/*
 * AHCI glue platform driver for Marvell EBU SOCs
 *
 * Copyright (C) 2014 Marvell
 *
 * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
 * Marcin Wojtas <mw@semihalf.com>
 *
 * This file is licensed under the terms of the GNU General Public
 * License version 2.  This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 */

#include <linux/ahci_platform.h>
#include <linux/kernel.h>
#include <linux/mbus.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include "ahci.h"

#define DRV_NAME "ahci-mvebu"

#define AHCI_VENDOR_SPECIFIC_0_ADDR  0xa0
#define AHCI_VENDOR_SPECIFIC_0_DATA  0xa4

#define AHCI_WINDOW_CTRL(win)   (0x60 + ((win) << 4))
#define AHCI_WINDOW_BASE(win)   (0x64 + ((win) << 4))
#define AHCI_WINDOW_SIZE(win)   (0x68 + ((win) << 4))

struct ahci_mvebu_plat_data {
        int (*plat_config)(struct ahci_host_priv *hpriv);
        unsigned int flags;
};

static void ahci_mvebu_mbus_config(struct ahci_host_priv *hpriv,
                                   const struct mbus_dram_target_info *dram)
{
        int i;

        for (i = 0; i < 4; i++) {
                writel(0, hpriv->mmio + AHCI_WINDOW_CTRL(i));
                writel(0, hpriv->mmio + AHCI_WINDOW_BASE(i));
                writel(0, hpriv->mmio + AHCI_WINDOW_SIZE(i));
        }

        for (i = 0; i < dram->num_cs; i++) {
                const struct mbus_dram_window *cs = dram->cs + i;

                writel((cs->mbus_attr << 8) |
                       (dram->mbus_dram_target_id << 4) | 1,
                       hpriv->mmio + AHCI_WINDOW_CTRL(i));
                writel(cs->base >> 16, hpriv->mmio + AHCI_WINDOW_BASE(i));
                writel(((cs->size - 1) & 0xffff0000),
                       hpriv->mmio + AHCI_WINDOW_SIZE(i));
        }
}

static void ahci_mvebu_regret_option(struct ahci_host_priv *hpriv)
{
        /*
         * Enable the regret bit to allow the SATA unit to regret a
         * request that didn't receive an acknowlegde and avoid a
         * deadlock
         */
        writel(0x4, hpriv->mmio + AHCI_VENDOR_SPECIFIC_0_ADDR);
        writel(0x80, hpriv->mmio + AHCI_VENDOR_SPECIFIC_0_DATA);
}

static int ahci_mvebu_armada_380_config(struct ahci_host_priv *hpriv)
{
        const struct mbus_dram_target_info *dram;
        int rc = 0;

        dram = mv_mbus_dram_info();
        if (dram)
                ahci_mvebu_mbus_config(hpriv, dram);
        else
                rc = -ENODEV;

        ahci_mvebu_regret_option(hpriv);

        return rc;
}

static int ahci_mvebu_armada_3700_config(struct ahci_host_priv *hpriv)
{
        u32 reg;

        writel(0, hpriv->mmio + AHCI_VENDOR_SPECIFIC_0_ADDR);

        reg = readl(hpriv->mmio + AHCI_VENDOR_SPECIFIC_0_DATA);
        reg |= BIT(6);
        writel(reg, hpriv->mmio + AHCI_VENDOR_SPECIFIC_0_DATA);

        return 0;
}

/**
 * ahci_mvebu_stop_engine
 *
 * @ap: Target ata port
 *
 * Errata Ref#226 - SATA Disk HOT swap issue when connected through
 * Port Multiplier in FIS-based Switching mode.
 *
 * To avoid the issue, according to design, the bits[11:8, 0] of
 * register PxFBS are cleared when Port Command and Status (0x18) bit[0]
 * changes its value from 1 to 0, i.e. falling edge of Port
 * Command and Status bit[0] sends PULSE that resets PxFBS
 * bits[11:8; 0].
 *
 * This function is used to override function of "ahci_stop_engine"
 * from libahci.c by adding the mvebu work around(WA) to save PxFBS
 * value before the PxCMD ST write of 0, then restore PxFBS value.
 *
 * Return: 0 on success; Error code otherwise.
 */
static int ahci_mvebu_stop_engine(struct ata_port *ap)
{
        void __iomem *port_mmio = ahci_port_base(ap);
        u32 tmp, port_fbs;

        tmp = readl(port_mmio + PORT_CMD);

        /* check if the HBA is idle */
        if ((tmp & (PORT_CMD_START | PORT_CMD_LIST_ON)) == 0)
                return 0;

        /* save the port PxFBS register for later restore */
        port_fbs = readl(port_mmio + PORT_FBS);

        /* setting HBA to idle */
        tmp &= ~PORT_CMD_START;
        writel(tmp, port_mmio + PORT_CMD);

        /*
         * bit #15 PxCMD signal doesn't clear PxFBS,
         * restore the PxFBS register right after clearing the PxCMD ST,
         * no need to wait for the PxCMD bit #15.
         */
        writel(port_fbs, port_mmio + PORT_FBS);

        /* wait for engine to stop. This could be as long as 500 msec */
        tmp = ata_wait_register(ap, port_mmio + PORT_CMD,
                                PORT_CMD_LIST_ON, PORT_CMD_LIST_ON, 1, 500);
        if (tmp & PORT_CMD_LIST_ON)
                return -EIO;

        return 0;
}

#ifdef CONFIG_PM_SLEEP
static int ahci_mvebu_suspend(struct platform_device *pdev, pm_message_t state)
{
        return ahci_platform_suspend_host(&pdev->dev);
}

static int ahci_mvebu_resume(struct platform_device *pdev)
{
        struct ata_host *host = platform_get_drvdata(pdev);
        struct ahci_host_priv *hpriv = host->private_data;
        const struct ahci_mvebu_plat_data *pdata = hpriv->plat_data;

        pdata->plat_config(hpriv);

        return ahci_platform_resume_host(&pdev->dev);
}
#else
#define ahci_mvebu_suspend NULL
#define ahci_mvebu_resume NULL
#endif

static const struct ata_port_info ahci_mvebu_port_info = {
        .flags     = AHCI_FLAG_COMMON,
        .pio_mask  = ATA_PIO4,
        .udma_mask = ATA_UDMA6,
        .port_ops  = &ahci_platform_ops,
};

static const struct scsi_host_template ahci_platform_sht = {
        AHCI_SHT(DRV_NAME),
};

static int ahci_mvebu_probe(struct platform_device *pdev)
{
        const struct ahci_mvebu_plat_data *pdata;
        struct ahci_host_priv *hpriv;
        int rc;

        pdata = of_device_get_match_data(&pdev->dev);
        if (!pdata)
                return -EINVAL;

        hpriv = ahci_platform_get_resources(pdev, 0);
        if (IS_ERR(hpriv))
                return PTR_ERR(hpriv);

        hpriv->flags |= pdata->flags;
        hpriv->plat_data = (void *)pdata;

        rc = ahci_platform_enable_resources(hpriv);
        if (rc)
                return rc;

        hpriv->stop_engine = ahci_mvebu_stop_engine;

        rc = pdata->plat_config(hpriv);
        if (rc)
                goto disable_resources;

        rc = ahci_platform_init_host(pdev, hpriv, &ahci_mvebu_port_info,
                                     &ahci_platform_sht);
        if (rc)
                goto disable_resources;

        return 0;

disable_resources:
        ahci_platform_disable_resources(hpriv);
        return rc;
}

static const struct ahci_mvebu_plat_data ahci_mvebu_armada_380_plat_data = {
        .plat_config = ahci_mvebu_armada_380_config,
};

static const struct ahci_mvebu_plat_data ahci_mvebu_armada_3700_plat_data = {
        .plat_config = ahci_mvebu_armada_3700_config,
        .flags = AHCI_HFLAG_SUSPEND_PHYS,
};

static const struct of_device_id ahci_mvebu_of_match[] = {
        {
                .compatible = "marvell,armada-380-ahci",
                .data = &ahci_mvebu_armada_380_plat_data,
        },
        {
                .compatible = "marvell,armada-3700-ahci",
                .data = &ahci_mvebu_armada_3700_plat_data,
        },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, ahci_mvebu_of_match);

static struct platform_driver ahci_mvebu_driver = {
        .probe = ahci_mvebu_probe,
        .remove = ata_platform_remove_one,
        .suspend = ahci_mvebu_suspend,
        .resume = ahci_mvebu_resume,
        .driver = {
                .name = DRV_NAME,
                .of_match_table = ahci_mvebu_of_match,
        },
};
module_platform_driver(ahci_mvebu_driver);

MODULE_DESCRIPTION("Marvell EBU AHCI SATA driver");
MODULE_AUTHOR("Thomas Petazzoni <thomas.petazzoni@free-electrons.com>, Marcin Wojtas <mw@semihalf.com>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:ahci_mvebu");