1 // SPDX-License-Identifier: GPL-2.0
2 // ChromeOS EC keyboard driver
4 // Copyright (C) 2012 Google, Inc.
6 // This driver uses the ChromeOS EC byte-level message-based protocol for
7 // communicating the keyboard state (which keys are pressed) from a keyboard EC
8 // to the AP over some bus (such as i2c, lpc, spi). The EC does debouncing,
9 // but everything else (including deghosting) is done here. The main
10 // motivation for this is to keep the EC firmware as simple as possible, since
11 // it cannot be easily upgraded and EC flash/IRAM space is relatively
14 #include <linux/module.h>
15 #include <linux/acpi.h>
16 #include <linux/bitops.h>
17 #include <linux/i2c.h>
18 #include <linux/input.h>
19 #include <linux/input/vivaldi-fmap.h>
20 #include <linux/interrupt.h>
21 #include <linux/kernel.h>
22 #include <linux/notifier.h>
23 #include <linux/platform_device.h>
24 #include <linux/slab.h>
25 #include <linux/sysrq.h>
26 #include <linux/input/matrix_keypad.h>
27 #include <linux/platform_data/cros_ec_commands.h>
28 #include <linux/platform_data/cros_ec_proto.h>
30 #include <linux/unaligned.h>
33 * struct cros_ec_keyb - Structure representing EC keyboard device
35 * @rows: Number of rows in the keypad
36 * @cols: Number of columns in the keypad
37 * @row_shift: log2 or number of rows, rounded up
38 * @ghost_filter: true to enable the matrix key-ghosting filter
39 * @valid_keys: bitmap of existing keys for each matrix column
40 * @old_kb_state: bitmap of keys pressed last scan
41 * @dev: Device pointer
42 * @ec: Top level ChromeOS device to use to talk to EC
43 * @idev: The input device for the matrix keys.
44 * @bs_idev: The input device for non-matrix buttons and switches (or NULL).
45 * @notifier: interrupt event notifier for transport devices
46 * @vdata: vivaldi function row data
54 uint8_t *old_kb_state
;
57 struct cros_ec_device
*ec
;
59 struct input_dev
*idev
;
60 struct input_dev
*bs_idev
;
61 struct notifier_block notifier
;
63 struct vivaldi_data vdata
;
67 * struct cros_ec_bs_map - Mapping between Linux keycodes and EC button/switch
70 * @ev_type: The type of the input event to generate (e.g., EV_KEY).
71 * @code: A linux keycode
72 * @bit: A #define like EC_MKBP_POWER_BUTTON or EC_MKBP_LID_OPEN
73 * @inverted: If the #define and EV_SW have opposite meanings, this is true.
74 * Only applicable to switches.
76 struct cros_ec_bs_map
{
83 /* cros_ec_keyb_bs - Map EC button/switch #defines into kernel ones */
84 static const struct cros_ec_bs_map cros_ec_keyb_bs
[] = {
89 .bit
= EC_MKBP_POWER_BUTTON
,
94 .bit
= EC_MKBP_VOL_UP
,
98 .code
= KEY_VOLUMEDOWN
,
99 .bit
= EC_MKBP_VOL_DOWN
,
103 .code
= KEY_BRIGHTNESSUP
,
104 .bit
= EC_MKBP_BRI_UP
,
108 .code
= KEY_BRIGHTNESSDOWN
,
109 .bit
= EC_MKBP_BRI_DOWN
,
113 .code
= KEY_SCREENLOCK
,
114 .bit
= EC_MKBP_SCREEN_LOCK
,
121 .bit
= EC_MKBP_LID_OPEN
,
126 .code
= SW_TABLET_MODE
,
127 .bit
= EC_MKBP_TABLET_MODE
,
132 * Returns true when there is at least one combination of pressed keys that
133 * results in ghosting.
135 static bool cros_ec_keyb_has_ghosting(struct cros_ec_keyb
*ckdev
, uint8_t *buf
)
137 int col1
, col2
, buf1
, buf2
;
138 struct device
*dev
= ckdev
->dev
;
139 uint8_t *valid_keys
= ckdev
->valid_keys
;
142 * Ghosting happens if for any pressed key X there are other keys
143 * pressed both in the same row and column of X as, for instance,
144 * in the following diagram:
151 * In this case only X, Y, and Z are pressed, but g appears to be
152 * pressed too (see Wikipedia).
154 for (col1
= 0; col1
< ckdev
->cols
; col1
++) {
155 buf1
= buf
[col1
] & valid_keys
[col1
];
156 for (col2
= col1
+ 1; col2
< ckdev
->cols
; col2
++) {
157 buf2
= buf
[col2
] & valid_keys
[col2
];
158 if (hweight8(buf1
& buf2
) > 1) {
159 dev_dbg(dev
, "ghost found at: B[%02d]:0x%02x & B[%02d]:0x%02x",
160 col1
, buf1
, col2
, buf2
);
171 * Compares the new keyboard state to the old one and produces key
172 * press/release events accordingly. The keyboard state is 13 bytes (one byte
175 static void cros_ec_keyb_process(struct cros_ec_keyb
*ckdev
,
176 uint8_t *kb_state
, int len
)
178 struct input_dev
*idev
= ckdev
->idev
;
183 if (ckdev
->ghost_filter
&& cros_ec_keyb_has_ghosting(ckdev
, kb_state
)) {
185 * Simple-minded solution: ignore this state. The obvious
186 * improvement is to only ignore changes to keys involved in
187 * the ghosting, but process the other changes.
189 dev_dbg(ckdev
->dev
, "ghosting found\n");
193 for (col
= 0; col
< ckdev
->cols
; col
++) {
194 for (row
= 0; row
< ckdev
->rows
; row
++) {
195 int pos
= MATRIX_SCAN_CODE(row
, col
, ckdev
->row_shift
);
196 const unsigned short *keycodes
= idev
->keycode
;
198 new_state
= kb_state
[col
] & (1 << row
);
199 old_state
= ckdev
->old_kb_state
[col
] & (1 << row
);
200 if (new_state
!= old_state
) {
202 "changed: [r%d c%d]: byte %02x\n",
203 row
, col
, new_state
);
205 input_event(idev
, EV_MSC
, MSC_SCAN
, pos
);
206 input_report_key(idev
, keycodes
[pos
],
210 ckdev
->old_kb_state
[col
] = kb_state
[col
];
212 input_sync(ckdev
->idev
);
216 * cros_ec_keyb_report_bs - Report non-matrixed buttons or switches
218 * This takes a bitmap of buttons or switches from the EC and reports events,
219 * syncing at the end.
221 * @ckdev: The keyboard device.
222 * @ev_type: The input event type (e.g., EV_KEY).
223 * @mask: A bitmap of buttons from the EC.
225 static void cros_ec_keyb_report_bs(struct cros_ec_keyb
*ckdev
,
226 unsigned int ev_type
, u32 mask
)
229 struct input_dev
*idev
= ckdev
->bs_idev
;
232 for (i
= 0; i
< ARRAY_SIZE(cros_ec_keyb_bs
); i
++) {
233 const struct cros_ec_bs_map
*map
= &cros_ec_keyb_bs
[i
];
235 if (map
->ev_type
!= ev_type
)
238 input_event(idev
, ev_type
, map
->code
,
239 !!(mask
& BIT(map
->bit
)) ^ map
->inverted
);
244 static int cros_ec_keyb_work(struct notifier_block
*nb
,
245 unsigned long queued_during_suspend
, void *_notify
)
247 struct cros_ec_keyb
*ckdev
= container_of(nb
, struct cros_ec_keyb
,
250 unsigned int ev_type
;
253 * If not wake enabled, discard key state changes during
254 * suspend. Switches will be re-checked in
255 * cros_ec_keyb_resume() to be sure nothing is lost.
257 if (queued_during_suspend
&& !device_may_wakeup(ckdev
->dev
))
260 switch (ckdev
->ec
->event_data
.event_type
) {
261 case EC_MKBP_EVENT_KEY_MATRIX
:
262 pm_wakeup_event(ckdev
->dev
, 0);
264 if (ckdev
->ec
->event_size
!= ckdev
->cols
) {
266 "Discarded incomplete key matrix event.\n");
270 cros_ec_keyb_process(ckdev
,
271 ckdev
->ec
->event_data
.data
.key_matrix
,
272 ckdev
->ec
->event_size
);
275 case EC_MKBP_EVENT_SYSRQ
:
276 pm_wakeup_event(ckdev
->dev
, 0);
278 val
= get_unaligned_le32(&ckdev
->ec
->event_data
.data
.sysrq
);
279 dev_dbg(ckdev
->dev
, "sysrq code from EC: %#x\n", val
);
283 case EC_MKBP_EVENT_BUTTON
:
284 case EC_MKBP_EVENT_SWITCH
:
285 pm_wakeup_event(ckdev
->dev
, 0);
287 if (ckdev
->ec
->event_data
.event_type
== EC_MKBP_EVENT_BUTTON
) {
288 val
= get_unaligned_le32(
289 &ckdev
->ec
->event_data
.data
.buttons
);
292 val
= get_unaligned_le32(
293 &ckdev
->ec
->event_data
.data
.switches
);
296 cros_ec_keyb_report_bs(ckdev
, ev_type
, val
);
307 * Walks keycodes flipping bit in buffer COLUMNS deep where bit is ROW. Used by
308 * ghosting logic to ignore NULL or virtual keys.
310 static void cros_ec_keyb_compute_valid_keys(struct cros_ec_keyb
*ckdev
)
313 int row_shift
= ckdev
->row_shift
;
314 unsigned short *keymap
= ckdev
->idev
->keycode
;
317 BUG_ON(ckdev
->idev
->keycodesize
!= sizeof(*keymap
));
319 for (col
= 0; col
< ckdev
->cols
; col
++) {
320 for (row
= 0; row
< ckdev
->rows
; row
++) {
321 code
= keymap
[MATRIX_SCAN_CODE(row
, col
, row_shift
)];
322 if (code
&& (code
!= KEY_BATTERY
))
323 ckdev
->valid_keys
[col
] |= 1 << row
;
325 dev_dbg(ckdev
->dev
, "valid_keys[%02d] = 0x%02x\n",
326 col
, ckdev
->valid_keys
[col
]);
331 * cros_ec_keyb_info - Wrap the EC command EC_CMD_MKBP_INFO
333 * This wraps the EC_CMD_MKBP_INFO, abstracting out all of the marshalling and
334 * unmarshalling and different version nonsense into something simple.
336 * @ec_dev: The EC device
337 * @info_type: Either EC_MKBP_INFO_SUPPORTED or EC_MKBP_INFO_CURRENT.
338 * @event_type: Either EC_MKBP_EVENT_BUTTON or EC_MKBP_EVENT_SWITCH. Actually
339 * in some cases this could be EC_MKBP_EVENT_KEY_MATRIX or
340 * EC_MKBP_EVENT_HOST_EVENT too but we don't use in this driver.
341 * @result: Where we'll store the result; a union
342 * @result_size: The size of the result. Expected to be the size of one of
343 * the elements in the union.
345 * Returns 0 if no error or -error upon error.
347 static int cros_ec_keyb_info(struct cros_ec_device
*ec_dev
,
348 enum ec_mkbp_info_type info_type
,
349 enum ec_mkbp_event event_type
,
350 union ec_response_get_next_data
*result
,
353 struct ec_params_mkbp_info
*params
;
354 struct cros_ec_command
*msg
;
357 msg
= kzalloc(sizeof(*msg
) + max_t(size_t, result_size
,
358 sizeof(*params
)), GFP_KERNEL
);
362 msg
->command
= EC_CMD_MKBP_INFO
;
364 msg
->outsize
= sizeof(*params
);
365 msg
->insize
= result_size
;
366 params
= (struct ec_params_mkbp_info
*)msg
->data
;
367 params
->info_type
= info_type
;
368 params
->event_type
= event_type
;
370 ret
= cros_ec_cmd_xfer_status(ec_dev
, msg
);
371 if (ret
== -ENOPROTOOPT
) {
372 /* With older ECs we just return 0 for everything */
373 memset(result
, 0, result_size
);
375 } else if (ret
< 0) {
376 dev_warn(ec_dev
->dev
, "Transfer error %d/%d: %d\n",
377 (int)info_type
, (int)event_type
, ret
);
378 } else if (ret
!= result_size
) {
379 dev_warn(ec_dev
->dev
, "Wrong size %d/%d: %d != %zu\n",
380 (int)info_type
, (int)event_type
,
384 memcpy(result
, msg
->data
, result_size
);
394 * cros_ec_keyb_query_switches - Query the state of switches and report
396 * This will ask the EC about the current state of switches and report to the
397 * kernel. Note that we don't query for buttons because they are more
398 * transitory and we'll get an update on the next release / press.
400 * @ckdev: The keyboard device
402 * Returns 0 if no error or -error upon error.
404 static int cros_ec_keyb_query_switches(struct cros_ec_keyb
*ckdev
)
406 struct cros_ec_device
*ec_dev
= ckdev
->ec
;
407 union ec_response_get_next_data event_data
= {};
410 ret
= cros_ec_keyb_info(ec_dev
, EC_MKBP_INFO_CURRENT
,
411 EC_MKBP_EVENT_SWITCH
, &event_data
,
412 sizeof(event_data
.switches
));
416 cros_ec_keyb_report_bs(ckdev
, EV_SW
,
417 get_unaligned_le32(&event_data
.switches
));
423 * cros_ec_keyb_resume - Resume the keyboard
425 * We use the resume notification as a chance to query the EC for switches.
427 * @dev: The keyboard device
429 * Returns 0 if no error or -error upon error.
431 static int cros_ec_keyb_resume(struct device
*dev
)
433 struct cros_ec_keyb
*ckdev
= dev_get_drvdata(dev
);
436 return cros_ec_keyb_query_switches(ckdev
);
442 * cros_ec_keyb_register_bs - Register non-matrix buttons/switches
444 * Handles all the bits of the keyboard driver related to non-matrix buttons
445 * and switches, including asking the EC about which are present and telling
446 * the kernel to expect them.
448 * If this device has no support for buttons and switches we'll return no error
449 * but the ckdev->bs_idev will remain NULL when this function exits.
451 * @ckdev: The keyboard device
452 * @expect_buttons_switches: Indicates that EC must report button and/or
455 * Returns 0 if no error or -error upon error.
457 static int cros_ec_keyb_register_bs(struct cros_ec_keyb
*ckdev
,
458 bool expect_buttons_switches
)
460 struct cros_ec_device
*ec_dev
= ckdev
->ec
;
461 struct device
*dev
= ckdev
->dev
;
462 struct input_dev
*idev
;
463 union ec_response_get_next_data event_data
= {};
470 ret
= cros_ec_keyb_info(ec_dev
, EC_MKBP_INFO_SUPPORTED
,
471 EC_MKBP_EVENT_BUTTON
, &event_data
,
472 sizeof(event_data
.buttons
));
475 buttons
= get_unaligned_le32(&event_data
.buttons
);
477 ret
= cros_ec_keyb_info(ec_dev
, EC_MKBP_INFO_SUPPORTED
,
478 EC_MKBP_EVENT_SWITCH
, &event_data
,
479 sizeof(event_data
.switches
));
482 switches
= get_unaligned_le32(&event_data
.switches
);
484 if (!buttons
&& !switches
)
485 return expect_buttons_switches
? -EINVAL
: 0;
488 * We call the non-matrix buttons/switches 'input1', if present.
489 * Allocate phys before input dev, to ensure correct tear-down
492 phys
= devm_kasprintf(dev
, GFP_KERNEL
, "%s/input1", ec_dev
->phys_name
);
496 idev
= devm_input_allocate_device(dev
);
500 idev
->name
= "cros_ec_buttons";
502 __set_bit(EV_REP
, idev
->evbit
);
504 idev
->id
.bustype
= BUS_VIRTUAL
;
505 idev
->id
.version
= 1;
506 idev
->id
.product
= 0;
507 idev
->dev
.parent
= dev
;
509 input_set_drvdata(idev
, ckdev
);
510 ckdev
->bs_idev
= idev
;
512 for (i
= 0; i
< ARRAY_SIZE(cros_ec_keyb_bs
); i
++) {
513 const struct cros_ec_bs_map
*map
= &cros_ec_keyb_bs
[i
];
515 if ((map
->ev_type
== EV_KEY
&& (buttons
& BIT(map
->bit
))) ||
516 (map
->ev_type
== EV_SW
&& (switches
& BIT(map
->bit
))))
517 input_set_capability(idev
, map
->ev_type
, map
->code
);
520 ret
= cros_ec_keyb_query_switches(ckdev
);
522 dev_err(dev
, "cannot query switches\n");
526 ret
= input_register_device(ckdev
->bs_idev
);
528 dev_err(dev
, "cannot register input device\n");
535 static void cros_ec_keyb_parse_vivaldi_physmap(struct cros_ec_keyb
*ckdev
)
537 u32
*physmap
= ckdev
->vdata
.function_row_physmap
;
538 unsigned int row
, col
, scancode
;
543 n_physmap
= device_property_count_u32(ckdev
->dev
,
544 "function-row-physmap");
548 if (n_physmap
>= VIVALDI_MAX_FUNCTION_ROW_KEYS
) {
550 "only up to %d top row keys is supported (%d specified)\n",
551 VIVALDI_MAX_FUNCTION_ROW_KEYS
, n_physmap
);
552 n_physmap
= VIVALDI_MAX_FUNCTION_ROW_KEYS
;
555 error
= device_property_read_u32_array(ckdev
->dev
,
556 "function-row-physmap",
560 "failed to parse function-row-physmap property: %d\n",
566 * Convert (in place) from row/column encoding to matrix "scancode"
567 * used by the driver.
569 for (i
= 0; i
< n_physmap
; i
++) {
570 row
= KEY_ROW(physmap
[i
]);
571 col
= KEY_COL(physmap
[i
]);
572 scancode
= MATRIX_SCAN_CODE(row
, col
, ckdev
->row_shift
);
573 physmap
[i
] = scancode
;
576 ckdev
->vdata
.num_function_row_keys
= n_physmap
;
580 * cros_ec_keyb_register_matrix - Register matrix keys
582 * Handles all the bits of the keyboard driver related to matrix keys.
584 * @ckdev: The keyboard device
586 * Returns 0 if no error or -error upon error.
588 static int cros_ec_keyb_register_matrix(struct cros_ec_keyb
*ckdev
)
590 struct cros_ec_device
*ec_dev
= ckdev
->ec
;
591 struct device
*dev
= ckdev
->dev
;
592 struct input_dev
*idev
;
596 err
= matrix_keypad_parse_properties(dev
, &ckdev
->rows
, &ckdev
->cols
);
600 ckdev
->valid_keys
= devm_kzalloc(dev
, ckdev
->cols
, GFP_KERNEL
);
601 if (!ckdev
->valid_keys
)
604 ckdev
->old_kb_state
= devm_kzalloc(dev
, ckdev
->cols
, GFP_KERNEL
);
605 if (!ckdev
->old_kb_state
)
609 * We call the keyboard matrix 'input0'. Allocate phys before input
610 * dev, to ensure correct tear-down ordering.
612 phys
= devm_kasprintf(dev
, GFP_KERNEL
, "%s/input0", ec_dev
->phys_name
);
616 idev
= devm_input_allocate_device(dev
);
620 idev
->name
= CROS_EC_DEV_NAME
;
622 __set_bit(EV_REP
, idev
->evbit
);
624 idev
->id
.bustype
= BUS_VIRTUAL
;
625 idev
->id
.version
= 1;
626 idev
->id
.product
= 0;
627 idev
->dev
.parent
= dev
;
629 ckdev
->ghost_filter
= device_property_read_bool(dev
,
630 "google,needs-ghost-filter");
632 err
= matrix_keypad_build_keymap(NULL
, NULL
, ckdev
->rows
, ckdev
->cols
,
635 dev_err(dev
, "cannot build key matrix\n");
639 ckdev
->row_shift
= get_count_order(ckdev
->cols
);
641 input_set_capability(idev
, EV_MSC
, MSC_SCAN
);
642 input_set_drvdata(idev
, ckdev
);
644 cros_ec_keyb_compute_valid_keys(ckdev
);
645 cros_ec_keyb_parse_vivaldi_physmap(ckdev
);
647 err
= input_register_device(ckdev
->idev
);
649 dev_err(dev
, "cannot register input device\n");
656 static ssize_t
function_row_physmap_show(struct device
*dev
,
657 struct device_attribute
*attr
,
660 const struct cros_ec_keyb
*ckdev
= dev_get_drvdata(dev
);
661 const struct vivaldi_data
*data
= &ckdev
->vdata
;
663 return vivaldi_function_row_physmap_show(data
, buf
);
666 static DEVICE_ATTR_RO(function_row_physmap
);
668 static struct attribute
*cros_ec_keyb_attrs
[] = {
669 &dev_attr_function_row_physmap
.attr
,
673 static umode_t
cros_ec_keyb_attr_is_visible(struct kobject
*kobj
,
674 struct attribute
*attr
,
677 struct device
*dev
= kobj_to_dev(kobj
);
678 struct cros_ec_keyb
*ckdev
= dev_get_drvdata(dev
);
680 if (attr
== &dev_attr_function_row_physmap
.attr
&&
681 !ckdev
->vdata
.num_function_row_keys
)
687 static const struct attribute_group cros_ec_keyb_group
= {
688 .is_visible
= cros_ec_keyb_attr_is_visible
,
689 .attrs
= cros_ec_keyb_attrs
,
691 __ATTRIBUTE_GROUPS(cros_ec_keyb
);
693 static int cros_ec_keyb_probe(struct platform_device
*pdev
)
695 struct cros_ec_device
*ec
;
696 struct device
*dev
= &pdev
->dev
;
697 struct cros_ec_keyb
*ckdev
;
698 bool buttons_switches_only
= device_get_match_data(dev
);
702 * If the parent ec device has not been probed yet, defer the probe of
703 * this keyboard/button driver until later.
705 ec
= dev_get_drvdata(pdev
->dev
.parent
);
707 return -EPROBE_DEFER
;
709 ckdev
= devm_kzalloc(dev
, sizeof(*ckdev
), GFP_KERNEL
);
715 dev_set_drvdata(dev
, ckdev
);
717 if (!buttons_switches_only
) {
718 err
= cros_ec_keyb_register_matrix(ckdev
);
720 dev_err(dev
, "cannot register matrix inputs: %d\n",
726 err
= cros_ec_keyb_register_bs(ckdev
, buttons_switches_only
);
728 dev_err(dev
, "cannot register non-matrix inputs: %d\n", err
);
732 ckdev
->notifier
.notifier_call
= cros_ec_keyb_work
;
733 err
= blocking_notifier_chain_register(&ckdev
->ec
->event_notifier
,
736 dev_err(dev
, "cannot register notifier: %d\n", err
);
740 device_init_wakeup(ckdev
->dev
, true);
744 static void cros_ec_keyb_remove(struct platform_device
*pdev
)
746 struct cros_ec_keyb
*ckdev
= dev_get_drvdata(&pdev
->dev
);
748 blocking_notifier_chain_unregister(&ckdev
->ec
->event_notifier
,
753 static const struct acpi_device_id cros_ec_keyb_acpi_match
[] = {
754 { "GOOG0007", true },
757 MODULE_DEVICE_TABLE(acpi
, cros_ec_keyb_acpi_match
);
761 static const struct of_device_id cros_ec_keyb_of_match
[] = {
762 { .compatible
= "google,cros-ec-keyb" },
763 { .compatible
= "google,cros-ec-keyb-switches", .data
= (void *)true },
766 MODULE_DEVICE_TABLE(of
, cros_ec_keyb_of_match
);
769 static DEFINE_SIMPLE_DEV_PM_OPS(cros_ec_keyb_pm_ops
, NULL
, cros_ec_keyb_resume
);
771 static struct platform_driver cros_ec_keyb_driver
= {
772 .probe
= cros_ec_keyb_probe
,
773 .remove_new
= cros_ec_keyb_remove
,
775 .name
= "cros-ec-keyb",
776 .dev_groups
= cros_ec_keyb_groups
,
777 .of_match_table
= of_match_ptr(cros_ec_keyb_of_match
),
778 .acpi_match_table
= ACPI_PTR(cros_ec_keyb_acpi_match
),
779 .pm
= pm_sleep_ptr(&cros_ec_keyb_pm_ops
),
783 module_platform_driver(cros_ec_keyb_driver
);
785 MODULE_LICENSE("GPL v2");
786 MODULE_DESCRIPTION("ChromeOS EC keyboard driver");
787 MODULE_ALIAS("platform:cros-ec-keyb");