[PATCH] [media] staging: allow omap4iss to be modular

Subsystems: arm port, media input infrastructure (v4l/dvb), omap2+ support, staging subsystem, the rest

STALE4468d

21 messages, 5 authors, 2014-06-13 · open the first message on its own page

[PATCH] [media] staging: allow omap4iss to be modular

From: Arnd Bergmann <arnd@arndb.de>
Date: 2014-06-11 14:36:21

The OMAP4 camera support depends on I2C and VIDEO_V4L2, both
of which can be loadable modules. This causes build failures
if we want the camera driver to be built-in.

This can be solved by turning the option into "tristate",
which unfortunately causes another problem, because the
driver incorrectly calls a platform-internal interface
for omap4_ctrl_pad_readl/omap4_ctrl_pad_writel.
To work around that, we can export those symbols, but
that isn't really the correct solution, as we should not
have dependencies on platform code this way.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
This is one of just two patches we currently need to get
'make allmodconfig' to build again on ARM.
diff --git a/arch/arm/mach-omap2/control.c b/arch/arm/mach-omap2/control.c
index 751f354..05d2d98 100644
--- a/arch/arm/mach-omap2/control.c
+++ b/arch/arm/mach-omap2/control.c
@@ -190,11 +190,13 @@ u32 omap4_ctrl_pad_readl(u16 offset)
 {
 	return readl_relaxed(OMAP4_CTRL_PAD_REGADDR(offset));
 }
+EXPORT_SYMBOL_GPL(omap4_ctrl_pad_readl);
 
 void omap4_ctrl_pad_writel(u32 val, u16 offset)
 {
 	writel_relaxed(val, OMAP4_CTRL_PAD_REGADDR(offset));
 }
+EXPORT_SYMBOL_GPL(omap4_ctrl_pad_writel);
 
 #ifdef CONFIG_ARCH_OMAP3
 
diff --git a/drivers/staging/media/omap4iss/Kconfig b/drivers/staging/media/omap4iss/Kconfig
index 78b0fba..0c3e3c1 100644
--- a/drivers/staging/media/omap4iss/Kconfig
+++ b/drivers/staging/media/omap4iss/Kconfig
@@ -1,5 +1,5 @@
 config VIDEO_OMAP4
-	bool "OMAP 4 Camera support"
+	tristate "OMAP 4 Camera support"
 	depends on VIDEO_V4L2 && VIDEO_V4L2_SUBDEV_API && I2C && ARCH_OMAP4
 	select VIDEOBUF2_DMA_CONTIG
 	---help---

Re: [PATCH] [media] staging: allow omap4iss to be modular

From: Nishanth Menon <nm@ti.com>
Date: 2014-06-11 14:42:42

On 06/11/2014 09:35 AM, Arnd Bergmann wrote:
quoted hunk
The OMAP4 camera support depends on I2C and VIDEO_V4L2, both
of which can be loadable modules. This causes build failures
if we want the camera driver to be built-in.

This can be solved by turning the option into "tristate",
which unfortunately causes another problem, because the
driver incorrectly calls a platform-internal interface
for omap4_ctrl_pad_readl/omap4_ctrl_pad_writel.
To work around that, we can export those symbols, but
that isn't really the correct solution, as we should not
have dependencies on platform code this way.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
This is one of just two patches we currently need to get
'make allmodconfig' to build again on ARM.
diff --git a/arch/arm/mach-omap2/control.c b/arch/arm/mach-omap2/control.c
index 751f354..05d2d98 100644
--- a/arch/arm/mach-omap2/control.c
+++ b/arch/arm/mach-omap2/control.c
@@ -190,11 +190,13 @@ u32 omap4_ctrl_pad_readl(u16 offset)
 {
 	return readl_relaxed(OMAP4_CTRL_PAD_REGADDR(offset));
 }
+EXPORT_SYMBOL_GPL(omap4_ctrl_pad_readl);
 
 void omap4_ctrl_pad_writel(u32 val, u16 offset)
 {
 	writel_relaxed(val, OMAP4_CTRL_PAD_REGADDR(offset));
 }
+EXPORT_SYMBOL_GPL(omap4_ctrl_pad_writel);
 
 #ifdef CONFIG_ARCH_OMAP3
 
diff --git a/drivers/staging/media/omap4iss/Kconfig b/drivers/staging/media/omap4iss/Kconfig
index 78b0fba..0c3e3c1 100644
--- a/drivers/staging/media/omap4iss/Kconfig
+++ b/drivers/staging/media/omap4iss/Kconfig
@@ -1,5 +1,5 @@
 config VIDEO_OMAP4
-	bool "OMAP 4 Camera support"
+	tristate "OMAP 4 Camera support"
 	depends on VIDEO_V4L2 && VIDEO_V4L2_SUBDEV_API && I2C && ARCH_OMAP4
 	select VIDEOBUF2_DMA_CONTIG
 	---help---

--
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This was discussed in detail here:
http://marc.info/?t=140198692500001&r=1&w=2
Direct dependency from a staging driver to mach-omap2 driver is not
something we'd like, right?

-- 
Regards,
Nishanth Menon

Re: [PATCH] [media] staging: allow omap4iss to be modular

From: Tony Lindgren <tony@atomide.com>
Date: 2014-06-11 14:48:04

* Arnd Bergmann [off-list ref] [140611 07:37]:
The OMAP4 camera support depends on I2C and VIDEO_V4L2, both
of which can be loadable modules. This causes build failures
if we want the camera driver to be built-in.
That's good news, but let's not fix it this way.
 
quoted hunk
This can be solved by turning the option into "tristate",
which unfortunately causes another problem, because the
driver incorrectly calls a platform-internal interface
for omap4_ctrl_pad_readl/omap4_ctrl_pad_writel.
To work around that, we can export those symbols, but
that isn't really the correct solution, as we should not
have dependencies on platform code this way.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
This is one of just two patches we currently need to get
'make allmodconfig' to build again on ARM.
diff --git a/arch/arm/mach-omap2/control.c b/arch/arm/mach-omap2/control.c
index 751f354..05d2d98 100644
--- a/arch/arm/mach-omap2/control.c
+++ b/arch/arm/mach-omap2/control.c
@@ -190,11 +190,13 @@ u32 omap4_ctrl_pad_readl(u16 offset)
 {
 	return readl_relaxed(OMAP4_CTRL_PAD_REGADDR(offset));
 }
+EXPORT_SYMBOL_GPL(omap4_ctrl_pad_readl);
 
 void omap4_ctrl_pad_writel(u32 val, u16 offset)
 {
 	writel_relaxed(val, OMAP4_CTRL_PAD_REGADDR(offset));
 }
+EXPORT_SYMBOL_GPL(omap4_ctrl_pad_writel);
 
 #ifdef CONFIG_ARCH_OMAP3
Exporting these will likely cause immediate misuse in other
drivers all over the place.

These should just use either pinctrl-single.c instead for muxing.
Or if they are not mux registers, we do have the syscon mapping
available in omap4.dtsi that pbias-regulator.c is already using.

Laurent, got any better ideas?

Regards,

Tony

Re: [PATCH] [media] staging: allow omap4iss to be modular

From: Arnd Bergmann <arnd@arndb.de>
Date: 2014-06-11 14:50:17

On Wednesday 11 June 2014 09:42:04 Nishanth Menon wrote:
On 06/11/2014 09:35 AM, Arnd Bergmann wrote:
quoted
The OMAP4 camera support depends on I2C and VIDEO_V4L2, both
of which can be loadable modules. This causes build failures
if we want the camera driver to be built-in.

This can be solved by turning the option into "tristate",
which unfortunately causes another problem, because the
driver incorrectly calls a platform-internal interface
for omap4_ctrl_pad_readl/omap4_ctrl_pad_writel.
To work around that, we can export those symbols, but
that isn't really the correct solution, as we should not
have dependencies on platform code this way.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
This is one of just two patches we currently need to get
'make allmodconfig' to build again on ARM.
diff --git a/arch/arm/mach-omap2/control.c b/arch/arm/mach-omap2/control.c
index 751f354..05d2d98 100644
--- a/arch/arm/mach-omap2/control.c
+++ b/arch/arm/mach-omap2/control.c
@@ -190,11 +190,13 @@ u32 omap4_ctrl_pad_readl(u16 offset)
 {
 	return readl_relaxed(OMAP4_CTRL_PAD_REGADDR(offset));
 }
+EXPORT_SYMBOL_GPL(omap4_ctrl_pad_readl);
 
 void omap4_ctrl_pad_writel(u32 val, u16 offset)
 {
 	writel_relaxed(val, OMAP4_CTRL_PAD_REGADDR(offset));
 }
+EXPORT_SYMBOL_GPL(omap4_ctrl_pad_writel);
 
 #ifdef CONFIG_ARCH_OMAP3
 
diff --git a/drivers/staging/media/omap4iss/Kconfig b/drivers/staging/media/omap4iss/Kconfig
index 78b0fba..0c3e3c1 100644
--- a/drivers/staging/media/omap4iss/Kconfig
+++ b/drivers/staging/media/omap4iss/Kconfig
@@ -1,5 +1,5 @@
 config VIDEO_OMAP4
-	bool "OMAP 4 Camera support"
+	tristate "OMAP 4 Camera support"
 	depends on VIDEO_V4L2 && VIDEO_V4L2_SUBDEV_API && I2C && ARCH_OMAP4
 	select VIDEOBUF2_DMA_CONTIG
 	---help---
This was discussed in detail here:
http://marc.info/?t=140198692500001&r=1&w=2
Direct dependency from a staging driver to mach-omap2 driver is not
something we'd like, right?
So it was decided to just leave ARM allmodconfig broken?

Why not at least do this instead?

8<----
From 3a965f4fd5a6b3ef4a66aa4e7c916cfd34fd5706 Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd@arndb.de>
Date: Tue, 21 Jan 2014 09:32:43 +0100
Subject: [PATCH] [media] staging: tighten omap4iss dependencies

The OMAP4 camera support depends on I2C and VIDEO_V4L2, both
of which can be loadable modules. This causes build failures
if we want the camera driver to be built-in.

This can be solved by turning the option into "tristate",
which unfortunately causes another problem, because the
driver incorrectly calls a platform-internal interface
for omap4_ctrl_pad_readl/omap4_ctrl_pad_writel.

Instead, this patch just forbids the invalid configurations
and ensures that the driver can only be built if all its
dependencies are built-in.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
diff --git a/drivers/staging/media/omap4iss/Kconfig b/drivers/staging/media/omap4iss/Kconfig
index 78b0fba..8afc6fe 100644
--- a/drivers/staging/media/omap4iss/Kconfig
+++ b/drivers/staging/media/omap4iss/Kconfig
@@ -1,6 +1,6 @@
 config VIDEO_OMAP4
 	bool "OMAP 4 Camera support"
-	depends on VIDEO_V4L2 && VIDEO_V4L2_SUBDEV_API && I2C && ARCH_OMAP4
+	depends on VIDEO_V4L2=y && VIDEO_V4L2_SUBDEV_API && I2C=y && ARCH_OMAP4
 	select VIDEOBUF2_DMA_CONTIG
 	---help---
 	  Driver for an OMAP 4 ISS controller.

Re: [PATCH] [media] staging: allow omap4iss to be modular

From: Nishanth Menon <nm@ti.com>
Date: 2014-06-11 14:54:09

On 06/11/2014 09:49 AM, Arnd Bergmann wrote:
quoted hunk
On Wednesday 11 June 2014 09:42:04 Nishanth Menon wrote:
quoted
On 06/11/2014 09:35 AM, Arnd Bergmann wrote:
quoted
The OMAP4 camera support depends on I2C and VIDEO_V4L2, both
of which can be loadable modules. This causes build failures
if we want the camera driver to be built-in.

This can be solved by turning the option into "tristate",
which unfortunately causes another problem, because the
driver incorrectly calls a platform-internal interface
for omap4_ctrl_pad_readl/omap4_ctrl_pad_writel.
To work around that, we can export those symbols, but
that isn't really the correct solution, as we should not
have dependencies on platform code this way.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
This is one of just two patches we currently need to get
'make allmodconfig' to build again on ARM.
diff --git a/arch/arm/mach-omap2/control.c b/arch/arm/mach-omap2/control.c
index 751f354..05d2d98 100644
--- a/arch/arm/mach-omap2/control.c
+++ b/arch/arm/mach-omap2/control.c
@@ -190,11 +190,13 @@ u32 omap4_ctrl_pad_readl(u16 offset)
 {
 	return readl_relaxed(OMAP4_CTRL_PAD_REGADDR(offset));
 }
+EXPORT_SYMBOL_GPL(omap4_ctrl_pad_readl);
 
 void omap4_ctrl_pad_writel(u32 val, u16 offset)
 {
 	writel_relaxed(val, OMAP4_CTRL_PAD_REGADDR(offset));
 }
+EXPORT_SYMBOL_GPL(omap4_ctrl_pad_writel);
 
 #ifdef CONFIG_ARCH_OMAP3
 
diff --git a/drivers/staging/media/omap4iss/Kconfig b/drivers/staging/media/omap4iss/Kconfig
index 78b0fba..0c3e3c1 100644
--- a/drivers/staging/media/omap4iss/Kconfig
+++ b/drivers/staging/media/omap4iss/Kconfig
@@ -1,5 +1,5 @@
 config VIDEO_OMAP4
-	bool "OMAP 4 Camera support"
+	tristate "OMAP 4 Camera support"
 	depends on VIDEO_V4L2 && VIDEO_V4L2_SUBDEV_API && I2C && ARCH_OMAP4
 	select VIDEOBUF2_DMA_CONTIG
 	---help---
This was discussed in detail here:
http://marc.info/?t=140198692500001&r=1&w=2
Direct dependency from a staging driver to mach-omap2 driver is not
something we'd like, right?
So it was decided to just leave ARM allmodconfig broken?

Why not at least do this instead?

8<----
From 3a965f4fd5a6b3ef4a66aa4e7c916cfd34fd5706 Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd@arndb.de>
Date: Tue, 21 Jan 2014 09:32:43 +0100
Subject: [PATCH] [media] staging: tighten omap4iss dependencies

The OMAP4 camera support depends on I2C and VIDEO_V4L2, both
of which can be loadable modules. This causes build failures
if we want the camera driver to be built-in.

This can be solved by turning the option into "tristate",
which unfortunately causes another problem, because the
driver incorrectly calls a platform-internal interface
for omap4_ctrl_pad_readl/omap4_ctrl_pad_writel.

Instead, this patch just forbids the invalid configurations
and ensures that the driver can only be built if all its
dependencies are built-in.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
diff --git a/drivers/staging/media/omap4iss/Kconfig b/drivers/staging/media/omap4iss/Kconfig
index 78b0fba..8afc6fe 100644
--- a/drivers/staging/media/omap4iss/Kconfig
+++ b/drivers/staging/media/omap4iss/Kconfig
@@ -1,6 +1,6 @@
 config VIDEO_OMAP4
 	bool "OMAP 4 Camera support"
-	depends on VIDEO_V4L2 && VIDEO_V4L2_SUBDEV_API && I2C && ARCH_OMAP4
+	depends on VIDEO_V4L2=y && VIDEO_V4L2_SUBDEV_API && I2C=y && ARCH_OMAP4
 	select VIDEOBUF2_DMA_CONTIG
 	---help---
 	  Driver for an OMAP 4 ISS controller.
I am ok with this if Tony and Laurent have no issues. Considering that
Laurent was working on coverting iss driver to dt, the detailed
discussion could take place at that point in time.

-- 
Regards,
Nishanth Menon

Re: [PATCH] [media] staging: allow omap4iss to be modular

From: Tony Lindgren <tony@atomide.com>
Date: 2014-06-11 15:02:42

* Arnd Bergmann [off-list ref] [140611 07:51]:
On Wednesday 11 June 2014 09:42:04 Nishanth Menon wrote:
quoted
On 06/11/2014 09:35 AM, Arnd Bergmann wrote:
quoted
The OMAP4 camera support depends on I2C and VIDEO_V4L2, both
of which can be loadable modules. This causes build failures
if we want the camera driver to be built-in.

This can be solved by turning the option into "tristate",
which unfortunately causes another problem, because the
driver incorrectly calls a platform-internal interface
for omap4_ctrl_pad_readl/omap4_ctrl_pad_writel.
To work around that, we can export those symbols, but
that isn't really the correct solution, as we should not
have dependencies on platform code this way.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
This is one of just two patches we currently need to get
'make allmodconfig' to build again on ARM.
diff --git a/arch/arm/mach-omap2/control.c b/arch/arm/mach-omap2/control.c
index 751f354..05d2d98 100644
--- a/arch/arm/mach-omap2/control.c
+++ b/arch/arm/mach-omap2/control.c
@@ -190,11 +190,13 @@ u32 omap4_ctrl_pad_readl(u16 offset)
 {
 	return readl_relaxed(OMAP4_CTRL_PAD_REGADDR(offset));
 }
+EXPORT_SYMBOL_GPL(omap4_ctrl_pad_readl);
 
 void omap4_ctrl_pad_writel(u32 val, u16 offset)
 {
 	writel_relaxed(val, OMAP4_CTRL_PAD_REGADDR(offset));
 }
+EXPORT_SYMBOL_GPL(omap4_ctrl_pad_writel);
 
 #ifdef CONFIG_ARCH_OMAP3
 
diff --git a/drivers/staging/media/omap4iss/Kconfig b/drivers/staging/media/omap4iss/Kconfig
index 78b0fba..0c3e3c1 100644
--- a/drivers/staging/media/omap4iss/Kconfig
+++ b/drivers/staging/media/omap4iss/Kconfig
@@ -1,5 +1,5 @@
 config VIDEO_OMAP4
-	bool "OMAP 4 Camera support"
+	tristate "OMAP 4 Camera support"
 	depends on VIDEO_V4L2 && VIDEO_V4L2_SUBDEV_API && I2C && ARCH_OMAP4
 	select VIDEOBUF2_DMA_CONTIG
 	---help---
This was discussed in detail here:
http://marc.info/?t=140198692500001&r=1&w=2
Direct dependency from a staging driver to mach-omap2 driver is not
something we'd like, right?
So it was decided to just leave ARM allmodconfig broken?

Why not at least do this instead?

8<----
From 3a965f4fd5a6b3ef4a66aa4e7c916cfd34fd5706 Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd@arndb.de>
Date: Tue, 21 Jan 2014 09:32:43 +0100
Subject: [PATCH] [media] staging: tighten omap4iss dependencies

The OMAP4 camera support depends on I2C and VIDEO_V4L2, both
of which can be loadable modules. This causes build failures
if we want the camera driver to be built-in.

This can be solved by turning the option into "tristate",
which unfortunately causes another problem, because the
driver incorrectly calls a platform-internal interface
for omap4_ctrl_pad_readl/omap4_ctrl_pad_writel.

Instead, this patch just forbids the invalid configurations
and ensures that the driver can only be built if all its
dependencies are built-in.
 
Makes sense to me if the media people are OK with this:

Acked-by: Tony Lindgren <tony@atomide.com>
quoted hunk
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
diff --git a/drivers/staging/media/omap4iss/Kconfig b/drivers/staging/media/omap4iss/Kconfig
index 78b0fba..8afc6fe 100644
--- a/drivers/staging/media/omap4iss/Kconfig
+++ b/drivers/staging/media/omap4iss/Kconfig
@@ -1,6 +1,6 @@
 config VIDEO_OMAP4
 	bool "OMAP 4 Camera support"
-	depends on VIDEO_V4L2 && VIDEO_V4L2_SUBDEV_API && I2C && ARCH_OMAP4
+	depends on VIDEO_V4L2=y && VIDEO_V4L2_SUBDEV_API && I2C=y && ARCH_OMAP4
 	select VIDEOBUF2_DMA_CONTIG
 	---help---
 	  Driver for an OMAP 4 ISS controller.

Re: [PATCH] [media] staging: allow omap4iss to be modular

From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Date: 2014-06-12 14:11:43

Hi Arnd,

On Wednesday 11 June 2014 16:49:31 Arnd Bergmann wrote:
On Wednesday 11 June 2014 09:42:04 Nishanth Menon wrote:
quoted
On 06/11/2014 09:35 AM, Arnd Bergmann wrote:
quoted
The OMAP4 camera support depends on I2C and VIDEO_V4L2, both
of which can be loadable modules. This causes build failures
if we want the camera driver to be built-in.

This can be solved by turning the option into "tristate",
which unfortunately causes another problem, because the
driver incorrectly calls a platform-internal interface
for omap4_ctrl_pad_readl/omap4_ctrl_pad_writel.
To work around that, we can export those symbols, but
that isn't really the correct solution, as we should not
have dependencies on platform code this way.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
This is one of just two patches we currently need to get
'make allmodconfig' to build again on ARM.
diff --git a/arch/arm/mach-omap2/control.c
b/arch/arm/mach-omap2/control.c
index 751f354..05d2d98 100644
--- a/arch/arm/mach-omap2/control.c
+++ b/arch/arm/mach-omap2/control.c
@@ -190,11 +190,13 @@ u32 omap4_ctrl_pad_readl(u16 offset)
 {
 	return readl_relaxed(OMAP4_CTRL_PAD_REGADDR(offset));
 }
+EXPORT_SYMBOL_GPL(omap4_ctrl_pad_readl);

 void omap4_ctrl_pad_writel(u32 val, u16 offset)
 {
 	writel_relaxed(val, OMAP4_CTRL_PAD_REGADDR(offset));
 }
+EXPORT_SYMBOL_GPL(omap4_ctrl_pad_writel);

 #ifdef CONFIG_ARCH_OMAP3
diff --git a/drivers/staging/media/omap4iss/Kconfig
b/drivers/staging/media/omap4iss/Kconfig index 78b0fba..0c3e3c1 100644
--- a/drivers/staging/media/omap4iss/Kconfig
+++ b/drivers/staging/media/omap4iss/Kconfig
@@ -1,5 +1,5 @@
 config VIDEO_OMAP4
-	bool "OMAP 4 Camera support"
+	tristate "OMAP 4 Camera support"
 	depends on VIDEO_V4L2 && VIDEO_V4L2_SUBDEV_API && I2C && ARCH_OMAP4
 	select VIDEOBUF2_DMA_CONTIG
 	---help---
This was discussed in detail here:
http://marc.info/?t=140198692500001&r=1&w=2
Direct dependency from a staging driver to mach-omap2 driver is not
something we'd like, right?
So it was decided to just leave ARM allmodconfig broken?

Why not at least do this instead?

8<----
From 3a965f4fd5a6b3ef4a66aa4e7c916cfd34fd5706 Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd@arndb.de>
Date: Tue, 21 Jan 2014 09:32:43 +0100
Subject: [PATCH] [media] staging: tighten omap4iss dependencies

The OMAP4 camera support depends on I2C and VIDEO_V4L2, both
of which can be loadable modules. This causes build failures
if we want the camera driver to be built-in.

This can be solved by turning the option into "tristate",
which unfortunately causes another problem, because the
driver incorrectly calls a platform-internal interface
for omap4_ctrl_pad_readl/omap4_ctrl_pad_writel.

Instead, this patch just forbids the invalid configurations
and ensures that the driver can only be built if all its
dependencies are built-in.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

Should I take this in my tree for v3.17 or would you like to fast-track it ?
quoted hunk
diff --git a/drivers/staging/media/omap4iss/Kconfig
b/drivers/staging/media/omap4iss/Kconfig index 78b0fba..8afc6fe 100644
--- a/drivers/staging/media/omap4iss/Kconfig
+++ b/drivers/staging/media/omap4iss/Kconfig
@@ -1,6 +1,6 @@
 config VIDEO_OMAP4
 	bool "OMAP 4 Camera support"
-	depends on VIDEO_V4L2 && VIDEO_V4L2_SUBDEV_API && I2C && ARCH_OMAP4
+	depends on VIDEO_V4L2=y && VIDEO_V4L2_SUBDEV_API && I2C=y && ARCH_OMAP4
 	select VIDEOBUF2_DMA_CONTIG
 	---help---
 	  Driver for an OMAP 4 ISS controller.
-- 
Regards,

Laurent Pinchart

Re: [PATCH] [media] staging: allow omap4iss to be modular

From: Arnd Bergmann <arnd@arndb.de>
Date: 2014-06-12 14:16:08

On Thursday 12 June 2014 16:12:17 Laurent Pinchart wrote:
quoted
From 3a965f4fd5a6b3ef4a66aa4e7c916cfd34fd5706 Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd@arndb.de>
Date: Tue, 21 Jan 2014 09:32:43 +0100
Subject: [PATCH] [media] staging: tighten omap4iss dependencies

The OMAP4 camera support depends on I2C and VIDEO_V4L2, both
of which can be loadable modules. This causes build failures
if we want the camera driver to be built-in.

This can be solved by turning the option into "tristate",
which unfortunately causes another problem, because the
driver incorrectly calls a platform-internal interface
for omap4_ctrl_pad_readl/omap4_ctrl_pad_writel.

Instead, this patch just forbids the invalid configurations
and ensures that the driver can only be built if all its
dependencies are built-in.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

Should I take this in my tree for v3.17 or would you like to fast-track it ?
I'd actually like to see it in 3.15 as a stable backport if possible,
but definitely in 3.16. What is the normal path for staging/media
but fix patches?

	Arnd

Re: [PATCH] [media] staging: allow omap4iss to be modular

From: Greg KH <gregkh@linuxfoundation.org>
Date: 2014-06-12 14:25:22

On Thu, Jun 12, 2014 at 04:15:32PM +0200, Arnd Bergmann wrote:
On Thursday 12 June 2014 16:12:17 Laurent Pinchart wrote:
quoted
quoted
From 3a965f4fd5a6b3ef4a66aa4e7c916cfd34fd5706 Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd@arndb.de>
Date: Tue, 21 Jan 2014 09:32:43 +0100
Subject: [PATCH] [media] staging: tighten omap4iss dependencies

The OMAP4 camera support depends on I2C and VIDEO_V4L2, both
of which can be loadable modules. This causes build failures
if we want the camera driver to be built-in.

This can be solved by turning the option into "tristate",
which unfortunately causes another problem, because the
driver incorrectly calls a platform-internal interface
for omap4_ctrl_pad_readl/omap4_ctrl_pad_writel.

Instead, this patch just forbids the invalid configurations
and ensures that the driver can only be built if all its
dependencies are built-in.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

Should I take this in my tree for v3.17 or would you like to fast-track it ?
I'd actually like to see it in 3.15 as a stable backport if possible,
It's not stable material, sorry.
but definitely in 3.16. What is the normal path for staging/media
but fix patches?
Through Mauro's tree.

greg k-h

Re: [PATCH] [media] staging: allow omap4iss to be modular

From: Arnd Bergmann <arnd@arndb.de>
Date: 2014-06-12 14:29:21

On Thursday 12 June 2014 07:25:15 Greg KH wrote:
On Thu, Jun 12, 2014 at 04:15:32PM +0200, Arnd Bergmann wrote:
quoted
On Thursday 12 June 2014 16:12:17 Laurent Pinchart wrote:
quoted
quoted
From 3a965f4fd5a6b3ef4a66aa4e7c916cfd34fd5706 Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd@arndb.de>
Date: Tue, 21 Jan 2014 09:32:43 +0100
Subject: [PATCH] [media] staging: tighten omap4iss dependencies

The OMAP4 camera support depends on I2C and VIDEO_V4L2, both
of which can be loadable modules. This causes build failures
if we want the camera driver to be built-in.

This can be solved by turning the option into "tristate",
which unfortunately causes another problem, because the
driver incorrectly calls a platform-internal interface
for omap4_ctrl_pad_readl/omap4_ctrl_pad_writel.

Instead, this patch just forbids the invalid configurations
and ensures that the driver can only be built if all its
dependencies are built-in.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

Should I take this in my tree for v3.17 or would you like to fast-track it ?
I'd actually like to see it in 3.15 as a stable backport if possible,
It's not stable material, sorry.
To clarify, I was talking about second version of the patch,
not the original one. It just does this:
 config VIDEO_OMAP4
      bool "OMAP 4 Camera support"
-     depends on VIDEO_V4L2 && VIDEO_V4L2_SUBDEV_API && I2C && ARCH_OMAP4
+     depends on VIDEO_V4L2=y && VIDEO_V4L2_SUBDEV_API && I2C=y && ARCH_OMAP4
      select VIDEOBUF2_DMA_CONTIG
      ---help---
        Driver for an OMAP 4 ISS controller.
which enforces that configurations that cannot be compiled
will not be selectable in Kconfig, so we can have allmodconfig
working. I thought that was ok for -stable.
quoted
but definitely in 3.16. What is the normal path for staging/media
but fix patches?
Through Mauro's tree.
Ok.

	Arnd

Re: [PATCH] [media] staging: allow omap4iss to be modular

From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Date: 2014-06-12 14:51:36

Hi Tony,

On Wednesday 11 June 2014 07:47:54 Tony Lindgren wrote:
* Arnd Bergmann [off-list ref] [140611 07:37]:
quoted
The OMAP4 camera support depends on I2C and VIDEO_V4L2, both
of which can be loadable modules. This causes build failures
if we want the camera driver to be built-in.
That's good news, but let's not fix it this way.
quoted
This can be solved by turning the option into "tristate",
which unfortunately causes another problem, because the
driver incorrectly calls a platform-internal interface
for omap4_ctrl_pad_readl/omap4_ctrl_pad_writel.
To work around that, we can export those symbols, but
that isn't really the correct solution, as we should not
have dependencies on platform code this way.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
This is one of just two patches we currently need to get
'make allmodconfig' to build again on ARM.
diff --git a/arch/arm/mach-omap2/control.c b/arch/arm/mach-omap2/control.c
index 751f354..05d2d98 100644
--- a/arch/arm/mach-omap2/control.c
+++ b/arch/arm/mach-omap2/control.c
@@ -190,11 +190,13 @@ u32 omap4_ctrl_pad_readl(u16 offset)
 {
 	return readl_relaxed(OMAP4_CTRL_PAD_REGADDR(offset));
 }
+EXPORT_SYMBOL_GPL(omap4_ctrl_pad_readl);

 void omap4_ctrl_pad_writel(u32 val, u16 offset)
 {
 	writel_relaxed(val, OMAP4_CTRL_PAD_REGADDR(offset));
 }
+EXPORT_SYMBOL_GPL(omap4_ctrl_pad_writel);

 #ifdef CONFIG_ARCH_OMAP3
Exporting these will likely cause immediate misuse in other
drivers all over the place.

These should just use either pinctrl-single.c instead for muxing.
Or if they are not mux registers, we do have the syscon mapping
available in omap4.dtsi that pbias-regulator.c is already using.

Laurent, got any better ideas?
The ISS driver needs to write a single register, which contains several 
independent fields. They thus need to be controlled by a single driver. Some 
of them might be considered to be related to pinmuxing (although I disagree on 
that), others are certainly not about muxing (there are clock gate bits for 
instance).

Using the syscon mapping seems like the best option. I'll give it a try.

-- 
Regards,

Laurent Pinchart

Re: [PATCH] [media] staging: allow omap4iss to be modular

From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Date: 2014-06-12 15:00:05

Hi Arnd,

On Thursday 12 June 2014 16:28:39 Arnd Bergmann wrote:
On Thursday 12 June 2014 07:25:15 Greg KH wrote:
quoted
On Thu, Jun 12, 2014 at 04:15:32PM +0200, Arnd Bergmann wrote:
quoted
On Thursday 12 June 2014 16:12:17 Laurent Pinchart wrote:
quoted
quoted
From 3a965f4fd5a6b3ef4a66aa4e7c916cfd34fd5706 Mon Sep 17 00:00:00
2001
From: Arnd Bergmann <arnd@arndb.de>
Date: Tue, 21 Jan 2014 09:32:43 +0100
Subject: [PATCH] [media] staging: tighten omap4iss dependencies

The OMAP4 camera support depends on I2C and VIDEO_V4L2, both
of which can be loadable modules. This causes build failures
if we want the camera driver to be built-in.

This can be solved by turning the option into "tristate",
which unfortunately causes another problem, because the
driver incorrectly calls a platform-internal interface
for omap4_ctrl_pad_readl/omap4_ctrl_pad_writel.

Instead, this patch just forbids the invalid configurations
and ensures that the driver can only be built if all its
dependencies are built-in.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

Should I take this in my tree for v3.17 or would you like to
fast-track it ?> > 
I'd actually like to see it in 3.15 as a stable backport if possible,
It's not stable material, sorry.
To clarify, I was talking about second version of the patch,
not the original one. It just does this:
quoted
 config VIDEO_OMAP4
      bool "OMAP 4 Camera support"
-     depends on VIDEO_V4L2 && VIDEO_V4L2_SUBDEV_API && I2C && ARCH_OMAP4
+     depends on VIDEO_V4L2=y && VIDEO_V4L2_SUBDEV_API && I2C=y &&
ARCH_OMAP4
      select VIDEOBUF2_DMA_CONTIG
      ---help---
        Driver for an OMAP 4 ISS controller.
which enforces that configurations that cannot be compiled
will not be selectable in Kconfig, so we can have allmodconfig
working. I thought that was ok for -stable.
quoted
quoted
but definitely in 3.16. What is the normal path for staging/media
but fix patches?
Through Mauro's tree.
Ok.
I've applied the patch to my tree and will send a pull request to Mauro for 
v3.16 as soon as you reach an agreement with Greg on whether I should add CC: 
stable or not.

-- 
Regards,

Laurent Pinchart

Re: [PATCH] [media] staging: allow omap4iss to be modular

From: Tony Lindgren <tony@atomide.com>
Date: 2014-06-12 15:15:42

* Laurent Pinchart [off-list ref] [140612 07:52]:
On Wednesday 11 June 2014 07:47:54 Tony Lindgren wrote:
quoted
These should just use either pinctrl-single.c instead for muxing.
Or if they are not mux registers, we do have the syscon mapping
available in omap4.dtsi that pbias-regulator.c is already using.

Laurent, got any better ideas?
The ISS driver needs to write a single register, which contains several 
independent fields. They thus need to be controlled by a single driver. Some 
of them might be considered to be related to pinmuxing (although I disagree on 
that), others are certainly not about muxing (there are clock gate bits for 
instance).

Using the syscon mapping seems like the best option. I'll give it a try.
OK if it's not strictly pinctrl related then let's not use
pinctrl-single,bits for it. You may be able to implement one or more
framework drivers for it for pinctrl/regulator/clock/transceiver
whatever that register is doing.

In any case it's best to have that handling in a separate helper driver
somewhere as it's a separate piece of hardware from the camera module.
If it does not fit into any existing frameworks then it's best to have
it in a separate driver with the camera driver.

Regards,

Tony

Re: [PATCH] [media] staging: allow omap4iss to be modular

From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Date: 2014-06-12 15:31:07

Hi Tony,

On Thursday 12 June 2014 08:15:35 Tony Lindgren wrote:
* Laurent Pinchart [off-list ref] [140612 07:52]:
quoted
On Wednesday 11 June 2014 07:47:54 Tony Lindgren wrote:
quoted
These should just use either pinctrl-single.c instead for muxing.
Or if they are not mux registers, we do have the syscon mapping
available in omap4.dtsi that pbias-regulator.c is already using.

Laurent, got any better ideas?
The ISS driver needs to write a single register, which contains several
independent fields. They thus need to be controlled by a single driver.
Some of them might be considered to be related to pinmuxing (although I
disagree on that), others are certainly not about muxing (there are clock
gate bits for instance).

Using the syscon mapping seems like the best option. I'll give it a try.
OK if it's not strictly pinctrl related then let's not use
pinctrl-single,bits for it. You may be able to implement one or more
framework drivers for it for pinctrl/regulator/clock/transceiver
whatever that register is doing.

In any case it's best to have that handling in a separate helper driver
somewhere as it's a separate piece of hardware from the camera module.
If it does not fit into any existing frameworks then it's best to have
it in a separate driver with the camera driver.
The register contains the following fields that control the two CSI2 PHYs 
(PHY1 and PHY2).

31    CAMERARX_CSI22_LANEENABLE2   PHY2 Lane 2 (CSI22_DX2, CSI22_DY2) Enable
30    CAMERARX_CSI22_LANEENABLE1   PHY2 Lane 1 (CSI22_DX1, CSI22_DY1) Enable
29    CAMERARX_CSI22_LANEENABLE0   PHY2 Lane 0 (CSI22_DX0, CSI22_DY0) Enable
28    CAMERARX_CSI21_LANEENABLE4   PHY1 Lane 4 (CSI21_DX4, CSI21_DY4) Enable
27    CAMERARX_CSI21_LANEENABLE3   PHY1 Lane 3 (CSI21_DX3, CSI21_DY3) Enable
26    CAMERARX_CSI21_LANEENABLE2   PHY1 Lane 2 (CSI21_DX2, CSI21_DY2) Enable
25    CAMERARX_CSI21_LANEENABLE1   PHY1 Lane 1 (CSI21_DX1, CSI21_DY1) Enable
24    CAMERARX_CSI21_LANEENABLE0   PHY1 Lane 0 (CSI21_DX0, CSI21_DY0) Enable
21    CAMERARX_CSI22_CTRLCLKEN     PHY2 Clock Enable
20:19 CAMERARX_CSI22_CAMMODE       PHY2 Mode (CCP2, CSI1, CSI2)
18    CAMERARX_CSI21_CTRLCLKEN     PHY1 Clock Enable
17:16 CAMERARX_CSI21_CAMMODE       PHY1 Mode (CCP2, CSI1, CSI2)

Bits 18 and 21 could be exposed through CCF. Bits 24 to 31 enable/disable the 
CSI2 lanes, so it could be argued that they could be exposed through the 
pinctrl framework. However, they need to be configured independently, possibly 
at runtime. I'm thus not sure pinctrl would be a good idea. Bits 17:16 and 
20:19 don't fit in existing frameworks.

Given that this register is specific to the ISS, I think handling it as a 
separate device through a separate driver would only complicate the 
implementation without any real benefit.

-- 
Regards,

Laurent Pinchart

Re: [PATCH] [media] staging: allow omap4iss to be modular

From: Greg KH <gregkh@linuxfoundation.org>
Date: 2014-06-12 15:55:12

On Thu, Jun 12, 2014 at 04:28:39PM +0200, Arnd Bergmann wrote:
On Thursday 12 June 2014 07:25:15 Greg KH wrote:
quoted
On Thu, Jun 12, 2014 at 04:15:32PM +0200, Arnd Bergmann wrote:
quoted
On Thursday 12 June 2014 16:12:17 Laurent Pinchart wrote:
quoted
quoted
From 3a965f4fd5a6b3ef4a66aa4e7c916cfd34fd5706 Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd@arndb.de>
Date: Tue, 21 Jan 2014 09:32:43 +0100
Subject: [PATCH] [media] staging: tighten omap4iss dependencies

The OMAP4 camera support depends on I2C and VIDEO_V4L2, both
of which can be loadable modules. This causes build failures
if we want the camera driver to be built-in.

This can be solved by turning the option into "tristate",
which unfortunately causes another problem, because the
driver incorrectly calls a platform-internal interface
for omap4_ctrl_pad_readl/omap4_ctrl_pad_writel.

Instead, this patch just forbids the invalid configurations
and ensures that the driver can only be built if all its
dependencies are built-in.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

Should I take this in my tree for v3.17 or would you like to fast-track it ?
I'd actually like to see it in 3.15 as a stable backport if possible,
It's not stable material, sorry.
To clarify, I was talking about second version of the patch,
not the original one. It just does this:
quoted
 config VIDEO_OMAP4
      bool "OMAP 4 Camera support"
-     depends on VIDEO_V4L2 && VIDEO_V4L2_SUBDEV_API && I2C && ARCH_OMAP4
+     depends on VIDEO_V4L2=y && VIDEO_V4L2_SUBDEV_API && I2C=y && ARCH_OMAP4
      select VIDEOBUF2_DMA_CONTIG
      ---help---
        Driver for an OMAP 4 ISS controller.
which enforces that configurations that cannot be compiled
will not be selectable in Kconfig, so we can have allmodconfig
working. I thought that was ok for -stable.
Ah, yes, that one works, sorry, I was thinking of the first one.

greg k-h

Re: [PATCH] [media] staging: allow omap4iss to be modular

From: Tony Lindgren <tony@atomide.com>
Date: 2014-06-13 05:30:51

* Laurent Pinchart [off-list ref] [140612 08:32]:
Hi Tony,

On Thursday 12 June 2014 08:15:35 Tony Lindgren wrote:
quoted
* Laurent Pinchart [off-list ref] [140612 07:52]:
quoted
On Wednesday 11 June 2014 07:47:54 Tony Lindgren wrote:
quoted
These should just use either pinctrl-single.c instead for muxing.
Or if they are not mux registers, we do have the syscon mapping
available in omap4.dtsi that pbias-regulator.c is already using.

Laurent, got any better ideas?
The ISS driver needs to write a single register, which contains several
independent fields. They thus need to be controlled by a single driver.
Some of them might be considered to be related to pinmuxing (although I
disagree on that), others are certainly not about muxing (there are clock
gate bits for instance).

Using the syscon mapping seems like the best option. I'll give it a try.
OK if it's not strictly pinctrl related then let's not use
pinctrl-single,bits for it. You may be able to implement one or more
framework drivers for it for pinctrl/regulator/clock/transceiver
whatever that register is doing.

In any case it's best to have that handling in a separate helper driver
somewhere as it's a separate piece of hardware from the camera module.
If it does not fit into any existing frameworks then it's best to have
it in a separate driver with the camera driver.
The register contains the following fields that control the two CSI2 PHYs 
(PHY1 and PHY2).

31    CAMERARX_CSI22_LANEENABLE2   PHY2 Lane 2 (CSI22_DX2, CSI22_DY2) Enable
30    CAMERARX_CSI22_LANEENABLE1   PHY2 Lane 1 (CSI22_DX1, CSI22_DY1) Enable
29    CAMERARX_CSI22_LANEENABLE0   PHY2 Lane 0 (CSI22_DX0, CSI22_DY0) Enable
28    CAMERARX_CSI21_LANEENABLE4   PHY1 Lane 4 (CSI21_DX4, CSI21_DY4) Enable
27    CAMERARX_CSI21_LANEENABLE3   PHY1 Lane 3 (CSI21_DX3, CSI21_DY3) Enable
26    CAMERARX_CSI21_LANEENABLE2   PHY1 Lane 2 (CSI21_DX2, CSI21_DY2) Enable
25    CAMERARX_CSI21_LANEENABLE1   PHY1 Lane 1 (CSI21_DX1, CSI21_DY1) Enable
24    CAMERARX_CSI21_LANEENABLE0   PHY1 Lane 0 (CSI21_DX0, CSI21_DY0) Enable
21    CAMERARX_CSI22_CTRLCLKEN     PHY2 Clock Enable
20:19 CAMERARX_CSI22_CAMMODE       PHY2 Mode (CCP2, CSI1, CSI2)
18    CAMERARX_CSI21_CTRLCLKEN     PHY1 Clock Enable
17:16 CAMERARX_CSI21_CAMMODE       PHY1 Mode (CCP2, CSI1, CSI2)

Bits 18 and 21 could be exposed through CCF. Bits 24 to 31 enable/disable the 
CSI2 lanes, so it could be argued that they could be exposed through the 
pinctrl framework. However, they need to be configured independently, possibly 
at runtime. I'm thus not sure pinctrl would be a good idea. Bits 17:16 and 
20:19 don't fit in existing frameworks.
OK thanks for the info. Sounds like drivers/phy might be the right location
for it then and then the phy driver can use the syscon regmap.
 
Given that this register is specific to the ISS, I think handling it as a 
separate device through a separate driver would only complicate the 
implementation without any real benefit.
Even though it's one register, it shoud still be treated separately from
the camera driver. The problems with keeping the register access to the
control module in the camera driver are at least following:

1. They live in separate hardware modules that can be clocked separately

2. Doing a read-back to flush a posted write in one hardware module most
   likely won't flush the write to other and that can lead into hard to
   find mysterious bugs

3. If we ever have a common system control module driver, we need to
   rewrite all the system control module register tinkering in the drivers

So it's best to try to use an existing framework for it. That avoids
tons of pain later on ;)

Regards,

Tony

Re: [PATCH] [media] staging: allow omap4iss to be modular

From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Date: 2014-06-13 06:47:00

Hi Tony,

On Thursday 12 June 2014 22:30:44 Tony Lindgren wrote:
* Laurent Pinchart [off-list ref] [140612 08:32]:
quoted
On Thursday 12 June 2014 08:15:35 Tony Lindgren wrote:
quoted
* Laurent Pinchart [off-list ref] [140612 07:52]:
quoted
On Wednesday 11 June 2014 07:47:54 Tony Lindgren wrote:
quoted
These should just use either pinctrl-single.c instead for muxing.
Or if they are not mux registers, we do have the syscon mapping
available in omap4.dtsi that pbias-regulator.c is already using.

Laurent, got any better ideas?
The ISS driver needs to write a single register, which contains
several independent fields. They thus need to be controlled by a
single driver. Some of them might be considered to be related to
pinmuxing (although I disagree on that), others are certainly not
about muxing (there are clock gate bits for instance).

Using the syscon mapping seems like the best option. I'll give it a
try.
OK if it's not strictly pinctrl related then let's not use
pinctrl-single,bits for it. You may be able to implement one or more
framework drivers for it for pinctrl/regulator/clock/transceiver
whatever that register is doing.

In any case it's best to have that handling in a separate helper driver
somewhere as it's a separate piece of hardware from the camera module.
If it does not fit into any existing frameworks then it's best to have
it in a separate driver with the camera driver.
The register contains the following fields that control the two CSI2 PHYs
(PHY1 and PHY2).

31    CAMERARX_CSI22_LANEENABLE2   PHY2 Lane 2 (CSI22_DX2, CSI22_DY2)
Enable
30    CAMERARX_CSI22_LANEENABLE1   PHY2 Lane 1 (CSI22_DX1, CSI22_DY1)
Enable
29    CAMERARX_CSI22_LANEENABLE0   PHY2 Lane 0 (CSI22_DX0, CSI22_DY0)
Enable
28    CAMERARX_CSI21_LANEENABLE4   PHY1 Lane 4 (CSI21_DX4, CSI21_DY4)
Enable
27    CAMERARX_CSI21_LANEENABLE3   PHY1 Lane 3 (CSI21_DX3, CSI21_DY3)
Enable
26    CAMERARX_CSI21_LANEENABLE2   PHY1 Lane 2 (CSI21_DX2, CSI21_DY2)
Enable
25    CAMERARX_CSI21_LANEENABLE1   PHY1 Lane 1 (CSI21_DX1, CSI21_DY1)
Enable
24    CAMERARX_CSI21_LANEENABLE0   PHY1 Lane 0 (CSI21_DX0, CSI21_DY0)
Enable
21    CAMERARX_CSI22_CTRLCLKEN     PHY2 Clock Enable
20:19 CAMERARX_CSI22_CAMMODE       PHY2 Mode (CCP2, CSI1, CSI2)
18    CAMERARX_CSI21_CTRLCLKEN     PHY1 Clock Enable
17:16 CAMERARX_CSI21_CAMMODE       PHY1 Mode (CCP2, CSI1, CSI2)

Bits 18 and 21 could be exposed through CCF. Bits 24 to 31 enable/disable
the CSI2 lanes, so it could be argued that they could be exposed through
the pinctrl framework. However, they need to be configured independently,
possibly at runtime. I'm thus not sure pinctrl would be a good idea. Bits
17:16 and 20:19 don't fit in existing frameworks.
OK thanks for the info. Sounds like drivers/phy might be the right location
for it then and then the phy driver can use the syscon regmap.
quoted
Given that this register is specific to the ISS, I think handling it as a
separate device through a separate driver would only complicate the
implementation without any real benefit.
Even though it's one register, it shoud still be treated separately from
the camera driver. The problems with keeping the register access to the
control module in the camera driver are at least following:

1. They live in separate hardware modules that can be clocked separately
Actually I don't think that's true. The CSI2 PHY is part of the camera device, 
with all its registers but the one above in the camera device register space. 
For some weird reason a couple of bits were pushed to the control module, but 
that doesn't make the CSI2 PHY itself a separate device.
2. Doing a read-back to flush a posted write in one hardware module most
   likely won't flush the write to other and that can lead into hard to
   find mysterious bugs
The OMAP4 ISS driver can just read back the CAMERA_RX register, can't it ?
3. If we ever have a common system control module driver, we need to
   rewrite all the system control module register tinkering in the drivers
Sure, but that's already the case today, as the OMAP4 ISS driver already 
accesses the control module register directly. I won't make that worse :-)
So it's best to try to use an existing framework for it. That avoids tons of
pain later on ;)
I agree, but I don't think the PHY framework would be the right abstraction. 
As explained above the CSI2 PHY is part of the OMAP4 ISS, so modeling its 
single control module register as a PHY would be a hack. 

-- 
Regards,

Laurent Pinchart

Re: [PATCH] [media] staging: allow omap4iss to be modular

From: Tony Lindgren <tony@atomide.com>
Date: 2014-06-13 07:53:34

* Laurent Pinchart [off-list ref] [140612 23:48]:
On Thursday 12 June 2014 22:30:44 Tony Lindgren wrote:
quoted
1. They live in separate hardware modules that can be clocked separately
Actually I don't think that's true. The CSI2 PHY is part of the camera device, 
with all its registers but the one above in the camera device register space. 
For some weird reason a couple of bits were pushed to the control module, but 
that doesn't make the CSI2 PHY itself a separate device.
Yes they are separate. Anything in the system control module is
a separate hardware module from the other devices. So in this case
the CSI2 PHY is part of the system control module, not the camera
module.
quoted
2. Doing a read-back to flush a posted write in one hardware module most
   likely won't flush the write to other and that can lead into hard to
   find mysterious bugs
The OMAP4 ISS driver can just read back the CAMERA_RX register, can't it ?
Right, but you would have to do readbacks both from the phy register and
camera register to ensure writes get written. It's best to keep the
logic completely separate especially considering that they can be
clocked separately.
quoted
3. If we ever have a common system control module driver, we need to
   rewrite all the system control module register tinkering in the drivers
Sure, but that's already the case today, as the OMAP4 ISS driver already 
accesses the control module register directly. I won't make that worse :-)
Well it's in staging for a reason :)
 
quoted
So it's best to try to use an existing framework for it. That avoids tons of
pain later on ;)
I agree, but I don't think the PHY framework would be the right abstraction. 
As explained above the CSI2 PHY is part of the OMAP4 ISS, so modeling its 
single control module register as a PHY would be a hack. 
Well that register belongs to the system control module, not the
camera module. It's not like the camera IO space is out of registers
or something! :)

We're already handling similar control module phy cases, see for
example drivers/phy/phy-omap-control.c. Maybe you have most of the
code already there?

Regards,

Tony

Re: [PATCH] [media] staging: allow omap4iss to be modular

From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Date: 2014-06-13 10:29:01

Hi Tony,

On Friday 13 June 2014 00:53:25 Tony Lindgren wrote:
* Laurent Pinchart [off-list ref] [140612 23:48]:
quoted
On Thursday 12 June 2014 22:30:44 Tony Lindgren wrote:
quoted
1. They live in separate hardware modules that can be clocked separately
Actually I don't think that's true. The CSI2 PHY is part of the camera
device, with all its registers but the one above in the camera device
register space. For some weird reason a couple of bits were pushed to the
control module, but that doesn't make the CSI2 PHY itself a separate
device.
Yes they are separate. Anything in the system control module is
a separate hardware module from the other devices. So in this case
the CSI2 PHY is part of the system control module, not the camera
module.
Section 8.2.3 ("ISS CSI2 PHY") of the OMAP4460 TRM (revision AA) documents the 
CSI2 PHY is being part of the ISS, with three PHY registers in the ISS 
register space (not counting the PHY interrupt and status bits in several 
other ISS registers) and one register in the system control module register 
space. It's far from clear which power domain(s) is (are) involved.
quoted
quoted
2. Doing a read-back to flush a posted write in one hardware module most
   likely won't flush the write to other and that can lead into hard to
   find mysterious bugs
The OMAP4 ISS driver can just read back the CAMERA_RX register, can't it ?
Right, but you would have to do readbacks both from the phy register and
camera register to ensure writes get written. It's best to keep the
logic completely separate especially considering that they can be
clocked separately.
quoted
quoted
3. If we ever have a common system control module driver, we need to
   rewrite all the system control module register tinkering in the
   drivers
Sure, but that's already the case today, as the OMAP4 ISS driver already
accesses the control module register directly. I won't make that worse :-)
Well it's in staging for a reason :)
quoted
quoted
So it's best to try to use an existing framework for it. That avoids
tons of pain later on ;)
I agree, but I don't think the PHY framework would be the right
abstraction. As explained above the CSI2 PHY is part of the OMAP4 ISS, so
modeling its single control module register as a PHY would be a hack.
Well that register belongs to the system control module, not the
camera module. It's not like the camera IO space is out of registers
or something! :)
The PHY has 3 registers in the ISS I/O space and one register in the control 
module I/O space. I have no idea why they've split it that way. The clock 
enable bits are especially "interested", the source clock (CAM_PHY_CTRL_FCLK) 
comes from the ISS as documented in section 8.1.1 ("ISS Integration"), is 
gated by the control module (the gated clock is called CTRLCLK) and then goes 
back to the ISS CSI2 PHY (it's mentioned in the CSI2 PHY "REGISTER1" 
documentation).
We're already handling similar control module phy cases, see for
example drivers/phy/phy-omap-control.c. Maybe you have most of the
code already there?
I'm afraid not. For PHYs that are in the system control module that solution 
is perfectly fine, but the CSI2 PHY isn't (or at least not all of it).

I would be fine with writing a separate PHY driver if the PHY was completely 
separate. As the documentation doesn't make it clear which part of the 
hardware belongs to which module, matching the software implementation with an 
unknown hardware implementation would be pretty difficult :-)

If you have a couple of minutes to spare and can look at the CSI2 PHY 
documentation in the TRM, you might be more successful than me figuring out 
how the hardware is implemented.

-- 
Regards,

Laurent Pinchart

Re: [PATCH] [media] staging: allow omap4iss to be modular

From: Tony Lindgren <tony@atomide.com>
Date: 2014-06-13 11:10:19

* Laurent Pinchart [off-list ref] [140613 03:30]:
Hi Tony,

On Friday 13 June 2014 00:53:25 Tony Lindgren wrote:
quoted
* Laurent Pinchart [off-list ref] [140612 23:48]:
quoted
On Thursday 12 June 2014 22:30:44 Tony Lindgren wrote:
quoted
1. They live in separate hardware modules that can be clocked separately
Actually I don't think that's true. The CSI2 PHY is part of the camera
device, with all its registers but the one above in the camera device
register space. For some weird reason a couple of bits were pushed to the
control module, but that doesn't make the CSI2 PHY itself a separate
device.
Yes they are separate. Anything in the system control module is
a separate hardware module from the other devices. So in this case
the CSI2 PHY is part of the system control module, not the camera
module.
Section 8.2.3 ("ISS CSI2 PHY") of the OMAP4460 TRM (revision AA) documents the 
CSI2 PHY is being part of the ISS, with three PHY registers in the ISS 
register space (not counting the PHY interrupt and status bits in several 
other ISS registers) and one register in the system control module register 
space. It's far from clear which power domain(s) is (are) involved.
OK I see. The register in the system control module just contains some
pin and clock related resources for the phy.
 
quoted
quoted
quoted
2. Doing a read-back to flush a posted write in one hardware module most
   likely won't flush the write to other and that can lead into hard to
   find mysterious bugs
The OMAP4 ISS driver can just read back the CAMERA_RX register, can't it ?
Right, but you would have to do readbacks both from the phy register and
camera register to ensure writes get written. It's best to keep the
logic completely separate especially considering that they can be
clocked separately.
quoted
quoted
3. If we ever have a common system control module driver, we need to
   rewrite all the system control module register tinkering in the
   drivers
Sure, but that's already the case today, as the OMAP4 ISS driver already
accesses the control module register directly. I won't make that worse :-)
Well it's in staging for a reason :)
quoted
quoted
So it's best to try to use an existing framework for it. That avoids
tons of pain later on ;)
I agree, but I don't think the PHY framework would be the right
abstraction. As explained above the CSI2 PHY is part of the OMAP4 ISS, so
modeling its single control module register as a PHY would be a hack.
Well that register belongs to the system control module, not the
camera module. It's not like the camera IO space is out of registers
or something! :)
The PHY has 3 registers in the ISS I/O space and one register in the control 
module I/O space. I have no idea why they've split it that way. The clock 
enable bits are especially "interested", the source clock (CAM_PHY_CTRL_FCLK) 
comes from the ISS as documented in section 8.1.1 ("ISS Integration"), is 
gated by the control module (the gated clock is called CTRLCLK) and then goes 
back to the ISS CSI2 PHY (it's mentioned in the CSI2 PHY "REGISTER1" 
documentation).
quoted
We're already handling similar control module phy cases, see for
example drivers/phy/phy-omap-control.c. Maybe you have most of the
code already there?
I'm afraid not. For PHYs that are in the system control module that solution 
is perfectly fine, but the CSI2 PHY isn't (or at least not all of it).

I would be fine with writing a separate PHY driver if the PHY was completely 
separate. As the documentation doesn't make it clear which part of the 
hardware belongs to which module, matching the software implementation with an 
unknown hardware implementation would be pretty difficult :-)
Yeah it seems the phy driver would still have to use the pin resources
in the system control module.
 
If you have a couple of minutes to spare and can look at the CSI2 PHY 
documentation in the TRM, you might be more successful than me figuring out 
how the hardware is implemented.
Took a look and it seems the phy is split into two parts. So probably
using the syscon mapping for the register in scm are is a good start.
At least then there's some protection from drivers tinkering directly
with the system control modules.

Maybe s	ee what drivers/regulator/pbias-regulator.c is doing with
syscon to see if that works? Moving that to some phy driver later on
should be trivial if needed :)

Regards,

Tony

Re: [PATCH] [media] staging: allow omap4iss to be modular

From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Date: 2014-06-13 13:16:28

Hi Tony,

On Friday 13 June 2014 04:10:12 Tony Lindgren wrote:
* Laurent Pinchart [off-list ref] [140613 03:30]:
quoted
On Friday 13 June 2014 00:53:25 Tony Lindgren wrote:
quoted
* Laurent Pinchart [off-list ref] [140612 23:48]:
quoted
On Thursday 12 June 2014 22:30:44 Tony Lindgren wrote:
quoted
1. They live in separate hardware modules that can be clocked
separately
Actually I don't think that's true. The CSI2 PHY is part of the camera
device, with all its registers but the one above in the camera device
register space. For some weird reason a couple of bits were pushed to
the control module, but that doesn't make the CSI2 PHY itself a
separate device.
Yes they are separate. Anything in the system control module is
a separate hardware module from the other devices. So in this case
the CSI2 PHY is part of the system control module, not the camera
module.
Section 8.2.3 ("ISS CSI2 PHY") of the OMAP4460 TRM (revision AA) documents
the CSI2 PHY is being part of the ISS, with three PHY registers in the
ISS register space (not counting the PHY interrupt and status bits in
several other ISS registers) and one register in the system control
module register space. It's far from clear which power domain(s) is (are)
involved.
OK I see. The register in the system control module just contains some
pin and clock related resources for the phy.
And the configuration of the PHY mode (CCP2, CSI1 or CSI2). It really seems 
like random bits :-)
quoted
quoted
quoted
quoted
2. Doing a read-back to flush a posted write in one hardware module
   most likely won't flush the write to other and that can lead into
   hard to find mysterious bugs
The OMAP4 ISS driver can just read back the CAMERA_RX register, can't
it ?
Right, but you would have to do readbacks both from the phy register and
camera register to ensure writes get written. It's best to keep the
logic completely separate especially considering that they can be
clocked separately.
quoted
quoted
3. If we ever have a common system control module driver, we need to
   rewrite all the system control module register tinkering in the
   drivers
Sure, but that's already the case today, as the OMAP4 ISS driver
already accesses the control module register directly. I won't make
that worse :-)
Well it's in staging for a reason :)
quoted
quoted
So it's best to try to use an existing framework for it. That avoids
tons of pain later on ;)
I agree, but I don't think the PHY framework would be the right
abstraction. As explained above the CSI2 PHY is part of the OMAP4 ISS,
so modeling its single control module register as a PHY would be a
hack.
Well that register belongs to the system control module, not the
camera module. It's not like the camera IO space is out of registers
or something! :)
The PHY has 3 registers in the ISS I/O space and one register in the
control module I/O space. I have no idea why they've split it that way.
The clock enable bits are especially "interested", the source clock
(CAM_PHY_CTRL_FCLK) comes from the ISS as documented in section 8.1.1
("ISS Integration"), is gated by the control module (the gated clock is
called CTRLCLK) and then goes back to the ISS CSI2 PHY (it's mentioned in
the CSI2 PHY "REGISTER1" documentation).
quoted
We're already handling similar control module phy cases, see for
example drivers/phy/phy-omap-control.c. Maybe you have most of the
code already there?
I'm afraid not. For PHYs that are in the system control module that
solution is perfectly fine, but the CSI2 PHY isn't (or at least not all
of it).

I would be fine with writing a separate PHY driver if the PHY was
completely separate. As the documentation doesn't make it clear which
part of the hardware belongs to which module, matching the software
implementation with an unknown hardware implementation would be pretty
difficult :-)
Yeah it seems the phy driver would still have to use the pin resources
in the system control module.
quoted
If you have a couple of minutes to spare and can look at the CSI2 PHY
documentation in the TRM, you might be more successful than me figuring
out how the hardware is implemented.
Took a look and it seems the phy is split into two parts. So probably
using the syscon mapping for the register in scm are is a good start.
At least then there's some protection from drivers tinkering directly
with the system control modules.
That's my plan.
Maybe s	ee what drivers/regulator/pbias-regulator.c is doing with
syscon to see if that works? Moving that to some phy driver later on
should be trivial if needed :)
I'll have a look, but I'm not sure whether the same approach will be possible.

-- 
Regards,

Laurent Pinchart
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