Hi Guennadi,
On Tuesday 19 March 2013 11:27:56 Guennadi Liakhovetski wrote:
> On Tue, 19 Mar 2013, Sylwester Nawrocki wrote:
> > >>> + if (!IS_ERR(clk)&& !try_module_get(clk->ops->owner))
> > >>> + clk = ERR_PTR(-ENODEV);
> > >>> + mutex_unlock(&clk_lock);
> > >>> +
> > >>> + if (!IS_ERR(clk)) {
> > >>> + clk->subdev = sd;
> > >>
> > >> Why is this needed ? It seems a strange addition that might potentially
> > >> make transition to the common clocks API more difficult.
> > >
> > > We got rid of the v4l2_clk_bind() function and the .bind() callback. Now
> > > I need a pointer to subdevice _before_ v4l2_clk_register() (former
> > > v4l2_clk_bound()), that's why I have to store it here.
> >
> > Hmm, sorry, I'm not following. How can we store a subdev pointer in the
> > clock data structure that has not been registered yet and thus cannot be
> > found with v4l2_clk_find() ?
>
> sorry, I meant v4l2_async_subdev_register(), not v4l2_clk_register(), my
> mistake. And I meant v4l2_async_subdev_bind(), v4l2_async_subdev_unbind().
> Before we had in the subdev driver (see imx074 example)
>
> /* Tell the bridge the subdevice is about to bind */
> v4l2_async_subdev_bind();
>
> /* get a clock */
> clk = v4l2_clk_get();
> if (IS_ERR(clk))
> return -EPROBE_DEFER;
>
> /*
> * enable the clock - this needs a subdev pointer, that we passed
> * to the bridge with v4l2_async_subdev_bind() above
> */
> v4l2_clk_enable(clk);
> do_probe();
> v4l2_clk_disable(clk);
>
> /* inform the bridge: binding successful */
> v4l2_async_subdev_bound();
>
> Now we have just
>
> /* get a clock */
> clk = v4l2_clk_get();
> if (IS_ERR(clk))
> return -EPROBE_DEFER;
>
> /*
> * enable the clock - this needs a subdev pointer, that we stored
> * in the clock object for the bridge driver to use with
> * v4l2_clk_get() above
> */
> v4l2_clk_enable(clk);
> do_probe();
> v4l2_clk_disable(clk);
I'm sorry, but I still don't understand why you need a pointer to the subdev
in the clock provider implementation of v4l2_clk_enable/disable() :-)
> /* inform the bridge: binding successful */
> v4l2_async_subdev_bound();
--
Regards,
Laurent Pinchart
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