From: jon-hunter@ti•com (Jon Hunter)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v5 3/3] ARM: OMAP2+: onenand: prepare for gpmc driver migration
Date: Tue, 3 Jul 2012 10:12:17 -0500 [thread overview]
Message-ID: <4FF30BD1.3040309@ti.com> (raw)
In-Reply-To: <20120703081746.GJ1122@atomide.com>
On 07/03/2012 03:17 AM, Tony Lindgren wrote:
> * Jon Hunter <jon-hunter@ti•com> [120702 10:30]:
>>
>> On 07/02/2012 01:36 AM, Tony Lindgren wrote:
>>>
>>> In general, I doubt that we can come up with better calculations. The existing
>>> code pretty well already follows the device spec timings. And using cycle values
>>> for some registers is the right thing to do according to the connected device
>>> specs no matter what the frequency is. In those cases converting from time values
>>> to cycles does not make sense.
>>
>> Ok agree, but the problem here is how to provide the timings to the
>> driver. The onenand code is doing a lot of rounding based upon the gpmc
>> clock before it presents the timings (in nano-seconds) to the gpmc
>> function to calculate the final timings and program the gpmc
>> chip-select. So therefore I think that we have the following options ...
>>
>> 1. The simplest is to continue using a global variable for storing the
>> gpmc f-clk handle and have the OneNAND timings calculated prior to
>> probing the gpmc driver.
>
> Well we should not expose gpmc fck handle to the drivers..
Yes, I was hoping we could avoid continuing to do this.
>> 2. Provide some sort of "retime" callback that the gpmc driver can call
>> at probe time to calculate the timings.
>
> Yes how about the gpmc using driver code registers itself with the gpmc code
> and also registers it's retime function with the gpmc? That way the gpmc fck
> stays inside the gpmc code, and the driver specific retime function should
> be able to do the calculation based on driver clocks. The retime function
> needs to have also a pointer to driver private data for it's clocks etc.
>
> It seems this retime function may need to be called by the gpmc code when
> L3 changes, and the driver code if the driver is switching between runtime
> and idle clocks like tusb6010 for example does.
Seems fine to me.
Cheers
Jon
next prev parent reply other threads:[~2012-07-03 15:12 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-27 6:33 [PATCH v5 0/3] Prepare for GPMC driver conversion Afzal Mohammed
2012-06-27 6:33 ` [PATCH v5 1/3] ARM: OMAP2+: nand: unify init functions Afzal Mohammed
2012-06-27 6:33 ` [PATCH v5 2/3] ARM: OMAP2+: gpmc: handle additional timings Afzal Mohammed
2012-06-27 6:34 ` [PATCH v5 3/3] ARM: OMAP2+: onenand: prepare for gpmc driver migration Afzal Mohammed
2012-06-27 14:58 ` Tony Lindgren
2012-06-28 9:32 ` Mohammed, Afzal
2012-06-28 12:32 ` Tony Lindgren
2012-06-28 12:33 ` Mohammed, Afzal
2012-06-28 12:44 ` Mohammed, Afzal
2012-07-30 7:36 ` Mohammed, Afzal
2012-06-28 16:43 ` Jon Hunter
2012-06-28 19:00 ` Jon Hunter
2012-07-02 6:26 ` Tony Lindgren
2012-06-29 6:15 ` Mohammed, Afzal
2012-06-29 6:38 ` Mohammed, Afzal
2012-06-29 14:15 ` Jon Hunter
2012-07-02 10:04 ` Mohammed, Afzal
2012-07-02 6:36 ` Tony Lindgren
2012-07-02 9:43 ` Mohammed, Afzal
2012-07-02 17:29 ` Jon Hunter
2012-07-03 4:35 ` Mohammed, Afzal
2012-07-03 15:10 ` Jon Hunter
2012-07-04 5:36 ` Mohammed, Afzal
2012-07-02 17:25 ` Jon Hunter
2012-07-03 8:17 ` Tony Lindgren
2012-07-03 15:12 ` Jon Hunter [this message]
2012-07-04 7:00 ` Mohammed, Afzal
2012-07-04 7:51 ` Tony Lindgren
2012-07-05 10:24 ` Mohammed, Afzal
2012-07-05 10:55 ` Tony Lindgren
2012-07-05 11:58 ` Mohammed, Afzal
2012-07-05 14:49 ` Tony Lindgren
2012-07-05 14:51 ` Mohammed, Afzal
2012-07-06 12:05 ` Tony Lindgren
2012-07-10 6:20 ` Mohammed, Afzal
2012-07-10 9:45 ` Tony Lindgren
2012-07-10 10:04 ` Mohammed, Afzal
2012-07-10 13:17 ` Tony Lindgren
2012-07-10 13:47 ` Mohammed, Afzal
2012-07-10 17:15 ` Jon Hunter
2012-07-11 6:47 ` Tony Lindgren
2012-07-13 4:36 ` Mohammed, Afzal
2012-08-06 13:38 ` gpmc generic retime function (subject was RE: [PATCH v5 3/3] ARM: OMAP2+: onenand: prepare for gpmc driver migration) Mohammed, Afzal
2012-08-17 15:02 ` Jon Hunter
2012-08-21 11:14 ` Mohammed, Afzal
2012-06-27 10:08 ` [PATCH v5 0/3] Prepare for GPMC driver conversion Mohammed, Afzal
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=4FF30BD1.3040309@ti.com \
--to=jon-hunter@ti$(echo .)com \
--cc=linux-arm-kernel@lists$(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