Looks like my gpio number was wrong for my 3.17 system. I confirmed on the datasheet that SIO_SPI_CS# goes to GPIO_S0_SC[66], which should be the 67th GPIO in the block of 102 GPIOs beginning at 154 on my system (so that checks out to the 220 on the wiki). However, I run into:
[ 143.049918] byt_gpio INT33FC:00: pin 66 cannot be used as GPIO. [ 143.056556] spi spi0.0: failed to request chip select GPIO220 [ 143.063007] pxa2xx-spi 80860F0E:00: can't setup spi0.0, status -22 On Thu, Jan 29, 2015 at 2:01 AM, Kevin Shelton <[email protected]> wrote: > pin 5 still idling high at 3.3V after the pxa2xx_spi_chip addition > > On Thu, Jan 29, 2015 at 1:06 AM, Kevin Shelton <[email protected]> wrote: >> added the following to my board file: >> >> #include <linux/spi/pxa2xx_spi.h> >> >> static struct pxa2xx_spi_chip mbm = { >> .gpio_cs = 476 >> }; >> >> as well as >> .controller_data = &mbm >> to the spi_board_info struct >> >> And now my module no longer returns from cs_setup before getting to >> the cs polarity logic (at least in ACPI mode, not yet tested in PCI >> mode). I've also yet to confirm that my SPI device is actually >> working, but I think this is on the right track. >> >> On Wed, Jan 28, 2015 at 11:31 PM, Kevin Shelton <[email protected]> wrote: >>> My board file loads, but with a NULL chip_info when I'm in ACPI mode >>> for LPSS & SCC Devices Mode (so IIUC, the NULL chip_info prevents >>> spi-pxa2xx.c from flipping the polarity on the SS line). >>> >>> My module will explode when in PCI mode (tried in PCI mode because >>> spi-pxa2xx.c has a comment "Slave devices enumerated from ACPI >>> namespace don't usually have chip_info") with: >>> >>> [ 559.236046] divide error: 0000 [#1] PREEMPT SMP >>> [ 559.241217] Modules linked in: low_speed_spidev(O+) >>> [ 559.246686] CPU: 0 PID: 11980 Comm: insmod Tainted: G O >>> 3.17.0-rc4-yocto-standard+ #13 >>> [ 559.256712] Hardware name: Circuitco MinnowBoard MAX B3 >>> PLATFORM/MinnowBoard MAX, BIOS MNW2MAX1.X64.0076.R01.1412081258 >>> 12/08/2014 >>> [ 559.269850] task: ffff880073e5dfc0 ti: ffff880078f30000 task.ti: >>> ffff880078f30000 >>> [ 559.278222] RIP: 0010:[<ffffffff8148c57d>] [<ffffffff8148c57d>] >>> ssp_get_clk_div+0x3b/0x4a >>> [ 559.287481] RSP: 0018:ffff880078f33c80 EFLAGS: 00010246 >>> [ 559.293422] RAX: 0000000000000000 RBX: ffff880073f4b660 RCX: >>> 000000000000003f >>> [ 559.301405] RDX: 0000000000000000 RSI: 0000000000000000 RDI: >>> ffff880073e54428 >>> [ 559.309388] RBP: ffff880078f33c80 R08: 00000000000000df R09: >>> ffffffff82075580 >>> [ 559.317370] R10: 0000000000000000 R11: 0000000000000000 R12: >>> ffff880078578400 >>> [ 559.325353] R13: 0000000000000000 R14: ffff880073e54428 R15: >>> 0000000000002710 >>> [ 559.333338] FS: 00007f8296dcd700(0000) GS:ffff880079200000(0000) >>> knlGS:0000000000000000 >>> [ 559.342392] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b >>> [ 559.348819] CR2: 00007f8296dc9000 CR3: 000000007418b000 CR4: >>> 00000000001007f0 >>> [ 559.356801] Stack: >>> [ 559.359046] ffff880078f33cc0 ffffffff8148caa8 000000e000000040 >>> ffff880078578400 >>> [ 559.367334] 0000000000000000 0000000000000000 ffff880073e54000 >>> 0000000000000000 >>> [ 559.375628] ffff880078f33d10 ffffffff814888e6 0000000000000000 >>> ffff880078f33d10 >>> [ 559.383923] Call Trace: >>> [ 559.386660] [<ffffffff8148caa8>] setup+0x1fb/0x4b8 >>> [ 559.392119] [<ffffffff814888e6>] spi_setup+0xfd/0x1ad >>> [ 559.397871] [<ffffffff8143b32f>] ? bus_for_each_dev+0x63/0x85 >>> [ 559.404399] [<ffffffff81488aa4>] spi_add_device+0x10e/0x1a6 >>> [ 559.410732] [<ffffffff81489062>] spi_new_device+0xb5/0xcb >>> [ 559.416874] [<ffffffffa00030bf>] >>> low_speed_spidev_module_init+0xbf/0x133 [low_speed_spidev] >>> [ 559.426318] [<ffffffffa0003000>] ? 0xffffffffa0003000 >>> [ 559.432070] [<ffffffff8100032d>] do_one_initcall+0xff/0x185 >>> [ 559.438404] [<ffffffff8110172a>] ? __vunmap+0xa9/0xaf >>> [ 559.444155] [<ffffffff8108e4fb>] load_module+0x1756/0x1ef0 >>> [ 559.450392] [<ffffffff8108bfd3>] ? free_modinfo_version+0x27/0x27 >>> [ 559.457311] [<ffffffff8108ed57>] SyS_init_module+0xc2/0xcf >>> [ 559.463550] [<ffffffff8175fed2>] system_call_fastpath+0x16/0x1b >>> >>> I notice the below that sounds a little curious when I'm in PCI mode >>> (these are present for other devices, but from looking at >>> /sys/class/spi_master it seems that pci0000:00/0000:00:1e.5 is the >>> pxa2xx). >>> >>> [ 1.282369] pci 0000:00:1e.5: BAR 0: reserving [mem >>> 0x9093c000-0x9093cfff flags 0x40200] (d=0, p=0) >>> [ 1.282377] pci 0000:00:1e.5: can't claim BAR 0 [mem >>> 0x9093c000-0x9093cfff]: no compatible bridge window >>> [ 1.292998] pci 0000:00:1e.5: BAR 1: reserving [mem >>> 0x9093d000-0x9093dfff flags 0x40200] (d=0, p=0) >>> [ 1.293007] pci 0000:00:1e.5: can't claim BAR 1 [mem >>> 0x9093d000-0x9093dfff]: no compatible bridge window >>> >>> >>> >>> On Wed, Jan 28, 2015 at 4:19 PM, Kevin Shelton <[email protected]> wrote: >>>> through liberal sprinkling of printks I find that when spi_new_device >>>> gets called in my board file, eventually setup_cs gets called in >>>> drivers/spi/spi-pxa2xx.c, but setup_cs returns before it can set >>>> gpio_cs_inverted because chip_info is NULL >>>> >>>> Should board files define a pxa2xx_spi_chip struct (I see this done in >>>> arch/arm/mach-pxa/hx4700.c)? >>>> >>>> Am I correct in calling hx4700.c a board file? >>>> >>>> On Tue, Jan 27, 2015 at 9:21 PM, Darren Hart <[email protected]> >>>> wrote: >>>>> This changes the mechanism used to enumerate the hardware device to the >>>>> OS. Recent Linux kernels 3.16+ support for ACPI and PCI enumeration. ACPI >>>>> is supported since 3.14. Either should work for a board-file. >>>>> >>>>> -- >>>>> Darren >>>>> >>>>> >>>>> On 1/27/15, 3:13 PM, "Kevin Shelton" <[email protected]> wrote: >>>>> >>>>>>sorry for the not clear writing: I meant to say ACPI mode for the >>>>>>"LPSS & SCC Devices Mode" setting >>>>>> >>>>>>On Tue, Jan 27, 2015 at 3:11 PM, Kevin Shelton <[email protected]> >>>>>>wrote: >>>>>>> I realized that in my BIOS settings, I was in ACPI mode. Do I need to >>>>>>> be in PCI mode to use a board file? What does that ACPI-PCI switch in >>>>>>> the BIOS do? thanks for all the help >>>>>>> >>>>>>> On Mon, Jan 26, 2015 at 11:35 PM, Darren Hart <[email protected]> >>>>>>>wrote: >>>>>>>> The SPI bus controlled by the pxa2xx driver is on the LPSS, which, yes, >>>>>>>> corresponds to the Low Power IO Controller in that block diagram. >>>>>>>> >>>>>>>> On 1/26/15, 10:38 PM, "Kevin Shelton" <[email protected]> wrote: >>>>>>>> >>>>>>>>>Thanks John and Darren. I will play with spid_devtest and have >>>>>>>>>reached out to [email protected]. >>>>>>>>> >>>>>>>>>A minnowmax-specific question: In the Baytrail block diagram at >>>>>>>>>http://media.bestofmicro.com/Y/3/400395/original/bay-trail-soc.jpg >>>>>>>>>does the Marvell pxa27x correspond to the "Low Power IO Controller"? >>>>>>>>> >>>>>>>>>On Mon, Jan 26, 2015 at 6:33 PM, Darren Hart <[email protected]> >>>>>>>>>wrote: >>>>>>>>>> On 1/26/15, 5:52 PM, "John Hawley" <[email protected]> wrote: >>>>>>>>>> >>>>>>>>>>>On 01/26/2015 05:47 PM, Kevin Shelton wrote: >>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>> On Fri, Jan 23, 2015 at 2:41 PM, John Hawley <[email protected] >>>>>>>>>>>> <mailto:[email protected]>> wrote: >>>>>>>>>>>> >>>>>>>>>>>> > I saw the thread 'Adding an SPI device to the Minnowboard' >>>>>>>>>>>>from >>>>>>>>>>>>late >>>>>>>>>>>> > 2013 and 'SPI support on minnowboard v1' from Aug 2014. >>>>>>>>>>>> > >>>>>>>>>>>> > Darren Hart notes: >>>>>>>>>>>> > Ultimately we want to do things like this without board >>>>>>>>>>>>files by >>>>>>>>>>>>using >>>>>>>>>>>> > the _DSD mechanisms introduced by the ACPI 5.1 specification >>>>>>>>>>>>last >>>>>>>>>>>>week >>>>>>>>>>>> > >>>>>>>>>>>> > I just wanted to confirm the ACPI mechanism is not the >>>>>>>>>>>>recommended way >>>>>>>>>>>> > yet, and that using low-speed-spidev.c as a template is still >>>>>>>>>>>>the >>>>>>>>>>>>way to go. >>>>>>>>>>>> >>>>>>>>>>>> The answer to that will depend on what kernel you are >>>>>>>>>>>>intending to >>>>>>>>>>>> target. Kernel's with ACPI 5.1 _DSD support, I think you'd >>>>>>>>>>>>want >>>>>>>>>>>>to >>>>>>>>>>>>push >>>>>>>>>>>> on that. Older kernels without that, likely spidev or a more >>>>>>>>>>>>targeted >>>>>>>>>>>> driver. >>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>> Currently, I am targeting 3.17. 3.17 does not have ACPI 5.1 _DSD >>>>>>>>>>>> support, correct? >>>>>>>>>>> >>>>>>>>>>>Off the top of my head that came in in 3.18, so yes that's correct. >>>>>>>>>> >>>>>>>>>> 3.19 iirc. >>>>>>>>>> >>>>>>>>>> Also, using _DSD required a firmware change, or at least a DSDT >>>>>>>>>>update. >>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>>> > Additional q: >>>>>>>>>>>> > How do you tell the SPI controller that you have an >>>>>>>>>>>>active-high >>>>>>>>>>>>instead >>>>>>>>>>>> > of the usual active-low device? Is it correct to do a >>>>>>>>>>>>bitwise >>>>>>>>>>>>or >>>>>>>>>>>>with >>>>>>>>>>>> > SPI_CS_HIGH (0x4) with your SPI_MODE in your spi_board_info >>>>>>>>>>>>struct, like: >>>>>>>>>>>> > .mode = SPI_MODE_0 | SPI_CS_HIGH >>>>>>>>>>>> >>>>>>>>>>>> That should work, but take my statement with a grain of salt >>>>>>>>>>>>as I >>>>>>>>>>>> haven't tried it with a device. >>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>> It seems to have no effect that I can discern. Pin 5 idles at 3.3V >>>>>>>>>>>> whether I have >>>>>>>>>>>> .mode = SPI_MODE_3 | SPI_CS_HIGH >>>>>>>>>>>> -or- >>>>>>>>>>>> .mode = SPI_MODE_3 >>>>>>>>>>>> >>>>>>>>>>>> I threw in a >>>>>>>>>>>> pr_info("SPI mode=%i\n", cod_spi_board_info.mode); >>>>>>>>>>>> to sanity check that I am setting the mode to what I think I am (3 >>>>>>>>>>>>or >>>>>>>>>>>>7). >>>>>>>>>>>> >>>>>>>>>>>> Any debugging ideas? >>>>>>>>>>>> What is the best way to learn more about the SPI master? It's >>>>>>>>>>>>built >>>>>>>>>>>> into the CPU, correct? >>>>>>>>>>>> This smells in the ballpark of >>>>>>>>>>>> relatedness: >>>>>>>>>>>>http://lists.infradead.org/pipermail/linux-arm-kernel/2014-June/2634 >>>>>>>>>>>>67. >>>>>>>>>>>>ht >>>>>>>>>>>>ml >>>>>>>>>>>> I don't grok that patch, but I confirmed my version of pxa2xx.c in >>>>>>>>>>>>my >>>>>>>>>>>> 3.17 tree appears to contain that change. >>>>>>>>>>> >>>>>>>>>>>The SPI interface is indeed built into the CPU. It's the pxa2xx >>>>>>>>>>>core, >>>>>>>>>>>which it looks like you've found. I'd have to punt to someone else, >>>>>>>>>>>as >>>>>>>>>>>I'll admit, I don't know the SPI code well enough to say what's going >>>>>>>>>>>on. I've CC'ed Darren Hart, he might know who to check with next. >>>>>>>>>> >>>>>>>>>> Those are some very specific SPI usage questions that I don't know >>>>>>>>>>the >>>>>>>>>> answer to off the top of my head. To find out, I would: >>>>>>>>>> >>>>>>>>>> 1) Search for other drivers in tree and externally that use >>>>>>>>>>active-high >>>>>>>>>> >>>>>>>>>> First hit looks interesting: >>>>>>>>>> https://www.kernel.org/doc/Documentation/spi/spidev_test.c >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> 2) Lookup the right mailing lists for SPI Linux kernel development >>>>>>>>>>and >>>>>>>>>>ask >>>>>>>>>> the same question there >>>>>>>>>> >>>>>>>>>> -- >>>>>>>>>> Darren Hart >>>>>>>>>> Intel Open Source Technology Center >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> _______________________________________________ >>>>>>>>>> elinux-MinnowBoard mailing list >>>>>>>>>> [email protected] >>>>>>>>>> http://lists.elinux.org/mailman/listinfo/elinux-minnowboard >>>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> -- >>>>>>>> Darren Hart >>>>>>>> Intel Open Source Technology Center >>>>>>>> >>>>>>>> >>>>>>>> >>>>>> >>>>> >>>>> >>>>> -- >>>>> Darren Hart >>>>> Intel Open Source Technology Center >>>>> >>>>> >>>>> _______________________________________________ elinux-MinnowBoard mailing list [email protected] http://lists.elinux.org/mailman/listinfo/elinux-minnowboard
