vchiq: Patch to separate platform and cdev code

Before this commit, vchiq cdev (/dev/vchiq) was always created during platform initialization. Introduce a new Kconfig option CONFIG_VCHIQ_CDEV which determines if the cdev will be created or not.

Signed-off-by Ojaswin Mujoo <[email protected]>

---
 drivers/staging/vc04_services/Kconfig                  | 10 ++++++++++
 drivers/staging/vc04_services/Makefile                 |  5 ++++-
 .../vc04_services/interface/vchiq_arm/vchiq_arm.h      |  9 +++++++++
 3 files changed, 23 insertions(+), 1 deletion(-)

drivers/staging/vc04_services/Kconfig +0 -0

index 4b886293f198..63caa6818d37 100644

Quoted 16 lines · Ojaswin Mujoo

Before this commit, vchiq cdev (/dev/vchiq) was always created during platform initialization. Introduce a new Kconfig option CONFIG_VCHIQ_CDEV which determines if the cdev will be created or not.

Signed-off-by Ojaswin Mujoo <[email protected]>

---
 drivers/staging/vc04_services/Kconfig                  | 10 ++++++++++
 drivers/staging/vc04_services/Makefile                 |  5 ++++-
 .../vc04_services/interface/vchiq_arm/vchiq_arm.h      |  9 +++++++++
 3 files changed, 23 insertions(+), 1 deletion(-)

drivers/staging/vc04_services/Kconfig +0 -0

index 4b886293f198..63caa6818d37 100644

drivers/staging/vc04_services/Kconfig config BCM2835_VCHIQ · line 28

Quoted 10 lines

drivers/staging/vc04_services/Kconfig +7 -0

@@ -19,6 +19,16 @@ config BCM2835_VCHIQ
 		Defaults to Y when the Broadcom Videocore services
 		are included in the build, N otherwise.
 
+if BCM2835_VCHIQ
+
+config VCHIQ_CDEV
+	bool "VCHIQ Character Driver"
+	help
+		Enable the creation of VCHIQ character driver to help
+		communicate with the Videocore platform.

I'll take this, but this really should say more about what this really is for. Who needs this? Why will I know if I want a character driver interface? What tools talk to this?

Or conversely, why would I want to turn this off?

Can you send a follow-on patch that makes this more descriptive?

thanks,

greg k-h

Hello,

This patchset adderesses the TODO item number 10 specified at:

drivers/staging/vc04-services/interface/TODO

For reference, the task is:

10) Reorganize file structure: Move char driver to it's own file and join both platform files

The cdev is defined alongside with the platform code in vchiq_arm.c. It would be nice to completely decouple it from the actual core code. For instance to be able to use bcm2835-audio without having /dev/vchiq created. One could argue it's better for security reasons or general cleanliness. It could even be interesting to create two different kernel modules, something the likes of vchiq-core.ko and vchiq-dev.ko. This would also ease the upstreaming process.

A summary of the patches is as follows:

- Patch 1: Move cdev init code into a function
- Patch 2: Shift some devlarations from vchiq_arm.c to vchiq_arm.h for sharing
- Patch 3: Move vchiq cdev init code from vchiq_arm.c into vchiq_dev.c
- Patch 4: Decouple cdev code by defining a Kconfig entry to allow optional compilation of it.
- Patch 5: Merge code in vchiq_2835_arm.c to vchiq_arm.c

Changes since v3 [2]:

* In Patch 5, replace forward declarations of some of the functions with function definition

Quoted 29 lines · Ojaswin Mujoo

Hello,

This patchset adderesses the TODO item number 10 specified at:

drivers/staging/vc04-services/interface/TODO

For reference, the task is:

10) Reorganize file structure: Move char driver to it's own file and join both platform files

The cdev is defined alongside with the platform code in vchiq_arm.c. It would be nice to completely decouple it from the actual core code. For instance to be able to use bcm2835-audio without having /dev/vchiq created. One could argue it's better for security reasons or general cleanliness. It could even be interesting to create two different kernel modules, something the likes of vchiq-core.ko and vchiq-dev.ko. This would also ease the upstreaming process.

A summary of the patches is as follows:

- Patch 1: Move cdev init code into a function
- Patch 2: Shift some devlarations from vchiq_arm.c to vchiq_arm.h for sharing
- Patch 3: Move vchiq cdev init code from vchiq_arm.c into vchiq_dev.c
- Patch 4: Decouple cdev code by defining a Kconfig entry to allow optional compilation of it.
- Patch 5: Merge code in vchiq_2835_arm.c to vchiq_arm.c

Quoted 4 lines

Changes since v3 [2]:

* In Patch 5, replace forward declarations of some of the functions with function definition

You dropped the reviews of others, so now I need to wait for them again :(

Quoted 34 lines · Ojaswin Mujoo

Quoted 33 lines

Hello,

This patchset adderesses the TODO item number 10 specified at:

drivers/staging/vc04-services/interface/TODO

For reference, the task is:

10) Reorganize file structure: Move char driver to it's own file and join both platform files

The cdev is defined alongside with the platform code in vchiq_arm.c. It would be nice to completely decouple it from the actual core code. For instance to be able to use bcm2835-audio without having /dev/vchiq created. One could argue it's better for security reasons or general cleanliness. It could even be interesting to create two different kernel modules, something the likes of vchiq-core.ko and vchiq-dev.ko. This would also ease the upstreaming process.

A summary of the patches is as follows:

- Patch 1: Move cdev init code into a function
- Patch 2: Shift some devlarations from vchiq_arm.c to vchiq_arm.h for sharing
- Patch 3: Move vchiq cdev init code from vchiq_arm.c into vchiq_dev.c
- Patch 4: Decouple cdev code by defining a Kconfig entry to allow optional compilation of it.
- Patch 5: Merge code in vchiq_2835_arm.c to vchiq_arm.c

Changes since v3 [2]:

* In Patch 5, replace forward declarations of some of the functions with function definition

Quoted 3 lines

You dropped the reviews of others, so now I need to wait for them again :(

Hello Greg,

Apologies for that, I was under the impression that a new version needed a separate review :(

If its okay, I can alternately resubmit this (as v5?) with Stefan's Reviewed-By tags on unchanged commits intact. Let me know if that's okay or if its better to wait out.

Thank you!
Ojaswin

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Am 23.07.21 um 14:59 schrieb Ojaswin Mujoo:

Quoted 35 lines · Greg KH

Quoted 34 lines · Ojaswin Mujoo

Quoted 33 lines

Hello,

This patchset adderesses the TODO item number 10 specified at:

drivers/staging/vc04-services/interface/TODO

For reference, the task is:

10) Reorganize file structure: Move char driver to it's own file and join both platform files

The cdev is defined alongside with the platform code in vchiq_arm.c. It would be nice to completely decouple it from the actual core code. For instance to be able to use bcm2835-audio without having /dev/vchiq created. One could argue it's better for security reasons or general cleanliness. It could even be interesting to create two different kernel modules, something the likes of vchiq-core.ko and vchiq-dev.ko. This would also ease the upstreaming process.

A summary of the patches is as follows:

- Patch 1: Move cdev init code into a function
- Patch 2: Shift some devlarations from vchiq_arm.c to vchiq_arm.h for sharing
- Patch 3: Move vchiq cdev init code from vchiq_arm.c into vchiq_dev.c
- Patch 4: Decouple cdev code by defining a Kconfig entry to allow optional compilation of it.
- Patch 5: Merge code in vchiq_2835_arm.c to vchiq_arm.c

Changes since v3 [2]:

* In Patch 5, replace forward declarations of some of the functions with function definition

Quoted 7 lines

Quoted 3 lines

You dropped the reviews of others, so now I need to wait for them again :(

Hello Greg,

Apologies for that, I was under the impression that a new version needed a separate review :(

No, just the patches which had functional changes.

Quoted 3 lines

If its okay, I can alternately resubmit this (as v5?) with Stefan's Reviewed-By tags on unchanged commits intact. Let me know if that's okay or if its better to wait out.

No, please don't resubmit. I will do the review soon.

Hello,

This patchset adderesses the TODO item number 10 specified at:

drivers/staging/vc04-services/interface/TODO

For reference, the task is:

10) Reorganize file structure: Move char driver to it's own file and join both platform files

The cdev is defined alongside with the platform code in vchiq_arm.c. It would be nice to completely decouple it from the actual core code. For instance to be able to use bcm2835-audio without having /dev/vchiq created. One could argue it's better for security reasons or general cleanliness. It could even be interesting to create two different kernel modules, something the likes of vchiq-core.ko and vchiq-dev.ko. This would also ease the upstreaming process.

A summary of the patches is as follows:

- Patch 1: Move cdev init code into a function
- Patch 2: Shift some devlarations from vchiq_arm.c to vchiq_arm.h for sharing
- Patch 3: Move vchiq cdev init code from vchiq_arm.c into vchiq_dev.c
- Patch 4: Decouple cdev code by defining a Kconfig entry to allow optional compilation of it.
- Patch 5: Merge code in vchiq_2835_arm.c to vchiq_arm.c

Changes since v3 [2]:

* In Patch 5, replace forward declarations of some of the functions with function definition