Re: [PATCH] mmc:sdhci:add support to request/free pins for controllers sharing hardware bus

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hi Philip,

2011/4/26 Philip Rakity <prakity@xxxxxxxxxxx>:
>
> Barry,
>
> How are interrupts from SDIO devices handled ? Â SDIO devices use one of the pins to signal a interrupt to the host when data is availabe.

Good question. in fact, it is impossible to support both sharing all
data bus and sdio interrupt in hardware except that hardware gives a
special design with data1. Otherwise, controllers with shared pins
requested at runtime will not support sdio devices with interrupts.

>
> Philip
>
> On Apr 26, 2011, at 12:27 AM, Barry Song wrote:
>
>> Hi Wolfram,
>>
>> 2011/4/26 Wolfram Sang <w.sang@xxxxxxxxxxxxxx>:
>>>>> * Where is the patch that implements the get_shared_pins() hook in
>>>>> Âyour driver?
>>>> We send the common level patch ahead to get the upstream agreement so
>>>> that we can maintain our bottom level sdhci codes better. We will send
>>>> the special driver patch after some time.
>>>
>>> Hmm, why should be there a functionality if there is no user for it? A
>>> reference user helps people understand how it is intended to be used.
>>
>> completely right. Of course this patch is based on real applications
>> and SoCs. We are using ARASAN sd controller IP, it can be configurated
>> to use shared pins mode in SoC design. And it looks like it is a
>> common requirement to save chip footprint by sharing data bus between
>> multi-controllers.
>>
>> Just because Our SoCs are still on the way to opensource and mainline.
>> Even our arch/arm/mach-xxx hasn't been merged yet. Our target is
>> syncing our codes with mainline. So as a modification to sdhci common
>> level, we just get upstream's opinion for local maintaining earlier.
>>
>> Anyway, this patch may be applied later after our others are ready. Or
>> it can be now so that other SoC companies can use this feature.
>>
>>>
>>> Regards,
>>>
>>> Â Wolfram
>>>
>>> --
>>> Pengutronix e.K.              | Wolfram Sang        Â|
>>> Industrial Linux Solutions         | http://www.pengutronix.de/ Â|
>>>
>
>
-barry
--
To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [Linux USB Devel]     [Linux Media]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux