API access I2C
Duy-Ky Nguyen
duykynguyen at hotmail.com
Fri Oct 10 10:11:22 EST 2008
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: <linuxppc-embedded-request at ozlabs.org>
To: <linuxppc-embedded at ozlabs.org>
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" <leon.woestenberg at gmail.com>
> Subject: Re: performance: memcpy vs. __copy_tofrom_user
> To: "Dominik Bozek" <domino at mikroswiat.pl>
> Cc: linuxppc-dev at ozlabs.org, Paul Mackerras <paulus at samba.org>,
> linuxppc-embedded at ozlabs.org
> Message-ID:
> <c384c5ea0810090504x570cb6aai6d136a150e74ac05 at mail.gmail.com>
> Content-Type: text/plain; charset=ISO-8859-1
>
> Hello all,
>
> On Thu, Oct 9, 2008 at 1:41 PM, Dominik Bozek <domino at mikroswiat.pl>
> wrote:
>> Paul Mackerras wrote:
>>> Dominik Bozek writes:
>>>> 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 at 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 <matt at genesi-usa.com>
> Subject: Re: performance: memcpy vs. __copy_tofrom_user
> To: Paul Mackerras <paulus at samba.org>
> Cc: linuxppc-dev at ozlabs.org, Dominik Bozek <domino at mikroswiat.pl>,
> linuxppc-embedded at ozlabs.org
> Message-ID: <48EE2553.30903 at genesi-usa.com>
> Content-Type: text/plain; charset=UTF-8; format=flowed
>
> Paul Mackerras wrote:
>> Dominik Bozek writes:
>>
>>> 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.
>
>> 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 <matt at genesi-usa.com>
> Genesi, Manager, Developer Relations
>
>
> ------------------------------
>
> Message: 3
> Date: Thu, 9 Oct 2008 16:08:18 -0300
> From: "Ademir Zanetti Junior" <ademirzanetti at gmail.com>
> Subject: Toolchain for ppc-440 without FPU
> To: linuxppc-embedded at ozlabs.org
> Message-ID:
> <2204d6480810091208u1776e81fx6597719734751edb at mail.gmail.com>
> 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" <rlefevre at gmail.com>
> Subject: Re: FS_ENET ERROR(s) 0x12 at second NFS RPC port lookup
> (100005/1)
> To: "Scott Wood" <scottwood at freescale.com>
> Cc: linuxppc-embedded at ozlabs.org
> Message-ID:
> <4e0b9cb00810091246i2f200dbn9f8dc9877800e629 at mail.gmail.com>
> 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 <xcarandiru at gmail.com>
> Subject: MTD map drivers (FSL UPM NAND)
> To: linuxppc-embedded at ozlabs.org
> Message-ID:
> <d970ff420810091404j49492e80xcd9250d0ffdcd592 at mail.gmail.com>
> 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 at 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 at 0,0 {
> compatible = "atmel,29LV256", "cfi-flash";
> reg = <0 0 1000000>;
> bank-width = <2>;
> device-width = <1>;
> };
>
> nand at 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" <AymanE at tanisys.com>
> Subject: RE: Toolchain for ppc-440 without FPU
> To: "Ademir Zanetti Junior" <ademirzanetti at gmail.com>,
> <linuxppc-embedded at ozlabs.org>
> Message-ID:
> <16691A8B34B5D9458EA3A1C37A11555A0137F80B at tanisys-ex2.Tanisys.Local>
> 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 at ozlabs.org
> [mailto:linuxppc-embedded-bounces+aymane=tanisys.com at ozlabs.org] On
> Behalf Of Ademir Zanetti Junior
> Sent: Thursday, October 09, 2008 2:08 PM
> To: linuxppc-embedded at 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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