From: "Michał Mirosław" <mirq-linux@rere.qmqm.pl>
To: linux-kernel@vger.kernel.org
Cc: drzeus-mmc@drzeus.cx, oakad@yahoo.com
Subject: MMC host driver requirements
Date: Sun, 7 Sep 2008 23:52:28 +0200 [thread overview]
Message-ID: <20080907215228.GA19193@rere.qmqm.pl> (raw)
Hello,
I'm writing a driver for ENE CB710/720 memory card readers found in some
laptops (ie. some versions of HP Compaq nx9500). This chip has three
memory card interfaces: MMC/SD, SmartMedia, MemoryStick. I started with
the MMC interface as I have a card to test it with, but I could not find
any documentation about MMC stack besides the source code.
So here are some questions:
1. Can I call mmc_detect_change() after mmc_alloc_host() but before or
during mmc_add_host() (ie. from interrupt handler)? If yes, what
if mmc_alloc_host() fails then?
2. Can I call mmc_request_done() from ->request() handler?
3. Does MMC stack serialize calls to ->request() or any other host
driver ops?
4. What is the difference (if any) between mrq->data and mrq->cmd->data
as seen from ->request()?
5. Are there any constraints to scatterlist passed to ->request()
- number of elements, data alignment, element data size?
(At first I assumed that there are none and have writted a simple
wrapper to guarantee multiple-of-16-byte data blocks - but maybe
its just not needed?)
If/when I finish the driver there is the question what are the
requirements for it to be accepted to mainline? It's based on
reverse-engineering work on a Windows driver so it will have
some magic register-access sequences, as the original driver used
completely different MMC/SD stack and probably not fully used chip's
capabilities.
BTW, Google said nothing interesting about the hardware: most hits are
about not existing drivers for it and manufacturer ignoring inquiries
for datasheets.
Best Regards,
Michał Mirosław
next reply other threads:[~2008-09-07 22:00 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-09-07 21:52 Michał Mirosław [this message]
2008-09-09 7:18 ` MMC host driver requirements Pierre Ossman
2008-09-09 9:06 ` Michał Mirosław
2008-09-11 20:13 ` Driver for CB710/720 memory card reader (MMC part) Michał Mirosław
2008-09-12 23:43 ` RFC: " Michał Mirosław
2008-09-20 11:00 ` Pierre Ossman
2008-09-25 6:29 ` RFC: Driver for CB710/720 memory card reader (MMC part) - v2 Michał Mirosław
2008-10-04 19:51 ` Pierre Ossman
2008-10-29 14:11 ` RFC: Driver for CB710/720 memory card reader (MMC part) - v3 Michał Mirosław
2008-11-14 21:06 ` Pierre Ossman
2009-02-01 18:54 ` Michał Mirosław
2009-02-21 12:46 ` Pierre Ossman
2009-05-08 15:16 ` [PATCH/RFC 2.6.29.2] Driver for CB710/720 memory card reader (MMC part) - v4 Michał Mirosław
2009-05-22 11:27 ` Pierre Ossman
2009-05-22 17:55 ` [PATCH 2.6.29.3] Driver for CB710/720 memory card reader (MMC part) - v5 Michał Mirosław
2009-05-22 18:33 ` [PATCH 2.6.29.4] Driver for CB710/720 memory card reader (MMC part) - v5 fixed Michał Mirosław
2009-05-27 20:13 ` Pierre Ossman
2009-06-04 10:24 ` Michał Mirosław
2009-06-05 9:26 ` Michał Mirosław
2009-06-13 10:39 ` Pierre Ossman
2009-05-22 19:04 ` [PATCH/RFC 2.6.29.2] Driver for CB710/720 memory card reader (MMC part) - v4 Bartlomiej Zolnierkiewicz
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