From: Jack Mitchell <ml@communistcode.co.uk>
To: ml@communistcode.co.uk
Cc: Ben Gamari <bgamari.foss@gmail.com>,
balbi@ti.com, linux-omap@vger.kernel.org
Subject: Re: AM335x BeagleBone SPI Issues
Date: Tue, 11 Dec 2012 17:02:19 +0000 [thread overview]
Message-ID: <50C7671B.80504@communistcode.co.uk> (raw)
In-Reply-To: <50C75E54.2080805@communistcode.co.uk>
On 11/12/12 16:24, Jack Mitchell wrote:
> On 11/12/12 15:22, Ben Gamari wrote:
>> Jack Mitchell <ml@communistcode.co.uk> writes:
>>
>>> Shubhro, Felipe,
>>>
>>> Thank you, the reordering dma patch fixed the dma issue I was having!
>>> However, the bad news, I now get the same results for the dma and
>>> non-dma spidev test. While the scope shows the SPI clk and data is
>>> fine,
>>> the reading from the program still shows 0x00 for all words.
>>>
>> Just to make sure this has been thought of: I've seen this sort of
>> behavior in the past when the CLK pin wasn't configured as an input.
>>
>> Cheers,
>>
>> - Ben
>>
>
> Ok, Ben, well spotted indeed! I changed the dtsi to use INPUT_PULLUP
> instead of OUTPUT_PULLUP and wallah!
>
> am3358_pinmux: pinmux@44e10800 {
> spi0_pins: pinmux_spi0_pins {
> pinctrl-single,pins = <
> 0x150 *0x30* /* spi0_sclk.gpio0_2, INPUT_PULLUP | MODE0
> */<------------ changed to INPUT
> 0x154 0x30 /* spi0_d0.gpio0_3, INPUT_PULLUP | MODE0 */
> 0x158 0x10 /* spi0_d1.i2c1_sda, OUTPUT_PULLUP | MODE0 */
> 0x15c 0x10 /* spi0_cs0.i2c1_scl, OUTPUT_PULLUP | MODE0 */
> >;
> };
> spi1_pins: pinmux_spi1_pins {
> pinctrl-single,pins = <
> 0x190 *0x33* /* mcasp0_aclkx.spi1_sclk, INPUT_PULLUP | MODE3
> */ <------------ changed to INPUT
> 0x194 0x33 /* mcasp0_fsx.spi1_d0, INPUT_PULLUP | MODE3 */
> 0x198 0x13 /* mcasp0_axr0.spi1_d1, OUTPUT_PULLUP | MODE3 */
> 0x19c 0x13 /* mcasp0_ahclkr.spi1_cs0, OUTPUT_PULLUP | MODE3 */
> >;
> };
>
>
> root@beaglebone:~# ./spidev
> spi mode: 0
> bits per word: 16
> max speed: 24000000 Hz (24000 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
> root@beaglebone:~# ./spidev_dma
> spi mode: 0
> bits per word: 8
> max speed: 500000 Hz (500 KHz)
>
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
> FF 00 FF 00 FF 00
>
> We are in business!
>
> Almost.
>
> I then tried spi1 and received:
>
> root@beaglebone:~# ./spidev -D /dev/spidev2.0
> spi mode: 0
> bits per word: 16
> max speed: 24000000 Hz (24000 KHz)
>
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF
> root@beaglebone:~# ./spidev_dma -D /dev/spidev2.0
> spi mode: 0
> bits per word: 8
> max speed: 500000 Hz (500 KHz)
>
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> root@beaglebone:~#
>
>
My bad! The jumper bridge had come loose, it works now! Yippee!
root@beaglebone:~# ./spidev -D /dev/spidev2.0
spi mode: 0
bits per word: 16
max speed: 24000000 Hz (24000 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
root@beaglebone:~#
Thanks everyone, and do I need to submit any patches to clear this all up?
Currently all I see is changing the clk pins from output to input (if
this is a valid change?).
--
Jack Mitchell (jack@embed.me.uk)
Embedded Systems Engineer
http://www.embed.me.uk
--
next prev parent reply other threads:[~2012-12-11 17:00 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-10 13:23 AM335x BeagleBone SPI Issues Jack Mitchell
2012-12-10 13:53 ` Felipe Balbi
2012-12-10 14:50 ` Jack Mitchell
2012-12-10 14:59 ` Felipe Balbi
2012-12-10 15:19 ` Jack Mitchell
2012-12-10 15:26 ` Shubhrajyoti Datta
2012-12-10 16:18 ` Jack Mitchell
2012-12-10 18:35 ` Felipe Balbi
2012-12-11 6:39 ` Shubhrajyoti Datta
2012-12-11 10:17 ` Jack Mitchell
2012-12-11 10:20 ` Felipe Balbi
2012-12-11 10:38 ` Jack Mitchell
2012-12-11 11:48 ` Felipe Balbi
2012-12-11 14:27 ` Felipe Balbi
2012-12-11 15:23 ` Jack Mitchell
2012-12-11 16:15 ` Felipe Balbi
2012-12-11 15:22 ` Ben Gamari
2012-12-11 16:24 ` Jack Mitchell
2012-12-11 16:36 ` Jack Mitchell
2012-12-11 17:02 ` Jack Mitchell [this message]
2013-01-04 14:46 ` Jan Lübbe
2013-01-04 16:21 ` Jack Mitchell
2013-01-04 16:36 ` Jack Mitchell
2012-12-11 17:03 ` Felipe Balbi
2012-12-11 17:52 ` Felipe Balbi
2012-12-12 8:07 ` Felipe Balbi
-- strict thread matches above, loose matches on Subject: below --
2012-12-10 13:17 Jack Mitchell
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