From: zhouqiao@marvell•com (Qiao Zhou)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 1/3] mfd: support 88pm80x in 80x driver
Date: Tue, 03 Jul 2012 10:28:39 +0800 [thread overview]
Message-ID: <4FF258D7.8050109@marvell.com> (raw)
In-Reply-To: <201207021558.51246.arnd@arndb.de>
On 07/02/2012 11:58 PM, Arnd Bergmann wrote:
> On Monday 02 July 2012, Qiao Zhou wrote:
>> On 07/02/2012 06:12 PM, Mark Brown wrote:
>>> On Mon, Jul 02, 2012 at 06:09:57PM +0800, Qiao Zhou wrote:
>>>> On 07/02/2012 06:03 PM, Mark Brown wrote:
>>>
>>>>> What do you mean by pages? regmap has paging support which just maps
>>>>> everything into a single flat register map from the point of view of
>>>>> callers.
>>>
>>>> Mark, let me explain: the 88pm800 chip has three i2c address
>>>> internally, which we called different page instead. it confuses you
>>>> with the register page_read/write operation. there are registers in
>>>> each i2c address domain, and we need to use different i2c client to
>>>> access reg in different domain. such as some common regs are in the
>>>> page of i2c_addr = 0x30, and power related regs are in the page of
>>>> i2c_addr = 0x31, and gpadc related regs are in the page of 0x32.
>>>
>>> These aren't what people normally call pages, those are just separate
>>> I2C devices from a Linux point of view.
>>>
>> Mark, surely I'll pay attention to the terms used. thanks!
>> due to there separate I2C devices, does it make sense to export separate
>> r/w interface for them? do you have suggestion in such case?
>
> (adding the i2c mailing list to get more insight)
>
> I think in case of device tree based probing, it would be straightforward
> to represent 88pm800 as a single device with three addresses in the "reg"
> property, while the natural linux representation would be one regular
> i2c_client device with two dummies. Do we or should we have any
> infrastructure to deal with this?
>
> If this is a common scenario, we could probably let regmap handle it
> entirely internally and represent the i2c client with its dummies
> as a single regmap.
actually there are many drivers under mfd which have this common issue,
which has i2c dummy devices, such as max77693.c, max8925-i2c.c,
ab3100-core.c, max8997.c, max8998.c, s5m-core.c etc. some use regmap
handle directly as param in exported r/w api, some add extra param to
differentiate i2c dummy. it seems to be a common scenario. how do we
handle the API in short term and long term?
>
> Arnd
>
--
Best Regards
Qiao
next prev parent reply other threads:[~2012-07-03 2:28 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-28 3:13 [PATCH 0/3 V1] add 88pm80x mfd driver Qiao Zhou
2012-06-28 3:13 ` [PATCH 1/3] mfd: support 88pm80x in 80x driver Qiao Zhou
2012-06-28 11:21 ` Arnd Bergmann
2012-06-28 11:46 ` Mark Brown
2012-06-28 14:32 ` Arnd Bergmann
2012-06-29 1:18 ` Haojian Zhuang
2012-06-29 1:29 ` Mark Brown
2012-06-29 14:18 ` Arnd Bergmann
2012-06-29 2:56 ` Qiao Zhou
2012-06-29 13:58 ` Arnd Bergmann
2012-07-02 7:50 ` Qiao Zhou
2012-07-02 9:22 ` Qiao Zhou
2012-07-02 10:03 ` Mark Brown
2012-07-02 10:09 ` Qiao Zhou
2012-07-02 10:12 ` Mark Brown
2012-07-02 10:15 ` Qiao Zhou
2012-07-02 15:58 ` Arnd Bergmann
2012-07-03 2:28 ` Qiao Zhou [this message]
2012-06-29 14:21 ` Arnd Bergmann
2012-06-30 12:02 ` Mark Brown
2012-06-28 3:13 ` [PATCH 2/3] rtc: add rtc support to 88PM80X PMIC Qiao Zhou
2012-06-28 3:13 ` [PATCH 3/3] input: add onkey " Qiao Zhou
-- strict thread matches above, loose matches on Subject: below --
2012-06-13 9:04 [PATCH 0/3 V0] add 88pm80x mfd driver Qiao Zhou
2012-06-13 9:04 ` [PATCH 1/3] mfd: support 88pm80x in 80x driver Qiao Zhou
2012-06-14 12:27 ` Arnd Bergmann
2012-06-14 18:43 ` Mark Brown
2012-06-15 5:23 ` Qiao Zhou
2012-06-15 3:17 ` Qiao Zhou
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=4FF258D7.8050109@marvell.com \
--to=zhouqiao@marvell$(echo .)com \
--cc=linux-arm-kernel@lists$(echo .)infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox