linux/drivers/platform/chrome/wilco_ec/properties.c

133 lines
2.9 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright 2019 Google LLC
*/
#include <linux/platform_data/wilco-ec.h>
#include <linux/string.h>
#include <linux/unaligned/le_memmove.h>
/* Operation code; what the EC should do with the property */
enum ec_property_op {
EC_OP_GET = 0,
EC_OP_SET = 1,
};
struct ec_property_request {
u8 op; /* One of enum ec_property_op */
u8 property_id[4]; /* The 32 bit PID is stored Little Endian */
u8 length;
u8 data[WILCO_EC_PROPERTY_MAX_SIZE];
} __packed;
struct ec_property_response {
u8 reserved[2];
u8 op; /* One of enum ec_property_op */
u8 property_id[4]; /* The 32 bit PID is stored Little Endian */
u8 length;
u8 data[WILCO_EC_PROPERTY_MAX_SIZE];
} __packed;
static int send_property_msg(struct wilco_ec_device *ec,
struct ec_property_request *rq,
struct ec_property_response *rs)
{
struct wilco_ec_message ec_msg;
int ret;
memset(&ec_msg, 0, sizeof(ec_msg));
ec_msg.type = WILCO_EC_MSG_PROPERTY;
ec_msg.request_data = rq;
ec_msg.request_size = sizeof(*rq);
ec_msg.response_data = rs;
ec_msg.response_size = sizeof(*rs);
ret = wilco_ec_mailbox(ec, &ec_msg);
if (ret < 0)
return ret;
if (rs->op != rq->op)
return -EBADMSG;
if (memcmp(rq->property_id, rs->property_id, sizeof(rs->property_id)))
return -EBADMSG;
return 0;
}
int wilco_ec_get_property(struct wilco_ec_device *ec,
struct wilco_ec_property_msg *prop_msg)
{
struct ec_property_request rq;
struct ec_property_response rs;
int ret;
memset(&rq, 0, sizeof(rq));
rq.op = EC_OP_GET;
put_unaligned_le32(prop_msg->property_id, rq.property_id);
ret = send_property_msg(ec, &rq, &rs);
if (ret < 0)
return ret;
prop_msg->length = rs.length;
memcpy(prop_msg->data, rs.data, rs.length);
return 0;
}
EXPORT_SYMBOL_GPL(wilco_ec_get_property);
int wilco_ec_set_property(struct wilco_ec_device *ec,
struct wilco_ec_property_msg *prop_msg)
{
struct ec_property_request rq;
struct ec_property_response rs;
int ret;
memset(&rq, 0, sizeof(rq));
rq.op = EC_OP_SET;
put_unaligned_le32(prop_msg->property_id, rq.property_id);
rq.length = prop_msg->length;
memcpy(rq.data, prop_msg->data, prop_msg->length);
ret = send_property_msg(ec, &rq, &rs);
if (ret < 0)
return ret;
if (rs.length != prop_msg->length)
return -EBADMSG;
return 0;
}
EXPORT_SYMBOL_GPL(wilco_ec_set_property);
int wilco_ec_get_byte_property(struct wilco_ec_device *ec, u32 property_id,
u8 *val)
{
struct wilco_ec_property_msg msg;
int ret;
msg.property_id = property_id;
ret = wilco_ec_get_property(ec, &msg);
if (ret < 0)
return ret;
if (msg.length != 1)
return -EBADMSG;
*val = msg.data[0];
return 0;
}
EXPORT_SYMBOL_GPL(wilco_ec_get_byte_property);
int wilco_ec_set_byte_property(struct wilco_ec_device *ec, u32 property_id,
u8 val)
{
struct wilco_ec_property_msg msg;
msg.property_id = property_id;
msg.data[0] = val;
msg.length = 1;
return wilco_ec_set_property(ec, &msg);
}
EXPORT_SYMBOL_GPL(wilco_ec_set_byte_property);