misc: add "call" uclass op
The call op requests that the callee pass a message to the underlying HW
or device, wait for a response, and then pass back the response error code
and message to the callee. It is useful for drivers that represent some
kind of messaging or IPC channel to a remote device.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/include/misc.h b/include/misc.h
index 2b78814..03ef55c 100644
--- a/include/misc.h
+++ b/include/misc.h
@@ -38,6 +38,27 @@
int misc_ioctl(struct udevice *dev, unsigned long request, void *buf);
/*
+ * Send a message to the device and wait for a response.
+ *
+ * The caller provides the message type/ID and payload to be sent.
+ * The callee constructs any message header required, transmits it to the
+ * target, waits for a response, checks any error code in the response,
+ * strips any message header from the response, and returns the error code
+ * (or a parsed version of it) and the response message payload.
+ *
+ * @dev: the device.
+ * @msgid: the message ID/number to send.
+ * tx_msg: the request/transmit message payload.
+ * tx_size: the size of the buffer pointed at by tx_msg.
+ * rx_msg: the buffer to receive the response message payload. May be NULL if
+ * the caller only cares about the error code.
+ * rx_size: the size of the buffer pointed at by rx_msg.
+ * @return the response message size if OK, -ve on error
+ */
+int misc_call(struct udevice *dev, int msgid, void *tx_msg, int tx_size,
+ void *rx_msg, int rx_size);
+
+/*
* struct misc_ops - Driver model Misc operations
*
* The uclass interface is implemented by all miscellaneous devices which
@@ -74,6 +95,20 @@
* @return: 0 if OK, -ve on error
*/
int (*ioctl)(struct udevice *dev, unsigned long request, void *buf);
+ /*
+ * Send a message to the device and wait for a response.
+ *
+ * @dev: the device
+ * @msgid: the message ID/number to send
+ * tx_msg: the request/transmit message payload
+ * tx_size: the size of the buffer pointed at by tx_msg
+ * rx_msg: the buffer to receive the response message payload. May be
+ * NULL if the caller only cares about the error code.
+ * rx_size: the size of the buffer pointed at by rx_msg
+ * @return the response message size if OK, -ve on error
+ */
+ int (*call)(struct udevice *dev, int msgid, void *tx_msg, int tx_size,
+ void *rx_msg, int rx_size);
};
#endif /* _MISC_H_ */