input_sync(dev);
134 ts_data->pen_tool = tool;
135 }
136
137 input_report_key(dev, BTN_TOUCH, st & 0x12);
138
139 input_report_key(dev, ts_data->pen_tool, prox);
140
141 if (st) {
142 input_report_key(dev,
143 BTN_STYLUS,
144 st & 0x04);
145
146 input_report_abs(dev,
147 ABS_X,
148 get_unaligned_le16(&pen->x));
149 input_report_abs(dev,
150 ABS_Y,
151 get_unaligned_le16(&pen->y));
152 input_report_abs(dev,
153 ABS_PRESSURE,
154 get_unaligned_le16(&pen->pressure));
155 }
156}
157
158static void surface3_spi_process_pen(struct surface3_ts_data *ts_data, u8 *data)
159{
160 struct surface3_ts_data_pen *pen;
161
162 pen = (struct surface3_ts_data_pen *)&data[15];
163
164 surface3_spi_report_pen(ts_data, pen);
165 input_sync(ts_data->pen_input_dev);
166}
167
168static void surface3_spi_process(struct surface3_ts_data *ts_data)
169{
170 static const char header[] = {
171 0xff, 0xff, 0xff, 0xff, 0xa5, 0x5a, 0xe7, 0x7e, 0x01
172 };
173 u8 *data = ts_data->rd_buf;
174
175 if (memcmp(header, data, sizeof(header)))
176 dev_err(&ts_data->spi->dev,
177 "%s header error: %*ph, ignoring...\n",
178 __func__, (int)sizeof(header), data);
179
180 switch (data[9]) {
181 case SURFACE3_REPORT_TOUCH:
182 surface3_spi_process_touch(ts_data, data);
183 break;
184 case SURFACE3_REPORT_PEN:
185 surface3_spi_process_pen(ts_data, data);
186 break;
187 default:
188 dev_err(&ts_data->spi->dev,
189 "%s unknown packet type: %x, ignoring...\n",
190 __func__, data[9]);
191 break;
192 }
193}
194
195static irqreturn_t surface3_spi_irq_handler(int irq, void *dev_id)
196{
197 struct surface3_ts_data *data = dev_id;
198
199 if (surface3_spi_read(data))
200 return IRQ_HANDLED;
201
202 dev_dbg(&data->spi->dev, "%s received -> %*ph\n",
203 __func__, SURFACE3_PACKET_SIZE, data->rd_buf);
204 surface3_spi_process(data);
205
206 return IRQ_HANDLED;
207}
208
209static void surface3_spi_power(struct surface3_ts_data *data, bool on)
210{
211 gpiod_set_value(data->gpiod_rst[0], on);
212 gpiod_set_value(data->gpiod_rst[1], on);
213 /* let the device settle a little */
214 msleep(20);
215}
216
217/**
218 * surface3_spi_get_gpio_config - Get GPIO config from ACPI/DT
219 *
220 * @data: surface3_spi_ts_data pointer
221 */
222static int surface3_spi_get_gpio_config(struct surface3_ts_data *data)
223{
224 struct device *dev;
225 struct gpio_desc *gpiod;
226 int i;
227
228 dev = &data->spi->dev;
229
230 /* Get the reset lines GPIO pin number */
231 for (i = 0; i < 2; i++) {
232 gpiod = devm_gpiod_get_index(dev, NULL, i, GPIOD_OUT_LOW);
233 if (IS_ERR(gpiod))
234 return dev_err_probe(dev, PTR_ERR(gpiod),
235 "Failed to get power GPIO %d\n", i);
236
237 data->gpiod_rst[i] = gpiod;
238 }
239
240 return 0;
241}
242
243static int surface3_spi_create_touch_input(struct surface3_ts_data *data)
244{
245 struct input_dev *input;
246 int error;
247
248 input = devm_input_allocate_device(&data->spi->dev);
249 if (!input)
250 return -ENOMEM;
251
252 data->input_dev = input;
253
254 input_set_abs_params(input, ABS_MT_POSITION_X, 0, 9600, 0, 0);
255 input_abs_set_res(input, ABS_MT_POSITION_X, 40);
256 input_set_abs_params(input, ABS_MT_POSITION_Y, 0, 7200, 0, 0);
257 input_abs_set_res(input, ABS_MT_POSITION_Y, 48);
258 input_set_abs_params(input, ABS_MT_WIDTH_MAJOR, 0, 1024, 0, 0);
259 input_set_abs_params(input, ABS_MT_WIDTH_MINOR, 0, 1024, 0, 0);
260 input_mt_init_slots(input, 10, INPUT_MT_DIRECT);
261
262 input->name = "Surface3 SPI Capacitive TouchScreen";
263 input->phys = "input/ts";
264 input->id.bustype = BUS_SPI;
265 input->id.vendor = 0x045e; /* Microsoft */
266 input->id.product = 0x0001;
267 input->id.version = 0x0000;
268
269 error = input_register_device(input);
270 if (error) {
271 dev_err(&data->spi->dev,
272 "Failed to register input device: %d", error);
273 return error;
274 }
275
276 return 0;
277}
278
279static int surface3_spi_create_pen_input(struct surface3_ts_data *data)
280{
281 struct input_dev *input;
282 int error;
283
284 input = devm_input_allocate_device(&data->spi->dev);
285 if (!input)
286 return -ENOMEM;
287
288 data->pen_input_dev = input;
289 data->pen_tool = BTN_TOOL_PEN;
290
291 __set_bit(INPUT_PROP_DIRECT, input->propbit);
292 __set_bit(INPUT_PROP_POINTER, input->propbit);
293 input_set_abs_params(input, ABS_X, 0, 9600, 0, 0);
294 input_abs_set_res(input, ABS_X, 40);
295 input_set_abs_params(input, ABS_Y, 0, 7200, 0, 0);
296 input_abs_set_res(input, ABS_Y, 48);
297 input_set_abs_params(input, ABS_PRESSURE, 0, 1024, 0, 0);
298 input_set_capability(input, EV_KEY, BTN_TOUCH);
299 input_set_capability(input, EV_KEY, BTN_STYLUS);
300 input_set_capability(input, EV_KEY, BTN_TOOL_PEN);
301 input_set_capability(input, EV_KEY, BTN_TOOL_RUBBER);
302
303 input->name = "Surface3 SPI Pen Input";
304 input->phys = "input/ts";
305 input->id.bustype = BUS_SPI;
306 input->id.vendor = 0x045e; /* Microsoft */
307 input->id.product = 0x0002;
308 input->id.version = 0x0000;
309
310 error = input_register_device(input);
311 if (error) {
312 dev_err(&data->spi->dev,
313 "Failed to register input device: %d", error);
314 return error;
315 }
316
317 return 0;
318}
319
320static int surface3_spi_probe(struct spi_device *spi)
321{
322 struct surface3_ts_data *data;
323 int error;
324
325 /* Set up SPI*/
326 spi->bits_per_word = 8;
327 spi->mode = SPI_MODE_0;
328 error = spi_setup(spi);
329 if (error)
330 return error;
331
332 data = devm_kzalloc(&spi->dev, sizeof(*data), GFP_KERNEL);
333 if (!data)
334 return -ENOMEM;
335
336 data->spi = spi;
337 spi_set_drvdata(spi, data);
338
339 error = surface3_spi_get_gpio_config(data);
340 if (error)
341 return error;
342
343 surface3_spi_power(data, true);
344 surface3_spi_power(data, false);
345 surface3_spi_power(data, true);
346
347 error = surface3_spi_create_touch_input(data);
348 if (error)
349 return error;
350
351 error = surface3_spi_create_pen_input(data);
352 if (error)
353 return error;
354
355 error = devm_request_threaded_irq(&spi->dev, spi->irq,
356 NULL, surface3_spi_irq_handler,
357 IRQF_ONESHOT,
358 "Surface3-irq", data);
359 if (error)
360 return error;
361
362 return 0;
363}
364
365static int surface3_spi_suspend(struct device *dev)
366{
367 struct spi_device *spi = to_spi_device(dev);
368 struct surface3_ts_data *data = spi_get_drvdata(spi);
369
370 disable_irq(data->spi->irq);
371
372 surface3_spi_power(data, false);
373
374 return 0;
375}
376
377static int surface3_spi_resume(struct device *dev)
378{
379 struct spi_device *spi = to_spi_device(dev);
380 struct surface3_ts_data *data = spi_get_drvdata(spi);
381
382 surface3_spi_power(data, true);
383
384 enable_irq(data->spi->irq);
385
386 return 0;
387}
388
389static DEFINE_SIMPLE_DEV_PM_OPS(surface3_spi_pm_ops,
390 surface3_spi_suspend,
391 surface3_spi_resume);
392
393#ifdef CONFIG_ACPI
394static const struct acpi_device_id surface3_spi_acpi_match[] = {
395 { "MSHW0037", 0 },
396 { }
397};
398MODULE_DEVICE_TABLE(acpi, surface3_spi_acpi_match);
399#endif
400
401static struct spi_driver surface3_spi_driver = {
402 .driver = {
403 .name = "Surface3-spi",
404 .acpi_match_table = ACPI_PTR(surface3_spi_acpi_match),
405 .pm = pm_sleep_ptr(&surface3_spi_pm_ops),
406 },
407 .probe = surface3_spi_probe,
408};
409
410module_spi_driver(surface3_spi_driver);
411
412MODULE_AUTHOR("Benjamin Tissoires <[email protected]>");
413MODULE_DESCRIPTION("Surface 3 SPI touchscreen driver");
414MODULE_LICENSE("GPL v2");