Retrieving the supported versions of a command is a fairly common
operation. Provide a helper for it.
If the command is not supported at all the EC returns
-EINVAL/EC_RES_INVALID_PARAMS.
This error is translated into an empty version mask as that is easier to
handle for callers and they don't need to know about the error details.
Signed-off-by: Thomas Weißschuh <[email protected]>
---
drivers/platform/chrome/cros_ec_proto.c | 26 ++++++++++++++++++++++++++
include/linux/platform_data/cros_ec_proto.h | 2 ++
2 files changed, 28 insertions(+)
diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
index fe68be66ee98..9cfe885a5301 100644
--- a/drivers/platform/chrome/cros_ec_proto.c
+++ b/drivers/platform/chrome/cros_ec_proto.c
@@ -1069,3 +1069,29 @@ int cros_ec_cmd_readmem(struct cros_ec_device *ec_dev, u8 offset, u8 size, void
¶ms, sizeof(params), dest, size);
}
EXPORT_SYMBOL_GPL(cros_ec_cmd_readmem);
+
+/**
+ * cros_ec_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_cmd_versions(struct cros_ec_device *ec_dev, u16 cmd)
+{
+ struct ec_params_get_cmd_versions_v1 req = {};
+ struct ec_response_get_cmd_versions resp;
+ int ret;
+
+ req.cmd = cmd;
+ ret = cros_ec_cmd(ec_dev, 1, EC_CMD_GET_CMD_VERSIONS,
+ &req, sizeof(req), &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_cmd_versions);
diff --git a/include/linux/platform_data/cros_ec_proto.h b/include/linux/platform_data/cros_ec_proto.h
index 6e9225bdf903..98ab5986f543 100644
--- a/include/linux/platform_data/cros_ec_proto.h
+++ b/include/linux/platform_data/cros_ec_proto.h
@@ -263,6 +263,8 @@ int cros_ec_cmd(struct cros_ec_device *ec_dev, unsigned int version, int command
int cros_ec_cmd_readmem(struct cros_ec_device *ec_dev, u8 offset, u8 size, void *dest);
+int cros_ec_cmd_versions(struct cros_ec_device *ec_dev, u16 cmd);
+
/**
* cros_ec_get_time_ns() - Return time in ns.
*
--
2.45.2