xref: /linux/drivers/platform/chrome/cros_ec_lpc.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
1 // SPDX-License-Identifier: GPL-2.0
2 // LPC interface for ChromeOS Embedded Controller
3 //
4 // Copyright (C) 2012-2015 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/acpi.h>
15 #include <linux/dmi.h>
16 #include <linux/delay.h>
17 #include <linux/io.h>
18 #include <linux/interrupt.h>
19 #include <linux/kobject.h>
20 #include <linux/module.h>
21 #include <linux/platform_data/cros_ec_commands.h>
22 #include <linux/platform_data/cros_ec_proto.h>
23 #include <linux/platform_device.h>
24 #include <linux/printk.h>
25 #include <linux/reboot.h>
26 #include <linux/suspend.h>
27 
28 #include "cros_ec.h"
29 #include "cros_ec_lpc_mec.h"
30 
31 #define DRV_NAME "cros_ec_lpcs"
32 #define ACPI_DRV_NAME "GOOG0004"
33 
34 /* True if ACPI device is present */
35 static bool cros_ec_lpc_acpi_device_found;
36 
37 /*
38  * Indicates that lpc_driver_data.quirk_mmio_memory_base should
39  * be used as the base port for EC mapped memory.
40  */
41 #define CROS_EC_LPC_QUIRK_REMAP_MEMORY              BIT(0)
42 /*
43  * Indicates that lpc_driver_data.quirk_acpi_id should be used to find
44  * the ACPI device.
45  */
46 #define CROS_EC_LPC_QUIRK_ACPI_ID                   BIT(1)
47 /*
48  * Indicates that lpc_driver_data.quirk_aml_mutex_name should be used
49  * to find an AML mutex to protect access to Microchip EC.
50  */
51 #define CROS_EC_LPC_QUIRK_AML_MUTEX                 BIT(2)
52 
53 /**
54  * struct lpc_driver_data - driver data attached to a DMI device ID to indicate
55  *                          hardware quirks.
56  * @quirks: a bitfield composed of quirks from CROS_EC_LPC_QUIRK_*
57  * @quirk_mmio_memory_base: The first I/O port addressing EC mapped memory (used
58  *                          when quirk ...REMAP_MEMORY is set.)
59  * @quirk_acpi_id: An ACPI HID to be used to find the ACPI device.
60  * @quirk_aml_mutex_name: The name of an AML mutex to be used to protect access
61  *                        to Microchip EC.
62  */
63 struct lpc_driver_data {
64 	u32 quirks;
65 	u16 quirk_mmio_memory_base;
66 	const char *quirk_acpi_id;
67 	const char *quirk_aml_mutex_name;
68 };
69 
70 /**
71  * struct cros_ec_lpc - LPC device-specific data
72  * @mmio_memory_base: The first I/O port addressing EC mapped memory.
73  */
74 struct cros_ec_lpc {
75 	u16 mmio_memory_base;
76 };
77 
78 /**
79  * struct lpc_driver_ops - LPC driver operations
80  * @read: Copy length bytes from EC address offset into buffer dest.
81  *        Returns a negative error code on error, or the 8-bit checksum
82  *        of all bytes read.
83  * @write: Copy length bytes from buffer msg into EC address offset.
84  *         Returns a negative error code on error, or the 8-bit checksum
85  *         of all bytes written.
86  */
87 struct lpc_driver_ops {
88 	int (*read)(unsigned int offset, unsigned int length, u8 *dest);
89 	int (*write)(unsigned int offset, unsigned int length, const u8 *msg);
90 };
91 
92 static struct lpc_driver_ops cros_ec_lpc_ops = { };
93 
94 /*
95  * A generic instance of the read function of struct lpc_driver_ops, used for
96  * the LPC EC.
97  */
98 static int cros_ec_lpc_read_bytes(unsigned int offset, unsigned int length,
99 				  u8 *dest)
100 {
101 	u8 sum = 0;
102 	int i;
103 
104 	for (i = 0; i < length; ++i) {
105 		dest[i] = inb(offset + i);
106 		sum += dest[i];
107 	}
108 
109 	/* Return checksum of all bytes read */
110 	return sum;
111 }
112 
113 /*
114  * A generic instance of the write function of struct lpc_driver_ops, used for
115  * the LPC EC.
116  */
117 static int cros_ec_lpc_write_bytes(unsigned int offset, unsigned int length,
118 				   const u8 *msg)
119 {
120 	u8 sum = 0;
121 	int i;
122 
123 	for (i = 0; i < length; ++i) {
124 		outb(msg[i], offset + i);
125 		sum += msg[i];
126 	}
127 
128 	/* Return checksum of all bytes written */
129 	return sum;
130 }
131 
132 /*
133  * An instance of the read function of struct lpc_driver_ops, used for the
134  * MEC variant of LPC EC.
135  */
136 static int cros_ec_lpc_mec_read_bytes(unsigned int offset, unsigned int length,
137 				      u8 *dest)
138 {
139 	int in_range = cros_ec_lpc_mec_in_range(offset, length);
140 
141 	if (in_range < 0)
142 		return in_range;
143 
144 	return in_range ?
145 		cros_ec_lpc_io_bytes_mec(MEC_IO_READ,
146 					 offset - EC_HOST_CMD_REGION0,
147 					 length, dest) :
148 		cros_ec_lpc_read_bytes(offset, length, dest);
149 }
150 
151 /*
152  * An instance of the write function of struct lpc_driver_ops, used for the
153  * MEC variant of LPC EC.
154  */
155 static int cros_ec_lpc_mec_write_bytes(unsigned int offset, unsigned int length,
156 				       const u8 *msg)
157 {
158 	int in_range = cros_ec_lpc_mec_in_range(offset, length);
159 
160 	if (in_range < 0)
161 		return in_range;
162 
163 	return in_range ?
164 		cros_ec_lpc_io_bytes_mec(MEC_IO_WRITE,
165 					 offset - EC_HOST_CMD_REGION0,
166 					 length, (u8 *)msg) :
167 		cros_ec_lpc_write_bytes(offset, length, msg);
168 }
169 
170 static int ec_response_timed_out(void)
171 {
172 	unsigned long one_second = jiffies + HZ;
173 	u8 data;
174 	int ret;
175 
176 	usleep_range(200, 300);
177 	do {
178 		ret = cros_ec_lpc_ops.read(EC_LPC_ADDR_HOST_CMD, 1, &data);
179 		if (ret < 0)
180 			return ret;
181 		if (!(data & EC_LPC_STATUS_BUSY_MASK))
182 			return 0;
183 		usleep_range(100, 200);
184 	} while (time_before(jiffies, one_second));
185 
186 	return 1;
187 }
188 
189 static int cros_ec_pkt_xfer_lpc(struct cros_ec_device *ec,
190 				struct cros_ec_command *msg)
191 {
192 	struct ec_host_response response;
193 	u8 sum;
194 	int ret = 0;
195 	u8 *dout;
196 
197 	ret = cros_ec_prepare_tx(ec, msg);
198 	if (ret < 0)
199 		goto done;
200 
201 	/* Write buffer */
202 	ret = cros_ec_lpc_ops.write(EC_LPC_ADDR_HOST_PACKET, ret, ec->dout);
203 	if (ret < 0)
204 		goto done;
205 
206 	/* Here we go */
207 	sum = EC_COMMAND_PROTOCOL_3;
208 	ret = cros_ec_lpc_ops.write(EC_LPC_ADDR_HOST_CMD, 1, &sum);
209 	if (ret < 0)
210 		goto done;
211 
212 	ret = ec_response_timed_out();
213 	if (ret < 0)
214 		goto done;
215 	if (ret) {
216 		dev_warn(ec->dev, "EC response timed out\n");
217 		ret = -EIO;
218 		goto done;
219 	}
220 
221 	/* Check result */
222 	ret = cros_ec_lpc_ops.read(EC_LPC_ADDR_HOST_DATA, 1, &sum);
223 	if (ret < 0)
224 		goto done;
225 	msg->result = ret;
226 	ret = cros_ec_check_result(ec, msg);
227 	if (ret)
228 		goto done;
229 
230 	/* Read back response */
231 	dout = (u8 *)&response;
232 	ret = cros_ec_lpc_ops.read(EC_LPC_ADDR_HOST_PACKET, sizeof(response),
233 				   dout);
234 	if (ret < 0)
235 		goto done;
236 	sum = ret;
237 
238 	msg->result = response.result;
239 
240 	if (response.data_len > msg->insize) {
241 		dev_err(ec->dev,
242 			"packet too long (%d bytes, expected %d)",
243 			response.data_len, msg->insize);
244 		ret = -EMSGSIZE;
245 		goto done;
246 	}
247 
248 	/* Read response and process checksum */
249 	ret = cros_ec_lpc_ops.read(EC_LPC_ADDR_HOST_PACKET +
250 				   sizeof(response), response.data_len,
251 				   msg->data);
252 	if (ret < 0)
253 		goto done;
254 	sum += ret;
255 
256 	if (sum) {
257 		dev_err(ec->dev,
258 			"bad packet checksum %02x\n",
259 			response.checksum);
260 		ret = -EBADMSG;
261 		goto done;
262 	}
263 
264 	/* Return actual amount of data received */
265 	ret = response.data_len;
266 done:
267 	return ret;
268 }
269 
270 static int cros_ec_cmd_xfer_lpc(struct cros_ec_device *ec,
271 				struct cros_ec_command *msg)
272 {
273 	struct ec_lpc_host_args args;
274 	u8 sum;
275 	int ret = 0;
276 
277 	if (msg->outsize > EC_PROTO2_MAX_PARAM_SIZE ||
278 	    msg->insize > EC_PROTO2_MAX_PARAM_SIZE) {
279 		dev_err(ec->dev,
280 			"invalid buffer sizes (out %d, in %d)\n",
281 			msg->outsize, msg->insize);
282 		return -EINVAL;
283 	}
284 
285 	/* Now actually send the command to the EC and get the result */
286 	args.flags = EC_HOST_ARGS_FLAG_FROM_HOST;
287 	args.command_version = msg->version;
288 	args.data_size = msg->outsize;
289 
290 	/* Initialize checksum */
291 	sum = msg->command + args.flags + args.command_version + args.data_size;
292 
293 	/* Copy data and update checksum */
294 	ret = cros_ec_lpc_ops.write(EC_LPC_ADDR_HOST_PARAM, msg->outsize,
295 				    msg->data);
296 	if (ret < 0)
297 		goto done;
298 	sum += ret;
299 
300 	/* Finalize checksum and write args */
301 	args.checksum = sum;
302 	ret = cros_ec_lpc_ops.write(EC_LPC_ADDR_HOST_ARGS, sizeof(args),
303 				    (u8 *)&args);
304 	if (ret < 0)
305 		goto done;
306 
307 	/* Here we go */
308 	sum = msg->command;
309 	ret = cros_ec_lpc_ops.write(EC_LPC_ADDR_HOST_CMD, 1, &sum);
310 	if (ret < 0)
311 		goto done;
312 
313 	ret = ec_response_timed_out();
314 	if (ret < 0)
315 		goto done;
316 	if (ret) {
317 		dev_warn(ec->dev, "EC response timed out\n");
318 		ret = -EIO;
319 		goto done;
320 	}
321 
322 	/* Check result */
323 	ret = cros_ec_lpc_ops.read(EC_LPC_ADDR_HOST_DATA, 1, &sum);
324 	if (ret < 0)
325 		goto done;
326 	msg->result = ret;
327 	ret = cros_ec_check_result(ec, msg);
328 	if (ret)
329 		goto done;
330 
331 	/* Read back args */
332 	ret = cros_ec_lpc_ops.read(EC_LPC_ADDR_HOST_ARGS, sizeof(args), (u8 *)&args);
333 	if (ret < 0)
334 		goto done;
335 
336 	if (args.data_size > msg->insize) {
337 		dev_err(ec->dev,
338 			"packet too long (%d bytes, expected %d)",
339 			args.data_size, msg->insize);
340 		ret = -ENOSPC;
341 		goto done;
342 	}
343 
344 	/* Start calculating response checksum */
345 	sum = msg->command + args.flags + args.command_version + args.data_size;
346 
347 	/* Read response and update checksum */
348 	ret = cros_ec_lpc_ops.read(EC_LPC_ADDR_HOST_PARAM, args.data_size,
349 				   msg->data);
350 	if (ret < 0)
351 		goto done;
352 	sum += ret;
353 
354 	/* Verify checksum */
355 	if (args.checksum != sum) {
356 		dev_err(ec->dev,
357 			"bad packet checksum, expected %02x, got %02x\n",
358 			args.checksum, sum);
359 		ret = -EBADMSG;
360 		goto done;
361 	}
362 
363 	/* Return actual amount of data received */
364 	ret = args.data_size;
365 done:
366 	return ret;
367 }
368 
369 /* Returns num bytes read, or negative on error. Doesn't need locking. */
370 static int cros_ec_lpc_readmem(struct cros_ec_device *ec, unsigned int offset,
371 			       unsigned int bytes, void *dest)
372 {
373 	struct cros_ec_lpc *ec_lpc = ec->priv;
374 	int i = offset;
375 	char *s = dest;
376 	int cnt = 0;
377 	int ret;
378 
379 	if (offset >= EC_MEMMAP_SIZE - bytes)
380 		return -EINVAL;
381 
382 	/* fixed length */
383 	if (bytes) {
384 		ret = cros_ec_lpc_ops.read(ec_lpc->mmio_memory_base + offset, bytes, s);
385 		if (ret < 0)
386 			return ret;
387 		return bytes;
388 	}
389 
390 	/* string */
391 	for (; i < EC_MEMMAP_SIZE; i++, s++) {
392 		ret = cros_ec_lpc_ops.read(ec_lpc->mmio_memory_base + i, 1, s);
393 		if (ret < 0)
394 			return ret;
395 		cnt++;
396 		if (!*s)
397 			break;
398 	}
399 
400 	return cnt;
401 }
402 
403 static void cros_ec_lpc_acpi_notify(acpi_handle device, u32 value, void *data)
404 {
405 	static const char *env[] = { "ERROR=PANIC", NULL };
406 	struct cros_ec_device *ec_dev = data;
407 	bool ec_has_more_events;
408 	int ret;
409 
410 	ec_dev->last_event_time = cros_ec_get_time_ns();
411 
412 	if (value == ACPI_NOTIFY_CROS_EC_PANIC) {
413 		dev_emerg(ec_dev->dev, "CrOS EC Panic Reported. Shutdown is imminent!");
414 		blocking_notifier_call_chain(&ec_dev->panic_notifier, 0, ec_dev);
415 		kobject_uevent_env(&ec_dev->dev->kobj, KOBJ_CHANGE, (char **)env);
416 		/* Begin orderly shutdown. EC will force reset after a short period. */
417 		hw_protection_shutdown("CrOS EC Panic", -1);
418 		/* Do not query for other events after a panic is reported */
419 		return;
420 	}
421 
422 	if (ec_dev->mkbp_event_supported)
423 		do {
424 			ret = cros_ec_get_next_event(ec_dev, NULL,
425 						     &ec_has_more_events);
426 			if (ret > 0)
427 				blocking_notifier_call_chain(
428 						&ec_dev->event_notifier, 0,
429 						ec_dev);
430 		} while (ec_has_more_events);
431 
432 	if (value == ACPI_NOTIFY_DEVICE_WAKE)
433 		pm_system_wakeup();
434 }
435 
436 static acpi_status cros_ec_lpc_parse_device(acpi_handle handle, u32 level,
437 					    void *context, void **retval)
438 {
439 	*(struct acpi_device **)context = acpi_fetch_acpi_dev(handle);
440 	return AE_CTRL_TERMINATE;
441 }
442 
443 static struct acpi_device *cros_ec_lpc_get_device(const char *id)
444 {
445 	struct acpi_device *adev = NULL;
446 	acpi_status status = acpi_get_devices(id, cros_ec_lpc_parse_device,
447 					      &adev, NULL);
448 	if (ACPI_FAILURE(status)) {
449 		pr_warn(DRV_NAME ": Looking for %s failed\n", id);
450 		return NULL;
451 	}
452 
453 	return adev;
454 }
455 
456 static int cros_ec_lpc_probe(struct platform_device *pdev)
457 {
458 	struct device *dev = &pdev->dev;
459 	struct acpi_device *adev;
460 	acpi_status status;
461 	struct cros_ec_device *ec_dev;
462 	struct cros_ec_lpc *ec_lpc;
463 	struct lpc_driver_data *driver_data;
464 	u8 buf[2] = {};
465 	int irq, ret;
466 	u32 quirks;
467 
468 	ec_lpc = devm_kzalloc(dev, sizeof(*ec_lpc), GFP_KERNEL);
469 	if (!ec_lpc)
470 		return -ENOMEM;
471 
472 	ec_lpc->mmio_memory_base = EC_LPC_ADDR_MEMMAP;
473 
474 	driver_data = platform_get_drvdata(pdev);
475 	if (driver_data) {
476 		quirks = driver_data->quirks;
477 
478 		if (quirks)
479 			dev_info(dev, "loaded with quirks %8.08x\n", quirks);
480 
481 		if (quirks & CROS_EC_LPC_QUIRK_REMAP_MEMORY)
482 			ec_lpc->mmio_memory_base = driver_data->quirk_mmio_memory_base;
483 
484 		if (quirks & CROS_EC_LPC_QUIRK_ACPI_ID) {
485 			adev = cros_ec_lpc_get_device(driver_data->quirk_acpi_id);
486 			if (!adev) {
487 				dev_err(dev, "failed to get ACPI device '%s'",
488 					driver_data->quirk_acpi_id);
489 				return -ENODEV;
490 			}
491 			ACPI_COMPANION_SET(dev, adev);
492 		}
493 
494 		if (quirks & CROS_EC_LPC_QUIRK_AML_MUTEX) {
495 			const char *name
496 				= driver_data->quirk_aml_mutex_name;
497 			ret = cros_ec_lpc_mec_acpi_mutex(ACPI_COMPANION(dev), name);
498 			if (ret) {
499 				dev_err(dev, "failed to get AML mutex '%s'", name);
500 				return ret;
501 			}
502 			dev_info(dev, "got AML mutex '%s'", name);
503 		}
504 	}
505 
506 	/*
507 	 * The Framework Laptop (and possibly other non-ChromeOS devices)
508 	 * only exposes the eight I/O ports that are required for the Microchip EC.
509 	 * Requesting a larger reservation will fail.
510 	 */
511 	if (!devm_request_region(dev, EC_HOST_CMD_REGION0,
512 				 EC_HOST_CMD_MEC_REGION_SIZE, dev_name(dev))) {
513 		dev_err(dev, "couldn't reserve MEC region\n");
514 		return -EBUSY;
515 	}
516 
517 	cros_ec_lpc_mec_init(EC_HOST_CMD_REGION0,
518 			     EC_LPC_ADDR_MEMMAP + EC_MEMMAP_SIZE);
519 
520 	/*
521 	 * Read the mapped ID twice, the first one is assuming the
522 	 * EC is a Microchip Embedded Controller (MEC) variant, if the
523 	 * protocol fails, fallback to the non MEC variant and try to
524 	 * read again the ID.
525 	 */
526 	cros_ec_lpc_ops.read = cros_ec_lpc_mec_read_bytes;
527 	cros_ec_lpc_ops.write = cros_ec_lpc_mec_write_bytes;
528 	ret = cros_ec_lpc_ops.read(EC_LPC_ADDR_MEMMAP + EC_MEMMAP_ID, 2, buf);
529 	if (ret < 0)
530 		return ret;
531 	if (buf[0] != 'E' || buf[1] != 'C') {
532 		if (!devm_request_region(dev, ec_lpc->mmio_memory_base, EC_MEMMAP_SIZE,
533 					 dev_name(dev))) {
534 			dev_err(dev, "couldn't reserve memmap region\n");
535 			return -EBUSY;
536 		}
537 
538 		/* Re-assign read/write operations for the non MEC variant */
539 		cros_ec_lpc_ops.read = cros_ec_lpc_read_bytes;
540 		cros_ec_lpc_ops.write = cros_ec_lpc_write_bytes;
541 		ret = cros_ec_lpc_ops.read(ec_lpc->mmio_memory_base + EC_MEMMAP_ID, 2,
542 					   buf);
543 		if (ret < 0)
544 			return ret;
545 		if (buf[0] != 'E' || buf[1] != 'C') {
546 			dev_err(dev, "EC ID not detected\n");
547 			return -ENODEV;
548 		}
549 
550 		/* Reserve the remaining I/O ports required by the non-MEC protocol. */
551 		if (!devm_request_region(dev, EC_HOST_CMD_REGION0 + EC_HOST_CMD_MEC_REGION_SIZE,
552 					 EC_HOST_CMD_REGION_SIZE - EC_HOST_CMD_MEC_REGION_SIZE,
553 					 dev_name(dev))) {
554 			dev_err(dev, "couldn't reserve remainder of region0\n");
555 			return -EBUSY;
556 		}
557 		if (!devm_request_region(dev, EC_HOST_CMD_REGION1,
558 					 EC_HOST_CMD_REGION_SIZE, dev_name(dev))) {
559 			dev_err(dev, "couldn't reserve region1\n");
560 			return -EBUSY;
561 		}
562 	}
563 
564 	ec_dev = devm_kzalloc(dev, sizeof(*ec_dev), GFP_KERNEL);
565 	if (!ec_dev)
566 		return -ENOMEM;
567 
568 	platform_set_drvdata(pdev, ec_dev);
569 	ec_dev->dev = dev;
570 	ec_dev->phys_name = dev_name(dev);
571 	ec_dev->cmd_xfer = cros_ec_cmd_xfer_lpc;
572 	ec_dev->pkt_xfer = cros_ec_pkt_xfer_lpc;
573 	ec_dev->cmd_readmem = cros_ec_lpc_readmem;
574 	ec_dev->din_size = sizeof(struct ec_host_response) +
575 			   sizeof(struct ec_response_get_protocol_info);
576 	ec_dev->dout_size = sizeof(struct ec_host_request);
577 	ec_dev->priv = ec_lpc;
578 
579 	/*
580 	 * Some boards do not have an IRQ allotted for cros_ec_lpc,
581 	 * which makes ENXIO an expected (and safe) scenario.
582 	 */
583 	irq = platform_get_irq_optional(pdev, 0);
584 	if (irq > 0)
585 		ec_dev->irq = irq;
586 	else if (irq != -ENXIO) {
587 		dev_err(dev, "couldn't retrieve IRQ number (%d)\n", irq);
588 		return irq;
589 	}
590 
591 	ret = cros_ec_register(ec_dev);
592 	if (ret) {
593 		dev_err(dev, "couldn't register ec_dev (%d)\n", ret);
594 		return ret;
595 	}
596 
597 	/*
598 	 * Connect a notify handler to process MKBP messages if we have a
599 	 * companion ACPI device.
600 	 */
601 	adev = ACPI_COMPANION(dev);
602 	if (adev) {
603 		status = acpi_install_notify_handler(adev->handle,
604 						     ACPI_ALL_NOTIFY,
605 						     cros_ec_lpc_acpi_notify,
606 						     ec_dev);
607 		if (ACPI_FAILURE(status))
608 			dev_warn(dev, "Failed to register notifier %08x\n",
609 				 status);
610 	}
611 
612 	return 0;
613 }
614 
615 static void cros_ec_lpc_remove(struct platform_device *pdev)
616 {
617 	struct cros_ec_device *ec_dev = platform_get_drvdata(pdev);
618 	struct acpi_device *adev;
619 
620 	adev = ACPI_COMPANION(&pdev->dev);
621 	if (adev)
622 		acpi_remove_notify_handler(adev->handle, ACPI_ALL_NOTIFY,
623 					   cros_ec_lpc_acpi_notify);
624 
625 	cros_ec_unregister(ec_dev);
626 }
627 
628 static const struct acpi_device_id cros_ec_lpc_acpi_device_ids[] = {
629 	{ ACPI_DRV_NAME, 0 },
630 	{ }
631 };
632 MODULE_DEVICE_TABLE(acpi, cros_ec_lpc_acpi_device_ids);
633 
634 static const struct lpc_driver_data framework_laptop_npcx_lpc_driver_data __initconst = {
635 	.quirks = CROS_EC_LPC_QUIRK_REMAP_MEMORY,
636 	.quirk_mmio_memory_base = 0xE00,
637 };
638 
639 static const struct lpc_driver_data framework_laptop_mec_lpc_driver_data __initconst = {
640 	.quirks = CROS_EC_LPC_QUIRK_ACPI_ID|CROS_EC_LPC_QUIRK_AML_MUTEX,
641 	.quirk_acpi_id = "PNP0C09",
642 	.quirk_aml_mutex_name = "ECMT",
643 };
644 
645 static const struct dmi_system_id cros_ec_lpc_dmi_table[] __initconst = {
646 	{
647 		/*
648 		 * Today all Chromebooks/boxes ship with Google_* as version and
649 		 * coreboot as bios vendor. No other systems with this
650 		 * combination are known to date.
651 		 */
652 		.matches = {
653 			DMI_MATCH(DMI_BIOS_VENDOR, "coreboot"),
654 			DMI_MATCH(DMI_BIOS_VERSION, "Google_"),
655 		},
656 	},
657 	{
658 		/*
659 		 * If the box is running custom coreboot firmware then the
660 		 * DMI BIOS version string will not be matched by "Google_",
661 		 * but the system vendor string will still be matched by
662 		 * "GOOGLE".
663 		 */
664 		.matches = {
665 			DMI_MATCH(DMI_BIOS_VENDOR, "coreboot"),
666 			DMI_MATCH(DMI_SYS_VENDOR, "GOOGLE"),
667 		},
668 	},
669 	{
670 		/* x86-link, the Chromebook Pixel. */
671 		.matches = {
672 			DMI_MATCH(DMI_SYS_VENDOR, "GOOGLE"),
673 			DMI_MATCH(DMI_PRODUCT_NAME, "Link"),
674 		},
675 	},
676 	{
677 		/* x86-samus, the Chromebook Pixel 2. */
678 		.matches = {
679 			DMI_MATCH(DMI_SYS_VENDOR, "GOOGLE"),
680 			DMI_MATCH(DMI_PRODUCT_NAME, "Samus"),
681 		},
682 	},
683 	{
684 		/* x86-peppy, the Acer C720 Chromebook. */
685 		.matches = {
686 			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
687 			DMI_MATCH(DMI_PRODUCT_NAME, "Peppy"),
688 		},
689 	},
690 	{
691 		/* x86-glimmer, the Lenovo Thinkpad Yoga 11e. */
692 		.matches = {
693 			DMI_MATCH(DMI_SYS_VENDOR, "GOOGLE"),
694 			DMI_MATCH(DMI_PRODUCT_NAME, "Glimmer"),
695 		},
696 	},
697 	/* A small number of non-Chromebook/box machines also use the ChromeOS EC */
698 	{
699 		/* Framework Laptop (11th Gen Intel Core) */
700 		.matches = {
701 			DMI_MATCH(DMI_SYS_VENDOR, "Framework"),
702 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Laptop"),
703 		},
704 		.driver_data = (void *)&framework_laptop_mec_lpc_driver_data,
705 	},
706 	{
707 		/* Framework Laptop (12th Gen Intel Core) */
708 		.matches = {
709 			DMI_MATCH(DMI_SYS_VENDOR, "Framework"),
710 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "12th Gen Intel Core"),
711 		},
712 		.driver_data = (void *)&framework_laptop_mec_lpc_driver_data,
713 	},
714 	{
715 		/* Framework Laptop (13th Gen Intel Core) */
716 		.matches = {
717 			DMI_MATCH(DMI_SYS_VENDOR, "Framework"),
718 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "13th Gen Intel Core"),
719 		},
720 		.driver_data = (void *)&framework_laptop_mec_lpc_driver_data,
721 	},
722 	{
723 		/*
724 		 * All remaining Framework Laptop models (13 AMD Ryzen, 16 AMD
725 		 * Ryzen, Intel Core Ultra)
726 		 */
727 		.matches = {
728 			DMI_MATCH(DMI_SYS_VENDOR, "Framework"),
729 			DMI_MATCH(DMI_PRODUCT_FAMILY, "Laptop"),
730 		},
731 		.driver_data = (void *)&framework_laptop_npcx_lpc_driver_data,
732 	},
733 	{ /* sentinel */ }
734 };
735 MODULE_DEVICE_TABLE(dmi, cros_ec_lpc_dmi_table);
736 
737 #ifdef CONFIG_PM_SLEEP
738 static int cros_ec_lpc_prepare(struct device *dev)
739 {
740 	struct cros_ec_device *ec_dev = dev_get_drvdata(dev);
741 	return cros_ec_suspend_prepare(ec_dev);
742 }
743 
744 static void cros_ec_lpc_complete(struct device *dev)
745 {
746 	struct cros_ec_device *ec_dev = dev_get_drvdata(dev);
747 	cros_ec_resume_complete(ec_dev);
748 }
749 
750 static int cros_ec_lpc_suspend_late(struct device *dev)
751 {
752 	struct cros_ec_device *ec_dev = dev_get_drvdata(dev);
753 
754 	return cros_ec_suspend_late(ec_dev);
755 }
756 
757 static int cros_ec_lpc_resume_early(struct device *dev)
758 {
759 	struct cros_ec_device *ec_dev = dev_get_drvdata(dev);
760 
761 	return cros_ec_resume_early(ec_dev);
762 }
763 #endif
764 
765 static const struct dev_pm_ops cros_ec_lpc_pm_ops = {
766 #ifdef CONFIG_PM_SLEEP
767 	.prepare = cros_ec_lpc_prepare,
768 	.complete = cros_ec_lpc_complete,
769 #endif
770 	SET_LATE_SYSTEM_SLEEP_PM_OPS(cros_ec_lpc_suspend_late, cros_ec_lpc_resume_early)
771 };
772 
773 static struct platform_driver cros_ec_lpc_driver = {
774 	.driver = {
775 		.name = DRV_NAME,
776 		.acpi_match_table = cros_ec_lpc_acpi_device_ids,
777 		.pm = &cros_ec_lpc_pm_ops,
778 		/*
779 		 * ACPI child devices may probe before us, and they racily
780 		 * check our drvdata pointer. Force synchronous probe until
781 		 * those races are resolved.
782 		 */
783 		.probe_type = PROBE_FORCE_SYNCHRONOUS,
784 	},
785 	.probe = cros_ec_lpc_probe,
786 	.remove_new = cros_ec_lpc_remove,
787 };
788 
789 static struct platform_device cros_ec_lpc_device = {
790 	.name = DRV_NAME
791 };
792 
793 static int __init cros_ec_lpc_init(void)
794 {
795 	int ret;
796 	const struct dmi_system_id *dmi_match;
797 
798 	cros_ec_lpc_acpi_device_found = !!cros_ec_lpc_get_device(ACPI_DRV_NAME);
799 
800 	dmi_match = dmi_first_match(cros_ec_lpc_dmi_table);
801 
802 	if (!cros_ec_lpc_acpi_device_found && !dmi_match) {
803 		pr_err(DRV_NAME ": unsupported system.\n");
804 		return -ENODEV;
805 	}
806 
807 	/* Register the driver */
808 	ret = platform_driver_register(&cros_ec_lpc_driver);
809 	if (ret) {
810 		pr_err(DRV_NAME ": can't register driver: %d\n", ret);
811 		return ret;
812 	}
813 
814 	if (!cros_ec_lpc_acpi_device_found) {
815 		/* Pass the DMI match's driver data down to the platform device */
816 		platform_set_drvdata(&cros_ec_lpc_device, dmi_match->driver_data);
817 
818 		/* Register the device, and it'll get hooked up automatically */
819 		ret = platform_device_register(&cros_ec_lpc_device);
820 		if (ret) {
821 			pr_err(DRV_NAME ": can't register device: %d\n", ret);
822 			platform_driver_unregister(&cros_ec_lpc_driver);
823 		}
824 	}
825 
826 	return ret;
827 }
828 
829 static void __exit cros_ec_lpc_exit(void)
830 {
831 	if (!cros_ec_lpc_acpi_device_found)
832 		platform_device_unregister(&cros_ec_lpc_device);
833 	platform_driver_unregister(&cros_ec_lpc_driver);
834 }
835 
836 module_init(cros_ec_lpc_init);
837 module_exit(cros_ec_lpc_exit);
838 
839 MODULE_LICENSE("GPL");
840 MODULE_DESCRIPTION("ChromeOS EC LPC driver");
841