From: "Lars K.W. Gohlke" <lkwg82@gmx.de>
To: Jan Engelhardt <jengelh@linux01.gwdg.de>
Cc: Tilman Schmidt <tilman@imap.cc>, linux-kernel@vger.kernel.org
Subject: Re: How to access correctly serial port inside module?
Date: Thu, 24 May 2007 21:15:47 +0200 [thread overview]
Message-ID: <4655E463.7000201@gmx.de> (raw)
In-Reply-To: <Pine.LNX.4.61.0705241927410.31549@yvahk01.tjqt.qr>
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Jan Engelhardt schrieb:
> On May 24 2007 19:19, Lars K.W. Gohlke wrote:
>> I want to read from serial port (I mean the port, which is called
>> /dev/ttyS0 in user-space). Then I want copy_to_user() it through
>> /proc/serialPort
>>
>> This is just to get familiar with driver programming (in kernelspace),
>> it could be better done in userspace - I know. But this is for learning.
>>
>> It is a kind of synthetic problem, but after this, I hope too know how
>> to handle further ones.
>>
>> Understood? It is a little bit strange, but hope it is explained well. ;)
>>
>> If tell me that for /dev/ttyS0 I can adept it to /dev/ttyS1 etc..
>
>
> struct file *filp = filp_open("/dev/ttyS0");
> char buf[4096];
> mm_segment_t oldfs = get_fs();
> loff_t pos = 0;
>
> set_ds(KERNEL_DS);
> while (vfs_read(filp, buf, sizeof(buf), &pos) > 0)
> printk("%s\n", buf);
>
> filp_close(filp);
>
>
>
> [I've warned about it... ;-) ]
>
> Jan
is it the way to access from kernelspace the userspace fs?
the not-correct-way?
If it is so, I will wait for another solution ;)
Dont want to learn writing nasty kernel code. *g*
Anyway thx.
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next prev parent reply other threads:[~2007-05-24 19:15 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-05-14 13:00 How to access correctly serial port inside module? Lars K.W. Gohlke
2007-05-14 17:40 ` Lars K.W. Gohlke
2007-05-14 20:00 ` Jan Engelhardt
2007-05-14 20:25 ` Lars K.W. Gohlke
2007-05-14 23:00 ` Tilman Schmidt
2007-05-15 8:43 ` Jan Engelhardt
2007-05-22 22:17 ` Tilman Schmidt
2007-05-24 10:22 ` Lars K.W. Gohlke
2007-05-24 10:26 ` Jan Engelhardt
2007-05-24 10:45 ` Lars K.W. Gohlke
2007-05-24 10:50 ` Jan Engelhardt
2007-05-24 11:20 ` Lars K.W. Gohlke
2007-05-24 17:03 ` Tilman Schmidt
2007-05-24 17:19 ` Lars K.W. Gohlke
2007-05-24 17:29 ` Jan Engelhardt
2007-05-24 19:15 ` Lars K.W. Gohlke [this message]
2007-05-28 17:05 ` Tilman Schmidt
2007-05-28 19:03 ` Jan Engelhardt
2007-05-30 7:07 ` Lars K.W. Gohlke
2007-05-30 7:46 ` Lars K.W. Gohlke
2007-05-30 9:38 ` Tilman Schmidt
[not found] ` <851fc09e0705162315w3380ddabh9b9f0b2198cb8457@mail.gmail.com>
2007-05-22 21:55 ` Tilman Schmidt
2007-06-03 20:28 ` Lars K.W. Gohlke
2007-06-05 21:41 ` Tilman Schmidt
2007-06-06 8:27 ` Lars K.W. Gohlke
2007-06-07 22:25 ` Lars K.W. Gohlke
2007-06-08 0:27 ` Tilman Schmidt
2007-05-14 22:37 ` Tilman Schmidt
2007-05-24 10:51 ` Lars K.W. Gohlke
-- strict thread matches above, loose matches on Subject: below --
2007-06-05 7:55 Lars K.W. Gohlke
2007-06-07 22:27 Lars K.W. Gohlke
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