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 <avorontsov@ru.mvista.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 6fbbc00..fc7cb48 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -112,6 +112,9 @@
{
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 @@
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 @@
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 @@
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;