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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 */
35static 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 */
63struct 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 */
74struct 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 */
87struct 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
92static 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 */
98static 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 */
117static 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 */
136static 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 */
155static 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
170static 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
189static 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;
266done:
267 return ret;
268}
269
270static 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;
365done:
366 return ret;
367}
368
369/* Returns num bytes read, or negative on error. Doesn't need locking. */
370static 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
403static 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
436static 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
443static 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
456static 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
615static 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
628static const struct acpi_device_id cros_ec_lpc_acpi_device_ids[] = {
629 { ACPI_DRV_NAME, 0 },
630 { }
631};
632MODULE_DEVICE_TABLE(acpi, cros_ec_lpc_acpi_device_ids);
633
634static 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
639static 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
645static 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, "Laptop (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, "Laptop (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};
735MODULE_DEVICE_TABLE(dmi, cros_ec_lpc_dmi_table);
736
737#ifdef CONFIG_PM_SLEEP
738static 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
744static 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
750static 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
757static 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
765static 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
773static 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 = cros_ec_lpc_remove,
787};
788
789static struct platform_device cros_ec_lpc_device = {
790 .name = DRV_NAME
791};
792
793static 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
829static 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
836module_init(cros_ec_lpc_init);
837module_exit(cros_ec_lpc_exit);
838
839MODULE_LICENSE("GPL");
840MODULE_DESCRIPTION("ChromeOS EC LPC driver");
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/module.h>
20#include <linux/platform_data/cros_ec_commands.h>
21#include <linux/platform_data/cros_ec_proto.h>
22#include <linux/platform_device.h>
23#include <linux/printk.h>
24#include <linux/suspend.h>
25
26#include "cros_ec.h"
27#include "cros_ec_lpc_mec.h"
28
29#define DRV_NAME "cros_ec_lpcs"
30#define ACPI_DRV_NAME "GOOG0004"
31
32/* True if ACPI device is present */
33static bool cros_ec_lpc_acpi_device_found;
34
35/**
36 * struct lpc_driver_ops - LPC driver operations
37 * @read: Copy length bytes from EC address offset into buffer dest. Returns
38 * the 8-bit checksum of all bytes read.
39 * @write: Copy length bytes from buffer msg into EC address offset. Returns
40 * the 8-bit checksum of all bytes written.
41 */
42struct lpc_driver_ops {
43 u8 (*read)(unsigned int offset, unsigned int length, u8 *dest);
44 u8 (*write)(unsigned int offset, unsigned int length, const u8 *msg);
45};
46
47static struct lpc_driver_ops cros_ec_lpc_ops = { };
48
49/*
50 * A generic instance of the read function of struct lpc_driver_ops, used for
51 * the LPC EC.
52 */
53static u8 cros_ec_lpc_read_bytes(unsigned int offset, unsigned int length,
54 u8 *dest)
55{
56 int sum = 0;
57 int i;
58
59 for (i = 0; i < length; ++i) {
60 dest[i] = inb(offset + i);
61 sum += dest[i];
62 }
63
64 /* Return checksum of all bytes read */
65 return sum;
66}
67
68/*
69 * A generic instance of the write function of struct lpc_driver_ops, used for
70 * the LPC EC.
71 */
72static u8 cros_ec_lpc_write_bytes(unsigned int offset, unsigned int length,
73 const u8 *msg)
74{
75 int sum = 0;
76 int i;
77
78 for (i = 0; i < length; ++i) {
79 outb(msg[i], offset + i);
80 sum += msg[i];
81 }
82
83 /* Return checksum of all bytes written */
84 return sum;
85}
86
87/*
88 * An instance of the read function of struct lpc_driver_ops, used for the
89 * MEC variant of LPC EC.
90 */
91static u8 cros_ec_lpc_mec_read_bytes(unsigned int offset, unsigned int length,
92 u8 *dest)
93{
94 int in_range = cros_ec_lpc_mec_in_range(offset, length);
95
96 if (in_range < 0)
97 return 0;
98
99 return in_range ?
100 cros_ec_lpc_io_bytes_mec(MEC_IO_READ,
101 offset - EC_HOST_CMD_REGION0,
102 length, dest) :
103 cros_ec_lpc_read_bytes(offset, length, dest);
104}
105
106/*
107 * An instance of the write function of struct lpc_driver_ops, used for the
108 * MEC variant of LPC EC.
109 */
110static u8 cros_ec_lpc_mec_write_bytes(unsigned int offset, unsigned int length,
111 const u8 *msg)
112{
113 int in_range = cros_ec_lpc_mec_in_range(offset, length);
114
115 if (in_range < 0)
116 return 0;
117
118 return in_range ?
119 cros_ec_lpc_io_bytes_mec(MEC_IO_WRITE,
120 offset - EC_HOST_CMD_REGION0,
121 length, (u8 *)msg) :
122 cros_ec_lpc_write_bytes(offset, length, msg);
123}
124
125static int ec_response_timed_out(void)
126{
127 unsigned long one_second = jiffies + HZ;
128 u8 data;
129
130 usleep_range(200, 300);
131 do {
132 if (!(cros_ec_lpc_ops.read(EC_LPC_ADDR_HOST_CMD, 1, &data) &
133 EC_LPC_STATUS_BUSY_MASK))
134 return 0;
135 usleep_range(100, 200);
136 } while (time_before(jiffies, one_second));
137
138 return 1;
139}
140
141static int cros_ec_pkt_xfer_lpc(struct cros_ec_device *ec,
142 struct cros_ec_command *msg)
143{
144 struct ec_host_response response;
145 u8 sum;
146 int ret = 0;
147 u8 *dout;
148
149 ret = cros_ec_prepare_tx(ec, msg);
150
151 /* Write buffer */
152 cros_ec_lpc_ops.write(EC_LPC_ADDR_HOST_PACKET, ret, ec->dout);
153
154 /* Here we go */
155 sum = EC_COMMAND_PROTOCOL_3;
156 cros_ec_lpc_ops.write(EC_LPC_ADDR_HOST_CMD, 1, &sum);
157
158 if (ec_response_timed_out()) {
159 dev_warn(ec->dev, "EC responsed timed out\n");
160 ret = -EIO;
161 goto done;
162 }
163
164 /* Check result */
165 msg->result = cros_ec_lpc_ops.read(EC_LPC_ADDR_HOST_DATA, 1, &sum);
166 ret = cros_ec_check_result(ec, msg);
167 if (ret)
168 goto done;
169
170 /* Read back response */
171 dout = (u8 *)&response;
172 sum = cros_ec_lpc_ops.read(EC_LPC_ADDR_HOST_PACKET, sizeof(response),
173 dout);
174
175 msg->result = response.result;
176
177 if (response.data_len > msg->insize) {
178 dev_err(ec->dev,
179 "packet too long (%d bytes, expected %d)",
180 response.data_len, msg->insize);
181 ret = -EMSGSIZE;
182 goto done;
183 }
184
185 /* Read response and process checksum */
186 sum += cros_ec_lpc_ops.read(EC_LPC_ADDR_HOST_PACKET +
187 sizeof(response), response.data_len,
188 msg->data);
189
190 if (sum) {
191 dev_err(ec->dev,
192 "bad packet checksum %02x\n",
193 response.checksum);
194 ret = -EBADMSG;
195 goto done;
196 }
197
198 /* Return actual amount of data received */
199 ret = response.data_len;
200done:
201 return ret;
202}
203
204static int cros_ec_cmd_xfer_lpc(struct cros_ec_device *ec,
205 struct cros_ec_command *msg)
206{
207 struct ec_lpc_host_args args;
208 u8 sum;
209 int ret = 0;
210
211 if (msg->outsize > EC_PROTO2_MAX_PARAM_SIZE ||
212 msg->insize > EC_PROTO2_MAX_PARAM_SIZE) {
213 dev_err(ec->dev,
214 "invalid buffer sizes (out %d, in %d)\n",
215 msg->outsize, msg->insize);
216 return -EINVAL;
217 }
218
219 /* Now actually send the command to the EC and get the result */
220 args.flags = EC_HOST_ARGS_FLAG_FROM_HOST;
221 args.command_version = msg->version;
222 args.data_size = msg->outsize;
223
224 /* Initialize checksum */
225 sum = msg->command + args.flags + args.command_version + args.data_size;
226
227 /* Copy data and update checksum */
228 sum += cros_ec_lpc_ops.write(EC_LPC_ADDR_HOST_PARAM, msg->outsize,
229 msg->data);
230
231 /* Finalize checksum and write args */
232 args.checksum = sum;
233 cros_ec_lpc_ops.write(EC_LPC_ADDR_HOST_ARGS, sizeof(args),
234 (u8 *)&args);
235
236 /* Here we go */
237 sum = msg->command;
238 cros_ec_lpc_ops.write(EC_LPC_ADDR_HOST_CMD, 1, &sum);
239
240 if (ec_response_timed_out()) {
241 dev_warn(ec->dev, "EC responsed timed out\n");
242 ret = -EIO;
243 goto done;
244 }
245
246 /* Check result */
247 msg->result = cros_ec_lpc_ops.read(EC_LPC_ADDR_HOST_DATA, 1, &sum);
248 ret = cros_ec_check_result(ec, msg);
249 if (ret)
250 goto done;
251
252 /* Read back args */
253 cros_ec_lpc_ops.read(EC_LPC_ADDR_HOST_ARGS, sizeof(args), (u8 *)&args);
254
255 if (args.data_size > msg->insize) {
256 dev_err(ec->dev,
257 "packet too long (%d bytes, expected %d)",
258 args.data_size, msg->insize);
259 ret = -ENOSPC;
260 goto done;
261 }
262
263 /* Start calculating response checksum */
264 sum = msg->command + args.flags + args.command_version + args.data_size;
265
266 /* Read response and update checksum */
267 sum += cros_ec_lpc_ops.read(EC_LPC_ADDR_HOST_PARAM, args.data_size,
268 msg->data);
269
270 /* Verify checksum */
271 if (args.checksum != sum) {
272 dev_err(ec->dev,
273 "bad packet checksum, expected %02x, got %02x\n",
274 args.checksum, sum);
275 ret = -EBADMSG;
276 goto done;
277 }
278
279 /* Return actual amount of data received */
280 ret = args.data_size;
281done:
282 return ret;
283}
284
285/* Returns num bytes read, or negative on error. Doesn't need locking. */
286static int cros_ec_lpc_readmem(struct cros_ec_device *ec, unsigned int offset,
287 unsigned int bytes, void *dest)
288{
289 int i = offset;
290 char *s = dest;
291 int cnt = 0;
292
293 if (offset >= EC_MEMMAP_SIZE - bytes)
294 return -EINVAL;
295
296 /* fixed length */
297 if (bytes) {
298 cros_ec_lpc_ops.read(EC_LPC_ADDR_MEMMAP + offset, bytes, s);
299 return bytes;
300 }
301
302 /* string */
303 for (; i < EC_MEMMAP_SIZE; i++, s++) {
304 cros_ec_lpc_ops.read(EC_LPC_ADDR_MEMMAP + i, 1, s);
305 cnt++;
306 if (!*s)
307 break;
308 }
309
310 return cnt;
311}
312
313static void cros_ec_lpc_acpi_notify(acpi_handle device, u32 value, void *data)
314{
315 struct cros_ec_device *ec_dev = data;
316 bool ec_has_more_events;
317 int ret;
318
319 ec_dev->last_event_time = cros_ec_get_time_ns();
320
321 if (ec_dev->mkbp_event_supported)
322 do {
323 ret = cros_ec_get_next_event(ec_dev, NULL,
324 &ec_has_more_events);
325 if (ret > 0)
326 blocking_notifier_call_chain(
327 &ec_dev->event_notifier, 0,
328 ec_dev);
329 } while (ec_has_more_events);
330
331 if (value == ACPI_NOTIFY_DEVICE_WAKE)
332 pm_system_wakeup();
333}
334
335static int cros_ec_lpc_probe(struct platform_device *pdev)
336{
337 struct device *dev = &pdev->dev;
338 struct acpi_device *adev;
339 acpi_status status;
340 struct cros_ec_device *ec_dev;
341 u8 buf[2];
342 int irq, ret;
343
344 if (!devm_request_region(dev, EC_LPC_ADDR_MEMMAP, EC_MEMMAP_SIZE,
345 dev_name(dev))) {
346 dev_err(dev, "couldn't reserve memmap region\n");
347 return -EBUSY;
348 }
349
350 /*
351 * Read the mapped ID twice, the first one is assuming the
352 * EC is a Microchip Embedded Controller (MEC) variant, if the
353 * protocol fails, fallback to the non MEC variant and try to
354 * read again the ID.
355 */
356 cros_ec_lpc_ops.read = cros_ec_lpc_mec_read_bytes;
357 cros_ec_lpc_ops.write = cros_ec_lpc_mec_write_bytes;
358 cros_ec_lpc_ops.read(EC_LPC_ADDR_MEMMAP + EC_MEMMAP_ID, 2, buf);
359 if (buf[0] != 'E' || buf[1] != 'C') {
360 /* Re-assign read/write operations for the non MEC variant */
361 cros_ec_lpc_ops.read = cros_ec_lpc_read_bytes;
362 cros_ec_lpc_ops.write = cros_ec_lpc_write_bytes;
363 cros_ec_lpc_ops.read(EC_LPC_ADDR_MEMMAP + EC_MEMMAP_ID, 2,
364 buf);
365 if (buf[0] != 'E' || buf[1] != 'C') {
366 dev_err(dev, "EC ID not detected\n");
367 return -ENODEV;
368 }
369 }
370
371 if (!devm_request_region(dev, EC_HOST_CMD_REGION0,
372 EC_HOST_CMD_REGION_SIZE, dev_name(dev))) {
373 dev_err(dev, "couldn't reserve region0\n");
374 return -EBUSY;
375 }
376 if (!devm_request_region(dev, EC_HOST_CMD_REGION1,
377 EC_HOST_CMD_REGION_SIZE, dev_name(dev))) {
378 dev_err(dev, "couldn't reserve region1\n");
379 return -EBUSY;
380 }
381
382 ec_dev = devm_kzalloc(dev, sizeof(*ec_dev), GFP_KERNEL);
383 if (!ec_dev)
384 return -ENOMEM;
385
386 platform_set_drvdata(pdev, ec_dev);
387 ec_dev->dev = dev;
388 ec_dev->phys_name = dev_name(dev);
389 ec_dev->cmd_xfer = cros_ec_cmd_xfer_lpc;
390 ec_dev->pkt_xfer = cros_ec_pkt_xfer_lpc;
391 ec_dev->cmd_readmem = cros_ec_lpc_readmem;
392 ec_dev->din_size = sizeof(struct ec_host_response) +
393 sizeof(struct ec_response_get_protocol_info);
394 ec_dev->dout_size = sizeof(struct ec_host_request);
395
396 /*
397 * Some boards do not have an IRQ allotted for cros_ec_lpc,
398 * which makes ENXIO an expected (and safe) scenario.
399 */
400 irq = platform_get_irq_optional(pdev, 0);
401 if (irq > 0)
402 ec_dev->irq = irq;
403 else if (irq != -ENXIO) {
404 dev_err(dev, "couldn't retrieve IRQ number (%d)\n", irq);
405 return irq;
406 }
407
408 ret = cros_ec_register(ec_dev);
409 if (ret) {
410 dev_err(dev, "couldn't register ec_dev (%d)\n", ret);
411 return ret;
412 }
413
414 /*
415 * Connect a notify handler to process MKBP messages if we have a
416 * companion ACPI device.
417 */
418 adev = ACPI_COMPANION(dev);
419 if (adev) {
420 status = acpi_install_notify_handler(adev->handle,
421 ACPI_ALL_NOTIFY,
422 cros_ec_lpc_acpi_notify,
423 ec_dev);
424 if (ACPI_FAILURE(status))
425 dev_warn(dev, "Failed to register notifier %08x\n",
426 status);
427 }
428
429 return 0;
430}
431
432static int cros_ec_lpc_remove(struct platform_device *pdev)
433{
434 struct cros_ec_device *ec_dev = platform_get_drvdata(pdev);
435 struct acpi_device *adev;
436
437 adev = ACPI_COMPANION(&pdev->dev);
438 if (adev)
439 acpi_remove_notify_handler(adev->handle, ACPI_ALL_NOTIFY,
440 cros_ec_lpc_acpi_notify);
441
442 return cros_ec_unregister(ec_dev);
443}
444
445static const struct acpi_device_id cros_ec_lpc_acpi_device_ids[] = {
446 { ACPI_DRV_NAME, 0 },
447 { }
448};
449MODULE_DEVICE_TABLE(acpi, cros_ec_lpc_acpi_device_ids);
450
451static const struct dmi_system_id cros_ec_lpc_dmi_table[] __initconst = {
452 {
453 /*
454 * Today all Chromebooks/boxes ship with Google_* as version and
455 * coreboot as bios vendor. No other systems with this
456 * combination are known to date.
457 */
458 .matches = {
459 DMI_MATCH(DMI_BIOS_VENDOR, "coreboot"),
460 DMI_MATCH(DMI_BIOS_VERSION, "Google_"),
461 },
462 },
463 {
464 /*
465 * If the box is running custom coreboot firmware then the
466 * DMI BIOS version string will not be matched by "Google_",
467 * but the system vendor string will still be matched by
468 * "GOOGLE".
469 */
470 .matches = {
471 DMI_MATCH(DMI_BIOS_VENDOR, "coreboot"),
472 DMI_MATCH(DMI_SYS_VENDOR, "GOOGLE"),
473 },
474 },
475 {
476 /* x86-link, the Chromebook Pixel. */
477 .matches = {
478 DMI_MATCH(DMI_SYS_VENDOR, "GOOGLE"),
479 DMI_MATCH(DMI_PRODUCT_NAME, "Link"),
480 },
481 },
482 {
483 /* x86-samus, the Chromebook Pixel 2. */
484 .matches = {
485 DMI_MATCH(DMI_SYS_VENDOR, "GOOGLE"),
486 DMI_MATCH(DMI_PRODUCT_NAME, "Samus"),
487 },
488 },
489 {
490 /* x86-peppy, the Acer C720 Chromebook. */
491 .matches = {
492 DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
493 DMI_MATCH(DMI_PRODUCT_NAME, "Peppy"),
494 },
495 },
496 {
497 /* x86-glimmer, the Lenovo Thinkpad Yoga 11e. */
498 .matches = {
499 DMI_MATCH(DMI_SYS_VENDOR, "GOOGLE"),
500 DMI_MATCH(DMI_PRODUCT_NAME, "Glimmer"),
501 },
502 },
503 { /* sentinel */ }
504};
505MODULE_DEVICE_TABLE(dmi, cros_ec_lpc_dmi_table);
506
507#ifdef CONFIG_PM_SLEEP
508static int cros_ec_lpc_suspend(struct device *dev)
509{
510 struct cros_ec_device *ec_dev = dev_get_drvdata(dev);
511
512 return cros_ec_suspend(ec_dev);
513}
514
515static int cros_ec_lpc_resume(struct device *dev)
516{
517 struct cros_ec_device *ec_dev = dev_get_drvdata(dev);
518
519 return cros_ec_resume(ec_dev);
520}
521#endif
522
523static const struct dev_pm_ops cros_ec_lpc_pm_ops = {
524 SET_LATE_SYSTEM_SLEEP_PM_OPS(cros_ec_lpc_suspend, cros_ec_lpc_resume)
525};
526
527static struct platform_driver cros_ec_lpc_driver = {
528 .driver = {
529 .name = DRV_NAME,
530 .acpi_match_table = cros_ec_lpc_acpi_device_ids,
531 .pm = &cros_ec_lpc_pm_ops,
532 },
533 .probe = cros_ec_lpc_probe,
534 .remove = cros_ec_lpc_remove,
535};
536
537static struct platform_device cros_ec_lpc_device = {
538 .name = DRV_NAME
539};
540
541static acpi_status cros_ec_lpc_parse_device(acpi_handle handle, u32 level,
542 void *context, void **retval)
543{
544 *(bool *)context = true;
545 return AE_CTRL_TERMINATE;
546}
547
548static int __init cros_ec_lpc_init(void)
549{
550 int ret;
551 acpi_status status;
552
553 status = acpi_get_devices(ACPI_DRV_NAME, cros_ec_lpc_parse_device,
554 &cros_ec_lpc_acpi_device_found, NULL);
555 if (ACPI_FAILURE(status))
556 pr_warn(DRV_NAME ": Looking for %s failed\n", ACPI_DRV_NAME);
557
558 if (!cros_ec_lpc_acpi_device_found &&
559 !dmi_check_system(cros_ec_lpc_dmi_table)) {
560 pr_err(DRV_NAME ": unsupported system.\n");
561 return -ENODEV;
562 }
563
564 cros_ec_lpc_mec_init(EC_HOST_CMD_REGION0,
565 EC_LPC_ADDR_MEMMAP + EC_MEMMAP_SIZE);
566
567 /* Register the driver */
568 ret = platform_driver_register(&cros_ec_lpc_driver);
569 if (ret) {
570 pr_err(DRV_NAME ": can't register driver: %d\n", ret);
571 cros_ec_lpc_mec_destroy();
572 return ret;
573 }
574
575 if (!cros_ec_lpc_acpi_device_found) {
576 /* Register the device, and it'll get hooked up automatically */
577 ret = platform_device_register(&cros_ec_lpc_device);
578 if (ret) {
579 pr_err(DRV_NAME ": can't register device: %d\n", ret);
580 platform_driver_unregister(&cros_ec_lpc_driver);
581 cros_ec_lpc_mec_destroy();
582 }
583 }
584
585 return ret;
586}
587
588static void __exit cros_ec_lpc_exit(void)
589{
590 if (!cros_ec_lpc_acpi_device_found)
591 platform_device_unregister(&cros_ec_lpc_device);
592 platform_driver_unregister(&cros_ec_lpc_driver);
593 cros_ec_lpc_mec_destroy();
594}
595
596module_init(cros_ec_lpc_init);
597module_exit(cros_ec_lpc_exit);
598
599MODULE_LICENSE("GPL");
600MODULE_DESCRIPTION("ChromeOS EC LPC driver");