greybus: power_supply: convert to bundle driver

Convert the legacy power_supply 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 2188de94a59029650b5b6eae5b5e05f42ed0b29a..58b277979a608e6a4fe78ffdc9597d731cce3a98 100644 (file)
--- a/drivers/staging/greybus/legacy.c
+++ b/drivers/staging/greybus/legacy.c
@@ -241,7 +241,6 @@ static const struct greybus_bundle_id legacy_id_table[] = {
        { GREYBUS_DEVICE_CLASS(GREYBUS_CLASS_UART) },
        { GREYBUS_DEVICE_CLASS(GREYBUS_CLASS_USB) },
        { GREYBUS_DEVICE_CLASS(GREYBUS_CLASS_SDIO) },
-       { GREYBUS_DEVICE_CLASS(GREYBUS_CLASS_POWER_SUPPLY) },
        { GREYBUS_DEVICE_CLASS(GREYBUS_CLASS_PWM) },
        { GREYBUS_DEVICE_CLASS(GREYBUS_CLASS_SPI) },
        { GREYBUS_DEVICE_CLASS(GREYBUS_CLASS_CAMERA) },

diff --git a/drivers/staging/greybus/power_supply.c b/drivers/staging/greybus/power_supply.c
index c50b30d1a632aa69776e8c1f7d789296beaaa3f0..0467537bf4f6cc280bee215a27c9200bfb3a2c24 100644 (file)
--- a/drivers/staging/greybus/power_supply.c
+++ b/drivers/staging/greybus/power_supply.c
@@ -708,7 +708,7 @@ static int gb_power_supplies_register(struct gb_power_supplies *supplies)
        return ret;
 }
 
-static int gb_power_supply_event_recv(u8 type, struct gb_operation *op)
+static int gb_supplies_request_handler(struct gb_operation *op)
 {
        struct gb_connection *connection = op->connection;
        struct gb_power_supplies *supplies = connection->private;
@@ -719,9 +719,9 @@ static int gb_power_supply_event_recv(u8 type, struct gb_operation *op)
        u8 event;
        int ret = 0;
 
-       if (type != GB_POWER_SUPPLY_TYPE_EVENT) {
+       if (op->type != GB_POWER_SUPPLY_TYPE_EVENT) {
                dev_err(&connection->bundle->dev,
-                       "Unsupported unsolicited event: %u\n", type);
+                       "Unsupported unsolicited event: %u\n", op->type);
                return -EINVAL;
        }
 
@@ -765,52 +765,90 @@ out_unlock:
        return ret;
 }
 
-static int gb_power_supply_connection_init(struct gb_connection *connection)
+static int gb_power_supply_probe(struct gb_bundle *bundle,
+                                const struct greybus_bundle_id *id)
 {
+       struct greybus_descriptor_cport *cport_desc;
+       struct gb_connection *connection;
        struct gb_power_supplies *supplies;
        int ret;
 
+       if (bundle->num_cports != 1)
+               return -ENODEV;
+
+       cport_desc = &bundle->cport_desc[0];
+       if (cport_desc->protocol_id != GREYBUS_PROTOCOL_POWER_SUPPLY)
+               return -ENODEV;
+
        supplies = kzalloc(sizeof(*supplies), GFP_KERNEL);
        if (!supplies)
                return -ENOMEM;
 
+       connection = gb_connection_create(bundle, le16_to_cpu(cport_desc->id),
+                                         gb_supplies_request_handler);
+       if (IS_ERR(connection)) {
+               ret = PTR_ERR(connection);
+               goto out;
+       }
+
        supplies->connection = connection;
        connection->private = supplies;
 
        mutex_init(&supplies->supplies_lock);
 
+       greybus_set_drvdata(bundle, supplies);
+
+       /* We aren't ready to receive an incoming request yet */
+       ret = gb_connection_enable_tx(connection);
+       if (ret)
+               goto error_connection_destroy;
+
        ret = gb_power_supplies_setup(supplies);
        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;
 
        ret = gb_power_supplies_register(supplies);
        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_power_supplies_release(supplies);
        return ret;
 }
 
-static void gb_power_supply_connection_exit(struct gb_connection *connection)
+static void gb_power_supply_disconnect(struct gb_bundle *bundle)
 {
-       struct gb_power_supplies *supplies = connection->private;
+       struct gb_power_supplies *supplies = greybus_get_drvdata(bundle);
+
+       gb_connection_disable(supplies->connection);
+       gb_connection_destroy(supplies->connection);
 
        _gb_power_supplies_release(supplies);
 }
 
-static struct gb_protocol power_supply_protocol = {
-       .name                   = "power_supply",
-       .id                     = GREYBUS_PROTOCOL_POWER_SUPPLY,
-       .major                  = GB_POWER_SUPPLY_VERSION_MAJOR,
-       .minor                  = GB_POWER_SUPPLY_VERSION_MINOR,
-       .connection_init        = gb_power_supply_connection_init,
-       .connection_exit        = gb_power_supply_connection_exit,
-       .request_recv           = gb_power_supply_event_recv,
+static const struct greybus_bundle_id gb_power_supply_id_table[] = {
+       { GREYBUS_DEVICE_CLASS(GREYBUS_CLASS_POWER_SUPPLY) },
+       { }
 };
+MODULE_DEVICE_TABLE(greybus, gb_power_supply_id_table);
 
-gb_protocol_driver(&power_supply_protocol);
+static struct greybus_driver gb_power_supply_driver = {
+       .name           = "power_supply",
+       .probe          = gb_power_supply_probe,
+       .disconnect     = gb_power_supply_disconnect,
+       .id_table       = gb_power_supply_id_table,
+};
+module_greybus_driver(gb_power_supply_driver);
 
 MODULE_LICENSE("GPL v2");