From: Lee Jones <lee.jones@linaro.org>
To: Dilip Kota <eswara.kota@linux.intel.com>
Cc: linux-kernel@vger.kernel.org, kishon@ti.com,
devicetree@vger.kernel.org, arnd@arndb.de, robh@kernel.org,
andriy.shevchenko@intel.com, cheol.yong.kim@intel.com,
chuanhua.lei@linux.intel.com, qi-ming.wu@intel.com,
yixin.zhu@intel.com
Subject: Re: [RESEND PATCH v6 1/4] mfd: syscon: Add fwnode_to_regmap
Date: Tue, 28 Apr 2020 11:05:38 +0100 [thread overview]
Message-ID: <20200428100538.GM3559@dell> (raw)
In-Reply-To: <d5b7eb87-7468-a1c4-bf19-d676c8e9c49d@linux.intel.com>
On Tue, 21 Apr 2020, Dilip Kota wrote:
>
> On 4/17/2020 5:35 PM, Lee Jones wrote:
> > On Mon, 06 Apr 2020, Dilip Kota wrote:
> >
> > > Traverse regmap handle entry from firmware node handle.
> > >
> > > Signed-off-by: Dilip Kota <eswara.kota@linux.intel.com>
> > > ---
> > > Changes on v5:
> > > No changes
> > > Changes on v5:
> > > No changes
> > >
> > > Changes on v4:
> > > No changes
> > >
> > > drivers/mfd/syscon.c | 8 ++++++++
> > > include/linux/mfd/syscon.h | 6 ++++++
> > > 2 files changed, 14 insertions(+)
> > >
> > > diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c
> > > index 3a97816d0cba..e085c50816b9 100644
> > > --- a/drivers/mfd/syscon.c
> > > +++ b/drivers/mfd/syscon.c
> > > @@ -178,6 +178,14 @@ struct regmap *device_node_to_regmap(struct device_node *np)
> > > }
> > > EXPORT_SYMBOL_GPL(device_node_to_regmap);
> > > +struct regmap *fwnode_to_regmap(struct fwnode_handle *fwnode)
> > > +{
> > > + struct device_node *np = to_of_node(fwnode);
> > You are assuming that the fwnode was Device Tree pointer.
> >
> > The point of a fwnode is that it could be one of multiple types.
> >
> > What if it was a pointer to an ACPI property?
> Yes, i missed to check in other perspective. Thanks for pointing it.
> While going through the System control driver to address the query, i
> noticed that System Control
> driver is talking with 'of' framework only. (No ACPI)
>
> So, i think to add a defensive check and return error pointer if
> 'to_of_node' returns NULL
> As System control Driver cannot talk with ACPI, so fwnode_to_regmap() cannot
> talk and return error.
>
> Or, the other option is removing the 'fwnode_to_regmap()' definition itself,
> to avoid confusion as fwnode can
> point to 'OF', 'ACPI'or 'swnode'.
>
> But, i feel return error for ACPI or oother, looks better because
> 'device_node' has fwnode pointer. And provide description
> in the header file, mentioning function is success for 'OF' and returns
> error for the rest.
I don't think this patch adds much to be honest.
Better to just do:
device_node_get_regmap(to_of_node(fwnode), false);
... from the call site I think.
--
Lee Jones [李琼斯]
Linaro Services Technical Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog
next prev parent reply other threads:[~2020-04-28 10:05 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-03 5:04 [PATCH v6 0/4] Add Intel ComboPhy driver Dilip Kota
2020-04-03 5:04 ` [PATCH v6 1/4] mfd: syscon: Add fwnode_to_regmap Dilip Kota
2020-04-06 7:39 ` [RESEND PATCH " Dilip Kota
2020-04-17 9:35 ` Lee Jones
2020-04-21 4:06 ` Dilip Kota
2020-04-28 10:05 ` Lee Jones [this message]
2020-04-28 10:29 ` Arnd Bergmann
2020-04-29 5:11 ` Dilip Kota
2020-04-03 5:04 ` [PATCH v6 2/4] dt-bindings: phy: Add PHY_TYPE_XPCS definition Dilip Kota
2020-04-06 7:39 ` [RESEND PATCH " Dilip Kota
2020-04-03 5:04 ` [PATCH v6 3/4] dt-bindings: phy: Add YAML schemas for Intel ComboPhy Dilip Kota
2020-04-06 7:39 ` [RESEND PATCH " Dilip Kota
2020-04-03 5:04 ` [PATCH v6 4/4] phy: intel: Add driver support for ComboPhy Dilip Kota
2020-04-06 7:39 ` [RESEND PATCH " Dilip Kota
2020-04-06 7:39 ` [RESEND PATCH v6 0/4] Add Intel ComboPhy driver Dilip Kota
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