RE: API access I2C

From: Nguyen Duc Quan <hidden>
Date: 2008-10-10 00:03:08 

I think I2C-tools is what you need as sample code to access I2C in Linux. Here is the link
http://dl.lm-sensors.org/i2c-tools/releases/i2c-tools-3.0.1.tar.bz2
There are a lot of tools to access, set/get/dump register, read/write the I2C eeprom...
But please use them with care, especially when you try to read/write the device at address 0x50 ( it's is bootstrap eeprom). 
You might not boot up your board after playing with this device :-)
Quan Nguyen



----- Thư gốc ----
Từ: Duy-Ky Nguyen [off-list ref]
Đến: linuxppc-embedded@ozlabs.org
Gửi ngày: Thứ Sáu, 10 tháng 10, 2008 6:11:22
Chủ đề: API access I2C

Hello,

I have an eva board MPC8313E-RDB with 3 I2C device at address 48, 50, 68.
I'm able to read data from those 3 devices

I follow linux/Documentation/i2c/dev-interface to create a C code to access 
those 3 devices in Linux env, but all are failed !!!

I really appreciate your help where to find  info or sample code running in 
Linyux to access I2C devices

Thanks so much,

Duy-Ky

----- Original Message ----- 
From: <redacted>
To: <redacted>
Sent: Thursday, October 09, 2008 2:05 PM
Subject: Linuxppc-embedded Digest, Vol 50, Issue 14


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Today's Topics:

  1. Re: performance: memcpy vs. __copy_tofrom_user (Leon Woestenberg)
  2. Re: performance: memcpy vs. __copy_tofrom_user (Matt Sealey)
  3. Toolchain for ppc-440 without FPU (Ademir Zanetti Junior)
  4. Re: FS_ENET ERROR(s) 0x12 at second NFS RPC port lookup
     (100005/1) (Remi Lefevre)
  5. MTD map drivers (FSL UPM NAND) (Alemao)
  6. RE: Toolchain for ppc-440 without FPU (Ayman El-Khashab)


----------------------------------------------------------------------

Message: 1
Date: Thu, 9 Oct 2008 14:04:53 +0200
From: "Leon Woestenberg" <redacted>
Subject: Re: performance: memcpy vs. __copy_tofrom_user
To: "Dominik Bozek" <redacted>
Cc: linuxppc-dev@ozlabs.org, Paul Mackerras <redacted>,
linuxppc-embedded@ozlabs.org
Message-ID:
[ref]
Content-Type: text/plain; charset=ISO-8859-1

Hello all,

On Thu, Oct 9, 2008 at 1:41 PM, Dominik Bozek [off-list ref] 
wrote:
quoted
Paul Mackerras wrote:
quoted
Dominik Bozek writes:
quoted
Actually I made couple of other tests on that mpc8313. Most of them are
to ugly to publish them, but... My problem is that I have to boost the
gigabit interface on the mpc8313. I made simple substitution and
Very interesting.  Can you work out where memcpy is being called on
the network data?  I wouldn't have expected that.
Also see this recent thread David Jander on August 25th, "Efficient
memcpy()/memmove() for G2/G3 cores..."
on linuxppc-dev@ozlabs.org.

http://ozlabs.org/pipermail/linuxppc-dev/2008-September/062449.html

BTW, I am interested in this work as well, I'm currently working with
a 8313 and 8315 design, both are e300 cores.

My current goal is PCIe though, but I need fast GbE performance as well.

Also, did you test Freescale's 2.6.24.3 patches that tune the gianfar
interfaces for higher performance?

Regards,
-- 
Leon


------------------------------

Message: 2
Date: Thu, 09 Oct 2008 10:37:55 -0500
From: Matt Sealey <redacted>
Subject: Re: performance: memcpy vs. __copy_tofrom_user
To: Paul Mackerras <redacted>
Cc: linuxppc-dev@ozlabs.org, Dominik Bozek <redacted>,
linuxppc-embedded@ozlabs.org
Message-ID: [ref]
Content-Type: text/plain; charset=UTF-8; format=flowed

Paul Mackerras wrote:
quoted
Dominik Bozek writes:
quoted
Actually I made couple of other tests on that mpc8313. Most of them are
to ugly to publish them, but... My problem is that I have to boost the
gigabit interface on the mpc8313. I made simple substitution and
__copy_tofrom_user was used instead of memcpy. I know, it's wrong, but I
speedup that way the network interface for about 10%.
Very interesting.  Can you work out where memcpy is being called on
the network data?  I wouldn't have expected that.
It probably is somewhere.. through some weird and wonderful code path that
needs some serious digging to find. At least in 2.4 memcpy was used and
optimizing it (see Freescale's libmotovec benchmarks) did produce a 
sizable
performance improvement. That, and offloading TCP checksumming to AltiVec
helped a lot.

No help at all on an 8313 but, relevant anyway.

Since then zero copy networking and other fancy things like the DMA
engine API (for intel ioat at least but also there is fsl dma support)
there's less to actually optimize now so you're less likely to see the
same benefits. All these got into mainline because it's essential to
have this kind of architecture to get reasonable speeds out of >gigabit
network links.
quoted
There is actually no strong reason not to use __copy_tofrom_user as
memcpy, in fact, as long as we are sure that source and destination
are both cacheable.
I do think there is probably a good benefit in doing things like zeroing
pages in AltiVec and copying entire pages with AltiVec (for instance
when copy-on-write happens in an application) - NetBSD and QNX implement
at least this because it's faster than using the cache management and
works fine on uncacheable pages too (also since you're always aligned to
a page, zeroing 4kb aligned to a 4kb boundary - or whatever your page
size happens to be, the number of errors that can occur are absolutely
tiny and performance can go through the roof).

Ahem, but nobody here wants AltiVec in the kernel do they?

-- 
Matt Sealey [off-list ref]
Genesi, Manager, Developer Relations


------------------------------

Message: 3
Date: Thu, 9 Oct 2008 16:08:18 -0300
From: "Ademir Zanetti Junior" <redacted>
Subject: Toolchain for ppc-440 without FPU
To: linuxppc-embedded@ozlabs.org
Message-ID:
[ref]
Content-Type: text/plain; charset="utf-8"

Hello all,

I am trying to create a toolchain by hand and I am facing some problems 
when
I try to configure the glibc 2.7 for a powerpc. When I try to configure 
the
glibc to install the headers I get the following error:

configure --prefix=/usr --host=powerpc-440-linux-gnu
--with-headers=${SYSROOT}/usr/include --disable-shared --without-cvs
--with-binutils=/home/azanetti/ml507/powerpc/bin/

checking build system type... i686-pc-linux-gnu
checking host system type... i686-pc-linux-gnu
configure: running configure fragment for add-on nptl
checking sysdep dirs... sysdeps/i386/elf
nptl/sysdeps/unix/sysv/linux/i386/i686 nptl/sysdeps/unix/sysv/linux/i386
sysdeps/unix/sysv/linux/i386 nptl/sysdeps/unix/sysv/linux
nptl/sysdeps/pthread sysdeps/pthread sysdeps/unix/sysv/linux sysdeps/gnu
sysdeps/unix/common sysdeps/unix/mman sysdeps/unix/inet
sysdeps/unix/sysv/i386 nptl/sysdeps/unix/sysv sysdeps/unix/sysv
sysdeps/unix/i386 nptl/sysdeps/unix sysdeps/unix sysdeps/posix
sysdeps/i386/i686/fpu nptl/sysdeps/i386/i686 sysdeps/i386/i686
sysdeps/i386/i486 nptl/sysdeps/i386/i486 sysdeps/i386/fpu 
nptl/sysdeps/i386
sysdeps/i386 sysdeps/wordsize-32 sysdeps/ieee754/ldbl-96
sysdeps/ieee754/dbl-64 sysdeps/ieee754/flt-32 sysdeps/ieee754
sysdeps/generic/elf sysdeps/generic
checking for a BSD-compatible install... /usr/bin/install -c
checking whether ln -s works... yes
checking for gcc... gcc
checking for suffix of object files... o
checking whether we are using the GNU C compiler... yes
checking whether gcc accepts -g... yes
checking for gcc option to accept ISO C89... none needed
checking how to run the C preprocessor... gcc -E
checking for g++... g++

.
.
.
checking for long double... yes
checking size of long double... 12
running configure fragment for sysdeps/powerpc/powerpc32/elf
checking for powerpc32 TLS support... no
running configure fragment for sysdeps/unix/sysv/linux/powerpc
checking whether gcc -B/home/azanetti/ml507/powerpc/bin/ -g -O2
-mlong-double-128 uses IBM extended format... no
checking whether gcc -B/home/azanetti/ml507/powerpc/bin/ -g -O2 supports
-mabi=ibmlongdouble... no
configure: error: this configuration requires -mlong-double-128 IBM 
extended
format support


I already have the binutils 2.18 compiled on my PATH. I know that it is
easier to use a script like crosstool to compile it but I do want to
understand what is happening behind the scenes.

Regards.

Ademir
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------------------------------

Message: 4
Date: Thu, 9 Oct 2008 21:46:42 +0200
From: "Remi Lefevre" <redacted>
Subject: Re: FS_ENET ERROR(s) 0x12 at second NFS RPC port lookup
(100005/1)
To: "Scott Wood" <redacted>
Cc: linuxppc-embedded@ozlabs.org
Message-ID:
[ref]
Content-Type: text/plain; charset=ISO-8859-1

Ok, I'm sorry, I have incorrectly set the 60x pipeline depth to 0
instead of 1 in BCR register.
It works fine now. The side effect is interesting to know...

regards,
r?mi


------------------------------

Message: 5
Date: Thu, 9 Oct 2008 18:04:25 -0300
From: Alemao <redacted>
Subject: MTD map drivers (FSL UPM NAND)
To: linuxppc-embedded@ozlabs.org
Message-ID:
[ref]
Content-Type: text/plain; charset=ISO-8859-1

Hi all,

Im trying to use a physmap driver for NOR and NAND flash devices.

With NOR, everything ok. It uses CFI driver.

The problem is with NAND, cause it is connected at Freescale
LocalBus UPM, and at a first look, the UPM driver is loading after the
physmap (lines 14-15 in kernel output)

Here some outputs from the board:

Bootloader (U-Boot 1.2.0):

CPU:   e300c1, MPC8360E, Rev: 21 at 499.999 MHz, CSB:  333 MHz
Board: MPC8360KTX
I2C:   ready
DDR RAM: 128 MB
FLASH: 16 MB
NAND:  64 MiB
In:    serial
Out:   serial
Err:   serial


Kernel (linux-2.6.17):

1               physmap nor flash device: 1000000 at ff000000
2               NOR flash: Found 1 x16 devices at 0x0 in 16-bit bank
3                Amd/Fujitsu Extended Query Table at 0x0040
4                number of CFI chips: 1
5               Using physmap partition definition
6               Creating 6 MTD partitions on "NOR flash":
7               0x00000000-0x00040000 : "u-boot"
8               0x00040000-0x00060000 : "env."
9               0x00060000-0x00080000 : "sys"
10              0x00080000-0x000c0000 : "logs"
11              0x000c0000-0x00860000 : "admin"
12              0x00860000-0x01000000 : "users"
13
14              physmap nand flash device: 4000000 at 60000000
15              UPM: User-Programmable Machine NAND driver


Device Tree Source:

localbus@e0005000 {
 compatible = "fsl,board-localbus";
 #address-cells = <2>;
 #size-cells = <1>;
 reg = <e0005000 d8>;    // BRx, ORx, etc

 ranges = <0 0 ff000000 1000000     // nor flash,  16 MB
                   1 0 60000000 4000000>;   // nand flash, 64 MB

 flash@0,0 {
     compatible = "atmel,29LV256", "cfi-flash";
     reg = <0 0 1000000>;
     bank-width = <2>;
     device-width = <1>;
 };

 nand@1,0 {
     compatible = "stmicro,NAND512W3A", "fsl,upm-nand";
     reg = <1 0 4000000>;   //reg = <1 0 1>;
     width = <1>;
     upm = "A";
     upm-addr-offset = <16>;
     upm-cmd-offset = <8>;
     gpios = <4 18>;
     gpio-parent = <&qe_pio>;
     wait-pattern;
     wait-write;
 };
};

The CFI driver is at linux/drivers/mtd/chips
The UPM driver is at linux/drivers/mtd/nand

So, how can I load the UPM driver before physmap?

Thanks in advance,

--
Alemao


------------------------------

Message: 6
Date: Thu, 9 Oct 2008 16:05:47 -0500
From: "Ayman El-Khashab" <redacted>
Subject: RE: Toolchain for ppc-440 without FPU
To: "Ademir Zanetti Junior" <redacted>,
[off-list ref]
Message-ID:
[ref]
Content-Type: text/plain; charset="us-ascii"

I was compiling for the 440FP under cygwin, I believe that I had to use
--enable-long-long when I configured gcc in order to build glibc.

________________________________

From: linuxppc-embedded-bounces+aymane=tanisys.com@ozlabs.org
[mailto:linuxppc-embedded-bounces+aymane=tanisys.com@ozlabs.org] On
Behalf Of Ademir Zanetti Junior
Sent: Thursday, October 09, 2008 2:08 PM
To: linuxppc-embedded@ozlabs.org
Subject: Toolchain for ppc-440 without FPU


Hello all,

I am trying to create a toolchain by hand and I am facing some problems
when I try to configure the glibc 2.7 for a powerpc. When I try to
configure the glibc to install the headers I get the following error:

configure --prefix=/usr --host=powerpc-440-linux-gnu
--with-headers=${SYSROOT}/usr/include --disable-shared --without-cvs
--with-binutils=/home/azanetti/ml507/powerpc/bin/

checking build system type... i686-pc-linux-gnu
checking host system type... i686-pc-linux-gnu
configure: running configure fragment for add-on nptl
checking sysdep dirs... sysdeps/i386/elf
nptl/sysdeps/unix/sysv/linux/i386/i686 nptl/sysdeps/unix/sysv/linux/i386
sysdeps/unix/sysv/linux/i386 nptl/sysdeps/unix/sysv/linux
nptl/sysdeps/pthread sysdeps/pthread sysdeps/unix/sysv/linux sysdeps/gnu
sysdeps/unix/common sysdeps/unix/mman sysdeps/unix/inet
sysdeps/unix/sysv/i386 nptl/sysdeps/unix/sysv sysdeps/unix/sysv
sysdeps/unix/i386 nptl/sysdeps/unix sysdeps/unix sysdeps/posix
sysdeps/i386/i686/fpu nptl/sysdeps/i386/i686 sysdeps/i386/i686
sysdeps/i386/i486 nptl/sysdeps/i386/i486 sysdeps/i386/fpu
nptl/sysdeps/i386 sysdeps/i386 sysdeps/wordsize-32
sysdeps/ieee754/ldbl-96 sysdeps/ieee754/dbl-64 sysdeps/ieee754/flt-32
sysdeps/ieee754 sysdeps/generic/elf sysdeps/generic
checking for a BSD-compatible install... /usr/bin/install -c
checking whether ln -s works... yes
checking for gcc... gcc
checking for suffix of object files... o
checking whether we are using the GNU C compiler... yes
checking whether gcc accepts -g... yes
checking for gcc option to accept ISO C89... none needed
checking how to run the C preprocessor... gcc -E
checking for g++... g++

.
.
.
checking for long double... yes
checking size of long double... 12
running configure fragment for sysdeps/powerpc/powerpc32/elf
checking for powerpc32 TLS support... no
running configure fragment for sysdeps/unix/sysv/linux/powerpc
checking whether gcc -B/home/azanetti/ml507/powerpc/bin/ -g -O2
-mlong-double-128 uses IBM extended format... no
checking whether gcc -B/home/azanetti/ml507/powerpc/bin/ -g -O2 supports
-mabi=ibmlongdouble... no
configure: error: this configuration requires -mlong-double-128 IBM
extended format support


I already have the binutils 2.18 compiled on my PATH. I know that it is
easier to use a script like crosstool to compile it but I do want to
understand what is happening behind the scenes.

Regards.

Ademir

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