mmc: core: use a more generic name for slot function types and fields

struct mmc_host::hotplug is becoming a generic hook for slot functions.
Rename it accordingly.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/core/host.c

@@ -327,6 +327,8 @@ struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
 
 	mmc_host_clk_init(host);
 
+	host->slot.cd_irq = -EINVAL;
+
 	spin_lock_init(&host->lock);
 	init_waitqueue_head(&host->wq);
 	INIT_DELAYED_WORK(&host->detect, mmc_rescan);

drivers/mmc/core/slot-gpio.c

@@ -56,8 +56,8 @@ int mmc_gpio_request_cd(struct mmc_host *host, unsigned int gpio)
 		goto eirqreq;
 
 	ctx->cd_gpio = gpio;
-	host->hotplug.irq = irq;
-	host->hotplug.handler_priv = ctx;
+	host->slot.cd_irq = irq;
+	host->slot.handler_priv = ctx;
 
 	return 0;
 
@@ -71,12 +71,12 @@ EXPORT_SYMBOL(mmc_gpio_request_cd);
 
 void mmc_gpio_free_cd(struct mmc_host *host)
 {
-	struct mmc_gpio *ctx = host->hotplug.handler_priv;
+	struct mmc_gpio *ctx = host->slot.handler_priv;
 
 	if (!ctx)
 		return;
 
-	free_irq(host->hotplug.irq, host);
+	free_irq(host->slot.cd_irq, host);
 	gpio_free(ctx->cd_gpio);
 	kfree(ctx);
 }

include/linux/mmc/host.h

@@ -150,8 +150,19 @@ struct mmc_async_req {
 	int (*err_check) (struct mmc_card *, struct mmc_async_req *);
 };
 
-struct mmc_hotplug {
-	unsigned int irq;
+/**
+ * struct mmc_slot - MMC slot functions
+ *
+ * @cd_irq:		MMC/SD-card slot hotplug detection IRQ or -EINVAL
+ * @handler_priv:	MMC/SD-card slot context
+ *
+ * Some MMC/SD host controllers implement slot-functions like card and
+ * write-protect detection natively. However, a large number of controllers
+ * leave these functions to the CPU. This struct provides a hook to attach
+ * such slot-function drivers.
+ */
+struct mmc_slot {
+	int cd_irq;
 	void *handler_priv;
 };
 
@@ -297,7 +308,7 @@ struct mmc_host {
 
 	struct delayed_work	detect;
 	int			detect_change;	/* card detect flag */
-	struct mmc_hotplug	hotplug;
+	struct mmc_slot		slot;
 
 	const struct mmc_bus_ops *bus_ops;	/* current bus driver */
 	unsigned int		bus_refs;	/* reference counter */