SPI on A10 Lime

[jerry]

Looking at the default configuration for the Linux kernel, I see that it doesn't generate SPI support.  Is there a reason for this?

TIA.

[samuele]

I'm intrested in SPI support too... looking at the a10-olinuxino-lime.fex seems that SPI si not enabled.. maybe we have to edit this file and rebuild the BSP...

[Lurch]

There was a notice (maybe on the A20 forum) that the Allwinner SPI code was broken.
You can try, but don't be disappointed if it doesn't work yet.

[samuele]

Hi Lurch,
perhaps you were referring to this post https://www.olimex.com/forum/index.php?topic=1773.msg9476#msg9476.
The SoC on the OLinuXino-Lime is an A10 (aka sun4i), so, referring to the previous link, it seems that for sun4i the linux-sunxi SPI driver should work... but it seems strange to me that Olimex didn't enable any SPI port by default on such board... needs some further investigations...

[fiosca]

Interested to have it working too!
If somebody has time to spend investigating if SPI driver works... please post results!

[fjnxg4fe]

One step further! 

Try this kernel config:

CONFIG_SPI=y
CONFIG_SPI_MASTER=y
CONFIG_SPI_SUN4I=y
CONFIG_SPI_SPIDEV=y

Try this fex config:

[spi0_para]
spi_used = 0
spi_cs_bitmap = 1
spi_cs0 = port:PI10<3><default><default><default>
spi_sclk = port:PI11<3><default><default><default>
spi_mosi = port:PI12<3><default><default><default>
spi_miso = port:PI13<3><default><default><default>

[spi1_para]
spi_used = 0
spi_cs_bitmap = 1
spi_cs0 = port:PA00<4><default><default><default>
spi_sclk = port:PA01<4><default><default><default>
spi_mosi = port:PA02<4><default><default><default>
spi_miso = port:PA03<4><default><default><default>

[spi2_para]
spi_used = 1
spi_cs_bitmap = 1
#spi_cs0 = port:PB14<2><default><default><default>
#spi_sclk = port:PB15<2><default><default><default>
#spi_mosi = port:PB16<2><default><default><default>
#spi_miso = port:PB17<2><default><default><default>
spi_cs0 = port:PC19<3><default><default><default>
spi_sclk = port:PC20<3><default><default><default>
spi_mosi = port:PC21<3><default><default><default>
spi_miso = port:PC22<3><default><default><default>

[spi3_para]
spi_used = 0
spi_cs_bitmap = 1
spi_cs0 = port:PA05<3><default><default><default>
spi_sclk = port:PI06<3><default><default><default>
spi_mosi = port:PI07<3><default><default><default>
spi_miso = port:PI08<3><default><default><default>
spi_cs1 = port:PA09<3><default><default><default>

[spi_devices]
spi_dev_num = 1

[spi_board0]
modalias = "spidev"
max_speed_hz = 12000000
bus_num = 2
chip_select = 0
mode = 0
full_duplex = 1
manual_cs = 0

I got this result:

root@a10Lime:~# dmesg|grep spi
[    1.313213] [spi]: sw spi init !!
[    1.320359] [spi]: Found 1 spi devices in config files
[    1.331770] [spi]: boards num modalias         max_spd_hz       bus_num  cs   mode
[    1.342571] [spi]: spi_board0 irq gpio not used
[    1.353519] [spi]: 0          spidev           12000000         2        0    0x0   
[    1.364404] [spi]: bus num = 2, spi used = 1
[    1.374596] [spi]: source = sdram_pll_p, src_clk = 480000000, mclk 96000000
[    1.387413] sun4i-spi sun4i-spi.2: master is unqueued, this is deprecated
[    1.400984] [spi]: allwinners SoC SPI Driver loaded for Bus SPI-2 with 2 Slaves attached
[    1.416894] [spi]: [spi-2]: driver probe succeed, base f1c17000, irq 12, dma_tx_id 40, dma_rx_id 41!

Time for testing... 

And the device /dev/spidev2.0 is found.