Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1037 insertions, 0 deletions

diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
new file mode 100644
index 000000000..475a6dd72
--- /dev/null
+++ b/drivers/platform/chrome/cros_ec_proto.c
@@ -0,0 +1,1037 @@
+// SPDX-License-Identifier: GPL-2.0
+// ChromeOS EC communication protocol helper functions
+//
+// Copyright (C) 2015 Google, Inc
+
+#include <linux/delay.h>
+#include <linux/device.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 "cros_ec_trace.h"
+
+#define EC_COMMAND_RETRIES	50
+
+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_tx(struct cros_ec_device *ec_dev,
+		      struct cros_ec_command *msg)
+{
+	struct ec_host_request *request;
+	u8 *out;
+	int i;
+	u8 csum = 0;
+
+	if (msg->outsize + sizeof(*request) > ec_dev->dout_size)
+		return -EINVAL;
+
+	out = ec_dev->dout;
+	request = (struct ec_host_request *)out;
+	request->struct_version = EC_HOST_REQUEST_VERSION;
+	request->checksum = 0;
+	request->command = msg->command;
+	request->command_version = msg->version;
+	request->reserved = 0;
+	request->data_len = msg->outsize;
+
+	for (i = 0; i < sizeof(*request); i++)
+		csum += out[i];
+
+	/* Copy data and update checksum */
+	memcpy(out + sizeof(*request), msg->data, msg->outsize);
+	for (i = 0; i < msg->outsize; i++)
+		csum += msg->data[i];
+
+	request->checksum = -csum;
+
+	return sizeof(*request) + msg->outsize;
+}
+
+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)
+		xfer_fxn = ec_dev->pkt_xfer;
+	else
+		xfer_fxn = ec_dev->cmd_xfer;
+
+	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;
+	}
+
+	trace_cros_ec_request_start(msg);
+	ret = (*xfer_fxn)(ec_dev, msg);
+	trace_cros_ec_request_done(msg, ret);
+
+	return ret;
+}
+
+static int cros_ec_wait_until_complete(struct cros_ec_device *ec_dev, uint32_t *result)
+{
+	struct {
+		struct cros_ec_command msg;
+		struct ec_response_get_comms_status status;
+	} __packed buf;
+	struct cros_ec_command *msg = &buf.msg;
+	struct ec_response_get_comms_status *status = &buf.status;
+	int ret = 0, i;
+
+	msg->version = 0;
+	msg->command = EC_CMD_GET_COMMS_STATUS;
+	msg->insize = sizeof(*status);
+	msg->outsize = 0;
+
+	/* 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);
+
+		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;
+		}
+
+		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)
+{
+	if (ec_dev->proto_version > 2)
+		return prepare_tx(ec_dev, msg);
+
+	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)
+{
+	switch (msg->result) {
+	case EC_RES_SUCCESS:
+		return 0;
+	case EC_RES_IN_PROGRESS:
+		dev_dbg(ec_dev->dev, "command 0x%02x in progress\n",
+			msg->command);
+		return -EAGAIN;
+	default:
+		dev_dbg(ec_dev->dev, "command 0x%02x returned %d\n",
+			msg->command, msg->result);
+		return 0;
+	}
+}
+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.
+ *
+ * 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, uint32_t *mask)
+{
+	struct cros_ec_command *msg;
+	struct ec_response_host_event_mask *r;
+	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->insize = sizeof(*r);
+
+	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_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;
+
+	msg->command = EC_CMD_PASSTHRU_OFFSET(devidx) | EC_CMD_GET_PROTOCOL_INFO;
+	msg->insize = sizeof(*info);
+
+	ret = cros_ec_send_command(ec_dev, msg);
+	/*
+	 * Send command once again when timeout occurred.
+	 * Fingerprint MCU (FPMCU) is restarted during system boot which
+	 * introduces small window in which FPMCU won't respond for any
+	 * messages sent by kernel. There is no need to wait before next
+	 * attempt because we waited at least EC_MSG_DEADLINE_MS.
+	 */
+	if (ret == -ETIMEDOUT)
+		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);
+		goto exit;
+	}
+
+	mapped = cros_ec_map_error(msg->result);
+	if (mapped) {
+		ret = mapped;
+		goto exit;
+	}
+
+	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;
+	}
+
+	ret = 0;
+exit:
+	kfree(msg);
+	return ret;
+}
+
+static int cros_ec_get_proto_info_legacy(struct cros_ec_device *ec_dev)
+{
+	struct cros_ec_command *msg;
+	struct ec_params_hello *params;
+	struct ec_response_hello *response;
+	int ret, mapped;
+
+	ec_dev->proto_version = 2;
+
+	msg = kzalloc(sizeof(*msg) + max(sizeof(*params), sizeof(*response)), GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
+	msg->command = EC_CMD_HELLO;
+	msg->insize = sizeof(*response);
+	msg->outsize = sizeof(*params);
+
+	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);
+		goto exit;
+	}
+
+	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;
+	}
+
+	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",
+			response->out_data);
+		ret = -EBADMSG;
+		goto exit;
+	}
+
+	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;
+
+	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.
+ *
+ * @return 0 on success, error code otherwise
+ *
+ * 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_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, mapped;
+
+	msg = kmalloc(sizeof(*msg) + max(sizeof(*rver), sizeof(*pver)),
+		      GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
+	msg->version = 0;
+	msg->command = EC_CMD_GET_CMD_VERSIONS;
+	msg->insize = sizeof(*rver);
+	msg->outsize = sizeof(*pver);
+
+	pver = (struct ec_params_get_cmd_versions *)msg->data;
+	pver->cmd = cmd;
+
+	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;
+	}
+
+	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;
+	u32 ver_mask;
+	int ret;
+
+	/* First try sending with proto v3. */
+	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. */
+		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
+			 * test later when the first command is run.
+			 */
+			ec_dev->proto_version = EC_PROTO_VERSION_UNKNOWN;
+			dev_dbg(ec_dev->dev, "EC query failed: %d\n", ret);
+			return ret;
+		}
+	}
+
+	devm_kfree(dev, ec_dev->din);
+	devm_kfree(dev, ec_dev->dout);
+
+	ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
+	if (!ec_dev->din) {
+		ret = -ENOMEM;
+		goto exit;
+	}
+
+	ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL);
+	if (!ec_dev->dout) {
+		devm_kfree(dev, ec_dev->din);
+		ret = -ENOMEM;
+		goto exit;
+	}
+
+	/* 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) {
+		ec_dev->mkbp_event_supported = 0;
+	} else {
+		ec_dev->mkbp_event_supported = fls(ver_mask);
+
+		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:
+	return ret;
+}
+EXPORT_SYMBOL(cros_ec_query_all);
+
+/**
+ * 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;
+
+	mutex_lock(&ec_dev->lock);
+	if (ec_dev->proto_version == EC_PROTO_VERSION_UNKNOWN) {
+		ret = cros_ec_query_all(ec_dev);
+		if (ret) {
+			dev_err(ec_dev->dev,
+				"EC version unknown and query failed; aborting command\n");
+			mutex_unlock(&ec_dev->lock);
+			return ret;
+		}
+	}
+
+	if (msg->insize > ec_dev->max_response) {
+		dev_dbg(ec_dev->dev, "clamping message receive buffer\n");
+		msg->insize = ec_dev->max_response;
+	}
+
+	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",
+				msg->outsize,
+				ec_dev->max_request);
+			mutex_unlock(&ec_dev->lock);
+			return -EMSGSIZE;
+		}
+	} else {
+		if (msg->outsize > ec_dev->max_passthru) {
+			dev_err(ec_dev->dev,
+				"passthru rq of size %u is too big (max: %u)\n",
+				msg->outsize,
+				ec_dev->max_passthru);
+			mutex_unlock(&ec_dev->lock);
+			return -EMSGSIZE;
+		}
+	}
+
+	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, mapped;
+
+	ret = cros_ec_cmd_xfer(ec_dev, msg);
+	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_xfer(struct cros_ec_device *ec_dev,
+			       struct cros_ec_command *msg,
+			       struct ec_response_get_next_event_v1 *event,
+			       int version, uint32_t size)
+{
+	int ret;
+
+	msg->version = version;
+	msg->command = EC_CMD_GET_NEXT_EVENT;
+	msg->insize = size;
+	msg->outsize = 0;
+
+	ret = cros_ec_cmd_xfer_status(ec_dev, msg);
+	if (ret > 0) {
+		ec_dev->event_size = ret - 1;
+		ec_dev->event_data = *event;
+	}
+
+	return ret;
+}
+
+static int get_next_event(struct cros_ec_device *ec_dev)
+{
+	struct {
+		struct cros_ec_command msg;
+		struct ec_response_get_next_event_v1 event;
+	} __packed buf;
+	struct cros_ec_command *msg = &buf.msg;
+	struct ec_response_get_next_event_v1 *event = &buf.event;
+	const int cmd_version = ec_dev->mkbp_event_supported - 1;
+
+	memset(msg, 0, sizeof(*msg));
+	if (ec_dev->suspended) {
+		dev_dbg(ec_dev->dev, "Device suspended.\n");
+		return -EHOSTDOWN;
+	}
+
+	if (cmd_version == 0)
+		return get_next_event_xfer(ec_dev, msg, event, 0,
+				  sizeof(struct ec_response_get_next_event));
+
+	return get_next_event_xfer(ec_dev, msg, event, cmd_version,
+				sizeof(struct ec_response_get_next_event_v1));
+}
+
+static int get_keyboard_state_event(struct cros_ec_device *ec_dev)
+{
+	u8 buffer[sizeof(struct cros_ec_command) +
+		  sizeof(ec_dev->event_data.data)];
+	struct cros_ec_command *msg = (struct cros_ec_command *)&buffer;
+
+	msg->version = 0;
+	msg->command = EC_CMD_MKBP_STATE;
+	msg->insize = sizeof(ec_dev->event_data.data);
+	msg->outsize = 0;
+
+	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));
+
+	return ec_dev->event_size;
+}
+
+/**
+ * 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;
+
+	/*
+	 * 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;
+
+	/*
+	 * 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;
+
+	if (!ec_dev->mkbp_event_supported)
+		return get_keyboard_state_event(ec_dev);
+
+	ret = get_next_event(ec_dev);
+	/*
+	 * -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");
+		ret = cros_ec_get_host_command_version_mask(ec_dev,
+							EC_CMD_GET_NEXT_EVENT,
+							&ver_mask);
+		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);
+
+		/*
+		 * 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;
+
+	if (!ec_dev->mkbp_event_supported)
+		return 0;
+
+	if (ec_dev->event_data.event_type != EC_MKBP_EVENT_HOST_EVENT)
+		return 0;
+
+	if (ec_dev->event_size != sizeof(host_event)) {
+		dev_warn(ec_dev->dev, "Invalid host event size\n");
+		return 0;
+	}
+
+	host_event = get_unaligned_le32(&ec_dev->event_data.data.host_event);
+
+	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,
+		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);