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