mmc: sdhci-pci: Read card detect from ACPI for Intel Merrifield

Intel Merrifield platform had been converted to use ACPI enumeration.
However, the driver missed an update to retrieve card detect GPIO.
Fix it here.

Unfortunately we can't rely on CD GPIO state because there are two
different PCB designs in the wild that are using the opposite card
detection sense and there is no way to distinguish those platforms,
that's why ignore CD GPIO completely and use it only as an event.

Fixes: 4590d98 ("sfi: Remove framework for deprecated firmware")
BugLink: edison-fw/meta-intel-edison#135
Signed-off-by: Andy Shevchenko <[email protected]>
Acked-by: Adrian Hunter <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Ulf Hansson <[email protected]>

Author: andy-shev

drivers/mmc/host/sdhci-pci-core.c

@@ -616,16 +616,12 @@ static int intel_select_drive_strength(struct mmc_card *card,
 	return intel_host->drv_strength;
 }
 
-static int bxt_get_cd(struct mmc_host *mmc)
+static int sdhci_get_cd_nogpio(struct mmc_host *mmc)
 {
-	int gpio_cd = mmc_gpio_get_cd(mmc);
 	struct sdhci_host *host = mmc_priv(mmc);
 	unsigned long flags;
 	int ret = 0;
 
-	if (!gpio_cd)
-		return 0;
-
 	spin_lock_irqsave(&host->lock, flags);
 
 	if (host->flags & SDHCI_DEVICE_DEAD)
@@ -638,6 +634,21 @@ static int bxt_get_cd(struct mmc_host *mmc)
 	return ret;
 }
 
+static int bxt_get_cd(struct mmc_host *mmc)
+{
+	int gpio_cd = mmc_gpio_get_cd(mmc);
+
+	if (!gpio_cd)
+		return 0;
+
+	return sdhci_get_cd_nogpio(mmc);
+}
+
+static int mrfld_get_cd(struct mmc_host *mmc)
+{
+	return sdhci_get_cd_nogpio(mmc);
+}
+
 #define SDHCI_INTEL_PWR_TIMEOUT_CNT	20
 #define SDHCI_INTEL_PWR_TIMEOUT_UDELAY	100
 
@@ -1341,6 +1352,14 @@ static int intel_mrfld_mmc_probe_slot(struct sdhci_pci_slot *slot)
 					 MMC_CAP_1_8V_DDR;
 		break;
 	case INTEL_MRFLD_SD:
+		slot->cd_idx = 0;
+		slot->cd_override_level = true;
+		/*
+		 * There are two PCB designs of SD card slot with the opposite
+		 * card detection sense. Quirk this out by ignoring GPIO state
+		 * completely in the custom ->get_cd() callback.
+		 */
+		slot->host->mmc_host_ops.get_cd = mrfld_get_cd;
 		slot->host->quirks2 |= SDHCI_QUIRK2_NO_1_8_V;
 		break;
 	case INTEL_MRFLD_SDIO: