1 /*
2 * HID over I2C protocol implementation
3 *
4 * Copyright (c) 2012 Benjamin Tissoires <benjamin.tissoires@gmail.com>
5 * Copyright (c) 2012 Ecole Nationale de l'Aviation Civile, France
6 * Copyright (c) 2012 Red Hat, Inc
7 *
8 * This code is partly based on "USB HID support for Linux":
9 *
10 * Copyright (c) 1999 Andreas Gal
11 * Copyright (c) 2000-2005 Vojtech Pavlik <vojtech@suse.cz>
12 * Copyright (c) 2005 Michael Haboustak <mike-@cinci.rr.com> for Concept2, Inc
13 * Copyright (c) 2007-2008 Oliver Neukum
14 * Copyright (c) 2006-2010 Jiri Kosina
15 *
16 * This file is subject to the terms and conditions of the GNU General Public
17 * License. See the file COPYING in the main directory of this archive for
18 * more details.
19 */
20
21 #include <linux/module.h>
22 #include <linux/i2c.h>
23 #include <linux/interrupt.h>
24 #include <linux/input.h>
25 #include <linux/irq.h>
26 #include <linux/delay.h>
27 #include <linux/slab.h>
28 #include <linux/pm.h>
29 #include <linux/pm_wakeirq.h>
30 #include <linux/device.h>
31 #include <linux/wait.h>
32 #include <linux/err.h>
33 #include <linux/string.h>
34 #include <linux/list.h>
35 #include <linux/jiffies.h>
36 #include <linux/kernel.h>
37 #include <linux/hid.h>
38 #include <linux/mutex.h>
39 #include <linux/unaligned.h>
40
41 #include <drm/drm_panel.h>
42
43 #include "../hid-ids.h"
44 #include "i2c-hid.h"
45
46 /* quirks to control the device */
47 #define I2C_HID_QUIRK_NO_IRQ_AFTER_RESET BIT(0)
48 #define I2C_HID_QUIRK_BOGUS_IRQ BIT(1)
49 #define I2C_HID_QUIRK_RESET_ON_RESUME BIT(2)
50 #define I2C_HID_QUIRK_BAD_INPUT_SIZE BIT(3)
51 #define I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET BIT(4)
52 #define I2C_HID_QUIRK_NO_SLEEP_ON_SUSPEND BIT(5)
53 #define I2C_HID_QUIRK_DELAY_WAKEUP_AFTER_RESUME BIT(6)
54
55 /* Command opcodes */
56 #define I2C_HID_OPCODE_RESET 0x01
57 #define I2C_HID_OPCODE_GET_REPORT 0x02
58 #define I2C_HID_OPCODE_SET_REPORT 0x03
59 #define I2C_HID_OPCODE_GET_IDLE 0x04
60 #define I2C_HID_OPCODE_SET_IDLE 0x05
61 #define I2C_HID_OPCODE_GET_PROTOCOL 0x06
62 #define I2C_HID_OPCODE_SET_PROTOCOL 0x07
63 #define I2C_HID_OPCODE_SET_POWER 0x08
64
65 /* flags */
66 #define I2C_HID_STARTED 0
67 #define I2C_HID_RESET_PENDING 1
68
69 #define I2C_HID_PWR_ON 0x00
70 #define I2C_HID_PWR_SLEEP 0x01
71
72 #define i2c_hid_dbg(ihid, ...) dev_dbg(&(ihid)->client->dev, __VA_ARGS__)
73
74 struct i2c_hid_desc {
75 __le16 wHIDDescLength;
76 __le16 bcdVersion;
77 __le16 wReportDescLength;
78 __le16 wReportDescRegister;
79 __le16 wInputRegister;
80 __le16 wMaxInputLength;
81 __le16 wOutputRegister;
82 __le16 wMaxOutputLength;
83 __le16 wCommandRegister;
84 __le16 wDataRegister;
85 __le16 wVendorID;
86 __le16 wProductID;
87 __le16 wVersionID;
88 __le32 reserved;
89 } __packed;
90
91 /* The main device structure */
92 struct i2c_hid {
93 struct i2c_client *client; /* i2c client */
94 struct hid_device *hid; /* pointer to corresponding HID dev */
95 struct i2c_hid_desc hdesc; /* the HID Descriptor */
96 __le16 wHIDDescRegister; /* location of the i2c
97 * register of the HID
98 * descriptor. */
99 unsigned int bufsize; /* i2c buffer size */
100 u8 *inbuf; /* Input buffer */
101 u8 *rawbuf; /* Raw Input buffer */
102 u8 *cmdbuf; /* Command buffer */
103
104 unsigned long flags; /* device flags */
105 unsigned long quirks; /* Various quirks */
106
107 wait_queue_head_t wait; /* For waiting the interrupt */
108
109 struct mutex cmd_lock; /* protects cmdbuf and rawbuf */
110 struct mutex reset_lock;
111
112 struct i2chid_ops *ops;
113 struct drm_panel_follower panel_follower;
114 struct work_struct panel_follower_prepare_work;
115 bool is_panel_follower;
116 bool prepare_work_finished;
117 };
118
119 static const struct i2c_hid_quirks {
120 __u16 idVendor;
121 __u16 idProduct;
122 __u32 quirks;
123 } i2c_hid_quirks[] = {
124 { I2C_VENDOR_ID_HANTICK, I2C_PRODUCT_ID_HANTICK_5288,
125 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
126 { I2C_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_VOYO_WINPAD_A15,
127 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
128 { I2C_VENDOR_ID_RAYDIUM, I2C_PRODUCT_ID_RAYDIUM_3118,
129 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
130 { USB_VENDOR_ID_ALPS_JP, HID_ANY_ID,
131 I2C_HID_QUIRK_RESET_ON_RESUME },
132 { I2C_VENDOR_ID_SYNAPTICS, I2C_PRODUCT_ID_SYNAPTICS_SYNA2393,
133 I2C_HID_QUIRK_RESET_ON_RESUME },
134 { USB_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_LENOVO_LEGION_Y720,
135 I2C_HID_QUIRK_BAD_INPUT_SIZE },
136 { I2C_VENDOR_ID_CIRQUE, I2C_PRODUCT_ID_CIRQUE_1063,
137 I2C_HID_QUIRK_NO_SLEEP_ON_SUSPEND },
138 /*
139 * Sending the wakeup after reset actually break ELAN touchscreen controller
140 */
141 { USB_VENDOR_ID_ELAN, HID_ANY_ID,
142 I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET |
143 I2C_HID_QUIRK_BOGUS_IRQ },
144 { I2C_VENDOR_ID_GOODIX, I2C_DEVICE_ID_GOODIX_0D42,
145 I2C_HID_QUIRK_DELAY_WAKEUP_AFTER_RESUME },
146 { 0, 0 }
147 };
148
149 /*
150 * i2c_hid_lookup_quirk: return any quirks associated with a I2C HID device
151 * @idVendor: the 16-bit vendor ID
152 * @idProduct: the 16-bit product ID
153 *
154 * Returns: a u32 quirks value.
155 */
i2c_hid_lookup_quirk(const u16 idVendor,const u16 idProduct)156 static u32 i2c_hid_lookup_quirk(const u16 idVendor, const u16 idProduct)
157 {
158 u32 quirks = 0;
159 int n;
160
161 for (n = 0; i2c_hid_quirks[n].idVendor; n++)
162 if (i2c_hid_quirks[n].idVendor == idVendor &&
163 (i2c_hid_quirks[n].idProduct == (__u16)HID_ANY_ID ||
164 i2c_hid_quirks[n].idProduct == idProduct))
165 quirks = i2c_hid_quirks[n].quirks;
166
167 return quirks;
168 }
169
i2c_hid_probe_address(struct i2c_hid * ihid)170 static int i2c_hid_probe_address(struct i2c_hid *ihid)
171 {
172 int ret;
173
174 /*
175 * Some STM-based devices need 400µs after a rising clock edge to wake
176 * from deep sleep, in which case the first read will fail. Try after a
177 * short sleep to see if the device came alive on the bus. Certain
178 * Weida Tech devices also need this.
179 */
180 ret = i2c_smbus_read_byte(ihid->client);
181 if (ret < 0) {
182 usleep_range(400, 500);
183 ret = i2c_smbus_read_byte(ihid->client);
184 }
185 return ret < 0 ? ret : 0;
186 }
187
i2c_hid_xfer(struct i2c_hid * ihid,u8 * send_buf,int send_len,u8 * recv_buf,int recv_len)188 static int i2c_hid_xfer(struct i2c_hid *ihid,
189 u8 *send_buf, int send_len, u8 *recv_buf, int recv_len)
190 {
191 struct i2c_client *client = ihid->client;
192 struct i2c_msg msgs[2] = { 0 };
193 int n = 0;
194 int ret;
195
196 if (send_len) {
197 i2c_hid_dbg(ihid, "%s: cmd=%*ph\n",
198 __func__, send_len, send_buf);
199
200 msgs[n].addr = client->addr;
201 msgs[n].flags = (client->flags & I2C_M_TEN) | I2C_M_DMA_SAFE;
202 msgs[n].len = send_len;
203 msgs[n].buf = send_buf;
204 n++;
205 }
206
207 if (recv_len) {
208 msgs[n].addr = client->addr;
209 msgs[n].flags = (client->flags & I2C_M_TEN) |
210 I2C_M_RD | I2C_M_DMA_SAFE;
211 msgs[n].len = recv_len;
212 msgs[n].buf = recv_buf;
213 n++;
214 }
215
216 ret = i2c_transfer(client->adapter, msgs, n);
217
218 if (ret != n)
219 return ret < 0 ? ret : -EIO;
220
221 return 0;
222 }
223
i2c_hid_read_register(struct i2c_hid * ihid,__le16 reg,void * buf,size_t len)224 static int i2c_hid_read_register(struct i2c_hid *ihid, __le16 reg,
225 void *buf, size_t len)
226 {
227 guard(mutex)(&ihid->cmd_lock);
228
229 *(__le16 *)ihid->cmdbuf = reg;
230
231 return i2c_hid_xfer(ihid, ihid->cmdbuf, sizeof(__le16), buf, len);
232 }
233
i2c_hid_encode_command(u8 * buf,u8 opcode,int report_type,int report_id)234 static size_t i2c_hid_encode_command(u8 *buf, u8 opcode,
235 int report_type, int report_id)
236 {
237 size_t length = 0;
238
239 if (report_id < 0x0F) {
240 buf[length++] = report_type << 4 | report_id;
241 buf[length++] = opcode;
242 } else {
243 buf[length++] = report_type << 4 | 0x0F;
244 buf[length++] = opcode;
245 buf[length++] = report_id;
246 }
247
248 return length;
249 }
250
i2c_hid_get_report(struct i2c_hid * ihid,u8 report_type,u8 report_id,u8 * recv_buf,size_t recv_len)251 static int i2c_hid_get_report(struct i2c_hid *ihid,
252 u8 report_type, u8 report_id,
253 u8 *recv_buf, size_t recv_len)
254 {
255 size_t length = 0;
256 size_t ret_count;
257 int error;
258
259 i2c_hid_dbg(ihid, "%s\n", __func__);
260
261 guard(mutex)(&ihid->cmd_lock);
262
263 /* Command register goes first */
264 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
265 length += sizeof(__le16);
266 /* Next is GET_REPORT command */
267 length += i2c_hid_encode_command(ihid->cmdbuf + length,
268 I2C_HID_OPCODE_GET_REPORT,
269 report_type, report_id);
270 /*
271 * Device will send report data through data register. Because
272 * command can be either 2 or 3 bytes destination for the data
273 * register may be not aligned.
274 */
275 put_unaligned_le16(le16_to_cpu(ihid->hdesc.wDataRegister),
276 ihid->cmdbuf + length);
277 length += sizeof(__le16);
278
279 /*
280 * In addition to report data device will supply data length
281 * in the first 2 bytes of the response, so adjust .
282 */
283 error = i2c_hid_xfer(ihid, ihid->cmdbuf, length,
284 ihid->rawbuf, recv_len + sizeof(__le16));
285 if (error) {
286 dev_err(&ihid->client->dev,
287 "failed to set a report to device: %d\n", error);
288 return error;
289 }
290
291 /* The buffer is sufficiently aligned */
292 ret_count = le16_to_cpup((__le16 *)ihid->rawbuf);
293
294 /* Check for empty report response */
295 if (ret_count <= sizeof(__le16))
296 return 0;
297
298 recv_len = min(recv_len, ret_count - sizeof(__le16));
299 memcpy(recv_buf, ihid->rawbuf + sizeof(__le16), recv_len);
300
301 if (report_id && recv_len != 0 && recv_buf[0] != report_id) {
302 dev_err(&ihid->client->dev,
303 "device returned incorrect report (%d vs %d expected)\n",
304 recv_buf[0], report_id);
305 return -EINVAL;
306 }
307
308 return recv_len;
309 }
310
i2c_hid_format_report(u8 * buf,int report_id,const u8 * data,size_t size)311 static size_t i2c_hid_format_report(u8 *buf, int report_id,
312 const u8 *data, size_t size)
313 {
314 size_t length = sizeof(__le16); /* reserve space to store size */
315
316 if (report_id)
317 buf[length++] = report_id;
318
319 memcpy(buf + length, data, size);
320 length += size;
321
322 /* Store overall size in the beginning of the buffer */
323 put_unaligned_le16(length, buf);
324
325 return length;
326 }
327
328 /**
329 * i2c_hid_set_or_send_report: forward an incoming report to the device
330 * @ihid: the i2c hid device
331 * @report_type: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT
332 * @report_id: the report ID
333 * @buf: the actual data to transfer, without the report ID
334 * @data_len: size of buf
335 * @do_set: true: use SET_REPORT HID command, false: send plain OUTPUT report
336 */
i2c_hid_set_or_send_report(struct i2c_hid * ihid,u8 report_type,u8 report_id,const u8 * buf,size_t data_len,bool do_set)337 static int i2c_hid_set_or_send_report(struct i2c_hid *ihid,
338 u8 report_type, u8 report_id,
339 const u8 *buf, size_t data_len,
340 bool do_set)
341 {
342 size_t length = 0;
343 int error;
344
345 i2c_hid_dbg(ihid, "%s\n", __func__);
346
347 if (data_len > ihid->bufsize)
348 return -EINVAL;
349
350 if (!do_set && le16_to_cpu(ihid->hdesc.wMaxOutputLength) == 0)
351 return -ENOSYS;
352
353 guard(mutex)(&ihid->cmd_lock);
354
355 if (do_set) {
356 /* Command register goes first */
357 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
358 length += sizeof(__le16);
359 /* Next is SET_REPORT command */
360 length += i2c_hid_encode_command(ihid->cmdbuf + length,
361 I2C_HID_OPCODE_SET_REPORT,
362 report_type, report_id);
363 /*
364 * Report data will go into the data register. Because
365 * command can be either 2 or 3 bytes destination for
366 * the data register may be not aligned.
367 */
368 put_unaligned_le16(le16_to_cpu(ihid->hdesc.wDataRegister),
369 ihid->cmdbuf + length);
370 length += sizeof(__le16);
371 } else {
372 /*
373 * With simple "send report" all data goes into the output
374 * register.
375 */
376 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wOutputRegister;
377 length += sizeof(__le16);
378 }
379
380 length += i2c_hid_format_report(ihid->cmdbuf + length,
381 report_id, buf, data_len);
382
383 error = i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0);
384 if (error) {
385 dev_err(&ihid->client->dev,
386 "failed to set a report to device: %d\n", error);
387 return error;
388 }
389
390 return data_len;
391 }
392
i2c_hid_set_power_command(struct i2c_hid * ihid,int power_state)393 static int i2c_hid_set_power_command(struct i2c_hid *ihid, int power_state)
394 {
395 size_t length;
396
397 guard(mutex)(&ihid->cmd_lock);
398
399 /* SET_POWER uses command register */
400 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
401 length = sizeof(__le16);
402
403 /* Now the command itself */
404 length += i2c_hid_encode_command(ihid->cmdbuf + length,
405 I2C_HID_OPCODE_SET_POWER,
406 0, power_state);
407
408 return i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0);
409 }
410
i2c_hid_set_power(struct i2c_hid * ihid,int power_state)411 static int i2c_hid_set_power(struct i2c_hid *ihid, int power_state)
412 {
413 int ret;
414
415 i2c_hid_dbg(ihid, "%s\n", __func__);
416
417 /*
418 * Some STM-based devices need 400µs after a rising clock edge to wake
419 * from deep sleep, in which case the first request will fail due to
420 * the address not being acknowledged. Try after a short sleep to see
421 * if the device came alive on the bus. Certain Weida Tech devices also
422 * need this.
423 */
424 ret = i2c_hid_set_power_command(ihid, power_state);
425 if (ret && power_state == I2C_HID_PWR_ON) {
426 usleep_range(400, 500);
427 ret = i2c_hid_set_power_command(ihid, I2C_HID_PWR_ON);
428 }
429
430 if (ret)
431 dev_err(&ihid->client->dev,
432 "failed to change power setting.\n");
433
434 /*
435 * The HID over I2C specification states that if a DEVICE needs time
436 * after the PWR_ON request, it should utilise CLOCK stretching.
437 * However, it has been observered that the Windows driver provides a
438 * 1ms sleep between the PWR_ON and RESET requests.
439 * According to Goodix Windows even waits 60 ms after (other?)
440 * PWR_ON requests. Testing has confirmed that several devices
441 * will not work properly without a delay after a PWR_ON request.
442 */
443 if (!ret && power_state == I2C_HID_PWR_ON)
444 msleep(60);
445
446 return ret;
447 }
448
i2c_hid_start_hwreset(struct i2c_hid * ihid)449 static int i2c_hid_start_hwreset(struct i2c_hid *ihid)
450 {
451 size_t length = 0;
452 int ret;
453
454 i2c_hid_dbg(ihid, "%s\n", __func__);
455
456 /*
457 * This prevents sending feature reports while the device is
458 * being reset. Otherwise we may lose the reset complete
459 * interrupt.
460 */
461 lockdep_assert_held(&ihid->reset_lock);
462
463 ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
464 if (ret)
465 return ret;
466
467 scoped_guard(mutex, &ihid->cmd_lock) {
468 /* Prepare reset command. Command register goes first. */
469 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
470 length += sizeof(__le16);
471 /* Next is RESET command itself */
472 length += i2c_hid_encode_command(ihid->cmdbuf + length,
473 I2C_HID_OPCODE_RESET, 0, 0);
474
475 set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
476
477 ret = i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0);
478 if (ret) {
479 dev_err(&ihid->client->dev,
480 "failed to reset device: %d\n", ret);
481 break;
482 }
483
484 return 0;
485 }
486
487 /* Clean up if sending reset command failed */
488 clear_bit(I2C_HID_RESET_PENDING, &ihid->flags);
489 i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
490 return ret;
491 }
492
i2c_hid_finish_hwreset(struct i2c_hid * ihid)493 static int i2c_hid_finish_hwreset(struct i2c_hid *ihid)
494 {
495 int ret = 0;
496
497 i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
498
499 if (ihid->quirks & I2C_HID_QUIRK_NO_IRQ_AFTER_RESET) {
500 msleep(100);
501 clear_bit(I2C_HID_RESET_PENDING, &ihid->flags);
502 } else if (!wait_event_timeout(ihid->wait,
503 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
504 msecs_to_jiffies(1000))) {
505 dev_warn(&ihid->client->dev, "device did not ack reset within 1000 ms\n");
506 clear_bit(I2C_HID_RESET_PENDING, &ihid->flags);
507 }
508 i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
509
510 /* At least some SIS devices need this after reset */
511 if (!(ihid->quirks & I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET))
512 ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
513
514 return ret;
515 }
516
i2c_hid_get_input(struct i2c_hid * ihid)517 static void i2c_hid_get_input(struct i2c_hid *ihid)
518 {
519 u16 size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
520 u16 ret_size;
521 int ret;
522
523 if (size > ihid->bufsize)
524 size = ihid->bufsize;
525
526 ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
527 if (ret != size) {
528 if (ret < 0)
529 return;
530
531 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
532 __func__, ret, size);
533 return;
534 }
535
536 /* Receiving buffer is properly aligned */
537 ret_size = le16_to_cpup((__le16 *)ihid->inbuf);
538 if (!ret_size) {
539 /* host or device initiated RESET completed */
540 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
541 wake_up(&ihid->wait);
542 return;
543 }
544
545 if ((ihid->quirks & I2C_HID_QUIRK_BOGUS_IRQ) && ret_size == 0xffff) {
546 dev_warn_once(&ihid->client->dev,
547 "%s: IRQ triggered but there's no data\n",
548 __func__);
549 return;
550 }
551
552 if (ret_size > size || ret_size < sizeof(__le16)) {
553 if (ihid->quirks & I2C_HID_QUIRK_BAD_INPUT_SIZE) {
554 *(__le16 *)ihid->inbuf = cpu_to_le16(size);
555 ret_size = size;
556 } else {
557 dev_err(&ihid->client->dev,
558 "%s: incomplete report (%d/%d)\n",
559 __func__, size, ret_size);
560 return;
561 }
562 }
563
564 i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
565
566 if (test_bit(I2C_HID_STARTED, &ihid->flags)) {
567 if (ihid->hid->group != HID_GROUP_RMI)
568 pm_wakeup_event(&ihid->client->dev, 0);
569
570 hid_input_report(ihid->hid, HID_INPUT_REPORT,
571 ihid->inbuf + sizeof(__le16),
572 ret_size - sizeof(__le16), 1);
573 }
574
575 return;
576 }
577
i2c_hid_irq(int irq,void * dev_id)578 static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
579 {
580 struct i2c_hid *ihid = dev_id;
581
582 i2c_hid_get_input(ihid);
583
584 return IRQ_HANDLED;
585 }
586
i2c_hid_get_report_length(struct hid_report * report)587 static int i2c_hid_get_report_length(struct hid_report *report)
588 {
589 return ((report->size - 1) >> 3) + 1 +
590 report->device->report_enum[report->type].numbered + 2;
591 }
592
593 /*
594 * Traverse the supplied list of reports and find the longest
595 */
i2c_hid_find_max_report(struct hid_device * hid,unsigned int type,unsigned int * max)596 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
597 unsigned int *max)
598 {
599 struct hid_report *report;
600 unsigned int size;
601
602 /* We should not rely on wMaxInputLength, as some devices may set it to
603 * a wrong length. */
604 list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
605 size = i2c_hid_get_report_length(report);
606 if (*max < size)
607 *max = size;
608 }
609 }
610
i2c_hid_free_buffers(struct i2c_hid * ihid)611 static void i2c_hid_free_buffers(struct i2c_hid *ihid)
612 {
613 kfree(ihid->inbuf);
614 kfree(ihid->rawbuf);
615 kfree(ihid->cmdbuf);
616 ihid->inbuf = NULL;
617 ihid->rawbuf = NULL;
618 ihid->cmdbuf = NULL;
619 ihid->bufsize = 0;
620 }
621
i2c_hid_alloc_buffers(struct i2c_hid * ihid,size_t report_size)622 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
623 {
624 /*
625 * The worst case is computed from the set_report command with a
626 * reportID > 15 and the maximum report length.
627 */
628 int cmd_len = sizeof(__le16) + /* command register */
629 sizeof(u8) + /* encoded report type/ID */
630 sizeof(u8) + /* opcode */
631 sizeof(u8) + /* optional 3rd byte report ID */
632 sizeof(__le16) + /* data register */
633 sizeof(__le16) + /* report data size */
634 sizeof(u8) + /* report ID if numbered report */
635 report_size;
636
637 ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
638 ihid->rawbuf = kzalloc(report_size, GFP_KERNEL);
639 ihid->cmdbuf = kzalloc(cmd_len, GFP_KERNEL);
640
641 if (!ihid->inbuf || !ihid->rawbuf || !ihid->cmdbuf) {
642 i2c_hid_free_buffers(ihid);
643 return -ENOMEM;
644 }
645
646 ihid->bufsize = report_size;
647
648 return 0;
649 }
650
i2c_hid_get_raw_report(struct hid_device * hid,u8 report_type,u8 report_id,u8 * buf,size_t count)651 static int i2c_hid_get_raw_report(struct hid_device *hid,
652 u8 report_type, u8 report_id,
653 u8 *buf, size_t count)
654 {
655 struct i2c_client *client = hid->driver_data;
656 struct i2c_hid *ihid = i2c_get_clientdata(client);
657 int ret_count;
658
659 if (report_type == HID_OUTPUT_REPORT)
660 return -EINVAL;
661
662 /*
663 * In case of unnumbered reports the response from the device will
664 * not have the report ID that the upper layers expect, so we need
665 * to stash it the buffer ourselves and adjust the data size.
666 */
667 if (!report_id) {
668 buf[0] = 0;
669 buf++;
670 count--;
671 }
672
673 ret_count = i2c_hid_get_report(ihid,
674 report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
675 report_id, buf, count);
676
677 if (ret_count > 0 && !report_id)
678 ret_count++;
679
680 return ret_count;
681 }
682
i2c_hid_output_raw_report(struct hid_device * hid,u8 report_type,const u8 * buf,size_t count,bool do_set)683 static int i2c_hid_output_raw_report(struct hid_device *hid, u8 report_type,
684 const u8 *buf, size_t count, bool do_set)
685 {
686 struct i2c_client *client = hid->driver_data;
687 struct i2c_hid *ihid = i2c_get_clientdata(client);
688 int report_id = buf[0];
689 int ret;
690
691 if (report_type == HID_INPUT_REPORT)
692 return -EINVAL;
693
694 mutex_lock(&ihid->reset_lock);
695
696 /*
697 * Note that both numbered and unnumbered reports passed here
698 * are supposed to have report ID stored in the 1st byte of the
699 * buffer, so we strip it off unconditionally before passing payload
700 * to i2c_hid_set_or_send_report which takes care of encoding
701 * everything properly.
702 */
703 ret = i2c_hid_set_or_send_report(ihid,
704 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
705 report_id, buf + 1, count - 1, do_set);
706
707 if (ret >= 0)
708 ret++; /* add report_id to the number of transferred bytes */
709
710 mutex_unlock(&ihid->reset_lock);
711
712 return ret;
713 }
714
i2c_hid_output_report(struct hid_device * hid,u8 * buf,size_t count)715 static int i2c_hid_output_report(struct hid_device *hid, u8 *buf, size_t count)
716 {
717 return i2c_hid_output_raw_report(hid, HID_OUTPUT_REPORT, buf, count,
718 false);
719 }
720
i2c_hid_raw_request(struct hid_device * hid,unsigned char reportnum,__u8 * buf,size_t len,unsigned char rtype,int reqtype)721 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
722 __u8 *buf, size_t len, unsigned char rtype,
723 int reqtype)
724 {
725 switch (reqtype) {
726 case HID_REQ_GET_REPORT:
727 return i2c_hid_get_raw_report(hid, rtype, reportnum, buf, len);
728 case HID_REQ_SET_REPORT:
729 if (buf[0] != reportnum)
730 return -EINVAL;
731 return i2c_hid_output_raw_report(hid, rtype, buf, len, true);
732 default:
733 return -EIO;
734 }
735 }
736
i2c_hid_parse(struct hid_device * hid)737 static int i2c_hid_parse(struct hid_device *hid)
738 {
739 struct i2c_client *client = hid->driver_data;
740 struct i2c_hid *ihid = i2c_get_clientdata(client);
741 struct i2c_hid_desc *hdesc = &ihid->hdesc;
742 char *rdesc = NULL, *use_override = NULL;
743 unsigned int rsize;
744 int ret;
745 int tries = 3;
746
747 i2c_hid_dbg(ihid, "entering %s\n", __func__);
748
749 rsize = le16_to_cpu(hdesc->wReportDescLength);
750 if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
751 dbg_hid("weird size of report descriptor (%u)\n", rsize);
752 return -EINVAL;
753 }
754
755 mutex_lock(&ihid->reset_lock);
756 do {
757 ret = i2c_hid_start_hwreset(ihid);
758 if (ret == 0)
759 ret = i2c_hid_finish_hwreset(ihid);
760 else
761 msleep(1000);
762 } while (tries-- > 0 && ret);
763 mutex_unlock(&ihid->reset_lock);
764
765 if (ret)
766 return ret;
767
768 use_override = i2c_hid_get_dmi_hid_report_desc_override(client->name,
769 &rsize);
770
771 if (use_override) {
772 rdesc = use_override;
773 i2c_hid_dbg(ihid, "Using a HID report descriptor override\n");
774 } else {
775 rdesc = kzalloc(rsize, GFP_KERNEL);
776 if (!rdesc)
777 return -ENOMEM;
778
779 i2c_hid_dbg(ihid, "asking HID report descriptor\n");
780
781 ret = i2c_hid_read_register(ihid,
782 ihid->hdesc.wReportDescRegister,
783 rdesc, rsize);
784 if (ret) {
785 hid_err(hid, "reading report descriptor failed\n");
786 goto out;
787 }
788 }
789
790 i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
791
792 ret = hid_parse_report(hid, rdesc, rsize);
793 if (ret)
794 dbg_hid("parsing report descriptor failed\n");
795
796 out:
797 if (!use_override)
798 kfree(rdesc);
799
800 return ret;
801 }
802
i2c_hid_start(struct hid_device * hid)803 static int i2c_hid_start(struct hid_device *hid)
804 {
805 struct i2c_client *client = hid->driver_data;
806 struct i2c_hid *ihid = i2c_get_clientdata(client);
807 int ret;
808 unsigned int bufsize = HID_MIN_BUFFER_SIZE;
809
810 i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
811 i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
812 i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
813
814 if (bufsize > ihid->bufsize) {
815 disable_irq(client->irq);
816 i2c_hid_free_buffers(ihid);
817
818 ret = i2c_hid_alloc_buffers(ihid, bufsize);
819 enable_irq(client->irq);
820
821 if (ret)
822 return ret;
823 }
824
825 return 0;
826 }
827
i2c_hid_stop(struct hid_device * hid)828 static void i2c_hid_stop(struct hid_device *hid)
829 {
830 hid->claimed = 0;
831 }
832
i2c_hid_open(struct hid_device * hid)833 static int i2c_hid_open(struct hid_device *hid)
834 {
835 struct i2c_client *client = hid->driver_data;
836 struct i2c_hid *ihid = i2c_get_clientdata(client);
837
838 set_bit(I2C_HID_STARTED, &ihid->flags);
839 return 0;
840 }
841
i2c_hid_close(struct hid_device * hid)842 static void i2c_hid_close(struct hid_device *hid)
843 {
844 struct i2c_client *client = hid->driver_data;
845 struct i2c_hid *ihid = i2c_get_clientdata(client);
846
847 clear_bit(I2C_HID_STARTED, &ihid->flags);
848 }
849
850 static const struct hid_ll_driver i2c_hid_ll_driver = {
851 .parse = i2c_hid_parse,
852 .start = i2c_hid_start,
853 .stop = i2c_hid_stop,
854 .open = i2c_hid_open,
855 .close = i2c_hid_close,
856 .output_report = i2c_hid_output_report,
857 .raw_request = i2c_hid_raw_request,
858 };
859
i2c_hid_init_irq(struct i2c_client * client)860 static int i2c_hid_init_irq(struct i2c_client *client)
861 {
862 struct i2c_hid *ihid = i2c_get_clientdata(client);
863 unsigned long irqflags = 0;
864 int ret;
865
866 i2c_hid_dbg(ihid, "Requesting IRQ: %d\n", client->irq);
867
868 if (!irq_get_trigger_type(client->irq))
869 irqflags = IRQF_TRIGGER_LOW;
870
871 ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq,
872 irqflags | IRQF_ONESHOT | IRQF_NO_AUTOEN,
873 client->name, ihid);
874 if (ret < 0) {
875 dev_warn(&client->dev,
876 "Could not register for %s interrupt, irq = %d,"
877 " ret = %d\n",
878 client->name, client->irq, ret);
879
880 return ret;
881 }
882
883 return 0;
884 }
885
i2c_hid_fetch_hid_descriptor(struct i2c_hid * ihid)886 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
887 {
888 struct i2c_client *client = ihid->client;
889 struct i2c_hid_desc *hdesc = &ihid->hdesc;
890 unsigned int dsize;
891 int error;
892
893 /* i2c hid fetch using a fixed descriptor size (30 bytes) */
894 if (i2c_hid_get_dmi_i2c_hid_desc_override(client->name)) {
895 i2c_hid_dbg(ihid, "Using a HID descriptor override\n");
896 ihid->hdesc =
897 *i2c_hid_get_dmi_i2c_hid_desc_override(client->name);
898 } else {
899 i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
900 error = i2c_hid_read_register(ihid,
901 ihid->wHIDDescRegister,
902 &ihid->hdesc,
903 sizeof(ihid->hdesc));
904 if (error) {
905 dev_err(&ihid->client->dev,
906 "failed to fetch HID descriptor: %d\n",
907 error);
908 return -ENODEV;
909 }
910 }
911
912 /* Validate the length of HID descriptor, the 4 first bytes:
913 * bytes 0-1 -> length
914 * bytes 2-3 -> bcdVersion (has to be 1.00) */
915 /* check bcdVersion == 1.0 */
916 if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
917 dev_err(&ihid->client->dev,
918 "unexpected HID descriptor bcdVersion (0x%04hx)\n",
919 le16_to_cpu(hdesc->bcdVersion));
920 return -ENODEV;
921 }
922
923 /* Descriptor length should be 30 bytes as per the specification */
924 dsize = le16_to_cpu(hdesc->wHIDDescLength);
925 if (dsize != sizeof(struct i2c_hid_desc)) {
926 dev_err(&ihid->client->dev,
927 "weird size of HID descriptor (%u)\n", dsize);
928 return -ENODEV;
929 }
930 i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, &ihid->hdesc);
931 return 0;
932 }
933
i2c_hid_core_power_up(struct i2c_hid * ihid)934 static int i2c_hid_core_power_up(struct i2c_hid *ihid)
935 {
936 if (!ihid->ops->power_up)
937 return 0;
938
939 return ihid->ops->power_up(ihid->ops);
940 }
941
i2c_hid_core_power_down(struct i2c_hid * ihid)942 static void i2c_hid_core_power_down(struct i2c_hid *ihid)
943 {
944 if (!ihid->ops->power_down)
945 return;
946
947 ihid->ops->power_down(ihid->ops);
948 }
949
i2c_hid_core_shutdown_tail(struct i2c_hid * ihid)950 static void i2c_hid_core_shutdown_tail(struct i2c_hid *ihid)
951 {
952 if (!ihid->ops->shutdown_tail)
953 return;
954
955 ihid->ops->shutdown_tail(ihid->ops);
956 }
957
i2c_hid_core_suspend(struct i2c_hid * ihid,bool force_poweroff)958 static int i2c_hid_core_suspend(struct i2c_hid *ihid, bool force_poweroff)
959 {
960 struct i2c_client *client = ihid->client;
961 struct hid_device *hid = ihid->hid;
962 int ret;
963
964 ret = hid_driver_suspend(hid, PMSG_SUSPEND);
965 if (ret < 0)
966 return ret;
967
968 /* Save some power */
969 if (!(ihid->quirks & I2C_HID_QUIRK_NO_SLEEP_ON_SUSPEND))
970 i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
971
972 disable_irq(client->irq);
973
974 if (force_poweroff || !device_may_wakeup(&client->dev))
975 i2c_hid_core_power_down(ihid);
976
977 return 0;
978 }
979
i2c_hid_core_resume(struct i2c_hid * ihid)980 static int i2c_hid_core_resume(struct i2c_hid *ihid)
981 {
982 struct i2c_client *client = ihid->client;
983 struct hid_device *hid = ihid->hid;
984 int ret;
985
986 if (!device_may_wakeup(&client->dev))
987 i2c_hid_core_power_up(ihid);
988
989 enable_irq(client->irq);
990
991 /* On Goodix 27c6:0d42 wait extra time before device wakeup.
992 * It's not clear why but if we send wakeup too early, the device will
993 * never trigger input interrupts.
994 */
995 if (ihid->quirks & I2C_HID_QUIRK_DELAY_WAKEUP_AFTER_RESUME)
996 msleep(1500);
997
998 /* Instead of resetting device, simply powers the device on. This
999 * solves "incomplete reports" on Raydium devices 2386:3118 and
1000 * 2386:4B33 and fixes various SIS touchscreens no longer sending
1001 * data after a suspend/resume.
1002 *
1003 * However some ALPS touchpads generate IRQ storm without reset, so
1004 * let's still reset them here.
1005 */
1006 if (ihid->quirks & I2C_HID_QUIRK_RESET_ON_RESUME) {
1007 mutex_lock(&ihid->reset_lock);
1008 ret = i2c_hid_start_hwreset(ihid);
1009 if (ret == 0)
1010 ret = i2c_hid_finish_hwreset(ihid);
1011 mutex_unlock(&ihid->reset_lock);
1012 } else {
1013 ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
1014 }
1015
1016 if (ret)
1017 return ret;
1018
1019 return hid_driver_reset_resume(hid);
1020 }
1021
1022 /*
1023 * Check that the device exists and parse the HID descriptor.
1024 */
__i2c_hid_core_probe(struct i2c_hid * ihid)1025 static int __i2c_hid_core_probe(struct i2c_hid *ihid)
1026 {
1027 struct i2c_client *client = ihid->client;
1028 struct hid_device *hid = ihid->hid;
1029 int ret;
1030
1031 ret = i2c_hid_probe_address(ihid);
1032 if (ret < 0) {
1033 i2c_hid_dbg(ihid, "nothing at this address: %d\n", ret);
1034 return -ENXIO;
1035 }
1036
1037 ret = i2c_hid_fetch_hid_descriptor(ihid);
1038 if (ret < 0) {
1039 dev_err(&client->dev,
1040 "Failed to fetch the HID Descriptor\n");
1041 return ret;
1042 }
1043
1044 hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
1045 hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
1046 hid->product = le16_to_cpu(ihid->hdesc.wProductID);
1047
1048 hid->initial_quirks |= i2c_hid_get_dmi_quirks(hid->vendor,
1049 hid->product);
1050
1051 snprintf(hid->name, sizeof(hid->name), "%s %04X:%04X",
1052 client->name, (u16)hid->vendor, (u16)hid->product);
1053 strscpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys));
1054
1055 ihid->quirks = i2c_hid_lookup_quirk(hid->vendor, hid->product);
1056
1057 return 0;
1058 }
1059
i2c_hid_core_register_hid(struct i2c_hid * ihid)1060 static int i2c_hid_core_register_hid(struct i2c_hid *ihid)
1061 {
1062 struct i2c_client *client = ihid->client;
1063 struct hid_device *hid = ihid->hid;
1064 int ret;
1065
1066 enable_irq(client->irq);
1067
1068 ret = hid_add_device(hid);
1069 if (ret) {
1070 if (ret != -ENODEV)
1071 hid_err(client, "can't add hid device: %d\n", ret);
1072 disable_irq(client->irq);
1073 return ret;
1074 }
1075
1076 return 0;
1077 }
1078
i2c_hid_core_probe_panel_follower(struct i2c_hid * ihid)1079 static int i2c_hid_core_probe_panel_follower(struct i2c_hid *ihid)
1080 {
1081 int ret;
1082
1083 ret = i2c_hid_core_power_up(ihid);
1084 if (ret)
1085 return ret;
1086
1087 ret = __i2c_hid_core_probe(ihid);
1088 if (ret)
1089 goto err_power_down;
1090
1091 ret = i2c_hid_core_register_hid(ihid);
1092 if (ret)
1093 goto err_power_down;
1094
1095 return 0;
1096
1097 err_power_down:
1098 i2c_hid_core_power_down(ihid);
1099
1100 return ret;
1101 }
1102
ihid_core_panel_prepare_work(struct work_struct * work)1103 static void ihid_core_panel_prepare_work(struct work_struct *work)
1104 {
1105 struct i2c_hid *ihid = container_of(work, struct i2c_hid,
1106 panel_follower_prepare_work);
1107 struct hid_device *hid = ihid->hid;
1108 int ret;
1109
1110 /*
1111 * hid->version is set on the first power up. If it's still zero then
1112 * this is the first power on so we should perform initial power up
1113 * steps.
1114 */
1115 if (!hid->version)
1116 ret = i2c_hid_core_probe_panel_follower(ihid);
1117 else
1118 ret = i2c_hid_core_resume(ihid);
1119
1120 if (ret)
1121 dev_warn(&ihid->client->dev, "Power on failed: %d\n", ret);
1122 else
1123 WRITE_ONCE(ihid->prepare_work_finished, true);
1124
1125 /*
1126 * The work APIs provide a number of memory ordering guarantees
1127 * including one that says that memory writes before schedule_work()
1128 * are always visible to the work function, but they don't appear to
1129 * guarantee that a write that happened in the work is visible after
1130 * cancel_work_sync(). We'll add a write memory barrier here to match
1131 * with i2c_hid_core_panel_unpreparing() to ensure that our write to
1132 * prepare_work_finished is visible there.
1133 */
1134 smp_wmb();
1135 }
1136
i2c_hid_core_panel_prepared(struct drm_panel_follower * follower)1137 static int i2c_hid_core_panel_prepared(struct drm_panel_follower *follower)
1138 {
1139 struct i2c_hid *ihid = container_of(follower, struct i2c_hid, panel_follower);
1140
1141 /*
1142 * Powering on a touchscreen can be a slow process. Queue the work to
1143 * the system workqueue so we don't block the panel's power up.
1144 */
1145 WRITE_ONCE(ihid->prepare_work_finished, false);
1146 schedule_work(&ihid->panel_follower_prepare_work);
1147
1148 return 0;
1149 }
1150
i2c_hid_core_panel_unpreparing(struct drm_panel_follower * follower)1151 static int i2c_hid_core_panel_unpreparing(struct drm_panel_follower *follower)
1152 {
1153 struct i2c_hid *ihid = container_of(follower, struct i2c_hid, panel_follower);
1154
1155 cancel_work_sync(&ihid->panel_follower_prepare_work);
1156
1157 /* Match with ihid_core_panel_prepare_work() */
1158 smp_rmb();
1159 if (!READ_ONCE(ihid->prepare_work_finished))
1160 return 0;
1161
1162 return i2c_hid_core_suspend(ihid, true);
1163 }
1164
1165 static const struct drm_panel_follower_funcs i2c_hid_core_panel_follower_funcs = {
1166 .panel_prepared = i2c_hid_core_panel_prepared,
1167 .panel_unpreparing = i2c_hid_core_panel_unpreparing,
1168 };
1169
i2c_hid_core_register_panel_follower(struct i2c_hid * ihid)1170 static int i2c_hid_core_register_panel_follower(struct i2c_hid *ihid)
1171 {
1172 struct device *dev = &ihid->client->dev;
1173 int ret;
1174
1175 ihid->panel_follower.funcs = &i2c_hid_core_panel_follower_funcs;
1176
1177 /*
1178 * If we're not in control of our own power up/power down then we can't
1179 * do the logic to manage wakeups. Give a warning if a user thought
1180 * that was possible then force the capability off.
1181 */
1182 if (device_can_wakeup(dev)) {
1183 dev_warn(dev, "Can't wakeup if following panel\n");
1184 device_set_wakeup_capable(dev, false);
1185 }
1186
1187 ret = drm_panel_add_follower(dev, &ihid->panel_follower);
1188 if (ret)
1189 return ret;
1190
1191 return 0;
1192 }
1193
i2c_hid_core_probe(struct i2c_client * client,struct i2chid_ops * ops,u16 hid_descriptor_address,u32 quirks)1194 int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops,
1195 u16 hid_descriptor_address, u32 quirks)
1196 {
1197 int ret;
1198 struct i2c_hid *ihid;
1199 struct hid_device *hid;
1200
1201 dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
1202
1203 if (!client->irq) {
1204 dev_err(&client->dev,
1205 "HID over i2c has not been provided an Int IRQ\n");
1206 return -EINVAL;
1207 }
1208
1209 if (client->irq < 0) {
1210 if (client->irq != -EPROBE_DEFER)
1211 dev_err(&client->dev,
1212 "HID over i2c doesn't have a valid IRQ\n");
1213 return client->irq;
1214 }
1215
1216 ihid = devm_kzalloc(&client->dev, sizeof(*ihid), GFP_KERNEL);
1217 if (!ihid)
1218 return -ENOMEM;
1219
1220 i2c_set_clientdata(client, ihid);
1221
1222 ihid->ops = ops;
1223 ihid->client = client;
1224 ihid->wHIDDescRegister = cpu_to_le16(hid_descriptor_address);
1225 ihid->is_panel_follower = drm_is_panel_follower(&client->dev);
1226
1227 init_waitqueue_head(&ihid->wait);
1228 mutex_init(&ihid->cmd_lock);
1229 mutex_init(&ihid->reset_lock);
1230 INIT_WORK(&ihid->panel_follower_prepare_work, ihid_core_panel_prepare_work);
1231
1232 /* we need to allocate the command buffer without knowing the maximum
1233 * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
1234 * real computation later. */
1235 ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
1236 if (ret < 0)
1237 return ret;
1238 device_enable_async_suspend(&client->dev);
1239
1240 hid = hid_allocate_device();
1241 if (IS_ERR(hid)) {
1242 ret = PTR_ERR(hid);
1243 goto err_free_buffers;
1244 }
1245
1246 ihid->hid = hid;
1247
1248 hid->driver_data = client;
1249 hid->ll_driver = &i2c_hid_ll_driver;
1250 hid->dev.parent = &client->dev;
1251 hid->bus = BUS_I2C;
1252 hid->initial_quirks = quirks;
1253
1254 /* Power on and probe unless device is a panel follower. */
1255 if (!ihid->is_panel_follower) {
1256 ret = i2c_hid_core_power_up(ihid);
1257 if (ret < 0)
1258 goto err_destroy_device;
1259
1260 ret = __i2c_hid_core_probe(ihid);
1261 if (ret < 0)
1262 goto err_power_down;
1263 }
1264
1265 ret = i2c_hid_init_irq(client);
1266 if (ret < 0)
1267 goto err_power_down;
1268
1269 /*
1270 * If we're a panel follower, we'll register when the panel turns on;
1271 * otherwise we do it right away.
1272 */
1273 if (ihid->is_panel_follower)
1274 ret = i2c_hid_core_register_panel_follower(ihid);
1275 else
1276 ret = i2c_hid_core_register_hid(ihid);
1277 if (ret)
1278 goto err_free_irq;
1279
1280 return 0;
1281
1282 err_free_irq:
1283 free_irq(client->irq, ihid);
1284 err_power_down:
1285 if (!ihid->is_panel_follower)
1286 i2c_hid_core_power_down(ihid);
1287 err_destroy_device:
1288 hid_destroy_device(hid);
1289 err_free_buffers:
1290 i2c_hid_free_buffers(ihid);
1291
1292 return ret;
1293 }
1294 EXPORT_SYMBOL_GPL(i2c_hid_core_probe);
1295
i2c_hid_core_remove(struct i2c_client * client)1296 void i2c_hid_core_remove(struct i2c_client *client)
1297 {
1298 struct i2c_hid *ihid = i2c_get_clientdata(client);
1299 struct hid_device *hid;
1300
1301 /*
1302 * If we're a follower, the act of unfollowing will cause us to be
1303 * powered down. Otherwise we need to manually do it.
1304 */
1305 if (ihid->is_panel_follower)
1306 drm_panel_remove_follower(&ihid->panel_follower);
1307 else
1308 i2c_hid_core_suspend(ihid, true);
1309
1310 hid = ihid->hid;
1311 hid_destroy_device(hid);
1312
1313 free_irq(client->irq, ihid);
1314
1315 if (ihid->bufsize)
1316 i2c_hid_free_buffers(ihid);
1317 }
1318 EXPORT_SYMBOL_GPL(i2c_hid_core_remove);
1319
i2c_hid_core_shutdown(struct i2c_client * client)1320 void i2c_hid_core_shutdown(struct i2c_client *client)
1321 {
1322 struct i2c_hid *ihid = i2c_get_clientdata(client);
1323
1324 i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
1325 free_irq(client->irq, ihid);
1326
1327 i2c_hid_core_shutdown_tail(ihid);
1328 }
1329 EXPORT_SYMBOL_GPL(i2c_hid_core_shutdown);
1330
i2c_hid_core_pm_suspend(struct device * dev)1331 static int i2c_hid_core_pm_suspend(struct device *dev)
1332 {
1333 struct i2c_client *client = to_i2c_client(dev);
1334 struct i2c_hid *ihid = i2c_get_clientdata(client);
1335
1336 if (ihid->is_panel_follower)
1337 return 0;
1338
1339 return i2c_hid_core_suspend(ihid, false);
1340 }
1341
i2c_hid_core_pm_resume(struct device * dev)1342 static int i2c_hid_core_pm_resume(struct device *dev)
1343 {
1344 struct i2c_client *client = to_i2c_client(dev);
1345 struct i2c_hid *ihid = i2c_get_clientdata(client);
1346
1347 if (ihid->is_panel_follower)
1348 return 0;
1349
1350 return i2c_hid_core_resume(ihid);
1351 }
1352
1353 const struct dev_pm_ops i2c_hid_core_pm = {
1354 SYSTEM_SLEEP_PM_OPS(i2c_hid_core_pm_suspend, i2c_hid_core_pm_resume)
1355 };
1356 EXPORT_SYMBOL_GPL(i2c_hid_core_pm);
1357
1358 MODULE_DESCRIPTION("HID over I2C core driver");
1359 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
1360 MODULE_LICENSE("GPL");
1361