On Tue, 2009-06-23 at 14:33 +0200, Hans Verkuil wrote: > > On Tue, 2009-06-23 at 11:39 +0800, Terry Wu wrote: > >> Hi, > >> > >> I add the following codes in the cx23885_initialize() of > >> cx25840-core.c: > >> /* Drive GPIO2 (GPIO 19~23) direction and values for DVB-T */ > >> cx25840_and_or(client, 0x160, 0x1d, 0x00); > >> cx25840_write(client, 0x164, 0x00); > >> > >> Before that, the tuning status is 0x1e, but <0> service found. > >> Now, I can watch DVB-T (Taiwan, 6MHz bandwidth). > >> > >> And if you are living in Australia, you should update the > >> tuner-xc2028.c too: > >> http://tw1965.myweb.hinet.net/Linux/v4l-dvb/20090611-TDA18271HDC2/tuner-xc2028.c > >> > >> Best Regards, > >> Terry > > > > > > Hans, > > > > As I think of potential ways to handle this, I thought we may need to > > add a v4l2_subdev interface for setting and reading GPIO's. > > There is already an s_gpio in the core ops. It would be simple to add a > g_gpio as well if needed. Ooops. Sorry for not doing my homework. Thanks. > > It is not a good idea to directly control GPIO pins from within a subdev > driver for the simple reason that the subdev driver has no idea how its > gpio pins are hooked up. This should really be done from the v4l driver > itself. Agree. This is what I waas thinking. Regards, Andy > If you need a notification from the subdev that the v4l driver > needs to take some action, then the subdev can send a notification through > the notify function in v4l2_device. That's currently used by one subdev > driver that requires that the v4l driver toggles a GPIO pin at the right > time. > > Regards, > > Hans -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
