| Message ID | 20200504092611.9798-31-laurent.pinchart@ideasonboard.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Drivers for the BCM283x CSI-2/CCP2 receiver and ISP | expand |
Hi Phil, Laurent, On Mon, 2020-05-04 at 12:26 +0300, Laurent Pinchart wrote: > From: Phil Elwell <phil@raspberrypi.com> > > vchiq kernel clients are now instantiated as platform drivers rather > than using DT, but the children of the vchiq interface may still > benefit from access to DT properties. Give them the option of a > a sub-node of the vchiq parent for configuration and to allow > them to be disabled. > > Signed-off-by: Phil Elwell <phil@raspberrypi.com> > Signed-off-by: Jacopo Mondi <jacopo@jmondi.org> > --- > .../staging/vc04_services/interface/vchiq_arm/vchiq_arm.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c > b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c > index dd3c8f829daa..2325ab825941 100644 > --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c > +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c > @@ -2734,12 +2734,20 @@ vchiq_register_child(struct platform_device *pdev, > const char *name) > pdevinfo.id = PLATFORM_DEVID_NONE; > pdevinfo.dma_mask = DMA_BIT_MASK(32); > > + np = of_get_child_by_name(pdev->dev.of_node, name); > + > + /* Skip the child if it is explicitly disabled */ > + if (np && !of_device_is_available(np)) > + return NULL; I think this is alright, although I'd reshufle the code a little so it looks nicer: + /* Skip the child if it is explicitly disabled */ + np = of_get_child_by_name(pdev->dev.of_node, name); + if (np && !of_device_is_available(np)) + return NULL; > child = platform_device_register_full(&pdevinfo); > if (IS_ERR(child)) { > dev_warn(&pdev->dev, "%s not registered\n", name); > child = NULL; > } > > + child->dev.of_node = np; Is this really needed? I'd rather have the parent's np (as commented in patch 26) as long as this is not a real device-tree defined platform device. Regards, Nicolas
Hi Nicolas, On 04/05/2020 18:12, Nicolas Saenz Julienne wrote: > Hi Phil, Laurent, > > On Mon, 2020-05-04 at 12:26 +0300, Laurent Pinchart wrote: >> From: Phil Elwell <phil@raspberrypi.com> >> >> vchiq kernel clients are now instantiated as platform drivers rather >> than using DT, but the children of the vchiq interface may still >> benefit from access to DT properties. Give them the option of a >> a sub-node of the vchiq parent for configuration and to allow >> them to be disabled. >> >> Signed-off-by: Phil Elwell <phil@raspberrypi.com> >> Signed-off-by: Jacopo Mondi <jacopo@jmondi.org> >> --- >> .../staging/vc04_services/interface/vchiq_arm/vchiq_arm.c | 8 ++++++++ >> 1 file changed, 8 insertions(+) >> >> diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c >> b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c >> index dd3c8f829daa..2325ab825941 100644 >> --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c >> +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c >> @@ -2734,12 +2734,20 @@ vchiq_register_child(struct platform_device *pdev, >> const char *name) >> pdevinfo.id = PLATFORM_DEVID_NONE; >> pdevinfo.dma_mask = DMA_BIT_MASK(32); >> >> + np = of_get_child_by_name(pdev->dev.of_node, name); >> + >> + /* Skip the child if it is explicitly disabled */ >> + if (np && !of_device_is_available(np)) >> + return NULL; > > I think this is alright, although I'd reshufle the code a little so it looks > nicer: > > + /* Skip the child if it is explicitly disabled */ > + np = of_get_child_by_name(pdev->dev.of_node, name); > + if (np && !of_device_is_available(np)) > + return NULL; I prefer the original. >> child = platform_device_register_full(&pdevinfo); >> if (IS_ERR(child)) { >> dev_warn(&pdev->dev, "%s not registered\n", name); >> child = NULL; >> } >> >> + child->dev.of_node = np; > > Is this really needed? I'd rather have the parent's np (as commented in patch > 26) as long as this is not a real device-tree defined platform device. Unless the of_node pointer refers to the sub-node for the child, all children would have to share a common set of properties, rather defeating the point of the change. Phil
On Mon, 2020-05-04 at 20:42 +0100, Phil Elwell wrote: > Hi Nicolas, > > On 04/05/2020 18:12, Nicolas Saenz Julienne wrote: > > Hi Phil, Laurent, > > > > On Mon, 2020-05-04 at 12:26 +0300, Laurent Pinchart wrote: > > > From: Phil Elwell <phil@raspberrypi.com> > > > > > > vchiq kernel clients are now instantiated as platform drivers rather > > > than using DT, but the children of the vchiq interface may still > > > benefit from access to DT properties. Give them the option of a > > > a sub-node of the vchiq parent for configuration and to allow > > > them to be disabled. > > > > > > Signed-off-by: Phil Elwell <phil@raspberrypi.com> > > > Signed-off-by: Jacopo Mondi <jacopo@jmondi.org> > > > --- > > > .../staging/vc04_services/interface/vchiq_arm/vchiq_arm.c | 8 ++++++++ > > > 1 file changed, 8 insertions(+) > > > > > > diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c > > > b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c > > > index dd3c8f829daa..2325ab825941 100644 > > > --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c > > > +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c > > > @@ -2734,12 +2734,20 @@ vchiq_register_child(struct platform_device *pdev, > > > const char *name) > > > pdevinfo.id = PLATFORM_DEVID_NONE; > > > pdevinfo.dma_mask = DMA_BIT_MASK(32); > > > > > > + np = of_get_child_by_name(pdev->dev.of_node, name); > > > + > > > + /* Skip the child if it is explicitly disabled */ > > > + if (np && !of_device_is_available(np)) > > > + return NULL; > > > > I think this is alright, although I'd reshufle the code a little so it looks > > nicer: > > > > + /* Skip the child if it is explicitly disabled */ > > + np = of_get_child_by_name(pdev->dev.of_node, name); > > + if (np && !of_device_is_available(np)) > > + return NULL; > > I prefer the original. Fair enough > > > child = platform_device_register_full(&pdevinfo); > > > if (IS_ERR(child)) { > > > dev_warn(&pdev->dev, "%s not registered\n", name); > > > child = NULL; > > > } > > > > > > + child->dev.of_node = np; > > > > Is this really needed? I'd rather have the parent's np (as commented in > > patch > > 26) as long as this is not a real device-tree defined platform device. > > Unless the of_node pointer refers to the sub-node for the child, all children > would have to share a common set of properties, rather defeating the point of > the > change. Sorry I wasn't clear, my main point is that, since manually editing device internals is bad a practice, specially after they have been registered (there are potential races with dma_configure()/probe()). I want to make sure we need it in the first place (i.e. I don't see any further usage of that device node). If we can get rid of this line, we're better-off. If we actually need the device node further down I propose two things: - Use dev.of_node_reused, and do an children lookup anytime you need to get a property. It's a one-liner in the end. - Move device registration to DT. There has been some push-back of this in the past, but IMO things like arm's SCMI already set a standard on what firmware devices can do trough DT and it fits this situation. Regards, Nicolas
Hi Nicolas, On Tue, 5 May 2020 at 11:37, Nicolas Saenz Julienne <nsaenzjulienne@suse.de> wrote: > > On Mon, 2020-05-04 at 20:42 +0100, Phil Elwell wrote: > > Hi Nicolas, > > > > On 04/05/2020 18:12, Nicolas Saenz Julienne wrote: > > > Hi Phil, Laurent, > > > > > > On Mon, 2020-05-04 at 12:26 +0300, Laurent Pinchart wrote: > > > > From: Phil Elwell <phil@raspberrypi.com> > > > > > > > > vchiq kernel clients are now instantiated as platform drivers rather > > > > than using DT, but the children of the vchiq interface may still > > > > benefit from access to DT properties. Give them the option of a > > > > a sub-node of the vchiq parent for configuration and to allow > > > > them to be disabled. > > > > > > > > Signed-off-by: Phil Elwell <phil@raspberrypi.com> > > > > Signed-off-by: Jacopo Mondi <jacopo@jmondi.org> > > > > --- > > > > .../staging/vc04_services/interface/vchiq_arm/vchiq_arm.c | 8 ++++++++ > > > > 1 file changed, 8 insertions(+) > > > > > > > > diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c > > > > b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c > > > > index dd3c8f829daa..2325ab825941 100644 > > > > --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c > > > > +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c > > > > @@ -2734,12 +2734,20 @@ vchiq_register_child(struct platform_device *pdev, > > > > const char *name) > > > > pdevinfo.id = PLATFORM_DEVID_NONE; > > > > pdevinfo.dma_mask = DMA_BIT_MASK(32); > > > > > > > > + np = of_get_child_by_name(pdev->dev.of_node, name); > > > > + > > > > + /* Skip the child if it is explicitly disabled */ > > > > + if (np && !of_device_is_available(np)) > > > > + return NULL; > > > > > > I think this is alright, although I'd reshufle the code a little so it looks > > > nicer: > > > > > > + /* Skip the child if it is explicitly disabled */ > > > + np = of_get_child_by_name(pdev->dev.of_node, name); > > > + if (np && !of_device_is_available(np)) > > > + return NULL; > > > > I prefer the original. > > Fair enough > > > > > child = platform_device_register_full(&pdevinfo); > > > > if (IS_ERR(child)) { > > > > dev_warn(&pdev->dev, "%s not registered\n", name); > > > > child = NULL; > > > > } > > > > > > > > + child->dev.of_node = np; > > > > > > Is this really needed? I'd rather have the parent's np (as commented in > > > patch > > > 26) as long as this is not a real device-tree defined platform device. > > > > Unless the of_node pointer refers to the sub-node for the child, all children > > would have to share a common set of properties, rather defeating the point of > > the > > change. > > Sorry I wasn't clear, my main point is that, since manually editing device > internals is bad a practice, specially after they have been registered (there > are potential races with dma_configure()/probe()). I want to make sure we need > it in the first place (i.e. I don't see any further usage of that device node). > > If we can get rid of this line, we're better-off. Thanks - that is much clearer. > If we actually need the device node further down I propose two things: > - Use dev.of_node_reused, and do an children lookup anytime you need to get a > property. It's a one-liner in the end. > - Move device registration to DT. There has been some push-back of this in the > past, but IMO things like arm's SCMI already set a standard on what firmware > devices can do trough DT and it fits this situation. I much prefer registration via DT - enumerating the children in code rather than data always felt like a baffling step backwards. Phil
diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c index dd3c8f829daa..2325ab825941 100644 --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c @@ -2734,12 +2734,20 @@ vchiq_register_child(struct platform_device *pdev, const char *name) pdevinfo.id = PLATFORM_DEVID_NONE; pdevinfo.dma_mask = DMA_BIT_MASK(32); + np = of_get_child_by_name(pdev->dev.of_node, name); + + /* Skip the child if it is explicitly disabled */ + if (np && !of_device_is_available(np)) + return NULL; + child = platform_device_register_full(&pdevinfo); if (IS_ERR(child)) { dev_warn(&pdev->dev, "%s not registered\n", name); child = NULL; } + child->dev.of_node = np; + /* * We want the dma-ranges etc to be copied from a device with the * correct dma-ranges for the VPU.