Re: [PATCH 01/15] drivers: phy: add generic PHY framework
On Sat, Jul 20, 2013 at 07:59:10PM -0700, Greg KH wrote: On Sat, Jul 20, 2013 at 10:32:26PM -0400, Alan Stern wrote: On Sat, 20 Jul 2013, Greg KH wrote: That should be passed using platform data. Ick, don't pass strings around, pass pointers. If you have platform data you can get to, then put the pointer there, don't use a name. I don't think I understood you here :-s We wont have phy pointer when we create the device for the controller no?(it'll be done in board file). Probably I'm missing something. Why will you not have that pointer? You can't rely on the name as the device id will not match up, so you should be able to rely on the pointer being in the structure that the board sets up, right? Don't use names, especially as ids can, and will, change, that is going to cause big problems. Use pointers, this is C, we are supposed to be doing that :) Kishon, I think what Greg means is this: The name you are using must be stored somewhere in a data structure constructed by the board file, right? Or at least, associated with some data structure somehow. Otherwise the platform code wouldn't know which PHY hardware corresponded to a particular name. Greg's suggestion is that you store the address of that data structure in the platform data instead of storing the name string. Have the consumer pass the data structure's address when it calls phy_create, instead of passing the name. Then you don't have to worry about two PHYs accidentally ending up with the same name or any other similar problems. Close, but the issue is that whatever returns from phy_create() should then be used, no need to call any find functions, as you can just use the pointer that phy_create() returns. Much like all other class api functions in the kernel work. I think the problem here is to connect two from the bus structure completely independent devices. Several frameworks (ASoC, soc-camera) had this problem and this wasn't solved until the advent of devicetrees and their phandles. phy_create might be called from the probe function of some i2c device (the phy device) and the resulting pointer is then needed in some other platform devices (the user of the phy) probe function. The best solution we have right now is implemented in the clk framework which uses a string matching of the device names in clk_get() (at least in the non-dt case). Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0| Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917- | ___ devicetree-discuss mailing list devicetree-discuss@lists.ozlabs.org https://lists.ozlabs.org/listinfo/devicetree-discuss
Re: [PATCH 01/15] drivers: phy: add generic PHY framework
Hi,
On Saturday 20 of July 2013 19:59:10 Greg KH wrote:
On Sat, Jul 20, 2013 at 10:32:26PM -0400, Alan Stern wrote:
On Sat, 20 Jul 2013, Greg KH wrote:
That should be passed using platform data.
Ick, don't pass strings around, pass pointers. If you have
platform
data you can get to, then put the pointer there, don't use a
name.
I don't think I understood you here :-s We wont have phy pointer
when we create the device for the controller no?(it'll be done in
board file). Probably I'm missing something.
Why will you not have that pointer? You can't rely on the name as
the device id will not match up, so you should be able to rely on
the pointer being in the structure that the board sets up, right?
Don't use names, especially as ids can, and will, change, that is
going
to cause big problems. Use pointers, this is C, we are supposed to
be
doing that :)
Kishon, I think what Greg means is this: The name you are using must
be stored somewhere in a data structure constructed by the board file,
right? Or at least, associated with some data structure somehow.
Otherwise the platform code wouldn't know which PHY hardware
corresponded to a particular name.
Greg's suggestion is that you store the address of that data structure
in the platform data instead of storing the name string. Have the
consumer pass the data structure's address when it calls phy_create,
instead of passing the name. Then you don't have to worry about two
PHYs accidentally ending up with the same name or any other similar
problems.
Close, but the issue is that whatever returns from phy_create() should
then be used, no need to call any find functions, as you can just use
the pointer that phy_create() returns. Much like all other class api
functions in the kernel work.
I think there is a confusion here about who registers the PHYs.
All platform code does is registering a platform/i2c/whatever device,
which causes a driver (located in drivers/phy/) to be instantiated. Such
drivers call phy_create(), usually in their probe() callbacks, so
platform_code has no way (and should have no way, for the sake of
layering) to get what phy_create() returns.
IMHO we need a lookup method for PHYs, just like for clocks, regulators,
PWMs or even i2c busses because there are complex cases when passing just
a name using platform data will not work. I would second what Stephen said
[1] and define a structure doing things in a DT-like way.
Example;
[platform code]
static const struct phy_lookup my_phy_lookup[] = {
PHY_LOOKUP(s3c-hsotg.0, otg, samsung-usbphy.1, phy.2),
/* etc... */
};
static void my_machine_init(void)
{
/* ... */
phy_register_lookup(my_phy_lookup, ARRAY_SIZE(my_phy_lookup));
/* ... */
}
/* Notice nothing stuffed in platform data. */
[provider code - samsung-usbphy driver]
static int samsung_usbphy_probe(...)
{
/* ... */
for (i = 0; i PHY_COUNT; ++i) {
usbphy-phy[i].name = phy;
usbphy-phy[i].id = i;
/* ... */
ret = phy_create(usbphy-phy);
/* err handling */
}
/* ... */
}
[consumer code - s3c-hsotg driver]
static int s3c_hsotg_probe(...)
{
/* ... */
phy = phy_get(pdev-dev, otg);
/* ... */
}
[1] http://thread.gmane.org/gmane.linux.ports.arm.kernel/252813
Best regards,
Tomasz
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Re: [PATCH 01/15] drivers: phy: add generic PHY framework
Hi,
On Sunday 21 July 2013 04:01 PM, Tomasz Figa wrote:
Hi,
On Saturday 20 of July 2013 19:59:10 Greg KH wrote:
On Sat, Jul 20, 2013 at 10:32:26PM -0400, Alan Stern wrote:
On Sat, 20 Jul 2013, Greg KH wrote:
That should be passed using platform data.
Ick, don't pass strings around, pass pointers. If you have
platform
data you can get to, then put the pointer there, don't use a
name.
I don't think I understood you here :-s We wont have phy pointer
when we create the device for the controller no?(it'll be done in
board file). Probably I'm missing something.
Why will you not have that pointer? You can't rely on the name as
the device id will not match up, so you should be able to rely on
the pointer being in the structure that the board sets up, right?
Don't use names, especially as ids can, and will, change, that is
going
to cause big problems. Use pointers, this is C, we are supposed to
be
doing that :)
Kishon, I think what Greg means is this: The name you are using must
be stored somewhere in a data structure constructed by the board file,
right? Or at least, associated with some data structure somehow.
Otherwise the platform code wouldn't know which PHY hardware
corresponded to a particular name.
Greg's suggestion is that you store the address of that data structure
in the platform data instead of storing the name string. Have the
consumer pass the data structure's address when it calls phy_create,
instead of passing the name. Then you don't have to worry about two
PHYs accidentally ending up with the same name or any other similar
problems.
Close, but the issue is that whatever returns from phy_create() should
then be used, no need to call any find functions, as you can just use
the pointer that phy_create() returns. Much like all other class api
functions in the kernel work.
I think there is a confusion here about who registers the PHYs.
All platform code does is registering a platform/i2c/whatever device,
which causes a driver (located in drivers/phy/) to be instantiated. Such
drivers call phy_create(), usually in their probe() callbacks, so
platform_code has no way (and should have no way, for the sake of
layering) to get what phy_create() returns.
right.
IMHO we need a lookup method for PHYs, just like for clocks, regulators,
PWMs or even i2c busses because there are complex cases when passing just
a name using platform data will not work. I would second what Stephen said
[1] and define a structure doing things in a DT-like way.
Example;
[platform code]
static const struct phy_lookup my_phy_lookup[] = {
PHY_LOOKUP(s3c-hsotg.0, otg, samsung-usbphy.1, phy.2),
The only problem here is that if *PLATFORM_DEVID_AUTO* is used while
creating the device, the ids in the device name would change and
PHY_LOOKUP wont be useful.
Thanks
Kishon
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Re: [PATCH 01/15] drivers: phy: add generic PHY framework
On Sunday 21 of July 2013 16:37:33 Kishon Vijay Abraham I wrote:
Hi,
On Sunday 21 July 2013 04:01 PM, Tomasz Figa wrote:
Hi,
On Saturday 20 of July 2013 19:59:10 Greg KH wrote:
On Sat, Jul 20, 2013 at 10:32:26PM -0400, Alan Stern wrote:
On Sat, 20 Jul 2013, Greg KH wrote:
That should be passed using platform data.
Ick, don't pass strings around, pass pointers. If you have
platform
data you can get to, then put the pointer there, don't use a
name.
I don't think I understood you here :-s We wont have phy pointer
when we create the device for the controller no?(it'll be done in
board file). Probably I'm missing something.
Why will you not have that pointer? You can't rely on the name
as
the device id will not match up, so you should be able to rely on
the pointer being in the structure that the board sets up, right?
Don't use names, especially as ids can, and will, change, that is
going
to cause big problems. Use pointers, this is C, we are supposed to
be
doing that :)
Kishon, I think what Greg means is this: The name you are using
must
be stored somewhere in a data structure constructed by the board
file,
right? Or at least, associated with some data structure somehow.
Otherwise the platform code wouldn't know which PHY hardware
corresponded to a particular name.
Greg's suggestion is that you store the address of that data
structure
in the platform data instead of storing the name string. Have the
consumer pass the data structure's address when it calls phy_create,
instead of passing the name. Then you don't have to worry about two
PHYs accidentally ending up with the same name or any other similar
problems.
Close, but the issue is that whatever returns from phy_create()
should
then be used, no need to call any find functions, as you can just
use
the pointer that phy_create() returns. Much like all other class api
functions in the kernel work.
I think there is a confusion here about who registers the PHYs.
All platform code does is registering a platform/i2c/whatever device,
which causes a driver (located in drivers/phy/) to be instantiated.
Such drivers call phy_create(), usually in their probe() callbacks,
so platform_code has no way (and should have no way, for the sake of
layering) to get what phy_create() returns.
right.
IMHO we need a lookup method for PHYs, just like for clocks,
regulators, PWMs or even i2c busses because there are complex cases
when passing just a name using platform data will not work. I would
second what Stephen said [1] and define a structure doing things in a
DT-like way.
Example;
[platform code]
static const struct phy_lookup my_phy_lookup[] = {
PHY_LOOKUP(s3c-hsotg.0, otg, samsung-usbphy.1, phy.2),
The only problem here is that if *PLATFORM_DEVID_AUTO* is used while
creating the device, the ids in the device name would change and
PHY_LOOKUP wont be useful.
I don't think this is a problem. All the existing lookup methods already
use ID to identify devices (see regulators, clkdev, PWMs, i2c, ...). You
can simply add a requirement that the ID must be assigned manually,
without using PLATFORM_DEVID_AUTO to use PHY lookup.
Best regards,
Tomasz
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Re: [PATCH 01/15] drivers: phy: add generic PHY framework
On Sun, Jul 21, 2013 at 01:12:07PM +0200, Tomasz Figa wrote:
On Sunday 21 of July 2013 16:37:33 Kishon Vijay Abraham I wrote:
Hi,
On Sunday 21 July 2013 04:01 PM, Tomasz Figa wrote:
Hi,
On Saturday 20 of July 2013 19:59:10 Greg KH wrote:
On Sat, Jul 20, 2013 at 10:32:26PM -0400, Alan Stern wrote:
On Sat, 20 Jul 2013, Greg KH wrote:
That should be passed using platform data.
Ick, don't pass strings around, pass pointers. If you have
platform
data you can get to, then put the pointer there, don't use a
name.
I don't think I understood you here :-s We wont have phy pointer
when we create the device for the controller no?(it'll be done in
board file). Probably I'm missing something.
Why will you not have that pointer? You can't rely on the name
as
the device id will not match up, so you should be able to rely on
the pointer being in the structure that the board sets up, right?
Don't use names, especially as ids can, and will, change, that is
going
to cause big problems. Use pointers, this is C, we are supposed to
be
doing that :)
Kishon, I think what Greg means is this: The name you are using
must
be stored somewhere in a data structure constructed by the board
file,
right? Or at least, associated with some data structure somehow.
Otherwise the platform code wouldn't know which PHY hardware
corresponded to a particular name.
Greg's suggestion is that you store the address of that data
structure
in the platform data instead of storing the name string. Have the
consumer pass the data structure's address when it calls phy_create,
instead of passing the name. Then you don't have to worry about two
PHYs accidentally ending up with the same name or any other similar
problems.
Close, but the issue is that whatever returns from phy_create()
should
then be used, no need to call any find functions, as you can just
use
the pointer that phy_create() returns. Much like all other class api
functions in the kernel work.
I think there is a confusion here about who registers the PHYs.
All platform code does is registering a platform/i2c/whatever device,
which causes a driver (located in drivers/phy/) to be instantiated.
Such drivers call phy_create(), usually in their probe() callbacks,
so platform_code has no way (and should have no way, for the sake of
layering) to get what phy_create() returns.
Why not put pointers in the platform data structure that can hold these
pointers? I thought that is why we created those structures in the
first place. If not, what are they there for?
IMHO we need a lookup method for PHYs, just like for clocks,
regulators, PWMs or even i2c busses because there are complex cases
when passing just a name using platform data will not work. I would
second what Stephen said [1] and define a structure doing things in a
DT-like way.
Example;
[platform code]
static const struct phy_lookup my_phy_lookup[] = {
PHY_LOOKUP(s3c-hsotg.0, otg, samsung-usbphy.1, phy.2),
The only problem here is that if *PLATFORM_DEVID_AUTO* is used while
creating the device, the ids in the device name would change and
PHY_LOOKUP wont be useful.
I don't think this is a problem. All the existing lookup methods already
use ID to identify devices (see regulators, clkdev, PWMs, i2c, ...). You
can simply add a requirement that the ID must be assigned manually,
without using PLATFORM_DEVID_AUTO to use PHY lookup.
And I'm saying that this idea, of using a specific name and id, is
frought with fragility and will break in the future in various ways when
devices get added to systems, making these strings constantly have to be
kept up to date with different board configurations.
People, NEVER, hardcode something like an id. The fact that this
happens today with the clock code, doesn't make it right, it makes the
clock code wrong. Others have already said that this is wrong there as
well, as systems change and dynamic ids get used more and more.
Let's not repeat the same mistakes of the past just because we refuse to
learn from them...
So again, the find a phy by a string functions should be removed, the
device id should be automatically created by the phy core just to make
things unique in sysfs, and no driver code should _ever_ be reliant on
the number that is being created, and the pointer to the phy structure
should be used everywhere instead.
With those types of changes, I will consider merging this subsystem, but
without them, sorry, I will not.
thanks,
greg k-h
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Re: [PATCH 01/15] drivers: phy: add generic PHY framework
On Sun, Jul 21, 2013 at 12:22:48PM +0200, Sascha Hauer wrote: On Sat, Jul 20, 2013 at 07:59:10PM -0700, Greg KH wrote: On Sat, Jul 20, 2013 at 10:32:26PM -0400, Alan Stern wrote: On Sat, 20 Jul 2013, Greg KH wrote: That should be passed using platform data. Ick, don't pass strings around, pass pointers. If you have platform data you can get to, then put the pointer there, don't use a name. I don't think I understood you here :-s We wont have phy pointer when we create the device for the controller no?(it'll be done in board file). Probably I'm missing something. Why will you not have that pointer? You can't rely on the name as the device id will not match up, so you should be able to rely on the pointer being in the structure that the board sets up, right? Don't use names, especially as ids can, and will, change, that is going to cause big problems. Use pointers, this is C, we are supposed to be doing that :) Kishon, I think what Greg means is this: The name you are using must be stored somewhere in a data structure constructed by the board file, right? Or at least, associated with some data structure somehow. Otherwise the platform code wouldn't know which PHY hardware corresponded to a particular name. Greg's suggestion is that you store the address of that data structure in the platform data instead of storing the name string. Have the consumer pass the data structure's address when it calls phy_create, instead of passing the name. Then you don't have to worry about two PHYs accidentally ending up with the same name or any other similar problems. Close, but the issue is that whatever returns from phy_create() should then be used, no need to call any find functions, as you can just use the pointer that phy_create() returns. Much like all other class api functions in the kernel work. I think the problem here is to connect two from the bus structure completely independent devices. Several frameworks (ASoC, soc-camera) had this problem and this wasn't solved until the advent of devicetrees and their phandles. phy_create might be called from the probe function of some i2c device (the phy device) and the resulting pointer is then needed in some other platform devices (the user of the phy) probe function. The best solution we have right now is implemented in the clk framework which uses a string matching of the device names in clk_get() (at least in the non-dt case). I would argue that clocks are wrong here as well, as others have already pointed out. What's wrong with the platform_data structure, why can't that be used for this? Or, if not, we can always add pointers to the platform device structure, or even the main 'struct device' as well, that's what it is there for. thanks, greg k-h ___ devicetree-discuss mailing list devicetree-discuss@lists.ozlabs.org https://lists.ozlabs.org/listinfo/devicetree-discuss
Re: [PATCH 01/15] drivers: phy: add generic PHY framework
On 07/21/2013 05:48 PM, Greg KH wrote: On Sun, Jul 21, 2013 at 12:22:48PM +0200, Sascha Hauer wrote: On Sat, Jul 20, 2013 at 07:59:10PM -0700, Greg KH wrote: On Sat, Jul 20, 2013 at 10:32:26PM -0400, Alan Stern wrote: On Sat, 20 Jul 2013, Greg KH wrote: That should be passed using platform data. Ick, don't pass strings around, pass pointers. If you have platform data you can get to, then put the pointer there, don't use a name. I don't think I understood you here :-s We wont have phy pointer when we create the device for the controller no?(it'll be done in board file). Probably I'm missing something. Why will you not have that pointer? You can't rely on the name as the device id will not match up, so you should be able to rely on the pointer being in the structure that the board sets up, right? Don't use names, especially as ids can, and will, change, that is going to cause big problems. Use pointers, this is C, we are supposed to be doing that :) Kishon, I think what Greg means is this: The name you are using must be stored somewhere in a data structure constructed by the board file, right? Or at least, associated with some data structure somehow. Otherwise the platform code wouldn't know which PHY hardware corresponded to a particular name. Greg's suggestion is that you store the address of that data structure in the platform data instead of storing the name string. Have the consumer pass the data structure's address when it calls phy_create, instead of passing the name. Then you don't have to worry about two PHYs accidentally ending up with the same name or any other similar problems. Close, but the issue is that whatever returns from phy_create() should then be used, no need to call any find functions, as you can just use the pointer that phy_create() returns. Much like all other class api functions in the kernel work. I think the problem here is to connect two from the bus structure completely independent devices. Several frameworks (ASoC, soc-camera) had this problem and this wasn't solved until the advent of devicetrees and their phandles. phy_create might be called from the probe function of some i2c device (the phy device) and the resulting pointer is then needed in some other platform devices (the user of the phy) probe function. The best solution we have right now is implemented in the clk framework which uses a string matching of the device names in clk_get() (at least in the non-dt case). I would argue that clocks are wrong here as well, as others have already pointed out. What's wrong with the platform_data structure, why can't that be used for this? At the point the platform data of some driver is initialized, e.g. in board setup code the PHY pointer is not known, since the PHY supplier driver has not initialized yet. Even though we wanted to pass pointer to a PHY through some notifier call, it would have been not clear which PHY user driver should match on such notifier. A single PHY supplier driver can create M PHY objects and this needs to be mapped to N PHY user drivers. This mapping needs to be defined somewhere by the system integrator. It works well with device tree, but except that there seems to be no other reliable infrastructure in the kernel to define links/dependencies between devices, since device identifiers are not known in advance in all cases. What Tomasz proposed seems currently most reasonable to me for non-dt. Or, if not, we can always add pointers to the platform device structure, or even the main 'struct device' as well, that's what it is there for. Still we would need to solve a problem which platform device structure gets which PHY pointer. -- Regards, Sylwester ___ devicetree-discuss mailing list devicetree-discuss@lists.ozlabs.org https://lists.ozlabs.org/listinfo/devicetree-discuss
Re: [PATCH 01/15] drivers: phy: add generic PHY framework
On Sun, 21 Jul 2013, Sylwester Nawrocki wrote: What's wrong with the platform_data structure, why can't that be used for this? At the point the platform data of some driver is initialized, e.g. in board setup code the PHY pointer is not known, since the PHY supplier driver has not initialized yet. Even though we wanted to pass pointer to a PHY through some notifier call, it would have been not clear which PHY user driver should match on such notifier. A single PHY supplier driver can create M PHY objects and this needs to be mapped to N PHY user drivers. This mapping needs to be defined somewhere by the system integrator. It works well with device tree, but except that there seems to be no other reliable infrastructure in the kernel to define links/dependencies between devices, since device identifiers are not known in advance in all cases. What Tomasz proposed seems currently most reasonable to me for non-dt. Or, if not, we can always add pointers to the platform device structure, or even the main 'struct device' as well, that's what it is there for. Still we would need to solve a problem which platform device structure gets which PHY pointer. Can you explain the issues in more detail? I don't fully understand the situation. Here's what I think I know: The PHY and the controller it is attached to are both physical devices. The connection between them is hardwired by the system manufacturer and cannot be changed by software. PHYs are generally described by fixed system-specific board files or by Device Tree information. Are they ever discovered dynamically? Is the same true for the controllers attached to the PHYs? If not -- if both a PHY and a controller are discovered dynamically -- how does the kernel know whether they are connected to each other? The kernel needs to know which controller is attached to which PHY. Currently this information is represented by name or ID strings embedded in platform data. The PHY's driver (the supplier) uses the platform data to construct a platform_device structure that represents the PHY. Until this is done, the controller's driver (the client) cannot use the PHY. Since there is no parent-child relation between the PHY and the controller, there is no guarantee that the PHY's driver will be ready when the controller's driver wants to use it. A deferred probe may be needed. The issue (or one of the issues) in this discussion is that Greg does not like the idea of using names or IDs to associate PHYs with controllers, because they are too prone to duplications or other errors. Pointers are more reliable. But pointers to what? Since the only data known to be available to both the PHY driver and controller driver is the platform data, the obvious answer is a pointer to platform data (either for the PHY or for the controller, or maybe both). Probably some of the details above are wrong; please indicate where I have gone astray. Also, I'm not clear about the role played by various APIs. For example, where does phy_create() fit into this picture? Alan Stern ___ devicetree-discuss mailing list devicetree-discuss@lists.ozlabs.org https://lists.ozlabs.org/listinfo/devicetree-discuss
Re: [PATCH 01/15] drivers: phy: add generic PHY framework
On Sat, Jul 20, 2013 at 08:49:32AM +0530, Kishon Vijay Abraham I wrote: Hi, On Saturday 20 July 2013 05:20 AM, Greg KH wrote: On Fri, Jul 19, 2013 at 12:06:01PM +0530, Kishon Vijay Abraham I wrote: Hi, On Friday 19 July 2013 11:59 AM, Greg KH wrote: On Fri, Jul 19, 2013 at 11:25:44AM +0530, Kishon Vijay Abraham I wrote: Hi, On Friday 19 July 2013 11:13 AM, Greg KH wrote: On Fri, Jul 19, 2013 at 11:07:10AM +0530, Kishon Vijay Abraham I wrote: + ret = dev_set_name(phy-dev, %s.%d, dev_name(dev), id); Your naming is odd, no phy anywhere in it? You rely on the sender to never send a duplicate name.id pair? Why not create your own ids based on the number of phys in the system, like almost all other classes and subsystems do? hmm.. some PHY drivers use the id they provide to perform some of their internal operation as in [1] (This is used only if a single PHY provider implements multiple PHYS). Probably I'll add an option like PLATFORM_DEVID_AUTO to give the PHY drivers an option to use auto id. [1] - http://archive.arm.linux.org.uk/lurker/message/20130628.134308.4a8f7668.ca.html No, who cares about the id? No one outside of the phy core ever should, because you pass back the only pointer that they really do care about, if they need to do anything with the device. Use that, and then you can hmm.. ok. rip out all of the search for a phy by a string logic, as that's not Actually this is needed for non-dt boot case. In the case of dt boot, we use a phandle by which the controller can get a reference to the phy. But in the case of non-dt boot, the controller can get a reference to the phy only by label. I don't understand. They registered the phy, and got back a pointer to it. Why can't they save it in their local structure to use it again later if needed? They should never have to ask for the device, as the One is a *PHY provider* driver which is a driver for some PHY device. This will use phy_create to create the phy. The other is a *PHY consumer* driver which might be any controller driver (can be USB/SATA/PCIE). The PHY consumer will use phy_get to get a reference to the phy (by *phandle* in the case of dt boot and *label* in the case of non-dt boot). device id might be unknown if there are multiple devices in the system. I agree with you on the device id part. That need not be known to the PHY driver. How does a consumer know which label to use in a non-dt system if there are multiple PHYs in the system? That should be passed using platform data. Ick, don't pass strings around, pass pointers. If you have platform data you can get to, then put the pointer there, don't use a name. I don't think I understood you here :-s We wont have phy pointer when we create the device for the controller no?(it'll be done in board file). Probably I'm missing something. Why will you not have that pointer? You can't rely on the name as the device id will not match up, so you should be able to rely on the pointer being in the structure that the board sets up, right? Don't use names, especially as ids can, and will, change, that is going to cause big problems. Use pointers, this is C, we are supposed to be doing that :) thanks, greg k-h ___ devicetree-discuss mailing list devicetree-discuss@lists.ozlabs.org https://lists.ozlabs.org/listinfo/devicetree-discuss
Re: [PATCH 01/15] drivers: phy: add generic PHY framework
On Sat, 20 Jul 2013, Greg KH wrote: That should be passed using platform data. Ick, don't pass strings around, pass pointers. If you have platform data you can get to, then put the pointer there, don't use a name. I don't think I understood you here :-s We wont have phy pointer when we create the device for the controller no?(it'll be done in board file). Probably I'm missing something. Why will you not have that pointer? You can't rely on the name as the device id will not match up, so you should be able to rely on the pointer being in the structure that the board sets up, right? Don't use names, especially as ids can, and will, change, that is going to cause big problems. Use pointers, this is C, we are supposed to be doing that :) Kishon, I think what Greg means is this: The name you are using must be stored somewhere in a data structure constructed by the board file, right? Or at least, associated with some data structure somehow. Otherwise the platform code wouldn't know which PHY hardware corresponded to a particular name. Greg's suggestion is that you store the address of that data structure in the platform data instead of storing the name string. Have the consumer pass the data structure's address when it calls phy_create, instead of passing the name. Then you don't have to worry about two PHYs accidentally ending up with the same name or any other similar problems. Alan Stern ___ devicetree-discuss mailing list devicetree-discuss@lists.ozlabs.org https://lists.ozlabs.org/listinfo/devicetree-discuss
Re: [PATCH 01/15] drivers: phy: add generic PHY framework
On Sat, Jul 20, 2013 at 10:32:26PM -0400, Alan Stern wrote: On Sat, 20 Jul 2013, Greg KH wrote: That should be passed using platform data. Ick, don't pass strings around, pass pointers. If you have platform data you can get to, then put the pointer there, don't use a name. I don't think I understood you here :-s We wont have phy pointer when we create the device for the controller no?(it'll be done in board file). Probably I'm missing something. Why will you not have that pointer? You can't rely on the name as the device id will not match up, so you should be able to rely on the pointer being in the structure that the board sets up, right? Don't use names, especially as ids can, and will, change, that is going to cause big problems. Use pointers, this is C, we are supposed to be doing that :) Kishon, I think what Greg means is this: The name you are using must be stored somewhere in a data structure constructed by the board file, right? Or at least, associated with some data structure somehow. Otherwise the platform code wouldn't know which PHY hardware corresponded to a particular name. Greg's suggestion is that you store the address of that data structure in the platform data instead of storing the name string. Have the consumer pass the data structure's address when it calls phy_create, instead of passing the name. Then you don't have to worry about two PHYs accidentally ending up with the same name or any other similar problems. Close, but the issue is that whatever returns from phy_create() should then be used, no need to call any find functions, as you can just use the pointer that phy_create() returns. Much like all other class api functions in the kernel work. thanks, greg k-h ___ devicetree-discuss mailing list devicetree-discuss@lists.ozlabs.org https://lists.ozlabs.org/listinfo/devicetree-discuss
Re: [PATCH 01/15] drivers: phy: add generic PHY framework
On Fri, Jul 19, 2013 at 11:25:44AM +0530, Kishon Vijay Abraham I wrote: Hi, On Friday 19 July 2013 11:13 AM, Greg KH wrote: On Fri, Jul 19, 2013 at 11:07:10AM +0530, Kishon Vijay Abraham I wrote: + ret = dev_set_name(phy-dev, %s.%d, dev_name(dev), id); Your naming is odd, no phy anywhere in it? You rely on the sender to never send a duplicate name.id pair? Why not create your own ids based on the number of phys in the system, like almost all other classes and subsystems do? hmm.. some PHY drivers use the id they provide to perform some of their internal operation as in [1] (This is used only if a single PHY provider implements multiple PHYS). Probably I'll add an option like PLATFORM_DEVID_AUTO to give the PHY drivers an option to use auto id. [1] - http://archive.arm.linux.org.uk/lurker/message/20130628.134308.4a8f7668.ca.html No, who cares about the id? No one outside of the phy core ever should, because you pass back the only pointer that they really do care about, if they need to do anything with the device. Use that, and then you can hmm.. ok. rip out all of the search for a phy by a string logic, as that's not Actually this is needed for non-dt boot case. In the case of dt boot, we use a phandle by which the controller can get a reference to the phy. But in the case of non-dt boot, the controller can get a reference to the phy only by label. I don't understand. They registered the phy, and got back a pointer to it. Why can't they save it in their local structure to use it again later if needed? They should never have to ask for the device, as the One is a *PHY provider* driver which is a driver for some PHY device. This will use phy_create to create the phy. The other is a *PHY consumer* driver which might be any controller driver (can be USB/SATA/PCIE). The PHY consumer will use phy_get to get a reference to the phy (by *phandle* in the case of dt boot and *label* in the case of non-dt boot). device id might be unknown if there are multiple devices in the system. I agree with you on the device id part. That need not be known to the PHY driver. How does a consumer know which label to use in a non-dt system if there are multiple PHYs in the system? Do you have any drivers that are non-dt using this yet? greg k-h ___ devicetree-discuss mailing list devicetree-discuss@lists.ozlabs.org https://lists.ozlabs.org/listinfo/devicetree-discuss
Re: [PATCH 01/15] drivers: phy: add generic PHY framework
Hi, On Friday 19 July 2013 11:59 AM, Greg KH wrote: On Fri, Jul 19, 2013 at 11:25:44AM +0530, Kishon Vijay Abraham I wrote: Hi, On Friday 19 July 2013 11:13 AM, Greg KH wrote: On Fri, Jul 19, 2013 at 11:07:10AM +0530, Kishon Vijay Abraham I wrote: + ret = dev_set_name(phy-dev, %s.%d, dev_name(dev), id); Your naming is odd, no phy anywhere in it? You rely on the sender to never send a duplicate name.id pair? Why not create your own ids based on the number of phys in the system, like almost all other classes and subsystems do? hmm.. some PHY drivers use the id they provide to perform some of their internal operation as in [1] (This is used only if a single PHY provider implements multiple PHYS). Probably I'll add an option like PLATFORM_DEVID_AUTO to give the PHY drivers an option to use auto id. [1] - http://archive.arm.linux.org.uk/lurker/message/20130628.134308.4a8f7668.ca.html No, who cares about the id? No one outside of the phy core ever should, because you pass back the only pointer that they really do care about, if they need to do anything with the device. Use that, and then you can hmm.. ok. rip out all of the search for a phy by a string logic, as that's not Actually this is needed for non-dt boot case. In the case of dt boot, we use a phandle by which the controller can get a reference to the phy. But in the case of non-dt boot, the controller can get a reference to the phy only by label. I don't understand. They registered the phy, and got back a pointer to it. Why can't they save it in their local structure to use it again later if needed? They should never have to ask for the device, as the One is a *PHY provider* driver which is a driver for some PHY device. This will use phy_create to create the phy. The other is a *PHY consumer* driver which might be any controller driver (can be USB/SATA/PCIE). The PHY consumer will use phy_get to get a reference to the phy (by *phandle* in the case of dt boot and *label* in the case of non-dt boot). device id might be unknown if there are multiple devices in the system. I agree with you on the device id part. That need not be known to the PHY driver. How does a consumer know which label to use in a non-dt system if there are multiple PHYs in the system? That should be passed using platform data. Do you have any drivers that are non-dt using this yet? yes. tw4030 (used in OMAP3) supports non-dt. [PATCH 04/15] ARM: OMAP: USB: Add phy binding information [PATCH 06/15] usb: musb: omap2430: use the new generic PHY framework of this patch series shows how it's used. Thanks Kishon ___ devicetree-discuss mailing list devicetree-discuss@lists.ozlabs.org https://lists.ozlabs.org/listinfo/devicetree-discuss
Re: [PATCH 01/15] drivers: phy: add generic PHY framework
On 07/19/2013 12:36 AM, Kishon Vijay Abraham I wrote: Hi, On Friday 19 July 2013 11:59 AM, Greg KH wrote: On Fri, Jul 19, 2013 at 11:25:44AM +0530, Kishon Vijay Abraham I wrote: Hi, On Friday 19 July 2013 11:13 AM, Greg KH wrote: On Fri, Jul 19, 2013 at 11:07:10AM +0530, Kishon Vijay Abraham I wrote: + ret = dev_set_name(phy-dev, %s.%d, dev_name(dev), id); Your naming is odd, no phy anywhere in it? You rely on the sender to never send a duplicate name.id pair? Why not create your own ids based on the number of phys in the system, like almost all other classes and subsystems do? hmm.. some PHY drivers use the id they provide to perform some of their internal operation as in [1] (This is used only if a single PHY provider implements multiple PHYS). Probably I'll add an option like PLATFORM_DEVID_AUTO to give the PHY drivers an option to use auto id. [1] - http://archive.arm.linux.org.uk/lurker/message/20130628.134308.4a8f7668.ca.html No, who cares about the id? No one outside of the phy core ever should, because you pass back the only pointer that they really do care about, if they need to do anything with the device. Use that, and then you can hmm.. ok. rip out all of the search for a phy by a string logic, as that's not Actually this is needed for non-dt boot case. In the case of dt boot, we use a phandle by which the controller can get a reference to the phy. But in the case of non-dt boot, the controller can get a reference to the phy only by label. I don't understand. They registered the phy, and got back a pointer to it. Why can't they save it in their local structure to use it again later if needed? They should never have to ask for the device, as the One is a *PHY provider* driver which is a driver for some PHY device. This will use phy_create to create the phy. The other is a *PHY consumer* driver which might be any controller driver (can be USB/SATA/PCIE). The PHY consumer will use phy_get to get a reference to the phy (by *phandle* in the case of dt boot and *label* in the case of non-dt boot). device id might be unknown if there are multiple devices in the system. I agree with you on the device id part. That need not be known to the PHY driver. How does a consumer know which label to use in a non-dt system if there are multiple PHYs in the system? That should be passed using platform data. I don't think that's right. That's just like passing clock names in platform data, which I believe is frowned upon. Instead, why not take the approach that e.g. regulators have taken? Each driver defines the names of the objects that it requires. There is a table (registered by a board file) that has lookup key (device name, regulator name), and the output is the regulator device (or global regulator name). This is almost the same way that DT works, except that in DT, the table is represented as properties in the DT. The DT binding defines the names of those properties, or the strings that must be in the foo-names properties, just like a driver in non-DT Linux is going to define the names it expects to be provided with. That way, you don't need platform data to define the names. ___ devicetree-discuss mailing list devicetree-discuss@lists.ozlabs.org https://lists.ozlabs.org/listinfo/devicetree-discuss
Re: [PATCH 01/15] drivers: phy: add generic PHY framework
On Fri, Jul 19, 2013 at 12:06:01PM +0530, Kishon Vijay Abraham I wrote: Hi, On Friday 19 July 2013 11:59 AM, Greg KH wrote: On Fri, Jul 19, 2013 at 11:25:44AM +0530, Kishon Vijay Abraham I wrote: Hi, On Friday 19 July 2013 11:13 AM, Greg KH wrote: On Fri, Jul 19, 2013 at 11:07:10AM +0530, Kishon Vijay Abraham I wrote: +ret = dev_set_name(phy-dev, %s.%d, dev_name(dev), id); Your naming is odd, no phy anywhere in it? You rely on the sender to never send a duplicate name.id pair? Why not create your own ids based on the number of phys in the system, like almost all other classes and subsystems do? hmm.. some PHY drivers use the id they provide to perform some of their internal operation as in [1] (This is used only if a single PHY provider implements multiple PHYS). Probably I'll add an option like PLATFORM_DEVID_AUTO to give the PHY drivers an option to use auto id. [1] - http://archive.arm.linux.org.uk/lurker/message/20130628.134308.4a8f7668.ca.html No, who cares about the id? No one outside of the phy core ever should, because you pass back the only pointer that they really do care about, if they need to do anything with the device. Use that, and then you can hmm.. ok. rip out all of the search for a phy by a string logic, as that's not Actually this is needed for non-dt boot case. In the case of dt boot, we use a phandle by which the controller can get a reference to the phy. But in the case of non-dt boot, the controller can get a reference to the phy only by label. I don't understand. They registered the phy, and got back a pointer to it. Why can't they save it in their local structure to use it again later if needed? They should never have to ask for the device, as the One is a *PHY provider* driver which is a driver for some PHY device. This will use phy_create to create the phy. The other is a *PHY consumer* driver which might be any controller driver (can be USB/SATA/PCIE). The PHY consumer will use phy_get to get a reference to the phy (by *phandle* in the case of dt boot and *label* in the case of non-dt boot). device id might be unknown if there are multiple devices in the system. I agree with you on the device id part. That need not be known to the PHY driver. How does a consumer know which label to use in a non-dt system if there are multiple PHYs in the system? That should be passed using platform data. Ick, don't pass strings around, pass pointers. If you have platform data you can get to, then put the pointer there, don't use a name. thanks, greg k-h ___ devicetree-discuss mailing list devicetree-discuss@lists.ozlabs.org https://lists.ozlabs.org/listinfo/devicetree-discuss
Re: [PATCH 01/15] drivers: phy: add generic PHY framework
Hi, On Friday 19 July 2013 09:24 PM, Stephen Warren wrote: On 07/19/2013 12:36 AM, Kishon Vijay Abraham I wrote: Hi, On Friday 19 July 2013 11:59 AM, Greg KH wrote: On Fri, Jul 19, 2013 at 11:25:44AM +0530, Kishon Vijay Abraham I wrote: Hi, On Friday 19 July 2013 11:13 AM, Greg KH wrote: On Fri, Jul 19, 2013 at 11:07:10AM +0530, Kishon Vijay Abraham I wrote: + ret = dev_set_name(phy-dev, %s.%d, dev_name(dev), id); Your naming is odd, no phy anywhere in it? You rely on the sender to never send a duplicate name.id pair? Why not create your own ids based on the number of phys in the system, like almost all other classes and subsystems do? hmm.. some PHY drivers use the id they provide to perform some of their internal operation as in [1] (This is used only if a single PHY provider implements multiple PHYS). Probably I'll add an option like PLATFORM_DEVID_AUTO to give the PHY drivers an option to use auto id. [1] - http://archive.arm.linux.org.uk/lurker/message/20130628.134308.4a8f7668.ca.html No, who cares about the id? No one outside of the phy core ever should, because you pass back the only pointer that they really do care about, if they need to do anything with the device. Use that, and then you can hmm.. ok. rip out all of the search for a phy by a string logic, as that's not Actually this is needed for non-dt boot case. In the case of dt boot, we use a phandle by which the controller can get a reference to the phy. But in the case of non-dt boot, the controller can get a reference to the phy only by label. I don't understand. They registered the phy, and got back a pointer to it. Why can't they save it in their local structure to use it again later if needed? They should never have to ask for the device, as the One is a *PHY provider* driver which is a driver for some PHY device. This will use phy_create to create the phy. The other is a *PHY consumer* driver which might be any controller driver (can be USB/SATA/PCIE). The PHY consumer will use phy_get to get a reference to the phy (by *phandle* in the case of dt boot and *label* in the case of non-dt boot). device id might be unknown if there are multiple devices in the system. I agree with you on the device id part. That need not be known to the PHY driver. How does a consumer know which label to use in a non-dt system if there are multiple PHYs in the system? That should be passed using platform data. I don't think that's right. That's just like passing clock names in platform data, which I believe is frowned upon. Instead, why not take the approach that e.g. regulators have taken? Each driver defines the names of the objects that it requires. There is a table (registered by a board file) that has lookup key (device name, We were using a similar approach with USB PHY layer but things started breaking after the device names are created using PLATFORM_DEVID_AUTO. Now theres no way to reliably know the device names in advance. Btw I had such device name binding in my v3 of this patch series [1] and had some discussion with Grant during that time [2]. [1] - http://archive.arm.linux.org.uk/lurker/message/20130320.091200.721a6fb5.hu.html [2] - https://lkml.org/lkml/2013/4/22/26 Thanks Kishon ___ devicetree-discuss mailing list devicetree-discuss@lists.ozlabs.org https://lists.ozlabs.org/listinfo/devicetree-discuss
Re: [PATCH 01/15] drivers: phy: add generic PHY framework
Hi, On Saturday 20 July 2013 05:20 AM, Greg KH wrote: On Fri, Jul 19, 2013 at 12:06:01PM +0530, Kishon Vijay Abraham I wrote: Hi, On Friday 19 July 2013 11:59 AM, Greg KH wrote: On Fri, Jul 19, 2013 at 11:25:44AM +0530, Kishon Vijay Abraham I wrote: Hi, On Friday 19 July 2013 11:13 AM, Greg KH wrote: On Fri, Jul 19, 2013 at 11:07:10AM +0530, Kishon Vijay Abraham I wrote: + ret = dev_set_name(phy-dev, %s.%d, dev_name(dev), id); Your naming is odd, no phy anywhere in it? You rely on the sender to never send a duplicate name.id pair? Why not create your own ids based on the number of phys in the system, like almost all other classes and subsystems do? hmm.. some PHY drivers use the id they provide to perform some of their internal operation as in [1] (This is used only if a single PHY provider implements multiple PHYS). Probably I'll add an option like PLATFORM_DEVID_AUTO to give the PHY drivers an option to use auto id. [1] - http://archive.arm.linux.org.uk/lurker/message/20130628.134308.4a8f7668.ca.html No, who cares about the id? No one outside of the phy core ever should, because you pass back the only pointer that they really do care about, if they need to do anything with the device. Use that, and then you can hmm.. ok. rip out all of the search for a phy by a string logic, as that's not Actually this is needed for non-dt boot case. In the case of dt boot, we use a phandle by which the controller can get a reference to the phy. But in the case of non-dt boot, the controller can get a reference to the phy only by label. I don't understand. They registered the phy, and got back a pointer to it. Why can't they save it in their local structure to use it again later if needed? They should never have to ask for the device, as the One is a *PHY provider* driver which is a driver for some PHY device. This will use phy_create to create the phy. The other is a *PHY consumer* driver which might be any controller driver (can be USB/SATA/PCIE). The PHY consumer will use phy_get to get a reference to the phy (by *phandle* in the case of dt boot and *label* in the case of non-dt boot). device id might be unknown if there are multiple devices in the system. I agree with you on the device id part. That need not be known to the PHY driver. How does a consumer know which label to use in a non-dt system if there are multiple PHYs in the system? That should be passed using platform data. Ick, don't pass strings around, pass pointers. If you have platform data you can get to, then put the pointer there, don't use a name. I don't think I understood you here :-s We wont have phy pointer when we create the device for the controller no?(it'll be done in board file). Probably I'm missing something. Thanks Kishon ___ devicetree-discuss mailing list devicetree-discuss@lists.ozlabs.org https://lists.ozlabs.org/listinfo/devicetree-discuss
Re: [PATCH 01/15] drivers: phy: add generic PHY framework
On Thu, Jul 18, 2013 at 12:16:10PM +0530, Kishon Vijay Abraham I wrote:
+struct phy_provider *__of_phy_provider_register(struct device *dev,
+ struct module *owner, struct phy * (*of_xlate)(struct device *dev,
+ struct of_phandle_args *args));
+struct phy_provider *__devm_of_phy_provider_register(struct device *dev,
+ struct module *owner, struct phy * (*of_xlate)(struct device *dev,
+ struct of_phandle_args *args))
+
+__of_phy_provider_register and __devm_of_phy_provider_register can be used to
+register the phy_provider and it takes device, owner and of_xlate as
+arguments. For the dt boot case, all PHY providers should use one of the
above
+2 APIs to register the PHY provider.
Why do you have __ for the prefix of a public function? Is that really
the way that OF handles this type of thing?
--- /dev/null
+++ b/drivers/phy/Kconfig
@@ -0,0 +1,13 @@
+#
+# PHY
+#
+
+menuconfig GENERIC_PHY
+ tristate PHY Subsystem
+ help
+ Generic PHY support.
+
+ This framework is designed to provide a generic interface for PHY
+ devices present in the kernel. This layer will have the generic
+ API by which phy drivers can create PHY using the phy framework and
+ phy users can obtain reference to the PHY.
Again, please reverse this. The drivers that use it should select it,
not depend on it, which will then enable this option. I will never know
if I need to enable it, and based on your follow-on patches, if I don't,
drivers that were working just fine, now disappeared from my build,
which isn't nice, and a pain to notice and fix up.
+/**
+ * phy_create() - create a new phy
+ * @dev: device that is creating the new phy
+ * @id: id of the phy
+ * @ops: function pointers for performing phy operations
+ * @label: label given to the phy
+ *
+ * Called to create a phy using phy framework.
+ */
+struct phy *phy_create(struct device *dev, u8 id, const struct phy_ops *ops,
+ const char *label)
+{
+ int ret;
+ struct phy *phy;
+
+ if (!dev) {
+ dev_WARN(dev, no device provided for PHY\n);
+ ret = -EINVAL;
+ goto err0;
+ }
+
+ phy = kzalloc(sizeof(*phy), GFP_KERNEL);
+ if (!phy) {
+ ret = -ENOMEM;
+ goto err0;
+ }
+
+ device_initialize(phy-dev);
+ mutex_init(phy-mutex);
+
+ phy-dev.class = phy_class;
+ phy-dev.parent = dev;
+ phy-dev.of_node = dev-of_node;
+ phy-id = id;
+ phy-ops = ops;
+ phy-label = kstrdup(label, GFP_KERNEL);
+
+ ret = dev_set_name(phy-dev, %s.%d, dev_name(dev), id);
Your naming is odd, no phy anywhere in it? You rely on the sender to
never send a duplicate name.id pair? Why not create your own ids based
on the number of phys in the system, like almost all other classes and
subsystems do?
+static inline int phy_pm_runtime_get(struct phy *phy)
+{
+ if (WARN(IS_ERR(phy), Invalid PHY reference\n))
+ return -EINVAL;
Why would phy ever not be valid and a error pointer? And why dump the
stack if that happens, that seems really extreme.
+
+ if (!pm_runtime_enabled(phy-dev))
+ return -ENOTSUPP;
+
+ return pm_runtime_get(phy-dev);
+}
This, and the other inline functions in this .h file seem huge, why are
they inline and not in the .c file? There's no speed issues, and it
should save space overall in the .c file. Please move them.
+static inline int phy_init(struct phy *phy)
+{
+ int ret;
+
+ ret = phy_pm_runtime_get_sync(phy);
+ if (ret 0 ret != -ENOTSUPP)
+ return ret;
+
+ mutex_lock(phy-mutex);
+ if (phy-init_count++ == 0 phy-ops-init) {
+ ret = phy-ops-init(phy);
+ if (ret 0) {
+ dev_err(phy-dev, phy init failed -- %d\n, ret);
+ goto out;
+ }
+ }
+
+out:
+ mutex_unlock(phy-mutex);
+ phy_pm_runtime_put(phy);
+ return ret;
+}
+
+static inline int phy_exit(struct phy *phy)
+{
+ int ret;
+
+ ret = phy_pm_runtime_get_sync(phy);
+ if (ret 0 ret != -ENOTSUPP)
+ return ret;
+
+ mutex_lock(phy-mutex);
+ if (--phy-init_count == 0 phy-ops-exit) {
+ ret = phy-ops-exit(phy);
+ if (ret 0) {
+ dev_err(phy-dev, phy exit failed -- %d\n, ret);
+ goto out;
+ }
+ }
+
+out:
+ mutex_unlock(phy-mutex);
+ phy_pm_runtime_put(phy);
+ return ret;
+}
+
+static inline int phy_power_on(struct phy *phy)
+{
+ int ret = -ENOTSUPP;
+
+ ret = phy_pm_runtime_get_sync(phy);
+ if (ret 0 ret != -ENOTSUPP)
+ return ret;
+
+ mutex_lock(phy-mutex);
+ if (phy-power_count++ == 0 phy-ops-power_on) {
+ ret = phy-ops-power_on(phy);
+ if (ret 0) {
+ dev_err(phy-dev, phy
Re: [PATCH 01/15] drivers: phy: add generic PHY framework
Hi,
On Thursday 18 July 2013 12:50 PM, Greg KH wrote:
On Thu, Jul 18, 2013 at 12:16:10PM +0530, Kishon Vijay Abraham I wrote:
+struct phy_provider *__of_phy_provider_register(struct device *dev,
+struct module *owner, struct phy * (*of_xlate)(struct device *dev,
+struct of_phandle_args *args));
+struct phy_provider *__devm_of_phy_provider_register(struct device *dev,
+struct module *owner, struct phy * (*of_xlate)(struct device *dev,
+struct of_phandle_args *args))
+
+__of_phy_provider_register and __devm_of_phy_provider_register can be used
to
+register the phy_provider and it takes device, owner and of_xlate as
+arguments. For the dt boot case, all PHY providers should use one of the
above
+2 APIs to register the PHY provider.
Why do you have __ for the prefix of a public function? Is that really
the way that OF handles this type of thing?
I have a macro of_phy_provider_register/devm_of_phy_provider_register that
calls these functions and should be used by the PHY drivers. Probably I should
make a mention of it in the Documentation.
--- /dev/null
+++ b/drivers/phy/Kconfig
@@ -0,0 +1,13 @@
+#
+# PHY
+#
+
+menuconfig GENERIC_PHY
+tristate PHY Subsystem
+help
+ Generic PHY support.
+
+ This framework is designed to provide a generic interface for PHY
+ devices present in the kernel. This layer will have the generic
+ API by which phy drivers can create PHY using the phy framework and
+ phy users can obtain reference to the PHY.
Again, please reverse this. The drivers that use it should select it,
not depend on it, which will then enable this option. I will never know
if I need to enable it, and based on your follow-on patches, if I don't,
drivers that were working just fine, now disappeared from my build,
which isn't nice, and a pain to notice and fix up.
ok.
+/**
+ * phy_create() - create a new phy
+ * @dev: device that is creating the new phy
+ * @id: id of the phy
+ * @ops: function pointers for performing phy operations
+ * @label: label given to the phy
+ *
+ * Called to create a phy using phy framework.
+ */
+struct phy *phy_create(struct device *dev, u8 id, const struct phy_ops *ops,
+const char *label)
+{
+int ret;
+struct phy *phy;
+
+if (!dev) {
+dev_WARN(dev, no device provided for PHY\n);
+ret = -EINVAL;
+goto err0;
+}
+
+phy = kzalloc(sizeof(*phy), GFP_KERNEL);
+if (!phy) {
+ret = -ENOMEM;
+goto err0;
+}
+
+device_initialize(phy-dev);
+mutex_init(phy-mutex);
+
+phy-dev.class = phy_class;
+phy-dev.parent = dev;
+phy-dev.of_node = dev-of_node;
+phy-id = id;
+phy-ops = ops;
+phy-label = kstrdup(label, GFP_KERNEL);
+
+ret = dev_set_name(phy-dev, %s.%d, dev_name(dev), id);
Your naming is odd, no phy anywhere in it? You rely on the sender to
never send a duplicate name.id pair? Why not create your own ids based
on the number of phys in the system, like almost all other classes and
subsystems do?
hmm.. some PHY drivers use the id they provide to perform some of their
internal operation as in [1] (This is used only if a single PHY provider
implements multiple PHYS). Probably I'll add an option like PLATFORM_DEVID_AUTO
to give the PHY drivers an option to use auto id.
[1] -
http://archive.arm.linux.org.uk/lurker/message/20130628.134308.4a8f7668.ca.html
+static inline int phy_pm_runtime_get(struct phy *phy)
+{
+if (WARN(IS_ERR(phy), Invalid PHY reference\n))
+return -EINVAL;
Why would phy ever not be valid and a error pointer? And why dump the
stack if that happens, that seems really extreme.
hmm.. there might be cases where the same controller in one soc needs PHY
control and in some other soc does not need PHY control. In such cases, we
might get error pointer here.
I'll change WARN to dev_err.
+
+if (!pm_runtime_enabled(phy-dev))
+return -ENOTSUPP;
+
+return pm_runtime_get(phy-dev);
+}
This, and the other inline functions in this .h file seem huge, why are
they inline and not in the .c file? There's no speed issues, and it
should save space overall in the .c file. Please move them.
ok
+static inline int phy_init(struct phy *phy)
+{
+int ret;
+
+ret = phy_pm_runtime_get_sync(phy);
+if (ret 0 ret != -ENOTSUPP)
+return ret;
+
+mutex_lock(phy-mutex);
+if (phy-init_count++ == 0 phy-ops-init) {
+ret = phy-ops-init(phy);
+if (ret 0) {
+dev_err(phy-dev, phy init failed -- %d\n, ret);
+goto out;
+}
+}
+
+out:
+mutex_unlock(phy-mutex);
+phy_pm_runtime_put(phy);
+return ret;
+}
+
+static inline int phy_exit(struct phy *phy)
+{
+int ret;
+
+ret = phy_pm_runtime_get_sync(phy);
+if (ret 0 ret != -ENOTSUPP)
Re: [PATCH 01/15] drivers: phy: add generic PHY framework
On Thu, Jul 18, 2013 at 02:29:52PM +0530, Kishon Vijay Abraham I wrote:
Hi,
On Thursday 18 July 2013 12:50 PM, Greg KH wrote:
On Thu, Jul 18, 2013 at 12:16:10PM +0530, Kishon Vijay Abraham I wrote:
+struct phy_provider *__of_phy_provider_register(struct device *dev,
+ struct module *owner, struct phy * (*of_xlate)(struct device *dev,
+ struct of_phandle_args *args));
+struct phy_provider *__devm_of_phy_provider_register(struct device *dev,
+ struct module *owner, struct phy * (*of_xlate)(struct device *dev,
+ struct of_phandle_args *args))
+
+__of_phy_provider_register and __devm_of_phy_provider_register can be
used to
+register the phy_provider and it takes device, owner and of_xlate as
+arguments. For the dt boot case, all PHY providers should use one of the
above
+2 APIs to register the PHY provider.
Why do you have __ for the prefix of a public function? Is that really
the way that OF handles this type of thing?
I have a macro of_phy_provider_register/devm_of_phy_provider_register that
calls these functions and should be used by the PHY drivers. Probably I should
make a mention of it in the Documentation.
Yes, mention those as you never want to be calling __* functions
directly, right?
+ ret = dev_set_name(phy-dev, %s.%d, dev_name(dev), id);
Your naming is odd, no phy anywhere in it? You rely on the sender to
never send a duplicate name.id pair? Why not create your own ids based
on the number of phys in the system, like almost all other classes and
subsystems do?
hmm.. some PHY drivers use the id they provide to perform some of their
internal operation as in [1] (This is used only if a single PHY provider
implements multiple PHYS). Probably I'll add an option like
PLATFORM_DEVID_AUTO
to give the PHY drivers an option to use auto id.
[1] -
http://archive.arm.linux.org.uk/lurker/message/20130628.134308.4a8f7668.ca.html
No, who cares about the id? No one outside of the phy core ever should,
because you pass back the only pointer that they really do care about,
if they need to do anything with the device. Use that, and then you can
rip out all of the search for a phy by a string logic, as that's not
needed either. Just stick to the pointer, it's easier, and safer that
way.
+static inline int phy_pm_runtime_get(struct phy *phy)
+{
+ if (WARN(IS_ERR(phy), Invalid PHY reference\n))
+ return -EINVAL;
Why would phy ever not be valid and a error pointer? And why dump the
stack if that happens, that seems really extreme.
hmm.. there might be cases where the same controller in one soc needs PHY
control and in some other soc does not need PHY control. In such cases, we
might get error pointer here.
I'll change WARN to dev_err.
I still don't understand. You have control over the code that calls
these functions, just ensure that they pass in a valid pointer, it's
that simple. Or am I missing something?
thanks,
greg k-h
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Re: [PATCH 01/15] drivers: phy: add generic PHY framework
Hi,
On Thursday 18 July 2013 09:19 PM, Greg KH wrote:
On Thu, Jul 18, 2013 at 02:29:52PM +0530, Kishon Vijay Abraham I wrote:
Hi,
On Thursday 18 July 2013 12:50 PM, Greg KH wrote:
On Thu, Jul 18, 2013 at 12:16:10PM +0530, Kishon Vijay Abraham I wrote:
+struct phy_provider *__of_phy_provider_register(struct device *dev,
+ struct module *owner, struct phy * (*of_xlate)(struct device *dev,
+ struct of_phandle_args *args));
+struct phy_provider *__devm_of_phy_provider_register(struct device *dev,
+ struct module *owner, struct phy * (*of_xlate)(struct device *dev,
+ struct of_phandle_args *args))
+
+__of_phy_provider_register and __devm_of_phy_provider_register can be
used to
+register the phy_provider and it takes device, owner and of_xlate as
+arguments. For the dt boot case, all PHY providers should use one of the
above
+2 APIs to register the PHY provider.
Why do you have __ for the prefix of a public function? Is that really
the way that OF handles this type of thing?
I have a macro of_phy_provider_register/devm_of_phy_provider_register that
calls these functions and should be used by the PHY drivers. Probably I
should
make a mention of it in the Documentation.
Yes, mention those as you never want to be calling __* functions
directly, right?
correct.
+ ret = dev_set_name(phy-dev, %s.%d, dev_name(dev), id);
Your naming is odd, no phy anywhere in it? You rely on the sender to
never send a duplicate name.id pair? Why not create your own ids based
on the number of phys in the system, like almost all other classes and
subsystems do?
hmm.. some PHY drivers use the id they provide to perform some of their
internal operation as in [1] (This is used only if a single PHY provider
implements multiple PHYS). Probably I'll add an option like
PLATFORM_DEVID_AUTO
to give the PHY drivers an option to use auto id.
[1] -
http://archive.arm.linux.org.uk/lurker/message/20130628.134308.4a8f7668.ca.html
No, who cares about the id? No one outside of the phy core ever should,
because you pass back the only pointer that they really do care about,
if they need to do anything with the device. Use that, and then you can
hmm.. ok.
rip out all of the search for a phy by a string logic, as that's not
Actually this is needed for non-dt boot case. In the case of dt boot, we use a
phandle by which the controller can get a reference to the phy. But in the case
of non-dt boot, the controller can get a reference to the phy only by label.
needed either. Just stick to the pointer, it's easier, and safer that
way.
+static inline int phy_pm_runtime_get(struct phy *phy)
+{
+ if (WARN(IS_ERR(phy), Invalid PHY reference\n))
+ return -EINVAL;
Why would phy ever not be valid and a error pointer? And why dump the
stack if that happens, that seems really extreme.
hmm.. there might be cases where the same controller in one soc needs PHY
control and in some other soc does not need PHY control. In such cases, we
might get error pointer here.
I'll change WARN to dev_err.
I still don't understand. You have control over the code that calls
these functions, just ensure that they pass in a valid pointer, it's
that simple. Or am I missing something?
You are right. Valid pointer check can be done in controller code as well.
Thanks
Kishon
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Re: [PATCH 01/15] drivers: phy: add generic PHY framework
On Fri, Jul 19, 2013 at 11:07:10AM +0530, Kishon Vijay Abraham I wrote: +ret = dev_set_name(phy-dev, %s.%d, dev_name(dev), id); Your naming is odd, no phy anywhere in it? You rely on the sender to never send a duplicate name.id pair? Why not create your own ids based on the number of phys in the system, like almost all other classes and subsystems do? hmm.. some PHY drivers use the id they provide to perform some of their internal operation as in [1] (This is used only if a single PHY provider implements multiple PHYS). Probably I'll add an option like PLATFORM_DEVID_AUTO to give the PHY drivers an option to use auto id. [1] - http://archive.arm.linux.org.uk/lurker/message/20130628.134308.4a8f7668.ca.html No, who cares about the id? No one outside of the phy core ever should, because you pass back the only pointer that they really do care about, if they need to do anything with the device. Use that, and then you can hmm.. ok. rip out all of the search for a phy by a string logic, as that's not Actually this is needed for non-dt boot case. In the case of dt boot, we use a phandle by which the controller can get a reference to the phy. But in the case of non-dt boot, the controller can get a reference to the phy only by label. I don't understand. They registered the phy, and got back a pointer to it. Why can't they save it in their local structure to use it again later if needed? They should never have to ask for the device, as the device id might be unknown if there are multiple devices in the system. Or am I missing something? thanks, greg k-h ___ devicetree-discuss mailing list devicetree-discuss@lists.ozlabs.org https://lists.ozlabs.org/listinfo/devicetree-discuss
Re: [PATCH 01/15] drivers: phy: add generic PHY framework
Hi, On Friday 19 July 2013 11:13 AM, Greg KH wrote: On Fri, Jul 19, 2013 at 11:07:10AM +0530, Kishon Vijay Abraham I wrote: +ret = dev_set_name(phy-dev, %s.%d, dev_name(dev), id); Your naming is odd, no phy anywhere in it? You rely on the sender to never send a duplicate name.id pair? Why not create your own ids based on the number of phys in the system, like almost all other classes and subsystems do? hmm.. some PHY drivers use the id they provide to perform some of their internal operation as in [1] (This is used only if a single PHY provider implements multiple PHYS). Probably I'll add an option like PLATFORM_DEVID_AUTO to give the PHY drivers an option to use auto id. [1] - http://archive.arm.linux.org.uk/lurker/message/20130628.134308.4a8f7668.ca.html No, who cares about the id? No one outside of the phy core ever should, because you pass back the only pointer that they really do care about, if they need to do anything with the device. Use that, and then you can hmm.. ok. rip out all of the search for a phy by a string logic, as that's not Actually this is needed for non-dt boot case. In the case of dt boot, we use a phandle by which the controller can get a reference to the phy. But in the case of non-dt boot, the controller can get a reference to the phy only by label. I don't understand. They registered the phy, and got back a pointer to it. Why can't they save it in their local structure to use it again later if needed? They should never have to ask for the device, as the One is a *PHY provider* driver which is a driver for some PHY device. This will use phy_create to create the phy. The other is a *PHY consumer* driver which might be any controller driver (can be USB/SATA/PCIE). The PHY consumer will use phy_get to get a reference to the phy (by *phandle* in the case of dt boot and *label* in the case of non-dt boot). device id might be unknown if there are multiple devices in the system. I agree with you on the device id part. That need not be known to the PHY driver. Thanks Kishon ___ devicetree-discuss mailing list devicetree-discuss@lists.ozlabs.org https://lists.ozlabs.org/listinfo/devicetree-discuss
