[PATCH] sdhci: Add support for hosts that are only capable of 1-bit transfers

[PATCH] sdhci: Add support for hosts that are only capable of 1-bit transfers

[Anton Vorontsov]

Some hosts (hardware configurations, or particular SD/MMC slots) may
not support 4-bit bus. For example, on MPC8569E-MDS boards we can
switch between serial (1-bit only) and nibble (4-bit) modes, thought
we have to disable more peripherals to work in 4-bit mode.

Along with some small core changes, this patch modifies sdhci-of
driver, so that now it looks for "mode" property in the device-tree.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
---

Pierre, I'm not sure if a quirk would be appropriate here. If so,
I can redo the patch with FORCE_1_BIT_DATA quirk.

Thanks,

 Documentation/powerpc/dts-bindings/fsl/esdhc.txt |    2 ++
 drivers/mmc/host/sdhci-of.c                      |    7 +++++++
 drivers/mmc/host/sdhci-pci.c                     |    1 +
 drivers/mmc/host/sdhci.c                         |    2 +-
 4 files changed, 11 insertions(+), 1 deletions(-)

diff --git a/Documentation/powerpc/dts-bindings/fsl/esdhc.txt b/Documentation/powerpc/dts-bindings/fsl/esdhc.txt
index 5093ddf..298b865 100644
--- a/Documentation/powerpc/dts-bindings/fsl/esdhc.txt
+++ b/Documentation/powerpc/dts-bindings/fsl/esdhc.txt
@@ -10,6 +10,8 @@ Required properties:
   - interrupts : should contain eSDHC interrupt.
   - interrupt-parent : interrupt source phandle.
   - clock-frequency : specifies eSDHC base clock frequency.
+  - mode : specifies eSDHC mode, valid values are: "1-bit" and "4-bit".
+    If mode is unspecified, then 4-bit mode is assumed.
 
 Example:
 
diff --git a/drivers/mmc/host/sdhci-of.c b/drivers/mmc/host/sdhci-of.c
index 09cc597..12b9615 100644
--- a/drivers/mmc/host/sdhci-of.c
+++ b/drivers/mmc/host/sdhci-of.c
@@ -14,6 +14,7 @@
  */
 
 #include <linux/module.h>
+#include <linux/string.h>
 #include <linux/init.h>
 #include <linux/io.h>
 #include <linux/interrupt.h>
@@ -212,6 +213,7 @@ static int __devinit sdhci_of_probe(struct of_device *ofdev,
 	struct sdhci_of_data *sdhci_of_data = match->data;
 	struct sdhci_host *host;
 	struct sdhci_of_host *of_host;
+	const char *mode;
 	const u32 *clk;
 	int size;
 	int ret;
@@ -244,6 +246,11 @@ static int __devinit sdhci_of_probe(struct of_device *ofdev,
 		host->ops = &sdhci_of_data->ops;
 	}
 
+	mode = of_get_property(np, "mode", &size);
+	if (!mode || (size == sizeof("4-bit") &&
+			!strncmp(mode, "4-bit", size)))
+		host->mmc->caps |= MMC_CAP_4_BIT_DATA;
+
 	clk = of_get_property(np, "clock-frequency", &size);
 	if (clk && size == sizeof(*clk) && *clk)
 		of_host->clock = *clk;
diff --git a/drivers/mmc/host/sdhci-pci.c b/drivers/mmc/host/sdhci-pci.c
index 65be279..c447d6c 100644
--- a/drivers/mmc/host/sdhci-pci.c
+++ b/drivers/mmc/host/sdhci-pci.c
@@ -535,6 +535,7 @@ static struct sdhci_pci_slot * __devinit sdhci_pci_probe_slot(
 	host->hw_name = "PCI";
 	host->ops = &sdhci_pci_ops;
 	host->quirks = chip->quirks;
+	host->mmc->caps = MMC_CAP_4_BIT_DATA;
 
 	host->irq = pdev->irq;
 
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 9234be2..e31dd2a 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1721,7 +1721,7 @@ int sdhci_add_host(struct sdhci_host *host)
 	mmc->ops = &sdhci_ops;
 	mmc->f_min = host->max_clk / 256;
 	mmc->f_max = host->max_clk;
-	mmc->caps = MMC_CAP_4_BIT_DATA | MMC_CAP_SDIO_IRQ;
+	mmc->caps |= MMC_CAP_SDIO_IRQ;
 
 	if (caps & SDHCI_CAN_DO_HISPD)
 		mmc->caps |= MMC_CAP_SD_HIGHSPEED;
-- 
1.6.3.1

Re: [PATCH] sdhci: Add support for hosts that are only capable of 1-bit transfers

[Pierre Ossman]

[-- Attachment #1: Type: text/plain, Size: 1192 bytes --]

On Fri, 12 Jun 2009 00:15:45 +0400
Anton Vorontsov <avorontsov@ru.mvista.com> wrote:

> Some hosts (hardware configurations, or particular SD/MMC slots) may
> not support 4-bit bus. For example, on MPC8569E-MDS boards we can
> switch between serial (1-bit only) and nibble (4-bit) modes, thought
> we have to disable more peripherals to work in 4-bit mode.
> 
> Along with some small core changes, this patch modifies sdhci-of
> driver, so that now it looks for "mode" property in the device-tree.
> 
> Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
> ---
> 
> Pierre, I'm not sure if a quirk would be appropriate here. If so,
> I can redo the patch with FORCE_1_BIT_DATA quirk.
> 

I'd prefer a quirk, yes. 4-bit support is mandated so this would be a
deviation from the spec and such should always be handled by quirks for
clarity.

(I do think it is silly that they made it mandatory though considering
the embedded market)

Rgds
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     -- Pierre Ossman

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Re: [PATCH] sdhci: Add support for hosts that are only capable of 1-bit transfers

[Grant Likely]

On Thu, Jun 11, 2009 at 2:15 PM, Anton
Vorontsov<avorontsov@ru.mvista.com> wrote:
> Some hosts (hardware configurations, or particular SD/MMC slots) may
> not support 4-bit bus. For example, on MPC8569E-MDS boards we can
> switch between serial (1-bit only) and nibble (4-bit) modes, thought
> we have to disable more peripherals to work in 4-bit mode.
>
> Along with some small core changes, this patch modifies sdhci-of
> driver, so that now it looks for "mode" property in the device-tree.
>
> Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
> ---
>
> Pierre, I'm not sure if a quirk would be appropriate here. If so,
> I can redo the patch with FORCE_1_BIT_DATA quirk.
>
> Thanks,
>
> =A0Documentation/powerpc/dts-bindings/fsl/esdhc.txt | =A0 =A02 ++
> =A0drivers/mmc/host/sdhci-of.c =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0| =A0 =A07 +++++++
> =A0drivers/mmc/host/sdhci-pci.c =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 |=
 =A0 =A01 +
> =A0drivers/mmc/host/sdhci.c =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 | =A0 =A02 +-
> =A04 files changed, 11 insertions(+), 1 deletions(-)
>
> diff --git a/Documentation/powerpc/dts-bindings/fsl/esdhc.txt b/Documenta=
tion/powerpc/dts-bindings/fsl/esdhc.txt
> index 5093ddf..298b865 100644
> --- a/Documentation/powerpc/dts-bindings/fsl/esdhc.txt
> +++ b/Documentation/powerpc/dts-bindings/fsl/esdhc.txt
> @@ -10,6 +10,8 @@ Required properties:
> =A0 - interrupts : should contain eSDHC interrupt.
> =A0 - interrupt-parent : interrupt source phandle.
> =A0 - clock-frequency : specifies eSDHC base clock frequency.
> + =A0- mode : specifies eSDHC mode, valid values are: "1-bit" and "4-bit"=
.
> + =A0 =A0If mode is unspecified, then 4-bit mode is assumed.

In light of Pierre's comment that 4-bit is mandatory and this is a
deviation, perhaps it would be better to define an empty property to
indicate that only 1-bit transfers work.  Maybe something along the
lines of "sdhc-1-bit-only"?

g.

--=20
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.

Re: [PATCH] sdhci: Add support for hosts that are only capable of 1-bit transfers

[Anton Vorontsov]

On Sat, Jun 13, 2009 at 09:40:02AM -0600, Grant Likely wrote:
> On Thu, Jun 11, 2009 at 2:15 PM, Anton
> Vorontsov<avorontsov@ru.mvista.com> wrote:
> > Some hosts (hardware configurations, or particular SD/MMC slots) may
> > not support 4-bit bus. For example, on MPC8569E-MDS boards we can
> > switch between serial (1-bit only) and nibble (4-bit) modes, thought
> > we have to disable more peripherals to work in 4-bit mode.
> >
> > Along with some small core changes, this patch modifies sdhci-of
> > driver, so that now it looks for "mode" property in the device-tree.
> >
> > Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
> > ---
> >
> > Pierre, I'm not sure if a quirk would be appropriate here. If so,
> > I can redo the patch with FORCE_1_BIT_DATA quirk.
> >
> > Thanks,
> >
> >  Documentation/powerpc/dts-bindings/fsl/esdhc.txt |    2 ++
> >  drivers/mmc/host/sdhci-of.c                      |    7 +++++++
> >  drivers/mmc/host/sdhci-pci.c                     |    1 +
> >  drivers/mmc/host/sdhci.c                         |    2 +-
> >  4 files changed, 11 insertions(+), 1 deletions(-)
> >
> > diff --git a/Documentation/powerpc/dts-bindings/fsl/esdhc.txt b/Documentation/powerpc/dts-bindings/fsl/esdhc.txt
> > index 5093ddf..298b865 100644
> > --- a/Documentation/powerpc/dts-bindings/fsl/esdhc.txt
> > +++ b/Documentation/powerpc/dts-bindings/fsl/esdhc.txt
> > @@ -10,6 +10,8 @@ Required properties:
> >   - interrupts : should contain eSDHC interrupt.
> >   - interrupt-parent : interrupt source phandle.
> >   - clock-frequency : specifies eSDHC base clock frequency.
> > +  - mode : specifies eSDHC mode, valid values are: "1-bit" and "4-bit".
> > +    If mode is unspecified, then 4-bit mode is assumed.
> 
> In light of Pierre's comment that 4-bit is mandatory and this is a
> deviation, perhaps it would be better to define an empty property to
> indicate that only 1-bit transfers work.  Maybe something along the
> lines of "sdhc-1-bit-only"?

Yeah, since it turned up to be a quirk, we'd better use a named
property.

(I think that by convention we should use commas for
controller-specific properties, i.e. "sdhci,property".)


Thanks!

-- 
Anton Vorontsov
email: cbouatmailru@gmail.com
irc://irc.freenode.net/bd2

[PATCH v2] sdhci: Add support for hosts that are only capable of 1-bit transfers

[Anton Vorontsov]

Some hosts (hardware configurations, or particular SD/MMC slots) may
not support 4-bit bus. For example, on MPC8569E-MDS boards we can
switch between serial (1-bit only) and nibble (4-bit) modes, thought
we have to disable more peripherals to work in 4-bit mode.

Along with some small core changes, this patch modifies sdhci-of
driver, so that now it looks for "sdhci,1-bit-only" property in the
device-tree, and if specified we enable a proper quirk.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
---

Pierre,

As promised, here is a version with a quirk.
Also incorporated suggestions by Grant Likely.


Thanks,

 Documentation/powerpc/dts-bindings/fsl/esdhc.txt |    2 ++
 drivers/mmc/host/sdhci-of.c                      |    3 +++
 drivers/mmc/host/sdhci.c                         |    5 ++++-
 drivers/mmc/host/sdhci.h                         |    2 ++
 4 files changed, 11 insertions(+), 1 deletions(-)

diff --git a/Documentation/powerpc/dts-bindings/fsl/esdhc.txt b/Documentation/powerpc/dts-bindings/fsl/esdhc.txt
index 5093ddf..3ed3797 100644
--- a/Documentation/powerpc/dts-bindings/fsl/esdhc.txt
+++ b/Documentation/powerpc/dts-bindings/fsl/esdhc.txt
@@ -10,6 +10,8 @@ Required properties:
   - interrupts : should contain eSDHC interrupt.
   - interrupt-parent : interrupt source phandle.
   - clock-frequency : specifies eSDHC base clock frequency.
+  - sdhci,1-bit-only : (optional) specifies that a controller can
+    only handle 1-bit data transfers.
 
 Example:
 
diff --git a/drivers/mmc/host/sdhci-of.c b/drivers/mmc/host/sdhci-of.c
index 09cc597..dd65f84 100644
--- a/drivers/mmc/host/sdhci-of.c
+++ b/drivers/mmc/host/sdhci-of.c
@@ -244,6 +244,9 @@ static int __devinit sdhci_of_probe(struct of_device *ofdev,
 		host->ops = &sdhci_of_data->ops;
 	}
 
+	if (of_get_property(np, "sdhci,1-bit-only", NULL))
+		host->quirks |= SDHCI_QUIRK_FORCE_1_BIT_DATA;
+
 	clk = of_get_property(np, "clock-frequency", &size);
 	if (clk && size == sizeof(*clk) && *clk)
 		of_host->clock = *clk;
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 9234be2..f28f94a 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1721,7 +1721,10 @@ int sdhci_add_host(struct sdhci_host *host)
 	mmc->ops = &sdhci_ops;
 	mmc->f_min = host->max_clk / 256;
 	mmc->f_max = host->max_clk;
-	mmc->caps = MMC_CAP_4_BIT_DATA | MMC_CAP_SDIO_IRQ;
+	mmc->caps = MMC_CAP_SDIO_IRQ;
+
+	if (!(host->quirks & SDHCI_QUIRK_FORCE_1_BIT_DATA))
+		mmc->caps |= MMC_CAP_4_BIT_DATA;
 
 	if (caps & SDHCI_CAN_DO_HISPD)
 		mmc->caps |= MMC_CAP_SD_HIGHSPEED;
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 65c6f99..834f877 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -226,6 +226,8 @@ struct sdhci_host {
 #define SDHCI_QUIRK_RESTORE_IRQS_AFTER_RESET		(1<<19)
 /* Controller has to be forced to use block size of 2048 bytes */
 #define SDHCI_QUIRK_FORCE_BLK_SZ_2048			(1<<20)
+/* Controller can only handle 1-bit data transfers */
+#define SDHCI_QUIRK_FORCE_1_BIT_DATA			(1<<21)
 
 	int			irq;		/* Device IRQ */
 	void __iomem *		ioaddr;		/* Mapped address */
-- 
1.6.3.1

Re: [PATCH v2] sdhci: Add support for hosts that are only capable of 1-bit transfers

[Grant Likely]

On Wed, Jun 17, 2009 at 2:14 PM, Anton
Vorontsov<avorontsov@ru.mvista.com> wrote:
> Some hosts (hardware configurations, or particular SD/MMC slots) may
> not support 4-bit bus. For example, on MPC8569E-MDS boards we can
> switch between serial (1-bit only) and nibble (4-bit) modes, thought
> we have to disable more peripherals to work in 4-bit mode.
>
> Along with some small core changes, this patch modifies sdhci-of
> driver, so that now it looks for "sdhci,1-bit-only" property in the
> device-tree, and if specified we enable a proper quirk.
>
> Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>

Looks good to me.

Acked-by: Grant Likely <grant.likely@secretlab.ca>

g.

> ---
>
> Pierre,
>
> As promised, here is a version with a quirk.
> Also incorporated suggestions by Grant Likely.
>
>
> Thanks,
>
> =A0Documentation/powerpc/dts-bindings/fsl/esdhc.txt | =A0 =A02 ++
> =A0drivers/mmc/host/sdhci-of.c =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0| =A0 =A03 +++
> =A0drivers/mmc/host/sdhci.c =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 | =A0 =A05 ++++-
> =A0drivers/mmc/host/sdhci.h =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 | =A0 =A02 ++
> =A04 files changed, 11 insertions(+), 1 deletions(-)
>
> diff --git a/Documentation/powerpc/dts-bindings/fsl/esdhc.txt b/Documenta=
tion/powerpc/dts-bindings/fsl/esdhc.txt
> index 5093ddf..3ed3797 100644
> --- a/Documentation/powerpc/dts-bindings/fsl/esdhc.txt
> +++ b/Documentation/powerpc/dts-bindings/fsl/esdhc.txt
> @@ -10,6 +10,8 @@ Required properties:
> =A0 - interrupts : should contain eSDHC interrupt.
> =A0 - interrupt-parent : interrupt source phandle.
> =A0 - clock-frequency : specifies eSDHC base clock frequency.
> + =A0- sdhci,1-bit-only : (optional) specifies that a controller can
> + =A0 =A0only handle 1-bit data transfers.
>
> =A0Example:
>
> diff --git a/drivers/mmc/host/sdhci-of.c b/drivers/mmc/host/sdhci-of.c
> index 09cc597..dd65f84 100644
> --- a/drivers/mmc/host/sdhci-of.c
> +++ b/drivers/mmc/host/sdhci-of.c
> @@ -244,6 +244,9 @@ static int __devinit sdhci_of_probe(struct of_device =
*ofdev,
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0host->ops =3D &sdhci_of_data->ops;
> =A0 =A0 =A0 =A0}
>
> + =A0 =A0 =A0 if (of_get_property(np, "sdhci,1-bit-only", NULL))
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 host->quirks |=3D SDHCI_QUIRK_FORCE_1_BIT_D=
ATA;
> +
> =A0 =A0 =A0 =A0clk =3D of_get_property(np, "clock-frequency", &size);
> =A0 =A0 =A0 =A0if (clk && size =3D=3D sizeof(*clk) && *clk)
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0of_host->clock =3D *clk;
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 9234be2..f28f94a 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -1721,7 +1721,10 @@ int sdhci_add_host(struct sdhci_host *host)
> =A0 =A0 =A0 =A0mmc->ops =3D &sdhci_ops;
> =A0 =A0 =A0 =A0mmc->f_min =3D host->max_clk / 256;
> =A0 =A0 =A0 =A0mmc->f_max =3D host->max_clk;
> - =A0 =A0 =A0 mmc->caps =3D MMC_CAP_4_BIT_DATA | MMC_CAP_SDIO_IRQ;
> + =A0 =A0 =A0 mmc->caps =3D MMC_CAP_SDIO_IRQ;
> +
> + =A0 =A0 =A0 if (!(host->quirks & SDHCI_QUIRK_FORCE_1_BIT_DATA))
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 mmc->caps |=3D MMC_CAP_4_BIT_DATA;
>
> =A0 =A0 =A0 =A0if (caps & SDHCI_CAN_DO_HISPD)
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0mmc->caps |=3D MMC_CAP_SD_HIGHSPEED;
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index 65c6f99..834f877 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -226,6 +226,8 @@ struct sdhci_host {
> =A0#define SDHCI_QUIRK_RESTORE_IRQS_AFTER_RESET =A0 =A0 =A0 =A0 =A0 (1<<1=
9)
> =A0/* Controller has to be forced to use block size of 2048 bytes */
> =A0#define SDHCI_QUIRK_FORCE_BLK_SZ_2048 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0(1<<20)
> +/* Controller can only handle 1-bit data transfers */
> +#define SDHCI_QUIRK_FORCE_1_BIT_DATA =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0=
 (1<<21)
>
> =A0 =A0 =A0 =A0int =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 irq; =A0 =A0 =
=A0 =A0 =A0 =A0/* Device IRQ */
> =A0 =A0 =A0 =A0void __iomem * =A0 =A0 =A0 =A0 =A0ioaddr; =A0 =A0 =A0 =A0 =
/* Mapped address */
> --
> 1.6.3.1
>



--=20
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.

Re: [PATCH v2] sdhci: Add support for hosts that are only capable of 1-bit transfers

[Pierre Ossman]

[-- Attachment #1: Type: text/plain, Size: 885 bytes --]

On Thu, 18 Jun 2009 00:14:08 +0400
Anton Vorontsov <avorontsov@ru.mvista.com> wrote:

> Some hosts (hardware configurations, or particular SD/MMC slots) may
> not support 4-bit bus. For example, on MPC8569E-MDS boards we can
> switch between serial (1-bit only) and nibble (4-bit) modes, thought
> we have to disable more peripherals to work in 4-bit mode.
> 
> Along with some small core changes, this patch modifies sdhci-of
> driver, so that now it looks for "sdhci,1-bit-only" property in the
> device-tree, and if specified we enable a proper quirk.
> 
> Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
> ---

Patch merged.

Rgds
-- 
     -- Pierre Ossman

  WARNING: This correspondence is being monitored by the
  Swedish government. Make sure your server uses encryption
  for SMTP traffic and consider using PGP for end-to-end
  encryption.

[-- Attachment #2: signature.asc --]
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