Hi Barry On Thu, 11 Apr 2013, Barry Song wrote: > Hi Guennadi, > > > Typical video devices like camera sensors require an external clock source. > > Many such devices cannot even access their hardware registers without a > > running clock. These clock sources should be controlled by their consumers. > > This should be performed, using the generic clock framework. Unfortunately > > so far only very few systems have been ported to that framework. This patch > > adds a set of temporary helpers, mimicking the generic clock API, to V4L2. > > Platforms, adopting the clock API, should switch to using it. Eventually > > this temporary API should be removed. > > > Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@xxxxxx> > > --- > > for your patch 1/8 and 3/8, i think it makes a lot of senses to let > the object manages its own clock by itself. > is it possible for us to implement v4l2-clk.c directly as an instance > of standard clk driver for those systems which don't have generic > clock, and remove the V4L2 clock APIs like v4l2_clk_get, > v4l2_clk_enable from the first day? i mean v4l2-clk.c becomes a temp > and fake clock controller driver. finally, after people have > generically clk, remove it. I don't think you can force-enable the CFF on systems, that don't support it, e.g. PXA. Thanks Guennadi > > v8: Updated both (C) dates > > > drivers/media/v4l2-core/Makefile | 2 +- > > drivers/media/v4l2-core/v4l2-clk.c | 177 ++++++++++++++++++++++++++++++++++++ > > include/media/v4l2-clk.h | 54 +++++++++++ > > 3 files changed, 232 insertions(+), 1 deletions(-) > > create mode 100644 drivers/media/v4l2-core/v4l2-clk.c > > create mode 100644 include/media/v4l2-clk.h > > > diff --git a/drivers/media/v4l2-core/Makefile b/drivers/media/v4l2-core/Makefile > > index aa50c46..628c630 100644 > > --- a/drivers/media/v4l2-core/Makefile > > +++ b/drivers/media/v4l2-core/Makefile > > @@ -5,7 +5,7 @@ > > tuner-objs := tuner-core.o > > > videodev-objs := v4l2-dev.o v4l2-ioctl.o v4l2-device.o v4l2-fh.o \ > > - v4l2-event.o v4l2-ctrls.o v4l2-subdev.o > > + v4l2-event.o v4l2-ctrls.o v4l2-subdev.o v4l2-clk.o > > ifeq ($(CONFIG_COMPAT),y) > > videodev-objs += v4l2-compat-ioctl32.o > > endif > > diff --git a/drivers/media/v4l2-core/v4l2-clk.c b/drivers/media/v4l2-core/v4l2-clk.c > > new file mode 100644 > > index 0000000..d7cc13e > > --- /dev/null > > +++ b/drivers/media/v4l2-core/v4l2-clk.c > > @@ -0,0 +1,177 @@ > > -barry > --- Guennadi Liakhovetski, Ph.D. Freelance Open-Source Software Developer http://www.open-technology.de/ -- 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
