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
 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	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
123static 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
160static 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
170static 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
197static 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
211static 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 * @ts: surface3_spi_ts_data pointer
223 */
224static 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
252static 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
288static 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
329static 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
374static 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
386static 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
398static SIMPLE_DEV_PM_OPS(surface3_spi_pm_ops,
399			 surface3_spi_suspend,
400			 surface3_spi_resume);
401
402#ifdef CONFIG_ACPI
403static const struct acpi_device_id surface3_spi_acpi_match[] = {
404	{ "MSHW0037", 0 },
405	{ }
406};
407MODULE_DEVICE_TABLE(acpi, surface3_spi_acpi_match);
408#endif
409
410static 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
419module_spi_driver(surface3_spi_driver);
420
421MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
422MODULE_DESCRIPTION("Surface 3 SPI touchscreen driver");
423MODULE_LICENSE("GPL v2");