greybus: move methods into protocol

Get rid of the connection handler structure, and instead put the
methods that were there into the protocol structure.

Eliminate the big switch statement in connection_init() and just
call the connection's protocol's init function there directly.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

drivers/staging/greybus/battery-gb.c

@@ -400,15 +400,12 @@ static void gb_battery_connection_exit(struct gb_connection *connection)
 	kfree(gb);
 }
 
-struct gb_connection_handler gb_battery_connection_handler = {
-	.connection_init	= gb_battery_connection_init,
-	.connection_exit	= gb_battery_connection_exit,
-};
-
 static struct gb_protocol battery_protocol = {
 	.id			= GREYBUS_PROTOCOL_BATTERY,
 	.major			= 0,
 	.minor			= 1,
+	.connection_init	= gb_battery_connection_init,
+	.connection_exit	= gb_battery_connection_exit,
 };
 
 bool gb_battery_protocol_init(void)

drivers/staging/greybus/connection.c

@@ -267,45 +267,18 @@ void gb_connection_err(struct gb_connection *connection, const char *fmt, ...)
 	va_end(args);
 }
 
-/*
- * XXX Protocols should have a set of function pointers:
- *	->init (called here, to initialize the device)
- *	->input_handler
- *	->exit (reverse of init)
- */
 int gb_connection_init(struct gb_connection *connection)
 {
 	int ret;
 
-	/* Need to enable the connection to initialize it */
-	connection->state = GB_CONNECTION_STATE_ENABLED;
-	switch (connection->protocol->id) {
-	case GREYBUS_PROTOCOL_I2C:
-		connection->handler = &gb_i2c_connection_handler;
-		break;
-	case GREYBUS_PROTOCOL_GPIO:
-		connection->handler = &gb_gpio_connection_handler;
-		break;
-	case GREYBUS_PROTOCOL_BATTERY:
-		connection->handler = &gb_battery_connection_handler;
-		break;
-	case GREYBUS_PROTOCOL_UART:
-		connection->handler = &gb_uart_connection_handler;
-		break;
-	case GREYBUS_PROTOCOL_CONTROL:
-	case GREYBUS_PROTOCOL_AP:
-	case GREYBUS_PROTOCOL_HID:
-	case GREYBUS_PROTOCOL_LED:
-	case GREYBUS_PROTOCOL_VENDOR:
-	default:
-		gb_connection_err(connection, "unimplemented protocol %hhu",
-			connection->protocol->id);
-		ret = -ENXIO;
-		break;
+	if (!connection->protocol) {
+		gb_connection_err(connection, "uninitialized connection");
+		return -EIO;
 	}
 
-	ret = connection->handler->connection_init(connection);
-
+	/* Need to enable the connection to initialize it */
+	connection->state = GB_CONNECTION_STATE_ENABLED;
+	ret = connection->protocol->connection_init(connection);
 	if (ret)
 		connection->state = GB_CONNECTION_STATE_ERROR;
 
@@ -314,10 +287,10 @@ int gb_connection_init(struct gb_connection *connection)
 
 void gb_connection_exit(struct gb_connection *connection)
 {
-	if (!connection->handler) {
+	if (!connection->protocol) {
 		gb_connection_err(connection, "uninitialized connection");
 		return;
 	}
 	connection->state = GB_CONNECTION_STATE_DESTROYING;
-	connection->handler->connection_exit(connection);
+	connection->protocol->connection_exit(connection);
 }

drivers/staging/greybus/connection.h

@@ -21,15 +21,6 @@ enum gb_connection_state {
 	GB_CONNECTION_STATE_DESTROYING	= 4,
 };
 
-struct gb_connection;
-typedef int (*gb_connection_init_t)(struct gb_connection *);
-typedef void (*gb_connection_exit_t)(struct gb_connection *);
-
-struct gb_connection_handler {
-	gb_connection_init_t	connection_init;
-	gb_connection_exit_t	connection_exit;
-};
-
 struct gb_connection {
 	struct greybus_host_device	*hd;
 	struct gb_interface		*interface;
@@ -48,8 +39,6 @@ struct gb_connection {
 	struct rb_root			pending;	/* awaiting reponse */
 	atomic_t			op_cycle;
 
-	struct gb_connection_handler	*handler;
-
 	void				*private;
 };
 #define to_gb_connection(d) container_of(d, struct gb_connection, dev)

drivers/staging/greybus/gpio-gb.c

@@ -792,15 +792,12 @@ static void gb_gpio_connection_exit(struct gb_connection *connection)
 	kfree(gb_gpio_controller);
 }
 
-struct gb_connection_handler gb_gpio_connection_handler = {
-	.connection_init	= gb_gpio_connection_init,
-	.connection_exit	= gb_gpio_connection_exit,
-};
-
 static struct gb_protocol gpio_protocol = {
 	.id			= GREYBUS_PROTOCOL_GPIO,
 	.major			= 0,
 	.minor			= 1,
+	.connection_init	= gb_gpio_connection_init,
+	.connection_exit	= gb_gpio_connection_exit,
 };
 
 bool gb_gpio_protocol_init(void)

drivers/staging/greybus/i2c-gb.c

@@ -518,15 +518,12 @@ static void gb_i2c_connection_exit(struct gb_connection *connection)
 	kfree(gb_i2c_dev);
 }
 
-struct gb_connection_handler gb_i2c_connection_handler = {
-	.connection_init	= gb_i2c_connection_init,
-	.connection_exit	= gb_i2c_connection_exit,
-};
-
 static struct gb_protocol i2c_protocol = {
 	.id			= GREYBUS_PROTOCOL_I2C,
 	.major			= 0,
 	.minor			= 1,
+	.connection_init	= gb_i2c_connection_init,
+	.connection_exit	= gb_i2c_connection_exit,
 };
 
 bool gb_i2c_protocol_init(void)

drivers/staging/greybus/protocol.h

@@ -11,6 +11,9 @@
 
 #include "greybus.h"
 
+typedef int (*gb_connection_init_t)(struct gb_connection *);
+typedef void (*gb_connection_exit_t)(struct gb_connection *);
+
 /*
  * Protocols having the same id but different major and/or minor
  * version numbers are treated as distinct protocols.  If it makes
@@ -23,6 +26,9 @@ struct gb_protocol {
 	u8			count;
 
 	struct list_head	links;		/* global list */
+
+	gb_connection_init_t	connection_init;
+	gb_connection_exit_t	connection_exit;
 };
 
 bool gb_protocol_register(struct gb_protocol *protocol);

drivers/staging/greybus/sdio-gb.c

@@ -77,15 +77,12 @@ static void gb_sdio_connection_exit(struct gb_connection *connection)
 	connection->private = NULL;
 }
 
-struct gb_connection_handler gb_sdio_connection_handler = {
-	.connection_init	= gb_sdio_connection_init,
-	.connection_exit	= gb_sdio_connection_exit,
-};
-
 static struct gb_protocol sdio_protocol = {
 	.id			= GREYBUS_PROTOCOL_SDIO,
 	.major			= 0,
 	.minor			= 1,
+	.connection_init	= gb_sdio_connection_init,
+	.connection_exit	= gb_sdio_connection_exit,
 };
 
 bool gb_sdio_protocol_init(void)

drivers/staging/greybus/uart-gb.c

@@ -520,15 +520,12 @@ static void gb_tty_exit(void)
 	unregister_chrdev_region(MKDEV(major, minor), GB_NUM_MINORS);
 }
 
-struct gb_connection_handler gb_uart_connection_handler = {
-	.connection_init	= gb_uart_connection_init,
-	.connection_exit	= gb_uart_connection_exit,
-};
-
 static struct gb_protocol uart_protocol = {
 	.id			= GREYBUS_PROTOCOL_UART,
 	.major			= 0,
 	.minor			= 1,
+	.connection_init	= gb_uart_connection_init,
+	.connection_exit	= gb_uart_connection_exit,
 };
 
 bool gb_uart_protocol_init(void)