From: jon-hunter@ti•com (Jon Hunter)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v7 5/5] ARM: OMAP: gpmc: add DT bindings for GPMC timings and NAND
Date: Thu, 6 Dec 2012 10:19:55 -0600 [thread overview]
Message-ID: <50C0C5AB.3030201@ti.com> (raw)
In-Reply-To: <20121205232426.BAD573E0E22@localhost>
On 12/05/2012 05:24 PM, Grant Likely wrote:
> On Wed, 5 Dec 2012 16:33:48 -0600, Jon Hunter <jon-hunter@ti•com> wrote:
>> Hi Grant,
>>
>> On 12/05/2012 04:22 PM, Grant Likely wrote:
>>> On Wed, 5 Dec 2012 20:09:31 +0100, Daniel Mack <zonque@gmail•com> wrote:
>>>> This patch adds basic DT bindings for OMAP GPMC.
>>>>
>>>> The actual peripherals are instantiated from child nodes within the GPMC
>>>> node, and the only type of device that is currently supported is NAND.
>>>>
>>>> Code was added to parse the generic GPMC timing parameters and some
>>>> documentation with examples on how to use them.
>>>>
>>>> Successfully tested on an AM33xx board.
>>>>
>>>> Signed-off-by: Daniel Mack <zonque@gmail•com>
>>>> ---
>>>> Documentation/devicetree/bindings/bus/ti-gpmc.txt | 77 ++++++++++
>>>> .../devicetree/bindings/mtd/gpmc-nand.txt | 76 +++++++++
>>>> arch/arm/mach-omap2/gpmc.c | 171 ++++++++++++++++++++-
>>>> 3 files changed, 323 insertions(+), 1 deletion(-)
>>>> create mode 100644 Documentation/devicetree/bindings/bus/ti-gpmc.txt
>>>> create mode 100644 Documentation/devicetree/bindings/mtd/gpmc-nand.txt
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/bus/ti-gpmc.txt b/Documentation/devicetree/bindings/bus/ti-gpmc.txt
>>>> new file mode 100644
>>>> index 0000000..7d2a645
>>>> --- /dev/null
>>>> +++ b/Documentation/devicetree/bindings/bus/ti-gpmc.txt
>>>> @@ -0,0 +1,77 @@
>>>> +Device tree bindings for OMAP general purpose memory controllers (GPMC)
>>>> +
>>>> +The actual devices are instantiated from the child nodes of a GPMC node.
>>>> +
>>>> +Required properties:
>>>> +
>>>> + - compatible: Should be set to "ti,gpmc"
>>>
>>> Please, be specific. Use something like "ti,am3340-gpmc" or
>>> "ti,omap3430-gpmc". The compatible property is a list so that new
>>> devices can claim compatibility with old. Compatible strings that are
>>> overly generic are a pet-peave of mine.
>>
>> We aim to use the binding for omap2,3,4,5 as well as the am33xx devices
>> (which are omap based). Would it be sufficient to have "ti,omap2-gpmc"
>> implying all omap2+ based devices or should we have a compatible string
>> for each device supported?
>
> Are they each register-level compatible with one another?
They are not 100% register compatible. There are a couple fields in the
binding that are only applicable to OMAP3+ devices.
> The general recommended approach here is to make subsequent silicon
> claim compatibility with the first compatible implementation.
>
> So, for an am3358 board:
> compatible = "ti,am3358-gpmc", "ti,omap2420-gpmc";
>
> Essentially, what this means is that "ti,omap2420-gpmc" is the generic
> value instead of "omap2-gpmc". The reason for this is so that the value
> is anchored against a specific implementation, and not against something
> completely imaginary or idealized. If a newer version isn't quite
> compatible with the omap2420-gpmc, then it can drop the compatible claim
> and the driver really should be told about the new device.
Ok, gotcha! I will do a register comparison and may be recommend to
Daniel which compatible strings we will need.
Thanks!
Jon
next prev parent reply other threads:[~2012-12-06 16:19 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-05 19:09 [PATCH v7 0/5] OMAP GPMC DT bindings Daniel Mack
2012-12-05 19:09 ` [PATCH v7 1/5] ARM: OMAP: gpmc: don't create devices from initcall on DT Daniel Mack
2012-12-05 19:09 ` [PATCH v7 2/5] mtd: omap-nand: pass device_node in platform data Daniel Mack
2012-12-05 19:09 ` [PATCH v7 3/5] ARM: OMAP: gpmc-nand: drop __init annotation Daniel Mack
2012-12-05 19:09 ` [PATCH v7 4/5] ARM: OMAP: gpmc: enable hwecc for AM33xx SoCs Daniel Mack
2012-12-05 19:09 ` [PATCH v7 5/5] ARM: OMAP: gpmc: add DT bindings for GPMC timings and NAND Daniel Mack
2012-12-05 22:22 ` Grant Likely
2012-12-05 22:33 ` Jon Hunter
2012-12-05 23:24 ` Grant Likely
2012-12-06 0:03 ` Tony Lindgren
2012-12-06 16:22 ` Jon Hunter
2012-12-06 16:54 ` Daniel Mack
2012-12-06 18:11 ` Jon Hunter
2012-12-06 16:19 ` Jon Hunter [this message]
2012-12-06 16:59 ` Daniel Mack
2012-12-12 9:13 ` Daniel Mack
2012-12-12 23:02 ` Jon Hunter
2012-12-15 0:37 ` Grant Likely
2012-12-05 19:22 ` [PATCH v7 0/5] OMAP GPMC DT bindings Jon Hunter
2012-12-05 19:24 ` Daniel Mack
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=50C0C5AB.3030201@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