// 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
  ",
  				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
  ",
  			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);
  		if (rc == -EPROBE_DEFER)
  			goto err_out;
  		rc = 0;
  		hpriv->phy_regulator = NULL;
  	}

  	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;

  				of_node_put(child);

  				goto err_out;
  			}

  			if (port >= hpriv->nports) {
  				dev_warn(dev, "invalid port number %d
  ", 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
  ");
  			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
  ");
  		return irq;

  	}

  	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
  ");
  
  	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.
  ");
  				return rc;
  			}
  			dev_warn(dev, "Enable 32-bit DMA instead of 64-bit.
  ");
  		}
  	}

  	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
  ");
  		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");