On Tue, 30 Mar 2010, Rodolfo Giometti wrote:
> On Tue, Mar 30, 2010 at 04:40:17PM +0200, Guennadi Liakhovetski wrote:
> > On Tue, 30 Mar 2010, Rodolfo Giometti wrote:
> >
> > > On Tue, Feb 23, 2010 at 12:19:13AM +0100, Richard Röjfors wrote:
> > > >
> > > > We use it as a subdev to a driver not yet committed from us. So I think
> > > > you should extend it, not move it.
> > >
> > > Finally I got something functional... but I'm puzzled to know how I
> > > can add platform data configuration struct by using the I2C's
> > > platform_data pointer if it is already used to hold struct
> > > soc_camera_device... O_o
> >
> > As usual, looking at existing examples helps, e.g., in ov772x:
> >
> > priv->info = icl->priv;
> >
> > i.e., icl->priv is where you pass subdevice-driver specific data with
> > the soc-camera API.
>
> This driver was developed as v4l2-sub device and I just add the
> soc-camera support.
>
> Doing what are you suggesting is not compatible with the v4l2-sub
> device support, in fact the I2C platform_data is used to know if the
> driver must enable soc-camera or not...
Yes, this is a known limitation, I have tried to discuss this on this ML
in the past to get some reasonable solution for this, i.e., to standardise
the use of the platform-data pointer. However, this hasn't worked until
now. Maybe we manage it this time. So, what we would need is some standard
optional struct, to which platform-data may point. If it is not NULL, then
there could be either a "priv" member, that we would then use for
soc-camera specific data, or we could embed that common struct in an
soc-camera specific one. I would prefer a priv pointer.
>
> Look the code:
>
> static __devinit int adv7180_probe(struct i2c_client *client,
> const struct i2c_device_id *id)
> {
> struct adv7180_state *state;
> struct soc_camera_device *icd = client->dev.platform_data;
>
> icd is set as client->dev.platform_data. This can be use for normal
> I2C devices to hold custom platform_data initialization.
>
> struct soc_camera_link *icl;
> struct adv7180_platform_data *pdata = NULL;
> struct v4l2_subdev *sd;
> int ret;
>
> /* Check if the adapter supports the needed features */
> if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
> return -EIO;
>
> v4l_info(client, "chip found @ 0x%02x (%s)\n",
> client->addr << 1, client->adapter->name);
>
> if (icd) {
>
> If the icd is set we assume it holds a soc-camera struct.
>
> icl = to_soc_camera_link(icd);
> if (!icl || !icl->priv) {
> v4l_err(client, "missing platform data!\n");
> return -EINVAL;
> }
>
> icd->ops = &adv7180_soc_ops;
>
> If soc-camera is defined we set some info in order to enable it...
>
> v4l_info(client, "soc-camera support enabled\n");
> }
> ...otherwise the driver works in the old way.
Exactly, now we just have to standardise the use of
client->dev.platform_data for v4l(2) I2C devices.
>
> state = kzalloc(sizeof(struct adv7180_state), GFP_KERNEL);
> if (state == NULL) {
> ret = -ENOMEM;
> goto err;
> }
>
> state->irq = client->irq;
> INIT_WORK(&state->work, adv7180_work);
> mutex_init(&state->mutex);
> state->autodetect = true;
> sd = &state->sd;
> v4l2_i2c_subdev_init(sd, client, &adv7180_ops);
>
> Ciao,
>
> Rodolfo
Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/
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