mmc: tmio_mmc: support the generic MMC GPIO card hotplug helper

If the platform specifies the TMIO_MMC_HAS_COLD_CD flag, use the generic
MMC GPIO card hotplug helper.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/include/linux/mfd/tmio.h b/include/linux/mfd/tmio.h
index 0dc9804..5a197de 100644
--- a/include/linux/mfd/tmio.h
+++ b/include/linux/mfd/tmio.h
@@ -1,8 +1,10 @@
 #ifndef MFD_TMIO_H
 #define MFD_TMIO_H
 
+#include <linux/device.h>
 #include <linux/fb.h>
 #include <linux/io.h>
+#include <linux/jiffies.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 
@@ -64,8 +66,8 @@
 #define TMIO_MMC_SDIO_IRQ		(1 << 2)
 /*
  * Some platforms can detect card insertion events with controller powered
- * down, in which case they have to call tmio_mmc_cd_wakeup() to power up the
- * controller and report the event to the driver.
+ * down, using a GPIO IRQ, in which case they have to fill in cd_irq, cd_gpio,
+ * and cd_flags fields of struct tmio_mmc_data.
  */
 #define TMIO_MMC_HAS_COLD_CD		(1 << 3)
 /*
@@ -73,6 +75,12 @@
  * idle before writing to some registers.
  */
 #define TMIO_MMC_HAS_IDLE_WAIT		(1 << 4)
+/*
+ * A GPIO is used for card hotplug detection. We need an extra flag for this,
+ * because 0 is a valid GPIO number too, and requiring users to specify
+ * cd_gpio < 0 to disable GPIO hotplug would break backwards compatibility.
+ */
+#define TMIO_MMC_USE_GPIO_CD		(1 << 5)
 
 int tmio_core_mmc_enable(void __iomem *cnf, int shift, unsigned long base);
 int tmio_core_mmc_resume(void __iomem *cnf, int shift, unsigned long base);
@@ -98,18 +106,23 @@
 	struct tmio_mmc_dma		*dma;
 	struct device			*dev;
 	bool				power;
+	unsigned int			cd_gpio;
 	void (*set_pwr)(struct platform_device *host, int state);
 	void (*set_clk_div)(struct platform_device *host, int state);
 	int (*get_cd)(struct platform_device *host);
 	int (*write16_hook)(struct tmio_mmc_host *host, int addr);
 };
 
+/*
+ * This function is deprecated and will be removed soon. Please, convert your
+ * platform to use drivers/mmc/core/cd-gpio.c
+ */
+#include <linux/mmc/host.h>
 static inline void tmio_mmc_cd_wakeup(struct tmio_mmc_data *pdata)
 {
-	if (pdata && !pdata->power) {
-		pdata->power = true;
-		pm_runtime_get(pdata->dev);
-	}
+	if (pdata)
+		mmc_detect_change(dev_get_drvdata(pdata->dev),
+				  msecs_to_jiffies(100));
 }
 
 /*