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);
/* inform the bridge: binding successful */
v4l2_async_subdev_bound();
Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/
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