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 	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 
121 static 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 
158 static 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 
168 static 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 
195 static 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 
209 static 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  */
222 static int surface3_spi_get_gpio_config(struct surface3_ts_data *data)
223 {
224 	int error;
225 	struct device *dev;
226 	struct gpio_desc *gpiod;
227 	int i;
228 
229 	dev = &data->spi->dev;
230 
231 	/* Get the reset lines GPIO pin number */
232 	for (i = 0; i < 2; i++) {
233 		gpiod = devm_gpiod_get_index(dev, NULL, i, GPIOD_OUT_LOW);
234 		if (IS_ERR(gpiod)) {
235 			error = PTR_ERR(gpiod);
236 			if (error != -EPROBE_DEFER)
237 				dev_err(dev,
238 					"Failed to get power GPIO %d: %d\n",
239 					i,
240 					error);
241 			return error;
242 		}
243 
244 		data->gpiod_rst[i] = gpiod;
245 	}
246 
247 	return 0;
248 }
249 
250 static int surface3_spi_create_touch_input(struct surface3_ts_data *data)
251 {
252 	struct input_dev *input;
253 	int error;
254 
255 	input = devm_input_allocate_device(&data->spi->dev);
256 	if (!input)
257 		return -ENOMEM;
258 
259 	data->input_dev = input;
260 
261 	input_set_abs_params(input, ABS_MT_POSITION_X, 0, 9600, 0, 0);
262 	input_abs_set_res(input, ABS_MT_POSITION_X, 40);
263 	input_set_abs_params(input, ABS_MT_POSITION_Y, 0, 7200, 0, 0);
264 	input_abs_set_res(input, ABS_MT_POSITION_Y, 48);
265 	input_set_abs_params(input, ABS_MT_WIDTH_MAJOR, 0, 1024, 0, 0);
266 	input_set_abs_params(input, ABS_MT_WIDTH_MINOR, 0, 1024, 0, 0);
267 	input_mt_init_slots(input, 10, INPUT_MT_DIRECT);
268 
269 	input->name = "Surface3 SPI Capacitive TouchScreen";
270 	input->phys = "input/ts";
271 	input->id.bustype = BUS_SPI;
272 	input->id.vendor = 0x045e;	/* Microsoft */
273 	input->id.product = 0x0001;
274 	input->id.version = 0x0000;
275 
276 	error = input_register_device(input);
277 	if (error) {
278 		dev_err(&data->spi->dev,
279 			"Failed to register input device: %d", error);
280 		return error;
281 	}
282 
283 	return 0;
284 }
285 
286 static int surface3_spi_create_pen_input(struct surface3_ts_data *data)
287 {
288 	struct input_dev *input;
289 	int error;
290 
291 	input = devm_input_allocate_device(&data->spi->dev);
292 	if (!input)
293 		return -ENOMEM;
294 
295 	data->pen_input_dev = input;
296 	data->pen_tool = BTN_TOOL_PEN;
297 
298 	__set_bit(INPUT_PROP_DIRECT, input->propbit);
299 	__set_bit(INPUT_PROP_POINTER, input->propbit);
300 	input_set_abs_params(input, ABS_X, 0, 9600, 0, 0);
301 	input_abs_set_res(input, ABS_X, 40);
302 	input_set_abs_params(input, ABS_Y, 0, 7200, 0, 0);
303 	input_abs_set_res(input, ABS_Y, 48);
304 	input_set_abs_params(input, ABS_PRESSURE, 0, 1024, 0, 0);
305 	input_set_capability(input, EV_KEY, BTN_TOUCH);
306 	input_set_capability(input, EV_KEY, BTN_STYLUS);
307 	input_set_capability(input, EV_KEY, BTN_TOOL_PEN);
308 	input_set_capability(input, EV_KEY, BTN_TOOL_RUBBER);
309 
310 	input->name = "Surface3 SPI Pen Input";
311 	input->phys = "input/ts";
312 	input->id.bustype = BUS_SPI;
313 	input->id.vendor = 0x045e;     /* Microsoft */
314 	input->id.product = 0x0002;
315 	input->id.version = 0x0000;
316 
317 	error = input_register_device(input);
318 	if (error) {
319 		dev_err(&data->spi->dev,
320 			"Failed to register input device: %d", error);
321 		return error;
322 	}
323 
324 	return 0;
325 }
326 
327 static int surface3_spi_probe(struct spi_device *spi)
328 {
329 	struct surface3_ts_data *data;
330 	int error;
331 
332 	/* Set up SPI*/
333 	spi->bits_per_word = 8;
334 	spi->mode = SPI_MODE_0;
335 	error = spi_setup(spi);
336 	if (error)
337 		return error;
338 
339 	data = devm_kzalloc(&spi->dev, sizeof(*data), GFP_KERNEL);
340 	if (!data)
341 		return -ENOMEM;
342 
343 	data->spi = spi;
344 	spi_set_drvdata(spi, data);
345 
346 	error = surface3_spi_get_gpio_config(data);
347 	if (error)
348 		return error;
349 
350 	surface3_spi_power(data, true);
351 	surface3_spi_power(data, false);
352 	surface3_spi_power(data, true);
353 
354 	error = surface3_spi_create_touch_input(data);
355 	if (error)
356 		return error;
357 
358 	error = surface3_spi_create_pen_input(data);
359 	if (error)
360 		return error;
361 
362 	error = devm_request_threaded_irq(&spi->dev, spi->irq,
363 					  NULL, surface3_spi_irq_handler,
364 					  IRQF_ONESHOT,
365 					  "Surface3-irq", data);
366 	if (error)
367 		return error;
368 
369 	return 0;
370 }
371 
372 static int surface3_spi_suspend(struct device *dev)
373 {
374 	struct spi_device *spi = to_spi_device(dev);
375 	struct surface3_ts_data *data = spi_get_drvdata(spi);
376 
377 	disable_irq(data->spi->irq);
378 
379 	surface3_spi_power(data, false);
380 
381 	return 0;
382 }
383 
384 static int surface3_spi_resume(struct device *dev)
385 {
386 	struct spi_device *spi = to_spi_device(dev);
387 	struct surface3_ts_data *data = spi_get_drvdata(spi);
388 
389 	surface3_spi_power(data, true);
390 
391 	enable_irq(data->spi->irq);
392 
393 	return 0;
394 }
395 
396 static DEFINE_SIMPLE_DEV_PM_OPS(surface3_spi_pm_ops,
397 				surface3_spi_suspend,
398 				surface3_spi_resume);
399 
400 #ifdef CONFIG_ACPI
401 static const struct acpi_device_id surface3_spi_acpi_match[] = {
402 	{ "MSHW0037", 0 },
403 	{ }
404 };
405 MODULE_DEVICE_TABLE(acpi, surface3_spi_acpi_match);
406 #endif
407 
408 static struct spi_driver surface3_spi_driver = {
409 	.driver = {
410 		.name	= "Surface3-spi",
411 		.acpi_match_table = ACPI_PTR(surface3_spi_acpi_match),
412 		.pm = pm_sleep_ptr(&surface3_spi_pm_ops),
413 	},
414 	.probe = surface3_spi_probe,
415 };
416 
417 module_spi_driver(surface3_spi_driver);
418 
419 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
420 MODULE_DESCRIPTION("Surface 3 SPI touchscreen driver");
421 MODULE_LICENSE("GPL v2");
422