diff mbox

sdhci: Add quirk and device tree parameter to force SD test mode

Message ID 1471906531-28668-1-git-send-email-zach.brown@ni.com
State New
Headers show

Commit Message

Zach Brown Aug. 22, 2016, 10:55 p.m. UTC
From: Jaeden Amero <jaeden.amero@ni.com>

On some devices, CD is broken so that we must force the SDHCI into test
mode and set CD, so that it always detects an SD card as present.

In order to get a device with broken CD working, we had previously
always set the SDHCI into test mode. Unfortunately, this had the side
effect of making all SD cards used with our Linux kernels undetectable
and non-removable.

By making this "SD test mode" setting optional via a quirk, we can avoid
this side effect for devices other than the device with broken CD.
Additionally, we add a device parameter to sdhci-pltfm to allow all
SDHCI drivers to enable this quirk.

Signed-off-by: Jaeden Amero <jaeden.amero@ni.com>
Signed-off-by: Zach Brown <zach.brown@ni.com>
---
 Documentation/devicetree/bindings/mmc/mmc.txt | 2 ++
 drivers/mmc/host/sdhci-pltfm.c                | 4 ++++
 drivers/mmc/host/sdhci.c                      | 9 +++++++++
 drivers/mmc/host/sdhci.h                      | 4 ++++
 4 files changed, 19 insertions(+)

Comments

Bough Chen Aug. 23, 2016, 1:34 a.m. UTC | #1
> -----Original Message-----
> From: linux-mmc-owner@vger.kernel.org [mailto:linux-mmc-
> owner@vger.kernel.org] On Behalf Of Zach Brown
> Sent: Tuesday, August 23, 2016 6:56 AM
> To: adrian.hunter@intel.com
> Cc: ulf.hansson@linaro.org; mark.rutland@arm.com; robh+dt@kernel.org;
> linux-mmc@vger.kernel.org; devicetree@vger.kernel.org; linux-
> kernel@vger.kernel.org
> Subject: [PATCH] sdhci: Add quirk and device tree parameter to force SD test
> mode
> 
> From: Jaeden Amero <jaeden.amero@ni.com>
> 
> On some devices, CD is broken so that we must force the SDHCI into test mode
> and set CD, so that it always detects an SD card as present.
> 
> In order to get a device with broken CD working, we had previously always set
> the SDHCI into test mode. Unfortunately, this had the side effect of making all
> SD cards used with our Linux kernels undetectable and non-removable.

Why not use the poll mode? You can set the flag MMC_CAP_NEEDS_POLL, then 
the mmc core will detect the card every second.

> 
> By making this "SD test mode" setting optional via a quirk, we can avoid this
> side effect for devices other than the device with broken CD.
> Additionally, we add a device parameter to sdhci-pltfm to allow all SDHCI
> drivers to enable this quirk.
> 
> Signed-off-by: Jaeden Amero <jaeden.amero@ni.com>
> Signed-off-by: Zach Brown <zach.brown@ni.com>
> ---
>  Documentation/devicetree/bindings/mmc/mmc.txt | 2 ++
>  drivers/mmc/host/sdhci-pltfm.c                | 4 ++++
>  drivers/mmc/host/sdhci.c                      | 9 +++++++++
>  drivers/mmc/host/sdhci.h                      | 4 ++++
>  4 files changed, 19 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/mmc/mmc.txt
> b/Documentation/devicetree/bindings/mmc/mmc.txt
> index 22d1e1f..3a9be41 100644
> --- a/Documentation/devicetree/bindings/mmc/mmc.txt
> +++ b/Documentation/devicetree/bindings/mmc/mmc.txt
> @@ -52,6 +52,8 @@ Optional properties:
>  - no-sdio: controller is limited to send sdio cmd during initialization
>  - no-sd: controller is limited to send sd cmd during initialization
>  - no-mmc: controller is limited to send mmc cmd during initialization
> +- force-sd-cd-test-mode: card detection is broken on device, force cd
> +test
> +  enable and cd test inserted so host will always detect a card.
> 
>  *NOTE* on CD and WP polarity. To use common for all SD/MMC host
> controllers line  polarity properties, we have to fix the meaning of the "normal"
> and "inverted"
> diff --git a/drivers/mmc/host/sdhci-pltfm.c b/drivers/mmc/host/sdhci-pltfm.c
> index 1d17dcf..056d101 100644
> --- a/drivers/mmc/host/sdhci-pltfm.c
> +++ b/drivers/mmc/host/sdhci-pltfm.c
> @@ -87,6 +87,10 @@ void sdhci_get_of_property(struct platform_device
> *pdev)
>  	if (of_get_property(np, "broken-cd", NULL))
>  		host->quirks |= SDHCI_QUIRK_BROKEN_CARD_DETECTION;
> 
> +	if (of_get_property(np, "force-sd-cd-test-mode", NULL))
> +		host->quirks2 |=
> +			SDHCI_QUIRK2_MUST_FORCE_SD_CD_TEST_MODE;
> +
>  	if (of_get_property(np, "no-1-8-v", NULL))
>  		host->quirks2 |= SDHCI_QUIRK2_NO_1_8_V;
> 
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index
> cd65d47..2f4c6f9 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -117,6 +117,15 @@ static inline bool sdhci_data_line_cmd(struct
> mmc_command *cmd)  static void sdhci_set_card_detection(struct sdhci_host
> *host, bool enable)  {
>  	u32 present;
> +	u8  ctrl;
> +
> +	if (host->quirks2 & SDHCI_QUIRK2_MUST_FORCE_SD_CD_TEST_MODE)
> {
> +		/* Put the card in test mode, with card inserted */
> +		ctrl = sdhci_readl(host, SDHCI_HOST_CONTROL);
> +		ctrl |= SDHCI_CTRL_CD_TEST_INSERTED |
> +			SDHCI_CTRL_CD_TEST_ENABLE;
> +		sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
> +	}
> 
>  	if ((host->quirks & SDHCI_QUIRK_BROKEN_CARD_DETECTION) ||
>  	    !mmc_card_is_removable(host->mmc))
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h index
> 0411c9f..dd609b2 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -84,6 +84,8 @@
>  #define   SDHCI_CTRL_ADMA32	0x10
>  #define   SDHCI_CTRL_ADMA64	0x18
>  #define   SDHCI_CTRL_8BITBUS	0x20
> +#define  SDHCI_CTRL_CD_TEST_INSERTED	0x40
> +#define  SDHCI_CTRL_CD_TEST_ENABLE	0x80
> 
>  #define SDHCI_POWER_CONTROL	0x29
>  #define  SDHCI_POWER_ON		0x01
> @@ -422,6 +424,8 @@ struct sdhci_host {
>  #define SDHCI_QUIRK2_ACMD23_BROKEN			(1<<14)
>  /* Broken Clock divider zero in controller */
>  #define SDHCI_QUIRK2_CLOCK_DIV_ZERO_BROKEN		(1<<15)
> +/* Controller must support device with broken CD */
> +#define SDHCI_QUIRK2_MUST_FORCE_SD_CD_TEST_MODE		(1<<16)
> 
>  	int irq;		/* Device IRQ */
>  	void __iomem *ioaddr;	/* Mapped address */
> --
> 2.7.4
> 
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Frank Rowand Aug. 23, 2016, 2:46 a.m. UTC | #2
On 08/22/16 15:55, Zach Brown wrote:
> From: Jaeden Amero <jaeden.amero@ni.com>
> 
> On some devices, CD is broken so that we must force the SDHCI into test
> mode and set CD, so that it always detects an SD card as present.
> 
> In order to get a device with broken CD working, we had previously
> always set the SDHCI into test mode. Unfortunately, this had the side
> effect of making all SD cards used with our Linux kernels undetectable
> and non-removable.
> 
> By making this "SD test mode" setting optional via a quirk, we can avoid
> this side effect for devices other than the device with broken CD.
> Additionally, we add a device parameter to sdhci-pltfm to allow all
> SDHCI drivers to enable this quirk.
> 
> Signed-off-by: Jaeden Amero <jaeden.amero@ni.com>
> Signed-off-by: Zach Brown <zach.brown@ni.com>
> ---
>  Documentation/devicetree/bindings/mmc/mmc.txt | 2 ++
>  drivers/mmc/host/sdhci-pltfm.c                | 4 ++++
>  drivers/mmc/host/sdhci.c                      | 9 +++++++++
>  drivers/mmc/host/sdhci.h                      | 4 ++++
>  4 files changed, 19 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/mmc/mmc.txt b/Documentation/devicetree/bindings/mmc/mmc.txt
> index 22d1e1f..3a9be41 100644
> --- a/Documentation/devicetree/bindings/mmc/mmc.txt
> +++ b/Documentation/devicetree/bindings/mmc/mmc.txt
> @@ -52,6 +52,8 @@ Optional properties:
>  - no-sdio: controller is limited to send sdio cmd during initialization
>  - no-sd: controller is limited to send sd cmd during initialization
>  - no-mmc: controller is limited to send mmc cmd during initialization
> +- force-sd-cd-test-mode: card detection is broken on device, force cd test
> +  enable and cd test inserted so host will always detect a card.

Do not create a property that tells the driver what to do.

Instead create a property that says that the hardware is broken in a certain way.
The driver can then choose to take the appropriate action based on the way that
the hardware is broken.


>  
>  *NOTE* on CD and WP polarity. To use common for all SD/MMC host controllers line
>  polarity properties, we have to fix the meaning of the "normal" and "inverted"
> diff --git a/drivers/mmc/host/sdhci-pltfm.c b/drivers/mmc/host/sdhci-pltfm.c
> index 1d17dcf..056d101 100644
> --- a/drivers/mmc/host/sdhci-pltfm.c
> +++ b/drivers/mmc/host/sdhci-pltfm.c
> @@ -87,6 +87,10 @@ void sdhci_get_of_property(struct platform_device *pdev)
>  	if (of_get_property(np, "broken-cd", NULL))
>  		host->quirks |= SDHCI_QUIRK_BROKEN_CARD_DETECTION;
>  
> +	if (of_get_property(np, "force-sd-cd-test-mode", NULL))
> +		host->quirks2 |=
> +			SDHCI_QUIRK2_MUST_FORCE_SD_CD_TEST_MODE;
> +
>  	if (of_get_property(np, "no-1-8-v", NULL))
>  		host->quirks2 |= SDHCI_QUIRK2_NO_1_8_V;
>  
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index cd65d47..2f4c6f9 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -117,6 +117,15 @@ static inline bool sdhci_data_line_cmd(struct mmc_command *cmd)
>  static void sdhci_set_card_detection(struct sdhci_host *host, bool enable)
>  {
>  	u32 present;
> +	u8  ctrl;
> +
> +	if (host->quirks2 & SDHCI_QUIRK2_MUST_FORCE_SD_CD_TEST_MODE) {
> +		/* Put the card in test mode, with card inserted */
> +		ctrl = sdhci_readl(host, SDHCI_HOST_CONTROL);
> +		ctrl |= SDHCI_CTRL_CD_TEST_INSERTED |
> +			SDHCI_CTRL_CD_TEST_ENABLE;
> +		sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
> +	}
>  
>  	if ((host->quirks & SDHCI_QUIRK_BROKEN_CARD_DETECTION) ||
>  	    !mmc_card_is_removable(host->mmc))
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index 0411c9f..dd609b2 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -84,6 +84,8 @@
>  #define   SDHCI_CTRL_ADMA32	0x10
>  #define   SDHCI_CTRL_ADMA64	0x18
>  #define   SDHCI_CTRL_8BITBUS	0x20
> +#define  SDHCI_CTRL_CD_TEST_INSERTED	0x40
> +#define  SDHCI_CTRL_CD_TEST_ENABLE	0x80
>  
>  #define SDHCI_POWER_CONTROL	0x29
>  #define  SDHCI_POWER_ON		0x01
> @@ -422,6 +424,8 @@ struct sdhci_host {
>  #define SDHCI_QUIRK2_ACMD23_BROKEN			(1<<14)
>  /* Broken Clock divider zero in controller */
>  #define SDHCI_QUIRK2_CLOCK_DIV_ZERO_BROKEN		(1<<15)
> +/* Controller must support device with broken CD */
> +#define SDHCI_QUIRK2_MUST_FORCE_SD_CD_TEST_MODE		(1<<16)
>  
>  	int irq;		/* Device IRQ */
>  	void __iomem *ioaddr;	/* Mapped address */
> 

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Adrian Hunter Aug. 23, 2016, 6:22 a.m. UTC | #3
On 23/08/16 01:55, Zach Brown wrote:
> From: Jaeden Amero <jaeden.amero@ni.com>
> 
> On some devices, CD is broken so that we must force the SDHCI into test
> mode and set CD, so that it always detects an SD card as present.
> 
> In order to get a device with broken CD working, we had previously
> always set the SDHCI into test mode. Unfortunately, this had the side
> effect of making all SD cards used with our Linux kernels undetectable
> and non-removable.
> 
> By making this "SD test mode" setting optional via a quirk, we can avoid
> this side effect for devices other than the device with broken CD.
> Additionally, we add a device parameter to sdhci-pltfm to allow all
> SDHCI drivers to enable this quirk.

Generally new quirks are not acceptable, but I don't see how test mode helps
very much since you still don't get any card detection events.  If you
really need test mode, please explain more about how it helps (as opposed to
polling for example).


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Zach Brown Aug. 23, 2016, 10:04 p.m. UTC | #4
On Tue, Aug 23, 2016 at 01:34:20AM +0000, Haibo Chen wrote:
> > -----Original Message-----
> > From: linux-mmc-owner@vger.kernel.org [mailto:linux-mmc-
> > owner@vger.kernel.org] On Behalf Of Zach Brown
> > Sent: Tuesday, August 23, 2016 6:56 AM
> > To: adrian.hunter@intel.com
> > Cc: ulf.hansson@linaro.org; mark.rutland@arm.com; robh+dt@kernel.org;
> > linux-mmc@vger.kernel.org; devicetree@vger.kernel.org; linux-
> > kernel@vger.kernel.org
> > Subject: [PATCH] sdhci: Add quirk and device tree parameter to force SD test
> > mode
> > 
> > From: Jaeden Amero <jaeden.amero@ni.com>
> > 
> > On some devices, CD is broken so that we must force the SDHCI into test mode
> > and set CD, so that it always detects an SD card as present.
> > 
> > In order to get a device with broken CD working, we had previously always set
> > the SDHCI into test mode. Unfortunately, this had the side effect of making all
> > SD cards used with our Linux kernels undetectable and non-removable.
> 
> Why not use the poll mode? You can set the flag MMC_CAP_NEEDS_POLL, then 
> the mmc core will detect the card every second.
> 

We're using a Xilinx Zynq device. In an AR they state:
"Signals card detect (CDn) and write protect (WPn) are required for the Zynq SD
card interface to work." http://www.xilinx.com/support/answers/61064.html
So polling won't work, since the interface itself won't work unless CDn is on.
Test mode allows us to get the interface working with no CDn signal.


> > 
> > By making this "SD test mode" setting optional via a quirk, we can avoid this
> > side effect for devices other than the device with broken CD.
> > Additionally, we add a device parameter to sdhci-pltfm to allow all SDHCI
> > drivers to enable this quirk.
> > 
> > Signed-off-by: Jaeden Amero <jaeden.amero@ni.com>
> > Signed-off-by: Zach Brown <zach.brown@ni.com>
> > ---
> >  Documentation/devicetree/bindings/mmc/mmc.txt | 2 ++
> >  drivers/mmc/host/sdhci-pltfm.c                | 4 ++++
> >  drivers/mmc/host/sdhci.c                      | 9 +++++++++
> >  drivers/mmc/host/sdhci.h                      | 4 ++++
> >  4 files changed, 19 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/mmc/mmc.txt
> > b/Documentation/devicetree/bindings/mmc/mmc.txt
> > index 22d1e1f..3a9be41 100644
> > --- a/Documentation/devicetree/bindings/mmc/mmc.txt
> > +++ b/Documentation/devicetree/bindings/mmc/mmc.txt
> > @@ -52,6 +52,8 @@ Optional properties:
> >  - no-sdio: controller is limited to send sdio cmd during initialization
> >  - no-sd: controller is limited to send sd cmd during initialization
> >  - no-mmc: controller is limited to send mmc cmd during initialization
> > +- force-sd-cd-test-mode: card detection is broken on device, force cd
> > +test
> > +  enable and cd test inserted so host will always detect a card.
> > 
> >  *NOTE* on CD and WP polarity. To use common for all SD/MMC host
> > controllers line  polarity properties, we have to fix the meaning of the "normal"
> > and "inverted"
> > diff --git a/drivers/mmc/host/sdhci-pltfm.c b/drivers/mmc/host/sdhci-pltfm.c
> > index 1d17dcf..056d101 100644
> > --- a/drivers/mmc/host/sdhci-pltfm.c
> > +++ b/drivers/mmc/host/sdhci-pltfm.c
> > @@ -87,6 +87,10 @@ void sdhci_get_of_property(struct platform_device
> > *pdev)
> >  	if (of_get_property(np, "broken-cd", NULL))
> >  		host->quirks |= SDHCI_QUIRK_BROKEN_CARD_DETECTION;
> > 
> > +	if (of_get_property(np, "force-sd-cd-test-mode", NULL))
> > +		host->quirks2 |=
> > +			SDHCI_QUIRK2_MUST_FORCE_SD_CD_TEST_MODE;
> > +
> >  	if (of_get_property(np, "no-1-8-v", NULL))
> >  		host->quirks2 |= SDHCI_QUIRK2_NO_1_8_V;
> > 
> > diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index
> > cd65d47..2f4c6f9 100644
> > --- a/drivers/mmc/host/sdhci.c
> > +++ b/drivers/mmc/host/sdhci.c
> > @@ -117,6 +117,15 @@ static inline bool sdhci_data_line_cmd(struct
> > mmc_command *cmd)  static void sdhci_set_card_detection(struct sdhci_host
> > *host, bool enable)  {
> >  	u32 present;
> > +	u8  ctrl;
> > +
> > +	if (host->quirks2 & SDHCI_QUIRK2_MUST_FORCE_SD_CD_TEST_MODE)
> > {
> > +		/* Put the card in test mode, with card inserted */
> > +		ctrl = sdhci_readl(host, SDHCI_HOST_CONTROL);
> > +		ctrl |= SDHCI_CTRL_CD_TEST_INSERTED |
> > +			SDHCI_CTRL_CD_TEST_ENABLE;
> > +		sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
> > +	}
> > 
> >  	if ((host->quirks & SDHCI_QUIRK_BROKEN_CARD_DETECTION) ||
> >  	    !mmc_card_is_removable(host->mmc))
> > diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h index
> > 0411c9f..dd609b2 100644
> > --- a/drivers/mmc/host/sdhci.h
> > +++ b/drivers/mmc/host/sdhci.h
> > @@ -84,6 +84,8 @@
> >  #define   SDHCI_CTRL_ADMA32	0x10
> >  #define   SDHCI_CTRL_ADMA64	0x18
> >  #define   SDHCI_CTRL_8BITBUS	0x20
> > +#define  SDHCI_CTRL_CD_TEST_INSERTED	0x40
> > +#define  SDHCI_CTRL_CD_TEST_ENABLE	0x80
> > 
> >  #define SDHCI_POWER_CONTROL	0x29
> >  #define  SDHCI_POWER_ON		0x01
> > @@ -422,6 +424,8 @@ struct sdhci_host {
> >  #define SDHCI_QUIRK2_ACMD23_BROKEN			(1<<14)
> >  /* Broken Clock divider zero in controller */
> >  #define SDHCI_QUIRK2_CLOCK_DIV_ZERO_BROKEN		(1<<15)
> > +/* Controller must support device with broken CD */
> > +#define SDHCI_QUIRK2_MUST_FORCE_SD_CD_TEST_MODE		(1<<16)
> > 
> >  	int irq;		/* Device IRQ */
> >  	void __iomem *ioaddr;	/* Mapped address */
> > --
> > 2.7.4
> > 
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the
> > body of a message to majordomo@vger.kernel.org More majordomo info at
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Zach Brown Aug. 23, 2016, 10:14 p.m. UTC | #5
On Tue, Aug 23, 2016 at 09:22:29AM +0300, Adrian Hunter wrote:
> On 23/08/16 01:55, Zach Brown wrote:
> > From: Jaeden Amero <jaeden.amero@ni.com>
> > 
> > On some devices, CD is broken so that we must force the SDHCI into test
> > mode and set CD, so that it always detects an SD card as present.
> > 
> > In order to get a device with broken CD working, we had previously
> > always set the SDHCI into test mode. Unfortunately, this had the side
> > effect of making all SD cards used with our Linux kernels undetectable
> > and non-removable.
> > 
> > By making this "SD test mode" setting optional via a quirk, we can avoid
> > this side effect for devices other than the device with broken CD.
> > Additionally, we add a device parameter to sdhci-pltfm to allow all
> > SDHCI drivers to enable this quirk.
> 
> Generally new quirks are not acceptable, but I don't see how test mode helps
> very much since you still don't get any card detection events.  If you
> really need test mode, please explain more about how it helps (as opposed to
> polling for example).
> 
> 

Polling doesnt work in our case, since the issue lies with the SD controller
itself. The SD controller in xilinx zynq devices requires the CDn signal to
work. http://www.xilinx.com/support/answers/61064.html We have a situation 
where the controller requires the signal, but we can't use any of our pins to
supply it. With test mode we can get the controller into a state where it works
despite not having the signal.
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Zach Brown Aug. 23, 2016, 10:19 p.m. UTC | #6
On Mon, Aug 22, 2016 at 07:46:09PM -0700, Frank Rowand wrote:
> On 08/22/16 15:55, Zach Brown wrote:
> > From: Jaeden Amero <jaeden.amero@ni.com>
> > 
> > On some devices, CD is broken so that we must force the SDHCI into test
> > mode and set CD, so that it always detects an SD card as present.
> > 
> > In order to get a device with broken CD working, we had previously
> > always set the SDHCI into test mode. Unfortunately, this had the side
> > effect of making all SD cards used with our Linux kernels undetectable
> > and non-removable.
> > 
> > By making this "SD test mode" setting optional via a quirk, we can avoid
> > this side effect for devices other than the device with broken CD.
> > Additionally, we add a device parameter to sdhci-pltfm to allow all
> > SDHCI drivers to enable this quirk.
> > 
> > Signed-off-by: Jaeden Amero <jaeden.amero@ni.com>
> > Signed-off-by: Zach Brown <zach.brown@ni.com>
> > ---
> >  Documentation/devicetree/bindings/mmc/mmc.txt | 2 ++
> >  drivers/mmc/host/sdhci-pltfm.c                | 4 ++++
> >  drivers/mmc/host/sdhci.c                      | 9 +++++++++
> >  drivers/mmc/host/sdhci.h                      | 4 ++++
> >  4 files changed, 19 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/mmc/mmc.txt b/Documentation/devicetree/bindings/mmc/mmc.txt
> > index 22d1e1f..3a9be41 100644
> > --- a/Documentation/devicetree/bindings/mmc/mmc.txt
> > +++ b/Documentation/devicetree/bindings/mmc/mmc.txt
> > @@ -52,6 +52,8 @@ Optional properties:
> >  - no-sdio: controller is limited to send sdio cmd during initialization
> >  - no-sd: controller is limited to send sd cmd during initialization
> >  - no-mmc: controller is limited to send mmc cmd during initialization
> > +- force-sd-cd-test-mode: card detection is broken on device, force cd test
> > +  enable and cd test inserted so host will always detect a card.
> 
> Do not create a property that tells the driver what to do.
> 
> Instead create a property that says that the hardware is broken in a certain way.
> The driver can then choose to take the appropriate action based on the way that
> the hardware is broken.
> 
> 

I understand the point you have raised. In the next version I will change the 
language of the property to reflect this. 

> >  
> >  *NOTE* on CD and WP polarity. To use common for all SD/MMC host controllers line
> >  polarity properties, we have to fix the meaning of the "normal" and "inverted"
> > diff --git a/drivers/mmc/host/sdhci-pltfm.c b/drivers/mmc/host/sdhci-pltfm.c
> > index 1d17dcf..056d101 100644
> > --- a/drivers/mmc/host/sdhci-pltfm.c
> > +++ b/drivers/mmc/host/sdhci-pltfm.c
> > @@ -87,6 +87,10 @@ void sdhci_get_of_property(struct platform_device *pdev)
> >  	if (of_get_property(np, "broken-cd", NULL))
> >  		host->quirks |= SDHCI_QUIRK_BROKEN_CARD_DETECTION;
> >  
> > +	if (of_get_property(np, "force-sd-cd-test-mode", NULL))
> > +		host->quirks2 |=
> > +			SDHCI_QUIRK2_MUST_FORCE_SD_CD_TEST_MODE;
> > +
> >  	if (of_get_property(np, "no-1-8-v", NULL))
> >  		host->quirks2 |= SDHCI_QUIRK2_NO_1_8_V;
> >  
> > diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> > index cd65d47..2f4c6f9 100644
> > --- a/drivers/mmc/host/sdhci.c
> > +++ b/drivers/mmc/host/sdhci.c
> > @@ -117,6 +117,15 @@ static inline bool sdhci_data_line_cmd(struct mmc_command *cmd)
> >  static void sdhci_set_card_detection(struct sdhci_host *host, bool enable)
> >  {
> >  	u32 present;
> > +	u8  ctrl;
> > +
> > +	if (host->quirks2 & SDHCI_QUIRK2_MUST_FORCE_SD_CD_TEST_MODE) {
> > +		/* Put the card in test mode, with card inserted */
> > +		ctrl = sdhci_readl(host, SDHCI_HOST_CONTROL);
> > +		ctrl |= SDHCI_CTRL_CD_TEST_INSERTED |
> > +			SDHCI_CTRL_CD_TEST_ENABLE;
> > +		sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
> > +	}
> >  
> >  	if ((host->quirks & SDHCI_QUIRK_BROKEN_CARD_DETECTION) ||
> >  	    !mmc_card_is_removable(host->mmc))
> > diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> > index 0411c9f..dd609b2 100644
> > --- a/drivers/mmc/host/sdhci.h
> > +++ b/drivers/mmc/host/sdhci.h
> > @@ -84,6 +84,8 @@
> >  #define   SDHCI_CTRL_ADMA32	0x10
> >  #define   SDHCI_CTRL_ADMA64	0x18
> >  #define   SDHCI_CTRL_8BITBUS	0x20
> > +#define  SDHCI_CTRL_CD_TEST_INSERTED	0x40
> > +#define  SDHCI_CTRL_CD_TEST_ENABLE	0x80
> >  
> >  #define SDHCI_POWER_CONTROL	0x29
> >  #define  SDHCI_POWER_ON		0x01
> > @@ -422,6 +424,8 @@ struct sdhci_host {
> >  #define SDHCI_QUIRK2_ACMD23_BROKEN			(1<<14)
> >  /* Broken Clock divider zero in controller */
> >  #define SDHCI_QUIRK2_CLOCK_DIV_ZERO_BROKEN		(1<<15)
> > +/* Controller must support device with broken CD */
> > +#define SDHCI_QUIRK2_MUST_FORCE_SD_CD_TEST_MODE		(1<<16)
> >  
> >  	int irq;		/* Device IRQ */
> >  	void __iomem *ioaddr;	/* Mapped address */
> > 
> 
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Adrian Hunter Aug. 24, 2016, 6:16 a.m. UTC | #7
On 24/08/16 01:14, Zach Brown wrote:
> On Tue, Aug 23, 2016 at 09:22:29AM +0300, Adrian Hunter wrote:
>> On 23/08/16 01:55, Zach Brown wrote:
>>> From: Jaeden Amero <jaeden.amero@ni.com>
>>>
>>> On some devices, CD is broken so that we must force the SDHCI into test
>>> mode and set CD, so that it always detects an SD card as present.
>>>
>>> In order to get a device with broken CD working, we had previously
>>> always set the SDHCI into test mode. Unfortunately, this had the side
>>> effect of making all SD cards used with our Linux kernels undetectable
>>> and non-removable.
>>>
>>> By making this "SD test mode" setting optional via a quirk, we can avoid
>>> this side effect for devices other than the device with broken CD.
>>> Additionally, we add a device parameter to sdhci-pltfm to allow all
>>> SDHCI drivers to enable this quirk.
>>
>> Generally new quirks are not acceptable, but I don't see how test mode helps
>> very much since you still don't get any card detection events.  If you
>> really need test mode, please explain more about how it helps (as opposed to
>> polling for example).
>>
>>
> 
> Polling doesnt work in our case, since the issue lies with the SD controller
> itself. The SD controller in xilinx zynq devices requires the CDn signal to
> work. http://www.xilinx.com/support/answers/61064.html We have a situation 
> where the controller requires the signal, but we can't use any of our pins to
> supply it. With test mode we can get the controller into a state where it works
> despite not having the signal.
> 

Doesn't sound like something we need in sdhci.c.  Have you considered adding
it to the driver, perhaps using the ->reset() callback?

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diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/mmc/mmc.txt b/Documentation/devicetree/bindings/mmc/mmc.txt
index 22d1e1f..3a9be41 100644
--- a/Documentation/devicetree/bindings/mmc/mmc.txt
+++ b/Documentation/devicetree/bindings/mmc/mmc.txt
@@ -52,6 +52,8 @@  Optional properties:
 - no-sdio: controller is limited to send sdio cmd during initialization
 - no-sd: controller is limited to send sd cmd during initialization
 - no-mmc: controller is limited to send mmc cmd during initialization
+- force-sd-cd-test-mode: card detection is broken on device, force cd test
+  enable and cd test inserted so host will always detect a card.
 
 *NOTE* on CD and WP polarity. To use common for all SD/MMC host controllers line
 polarity properties, we have to fix the meaning of the "normal" and "inverted"
diff --git a/drivers/mmc/host/sdhci-pltfm.c b/drivers/mmc/host/sdhci-pltfm.c
index 1d17dcf..056d101 100644
--- a/drivers/mmc/host/sdhci-pltfm.c
+++ b/drivers/mmc/host/sdhci-pltfm.c
@@ -87,6 +87,10 @@  void sdhci_get_of_property(struct platform_device *pdev)
 	if (of_get_property(np, "broken-cd", NULL))
 		host->quirks |= SDHCI_QUIRK_BROKEN_CARD_DETECTION;
 
+	if (of_get_property(np, "force-sd-cd-test-mode", NULL))
+		host->quirks2 |=
+			SDHCI_QUIRK2_MUST_FORCE_SD_CD_TEST_MODE;
+
 	if (of_get_property(np, "no-1-8-v", NULL))
 		host->quirks2 |= SDHCI_QUIRK2_NO_1_8_V;
 
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index cd65d47..2f4c6f9 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -117,6 +117,15 @@  static inline bool sdhci_data_line_cmd(struct mmc_command *cmd)
 static void sdhci_set_card_detection(struct sdhci_host *host, bool enable)
 {
 	u32 present;
+	u8  ctrl;
+
+	if (host->quirks2 & SDHCI_QUIRK2_MUST_FORCE_SD_CD_TEST_MODE) {
+		/* Put the card in test mode, with card inserted */
+		ctrl = sdhci_readl(host, SDHCI_HOST_CONTROL);
+		ctrl |= SDHCI_CTRL_CD_TEST_INSERTED |
+			SDHCI_CTRL_CD_TEST_ENABLE;
+		sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
+	}
 
 	if ((host->quirks & SDHCI_QUIRK_BROKEN_CARD_DETECTION) ||
 	    !mmc_card_is_removable(host->mmc))
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 0411c9f..dd609b2 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -84,6 +84,8 @@ 
 #define   SDHCI_CTRL_ADMA32	0x10
 #define   SDHCI_CTRL_ADMA64	0x18
 #define   SDHCI_CTRL_8BITBUS	0x20
+#define  SDHCI_CTRL_CD_TEST_INSERTED	0x40
+#define  SDHCI_CTRL_CD_TEST_ENABLE	0x80
 
 #define SDHCI_POWER_CONTROL	0x29
 #define  SDHCI_POWER_ON		0x01
@@ -422,6 +424,8 @@  struct sdhci_host {
 #define SDHCI_QUIRK2_ACMD23_BROKEN			(1<<14)
 /* Broken Clock divider zero in controller */
 #define SDHCI_QUIRK2_CLOCK_DIV_ZERO_BROKEN		(1<<15)
+/* Controller must support device with broken CD */
+#define SDHCI_QUIRK2_MUST_FORCE_SD_CD_TEST_MODE		(1<<16)
 
 	int irq;		/* Device IRQ */
 	void __iomem *ioaddr;	/* Mapped address */