mmc: add led trigger

Add a led trigger for each host controller that indicates if there
is a request active on the controller.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

drivers/mmc/core/core.c

@@ -18,6 +18,7 @@
 #include <linux/delay.h>
 #include <linux/pagemap.h>
 #include <linux/err.h>
+#include <linux/leds.h>
 #include <asm/scatterlist.h>
 #include <linux/scatterlist.h>
 
@@ -92,6 +93,8 @@ void mmc_request_done(struct mmc_host *host, struct mmc_request *mrq)
 		cmd->error = 0;
 		host->ops->request(host, mrq);
 	} else {
+		led_trigger_event(host->led, LED_OFF);
+
 		pr_debug("%s: req done (CMD%u): %d: %08x %08x %08x %08x\n",
 			mmc_hostname(host), cmd->opcode, err,
 			cmd->resp[0], cmd->resp[1],
@@ -146,6 +149,8 @@ mmc_start_request(struct mmc_host *host, struct mmc_request *mrq)
 
 	WARN_ON(!host->claimed);
 
+	led_trigger_event(host->led, LED_FULL);
+
 	mrq->cmd->error = 0;
 	mrq->cmd->mrq = mrq;
 	if (mrq->data) {

drivers/mmc/core/host.c

@@ -15,6 +15,7 @@
 #include <linux/err.h>
 #include <linux/idr.h>
 #include <linux/pagemap.h>
+#include <linux/leds.h>
 
 #include <linux/mmc/host.h>
 
@@ -115,6 +116,8 @@ int mmc_add_host(struct mmc_host *host)
 	snprintf(host->class_dev.bus_id, BUS_ID_SIZE,
 		 "mmc%d", host->index);
 
+	led_trigger_register_simple(host->class_dev.bus_id, &host->led);
+
 	err = device_add(&host->class_dev);
 	if (err)
 		return err;
@@ -140,6 +143,8 @@ void mmc_remove_host(struct mmc_host *host)
 
 	device_del(&host->class_dev);
 
+	led_trigger_unregister(host->led);
+
 	spin_lock(&mmc_host_lock);
 	idr_remove(&mmc_host_idr, host->index);
 	spin_unlock(&mmc_host_lock);

include/linux/mmc/host.h

@@ -10,6 +10,8 @@
 #ifndef LINUX_MMC_HOST_H
 #define LINUX_MMC_HOST_H
 
+#include <linux/leds.h>
+
 #include <linux/mmc/core.h>
 
 struct mmc_ios {
@@ -133,6 +135,10 @@ struct mmc_host {
 	struct task_struct	*sdio_irq_thread;
 	atomic_t		sdio_irq_thread_abort;
 
+#ifdef CONFIG_LEDS_TRIGGERS
+	struct led_trigger	*led;		/* activity led */
+#endif
+
 	unsigned long		private[0] ____cacheline_aligned;
 };