Query ISP1301 with OMAP

Query ISP1301 with OMAP

[Pandita, Vikram]

I am facing issues with configuring ISP1301 in 3-pin Host only mode.

I have a board with ISP1301 connected in 3-pin mode to OMAP3430-OHCI controller.
I am trying to reuse the file: drivers/i2c/chips/isp1301_omap.c to configure in HOST only mode.

I have setup the OHCI HCD successfully, but what I observe is that with or without the device,
OHCI is getting a "LOW SPEED" device attach interrupts.

I am suspecting something going wrong with ISP1301. Any clues from logs?

Logs:
usb usb1: configuration #1 chosen from 1 choice
hub 1-0:1.0: USB hub found
hub 1-0:1.0: 3 ports detected
usb usb1: Product: OMAP OHCI
usb usb1: Manufacturer: Linux 2.6.24.5-omap1-arm2 ohci_hcd
usb usb1: SerialNumber: ohci-omap.0

>
>usb 1-1: new low speed USB device using ohci-omap and address 2
>
 OHCI-IRQ 46

 OHCI-IRQ 44

 OHCI-IRQ 46

 OHCI-IRQ 44

 OHCI-IRQ 46

 OHCI-IRQ 44
usb 1-1: device descriptor read/64, error -62

 OHCI-IRQ 46

 OHCI-IRQ 44

 OHCI-IRQ 46

 OHCI-IRQ 44

 OHCI-IRQ 46

 OHCI-IRQ 44
usb 1-1: device descriptor read/64, error -62



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RE: Query ISP1301 with OMAP

[Pandita, Vikram]

> To: linux-usb@vger.kernel.org; linux-omap@vger.kernel.org
> Subject: Query ISP1301 with OMAP

Another observation:
There is a comment in isp1301_omap.c file:

static void power_up(struct isp1301 *isp)
        /* do this only when cpu is driving transceiver,
         * so host won't see a low speed device...
         */

Could anyone give more details as to what this means?
When will OHCI host see a low speed device (even when no device is connected)?

In this state, the OHCI portsc register is: reg-0x48064454 => 0x10301
And ISP1301 register value is:
ISP1301_INTERRUPT_SOURCE= 1a => DM_HI

I have ensured in h/w that DM line is not pulled high at all.

>
>
> I am facing issues with configuring ISP1301 in 3-pin Host only mode.
>
> I have a board with ISP1301 connected in 3-pin mode to OMAP3430-OHCI
> controller.
> I am trying to reuse the file: drivers/i2c/chips/isp1301_omap.c to
> configure in HOST only mode.
>
> I have setup the OHCI HCD successfully, but what I observe is that with or
> without the device,
> OHCI is getting a "LOW SPEED" device attach interrupts.
>
> I am suspecting something going wrong with ISP1301. Any clues from logs?
>
> Logs:
> usb usb1: configuration #1 chosen from 1 choice
> hub 1-0:1.0: USB hub found
> hub 1-0:1.0: 3 ports detected
> usb usb1: Product: OMAP OHCI
> usb usb1: Manufacturer: Linux 2.6.24.5-omap1-arm2 ohci_hcd
> usb usb1: SerialNumber: ohci-omap.0
>
> >
> >usb 1-1: new low speed USB device using ohci-omap and address 2
> >
>  OHCI-IRQ 46
>
>  OHCI-IRQ 44
>
>  OHCI-IRQ 46
>
>  OHCI-IRQ 44
>
>  OHCI-IRQ 46
>
>  OHCI-IRQ 44
> usb 1-1: device descriptor read/64, error -62
>
>  OHCI-IRQ 46
>
>  OHCI-IRQ 44
>
>  OHCI-IRQ 46
>
>  OHCI-IRQ 44
>
>  OHCI-IRQ 46
>
>  OHCI-IRQ 44
> usb 1-1: device descriptor read/64, error -62
>
>
>
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Re: Query ISP1301 with OMAP

[David Brownell]

On Thursday 15 May 2008, Pandita, Vikram wrote:
> Another observation:
> There is a comment in isp1301_omap.c file:
> 
> static void power_up(struct isp1301 *isp)
>         /* do this only when cpu is driving transceiver,
>          * so host won't see a low speed device...
>          */
> 
> Could anyone give more details as to what this means?

The "this" was putting the transceiver into DAT_SEO mode,
so evidently there were problems observed doing that
earlier in the setup sequence -- before the immediately
preceding line which took it out of USB suspend mode.

The comment before those functions is relevant to your
general question (how to set it up for 3-pin host-only
mode):  some of the details presumed setup like an H2
board needed, and the DAT_SEO bit was one of them.

The H2 board certainly supported both host and peripheral
modes, and as I recall from the dusty mists of time it
didn't use three wire signaling.  So I suspect that you
won't be able to reuse much of that init code.  You'll
need to dig through the chip docs to figure out how it
needs to be set up.

- Dave

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