Date: Sat, 20 Jan 2001 19:27:39 -0500 From: "Donald J . Maddox" <dmaddox@sc.rr.com> To: Nicolas Souchu <nsouch@alcove.fr> Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: more info about: odd result of pci_read_config Message-ID: <20010120192739.A2127@cae88-102-101.sc.rr.com> In-Reply-To: <20010121004349.A27198@ontario.alcove-int>; from nsouch@alcove.fr on Sun, Jan 21, 2001 at 12:43:49AM %2B0100 References: <20010120161834.B20753@ontario.alcove-int> <20010121004349.A27198@ontario.alcove-int>
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Heh, this is pretty wierd :)
I was intrigued by your little problem, so I started looking around.
In sys/dev/pci/pciar.h is:
static __inline u_int32_t
pci_read_config(device_t dev, int reg, int width)
{
return PCI_READ_CONFIG(device_get_parent(dev), dev, reg, width);
}
However, this is the only occurence of the string "PCI_READ_CONFIG"
that I can find in the whole damn source tree! Where is this defined?
On Sun, Jan 21, 2001 at 12:43:49AM +0100, Nicolas Souchu wrote:
> On Sat, Jan 20, 2001 at 04:18:35PM +0100, Nicolas Souchu wrote:
> > Hi folks,
> >
> > I have a problem with R4.2. The device driver I'm currently
> > writing can't retrieve correctly the value from a PCI configuration
> > register. What is strange is that when using the pciconf tool I get
> > the result I expect, not with pci_read_config().
> >
> > pciconf -r pci0:7:3: 0x48 returns 0x00006001
> >
> > but
> >
> > value = pci_read_config(dev, 0x48, 4); returns 0x6 !!!
> >
>
> Here is some more testing:
>
> Reading any configuration register gives 0x6!
>
> But
>
> when creating a cfg structure with bus=0, slot=7 and func=3 in the
> attach routine then pass it to pci_cfgread(), it works. Also, when
> querying the pci bus with BUS_READ_IVAR() for BUS, SLOT and FUNC,
> I get 0,7,3.
>
> What is the hose field?
>
> Note also that I had to return NULL on the detection of the device
> 0x30401106 in pcisupport.c pcib_match() because it has a bridge class and the
> pcib driver was attached to it before viapm.
>
> Here is the piece of code:
>
> static int
> viapm_attach(device_t dev)
> {
> u_int32_t l, base_cfgreg;
> u_int16_t s;
> u_int8_t c;
> struct viapm_data *viapm;
> struct resource *res;
> device_t bitbang;
> pcicfgregs cfg;
>
> if (!(viapm = (struct viapm_data *)device_get_softc(dev)))
> return ENXIO;
>
> bzero(viapm, sizeof(struct viapm_data));
>
> l = pci_read_config(dev, 0x8, 1);
> printf("%s: rev id 0x%x\n", __FUNCTION__, l);
>
> ## returns 0x6! Which is stupid
>
> switch (l) {
> case VIAPM_OEM_REV_E:
> base_cfgreg = VIAPM_CFG_3040E_BASE;
>
> /* Activate IO block access */
> s = pci_read_config(dev, VIAPM_CFG_3040E_ACTIV, 2);
> pci_write_config(dev, VIAPM_CFG_3040F_ACTIV,
> s | VIAPM_ACTIV_E_MASK, 2);
> break;
> case VIAPM_OEM_REV_F:
> case VIAPM_PROD_REV_A:
> default:
> base_cfgreg = VIAPM_CFG_3040F_BASE;
>
> /* Activate IO block access */
> c = pci_read_config(dev, VIAPM_CFG_3040F_ACTIV, 1);
> pci_write_config(dev, VIAPM_CFG_3040F_ACTIV,
> c | VIAPM_ACTIV_F_MASK, 1);
> break;
> }
>
> cfg.hose = -1;
> cfg.bus = 0;
> cfg.slot = 7;
> cfg.func = 3;
> l = pci_cfgread(&cfg, VIAPM_CFG_3040F_BASE, 4);
> printf("%s: base addr 0x%x\n", __FUNCTION__, l);
>
> ## return 0x6001! the correct value
>
> BUS_READ_IVAR(device_get_parent(dev), dev, PCI_IVAR_BUS, &l);
> printf("bus=%d\n", l);
> BUS_READ_IVAR(device_get_parent(dev), dev, PCI_IVAR_SLOT, &l);
> printf("slot=%d\n", l);
> BUS_READ_IVAR(device_get_parent(dev), dev, PCI_IVAR_FUNCTION, &l);
> printf("func=%d\n", l);
>
> ## return 0,7,3
>
> if (!(res = bus_alloc_resource(dev, SYS_RES_IOPORT, &base_cfgreg,
> 0l, ~0l, 1, RF_ACTIVE))) {
> device_printf(dev, "could not allocate bus space\n");
> return ENXIO;
> }
> viapm->st = rman_get_bustag(res);
> viapm->sh = rman_get_bushandle(res);
>
> printf("viapm: 0x%x and 0x%x\n", viapm->st, viapm->sh);
>
> VIAPM_OUTB(GPIO_DIR, VIAPM_INB(GPIO_DIR) | VIAPM_SCL | VIAPM_SDA);
>
> device_printf(dev, "attaching bitbanging...\n");
>
> /* add generic bit-banging code */
> if (!(bitbang = device_add_child(dev, "iicbb", -1)))
> return ENXIO;
>
> return (device_probe_and_attach(bitbang));
> }
>
> --
> Nicolas.Souchu@alcove.fr
> Alcôve - Open Source Software Engineer - http://www.alcove.fr
>
>
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