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/irq.h>
26 #include <linux/delay.h>
27 #include <linux/slab.h>
29 #include <linux/pm_runtime.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/acpi.h>
41 #include <linux/regulator/consumer.h>
43 #include <linux/i2c/i2c-hid.h>
45 #include "../hid-ids.h"
47 /* quirks to control the device */
48 #define I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV BIT(0)
51 #define I2C_HID_STARTED 0
52 #define I2C_HID_RESET_PENDING 1
53 #define I2C_HID_READ_PENDING 2
55 #define I2C_HID_PWR_ON 0x00
56 #define I2C_HID_PWR_SLEEP 0x01
60 module_param(debug, bool, 0444);
61 MODULE_PARM_DESC(debug, "print a lot of debug information");
63 #define i2c_hid_dbg(ihid, fmt, arg...) \
66 dev_printk(KERN_DEBUG, &(ihid)->client->dev, fmt, ##arg); \
70 __le16 wHIDDescLength;
72 __le16 wReportDescLength;
73 __le16 wReportDescRegister;
74 __le16 wInputRegister;
75 __le16 wMaxInputLength;
76 __le16 wOutputRegister;
77 __le16 wMaxOutputLength;
78 __le16 wCommandRegister;
87 unsigned int registerIndex;
102 #define I2C_HID_CMD(opcode_) \
103 .opcode = opcode_, .length = 4, \
104 .registerIndex = offsetof(struct i2c_hid_desc, wCommandRegister)
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),
115 static const struct i2c_hid_cmd hid_reset_cmd = { I2C_HID_CMD(0x01),
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 };
123 * These definitions are not used here, but are defined by the spec.
124 * Keeping them here for documentation purposes.
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) };
132 static DEFINE_MUTEX(i2c_hid_open_mut);
134 /* The main device structure */
136 struct i2c_client *client; /* i2c client */
137 struct hid_device *hid; /* pointer to corresponding HID dev */
139 __u8 hdesc_buffer[sizeof(struct i2c_hid_desc)];
140 struct i2c_hid_desc hdesc; /* the HID Descriptor */
142 __le16 wHIDDescRegister; /* location of the i2c
143 * register of the HID
145 unsigned int bufsize; /* i2c buffer size */
146 char *inbuf; /* Input buffer */
147 char *rawbuf; /* Raw Input buffer */
148 char *cmdbuf; /* Command buffer */
149 char *argsbuf; /* Command arguments buffer */
151 unsigned long flags; /* device flags */
152 unsigned long quirks; /* Various quirks */
154 wait_queue_head_t wait; /* For waiting the interrupt */
156 struct i2c_hid_platform_data pdata;
158 bool irq_wake_enabled;
159 struct mutex reset_lock;
162 static const struct i2c_hid_quirks {
166 } i2c_hid_quirks[] = {
167 { USB_VENDOR_ID_WEIDA, USB_DEVICE_ID_WEIDA_8752,
168 I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV },
169 { USB_VENDOR_ID_WEIDA, USB_DEVICE_ID_WEIDA_8755,
170 I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV },
175 * i2c_hid_lookup_quirk: return any quirks associated with a I2C HID device
176 * @idVendor: the 16-bit vendor ID
177 * @idProduct: the 16-bit product ID
179 * Returns: a u32 quirks value.
181 static u32 i2c_hid_lookup_quirk(const u16 idVendor, const u16 idProduct)
186 for (n = 0; i2c_hid_quirks[n].idVendor; n++)
187 if (i2c_hid_quirks[n].idVendor == idVendor &&
188 (i2c_hid_quirks[n].idProduct == (__u16)HID_ANY_ID ||
189 i2c_hid_quirks[n].idProduct == idProduct))
190 quirks = i2c_hid_quirks[n].quirks;
195 static int __i2c_hid_command(struct i2c_client *client,
196 const struct i2c_hid_cmd *command, u8 reportID,
197 u8 reportType, u8 *args, int args_len,
198 unsigned char *buf_recv, int data_len)
200 struct i2c_hid *ihid = i2c_get_clientdata(client);
201 union command *cmd = (union command *)ihid->cmdbuf;
203 struct i2c_msg msg[2];
206 int length = command->length;
207 bool wait = command->wait;
208 unsigned int registerIndex = command->registerIndex;
210 /* special case for hid_descr_cmd */
211 if (command == &hid_descr_cmd) {
212 cmd->c.reg = ihid->wHIDDescRegister;
214 cmd->data[0] = ihid->hdesc_buffer[registerIndex];
215 cmd->data[1] = ihid->hdesc_buffer[registerIndex + 1];
219 cmd->c.opcode = command->opcode;
220 cmd->c.reportTypeID = reportID | reportType << 4;
223 memcpy(cmd->data + length, args, args_len);
226 i2c_hid_dbg(ihid, "%s: cmd=%*ph\n", __func__, length, cmd->data);
228 msg[0].addr = client->addr;
229 msg[0].flags = client->flags & I2C_M_TEN;
231 msg[0].buf = cmd->data;
233 msg[1].addr = client->addr;
234 msg[1].flags = client->flags & I2C_M_TEN;
235 msg[1].flags |= I2C_M_RD;
236 msg[1].len = data_len;
237 msg[1].buf = buf_recv;
239 set_bit(I2C_HID_READ_PENDING, &ihid->flags);
243 set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
245 ret = i2c_transfer(client->adapter, msg, msg_num);
248 clear_bit(I2C_HID_READ_PENDING, &ihid->flags);
251 return ret < 0 ? ret : -EIO;
256 i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
257 if (!wait_event_timeout(ihid->wait,
258 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
259 msecs_to_jiffies(5000)))
261 i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
267 static int i2c_hid_command(struct i2c_client *client,
268 const struct i2c_hid_cmd *command,
269 unsigned char *buf_recv, int data_len)
271 return __i2c_hid_command(client, command, 0, 0, NULL, 0,
275 static int i2c_hid_get_report(struct i2c_client *client, u8 reportType,
276 u8 reportID, unsigned char *buf_recv, int data_len)
278 struct i2c_hid *ihid = i2c_get_clientdata(client);
282 u16 readRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
284 i2c_hid_dbg(ihid, "%s\n", __func__);
286 if (reportID >= 0x0F) {
287 args[args_len++] = reportID;
291 args[args_len++] = readRegister & 0xFF;
292 args[args_len++] = readRegister >> 8;
294 ret = __i2c_hid_command(client, &hid_get_report_cmd, reportID,
295 reportType, args, args_len, buf_recv, data_len);
297 dev_err(&client->dev,
298 "failed to retrieve report from device.\n");
306 * i2c_hid_set_or_send_report: forward an incoming report to the device
307 * @client: the i2c_client of the device
308 * @reportType: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT
309 * @reportID: the report ID
310 * @buf: the actual data to transfer, without the report ID
312 * @use_data: true: use SET_REPORT HID command, false: send plain OUTPUT report
314 static int i2c_hid_set_or_send_report(struct i2c_client *client, u8 reportType,
315 u8 reportID, unsigned char *buf, size_t data_len, bool use_data)
317 struct i2c_hid *ihid = i2c_get_clientdata(client);
318 u8 *args = ihid->argsbuf;
319 const struct i2c_hid_cmd *hidcmd;
321 u16 dataRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
322 u16 outputRegister = le16_to_cpu(ihid->hdesc.wOutputRegister);
323 u16 maxOutputLength = le16_to_cpu(ihid->hdesc.wMaxOutputLength);
328 i2c_hid_dbg(ihid, "%s\n", __func__);
330 if (data_len > ihid->bufsize)
333 size = 2 /* size */ +
334 (reportID ? 1 : 0) /* reportID */ +
336 args_len = (reportID >= 0x0F ? 1 : 0) /* optional third byte */ +
337 2 /* dataRegister */ +
340 if (!use_data && maxOutputLength == 0)
343 if (reportID >= 0x0F) {
344 args[index++] = reportID;
349 * use the data register for feature reports or if the device does not
350 * support the output register
353 args[index++] = dataRegister & 0xFF;
354 args[index++] = dataRegister >> 8;
355 hidcmd = &hid_set_report_cmd;
357 args[index++] = outputRegister & 0xFF;
358 args[index++] = outputRegister >> 8;
359 hidcmd = &hid_no_cmd;
362 args[index++] = size & 0xFF;
363 args[index++] = size >> 8;
366 args[index++] = reportID;
368 memcpy(&args[index], buf, data_len);
370 ret = __i2c_hid_command(client, hidcmd, reportID,
371 reportType, args, args_len, NULL, 0);
373 dev_err(&client->dev, "failed to set a report to device.\n");
380 static int i2c_hid_set_power(struct i2c_client *client, int power_state)
382 struct i2c_hid *ihid = i2c_get_clientdata(client);
385 i2c_hid_dbg(ihid, "%s\n", __func__);
388 * Some devices require to send a command to wakeup before power on.
389 * The call will get a return value (EREMOTEIO) but device will be
390 * triggered and activated. After that, it goes like a normal device.
392 if (power_state == I2C_HID_PWR_ON &&
393 ihid->quirks & I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV) {
394 ret = i2c_hid_command(client, &hid_set_power_cmd, NULL, 0);
396 /* Device was already activated */
401 ret = __i2c_hid_command(client, &hid_set_power_cmd, power_state,
402 0, NULL, 0, NULL, 0);
405 dev_err(&client->dev, "failed to change power setting.\n");
411 static int i2c_hid_hwreset(struct i2c_client *client)
413 struct i2c_hid *ihid = i2c_get_clientdata(client);
416 i2c_hid_dbg(ihid, "%s\n", __func__);
419 * This prevents sending feature reports while the device is
420 * being reset. Otherwise we may lose the reset complete
423 mutex_lock(&ihid->reset_lock);
425 ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
430 * The HID over I2C specification states that if a DEVICE needs time
431 * after the PWR_ON request, it should utilise CLOCK stretching.
432 * However, it has been observered that the Windows driver provides a
433 * 1ms sleep between the PWR_ON and RESET requests and that some devices
436 usleep_range(1000, 5000);
438 i2c_hid_dbg(ihid, "resetting...\n");
440 ret = i2c_hid_command(client, &hid_reset_cmd, NULL, 0);
442 dev_err(&client->dev, "failed to reset device.\n");
443 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
447 mutex_unlock(&ihid->reset_lock);
451 static void i2c_hid_get_input(struct i2c_hid *ihid)
454 int size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
456 if (size > ihid->bufsize)
457 size = ihid->bufsize;
459 ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
464 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
465 __func__, ret, size);
469 ret_size = ihid->inbuf[0] | ihid->inbuf[1] << 8;
472 /* host or device initiated RESET completed */
473 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
474 wake_up(&ihid->wait);
478 if (ret_size > size) {
479 dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n",
480 __func__, size, ret_size);
484 i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
486 if (test_bit(I2C_HID_STARTED, &ihid->flags))
487 hid_input_report(ihid->hid, HID_INPUT_REPORT, ihid->inbuf + 2,
493 static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
495 struct i2c_hid *ihid = dev_id;
497 if (test_bit(I2C_HID_READ_PENDING, &ihid->flags))
500 i2c_hid_get_input(ihid);
505 static int i2c_hid_get_report_length(struct hid_report *report)
507 return ((report->size - 1) >> 3) + 1 +
508 report->device->report_enum[report->type].numbered + 2;
511 static void i2c_hid_init_report(struct hid_report *report, u8 *buffer,
514 struct hid_device *hid = report->device;
515 struct i2c_client *client = hid->driver_data;
516 struct i2c_hid *ihid = i2c_get_clientdata(client);
517 unsigned int size, ret_size;
519 size = i2c_hid_get_report_length(report);
520 if (i2c_hid_get_report(client,
521 report->type == HID_FEATURE_REPORT ? 0x03 : 0x01,
522 report->id, buffer, size))
525 i2c_hid_dbg(ihid, "report (len=%d): %*ph\n", size, size, buffer);
527 ret_size = buffer[0] | (buffer[1] << 8);
529 if (ret_size != size) {
530 dev_err(&client->dev, "error in %s size:%d / ret_size:%d\n",
531 __func__, size, ret_size);
535 /* hid->driver_lock is held as we are in probe function,
536 * we just need to setup the input fields, so using
537 * hid_report_raw_event is safe. */
538 hid_report_raw_event(hid, report->type, buffer + 2, size - 2, 1);
542 * Initialize all reports
544 static void i2c_hid_init_reports(struct hid_device *hid)
546 struct hid_report *report;
547 struct i2c_client *client = hid->driver_data;
548 struct i2c_hid *ihid = i2c_get_clientdata(client);
549 u8 *inbuf = kzalloc(ihid->bufsize, GFP_KERNEL);
552 dev_err(&client->dev, "can not retrieve initial reports\n");
557 * The device must be powered on while we fetch initial reports
560 pm_runtime_get_sync(&client->dev);
562 list_for_each_entry(report,
563 &hid->report_enum[HID_FEATURE_REPORT].report_list, list)
564 i2c_hid_init_report(report, inbuf, ihid->bufsize);
566 pm_runtime_put(&client->dev);
572 * Traverse the supplied list of reports and find the longest
574 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
577 struct hid_report *report;
580 /* We should not rely on wMaxInputLength, as some devices may set it to
582 list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
583 size = i2c_hid_get_report_length(report);
589 static void i2c_hid_free_buffers(struct i2c_hid *ihid)
593 kfree(ihid->argsbuf);
598 ihid->argsbuf = NULL;
602 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
604 /* the worst case is computed from the set_report command with a
605 * reportID > 15 and the maximum report length */
606 int args_len = sizeof(__u8) + /* optional ReportID byte */
607 sizeof(__u16) + /* data register */
608 sizeof(__u16) + /* size of the report */
609 report_size; /* report */
611 ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
612 ihid->rawbuf = kzalloc(report_size, GFP_KERNEL);
613 ihid->argsbuf = kzalloc(args_len, GFP_KERNEL);
614 ihid->cmdbuf = kzalloc(sizeof(union command) + args_len, GFP_KERNEL);
616 if (!ihid->inbuf || !ihid->rawbuf || !ihid->argsbuf || !ihid->cmdbuf) {
617 i2c_hid_free_buffers(ihid);
621 ihid->bufsize = report_size;
626 static int i2c_hid_get_raw_report(struct hid_device *hid,
627 unsigned char report_number, __u8 *buf, size_t count,
628 unsigned char report_type)
630 struct i2c_client *client = hid->driver_data;
631 struct i2c_hid *ihid = i2c_get_clientdata(client);
632 size_t ret_count, ask_count;
635 if (report_type == HID_OUTPUT_REPORT)
638 /* +2 bytes to include the size of the reply in the query buffer */
639 ask_count = min(count + 2, (size_t)ihid->bufsize);
641 ret = i2c_hid_get_report(client,
642 report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
643 report_number, ihid->rawbuf, ask_count);
648 ret_count = ihid->rawbuf[0] | (ihid->rawbuf[1] << 8);
653 ret_count = min(ret_count, ask_count);
655 /* The query buffer contains the size, dropping it in the reply */
656 count = min(count, ret_count - 2);
657 memcpy(buf, ihid->rawbuf + 2, count);
662 static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
663 size_t count, unsigned char report_type, bool use_data)
665 struct i2c_client *client = hid->driver_data;
666 struct i2c_hid *ihid = i2c_get_clientdata(client);
667 int report_id = buf[0];
670 if (report_type == HID_INPUT_REPORT)
673 mutex_lock(&ihid->reset_lock);
680 ret = i2c_hid_set_or_send_report(client,
681 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
682 report_id, buf, count, use_data);
684 if (report_id && ret >= 0)
685 ret++; /* add report_id to the number of transfered bytes */
687 mutex_unlock(&ihid->reset_lock);
692 static int i2c_hid_output_report(struct hid_device *hid, __u8 *buf,
695 return i2c_hid_output_raw_report(hid, buf, count, HID_OUTPUT_REPORT,
699 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
700 __u8 *buf, size_t len, unsigned char rtype,
704 case HID_REQ_GET_REPORT:
705 return i2c_hid_get_raw_report(hid, reportnum, buf, len, rtype);
706 case HID_REQ_SET_REPORT:
707 if (buf[0] != reportnum)
709 return i2c_hid_output_raw_report(hid, buf, len, rtype, true);
715 static int i2c_hid_parse(struct hid_device *hid)
717 struct i2c_client *client = hid->driver_data;
718 struct i2c_hid *ihid = i2c_get_clientdata(client);
719 struct i2c_hid_desc *hdesc = &ihid->hdesc;
725 i2c_hid_dbg(ihid, "entering %s\n", __func__);
727 rsize = le16_to_cpu(hdesc->wReportDescLength);
728 if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
729 dbg_hid("weird size of report descriptor (%u)\n", rsize);
734 ret = i2c_hid_hwreset(client);
737 } while (tries-- > 0 && ret);
742 rdesc = kzalloc(rsize, GFP_KERNEL);
745 dbg_hid("couldn't allocate rdesc memory\n");
749 i2c_hid_dbg(ihid, "asking HID report descriptor\n");
751 ret = i2c_hid_command(client, &hid_report_descr_cmd, rdesc, rsize);
753 hid_err(hid, "reading report descriptor failed\n");
758 i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
760 ret = hid_parse_report(hid, rdesc, rsize);
763 dbg_hid("parsing report descriptor failed\n");
770 static int i2c_hid_start(struct hid_device *hid)
772 struct i2c_client *client = hid->driver_data;
773 struct i2c_hid *ihid = i2c_get_clientdata(client);
775 unsigned int bufsize = HID_MIN_BUFFER_SIZE;
777 i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
778 i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
779 i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
781 if (bufsize > ihid->bufsize) {
782 disable_irq(client->irq);
783 i2c_hid_free_buffers(ihid);
785 ret = i2c_hid_alloc_buffers(ihid, bufsize);
786 enable_irq(client->irq);
792 if (!(hid->quirks & HID_QUIRK_NO_INIT_REPORTS))
793 i2c_hid_init_reports(hid);
798 static void i2c_hid_stop(struct hid_device *hid)
803 static int i2c_hid_open(struct hid_device *hid)
805 struct i2c_client *client = hid->driver_data;
806 struct i2c_hid *ihid = i2c_get_clientdata(client);
809 mutex_lock(&i2c_hid_open_mut);
811 ret = pm_runtime_get_sync(&client->dev);
816 set_bit(I2C_HID_STARTED, &ihid->flags);
819 mutex_unlock(&i2c_hid_open_mut);
820 return ret < 0 ? ret : 0;
823 static void i2c_hid_close(struct hid_device *hid)
825 struct i2c_client *client = hid->driver_data;
826 struct i2c_hid *ihid = i2c_get_clientdata(client);
828 /* protecting hid->open to make sure we don't restart
829 * data acquistion due to a resumption we no longer
832 mutex_lock(&i2c_hid_open_mut);
834 clear_bit(I2C_HID_STARTED, &ihid->flags);
836 /* Save some power */
837 pm_runtime_put(&client->dev);
839 mutex_unlock(&i2c_hid_open_mut);
842 static int i2c_hid_power(struct hid_device *hid, int lvl)
844 struct i2c_client *client = hid->driver_data;
845 struct i2c_hid *ihid = i2c_get_clientdata(client);
847 i2c_hid_dbg(ihid, "%s lvl:%d\n", __func__, lvl);
851 pm_runtime_get_sync(&client->dev);
854 pm_runtime_put(&client->dev);
860 static struct hid_ll_driver i2c_hid_ll_driver = {
861 .parse = i2c_hid_parse,
862 .start = i2c_hid_start,
863 .stop = i2c_hid_stop,
864 .open = i2c_hid_open,
865 .close = i2c_hid_close,
866 .power = i2c_hid_power,
867 .output_report = i2c_hid_output_report,
868 .raw_request = i2c_hid_raw_request,
871 static int i2c_hid_init_irq(struct i2c_client *client)
873 struct i2c_hid *ihid = i2c_get_clientdata(client);
874 unsigned long irqflags = 0;
877 dev_dbg(&client->dev, "Requesting IRQ: %d\n", client->irq);
879 if (!irq_get_trigger_type(client->irq))
880 irqflags = IRQF_TRIGGER_LOW;
882 ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq,
883 irqflags | IRQF_ONESHOT, client->name, ihid);
885 dev_warn(&client->dev,
886 "Could not register for %s interrupt, irq = %d,"
888 client->name, client->irq, ret);
896 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
898 struct i2c_client *client = ihid->client;
899 struct i2c_hid_desc *hdesc = &ihid->hdesc;
903 /* i2c hid fetch using a fixed descriptor size (30 bytes) */
904 i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
905 ret = i2c_hid_command(client, &hid_descr_cmd, ihid->hdesc_buffer,
906 sizeof(struct i2c_hid_desc));
908 dev_err(&client->dev, "hid_descr_cmd failed\n");
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(&client->dev,
918 "unexpected HID descriptor bcdVersion (0x%04hx)\n",
919 le16_to_cpu(hdesc->bcdVersion));
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(&client->dev, "weird size of HID descriptor (%u)\n",
930 i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer);
935 static int i2c_hid_acpi_pdata(struct i2c_client *client,
936 struct i2c_hid_platform_data *pdata)
938 static u8 i2c_hid_guid[] = {
939 0xF7, 0xF6, 0xDF, 0x3C, 0x67, 0x42, 0x55, 0x45,
940 0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE,
942 union acpi_object *obj;
943 struct acpi_device *adev;
946 handle = ACPI_HANDLE(&client->dev);
947 if (!handle || acpi_bus_get_device(handle, &adev))
950 obj = acpi_evaluate_dsm_typed(handle, i2c_hid_guid, 1, 1, NULL,
953 dev_err(&client->dev, "device _DSM execution failed\n");
957 pdata->hid_descriptor_address = obj->integer.value;
963 static const struct acpi_device_id i2c_hid_acpi_match[] = {
968 MODULE_DEVICE_TABLE(acpi, i2c_hid_acpi_match);
970 static inline int i2c_hid_acpi_pdata(struct i2c_client *client,
971 struct i2c_hid_platform_data *pdata)
978 static int i2c_hid_of_probe(struct i2c_client *client,
979 struct i2c_hid_platform_data *pdata)
981 struct device *dev = &client->dev;
985 ret = of_property_read_u32(dev->of_node, "hid-descr-addr", &val);
987 dev_err(&client->dev, "HID register address not provided\n");
991 dev_err(&client->dev, "Bad HID register address: 0x%08x\n",
995 pdata->hid_descriptor_address = val;
1000 static const struct of_device_id i2c_hid_of_match[] = {
1001 { .compatible = "hid-over-i2c" },
1004 MODULE_DEVICE_TABLE(of, i2c_hid_of_match);
1006 static inline int i2c_hid_of_probe(struct i2c_client *client,
1007 struct i2c_hid_platform_data *pdata)
1013 static int i2c_hid_probe(struct i2c_client *client,
1014 const struct i2c_device_id *dev_id)
1017 struct i2c_hid *ihid;
1018 struct hid_device *hid;
1020 struct i2c_hid_platform_data *platform_data = client->dev.platform_data;
1022 dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
1025 dev_err(&client->dev,
1026 "HID over i2c has not been provided an Int IRQ\n");
1030 if (client->irq < 0) {
1031 if (client->irq != -EPROBE_DEFER)
1032 dev_err(&client->dev,
1033 "HID over i2c doesn't have a valid IRQ\n");
1037 ihid = kzalloc(sizeof(struct i2c_hid), GFP_KERNEL);
1041 if (client->dev.of_node) {
1042 ret = i2c_hid_of_probe(client, &ihid->pdata);
1045 } else if (!platform_data) {
1046 ret = i2c_hid_acpi_pdata(client, &ihid->pdata);
1048 dev_err(&client->dev,
1049 "HID register address not provided\n");
1053 ihid->pdata = *platform_data;
1056 i2c_set_clientdata(client, ihid);
1058 ihid->client = client;
1060 hidRegister = ihid->pdata.hid_descriptor_address;
1061 ihid->wHIDDescRegister = cpu_to_le16(hidRegister);
1063 init_waitqueue_head(&ihid->wait);
1064 mutex_init(&ihid->reset_lock);
1066 /* we need to allocate the command buffer without knowing the maximum
1067 * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
1068 * real computation later. */
1069 ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
1073 pm_runtime_get_noresume(&client->dev);
1074 pm_runtime_set_active(&client->dev);
1075 pm_runtime_enable(&client->dev);
1076 device_enable_async_suspend(&client->dev);
1078 ret = i2c_hid_fetch_hid_descriptor(ihid);
1082 ret = i2c_hid_init_irq(client);
1086 hid = hid_allocate_device();
1094 hid->driver_data = client;
1095 hid->ll_driver = &i2c_hid_ll_driver;
1096 hid->dev.parent = &client->dev;
1098 hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
1099 hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
1100 hid->product = le16_to_cpu(ihid->hdesc.wProductID);
1102 snprintf(hid->name, sizeof(hid->name), "%s %04hX:%04hX",
1103 client->name, hid->vendor, hid->product);
1104 strlcpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys));
1106 ihid->quirks = i2c_hid_lookup_quirk(hid->vendor, hid->product);
1108 ret = hid_add_device(hid);
1111 hid_err(client, "can't add hid device: %d\n", ret);
1115 pm_runtime_put(&client->dev);
1119 hid_destroy_device(hid);
1122 free_irq(client->irq, ihid);
1125 pm_runtime_put_noidle(&client->dev);
1126 pm_runtime_disable(&client->dev);
1129 i2c_hid_free_buffers(ihid);
1134 static int i2c_hid_remove(struct i2c_client *client)
1136 struct i2c_hid *ihid = i2c_get_clientdata(client);
1137 struct hid_device *hid;
1139 pm_runtime_get_sync(&client->dev);
1140 pm_runtime_disable(&client->dev);
1141 pm_runtime_set_suspended(&client->dev);
1142 pm_runtime_put_noidle(&client->dev);
1145 hid_destroy_device(hid);
1147 free_irq(client->irq, ihid);
1150 i2c_hid_free_buffers(ihid);
1157 static void i2c_hid_shutdown(struct i2c_client *client)
1159 struct i2c_hid *ihid = i2c_get_clientdata(client);
1161 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1162 free_irq(client->irq, ihid);
1165 #ifdef CONFIG_PM_SLEEP
1166 static int i2c_hid_suspend(struct device *dev)
1168 struct i2c_client *client = to_i2c_client(dev);
1169 struct i2c_hid *ihid = i2c_get_clientdata(client);
1170 struct hid_device *hid = ihid->hid;
1174 if (hid->driver && hid->driver->suspend) {
1176 * Wake up the device so that IO issues in
1177 * HID driver's suspend code can succeed.
1179 ret = pm_runtime_resume(dev);
1183 ret = hid->driver->suspend(hid, PMSG_SUSPEND);
1188 if (!pm_runtime_suspended(dev)) {
1189 /* Save some power */
1190 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1192 disable_irq(client->irq);
1195 if (device_may_wakeup(&client->dev)) {
1196 wake_status = enable_irq_wake(client->irq);
1198 ihid->irq_wake_enabled = true;
1200 hid_warn(hid, "Failed to enable irq wake: %d\n",
1207 static int i2c_hid_resume(struct device *dev)
1210 struct i2c_client *client = to_i2c_client(dev);
1211 struct i2c_hid *ihid = i2c_get_clientdata(client);
1212 struct hid_device *hid = ihid->hid;
1215 if (device_may_wakeup(&client->dev) && ihid->irq_wake_enabled) {
1216 wake_status = disable_irq_wake(client->irq);
1218 ihid->irq_wake_enabled = false;
1220 hid_warn(hid, "Failed to disable irq wake: %d\n",
1224 /* We'll resume to full power */
1225 pm_runtime_disable(dev);
1226 pm_runtime_set_active(dev);
1227 pm_runtime_enable(dev);
1229 enable_irq(client->irq);
1230 ret = i2c_hid_hwreset(client);
1234 if (hid->driver && hid->driver->reset_resume) {
1235 ret = hid->driver->reset_resume(hid);
1244 static int i2c_hid_runtime_suspend(struct device *dev)
1246 struct i2c_client *client = to_i2c_client(dev);
1248 i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1249 disable_irq(client->irq);
1253 static int i2c_hid_runtime_resume(struct device *dev)
1255 struct i2c_client *client = to_i2c_client(dev);
1257 enable_irq(client->irq);
1258 i2c_hid_set_power(client, I2C_HID_PWR_ON);
1263 static const struct dev_pm_ops i2c_hid_pm = {
1264 SET_SYSTEM_SLEEP_PM_OPS(i2c_hid_suspend, i2c_hid_resume)
1265 SET_RUNTIME_PM_OPS(i2c_hid_runtime_suspend, i2c_hid_runtime_resume,
1269 static const struct i2c_device_id i2c_hid_id_table[] = {
1271 { "hid-over-i2c", 0 },
1274 MODULE_DEVICE_TABLE(i2c, i2c_hid_id_table);
1277 static struct i2c_driver i2c_hid_driver = {
1281 .acpi_match_table = ACPI_PTR(i2c_hid_acpi_match),
1282 .of_match_table = of_match_ptr(i2c_hid_of_match),
1285 .probe = i2c_hid_probe,
1286 .remove = i2c_hid_remove,
1287 .shutdown = i2c_hid_shutdown,
1288 .id_table = i2c_hid_id_table,
1291 module_i2c_driver(i2c_hid_driver);
1293 MODULE_DESCRIPTION("HID over I2C core driver");
1294 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
1295 MODULE_LICENSE("GPL");