| Message ID | 50C5E23D.5040605@communistcode.co.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi, On Mon, Dec 10, 2012 at 01:23:09PM +0000, Jack Mitchell wrote: > Hi, > > I am currently having issues with the SPI driver on the beaglebone > using the 3.7-rc8 kernel[1]. I have probed the SPI pins and I have > found that writing works however reading doesn't. When using DMA the > program seems to lock hard and no data is sent on the bus. I am > testing the bus using spidev and the spidev_test[2] application, > however I first came across spi issues with a custom spi driver which > stopped working when I transitioned from 3.2-psp to 3.7-rc8. > > The current output I am seeing from the spidev_test program is just a > series of 0x00 data, which looks to me like no data is getting in at > all. The spidev_test program is not using DMA as the buffer size is > too low, so I forced the dma on when buffer size is > 1 and the > program hangs hard with the system still responding to other > commands.I have briged the pins 18 and 21 on the BeagleBone P9 > header. > > Has anyone seen issues like this, or if not if someone could please > test the latest 3.7-rc8 from [1] and let me know if it works for them > and the issue is at my end. > > To get spidev working with devicetree I applied the patch from [3] > and changed the dtb as in the patch pasted below. > > [1] https://github.com/beagleboard/kernel/tree/3.7 > [2] http://lxr.linux.no/#linux+v3.6.9/Documentation/spi/spidev_test.c > [3] http://www.mail-archive.com/spi-devel-general@lists.sourceforge.net/msg09958.html do you have any debugging output from that driver ? It would be cool to see if DMA is at least being kicked properly for small transfers. It would also be nice to have a clear picture of what "custom spi driver" you're talking about. cheers
Hi Felipe, On 10/12/12 13:53, Felipe Balbi wrote: > Hi, > > On Mon, Dec 10, 2012 at 01:23:09PM +0000, Jack Mitchell wrote: >> Hi, >> >> I am currently having issues with the SPI driver on the beaglebone >> using the 3.7-rc8 kernel[1]. I have probed the SPI pins and I have >> found that writing works however reading doesn't. When using DMA the >> program seems to lock hard and no data is sent on the bus. I am >> testing the bus using spidev and the spidev_test[2] application, >> however I first came across spi issues with a custom spi driver which >> stopped working when I transitioned from 3.2-psp to 3.7-rc8. >> >> The current output I am seeing from the spidev_test program is just a >> series of 0x00 data, which looks to me like no data is getting in at >> all. The spidev_test program is not using DMA as the buffer size is >> too low, so I forced the dma on when buffer size is > 1 and the >> program hangs hard with the system still responding to other >> commands.I have briged the pins 18 and 21 on the BeagleBone P9 >> header. >> >> Has anyone seen issues like this, or if not if someone could please >> test the latest 3.7-rc8 from [1] and let me know if it works for them >> and the issue is at my end. >> >> To get spidev working with devicetree I applied the patch from [3] >> and changed the dtb as in the patch pasted below. >> >> [1] https://github.com/beagleboard/kernel/tree/3.7 >> [2] http://lxr.linux.no/#linux+v3.6.9/Documentation/spi/spidev_test.c >> [3] http://www.mail-archive.com/spi-devel-general@lists.sourceforge.net/msg09958.html > do you have any debugging output from that driver ? It would be cool to > see if DMA is at least being kicked properly for small transfers. When I run the spidev program with dma for transfers > 1, the program hangs and the only output in dmesg is: [ 12.613952] libphy: 4a101000.mdio:00 - Link is Up - 100/Full <---- Last line from initial log in [2] [ 47.669202] spidev spi1.0: setup: speed 24000000, sample leading edge, clk normal [ 47.669246] spidev spi1.0: setup mode 0, 8 bits/w, 24000000 Hz max --> 0 [ 47.669260] spidev spi1.0: spi mode 00 [ 47.669283] spidev spi1.0: setup: speed 24000000, sample leading edge, clk normal [ 47.669300] spidev spi1.0: setup mode 0, 16 bits/w, 24000000 Hz max --> 0 [ 47.669312] spidev spi1.0: 16 bits per word [ 47.669330] spidev spi1.0: setup: speed 24000000, sample leading edge, clk normal [ 47.669347] spidev spi1.0: setup mode 0, 16 bits/w, 24000000 Hz max --> 0 [ 47.669358] spidev spi1.0: 24000000 Hz (max) [ 47.673811] spidev spi1.0: setup: speed 24000000, sample leading edge, clk normal The initial dmesg statup log is at [2]. > > It would also be nice to have a clear picture of what "custom spi > driver" you're talking about. The custom SPI driver is for connecting and reading registers from an in house FPGA design and can be found at [1]. It's fairly rudimentary and also in the development stages, I'm very new to Linux kernel programming so please take that into account :) However it did work flawlessly with 3.2-psp. > > cheers > [1] http://embed.me.uk/fpgaSPI.c [2] http://embed.me.uk/bone-log.1 Cheers,
diff --git a/arch/arm/boot/dts/am335x-bone-common.dtsi b/arch/arm/boot/dts/am335x-bone-common.dtsi index 543365d..8fff665 100644 --- a/arch/arm/boot/dts/am335x-bone-common.dtsi +++ b/arch/arm/boot/dts/am335x-bone-common.dtsi @@ -440,10 +440,19 @@ }; &spi0 { + status = "okay"; pinctrl-names = "default"; pinctrl-0 = <&spi0_pins>; + + spidev: spidev@0 { + compatible = "linux,spidev"; + reg = <0>; + spi-max-frequency = <24000000>; + }; + }; + &spi1 { pinctrl-names = "default"; pinctrl-0 = <&spi1_pins>;