[PATCH 3/5] mfd: axp20x: Allow multiple regulators

Andre Przywara posted 5 patches 1 month, 3 weeks ago
There is a newer version of this series
[PATCH 3/5] mfd: axp20x: Allow multiple regulators
Posted by Andre Przywara 1 month, 3 weeks ago
At the moment trying to register a second AXP chip makes the probe fail,
as some sysfs registration fails due to a duplicate name:

...
[    3.688215] axp20x-i2c 0-0035: AXP20X driver loaded
[    3.695610] axp20x-i2c 0-0036: AXP20x variant AXP323 found
[    3.706151] sysfs: cannot create duplicate filename '/bus/platform/devices/axp20x-regulator'
[    3.714718] CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.12.0-rc1-00026-g50bf2e2c079d-dirty #192
[    3.724020] Hardware name: Avaota A1 (DT)
[    3.728029] Call trace:
[    3.730477]  dump_backtrace+0x94/0xec
[    3.734146]  show_stack+0x18/0x24
[    3.737462]  dump_stack_lvl+0x80/0xf4
[    3.741128]  dump_stack+0x18/0x24
[    3.744444]  sysfs_warn_dup+0x64/0x80
[    3.748109]  sysfs_do_create_link_sd+0xf0/0xf8
[    3.752553]  sysfs_create_link+0x20/0x40
[    3.756476]  bus_add_device+0x64/0x104
[    3.760229]  device_add+0x310/0x760
[    3.763717]  platform_device_add+0x10c/0x238
[    3.767990]  mfd_add_device+0x4ec/0x5c8
[    3.771829]  mfd_add_devices+0x88/0x11c
[    3.775666]  axp20x_device_probe+0x70/0x184
[    3.779851]  axp20x_i2c_probe+0x9c/0xd8
...

This is because we use PLATFORM_DEVID_NONE for the mfd_add_devices()
call, which would number the child devices in the same 0-based way, even
for the second (or any other) instance.

Use PLATFORM_DEVID_AUTO instead, which automatically assigns
non-conflicting device numbers.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
---
 drivers/mfd/axp20x.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mfd/axp20x.c b/drivers/mfd/axp20x.c
index 5ceea359289f..bc08ae433260 100644
--- a/drivers/mfd/axp20x.c
+++ b/drivers/mfd/axp20x.c
@@ -1419,7 +1419,7 @@ int axp20x_device_probe(struct axp20x_dev *axp20x)
 		}
 	}
 
-	ret = mfd_add_devices(axp20x->dev, -1, axp20x->cells,
+	ret = mfd_add_devices(axp20x->dev, PLATFORM_DEVID_AUTO, axp20x->cells,
 			      axp20x->nr_cells, NULL, 0, NULL);
 
 	if (ret) {
-- 
2.25.1
Re: [PATCH 3/5] mfd: axp20x: Allow multiple regulators
Posted by Chen-Yu Tsai 1 month, 3 weeks ago
On Thu, Oct 3, 2024 at 7:15 PM Andre Przywara <andre.przywara@arm.com> wrote:
>
> At the moment trying to register a second AXP chip makes the probe fail,
> as some sysfs registration fails due to a duplicate name:
>
> ...
> [    3.688215] axp20x-i2c 0-0035: AXP20X driver loaded
> [    3.695610] axp20x-i2c 0-0036: AXP20x variant AXP323 found
> [    3.706151] sysfs: cannot create duplicate filename '/bus/platform/devices/axp20x-regulator'
> [    3.714718] CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.12.0-rc1-00026-g50bf2e2c079d-dirty #192
> [    3.724020] Hardware name: Avaota A1 (DT)
> [    3.728029] Call trace:
> [    3.730477]  dump_backtrace+0x94/0xec
> [    3.734146]  show_stack+0x18/0x24
> [    3.737462]  dump_stack_lvl+0x80/0xf4
> [    3.741128]  dump_stack+0x18/0x24
> [    3.744444]  sysfs_warn_dup+0x64/0x80
> [    3.748109]  sysfs_do_create_link_sd+0xf0/0xf8
> [    3.752553]  sysfs_create_link+0x20/0x40
> [    3.756476]  bus_add_device+0x64/0x104
> [    3.760229]  device_add+0x310/0x760
> [    3.763717]  platform_device_add+0x10c/0x238
> [    3.767990]  mfd_add_device+0x4ec/0x5c8
> [    3.771829]  mfd_add_devices+0x88/0x11c
> [    3.775666]  axp20x_device_probe+0x70/0x184
> [    3.779851]  axp20x_i2c_probe+0x9c/0xd8
> ...
>
> This is because we use PLATFORM_DEVID_NONE for the mfd_add_devices()
> call, which would number the child devices in the same 0-based way, even
> for the second (or any other) instance.
>
> Use PLATFORM_DEVID_AUTO instead, which automatically assigns
> non-conflicting device numbers.

That's weird... I don't remember running into this when working on the A80,
which had two albeit different AXP chips. That was a long time ago though.

> Signed-off-by: Andre Przywara <andre.przywara@arm.com>

Reviewed-by: Chen-Yu Tsai <wens@csie.org>

> ---
>  drivers/mfd/axp20x.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/mfd/axp20x.c b/drivers/mfd/axp20x.c
> index 5ceea359289f..bc08ae433260 100644
> --- a/drivers/mfd/axp20x.c
> +++ b/drivers/mfd/axp20x.c
> @@ -1419,7 +1419,7 @@ int axp20x_device_probe(struct axp20x_dev *axp20x)
>                 }
>         }
>
> -       ret = mfd_add_devices(axp20x->dev, -1, axp20x->cells,
> +       ret = mfd_add_devices(axp20x->dev, PLATFORM_DEVID_AUTO, axp20x->cells,
>                               axp20x->nr_cells, NULL, 0, NULL);
>
>         if (ret) {
> --
> 2.25.1
>
Re: [PATCH 3/5] mfd: axp20x: Allow multiple regulators
Posted by Andre Przywara 1 month, 3 weeks ago
On Thu, 3 Oct 2024 23:19:16 +0800
Chen-Yu Tsai <wens@csie.org> wrote:

> On Thu, Oct 3, 2024 at 7:15 PM Andre Przywara <andre.przywara@arm.com> wrote:
> >
> > At the moment trying to register a second AXP chip makes the probe fail,
> > as some sysfs registration fails due to a duplicate name:
> >
> > ...
> > [    3.688215] axp20x-i2c 0-0035: AXP20X driver loaded
> > [    3.695610] axp20x-i2c 0-0036: AXP20x variant AXP323 found
> > [    3.706151] sysfs: cannot create duplicate filename '/bus/platform/devices/axp20x-regulator'
> > [    3.714718] CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.12.0-rc1-00026-g50bf2e2c079d-dirty #192
> > [    3.724020] Hardware name: Avaota A1 (DT)
> > [    3.728029] Call trace:
> > [    3.730477]  dump_backtrace+0x94/0xec
> > [    3.734146]  show_stack+0x18/0x24
> > [    3.737462]  dump_stack_lvl+0x80/0xf4
> > [    3.741128]  dump_stack+0x18/0x24
> > [    3.744444]  sysfs_warn_dup+0x64/0x80
> > [    3.748109]  sysfs_do_create_link_sd+0xf0/0xf8
> > [    3.752553]  sysfs_create_link+0x20/0x40
> > [    3.756476]  bus_add_device+0x64/0x104
> > [    3.760229]  device_add+0x310/0x760
> > [    3.763717]  platform_device_add+0x10c/0x238
> > [    3.767990]  mfd_add_device+0x4ec/0x5c8
> > [    3.771829]  mfd_add_devices+0x88/0x11c
> > [    3.775666]  axp20x_device_probe+0x70/0x184
> > [    3.779851]  axp20x_i2c_probe+0x9c/0xd8
> > ...
> >
> > This is because we use PLATFORM_DEVID_NONE for the mfd_add_devices()
> > call, which would number the child devices in the same 0-based way, even
> > for the second (or any other) instance.
> >
> > Use PLATFORM_DEVID_AUTO instead, which automatically assigns
> > non-conflicting device numbers.  
> 
> That's weird... I don't remember running into this when working on the A80,
> which had two albeit different AXP chips. That was a long time ago though.

So I tested this on a Cubieboard 4, and it works there either way,
with or without this patch. That's RSB instead of I2C, which honestly
shouldn't make much of a difference, but maybe the call path differs?

But since it still works, I think this patch is correct regardless.

Thanks,
Andre


> > Signed-off-by: Andre Przywara <andre.przywara@arm.com>  
> 
> Reviewed-by: Chen-Yu Tsai <wens@csie.org>
> 
> > ---
> >  drivers/mfd/axp20x.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/mfd/axp20x.c b/drivers/mfd/axp20x.c
> > index 5ceea359289f..bc08ae433260 100644
> > --- a/drivers/mfd/axp20x.c
> > +++ b/drivers/mfd/axp20x.c
> > @@ -1419,7 +1419,7 @@ int axp20x_device_probe(struct axp20x_dev *axp20x)
> >                 }
> >         }
> >
> > -       ret = mfd_add_devices(axp20x->dev, -1, axp20x->cells,
> > +       ret = mfd_add_devices(axp20x->dev, PLATFORM_DEVID_AUTO, axp20x->cells,
> >                               axp20x->nr_cells, NULL, 0, NULL);
> >
> >         if (ret) {
> > --
> > 2.25.1
> >  
> 
Re: [PATCH 3/5] mfd: axp20x: Allow multiple regulators
Posted by Andre Przywara 1 month, 3 weeks ago
On Thu, 3 Oct 2024 23:19:16 +0800
Chen-Yu Tsai <wens@csie.org> wrote:

Hi Chen-Yu,

thanks for having a look!

> On Thu, Oct 3, 2024 at 7:15 PM Andre Przywara <andre.przywara@arm.com> wrote:
> >
> > At the moment trying to register a second AXP chip makes the probe fail,
> > as some sysfs registration fails due to a duplicate name:
> >
> > ...
> > [    3.688215] axp20x-i2c 0-0035: AXP20X driver loaded
> > [    3.695610] axp20x-i2c 0-0036: AXP20x variant AXP323 found
> > [    3.706151] sysfs: cannot create duplicate filename '/bus/platform/devices/axp20x-regulator'
> > [    3.714718] CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.12.0-rc1-00026-g50bf2e2c079d-dirty #192
> > [    3.724020] Hardware name: Avaota A1 (DT)
> > [    3.728029] Call trace:
> > [    3.730477]  dump_backtrace+0x94/0xec
> > [    3.734146]  show_stack+0x18/0x24
> > [    3.737462]  dump_stack_lvl+0x80/0xf4
> > [    3.741128]  dump_stack+0x18/0x24
> > [    3.744444]  sysfs_warn_dup+0x64/0x80
> > [    3.748109]  sysfs_do_create_link_sd+0xf0/0xf8
> > [    3.752553]  sysfs_create_link+0x20/0x40
> > [    3.756476]  bus_add_device+0x64/0x104
> > [    3.760229]  device_add+0x310/0x760
> > [    3.763717]  platform_device_add+0x10c/0x238
> > [    3.767990]  mfd_add_device+0x4ec/0x5c8
> > [    3.771829]  mfd_add_devices+0x88/0x11c
> > [    3.775666]  axp20x_device_probe+0x70/0x184
> > [    3.779851]  axp20x_i2c_probe+0x9c/0xd8
> > ...
> >
> > This is because we use PLATFORM_DEVID_NONE for the mfd_add_devices()
> > call, which would number the child devices in the same 0-based way, even
> > for the second (or any other) instance.
> >
> > Use PLATFORM_DEVID_AUTO instead, which automatically assigns
> > non-conflicting device numbers.  
> 
> That's weird... I don't remember running into this when working on the A80,
> which had two albeit different AXP chips. That was a long time ago though.

Yeah, I was wondering about this as well. And it's two different PMICs here
as well: most A523/T527 system seem to come with an AXP717/AXP323 combo.
Though there are not linked together in any way, like in this master/slave
mode of the AXP806.
I will test on (your old) A80 board, and will add a Fixes: tag in v2,
should it also fail there.

> > Signed-off-by: Andre Przywara <andre.przywara@arm.com>  
> 
> Reviewed-by: Chen-Yu Tsai <wens@csie.org>

Thanks,
Andre

> 
> > ---
> >  drivers/mfd/axp20x.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/mfd/axp20x.c b/drivers/mfd/axp20x.c
> > index 5ceea359289f..bc08ae433260 100644
> > --- a/drivers/mfd/axp20x.c
> > +++ b/drivers/mfd/axp20x.c
> > @@ -1419,7 +1419,7 @@ int axp20x_device_probe(struct axp20x_dev *axp20x)
> >                 }
> >         }
> >
> > -       ret = mfd_add_devices(axp20x->dev, -1, axp20x->cells,
> > +       ret = mfd_add_devices(axp20x->dev, PLATFORM_DEVID_AUTO, axp20x->cells,
> >                               axp20x->nr_cells, NULL, 0, NULL);
> >
> >         if (ret) {
> > --
> > 2.25.1
> >