Messages in this thread Patch in this message | | | From | James Walmsley <> | Subject | SDHCI - Add QUIRK2_BROKEN_WRITE_PROTEXT - Support Xilinx Zynq (Linux 3.9.0) | Date | Fri, 16 Aug 2013 12:14:50 +0000 |
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Hi Michal,
I have built a Xilinx Zynq based design which doesn't use the SDHCI Write-protect line. However, we use the MIO_0 pin for configuring a multiplexer and consequently the SDHCI driver thinks that the card is read-only (RO).
In the patch below I have proposed a new quirk, similar to the QUIRK_BROKEN_CARD_DETECTION flag, which causes the sdhci driver to assume a card with RW access.
This patch was made against the latest tree from Xilinx (github.com/Xilinx/linux-xlnx), Kernel 3.9.0 and I have attached it to the LKML to propose the additional quirk which may be useful on other platforms.
Kind regards,
James Walmsley
--- drivers/mmc/host/sdhci-of-xilinxps.c | 4 ++++ drivers/mmc/host/sdhci.c | 4 ++++ include/linux/mmc/sdhci.h | 1 + 3 files changed, 9 insertions(+)
diff --git a/drivers/mmc/host/sdhci-of-xilinxps.c b/drivers/mmc/host/sdhci-of-xilinxps.c index f79e0db..5553bc0 100644 --- a/drivers/mmc/host/sdhci-of-xilinxps.c +++ b/drivers/mmc/host/sdhci-of-xilinxps.c @@ -211,6 +211,10 @@ static int sdhci_zynq_probe(struct platform_device *pdev) if (prop == NULL || (!(u32) be32_to_cpup(prop))) host->quirks |= SDHCI_QUIRK_BROKEN_CARD_DETECTION; + prop = of_get_property(np, "xlnx,has-wp", NULL); + if (prop == NULL || (!(u32) be32_to_cpup(prop))) + host->quirks2 |= SDHCI_QUIRK2_BROKEN_WRITE_PROTECT; + return 0; clk_notif_unreg: diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index 51bbba4..c40365f 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -1609,6 +1609,10 @@ static int sdhci_do_get_ro(struct sdhci_host *host) { int i, ro_count; + if(host->quirks2 & SDHCI_QUIRK2_BROKEN_WRITE_PROTECT) { + return 0; // Return zero to assume RW. + } + if (!(host->quirks & SDHCI_QUIRK_UNSTABLE_RO_DETECT)) return sdhci_check_ro(host); diff --git a/include/linux/mmc/sdhci.h b/include/linux/mmc/sdhci.h index b838ffc..3eccf12 100644 --- a/include/linux/mmc/sdhci.h +++ b/include/linux/mmc/sdhci.h @@ -95,6 +95,7 @@ struct sdhci_host { /* The system physically doesn't support 1.8v, even if the host does */ #define SDHCI_QUIRK2_NO_1_8_V (1<<2) #define SDHCI_QUIRK2_PRESET_VALUE_BROKEN (1<<3) +#define SDHCI_QUIRK2_BROKEN_WRITE_PROTECT (1<<4) int irq; /* Device IRQ */ void __iomem *ioaddr; /* Mapped address */ -- 1.8.1.2
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