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[net-next:,0/3] ACPI MDIO support for Marvell controllers

Message ID 20210613183520.2247415-1-mw@semihalf.com
Headers show
Series ACPI MDIO support for Marvell controllers | expand

Message

Marcin Wojtas June 13, 2021, 6:35 p.m. UTC
Hi,

The MDIO ACPI binding has been established and merged to the
Linux tree, hence it is now possible to use it on the platforms
that base on the Marvell SoCs.

This short patchset adds ACPI support for the mvmdio controller.
mvpp2 driver is also updated in order to use the phylink in
ACPI world. For the latter a backward compatibility is ensured
- in case an older firmware is used, the driver would fall back to the
hitherto link interrupt handling.

The feature was verified with ACPI on MacchiatoBin and CN913x-DB.
Moreover regression tests were performed (old firmware with updated kernel,
new firmware with old kernel and the operation with DT).

The firmware ACPI description is exposed in the public github branch:
https://github.com/semihalf-wojtas-marcin/edk2-platforms/commits/acpi-mdio-r20210613
There is also MacchiatoBin firmware binary available for testing:
https://drive.google.com/file/d/1eigP_aeM4wYQpEaLAlQzs3IN_w1-kQr0

I'm looking forward to the comments or remarks.

Best regards,
Marcin


Marcin Wojtas (3):
  net: mvmdio: add ACPI support
  net: mvpp2: enable using phylink with ACPI
  net: mvpp2: remove unused 'has_phy' field

 drivers/net/ethernet/marvell/mvpp2/mvpp2.h      |  3 ---
 drivers/net/ethernet/marvell/mvmdio.c           | 27 +++++++++++++++++---
 drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 22 ++++++++++++----
 3 files changed, 41 insertions(+), 11 deletions(-)

Comments

Andrew Lunn June 13, 2021, 7:34 p.m. UTC | #1
> @@ -336,7 +338,7 @@ static int orion_mdio_probe(struct platform_device *pdev)
>  			dev_warn(&pdev->dev,
>  				 "unsupported number of clocks, limiting to the first "
>  				 __stringify(ARRAY_SIZE(dev->clk)) "\n");
> -	} else {
> +	} else if (!has_acpi_companion(&pdev->dev)) {
>  		dev->clk[0] = clk_get(&pdev->dev, NULL);
>  		if (PTR_ERR(dev->clk[0]) == -EPROBE_DEFER) {
>  			ret = -EPROBE_DEFER;

Is this needed? As you said, there are no clocks when ACPI is used, So
doesn't clk_get() return -ENODEV? Since this is not EPRODE_DEFER, it
keeps going. The clk_prepare_enable() won't be called.

> -	ret = of_mdiobus_register(bus, pdev->dev.of_node);
> +	if (pdev->dev.of_node)
> +		ret = of_mdiobus_register(bus, pdev->dev.of_node);
> +	else if (is_acpi_node(pdev->dev.fwnode))
> +		ret = acpi_mdiobus_register(bus, pdev->dev.fwnode);
> +	else
> +		ret = -EINVAL;
>  	if (ret < 0) {
>  		dev_err(&pdev->dev, "Cannot register MDIO bus (%d)\n", ret);
>  		goto out_mdio;
> @@ -383,6 +390,9 @@ static int orion_mdio_probe(struct platform_device *pdev)
>  	if (dev->err_interrupt > 0)
>  		writel(0, dev->regs + MVMDIO_ERR_INT_MASK);
>  
> +	if (has_acpi_companion(&pdev->dev))
> +		return ret;
> +

I think this can also be removed for the same reason.

We should try to avoid adding has_acpi_companion() and
!pdev->dev.of_node whenever we can. It makes the driver code too much
of a maze.

   Andrew
Marcin Wojtas June 15, 2021, 3:09 p.m. UTC | #2
Hi,

niedz., 13 cze 2021 o 22:08 Andy Shevchenko
<andy.shevchenko@gmail.com> napisał(a):
>

>

>

> On Sunday, June 13, 2021, Andrew Lunn <andrew@lunn.ch> wrote:

>>

>> > @@ -336,7 +338,7 @@ static int orion_mdio_probe(struct platform_device *pdev)

>> >                       dev_warn(&pdev->dev,

>> >                                "unsupported number of clocks, limiting to the first "

>> >                                __stringify(ARRAY_SIZE(dev->clk)) "\n");

>> > -     } else {

>> > +     } else if (!has_acpi_companion(&pdev->dev)) {

>> >               dev->clk[0] = clk_get(&pdev->dev, NULL);

>> >               if (PTR_ERR(dev->clk[0]) == -EPROBE_DEFER) {

>> >                       ret = -EPROBE_DEFER;

>>

>> Is this needed? As you said, there are no clocks when ACPI is used, So

>> doesn't clk_get() return -ENODEV? Since this is not EPRODE_DEFER, it

>> keeps going. The clk_prepare_enable() won't be called.

>


Indeed, I'll double check if it works and will keep the if {} else {} intact.

>

>

> The better approach is to switch to devm_get_clk_optional() as I have done in several drivers, IIRC recently in mvpp2

>

>

> https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/commit/?id=cf3399b731d36bc780803ff63e4d480a1efa33ac

>


Yes, this would be a nice improvement, however the
devm_get_clk_optional requires clock name (type char *) - mvmdio uses
raw indexes, so this helper unfortunately seems to be not applicable.

>>

>> > -     ret = of_mdiobus_register(bus, pdev->dev.of_node);

>> > +     if (pdev->dev.of_node)

>> > +             ret = of_mdiobus_register(bus, pdev->dev.of_node);

>> > +     else if (is_acpi_node(pdev->dev.fwnode))

>> > +             ret = acpi_mdiobus_register(bus, pdev->dev.fwnode);

>> > +     else

>> > +             ret = -EINVAL;

>> >       if (ret < 0) {

>> >               dev_err(&pdev->dev, "Cannot register MDIO bus (%d)\n", ret);

>> >               goto out_mdio;

>> > @@ -383,6 +390,9 @@ static int orion_mdio_probe(struct platform_device *pdev)

>> >       if (dev->err_interrupt > 0)

>> >               writel(0, dev->regs + MVMDIO_ERR_INT_MASK);

>> >

>> > +     if (has_acpi_companion(&pdev->dev))

>> > +             return ret;

>> > +

>>

>> I think this can also be removed for the same reason.

>>

>> We should try to avoid adding has_acpi_companion() and

>> !pdev->dev.of_node whenever we can. It makes the driver code too much

>> of a maze.


Clock routines silently accept NULL pointers, so it will be safe to
drop this addition in v2.

Best regards,
Marcin
Marcin Wojtas June 15, 2021, 3:13 p.m. UTC | #3
Hi,

niedz., 13 cze 2021 o 21:20 Andrew Lunn <andrew@lunn.ch> napisał(a):
>

> > -     ret = of_mdiobus_register(bus, pdev->dev.of_node);

> > +     if (pdev->dev.of_node)

> > +             ret = of_mdiobus_register(bus, pdev->dev.of_node);

> > +     else if (is_acpi_node(pdev->dev.fwnode))

> > +             ret = acpi_mdiobus_register(bus, pdev->dev.fwnode);

> > +     else

> > +             ret = -EINVAL;

>

>

> This seems like something which could be put into fwnode_mdio.c.

>


Agree - I'll create a simple fwnode_mdiobus_register() helper there.

Best regards,
Marcin
Andy Shevchenko June 15, 2021, 7:50 p.m. UTC | #4
On Tue, Jun 15, 2021 at 6:09 PM Marcin Wojtas <mw@semihalf.com> wrote:
> niedz., 13 cze 2021 o 22:08 Andy Shevchenko

> <andy.shevchenko@gmail.com> napisał(a):

> > On Sunday, June 13, 2021, Andrew Lunn <andrew@lunn.ch> wrote:


> > The better approach is to switch to devm_get_clk_optional() as I have done in several drivers, IIRC recently in mvpp2

> >

> > https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/commit/?id=cf3399b731d36bc780803ff63e4d480a1efa33ac

>

> Yes, this would be a nice improvement, however the

> devm_get_clk_optional requires clock name (type char *) - mvmdio uses

> raw indexes, so this helper unfortunately seems to be not applicable.


As far as I can read the code it smells like devm_clk_bulk_get_optional().
Am I mistaken?

-- 
With Best Regards,
Andy Shevchenko
Andy Shevchenko June 15, 2021, 7:53 p.m. UTC | #5
On Tue, Jun 15, 2021 at 6:14 PM Marcin Wojtas <mw@semihalf.com> wrote:
> Hi,

> niedz., 13 cze 2021 o 21:20 Andrew Lunn <andrew@lunn.ch> napisał(a):

> >

> > > -     ret = of_mdiobus_register(bus, pdev->dev.of_node);

> > > +     if (pdev->dev.of_node)

> > > +             ret = of_mdiobus_register(bus, pdev->dev.of_node);

> > > +     else if (is_acpi_node(pdev->dev.fwnode))

> > > +             ret = acpi_mdiobus_register(bus, pdev->dev.fwnode);

> > > +     else

> > > +             ret = -EINVAL;

> >

> >

> > This seems like something which could be put into fwnode_mdio.c.

> >

>

> Agree - I'll create a simple fwnode_mdiobus_register() helper there.


Please, also convert the users that we will not have again some
open-coded examples here and there
https://lore.kernel.org/netdev/162344280835.13501.16334655818490594799.git-patchwork-notify@kernel.org/T/#mff706861dea5d3be037d1546fa9c362b27d5839b

(Btw, note the is_of_node() usage there, so should
fwnode_mdiobus_register() have)

-- 
With Best Regards,
Andy Shevchenko