/*
 * Copyright (C) Freescale Semiconductor, Inc. 2006.
 * Author: Jason Jin<Jason.jin@freescale.com>
 *         Zhang Wei<wei.zhang@freescale.com>
 *
 * SPDX-License-Identifier:     GPL-2.0+
 *
 * with the reference on libata and ahci drvier in kernel
 *
 * This driver provides a SCSI interface to SATA.
 */
#include <common.h>

#include <command.h>
#include <dm.h>
#include <pci.h>
#include <asm/processor.h>
#include <linux/errno.h>
#include <asm/io.h>
#include <malloc.h>
#include <memalign.h>
#include <pci.h>
#include <scsi.h>
#include <libata.h>
#include <linux/ctype.h>
#include <ahci.h>
#include <dm/device-internal.h>
#include <dm/lists.h>

static int ata_io_flush(struct ahci_uc_priv *uc_priv, u8 port);

#ifndef CONFIG_DM_SCSI
struct ahci_uc_priv *probe_ent = NULL;
#endif

#define writel_with_flush(a,b)  do { writel(a,b); readl(b); } while (0)

/*
 * Some controllers limit number of blocks they can read/write at once.
 * Contemporary SSD devices work much faster if the read/write size is aligned
 * to a power of 2.  Let's set default to 128 and allowing to be overwritten if
 * needed.
 */
#ifndef MAX_SATA_BLOCKS_READ_WRITE
#define MAX_SATA_BLOCKS_READ_WRITE      0x80
#endif

/* Maximum timeouts for each event */
#define WAIT_MS_SPINUP  20000
#define WAIT_MS_DATAIO  10000
#define WAIT_MS_FLUSH   5000
#define WAIT_MS_LINKUP  200

__weak void __iomem *ahci_port_base(void __iomem *base, u32 port)
{
        return base + 0x100 + (port * 0x80);
}


static void ahci_setup_port(struct ahci_ioports *port, void __iomem *base,
                            unsigned int port_idx)
{
        base = ahci_port_base(base, port_idx);

        port->cmd_addr = base;
        port->scr_addr = base + PORT_SCR;
}


#define msleep(a) udelay(a * 1000)

static void ahci_dcache_flush_range(unsigned long begin, unsigned long len)
{
        const unsigned long start = begin;
        const unsigned long end = start + len;

        debug("%s: flush dcache: [%#lx, %#lx)\n", __func__, start, end);
        flush_dcache_range(start, end);
}

/*
 * SATA controller DMAs to physical RAM.  Ensure data from the
 * controller is invalidated from dcache; next access comes from
 * physical RAM.
 */
static void ahci_dcache_invalidate_range(unsigned long begin, unsigned long len)
{
        const unsigned long start = begin;
        const unsigned long end = start + len;

        debug("%s: invalidate dcache: [%#lx, %#lx)\n", __func__, start, end);
        invalidate_dcache_range(start, end);
}

/*
 * Ensure data for SATA controller is flushed out of dcache and
 * written to physical memory.
 */
static void ahci_dcache_flush_sata_cmd(struct ahci_ioports *pp)
{
        ahci_dcache_flush_range((unsigned long)pp->cmd_slot,
                                AHCI_PORT_PRIV_DMA_SZ);
}

static int waiting_for_cmd_completed(void __iomem *offset,
                                     int timeout_msec,
                                     u32 sign)
{
        int i;
        u32 status;

        for (i = 0; ((status = readl(offset)) & sign) && i < timeout_msec; i++)
                msleep(1);

        return (i < timeout_msec) ? 0 : -1;
}

int __weak ahci_link_up(struct ahci_uc_priv *uc_priv, u8 port)
{
        u32 tmp;
        int j = 0;
        void __iomem *port_mmio = uc_priv->port[port].port_mmio;

        /*
         * Bring up SATA link.
         * SATA link bringup time is usually less than 1 ms; only very
         * rarely has it taken between 1-2 ms. Never seen it above 2 ms.
         */
        while (j < WAIT_MS_LINKUP) {
                tmp = readl(port_mmio + PORT_SCR_STAT);
                tmp &= PORT_SCR_STAT_DET_MASK;
                if (tmp == PORT_SCR_STAT_DET_PHYRDY)
                        return 0;
                udelay(1000);
                j++;
        }
        return 1;
}

#ifdef CONFIG_SUNXI_AHCI
/* The sunxi AHCI controller requires this undocumented setup */
static void sunxi_dma_init(void __iomem *port_mmio)
{
        clrsetbits_le32(port_mmio + PORT_P0DMACR, 0x0000ff00, 0x00004400);
}
#endif

int ahci_reset(void __iomem *base)
{
        int i = 1000;
        u32 __iomem *host_ctl_reg = base + HOST_CTL;
        u32 tmp = readl(host_ctl_reg); /* global controller reset */

        if ((tmp & HOST_RESET) == 0)
                writel_with_flush(tmp | HOST_RESET, host_ctl_reg);

        /*
         * reset must complete within 1 second, or
         * the hardware should be considered fried.
         */
        do {
                udelay(1000);
                tmp = readl(host_ctl_reg);
                i--;
        } while ((i > 0) && (tmp & HOST_RESET));

        if (i == 0) {
                printf("controller reset failed (0x%x)\n", tmp);
                return -1;
        }

        return 0;
}

static int ahci_host_init(struct ahci_uc_priv *uc_priv)
{
#if !defined(CONFIG_SCSI_AHCI_PLAT) && !defined(CONFIG_DM_SCSI)
# ifdef CONFIG_DM_PCI
        struct udevice *dev = uc_priv->dev;
        struct pci_child_platdata *pplat = dev_get_parent_platdata(dev);
# else
        pci_dev_t pdev = uc_priv->dev;
        unsigned short vendor;
# endif
        u16 tmp16;
#endif
        void __iomem *mmio = uc_priv->mmio_base;
        u32 tmp, cap_save, cmd;
        int i, j, ret;
        void __iomem *port_mmio;
        u32 port_map;

        debug("ahci_host_init: start\n");

        cap_save = readl(mmio + HOST_CAP);
        cap_save &= ((1 << 28) | (1 << 17));
        cap_save |= (1 << 27);  /* Staggered Spin-up. Not needed. */

        ret = ahci_reset(uc_priv->mmio_base);
        if (ret)
                return ret;

        writel_with_flush(HOST_AHCI_EN, mmio + HOST_CTL);
        writel(cap_save, mmio + HOST_CAP);
        writel_with_flush(0xf, mmio + HOST_PORTS_IMPL);

#if !defined(CONFIG_SCSI_AHCI_PLAT) && !defined(CONFIG_DM_SCSI)
# ifdef CONFIG_DM_PCI
        if (pplat->vendor == PCI_VENDOR_ID_INTEL) {
                u16 tmp16;

                dm_pci_read_config16(dev, 0x92, &tmp16);
                dm_pci_write_config16(dev, 0x92, tmp16 | 0xf);
        }
# else
        pci_read_config_word(pdev, PCI_VENDOR_ID, &vendor);

        if (vendor == PCI_VENDOR_ID_INTEL) {
                u16 tmp16;
                pci_read_config_word(pdev, 0x92, &tmp16);
                tmp16 |= 0xf;
                pci_write_config_word(pdev, 0x92, tmp16);
        }
# endif
#endif
        uc_priv->cap = readl(mmio + HOST_CAP);
        uc_priv->port_map = readl(mmio + HOST_PORTS_IMPL);
        port_map = uc_priv->port_map;
        uc_priv->n_ports = (uc_priv->cap & 0x1f) + 1;

        debug("cap 0x%x  port_map 0x%x  n_ports %d\n",
              uc_priv->cap, uc_priv->port_map, uc_priv->n_ports);

        if (uc_priv->n_ports > CONFIG_SYS_SCSI_MAX_SCSI_ID)
                uc_priv->n_ports = CONFIG_SYS_SCSI_MAX_SCSI_ID;

        for (i = 0; i < uc_priv->n_ports; i++) {
                if (!(port_map & (1 << i)))
                        continue;
                uc_priv->port[i].port_mmio = ahci_port_base(mmio, i);
                port_mmio = (u8 *)uc_priv->port[i].port_mmio;
                ahci_setup_port(&uc_priv->port[i], mmio, i);

                /* make sure port is not active */
                tmp = readl(port_mmio + PORT_CMD);
                if (tmp & (PORT_CMD_LIST_ON | PORT_CMD_FIS_ON |
                           PORT_CMD_FIS_RX | PORT_CMD_START)) {
                        debug("Port %d is active. Deactivating.\n", i);
                        tmp &= ~(PORT_CMD_LIST_ON | PORT_CMD_FIS_ON |
                                 PORT_CMD_FIS_RX | PORT_CMD_START);
                        writel_with_flush(tmp, port_mmio + PORT_CMD);

                        /* spec says 500 msecs for each bit, so
                         * this is slightly incorrect.
                         */
                        msleep(500);
                }

#ifdef CONFIG_SUNXI_AHCI
                sunxi_dma_init(port_mmio);
#endif

                /* Add the spinup command to whatever mode bits may
                 * already be on in the command register.
                 */
                cmd = readl(port_mmio + PORT_CMD);
                cmd |= PORT_CMD_SPIN_UP;
                writel_with_flush(cmd, port_mmio + PORT_CMD);

                /* Bring up SATA link. */
                ret = ahci_link_up(uc_priv, i);
                if (ret) {
                        printf("SATA link %d timeout.\n", i);
                        continue;
                } else {
                        debug("SATA link ok.\n");
                }

                /* Clear error status */
                tmp = readl(port_mmio + PORT_SCR_ERR);
                if (tmp)
                        writel(tmp, port_mmio + PORT_SCR_ERR);

                debug("Spinning up device on SATA port %d... ", i);

                j = 0;
                while (j < WAIT_MS_SPINUP) {
                        tmp = readl(port_mmio + PORT_TFDATA);
                        if (!(tmp & (ATA_BUSY | ATA_DRQ)))
                                break;
                        udelay(1000);
                        tmp = readl(port_mmio + PORT_SCR_STAT);
                        tmp &= PORT_SCR_STAT_DET_MASK;
                        if (tmp == PORT_SCR_STAT_DET_PHYRDY)
                                break;
                        j++;
                }

                tmp = readl(port_mmio + PORT_SCR_STAT) & PORT_SCR_STAT_DET_MASK;
                if (tmp == PORT_SCR_STAT_DET_COMINIT) {
                        debug("SATA link %d down (COMINIT received), retrying...\n", i);
                        i--;
                        continue;
                }

                printf("Target spinup took %d ms.\n", j);
                if (j == WAIT_MS_SPINUP)
                        debug("timeout.\n");
                else
                        debug("ok.\n");

                tmp = readl(port_mmio + PORT_SCR_ERR);
                debug("PORT_SCR_ERR 0x%x\n", tmp);
                writel(tmp, port_mmio + PORT_SCR_ERR);

                /* ack any pending irq events for this port */
                tmp = readl(port_mmio + PORT_IRQ_STAT);
                debug("PORT_IRQ_STAT 0x%x\n", tmp);
                if (tmp)
                        writel(tmp, port_mmio + PORT_IRQ_STAT);

                writel(1 << i, mmio + HOST_IRQ_STAT);

                /* register linkup ports */
                tmp = readl(port_mmio + PORT_SCR_STAT);
                debug("SATA port %d status: 0x%x\n", i, tmp);
                if ((tmp & PORT_SCR_STAT_DET_MASK) == PORT_SCR_STAT_DET_PHYRDY)
                        uc_priv->link_port_map |= (0x01 << i);
        }

        tmp = readl(mmio + HOST_CTL);
        debug("HOST_CTL 0x%x\n", tmp);
        writel(tmp | HOST_IRQ_EN, mmio + HOST_CTL);
        tmp = readl(mmio + HOST_CTL);
        debug("HOST_CTL 0x%x\n", tmp);
#if !defined(CONFIG_DM_SCSI)
#ifndef CONFIG_SCSI_AHCI_PLAT
# ifdef CONFIG_DM_PCI
        dm_pci_read_config16(dev, PCI_COMMAND, &tmp16);
        tmp |= PCI_COMMAND_MASTER;
        dm_pci_write_config16(dev, PCI_COMMAND, tmp16);
# else
        pci_read_config_word(pdev, PCI_COMMAND, &tmp16);
        tmp |= PCI_COMMAND_MASTER;
        pci_write_config_word(pdev, PCI_COMMAND, tmp16);
# endif
#endif
#endif
        return 0;
}


static void ahci_print_info(struct ahci_uc_priv *uc_priv)
{
#if !defined(CONFIG_SCSI_AHCI_PLAT) && !defined(CONFIG_DM_SCSI)
# if defined(CONFIG_DM_PCI)
        struct udevice *dev = uc_priv->dev;
# else
        pci_dev_t pdev = uc_priv->dev;
# endif
        u16 cc;
#endif
        void __iomem *mmio = uc_priv->mmio_base;
        u32 vers, cap, cap2, impl, speed;
        const char *speed_s;
        const char *scc_s;

        vers = readl(mmio + HOST_VERSION);
        cap = uc_priv->cap;
        cap2 = readl(mmio + HOST_CAP2);
        impl = uc_priv->port_map;

        speed = (cap >> 20) & 0xf;
        if (speed == 1)
                speed_s = "1.5";
        else if (speed == 2)
                speed_s = "3";
        else if (speed == 3)
                speed_s = "6";
        else
                speed_s = "?";

#if defined(CONFIG_SCSI_AHCI_PLAT) || defined(CONFIG_DM_SCSI)
        scc_s = "SATA";
#else
# ifdef CONFIG_DM_PCI
        dm_pci_read_config16(dev, 0x0a, &cc);
# else
        pci_read_config_word(pdev, 0x0a, &cc);
# endif
        if (cc == 0x0101)
                scc_s = "IDE";
        else if (cc == 0x0106)
                scc_s = "SATA";
        else if (cc == 0x0104)
                scc_s = "RAID";
        else
                scc_s = "unknown";
#endif
        printf("AHCI %02x%02x.%02x%02x "
               "%u slots %u ports %s Gbps 0x%x impl %s mode\n",
               (vers >> 24) & 0xff,
               (vers >> 16) & 0xff,
               (vers >> 8) & 0xff,
               vers & 0xff,
               ((cap >> 8) & 0x1f) + 1, (cap & 0x1f) + 1, speed_s, impl, scc_s);

        printf("flags: "
               "%s%s%s%s%s%s%s"
               "%s%s%s%s%s%s%s"
               "%s%s%s%s%s%s\n",
               cap & (1 << 31) ? "64bit " : "",
               cap & (1 << 30) ? "ncq " : "",
               cap & (1 << 28) ? "ilck " : "",
               cap & (1 << 27) ? "stag " : "",
               cap & (1 << 26) ? "pm " : "",
               cap & (1 << 25) ? "led " : "",
               cap & (1 << 24) ? "clo " : "",
               cap & (1 << 19) ? "nz " : "",
               cap & (1 << 18) ? "only " : "",
               cap & (1 << 17) ? "pmp " : "",
               cap & (1 << 16) ? "fbss " : "",
               cap & (1 << 15) ? "pio " : "",
               cap & (1 << 14) ? "slum " : "",
               cap & (1 << 13) ? "part " : "",
               cap & (1 << 7) ? "ccc " : "",
               cap & (1 << 6) ? "ems " : "",
               cap & (1 << 5) ? "sxs " : "",
               cap2 & (1 << 2) ? "apst " : "",
               cap2 & (1 << 1) ? "nvmp " : "",
               cap2 & (1 << 0) ? "boh " : "");
}

#if defined(CONFIG_DM_SCSI) || !defined(CONFIG_SCSI_AHCI_PLAT)
# if defined(CONFIG_DM_PCI) || defined(CONFIG_DM_SCSI)
static int ahci_init_one(struct ahci_uc_priv *uc_priv, struct udevice *dev)
# else
static int ahci_init_one(struct ahci_uc_priv *uc_priv, pci_dev_t dev)
# endif
{
#if !defined(CONFIG_DM_SCSI)
        u16 vendor;
#endif
        int rc;

        uc_priv->dev = dev;

        uc_priv->host_flags = ATA_FLAG_SATA
                                | ATA_FLAG_NO_LEGACY
                                | ATA_FLAG_MMIO
                                | ATA_FLAG_PIO_DMA
                                | ATA_FLAG_NO_ATAPI;
        uc_priv->pio_mask = 0x1f;
        uc_priv->udma_mask = 0x7f;      /*Fixme,assume to support UDMA6 */

#if !defined(CONFIG_DM_SCSI)
#ifdef CONFIG_DM_PCI
        uc_priv->mmio_base = dm_pci_map_bar(dev, PCI_BASE_ADDRESS_5,
                                              PCI_REGION_MEM);

        /* Take from kernel:
         * JMicron-specific fixup:
         * make sure we're in AHCI mode
         */
        dm_pci_read_config16(dev, PCI_VENDOR_ID, &vendor);
        if (vendor == 0x197b)
                dm_pci_write_config8(dev, 0x41, 0xa1);
#else
        uc_priv->mmio_base = pci_map_bar(dev, PCI_BASE_ADDRESS_5,
                                           PCI_REGION_MEM);

        /* Take from kernel:
         * JMicron-specific fixup:
         * make sure we're in AHCI mode
         */
        pci_read_config_word(dev, PCI_VENDOR_ID, &vendor);
        if (vendor == 0x197b)
                pci_write_config_byte(dev, 0x41, 0xa1);
#endif
#else
        struct scsi_platdata *plat = dev_get_uclass_platdata(dev);
        uc_priv->mmio_base = (void *)plat->base;
#endif

        debug("ahci mmio_base=0x%p\n", uc_priv->mmio_base);
        /* initialize adapter */
        rc = ahci_host_init(uc_priv);
        if (rc)
                goto err_out;

        ahci_print_info(uc_priv);

        return 0;

      err_out:
        return rc;
}
#endif

#define MAX_DATA_BYTE_COUNT  (4*1024*1024)

static int ahci_fill_sg(struct ahci_uc_priv *uc_priv, u8 port,
                        unsigned char *buf, int buf_len)
{
        struct ahci_ioports *pp = &(uc_priv->port[port]);
        struct ahci_sg *ahci_sg = pp->cmd_tbl_sg;
        u32 sg_count;
        int i;

        sg_count = ((buf_len - 1) / MAX_DATA_BYTE_COUNT) + 1;
        if (sg_count > AHCI_MAX_SG) {
                printf("Error:Too much sg!\n");
                return -1;
        }

        for (i = 0; i < sg_count; i++) {
                ahci_sg->addr =
                    cpu_to_le32((unsigned long) buf + i * MAX_DATA_BYTE_COUNT);
                ahci_sg->addr_hi = 0;
                ahci_sg->flags_size = cpu_to_le32(0x3fffff &
                                          (buf_len < MAX_DATA_BYTE_COUNT
                                           ? (buf_len - 1)
                                           : (MAX_DATA_BYTE_COUNT - 1)));
                ahci_sg++;
                buf_len -= MAX_DATA_BYTE_COUNT;
        }

        return sg_count;
}


static void ahci_fill_cmd_slot(struct ahci_ioports *pp, u32 opts)
{
        pp->cmd_slot->opts = cpu_to_le32(opts);
        pp->cmd_slot->status = 0;
        pp->cmd_slot->tbl_addr = cpu_to_le32((u32)pp->cmd_tbl & 0xffffffff);
#ifdef CONFIG_PHYS_64BIT
        pp->cmd_slot->tbl_addr_hi =
            cpu_to_le32((u32)(((pp->cmd_tbl) >> 16) >> 16));
#endif
}

static int wait_spinup(void __iomem *port_mmio)
{
        ulong start;
        u32 tf_data;

        start = get_timer(0);
        do {
                tf_data = readl(port_mmio + PORT_TFDATA);
                if (!(tf_data & ATA_BUSY))
                        return 0;
        } while (get_timer(start) < WAIT_MS_SPINUP);

        return -ETIMEDOUT;
}

static int ahci_port_start(struct ahci_uc_priv *uc_priv, u8 port)
{
        struct ahci_ioports *pp = &(uc_priv->port[port]);
        void __iomem *port_mmio = pp->port_mmio;
        u32 port_status;
        void __iomem *mem;

        debug("Enter start port: %d\n", port);
        port_status = readl(port_mmio + PORT_SCR_STAT);
        debug("Port %d status: %x\n", port, port_status);
        if ((port_status & 0xf) != 0x03) {
                printf("No Link on this port!\n");
                return -1;
        }

        mem = malloc(AHCI_PORT_PRIV_DMA_SZ + 2048);
        if (!mem) {
                free(pp);
                printf("%s: No mem for table!\n", __func__);
                return -ENOMEM;
        }

        /* Aligned to 2048-bytes */
        mem = memalign(2048, AHCI_PORT_PRIV_DMA_SZ);
        memset(mem, 0, AHCI_PORT_PRIV_DMA_SZ);

        /*
         * First item in chunk of DMA memory: 32-slot command table,
         * 32 bytes each in size
         */
        pp->cmd_slot =
                (struct ahci_cmd_hdr *)(uintptr_t)virt_to_phys((void *)mem);
        debug("cmd_slot = %p\n", pp->cmd_slot);
        mem += (AHCI_CMD_SLOT_SZ + 224);

        /*
         * Second item: Received-FIS area
         */
        pp->rx_fis = virt_to_phys((void *)mem);
        mem += AHCI_RX_FIS_SZ;

        /*
         * Third item: data area for storing a single command
         * and its scatter-gather table
         */
        pp->cmd_tbl = virt_to_phys((void *)mem);
        debug("cmd_tbl_dma = %lx\n", pp->cmd_tbl);

        mem += AHCI_CMD_TBL_HDR;
        pp->cmd_tbl_sg =
                        (struct ahci_sg *)(uintptr_t)virt_to_phys((void *)mem);

        writel_with_flush((unsigned long)pp->cmd_slot,
                          port_mmio + PORT_LST_ADDR);

        writel_with_flush(pp->rx_fis, port_mmio + PORT_FIS_ADDR);

#ifdef CONFIG_SUNXI_AHCI
        sunxi_dma_init(port_mmio);
#endif

        writel_with_flush(PORT_CMD_ICC_ACTIVE | PORT_CMD_FIS_RX |
                          PORT_CMD_POWER_ON | PORT_CMD_SPIN_UP |
                          PORT_CMD_START, port_mmio + PORT_CMD);

        debug("Exit start port %d\n", port);

        /*
         * Make sure interface is not busy based on error and status
         * information from task file data register before proceeding
         */
        return wait_spinup(port_mmio);
}


static int ahci_device_data_io(struct ahci_uc_priv *uc_priv, u8 port, u8 *fis,
                               int fis_len, u8 *buf, int buf_len, u8 is_write)
{

        struct ahci_ioports *pp = &(uc_priv->port[port]);
        void __iomem *port_mmio = pp->port_mmio;
        u32 opts;
        u32 port_status;
        int sg_count;

        debug("Enter %s: for port %d\n", __func__, port);

        if (port > uc_priv->n_ports) {
                printf("Invalid port number %d\n", port);
                return -1;
        }

        port_status = readl(port_mmio + PORT_SCR_STAT);
        if ((port_status & 0xf) != 0x03) {
                debug("No Link on port %d!\n", port);
                return -1;
        }

        memcpy((unsigned char *)pp->cmd_tbl, fis, fis_len);

        sg_count = ahci_fill_sg(uc_priv, port, buf, buf_len);
        opts = (fis_len >> 2) | (sg_count << 16) | (is_write << 6);
        ahci_fill_cmd_slot(pp, opts);

        ahci_dcache_flush_sata_cmd(pp);
        ahci_dcache_flush_range((unsigned long)buf, (unsigned long)buf_len);

        writel_with_flush(1, port_mmio + PORT_CMD_ISSUE);

        if (waiting_for_cmd_completed(port_mmio + PORT_CMD_ISSUE,
                                WAIT_MS_DATAIO, 0x1)) {
                printf("timeout exit!\n");
                return -1;
        }

        ahci_dcache_invalidate_range((unsigned long)buf,
                                     (unsigned long)buf_len);
        debug("%s: %d byte transferred.\n", __func__, pp->cmd_slot->status);

        return 0;
}


static char *ata_id_strcpy(u16 *target, u16 *src, int len)
{
        int i;
        for (i = 0; i < len / 2; i++)
                target[i] = swab16(src[i]);
        return (char *)target;
}

/*
 * SCSI INQUIRY command operation.
 */
static int ata_scsiop_inquiry(struct ahci_uc_priv *uc_priv,
                              struct scsi_cmd *pccb)
{
        static const u8 hdr[] = {
                0,
                0,
                0x5,            /* claim SPC-3 version compatibility */
                2,
                95 - 4,
        };
        u8 fis[20];
        u16 *idbuf;
        ALLOC_CACHE_ALIGN_BUFFER(u16, tmpid, ATA_ID_WORDS);
        u8 port;

        /* Clean ccb data buffer */
        memset(pccb->pdata, 0, pccb->datalen);

        memcpy(pccb->pdata, hdr, sizeof(hdr));

        if (pccb->datalen <= 35)
                return 0;

        memset(fis, 0, sizeof(fis));
        /* Construct the FIS */
        fis[0] = 0x27;          /* Host to device FIS. */
        fis[1] = 1 << 7;        /* Command FIS. */
        fis[2] = ATA_CMD_ID_ATA; /* Command byte. */

        /* Read id from sata */
        port = pccb->target;

        if (ahci_device_data_io(uc_priv, port, (u8 *)&fis, sizeof(fis),
                                (u8 *)tmpid, ATA_ID_WORDS * 2, 0)) {
                debug("scsi_ahci: SCSI inquiry command failure.\n");
                return -EIO;
        }

        if (!uc_priv->ataid[port]) {
                uc_priv->ataid[port] = malloc(ATA_ID_WORDS * 2);
                if (!uc_priv->ataid[port]) {
                        printf("%s: No memory for ataid[port]\n", __func__);
                        return -ENOMEM;
                }
        }

        idbuf = uc_priv->ataid[port];

        memcpy(idbuf, tmpid, ATA_ID_WORDS * 2);
        ata_swap_buf_le16(idbuf, ATA_ID_WORDS);

        memcpy(&pccb->pdata[8], "ATA     ", 8);
        ata_id_strcpy((u16 *)&pccb->pdata[16], &idbuf[ATA_ID_PROD], 16);
        ata_id_strcpy((u16 *)&pccb->pdata[32], &idbuf[ATA_ID_FW_REV], 4);

#ifdef DEBUG
        ata_dump_id(idbuf);
#endif
        return 0;
}


/*
 * SCSI READ10/WRITE10 command operation.
 */
static int ata_scsiop_read_write(struct ahci_uc_priv *uc_priv,
                                 struct scsi_cmd *pccb, u8 is_write)
{
        lbaint_t lba = 0;
        u16 blocks = 0;
        u8 fis[20];
        u8 *user_buffer = pccb->pdata;
        u32 user_buffer_size = pccb->datalen;

        /* Retrieve the base LBA number from the ccb structure. */
        if (pccb->cmd[0] == SCSI_READ16) {
                memcpy(&lba, pccb->cmd + 2, 8);
                lba = be64_to_cpu(lba);
        } else {
                u32 temp;
                memcpy(&temp, pccb->cmd + 2, 4);
                lba = be32_to_cpu(temp);
        }

        /*
         * Retrieve the base LBA number and the block count from
         * the ccb structure.
         *
         * For 10-byte and 16-byte SCSI R/W commands, transfer
         * length 0 means transfer 0 block of data.
         * However, for ATA R/W commands, sector count 0 means
         * 256 or 65536 sectors, not 0 sectors as in SCSI.
         *
         * WARNING: one or two older ATA drives treat 0 as 0...
         */
        if (pccb->cmd[0] == SCSI_READ16)
                blocks = (((u16)pccb->cmd[13]) << 8) | ((u16) pccb->cmd[14]);
        else
                blocks = (((u16)pccb->cmd[7]) << 8) | ((u16) pccb->cmd[8]);

        debug("scsi_ahci: %s %u blocks starting from lba 0x" LBAFU "\n",
              is_write ?  "write" : "read", blocks, lba);

        /* Preset the FIS */
        memset(fis, 0, sizeof(fis));
        fis[0] = 0x27;           /* Host to device FIS. */
        fis[1] = 1 << 7;         /* Command FIS. */
        /* Command byte (read/write). */
        fis[2] = is_write ? ATA_CMD_WRITE_EXT : ATA_CMD_READ_EXT;

        while (blocks) {
                u16 now_blocks; /* number of blocks per iteration */
                u32 transfer_size; /* number of bytes per iteration */

                now_blocks = min((u16)MAX_SATA_BLOCKS_READ_WRITE, blocks);

                transfer_size = ATA_SECT_SIZE * now_blocks;
                if (transfer_size > user_buffer_size) {
                        printf("scsi_ahci: Error: buffer too small.\n");
                        return -EIO;
                }

                /*
                 * LBA48 SATA command but only use 32bit address range within
                 * that (unless we've enabled 64bit LBA support). The next
                 * smaller command range (28bit) is too small.
                 */
                fis[4] = (lba >> 0) & 0xff;
                fis[5] = (lba >> 8) & 0xff;
                fis[6] = (lba >> 16) & 0xff;
                fis[7] = 1 << 6; /* device reg: set LBA mode */
                fis[8] = ((lba >> 24) & 0xff);
#ifdef CONFIG_SYS_64BIT_LBA
                if (pccb->cmd[0] == SCSI_READ16) {
                        fis[9] = ((lba >> 32) & 0xff);
                        fis[10] = ((lba >> 40) & 0xff);
                }
#endif

                fis[3] = 0xe0; /* features */

                /* Block (sector) count */
                fis[12] = (now_blocks >> 0) & 0xff;
                fis[13] = (now_blocks >> 8) & 0xff;

                /* Read/Write from ahci */
                if (ahci_device_data_io(uc_priv, pccb->target, (u8 *)&fis,
                                        sizeof(fis), user_buffer, transfer_size,
                                        is_write)) {
                        debug("scsi_ahci: SCSI %s10 command failure.\n",
                              is_write ? "WRITE" : "READ");
                        return -EIO;
                }

                /* If this transaction is a write, do a following flush.
                 * Writes in u-boot are so rare, and the logic to know when is
                 * the last write and do a flush only there is sufficiently
                 * difficult. Just do a flush after every write. This incurs,
                 * usually, one extra flush when the rare writes do happen.
                 */
                if (is_write) {
                        if (-EIO == ata_io_flush(uc_priv, pccb->target))
                                return -EIO;
                }
                user_buffer += transfer_size;
                user_buffer_size -= transfer_size;
                blocks -= now_blocks;
                lba += now_blocks;
        }

        return 0;
}


/*
 * SCSI READ CAPACITY10 command operation.
 */
static int ata_scsiop_read_capacity10(struct ahci_uc_priv *uc_priv,
                                      struct scsi_cmd *pccb)
{
        u32 cap;
        u64 cap64;
        u32 block_size;

        if (!uc_priv->ataid[pccb->target]) {
                printf("scsi_ahci: SCSI READ CAPACITY10 command failure. "
                       "\tNo ATA info!\n"
                       "\tPlease run SCSI command INQUIRY first!\n");
                return -EPERM;
        }

        cap64 = ata_id_n_sectors(uc_priv->ataid[pccb->target]);
        if (cap64 > 0x100000000ULL)
                cap64 = 0xffffffff;

        cap = cpu_to_be32(cap64);
        memcpy(pccb->pdata, &cap, sizeof(cap));

        block_size = cpu_to_be32((u32)512);
        memcpy(&pccb->pdata[4], &block_size, 4);

        return 0;
}


/*
 * SCSI READ CAPACITY16 command operation.
 */
static int ata_scsiop_read_capacity16(struct ahci_uc_priv *uc_priv,
                                      struct scsi_cmd *pccb)
{
        u64 cap;
        u64 block_size;

        if (!uc_priv->ataid[pccb->target]) {
                printf("scsi_ahci: SCSI READ CAPACITY16 command failure. "
                       "\tNo ATA info!\n"
                       "\tPlease run SCSI command INQUIRY first!\n");
                return -EPERM;
        }

        cap = ata_id_n_sectors(uc_priv->ataid[pccb->target]);
        cap = cpu_to_be64(cap);
        memcpy(pccb->pdata, &cap, sizeof(cap));

        block_size = cpu_to_be64((u64)512);
        memcpy(&pccb->pdata[8], &block_size, 8);

        return 0;
}


/*
 * SCSI TEST UNIT READY command operation.
 */
static int ata_scsiop_test_unit_ready(struct ahci_uc_priv *uc_priv,
                                      struct scsi_cmd *pccb)
{
        return (uc_priv->ataid[pccb->target]) ? 0 : -EPERM;
}


static int ahci_scsi_exec(struct udevice *dev, struct scsi_cmd *pccb)
{
        struct ahci_uc_priv *uc_priv;
#ifdef CONFIG_DM_SCSI
        uc_priv = dev_get_uclass_priv(dev);
#else
        uc_priv = probe_ent;
#endif
        int ret;

        switch (pccb->cmd[0]) {
        case SCSI_READ16:
        case SCSI_READ10:
                ret = ata_scsiop_read_write(uc_priv, pccb, 0);
                break;
        case SCSI_WRITE10:
                ret = ata_scsiop_read_write(uc_priv, pccb, 1);
                break;
        case SCSI_RD_CAPAC10:
                ret = ata_scsiop_read_capacity10(uc_priv, pccb);
                break;
        case SCSI_RD_CAPAC16:
                ret = ata_scsiop_read_capacity16(uc_priv, pccb);
                break;
        case SCSI_TST_U_RDY:
                ret = ata_scsiop_test_unit_ready(uc_priv, pccb);
                break;
        case SCSI_INQUIRY:
                ret = ata_scsiop_inquiry(uc_priv, pccb);
                break;
        default:
                printf("Unsupport SCSI command 0x%02x\n", pccb->cmd[0]);
                return -ENOTSUPP;
        }

        if (ret) {
                debug("SCSI command 0x%02x ret errno %d\n", pccb->cmd[0], ret);
                return ret;
        }
        return 0;

}

static int ahci_start_ports(struct ahci_uc_priv *uc_priv)
{
        u32 linkmap;
        int i;

        linkmap = uc_priv->link_port_map;

        for (i = 0; i < CONFIG_SYS_SCSI_MAX_SCSI_ID; i++) {
                if (((linkmap >> i) & 0x01)) {
                        if (ahci_port_start(uc_priv, (u8) i)) {
                                printf("Can not start port %d\n", i);
                                continue;
                        }
                }
        }

        return 0;
}

#ifndef CONFIG_DM_SCSI
void scsi_low_level_init(int busdevfunc)
{
        struct ahci_uc_priv *uc_priv;

#ifndef CONFIG_SCSI_AHCI_PLAT
        probe_ent = calloc(1, sizeof(struct ahci_uc_priv));
        if (!probe_ent) {
                printf("%s: No memory for uc_priv\n", __func__);
                return;
        }
        uc_priv = probe_ent;
# if defined(CONFIG_DM_PCI)
        struct udevice *dev;
        int ret;

        ret = dm_pci_bus_find_bdf(busdevfunc, &dev);
        if (ret)
                return;
        ahci_init_one(uc_priv, dev);
# else
        ahci_init_one(uc_priv, busdevfunc);
# endif
#else
        uc_priv = probe_ent;
#endif

        ahci_start_ports(uc_priv);
}
#endif

#ifndef CONFIG_SCSI_AHCI_PLAT
# if defined(CONFIG_DM_PCI) || defined(CONFIG_DM_SCSI)
int ahci_init_one_dm(struct udevice *dev)
{
        struct ahci_uc_priv *uc_priv = dev_get_uclass_priv(dev);

        return ahci_init_one(uc_priv, dev);
}
#endif
#endif

int ahci_start_ports_dm(struct udevice *dev)
{
        struct ahci_uc_priv *uc_priv = dev_get_uclass_priv(dev);

        return ahci_start_ports(uc_priv);
}

#ifdef CONFIG_SCSI_AHCI_PLAT
static int ahci_init_common(struct ahci_uc_priv *uc_priv, void __iomem *base)
{
        int rc;

        uc_priv->host_flags = ATA_FLAG_SATA
                                | ATA_FLAG_NO_LEGACY
                                | ATA_FLAG_MMIO
                                | ATA_FLAG_PIO_DMA
                                | ATA_FLAG_NO_ATAPI;
        uc_priv->pio_mask = 0x1f;
        uc_priv->udma_mask = 0x7f;      /*Fixme,assume to support UDMA6 */

        uc_priv->mmio_base = base;

        /* initialize adapter */
        rc = ahci_host_init(uc_priv);
        if (rc)
                goto err_out;

        ahci_print_info(uc_priv);

        rc = ahci_start_ports(uc_priv);

err_out:
        return rc;
}

#ifndef CONFIG_DM_SCSI
int ahci_init(void __iomem *base)
{
        struct ahci_uc_priv *uc_priv;

        probe_ent = malloc(sizeof(struct ahci_uc_priv));
        if (!probe_ent) {
                printf("%s: No memory for uc_priv\n", __func__);
                return -ENOMEM;
        }

        uc_priv = probe_ent;
        memset(uc_priv, 0, sizeof(struct ahci_uc_priv));

        return ahci_init_common(uc_priv, base);
}
#endif

int ahci_init_dm(struct udevice *dev, void __iomem *base)
{
        struct ahci_uc_priv *uc_priv = dev_get_uclass_priv(dev);

        return ahci_init_common(uc_priv, base);
}

void __weak scsi_init(void)
{
}

#endif /* CONFIG_SCSI_AHCI_PLAT */

/*
 * In the general case of generic rotating media it makes sense to have a
 * flush capability. It probably even makes sense in the case of SSDs because
 * one cannot always know for sure what kind of internal cache/flush mechanism
 * is embodied therein. At first it was planned to invoke this after the last
 * write to disk and before rebooting. In practice, knowing, a priori, which
 * is the last write is difficult. Because writing to the disk in u-boot is
 * very rare, this flush command will be invoked after every block write.
 */
static int ata_io_flush(struct ahci_uc_priv *uc_priv, u8 port)
{
        u8 fis[20];
        struct ahci_ioports *pp = &(uc_priv->port[port]);
        void __iomem *port_mmio = pp->port_mmio;
        u32 cmd_fis_len = 5;    /* five dwords */

        /* Preset the FIS */
        memset(fis, 0, 20);
        fis[0] = 0x27;           /* Host to device FIS. */
        fis[1] = 1 << 7;         /* Command FIS. */
        fis[2] = ATA_CMD_FLUSH_EXT;

        memcpy((unsigned char *)pp->cmd_tbl, fis, 20);
        ahci_fill_cmd_slot(pp, cmd_fis_len);
        ahci_dcache_flush_sata_cmd(pp);
        writel_with_flush(1, port_mmio + PORT_CMD_ISSUE);

        if (waiting_for_cmd_completed(port_mmio + PORT_CMD_ISSUE,
                        WAIT_MS_FLUSH, 0x1)) {
                debug("scsi_ahci: flush command timeout on port %d.\n", port);
                return -EIO;
        }

        return 0;
}

static int ahci_scsi_bus_reset(struct udevice *dev)
{
        /* Not implemented */

        return 0;
}

#ifdef CONFIG_DM_SCSI
int ahci_bind_scsi(struct udevice *ahci_dev, struct udevice **devp)
{
        struct udevice *dev;
        int ret;

        ret = device_bind_driver(ahci_dev, "ahci_scsi", "ahci_scsi", &dev);
        if (ret)
                return ret;
        *devp = dev;

        return 0;
}

int ahci_probe_scsi(struct udevice *ahci_dev, ulong base)
{
        struct ahci_uc_priv *uc_priv;
        struct scsi_platdata *uc_plat;
        struct udevice *dev;
        int ret;

        device_find_first_child(ahci_dev, &dev);
        if (!dev)
                return -ENODEV;
        uc_plat = dev_get_uclass_platdata(dev);
        uc_plat->base = base;
        uc_plat->max_lun = 1;
        uc_plat->max_id = 2;

        uc_priv = dev_get_uclass_priv(ahci_dev);
        ret = ahci_init_one(uc_priv, dev);
        if (ret)
                return ret;
        ret = ahci_start_ports(uc_priv);
        if (ret)
                return ret;

        return 0;
}

#ifdef CONFIG_DM_PCI
int ahci_probe_scsi_pci(struct udevice *ahci_dev)
{
        ulong base;

        base = (ulong)dm_pci_map_bar(ahci_dev, PCI_BASE_ADDRESS_5,
                                     PCI_REGION_MEM);

        return ahci_probe_scsi(ahci_dev, base);
}
#endif

struct scsi_ops scsi_ops = {
        .exec           = ahci_scsi_exec,
        .bus_reset      = ahci_scsi_bus_reset,
};

U_BOOT_DRIVER(ahci_scsi) = {
        .name           = "ahci_scsi",
        .id             = UCLASS_SCSI,
        .ops            = &scsi_ops,
};
#else
int scsi_exec(struct udevice *dev, struct scsi_cmd *pccb)
{
        return ahci_scsi_exec(dev, pccb);
}

__weak int scsi_bus_reset(struct udevice *dev)
{
        return ahci_scsi_bus_reset(dev);

        return 0;
}
#endif