On Wed, Feb 27, 2013 at 12:08 AM, Jon Hunter <jon-hunter@xxxxxx> wrote:
>
> On 02/26/2013 04:01 AM, Javier Martinez Canillas wrote:
>
> [snip]
>
>> I was wondering if the level/edge settings for gpios is working on OMAP.
>>
>> I'm adding DT support for an SMSC911x ethernet chip connected to the
>> GPMC for an OMAP3 SoC based board.
>>
>> In the smsc911x driver probe function (smsc911x_drv_probe() in
>> drivers/net/ethernet/smsc/smsc911x.c), a call to request_irq() with
>> the flag IRQF_TRIGGER_LOW is needed because of the wiring on my board.
>>
>> Reading the gpio-omap.txt documentation it says that #interrupt-cells
>> should be <2> and that a value of 8 is "active low level-sensitive".
>>
>> So I tried this:
>>
>> &gpmc {
>> ethernet@5,0 {
>> pinctrl-names = "default";
>> pinctrl-0 = <&smsc911x_pins>;
>> compatible = "smsc,lan9221", "smsc,lan9115";
>> reg = <5 0 0xff>; /* CS5 */
>> interrupt-parent = <&gpio6>;
>> interrupts = <16 8>; /* gpio line 176 */
>> interrupt-names = "smsc911x irq";
>> vmmc-supply = <&vddvario>;
>> vmmc_aux-supply = <&vdd33a>;
>> reg-io-width = <4>;
>
> By the way, reg-io-width for omap does not look correct. The GPMC only
> supports 8-bit or 16-bit devices IIRC. I believe all my omap boards use
> 16-bit.
>
I thought that even when the GPMC was a 16-bit external memory
controller it could do some access adaptation to support 32-bit
devices.
By looking at the board files for others OMAP3 based boards
(board-{omap3evm,overo,zoom-debugboard}.c) most of them set the struct
omap_smsc911x_platform_data .flags member to SMSC911X_USE_32BIT.
And by looking at Documentation/devicetree/bindings/net/smsc911x.txt I
thought that the corresponding DT property for this flag was
"reg-io-width"
Anyway, I tried using both reg-io-width = <4> and reg-io-width = <2>.
The ethernet chip works with both of them and I don't see too much
difference in performance:
16-bit
round-trip min/avg/max = 0.611/0.738/0.946 ms
32-bit
round-trip min/avg/max = 0.519/0.690/0.976 ms
So, is your call ;-)
> Cheers
> Jon
Thanks a lot for your help,
Javier
--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
