diff options
-rw-r--r-- | drivers/platform/chrome/wilco_ec/Makefile | 2 | ||||
-rw-r--r-- | drivers/platform/chrome/wilco_ec/properties.c | 132 | ||||
-rw-r--r-- | include/linux/platform_data/wilco-ec.h | 71 |
3 files changed, 204 insertions, 1 deletions
diff --git a/drivers/platform/chrome/wilco_ec/Makefile b/drivers/platform/chrome/wilco_ec/Makefile index 063e7fb4ea17..29b734137786 100644 --- a/drivers/platform/chrome/wilco_ec/Makefile +++ b/drivers/platform/chrome/wilco_ec/Makefile @@ -1,6 +1,6 @@ # SPDX-License-Identifier: GPL-2.0 -wilco_ec-objs := core.o mailbox.o +wilco_ec-objs := core.o mailbox.o properties.o obj-$(CONFIG_WILCO_EC) += wilco_ec.o wilco_ec_debugfs-objs := debugfs.o obj-$(CONFIG_WILCO_EC_DEBUGFS) += wilco_ec_debugfs.o diff --git a/drivers/platform/chrome/wilco_ec/properties.c b/drivers/platform/chrome/wilco_ec/properties.c new file mode 100644 index 000000000000..e69682c95ea2 --- /dev/null +++ b/drivers/platform/chrome/wilco_ec/properties.c @@ -0,0 +1,132 @@ +// 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); diff --git a/include/linux/platform_data/wilco-ec.h b/include/linux/platform_data/wilco-ec.h index 1ff224793c99..50a21bd5fd44 100644 --- a/include/linux/platform_data/wilco-ec.h +++ b/include/linux/platform_data/wilco-ec.h @@ -123,4 +123,75 @@ struct wilco_ec_message { */ int wilco_ec_mailbox(struct wilco_ec_device *ec, struct wilco_ec_message *msg); +/* + * A Property is typically a data item that is stored to NVRAM + * by the EC. Each of these data items has an index associated + * with it, known as the Property ID (PID). Properties may have + * variable lengths, up to a max of WILCO_EC_PROPERTY_MAX_SIZE + * bytes. Properties can be simple integers, or they may be more + * complex binary data. + */ + +#define WILCO_EC_PROPERTY_MAX_SIZE 4 + +/** + * struct ec_property_set_msg - Message to get or set a property. + * @property_id: Which property to get or set. + * @length: Number of bytes of |data| that are used. + * @data: Actual property data. + */ +struct wilco_ec_property_msg { + u32 property_id; + int length; + u8 data[WILCO_EC_PROPERTY_MAX_SIZE]; +}; + +/** + * wilco_ec_get_property() - Retrieve a property from the EC. + * @ec: Embedded Controller device. + * @prop_msg: Message for request and response. + * + * The property_id field of |prop_msg| should be filled before calling this + * function. The result will be stored in the data and length fields. + * + * Return: 0 on success, negative error code on failure. + */ +int wilco_ec_get_property(struct wilco_ec_device *ec, + struct wilco_ec_property_msg *prop_msg); + +/** + * wilco_ec_set_property() - Store a property on the EC. + * @ec: Embedded Controller device. + * @prop_msg: Message for request and response. + * + * The property_id, length, and data fields of |prop_msg| should be + * filled before calling this function. + * + * Return: 0 on success, negative error code on failure. + */ +int wilco_ec_set_property(struct wilco_ec_device *ec, + struct wilco_ec_property_msg *prop_msg); + +/** + * wilco_ec_get_byte_property() - Retrieve a byte-size property from the EC. + * @ec: Embedded Controller device. + * @property_id: Which property to retrieve. + * @val: The result value, will be filled by this function. + * + * Return: 0 on success, negative error code on failure. + */ +int wilco_ec_get_byte_property(struct wilco_ec_device *ec, u32 property_id, + u8 *val); + +/** + * wilco_ec_get_byte_property() - Store a byte-size property on the EC. + * @ec: Embedded Controller device. + * @property_id: Which property to store. + * @val: Value to store. + * + * Return: 0 on success, negative error code on failure. + */ +int wilco_ec_set_byte_property(struct wilco_ec_device *ec, u32 property_id, + u8 val); + #endif /* WILCO_EC_H */ |