mmc: sdhci-pci: Add Bay Trail and Braswell SD card detect

Add support for card detect for Bay Trail
and Braswell SD Card host controllers in PCI
mode.

This uses the gpio descriptor API which can find
gpio descriptors, for example, on an ACPI comapnion
device.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/sdhci-pci.c

@@ -24,6 +24,7 @@
 #include <linux/io.h>
 #include <linux/gpio.h>
 #include <linux/pm_runtime.h>
+#include <linux/mmc/slot-gpio.h>
 #include <linux/mmc/sdhci-pci-data.h>
 
 #include "sdhci.h"
@@ -280,6 +281,14 @@ static int byt_sdio_probe_slot(struct sdhci_pci_slot *slot)
 	return 0;
 }
 
+static int byt_sd_probe_slot(struct sdhci_pci_slot *slot)
+{
+	slot->cd_con_id = NULL;
+	slot->cd_idx = 0;
+	slot->cd_override_level = true;
+	return 0;
+}
+
 static const struct sdhci_pci_fixes sdhci_intel_byt_emmc = {
 	.allow_runtime_pm = true,
 	.probe_slot	= byt_emmc_probe_slot,
@@ -300,6 +309,7 @@ static const struct sdhci_pci_fixes sdhci_intel_byt_sd = {
 			  SDHCI_QUIRK2_STOP_WITH_TC,
 	.allow_runtime_pm = true,
 	.own_cd_for_runtime_pm = true,
+	.probe_slot	= byt_sd_probe_slot,
 };
 
 /* Define Host controllers for Intel Merrifield platform */
@@ -1354,6 +1364,7 @@ static struct sdhci_pci_slot *sdhci_pci_probe_slot(
 	slot->pci_bar = bar;
 	slot->rst_n_gpio = -EINVAL;
 	slot->cd_gpio = -EINVAL;
+	slot->cd_idx = -1;
 
 	/* Retrieve platform data if there is any */
 	if (*sdhci_pci_get_data)
@@ -1412,6 +1423,13 @@ static struct sdhci_pci_slot *sdhci_pci_probe_slot(
 	host->mmc->slotno = slotno;
 	host->mmc->caps2 |= MMC_CAP2_NO_PRESCAN_POWERUP;
 
+	if (slot->cd_idx >= 0 &&
+	    mmc_gpiod_request_cd(host->mmc, slot->cd_con_id, slot->cd_idx,
+				 slot->cd_override_level, 0, NULL)) {
+		dev_warn(&pdev->dev, "failed to setup card detect gpio\n");
+		slot->cd_idx = -1;
+	}
+
 	ret = sdhci_add_host(host);
 	if (ret)
 		goto remove;
@@ -1424,7 +1442,7 @@ static struct sdhci_pci_slot *sdhci_pci_probe_slot(
 	 * Note sdhci_pci_add_own_cd() sets slot->cd_gpio to -EINVAL on failure.
 	 */
 	if (chip->fixes && chip->fixes->own_cd_for_runtime_pm &&
-	    !gpio_is_valid(slot->cd_gpio))
+	    !gpio_is_valid(slot->cd_gpio) && slot->cd_idx < 0)
 		chip->allow_runtime_pm = false;
 
 	return slot;

drivers/mmc/host/sdhci-pci.h

@@ -64,6 +64,10 @@ struct sdhci_pci_slot {
 	int			cd_gpio;
 	int			cd_irq;
 
+	char			*cd_con_id;
+	int			cd_idx;
+	bool			cd_override_level;
+
 	void (*hw_reset)(struct sdhci_host *host);
 };