greybus: lights: convert to bundle driver

Convert the legacy lights protocol driver to a bundle driver.

This also fixes a potential crash should a (malicious) module have sent
an early request before the private data had been initialised.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

diff --git a/drivers/staging/greybus/legacy.c b/drivers/staging/greybus/legacy.c
index 63597f7..2188de9 100644 (file)
--- a/drivers/staging/greybus/legacy.c
+++ b/drivers/staging/greybus/legacy.c
@@ -245,7 +245,6 @@ static const struct greybus_bundle_id legacy_id_table[] = {
        { GREYBUS_DEVICE_CLASS(GREYBUS_CLASS_PWM) },
        { GREYBUS_DEVICE_CLASS(GREYBUS_CLASS_SPI) },
        { GREYBUS_DEVICE_CLASS(GREYBUS_CLASS_CAMERA) },
-       { GREYBUS_DEVICE_CLASS(GREYBUS_CLASS_LIGHTS) },
        { }
 };
 MODULE_DEVICE_TABLE(greybus, legacy_id_table);

diff --git a/drivers/staging/greybus/light.c b/drivers/staging/greybus/light.c
index c1ad6b1..70fcade 100644 (file)
--- a/drivers/staging/greybus/light.c
+++ b/drivers/staging/greybus/light.c
@@ -1149,7 +1149,7 @@ static int gb_lights_register_all(struct gb_lights *glights)
        return ret;
 }
 
-static int gb_lights_event_recv(u8 type, struct gb_operation *op)
+static int gb_lights_request_handler(struct gb_operation *op)
 {
        struct gb_connection *connection = op->connection;
        struct device *dev = &connection->bundle->dev;
@@ -1161,8 +1161,8 @@ static int gb_lights_event_recv(u8 type, struct gb_operation *op)
        u8 light_id;
        u8 event;
 
-       if (type != GB_LIGHTS_TYPE_EVENT) {
-               dev_err(dev, "Unsupported unsolicited event: %u\n", type);
+       if (op->type != GB_LIGHTS_TYPE_EVENT) {
+               dev_err(dev, "Unsupported unsolicited event: %u\n", op->type);
                return -EINVAL;
        }
 
@@ -1201,57 +1201,95 @@ static int gb_lights_event_recv(u8 type, struct gb_operation *op)
        return ret;
 }
 
-static int gb_lights_connection_init(struct gb_connection *connection)
+static int gb_lights_probe(struct gb_bundle *bundle,
+                          const struct greybus_bundle_id *id)
 {
+       struct greybus_descriptor_cport *cport_desc;
+       struct gb_connection *connection;
        struct gb_lights *glights;
        int ret;
 
+       if (bundle->num_cports != 1)
+               return -ENODEV;
+
+       cport_desc = &bundle->cport_desc[0];
+       if (cport_desc->protocol_id != GREYBUS_PROTOCOL_LIGHTS)
+               return -ENODEV;
+
        glights = kzalloc(sizeof(*glights), GFP_KERNEL);
        if (!glights)
                return -ENOMEM;
 
+       connection = gb_connection_create(bundle, le16_to_cpu(cport_desc->id),
+                                         gb_lights_request_handler);
+       if (IS_ERR(connection)) {
+               ret = PTR_ERR(connection);
+               goto out;
+       }
+
        glights->connection = connection;
        connection->private = glights;
 
        mutex_init(&glights->lights_lock);
 
+       greybus_set_drvdata(bundle, glights);
+
+       /* We aren't ready to receive an incoming request yet */
+       ret = gb_connection_enable_tx(connection);
+       if (ret)
+               goto error_connection_destroy;
+
        /*
         * Setup all the lights devices over this connection, if anything goes
         * wrong tear down all lights
         */
        ret = gb_lights_create_all(glights);
        if (ret < 0)
-               goto out;
+               goto error_connection_disable;
+
+       /* We are ready to receive an incoming request now, enable RX as well */
+       ret = gb_connection_enable(connection);
+       if (ret)
+               goto error_connection_disable;
 
        /* Enable & register lights */
        ret = gb_lights_register_all(glights);
        if (ret < 0)
-               goto out;
+               goto error_connection_disable;
 
        return 0;
 
+error_connection_disable:
+       gb_connection_disable(connection);
+error_connection_destroy:
+       gb_connection_destroy(connection);
 out:
        gb_lights_release(glights);
        return ret;
 }
 
-static void gb_lights_connection_exit(struct gb_connection *connection)
+static void gb_lights_disconnect(struct gb_bundle *bundle)
 {
-       struct gb_lights *glights = connection->private;
+       struct gb_lights *glights = greybus_get_drvdata(bundle);
+
+       gb_connection_disable(glights->connection);
+       gb_connection_destroy(glights->connection);
 
        gb_lights_release(glights);
 }
 
-static struct gb_protocol lights_protocol = {
-       .name                   = "lights",
-       .id                     = GREYBUS_PROTOCOL_LIGHTS,
-       .major                  = GB_LIGHTS_VERSION_MAJOR,
-       .minor                  = GB_LIGHTS_VERSION_MINOR,
-       .connection_init        = gb_lights_connection_init,
-       .connection_exit        = gb_lights_connection_exit,
-       .request_recv           = gb_lights_event_recv,
+static const struct greybus_bundle_id gb_lights_id_table[] = {
+       { GREYBUS_DEVICE_CLASS(GREYBUS_CLASS_LIGHTS) },
+       { }
 };
+MODULE_DEVICE_TABLE(greybus, gb_lights_id_table);
 
-gb_protocol_driver(&lights_protocol);
+static struct greybus_driver gb_lights_driver = {
+       .name           = "lights",
+       .probe          = gb_lights_probe,
+       .disconnect     = gb_lights_disconnect,
+       .id_table       = gb_lights_id_table,
+};
+module_greybus_driver(gb_lights_driver);
 
 MODULE_LICENSE("GPL v2");