From 68d1fb7e229c6f95be4fbbe3eb46b24e41184924 Mon Sep 17 00:00:00 2001 From: Anton Vorontsov Date: Tue, 17 Mar 2009 00:13:52 +0300 Subject: [PATCH] sdhci: Add support for card-detection polling This patch adds SDHCI_QUIRK_BROKEN_CARD_DETECTION quirk. When specified, sdhci driver will set MMC_CAP_NEEDS_POLL MMC host capability, and won't enable card insert/remove interrupts. This is needed for hosts with unreliable card detection, such as FSL eSDHC. The original eSDHC driver was tring to "debounce" card-detection IRQs by reading present state and disabling particular interrupts. But with this debouncing scheme I noticed that sometimes we miss card insertion/removal events. Signed-off-by: Anton Vorontsov Signed-off-by: Pierre Ossman --- drivers/mmc/host/sdhci.c | 17 +++++++++++++++-- drivers/mmc/host/sdhci.h | 2 ++ 2 files changed, 17 insertions(+), 2 deletions(-) diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index 6fbbc005dd7..fc7cb489bdb 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -112,6 +112,9 @@ static void sdhci_set_card_detection(struct sdhci_host *host, bool enable) { u32 irqs = SDHCI_INT_CARD_REMOVE | SDHCI_INT_CARD_INSERT; + if (host->quirks & SDHCI_QUIRK_BROKEN_CARD_DETECTION) + return; + if (enable) sdhci_unmask_irqs(host, irqs); else @@ -1041,6 +1044,7 @@ out: static void sdhci_request(struct mmc_host *mmc, struct mmc_request *mrq) { struct sdhci_host *host; + bool present; unsigned long flags; host = mmc_priv(mmc); @@ -1055,8 +1059,14 @@ static void sdhci_request(struct mmc_host *mmc, struct mmc_request *mrq) host->mrq = mrq; - if (!(sdhci_readl(host, SDHCI_PRESENT_STATE) & SDHCI_CARD_PRESENT) - || (host->flags & SDHCI_DEVICE_DEAD)) { + /* If polling, assume that the card is always present. */ + if (host->quirks & SDHCI_QUIRK_BROKEN_CARD_DETECTION) + present = true; + else + present = sdhci_readl(host, SDHCI_PRESENT_STATE) & + SDHCI_CARD_PRESENT; + + if (!present || host->flags & SDHCI_DEVICE_DEAD) { host->mrq->cmd->error = -ENOMEDIUM; tasklet_schedule(&host->finish_tasklet); } else @@ -1690,6 +1700,9 @@ int sdhci_add_host(struct sdhci_host *host) if (caps & SDHCI_CAN_DO_HISPD) mmc->caps |= MMC_CAP_SD_HIGHSPEED; + if (host->quirks & SDHCI_QUIRK_BROKEN_CARD_DETECTION) + mmc->caps |= MMC_CAP_NEEDS_POLL; + mmc->ocr_avail = 0; if (caps & SDHCI_CAN_VDD_330) mmc->ocr_avail |= MMC_VDD_32_33|MMC_VDD_33_34; diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h index a9e25c6c0c0..968d713950f 100644 --- a/drivers/mmc/host/sdhci.h +++ b/drivers/mmc/host/sdhci.h @@ -214,6 +214,8 @@ struct sdhci_host { #define SDHCI_QUIRK_BROKEN_SMALL_PIO (1<<13) /* Controller does not provide transfer-complete interrupt when not busy */ #define SDHCI_QUIRK_NO_BUSY_IRQ (1<<14) +/* Controller has unreliable card detection */ +#define SDHCI_QUIRK_BROKEN_CARD_DETECTION (1<<15) int irq; /* Device IRQ */ void __iomem * ioaddr; /* Mapped address */ -- 2.41.1