From: Arnd Bergmann <arnd@arndb.de>
To: linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH 1/2] sdhci-of-esdhc: Support 8BIT bus width.
Date: Tue, 05 May 2015 12:03:58 +0200 [thread overview]
Message-ID: <2759482.d3jNK4pMnc@wuerfel> (raw)
In-Reply-To: <1430774247.27859.62.camel@transmode.se>
On Monday 04 May 2015 21:17:27 Joakim Tjernlund wrote:
> On Mon, 2015-05-04 at 19:31 +0200, Arnd Bergmann wrote:
> > On Monday 04 May 2015 18:31:31 Joakim Tjernlund wrote:
> > > @@ -252,6 +260,8 @@ static void esdhc_of_platform_init(struct sdhci_host *host)
> > >
> > > if (vvn > VENDOR_V_22)
> > > host->quirks &= ~SDHCI_QUIRK_NO_BUSY_IRQ;
> > > +
> > > + host->mmc->caps |= MMC_CAP_8_BIT_DATA;
> > > }
> > >
> >
> > Shouldn't this check the "bus-width" property before setting the width?
> >
> > There might be an eMMC or SDIO with 4-bit interface connected.
>
> This is for an eMMC chip we got and I THINK(this is new to me) that
> this only allows 8 bit negotiation but I might be way off.
>
> Anyone knows for sure?
>
Most mmc host controllers can work with both eMMC and SD cards or
some of the less common variants (SDIO, eSD, MMC, ...), and most of those
are not 8 bit wide.
Arnd
prev parent reply other threads:[~2015-05-05 10:04 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-04 16:31 [PATCH 1/2] sdhci-of-esdhc: Support 8BIT bus width Joakim Tjernlund
2015-05-04 16:31 ` [PATCH 2/2] sdhci-of-esdhc: Pre divider starts at 1 Joakim Tjernlund
2015-05-04 17:31 ` [PATCH 1/2] sdhci-of-esdhc: Support 8BIT bus width Arnd Bergmann
2015-05-04 21:17 ` Joakim Tjernlund
2015-05-04 21:49 ` Joakim Tjernlund
2015-05-05 10:03 ` Arnd Bergmann [this message]
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