On 08/22/16 15:55, Zach Brown wrote:
> From: Jaeden Amero <jaeden.amero@xxxxxx>
>
> 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@xxxxxx>
> Signed-off-by: Zach Brown <zach.brown@xxxxxx>
> ---
> 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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