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
