mbox series

[v11,0/5] staging: vc04_services: vchiq: Register devices with a custom bus_type

Message ID 20230913195354.835884-1-umang.jain@ideasonboard.com
Headers
Series staging: vc04_services: vchiq: Register devices with a custom bus_type |

Message

Umang Jain Sept. 13, 2023, 7:53 p.m. UTC 
  The patch series added a new bus type vchiq_bus_type and registers
child devices in order to move them away from using platform
device/driver.

Tested on RPi-3-b with media tree master branch.

Patch 1/5 and 2/5 adds a new bus_type and registers them to vchiq
interface

Patch 3/5 and 4/5 moves the bcm2835-camera and bcm2835-audio
to the new bus respectively

Patch 5/5 removes a platform registeration helper which is no
longer required.

Changes in v11:
- Move setting of DMA mask in child devices (3/5 and 4/5)
- Fixes "DMA mask not set issue" reported in v10.

Changes in v10:
- fix dma_attr WARN issue with bcm2835-audio module loading
- Unregister bus on parent platform device fails to register
- Reword commit to highlight bcm2835_audio to bcm2835-audio name change

Changes in v9:
- Fix module autoloading
- Implement bus_type's probe() callback to load drivers
- Implement bus_type's uevent() to make sure appropriate drivers are
  loaded when device are registed from vchiq.

Changes in v8:
- Drop dual licensing. Instead use GPL-2.0 only for patch 1/5

Changes in v7:
(5 out of 6 patches from v6 merged)
- Split the main patch (6/6) as requested.
- Use struct vchiq_device * instead of struct device * in
  all bus functions.
- Drop additional name attribute displayed in sysfs (redundant info)
- Document vchiq_interface doesn't enumerate device discovery
- remove EXPORT_SYMBOL_GPL(vchiq_bus_type)

Changes in v6:
- Split struct device and struct driver wrappers in vchiq_device.[ch]
- Move vchiq_bus_type definition to vchiq_device.[ch] as well
- return error on bus_register() failure
- drop dma_set_mask_and_coherent
- trivial variable name change

Changes in v5:
- Fixup missing "staging: " in commits' subject line
- No code changes from v4

Changes in v4:
- Introduce patches to drop include directives from Makefile

Changes in v3:
- Rework entirely to replace platform devices/driver model

-v2:
https://lore.kernel.org/all/20221222191500.515795-1-umang.jain@ideasonboard.com/

-v1:
https://lore.kernel.org/all/20221220084404.19280-1-umang.jain@ideasonboard.com/

Umang Jain (5):
  staging: vc04_services: vchiq_arm: Add new bus type and device type
  staging: vc04_services: vchiq_arm: Register vchiq_bus_type
  staging: bcm2835-camera: Register bcm2835-camera with vchiq_bus_type
  staging: bcm2835-audio: Register bcm2835-audio with vchiq_bus_type
  staging: vc04_services: vchiq_arm: Remove vchiq_register_child()

 drivers/staging/vc04_services/Makefile        |   1 +
 .../vc04_services/bcm2835-audio/bcm2835.c     |  29 +++--
 .../bcm2835-camera/bcm2835-camera.c           |  26 +++--
 .../interface/vchiq_arm/vchiq_arm.c           |  52 ++++-----
 .../interface/vchiq_arm/vchiq_device.c        | 104 ++++++++++++++++++
 .../interface/vchiq_arm/vchiq_device.h        |  54 +++++++++
 6 files changed, 219 insertions(+), 47 deletions(-)
 create mode 100644 drivers/staging/vc04_services/interface/vchiq_arm/vchiq_device.c
 create mode 100644 drivers/staging/vc04_services/interface/vchiq_arm/vchiq_device.h


base-commit: 0bb80ecc33a8fb5a682236443c1e740d5c917d1d

Comments

Dan Carpenter Sept. 14, 2023, 6:55 a.m. UTC | #1 
On Thu, Sep 14, 2023 at 01:23:50AM +0530, Umang Jain wrote:
> +static int vchiq_bus_type_match(struct device *dev, struct device_driver *drv)
> +{
> +	if (dev->bus == &vchiq_bus_type &&
> +	    strcmp(dev_name(dev), drv->name) == 0)
> +		return 1;
> +
> +	return 0;
> +}

I was not going to comment on this, because it's unfair to nitpick a
v11 patch...  But since you're going to have to redo it anyway, could
you make this function bool and change it to return true/false.

static bool vchiq_bus_type_match(struct device *dev, struct device_driver *drv)
{
	if (dev->bus == &vchiq_bus_type &&
	    strcmp(dev_name(dev), drv->name) == 0)
		return true;

	return false;
}

> +static int vchiq_bus_probe(struct device *dev)
> +{
> +	struct vchiq_device *device = to_vchiq_device(dev);
> +	struct vchiq_driver *driver = to_vchiq_driver(dev->driver);
> +	int ret;
> +
> +	ret = driver->probe(device);
> +	if (ret == 0)
> +		return 0;
> +
> +	return ret;

Ugh...  I was going to ignore this as well, but later there is a
checkpatch warning so then I decided nitpicking was ok.  Always do
error handling.  if (ret).  Never do success handling.  if (!ret).  But
here it can be done on one line.

	return driver->probe(device);

> +}
> +
> +struct bus_type vchiq_bus_type = {
> +	.name   = "vchiq-bus",
> +	.match  = vchiq_bus_type_match,
> +	.uevent = vchiq_bus_uevent,
> +	.probe  = vchiq_bus_probe,
> +};
> +
> +static void vchiq_device_release(struct device *dev)
> +{
> +	struct vchiq_device *device = to_vchiq_device(dev);
> +
> +	kfree(device);
> +}
> +
> +struct vchiq_device *
> +vchiq_device_register(struct device *parent, const char *name)
> +{
> +	struct vchiq_device *device;
> +	int ret;
> +
> +	device = kzalloc(sizeof(*device), GFP_KERNEL);
> +	if (!device) {
> +		dev_err(parent, "Cannot register %s: Insufficient memory\n",
> +			name);

Run checkpatch.pl -f on your files.

> +		return NULL;
> +	}

Stefan already commented on the other stuff I was going to say.

regards,
dan carpenter