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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /drivers/ata/libahci_platform.c
parentInitial commit. (diff)
downloadlinux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz
linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/ata/libahci_platform.c')
-rw-r--r--drivers/ata/libahci_platform.c807
1 files changed, 807 insertions, 0 deletions
diff --git a/drivers/ata/libahci_platform.c b/drivers/ata/libahci_platform.c
new file mode 100644
index 000000000..6a55aac0c
--- /dev/null
+++ b/drivers/ata/libahci_platform.c
@@ -0,0 +1,807 @@
+/*
+ * 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>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ */
+
+#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_power_on(hpriv->phys[i]);
+ if (rc) {
+ 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
+ * 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;
+
+ 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]);
+
+ 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.
+ */
+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]);
+ }
+}
+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 %s: ENOSYS\n",
+ node->name);
+ break;
+ }
+ /* fall through */
+ 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 %s: %d\n",
+ node->name, 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_optional(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)
+ * 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)) {
+ dev_err(dev, "no mmio space\n");
+ 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;
+ }
+
+ 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;
+ }
+ }
+
+ hpriv->nports = child_nodes = of_get_child_count(dev->of_node);
+
+ /*
+ * 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 = 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;
+ 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)
+ goto err_out;
+ }
+#endif
+
+ rc = ahci_platform_get_phy(hpriv, port, dev, child);
+ if (rc)
+ 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 */
+
+ 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);
+ int rc;
+
+ if (dev->power.power_state.event == PM_EVENT_SUSPEND) {
+ rc = ahci_reset_controller(host);
+ if (rc)
+ return rc;
+
+ ahci_init_controller(host);
+ }
+
+ 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");