Add host_command_process() to process a command immediately

Rather than go through the task queue, host_command_process() processes
the command immediately, has all of its required state passed in,
allowing the caller complete control of the buffers.

BUG=chrome-os-partner:10533
TEST=manual:
build and boot on link, see that messages are stil processed
build and boot on snow, which uses this new command
See that the SPI keyboard works now

Change-Id: Ib7587de10c42caf01bc95bb4d515fd0afc3da7d8
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/25983
Reviewed-by: David Hendricks <dhendrix@chromium.org>

2 files changed, 33 insertions, 11 deletions

diff --git a/common/host_command.c b/common/host_command.c
index 4de9f36404..cc7de1e473 100644
--- a/common/host_command.c
+++ b/common/host_command.c
@@ -132,25 +132,34 @@ static const struct host_command *find_host_command(int command)
 }
 
 
-/* Handle a LPC command */
-static void command_process(int slot)
+enum ec_status host_command_process(int slot, int command, uint8_t *data,
+				    int *response_size)
 {
-	int command = host_command[slot];
-	uint8_t *data = host_get_buffer(slot);
 	const struct host_command *cmd = find_host_command(command);
+	enum ec_status res = EC_RES_INVALID_COMMAND;
 
 	CPRINTF("[hostcmd%d 0x%02x]\n", slot, command);
 
-	if (cmd) {
-		int size = 0;
-		int res = cmd->handler(data, &size);
+	*response_size = 0;
+	if (cmd)
+		res = cmd->handler(data, response_size);
 
-		host_send_response(slot, res, data, size);
-	} else {
-		host_send_response(slot, EC_RES_INVALID_COMMAND, data, 0);
-	}
+	return res;
 }
 
+/* Handle a host command */
+static void command_process(int slot)
+{
+	int size;
+	int res;
+
+	CPRINTF("[hostcmd%d 0x%02x]\n", slot, host_command[slot]);
+
+	res = host_command_process(slot, host_command[slot],
+				   host_get_buffer(slot), &size);
+
+	host_send_response(slot, res, host_get_buffer(slot), size);
+}
 /*****************************************************************************/
 /* Initialization / task */
 
diff --git a/include/host_command.h b/include/host_command.h
index ea31bdcc41..69facb6268 100644
--- a/include/host_command.h
+++ b/include/host_command.h
@@ -21,6 +21,19 @@ struct host_command {
 	int (*handler)(uint8_t *data, int *response_size);
 };
 
+/**
+ * Process a host command and return its response
+ *
+ * @param slot		is 0 for kernel-originated commands,
+ *			1 for usermode-originated commands.
+ * @param command	The command code
+ * @param data		Buffer holding the command, and used for the
+ * 			response payload.
+ * @param response_size	Returns the size of the response
+ * @return resulting status
+ */
+enum ec_status host_command_process(int slot, int command, uint8_t *data,
+				    int *response_size);
 
 /* Called by LPC module when a command is written to one of the
    command slots (0=kernel, 1=user). */