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9c92ab61 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
a485cb03 MP |
2 | /* |
3 | * Touch Screen driver for SiS 9200 family I2C Touch panels | |
4 | * | |
5 | * Copyright (C) 2015 SiS, Inc. | |
6 | * Copyright (C) 2016 Nextfour Group | |
a485cb03 MP |
7 | */ |
8 | ||
9 | #include <linux/crc-itu-t.h> | |
10 | #include <linux/delay.h> | |
11 | #include <linux/i2c.h> | |
12 | #include <linux/input.h> | |
13 | #include <linux/input/mt.h> | |
14 | #include <linux/interrupt.h> | |
15 | #include <linux/gpio/consumer.h> | |
16 | #include <linux/module.h> | |
17 | #include <linux/slab.h> | |
18 | #include <asm/unaligned.h> | |
19 | ||
20 | #define SIS_I2C_NAME "sis_i2c_ts" | |
21 | ||
22 | /* | |
23 | * The I2C packet format: | |
24 | * le16 byte count | |
25 | * u8 Report ID | |
26 | * <contact data - variable length> | |
27 | * u8 Number of contacts | |
28 | * le16 Scan Time (optional) | |
29 | * le16 CRC | |
30 | * | |
31 | * One touch point information consists of 6+ bytes, the order is: | |
32 | * u8 contact state | |
33 | * u8 finger id | |
34 | * le16 x axis | |
35 | * le16 y axis | |
36 | * u8 contact width (optional) | |
37 | * u8 contact height (optional) | |
38 | * u8 pressure (optional) | |
39 | * | |
40 | * Maximum amount of data transmitted in one shot is 64 bytes, if controller | |
41 | * needs to report more contacts than fit in one packet it will send true | |
42 | * number of contacts in first packet and 0 as number of contacts in second | |
43 | * packet. | |
44 | */ | |
45 | ||
46 | #define SIS_MAX_PACKET_SIZE 64 | |
47 | ||
48 | #define SIS_PKT_LEN_OFFSET 0 | |
49 | #define SIS_PKT_REPORT_OFFSET 2 /* Report ID/type */ | |
50 | #define SIS_PKT_CONTACT_OFFSET 3 /* First contact */ | |
51 | ||
52 | #define SIS_SCAN_TIME_LEN 2 | |
53 | ||
54 | /* Supported report types */ | |
55 | #define SIS_ALL_IN_ONE_PACKAGE 0x10 | |
56 | #define SIS_PKT_IS_TOUCH(x) (((x) & 0x0f) == 0x01) | |
57 | #define SIS_PKT_IS_HIDI2C(x) (((x) & 0x0f) == 0x06) | |
58 | ||
59 | /* Contact properties within report */ | |
60 | #define SIS_PKT_HAS_AREA(x) ((x) & BIT(4)) | |
61 | #define SIS_PKT_HAS_PRESSURE(x) ((x) & BIT(5)) | |
62 | #define SIS_PKT_HAS_SCANTIME(x) ((x) & BIT(6)) | |
63 | ||
64 | /* Contact size */ | |
65 | #define SIS_BASE_LEN_PER_CONTACT 6 | |
66 | #define SIS_AREA_LEN_PER_CONTACT 2 | |
67 | #define SIS_PRESSURE_LEN_PER_CONTACT 1 | |
68 | ||
69 | /* Offsets within contact data */ | |
70 | #define SIS_CONTACT_STATUS_OFFSET 0 | |
71 | #define SIS_CONTACT_ID_OFFSET 1 /* Contact ID */ | |
72 | #define SIS_CONTACT_X_OFFSET 2 | |
73 | #define SIS_CONTACT_Y_OFFSET 4 | |
74 | #define SIS_CONTACT_WIDTH_OFFSET 6 | |
75 | #define SIS_CONTACT_HEIGHT_OFFSET 7 | |
76 | #define SIS_CONTACT_PRESSURE_OFFSET(id) (SIS_PKT_HAS_AREA(id) ? 8 : 6) | |
77 | ||
78 | /* Individual contact state */ | |
79 | #define SIS_STATUS_UP 0x0 | |
80 | #define SIS_STATUS_DOWN 0x3 | |
81 | ||
82 | /* Touchscreen parameters */ | |
83 | #define SIS_MAX_FINGERS 10 | |
84 | #define SIS_MAX_X 4095 | |
85 | #define SIS_MAX_Y 4095 | |
86 | #define SIS_MAX_PRESSURE 255 | |
87 | ||
88 | /* Resolution diagonal */ | |
89 | #define SIS_AREA_LENGTH_LONGER 5792 | |
90 | /*((SIS_MAX_X^2) + (SIS_MAX_Y^2))^0.5*/ | |
91 | #define SIS_AREA_LENGTH_SHORT 5792 | |
92 | #define SIS_AREA_UNIT (5792 / 32) | |
93 | ||
94 | struct sis_ts_data { | |
95 | struct i2c_client *client; | |
96 | struct input_dev *input; | |
97 | ||
98 | struct gpio_desc *attn_gpio; | |
99 | struct gpio_desc *reset_gpio; | |
100 | ||
101 | u8 packet[SIS_MAX_PACKET_SIZE]; | |
102 | }; | |
103 | ||
104 | static int sis_read_packet(struct i2c_client *client, u8 *buf, | |
105 | unsigned int *num_contacts, | |
106 | unsigned int *contact_size) | |
107 | { | |
108 | int count_idx; | |
109 | int ret; | |
110 | u16 len; | |
111 | u16 crc, pkg_crc; | |
112 | u8 report_id; | |
113 | ||
114 | ret = i2c_master_recv(client, buf, SIS_MAX_PACKET_SIZE); | |
115 | if (ret <= 0) | |
116 | return -EIO; | |
117 | ||
118 | len = get_unaligned_le16(&buf[SIS_PKT_LEN_OFFSET]); | |
119 | if (len > SIS_MAX_PACKET_SIZE) { | |
120 | dev_err(&client->dev, | |
121 | "%s: invalid packet length (%d vs %d)\n", | |
122 | __func__, len, SIS_MAX_PACKET_SIZE); | |
123 | return -E2BIG; | |
124 | } | |
125 | ||
126 | if (len < 10) | |
127 | return -EINVAL; | |
128 | ||
129 | report_id = buf[SIS_PKT_REPORT_OFFSET]; | |
130 | count_idx = len - 1; | |
131 | *contact_size = SIS_BASE_LEN_PER_CONTACT; | |
132 | ||
133 | if (report_id != SIS_ALL_IN_ONE_PACKAGE) { | |
134 | if (SIS_PKT_IS_TOUCH(report_id)) { | |
135 | /* | |
136 | * Calculate CRC ignoring packet length | |
137 | * in the beginning and CRC transmitted | |
138 | * at the end of the packet. | |
139 | */ | |
140 | crc = crc_itu_t(0, buf + 2, len - 2 - 2); | |
141 | pkg_crc = get_unaligned_le16(&buf[len - 2]); | |
142 | ||
143 | if (crc != pkg_crc) { | |
144 | dev_err(&client->dev, | |
145 | "%s: CRC Error (%d vs %d)\n", | |
146 | __func__, crc, pkg_crc); | |
147 | return -EINVAL; | |
148 | } | |
149 | ||
150 | count_idx -= 2; | |
151 | ||
152 | } else if (!SIS_PKT_IS_HIDI2C(report_id)) { | |
153 | dev_err(&client->dev, | |
154 | "%s: invalid packet ID %#02x\n", | |
155 | __func__, report_id); | |
156 | return -EINVAL; | |
157 | } | |
158 | ||
159 | if (SIS_PKT_HAS_SCANTIME(report_id)) | |
160 | count_idx -= SIS_SCAN_TIME_LEN; | |
161 | ||
162 | if (SIS_PKT_HAS_AREA(report_id)) | |
163 | *contact_size += SIS_AREA_LEN_PER_CONTACT; | |
164 | if (SIS_PKT_HAS_PRESSURE(report_id)) | |
165 | *contact_size += SIS_PRESSURE_LEN_PER_CONTACT; | |
166 | } | |
167 | ||
168 | *num_contacts = buf[count_idx]; | |
169 | return 0; | |
170 | } | |
171 | ||
172 | static int sis_ts_report_contact(struct sis_ts_data *ts, const u8 *data, u8 id) | |
173 | { | |
174 | struct input_dev *input = ts->input; | |
175 | int slot; | |
176 | u8 status = data[SIS_CONTACT_STATUS_OFFSET]; | |
177 | u8 pressure; | |
178 | u8 height, width; | |
179 | u16 x, y; | |
180 | ||
181 | if (status != SIS_STATUS_DOWN && status != SIS_STATUS_UP) { | |
182 | dev_err(&ts->client->dev, "Unexpected touch status: %#02x\n", | |
183 | data[SIS_CONTACT_STATUS_OFFSET]); | |
184 | return -EINVAL; | |
185 | } | |
186 | ||
187 | slot = input_mt_get_slot_by_key(input, data[SIS_CONTACT_ID_OFFSET]); | |
188 | if (slot < 0) | |
189 | return -ENOENT; | |
190 | ||
191 | input_mt_slot(input, slot); | |
192 | input_mt_report_slot_state(input, MT_TOOL_FINGER, | |
193 | status == SIS_STATUS_DOWN); | |
194 | ||
195 | if (status == SIS_STATUS_DOWN) { | |
196 | pressure = height = width = 1; | |
197 | if (id != SIS_ALL_IN_ONE_PACKAGE) { | |
198 | if (SIS_PKT_HAS_AREA(id)) { | |
199 | width = data[SIS_CONTACT_WIDTH_OFFSET]; | |
200 | height = data[SIS_CONTACT_HEIGHT_OFFSET]; | |
201 | } | |
202 | ||
203 | if (SIS_PKT_HAS_PRESSURE(id)) | |
204 | pressure = | |
205 | data[SIS_CONTACT_PRESSURE_OFFSET(id)]; | |
206 | } | |
207 | ||
208 | x = get_unaligned_le16(&data[SIS_CONTACT_X_OFFSET]); | |
209 | y = get_unaligned_le16(&data[SIS_CONTACT_Y_OFFSET]); | |
210 | ||
211 | input_report_abs(input, ABS_MT_TOUCH_MAJOR, | |
212 | width * SIS_AREA_UNIT); | |
213 | input_report_abs(input, ABS_MT_TOUCH_MINOR, | |
214 | height * SIS_AREA_UNIT); | |
215 | input_report_abs(input, ABS_MT_PRESSURE, pressure); | |
216 | input_report_abs(input, ABS_MT_POSITION_X, x); | |
217 | input_report_abs(input, ABS_MT_POSITION_Y, y); | |
218 | } | |
219 | ||
220 | return 0; | |
221 | } | |
222 | ||
223 | static void sis_ts_handle_packet(struct sis_ts_data *ts) | |
224 | { | |
225 | const u8 *contact; | |
226 | unsigned int num_to_report = 0; | |
227 | unsigned int num_contacts; | |
228 | unsigned int num_reported; | |
229 | unsigned int contact_size; | |
230 | int error; | |
231 | u8 report_id; | |
232 | ||
233 | do { | |
234 | error = sis_read_packet(ts->client, ts->packet, | |
235 | &num_contacts, &contact_size); | |
236 | if (error) | |
237 | break; | |
238 | ||
239 | if (num_to_report == 0) { | |
240 | num_to_report = num_contacts; | |
241 | } else if (num_contacts != 0) { | |
242 | dev_err(&ts->client->dev, | |
243 | "%s: nonzero (%d) point count in tail packet\n", | |
244 | __func__, num_contacts); | |
245 | break; | |
246 | } | |
247 | ||
248 | report_id = ts->packet[SIS_PKT_REPORT_OFFSET]; | |
249 | contact = &ts->packet[SIS_PKT_CONTACT_OFFSET]; | |
250 | num_reported = 0; | |
251 | ||
252 | while (num_to_report > 0) { | |
253 | error = sis_ts_report_contact(ts, contact, report_id); | |
254 | if (error) | |
255 | break; | |
256 | ||
257 | contact += contact_size; | |
258 | num_to_report--; | |
259 | num_reported++; | |
260 | ||
261 | if (report_id != SIS_ALL_IN_ONE_PACKAGE && | |
262 | num_reported >= 5) { | |
263 | /* | |
264 | * The remainder of contacts is sent | |
265 | * in the 2nd packet. | |
266 | */ | |
267 | break; | |
268 | } | |
269 | } | |
270 | } while (num_to_report > 0); | |
271 | ||
272 | input_mt_sync_frame(ts->input); | |
273 | input_sync(ts->input); | |
274 | } | |
275 | ||
276 | static irqreturn_t sis_ts_irq_handler(int irq, void *dev_id) | |
277 | { | |
278 | struct sis_ts_data *ts = dev_id; | |
279 | ||
280 | do { | |
281 | sis_ts_handle_packet(ts); | |
282 | } while (ts->attn_gpio && gpiod_get_value_cansleep(ts->attn_gpio)); | |
283 | ||
284 | return IRQ_HANDLED; | |
285 | } | |
286 | ||
287 | static void sis_ts_reset(struct sis_ts_data *ts) | |
288 | { | |
289 | if (ts->reset_gpio) { | |
290 | /* Get out of reset */ | |
291 | usleep_range(1000, 2000); | |
292 | gpiod_set_value(ts->reset_gpio, 1); | |
293 | usleep_range(1000, 2000); | |
294 | gpiod_set_value(ts->reset_gpio, 0); | |
295 | msleep(100); | |
296 | } | |
297 | } | |
298 | ||
299 | static int sis_ts_probe(struct i2c_client *client, | |
300 | const struct i2c_device_id *id) | |
301 | { | |
302 | struct sis_ts_data *ts; | |
303 | struct input_dev *input; | |
304 | int error; | |
305 | ||
306 | ts = devm_kzalloc(&client->dev, sizeof(*ts), GFP_KERNEL); | |
307 | if (!ts) | |
308 | return -ENOMEM; | |
309 | ||
310 | ts->client = client; | |
a485cb03 MP |
311 | |
312 | ts->attn_gpio = devm_gpiod_get_optional(&client->dev, | |
313 | "attn", GPIOD_IN); | |
314 | if (IS_ERR(ts->attn_gpio)) { | |
315 | error = PTR_ERR(ts->attn_gpio); | |
316 | if (error != -EPROBE_DEFER) | |
317 | dev_err(&client->dev, | |
318 | "Failed to get attention GPIO: %d\n", error); | |
319 | return error; | |
320 | } | |
321 | ||
322 | ts->reset_gpio = devm_gpiod_get_optional(&client->dev, | |
323 | "reset", GPIOD_OUT_LOW); | |
324 | if (IS_ERR(ts->reset_gpio)) { | |
325 | error = PTR_ERR(ts->reset_gpio); | |
326 | if (error != -EPROBE_DEFER) | |
327 | dev_err(&client->dev, | |
328 | "Failed to get reset GPIO: %d\n", error); | |
329 | return error; | |
330 | } | |
331 | ||
332 | sis_ts_reset(ts); | |
333 | ||
334 | ts->input = input = devm_input_allocate_device(&client->dev); | |
335 | if (!input) { | |
336 | dev_err(&client->dev, "Failed to allocate input device\n"); | |
337 | return -ENOMEM; | |
338 | } | |
339 | ||
340 | input->name = "SiS Touchscreen"; | |
341 | input->id.bustype = BUS_I2C; | |
342 | ||
343 | input_set_abs_params(input, ABS_MT_POSITION_X, 0, SIS_MAX_X, 0, 0); | |
344 | input_set_abs_params(input, ABS_MT_POSITION_Y, 0, SIS_MAX_Y, 0, 0); | |
345 | input_set_abs_params(input, ABS_MT_PRESSURE, 0, SIS_MAX_PRESSURE, 0, 0); | |
346 | input_set_abs_params(input, ABS_MT_TOUCH_MAJOR, | |
347 | 0, SIS_AREA_LENGTH_LONGER, 0, 0); | |
348 | input_set_abs_params(input, ABS_MT_TOUCH_MINOR, | |
349 | 0, SIS_AREA_LENGTH_SHORT, 0, 0); | |
350 | ||
351 | error = input_mt_init_slots(input, SIS_MAX_FINGERS, INPUT_MT_DIRECT); | |
352 | if (error) { | |
353 | dev_err(&client->dev, | |
354 | "Failed to initialize MT slots: %d\n", error); | |
355 | return error; | |
356 | } | |
357 | ||
358 | error = devm_request_threaded_irq(&client->dev, client->irq, | |
359 | NULL, sis_ts_irq_handler, | |
360 | IRQF_ONESHOT, | |
361 | client->name, ts); | |
362 | if (error) { | |
363 | dev_err(&client->dev, "Failed to request IRQ: %d\n", error); | |
364 | return error; | |
365 | } | |
366 | ||
367 | error = input_register_device(ts->input); | |
368 | if (error) { | |
369 | dev_err(&client->dev, | |
370 | "Failed to register input device: %d\n", error); | |
371 | return error; | |
372 | } | |
373 | ||
374 | return 0; | |
375 | } | |
376 | ||
377 | #ifdef CONFIG_OF | |
378 | static const struct of_device_id sis_ts_dt_ids[] = { | |
379 | { .compatible = "sis,9200-ts" }, | |
380 | { /* sentinel */ } | |
381 | }; | |
382 | MODULE_DEVICE_TABLE(of, sis_ts_dt_ids); | |
383 | #endif | |
384 | ||
385 | static const struct i2c_device_id sis_ts_id[] = { | |
386 | { SIS_I2C_NAME, 0 }, | |
387 | { "9200-ts", 0 }, | |
388 | { /* sentinel */ } | |
389 | }; | |
390 | MODULE_DEVICE_TABLE(i2c, sis_ts_id); | |
391 | ||
392 | static struct i2c_driver sis_ts_driver = { | |
393 | .driver = { | |
394 | .name = SIS_I2C_NAME, | |
395 | .of_match_table = of_match_ptr(sis_ts_dt_ids), | |
396 | }, | |
397 | .probe = sis_ts_probe, | |
398 | .id_table = sis_ts_id, | |
399 | }; | |
400 | module_i2c_driver(sis_ts_driver); | |
401 | ||
402 | MODULE_DESCRIPTION("SiS 9200 Family Touchscreen Driver"); | |
403 | MODULE_LICENSE("GPL v2"); | |
404 | MODULE_AUTHOR("Mika Penttilä <mika.penttila@nextfour.com>"); |