LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: John Garry <john.garry@huawei.com>
To: Lee Jones <lee.jones@linaro.org>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: <xuwei5@huawei.com>, <mika.westerberg@linux.intel.com>,
	<rjw@rjwysocki.net>, <linux-kernel@vger.kernel.org>,
	<arnd@arndb.de>, <graeme.gregory@linaro.org>,
	<helgaas@kernel.org>, <z.liuxinliang@hisilicon.com>,
	<linuxarm@huawei.com>
Subject: Re: [PATCH 1/2] HISI LPC: Reference static MFD cells for ACPI support
Date: Fri, 4 May 2018 10:27:10 +0100	[thread overview]
Message-ID: <4a15b0b4-5707-d51b-4762-02df8e153bd9@huawei.com> (raw)
In-Reply-To: <20180504090216.GC3928@dell>

On 04/05/2018 10:02, Lee Jones wrote:
> On Thu, 03 May 2018, Andy Shevchenko wrote:
>
>> On Thu, 2018-05-03 at 23:08 +0800, John Garry wrote:
>>> Currently for ACPI support the driver models the host as
>>> an MFD. For a device connected to the LPC bus, we dynamically
>>> create an MFD cell for that device, configuring the cell
>>> name and ACPI match parameters manually. This makes supporting
>>> named devices and also special setup handling for certain devices
>>> awkward, as we would need to introduce some special ACPI device
>>> handling according to device HID.
>>>
>>> To avoid this, create reference static MFD cells for known
>>> child devices, so when adding an MFD cell we can fix the cell
>>> platform data as required. For this, a setup callback function
>>> is added.
>>>
>>> For now, only the IPMI cell is added.
>>
>>> +static const struct mfd_cell *hisi_lpc_acpi_mfd_get_cell(const char
>>> *hid)
>>> +{
>>> +	const struct hisi_lpc_acpi_mfd_cell *cell =
>>> hisi_lpc_acpi_mfd_cells;
>>> +
>>> +	for (; cell && cell->mfd_cell.name; cell++) {
>>> +		const struct mfd_cell *mfd_cell = &cell->mfd_cell;
>>> +		const struct mfd_cell_acpi_match *acpi_match;
>>> +
>>> +		acpi_match = mfd_cell->acpi_match;
>>> +		if (!strcmp(acpi_match->pnpid, hid))
>>> +			return mfd_cell;
>>> +	}
>>> +
>>> +	return NULL;
>>> +}
>>
>> I'm not sure I understand why MFD core can't do it (as seen in lines
>> drivers/mfd/core.c:105 and below).
>

Hi Lee,

> You shouldn't be using the MFD API outside of MFD anyway.  Either it
> is an MFD driver, or it isn't.  If it is, please move it. If it's not,
> please don't use the API.

We're modelling as an MFD, but it's not an MFD in the classic sense. 
We're just using the MFD API for convenience (and to avoid code 
duplication), as the MFD API does what we require for this driver.

>
> My current suspicion is that the driver needs splitting and only part
> of it ends up in MFD.
>

How would you propose splitting the driver? By adding a lib function 
specific for this driver for the ACPI probe?

Cheers,
John

  reply	other threads:[~2018-05-04  9:27 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-03 15:08 [PATCH 0/2] HISI LPC ACPI UART support John Garry
2018-05-03 15:08 ` [PATCH 1/2] HISI LPC: Reference static MFD cells for ACPI support John Garry
2018-05-03 16:54   ` Andy Shevchenko
2018-05-04  9:02     ` Lee Jones
2018-05-04  9:27       ` John Garry [this message]
2018-05-04 10:03         ` Lee Jones
2018-05-04 10:21           ` John Garry
2018-05-04 12:29     ` John Garry
2018-05-03 15:08 ` [PATCH 2/2] HISI LPC: Add ACPI UART support John Garry
2018-05-03 16:56   ` Andy Shevchenko
2018-05-04 12:33     ` John Garry

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=4a15b0b4-5707-d51b-4762-02df8e153bd9@huawei.com \
    --to=john.garry@huawei.com \
    --cc=andriy.shevchenko@linux.intel.com \
    --cc=arnd@arndb.de \
    --cc=graeme.gregory@linaro.org \
    --cc=helgaas@kernel.org \
    --cc=lee.jones@linaro.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linuxarm@huawei.com \
    --cc=mika.westerberg@linux.intel.com \
    --cc=rjw@rjwysocki.net \
    --cc=xuwei5@huawei.com \
    --cc=z.liuxinliang@hisilicon.com \
    --subject='Re: [PATCH 1/2] HISI LPC: Reference static MFD cells for ACPI support' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).