// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Broadcom SATA3 AHCI Controller Driver
 *
 * Copyright © 2009-2015 Broadcom Corporation
 */

#include <linux/ahci_platform.h>
#include <linux/compiler.h>
#include <linux/device.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/libata.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/reset.h>
#include <linux/string.h>

#include "ahci.h"

#define DRV_NAME                                        "brcm-ahci"

#define SATA_TOP_CTRL_VERSION                           0x0
#define SATA_TOP_CTRL_BUS_CTRL                          0x4
 #define MMIO_ENDIAN_SHIFT                              0 /* CPU->AHCI */
 #define DMADESC_ENDIAN_SHIFT                           2 /* AHCI->DDR */
 #define DMADATA_ENDIAN_SHIFT                           4 /* AHCI->DDR */
 #define PIODATA_ENDIAN_SHIFT                           6
  #define ENDIAN_SWAP_NONE                              0
  #define ENDIAN_SWAP_FULL                              2
#define SATA_TOP_CTRL_TP_CTRL                           0x8
#define SATA_TOP_CTRL_PHY_CTRL                          0xc
 #define SATA_TOP_CTRL_PHY_CTRL_1                       0x0
  #define SATA_TOP_CTRL_1_PHY_DEFAULT_POWER_STATE       BIT(14)
 #define SATA_TOP_CTRL_PHY_CTRL_2                       0x4
  #define SATA_TOP_CTRL_2_SW_RST_MDIOREG                BIT(0)
  #define SATA_TOP_CTRL_2_SW_RST_OOB                    BIT(1)
  #define SATA_TOP_CTRL_2_SW_RST_RX                     BIT(2)
  #define SATA_TOP_CTRL_2_SW_RST_TX                     BIT(3)
  #define SATA_TOP_CTRL_2_PHY_GLOBAL_RESET              BIT(14)
 #define SATA_TOP_CTRL_PHY_OFFS                         0x8
 #define SATA_TOP_MAX_PHYS                              2

#define SATA_FIRST_PORT_CTRL                            0x700
#define SATA_NEXT_PORT_CTRL_OFFSET                      0x80
#define SATA_PORT_PCTRL6(reg_base)                      (reg_base + 0x18)

/* On big-endian MIPS, buses are reversed to big endian, so switch them back */
#if defined(CONFIG_MIPS) && defined(__BIG_ENDIAN)
#define DATA_ENDIAN                      2 /* AHCI->DDR inbound accesses */
#define MMIO_ENDIAN                      2 /* CPU->AHCI outbound accesses */
#else
#define DATA_ENDIAN                      0
#define MMIO_ENDIAN                      0
#endif

#define BUS_CTRL_ENDIAN_CONF                            \
        ((DATA_ENDIAN << DMADATA_ENDIAN_SHIFT) |        \
        (DATA_ENDIAN << DMADESC_ENDIAN_SHIFT) |         \
        (MMIO_ENDIAN << MMIO_ENDIAN_SHIFT))

#define BUS_CTRL_ENDIAN_NSP_CONF                        \
        (0x02 << DMADATA_ENDIAN_SHIFT | 0x02 << DMADESC_ENDIAN_SHIFT)

#define BUS_CTRL_ENDIAN_CONF_MASK                       \
        (0x3 << MMIO_ENDIAN_SHIFT | 0x3 << DMADESC_ENDIAN_SHIFT |       \
         0x3 << DMADATA_ENDIAN_SHIFT | 0x3 << PIODATA_ENDIAN_SHIFT)

enum brcm_ahci_version {
        BRCM_SATA_BCM7425 = 1,
        BRCM_SATA_BCM7445,
        BRCM_SATA_NSP,
        BRCM_SATA_BCM7216,
};

enum brcm_ahci_quirks {
        BRCM_AHCI_QUIRK_SKIP_PHY_ENABLE = BIT(0),
};

struct brcm_ahci_priv {
        struct device *dev;
        void __iomem *top_ctrl;
        u32 port_mask;
        u32 quirks;
        enum brcm_ahci_version version;
        struct reset_control *rcdev_rescal;
        struct reset_control *rcdev_ahci;
};

static inline u32 brcm_sata_readreg(void __iomem *addr)
{
        /*
         * MIPS endianness is configured by boot strap, which also reverses all
         * bus endianness (i.e., big-endian CPU + big endian bus ==> native
         * endian I/O).
         *
         * Other architectures (e.g., ARM) either do not support big endian, or
         * else leave I/O in little endian mode.
         */
        if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
                return __raw_readl(addr);
        else
                return readl_relaxed(addr);
}

static inline void brcm_sata_writereg(u32 val, void __iomem *addr)
{
        /* See brcm_sata_readreg() comments */
        if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
                __raw_writel(val, addr);
        else
                writel_relaxed(val, addr);
}

static void brcm_sata_alpm_init(struct ahci_host_priv *hpriv)
{
        struct brcm_ahci_priv *priv = hpriv->plat_data;
        u32 port_ctrl, host_caps;
        int i;

        /* Enable support for ALPM */
        host_caps = readl(hpriv->mmio + HOST_CAP);
        if (!(host_caps & HOST_CAP_ALPM))
                hpriv->flags |= AHCI_HFLAG_YES_ALPM;

        /*
         * Adjust timeout to allow PLL sufficient time to lock while waking
         * up from slumber mode.
         */
        for (i = 0, port_ctrl = SATA_FIRST_PORT_CTRL;
             i < SATA_TOP_MAX_PHYS;
             i++, port_ctrl += SATA_NEXT_PORT_CTRL_OFFSET) {
                if (priv->port_mask & BIT(i))
                        writel(0xff1003fc,
                               hpriv->mmio + SATA_PORT_PCTRL6(port_ctrl));
        }
}

static void brcm_sata_phy_enable(struct brcm_ahci_priv *priv, int port)
{
        void __iomem *phyctrl = priv->top_ctrl + SATA_TOP_CTRL_PHY_CTRL +
                                (port * SATA_TOP_CTRL_PHY_OFFS);
        void __iomem *p;
        u32 reg;

        if (priv->quirks & BRCM_AHCI_QUIRK_SKIP_PHY_ENABLE)
                return;

        /* clear PHY_DEFAULT_POWER_STATE */
        p = phyctrl + SATA_TOP_CTRL_PHY_CTRL_1;
        reg = brcm_sata_readreg(p);
        reg &= ~SATA_TOP_CTRL_1_PHY_DEFAULT_POWER_STATE;
        brcm_sata_writereg(reg, p);

        /* reset the PHY digital logic */
        p = phyctrl + SATA_TOP_CTRL_PHY_CTRL_2;
        reg = brcm_sata_readreg(p);
        reg &= ~(SATA_TOP_CTRL_2_SW_RST_MDIOREG | SATA_TOP_CTRL_2_SW_RST_OOB |
                 SATA_TOP_CTRL_2_SW_RST_RX);
        reg |= SATA_TOP_CTRL_2_SW_RST_TX;
        brcm_sata_writereg(reg, p);
        reg = brcm_sata_readreg(p);
        reg |= SATA_TOP_CTRL_2_PHY_GLOBAL_RESET;
        brcm_sata_writereg(reg, p);
        reg = brcm_sata_readreg(p);
        reg &= ~SATA_TOP_CTRL_2_PHY_GLOBAL_RESET;
        brcm_sata_writereg(reg, p);
        (void)brcm_sata_readreg(p);
}

static void brcm_sata_phy_disable(struct brcm_ahci_priv *priv, int port)
{
        void __iomem *phyctrl = priv->top_ctrl + SATA_TOP_CTRL_PHY_CTRL +
                                (port * SATA_TOP_CTRL_PHY_OFFS);
        void __iomem *p;
        u32 reg;

        if (priv->quirks & BRCM_AHCI_QUIRK_SKIP_PHY_ENABLE)
                return;

        /* power-off the PHY digital logic */
        p = phyctrl + SATA_TOP_CTRL_PHY_CTRL_2;
        reg = brcm_sata_readreg(p);
        reg |= (SATA_TOP_CTRL_2_SW_RST_MDIOREG | SATA_TOP_CTRL_2_SW_RST_OOB |
                SATA_TOP_CTRL_2_SW_RST_RX | SATA_TOP_CTRL_2_SW_RST_TX |
                SATA_TOP_CTRL_2_PHY_GLOBAL_RESET);
        brcm_sata_writereg(reg, p);

        /* set PHY_DEFAULT_POWER_STATE */
        p = phyctrl + SATA_TOP_CTRL_PHY_CTRL_1;
        reg = brcm_sata_readreg(p);
        reg |= SATA_TOP_CTRL_1_PHY_DEFAULT_POWER_STATE;
        brcm_sata_writereg(reg, p);
}

static void brcm_sata_phys_enable(struct brcm_ahci_priv *priv)
{
        int i;

        for (i = 0; i < SATA_TOP_MAX_PHYS; i++)
                if (priv->port_mask & BIT(i))
                        brcm_sata_phy_enable(priv, i);
}

static void brcm_sata_phys_disable(struct brcm_ahci_priv *priv)
{
        int i;

        for (i = 0; i < SATA_TOP_MAX_PHYS; i++)
                if (priv->port_mask & BIT(i))
                        brcm_sata_phy_disable(priv, i);
}

static u32 brcm_ahci_get_portmask(struct ahci_host_priv *hpriv,
                                  struct brcm_ahci_priv *priv)
{
        u32 impl;

        impl = readl(hpriv->mmio + HOST_PORTS_IMPL);

        if (fls(impl) > SATA_TOP_MAX_PHYS)
                dev_warn(priv->dev, "warning: more ports than PHYs (%#x)\n",
                         impl);
        else if (!impl)
                dev_info(priv->dev, "no ports found\n");

        return impl;
}

static void brcm_sata_init(struct brcm_ahci_priv *priv)
{
        void __iomem *ctrl = priv->top_ctrl + SATA_TOP_CTRL_BUS_CTRL;
        u32 data;

        /* Configure endianness */
        data = brcm_sata_readreg(ctrl);
        data &= ~BUS_CTRL_ENDIAN_CONF_MASK;
        if (priv->version == BRCM_SATA_NSP)
                data |= BUS_CTRL_ENDIAN_NSP_CONF;
        else
                data |= BUS_CTRL_ENDIAN_CONF;
        brcm_sata_writereg(data, ctrl);
}

static unsigned int brcm_ahci_read_id(struct ata_device *dev,
                                      struct ata_taskfile *tf, __le16 *id)
{
        struct ata_port *ap = dev->link->ap;
        struct ata_host *host = ap->host;
        struct ahci_host_priv *hpriv = host->private_data;
        struct brcm_ahci_priv *priv = hpriv->plat_data;
        void __iomem *mmio = hpriv->mmio;
        unsigned int err_mask;
        unsigned long flags;
        int i, rc;
        u32 ctl;

        /* Try to read the device ID and, if this fails, proceed with the
         * recovery sequence below
         */
        err_mask = ata_do_dev_read_id(dev, tf, id);
        if (likely(!err_mask))
                return err_mask;

        /* Disable host interrupts */
        spin_lock_irqsave(&host->lock, flags);
        ctl = readl(mmio + HOST_CTL);
        ctl &= ~HOST_IRQ_EN;
        writel(ctl, mmio + HOST_CTL);
        readl(mmio + HOST_CTL); /* flush */
        spin_unlock_irqrestore(&host->lock, flags);

        /* Perform the SATA PHY reset sequence */
        brcm_sata_phy_disable(priv, ap->port_no);

        /* Reset the SATA clock */
        ahci_platform_disable_clks(hpriv);
        msleep(10);

        ahci_platform_enable_clks(hpriv);
        msleep(10);

        /* Bring the PHY back on */
        brcm_sata_phy_enable(priv, ap->port_no);

        /* Re-initialize and calibrate the PHY */
        for (i = 0; i < hpriv->nports; i++) {
                if (ahci_ignore_port(hpriv, i))
                        continue;

                rc = phy_init(hpriv->phys[i]);
                if (rc)
                        goto disable_phys;

                rc = phy_calibrate(hpriv->phys[i]);
                if (rc) {
                        phy_exit(hpriv->phys[i]);
                        goto disable_phys;
                }
        }

        /* Re-enable host interrupts */
        spin_lock_irqsave(&host->lock, flags);
        ctl = readl(mmio + HOST_CTL);
        ctl |= HOST_IRQ_EN;
        writel(ctl, mmio + HOST_CTL);
        readl(mmio + HOST_CTL); /* flush */
        spin_unlock_irqrestore(&host->lock, flags);

        return ata_do_dev_read_id(dev, tf, id);

disable_phys:
        while (--i >= 0) {
                phy_power_off(hpriv->phys[i]);
                phy_exit(hpriv->phys[i]);
        }

        return AC_ERR_OTHER;
}

static void brcm_ahci_host_stop(struct ata_host *host)
{
        struct ahci_host_priv *hpriv = host->private_data;

        ahci_platform_disable_resources(hpriv);
}

static struct ata_port_operations ahci_brcm_platform_ops = {
        .inherits       = &ahci_ops,
        .host_stop      = brcm_ahci_host_stop,
        .read_id        = brcm_ahci_read_id,
};

static const struct ata_port_info ahci_brcm_port_info = {
        .flags          = AHCI_FLAG_COMMON | ATA_FLAG_NO_DIPM,
        .link_flags     = ATA_LFLAG_NO_DEBOUNCE_DELAY,
        .pio_mask       = ATA_PIO4,
        .udma_mask      = ATA_UDMA6,
        .port_ops       = &ahci_brcm_platform_ops,
};

static int brcm_ahci_suspend(struct device *dev)
{
        struct ata_host *host = dev_get_drvdata(dev);
        struct ahci_host_priv *hpriv = host->private_data;
        struct brcm_ahci_priv *priv = hpriv->plat_data;
        int ret;

        brcm_sata_phys_disable(priv);

        if (IS_ENABLED(CONFIG_PM_SLEEP))
                ret = ahci_platform_suspend(dev);
        else
                ret = 0;

        reset_control_assert(priv->rcdev_ahci);
        reset_control_rearm(priv->rcdev_rescal);

        return ret;
}

static int __maybe_unused brcm_ahci_resume(struct device *dev)
{
        struct ata_host *host = dev_get_drvdata(dev);
        struct ahci_host_priv *hpriv = host->private_data;
        struct brcm_ahci_priv *priv = hpriv->plat_data;
        int ret = 0;

        ret = reset_control_deassert(priv->rcdev_ahci);
        if (ret)
                return ret;
        ret = reset_control_reset(priv->rcdev_rescal);
        if (ret)
                return ret;

        /* Make sure clocks are turned on before re-configuration */
        ret = ahci_platform_enable_clks(hpriv);
        if (ret)
                return ret;

        ret = ahci_platform_enable_regulators(hpriv);
        if (ret)
                goto out_disable_clks;

        brcm_sata_init(priv);
        brcm_sata_phys_enable(priv);
        brcm_sata_alpm_init(hpriv);

        /* Since we had to enable clocks earlier on, we cannot use
         * ahci_platform_resume() as-is since a second call to
         * ahci_platform_enable_resources() would bump up the resources
         * (regulators, clocks, PHYs) count artificially so we copy the part
         * after ahci_platform_enable_resources().
         */
        ret = ahci_platform_enable_phys(hpriv);
        if (ret)
                goto out_disable_phys;

        ret = ahci_platform_resume_host(dev);
        if (ret)
                goto out_disable_platform_phys;

        /* We resumed so update PM runtime state */
        pm_runtime_disable(dev);
        pm_runtime_set_active(dev);
        pm_runtime_enable(dev);

        return 0;

out_disable_platform_phys:
        ahci_platform_disable_phys(hpriv);
out_disable_phys:
        brcm_sata_phys_disable(priv);
        ahci_platform_disable_regulators(hpriv);
out_disable_clks:
        ahci_platform_disable_clks(hpriv);
        return ret;
}

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

static const struct of_device_id ahci_of_match[] = {
        {.compatible = "brcm,bcm7425-ahci", .data = (void *)BRCM_SATA_BCM7425},
        {.compatible = "brcm,bcm7445-ahci", .data = (void *)BRCM_SATA_BCM7445},
        {.compatible = "brcm,bcm63138-ahci", .data = (void *)BRCM_SATA_BCM7445},
        {.compatible = "brcm,bcm-nsp-ahci", .data = (void *)BRCM_SATA_NSP},
        {.compatible = "brcm,bcm7216-ahci", .data = (void *)BRCM_SATA_BCM7216},
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, ahci_of_match);

static int brcm_ahci_probe(struct platform_device *pdev)
{
        const struct of_device_id *of_id;
        struct device *dev = &pdev->dev;
        struct brcm_ahci_priv *priv;
        struct ahci_host_priv *hpriv;
        int ret;

        priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
        if (!priv)
                return -ENOMEM;

        of_id = of_match_node(ahci_of_match, pdev->dev.of_node);
        if (!of_id)
                return -ENODEV;

        priv->version = (unsigned long)of_id->data;
        priv->dev = dev;

        priv->top_ctrl = devm_platform_ioremap_resource_byname(pdev, "top-ctrl");
        if (IS_ERR(priv->top_ctrl))
                return PTR_ERR(priv->top_ctrl);

        if (priv->version == BRCM_SATA_BCM7216) {
                priv->rcdev_rescal = devm_reset_control_get_optional_shared(
                        &pdev->dev, "rescal");
                if (IS_ERR(priv->rcdev_rescal))
                        return PTR_ERR(priv->rcdev_rescal);
        }
        priv->rcdev_ahci = devm_reset_control_get_optional(&pdev->dev, "ahci");
        if (IS_ERR(priv->rcdev_ahci))
                return PTR_ERR(priv->rcdev_ahci);

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

        hpriv->plat_data = priv;
        hpriv->flags = AHCI_HFLAG_WAKE_BEFORE_STOP | AHCI_HFLAG_NO_WRITE_TO_RO;

        switch (priv->version) {
        case BRCM_SATA_BCM7425:
                hpriv->flags |= AHCI_HFLAG_DELAY_ENGINE;
                fallthrough;
        case BRCM_SATA_NSP:
                hpriv->flags |= AHCI_HFLAG_NO_NCQ;
                priv->quirks |= BRCM_AHCI_QUIRK_SKIP_PHY_ENABLE;
                break;
        default:
                break;
        }

        ret = reset_control_reset(priv->rcdev_rescal);
        if (ret)
                return ret;
        ret = reset_control_deassert(priv->rcdev_ahci);
        if (ret)
                return ret;

        ret = ahci_platform_enable_clks(hpriv);
        if (ret)
                goto out_reset;

        ret = ahci_platform_enable_regulators(hpriv);
        if (ret)
                goto out_disable_clks;

        /* Must be first so as to configure endianness including that
         * of the standard AHCI register space.
         */
        brcm_sata_init(priv);

        /* Initializes priv->port_mask which is used below */
        priv->port_mask = brcm_ahci_get_portmask(hpriv, priv);
        if (!priv->port_mask) {
                ret = -ENODEV;
                goto out_disable_regulators;
        }

        /* Must be done before ahci_platform_enable_phys() */
        brcm_sata_phys_enable(priv);

        brcm_sata_alpm_init(hpriv);

        ret = ahci_platform_enable_phys(hpriv);
        if (ret)
                goto out_disable_phys;

        ret = ahci_platform_init_host(pdev, hpriv, &ahci_brcm_port_info,
                                      &ahci_platform_sht);
        if (ret)
                goto out_disable_platform_phys;

        dev_info(dev, "Broadcom AHCI SATA3 registered\n");

        return 0;

out_disable_platform_phys:
        ahci_platform_disable_phys(hpriv);
out_disable_phys:
        brcm_sata_phys_disable(priv);
out_disable_regulators:
        ahci_platform_disable_regulators(hpriv);
out_disable_clks:
        ahci_platform_disable_clks(hpriv);
out_reset:
        reset_control_assert(priv->rcdev_ahci);
        reset_control_rearm(priv->rcdev_rescal);
        return ret;
}

static void brcm_ahci_remove(struct platform_device *pdev)
{
        struct ata_host *host = dev_get_drvdata(&pdev->dev);
        struct ahci_host_priv *hpriv = host->private_data;
        struct brcm_ahci_priv *priv = hpriv->plat_data;

        brcm_sata_phys_disable(priv);

        ata_platform_remove_one(pdev);
}

static void brcm_ahci_shutdown(struct platform_device *pdev)
{
        int ret;

        /* All resources releasing happens via devres, but our device, unlike a
         * proper remove is not disappearing, therefore using
         * brcm_ahci_suspend() here which does explicit power management is
         * appropriate.
         */
        ret = brcm_ahci_suspend(&pdev->dev);
        if (ret)
                dev_err(&pdev->dev, "failed to shutdown\n");
}

static SIMPLE_DEV_PM_OPS(ahci_brcm_pm_ops, brcm_ahci_suspend, brcm_ahci_resume);

static struct platform_driver brcm_ahci_driver = {
        .probe = brcm_ahci_probe,
        .remove = brcm_ahci_remove,
        .shutdown = brcm_ahci_shutdown,
        .driver = {
                .name = DRV_NAME,
                .of_match_table = ahci_of_match,
                .pm = &ahci_brcm_pm_ops,
        },
};
module_platform_driver(brcm_ahci_driver);

MODULE_DESCRIPTION("Broadcom SATA3 AHCI Controller Driver");
MODULE_AUTHOR("Brian Norris");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:sata-brcmstb");