Re: [PATCH] mmc: make sdhci work with ricoh mmc controller

From: Maxim Levitsky
Date: Thu Jun 03 2010 - 12:32:05 EST


On Thu, 2010-06-03 at 09:11 -0700, Philip Langdale wrote:
> On Thu, 3 Jun 2010 04:16:27 +0300
> Maxim Levitsky <maximlevitsky@xxxxxxxxx> wrote:
>
> > The current way of disabling it is not well tested by vendor
> > and has all kinds of bugs that show up on resume from ram/disk.
> >
> > Old way of disabling is still supported by
> > continuing to use CONFIG_MMC_RICOH_MMC.
> >
> > Based on
> > 'http://list.drzeus.cx/pipermail/sdhci-devel/2007-December/002085.html'
>
> As long as this doesn't limit the performance of MMC cards, I can't
> complain.
>
> BTW, the new PCIe native controllers from Ricoh don't require the
> MMC controller to be disabled - the SD controller sees the cards by
> default; I guess some bit has to be twiddled by the MMC driver.
Can I distinguish between this and newer controllers.
Could you help me with that?


>
> > Signed-off-by: Maxim Levitsky <maximlevitsky@xxxxxxxxx>
> > CC: adq_dvb@xxxxxxxxxxxxx
> > CC: linux-mmc@xxxxxxxxxxxxxxx <linux-mmc@xxxxxxxxxxxxxxx>
> > ---
> > drivers/mmc/host/sdhci-pci.c | 34
> > ++++++++++++++++++++++++++++++++++ drivers/mmc/host/sdhci.c |
> > 5 ++++- drivers/mmc/host/sdhci.h | 2 ++
> > 3 files changed, 40 insertions(+), 1 deletions(-)
> >
> > diff --git a/drivers/mmc/host/sdhci-pci.c
> > b/drivers/mmc/host/sdhci-pci.c index 65483fd..3843780 100644
> > --- a/drivers/mmc/host/sdhci-pci.c
> > +++ b/drivers/mmc/host/sdhci-pci.c
> > @@ -17,6 +17,7 @@
> > #include <linux/pci.h>
> > #include <linux/dma-mapping.h>
> > #include <linux/slab.h>
> > +#include <linux/device.h>
> >
> > #include <linux/mmc/host.h>
> >
> > @@ -85,6 +86,26 @@ static int ricoh_probe(struct sdhci_pci_chip *chip)
> > chip->pdev->subsystem_vendor == PCI_VENDOR_ID_SONY)
> > chip->quirks |= SDHCI_QUIRK_NO_CARD_NO_RESET;
> >
> > + /* To disable hardware races against MMC part */
> > + device_disable_async_suspend(&chip->pci_dev->dev);
> > + return 0;
> > +}
>
> It would be nice if this could be more selective so it only happens
> if it's really needed.
Same as above

>
> > +
> > +static int ricoh_mmc_probe_slot(struct sdhci_pci_slot *slot)
> > +{
> > + slot->host->caps =
> > + ((0x21 << SDHCI_TIMEOUT_CLK_SHIFT)
> > + & SDHCI_TIMEOUT_CLK_MASK) |
> > +
> > + ((0x21 << SDHCI_CLOCK_BASE_SHIFT)
> > + & SDHCI_CLOCK_BASE_MASK) |
> > +
> > + SDHCI_TIMEOUT_CLK_UNIT |
> > + SDHCI_CAN_VDD_330 |
> > + SDHCI_CAN_DO_SDMA ;
>
> Have you been able to establish if 4bit and high-speed operations
> work correctly through the MMC controller? I note that you didn't
> set SDHCI_CAN_DO_HISPD.
Didn't test that yet, will do.
I hope my MMCPlus card can do high-speed.

>
> > +
> > + /* To disable hardware races against SDHC part */
> > + device_disable_async_suspend(&slot->chip->pci_dev->dev);
> > return 0;
> > }
> >
> > @@ -95,6 +116,11 @@ static const struct sdhci_pci_fixes sdhci_ricoh =
> > { SDHCI_QUIRK_CLOCK_BEFORE_RESET,
> > };
> >
> > +static const struct sdhci_pci_fixes sdhci_ricoh_mmc = {
> > + .probe_slot = ricoh_mmc_probe_slot,
> > + .quirks = SDHCI_QUIRK_NO_CARD_NO_RESET,
> > +};
> > +
> > static const struct sdhci_pci_fixes sdhci_ene_712 = {
> > .quirks = SDHCI_QUIRK_SINGLE_POWER_WRITE |
> > SDHCI_QUIRK_BROKEN_DMA,
> > @@ -374,6 +400,14 @@ static const struct pci_device_id pci_ids[]
> > __devinitdata = { },
> >
> > {
> > + .vendor = PCI_VENDOR_ID_RICOH,
> > + .device = 0x843,
> > + .subvendor = PCI_ANY_ID,
> > + .subdevice = PCI_ANY_ID,
> > + .driver_data = (kernel_ulong_t)&sdhci_ricoh_mmc,
> > + },
> > +
> > + {
> > .vendor = PCI_VENDOR_ID_ENE,
> > .device = PCI_DEVICE_ID_ENE_CB712_SD,
> > .subvendor = PCI_ANY_ID,
> > diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> > index c6d1bd8..dbd9367 100644
> > --- a/drivers/mmc/host/sdhci.c
> > +++ b/drivers/mmc/host/sdhci.c
> > @@ -1687,7 +1687,10 @@ int sdhci_add_host(struct sdhci_host *host)
> > host->version);
> > }
> >
> > - caps = sdhci_readl(host, SDHCI_CAPABILITIES);
> > + if (host->caps)
> > + caps = host->caps;
> > + else
> > + caps = sdhci_readl(host, SDHCI_CAPABILITIES);
>
> I'd prefer keying this off an explicit quirk.
Could you explain?

Do you mean I should add SDHCI_QUIRK_MISSING_CAPS ?
This is fine.

If you mean that I should create a SDHCI_QUIRK_RICOH_MMC_CAPS,
and hardcode caps in sdhci, I kind of disagree, too ugly :-)


Btw, suspend/resume races seem to disappear. Maybe I didn't install the
kernel (will test more)
> >
> > if (host->quirks & SDHCI_QUIRK_FORCE_DMA)
> > host->flags |= SDHCI_USE_SDMA;
> > diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> > index c846813..b41581a 100644
> > --- a/drivers/mmc/host/sdhci.h
> > +++ b/drivers/mmc/host/sdhci.h
> > @@ -292,6 +292,8 @@ struct sdhci_host {
> >
> > struct timer_list timer; /* Timer for
> > timeouts */
> > + unsigned int caps; /*
> > Alternative capabilities */ +
> > unsigned long private[0]
> > ____cacheline_aligned; };
> >
>
> --phil


Best regards,
Maxim Levitsky

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