RE: [beagleboard] ioctl messages to Beagle SPI port.
Alright. Doing some more research on the web turned up one page where the user is referencing the original Molloy book and complaining about $SLOTs in chapter six not being relevant but using a current OS which doesn't have $SLOTS. The new edition of the book does not mention $SLOTS but instead config-pin for GPIO management. The sad thing is that Derek Molloy's book, only in passing refers to enabling the SPI port, and the book, in trying to also deal with the pocket beagle pins leaves out things where repetition is actually beneficial. Maybe somewhere it says that you have to use config-pin to set up SPI. I missed it. I think in Chapter 8 page 363 needs a bit of work. So here's what I did following part of that web page suggestion on the Buster image: debian@beaglebone:~/exploringBB/chp08/spi/spidev_test$ config-pin p9.17 spi_cs Current mode for P9_17 is: spi_cs debian@beaglebone:~/exploringBB/chp08/spi/spidev_test$ config-pin p9.22 spi_sclk Current mode for P9_22 is: spi_sclk debian@beaglebone:~/exploringBB/chp08/spi/spidev_test$ config-pin p9.21 spi Current mode for P9_21 is: spi debian@beaglebone:~/exploringBB/chp08/spi/spidev_test$ config-pin p9.18 spi Current mode for P9_18 is: spi I hadn't realized that this was needed if the spi device was opened as a fille. I assumed opening a /dev/spi0.0 would automatically claim the pins for SPI. So with MOSI connected to MISO and specifying the SPI0 port since SPI1 is used by HDMI I get: debian@beaglebone:~/exploringBB/chp08/spi/spidev_test$ ./spidev_test -D /dev/spidev0.0 spi mode: 0 bits per word: 8 max speed: 50 Hz (500 KHz) FF FF FF FF FF FF 40 00 00 00 00 95 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF DE AD BE EF BA AD F0 0D And that data matches what the scope tells me in the attached photo. Clock is yellow trace. MOSI is Blue. Green is CS. Oh and none of this explains why the ioctl regardless of C or Pascal can't handle more than 4096 data bytes while the Python code can when sending a large bitmap to the SPI port. Nor why, according to this web site https://learn.adafruit.com/setting-up-io-python-library-on-beaglebone-black/spi nothing is said about config-pin operations so the python library must do this automatically? Now to try this on the Stretch OS based Beagle. John From: beagleboard@googlegroups.com [mailto:beagleboard@googlegroups.com] On Behalf Of John Dammeyer Sent: May-20-21 5:43 PM To: beagleboard@googlegroups.com Subject: RE: [beagleboard] ioctl messages to Beagle SPI port. The latest version of Buster does this when I look for SPI bus ports. The older Stretch version doesn't have the 0.0 and 0.1 and everything is scaled up by 1. On either system the scope doesn't show any activity on the SPI0 pins. No CS, no CLK no Data Out. The test program from Exploring Beaglebone with the DI connected to the DO does not behave with the table changed from the output stream to input which makes sense since there isn't any output on the MOSI or MISO pins. Any suggestions on how to get SPI working? debian@beaglebone:~$ uname -a Linux beaglebone 4.19.94-ti-r63 #1buster SMP PREEMPT Fri May 14 16:42:32 UTC 2021 armv7l GNU/Linux debian@beaglebone:~$ ls -l /dev/spi* crw-rw 1 root spi 153, 0 May 20 17:24 /dev/spidev0.0 crw-rw 1 root spi 153, 1 May 20 17:24 /dev/spidev0.1 crw-rw 1 root spi 153, 2 May 20 17:24 /dev/spidev1.0 crw-rw 1 root spi 153, 3 May 20 17:24 /dev/spidev1.1 debian@beaglebone:~$ debian@ebb:~$ uname -a Linux ebb 4.14.108-ti-r136 #1stretch SMP PREEMPT Mon Jun 8 15:38:30 UTC 2020 armv7l GNU/Linux debian@ebb:~$ ls -l /dev/spi* crw-rw 1 root spi 153, 0 May 20 16:45 /dev/spidev1.0 crw-rw 1 root spi 153, 1 May 20 16:45 /dev/spidev1.1 crw-rw 1 root spi 153, 2 May 20 16:45 /dev/spidev2.0 crw-rw 1 root spi 153, 3 May 20 16:45 /dev/spidev2.1 /dev/spi: total 0 lrwxrwxrwx 1 root root 12 May 20 16:45 0.0 -> ../spidev1.0 lrwxrwxrwx 1 root root 12 May 20 16:45 0.1 -> ../spidev1.1 lrwxrwxrwx 1 root root 12 May 20 16:45 1.0 -> ../spidev2.0 lrwxrwxrwx 1 root root 12 May 20 16:45 1.1 -> ../spidev2.1 debian@ebb:~$ == debian@beaglebone:~/exploringBB/chp08/spi/spidev_test$ ./spidev_test -D /dev/spidev0.0 spi mode: 0 bits per word: 8 max speed: 50 Hz (500 KHz) 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 debian@beaglebone:~/exploringBB/chp08/spi/spidev_test$ -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/0
RE: [beagleboard] ioctl messages to Beagle SPI port.
The latest version of Buster does this when I look for SPI bus ports. The older Stretch version doesn't have the 0.0 and 0.1 and everything is scaled up by 1. On either system the scope doesn't show any activity on the SPI0 pins. No CS, no CLK no Data Out. The test program from Exploring Beaglebone with the DI connected to the DO does not behave with the table changed from the output stream to input which makes sense since there isn't any output on the MOSI or MISO pins. Any suggestions on how to get SPI working? debian@beaglebone:~$ uname -a Linux beaglebone 4.19.94-ti-r63 #1buster SMP PREEMPT Fri May 14 16:42:32 UTC 2021 armv7l GNU/Linux debian@beaglebone:~$ ls -l /dev/spi* crw-rw 1 root spi 153, 0 May 20 17:24 /dev/spidev0.0 crw-rw 1 root spi 153, 1 May 20 17:24 /dev/spidev0.1 crw-rw 1 root spi 153, 2 May 20 17:24 /dev/spidev1.0 crw-rw 1 root spi 153, 3 May 20 17:24 /dev/spidev1.1 debian@beaglebone:~$ debian@ebb:~$ uname -a Linux ebb 4.14.108-ti-r136 #1stretch SMP PREEMPT Mon Jun 8 15:38:30 UTC 2020 armv7l GNU/Linux debian@ebb:~$ ls -l /dev/spi* crw-rw 1 root spi 153, 0 May 20 16:45 /dev/spidev1.0 crw-rw 1 root spi 153, 1 May 20 16:45 /dev/spidev1.1 crw-rw 1 root spi 153, 2 May 20 16:45 /dev/spidev2.0 crw-rw 1 root spi 153, 3 May 20 16:45 /dev/spidev2.1 /dev/spi: total 0 lrwxrwxrwx 1 root root 12 May 20 16:45 0.0 -> ../spidev1.0 lrwxrwxrwx 1 root root 12 May 20 16:45 0.1 -> ../spidev1.1 lrwxrwxrwx 1 root root 12 May 20 16:45 1.0 -> ../spidev2.0 lrwxrwxrwx 1 root root 12 May 20 16:45 1.1 -> ../spidev2.1 debian@ebb:~$ == debian@beaglebone:~/exploringBB/chp08/spi/spidev_test$ ./spidev_test -D /dev/spidev0.0 spi mode: 0 bits per word: 8 max speed: 50 Hz (500 KHz) 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 debian@beaglebone:~/exploringBB/chp08/spi/spidev_test$ -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/034801d74dda%2435a8c060%24a0fa4120%24%40autoartisans.com.
RE: [beagleboard] ioctl messages to Beagle SPI port.
Unlike Delphi or say the 9S12 or PIC debugger the Lazarus shows the source but
doesn't seem to have a step ability in machine language. So I can see what
it's doing and even the registers but nothing more.
Given that the C code works perfectly and the Pascal stuff sends the same
information I suspect the problem isn't with the OS but perhaps pointer
formatting or something like that.
Still working on it. Without these kinds of problems I never really learn how
things are put together. So it's not a bad thing. Just annoying. The system
can send ioctl messages directly as shown in the log. But when using the
transfer function it dies.
So something between 2017 when this code was released and now there is
something slightly different.
John
From: 'Mark Lazarewicz' via BeagleBoard [mailto:beagleboard@googlegroups.com]
Sent: May-19-21 10:43 PM
To: beagleboard@googlegroups.com
Subject: RE: [beagleboard] ioctl messages to Beagle SPI port.
# I can't step the machine code past the ioctl system call
Hi John
What are using to step? It's been a long time but I remember being able to go
as deep as I wanted into the linux OS. The hard part was getting kernel source
code setup but i had that working requires debugging from linux build machine
but you don't seem adverse to assembly language. Probally unrelated but each
high level language passes it's function parameters to the registers in a
certain order. I know because we switched from PLM 86 to C one was right to
left the other was reversed I wrote an assembler library to fix this in the 80s.
You should be able to step into into anything in mixed c and assembler mode.
Sorry if I'm not totally understanding but it sounds like you could get insight
if you could step into the ioctl
if its a function you should be able to . C Macros you can't but it doesn't
look like what that is.
Mark
Sent from Yahoo Mail on Android
<https://go.onelink.me/107872968?pid=InProduct=Global_Internal_YGrowth_AndroidEmailSig__AndroidUsers_wl=ym_sub1=Internal_sub2=Global_YGrowth_sub3=EmailSignature>
On Wed, May 19, 2021 at 11:10 PM, John Dammeyer
wrote:
So to add this so the research I did isn't repeated.
The control message breaks down as follows:
Top two bits are the direction. The 'k' (0x6B) identifies the SPI type. The
number of bytes is placed into the 32 bit word with the _IOC_NRSHIFT which in
itself is also a macro all defined in the asm generic ioctl.h file.
ret = ioctl(fd, _IOC(_IOC_WRITE,('k'),(1),(8), );
#define _IOC(dir,type,nr,size) \
(((dir) << _IOC_DIRSHIFT) | \
((type) << _IOC_TYPESHIFT) | \
((nr) << _IOC_NRSHIFT) | \
((size) << _IOC_SIZESHIFT))
The shifts are defined to create this and it's quite convoluted to get there.
SPI_IOC_MESSAGE(1) = 40206B00
define _IOC_NRBITS 8
#define _IOC_TYPEBITS 8
/*
* Let any architecture override either of the following before
* including this file.
*/
#ifndef _IOC_SIZEBITS
# define _IOC_SIZEBITS 14
#endif
#ifndef _IOC_DIRBITS
# define _IOC_DIRBITS 2
#endif
#define _IOC_NRMASK ((1 << _IOC_NRBITS)-1)
#define _IOC_TYPEMASK ((1 << _IOC_TYPEBITS)-1)
#define _IOC_SIZEMASK ((1 << _IOC_SIZEBITS)-1)
#define _IOC_DIRMASK((1 << _IOC_DIRBITS)-1)
#define _IOC_NRSHIFT0
#define _IOC_TYPESHIFT (_IOC_NRSHIFT+_IOC_NRBITS)
#define _IOC_SIZESHIFT (_IOC_TYPESHIFT+_IOC_TYPEBITS)
#define _IOC_DIRSHIFT (_IOC_SIZESHIFT+_IOC_SIZEBITS)
#define _IOC_NRSHIFT0
#define _IOC_TYPESHIFT (_IOC_NRSHIFT+_IOC_NRBITS)
#define _IOC_SIZESHIFT (_IOC_TYPESHIFT+_IOC_TYPEBITS)
#define _IOC_DIRSHIFT (_IOC_SIZESHIFT+_IOC_SIZEBITS)
From: beagleboard@googlegroups.com [mailto:beagleboard@googlegroups.com] On
Behalf Of John Dammeyer
Sent: May-19-21 8:44 PM
To: beagleboard@googlegroups.com
Subject: [beagleboard] ioctl messages to Beagle SPI port.
The spidev_test.c program from the Exploring BeagleBone by Derek Molloy (chp08)
tests the SPI port by setting the SPI parameters and then writing out a test
block. The text diagnostics I've added show what the macro was that is sent as
part of the ioctl call. Trying to break down the macro through multiple files
turned into a dead end and I'm not exactly sure what the 32 bit word means
other than byte count and I believe message type.
The program starts out by sending 6 ioctl messages that configure mode, size
and speed.
Here's the call that returns the 0x4006B00 and below the result of the message.
ret = ioctl(fd, SPI_IOC_MESSAGE(1), );
debian@ebb:~/exploringBB/chp08/spi/spidev_test$ ./spidev_test
SPI_IOC_WR_MODE = 40016B01
SPI_IOC_RD_MODE = 80016B01
SPI_IOC_WR_BITS_PER_WORD = 40016B03
SPI_IOC_RD_BITS_PER_WORD = 80016B03
SPI_IOC_WR_MAX_SPEED_HZ = 40046B04
SPI_IOC_RD_MAX_SPEED_HZ = 80046B04
spi mode: 0
bits per word: 8
max speed: 50 Hz (500 KHz)
SPI_IOC_MESSAGE(1) = 40206B00
00 00 00 00 00 00
RE: [beagleboard] ioctl messages to Beagle SPI port.
# I can't step the machine code past the ioctl system call
Hi John
What are using to step? It's been a long time but I remember being able to go
as deep as I wanted into the linux OS. The hard part was getting kernel source
code setup but i had that working requires debugging from linux build machine
but you don't seem adverse to assembly language. Probally unrelated but each
high level language passes it's function parameters to the registers in a
certain order. I know because we switched from PLM 86 to C one was right to
left the other was reversed I wrote an assembler library to fix this in the 80s.
You should be able to step into into anything in mixed c and assembler mode.
Sorry if I'm not totally understanding but it sounds like you could get insight
if you could step into the ioctl
if its a function you should be able to . C Macros you can't but it doesn't
look like what that is.
Mark
Sent from Yahoo Mail on Android
On Wed, May 19, 2021 at 11:10 PM, John Dammeyer
wrote: #yiv3788565027 #yiv3788565027 -- _filtered {} _filtered {} _filtered
{}#yiv3788565027 #yiv3788565027 p.yiv3788565027MsoNormal, #yiv3788565027
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So to add this so the research I did isn't repeated.
The control message breaks down as follows:
Top two bits are the direction. The 'k' (0x6B) identifies the SPI type. The
number of bytes is placed into the 32 bit word with the _IOC_NRSHIFT which in
itself is also a macro all defined in the asm generic ioctl.h file.
ret = ioctl(fd, _IOC(_IOC_WRITE,('k'),(1),(8), );
#define _IOC(dir,type,nr,size) \
(((dir) << _IOC_DIRSHIFT) | \
((type) << _IOC_TYPESHIFT) | \
((nr) << _IOC_NRSHIFT) | \
((size) << _IOC_SIZESHIFT))
The shifts are defined to create this and it's quite convoluted to get there.
SPI_IOC_MESSAGE(1) = 40206B00
define _IOC_NRBITS 8
#define _IOC_TYPEBITS 8
/*
* Let any architecture override either of the following before
* including this file.
*/
#ifndef _IOC_SIZEBITS
# define _IOC_SIZEBITS 14
#endif
#ifndef _IOC_DIRBITS
# define _IOC_DIRBITS 2
#endif
#define _IOC_NRMASK ((1 << _IOC_NRBITS)-1)
#define _IOC_TYPEMASK ((1 << _IOC_TYPEBITS)-1)
#define _IOC_SIZEMASK ((1 << _IOC_SIZEBITS)-1)
#define _IOC_DIRMASK ((1 << _IOC_DIRBITS)-1)
#define _IOC_NRSHIFT 0
#define _IOC_TYPESHIFT (_IOC_NRSHIFT+_IOC_NRBITS)
#define _IOC_SIZESHIFT (_IOC_TYPESHIFT+_IOC_TYPEBITS)
#define _IOC_DIRSHIFT (_IOC_SIZESHIFT+_IOC_SIZEBITS)
#define _IOC_NRSHIFT 0
#define _IOC_TYPESHIFT (_IOC_NRSHIFT+_IOC_NRBITS)
#define _IOC_SIZESHIFT (_IOC_TYPESHIFT+_IOC_TYPEBITS)
#define _IOC_DIRSHIFT (_IOC_SIZESHIFT+_IOC_SIZEBITS)
From: beagleboard@googlegroups.com [mailto:beagleboard@googlegroups.com] On
Behalf Of John Dammeyer
Sent: May-19-21 8:44 PM
To: beagleboard@googlegroups.com
Subject: [beagleboard] ioctl messages to Beagle SPI port.
The spidev_test.c program from the Exploring BeagleBone by Derek Molloy (chp08)
tests the SPI port by setting the SPI parameters and then writing out a test
block. The text diagnostics I've added show what the macro was that is sent as
part of the ioctl call. Trying to break down the macro through multiple files
turned into a dead end and I'm not exactly sure what the 32 bit word means
other than byte count and I believe message type.
The program starts out by sending 6 ioctl messages that configure mode, size
and speed.
Here's the call that returns the 0x4006B00 and below the result of the message.
ret = ioctl(fd, SPI_IOC_MESSAGE(1), );
debian@ebb:~/exploringBB/chp08/spi/spidev_test$ ./spidev_test
SPI_IOC_WR_MODE = 40016B01
SPI_IOC_RD_MODE = 80016B01
SPI_IOC_WR_BITS_PER_WORD = 40016B03
SPI_IOC_RD_BITS_PER_WORD = 80016B03
SPI_IOC_WR_MAX_SPEED_HZ = 40046B04
SPI_IOC_RD_MAX_SPEED_HZ = 80046B04
spi mode: 0
bits per word: 8
max speed: 50 Hz (500 KHz)
SPI_IOC_MESSAGE(1) = 40206B00
00 00 00 00 00 00
00 00 00 00
RE: [beagleboard] ioctl messages to Beagle SPI port.
So to add this so the research I did isn't repeated.
The control message breaks down as follows:
Top two bits are the direction. The 'k' (0x6B) identifies the SPI type. The
number of bytes is placed into the 32 bit word with the _IOC_NRSHIFT which in
itself is also a macro all defined in the asm generic ioctl.h file.
ret = ioctl(fd, _IOC(_IOC_WRITE,('k'),(1),(8), );
#define _IOC(dir,type,nr,size) \
(((dir) << _IOC_DIRSHIFT) | \
((type) << _IOC_TYPESHIFT) | \
((nr) << _IOC_NRSHIFT) | \
((size) << _IOC_SIZESHIFT))
The shifts are defined to create this and it's quite convoluted to get there.
SPI_IOC_MESSAGE(1) = 40206B00
define _IOC_NRBITS 8
#define _IOC_TYPEBITS 8
/*
* Let any architecture override either of the following before
* including this file.
*/
#ifndef _IOC_SIZEBITS
# define _IOC_SIZEBITS 14
#endif
#ifndef _IOC_DIRBITS
# define _IOC_DIRBITS 2
#endif
#define _IOC_NRMASK ((1 << _IOC_NRBITS)-1)
#define _IOC_TYPEMASK ((1 << _IOC_TYPEBITS)-1)
#define _IOC_SIZEMASK ((1 << _IOC_SIZEBITS)-1)
#define _IOC_DIRMASK((1 << _IOC_DIRBITS)-1)
#define _IOC_NRSHIFT0
#define _IOC_TYPESHIFT (_IOC_NRSHIFT+_IOC_NRBITS)
#define _IOC_SIZESHIFT (_IOC_TYPESHIFT+_IOC_TYPEBITS)
#define _IOC_DIRSHIFT (_IOC_SIZESHIFT+_IOC_SIZEBITS)
#define _IOC_NRSHIFT0
#define _IOC_TYPESHIFT (_IOC_NRSHIFT+_IOC_NRBITS)
#define _IOC_SIZESHIFT (_IOC_TYPESHIFT+_IOC_TYPEBITS)
#define _IOC_DIRSHIFT (_IOC_SIZESHIFT+_IOC_SIZEBITS)
From: beagleboard@googlegroups.com [mailto:beagleboard@googlegroups.com] On
Behalf Of John Dammeyer
Sent: May-19-21 8:44 PM
To: beagleboard@googlegroups.com
Subject: [beagleboard] ioctl messages to Beagle SPI port.
The spidev_test.c program from the Exploring BeagleBone by Derek Molloy (chp08)
tests the SPI port by setting the SPI parameters and then writing out a test
block. The text diagnostics I've added show what the macro was that is sent as
part of the ioctl call. Trying to break down the macro through multiple files
turned into a dead end and I'm not exactly sure what the 32 bit word means
other than byte count and I believe message type.
The program starts out by sending 6 ioctl messages that configure mode, size
and speed.
Here's the call that returns the 0x4006B00 and below the result of the message.
ret = ioctl(fd, SPI_IOC_MESSAGE(1), );
debian@ebb:~/exploringBB/chp08/spi/spidev_test$ ./spidev_test
SPI_IOC_WR_MODE = 40016B01
SPI_IOC_RD_MODE = 80016B01
SPI_IOC_WR_BITS_PER_WORD = 40016B03
SPI_IOC_RD_BITS_PER_WORD = 80016B03
SPI_IOC_WR_MAX_SPEED_HZ = 40046B04
SPI_IOC_RD_MAX_SPEED_HZ = 80046B04
spi mode: 0
bits per word: 8
max speed: 50 Hz (500 KHz)
SPI_IOC_MESSAGE(1) = 40206B00
00 00 00 00 00 00
00 00 00 00 00 00
00 00 00 00 00 00
00 00 00 00 00 00
00 00 00 00 00 00
00 00 00 00 00 00
00 00
Now. Switch over to a part of the DisplaySPI program in the Lazarus Free
Pascal pxl library the function call looks the same as do the SPI
initialization calls to fpioctl. They are in a different order from the C
program.
Res := fpioctl(FHandle, SPI_IOC_MESSAGE(1), @Data);
Six of the ioctl function calls do not return an error. The main one to send
data has the correct
SPI_IOC_MESSAGE(1) value yet it fails.
debian@ebb:~/lazarus/pxl/Samples/FreePascal/SingleBoard/Generic/DisplaySPI$
./DisplaySPI
UpdateFrequency -- SPI_IOC_WR_MAX_SPEED_HZ is 40046B04
UpdateFrequency -- SPI_IOC_RD_MAX_SPEED_HZ is 80046B04
UpdateBitsPerWord -- SPI_IOC_WR_BITS_PER_WORD is 40016B03
UpdateBitsPerWord -- SPI_IOC_RD_BITS_PER_WORD is 80016B03
UpdateRWMode -- SPI_IOC_WR_MODE is 40016B01
UpdateRWMode -- SPI_IOC_RD_MODE is 80016B01
SPI_IOC_MESSAGE(1) is 40206B00
An unhandled exception occurred at $000330A8:
ESysfsSPITransfer: Cannot transfer
<1> data byte(s) through SPI bus.
$000330A8 TSYSFSSPI__TRANSFER, line 263 of
/home/debian/lazarus/pxl/Source/PXL.Sysfs.SPI.pas
$00032F54 TSYSFSSPI__WRITE,
line 241 of /home/debian/lazarus/pxl/Source/PXL.Sysfs.SPI.pas
Is there some documentation out there on the ioctl call and what the actual
parameter means in detail with respect to the BeagleBone processor? The man
page states that command is specific to the device.
https://man7.org/linux/man-pages/man2/ioctl.2.html
I'm having trouble figuring out why it fails or more specifically where to look
next. I can't step the machine code past the ioctl system call so I'd like to
know what is actually going on inside the OS with this call inside the Beagle.
Thanks
John
"ELS! Nothing else works as well for your Lathe"
Automation Artisans Inc.
www dot autoartisans dot com
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