Re: [PATCH v8 1/7] media: V4L2: add temporary clock helpers
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@xx --- 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 000..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 majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH v8 1/7] media: V4L2: add temporary clock helpers
2013/4/11 Guennadi Liakhovetski g.liakhovet...@gmx.de: 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@xx --- 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. yes. we can. clock is only a framework, has it any limitation to implement a driver instance on any platform? people have tried to move to common clk and generic framework for a long time, now you still try to provide a v4l2 specific clock APIs, it just makes v4l2 unacceptable and much complex. 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 000..d7cc13e --- /dev/null +++ b/drivers/media/v4l2-core/v4l2-clk.c @@ -0,0 +1,177 @@ -barry -barry -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH v8 1/7] media: V4L2: add temporary clock helpers
On Thu, 11 Apr 2013, Barry Song wrote: 2013/4/11 Guennadi Liakhovetski g.liakhovet...@gmx.de: 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@xx --- 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. yes. we can. clock is only a framework, has it any limitation to implement a driver instance on any platform? So, you enable CFF, it provides its own clk_* implementation like clk_get_rate() etc. Now, PXA already has it defined in arch/arm/mach-pxa/clock.c. Don't think this is going to fly. Thanks Guennadi people have tried to move to common clk and generic framework for a long time, now you still try to provide a v4l2 specific clock APIs, it just makes v4l2 unacceptable and much complex. 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 000..d7cc13e --- /dev/null +++ b/drivers/media/v4l2-core/v4l2-clk.c @@ -0,0 +1,177 @@ -barry -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 majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH v8 1/7] media: V4L2: add temporary clock helpers
2013/4/11 Guennadi Liakhovetski g.liakhovet...@gmx.de: On Thu, 11 Apr 2013, Barry Song wrote: 2013/4/11 Guennadi Liakhovetski g.liakhovet...@gmx.de: 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@xx --- 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. yes. we can. clock is only a framework, has it any limitation to implement a driver instance on any platform? So, you enable CFF, it provides its own clk_* implementation like clk_get_rate() etc. Now, PXA already has it defined in arch/arm/mach-pxa/clock.c. Don't think this is going to fly. agree. Thanks Guennadi people have tried to move to common clk and generic framework for a long time, now you still try to provide a v4l2 specific clock APIs, it just makes v4l2 unacceptable and much complex. 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 000..d7cc13e --- /dev/null +++ b/drivers/media/v4l2-core/v4l2-clk.c @@ -0,0 +1,177 @@ -barry -barry -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH v8 1/7] media: V4L2: add temporary clock helpers
Quoting Barry Song (2013-04-11 01:59:28) 2013/4/11 Guennadi Liakhovetski g.liakhovet...@gmx.de: On Thu, 11 Apr 2013, Barry Song wrote: 2013/4/11 Guennadi Liakhovetski g.liakhovet...@gmx.de: 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@xx --- 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. yes. we can. clock is only a framework, has it any limitation to implement a driver instance on any platform? So, you enable CFF, it provides its own clk_* implementation like clk_get_rate() etc. Now, PXA already has it defined in arch/arm/mach-pxa/clock.c. Don't think this is going to fly. agree. Hi, I came into this thread late and don't have the actual patches in my inbox for review. That said, I don't understand why V4L2 cares about the clk framework *implementation*? The clk.h api is the same for platforms using the common struct clk and those still using the legacy method of defining their own struct clk. If drivers are only consumers of the clk.h api then the implementation underneath should not matter. Regards, Mike Thanks Guennadi people have tried to move to common clk and generic framework for a long time, now you still try to provide a v4l2 specific clock APIs, it just makes v4l2 unacceptable and much complex. 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 000..d7cc13e --- /dev/null +++ b/drivers/media/v4l2-core/v4l2-clk.c @@ -0,0 +1,177 @@ -barry -barry ___ linux-arm-kernel mailing list linux-arm-ker...@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH v8 1/7] media: V4L2: add temporary clock helpers
Hi, On 04/11/2013 08:52 PM, Mike Turquette wrote: [...] So, you enable CFF, it provides its own clk_* implementation like clk_get_rate() etc. Now, PXA already has it defined in arch/arm/mach-pxa/clock.c. Don't think this is going to fly. agree. Hi, I came into this thread late and don't have the actual patches in my inbox for review. That said, I don't understand why V4L2 cares about the clk framework *implementation*? The clk.h api is the same for platforms using the common struct clk and those still using the legacy method of defining their own struct clk. If drivers are only consumers of the clk.h api then the implementation underneath should not matter. I came to similar conclusions previously, but in case when one of the two drivers is the clock provider I think there is still an issue there. The drivers are supposed to be platform agnostic, but the clock provider would have to include mach specific declarations of struct clk, wouldn't it ? Regards, Sylwester -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH v8 1/7] media: V4L2: add temporary clock helpers
Hi Mike, On Thursday 11 April 2013 11:52:58 Mike Turquette wrote: Quoting Barry Song (2013-04-11 01:59:28) 2013/4/11 Guennadi Liakhovetski g.liakhovet...@gmx.de: On Thu, 11 Apr 2013, Barry Song wrote: 2013/4/11 Guennadi Liakhovetski g.liakhovet...@gmx.de: 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@xx --- 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. yes. we can. clock is only a framework, has it any limitation to implement a driver instance on any platform? So, you enable CFF, it provides its own clk_* implementation like clk_get_rate() etc. Now, PXA already has it defined in arch/arm/mach-pxa/clock.c. Don't think this is going to fly. agree. I came into this thread late and don't have the actual patches in my inbox for review. That said, I don't understand why V4L2 cares about the clk framework *implementation*? The clk.h api is the same for platforms using the common struct clk and those still using the legacy method of defining their own struct clk. If drivers are only consumers of the clk.h api then the implementation underneath should not matter. The issue on non-CCF systems is that devices usually can't register clocks dynamically. (Most of) those systems provide system clocks only through their clock API, without a way for the camera IP core to hook up the clock(s) it can provide to the camera sensor. On the consumer side we don't care much about the clock framework implementation, but on the provider side we need a framework that allows registering non-system clocks at runtime. -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH v8 1/7] media: V4L2: add temporary clock helpers
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@xx --- 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. 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 000..d7cc13e --- /dev/null +++ b/drivers/media/v4l2-core/v4l2-clk.c @@ -0,0 +1,177 @@ -barry -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
[PATCH v8 1/7] media: V4L2: add temporary clock helpers
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.liakhovet...@gmx.de
---
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 000..d7cc13e
--- /dev/null
+++ b/drivers/media/v4l2-core/v4l2-clk.c
@@ -0,0 +1,177 @@
+/*
+ * V4L2 clock service
+ *
+ * Copyright (C) 2012-2013, Guennadi Liakhovetski g.liakhovet...@gmx.de
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include linux/atomic.h
+#include linux/device.h
+#include linux/errno.h
+#include linux/list.h
+#include linux/module.h
+#include linux/mutex.h
+#include linux/slab.h
+#include linux/string.h
+
+#include media/v4l2-clk.h
+#include media/v4l2-subdev.h
+
+static DEFINE_MUTEX(clk_lock);
+static LIST_HEAD(clk_list);
+
+static struct v4l2_clk *v4l2_clk_find(const char *dev_id, const char *id)
+{
+ struct v4l2_clk *clk;
+
+ list_for_each_entry(clk, clk_list, list) {
+ if (strcmp(dev_id, clk-dev_id))
+ continue;
+
+ if (!id || !clk-id || !strcmp(clk-id, id))
+ return clk;
+ }
+
+ return ERR_PTR(-ENODEV);
+}
+
+struct v4l2_clk *v4l2_clk_get(struct device *dev, const char *id)
+{
+ struct v4l2_clk *clk;
+
+ mutex_lock(clk_lock);
+ clk = v4l2_clk_find(dev_name(dev), id);
+
+ if (!IS_ERR(clk) !try_module_get(clk-ops-owner))
+ clk = ERR_PTR(-ENODEV);
+ mutex_unlock(clk_lock);
+
+ if (!IS_ERR(clk))
+ atomic_inc(clk-use_count);
+
+ return clk;
+}
+EXPORT_SYMBOL(v4l2_clk_get);
+
+void v4l2_clk_put(struct v4l2_clk *clk)
+{
+ if (!IS_ERR(clk)) {
+ atomic_dec(clk-use_count);
+ module_put(clk-ops-owner);
+ }
+}
+EXPORT_SYMBOL(v4l2_clk_put);
+
+int v4l2_clk_enable(struct v4l2_clk *clk)
+{
+ int ret;
+ mutex_lock(clk-lock);
+ if (++clk-enable == 1 clk-ops-enable) {
+ ret = clk-ops-enable(clk);
+ if (ret 0)
+ clk-enable--;
+ } else {
+ ret = 0;
+ }
+ mutex_unlock(clk-lock);
+ return ret;
+}
+EXPORT_SYMBOL(v4l2_clk_enable);
+
+void v4l2_clk_disable(struct v4l2_clk *clk)
+{
+ int enable;
+
+ mutex_lock(clk-lock);
+ enable = --clk-enable;
+ if (WARN(enable 0, Unbalanced %s() on %s:%s!\n, __func__,
+clk-dev_id, clk-id))
+ clk-enable++;
+ else if (!enable clk-ops-disable)
+ clk-ops-disable(clk);
+ mutex_unlock(clk-lock);
+}
+EXPORT_SYMBOL(v4l2_clk_disable);
+
+unsigned long v4l2_clk_get_rate(struct v4l2_clk *clk)
+{
+ if (!clk-ops-get_rate)
+ return -ENOSYS;
+
+ return clk-ops-get_rate(clk);
+}
+EXPORT_SYMBOL(v4l2_clk_get_rate);
+
+int v4l2_clk_set_rate(struct v4l2_clk *clk, unsigned long rate)
+{
+ if (!clk-ops-set_rate)
+ return -ENOSYS;
+
+ return clk-ops-set_rate(clk, rate);
+}
+EXPORT_SYMBOL(v4l2_clk_set_rate);
+
+struct v4l2_clk *v4l2_clk_register(const struct v4l2_clk_ops *ops,
+ const char *dev_id,
+ const char *id, void *priv)
+{
+ struct v4l2_clk *clk;
+ int ret;
+
+ if (!ops || !dev_id)
+ return ERR_PTR(-EINVAL);
+
+ clk = kzalloc(sizeof(struct v4l2_clk), GFP_KERNEL);
+ if (!clk)
+
