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-rw-r--r--drivers/platform/chrome/wilco_ec/Makefile2
-rw-r--r--drivers/platform/chrome/wilco_ec/properties.c132
-rw-r--r--include/linux/platform_data/wilco-ec.h71
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 */