1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Driver for ChipOne icn8505 i2c touchscreen controller
4 *
5 * Copyright (c) 2015-2018 Red Hat Inc.
6 *
7 * Red Hat authors:
8 * Hans de Goede <hdegoede@redhat.com>
9 */
10
11#include <asm/unaligned.h>
12#include <linux/acpi.h>
13#include <linux/crc32.h>
14#include <linux/delay.h>
15#include <linux/firmware.h>
16#include <linux/interrupt.h>
17#include <linux/i2c.h>
18#include <linux/input.h>
19#include <linux/input/mt.h>
20#include <linux/input/touchscreen.h>
21#include <linux/module.h>
22
23/* Normal operation mode defines */
24#define ICN8505_REG_ADDR_WIDTH 16
25
26#define ICN8505_REG_POWER 0x0004
27#define ICN8505_REG_TOUCHDATA 0x1000
28#define ICN8505_REG_CONFIGDATA 0x8000
29
30/* ICN8505_REG_POWER commands */
31#define ICN8505_POWER_ACTIVE 0x00
32#define ICN8505_POWER_MONITOR 0x01
33#define ICN8505_POWER_HIBERNATE 0x02
34/*
35 * The Android driver uses these to turn on/off the charger filter, but the
36 * filter is way too aggressive making e.g. onscreen keyboards unusable.
37 */
38#define ICN8505_POWER_ENA_CHARGER_MODE 0x55
39#define ICN8505_POWER_DIS_CHARGER_MODE 0x66
40
41#define ICN8505_MAX_TOUCHES 10
42
43/* Programming mode defines */
44#define ICN8505_PROG_I2C_ADDR 0x30
45#define ICN8505_PROG_REG_ADDR_WIDTH 24
46
47#define MAX_FW_UPLOAD_TRIES 3
48
49struct icn8505_touch {
50 u8 slot;
51 u8 x[2];
52 u8 y[2];
53 u8 pressure; /* Seems more like finger width then pressure really */
54 u8 event;
55/* The difference between 2 and 3 is unclear */
56#define ICN8505_EVENT_NO_DATA 1 /* No finger seen yet since wakeup */
57#define ICN8505_EVENT_UPDATE1 2 /* New or updated coordinates */
58#define ICN8505_EVENT_UPDATE2 3 /* New or updated coordinates */
59#define ICN8505_EVENT_END 4 /* Finger lifted */
60} __packed;
61
62struct icn8505_touch_data {
63 u8 softbutton;
64 u8 touch_count;
65 struct icn8505_touch touches[ICN8505_MAX_TOUCHES];
66} __packed;
67
68struct icn8505_data {
69 struct i2c_client *client;
70 struct input_dev *input;
71 struct gpio_desc *wake_gpio;
72 struct touchscreen_properties prop;
73 char firmware_name[32];
74};
75
76static int icn8505_read_xfer(struct i2c_client *client, u16 i2c_addr,
77 int reg_addr, int reg_addr_width,
78 void *data, int len, bool silent)
79{
80 u8 buf[3];
81 int i, ret;
82 struct i2c_msg msg[2] = {
83 {
84 .addr = i2c_addr,
85 .buf = buf,
86 .len = reg_addr_width / 8,
87 },
88 {
89 .addr = i2c_addr,
90 .flags = I2C_M_RD,
91 .buf = data,
92 .len = len,
93 }
94 };
95
96 for (i = 0; i < (reg_addr_width / 8); i++)
97 buf[i] = (reg_addr >> (reg_addr_width - (i + 1) * 8)) & 0xff;
98
99 ret = i2c_transfer(client->adapter, msg, 2);
100 if (ret != ARRAY_SIZE(msg)) {
101 if (ret >= 0)
102 ret = -EIO;
103 if (!silent)
104 dev_err(&client->dev,
105 "Error reading addr %#x reg %#x: %d\n",
106 i2c_addr, reg_addr, ret);
107 return ret;
108 }
109
110 return 0;
111}
112
113static int icn8505_write_xfer(struct i2c_client *client, u16 i2c_addr,
114 int reg_addr, int reg_addr_width,
115 const void *data, int len, bool silent)
116{
117 u8 buf[3 + 32]; /* 3 bytes for 24 bit reg-addr + 32 bytes max len */
118 int i, ret;
119 struct i2c_msg msg = {
120 .addr = i2c_addr,
121 .buf = buf,
122 .len = reg_addr_width / 8 + len,
123 };
124
125 if (WARN_ON(len > 32))
126 return -EINVAL;
127
128 for (i = 0; i < (reg_addr_width / 8); i++)
129 buf[i] = (reg_addr >> (reg_addr_width - (i + 1) * 8)) & 0xff;
130
131 memcpy(buf + reg_addr_width / 8, data, len);
132
133 ret = i2c_transfer(client->adapter, &msg, 1);
134 if (ret != 1) {
135 if (ret >= 0)
136 ret = -EIO;
137 if (!silent)
138 dev_err(&client->dev,
139 "Error writing addr %#x reg %#x: %d\n",
140 i2c_addr, reg_addr, ret);
141 return ret;
142 }
143
144 return 0;
145}
146
147static int icn8505_read_data(struct icn8505_data *icn8505, int reg,
148 void *buf, int len)
149{
150 return icn8505_read_xfer(icn8505->client, icn8505->client->addr, reg,
151 ICN8505_REG_ADDR_WIDTH, buf, len, false);
152}
153
154static int icn8505_read_reg_silent(struct icn8505_data *icn8505, int reg)
155{
156 u8 buf;
157 int error;
158
159 error = icn8505_read_xfer(icn8505->client, icn8505->client->addr, reg,
160 ICN8505_REG_ADDR_WIDTH, &buf, 1, true);
161 if (error)
162 return error;
163
164 return buf;
165}
166
167static int icn8505_write_reg(struct icn8505_data *icn8505, int reg, u8 val)
168{
169 return icn8505_write_xfer(icn8505->client, icn8505->client->addr, reg,
170 ICN8505_REG_ADDR_WIDTH, &val, 1, false);
171}
172
173static int icn8505_read_prog_data(struct icn8505_data *icn8505, int reg,
174 void *buf, int len)
175{
176 return icn8505_read_xfer(icn8505->client, ICN8505_PROG_I2C_ADDR, reg,
177 ICN8505_PROG_REG_ADDR_WIDTH, buf, len, false);
178}
179
180static int icn8505_write_prog_data(struct icn8505_data *icn8505, int reg,
181 const void *buf, int len)
182{
183 return icn8505_write_xfer(icn8505->client, ICN8505_PROG_I2C_ADDR, reg,
184 ICN8505_PROG_REG_ADDR_WIDTH, buf, len, false);
185}
186
187static int icn8505_write_prog_reg(struct icn8505_data *icn8505, int reg, u8 val)
188{
189 return icn8505_write_xfer(icn8505->client, ICN8505_PROG_I2C_ADDR, reg,
190 ICN8505_PROG_REG_ADDR_WIDTH, &val, 1, false);
191}
192
193/*
194 * Note this function uses a number of magic register addresses and values,
195 * there are deliberately no defines for these because the algorithm is taken
196 * from the icn85xx Android driver and I do not want to make up possibly wrong
197 * names for the addresses and/or values.
198 */
199static int icn8505_try_fw_upload(struct icn8505_data *icn8505,
200 const struct firmware *fw)
201{
202 struct device *dev = &icn8505->client->dev;
203 size_t offset, count;
204 int error;
205 u8 buf[4];
206 u32 crc;
207
208 /* Put the controller in programming mode */
209 error = icn8505_write_prog_reg(icn8505, 0xcc3355, 0x5a);
210 if (error)
211 return error;
212
213 usleep_range(2000, 5000);
214
215 error = icn8505_write_prog_reg(icn8505, 0x040400, 0x01);
216 if (error)
217 return error;
218
219 usleep_range(2000, 5000);
220
221 error = icn8505_read_prog_data(icn8505, 0x040002, buf, 1);
222 if (error)
223 return error;
224
225 if (buf[0] != 0x85) {
226 dev_err(dev, "Failed to enter programming mode\n");
227 return -ENODEV;
228 }
229
230 usleep_range(1000, 5000);
231
232 /* Enable CRC mode */
233 error = icn8505_write_prog_reg(icn8505, 0x40028, 1);
234 if (error)
235 return error;
236
237 /* Send the firmware to SRAM */
238 for (offset = 0; offset < fw->size; offset += count) {
239 count = min_t(size_t, fw->size - offset, 32);
240 error = icn8505_write_prog_data(icn8505, offset,
241 fw->data + offset, count);
242 if (error)
243 return error;
244 }
245
246 /* Disable CRC mode */
247 error = icn8505_write_prog_reg(icn8505, 0x40028, 0);
248 if (error)
249 return error;
250
251 /* Get and check length and CRC */
252 error = icn8505_read_prog_data(icn8505, 0x40034, buf, 2);
253 if (error)
254 return error;
255
256 if (get_unaligned_le16(buf) != fw->size) {
257 dev_warn(dev, "Length mismatch after uploading fw\n");
258 return -EIO;
259 }
260
261 error = icn8505_read_prog_data(icn8505, 0x4002c, buf, 4);
262 if (error)
263 return error;
264
265 crc = crc32_be(0, fw->data, fw->size);
266 if (get_unaligned_le32(buf) != crc) {
267 dev_warn(dev, "CRC mismatch after uploading fw\n");
268 return -EIO;
269 }
270
271 /* Boot controller from SRAM */
272 error = icn8505_write_prog_reg(icn8505, 0x40400, 0x03);
273 if (error)
274 return error;
275
276 usleep_range(2000, 5000);
277 return 0;
278}
279
280static int icn8505_upload_fw(struct icn8505_data *icn8505)
281{
282 struct device *dev = &icn8505->client->dev;
283 const struct firmware *fw;
284 int i, error;
285
286 /*
287 * Always load the firmware, even if we don't need it at boot, we
288 * we may need it at resume. Having loaded it once will make the
289 * firmware class code cache it at suspend/resume.
290 */
291 error = request_firmware(&fw, icn8505->firmware_name, dev);
292 if (error) {
293 dev_err(dev, "Firmware request error %d\n", error);
294 return error;
295 }
296
297 /* Check if the controller is not already up and running */
298 if (icn8505_read_reg_silent(icn8505, 0x000a) == 0x85)
299 goto success;
300
301 for (i = 1; i <= MAX_FW_UPLOAD_TRIES; i++) {
302 error = icn8505_try_fw_upload(icn8505, fw);
303 if (!error)
304 goto success;
305
306 dev_err(dev, "Failed to upload firmware: %d (attempt %d/%d)\n",
307 error, i, MAX_FW_UPLOAD_TRIES);
308 usleep_range(2000, 5000);
309 }
310
311success:
312 release_firmware(fw);
313 return error;
314}
315
316static bool icn8505_touch_active(u8 event)
317{
318 return event == ICN8505_EVENT_UPDATE1 ||
319 event == ICN8505_EVENT_UPDATE2;
320}
321
322static irqreturn_t icn8505_irq(int irq, void *dev_id)
323{
324 struct icn8505_data *icn8505 = dev_id;
325 struct device *dev = &icn8505->client->dev;
326 struct icn8505_touch_data touch_data;
327 int i, error;
328
329 error = icn8505_read_data(icn8505, ICN8505_REG_TOUCHDATA,
330 &touch_data, sizeof(touch_data));
331 if (error) {
332 dev_err(dev, "Error reading touch data: %d\n", error);
333 return IRQ_HANDLED;
334 }
335
336 if (touch_data.touch_count > ICN8505_MAX_TOUCHES) {
337 dev_warn(dev, "Too many touches %d > %d\n",
338 touch_data.touch_count, ICN8505_MAX_TOUCHES);
339 touch_data.touch_count = ICN8505_MAX_TOUCHES;
340 }
341
342 for (i = 0; i < touch_data.touch_count; i++) {
343 struct icn8505_touch *touch = &touch_data.touches[i];
344 bool act = icn8505_touch_active(touch->event);
345
346 input_mt_slot(icn8505->input, touch->slot);
347 input_mt_report_slot_state(icn8505->input, MT_TOOL_FINGER, act);
348 if (!act)
349 continue;
350
351 touchscreen_report_pos(icn8505->input, &icn8505->prop,
352 get_unaligned_le16(touch->x),
353 get_unaligned_le16(touch->y),
354 true);
355 }
356
357 input_mt_sync_frame(icn8505->input);
358 input_report_key(icn8505->input, KEY_LEFTMETA,
359 touch_data.softbutton == 1);
360 input_sync(icn8505->input);
361
362 return IRQ_HANDLED;
363}
364
365static int icn8505_probe_acpi(struct icn8505_data *icn8505, struct device *dev)
366{
367 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
368 const char *subsys = "unknown";
369 struct acpi_device *adev;
370 union acpi_object *obj;
371 acpi_status status;
372
373 adev = ACPI_COMPANION(dev);
374 if (!adev)
375 return -ENODEV;
376
377 status = acpi_evaluate_object(adev->handle, "_SUB", NULL, &buffer);
378 if (ACPI_SUCCESS(status)) {
379 obj = buffer.pointer;
380 if (obj->type == ACPI_TYPE_STRING)
381 subsys = obj->string.pointer;
382 else
383 dev_warn(dev, "Warning ACPI _SUB did not return a string\n");
384 } else {
385 dev_warn(dev, "Warning ACPI _SUB failed: %#x\n", status);
386 buffer.pointer = NULL;
387 }
388
389 snprintf(icn8505->firmware_name, sizeof(icn8505->firmware_name),
390 "chipone/icn8505-%s.fw", subsys);
391
392 kfree(buffer.pointer);
393 return 0;
394}
395
396static int icn8505_probe(struct i2c_client *client)
397{
398 struct device *dev = &client->dev;
399 struct icn8505_data *icn8505;
400 struct input_dev *input;
401 __le16 resolution[2];
402 int error;
403
404 if (!client->irq) {
405 dev_err(dev, "No irq specified\n");
406 return -EINVAL;
407 }
408
409 icn8505 = devm_kzalloc(dev, sizeof(*icn8505), GFP_KERNEL);
410 if (!icn8505)
411 return -ENOMEM;
412
413 input = devm_input_allocate_device(dev);
414 if (!input)
415 return -ENOMEM;
416
417 input->name = client->name;
418 input->id.bustype = BUS_I2C;
419
420 input_set_capability(input, EV_ABS, ABS_MT_POSITION_X);
421 input_set_capability(input, EV_ABS, ABS_MT_POSITION_Y);
422 input_set_capability(input, EV_KEY, KEY_LEFTMETA);
423
424 icn8505->client = client;
425 icn8505->input = input;
426 input_set_drvdata(input, icn8505);
427
428 error = icn8505_probe_acpi(icn8505, dev);
429 if (error)
430 return error;
431
432 error = icn8505_upload_fw(icn8505);
433 if (error)
434 return error;
435
436 error = icn8505_read_data(icn8505, ICN8505_REG_CONFIGDATA,
437 resolution, sizeof(resolution));
438 if (error) {
439 dev_err(dev, "Error reading resolution: %d\n", error);
440 return error;
441 }
442
443 input_set_abs_params(input, ABS_MT_POSITION_X, 0,
444 le16_to_cpu(resolution[0]) - 1, 0, 0);
445 input_set_abs_params(input, ABS_MT_POSITION_Y, 0,
446 le16_to_cpu(resolution[1]) - 1, 0, 0);
447
448 touchscreen_parse_properties(input, true, &icn8505->prop);
449 if (!input_abs_get_max(input, ABS_MT_POSITION_X) ||
450 !input_abs_get_max(input, ABS_MT_POSITION_Y)) {
451 dev_err(dev, "Error touchscreen-size-x and/or -y missing\n");
452 return -EINVAL;
453 }
454
455 error = input_mt_init_slots(input, ICN8505_MAX_TOUCHES,
456 INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
457 if (error)
458 return error;
459
460 error = devm_request_threaded_irq(dev, client->irq, NULL, icn8505_irq,
461 IRQF_ONESHOT, client->name, icn8505);
462 if (error) {
463 dev_err(dev, "Error requesting irq: %d\n", error);
464 return error;
465 }
466
467 error = input_register_device(input);
468 if (error)
469 return error;
470
471 i2c_set_clientdata(client, icn8505);
472 return 0;
473}
474
475static int __maybe_unused icn8505_suspend(struct device *dev)
476{
477 struct icn8505_data *icn8505 = i2c_get_clientdata(to_i2c_client(dev));
478
479 disable_irq(icn8505->client->irq);
480
481 icn8505_write_reg(icn8505, ICN8505_REG_POWER, ICN8505_POWER_HIBERNATE);
482
483 return 0;
484}
485
486static int __maybe_unused icn8505_resume(struct device *dev)
487{
488 struct icn8505_data *icn8505 = i2c_get_clientdata(to_i2c_client(dev));
489 int error;
490
491 error = icn8505_upload_fw(icn8505);
492 if (error)
493 return error;
494
495 enable_irq(icn8505->client->irq);
496 return 0;
497}
498
499static SIMPLE_DEV_PM_OPS(icn8505_pm_ops, icn8505_suspend, icn8505_resume);
500
501static const struct acpi_device_id icn8505_acpi_match[] = {
502 { "CHPN0001" },
503 { }
504};
505MODULE_DEVICE_TABLE(acpi, icn8505_acpi_match);
506
507static struct i2c_driver icn8505_driver = {
508 .driver = {
509 .name = "chipone_icn8505",
510 .pm = &icn8505_pm_ops,
511 .acpi_match_table = icn8505_acpi_match,
512 },
513 .probe_new = icn8505_probe,
514};
515
516module_i2c_driver(icn8505_driver);
517
518MODULE_DESCRIPTION("ChipOne icn8505 I2C Touchscreen Driver");
519MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
520MODULE_LICENSE("GPL");
521