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/device.h>
30 #include <linux/wait.h>
31 #include <linux/err.h>
32 #include <linux/string.h>
33 #include <linux/list.h>
34 #include <linux/jiffies.h>
35 #include <linux/kernel.h>
36 #include <linux/hid.h>
37 #include <linux/mutex.h>
38
39 #include "../hid-ids.h"
40 #include "i2c-hid.h"
41
42 /* quirks to control the device */
43 #define I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV BIT(0)
44 #define I2C_HID_QUIRK_NO_IRQ_AFTER_RESET BIT(1)
45 #define I2C_HID_QUIRK_BOGUS_IRQ BIT(4)
46 #define I2C_HID_QUIRK_RESET_ON_RESUME BIT(5)
47 #define I2C_HID_QUIRK_BAD_INPUT_SIZE BIT(6)
48
49
50 /* flags */
51 #define I2C_HID_STARTED 0
52 #define I2C_HID_RESET_PENDING 1
53 #define I2C_HID_READ_PENDING 2
54
55 #define I2C_HID_PWR_ON 0x00
56 #define I2C_HID_PWR_SLEEP 0x01
57
58 /* debug option */
59 static bool debug;
60 module_param(debug, bool, 0444);
61 MODULE_PARM_DESC(debug, "print a lot of debug information");
62
63 #define i2c_hid_dbg(ihid, fmt, arg...) \
64 do { \
65 if (debug) \
66 dev_printk(KERN_DEBUG, &(ihid)->client->dev, fmt, ##arg); \
67 } while (0)
68
69 struct i2c_hid_desc {
70 __le16 wHIDDescLength;
71 __le16 bcdVersion;
72 __le16 wReportDescLength;
73 __le16 wReportDescRegister;
74 __le16 wInputRegister;
75 __le16 wMaxInputLength;
76 __le16 wOutputRegister;
77 __le16 wMaxOutputLength;
78 __le16 wCommandRegister;
79 __le16 wDataRegister;
80 __le16 wVendorID;
81 __le16 wProductID;
82 __le16 wVersionID;
83 __le32 reserved;
84 } __packed;
85
86 struct i2c_hid_cmd {
87 unsigned int registerIndex;
88 __u8 opcode;
89 unsigned int length;
90 bool wait;
91 };
92
93 union command {
94 u8 data[0];
95 struct cmd {
96 __le16 reg;
97 __u8 reportTypeID;
98 __u8 opcode;
99 } __packed c;
100 };
101
102 #define I2C_HID_CMD(opcode_) \
103 .opcode = opcode_, .length = 4, \
104 .registerIndex = offsetof(struct i2c_hid_desc, wCommandRegister)
105
106 /* fetch HID descriptor */
107 static const struct i2c_hid_cmd hid_descr_cmd = { .length = 2 };
108 /* fetch report descriptors */
109 static const struct i2c_hid_cmd hid_report_descr_cmd = {
110 .registerIndex = offsetof(struct i2c_hid_desc,
111 wReportDescRegister),
112 .opcode = 0x00,
113 .length = 2 };
114 /* commands */
115 static const struct i2c_hid_cmd hid_reset_cmd = { I2C_HID_CMD(0x01),
116 .wait = true };
117 static const struct i2c_hid_cmd hid_get_report_cmd = { I2C_HID_CMD(0x02) };
118 static const struct i2c_hid_cmd hid_set_report_cmd = { I2C_HID_CMD(0x03) };
119 static const struct i2c_hid_cmd hid_set_power_cmd = { I2C_HID_CMD(0x08) };
120 static const struct i2c_hid_cmd hid_no_cmd = { .length = 0 };
121
122 /*
123 * These definitions are not used here, but are defined by the spec.
124 * Keeping them here for documentation purposes.
125 *
126 * static const struct i2c_hid_cmd hid_get_idle_cmd = { I2C_HID_CMD(0x04) };
127 * static const struct i2c_hid_cmd hid_set_idle_cmd = { I2C_HID_CMD(0x05) };
128 * static const struct i2c_hid_cmd hid_get_protocol_cmd = { I2C_HID_CMD(0x06) };
129 * static const struct i2c_hid_cmd hid_set_protocol_cmd = { I2C_HID_CMD(0x07) };
130 */
131
132 /* The main device structure */
133 struct i2c_hid {
134 struct i2c_client *client; /* i2c client */
135 struct hid_device *hid; /* pointer to corresponding HID dev */
136 union {
137 __u8 hdesc_buffer[sizeof(struct i2c_hid_desc)];
138 struct i2c_hid_desc hdesc; /* the HID Descriptor */
139 };
140 __le16 wHIDDescRegister; /* location of the i2c
141 * register of the HID
142 * descriptor. */
143 unsigned int bufsize; /* i2c buffer size */
144 u8 *inbuf; /* Input buffer */
145 u8 *rawbuf; /* Raw Input buffer */
146 u8 *cmdbuf; /* Command buffer */
147 u8 *argsbuf; /* Command arguments buffer */
148
149 unsigned long flags; /* device flags */
150 unsigned long quirks; /* Various quirks */
151
152 wait_queue_head_t wait; /* For waiting the interrupt */
153
154 bool irq_wake_enabled;
155 struct mutex reset_lock;
156
157 struct i2chid_ops *ops;
158 };
159
160 static const struct i2c_hid_quirks {
161 __u16 idVendor;
162 __u16 idProduct;
163 __u32 quirks;
164 } i2c_hid_quirks[] = {
165 { USB_VENDOR_ID_WEIDA, HID_ANY_ID,
166 I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV },
167 { I2C_VENDOR_ID_HANTICK, I2C_PRODUCT_ID_HANTICK_5288,
168 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
169 { I2C_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_VOYO_WINPAD_A15,
170 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
171 { I2C_VENDOR_ID_RAYDIUM, I2C_PRODUCT_ID_RAYDIUM_3118,
172 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
173 { USB_VENDOR_ID_ELAN, HID_ANY_ID,
174 I2C_HID_QUIRK_BOGUS_IRQ },
175 { USB_VENDOR_ID_ALPS_JP, HID_ANY_ID,
176 I2C_HID_QUIRK_RESET_ON_RESUME },
177 { I2C_VENDOR_ID_SYNAPTICS, I2C_PRODUCT_ID_SYNAPTICS_SYNA2393,
178 I2C_HID_QUIRK_RESET_ON_RESUME },
179 { USB_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_LENOVO_LEGION_Y720,
180 I2C_HID_QUIRK_BAD_INPUT_SIZE },
181 { 0, 0 }
182 };
183
184 /*
185 * i2c_hid_lookup_quirk: return any quirks associated with a I2C HID device
186 * @idVendor: the 16-bit vendor ID
187 * @idProduct: the 16-bit product ID
188 *
189 * Returns: a u32 quirks value.
190 */
i2c_hid_lookup_quirk(const u16 idVendor,const u16 idProduct)191 static u32 i2c_hid_lookup_quirk(const u16 idVendor, const u16 idProduct)
192 {
193 u32 quirks = 0;
194 int n;
195
196 for (n = 0; i2c_hid_quirks[n].idVendor; n++)
197 if (i2c_hid_quirks[n].idVendor == idVendor &&
198 (i2c_hid_quirks[n].idProduct == (__u16)HID_ANY_ID ||
199 i2c_hid_quirks[n].idProduct == idProduct))
200 quirks = i2c_hid_quirks[n].quirks;
201
202 return quirks;
203 }
204
__i2c_hid_command(struct i2c_client * client,const struct i2c_hid_cmd * command,u8 reportID,u8 reportType,u8 * args,int args_len,unsigned char * buf_recv,int data_len)205 static int __i2c_hid_command(struct i2c_client *client,
206 const struct i2c_hid_cmd *command, u8 reportID,
207 u8 reportType, u8 *args, int args_len,
208 unsigned char *buf_recv, int data_len)
209 {
210 struct i2c_hid *ihid = i2c_get_clientdata(client);
211 union command *cmd = (union command *)ihid->cmdbuf;
212 int ret;
213 struct i2c_msg msg[2];
214 int msg_num = 1;
215
216 int length = command->length;
217 bool wait = command->wait;
218 unsigned int registerIndex = command->registerIndex;
219
220 /* special case for hid_descr_cmd */
221 if (command == &hid_descr_cmd) {
222 cmd->c.reg = ihid->wHIDDescRegister;
223 } else {
224 cmd->data[0] = ihid->hdesc_buffer[registerIndex];
225 cmd->data[1] = ihid->hdesc_buffer[registerIndex + 1];
226 }
227
228 if (length > 2) {
229 cmd->c.opcode = command->opcode;
230 cmd->c.reportTypeID = reportID | reportType << 4;
231 }
232
233 memcpy(cmd->data + length, args, args_len);
234 length += args_len;
235
236 i2c_hid_dbg(ihid, "%s: cmd=%*ph\n", __func__, length, cmd->data);
237
238 msg[0].addr = client->addr;
239 msg[0].flags = client->flags & I2C_M_TEN;
240 msg[0].len = length;
241 msg[0].buf = cmd->data;
242 if (data_len > 0) {
243 msg[1].addr = client->addr;
244 msg[1].flags = client->flags & I2C_M_TEN;
245 msg[1].flags |= I2C_M_RD;
246 msg[1].len = data_len;
247 msg[1].buf = buf_recv;
248 msg_num = 2;
249 set_bit(I2C_HID_READ_PENDING, &ihid->flags);
250 }
251
252 if (wait)
253 set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
254
255 ret = i2c_transfer(client->adapter, msg, msg_num);
256
257 if (data_len > 0)
258 clear_bit(I2C_HID_READ_PENDING, &ihid->flags);
259
260 if (ret != msg_num)
261 return ret < 0 ? ret : -EIO;
262
263 ret = 0;
264
265 if (wait && (ihid->quirks & I2C_HID_QUIRK_NO_IRQ_AFTER_RESET)) {
266 msleep(100);
267 } else if (wait) {
268 i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
269 if (!wait_event_timeout(ihid->wait,
270 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
271 msecs_to_jiffies(5000)))
272 ret = -ENODATA;
273 i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
274 }
275
276 return ret;
277 }
278
i2c_hid_command(struct i2c_client * client,const struct i2c_hid_cmd * command,unsigned char * buf_recv,int data_len)279 static int i2c_hid_command(struct i2c_client *client,
280 const struct i2c_hid_cmd *command,
281 unsigned char *buf_recv, int data_len)
282 {
283 return __i2c_hid_command(client, command, 0, 0, NULL, 0,
284 buf_recv, data_len);
285 }
286
i2c_hid_get_report(struct i2c_client * client,u8 reportType,u8 reportID,unsigned char * buf_recv,int data_len)287 static int i2c_hid_get_report(struct i2c_client *client, u8 reportType,
288 u8 reportID, unsigned char *buf_recv, int data_len)
289 {
290 struct i2c_hid *ihid = i2c_get_clientdata(client);
291 u8 args[3];
292 int ret;
293 int args_len = 0;
294 u16 readRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
295
296 i2c_hid_dbg(ihid, "%s\n", __func__);
297
298 if (reportID >= 0x0F) {
299 args[args_len++] = reportID;
300 reportID = 0x0F;
301 }
302
303 args[args_len++] = readRegister & 0xFF;
304 args[args_len++] = readRegister >> 8;
305
306 ret = __i2c_hid_command(client, &hid_get_report_cmd, reportID,
307 reportType, args, args_len, buf_recv, data_len);
308 if (ret) {
309 dev_err(&client->dev,
310 "failed to retrieve report from device.\n");
311 return ret;
312 }
313
314 return 0;
315 }
316
317 /**
318 * i2c_hid_set_or_send_report: forward an incoming report to the device
319 * @client: the i2c_client of the device
320 * @reportType: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT
321 * @reportID: the report ID
322 * @buf: the actual data to transfer, without the report ID
323 * @data_len: size of buf
324 * @use_data: true: use SET_REPORT HID command, false: send plain OUTPUT report
325 */
i2c_hid_set_or_send_report(struct i2c_client * client,u8 reportType,u8 reportID,unsigned char * buf,size_t data_len,bool use_data)326 static int i2c_hid_set_or_send_report(struct i2c_client *client, u8 reportType,
327 u8 reportID, unsigned char *buf, size_t data_len, bool use_data)
328 {
329 struct i2c_hid *ihid = i2c_get_clientdata(client);
330 u8 *args = ihid->argsbuf;
331 const struct i2c_hid_cmd *hidcmd;
332 int ret;
333 u16 dataRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
334 u16 outputRegister = le16_to_cpu(ihid->hdesc.wOutputRegister);
335 u16 maxOutputLength = le16_to_cpu(ihid->hdesc.wMaxOutputLength);
336 u16 size;
337 int args_len;
338 int index = 0;
339
340 i2c_hid_dbg(ihid, "%s\n", __func__);
341
342 if (data_len > ihid->bufsize)
343 return -EINVAL;
344
345 size = 2 /* size */ +
346 (reportID ? 1 : 0) /* reportID */ +
347 data_len /* buf */;
348 args_len = (reportID >= 0x0F ? 1 : 0) /* optional third byte */ +
349 2 /* dataRegister */ +
350 size /* args */;
351
352 if (!use_data && maxOutputLength == 0)
353 return -ENOSYS;
354
355 if (reportID >= 0x0F) {
356 args[index++] = reportID;
357 reportID = 0x0F;
358 }
359
360 /*
361 * use the data register for feature reports or if the device does not
362 * support the output register
363 */
364 if (use_data) {
365 args[index++] = dataRegister & 0xFF;
366 args[index++] = dataRegister >> 8;
367 hidcmd = &hid_set_report_cmd;
368 } else {
369 args[index++] = outputRegister & 0xFF;
370 args[index++] = outputRegister >> 8;
371 hidcmd = &hid_no_cmd;
372 }
373
374 args[index++] = size & 0xFF;
375 args[index++] = size >> 8;
376
377 if (reportID)
378 args[index++] = reportID;
379
380 memcpy(&args[index], buf, data_len);
381
382 ret = __i2c_hid_command(client, hidcmd, reportID,
383 reportType, args, args_len, NULL, 0);
384 if (ret) {
385 dev_err(&client->dev, "failed to set a report to device.\n");
386 return ret;
387 }
388
389 return data_len;
390 }
391
i2c_hid_set_power(struct i2c_client * client,int power_state)392 static int i2c_hid_set_power(struct i2c_client *client, int power_state)
393 {
394 struct i2c_hid *ihid = i2c_get_clientdata(client);
395 int ret;
396
397 i2c_hid_dbg(ihid, "%s\n", __func__);
398
399 /*
400 * Some devices require to send a command to wakeup before power on.
401 * The call will get a return value (EREMOTEIO) but device will be
402 * triggered and activated. After that, it goes like a normal device.
403 */
404 if (power_state == I2C_HID_PWR_ON &&
405 ihid->quirks & I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV) {
406 ret = i2c_hid_command(client, &hid_set_power_cmd, NULL, 0);
407
408 /* Device was already activated */
409 if (!ret)
410 goto set_pwr_exit;
411 }
412
413 ret = __i2c_hid_command(client, &hid_set_power_cmd, power_state,
414 0, NULL, 0, NULL, 0);
415
416 if (ret)
417 dev_err(&client->dev, "failed to change power setting.\n");
418
419 set_pwr_exit:
420
421 /*
422 * The HID over I2C specification states that if a DEVICE needs time
423 * after the PWR_ON request, it should utilise CLOCK stretching.
424 * However, it has been observered that the Windows driver provides a
425 * 1ms sleep between the PWR_ON and RESET requests.
426 * According to Goodix Windows even waits 60 ms after (other?)
427 * PWR_ON requests. Testing has confirmed that several devices
428 * will not work properly without a delay after a PWR_ON request.
429 */
430 if (!ret && power_state == I2C_HID_PWR_ON)
431 msleep(60);
432
433 return ret;
434 }
435
i2c_hid_hwreset(struct i2c_client * client)436 static int i2c_hid_hwreset(struct i2c_client *client)
437 {
438 struct i2c_hid *ihid = i2c_get_clientdata(client);
439 int ret;
440
441 i2c_hid_dbg(ihid, "%s\n", __func__);
442
443 /*
444 * This prevents sending feature reports while the device is
445 * being reset. Otherwise we may lose the reset complete
446 * interrupt.
447 */
448 mutex_lock(&ihid->reset_lock);
449
450 ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
451 if (ret)
452 goto out_unlock;
453
454 i2c_hid_dbg(ihid, "resetting...\n");
455
456 ret = i2c_hid_command(client, &hid_reset_cmd, NULL, 0);
457 if (ret) {
458 dev_err(&client->dev, "failed to reset device.\n");
459 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
460 goto out_unlock;
461 }
462
463 /* At least some SIS devices need this after reset */
464 ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
465
466 out_unlock:
467 mutex_unlock(&ihid->reset_lock);
468 return ret;
469 }
470
i2c_hid_get_input(struct i2c_hid * ihid)471 static void i2c_hid_get_input(struct i2c_hid *ihid)
472 {
473 int ret;
474 u32 ret_size;
475 int size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
476
477 if (size > ihid->bufsize)
478 size = ihid->bufsize;
479
480 ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
481 if (ret != size) {
482 if (ret < 0)
483 return;
484
485 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
486 __func__, ret, size);
487 return;
488 }
489
490 ret_size = ihid->inbuf[0] | ihid->inbuf[1] << 8;
491
492 if (!ret_size) {
493 /* host or device initiated RESET completed */
494 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
495 wake_up(&ihid->wait);
496 return;
497 }
498
499 if (ihid->quirks & I2C_HID_QUIRK_BOGUS_IRQ && ret_size == 0xffff) {
500 dev_warn_once(&ihid->client->dev, "%s: IRQ triggered but "
501 "there's no data\n", __func__);
502 return;
503 }
504
505 if ((ret_size > size) || (ret_size < 2)) {
506 if (ihid->quirks & I2C_HID_QUIRK_BAD_INPUT_SIZE) {
507 ihid->inbuf[0] = size & 0xff;
508 ihid->inbuf[1] = size >> 8;
509 ret_size = size;
510 } else {
511 dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n",
512 __func__, size, ret_size);
513 return;
514 }
515 }
516
517 i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
518
519 if (test_bit(I2C_HID_STARTED, &ihid->flags))
520 hid_input_report(ihid->hid, HID_INPUT_REPORT, ihid->inbuf + 2,
521 ret_size - 2, 1);
522
523 return;
524 }
525
i2c_hid_irq(int irq,void * dev_id)526 static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
527 {
528 struct i2c_hid *ihid = dev_id;
529
530 if (test_bit(I2C_HID_READ_PENDING, &ihid->flags))
531 return IRQ_HANDLED;
532
533 i2c_hid_get_input(ihid);
534
535 return IRQ_HANDLED;
536 }
537
i2c_hid_get_report_length(struct hid_report * report)538 static int i2c_hid_get_report_length(struct hid_report *report)
539 {
540 return ((report->size - 1) >> 3) + 1 +
541 report->device->report_enum[report->type].numbered + 2;
542 }
543
544 /*
545 * Traverse the supplied list of reports and find the longest
546 */
i2c_hid_find_max_report(struct hid_device * hid,unsigned int type,unsigned int * max)547 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
548 unsigned int *max)
549 {
550 struct hid_report *report;
551 unsigned int size;
552
553 /* We should not rely on wMaxInputLength, as some devices may set it to
554 * a wrong length. */
555 list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
556 size = i2c_hid_get_report_length(report);
557 if (*max < size)
558 *max = size;
559 }
560 }
561
i2c_hid_free_buffers(struct i2c_hid * ihid)562 static void i2c_hid_free_buffers(struct i2c_hid *ihid)
563 {
564 kfree(ihid->inbuf);
565 kfree(ihid->rawbuf);
566 kfree(ihid->argsbuf);
567 kfree(ihid->cmdbuf);
568 ihid->inbuf = NULL;
569 ihid->rawbuf = NULL;
570 ihid->cmdbuf = NULL;
571 ihid->argsbuf = NULL;
572 ihid->bufsize = 0;
573 }
574
i2c_hid_alloc_buffers(struct i2c_hid * ihid,size_t report_size)575 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
576 {
577 /* the worst case is computed from the set_report command with a
578 * reportID > 15 and the maximum report length */
579 int args_len = sizeof(__u8) + /* ReportID */
580 sizeof(__u8) + /* optional ReportID byte */
581 sizeof(__u16) + /* data register */
582 sizeof(__u16) + /* size of the report */
583 report_size; /* report */
584
585 ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
586 ihid->rawbuf = kzalloc(report_size, GFP_KERNEL);
587 ihid->argsbuf = kzalloc(args_len, GFP_KERNEL);
588 ihid->cmdbuf = kzalloc(sizeof(union command) + args_len, GFP_KERNEL);
589
590 if (!ihid->inbuf || !ihid->rawbuf || !ihid->argsbuf || !ihid->cmdbuf) {
591 i2c_hid_free_buffers(ihid);
592 return -ENOMEM;
593 }
594
595 ihid->bufsize = report_size;
596
597 return 0;
598 }
599
i2c_hid_get_raw_report(struct hid_device * hid,unsigned char report_number,__u8 * buf,size_t count,unsigned char report_type)600 static int i2c_hid_get_raw_report(struct hid_device *hid,
601 unsigned char report_number, __u8 *buf, size_t count,
602 unsigned char report_type)
603 {
604 struct i2c_client *client = hid->driver_data;
605 struct i2c_hid *ihid = i2c_get_clientdata(client);
606 size_t ret_count, ask_count;
607 int ret;
608
609 if (report_type == HID_OUTPUT_REPORT)
610 return -EINVAL;
611
612 /* +2 bytes to include the size of the reply in the query buffer */
613 ask_count = min(count + 2, (size_t)ihid->bufsize);
614
615 ret = i2c_hid_get_report(client,
616 report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
617 report_number, ihid->rawbuf, ask_count);
618
619 if (ret < 0)
620 return ret;
621
622 ret_count = ihid->rawbuf[0] | (ihid->rawbuf[1] << 8);
623
624 if (ret_count <= 2)
625 return 0;
626
627 ret_count = min(ret_count, ask_count);
628
629 /* The query buffer contains the size, dropping it in the reply */
630 count = min(count, ret_count - 2);
631 memcpy(buf, ihid->rawbuf + 2, count);
632
633 return count;
634 }
635
i2c_hid_output_raw_report(struct hid_device * hid,__u8 * buf,size_t count,unsigned char report_type,bool use_data)636 static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
637 size_t count, unsigned char report_type, bool use_data)
638 {
639 struct i2c_client *client = hid->driver_data;
640 struct i2c_hid *ihid = i2c_get_clientdata(client);
641 int report_id = buf[0];
642 int ret;
643
644 if (report_type == HID_INPUT_REPORT)
645 return -EINVAL;
646
647 mutex_lock(&ihid->reset_lock);
648
649 if (report_id) {
650 buf++;
651 count--;
652 }
653
654 ret = i2c_hid_set_or_send_report(client,
655 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
656 report_id, buf, count, use_data);
657
658 if (report_id && ret >= 0)
659 ret++; /* add report_id to the number of transfered bytes */
660
661 mutex_unlock(&ihid->reset_lock);
662
663 return ret;
664 }
665
i2c_hid_output_report(struct hid_device * hid,__u8 * buf,size_t count)666 static int i2c_hid_output_report(struct hid_device *hid, __u8 *buf,
667 size_t count)
668 {
669 return i2c_hid_output_raw_report(hid, buf, count, HID_OUTPUT_REPORT,
670 false);
671 }
672
i2c_hid_raw_request(struct hid_device * hid,unsigned char reportnum,__u8 * buf,size_t len,unsigned char rtype,int reqtype)673 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
674 __u8 *buf, size_t len, unsigned char rtype,
675 int reqtype)
676 {
677 switch (reqtype) {
678 case HID_REQ_GET_REPORT:
679 return i2c_hid_get_raw_report(hid, reportnum, buf, len, rtype);
680 case HID_REQ_SET_REPORT:
681 if (buf[0] != reportnum)
682 return -EINVAL;
683 return i2c_hid_output_raw_report(hid, buf, len, rtype, true);
684 default:
685 return -EIO;
686 }
687 }
688
i2c_hid_parse(struct hid_device * hid)689 static int i2c_hid_parse(struct hid_device *hid)
690 {
691 struct i2c_client *client = hid->driver_data;
692 struct i2c_hid *ihid = i2c_get_clientdata(client);
693 struct i2c_hid_desc *hdesc = &ihid->hdesc;
694 unsigned int rsize;
695 char *rdesc;
696 int ret;
697 int tries = 3;
698 char *use_override;
699
700 i2c_hid_dbg(ihid, "entering %s\n", __func__);
701
702 rsize = le16_to_cpu(hdesc->wReportDescLength);
703 if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
704 dbg_hid("weird size of report descriptor (%u)\n", rsize);
705 return -EINVAL;
706 }
707
708 do {
709 ret = i2c_hid_hwreset(client);
710 if (ret)
711 msleep(1000);
712 } while (tries-- > 0 && ret);
713
714 if (ret)
715 return ret;
716
717 use_override = i2c_hid_get_dmi_hid_report_desc_override(client->name,
718 &rsize);
719
720 if (use_override) {
721 rdesc = use_override;
722 i2c_hid_dbg(ihid, "Using a HID report descriptor override\n");
723 } else {
724 rdesc = kzalloc(rsize, GFP_KERNEL);
725
726 if (!rdesc) {
727 dbg_hid("couldn't allocate rdesc memory\n");
728 return -ENOMEM;
729 }
730
731 i2c_hid_dbg(ihid, "asking HID report descriptor\n");
732
733 ret = i2c_hid_command(client, &hid_report_descr_cmd,
734 rdesc, rsize);
735 if (ret) {
736 hid_err(hid, "reading report descriptor failed\n");
737 kfree(rdesc);
738 return -EIO;
739 }
740 }
741
742 i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
743
744 ret = hid_parse_report(hid, rdesc, rsize);
745 if (!use_override)
746 kfree(rdesc);
747
748 if (ret) {
749 dbg_hid("parsing report descriptor failed\n");
750 return ret;
751 }
752
753 return 0;
754 }
755
i2c_hid_start(struct hid_device * hid)756 static int i2c_hid_start(struct hid_device *hid)
757 {
758 struct i2c_client *client = hid->driver_data;
759 struct i2c_hid *ihid = i2c_get_clientdata(client);
760 int ret;
761 unsigned int bufsize = HID_MIN_BUFFER_SIZE;
762
763 i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
764 i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
765 i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
766
767 if (bufsize > ihid->bufsize) {
768 disable_irq(client->irq);
769 i2c_hid_free_buffers(ihid);
770
771 ret = i2c_hid_alloc_buffers(ihid, bufsize);
772 enable_irq(client->irq);
773
774 if (ret)
775 return ret;
776 }
777
778 return 0;
779 }
780
i2c_hid_stop(struct hid_device * hid)781 static void i2c_hid_stop(struct hid_device *hid)
782 {
783 hid->claimed = 0;
784 }
785
i2c_hid_open(struct hid_device * hid)786 static int i2c_hid_open(struct hid_device *hid)
787 {
788 struct i2c_client *client = hid->driver_data;
789 struct i2c_hid *ihid = i2c_get_clientdata(client);
790
791 set_bit(I2C_HID_STARTED, &ihid->flags);
792 return 0;
793 }
794
i2c_hid_close(struct hid_device * hid)795 static void i2c_hid_close(struct hid_device *hid)
796 {
797 struct i2c_client *client = hid->driver_data;
798 struct i2c_hid *ihid = i2c_get_clientdata(client);
799
800 clear_bit(I2C_HID_STARTED, &ihid->flags);
801 }
802
803 struct hid_ll_driver i2c_hid_ll_driver = {
804 .parse = i2c_hid_parse,
805 .start = i2c_hid_start,
806 .stop = i2c_hid_stop,
807 .open = i2c_hid_open,
808 .close = i2c_hid_close,
809 .output_report = i2c_hid_output_report,
810 .raw_request = i2c_hid_raw_request,
811 };
812 EXPORT_SYMBOL_GPL(i2c_hid_ll_driver);
813
i2c_hid_init_irq(struct i2c_client * client)814 static int i2c_hid_init_irq(struct i2c_client *client)
815 {
816 struct i2c_hid *ihid = i2c_get_clientdata(client);
817 unsigned long irqflags = 0;
818 int ret;
819
820 dev_dbg(&client->dev, "Requesting IRQ: %d\n", client->irq);
821
822 if (!irq_get_trigger_type(client->irq))
823 irqflags = IRQF_TRIGGER_LOW;
824
825 ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq,
826 irqflags | IRQF_ONESHOT, client->name, ihid);
827 if (ret < 0) {
828 dev_warn(&client->dev,
829 "Could not register for %s interrupt, irq = %d,"
830 " ret = %d\n",
831 client->name, client->irq, ret);
832
833 return ret;
834 }
835
836 return 0;
837 }
838
i2c_hid_fetch_hid_descriptor(struct i2c_hid * ihid)839 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
840 {
841 struct i2c_client *client = ihid->client;
842 struct i2c_hid_desc *hdesc = &ihid->hdesc;
843 unsigned int dsize;
844 int ret;
845
846 /* i2c hid fetch using a fixed descriptor size (30 bytes) */
847 if (i2c_hid_get_dmi_i2c_hid_desc_override(client->name)) {
848 i2c_hid_dbg(ihid, "Using a HID descriptor override\n");
849 ihid->hdesc =
850 *i2c_hid_get_dmi_i2c_hid_desc_override(client->name);
851 } else {
852 i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
853 ret = i2c_hid_command(client, &hid_descr_cmd,
854 ihid->hdesc_buffer,
855 sizeof(struct i2c_hid_desc));
856 if (ret) {
857 dev_err(&client->dev, "hid_descr_cmd failed\n");
858 return -ENODEV;
859 }
860 }
861
862 /* Validate the length of HID descriptor, the 4 first bytes:
863 * bytes 0-1 -> length
864 * bytes 2-3 -> bcdVersion (has to be 1.00) */
865 /* check bcdVersion == 1.0 */
866 if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
867 dev_err(&client->dev,
868 "unexpected HID descriptor bcdVersion (0x%04hx)\n",
869 le16_to_cpu(hdesc->bcdVersion));
870 return -ENODEV;
871 }
872
873 /* Descriptor length should be 30 bytes as per the specification */
874 dsize = le16_to_cpu(hdesc->wHIDDescLength);
875 if (dsize != sizeof(struct i2c_hid_desc)) {
876 dev_err(&client->dev, "weird size of HID descriptor (%u)\n",
877 dsize);
878 return -ENODEV;
879 }
880 i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer);
881 return 0;
882 }
883
i2c_hid_core_power_up(struct i2c_hid * ihid)884 static int i2c_hid_core_power_up(struct i2c_hid *ihid)
885 {
886 if (!ihid->ops->power_up)
887 return 0;
888
889 return ihid->ops->power_up(ihid->ops);
890 }
891
i2c_hid_core_power_down(struct i2c_hid * ihid)892 static void i2c_hid_core_power_down(struct i2c_hid *ihid)
893 {
894 if (!ihid->ops->power_down)
895 return;
896
897 ihid->ops->power_down(ihid->ops);
898 }
899
i2c_hid_core_shutdown_tail(struct i2c_hid * ihid)900 static void i2c_hid_core_shutdown_tail(struct i2c_hid *ihid)
901 {
902 if (!ihid->ops->shutdown_tail)
903 return;
904
905 ihid->ops->shutdown_tail(ihid->ops);
906 }
907
i2c_hid_core_probe(struct i2c_client * client,struct i2chid_ops * ops,u16 hid_descriptor_address)908 int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops,
909 u16 hid_descriptor_address)
910 {
911 int ret;
912 struct i2c_hid *ihid;
913 struct hid_device *hid;
914
915 dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
916
917 if (!client->irq) {
918 dev_err(&client->dev,
919 "HID over i2c has not been provided an Int IRQ\n");
920 return -EINVAL;
921 }
922
923 if (client->irq < 0) {
924 if (client->irq != -EPROBE_DEFER)
925 dev_err(&client->dev,
926 "HID over i2c doesn't have a valid IRQ\n");
927 return client->irq;
928 }
929
930 ihid = devm_kzalloc(&client->dev, sizeof(*ihid), GFP_KERNEL);
931 if (!ihid)
932 return -ENOMEM;
933
934 ihid->ops = ops;
935
936 ret = i2c_hid_core_power_up(ihid);
937 if (ret)
938 return ret;
939
940 i2c_set_clientdata(client, ihid);
941
942 ihid->client = client;
943
944 ihid->wHIDDescRegister = cpu_to_le16(hid_descriptor_address);
945
946 init_waitqueue_head(&ihid->wait);
947 mutex_init(&ihid->reset_lock);
948
949 /* we need to allocate the command buffer without knowing the maximum
950 * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
951 * real computation later. */
952 ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
953 if (ret < 0)
954 goto err_powered;
955
956 device_enable_async_suspend(&client->dev);
957
958 /* Make sure there is something at this address */
959 ret = i2c_smbus_read_byte(client);
960 if (ret < 0) {
961 dev_dbg(&client->dev, "nothing at this address: %d\n", ret);
962 ret = -ENXIO;
963 goto err_powered;
964 }
965
966 ret = i2c_hid_fetch_hid_descriptor(ihid);
967 if (ret < 0) {
968 dev_err(&client->dev,
969 "Failed to fetch the HID Descriptor\n");
970 goto err_powered;
971 }
972
973 ret = i2c_hid_init_irq(client);
974 if (ret < 0)
975 goto err_powered;
976
977 hid = hid_allocate_device();
978 if (IS_ERR(hid)) {
979 ret = PTR_ERR(hid);
980 goto err_irq;
981 }
982
983 ihid->hid = hid;
984
985 hid->driver_data = client;
986 hid->ll_driver = &i2c_hid_ll_driver;
987 hid->dev.parent = &client->dev;
988 hid->bus = BUS_I2C;
989 hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
990 hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
991 hid->product = le16_to_cpu(ihid->hdesc.wProductID);
992
993 snprintf(hid->name, sizeof(hid->name), "%s %04hX:%04hX",
994 client->name, hid->vendor, hid->product);
995 strlcpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys));
996
997 ihid->quirks = i2c_hid_lookup_quirk(hid->vendor, hid->product);
998
999 ret = hid_add_device(hid);
1000 if (ret) {
1001 if (ret != -ENODEV)
1002 hid_err(client, "can't add hid device: %d\n", ret);
1003 goto err_mem_free;
1004 }
1005
1006 return 0;
1007
1008 err_mem_free:
1009 hid_destroy_device(hid);
1010
1011 err_irq:
1012 free_irq(client->irq, ihid);
1013
1014 err_powered:
1015 i2c_hid_core_power_down(ihid);
1016 i2c_hid_free_buffers(ihid);
1017 return ret;
1018 }
1019 EXPORT_SYMBOL_GPL(i2c_hid_core_probe);
1020
i2c_hid_core_remove(struct i2c_client * client)1021 int i2c_hid_core_remove(struct i2c_client *client)
1022 {
1023 struct i2c_hid *ihid = i2c_get_clientdata(client);
1024 struct hid_device *hid;
1025
1026 hid = ihid->hid;
1027 hid_destroy_device(hid);
1028
1029 free_irq(client->irq, ihid);
1030
1031 if (ihid->bufsize)
1032 i2c_hid_free_buffers(ihid);
1033
1034 i2c_hid_core_power_down(ihid);
1035
1036 return 0;
1037 }
1038 EXPORT_SYMBOL_GPL(i2c_hid_core_remove);
1039
i2c_hid_core_shutdown(struct i2c_client * client)1040 void i2c_hid_core_shutdown(struct i2c_client *client)
1041 {
1042 struct i2c_hid *ihid = i2c_get_clientdata(client);
1043
1044 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1045 free_irq(client->irq, ihid);
1046
1047 i2c_hid_core_shutdown_tail(ihid);
1048 }
1049 EXPORT_SYMBOL_GPL(i2c_hid_core_shutdown);
1050
1051 #ifdef CONFIG_PM_SLEEP
i2c_hid_core_suspend(struct device * dev)1052 static int i2c_hid_core_suspend(struct device *dev)
1053 {
1054 struct i2c_client *client = to_i2c_client(dev);
1055 struct i2c_hid *ihid = i2c_get_clientdata(client);
1056 struct hid_device *hid = ihid->hid;
1057 int ret;
1058 int wake_status;
1059
1060 if (hid->driver && hid->driver->suspend) {
1061 ret = hid->driver->suspend(hid, PMSG_SUSPEND);
1062 if (ret < 0)
1063 return ret;
1064 }
1065
1066 /* Save some power */
1067 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1068
1069 disable_irq(client->irq);
1070
1071 if (device_may_wakeup(&client->dev)) {
1072 wake_status = enable_irq_wake(client->irq);
1073 if (!wake_status)
1074 ihid->irq_wake_enabled = true;
1075 else
1076 hid_warn(hid, "Failed to enable irq wake: %d\n",
1077 wake_status);
1078 } else {
1079 i2c_hid_core_power_down(ihid);
1080 }
1081
1082 return 0;
1083 }
1084
i2c_hid_core_resume(struct device * dev)1085 static int i2c_hid_core_resume(struct device *dev)
1086 {
1087 int ret;
1088 struct i2c_client *client = to_i2c_client(dev);
1089 struct i2c_hid *ihid = i2c_get_clientdata(client);
1090 struct hid_device *hid = ihid->hid;
1091 int wake_status;
1092
1093 if (!device_may_wakeup(&client->dev)) {
1094 i2c_hid_core_power_up(ihid);
1095 } else if (ihid->irq_wake_enabled) {
1096 wake_status = disable_irq_wake(client->irq);
1097 if (!wake_status)
1098 ihid->irq_wake_enabled = false;
1099 else
1100 hid_warn(hid, "Failed to disable irq wake: %d\n",
1101 wake_status);
1102 }
1103
1104 enable_irq(client->irq);
1105
1106 /* Instead of resetting device, simply powers the device on. This
1107 * solves "incomplete reports" on Raydium devices 2386:3118 and
1108 * 2386:4B33 and fixes various SIS touchscreens no longer sending
1109 * data after a suspend/resume.
1110 *
1111 * However some ALPS touchpads generate IRQ storm without reset, so
1112 * let's still reset them here.
1113 */
1114 if (ihid->quirks & I2C_HID_QUIRK_RESET_ON_RESUME)
1115 ret = i2c_hid_hwreset(client);
1116 else
1117 ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
1118
1119 if (ret)
1120 return ret;
1121
1122 if (hid->driver && hid->driver->reset_resume) {
1123 ret = hid->driver->reset_resume(hid);
1124 return ret;
1125 }
1126
1127 return 0;
1128 }
1129 #endif
1130
1131 const struct dev_pm_ops i2c_hid_core_pm = {
1132 SET_SYSTEM_SLEEP_PM_OPS(i2c_hid_core_suspend, i2c_hid_core_resume)
1133 };
1134 EXPORT_SYMBOL_GPL(i2c_hid_core_pm);
1135
1136 MODULE_DESCRIPTION("HID over I2C core driver");
1137 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
1138 MODULE_LICENSE("GPL");
1139