/*
 * 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 "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
 */
static 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;
}

/**
 * ahci_platform_disable_phys - Disable PHYs
 * @hpriv: host private area to store config values
 *
 * This function disables all PHYs found in hpriv->phys.
 */
static 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]);
        }
}

/**
 * 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) 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 = ahci_platform_enable_phys(hpriv);
        if (rc)
                goto disable_clks;

        return 0;

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) Clocks (through ahci_platform_disable_clks)
 * 3) Regulator
 */
void ahci_platform_disable_resources(struct ahci_host_priv *hpriv)
{
        ahci_platform_disable_phys(hpriv);

        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;

        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
 *
 * 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) 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)
{
        struct device *dev = &pdev->dev;
        struct ahci_host_priv *hpriv;
        struct clk *clk;
        struct device_node *child;
        int i, sz, 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;
        }

        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;

        sz = hpriv->nports * sizeof(*hpriv->phys);
        hpriv->phys = devm_kzalloc(dev, sz, GFP_KERNEL);
        if (!hpriv->phys) {
                rc = -ENOMEM;
                goto err_out;
        }
        sz = hpriv->nports * sizeof(*hpriv->target_pwrs);
        hpriv->target_pwrs = kzalloc(sz, 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;
        }

        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
 * @dev: 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");