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SubjectRe: [PATCH v2 2/2] mmc: sdhci-of-aspeed: add inversion sighttps://elixir.bootlin.com/linux/v4.6/ident/sdhci_opsnal presence
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On 14/11/19 7:19 PM, Ivan Mikhaylov wrote:
> On Thu, 2019-11-14 at 15:10 +0200, Adrian Hunter wrote:
>> On 14/11/19 2:54 PM, Ivan Mikhaylov wrote:
>>> Change the default .get_cd callback. Add inverted signal card detection
>>> check.
>>>
>>> Signed-off-by: Ivan Mikhaylov <i.mikhaylov@yadro.com>
>>>
>>> diff --git a/drivers/mmc/host/sdhci-of-aspeed.c b/drivers/mmc/host/sdhci-of-
>>> aspeed.c
>>> index 8962f6664381..186559ee8fcc 100644
>>> --- a/drivers/mmc/host/sdhci-of-aspeed.c
>>> +++ b/drivers/mmc/host/sdhci-of-aspeed.c
>>> @@ -143,6 +143,19 @@ static inline int aspeed_sdhci_calculate_slot(struct
>>> aspeed_sdhci *dev,
>>> return (delta / 0x100) - 1;
>>> }
>>>
>>> +static int aspeed_get_cd(struct mmc_host *mmc)
>>> +{
>>> + struct sdhci_host *host = mmc_priv(mmc);
>>> +
>>> + int present = !!(sdhci_readl(host, SDHCI_PRESENT_STATE)
>>> + & SDHCI_CARD_PRESENT);
>>> +
>>> + if (mmc->caps2 & MMC_CAP2_CD_ACTIVE_HIGH)
>>> + present = !present;
>>
>> Perhaps safer to flip the bit using CONFIG_MMC_SDHCI_IO_ACCESSORS and
>> ->readl() callback
>>
>
> Sorry, don't quite understand what you're saying. You want to instantiate
> '.read_l' callback instead of '.get_cd' in sdhci_ops and substitute the real
> value?
>
> res = readl(base, reg);
> if (reg == SDHCI_PRESENT_STATE)
> if (mmc->caps2 & MMC_CAP2_CD_ACTIVE_HIGH)
> return !res;

Presumably just flip the SDHCI_CARD_PRESENT bit i.e.

return res ^ SDHCI_CARD_PRESENT;

> return res;
>
> Something like this?

Yes

>
>>
>>> + host->mmc_host_ops.get_cd = aspeed_get_cd;
>>> + if (of_property_read_bool(pdev->dev.of_node, "cd-inverted"))
>>> + dev_info(&pdev->dev, "aspeed: sdhci: presence signal inversion
>>> enabled\n");
>>
>> Is this print really needed?
>>
> I can remove it if you think it's redundant.
>
> Thanks.
>
>

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