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path: root/drivers/platform/chrome/cros_ec_proto.c
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Diffstat (limited to 'drivers/platform/chrome/cros_ec_proto.c')
-rw-r--r--drivers/platform/chrome/cros_ec_proto.c1080
1 files changed, 826 insertions, 254 deletions
diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
index 8dfa7fcb1248..1d8d9168ec1a 100644
--- a/drivers/platform/chrome/cros_ec_proto.c
+++ b/drivers/platform/chrome/cros_ec_proto.c
@@ -1,38 +1,71 @@
-/*
- * ChromeOS EC communication protocol helper functions
- *
- * Copyright (C) 2015 Google, Inc
- *
- * This software is licensed under the terms of the GNU General Public
- * License version 2, as published by the Free Software Foundation, and
- * may be copied, distributed, and modified under those terms.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- */
+// SPDX-License-Identifier: GPL-2.0
+// ChromeOS EC communication protocol helper functions
+//
+// Copyright (C) 2015 Google, Inc
-#include <linux/mfd/cros_ec.h>
+#include <linux/cleanup.h>
#include <linux/delay.h>
#include <linux/device.h>
+#include <linux/limits.h>
#include <linux/module.h>
+#include <linux/platform_data/cros_ec_commands.h>
+#include <linux/platform_data/cros_ec_proto.h>
#include <linux/slab.h>
-#include <asm/unaligned.h>
+#include <linux/unaligned.h>
+
+#include "cros_ec_trace.h"
#define EC_COMMAND_RETRIES 50
+#define RWSIG_CONTINUE_RETRIES 8
+#define RWSIG_CONTINUE_MAX_ERRORS_IN_ROW 3
+
+static const int cros_ec_error_map[] = {
+ [EC_RES_INVALID_COMMAND] = -EOPNOTSUPP,
+ [EC_RES_ERROR] = -EIO,
+ [EC_RES_INVALID_PARAM] = -EINVAL,
+ [EC_RES_ACCESS_DENIED] = -EACCES,
+ [EC_RES_INVALID_RESPONSE] = -EPROTO,
+ [EC_RES_INVALID_VERSION] = -ENOPROTOOPT,
+ [EC_RES_INVALID_CHECKSUM] = -EBADMSG,
+ [EC_RES_IN_PROGRESS] = -EINPROGRESS,
+ [EC_RES_UNAVAILABLE] = -ENODATA,
+ [EC_RES_TIMEOUT] = -ETIMEDOUT,
+ [EC_RES_OVERFLOW] = -EOVERFLOW,
+ [EC_RES_INVALID_HEADER] = -EBADR,
+ [EC_RES_REQUEST_TRUNCATED] = -EBADR,
+ [EC_RES_RESPONSE_TOO_BIG] = -EFBIG,
+ [EC_RES_BUS_ERROR] = -EFAULT,
+ [EC_RES_BUSY] = -EBUSY,
+ [EC_RES_INVALID_HEADER_VERSION] = -EBADMSG,
+ [EC_RES_INVALID_HEADER_CRC] = -EBADMSG,
+ [EC_RES_INVALID_DATA_CRC] = -EBADMSG,
+ [EC_RES_DUP_UNAVAILABLE] = -ENODATA,
+};
+
+static int cros_ec_map_error(uint32_t result)
+{
+ int ret = 0;
+
+ if (result != EC_RES_SUCCESS) {
+ if (result < ARRAY_SIZE(cros_ec_error_map) && cros_ec_error_map[result])
+ ret = cros_ec_error_map[result];
+ else
+ ret = -EPROTO;
+ }
+
+ return ret;
+}
-static int prepare_packet(struct cros_ec_device *ec_dev,
- struct cros_ec_command *msg)
+static int prepare_tx(struct cros_ec_device *ec_dev,
+ struct cros_ec_command *msg)
{
struct ec_host_request *request;
u8 *out;
int i;
u8 csum = 0;
- BUG_ON(ec_dev->proto_version != EC_HOST_REQUEST_VERSION);
- BUG_ON(msg->outsize + sizeof(*request) > ec_dev->dout_size);
+ if (msg->outsize + sizeof(*request) > ec_dev->dout_size)
+ return -EINVAL;
out = ec_dev->dout;
request = (struct ec_host_request *)out;
@@ -56,82 +89,140 @@ static int prepare_packet(struct cros_ec_device *ec_dev,
return sizeof(*request) + msg->outsize;
}
-static int send_command(struct cros_ec_device *ec_dev,
- struct cros_ec_command *msg)
+static int prepare_tx_legacy(struct cros_ec_device *ec_dev,
+ struct cros_ec_command *msg)
+{
+ u8 *out;
+ u8 csum;
+ int i;
+
+ if (msg->outsize > EC_PROTO2_MAX_PARAM_SIZE)
+ return -EINVAL;
+
+ out = ec_dev->dout;
+ out[0] = EC_CMD_VERSION0 + msg->version;
+ out[1] = msg->command;
+ out[2] = msg->outsize;
+ csum = out[0] + out[1] + out[2];
+ for (i = 0; i < msg->outsize; i++)
+ csum += out[EC_MSG_TX_HEADER_BYTES + i] = msg->data[i];
+ out[EC_MSG_TX_HEADER_BYTES + msg->outsize] = csum;
+
+ return EC_MSG_TX_PROTO_BYTES + msg->outsize;
+}
+
+static int cros_ec_xfer_command(struct cros_ec_device *ec_dev, struct cros_ec_command *msg)
{
int ret;
+ int (*xfer_fxn)(struct cros_ec_device *ec, struct cros_ec_command *msg);
if (ec_dev->proto_version > 2)
- ret = ec_dev->pkt_xfer(ec_dev, msg);
+ xfer_fxn = ec_dev->pkt_xfer;
else
- ret = ec_dev->cmd_xfer(ec_dev, msg);
+ xfer_fxn = ec_dev->cmd_xfer;
- if (msg->result == EC_RES_IN_PROGRESS) {
- int i;
- struct cros_ec_command *status_msg;
- struct ec_response_get_comms_status *status;
+ if (!xfer_fxn) {
+ /*
+ * This error can happen if a communication error happened and
+ * the EC is trying to use protocol v2, on an underlying
+ * communication mechanism that does not support v2.
+ */
+ dev_err_once(ec_dev->dev, "missing EC transfer API, cannot send command\n");
+ return -EIO;
+ }
- status_msg = kmalloc(sizeof(*status_msg) + sizeof(*status),
- GFP_KERNEL);
- if (!status_msg)
- return -ENOMEM;
+ trace_cros_ec_request_start(msg);
+ ret = (*xfer_fxn)(ec_dev, msg);
+ trace_cros_ec_request_done(msg, ret);
- status_msg->version = 0;
- status_msg->command = EC_CMD_GET_COMMS_STATUS;
- status_msg->insize = sizeof(*status);
- status_msg->outsize = 0;
+ return ret;
+}
- /*
- * Query the EC's status until it's no longer busy or
- * we encounter an error.
- */
- for (i = 0; i < EC_COMMAND_RETRIES; i++) {
- usleep_range(10000, 11000);
+static int cros_ec_wait_until_complete(struct cros_ec_device *ec_dev, uint32_t *result)
+{
+ DEFINE_RAW_FLEX(struct cros_ec_command, msg, data,
+ sizeof(struct ec_response_get_comms_status));
+ struct ec_response_get_comms_status *status =
+ (struct ec_response_get_comms_status *)msg->data;
+ int ret = 0, i;
- ret = ec_dev->cmd_xfer(ec_dev, status_msg);
- if (ret < 0)
- break;
+ msg->version = 0;
+ msg->command = EC_CMD_GET_COMMS_STATUS;
+ msg->insize = sizeof(*status);
+ msg->outsize = 0;
- msg->result = status_msg->result;
- if (status_msg->result != EC_RES_SUCCESS)
- break;
+ /* Query the EC's status until it's no longer busy or we encounter an error. */
+ for (i = 0; i < EC_COMMAND_RETRIES; ++i) {
+ usleep_range(10000, 11000);
- status = (struct ec_response_get_comms_status *)
- status_msg->data;
- if (!(status->flags & EC_COMMS_STATUS_PROCESSING))
- break;
+ ret = cros_ec_xfer_command(ec_dev, msg);
+ if (ret == -EAGAIN)
+ continue;
+ if (ret < 0)
+ return ret;
+
+ *result = msg->result;
+ if (msg->result != EC_RES_SUCCESS)
+ return ret;
+
+ if (ret == 0) {
+ ret = -EPROTO;
+ break;
}
- kfree(status_msg);
+ if (!(status->flags & EC_COMMS_STATUS_PROCESSING))
+ return ret;
}
+ if (i >= EC_COMMAND_RETRIES)
+ ret = -EAGAIN;
+
+ return ret;
+}
+
+static int cros_ec_send_command(struct cros_ec_device *ec_dev, struct cros_ec_command *msg)
+{
+ int ret = cros_ec_xfer_command(ec_dev, msg);
+
+ if (msg->result == EC_RES_IN_PROGRESS)
+ ret = cros_ec_wait_until_complete(ec_dev, &msg->result);
+
return ret;
}
+/**
+ * cros_ec_prepare_tx() - Prepare an outgoing message in the output buffer.
+ * @ec_dev: Device to register.
+ * @msg: Message to write.
+ *
+ * This is used by all ChromeOS EC drivers to prepare the outgoing message
+ * according to different protocol versions.
+ *
+ * Return: number of prepared bytes on success or negative error code.
+ */
int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
struct cros_ec_command *msg)
{
- u8 *out;
- u8 csum;
- int i;
-
if (ec_dev->proto_version > 2)
- return prepare_packet(ec_dev, msg);
-
- BUG_ON(msg->outsize > EC_PROTO2_MAX_PARAM_SIZE);
- out = ec_dev->dout;
- out[0] = EC_CMD_VERSION0 + msg->version;
- out[1] = msg->command;
- out[2] = msg->outsize;
- csum = out[0] + out[1] + out[2];
- for (i = 0; i < msg->outsize; i++)
- csum += out[EC_MSG_TX_HEADER_BYTES + i] = msg->data[i];
- out[EC_MSG_TX_HEADER_BYTES + msg->outsize] = csum;
+ return prepare_tx(ec_dev, msg);
- return EC_MSG_TX_PROTO_BYTES + msg->outsize;
+ return prepare_tx_legacy(ec_dev, msg);
}
EXPORT_SYMBOL(cros_ec_prepare_tx);
+/**
+ * cros_ec_check_result() - Check ec_msg->result.
+ * @ec_dev: EC device.
+ * @msg: Message to check.
+ *
+ * This is used by ChromeOS EC drivers to check the ec_msg->result for
+ * EC_RES_IN_PROGRESS and to warn about them.
+ *
+ * The function should not check for furthermore error codes. Otherwise,
+ * it would break the ABI.
+ *
+ * Return: -EAGAIN if ec_msg->result == EC_RES_IN_PROGRESS. Otherwise, 0.
+ */
int cros_ec_check_result(struct cros_ec_device *ec_dev,
struct cros_ec_command *msg)
{
@@ -150,132 +241,248 @@ int cros_ec_check_result(struct cros_ec_device *ec_dev,
}
EXPORT_SYMBOL(cros_ec_check_result);
-/*
+/**
* cros_ec_get_host_event_wake_mask
*
* Get the mask of host events that cause wake from suspend.
*
* @ec_dev: EC device to call
- * @msg: message structure to use
- * @mask: result when function returns >=0.
+ * @mask: result when function returns 0.
*
* LOCKING:
* the caller has ec_dev->lock mutex, or the caller knows there is
* no other command in progress.
*/
-static int cros_ec_get_host_event_wake_mask(struct cros_ec_device *ec_dev,
- struct cros_ec_command *msg,
- uint32_t *mask)
+static int cros_ec_get_host_event_wake_mask(struct cros_ec_device *ec_dev, uint32_t *mask)
{
+ struct cros_ec_command *msg;
struct ec_response_host_event_mask *r;
- int ret;
+ int ret, mapped;
+
+ msg = kzalloc(sizeof(*msg) + sizeof(*r), GFP_KERNEL);
+ if (!msg)
+ return -ENOMEM;
msg->command = EC_CMD_HOST_EVENT_GET_WAKE_MASK;
- msg->version = 0;
- msg->outsize = 0;
msg->insize = sizeof(*r);
- ret = send_command(ec_dev, msg);
- if (ret > 0) {
- r = (struct ec_response_host_event_mask *)msg->data;
- *mask = r->mask;
+ ret = cros_ec_send_command(ec_dev, msg);
+ if (ret < 0)
+ goto exit;
+
+ mapped = cros_ec_map_error(msg->result);
+ if (mapped) {
+ ret = mapped;
+ goto exit;
+ }
+
+ if (ret == 0) {
+ ret = -EPROTO;
+ goto exit;
}
+ r = (struct ec_response_host_event_mask *)msg->data;
+ *mask = r->mask;
+ ret = 0;
+exit:
+ kfree(msg);
return ret;
}
-static int cros_ec_host_command_proto_query(struct cros_ec_device *ec_dev,
- int devidx,
- struct cros_ec_command *msg)
+int cros_ec_rwsig_continue(struct cros_ec_device *ec_dev)
{
- /*
- * Try using v3+ to query for supported protocols. If this
- * command fails, fall back to v2. Returns the highest protocol
- * supported by the EC.
- * Also sets the max request/response/passthru size.
- */
- int ret;
+ struct cros_ec_command *msg;
+ struct ec_params_rwsig_action *rwsig_action;
+ int ret = 0;
+ int error_count = 0;
+
+ ec_dev->proto_version = 3;
+
+ msg = kmalloc(sizeof(*msg) + sizeof(*rwsig_action), GFP_KERNEL);
+ if (!msg)
+ return -ENOMEM;
+
+ msg->version = 0;
+ msg->command = EC_CMD_RWSIG_ACTION;
+ msg->insize = 0;
+ msg->outsize = sizeof(*rwsig_action);
+
+ rwsig_action = (struct ec_params_rwsig_action *)msg->data;
+ rwsig_action->action = RWSIG_ACTION_CONTINUE;
+
+ for (int i = 0; i < RWSIG_CONTINUE_RETRIES; i++) {
+ ret = cros_ec_send_command(ec_dev, msg);
+
+ if (ret < 0) {
+ if (++error_count >= RWSIG_CONTINUE_MAX_ERRORS_IN_ROW)
+ break;
+ } else if (msg->result == EC_RES_INVALID_COMMAND) {
+ /*
+ * If EC_RES_INVALID_COMMAND is retured, it means RWSIG
+ * is not supported or EC is already in RW, so there is
+ * nothing left to do.
+ */
+ break;
+ } else if (msg->result != EC_RES_SUCCESS) {
+ /* Unexpected command error. */
+ ret = cros_ec_map_error(msg->result);
+ break;
+ } else {
+ /*
+ * The EC_CMD_RWSIG_ACTION succeed. Send the command
+ * more times, to make sure EC is in RW. A following
+ * command can timeout, because EC may need some time to
+ * initialize after jump to RW.
+ */
+ error_count = 0;
+ }
+
+ if (ret != -ETIMEDOUT)
+ usleep_range(90000, 100000);
+ }
- if (!ec_dev->pkt_xfer)
- return -EPROTONOSUPPORT;
+ kfree(msg);
+
+ return ret;
+}
+EXPORT_SYMBOL(cros_ec_rwsig_continue);
+
+static int cros_ec_get_proto_info(struct cros_ec_device *ec_dev, int devidx)
+{
+ struct cros_ec_command *msg;
+ struct ec_response_get_protocol_info *info;
+ int ret, mapped;
+
+ ec_dev->proto_version = 3;
+ if (devidx > 0)
+ ec_dev->max_passthru = 0;
+
+ msg = kzalloc(sizeof(*msg) + sizeof(*info), GFP_KERNEL);
+ if (!msg)
+ return -ENOMEM;
- memset(msg, 0, sizeof(*msg));
msg->command = EC_CMD_PASSTHRU_OFFSET(devidx) | EC_CMD_GET_PROTOCOL_INFO;
- msg->insize = sizeof(struct ec_response_get_protocol_info);
+ msg->insize = sizeof(*info);
- ret = send_command(ec_dev, msg);
+ ret = cros_ec_send_command(ec_dev, msg);
if (ret < 0) {
dev_dbg(ec_dev->dev,
"failed to check for EC[%d] protocol version: %d\n",
devidx, ret);
- return ret;
+ goto exit;
+ }
+
+ mapped = cros_ec_map_error(msg->result);
+ if (mapped) {
+ ret = mapped;
+ goto exit;
}
- if (devidx > 0 && msg->result == EC_RES_INVALID_COMMAND)
- return -ENODEV;
- else if (msg->result != EC_RES_SUCCESS)
- return msg->result;
+ if (ret == 0) {
+ ret = -EPROTO;
+ goto exit;
+ }
+
+ info = (struct ec_response_get_protocol_info *)msg->data;
+
+ switch (devidx) {
+ case CROS_EC_DEV_EC_INDEX:
+ ec_dev->max_request = info->max_request_packet_size -
+ sizeof(struct ec_host_request);
+ ec_dev->max_response = info->max_response_packet_size -
+ sizeof(struct ec_host_response);
+ ec_dev->proto_version = min(EC_HOST_REQUEST_VERSION,
+ fls(info->protocol_versions) - 1);
+ ec_dev->din_size = info->max_response_packet_size + EC_MAX_RESPONSE_OVERHEAD;
+ ec_dev->dout_size = info->max_request_packet_size + EC_MAX_REQUEST_OVERHEAD;
+
+ dev_dbg(ec_dev->dev, "using proto v%u\n", ec_dev->proto_version);
+ break;
+ case CROS_EC_DEV_PD_INDEX:
+ ec_dev->max_passthru = info->max_request_packet_size -
+ sizeof(struct ec_host_request);
+
+ dev_dbg(ec_dev->dev, "found PD chip\n");
+ break;
+ default:
+ dev_dbg(ec_dev->dev, "unknown passthru index: %d\n", devidx);
+ break;
+ }
- return 0;
+ ret = 0;
+exit:
+ kfree(msg);
+ return ret;
}
-static int cros_ec_host_command_proto_query_v2(struct cros_ec_device *ec_dev)
+static int cros_ec_get_proto_info_legacy(struct cros_ec_device *ec_dev)
{
struct cros_ec_command *msg;
- struct ec_params_hello *hello_params;
- struct ec_response_hello *hello_response;
- int ret;
- int len = max(sizeof(*hello_params), sizeof(*hello_response));
+ struct ec_params_hello *params;
+ struct ec_response_hello *response;
+ int ret, mapped;
+
+ ec_dev->proto_version = 2;
- msg = kmalloc(sizeof(*msg) + len, GFP_KERNEL);
+ msg = kzalloc(sizeof(*msg) + max(sizeof(*params), sizeof(*response)), GFP_KERNEL);
if (!msg)
return -ENOMEM;
- msg->version = 0;
msg->command = EC_CMD_HELLO;
- hello_params = (struct ec_params_hello *)msg->data;
- msg->outsize = sizeof(*hello_params);
- hello_response = (struct ec_response_hello *)msg->data;
- msg->insize = sizeof(*hello_response);
-
- hello_params->in_data = 0xa0b0c0d0;
+ msg->insize = sizeof(*response);
+ msg->outsize = sizeof(*params);
- ret = send_command(ec_dev, msg);
+ params = (struct ec_params_hello *)msg->data;
+ params->in_data = 0xa0b0c0d0;
+ ret = cros_ec_send_command(ec_dev, msg);
if (ret < 0) {
- dev_dbg(ec_dev->dev,
- "EC failed to respond to v2 hello: %d\n",
- ret);
+ dev_dbg(ec_dev->dev, "EC failed to respond to v2 hello: %d\n", ret);
goto exit;
- } else if (msg->result != EC_RES_SUCCESS) {
- dev_err(ec_dev->dev,
- "EC responded to v2 hello with error: %d\n",
- msg->result);
- ret = msg->result;
+ }
+
+ mapped = cros_ec_map_error(msg->result);
+ if (mapped) {
+ ret = mapped;
+ dev_err(ec_dev->dev, "EC responded to v2 hello with error: %d\n", msg->result);
goto exit;
- } else if (hello_response->out_data != 0xa1b2c3d4) {
+ }
+
+ if (ret == 0) {
+ ret = -EPROTO;
+ goto exit;
+ }
+
+ response = (struct ec_response_hello *)msg->data;
+ if (response->out_data != 0xa1b2c3d4) {
dev_err(ec_dev->dev,
"EC responded to v2 hello with bad result: %u\n",
- hello_response->out_data);
+ response->out_data);
ret = -EBADMSG;
goto exit;
}
- ret = 0;
+ ec_dev->max_request = EC_PROTO2_MAX_PARAM_SIZE;
+ ec_dev->max_response = EC_PROTO2_MAX_PARAM_SIZE;
+ ec_dev->max_passthru = 0;
+ ec_dev->pkt_xfer = NULL;
+ ec_dev->din_size = EC_PROTO2_MSG_BYTES;
+ ec_dev->dout_size = EC_PROTO2_MSG_BYTES;
- exit:
+ dev_dbg(ec_dev->dev, "falling back to proto v2\n");
+ ret = 0;
+exit:
kfree(msg);
return ret;
}
-/*
+/**
* cros_ec_get_host_command_version_mask
*
* Get the version mask of a given command.
*
* @ec_dev: EC device to call
- * @msg: message structure to use
* @cmd: command to get the version of.
* @mask: result when function returns 0.
*
@@ -285,13 +492,12 @@ static int cros_ec_host_command_proto_query_v2(struct cros_ec_device *ec_dev)
* the caller has ec_dev->lock mutex or the caller knows there is
* no other command in progress.
*/
-static int cros_ec_get_host_command_version_mask(struct cros_ec_device *ec_dev,
- u16 cmd, u32 *mask)
+static int cros_ec_get_host_command_version_mask(struct cros_ec_device *ec_dev, u16 cmd, u32 *mask)
{
struct ec_params_get_cmd_versions *pver;
struct ec_response_get_cmd_versions *rver;
struct cros_ec_command *msg;
- int ret;
+ int ret, mapped;
msg = kmalloc(sizeof(*msg) + max(sizeof(*rver), sizeof(*pver)),
GFP_KERNEL);
@@ -306,85 +512,50 @@ static int cros_ec_get_host_command_version_mask(struct cros_ec_device *ec_dev,
pver = (struct ec_params_get_cmd_versions *)msg->data;
pver->cmd = cmd;
- ret = send_command(ec_dev, msg);
- if (ret > 0) {
- rver = (struct ec_response_get_cmd_versions *)msg->data;
- *mask = rver->version_mask;
+ ret = cros_ec_send_command(ec_dev, msg);
+ if (ret < 0)
+ goto exit;
+
+ mapped = cros_ec_map_error(msg->result);
+ if (mapped) {
+ ret = mapped;
+ goto exit;
}
- kfree(msg);
+ if (ret == 0) {
+ ret = -EPROTO;
+ goto exit;
+ }
+ rver = (struct ec_response_get_cmd_versions *)msg->data;
+ *mask = rver->version_mask;
+ ret = 0;
+exit:
+ kfree(msg);
return ret;
}
+/**
+ * cros_ec_query_all() - Query the protocol version supported by the
+ * ChromeOS EC.
+ * @ec_dev: Device to register.
+ *
+ * Return: 0 on success or negative error code.
+ */
int cros_ec_query_all(struct cros_ec_device *ec_dev)
{
struct device *dev = ec_dev->dev;
- struct cros_ec_command *proto_msg;
- struct ec_response_get_protocol_info *proto_info;
- u32 ver_mask = 0;
+ u32 ver_mask;
int ret;
- proto_msg = kzalloc(sizeof(*proto_msg) + sizeof(*proto_info),
- GFP_KERNEL);
- if (!proto_msg)
- return -ENOMEM;
-
/* First try sending with proto v3. */
- ec_dev->proto_version = 3;
- ret = cros_ec_host_command_proto_query(ec_dev, 0, proto_msg);
-
- if (ret == 0) {
- proto_info = (struct ec_response_get_protocol_info *)
- proto_msg->data;
- ec_dev->max_request = proto_info->max_request_packet_size -
- sizeof(struct ec_host_request);
- ec_dev->max_response = proto_info->max_response_packet_size -
- sizeof(struct ec_host_response);
- ec_dev->proto_version =
- min(EC_HOST_REQUEST_VERSION,
- fls(proto_info->protocol_versions) - 1);
- dev_dbg(ec_dev->dev,
- "using proto v%u\n",
- ec_dev->proto_version);
-
- ec_dev->din_size = ec_dev->max_response +
- sizeof(struct ec_host_response) +
- EC_MAX_RESPONSE_OVERHEAD;
- ec_dev->dout_size = ec_dev->max_request +
- sizeof(struct ec_host_request) +
- EC_MAX_REQUEST_OVERHEAD;
-
- /*
- * Check for PD
- */
- ret = cros_ec_host_command_proto_query(ec_dev, 1, proto_msg);
-
- if (ret) {
- dev_dbg(ec_dev->dev, "no PD chip found: %d\n", ret);
- ec_dev->max_passthru = 0;
- } else {
- dev_dbg(ec_dev->dev, "found PD chip\n");
- ec_dev->max_passthru =
- proto_info->max_request_packet_size -
- sizeof(struct ec_host_request);
- }
+ if (!cros_ec_get_proto_info(ec_dev, CROS_EC_DEV_EC_INDEX)) {
+ /* Check for PD. */
+ cros_ec_get_proto_info(ec_dev, CROS_EC_DEV_PD_INDEX);
} else {
/* Try querying with a v2 hello message. */
- ec_dev->proto_version = 2;
- ret = cros_ec_host_command_proto_query_v2(ec_dev);
-
- if (ret == 0) {
- /* V2 hello succeeded. */
- dev_dbg(ec_dev->dev, "falling back to proto v2\n");
-
- ec_dev->max_request = EC_PROTO2_MAX_PARAM_SIZE;
- ec_dev->max_response = EC_PROTO2_MAX_PARAM_SIZE;
- ec_dev->max_passthru = 0;
- ec_dev->pkt_xfer = NULL;
- ec_dev->din_size = EC_PROTO2_MSG_BYTES;
- ec_dev->dout_size = EC_PROTO2_MSG_BYTES;
- } else {
+ ret = cros_ec_get_proto_info_legacy(ec_dev);
+ if (ret) {
/*
* It's possible for a test to occur too early when
* the EC isn't listening. If this happens, we'll
@@ -392,7 +563,7 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev)
*/
ec_dev->proto_version = EC_PROTO_VERSION_UNKNOWN;
dev_dbg(ec_dev->dev, "EC query failed: %d\n", ret);
- goto exit;
+ return ret;
}
}
@@ -413,33 +584,76 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev)
}
/* Probe if MKBP event is supported */
- ret = cros_ec_get_host_command_version_mask(ec_dev,
- EC_CMD_GET_NEXT_EVENT,
- &ver_mask);
- if (ret < 0 || ver_mask == 0)
+ ret = cros_ec_get_host_command_version_mask(ec_dev, EC_CMD_GET_NEXT_EVENT, &ver_mask);
+ if (ret < 0 || ver_mask == 0) {
ec_dev->mkbp_event_supported = 0;
- else
- ec_dev->mkbp_event_supported = 1;
+ } else {
+ ec_dev->mkbp_event_supported = fls(ver_mask);
- /*
- * Get host event wake mask, assume all events are wake events
- * if unavailable.
- */
- ret = cros_ec_get_host_event_wake_mask(ec_dev, proto_msg,
- &ec_dev->host_event_wake_mask);
- if (ret < 0)
- ec_dev->host_event_wake_mask = U32_MAX;
+ dev_dbg(ec_dev->dev, "MKBP support version %u\n", ec_dev->mkbp_event_supported - 1);
+ }
+
+ /* Probe if host sleep v1 is supported for S0ix failure detection. */
+ ret = cros_ec_get_host_command_version_mask(ec_dev, EC_CMD_HOST_SLEEP_EVENT, &ver_mask);
+ ec_dev->host_sleep_v1 = (ret == 0 && (ver_mask & EC_VER_MASK(1)));
+
+ /* Get host event wake mask. */
+ ret = cros_ec_get_host_event_wake_mask(ec_dev, &ec_dev->host_event_wake_mask);
+ if (ret < 0) {
+ /*
+ * If the EC doesn't support EC_CMD_HOST_EVENT_GET_WAKE_MASK,
+ * use a reasonable default. Note that we ignore various
+ * battery, AC status, and power-state events, because (a)
+ * those can be quite common (e.g., when sitting at full
+ * charge, on AC) and (b) these are not actionable wake events;
+ * if anything, we'd like to continue suspending (to save
+ * power), not wake up.
+ */
+ ec_dev->host_event_wake_mask = U32_MAX &
+ ~(EC_HOST_EVENT_MASK(EC_HOST_EVENT_LID_CLOSED) |
+ EC_HOST_EVENT_MASK(EC_HOST_EVENT_AC_DISCONNECTED) |
+ EC_HOST_EVENT_MASK(EC_HOST_EVENT_BATTERY_LOW) |
+ EC_HOST_EVENT_MASK(EC_HOST_EVENT_BATTERY_CRITICAL) |
+ EC_HOST_EVENT_MASK(EC_HOST_EVENT_BATTERY) |
+ EC_HOST_EVENT_MASK(EC_HOST_EVENT_PD_MCU) |
+ EC_HOST_EVENT_MASK(EC_HOST_EVENT_BATTERY_STATUS));
+ /*
+ * Old ECs may not support this command. Complain about all
+ * other errors.
+ */
+ if (ret != -EOPNOTSUPP)
+ dev_err(ec_dev->dev,
+ "failed to retrieve wake mask: %d\n", ret);
+ }
ret = 0;
exit:
- kfree(proto_msg);
return ret;
}
EXPORT_SYMBOL(cros_ec_query_all);
-int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev,
- struct cros_ec_command *msg)
+/**
+ * cros_ec_cmd_xfer() - Send a command to the ChromeOS EC.
+ * @ec_dev: EC device.
+ * @msg: Message to write.
+ *
+ * Call this to send a command to the ChromeOS EC. This should be used instead
+ * of calling the EC's cmd_xfer() callback directly. This function does not
+ * convert EC command execution error codes to Linux error codes. Most
+ * in-kernel users will want to use cros_ec_cmd_xfer_status() instead since
+ * that function implements the conversion.
+ *
+ * Return:
+ * >0 - EC command was executed successfully. The return value is the number
+ * of bytes returned by the EC (excluding the header).
+ * =0 - EC communication was successful. EC command execution results are
+ * reported in msg->result. The result will be EC_RES_SUCCESS if the
+ * command was executed successfully or report an EC command execution
+ * error.
+ * <0 - EC communication error. Return value is the Linux error code.
+ */
+int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev, struct cros_ec_command *msg)
{
int ret;
@@ -459,7 +673,7 @@ int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev,
msg->insize = ec_dev->max_response;
}
- if (msg->command < EC_CMD_PASSTHRU_OFFSET(1)) {
+ if (msg->command < EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_PD_INDEX)) {
if (msg->outsize > ec_dev->max_request) {
dev_err(ec_dev->dev,
"request of size %u is too big (max: %u)\n",
@@ -478,56 +692,98 @@ int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev,
return -EMSGSIZE;
}
}
- ret = send_command(ec_dev, msg);
+
+ ret = cros_ec_send_command(ec_dev, msg);
mutex_unlock(&ec_dev->lock);
return ret;
}
EXPORT_SYMBOL(cros_ec_cmd_xfer);
+/**
+ * cros_ec_cmd_xfer_status() - Send a command to the ChromeOS EC.
+ * @ec_dev: EC device.
+ * @msg: Message to write.
+ *
+ * Call this to send a command to the ChromeOS EC. This should be used instead of calling the EC's
+ * cmd_xfer() callback directly. It returns success status only if both the command was transmitted
+ * successfully and the EC replied with success status.
+ *
+ * Return:
+ * >=0 - The number of bytes transferred.
+ * <0 - Linux error code
+ */
int cros_ec_cmd_xfer_status(struct cros_ec_device *ec_dev,
struct cros_ec_command *msg)
{
- int ret;
+ int ret, mapped;
ret = cros_ec_cmd_xfer(ec_dev, msg);
- if (ret < 0) {
- dev_err(ec_dev->dev, "Command xfer error (err:%d)\n", ret);
- } else if (msg->result != EC_RES_SUCCESS) {
- dev_dbg(ec_dev->dev, "Command result (err: %d)\n", msg->result);
- return -EPROTO;
+ if (ret < 0)
+ return ret;
+
+ mapped = cros_ec_map_error(msg->result);
+ if (mapped) {
+ dev_dbg(ec_dev->dev, "Command result (err: %d [%d])\n",
+ msg->result, mapped);
+ ret = mapped;
}
return ret;
}
EXPORT_SYMBOL(cros_ec_cmd_xfer_status);
-static int get_next_event(struct cros_ec_device *ec_dev)
+static int get_next_event_xfer(struct cros_ec_device *ec_dev,
+ struct cros_ec_command *msg,
+ struct ec_response_get_next_event_v3 *event,
+ int version, uint32_t size)
{
- u8 buffer[sizeof(struct cros_ec_command) + sizeof(ec_dev->event_data)];
- struct cros_ec_command *msg = (struct cros_ec_command *)&buffer;
int ret;
- if (ec_dev->suspended) {
- dev_dbg(ec_dev->dev, "Device suspended.\n");
- return -EHOSTDOWN;
- }
-
- msg->version = 0;
+ msg->version = version;
msg->command = EC_CMD_GET_NEXT_EVENT;
- msg->insize = sizeof(ec_dev->event_data);
+ msg->insize = size;
msg->outsize = 0;
- ret = cros_ec_cmd_xfer(ec_dev, msg);
+ ret = cros_ec_cmd_xfer_status(ec_dev, msg);
if (ret > 0) {
ec_dev->event_size = ret - 1;
- memcpy(&ec_dev->event_data, msg->data,
- sizeof(ec_dev->event_data));
+ ec_dev->event_data = *event;
}
return ret;
}
+static int get_next_event(struct cros_ec_device *ec_dev)
+{
+ DEFINE_RAW_FLEX(struct cros_ec_command, msg, data,
+ sizeof(struct ec_response_get_next_event_v3));
+ struct ec_response_get_next_event_v3 *event =
+ (struct ec_response_get_next_event_v3 *)msg->data;
+ int cmd_version = ec_dev->mkbp_event_supported - 1;
+ u32 size;
+
+ if (ec_dev->suspended) {
+ dev_dbg(ec_dev->dev, "Device suspended.\n");
+ return -EHOSTDOWN;
+ }
+
+ if (cmd_version == 0) {
+ size = sizeof(struct ec_response_get_next_event);
+ } else if (cmd_version < 3) {
+ size = sizeof(struct ec_response_get_next_event_v1);
+ } else {
+ /*
+ * The max version we support is v3. So, we speak v3 even if the
+ * EC says it supports v4+.
+ */
+ cmd_version = 3;
+ size = sizeof(struct ec_response_get_next_event_v3);
+ }
+
+ return get_next_event_xfer(ec_dev, msg, event, cmd_version, size);
+}
+
static int get_keyboard_state_event(struct cros_ec_device *ec_dev)
{
u8 buffer[sizeof(struct cros_ec_command) +
@@ -539,7 +795,7 @@ static int get_keyboard_state_event(struct cros_ec_device *ec_dev)
msg->insize = sizeof(ec_dev->event_data.data);
msg->outsize = 0;
- ec_dev->event_size = cros_ec_cmd_xfer(ec_dev, msg);
+ ec_dev->event_size = cros_ec_cmd_xfer_status(ec_dev, msg);
ec_dev->event_data.event_type = EC_MKBP_EVENT_KEY_MATRIX;
memcpy(&ec_dev->event_data.data, msg->data,
sizeof(ec_dev->event_data.data));
@@ -547,43 +803,134 @@ static int get_keyboard_state_event(struct cros_ec_device *ec_dev)
return ec_dev->event_size;
}
-int cros_ec_get_next_event(struct cros_ec_device *ec_dev, bool *wake_event)
+/**
+ * cros_ec_get_next_event() - Fetch next event from the ChromeOS EC.
+ * @ec_dev: Device to fetch event from.
+ * @wake_event: Pointer to a bool set to true upon return if the event might be
+ * treated as a wake event. Ignored if null.
+ * @has_more_events: Pointer to bool set to true if more than one event is
+ * pending.
+ * Some EC will set this flag to indicate cros_ec_get_next_event()
+ * can be called multiple times in a row.
+ * It is an optimization to prevent issuing a EC command for
+ * nothing or wait for another interrupt from the EC to process
+ * the next message.
+ * Ignored if null.
+ *
+ * Return: negative error code on errors; 0 for no data; or else number of
+ * bytes received (i.e., an event was retrieved successfully). Event types are
+ * written out to @ec_dev->event_data.event_type on success.
+ */
+int cros_ec_get_next_event(struct cros_ec_device *ec_dev,
+ bool *wake_event,
+ bool *has_more_events)
{
+ u8 event_type;
u32 host_event;
int ret;
+ u32 ver_mask;
- if (!ec_dev->mkbp_event_supported) {
- ret = get_keyboard_state_event(ec_dev);
- if (ret < 0)
- return ret;
+ /*
+ * Default value for wake_event.
+ * Wake up on keyboard event, wake up for spurious interrupt or link
+ * error to the EC.
+ */
+ if (wake_event)
+ *wake_event = true;
- if (wake_event)
- *wake_event = true;
+ /*
+ * Default value for has_more_events.
+ * EC will raise another interrupt if AP does not process all events
+ * anyway.
+ */
+ if (has_more_events)
+ *has_more_events = false;
- return ret;
- }
+ if (!ec_dev->mkbp_event_supported)
+ return get_keyboard_state_event(ec_dev);
ret = get_next_event(ec_dev);
- if (ret < 0)
+ /*
+ * -ENOPROTOOPT is returned when EC returns EC_RES_INVALID_VERSION.
+ * This can occur when EC based device (e.g. Fingerprint MCU) jumps to
+ * the RO image which doesn't support newer version of the command. In
+ * this case we will attempt to update maximum supported version of the
+ * EC_CMD_GET_NEXT_EVENT.
+ */
+ if (ret == -ENOPROTOOPT) {
+ dev_dbg(ec_dev->dev,
+ "GET_NEXT_EVENT returned invalid version error.\n");
+ mutex_lock(&ec_dev->lock);
+ ret = cros_ec_get_host_command_version_mask(ec_dev,
+ EC_CMD_GET_NEXT_EVENT,
+ &ver_mask);
+ mutex_unlock(&ec_dev->lock);
+ if (ret < 0 || ver_mask == 0)
+ /*
+ * Do not change the MKBP supported version if we can't
+ * obtain supported version correctly. Please note that
+ * calling EC_CMD_GET_NEXT_EVENT returned
+ * EC_RES_INVALID_VERSION which means that the command
+ * is present.
+ */
+ return -ENOPROTOOPT;
+
+ ec_dev->mkbp_event_supported = fls(ver_mask);
+ dev_dbg(ec_dev->dev, "MKBP support version changed to %u\n",
+ ec_dev->mkbp_event_supported - 1);
+
+ /* Try to get next event with new MKBP support version set. */
+ ret = get_next_event(ec_dev);
+ }
+
+ if (ret <= 0)
return ret;
+ if (has_more_events)
+ *has_more_events = ec_dev->event_data.event_type &
+ EC_MKBP_HAS_MORE_EVENTS;
+ ec_dev->event_data.event_type &= EC_MKBP_EVENT_TYPE_MASK;
+
if (wake_event) {
+ event_type = ec_dev->event_data.event_type;
host_event = cros_ec_get_host_event(ec_dev);
- /* Consider non-host_event as wake event */
- *wake_event = !host_event ||
- !!(host_event & ec_dev->host_event_wake_mask);
+ /*
+ * Sensor events need to be parsed by the sensor sub-device.
+ * Defer them, and don't report the wakeup here.
+ */
+ if (event_type == EC_MKBP_EVENT_SENSOR_FIFO) {
+ *wake_event = false;
+ } else if (host_event) {
+ /* rtc_update_irq() already handles wakeup events. */
+ if (host_event & EC_HOST_EVENT_MASK(EC_HOST_EVENT_RTC))
+ *wake_event = false;
+ /* Masked host-events should not count as wake events. */
+ if (!(host_event & ec_dev->host_event_wake_mask))
+ *wake_event = false;
+ }
}
return ret;
}
EXPORT_SYMBOL(cros_ec_get_next_event);
+/**
+ * cros_ec_get_host_event() - Return a mask of event set by the ChromeOS EC.
+ * @ec_dev: Device to fetch event from.
+ *
+ * When MKBP is supported, when the EC raises an interrupt, we collect the
+ * events raised and call the functions in the ec notifier. This function
+ * is a helper to know which events are raised.
+ *
+ * Return: 0 on error or non-zero bitmask of one or more EC_HOST_EVENT_*.
+ */
u32 cros_ec_get_host_event(struct cros_ec_device *ec_dev)
{
u32 host_event;
- BUG_ON(!ec_dev->mkbp_event_supported);
+ if (!ec_dev->mkbp_event_supported)
+ return 0;
if (ec_dev->event_data.event_type != EC_MKBP_EVENT_HOST_EVENT)
return 0;
@@ -598,3 +945,228 @@ u32 cros_ec_get_host_event(struct cros_ec_device *ec_dev)
return host_event;
}
EXPORT_SYMBOL(cros_ec_get_host_event);
+
+/**
+ * cros_ec_check_features() - Test for the presence of EC features
+ *
+ * @ec: EC device, does not have to be connected directly to the AP,
+ * can be daisy chained through another device.
+ * @feature: One of ec_feature_code bit.
+ *
+ * Call this function to test whether the ChromeOS EC supports a feature.
+ *
+ * Return: true if supported, false if not (or if an error was encountered).
+ */
+bool cros_ec_check_features(struct cros_ec_dev *ec, int feature)
+{
+ struct ec_response_get_features *features = &ec->features;
+ int ret;
+
+ if (features->flags[0] == -1U && features->flags[1] == -1U) {
+ /* features bitmap not read yet */
+ ret = cros_ec_cmd(ec->ec_dev, 0, EC_CMD_GET_FEATURES + ec->cmd_offset,
+ NULL, 0, features, sizeof(*features));
+ if (ret < 0) {
+ dev_warn(ec->dev, "cannot get EC features: %d\n", ret);
+ memset(features, 0, sizeof(*features));
+ }
+
+ dev_dbg(ec->dev, "EC features %08x %08x\n",
+ features->flags[0], features->flags[1]);
+ }
+
+ return !!(features->flags[feature / 32] & EC_FEATURE_MASK_0(feature));
+}
+EXPORT_SYMBOL_GPL(cros_ec_check_features);
+
+/**
+ * cros_ec_get_sensor_count() - Return the number of MEMS sensors supported.
+ *
+ * @ec: EC device, does not have to be connected directly to the AP,
+ * can be daisy chained through another device.
+ * Return: < 0 in case of error.
+ */
+int cros_ec_get_sensor_count(struct cros_ec_dev *ec)
+{
+ /*
+ * Issue a command to get the number of sensor reported.
+ * If not supported, check for legacy mode.
+ */
+ int ret, sensor_count;
+ struct ec_params_motion_sense *params;
+ struct ec_response_motion_sense *resp;
+ struct cros_ec_command *msg;
+ struct cros_ec_device *ec_dev = ec->ec_dev;
+ u8 status;
+
+ msg = kzalloc(sizeof(*msg) + max(sizeof(*params), sizeof(*resp)),
+ GFP_KERNEL);
+ if (!msg)
+ return -ENOMEM;
+
+ msg->version = 1;
+ msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
+ msg->outsize = sizeof(*params);
+ msg->insize = sizeof(*resp);
+
+ params = (struct ec_params_motion_sense *)msg->data;
+ params->cmd = MOTIONSENSE_CMD_DUMP;
+
+ ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
+ if (ret < 0) {
+ sensor_count = ret;
+ } else {
+ resp = (struct ec_response_motion_sense *)msg->data;
+ sensor_count = resp->dump.sensor_count;
+ }
+ kfree(msg);
+
+ /*
+ * Check legacy mode: Let's find out if sensors are accessible
+ * via LPC interface.
+ */
+ if (sensor_count < 0 && ec->cmd_offset == 0 && ec_dev->cmd_readmem) {
+ ret = ec_dev->cmd_readmem(ec_dev, EC_MEMMAP_ACC_STATUS,
+ 1, &status);
+ if (ret >= 0 &&
+ (status & EC_MEMMAP_ACC_STATUS_PRESENCE_BIT)) {
+ /*
+ * We have 2 sensors, one in the lid, one in the base.
+ */
+ sensor_count = 2;
+ } else {
+ /*
+ * EC uses LPC interface and no sensors are presented.
+ */
+ sensor_count = 0;
+ }
+ }
+ return sensor_count;
+}
+EXPORT_SYMBOL_GPL(cros_ec_get_sensor_count);
+
+/**
+ * cros_ec_cmd - Send a command to the EC.
+ *
+ * @ec_dev: EC device
+ * @version: EC command version
+ * @command: EC command
+ * @outdata: EC command output data
+ * @outsize: Size of outdata
+ * @indata: EC command input data
+ * @insize: Size of indata
+ *
+ * Return: >= 0 on success, negative error number on failure.
+ */
+int cros_ec_cmd(struct cros_ec_device *ec_dev,
+ unsigned int version,
+ int command,
+ const void *outdata,
+ size_t outsize,
+ void *indata,
+ size_t insize)
+{
+ struct cros_ec_command *msg;
+ int ret;
+
+ msg = kzalloc(sizeof(*msg) + max(insize, outsize), GFP_KERNEL);
+ if (!msg)
+ return -ENOMEM;
+
+ msg->version = version;
+ msg->command = command;
+ msg->outsize = outsize;
+ msg->insize = insize;
+
+ if (outsize)
+ memcpy(msg->data, outdata, outsize);
+
+ ret = cros_ec_cmd_xfer_status(ec_dev, msg);
+ if (ret < 0)
+ goto error;
+
+ if (insize)
+ memcpy(indata, msg->data, insize);
+error:
+ kfree(msg);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(cros_ec_cmd);
+
+/**
+ * cros_ec_cmd_readmem - Read from EC memory.
+ *
+ * @ec_dev: EC device
+ * @offset: Is within EC_LPC_ADDR_MEMMAP region.
+ * @size: Number of bytes to read.
+ * @dest: EC command output data
+ *
+ * Return: >= 0 on success, negative error number on failure.
+ */
+int cros_ec_cmd_readmem(struct cros_ec_device *ec_dev, u8 offset, u8 size, void *dest)
+{
+ struct ec_params_read_memmap params = {};
+
+ if (!size)
+ return -EINVAL;
+
+ if (ec_dev->cmd_readmem)
+ return ec_dev->cmd_readmem(ec_dev, offset, size, dest);
+
+ params.offset = offset;
+ params.size = size;
+ return cros_ec_cmd(ec_dev, 0, EC_CMD_READ_MEMMAP,
+ &params, sizeof(params), dest, size);
+}
+EXPORT_SYMBOL_GPL(cros_ec_cmd_readmem);
+
+/**
+ * cros_ec_get_cmd_versions - Get supported version mask.
+ *
+ * @ec_dev: EC device
+ * @cmd: Command to test
+ *
+ * Return: version mask on success, negative error number on failure.
+ */
+int cros_ec_get_cmd_versions(struct cros_ec_device *ec_dev, u16 cmd)
+{
+ struct ec_params_get_cmd_versions req_v0;
+ struct ec_params_get_cmd_versions_v1 req_v1;
+ struct ec_response_get_cmd_versions resp;
+ int ret;
+
+ if (cmd <= U8_MAX) {
+ req_v0.cmd = cmd;
+ ret = cros_ec_cmd(ec_dev, 0, EC_CMD_GET_CMD_VERSIONS,
+ &req_v0, sizeof(req_v0), &resp, sizeof(resp));
+ } else {
+ req_v1.cmd = cmd;
+ ret = cros_ec_cmd(ec_dev, 1, EC_CMD_GET_CMD_VERSIONS,
+ &req_v1, sizeof(req_v1), &resp, sizeof(resp));
+ }
+
+ if (ret == -EINVAL)
+ return 0; /* Command not implemented */
+ else if (ret < 0)
+ return ret;
+ else
+ return resp.version_mask;
+}
+EXPORT_SYMBOL_GPL(cros_ec_get_cmd_versions);
+
+/**
+ * cros_ec_device_registered - Return if the ec_dev is registered.
+ *
+ * @ec_dev: EC device
+ *
+ * Return: true if registered. Otherwise, false.
+ */
+bool cros_ec_device_registered(struct cros_ec_device *ec_dev)
+{
+ guard(mutex)(&ec_dev->lock);
+ return ec_dev->registered;
+}
+EXPORT_SYMBOL_GPL(cros_ec_device_registered);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("ChromeOS EC communication protocol helpers");