BeagleBoard/SPI - Revision history

Bhensley at 04:03, 20 January 2013

2013-01-20T04:03:52Z

2012-02-27T01:12:33Z

2012-02-05T07:31:57Z

‎Discussion

2012-02-05T07:31:44Z

‎Discussion

2012-02-05T07:30:52Z

‎Discussion

2011-04-28T09:12:40Z

‎Little Word about recompiling the Kernel: Added link to rcn-ee kernel tools

2011-04-28T08:53:33Z

‎Patches: Added 2.6.38.2-d9 rcn-ee patch

2011-02-08T11:16:25Z

‎Configuring spi_board_info

2011-01-03T14:45:18Z

‎Patches

2010-12-15T01:04:18Z

‎Chip Select polarity

@@ Line 137: / Line 137: @@
 Here are some mailing list threads of various peoples' experiences getting SPI running on the Beagle:
 * [http://www.brianhensley.net/2012/02/spi-working-on-beagleboard-xm-rev-c.html MCSPI3 Detailed example (BBXm), Start->Finish]
 * [http://www.brianhensley.net/2012/02/python-controlling-spi-bus-on.html PYTHON SPI how to, BBXM]

@@ Line 138: / Line 138: @@
 * [http://www.brianhensley.net/2012/02/spi-working-on-beagleboard-xm-rev-c.html MCSPI3 Detailed example (BBXm), Start->Finish]
 * [http://groups.google.com/group/beagleboard/browse_thread/thread/42988f0e14db0f01/816397901ec999c4 MCSPI3 working, both ways]
 * [http://groups.google.com/group/beagleboard/browse_thread/thread/c72b69ed45d74403/39094d6bf4f457ad MCSPI TX works fine, but RX all zeros]

@@ Line 137: / Line 137: @@
 Here are some mailing list threads of various peoples' experiences getting SPI running on the Beagle:
-* [http://www.brianhensley.net/2012/02/spi-working-on-beagleboard-xm-rev-c.html MCSPI3 Detailed example (BBXm), start->Finish]
+* [http://www.brianhensley.net/2012/02/spi-working-on-beagleboard-xm-rev-c.html MCSPI3 Detailed example (BBXm), Start->Finish]
 * [http://groups.google.com/group/beagleboard/browse_thread/thread/42988f0e14db0f01/816397901ec999c4 MCSPI3 working, both ways]
 * [http://groups.google.com/group/beagleboard/browse_thread/thread/c72b69ed45d74403/39094d6bf4f457ad MCSPI TX works fine, but RX all zeros]

@@ Line 137: / Line 137: @@
 Here are some mailing list threads of various peoples' experiences getting SPI running on the Beagle:
-* [http://www.brianhensley.net/2012/02/spi-working-on-beagleboard-xm-rev-c.html MCSPI3 Detailed example, start->Finish]
+* [http://www.brianhensley.net/2012/02/spi-working-on-beagleboard-xm-rev-c.html MCSPI3 Detailed example (BBXm), start->Finish]
 * [http://groups.google.com/group/beagleboard/browse_thread/thread/42988f0e14db0f01/816397901ec999c4 MCSPI3 working, both ways]
 * [http://groups.google.com/group/beagleboard/browse_thread/thread/c72b69ed45d74403/39094d6bf4f457ad MCSPI TX works fine, but RX all zeros]

@@ Line 137: / Line 137: @@
 Here are some mailing list threads of various peoples' experiences getting SPI running on the Beagle:
 * [http://groups.google.com/group/beagleboard/browse_thread/thread/42988f0e14db0f01/816397901ec999c4 MCSPI3 working, both ways]
 * [http://groups.google.com/group/beagleboard/browse_thread/thread/c72b69ed45d74403/39094d6bf4f457ad MCSPI TX works fine, but RX all zeros]

@@ Line 96: / Line 96: @@
 == Little Word about recompiling the Kernel ==
 Ok, one would have acquired by now all the knowledge necessary to get SPI going on the Beagle Board. However, reconstructing the kernel via OE may be a little tricky, since it is a complex tool and some time is demanded to really understand it. Therefore, it is really useful to know how to compile the kernel by yourself, the instructions on [http://elinux.org/BeagleBoardLinuxKernel] tell you how to do it using "Quilt" (very very handy) kernel 2.6.28 is a good option for the ones using Quilt (take a look at the recipe and you will get why).
-Finally, Andruk has been very kind to provide his files mux.c(arch/arm/mach-omap2), mux.h(arch/arm/plat-omap/include/mach) and board-omap3beagle.c(arch/arm/mach-omap2) they are not to be copied but to be consulted and adapted to your needs.  Philip Balister has also made his patch for OE available (useful because it shows which configuration must be active in the kernel .config file).
 They can be found here: [[FILE:Reference_spi_files.tar.gz|get them here]]

@@ Line 91: / Line 91: @@
 == Patches ==
-These patches expose both McSPI 3 and 4 to userspace through spidev.
+* [[BeagleBoard/SPI/Patch-2.6.37|2.6.37]] ([[BeagleBoard/SPI/Config-2.6.37|config]]) Patch against kernel 2.6.37 to expose both McSPI 3 and 4 to userspace through spidev.
-* [[BeagleBoard/SPI/Patch-2.6.37|2.6.37]] ([[BeagleBoard/SPI/Config-2.6.37|config]])
+* [[BeagleBoard/SPI/Patch-rcn-ee-2.6.38.2-d9_mcspi3_gpio144_gpio183|rcn-ee 2.6.38.2-d9]] ([[BeagleBoard/SPI/Config-rcn-ee-2.6.38.2-d9|config]]) Patch against [[https://github.com/RobertCNelson/2.6.38-devel/tree/2.6.38.2-d9 rcn-ee patched kernel 2.6.38.2-d9]] to expose McSPI3 to userspace through spidev. One of the rcn-ee patches enables MMC2 which overrides mux settings for the McSPI3 pins; this patch disables this. It also disables I2C2 and makes GPIO_144 and GPIO_183 available via /sys/class/gpio.
 == Little Word about recompiling the Kernel ==

@@ Line 73: / Line 73: @@
 following,
 <pre>
-static struct spi_board_info beagle_mcspi_board_info = {
+static struct spi_board_info beagle_mcspi_board_info[] __initdata = {
 	.modalias	= "spidev",
 	.max_speed_hz	= 48000000, //48 Mbps
@@ Line 79: / Line 80: @@
 	.chip_select	= 0,
 	.mode = SPI_MODE_1,
 };
 </pre>

@@ Line 122: / Line 122: @@
 +               .mode = SPI_MODE_1 | SPI_CS_HIGH,
          },
 </pre>