Re: saa7115/gm7113c - device specific initialization

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Mon, May 20, 2013 at 06:00:29PM -0300, Mauro Carvalho Chehab wrote:
> Em Mon, 20 May 2013 18:20:44 +0200
> Jon Arne Jørgensen <jonarne@xxxxxxxxxx> escreveu:
> 
> > On Mon, May 20, 2013 at 06:33:20AM -0400, Andy Walls wrote:
> > > "Jon Arne Jørgensen" <jonarne@xxxxxxxxxx> wrote:
> > > 
> > > >Hi,
> > > >I've recently discovered that the smi2021 device have some pretty
> > > >specific
> > > >needs for the setup of the gm7113c chip.
> > > >
> > > >Both the smi2021 driver and the stk1160 driver needs registers
> > > >0x14 -> 0x17 to be zeroed, this is what forced me to add the gm7113c
> > > >chip to the saa7115 driver in the first place.
> > > >
> > > >Then Timo reported that the Terratec Grabby hwrev2 needs some of the
> > > >initial register settings to be changed for the device to work.
> > > >He posted a small list of required changes.
> > > >One of these changes is a change to register 0x12 which sets
> > > >up what to output on the RTS0 pin on the chip.
> > > >
> > > >Then I discovered that the smi2021 needs the V-Flag in the SAV/EAV
> > > >to be generated by VREF - whatever that means :).
> > > >That is, I need bit 7 to be clear and bit 6 to be set in register 0x10.
> > > >To have the device behave correctly.
> > > >
> > > >Both the change for the smi2021 driver and the changes for the Terratec
> > > >device are pretty hardware specific.
> > > >They should probably not be part of the generic gm7113c setup.
> > > >
> > > >I would also guess that if other devices with the gm7113c chip should
> > > >surface, these devices might also have different needs for the setup of
> > > >the chip.
> > > >
> > > >I'm not sure what would be the correct way to handle these
> > > >differences.
> > > >The only sollution I'we tried is to bypass the saa7115
> > > >driver, and push the needed changes directly over usb to the device,
> > > >after the initial setup is sent by the saa7115 driver.
> > > >This is a major hack, and the changes should probably go through
> > > >the saa7115 driver.
> > > >
> > > >Should the saa7115 driver be extended with an interface to change
> > > >random
> > > >register settings, or does the i2c subsystem already have a way to
> > > >handle this?
> > > >
> > > >Any idea about what might could be a better sollution?
> > > >
> > > >Best regards
> > > >Jon Arne Jørgensen
> > > >
> > > >--
> > > >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
> > > 
> > > For v4l2_subdev's there is a way to pass in platform/bridge device specific data so initialization can be different than the default, based on the needs of the bridge driver.
> > 
> > Ok, can you give any pointers to any documentation/source files I can
> > look at for this?
> 
> Look, for example, at drivers/media/i2c/mt9v011.c. At mt9v011_probe, it
> checks if c->dev.platform_data exists. If so, it changes the xtal frequency
> to the one specified by the driver.
> 

Thanks.
Exactly what I need.

Best regards,
Jon Arne

> -- 
> 
> Cheers,
> Mauro
--
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




[Index of Archives]     [Linux Input]     [Video for Linux]     [Gstreamer Embedded]     [Mplayer Users]     [Linux USB Devel]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [Yosemite Backpacking]
  Powered by Linux