I did some more planning and made alternative RFC.
As the earlier alternative was more like changing old functionality that
new one goes much more deeper.
As a basic rule I designed it to reduce stuff from the current struct
dvb_usb_device_properties. Currently there is many nested structs
introducing same callbacks. For that one I dropped all frontend and
adapter level callbacks to device level. Currently struct contains 2
adapters and 3 frontends - which means we have 2 * 3 = 6 "similar"
callbacks and only 1 is used. It wastes some space since devices having
more than one adapter or frontend are rather rare. Making callback
selection inside individual driver is very trivial even without a
designated callback. Here is common example from the use of
.frontend_attach() callback in case of only one callback used:
static int frontend_attach(struct dvb_usb_adapter *adap)
{
if (adap->id == 0)
return frontend_attach_1();
else
return frontend_attach_2();
}
Functionality enhancement mentioned earlier RFC are valid too:
http://www.mail-archive.com/linux-media@vger.kernel.org/msg46352.html
As I was a little bit lazy I wrote only quick skeleton code to represent
new simplified "struct dvb_usb_device_properties":
struct dvb_usb_device_properties = {
/* download_firmware() success return values to signal what happens
next */
#define RECONNECTS_USB (1 << 0)
#define RECONNECTS_USB_USING_NEW_ID (1 << 1)
.size_of_priv = sizeof(struct 'state'),
/* firmware download */
.identify_state(struct dvb_usb_device *d, int *cold),
.get_firmware_name(struct dvb_usb_device *d, char *firmware_name),
.download_firmware(struct dvb_usb_device *d, const struct firmware *fw),
.allow_dynamic_id = true,
.power_ctrl(struct dvb_usb_device *d, int onoff),
.read_config(struct dvb_usb_device *d, u8 mac[6]),
.get_adapter_count(struct dvb_usb_device *d, int *count),
.frontend_attach(struct dvb_usb_adapter *adap),
.tuner_attach(struct dvb_usb_adapter *adap),
.init(struct dvb_usb_device *d),
.get_rc(struct dvb_rc *),
.i2c_algo = (struct i2c_algorithm),
.frontend_ctrl(struct dvb_frontend *fe, int onoff),
.get_stream_props(struct usb_data_stream_properties *),
.streaming_ctrl(struct dvb_usb_adapter *adap, int onoff),
.generic_bulk_ctrl_endpoint = (int),
.generic_bulk_ctrl_endpoint_response = (int),
.devices = (struct dvb_usb_device)[],
};
struct dvb_usb_device dvb_usb_devices {
char *name = "name",
.rc_map = RC_MAP_EMPTY,
.device_id = (struct usb_device_id),
}
It is likely Wednesday I am going to start implementing that one unless
some big issues are raised. Making simple test code as a
proof-of-concept should not be very many days of work.
regards
Antti
--
http://palosaari.fi/
--
To unsubscribe from this list: send the line "unsubscribe linux-media" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
