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1/*
2 * ChromeOS EC keyboard driver
3 *
4 * Copyright (C) 2012 Google, Inc
5 *
6 * This software is licensed under the terms of the GNU General Public
7 * License version 2, as published by the Free Software Foundation, and
8 * may be copied, distributed, and modified under those terms.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * This driver uses the Chrome OS EC byte-level message-based protocol for
16 * communicating the keyboard state (which keys are pressed) from a keyboard EC
17 * to the AP over some bus (such as i2c, lpc, spi). The EC does debouncing,
18 * but everything else (including deghosting) is done here. The main
19 * motivation for this is to keep the EC firmware as simple as possible, since
20 * it cannot be easily upgraded and EC flash/IRAM space is relatively
21 * expensive.
22 */
23
24#include <linux/module.h>
25#include <linux/bitops.h>
26#include <linux/i2c.h>
27#include <linux/input.h>
28#include <linux/interrupt.h>
29#include <linux/kernel.h>
30#include <linux/platform_device.h>
31#include <linux/slab.h>
32#include <linux/input/matrix_keypad.h>
33#include <linux/mfd/cros_ec.h>
34#include <linux/mfd/cros_ec_commands.h>
35
36/*
37 * @rows: Number of rows in the keypad
38 * @cols: Number of columns in the keypad
39 * @row_shift: log2 or number of rows, rounded up
40 * @keymap_data: Matrix keymap data used to convert to keyscan values
41 * @ghost_filter: true to enable the matrix key-ghosting filter
42 * @valid_keys: bitmap of existing keys for each matrix column
43 * @old_kb_state: bitmap of keys pressed last scan
44 * @dev: Device pointer
45 * @idev: Input device
46 * @ec: Top level ChromeOS device to use to talk to EC
47 */
48struct cros_ec_keyb {
49 unsigned int rows;
50 unsigned int cols;
51 int row_shift;
52 const struct matrix_keymap_data *keymap_data;
53 bool ghost_filter;
54 uint8_t *valid_keys;
55 uint8_t *old_kb_state;
56
57 struct device *dev;
58 struct input_dev *idev;
59 struct cros_ec_device *ec;
60};
61
62
63/*
64 * Returns true when there is at least one combination of pressed keys that
65 * results in ghosting.
66 */
67static bool cros_ec_keyb_has_ghosting(struct cros_ec_keyb *ckdev, uint8_t *buf)
68{
69 int col1, col2, buf1, buf2;
70 struct device *dev = ckdev->dev;
71 uint8_t *valid_keys = ckdev->valid_keys;
72
73 /*
74 * Ghosting happens if for any pressed key X there are other keys
75 * pressed both in the same row and column of X as, for instance,
76 * in the following diagram:
77 *
78 * . . Y . g .
79 * . . . . . .
80 * . . . . . .
81 * . . X . Z .
82 *
83 * In this case only X, Y, and Z are pressed, but g appears to be
84 * pressed too (see Wikipedia).
85 */
86 for (col1 = 0; col1 < ckdev->cols; col1++) {
87 buf1 = buf[col1] & valid_keys[col1];
88 for (col2 = col1 + 1; col2 < ckdev->cols; col2++) {
89 buf2 = buf[col2] & valid_keys[col2];
90 if (hweight8(buf1 & buf2) > 1) {
91 dev_dbg(dev, "ghost found at: B[%02d]:0x%02x & B[%02d]:0x%02x",
92 col1, buf1, col2, buf2);
93 return true;
94 }
95 }
96 }
97
98 return false;
99}
100
101
102/*
103 * Compares the new keyboard state to the old one and produces key
104 * press/release events accordingly. The keyboard state is 13 bytes (one byte
105 * per column)
106 */
107static void cros_ec_keyb_process(struct cros_ec_keyb *ckdev,
108 uint8_t *kb_state, int len)
109{
110 struct input_dev *idev = ckdev->idev;
111 int col, row;
112 int new_state;
113 int old_state;
114 int num_cols;
115
116 num_cols = len;
117
118 if (ckdev->ghost_filter && cros_ec_keyb_has_ghosting(ckdev, kb_state)) {
119 /*
120 * Simple-minded solution: ignore this state. The obvious
121 * improvement is to only ignore changes to keys involved in
122 * the ghosting, but process the other changes.
123 */
124 dev_dbg(ckdev->dev, "ghosting found\n");
125 return;
126 }
127
128 for (col = 0; col < ckdev->cols; col++) {
129 for (row = 0; row < ckdev->rows; row++) {
130 int pos = MATRIX_SCAN_CODE(row, col, ckdev->row_shift);
131 const unsigned short *keycodes = idev->keycode;
132
133 new_state = kb_state[col] & (1 << row);
134 old_state = ckdev->old_kb_state[col] & (1 << row);
135 if (new_state != old_state) {
136 dev_dbg(ckdev->dev,
137 "changed: [r%d c%d]: byte %02x\n",
138 row, col, new_state);
139
140 input_report_key(idev, keycodes[pos],
141 new_state);
142 }
143 }
144 ckdev->old_kb_state[col] = kb_state[col];
145 }
146 input_sync(ckdev->idev);
147}
148
149static int cros_ec_keyb_get_state(struct cros_ec_keyb *ckdev, uint8_t *kb_state)
150{
151 int ret = 0;
152 struct cros_ec_command *msg;
153
154 msg = kmalloc(sizeof(*msg) + ckdev->cols, GFP_KERNEL);
155 if (!msg)
156 return -ENOMEM;
157
158 msg->version = 0;
159 msg->command = EC_CMD_MKBP_STATE;
160 msg->insize = ckdev->cols;
161 msg->outsize = 0;
162
163 ret = cros_ec_cmd_xfer(ckdev->ec, msg);
164 if (ret < 0) {
165 dev_err(ckdev->dev, "Error transferring EC message %d\n", ret);
166 goto exit;
167 }
168
169 memcpy(kb_state, msg->data, ckdev->cols);
170exit:
171 kfree(msg);
172 return ret;
173}
174
175static irqreturn_t cros_ec_keyb_irq(int irq, void *data)
176{
177 struct cros_ec_keyb *ckdev = data;
178 struct cros_ec_device *ec = ckdev->ec;
179 int ret;
180 uint8_t kb_state[ckdev->cols];
181
182 if (device_may_wakeup(ec->dev))
183 pm_wakeup_event(ec->dev, 0);
184
185 ret = cros_ec_keyb_get_state(ckdev, kb_state);
186 if (ret >= 0)
187 cros_ec_keyb_process(ckdev, kb_state, ret);
188 else
189 dev_err(ec->dev, "failed to get keyboard state: %d\n", ret);
190
191 return IRQ_HANDLED;
192}
193
194static int cros_ec_keyb_open(struct input_dev *dev)
195{
196 struct cros_ec_keyb *ckdev = input_get_drvdata(dev);
197 struct cros_ec_device *ec = ckdev->ec;
198
199 return request_threaded_irq(ec->irq, NULL, cros_ec_keyb_irq,
200 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
201 "cros_ec_keyb", ckdev);
202}
203
204static void cros_ec_keyb_close(struct input_dev *dev)
205{
206 struct cros_ec_keyb *ckdev = input_get_drvdata(dev);
207 struct cros_ec_device *ec = ckdev->ec;
208
209 free_irq(ec->irq, ckdev);
210}
211
212/*
213 * Walks keycodes flipping bit in buffer COLUMNS deep where bit is ROW. Used by
214 * ghosting logic to ignore NULL or virtual keys.
215 */
216static void cros_ec_keyb_compute_valid_keys(struct cros_ec_keyb *ckdev)
217{
218 int row, col;
219 int row_shift = ckdev->row_shift;
220 unsigned short *keymap = ckdev->idev->keycode;
221 unsigned short code;
222
223 BUG_ON(ckdev->idev->keycodesize != sizeof(*keymap));
224
225 for (col = 0; col < ckdev->cols; col++) {
226 for (row = 0; row < ckdev->rows; row++) {
227 code = keymap[MATRIX_SCAN_CODE(row, col, row_shift)];
228 if (code && (code != KEY_BATTERY))
229 ckdev->valid_keys[col] |= 1 << row;
230 }
231 dev_dbg(ckdev->dev, "valid_keys[%02d] = 0x%02x\n",
232 col, ckdev->valid_keys[col]);
233 }
234}
235
236static int cros_ec_keyb_probe(struct platform_device *pdev)
237{
238 struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent);
239 struct device *dev = ec->dev;
240 struct cros_ec_keyb *ckdev;
241 struct input_dev *idev;
242 struct device_node *np;
243 int err;
244
245 np = pdev->dev.of_node;
246 if (!np)
247 return -ENODEV;
248
249 ckdev = devm_kzalloc(&pdev->dev, sizeof(*ckdev), GFP_KERNEL);
250 if (!ckdev)
251 return -ENOMEM;
252 err = matrix_keypad_parse_of_params(&pdev->dev, &ckdev->rows,
253 &ckdev->cols);
254 if (err)
255 return err;
256
257 ckdev->valid_keys = devm_kzalloc(&pdev->dev, ckdev->cols, GFP_KERNEL);
258 if (!ckdev->valid_keys)
259 return -ENOMEM;
260
261 ckdev->old_kb_state = devm_kzalloc(&pdev->dev, ckdev->cols, GFP_KERNEL);
262 if (!ckdev->old_kb_state)
263 return -ENOMEM;
264
265 idev = devm_input_allocate_device(&pdev->dev);
266 if (!idev)
267 return -ENOMEM;
268
269 if (!ec->irq) {
270 dev_err(dev, "no EC IRQ specified\n");
271 return -EINVAL;
272 }
273
274 ckdev->ec = ec;
275 ckdev->dev = dev;
276 dev_set_drvdata(&pdev->dev, ckdev);
277
278 idev->name = CROS_EC_DEV_NAME;
279 idev->phys = ec->phys_name;
280 __set_bit(EV_REP, idev->evbit);
281
282 idev->id.bustype = BUS_VIRTUAL;
283 idev->id.version = 1;
284 idev->id.product = 0;
285 idev->dev.parent = &pdev->dev;
286 idev->open = cros_ec_keyb_open;
287 idev->close = cros_ec_keyb_close;
288
289 ckdev->ghost_filter = of_property_read_bool(np,
290 "google,needs-ghost-filter");
291
292 err = matrix_keypad_build_keymap(NULL, NULL, ckdev->rows, ckdev->cols,
293 NULL, idev);
294 if (err) {
295 dev_err(dev, "cannot build key matrix\n");
296 return err;
297 }
298
299 ckdev->row_shift = get_count_order(ckdev->cols);
300
301 input_set_capability(idev, EV_MSC, MSC_SCAN);
302 input_set_drvdata(idev, ckdev);
303 ckdev->idev = idev;
304 cros_ec_keyb_compute_valid_keys(ckdev);
305
306 err = input_register_device(ckdev->idev);
307 if (err) {
308 dev_err(dev, "cannot register input device\n");
309 return err;
310 }
311
312 return 0;
313}
314
315#ifdef CONFIG_PM_SLEEP
316/* Clear any keys in the buffer */
317static void cros_ec_keyb_clear_keyboard(struct cros_ec_keyb *ckdev)
318{
319 uint8_t old_state[ckdev->cols];
320 uint8_t new_state[ckdev->cols];
321 unsigned long duration;
322 int i, ret;
323
324 /*
325 * Keep reading until we see that the scan state does not change.
326 * That indicates that we are done.
327 *
328 * Assume that the EC keyscan buffer is at most 32 deep.
329 */
330 duration = jiffies;
331 ret = cros_ec_keyb_get_state(ckdev, new_state);
332 for (i = 1; !ret && i < 32; i++) {
333 memcpy(old_state, new_state, sizeof(old_state));
334 ret = cros_ec_keyb_get_state(ckdev, new_state);
335 if (0 == memcmp(old_state, new_state, sizeof(old_state)))
336 break;
337 }
338 duration = jiffies - duration;
339 dev_info(ckdev->dev, "Discarded %d keyscan(s) in %dus\n", i,
340 jiffies_to_usecs(duration));
341}
342
343static int cros_ec_keyb_resume(struct device *dev)
344{
345 struct cros_ec_keyb *ckdev = dev_get_drvdata(dev);
346
347 /*
348 * When the EC is not a wake source, then it could not have caused the
349 * resume, so we clear the EC's key scan buffer. If the EC was a
350 * wake source (e.g. the lid is open and the user might press a key to
351 * wake) then the key scan buffer should be preserved.
352 */
353 if (!ckdev->ec->was_wake_device)
354 cros_ec_keyb_clear_keyboard(ckdev);
355
356 return 0;
357}
358
359#endif
360
361static SIMPLE_DEV_PM_OPS(cros_ec_keyb_pm_ops, NULL, cros_ec_keyb_resume);
362
363#ifdef CONFIG_OF
364static const struct of_device_id cros_ec_keyb_of_match[] = {
365 { .compatible = "google,cros-ec-keyb" },
366 {},
367};
368MODULE_DEVICE_TABLE(of, cros_ec_keyb_of_match);
369#endif
370
371static struct platform_driver cros_ec_keyb_driver = {
372 .probe = cros_ec_keyb_probe,
373 .driver = {
374 .name = "cros-ec-keyb",
375 .of_match_table = of_match_ptr(cros_ec_keyb_of_match),
376 .pm = &cros_ec_keyb_pm_ops,
377 },
378};
379
380module_platform_driver(cros_ec_keyb_driver);
381
382MODULE_LICENSE("GPL");
383MODULE_DESCRIPTION("ChromeOS EC keyboard driver");
384MODULE_ALIAS("platform:cros-ec-keyb");
1// SPDX-License-Identifier: GPL-2.0
2// ChromeOS EC keyboard driver
3//
4// Copyright (C) 2012 Google, Inc.
5//
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
12// expensive.
13
14#include <linux/module.h>
15#include <linux/bitops.h>
16#include <linux/i2c.h>
17#include <linux/input.h>
18#include <linux/interrupt.h>
19#include <linux/kernel.h>
20#include <linux/notifier.h>
21#include <linux/platform_device.h>
22#include <linux/slab.h>
23#include <linux/sysrq.h>
24#include <linux/input/matrix_keypad.h>
25#include <linux/platform_data/cros_ec_commands.h>
26#include <linux/platform_data/cros_ec_proto.h>
27
28#include <asm/unaligned.h>
29
30/*
31 * @rows: Number of rows in the keypad
32 * @cols: Number of columns in the keypad
33 * @row_shift: log2 or number of rows, rounded up
34 * @keymap_data: Matrix keymap data used to convert to keyscan values
35 * @ghost_filter: true to enable the matrix key-ghosting filter
36 * @valid_keys: bitmap of existing keys for each matrix column
37 * @old_kb_state: bitmap of keys pressed last scan
38 * @dev: Device pointer
39 * @ec: Top level ChromeOS device to use to talk to EC
40 * @idev: The input device for the matrix keys.
41 * @bs_idev: The input device for non-matrix buttons and switches (or NULL).
42 * @notifier: interrupt event notifier for transport devices
43 */
44struct cros_ec_keyb {
45 unsigned int rows;
46 unsigned int cols;
47 int row_shift;
48 const struct matrix_keymap_data *keymap_data;
49 bool ghost_filter;
50 uint8_t *valid_keys;
51 uint8_t *old_kb_state;
52
53 struct device *dev;
54 struct cros_ec_device *ec;
55
56 struct input_dev *idev;
57 struct input_dev *bs_idev;
58 struct notifier_block notifier;
59};
60
61
62/**
63 * cros_ec_bs_map - Struct mapping Linux keycodes to EC button/switch bitmap
64 * #defines
65 *
66 * @ev_type: The type of the input event to generate (e.g., EV_KEY).
67 * @code: A linux keycode
68 * @bit: A #define like EC_MKBP_POWER_BUTTON or EC_MKBP_LID_OPEN
69 * @inverted: If the #define and EV_SW have opposite meanings, this is true.
70 * Only applicable to switches.
71 */
72struct cros_ec_bs_map {
73 unsigned int ev_type;
74 unsigned int code;
75 u8 bit;
76 bool inverted;
77};
78
79/* cros_ec_keyb_bs - Map EC button/switch #defines into kernel ones */
80static const struct cros_ec_bs_map cros_ec_keyb_bs[] = {
81 /* Buttons */
82 {
83 .ev_type = EV_KEY,
84 .code = KEY_POWER,
85 .bit = EC_MKBP_POWER_BUTTON,
86 },
87 {
88 .ev_type = EV_KEY,
89 .code = KEY_VOLUMEUP,
90 .bit = EC_MKBP_VOL_UP,
91 },
92 {
93 .ev_type = EV_KEY,
94 .code = KEY_VOLUMEDOWN,
95 .bit = EC_MKBP_VOL_DOWN,
96 },
97
98 /* Switches */
99 {
100 .ev_type = EV_SW,
101 .code = SW_LID,
102 .bit = EC_MKBP_LID_OPEN,
103 .inverted = true,
104 },
105 {
106 .ev_type = EV_SW,
107 .code = SW_TABLET_MODE,
108 .bit = EC_MKBP_TABLET_MODE,
109 },
110};
111
112/*
113 * Returns true when there is at least one combination of pressed keys that
114 * results in ghosting.
115 */
116static bool cros_ec_keyb_has_ghosting(struct cros_ec_keyb *ckdev, uint8_t *buf)
117{
118 int col1, col2, buf1, buf2;
119 struct device *dev = ckdev->dev;
120 uint8_t *valid_keys = ckdev->valid_keys;
121
122 /*
123 * Ghosting happens if for any pressed key X there are other keys
124 * pressed both in the same row and column of X as, for instance,
125 * in the following diagram:
126 *
127 * . . Y . g .
128 * . . . . . .
129 * . . . . . .
130 * . . X . Z .
131 *
132 * In this case only X, Y, and Z are pressed, but g appears to be
133 * pressed too (see Wikipedia).
134 */
135 for (col1 = 0; col1 < ckdev->cols; col1++) {
136 buf1 = buf[col1] & valid_keys[col1];
137 for (col2 = col1 + 1; col2 < ckdev->cols; col2++) {
138 buf2 = buf[col2] & valid_keys[col2];
139 if (hweight8(buf1 & buf2) > 1) {
140 dev_dbg(dev, "ghost found at: B[%02d]:0x%02x & B[%02d]:0x%02x",
141 col1, buf1, col2, buf2);
142 return true;
143 }
144 }
145 }
146
147 return false;
148}
149
150
151/*
152 * Compares the new keyboard state to the old one and produces key
153 * press/release events accordingly. The keyboard state is 13 bytes (one byte
154 * per column)
155 */
156static void cros_ec_keyb_process(struct cros_ec_keyb *ckdev,
157 uint8_t *kb_state, int len)
158{
159 struct input_dev *idev = ckdev->idev;
160 int col, row;
161 int new_state;
162 int old_state;
163
164 if (ckdev->ghost_filter && cros_ec_keyb_has_ghosting(ckdev, kb_state)) {
165 /*
166 * Simple-minded solution: ignore this state. The obvious
167 * improvement is to only ignore changes to keys involved in
168 * the ghosting, but process the other changes.
169 */
170 dev_dbg(ckdev->dev, "ghosting found\n");
171 return;
172 }
173
174 for (col = 0; col < ckdev->cols; col++) {
175 for (row = 0; row < ckdev->rows; row++) {
176 int pos = MATRIX_SCAN_CODE(row, col, ckdev->row_shift);
177 const unsigned short *keycodes = idev->keycode;
178
179 new_state = kb_state[col] & (1 << row);
180 old_state = ckdev->old_kb_state[col] & (1 << row);
181 if (new_state != old_state) {
182 dev_dbg(ckdev->dev,
183 "changed: [r%d c%d]: byte %02x\n",
184 row, col, new_state);
185
186 input_report_key(idev, keycodes[pos],
187 new_state);
188 }
189 }
190 ckdev->old_kb_state[col] = kb_state[col];
191 }
192 input_sync(ckdev->idev);
193}
194
195/**
196 * cros_ec_keyb_report_bs - Report non-matrixed buttons or switches
197 *
198 * This takes a bitmap of buttons or switches from the EC and reports events,
199 * syncing at the end.
200 *
201 * @ckdev: The keyboard device.
202 * @ev_type: The input event type (e.g., EV_KEY).
203 * @mask: A bitmap of buttons from the EC.
204 */
205static void cros_ec_keyb_report_bs(struct cros_ec_keyb *ckdev,
206 unsigned int ev_type, u32 mask)
207
208{
209 struct input_dev *idev = ckdev->bs_idev;
210 int i;
211
212 for (i = 0; i < ARRAY_SIZE(cros_ec_keyb_bs); i++) {
213 const struct cros_ec_bs_map *map = &cros_ec_keyb_bs[i];
214
215 if (map->ev_type != ev_type)
216 continue;
217
218 input_event(idev, ev_type, map->code,
219 !!(mask & BIT(map->bit)) ^ map->inverted);
220 }
221 input_sync(idev);
222}
223
224static int cros_ec_keyb_work(struct notifier_block *nb,
225 unsigned long queued_during_suspend, void *_notify)
226{
227 struct cros_ec_keyb *ckdev = container_of(nb, struct cros_ec_keyb,
228 notifier);
229 u32 val;
230 unsigned int ev_type;
231
232 /*
233 * If not wake enabled, discard key state changes during
234 * suspend. Switches will be re-checked in
235 * cros_ec_keyb_resume() to be sure nothing is lost.
236 */
237 if (queued_during_suspend && !device_may_wakeup(ckdev->dev))
238 return NOTIFY_OK;
239
240 switch (ckdev->ec->event_data.event_type) {
241 case EC_MKBP_EVENT_KEY_MATRIX:
242 pm_wakeup_event(ckdev->dev, 0);
243
244 if (ckdev->ec->event_size != ckdev->cols) {
245 dev_err(ckdev->dev,
246 "Discarded incomplete key matrix event.\n");
247 return NOTIFY_OK;
248 }
249
250 cros_ec_keyb_process(ckdev,
251 ckdev->ec->event_data.data.key_matrix,
252 ckdev->ec->event_size);
253 break;
254
255 case EC_MKBP_EVENT_SYSRQ:
256 pm_wakeup_event(ckdev->dev, 0);
257
258 val = get_unaligned_le32(&ckdev->ec->event_data.data.sysrq);
259 dev_dbg(ckdev->dev, "sysrq code from EC: %#x\n", val);
260 handle_sysrq(val);
261 break;
262
263 case EC_MKBP_EVENT_BUTTON:
264 case EC_MKBP_EVENT_SWITCH:
265 pm_wakeup_event(ckdev->dev, 0);
266
267 if (ckdev->ec->event_data.event_type == EC_MKBP_EVENT_BUTTON) {
268 val = get_unaligned_le32(
269 &ckdev->ec->event_data.data.buttons);
270 ev_type = EV_KEY;
271 } else {
272 val = get_unaligned_le32(
273 &ckdev->ec->event_data.data.switches);
274 ev_type = EV_SW;
275 }
276 cros_ec_keyb_report_bs(ckdev, ev_type, val);
277 break;
278
279 default:
280 return NOTIFY_DONE;
281 }
282
283 return NOTIFY_OK;
284}
285
286/*
287 * Walks keycodes flipping bit in buffer COLUMNS deep where bit is ROW. Used by
288 * ghosting logic to ignore NULL or virtual keys.
289 */
290static void cros_ec_keyb_compute_valid_keys(struct cros_ec_keyb *ckdev)
291{
292 int row, col;
293 int row_shift = ckdev->row_shift;
294 unsigned short *keymap = ckdev->idev->keycode;
295 unsigned short code;
296
297 BUG_ON(ckdev->idev->keycodesize != sizeof(*keymap));
298
299 for (col = 0; col < ckdev->cols; col++) {
300 for (row = 0; row < ckdev->rows; row++) {
301 code = keymap[MATRIX_SCAN_CODE(row, col, row_shift)];
302 if (code && (code != KEY_BATTERY))
303 ckdev->valid_keys[col] |= 1 << row;
304 }
305 dev_dbg(ckdev->dev, "valid_keys[%02d] = 0x%02x\n",
306 col, ckdev->valid_keys[col]);
307 }
308}
309
310/**
311 * cros_ec_keyb_info - Wrap the EC command EC_CMD_MKBP_INFO
312 *
313 * This wraps the EC_CMD_MKBP_INFO, abstracting out all of the marshalling and
314 * unmarshalling and different version nonsense into something simple.
315 *
316 * @ec_dev: The EC device
317 * @info_type: Either EC_MKBP_INFO_SUPPORTED or EC_MKBP_INFO_CURRENT.
318 * @event_type: Either EC_MKBP_EVENT_BUTTON or EC_MKBP_EVENT_SWITCH. Actually
319 * in some cases this could be EC_MKBP_EVENT_KEY_MATRIX or
320 * EC_MKBP_EVENT_HOST_EVENT too but we don't use in this driver.
321 * @result: Where we'll store the result; a union
322 * @result_size: The size of the result. Expected to be the size of one of
323 * the elements in the union.
324 *
325 * Returns 0 if no error or -error upon error.
326 */
327static int cros_ec_keyb_info(struct cros_ec_device *ec_dev,
328 enum ec_mkbp_info_type info_type,
329 enum ec_mkbp_event event_type,
330 union ec_response_get_next_data *result,
331 size_t result_size)
332{
333 struct ec_params_mkbp_info *params;
334 struct cros_ec_command *msg;
335 int ret;
336
337 msg = kzalloc(sizeof(*msg) + max_t(size_t, result_size,
338 sizeof(*params)), GFP_KERNEL);
339 if (!msg)
340 return -ENOMEM;
341
342 msg->command = EC_CMD_MKBP_INFO;
343 msg->version = 1;
344 msg->outsize = sizeof(*params);
345 msg->insize = result_size;
346 params = (struct ec_params_mkbp_info *)msg->data;
347 params->info_type = info_type;
348 params->event_type = event_type;
349
350 ret = cros_ec_cmd_xfer_status(ec_dev, msg);
351 if (ret == -ENOTSUPP) {
352 /* With older ECs we just return 0 for everything */
353 memset(result, 0, result_size);
354 ret = 0;
355 } else if (ret < 0) {
356 dev_warn(ec_dev->dev, "Transfer error %d/%d: %d\n",
357 (int)info_type, (int)event_type, ret);
358 } else if (ret != result_size) {
359 dev_warn(ec_dev->dev, "Wrong size %d/%d: %d != %zu\n",
360 (int)info_type, (int)event_type,
361 ret, result_size);
362 ret = -EPROTO;
363 } else {
364 memcpy(result, msg->data, result_size);
365 ret = 0;
366 }
367
368 kfree(msg);
369
370 return ret;
371}
372
373/**
374 * cros_ec_keyb_query_switches - Query the state of switches and report
375 *
376 * This will ask the EC about the current state of switches and report to the
377 * kernel. Note that we don't query for buttons because they are more
378 * transitory and we'll get an update on the next release / press.
379 *
380 * @ckdev: The keyboard device
381 *
382 * Returns 0 if no error or -error upon error.
383 */
384static int cros_ec_keyb_query_switches(struct cros_ec_keyb *ckdev)
385{
386 struct cros_ec_device *ec_dev = ckdev->ec;
387 union ec_response_get_next_data event_data = {};
388 int ret;
389
390 ret = cros_ec_keyb_info(ec_dev, EC_MKBP_INFO_CURRENT,
391 EC_MKBP_EVENT_SWITCH, &event_data,
392 sizeof(event_data.switches));
393 if (ret)
394 return ret;
395
396 cros_ec_keyb_report_bs(ckdev, EV_SW,
397 get_unaligned_le32(&event_data.switches));
398
399 return 0;
400}
401
402/**
403 * cros_ec_keyb_resume - Resume the keyboard
404 *
405 * We use the resume notification as a chance to query the EC for switches.
406 *
407 * @dev: The keyboard device
408 *
409 * Returns 0 if no error or -error upon error.
410 */
411static __maybe_unused int cros_ec_keyb_resume(struct device *dev)
412{
413 struct cros_ec_keyb *ckdev = dev_get_drvdata(dev);
414
415 if (ckdev->bs_idev)
416 return cros_ec_keyb_query_switches(ckdev);
417
418 return 0;
419}
420
421/**
422 * cros_ec_keyb_register_bs - Register non-matrix buttons/switches
423 *
424 * Handles all the bits of the keyboard driver related to non-matrix buttons
425 * and switches, including asking the EC about which are present and telling
426 * the kernel to expect them.
427 *
428 * If this device has no support for buttons and switches we'll return no error
429 * but the ckdev->bs_idev will remain NULL when this function exits.
430 *
431 * @ckdev: The keyboard device
432 *
433 * Returns 0 if no error or -error upon error.
434 */
435static int cros_ec_keyb_register_bs(struct cros_ec_keyb *ckdev)
436{
437 struct cros_ec_device *ec_dev = ckdev->ec;
438 struct device *dev = ckdev->dev;
439 struct input_dev *idev;
440 union ec_response_get_next_data event_data = {};
441 const char *phys;
442 u32 buttons;
443 u32 switches;
444 int ret;
445 int i;
446
447 ret = cros_ec_keyb_info(ec_dev, EC_MKBP_INFO_SUPPORTED,
448 EC_MKBP_EVENT_BUTTON, &event_data,
449 sizeof(event_data.buttons));
450 if (ret)
451 return ret;
452 buttons = get_unaligned_le32(&event_data.buttons);
453
454 ret = cros_ec_keyb_info(ec_dev, EC_MKBP_INFO_SUPPORTED,
455 EC_MKBP_EVENT_SWITCH, &event_data,
456 sizeof(event_data.switches));
457 if (ret)
458 return ret;
459 switches = get_unaligned_le32(&event_data.switches);
460
461 if (!buttons && !switches)
462 return 0;
463
464 /*
465 * We call the non-matrix buttons/switches 'input1', if present.
466 * Allocate phys before input dev, to ensure correct tear-down
467 * ordering.
468 */
469 phys = devm_kasprintf(dev, GFP_KERNEL, "%s/input1", ec_dev->phys_name);
470 if (!phys)
471 return -ENOMEM;
472
473 idev = devm_input_allocate_device(dev);
474 if (!idev)
475 return -ENOMEM;
476
477 idev->name = "cros_ec_buttons";
478 idev->phys = phys;
479 __set_bit(EV_REP, idev->evbit);
480
481 idev->id.bustype = BUS_VIRTUAL;
482 idev->id.version = 1;
483 idev->id.product = 0;
484 idev->dev.parent = dev;
485
486 input_set_drvdata(idev, ckdev);
487 ckdev->bs_idev = idev;
488
489 for (i = 0; i < ARRAY_SIZE(cros_ec_keyb_bs); i++) {
490 const struct cros_ec_bs_map *map = &cros_ec_keyb_bs[i];
491
492 if ((map->ev_type == EV_KEY && (buttons & BIT(map->bit))) ||
493 (map->ev_type == EV_SW && (switches & BIT(map->bit))))
494 input_set_capability(idev, map->ev_type, map->code);
495 }
496
497 ret = cros_ec_keyb_query_switches(ckdev);
498 if (ret) {
499 dev_err(dev, "cannot query switches\n");
500 return ret;
501 }
502
503 ret = input_register_device(ckdev->bs_idev);
504 if (ret) {
505 dev_err(dev, "cannot register input device\n");
506 return ret;
507 }
508
509 return 0;
510}
511
512/**
513 * cros_ec_keyb_register_bs - Register matrix keys
514 *
515 * Handles all the bits of the keyboard driver related to matrix keys.
516 *
517 * @ckdev: The keyboard device
518 *
519 * Returns 0 if no error or -error upon error.
520 */
521static int cros_ec_keyb_register_matrix(struct cros_ec_keyb *ckdev)
522{
523 struct cros_ec_device *ec_dev = ckdev->ec;
524 struct device *dev = ckdev->dev;
525 struct input_dev *idev;
526 const char *phys;
527 int err;
528
529 err = matrix_keypad_parse_properties(dev, &ckdev->rows, &ckdev->cols);
530 if (err)
531 return err;
532
533 ckdev->valid_keys = devm_kzalloc(dev, ckdev->cols, GFP_KERNEL);
534 if (!ckdev->valid_keys)
535 return -ENOMEM;
536
537 ckdev->old_kb_state = devm_kzalloc(dev, ckdev->cols, GFP_KERNEL);
538 if (!ckdev->old_kb_state)
539 return -ENOMEM;
540
541 /*
542 * We call the keyboard matrix 'input0'. Allocate phys before input
543 * dev, to ensure correct tear-down ordering.
544 */
545 phys = devm_kasprintf(dev, GFP_KERNEL, "%s/input0", ec_dev->phys_name);
546 if (!phys)
547 return -ENOMEM;
548
549 idev = devm_input_allocate_device(dev);
550 if (!idev)
551 return -ENOMEM;
552
553 idev->name = CROS_EC_DEV_NAME;
554 idev->phys = phys;
555 __set_bit(EV_REP, idev->evbit);
556
557 idev->id.bustype = BUS_VIRTUAL;
558 idev->id.version = 1;
559 idev->id.product = 0;
560 idev->dev.parent = dev;
561
562 ckdev->ghost_filter = of_property_read_bool(dev->of_node,
563 "google,needs-ghost-filter");
564
565 err = matrix_keypad_build_keymap(NULL, NULL, ckdev->rows, ckdev->cols,
566 NULL, idev);
567 if (err) {
568 dev_err(dev, "cannot build key matrix\n");
569 return err;
570 }
571
572 ckdev->row_shift = get_count_order(ckdev->cols);
573
574 input_set_capability(idev, EV_MSC, MSC_SCAN);
575 input_set_drvdata(idev, ckdev);
576 ckdev->idev = idev;
577 cros_ec_keyb_compute_valid_keys(ckdev);
578
579 err = input_register_device(ckdev->idev);
580 if (err) {
581 dev_err(dev, "cannot register input device\n");
582 return err;
583 }
584
585 return 0;
586}
587
588static int cros_ec_keyb_probe(struct platform_device *pdev)
589{
590 struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent);
591 struct device *dev = &pdev->dev;
592 struct cros_ec_keyb *ckdev;
593 int err;
594
595 if (!dev->of_node)
596 return -ENODEV;
597
598 ckdev = devm_kzalloc(dev, sizeof(*ckdev), GFP_KERNEL);
599 if (!ckdev)
600 return -ENOMEM;
601
602 ckdev->ec = ec;
603 ckdev->dev = dev;
604 dev_set_drvdata(dev, ckdev);
605
606 err = cros_ec_keyb_register_matrix(ckdev);
607 if (err) {
608 dev_err(dev, "cannot register matrix inputs: %d\n", err);
609 return err;
610 }
611
612 err = cros_ec_keyb_register_bs(ckdev);
613 if (err) {
614 dev_err(dev, "cannot register non-matrix inputs: %d\n", err);
615 return err;
616 }
617
618 ckdev->notifier.notifier_call = cros_ec_keyb_work;
619 err = blocking_notifier_chain_register(&ckdev->ec->event_notifier,
620 &ckdev->notifier);
621 if (err) {
622 dev_err(dev, "cannot register notifier: %d\n", err);
623 return err;
624 }
625
626 device_init_wakeup(ckdev->dev, true);
627 return 0;
628}
629
630static int cros_ec_keyb_remove(struct platform_device *pdev)
631{
632 struct cros_ec_keyb *ckdev = dev_get_drvdata(&pdev->dev);
633
634 blocking_notifier_chain_unregister(&ckdev->ec->event_notifier,
635 &ckdev->notifier);
636
637 return 0;
638}
639
640#ifdef CONFIG_OF
641static const struct of_device_id cros_ec_keyb_of_match[] = {
642 { .compatible = "google,cros-ec-keyb" },
643 {},
644};
645MODULE_DEVICE_TABLE(of, cros_ec_keyb_of_match);
646#endif
647
648static SIMPLE_DEV_PM_OPS(cros_ec_keyb_pm_ops, NULL, cros_ec_keyb_resume);
649
650static struct platform_driver cros_ec_keyb_driver = {
651 .probe = cros_ec_keyb_probe,
652 .remove = cros_ec_keyb_remove,
653 .driver = {
654 .name = "cros-ec-keyb",
655 .of_match_table = of_match_ptr(cros_ec_keyb_of_match),
656 .pm = &cros_ec_keyb_pm_ops,
657 },
658};
659
660module_platform_driver(cros_ec_keyb_driver);
661
662MODULE_LICENSE("GPL v2");
663MODULE_DESCRIPTION("ChromeOS EC keyboard driver");
664MODULE_ALIAS("platform:cros-ec-keyb");