Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 859 insertions, 0 deletions

diff --git a/drivers/ata/libahci_platform.c b/drivers/ata/libahci_platform.c
new file mode 100644
index 000000000..64d6da0a5
--- /dev/null
+++ b/drivers/ata/libahci_platform.c
@@ -0,0 +1,859 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * AHCI SATA platform library
+ *
+ * Copyright 2004-2005  Red Hat, Inc.
+ *   Jeff Garzik <jgarzik@pobox.com>
+ * Copyright 2010  MontaVista Software, LLC.
+ *   Anton Vorontsov <avorontsov@ru.mvista.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/kernel.h>
+#include <linux/gfp.h>
+#include <linux/module.h>
+#include <linux/pm.h>
+#include <linux/interrupt.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/libata.h>
+#include <linux/ahci_platform.h>
+#include <linux/phy/phy.h>
+#include <linux/pm_runtime.h>
+#include <linux/of_platform.h>
+#include <linux/reset.h>
+#include "ahci.h"
+
+static void ahci_host_stop(struct ata_host *host);
+
+struct ata_port_operations ahci_platform_ops = {
+	.inherits	= &ahci_ops,
+	.host_stop	= ahci_host_stop,
+};
+EXPORT_SYMBOL_GPL(ahci_platform_ops);
+
+/**
+ * ahci_platform_enable_phys - Enable PHYs
+ * @hpriv: host private area to store config values
+ *
+ * This function enables all the PHYs found in hpriv->phys, if any.
+ * If a PHY fails to be enabled, it disables all the PHYs already
+ * enabled in reverse order and returns an error.
+ *
+ * RETURNS:
+ * 0 on success otherwise a negative error code
+ */
+int ahci_platform_enable_phys(struct ahci_host_priv *hpriv)
+{
+	int rc, i;
+
+	for (i = 0; i < hpriv->nports; i++) {
+		rc = phy_init(hpriv->phys[i]);
+		if (rc)
+			goto disable_phys;
+
+		rc = phy_set_mode(hpriv->phys[i], PHY_MODE_SATA);
+		if (rc) {
+			phy_exit(hpriv->phys[i]);
+			goto disable_phys;
+		}
+
+		rc = phy_power_on(hpriv->phys[i]);
+		if (rc && !(rc == -EOPNOTSUPP && (hpriv->flags & AHCI_HFLAG_IGN_NOTSUPP_POWER_ON))) {
+			phy_exit(hpriv->phys[i]);
+			goto disable_phys;
+		}
+	}
+
+	return 0;
+
+disable_phys:
+	while (--i >= 0) {
+		phy_power_off(hpriv->phys[i]);
+		phy_exit(hpriv->phys[i]);
+	}
+	return rc;
+}
+EXPORT_SYMBOL_GPL(ahci_platform_enable_phys);
+
+/**
+ * ahci_platform_disable_phys - Disable PHYs
+ * @hpriv: host private area to store config values
+ *
+ * This function disables all PHYs found in hpriv->phys.
+ */
+void ahci_platform_disable_phys(struct ahci_host_priv *hpriv)
+{
+	int i;
+
+	for (i = 0; i < hpriv->nports; i++) {
+		phy_power_off(hpriv->phys[i]);
+		phy_exit(hpriv->phys[i]);
+	}
+}
+EXPORT_SYMBOL_GPL(ahci_platform_disable_phys);
+
+/**
+ * ahci_platform_enable_clks - Enable platform clocks
+ * @hpriv: host private area to store config values
+ *
+ * This function enables all the clks found in hpriv->clks, starting at
+ * index 0. If any clk fails to enable it disables all the clks already
+ * enabled in reverse order, and then returns an error.
+ *
+ * RETURNS:
+ * 0 on success otherwise a negative error code
+ */
+int ahci_platform_enable_clks(struct ahci_host_priv *hpriv)
+{
+	int c, rc;
+
+	for (c = 0; c < AHCI_MAX_CLKS && hpriv->clks[c]; c++) {
+		rc = clk_prepare_enable(hpriv->clks[c]);
+		if (rc)
+			goto disable_unprepare_clk;
+	}
+	return 0;
+
+disable_unprepare_clk:
+	while (--c >= 0)
+		clk_disable_unprepare(hpriv->clks[c]);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(ahci_platform_enable_clks);
+
+/**
+ * ahci_platform_disable_clks - Disable platform clocks
+ * @hpriv: host private area to store config values
+ *
+ * This function disables all the clks found in hpriv->clks, in reverse
+ * order of ahci_platform_enable_clks (starting at the end of the array).
+ */
+void ahci_platform_disable_clks(struct ahci_host_priv *hpriv)
+{
+	int c;
+
+	for (c = AHCI_MAX_CLKS - 1; c >= 0; c--)
+		if (hpriv->clks[c])
+			clk_disable_unprepare(hpriv->clks[c]);
+}
+EXPORT_SYMBOL_GPL(ahci_platform_disable_clks);
+
+/**
+ * ahci_platform_enable_regulators - Enable regulators
+ * @hpriv: host private area to store config values
+ *
+ * This function enables all the regulators found in controller and
+ * hpriv->target_pwrs, if any.  If a regulator fails to be enabled, it
+ * disables all the regulators already enabled in reverse order and
+ * returns an error.
+ *
+ * RETURNS:
+ * 0 on success otherwise a negative error code
+ */
+int ahci_platform_enable_regulators(struct ahci_host_priv *hpriv)
+{
+	int rc, i;
+
+	rc = regulator_enable(hpriv->ahci_regulator);
+	if (rc)
+		return rc;
+
+	rc = regulator_enable(hpriv->phy_regulator);
+	if (rc)
+		goto disable_ahci_pwrs;
+
+	for (i = 0; i < hpriv->nports; i++) {
+		if (!hpriv->target_pwrs[i])
+			continue;
+
+		rc = regulator_enable(hpriv->target_pwrs[i]);
+		if (rc)
+			goto disable_target_pwrs;
+	}
+
+	return 0;
+
+disable_target_pwrs:
+	while (--i >= 0)
+		if (hpriv->target_pwrs[i])
+			regulator_disable(hpriv->target_pwrs[i]);
+
+	regulator_disable(hpriv->phy_regulator);
+disable_ahci_pwrs:
+	regulator_disable(hpriv->ahci_regulator);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(ahci_platform_enable_regulators);
+
+/**
+ * ahci_platform_disable_regulators - Disable regulators
+ * @hpriv: host private area to store config values
+ *
+ * This function disables all regulators found in hpriv->target_pwrs and
+ * AHCI controller.
+ */
+void ahci_platform_disable_regulators(struct ahci_host_priv *hpriv)
+{
+	int i;
+
+	for (i = 0; i < hpriv->nports; i++) {
+		if (!hpriv->target_pwrs[i])
+			continue;
+		regulator_disable(hpriv->target_pwrs[i]);
+	}
+
+	regulator_disable(hpriv->ahci_regulator);
+	regulator_disable(hpriv->phy_regulator);
+}
+EXPORT_SYMBOL_GPL(ahci_platform_disable_regulators);
+/**
+ * ahci_platform_enable_resources - Enable platform resources
+ * @hpriv: host private area to store config values
+ *
+ * This function enables all ahci_platform managed resources in the
+ * following order:
+ * 1) Regulator
+ * 2) Clocks (through ahci_platform_enable_clks)
+ * 3) Resets
+ * 4) Phys
+ *
+ * If resource enabling fails at any point the previous enabled resources
+ * are disabled in reverse order.
+ *
+ * RETURNS:
+ * 0 on success otherwise a negative error code
+ */
+int ahci_platform_enable_resources(struct ahci_host_priv *hpriv)
+{
+	int rc;
+
+	rc = ahci_platform_enable_regulators(hpriv);
+	if (rc)
+		return rc;
+
+	rc = ahci_platform_enable_clks(hpriv);
+	if (rc)
+		goto disable_regulator;
+
+	rc = reset_control_deassert(hpriv->rsts);
+	if (rc)
+		goto disable_clks;
+
+	rc = ahci_platform_enable_phys(hpriv);
+	if (rc)
+		goto disable_resets;
+
+	return 0;
+
+disable_resets:
+	reset_control_assert(hpriv->rsts);
+
+disable_clks:
+	ahci_platform_disable_clks(hpriv);
+
+disable_regulator:
+	ahci_platform_disable_regulators(hpriv);
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(ahci_platform_enable_resources);
+
+/**
+ * ahci_platform_disable_resources - Disable platform resources
+ * @hpriv: host private area to store config values
+ *
+ * This function disables all ahci_platform managed resources in the
+ * following order:
+ * 1) Phys
+ * 2) Resets
+ * 3) Clocks (through ahci_platform_disable_clks)
+ * 4) Regulator
+ */
+void ahci_platform_disable_resources(struct ahci_host_priv *hpriv)
+{
+	ahci_platform_disable_phys(hpriv);
+
+	reset_control_assert(hpriv->rsts);
+
+	ahci_platform_disable_clks(hpriv);
+
+	ahci_platform_disable_regulators(hpriv);
+}
+EXPORT_SYMBOL_GPL(ahci_platform_disable_resources);
+
+static void ahci_platform_put_resources(struct device *dev, void *res)
+{
+	struct ahci_host_priv *hpriv = res;
+	int c;
+
+	if (hpriv->got_runtime_pm) {
+		pm_runtime_put_sync(dev);
+		pm_runtime_disable(dev);
+	}
+
+	for (c = 0; c < AHCI_MAX_CLKS && hpriv->clks[c]; c++)
+		clk_put(hpriv->clks[c]);
+	/*
+	 * The regulators are tied to child node device and not to the
+	 * SATA device itself. So we can't use devm for automatically
+	 * releasing them. We have to do it manually here.
+	 */
+	for (c = 0; c < hpriv->nports; c++)
+		if (hpriv->target_pwrs && hpriv->target_pwrs[c])
+			regulator_put(hpriv->target_pwrs[c]);
+
+	kfree(hpriv->target_pwrs);
+}
+
+static int ahci_platform_get_phy(struct ahci_host_priv *hpriv, u32 port,
+				struct device *dev, struct device_node *node)
+{
+	int rc;
+
+	hpriv->phys[port] = devm_of_phy_get(dev, node, NULL);
+
+	if (!IS_ERR(hpriv->phys[port]))
+		return 0;
+
+	rc = PTR_ERR(hpriv->phys[port]);
+	switch (rc) {
+	case -ENOSYS:
+		/* No PHY support. Check if PHY is required. */
+		if (of_find_property(node, "phys", NULL)) {
+			dev_err(dev,
+				"couldn't get PHY in node %pOFn: ENOSYS\n",
+				node);
+			break;
+		}
+		fallthrough;
+	case -ENODEV:
+		/* continue normally */
+		hpriv->phys[port] = NULL;
+		rc = 0;
+		break;
+	case -EPROBE_DEFER:
+		/* Do not complain yet */
+		break;
+
+	default:
+		dev_err(dev,
+			"couldn't get PHY in node %pOFn: %d\n",
+			node, rc);
+
+		break;
+	}
+
+	return rc;
+}
+
+static int ahci_platform_get_regulator(struct ahci_host_priv *hpriv, u32 port,
+				struct device *dev)
+{
+	struct regulator *target_pwr;
+	int rc = 0;
+
+	target_pwr = regulator_get(dev, "target");
+
+	if (!IS_ERR(target_pwr))
+		hpriv->target_pwrs[port] = target_pwr;
+	else
+		rc = PTR_ERR(target_pwr);
+
+	return rc;
+}
+
+/**
+ * ahci_platform_get_resources - Get platform resources
+ * @pdev: platform device to get resources for
+ * @flags: bitmap representing the resource to get
+ *
+ * This function allocates an ahci_host_priv struct, and gets the following
+ * resources, storing a reference to them inside the returned struct:
+ *
+ * 1) mmio registers (IORESOURCE_MEM 0, mandatory)
+ * 2) regulator for controlling the targets power (optional)
+ *    regulator for controlling the AHCI controller (optional)
+ * 3) 0 - AHCI_MAX_CLKS clocks, as specified in the devs devicetree node,
+ *    or for non devicetree enabled platforms a single clock
+ * 4) resets, if flags has AHCI_PLATFORM_GET_RESETS (optional)
+ * 5) phys (optional)
+ *
+ * RETURNS:
+ * The allocated ahci_host_priv on success, otherwise an ERR_PTR value
+ */
+struct ahci_host_priv *ahci_platform_get_resources(struct platform_device *pdev,
+						   unsigned int flags)
+{
+	struct device *dev = &pdev->dev;
+	struct ahci_host_priv *hpriv;
+	struct clk *clk;
+	struct device_node *child;
+	int i, enabled_ports = 0, rc = -ENOMEM, child_nodes;
+	u32 mask_port_map = 0;
+
+	if (!devres_open_group(dev, NULL, GFP_KERNEL))
+		return ERR_PTR(-ENOMEM);
+
+	hpriv = devres_alloc(ahci_platform_put_resources, sizeof(*hpriv),
+			     GFP_KERNEL);
+	if (!hpriv)
+		goto err_out;
+
+	devres_add(dev, hpriv);
+
+	hpriv->mmio = devm_ioremap_resource(dev,
+			      platform_get_resource(pdev, IORESOURCE_MEM, 0));
+	if (IS_ERR(hpriv->mmio)) {
+		rc = PTR_ERR(hpriv->mmio);
+		goto err_out;
+	}
+
+	for (i = 0; i < AHCI_MAX_CLKS; i++) {
+		/*
+		 * For now we must use clk_get(dev, NULL) for the first clock,
+		 * because some platforms (da850, spear13xx) are not yet
+		 * converted to use devicetree for clocks.  For new platforms
+		 * this is equivalent to of_clk_get(dev->of_node, 0).
+		 */
+		if (i == 0)
+			clk = clk_get(dev, NULL);
+		else
+			clk = of_clk_get(dev->of_node, i);
+
+		if (IS_ERR(clk)) {
+			rc = PTR_ERR(clk);
+			if (rc == -EPROBE_DEFER)
+				goto err_out;
+			break;
+		}
+		hpriv->clks[i] = clk;
+	}
+
+	hpriv->ahci_regulator = devm_regulator_get(dev, "ahci");
+	if (IS_ERR(hpriv->ahci_regulator)) {
+		rc = PTR_ERR(hpriv->ahci_regulator);
+		if (rc != 0)
+			goto err_out;
+	}
+
+	hpriv->phy_regulator = devm_regulator_get(dev, "phy");
+	if (IS_ERR(hpriv->phy_regulator)) {
+		rc = PTR_ERR(hpriv->phy_regulator);
+		goto err_out;
+	}
+
+	if (flags & AHCI_PLATFORM_GET_RESETS) {
+		hpriv->rsts = devm_reset_control_array_get_optional_shared(dev);
+		if (IS_ERR(hpriv->rsts)) {
+			rc = PTR_ERR(hpriv->rsts);
+			goto err_out;
+		}
+	}
+
+	/*
+	 * Too many sub-nodes most likely means having something wrong with
+	 * the firmware.
+	 */
+	child_nodes = of_get_child_count(dev->of_node);
+	if (child_nodes > AHCI_MAX_PORTS) {
+		rc = -EINVAL;
+		goto err_out;
+	}
+
+	/*
+	 * If no sub-node was found, we still need to set nports to
+	 * one in order to be able to use the
+	 * ahci_platform_[en|dis]able_[phys|regulators] functions.
+	 */
+	if (child_nodes)
+		hpriv->nports = child_nodes;
+	else
+		hpriv->nports = 1;
+
+	hpriv->phys = devm_kcalloc(dev, hpriv->nports, sizeof(*hpriv->phys), GFP_KERNEL);
+	if (!hpriv->phys) {
+		rc = -ENOMEM;
+		goto err_out;
+	}
+	/*
+	 * We cannot use devm_ here, since ahci_platform_put_resources() uses
+	 * target_pwrs after devm_ have freed memory
+	 */
+	hpriv->target_pwrs = kcalloc(hpriv->nports, sizeof(*hpriv->target_pwrs), GFP_KERNEL);
+	if (!hpriv->target_pwrs) {
+		rc = -ENOMEM;
+		goto err_out;
+	}
+
+	if (child_nodes) {
+		for_each_child_of_node(dev->of_node, child) {
+			u32 port;
+			struct platform_device *port_dev __maybe_unused;
+
+			if (!of_device_is_available(child))
+				continue;
+
+			if (of_property_read_u32(child, "reg", &port)) {
+				rc = -EINVAL;
+				of_node_put(child);
+				goto err_out;
+			}
+
+			if (port >= hpriv->nports) {
+				dev_warn(dev, "invalid port number %d\n", port);
+				continue;
+			}
+			mask_port_map |= BIT(port);
+
+#ifdef CONFIG_OF_ADDRESS
+			of_platform_device_create(child, NULL, NULL);
+
+			port_dev = of_find_device_by_node(child);
+
+			if (port_dev) {
+				rc = ahci_platform_get_regulator(hpriv, port,
+								&port_dev->dev);
+				if (rc == -EPROBE_DEFER) {
+					of_node_put(child);
+					goto err_out;
+				}
+			}
+#endif
+
+			rc = ahci_platform_get_phy(hpriv, port, dev, child);
+			if (rc) {
+				of_node_put(child);
+				goto err_out;
+			}
+
+			enabled_ports++;
+		}
+		if (!enabled_ports) {
+			dev_warn(dev, "No port enabled\n");
+			rc = -ENODEV;
+			goto err_out;
+		}
+
+		if (!hpriv->mask_port_map)
+			hpriv->mask_port_map = mask_port_map;
+	} else {
+		/*
+		 * If no sub-node was found, keep this for device tree
+		 * compatibility
+		 */
+		rc = ahci_platform_get_phy(hpriv, 0, dev, dev->of_node);
+		if (rc)
+			goto err_out;
+
+		rc = ahci_platform_get_regulator(hpriv, 0, dev);
+		if (rc == -EPROBE_DEFER)
+			goto err_out;
+	}
+	pm_runtime_enable(dev);
+	pm_runtime_get_sync(dev);
+	hpriv->got_runtime_pm = true;
+
+	devres_remove_group(dev, NULL);
+	return hpriv;
+
+err_out:
+	devres_release_group(dev, NULL);
+	return ERR_PTR(rc);
+}
+EXPORT_SYMBOL_GPL(ahci_platform_get_resources);
+
+/**
+ * ahci_platform_init_host - Bring up an ahci-platform host
+ * @pdev: platform device pointer for the host
+ * @hpriv: ahci-host private data for the host
+ * @pi_template: template for the ata_port_info to use
+ * @sht: scsi_host_template to use when registering
+ *
+ * This function does all the usual steps needed to bring up an
+ * ahci-platform host, note any necessary resources (ie clks, phys, etc.)
+ * must be initialized / enabled before calling this.
+ *
+ * RETURNS:
+ * 0 on success otherwise a negative error code
+ */
+int ahci_platform_init_host(struct platform_device *pdev,
+			    struct ahci_host_priv *hpriv,
+			    const struct ata_port_info *pi_template,
+			    struct scsi_host_template *sht)
+{
+	struct device *dev = &pdev->dev;
+	struct ata_port_info pi = *pi_template;
+	const struct ata_port_info *ppi[] = { &pi, NULL };
+	struct ata_host *host;
+	int i, irq, n_ports, rc;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		if (irq != -EPROBE_DEFER)
+			dev_err(dev, "no irq\n");
+		return irq;
+	}
+	if (!irq)
+		return -EINVAL;
+
+	hpriv->irq = irq;
+
+	/* prepare host */
+	pi.private_data = (void *)(unsigned long)hpriv->flags;
+
+	ahci_save_initial_config(dev, hpriv);
+
+	if (hpriv->cap & HOST_CAP_NCQ)
+		pi.flags |= ATA_FLAG_NCQ;
+
+	if (hpriv->cap & HOST_CAP_PMP)
+		pi.flags |= ATA_FLAG_PMP;
+
+	ahci_set_em_messages(hpriv, &pi);
+
+	/* 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
+	 * both CAP.NP and port_map.
+	 */
+	n_ports = max(ahci_nr_ports(hpriv->cap), fls(hpriv->port_map));
+
+	host = ata_host_alloc_pinfo(dev, ppi, n_ports);
+	if (!host)
+		return -ENOMEM;
+
+	host->private_data = hpriv;
+
+	if (!(hpriv->cap & HOST_CAP_SSS) || ahci_ignore_sss)
+		host->flags |= ATA_HOST_PARALLEL_SCAN;
+	else
+		dev_info(dev, "SSS flag set, parallel bus scan disabled\n");
+
+	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];
+
+		ata_port_desc(ap, "mmio %pR",
+			      platform_get_resource(pdev, IORESOURCE_MEM, 0));
+		ata_port_desc(ap, "port 0x%x", 0x100 + ap->port_no * 0x80);
+
+		/* set enclosure management message type */
+		if (ap->flags & ATA_FLAG_EM)
+			ap->em_message_type = hpriv->em_msg_type;
+
+		/* disabled/not-implemented port */
+		if (!(hpriv->port_map & (1 << i)))
+			ap->ops = &ata_dummy_port_ops;
+	}
+
+	if (hpriv->cap & HOST_CAP_64) {
+		rc = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(64));
+		if (rc) {
+			rc = dma_coerce_mask_and_coherent(dev,
+							  DMA_BIT_MASK(32));
+			if (rc) {
+				dev_err(dev, "Failed to enable 64-bit DMA.\n");
+				return rc;
+			}
+			dev_warn(dev, "Enable 32-bit DMA instead of 64-bit.\n");
+		}
+	}
+
+	rc = ahci_reset_controller(host);
+	if (rc)
+		return rc;
+
+	ahci_init_controller(host);
+	ahci_print_info(host, "platform");
+
+	return ahci_host_activate(host, sht);
+}
+EXPORT_SYMBOL_GPL(ahci_platform_init_host);
+
+static void ahci_host_stop(struct ata_host *host)
+{
+	struct ahci_host_priv *hpriv = host->private_data;
+
+	ahci_platform_disable_resources(hpriv);
+}
+
+/**
+ * ahci_platform_shutdown - Disable interrupts and stop DMA for host ports
+ * @pdev: platform device pointer for the host
+ *
+ * This function is called during system shutdown and performs the minimal
+ * deconfiguration required to ensure that an ahci_platform host cannot
+ * corrupt or otherwise interfere with a new kernel being started with kexec.
+ */
+void ahci_platform_shutdown(struct platform_device *pdev)
+{
+	struct ata_host *host = platform_get_drvdata(pdev);
+	struct ahci_host_priv *hpriv = host->private_data;
+	void __iomem *mmio = hpriv->mmio;
+	int i;
+
+	for (i = 0; i < host->n_ports; i++) {
+		struct ata_port *ap = host->ports[i];
+
+		/* Disable port interrupts */
+		if (ap->ops->freeze)
+			ap->ops->freeze(ap);
+
+		/* Stop the port DMA engines */
+		if (ap->ops->port_stop)
+			ap->ops->port_stop(ap);
+	}
+
+	/* Disable and clear host interrupts */
+	writel(readl(mmio + HOST_CTL) & ~HOST_IRQ_EN, mmio + HOST_CTL);
+	readl(mmio + HOST_CTL); /* flush */
+	writel(GENMASK(host->n_ports, 0), mmio + HOST_IRQ_STAT);
+}
+EXPORT_SYMBOL_GPL(ahci_platform_shutdown);
+
+#ifdef CONFIG_PM_SLEEP
+/**
+ * ahci_platform_suspend_host - Suspend an ahci-platform host
+ * @dev: device pointer for the host
+ *
+ * This function does all the usual steps needed to suspend an
+ * ahci-platform host, note any necessary resources (ie clks, phys, etc.)
+ * must be disabled after calling this.
+ *
+ * RETURNS:
+ * 0 on success otherwise a negative error code
+ */
+int ahci_platform_suspend_host(struct device *dev)
+{
+	struct ata_host *host = dev_get_drvdata(dev);
+	struct ahci_host_priv *hpriv = host->private_data;
+	void __iomem *mmio = hpriv->mmio;
+	u32 ctl;
+
+	if (hpriv->flags & AHCI_HFLAG_NO_SUSPEND) {
+		dev_err(dev, "firmware update required for suspend/resume\n");
+		return -EIO;
+	}
+
+	/*
+	 * AHCI spec rev1.1 section 8.3.3:
+	 * Software must disable interrupts prior to requesting a
+	 * transition of the HBA to D3 state.
+	 */
+	ctl = readl(mmio + HOST_CTL);
+	ctl &= ~HOST_IRQ_EN;
+	writel(ctl, mmio + HOST_CTL);
+	readl(mmio + HOST_CTL); /* flush */
+
+	if (hpriv->flags & AHCI_HFLAG_SUSPEND_PHYS)
+		ahci_platform_disable_phys(hpriv);
+
+	return ata_host_suspend(host, PMSG_SUSPEND);
+}
+EXPORT_SYMBOL_GPL(ahci_platform_suspend_host);
+
+/**
+ * ahci_platform_resume_host - Resume an ahci-platform host
+ * @dev: device pointer for the host
+ *
+ * This function does all the usual steps needed to resume an ahci-platform
+ * host, note any necessary resources (ie clks, phys, etc.)  must be
+ * initialized / enabled before calling this.
+ *
+ * RETURNS:
+ * 0 on success otherwise a negative error code
+ */
+int ahci_platform_resume_host(struct device *dev)
+{
+	struct ata_host *host = dev_get_drvdata(dev);
+	struct ahci_host_priv *hpriv = host->private_data;
+	int rc;
+
+	if (dev->power.power_state.event == PM_EVENT_SUSPEND) {
+		rc = ahci_reset_controller(host);
+		if (rc)
+			return rc;
+
+		ahci_init_controller(host);
+	}
+
+	if (hpriv->flags & AHCI_HFLAG_SUSPEND_PHYS)
+		ahci_platform_enable_phys(hpriv);
+
+	ata_host_resume(host);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ahci_platform_resume_host);
+
+/**
+ * ahci_platform_suspend - Suspend an ahci-platform device
+ * @dev: the platform device to suspend
+ *
+ * This function suspends the host associated with the device, followed by
+ * disabling all the resources of the device.
+ *
+ * RETURNS:
+ * 0 on success otherwise a negative error code
+ */
+int ahci_platform_suspend(struct device *dev)
+{
+	struct ata_host *host = dev_get_drvdata(dev);
+	struct ahci_host_priv *hpriv = host->private_data;
+	int rc;
+
+	rc = ahci_platform_suspend_host(dev);
+	if (rc)
+		return rc;
+
+	ahci_platform_disable_resources(hpriv);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ahci_platform_suspend);
+
+/**
+ * ahci_platform_resume - Resume an ahci-platform device
+ * @dev: the platform device to resume
+ *
+ * This function enables all the resources of the device followed by
+ * resuming the host associated with the device.
+ *
+ * RETURNS:
+ * 0 on success otherwise a negative error code
+ */
+int ahci_platform_resume(struct device *dev)
+{
+	struct ata_host *host = dev_get_drvdata(dev);
+	struct ahci_host_priv *hpriv = host->private_data;
+	int rc;
+
+	rc = ahci_platform_enable_resources(hpriv);
+	if (rc)
+		return rc;
+
+	rc = ahci_platform_resume_host(dev);
+	if (rc)
+		goto disable_resources;
+
+	/* We resumed so update PM runtime state */
+	pm_runtime_disable(dev);
+	pm_runtime_set_active(dev);
+	pm_runtime_enable(dev);
+
+	return 0;
+
+disable_resources:
+	ahci_platform_disable_resources(hpriv);
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(ahci_platform_resume);
+#endif
+
+MODULE_DESCRIPTION("AHCI SATA platform library");
+MODULE_AUTHOR("Anton Vorontsov <avorontsov@ru.mvista.com>");
+MODULE_LICENSE("GPL");