diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 5e6468a..65d4e96 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -56,6 +56,12 @@
 static int ahci_enable_alpm(struct ata_port *ap,
 		enum link_pm policy);
 static void ahci_disable_alpm(struct ata_port *ap);
+static ssize_t ahci_led_show(struct ata_port *ap, char *buf);
+static ssize_t ahci_led_store(struct ata_port *ap, const char *buf,
+			      size_t size);
+static ssize_t ahci_transmit_led_message(struct ata_port *ap, u32 state,
+					ssize_t size);
+#define MAX_SLOTS 8
 
 enum {
 	AHCI_PCI_BAR		= 5,
@@ -98,6 +104,8 @@
 	HOST_IRQ_STAT		= 0x08, /* interrupt status */
 	HOST_PORTS_IMPL		= 0x0c, /* bitmap of implemented ports */
 	HOST_VERSION		= 0x10, /* AHCI spec. version compliancy */
+	HOST_EM_LOC		= 0x1c, /* Enclosure Management location */
+	HOST_EM_CTL		= 0x20, /* Enclosure Management Control */
 
 	/* HOST_CTL bits */
 	HOST_RESET		= (1 << 0),  /* reset controller; self-clear */
@@ -105,6 +113,7 @@
 	HOST_AHCI_EN		= (1 << 31), /* AHCI enabled */
 
 	/* HOST_CAP bits */
+	HOST_CAP_EMS		= (1 << 6),  /* Enclosure Management support */
 	HOST_CAP_SSC		= (1 << 14), /* Slumber capable */
 	HOST_CAP_PMP		= (1 << 17), /* Port Multiplier support */
 	HOST_CAP_CLO		= (1 << 24), /* Command List Override support */
@@ -202,6 +211,11 @@
 					  ATA_FLAG_IPM,
 
 	ICH_MAP				= 0x90, /* ICH MAP register */
+
+	/* em_ctl bits */
+	EM_CTL_RST			= (1 << 9), /* Reset */
+	EM_CTL_TM			= (1 << 8), /* Transmit Message */
+	EM_CTL_ALHD			= (1 << 26), /* Activity LED */
 };
 
 struct ahci_cmd_hdr {
@@ -219,12 +233,21 @@
 	__le32			flags_size;
 };
 
+struct ahci_em_priv {
+	enum sw_activity blink_policy;
+	struct timer_list timer;
+	unsigned long saved_activity;
+	unsigned long activity;
+	unsigned long led_state;
+};
+
 struct ahci_host_priv {
 	unsigned int		flags;		/* AHCI_HFLAG_* */
 	u32			cap;		/* cap to use */
 	u32			port_map;	/* port map to use */
 	u32			saved_cap;	/* saved initial cap */
 	u32			saved_port_map;	/* saved initial port_map */
+	u32 			em_loc; /* enclosure management location */
 };
 
 struct ahci_port_priv {
@@ -240,6 +263,8 @@
 	unsigned int		ncq_saw_dmas:1;
 	unsigned int		ncq_saw_sdb:1;
 	u32 			intr_mask;	/* interrupts to enable */
+	struct ahci_em_priv	em_priv[MAX_SLOTS];/* enclosure management info
+					 	 * per PM slot */
 };
 
 static int ahci_scr_read(struct ata_port *ap, unsigned int sc_reg, u32 *val);
@@ -277,9 +302,20 @@
 static int ahci_pci_device_suspend(struct pci_dev *pdev, pm_message_t mesg);
 static int ahci_pci_device_resume(struct pci_dev *pdev);
 #endif
+static ssize_t ahci_activity_show(struct ata_device *dev, char *buf);
+static ssize_t ahci_activity_store(struct ata_device *dev,
+				   enum sw_activity val);
+static void ahci_init_sw_activity(struct ata_link *link);
 
 static struct device_attribute *ahci_shost_attrs[] = {
 	&dev_attr_link_power_management_policy,
+	&dev_attr_em_message_type,
+	&dev_attr_em_message,
+	NULL
+};
+
+static struct device_attribute *ahci_sdev_attrs[] = {
+	&dev_attr_sw_activity,
 	NULL
 };
 
@@ -289,6 +325,7 @@
 	.sg_tablesize		= AHCI_MAX_SG,
 	.dma_boundary		= AHCI_DMA_BOUNDARY,
 	.shost_attrs		= ahci_shost_attrs,
+	.sdev_attrs		= ahci_sdev_attrs,
 };
 
 static struct ata_port_operations ahci_ops = {
@@ -316,6 +353,10 @@
 
 	.enable_pm		= ahci_enable_alpm,
 	.disable_pm		= ahci_disable_alpm,
+	.em_show		= ahci_led_show,
+	.em_store		= ahci_led_store,
+	.sw_activity_show	= ahci_activity_show,
+	.sw_activity_store	= ahci_activity_store,
 #ifdef CONFIG_PM
 	.port_suspend		= ahci_port_suspend,
 	.port_resume		= ahci_port_resume,
@@ -561,6 +602,11 @@
 #endif
 };
 
+static int ahci_em_messages = 1;
+module_param(ahci_em_messages, int, 0444);
+/* add other LED protocol types when they become supported */
+MODULE_PARM_DESC(ahci_em_messages,
+	"Set AHCI Enclosure Management Message type (0 = disabled, 1 = LED");
 
 static inline int ahci_nr_ports(u32 cap)
 {
@@ -1031,11 +1077,28 @@
 
 static void ahci_start_port(struct ata_port *ap)
 {
+	struct ahci_port_priv *pp = ap->private_data;
+	struct ata_link *link;
+	struct ahci_em_priv *emp;
+
 	/* enable FIS reception */
 	ahci_start_fis_rx(ap);
 
 	/* enable DMA */
 	ahci_start_engine(ap);
+
+	/* turn on LEDs */
+	if (ap->flags & ATA_FLAG_EM) {
+		ata_port_for_each_link(link, ap) {
+			emp = &pp->em_priv[link->pmp];
+			ahci_transmit_led_message(ap, emp->led_state, 4);
+		}
+	}
+
+	if (ap->flags & ATA_FLAG_SW_ACTIVITY)
+		ata_port_for_each_link(link, ap)
+			ahci_init_sw_activity(link);
+
 }
 
 static int ahci_deinit_port(struct ata_port *ap, const char **emsg)
@@ -1116,6 +1179,230 @@
 	return 0;
 }
 
+static void ahci_sw_activity(struct ata_link *link)
+{
+	struct ata_port *ap = link->ap;
+	struct ahci_port_priv *pp = ap->private_data;
+	struct ahci_em_priv *emp = &pp->em_priv[link->pmp];
+
+	if (!(link->flags & ATA_LFLAG_SW_ACTIVITY))
+		return;
+
+	emp->activity++;
+	if (!timer_pending(&emp->timer))
+		mod_timer(&emp->timer, jiffies + msecs_to_jiffies(10));
+}
+
+static void ahci_sw_activity_blink(unsigned long arg)
+{
+	struct ata_link *link = (struct ata_link *)arg;
+	struct ata_port *ap = link->ap;
+	struct ahci_port_priv *pp = ap->private_data;
+	struct ahci_em_priv *emp = &pp->em_priv[link->pmp];
+	unsigned long led_message = emp->led_state;
+	u32 activity_led_state;
+
+	led_message &= 0xffff0000;
+	led_message |= ap->port_no | (link->pmp << 8);
+
+	/* check to see if we've had activity.  If so,
+	 * toggle state of LED and reset timer.  If not,
+	 * turn LED to desired idle state.
+	 */
+	if (emp->saved_activity != emp->activity) {
+		emp->saved_activity = emp->activity;
+		/* get the current LED state */
+		activity_led_state = led_message & 0x00010000;
+
+		if (activity_led_state)
+			activity_led_state = 0;
+		else
+			activity_led_state = 1;
+
+		/* clear old state */
+		led_message &= 0xfff8ffff;
+
+		/* toggle state */
+		led_message |= (activity_led_state << 16);
+		mod_timer(&emp->timer, jiffies + msecs_to_jiffies(100));
+	} else {
+		/* switch to idle */
+		led_message &= 0xfff8ffff;
+		if (emp->blink_policy == BLINK_OFF)
+			led_message |= (1 << 16);
+	}
+	ahci_transmit_led_message(ap, led_message, 4);
+}
+
+static void ahci_init_sw_activity(struct ata_link *link)
+{
+	struct ata_port *ap = link->ap;
+	struct ahci_port_priv *pp = ap->private_data;
+	struct ahci_em_priv *emp = &pp->em_priv[link->pmp];
+
+	/* init activity stats, setup timer */
+	emp->saved_activity = emp->activity = 0;
+	setup_timer(&emp->timer, ahci_sw_activity_blink, (unsigned long)link);
+
+	/* check our blink policy and set flag for link if it's enabled */
+	if (emp->blink_policy)
+		link->flags |= ATA_LFLAG_SW_ACTIVITY;
+}
+
+static int ahci_reset_em(struct ata_host *host)
+{
+	void __iomem *mmio = host->iomap[AHCI_PCI_BAR];
+	u32 em_ctl;
+
+	em_ctl = readl(mmio + HOST_EM_CTL);
+	if ((em_ctl & EM_CTL_TM) || (em_ctl & EM_CTL_RST))
+		return -EINVAL;
+
+	writel(em_ctl | EM_CTL_RST, mmio + HOST_EM_CTL);
+	return 0;
+}
+
+static ssize_t ahci_transmit_led_message(struct ata_port *ap, u32 state,
+					ssize_t size)
+{
+	struct ahci_host_priv *hpriv = ap->host->private_data;
+	struct ahci_port_priv *pp = ap->private_data;
+	void __iomem *mmio = ap->host->iomap[AHCI_PCI_BAR];
+	u32 em_ctl;
+	u32 message[] = {0, 0};
+	unsigned int flags;
+	int pmp;
+	struct ahci_em_priv *emp;
+
+	/* get the slot number from the message */
+	pmp = (state & 0x0000ff00) >> 8;
+	if (pmp < MAX_SLOTS)
+		emp = &pp->em_priv[pmp];
+	else
+		return -EINVAL;
+
+	spin_lock_irqsave(ap->lock, flags);
+
+	/*
+	 * if we are still busy transmitting a previous message,
+	 * do not allow
+	 */
+	em_ctl = readl(mmio + HOST_EM_CTL);
+	if (em_ctl & EM_CTL_TM) {
+		spin_unlock_irqrestore(ap->lock, flags);
+		return -EINVAL;
+	}
+
+	/*
+	 * create message header - this is all zero except for
+	 * the message size, which is 4 bytes.
+	 */
+	message[0] |= (4 << 8);
+
+	/* ignore 0:4 of byte zero, fill in port info yourself */
+	message[1] = ((state & 0xfffffff0) | ap->port_no);
+
+	/* write message to EM_LOC */
+	writel(message[0], mmio + hpriv->em_loc);
+	writel(message[1], mmio + hpriv->em_loc+4);
+
+	/* save off new led state for port/slot */
+	emp->led_state = message[1];
+
+	/*
+	 * tell hardware to transmit the message
+	 */
+	writel(em_ctl | EM_CTL_TM, mmio + HOST_EM_CTL);
+
+	spin_unlock_irqrestore(ap->lock, flags);
+	return size;
+}
+
+static ssize_t ahci_led_show(struct ata_port *ap, char *buf)
+{
+	struct ahci_port_priv *pp = ap->private_data;
+	struct ata_link *link;
+	struct ahci_em_priv *emp;
+	int rc = 0;
+
+	ata_port_for_each_link(link, ap) {
+		emp = &pp->em_priv[link->pmp];
+		rc += sprintf(buf, "%lx\n", emp->led_state);
+	}
+	return rc;
+}
+
+static ssize_t ahci_led_store(struct ata_port *ap, const char *buf,
+				size_t size)
+{
+	int state;
+	int pmp;
+	struct ahci_port_priv *pp = ap->private_data;
+	struct ahci_em_priv *emp;
+
+	state = simple_strtoul(buf, NULL, 0);
+
+	/* get the slot number from the message */
+	pmp = (state & 0x0000ff00) >> 8;
+	if (pmp < MAX_SLOTS)
+		emp = &pp->em_priv[pmp];
+	else
+		return -EINVAL;
+
+	/* mask off the activity bits if we are in sw_activity
+	 * mode, user should turn off sw_activity before setting
+	 * activity led through em_message
+	 */
+	if (emp->blink_policy)
+		state &= 0xfff8ffff;
+
+	return ahci_transmit_led_message(ap, state, size);
+}
+
+static ssize_t ahci_activity_store(struct ata_device *dev, enum sw_activity val)
+{
+	struct ata_link *link = dev->link;
+	struct ata_port *ap = link->ap;
+	struct ahci_port_priv *pp = ap->private_data;
+	struct ahci_em_priv *emp = &pp->em_priv[link->pmp];
+	u32 port_led_state = emp->led_state;
+
+	/* save the desired Activity LED behavior */
+	if (val == OFF) {
+		/* clear LFLAG */
+		link->flags &= ~(ATA_LFLAG_SW_ACTIVITY);
+
+		/* set the LED to OFF */
+		port_led_state &= 0xfff80000;
+		port_led_state |= (ap->port_no | (link->pmp << 8));
+		ahci_transmit_led_message(ap, port_led_state, 4);
+	} else {
+		link->flags |= ATA_LFLAG_SW_ACTIVITY;
+		if (val == BLINK_OFF) {
+			/* set LED to ON for idle */
+			port_led_state &= 0xfff80000;
+			port_led_state |= (ap->port_no | (link->pmp << 8));
+			port_led_state |= 0x00010000; /* check this */
+			ahci_transmit_led_message(ap, port_led_state, 4);
+		}
+	}
+	emp->blink_policy = val;
+	return 0;
+}
+
+static ssize_t ahci_activity_show(struct ata_device *dev, char *buf)
+{
+	struct ata_link *link = dev->link;
+	struct ata_port *ap = link->ap;
+	struct ahci_port_priv *pp = ap->private_data;
+	struct ahci_em_priv *emp = &pp->em_priv[link->pmp];
+
+	/* display the saved value of activity behavior for this
+	 * disk.
+	 */
+	return sprintf(buf, "%d\n", emp->blink_policy);
+}
+
 static void ahci_port_init(struct pci_dev *pdev, struct ata_port *ap,
 			   int port_no, void __iomem *mmio,
 			   void __iomem *port_mmio)
@@ -1848,6 +2135,8 @@
 	writel(1 << qc->tag, port_mmio + PORT_CMD_ISSUE);
 	readl(port_mmio + PORT_CMD_ISSUE);	/* flush */
 
+	ahci_sw_activity(qc->dev->link);
+
 	return 0;
 }
 
@@ -2154,7 +2443,8 @@
 	dev_printk(KERN_INFO, &pdev->dev,
 		"flags: "
 		"%s%s%s%s%s%s%s"
-		"%s%s%s%s%s%s%s\n"
+		"%s%s%s%s%s%s%s"
+		"%s\n"
 		,
 
 		cap & (1 << 31) ? "64bit " : "",
@@ -2171,7 +2461,8 @@
 		cap & (1 << 17) ? "pmp " : "",
 		cap & (1 << 15) ? "pio " : "",
 		cap & (1 << 14) ? "slum " : "",
-		cap & (1 << 13) ? "part " : ""
+		cap & (1 << 13) ? "part " : "",
+		cap & (1 << 6) ? "ems ": ""
 		);
 }
 
@@ -2291,6 +2582,24 @@
 	if (hpriv->cap & HOST_CAP_PMP)
 		pi.flags |= ATA_FLAG_PMP;
 
+	if (ahci_em_messages && (hpriv->cap & HOST_CAP_EMS)) {
+		u8 messages;
+		void __iomem *mmio = pcim_iomap_table(pdev)[AHCI_PCI_BAR];
+		u32 em_loc = readl(mmio + HOST_EM_LOC);
+		u32 em_ctl = readl(mmio + HOST_EM_CTL);
+
+		messages = (em_ctl & 0x000f0000) >> 16;
+
+		/* we only support LED message type right now */
+		if ((messages & 0x01) && (ahci_em_messages == 1)) {
+			/* store em_loc */
+			hpriv->em_loc = ((em_loc >> 16) * 4);
+			pi.flags |= ATA_FLAG_EM;
+			if (!(em_ctl & EM_CTL_ALHD))
+				pi.flags |= ATA_FLAG_SW_ACTIVITY;
+		}
+	}
+
 	/* CAP.NP sometimes indicate the index of the last enabled
 	 * port, at other times, that of the last possible port, so
 	 * determining the maximum port number requires looking at
@@ -2304,6 +2613,9 @@
 	host->iomap = pcim_iomap_table(pdev);
 	host->private_data = hpriv;
 
+	if (pi.flags & ATA_FLAG_EM)
+		ahci_reset_em(host);
+
 	for (i = 0; i < host->n_ports; i++) {
 		struct ata_port *ap = host->ports[i];
 
@@ -2314,6 +2626,11 @@
 		/* set initial link pm policy */
 		ap->pm_policy = NOT_AVAILABLE;
 
+		/* set enclosure management message type */
+		if (ap->flags & ATA_FLAG_EM)
+			ap->em_message_type = ahci_em_messages;
+
+
 		/* disabled/not-implemented port */
 		if (!(hpriv->port_map & (1 << i)))
 			ap->ops = &ata_dummy_port_ops;