From: mishal@softerra.com (Mykhail Lodygin)
To: linux-arm-kernel@lists.infradead.org
Subject: Using SPI in a kernel module
Date: Sun, 27 Jun 2010 23:09:55 +0300 [thread overview]
Message-ID: <4C27B013.4010400@softerra.com> (raw)
In-Reply-To: <419523.332.qm@web33805.mail.mud.yahoo.com>
Hello
How about specifying correct data (for your particular board) in the
machine-specific code?(arch/your_arch/mach-your_machine/your_machine.c)
Basically it is enough for the system to invoke proper probes.
Mikhail
On 06/27/2010 09:25 PM, Alfredo Quesada S?nchez wrote:
> After reading many things about SPI in linux (including the kernel Documentation, that is, spi_summary.txt) and having read many source files in the kernel itself I'm not sure which is the right way to deal with SPI from a kernel module if you don't want to use the spidev (neither the spi-gpio) implementation.
>
> My goal is to create an spidev-like module, which generates a /dev entry (that is the easy part) and hides the details of the device, such as an EEPROM. The way to communicate with userspace using /dev files is simple, but the access to spi.h features isn't that much.
>
> According to some board specific code there is one spi device registered in the system (it's wired to a serial dataflash in my development board), but I don't know how I can get a reference to the spi_device that should give me access to it.
>
> By looking to other existing drivers I should register my own spi_driver, mostly providing probe and remove functions. And the questions are:
> - When should I receive a probe call?
> - What if I have more than 1 spi device on my system (let's say.. 3)? Will I receive 3 calls to probe?
> - Is this the only way to get valid references to spi_device's? Is there any other way to access to the "list" of available spi_device's?
>
> I did a small test with a fake module, which registers a spi_driver, but I did not receive any probe call, that's why this might not be the right way to access to the spi_device.
> Besides in other low level code I can see calls to
>
> Regards
>
>
>
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>
next prev parent reply other threads:[~2010-06-27 20:09 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-06-27 18:25 Using SPI in a kernel module Alfredo Quesada Sánchez
2010-06-27 20:09 ` Mykhail Lodygin [this message]
2010-06-27 20:55 ` Alfredo Quesada Sánchez
2010-06-27 21:26 ` Mykhail Lodygin
2010-06-27 21:47 ` Alfredo Quesada Sánchez
2010-06-27 22:30 ` Mykhail Lodygin
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=4C27B013.4010400@softerra.com \
--to=mishal@softerra.com \
--cc=linux-arm-kernel@lists.infradead.org \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.