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https://github.com/brain-hackers/u-boot-brain
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![Tom Rini](/assets/img/avatar_default.png)
When U-Boot started using SPDX tags we were among the early adopters and there weren't a lot of other examples to borrow from. So we picked the area of the file that usually had a full license text and replaced it with an appropriate SPDX-License-Identifier: entry. Since then, the Linux Kernel has adopted SPDX tags and they place it as the very first line in a file (except where shebangs are used, then it's second line) and with slightly different comment styles than us. In part due to community overlap, in part due to better tag visibility and in part for other minor reasons, switch over to that style. This commit changes all instances where we have a single declared license in the tag as both the before and after are identical in tag contents. There's also a few places where I found we did not have a tag and have introduced one. Signed-off-by: Tom Rini <trini@konsulko.com>
219 lines
5.2 KiB
C
219 lines
5.2 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Chromium OS cros_ec driver - LPC interface
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*
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* Copyright (c) 2012 The Chromium OS Authors.
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*/
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/*
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* The Matrix Keyboard Protocol driver handles talking to the keyboard
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* controller chip. Mostly this is for keyboard functions, but some other
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* things have slipped in, so we provide generic services to talk to the
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* KBC.
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*/
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#include <common.h>
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#include <dm.h>
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#include <command.h>
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#include <cros_ec.h>
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#include <asm/io.h>
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#ifdef DEBUG_TRACE
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#define debug_trace(fmt, b...) debug(fmt, ##b)
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#else
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#define debug_trace(fmt, b...)
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#endif
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static int wait_for_sync(struct cros_ec_dev *dev)
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{
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unsigned long start;
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start = get_timer(0);
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while (inb(EC_LPC_ADDR_HOST_CMD) & EC_LPC_STATUS_BUSY_MASK) {
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if (get_timer(start) > 1000) {
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debug("%s: Timeout waiting for CROS_EC sync\n",
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__func__);
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return -1;
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}
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}
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return 0;
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}
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int cros_ec_lpc_command(struct udevice *udev, uint8_t cmd, int cmd_version,
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const uint8_t *dout, int dout_len,
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uint8_t **dinp, int din_len)
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{
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struct cros_ec_dev *dev = dev_get_uclass_priv(udev);
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const int cmd_addr = EC_LPC_ADDR_HOST_CMD;
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const int data_addr = EC_LPC_ADDR_HOST_DATA;
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const int args_addr = EC_LPC_ADDR_HOST_ARGS;
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const int param_addr = EC_LPC_ADDR_HOST_PARAM;
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struct ec_lpc_host_args args;
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uint8_t *d;
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int csum;
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int i;
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if (dout_len > EC_PROTO2_MAX_PARAM_SIZE) {
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debug("%s: Cannot send %d bytes\n", __func__, dout_len);
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return -1;
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}
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/* Fill in args */
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args.flags = EC_HOST_ARGS_FLAG_FROM_HOST;
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args.command_version = cmd_version;
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args.data_size = dout_len;
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/* Calculate checksum */
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csum = cmd + args.flags + args.command_version + args.data_size;
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for (i = 0, d = (uint8_t *)dout; i < dout_len; i++, d++)
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csum += *d;
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args.checksum = (uint8_t)csum;
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if (wait_for_sync(dev)) {
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debug("%s: Timeout waiting ready\n", __func__);
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return -1;
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}
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/* Write args */
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for (i = 0, d = (uint8_t *)&args; i < sizeof(args); i++, d++)
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outb(*d, args_addr + i);
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/* Write data, if any */
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debug_trace("cmd: %02x, ver: %02x", cmd, cmd_version);
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for (i = 0, d = (uint8_t *)dout; i < dout_len; i++, d++) {
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outb(*d, param_addr + i);
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debug_trace("%02x ", *d);
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}
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outb(cmd, cmd_addr);
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debug_trace("\n");
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if (wait_for_sync(dev)) {
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debug("%s: Timeout waiting for response\n", __func__);
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return -1;
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}
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/* Check result */
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i = inb(data_addr);
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if (i) {
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debug("%s: CROS_EC result code %d\n", __func__, i);
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return -i;
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}
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/* Read back args */
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for (i = 0, d = (uint8_t *)&args; i < sizeof(args); i++, d++)
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*d = inb(args_addr + i);
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/*
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* If EC didn't modify args flags, then somehow we sent a new-style
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* command to an old EC, which means it would have read its params
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* from the wrong place.
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*/
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if (!(args.flags & EC_HOST_ARGS_FLAG_TO_HOST)) {
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debug("%s: CROS_EC protocol mismatch\n", __func__);
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return -EC_RES_INVALID_RESPONSE;
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}
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if (args.data_size > din_len) {
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debug("%s: CROS_EC returned too much data %d > %d\n",
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__func__, args.data_size, din_len);
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return -EC_RES_INVALID_RESPONSE;
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}
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/* Read data, if any */
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for (i = 0, d = (uint8_t *)dev->din; i < args.data_size; i++, d++) {
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*d = inb(param_addr + i);
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debug_trace("%02x ", *d);
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}
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debug_trace("\n");
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/* Verify checksum */
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csum = cmd + args.flags + args.command_version + args.data_size;
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for (i = 0, d = (uint8_t *)dev->din; i < args.data_size; i++, d++)
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csum += *d;
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if (args.checksum != (uint8_t)csum) {
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debug("%s: CROS_EC response has invalid checksum\n", __func__);
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return -EC_RES_INVALID_CHECKSUM;
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}
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*dinp = dev->din;
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/* Return actual amount of data received */
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return args.data_size;
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}
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/**
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* Initialize LPC protocol.
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*
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* @param dev CROS_EC device
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* @param blob Device tree blob
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* @return 0 if ok, -1 on error
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*/
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int cros_ec_lpc_init(struct cros_ec_dev *dev, const void *blob)
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{
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int byte, i;
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/* See if we can find an EC at the other end */
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byte = 0xff;
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byte &= inb(EC_LPC_ADDR_HOST_CMD);
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byte &= inb(EC_LPC_ADDR_HOST_DATA);
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for (i = 0; i < EC_PROTO2_MAX_PARAM_SIZE && (byte == 0xff); i++)
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byte &= inb(EC_LPC_ADDR_HOST_PARAM + i);
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if (byte == 0xff) {
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debug("%s: CROS_EC device not found on LPC bus\n",
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__func__);
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return -1;
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}
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return 0;
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}
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/*
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* Test if LPC command args are supported.
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*
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* The cheapest way to do this is by looking for the memory-mapped
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* flag. This is faster than sending a new-style 'hello' command and
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* seeing whether the EC sets the EC_HOST_ARGS_FLAG_FROM_HOST flag
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* in args when it responds.
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*/
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static int cros_ec_lpc_check_version(struct udevice *dev)
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{
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if (inb(EC_LPC_ADDR_MEMMAP + EC_MEMMAP_ID) == 'E' &&
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inb(EC_LPC_ADDR_MEMMAP + EC_MEMMAP_ID + 1)
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== 'C' &&
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(inb(EC_LPC_ADDR_MEMMAP +
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EC_MEMMAP_HOST_CMD_FLAGS) &
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EC_HOST_CMD_FLAG_LPC_ARGS_SUPPORTED)) {
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return 0;
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}
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printf("%s: ERROR: old EC interface not supported\n", __func__);
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return -1;
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}
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static int cros_ec_probe(struct udevice *dev)
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{
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return cros_ec_register(dev);
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}
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static struct dm_cros_ec_ops cros_ec_ops = {
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.command = cros_ec_lpc_command,
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.check_version = cros_ec_lpc_check_version,
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};
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static const struct udevice_id cros_ec_ids[] = {
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{ .compatible = "google,cros-ec-lpc" },
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{ }
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};
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U_BOOT_DRIVER(cros_ec_lpc) = {
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.name = "cros_ec_lpc",
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.id = UCLASS_CROS_EC,
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.of_match = cros_ec_ids,
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.probe = cros_ec_probe,
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.ops = &cros_ec_ops,
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};
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