On Tue, Aug 23, 2016 at 01:34:20AM +0000, Haibo Chen wrote: > > -----Original Message----- > > From: [email protected] [mailto:linux-mmc- > > [email protected]] On Behalf Of Zach Brown > > Sent: Tuesday, August 23, 2016 6:56 AM > > To: [email protected] > > Cc: [email protected]; [email protected]; [email protected]; > > [email protected]; [email protected]; linux- > > [email protected] > > Subject: [PATCH] sdhci: Add quirk and device tree parameter to force SD test > > mode > > > > From: Jaeden Amero <[email protected]> > > > > 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 <[email protected]> > > Signed-off-by: Zach Brown <[email protected]> > > --- > > 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 [email protected] More majordomo info at > > http://vger.kernel.org/majordomo-info.html
