Em Mon, 8 Feb 2021 14:11:02 +0100
Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx> escreveu:
> Em Mon, 8 Feb 2021 12:41:42 +0100
> Jacopo Mondi <jacopo@xxxxxxxxxx> escreveu:
>
> > > > If you do, instead:
> > > >
> > > > if VIDEO_V4L2 && I2C
> > > > config VIDEO_MAX9271_SERIALIZER
> > > > tristate
> > > >
> > > > config VIDEO_RDACM20
> > > > select VIDEO_MAX9271_SERIALIZER
> > > > ...
> > > >
> > > > config VIDEO_RDACM21
> > > > select VIDEO_MAX9271_SERIALIZER
> > > > ...
> > > > endif
> > > >
> > > > Then you also won't need:
> > > > depends on VIDEO_MAX9271_SERIALIZER || !VIDEO_MAX9271_SERIALIZER
> > > >
> > > > As select should do the right thing in this case, ensuring that MAX9271
> > > > will be builtin either if RDACM20 or RDACM21 is builtin.
> > >
> > > I also vote for usage of "select".
> > >
> >
> > I would prefer that too, I was concerned about possible un-met
> > dependencies, as Sakari pointed out, but the current situation is no
> > better, as the only Kconfig symbols where those can be listed are the
> > camera modules one.
>
> Works for me. I'll make a patch for it.
Hmm... after taking a deeper look at the rcma20 drivers, and on its
Kconfig help text:
config VIDEO_RDACM20
tristate "IMI RDACM20 camera support"
select V4L2_FWNODE
select VIDEO_V4L2_SUBDEV_API
select MEDIA_CONTROLLER
help
This driver supports the IMI RDACM20 GMSL camera, used in
ADAS systems.
This camera should be used in conjunction with a GMSL
deserialiser such as the MAX9286.
I'm starting to suspect that there's something very wrong here...
The help text mentions the MAX9286 driver, which is a complete
driver, and not MAX9271, which seems to implement a set of PHY functions
needed by those drivers, and which lacks a proper I2C binding code on it.
The I2C binding code is, instead, inside RDACM20 and RDACM21:
static int rdacm21_initialize(struct rdacm21_device *dev)
{
int ret;
/* Verify communication with the MAX9271: ping to wakeup. */
dev->serializer.client->addr = MAX9271_DEFAULT_ADDR;
i2c_smbus_read_byte(dev->serializer.client);
usleep_range(3000, 5000);
/* Enable reverse channel and disable the serial link. */
ret = max9271_set_serial_link(&dev->serializer, false);
if (ret)
return ret;
/* Configure I2C bus at 105Kbps speed and configure GMSL. */
ret = max9271_configure_i2c(&dev->serializer,
MAX9271_I2CSLVSH_469NS_234NS |
MAX9271_I2CSLVTO_1024US |
MAX9271_I2CMSTBT_105KBPS);
/* Several other max9271-specific init code */
ret = ov490_initialize(dev);
if (ret)
return ret;
And, at max9271 "driver", there's just a bunch of exported functions.
This is all wrong.
I'm seriously considering to move all those 3 drivers to staging,
while they're not fixed to use a proper I2C binding mechanism.
Thanks,
Mauro
