2 * HID over I2C protocol implementation
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
8 * This code is partly based on "USB HID support for Linux":
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
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
21 #include <linux/module.h>
22 #include <linux/i2c.h>
23 #include <linux/interrupt.h>
24 #include <linux/input.h>
25 #include <linux/delay.h>
26 #include <linux/slab.h>
28 #include <linux/pm_runtime.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 #include <linux/acpi.h>
40 #include <linux/gpio/consumer.h>
42 #include <linux/i2c/i2c-hid.h>
45 #define I2C_HID_STARTED 0
46 #define I2C_HID_RESET_PENDING 1
47 #define I2C_HID_READ_PENDING 2
49 #define I2C_HID_PWR_ON 0x00
50 #define I2C_HID_PWR_SLEEP 0x01
54 module_param(debug
, bool, 0444);
55 MODULE_PARM_DESC(debug
, "print a lot of debug information");
57 #define i2c_hid_dbg(ihid, fmt, arg...) \
60 dev_printk(KERN_DEBUG, &(ihid)->client->dev, fmt, ##arg); \
64 __le16 wHIDDescLength
;
66 __le16 wReportDescLength
;
67 __le16 wReportDescRegister
;
68 __le16 wInputRegister
;
69 __le16 wMaxInputLength
;
70 __le16 wOutputRegister
;
71 __le16 wMaxOutputLength
;
72 __le16 wCommandRegister
;
81 unsigned int registerIndex
;
96 #define I2C_HID_CMD(opcode_) \
97 .opcode = opcode_, .length = 4, \
98 .registerIndex = offsetof(struct i2c_hid_desc, wCommandRegister)
100 /* fetch HID descriptor */
101 static const struct i2c_hid_cmd hid_descr_cmd
= { .length
= 2 };
102 /* fetch report descriptors */
103 static const struct i2c_hid_cmd hid_report_descr_cmd
= {
104 .registerIndex
= offsetof(struct i2c_hid_desc
,
105 wReportDescRegister
),
109 static const struct i2c_hid_cmd hid_reset_cmd
= { I2C_HID_CMD(0x01),
111 static const struct i2c_hid_cmd hid_get_report_cmd
= { I2C_HID_CMD(0x02) };
112 static const struct i2c_hid_cmd hid_set_report_cmd
= { I2C_HID_CMD(0x03) };
113 static const struct i2c_hid_cmd hid_set_power_cmd
= { I2C_HID_CMD(0x08) };
114 static const struct i2c_hid_cmd hid_no_cmd
= { .length
= 0 };
117 * These definitions are not used here, but are defined by the spec.
118 * Keeping them here for documentation purposes.
120 * static const struct i2c_hid_cmd hid_get_idle_cmd = { I2C_HID_CMD(0x04) };
121 * static const struct i2c_hid_cmd hid_set_idle_cmd = { I2C_HID_CMD(0x05) };
122 * static const struct i2c_hid_cmd hid_get_protocol_cmd = { I2C_HID_CMD(0x06) };
123 * static const struct i2c_hid_cmd hid_set_protocol_cmd = { I2C_HID_CMD(0x07) };
126 static DEFINE_MUTEX(i2c_hid_open_mut
);
128 /* The main device structure */
130 struct i2c_client
*client
; /* i2c client */
131 struct hid_device
*hid
; /* pointer to corresponding HID dev */
133 __u8 hdesc_buffer
[sizeof(struct i2c_hid_desc
)];
134 struct i2c_hid_desc hdesc
; /* the HID Descriptor */
136 __le16 wHIDDescRegister
; /* location of the i2c
137 * register of the HID
139 unsigned int bufsize
; /* i2c buffer size */
140 char *inbuf
; /* Input buffer */
141 char *rawbuf
; /* Raw Input buffer */
142 char *cmdbuf
; /* Command buffer */
143 char *argsbuf
; /* Command arguments buffer */
145 unsigned long flags
; /* device flags */
147 wait_queue_head_t wait
; /* For waiting the interrupt */
148 struct gpio_desc
*desc
;
151 struct i2c_hid_platform_data pdata
;
153 bool irq_wake_enabled
;
154 struct mutex reset_lock
;
157 static int __i2c_hid_command(struct i2c_client
*client
,
158 const struct i2c_hid_cmd
*command
, u8 reportID
,
159 u8 reportType
, u8
*args
, int args_len
,
160 unsigned char *buf_recv
, int data_len
)
162 struct i2c_hid
*ihid
= i2c_get_clientdata(client
);
163 union command
*cmd
= (union command
*)ihid
->cmdbuf
;
165 struct i2c_msg msg
[2];
168 int length
= command
->length
;
169 bool wait
= command
->wait
;
170 unsigned int registerIndex
= command
->registerIndex
;
172 /* special case for hid_descr_cmd */
173 if (command
== &hid_descr_cmd
) {
174 cmd
->c
.reg
= ihid
->wHIDDescRegister
;
176 cmd
->data
[0] = ihid
->hdesc_buffer
[registerIndex
];
177 cmd
->data
[1] = ihid
->hdesc_buffer
[registerIndex
+ 1];
181 cmd
->c
.opcode
= command
->opcode
;
182 cmd
->c
.reportTypeID
= reportID
| reportType
<< 4;
185 memcpy(cmd
->data
+ length
, args
, args_len
);
188 i2c_hid_dbg(ihid
, "%s: cmd=%*ph\n", __func__
, length
, cmd
->data
);
190 msg
[0].addr
= client
->addr
;
191 msg
[0].flags
= client
->flags
& I2C_M_TEN
;
193 msg
[0].buf
= cmd
->data
;
195 msg
[1].addr
= client
->addr
;
196 msg
[1].flags
= client
->flags
& I2C_M_TEN
;
197 msg
[1].flags
|= I2C_M_RD
;
198 msg
[1].len
= data_len
;
199 msg
[1].buf
= buf_recv
;
201 set_bit(I2C_HID_READ_PENDING
, &ihid
->flags
);
205 set_bit(I2C_HID_RESET_PENDING
, &ihid
->flags
);
207 ret
= i2c_transfer(client
->adapter
, msg
, msg_num
);
210 clear_bit(I2C_HID_READ_PENDING
, &ihid
->flags
);
213 return ret
< 0 ? ret
: -EIO
;
218 i2c_hid_dbg(ihid
, "%s: waiting...\n", __func__
);
219 if (!wait_event_timeout(ihid
->wait
,
220 !test_bit(I2C_HID_RESET_PENDING
, &ihid
->flags
),
221 msecs_to_jiffies(5000)))
223 i2c_hid_dbg(ihid
, "%s: finished.\n", __func__
);
229 static int i2c_hid_command(struct i2c_client
*client
,
230 const struct i2c_hid_cmd
*command
,
231 unsigned char *buf_recv
, int data_len
)
233 return __i2c_hid_command(client
, command
, 0, 0, NULL
, 0,
237 static int i2c_hid_get_report(struct i2c_client
*client
, u8 reportType
,
238 u8 reportID
, unsigned char *buf_recv
, int data_len
)
240 struct i2c_hid
*ihid
= i2c_get_clientdata(client
);
244 u16 readRegister
= le16_to_cpu(ihid
->hdesc
.wDataRegister
);
246 i2c_hid_dbg(ihid
, "%s\n", __func__
);
248 if (reportID
>= 0x0F) {
249 args
[args_len
++] = reportID
;
253 args
[args_len
++] = readRegister
& 0xFF;
254 args
[args_len
++] = readRegister
>> 8;
256 ret
= __i2c_hid_command(client
, &hid_get_report_cmd
, reportID
,
257 reportType
, args
, args_len
, buf_recv
, data_len
);
259 dev_err(&client
->dev
,
260 "failed to retrieve report from device.\n");
268 * i2c_hid_set_or_send_report: forward an incoming report to the device
269 * @client: the i2c_client of the device
270 * @reportType: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT
271 * @reportID: the report ID
272 * @buf: the actual data to transfer, without the report ID
274 * @use_data: true: use SET_REPORT HID command, false: send plain OUTPUT report
276 static int i2c_hid_set_or_send_report(struct i2c_client
*client
, u8 reportType
,
277 u8 reportID
, unsigned char *buf
, size_t data_len
, bool use_data
)
279 struct i2c_hid
*ihid
= i2c_get_clientdata(client
);
280 u8
*args
= ihid
->argsbuf
;
281 const struct i2c_hid_cmd
*hidcmd
;
283 u16 dataRegister
= le16_to_cpu(ihid
->hdesc
.wDataRegister
);
284 u16 outputRegister
= le16_to_cpu(ihid
->hdesc
.wOutputRegister
);
285 u16 maxOutputLength
= le16_to_cpu(ihid
->hdesc
.wMaxOutputLength
);
287 /* hid_hw_* already checked that data_len < HID_MAX_BUFFER_SIZE */
288 u16 size
= 2 /* size */ +
289 (reportID
? 1 : 0) /* reportID */ +
291 int args_len
= (reportID
>= 0x0F ? 1 : 0) /* optional third byte */ +
292 2 /* dataRegister */ +
296 i2c_hid_dbg(ihid
, "%s\n", __func__
);
298 if (!use_data
&& maxOutputLength
== 0)
301 if (reportID
>= 0x0F) {
302 args
[index
++] = reportID
;
307 * use the data register for feature reports or if the device does not
308 * support the output register
311 args
[index
++] = dataRegister
& 0xFF;
312 args
[index
++] = dataRegister
>> 8;
313 hidcmd
= &hid_set_report_cmd
;
315 args
[index
++] = outputRegister
& 0xFF;
316 args
[index
++] = outputRegister
>> 8;
317 hidcmd
= &hid_no_cmd
;
320 args
[index
++] = size
& 0xFF;
321 args
[index
++] = size
>> 8;
324 args
[index
++] = reportID
;
326 memcpy(&args
[index
], buf
, data_len
);
328 ret
= __i2c_hid_command(client
, hidcmd
, reportID
,
329 reportType
, args
, args_len
, NULL
, 0);
331 dev_err(&client
->dev
, "failed to set a report to device.\n");
338 static int i2c_hid_set_power(struct i2c_client
*client
, int power_state
)
340 struct i2c_hid
*ihid
= i2c_get_clientdata(client
);
343 i2c_hid_dbg(ihid
, "%s\n", __func__
);
345 ret
= __i2c_hid_command(client
, &hid_set_power_cmd
, power_state
,
346 0, NULL
, 0, NULL
, 0);
348 dev_err(&client
->dev
, "failed to change power setting.\n");
353 static int i2c_hid_hwreset(struct i2c_client
*client
)
355 struct i2c_hid
*ihid
= i2c_get_clientdata(client
);
358 i2c_hid_dbg(ihid
, "%s\n", __func__
);
361 * This prevents sending feature reports while the device is
362 * being reset. Otherwise we may lose the reset complete
365 mutex_lock(&ihid
->reset_lock
);
367 ret
= i2c_hid_set_power(client
, I2C_HID_PWR_ON
);
371 i2c_hid_dbg(ihid
, "resetting...\n");
373 ret
= i2c_hid_command(client
, &hid_reset_cmd
, NULL
, 0);
375 dev_err(&client
->dev
, "failed to reset device.\n");
376 i2c_hid_set_power(client
, I2C_HID_PWR_SLEEP
);
380 mutex_unlock(&ihid
->reset_lock
);
384 static void i2c_hid_get_input(struct i2c_hid
*ihid
)
387 int size
= le16_to_cpu(ihid
->hdesc
.wMaxInputLength
);
389 if (size
> ihid
->bufsize
)
390 size
= ihid
->bufsize
;
392 ret
= i2c_master_recv(ihid
->client
, ihid
->inbuf
, size
);
397 dev_err(&ihid
->client
->dev
, "%s: got %d data instead of %d\n",
398 __func__
, ret
, size
);
402 ret_size
= ihid
->inbuf
[0] | ihid
->inbuf
[1] << 8;
405 /* host or device initiated RESET completed */
406 if (test_and_clear_bit(I2C_HID_RESET_PENDING
, &ihid
->flags
))
407 wake_up(&ihid
->wait
);
411 if (ret_size
> size
) {
412 dev_err(&ihid
->client
->dev
, "%s: incomplete report (%d/%d)\n",
413 __func__
, size
, ret_size
);
417 i2c_hid_dbg(ihid
, "input: %*ph\n", ret_size
, ihid
->inbuf
);
419 if (test_bit(I2C_HID_STARTED
, &ihid
->flags
))
420 hid_input_report(ihid
->hid
, HID_INPUT_REPORT
, ihid
->inbuf
+ 2,
426 static irqreturn_t
i2c_hid_irq(int irq
, void *dev_id
)
428 struct i2c_hid
*ihid
= dev_id
;
430 if (test_bit(I2C_HID_READ_PENDING
, &ihid
->flags
))
433 i2c_hid_get_input(ihid
);
438 static int i2c_hid_get_report_length(struct hid_report
*report
)
440 return ((report
->size
- 1) >> 3) + 1 +
441 report
->device
->report_enum
[report
->type
].numbered
+ 2;
444 static void i2c_hid_init_report(struct hid_report
*report
, u8
*buffer
,
447 struct hid_device
*hid
= report
->device
;
448 struct i2c_client
*client
= hid
->driver_data
;
449 struct i2c_hid
*ihid
= i2c_get_clientdata(client
);
450 unsigned int size
, ret_size
;
452 size
= i2c_hid_get_report_length(report
);
453 if (i2c_hid_get_report(client
,
454 report
->type
== HID_FEATURE_REPORT
? 0x03 : 0x01,
455 report
->id
, buffer
, size
))
458 i2c_hid_dbg(ihid
, "report (len=%d): %*ph\n", size
, size
, buffer
);
460 ret_size
= buffer
[0] | (buffer
[1] << 8);
462 if (ret_size
!= size
) {
463 dev_err(&client
->dev
, "error in %s size:%d / ret_size:%d\n",
464 __func__
, size
, ret_size
);
468 /* hid->driver_lock is held as we are in probe function,
469 * we just need to setup the input fields, so using
470 * hid_report_raw_event is safe. */
471 hid_report_raw_event(hid
, report
->type
, buffer
+ 2, size
- 2, 1);
475 * Initialize all reports
477 static void i2c_hid_init_reports(struct hid_device
*hid
)
479 struct hid_report
*report
;
480 struct i2c_client
*client
= hid
->driver_data
;
481 struct i2c_hid
*ihid
= i2c_get_clientdata(client
);
482 u8
*inbuf
= kzalloc(ihid
->bufsize
, GFP_KERNEL
);
485 dev_err(&client
->dev
, "can not retrieve initial reports\n");
490 * The device must be powered on while we fetch initial reports
493 pm_runtime_get_sync(&client
->dev
);
495 list_for_each_entry(report
,
496 &hid
->report_enum
[HID_FEATURE_REPORT
].report_list
, list
)
497 i2c_hid_init_report(report
, inbuf
, ihid
->bufsize
);
499 pm_runtime_put(&client
->dev
);
505 * Traverse the supplied list of reports and find the longest
507 static void i2c_hid_find_max_report(struct hid_device
*hid
, unsigned int type
,
510 struct hid_report
*report
;
513 /* We should not rely on wMaxInputLength, as some devices may set it to
515 list_for_each_entry(report
, &hid
->report_enum
[type
].report_list
, list
) {
516 size
= i2c_hid_get_report_length(report
);
522 static void i2c_hid_free_buffers(struct i2c_hid
*ihid
)
526 kfree(ihid
->argsbuf
);
531 ihid
->argsbuf
= NULL
;
535 static int i2c_hid_alloc_buffers(struct i2c_hid
*ihid
, size_t report_size
)
537 /* the worst case is computed from the set_report command with a
538 * reportID > 15 and the maximum report length */
539 int args_len
= sizeof(__u8
) + /* optional ReportID byte */
540 sizeof(__u16
) + /* data register */
541 sizeof(__u16
) + /* size of the report */
542 report_size
; /* report */
544 ihid
->inbuf
= kzalloc(report_size
, GFP_KERNEL
);
545 ihid
->rawbuf
= kzalloc(report_size
, GFP_KERNEL
);
546 ihid
->argsbuf
= kzalloc(args_len
, GFP_KERNEL
);
547 ihid
->cmdbuf
= kzalloc(sizeof(union command
) + args_len
, GFP_KERNEL
);
549 if (!ihid
->inbuf
|| !ihid
->rawbuf
|| !ihid
->argsbuf
|| !ihid
->cmdbuf
) {
550 i2c_hid_free_buffers(ihid
);
554 ihid
->bufsize
= report_size
;
559 static int i2c_hid_get_raw_report(struct hid_device
*hid
,
560 unsigned char report_number
, __u8
*buf
, size_t count
,
561 unsigned char report_type
)
563 struct i2c_client
*client
= hid
->driver_data
;
564 struct i2c_hid
*ihid
= i2c_get_clientdata(client
);
565 size_t ret_count
, ask_count
;
568 if (report_type
== HID_OUTPUT_REPORT
)
571 /* +2 bytes to include the size of the reply in the query buffer */
572 ask_count
= min(count
+ 2, (size_t)ihid
->bufsize
);
574 ret
= i2c_hid_get_report(client
,
575 report_type
== HID_FEATURE_REPORT
? 0x03 : 0x01,
576 report_number
, ihid
->rawbuf
, ask_count
);
581 ret_count
= ihid
->rawbuf
[0] | (ihid
->rawbuf
[1] << 8);
586 ret_count
= min(ret_count
, ask_count
);
588 /* The query buffer contains the size, dropping it in the reply */
589 count
= min(count
, ret_count
- 2);
590 memcpy(buf
, ihid
->rawbuf
+ 2, count
);
595 static int i2c_hid_output_raw_report(struct hid_device
*hid
, __u8
*buf
,
596 size_t count
, unsigned char report_type
, bool use_data
)
598 struct i2c_client
*client
= hid
->driver_data
;
599 struct i2c_hid
*ihid
= i2c_get_clientdata(client
);
600 int report_id
= buf
[0];
603 if (report_type
== HID_INPUT_REPORT
)
606 mutex_lock(&ihid
->reset_lock
);
613 ret
= i2c_hid_set_or_send_report(client
,
614 report_type
== HID_FEATURE_REPORT
? 0x03 : 0x02,
615 report_id
, buf
, count
, use_data
);
617 if (report_id
&& ret
>= 0)
618 ret
++; /* add report_id to the number of transfered bytes */
620 mutex_unlock(&ihid
->reset_lock
);
625 static int i2c_hid_output_report(struct hid_device
*hid
, __u8
*buf
,
628 return i2c_hid_output_raw_report(hid
, buf
, count
, HID_OUTPUT_REPORT
,
632 static int i2c_hid_raw_request(struct hid_device
*hid
, unsigned char reportnum
,
633 __u8
*buf
, size_t len
, unsigned char rtype
,
637 case HID_REQ_GET_REPORT
:
638 return i2c_hid_get_raw_report(hid
, reportnum
, buf
, len
, rtype
);
639 case HID_REQ_SET_REPORT
:
640 if (buf
[0] != reportnum
)
642 return i2c_hid_output_raw_report(hid
, buf
, len
, rtype
, true);
648 static int i2c_hid_parse(struct hid_device
*hid
)
650 struct i2c_client
*client
= hid
->driver_data
;
651 struct i2c_hid
*ihid
= i2c_get_clientdata(client
);
652 struct i2c_hid_desc
*hdesc
= &ihid
->hdesc
;
658 i2c_hid_dbg(ihid
, "entering %s\n", __func__
);
660 rsize
= le16_to_cpu(hdesc
->wReportDescLength
);
661 if (!rsize
|| rsize
> HID_MAX_DESCRIPTOR_SIZE
) {
662 dbg_hid("weird size of report descriptor (%u)\n", rsize
);
667 ret
= i2c_hid_hwreset(client
);
670 } while (tries
-- > 0 && ret
);
675 rdesc
= kzalloc(rsize
, GFP_KERNEL
);
678 dbg_hid("couldn't allocate rdesc memory\n");
682 i2c_hid_dbg(ihid
, "asking HID report descriptor\n");
684 ret
= i2c_hid_command(client
, &hid_report_descr_cmd
, rdesc
, rsize
);
686 hid_err(hid
, "reading report descriptor failed\n");
691 i2c_hid_dbg(ihid
, "Report Descriptor: %*ph\n", rsize
, rdesc
);
693 ret
= hid_parse_report(hid
, rdesc
, rsize
);
696 dbg_hid("parsing report descriptor failed\n");
703 static int i2c_hid_start(struct hid_device
*hid
)
705 struct i2c_client
*client
= hid
->driver_data
;
706 struct i2c_hid
*ihid
= i2c_get_clientdata(client
);
708 unsigned int bufsize
= HID_MIN_BUFFER_SIZE
;
710 i2c_hid_find_max_report(hid
, HID_INPUT_REPORT
, &bufsize
);
711 i2c_hid_find_max_report(hid
, HID_OUTPUT_REPORT
, &bufsize
);
712 i2c_hid_find_max_report(hid
, HID_FEATURE_REPORT
, &bufsize
);
714 if (bufsize
> ihid
->bufsize
) {
715 i2c_hid_free_buffers(ihid
);
717 ret
= i2c_hid_alloc_buffers(ihid
, bufsize
);
723 if (!(hid
->quirks
& HID_QUIRK_NO_INIT_REPORTS
))
724 i2c_hid_init_reports(hid
);
729 static void i2c_hid_stop(struct hid_device
*hid
)
734 static int i2c_hid_open(struct hid_device
*hid
)
736 struct i2c_client
*client
= hid
->driver_data
;
737 struct i2c_hid
*ihid
= i2c_get_clientdata(client
);
740 mutex_lock(&i2c_hid_open_mut
);
742 ret
= pm_runtime_get_sync(&client
->dev
);
747 set_bit(I2C_HID_STARTED
, &ihid
->flags
);
750 mutex_unlock(&i2c_hid_open_mut
);
751 return ret
< 0 ? ret
: 0;
754 static void i2c_hid_close(struct hid_device
*hid
)
756 struct i2c_client
*client
= hid
->driver_data
;
757 struct i2c_hid
*ihid
= i2c_get_clientdata(client
);
759 /* protecting hid->open to make sure we don't restart
760 * data acquistion due to a resumption we no longer
763 mutex_lock(&i2c_hid_open_mut
);
765 clear_bit(I2C_HID_STARTED
, &ihid
->flags
);
767 /* Save some power */
768 pm_runtime_put(&client
->dev
);
770 mutex_unlock(&i2c_hid_open_mut
);
773 static int i2c_hid_power(struct hid_device
*hid
, int lvl
)
775 struct i2c_client
*client
= hid
->driver_data
;
776 struct i2c_hid
*ihid
= i2c_get_clientdata(client
);
778 i2c_hid_dbg(ihid
, "%s lvl:%d\n", __func__
, lvl
);
782 pm_runtime_get_sync(&client
->dev
);
785 pm_runtime_put(&client
->dev
);
791 static struct hid_ll_driver i2c_hid_ll_driver
= {
792 .parse
= i2c_hid_parse
,
793 .start
= i2c_hid_start
,
794 .stop
= i2c_hid_stop
,
795 .open
= i2c_hid_open
,
796 .close
= i2c_hid_close
,
797 .power
= i2c_hid_power
,
798 .output_report
= i2c_hid_output_report
,
799 .raw_request
= i2c_hid_raw_request
,
802 static int i2c_hid_init_irq(struct i2c_client
*client
)
804 struct i2c_hid
*ihid
= i2c_get_clientdata(client
);
807 dev_dbg(&client
->dev
, "Requesting IRQ: %d\n", ihid
->irq
);
809 ret
= request_threaded_irq(ihid
->irq
, NULL
, i2c_hid_irq
,
810 IRQF_TRIGGER_LOW
| IRQF_ONESHOT
,
813 dev_warn(&client
->dev
,
814 "Could not register for %s interrupt, irq = %d,"
816 client
->name
, ihid
->irq
, ret
);
824 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid
*ihid
)
826 struct i2c_client
*client
= ihid
->client
;
827 struct i2c_hid_desc
*hdesc
= &ihid
->hdesc
;
831 /* i2c hid fetch using a fixed descriptor size (30 bytes) */
832 i2c_hid_dbg(ihid
, "Fetching the HID descriptor\n");
833 ret
= i2c_hid_command(client
, &hid_descr_cmd
, ihid
->hdesc_buffer
,
834 sizeof(struct i2c_hid_desc
));
836 dev_err(&client
->dev
, "hid_descr_cmd failed\n");
840 /* Validate the length of HID descriptor, the 4 first bytes:
841 * bytes 0-1 -> length
842 * bytes 2-3 -> bcdVersion (has to be 1.00) */
843 /* check bcdVersion == 1.0 */
844 if (le16_to_cpu(hdesc
->bcdVersion
) != 0x0100) {
845 dev_err(&client
->dev
,
846 "unexpected HID descriptor bcdVersion (0x%04hx)\n",
847 le16_to_cpu(hdesc
->bcdVersion
));
851 /* Descriptor length should be 30 bytes as per the specification */
852 dsize
= le16_to_cpu(hdesc
->wHIDDescLength
);
853 if (dsize
!= sizeof(struct i2c_hid_desc
)) {
854 dev_err(&client
->dev
, "weird size of HID descriptor (%u)\n",
858 i2c_hid_dbg(ihid
, "HID Descriptor: %*ph\n", dsize
, ihid
->hdesc_buffer
);
864 /* Default GPIO mapping */
865 static const struct acpi_gpio_params i2c_hid_irq_gpio
= { 0, 0, true };
866 static const struct acpi_gpio_mapping i2c_hid_acpi_gpios
[] = {
867 { "gpios", &i2c_hid_irq_gpio
, 1 },
871 static int i2c_hid_acpi_pdata(struct i2c_client
*client
,
872 struct i2c_hid_platform_data
*pdata
)
874 static u8 i2c_hid_guid
[] = {
875 0xF7, 0xF6, 0xDF, 0x3C, 0x67, 0x42, 0x55, 0x45,
876 0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE,
878 union acpi_object
*obj
;
879 struct acpi_device
*adev
;
883 handle
= ACPI_HANDLE(&client
->dev
);
884 if (!handle
|| acpi_bus_get_device(handle
, &adev
))
887 obj
= acpi_evaluate_dsm_typed(handle
, i2c_hid_guid
, 1, 1, NULL
,
890 dev_err(&client
->dev
, "device _DSM execution failed\n");
894 pdata
->hid_descriptor_address
= obj
->integer
.value
;
897 /* GPIOs are optional */
898 ret
= acpi_dev_add_driver_gpios(adev
, i2c_hid_acpi_gpios
);
899 return ret
< 0 && ret
!= -ENXIO
? ret
: 0;
902 static const struct acpi_device_id i2c_hid_acpi_match
[] = {
907 MODULE_DEVICE_TABLE(acpi
, i2c_hid_acpi_match
);
909 static inline int i2c_hid_acpi_pdata(struct i2c_client
*client
,
910 struct i2c_hid_platform_data
*pdata
)
917 static int i2c_hid_of_probe(struct i2c_client
*client
,
918 struct i2c_hid_platform_data
*pdata
)
920 struct device
*dev
= &client
->dev
;
924 ret
= of_property_read_u32(dev
->of_node
, "hid-descr-addr", &val
);
926 dev_err(&client
->dev
, "HID register address not provided\n");
930 dev_err(&client
->dev
, "Bad HID register address: 0x%08x\n",
934 pdata
->hid_descriptor_address
= val
;
939 static const struct of_device_id i2c_hid_of_match
[] = {
940 { .compatible
= "hid-over-i2c" },
943 MODULE_DEVICE_TABLE(of
, i2c_hid_of_match
);
945 static inline int i2c_hid_of_probe(struct i2c_client
*client
,
946 struct i2c_hid_platform_data
*pdata
)
952 static int i2c_hid_probe(struct i2c_client
*client
,
953 const struct i2c_device_id
*dev_id
)
956 struct i2c_hid
*ihid
;
957 struct hid_device
*hid
;
959 struct i2c_hid_platform_data
*platform_data
= client
->dev
.platform_data
;
961 dbg_hid("HID probe called for i2c 0x%02x\n", client
->addr
);
963 ihid
= kzalloc(sizeof(struct i2c_hid
), GFP_KERNEL
);
967 if (client
->dev
.of_node
) {
968 ret
= i2c_hid_of_probe(client
, &ihid
->pdata
);
971 } else if (!platform_data
) {
972 ret
= i2c_hid_acpi_pdata(client
, &ihid
->pdata
);
974 dev_err(&client
->dev
,
975 "HID register address not provided\n");
979 ihid
->pdata
= *platform_data
;
982 if (client
->irq
> 0) {
983 ihid
->irq
= client
->irq
;
984 } else if (ACPI_COMPANION(&client
->dev
)) {
985 ihid
->desc
= gpiod_get(&client
->dev
, NULL
, GPIOD_IN
);
986 if (IS_ERR(ihid
->desc
)) {
987 dev_err(&client
->dev
, "Failed to get GPIO interrupt\n");
988 return PTR_ERR(ihid
->desc
);
991 ihid
->irq
= gpiod_to_irq(ihid
->desc
);
993 gpiod_put(ihid
->desc
);
994 dev_err(&client
->dev
, "Failed to convert GPIO to IRQ\n");
999 i2c_set_clientdata(client
, ihid
);
1001 ihid
->client
= client
;
1003 hidRegister
= ihid
->pdata
.hid_descriptor_address
;
1004 ihid
->wHIDDescRegister
= cpu_to_le16(hidRegister
);
1006 init_waitqueue_head(&ihid
->wait
);
1007 mutex_init(&ihid
->reset_lock
);
1009 /* we need to allocate the command buffer without knowing the maximum
1010 * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
1011 * real computation later. */
1012 ret
= i2c_hid_alloc_buffers(ihid
, HID_MIN_BUFFER_SIZE
);
1016 pm_runtime_get_noresume(&client
->dev
);
1017 pm_runtime_set_active(&client
->dev
);
1018 pm_runtime_enable(&client
->dev
);
1020 ret
= i2c_hid_fetch_hid_descriptor(ihid
);
1024 ret
= i2c_hid_init_irq(client
);
1028 hid
= hid_allocate_device();
1036 hid
->driver_data
= client
;
1037 hid
->ll_driver
= &i2c_hid_ll_driver
;
1038 hid
->dev
.parent
= &client
->dev
;
1040 hid
->version
= le16_to_cpu(ihid
->hdesc
.bcdVersion
);
1041 hid
->vendor
= le16_to_cpu(ihid
->hdesc
.wVendorID
);
1042 hid
->product
= le16_to_cpu(ihid
->hdesc
.wProductID
);
1044 snprintf(hid
->name
, sizeof(hid
->name
), "%s %04hX:%04hX",
1045 client
->name
, hid
->vendor
, hid
->product
);
1046 strlcpy(hid
->phys
, dev_name(&client
->dev
), sizeof(hid
->phys
));
1048 ret
= hid_add_device(hid
);
1051 hid_err(client
, "can't add hid device: %d\n", ret
);
1055 pm_runtime_put(&client
->dev
);
1059 hid_destroy_device(hid
);
1062 free_irq(ihid
->irq
, ihid
);
1065 pm_runtime_put_noidle(&client
->dev
);
1066 pm_runtime_disable(&client
->dev
);
1070 gpiod_put(ihid
->desc
);
1072 i2c_hid_free_buffers(ihid
);
1077 static int i2c_hid_remove(struct i2c_client
*client
)
1079 struct i2c_hid
*ihid
= i2c_get_clientdata(client
);
1080 struct hid_device
*hid
;
1082 pm_runtime_get_sync(&client
->dev
);
1083 pm_runtime_disable(&client
->dev
);
1084 pm_runtime_set_suspended(&client
->dev
);
1085 pm_runtime_put_noidle(&client
->dev
);
1088 hid_destroy_device(hid
);
1090 free_irq(ihid
->irq
, ihid
);
1093 i2c_hid_free_buffers(ihid
);
1096 gpiod_put(ihid
->desc
);
1100 acpi_dev_remove_driver_gpios(ACPI_COMPANION(&client
->dev
));
1105 #ifdef CONFIG_PM_SLEEP
1106 static int i2c_hid_suspend(struct device
*dev
)
1108 struct i2c_client
*client
= to_i2c_client(dev
);
1109 struct i2c_hid
*ihid
= i2c_get_clientdata(client
);
1110 struct hid_device
*hid
= ihid
->hid
;
1114 if (hid
->driver
&& hid
->driver
->suspend
)
1115 ret
= hid
->driver
->suspend(hid
, PMSG_SUSPEND
);
1117 disable_irq(ihid
->irq
);
1118 if (device_may_wakeup(&client
->dev
)) {
1119 wake_status
= enable_irq_wake(ihid
->irq
);
1121 ihid
->irq_wake_enabled
= true;
1123 hid_warn(hid
, "Failed to enable irq wake: %d\n",
1127 /* Save some power */
1128 i2c_hid_set_power(client
, I2C_HID_PWR_SLEEP
);
1133 static int i2c_hid_resume(struct device
*dev
)
1136 struct i2c_client
*client
= to_i2c_client(dev
);
1137 struct i2c_hid
*ihid
= i2c_get_clientdata(client
);
1138 struct hid_device
*hid
= ihid
->hid
;
1141 enable_irq(ihid
->irq
);
1142 ret
= i2c_hid_hwreset(client
);
1146 if (device_may_wakeup(&client
->dev
) && ihid
->irq_wake_enabled
) {
1147 wake_status
= disable_irq_wake(ihid
->irq
);
1149 ihid
->irq_wake_enabled
= false;
1151 hid_warn(hid
, "Failed to disable irq wake: %d\n",
1155 if (hid
->driver
&& hid
->driver
->reset_resume
) {
1156 ret
= hid
->driver
->reset_resume(hid
);
1165 static int i2c_hid_runtime_suspend(struct device
*dev
)
1167 struct i2c_client
*client
= to_i2c_client(dev
);
1168 struct i2c_hid
*ihid
= i2c_get_clientdata(client
);
1170 i2c_hid_set_power(client
, I2C_HID_PWR_SLEEP
);
1171 disable_irq(ihid
->irq
);
1175 static int i2c_hid_runtime_resume(struct device
*dev
)
1177 struct i2c_client
*client
= to_i2c_client(dev
);
1178 struct i2c_hid
*ihid
= i2c_get_clientdata(client
);
1180 enable_irq(ihid
->irq
);
1181 i2c_hid_set_power(client
, I2C_HID_PWR_ON
);
1186 static const struct dev_pm_ops i2c_hid_pm
= {
1187 SET_SYSTEM_SLEEP_PM_OPS(i2c_hid_suspend
, i2c_hid_resume
)
1188 SET_RUNTIME_PM_OPS(i2c_hid_runtime_suspend
, i2c_hid_runtime_resume
,
1192 static const struct i2c_device_id i2c_hid_id_table
[] = {
1196 MODULE_DEVICE_TABLE(i2c
, i2c_hid_id_table
);
1199 static struct i2c_driver i2c_hid_driver
= {
1203 .acpi_match_table
= ACPI_PTR(i2c_hid_acpi_match
),
1204 .of_match_table
= of_match_ptr(i2c_hid_of_match
),
1207 .probe
= i2c_hid_probe
,
1208 .remove
= i2c_hid_remove
,
1210 .id_table
= i2c_hid_id_table
,
1213 module_i2c_driver(i2c_hid_driver
);
1215 MODULE_DESCRIPTION("HID over I2C core driver");
1216 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
1217 MODULE_LICENSE("GPL");