/*
 * Copyright (C) 2010-2011 Freescale Semiconductor, Inc.
 * Terry Lv <r65388@freescale.com>
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * 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 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc.
 *
 */

#include <libata.h>
#include <ahci.h>
#include <fis.h>

#include <common.h>
#include <malloc.h>
#include <linux/ctype.h>
#include <asm/errno.h>
#include <asm/io.h>
#include <linux/bitops.h>
#include <asm/arch/clock.h>
#include "dwc_ahsata.h"

struct sata_port_regs {
        u32 clb;
        u32 clbu;
        u32 fb;
        u32 fbu;
        u32 is;
        u32 ie;
        u32 cmd;
        u32 res1[1];
        u32 tfd;
        u32 sig;
        u32 ssts;
        u32 sctl;
        u32 serr;
        u32 sact;
        u32 ci;
        u32 sntf;
        u32 res2[1];
        u32 dmacr;
        u32 res3[1];
        u32 phycr;
        u32 physr;
};

struct sata_host_regs {
        u32 cap;
        u32 ghc;
        u32 is;
        u32 pi;
        u32 vs;
        u32 ccc_ctl;
        u32 ccc_ports;
        u32 res1[2];
        u32 cap2;
        u32 res2[30];
        u32 bistafr;
        u32 bistcr;
        u32 bistfctr;
        u32 bistsr;
        u32 bistdecr;
        u32 res3[2];
        u32 oobr;
        u32 res4[8];
        u32 timer1ms;
        u32 res5[1];
        u32 gparam1r;
        u32 gparam2r;
        u32 pparamr;
        u32 testr;
        u32 versionr;
        u32 idr;
};

#define MAX_DATA_BYTES_PER_SG  (4 * 1024 * 1024)
#define MAX_BYTES_PER_TRANS (AHCI_MAX_SG * MAX_DATA_BYTES_PER_SG)

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

static int is_ready;

static inline u32 ahci_port_base(u32 base, u32 port)
{
        return base + 0x100 + (port * 0x80);
}

static int waiting_for_cmd_completed(u8 *offset,
                                        int timeout_msec,
                                        u32 sign)
{
        int i;
        u32 status;

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

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

static int ahci_setup_oobr(struct ahci_probe_ent *probe_ent,
                                                int clk)
{
        struct sata_host_regs *host_mmio =
                (struct sata_host_regs *)probe_ent->mmio_base;

        writel(SATA_HOST_OOBR_WE, &(host_mmio->oobr));
        writel(0x02060b14, &(host_mmio->oobr));

        return 0;
}

static int ahci_host_init(struct ahci_probe_ent *probe_ent)
{
        u32 tmp, cap_save, num_ports;
        int i, j, timeout = 1000;
        struct sata_port_regs *port_mmio = NULL;
        struct sata_host_regs *host_mmio =
                (struct sata_host_regs *)probe_ent->mmio_base;
        int clk = mxc_get_clock(MXC_SATA_CLK);

        cap_save = readl(&(host_mmio->cap));
        cap_save |= SATA_HOST_CAP_SSS;

        /* global controller reset */
        tmp = readl(&(host_mmio->ghc));
        if ((tmp & SATA_HOST_GHC_HR) == 0)
                writel_with_flush(tmp | SATA_HOST_GHC_HR, &(host_mmio->ghc));

        while ((readl(&(host_mmio->ghc)) & SATA_HOST_GHC_HR)
                && --timeout)
                ;

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

        /* Set timer 1ms */
        writel(clk / 1000, &(host_mmio->timer1ms));

        ahci_setup_oobr(probe_ent, 0);

        writel_with_flush(SATA_HOST_GHC_AE, &(host_mmio->ghc));
        writel(cap_save, &(host_mmio->cap));
        num_ports = (cap_save & SATA_HOST_CAP_NP_MASK) + 1;
        writel_with_flush((1 << num_ports) - 1,
                                &(host_mmio->pi));

        /*
         * Determine which Ports are implemented by the DWC_ahsata,
         * by reading the PI register. This bit map value aids the
         * software to determine how many Ports are available and
         * which Port registers need to be initialized.
         */
        probe_ent->cap = readl(&(host_mmio->cap));
        probe_ent->port_map = readl(&(host_mmio->pi));

        /* Determine how many command slots the HBA supports */
        probe_ent->n_ports =
                (probe_ent->cap & SATA_HOST_CAP_NP_MASK) + 1;

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

        for (i = 0; i < probe_ent->n_ports; i++) {
                probe_ent->port[i].port_mmio =
                        ahci_port_base((u32)host_mmio, i);
                port_mmio =
                        (struct sata_port_regs *)probe_ent->port[i].port_mmio;

                /* Ensure that the DWC_ahsata is in idle state */
                tmp = readl(&(port_mmio->cmd));

                /*
                 * When P#CMD.ST, P#CMD.CR, P#CMD.FRE and P#CMD.FR
                 * are all cleared, the Port is in an idle state.
                 */
                if (tmp & (SATA_PORT_CMD_CR | SATA_PORT_CMD_FR |
                        SATA_PORT_CMD_FRE | SATA_PORT_CMD_ST)) {

                        /*
                         * System software places a Port into the idle state by
                         * clearing P#CMD.ST and waiting for P#CMD.CR to return
                         * 0 when read.
                         */
                        tmp &= ~SATA_PORT_CMD_ST;
                        writel_with_flush(tmp, &(port_mmio->cmd));

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

                        timeout = 1000;
                        while ((readl(&(port_mmio->cmd)) & SATA_PORT_CMD_CR)
                                && --timeout)
                                ;

                        if (timeout <= 0) {
                                debug("port reset failed (0x%x)\n", tmp);
                                return -1;
                        }
                }

                /* Spin-up device */
                tmp = readl(&(port_mmio->cmd));
                writel((tmp | SATA_PORT_CMD_SUD), &(port_mmio->cmd));

                /* Wait for spin-up to finish */
                timeout = 1000;
                while (!(readl(&(port_mmio->cmd)) | SATA_PORT_CMD_SUD)
                        && --timeout)
                        ;
                if (timeout <= 0) {
                        debug("Spin-Up can't finish!\n");
                        return -1;
                }

                for (j = 0; j < 100; ++j) {
                        mdelay(10);
                        tmp = readl(&(port_mmio->ssts));
                        if (((tmp & SATA_PORT_SSTS_DET_MASK) == 0x3) ||
                                ((tmp & SATA_PORT_SSTS_DET_MASK) == 0x1))
                                break;
                }

                /* Wait for COMINIT bit 26 (DIAG_X) in SERR */
                timeout = 1000;
                while (!(readl(&(port_mmio->serr)) | SATA_PORT_SERR_DIAG_X)
                        && --timeout)
                        ;
                if (timeout <= 0) {
                        debug("Can't find DIAG_X set!\n");
                        return -1;
                }

                /*
                 * For each implemented Port, clear the P#SERR
                 * register, by writing ones to each implemented\
                 * bit location.
                 */
                tmp = readl(&(port_mmio->serr));
                debug("P#SERR 0x%x\n",
                                tmp);
                writel(tmp, &(port_mmio->serr));

                /* Ack any pending irq events for this port */
                tmp = readl(&(host_mmio->is));
                debug("IS 0x%x\n", tmp);
                if (tmp)
                        writel(tmp, &(host_mmio->is));

                writel(1 << i, &(host_mmio->is));

                /* set irq mask (enables interrupts) */
                writel(DEF_PORT_IRQ, &(port_mmio->ie));

                /* register linkup ports */
                tmp = readl(&(port_mmio->ssts));
                debug("Port %d status: 0x%x\n", i, tmp);
                if ((tmp & SATA_PORT_SSTS_DET_MASK) == 0x03)
                        probe_ent->link_port_map |= (0x01 << i);
        }

        tmp = readl(&(host_mmio->ghc));
        debug("GHC 0x%x\n", tmp);
        writel(tmp | SATA_HOST_GHC_IE, &(host_mmio->ghc));
        tmp = readl(&(host_mmio->ghc));
        debug("GHC 0x%x\n", tmp);

        return 0;
}

static void ahci_print_info(struct ahci_probe_ent *probe_ent)
{
        struct sata_host_regs *host_mmio =
                (struct sata_host_regs *)probe_ent->mmio_base;
        u32 vers, cap, impl, speed;
        const char *speed_s;
        const char *scc_s;

        vers = readl(&(host_mmio->vs));
        cap = probe_ent->cap;
        impl = probe_ent->port_map;

        speed = (cap & SATA_HOST_CAP_ISS_MASK)
                >> SATA_HOST_CAP_ISS_OFFSET;
        if (speed == 1)
                speed_s = "1.5";
        else if (speed == 2)
                speed_s = "3";
        else
                speed_s = "?";

        scc_s = "SATA";

        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\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 << 15) ? "pio " : "",
                cap & (1 << 14) ? "slum " : "",
                cap & (1 << 13) ? "part " : "");
}

static int ahci_init_one(int pdev)
{
        int rc;
        struct ahci_probe_ent *probe_ent = NULL;

        probe_ent = malloc(sizeof(struct ahci_probe_ent));
        memset(probe_ent, 0, sizeof(struct ahci_probe_ent));
        probe_ent->dev = pdev;

        probe_ent->host_flags = ATA_FLAG_SATA
                                | ATA_FLAG_NO_LEGACY
                                | ATA_FLAG_MMIO
                                | ATA_FLAG_PIO_DMA
                                | ATA_FLAG_NO_ATAPI;

        probe_ent->mmio_base = CONFIG_DWC_AHSATA_BASE_ADDR;

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

        ahci_print_info(probe_ent);

        /* Save the private struct to block device struct */
        sata_dev_desc[pdev].priv = (void *)probe_ent;

        return 0;

err_out:
        return rc;
}

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

        max_bytes = MAX_DATA_BYTES_PER_SG;
        sg_count = ((buf_len - 1) / max_bytes) + 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((u32)buf + i * max_bytes);
                ahci_sg->addr_hi = 0;
                ahci_sg->flags_size = cpu_to_le32(0x3fffff &
                                        (buf_len < max_bytes
                                        ? (buf_len - 1)
                                        : (max_bytes - 1)));
                ahci_sg++;
                buf_len -= max_bytes;
        }

        return sg_count;
}

static void ahci_fill_cmd_slot(struct ahci_ioports *pp, u32 cmd_slot, u32 opts)
{
        struct ahci_cmd_hdr *cmd_hdr = (struct ahci_cmd_hdr *)(pp->cmd_slot +
                                        AHCI_CMD_SLOT_SZ * cmd_slot);

        memset(cmd_hdr, 0, AHCI_CMD_SLOT_SZ);
        cmd_hdr->opts = cpu_to_le32(opts);
        cmd_hdr->status = 0;
        cmd_hdr->tbl_addr = cpu_to_le32(pp->cmd_tbl & 0xffffffff);
        cmd_hdr->tbl_addr_hi = 0;
}

#define AHCI_GET_CMD_SLOT(c) ((c) ? ffs(c) : 0)

static int ahci_exec_ata_cmd(struct ahci_probe_ent *probe_ent,
                u8 port, struct sata_fis_h2d *cfis,
                u8 *buf, u32 buf_len, s32 is_write)
{
        struct ahci_ioports *pp = &(probe_ent->port[port]);
        struct sata_port_regs *port_mmio =
                        (struct sata_port_regs *)pp->port_mmio;
        u32 opts;
        int sg_count = 0, cmd_slot = 0;

        cmd_slot = AHCI_GET_CMD_SLOT(readl(&(port_mmio->ci)));
        if (32 == cmd_slot) {
                printf("Can't find empty command slot!\n");
                return 0;
        }

        /* Check xfer length */
        if (buf_len > MAX_BYTES_PER_TRANS) {
                printf("Max transfer length is %dB\n\r",
                        MAX_BYTES_PER_TRANS);
                return 0;
        }

        memcpy((u8 *)(pp->cmd_tbl), cfis, sizeof(struct sata_fis_h2d));
        if (buf && buf_len)
                sg_count = ahci_fill_sg(probe_ent, port, buf, buf_len);
        opts = (sizeof(struct sata_fis_h2d) >> 2) | (sg_count << 16);
        if (is_write)
                opts |= 0x40;
        ahci_fill_cmd_slot(pp, cmd_slot, opts);

        writel_with_flush(1 << cmd_slot, &(port_mmio->ci));

        if (waiting_for_cmd_completed((u8 *)&(port_mmio->ci),
                                10000, 0x1 << cmd_slot)) {
                printf("timeout exit!\n");
                return -1;
        }
        debug("ahci_exec_ata_cmd: %d byte transferred.\n",
              pp->cmd_slot->status);

        return buf_len;
}

static void ahci_set_feature(u8 dev, u8 port)
{
        struct ahci_probe_ent *probe_ent =
                (struct ahci_probe_ent *)sata_dev_desc[dev].priv;
        struct sata_fis_h2d h2d, *cfis = &h2d;

        memset(cfis, 0, sizeof(struct sata_fis_h2d));
        cfis->fis_type = SATA_FIS_TYPE_REGISTER_H2D;
        cfis->pm_port_c = 1 << 7;
        cfis->command = ATA_CMD_SET_FEATURES;
        cfis->features = SETFEATURES_XFER;
        cfis->sector_count = ffs(probe_ent->udma_mask + 1) + 0x3e;

        ahci_exec_ata_cmd(probe_ent, port, cfis, NULL, 0, READ_CMD);
}

static int ahci_port_start(struct ahci_probe_ent *probe_ent,
                                        u8 port)
{
        struct ahci_ioports *pp = &(probe_ent->port[port]);
        struct sata_port_regs *port_mmio =
                (struct sata_port_regs *)pp->port_mmio;
        u32 port_status;
        u32 mem;
        int timeout = 10000000;

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

        mem = (u32)malloc(AHCI_PORT_PRIV_DMA_SZ + 1024);
        if (!mem) {
                free(pp);
                printf("No mem for table!\n");
                return -ENOMEM;
        }

        mem = (mem + 0x400) & (~0x3ff); /* Aligned to 1024-bytes */
        memset((u8 *)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 *)mem;
        debug("cmd_slot = 0x%x\n", (unsigned int) pp->cmd_slot);
        mem += (AHCI_CMD_SLOT_SZ * DWC_AHSATA_MAX_CMD_SLOTS);

        /*
         * Second item: Received-FIS area, 256-Byte aligned
         */
        pp->rx_fis = mem;
        mem += AHCI_RX_FIS_SZ;

        /*
         * Third item: data area for storing a single command
         * and its scatter-gather table
         */
        pp->cmd_tbl = mem;
        debug("cmd_tbl_dma = 0x%x\n", pp->cmd_tbl);

        mem += AHCI_CMD_TBL_HDR;

        writel_with_flush(0x00004444, &(port_mmio->dmacr));
        pp->cmd_tbl_sg = (struct ahci_sg *)mem;
        writel_with_flush((u32)pp->cmd_slot, &(port_mmio->clb));
        writel_with_flush(pp->rx_fis, &(port_mmio->fb));

        /* Enable FRE */
        writel_with_flush((SATA_PORT_CMD_FRE | readl(&(port_mmio->cmd))),
                        &(port_mmio->cmd));

        /* Wait device ready */
        while ((readl(&(port_mmio->tfd)) & (SATA_PORT_TFD_STS_ERR |
                SATA_PORT_TFD_STS_DRQ | SATA_PORT_TFD_STS_BSY))
                && --timeout)
                ;
        if (timeout <= 0) {
                debug("Device not ready for BSY, DRQ and"
                        "ERR in TFD!\n");
                return -1;
        }

        writel_with_flush(PORT_CMD_ICC_ACTIVE | PORT_CMD_FIS_RX |
                          PORT_CMD_POWER_ON | PORT_CMD_SPIN_UP |
                          PORT_CMD_START, &(port_mmio->cmd));

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

        return 0;
}

int init_sata(int dev)
{
        int i;
        u32 linkmap;
        struct ahci_probe_ent *probe_ent = NULL;

        if (dev < 0 || dev > (CONFIG_SYS_SATA_MAX_DEVICE - 1)) {
                printf("The sata index %d is out of ranges\n\r", dev);
                return -1;
        }

        ahci_init_one(dev);

        probe_ent = (struct ahci_probe_ent *)sata_dev_desc[dev].priv;
        linkmap = probe_ent->link_port_map;

        if (0 == linkmap) {
                printf("No port device detected!\n");
                return 1;
        }

        for (i = 0; i < probe_ent->n_ports; i++) {
                if ((linkmap >> i) && ((linkmap >> i) & 0x01)) {
                        if (ahci_port_start(probe_ent, (u8)i)) {
                                printf("Can not start port %d\n", i);
                                return 1;
                        }
                        probe_ent->hard_port_no = i;
                        break;
                }
        }

        return 0;
}

static void dwc_ahsata_print_info(int dev)
{
        block_dev_desc_t *pdev = &(sata_dev_desc[dev]);

        printf("SATA Device Info:\n\r");
#ifdef CONFIG_SYS_64BIT_LBA
        printf("S/N: %s\n\rProduct model number: %s\n\r"
                "Firmware version: %s\n\rCapacity: %lld sectors\n\r",
                pdev->product, pdev->vendor, pdev->revision, pdev->lba);
#else
        printf("S/N: %s\n\rProduct model number: %s\n\r"
                "Firmware version: %s\n\rCapacity: %ld sectors\n\r",
                pdev->product, pdev->vendor, pdev->revision, pdev->lba);
#endif
}

static void dwc_ahsata_identify(int dev, u16 *id)
{
        struct ahci_probe_ent *probe_ent =
                (struct ahci_probe_ent *)sata_dev_desc[dev].priv;
        struct sata_fis_h2d h2d, *cfis = &h2d;
        u8 port = probe_ent->hard_port_no;

        memset(cfis, 0, sizeof(struct sata_fis_h2d));

        cfis->fis_type = SATA_FIS_TYPE_REGISTER_H2D;
        cfis->pm_port_c = 0x80; /* is command */
        cfis->command = ATA_CMD_ID_ATA;

        ahci_exec_ata_cmd(probe_ent, port, cfis,
                        (u8 *)id, ATA_ID_WORDS * 2, READ_CMD);
        ata_swap_buf_le16(id, ATA_ID_WORDS);
}

static void dwc_ahsata_xfer_mode(int dev, u16 *id)
{
        struct ahci_probe_ent *probe_ent =
                (struct ahci_probe_ent *)sata_dev_desc[dev].priv;

        probe_ent->pio_mask = id[ATA_ID_PIO_MODES];
        probe_ent->udma_mask = id[ATA_ID_UDMA_MODES];
        debug("pio %04x, udma %04x\n\r",
                probe_ent->pio_mask, probe_ent->udma_mask);
}

static u32 dwc_ahsata_rw_cmd(int dev, u32 start, u32 blkcnt,
                                u8 *buffer, int is_write)
{
        struct ahci_probe_ent *probe_ent =
                (struct ahci_probe_ent *)sata_dev_desc[dev].priv;
        struct sata_fis_h2d h2d, *cfis = &h2d;
        u8 port = probe_ent->hard_port_no;
        u32 block;

        block = start;

        memset(cfis, 0, sizeof(struct sata_fis_h2d));

        cfis->fis_type = SATA_FIS_TYPE_REGISTER_H2D;
        cfis->pm_port_c = 0x80; /* is command */
        cfis->command = (is_write) ? ATA_CMD_WRITE : ATA_CMD_READ;
        cfis->device = ATA_LBA;

        cfis->device |= (block >> 24) & 0xf;
        cfis->lba_high = (block >> 16) & 0xff;
        cfis->lba_mid = (block >> 8) & 0xff;
        cfis->lba_low = block & 0xff;
        cfis->sector_count = (u8)(blkcnt & 0xff);

        if (ahci_exec_ata_cmd(probe_ent, port, cfis,
                        buffer, ATA_SECT_SIZE * blkcnt, is_write) > 0)
                return blkcnt;
        else
                return 0;
}

void dwc_ahsata_flush_cache(int dev)
{
        struct ahci_probe_ent *probe_ent =
                (struct ahci_probe_ent *)sata_dev_desc[dev].priv;
        struct sata_fis_h2d h2d, *cfis = &h2d;
        u8 port = probe_ent->hard_port_no;

        memset(cfis, 0, sizeof(struct sata_fis_h2d));

        cfis->fis_type = SATA_FIS_TYPE_REGISTER_H2D;
        cfis->pm_port_c = 0x80; /* is command */
        cfis->command = ATA_CMD_FLUSH;

        ahci_exec_ata_cmd(probe_ent, port, cfis, NULL, 0, 0);
}

static u32 dwc_ahsata_rw_cmd_ext(int dev, u32 start, lbaint_t blkcnt,
                                u8 *buffer, int is_write)
{
        struct ahci_probe_ent *probe_ent =
                (struct ahci_probe_ent *)sata_dev_desc[dev].priv;
        struct sata_fis_h2d h2d, *cfis = &h2d;
        u8 port = probe_ent->hard_port_no;
        u64 block;

        block = (u64)start;

        memset(cfis, 0, sizeof(struct sata_fis_h2d));

        cfis->fis_type = SATA_FIS_TYPE_REGISTER_H2D;
        cfis->pm_port_c = 0x80; /* is command */

        cfis->command = (is_write) ? ATA_CMD_WRITE_EXT
                                 : ATA_CMD_READ_EXT;

        cfis->lba_high_exp = (block >> 40) & 0xff;
        cfis->lba_mid_exp = (block >> 32) & 0xff;
        cfis->lba_low_exp = (block >> 24) & 0xff;
        cfis->lba_high = (block >> 16) & 0xff;
        cfis->lba_mid = (block >> 8) & 0xff;
        cfis->lba_low = block & 0xff;
        cfis->device = ATA_LBA;
        cfis->sector_count_exp = (blkcnt >> 8) & 0xff;
        cfis->sector_count = blkcnt & 0xff;

        if (ahci_exec_ata_cmd(probe_ent, port, cfis, buffer,
                        ATA_SECT_SIZE * blkcnt, is_write) > 0)
                return blkcnt;
        else
                return 0;
}

u32 dwc_ahsata_rw_ncq_cmd(int dev, u32 start, lbaint_t blkcnt,
                                u8 *buffer, int is_write)
{
        struct ahci_probe_ent *probe_ent =
                (struct ahci_probe_ent *)sata_dev_desc[dev].priv;
        struct sata_fis_h2d h2d, *cfis = &h2d;
        u8 port = probe_ent->hard_port_no;
        u64 block;

        if (sata_dev_desc[dev].lba48 != 1) {
                printf("execute FPDMA command on non-LBA48 hard disk\n\r");
                return -1;
        }

        block = (u64)start;

        memset(cfis, 0, sizeof(struct sata_fis_h2d));

        cfis->fis_type = SATA_FIS_TYPE_REGISTER_H2D;
        cfis->pm_port_c = 0x80; /* is command */

        cfis->command = (is_write) ? ATA_CMD_FPDMA_WRITE
                                 : ATA_CMD_FPDMA_READ;

        cfis->lba_high_exp = (block >> 40) & 0xff;
        cfis->lba_mid_exp = (block >> 32) & 0xff;
        cfis->lba_low_exp = (block >> 24) & 0xff;
        cfis->lba_high = (block >> 16) & 0xff;
        cfis->lba_mid = (block >> 8) & 0xff;
        cfis->lba_low = block & 0xff;

        cfis->device = ATA_LBA;
        cfis->features_exp = (blkcnt >> 8) & 0xff;
        cfis->features = blkcnt & 0xff;

        /* Use the latest queue */
        ahci_exec_ata_cmd(probe_ent, port, cfis,
                        buffer, ATA_SECT_SIZE * blkcnt, is_write);

        return blkcnt;
}

void dwc_ahsata_flush_cache_ext(int dev)
{
        struct ahci_probe_ent *probe_ent =
                (struct ahci_probe_ent *)sata_dev_desc[dev].priv;
        struct sata_fis_h2d h2d, *cfis = &h2d;
        u8 port = probe_ent->hard_port_no;

        memset(cfis, 0, sizeof(struct sata_fis_h2d));

        cfis->fis_type = SATA_FIS_TYPE_REGISTER_H2D;
        cfis->pm_port_c = 0x80; /* is command */
        cfis->command = ATA_CMD_FLUSH_EXT;

        ahci_exec_ata_cmd(probe_ent, port, cfis, NULL, 0, 0);
}

static void dwc_ahsata_init_wcache(int dev, u16 *id)
{
        struct ahci_probe_ent *probe_ent =
                (struct ahci_probe_ent *)sata_dev_desc[dev].priv;

        if (ata_id_has_wcache(id) && ata_id_wcache_enabled(id))
                probe_ent->flags |= SATA_FLAG_WCACHE;
        if (ata_id_has_flush(id))
                probe_ent->flags |= SATA_FLAG_FLUSH;
        if (ata_id_has_flush_ext(id))
                probe_ent->flags |= SATA_FLAG_FLUSH_EXT;
}

u32 ata_low_level_rw_lba48(int dev, u32 blknr, lbaint_t blkcnt,
                                void *buffer, int is_write)
{
        u32 start, blks;
        u8 *addr;
        int max_blks;

        start = blknr;
        blks = blkcnt;
        addr = (u8 *)buffer;

        max_blks = ATA_MAX_SECTORS_LBA48;

        do {
                if (blks > max_blks) {
                        if (max_blks != dwc_ahsata_rw_cmd_ext(dev, start,
                                                max_blks, addr, is_write))
                                return 0;
                        start += max_blks;
                        blks -= max_blks;
                        addr += ATA_SECT_SIZE * max_blks;
                } else {
                        if (blks != dwc_ahsata_rw_cmd_ext(dev, start,
                                                blks, addr, is_write))
                                return 0;
                        start += blks;
                        blks = 0;
                        addr += ATA_SECT_SIZE * blks;
                }
        } while (blks != 0);

        return blkcnt;
}

u32 ata_low_level_rw_lba28(int dev, u32 blknr, lbaint_t blkcnt,
                                void *buffer, int is_write)
{
        u32 start, blks;
        u8 *addr;
        int max_blks;

        start = blknr;
        blks = blkcnt;
        addr = (u8 *)buffer;

        max_blks = ATA_MAX_SECTORS;
        do {
                if (blks > max_blks) {
                        if (max_blks != dwc_ahsata_rw_cmd(dev, start,
                                                max_blks, addr, is_write))
                                return 0;
                        start += max_blks;
                        blks -= max_blks;
                        addr += ATA_SECT_SIZE * max_blks;
                } else {
                        if (blks != dwc_ahsata_rw_cmd(dev, start,
                                                blks, addr, is_write))
                                return 0;
                        start += blks;
                        blks = 0;
                        addr += ATA_SECT_SIZE * blks;
                }
        } while (blks != 0);

        return blkcnt;
}

/*
 * SATA interface between low level driver and command layer
 */
ulong sata_read(int dev, unsigned long blknr, lbaint_t blkcnt, void *buffer)
{
        u32 rc;

        if (sata_dev_desc[dev].lba48)
                rc = ata_low_level_rw_lba48(dev, blknr, blkcnt,
                                                buffer, READ_CMD);
        else
                rc = ata_low_level_rw_lba28(dev, blknr, blkcnt,
                                                buffer, READ_CMD);
        return rc;
}

ulong sata_write(int dev, unsigned long blknr, lbaint_t blkcnt, void *buffer)
{
        u32 rc;
        struct ahci_probe_ent *probe_ent =
                (struct ahci_probe_ent *)sata_dev_desc[dev].priv;
        u32 flags = probe_ent->flags;

        if (sata_dev_desc[dev].lba48) {
                rc = ata_low_level_rw_lba48(dev, blknr, blkcnt,
                                                buffer, WRITE_CMD);
                if ((flags & SATA_FLAG_WCACHE) &&
                        (flags & SATA_FLAG_FLUSH_EXT))
                        dwc_ahsata_flush_cache_ext(dev);
        } else {
                rc = ata_low_level_rw_lba28(dev, blknr, blkcnt,
                                                buffer, WRITE_CMD);
                if ((flags & SATA_FLAG_WCACHE) &&
                        (flags & SATA_FLAG_FLUSH))
                        dwc_ahsata_flush_cache(dev);
        }
        return rc;
}

int scan_sata(int dev)
{
        u8 serial[ATA_ID_SERNO_LEN + 1] = { 0 };
        u8 firmware[ATA_ID_FW_REV_LEN + 1] = { 0 };
        u8 product[ATA_ID_PROD_LEN + 1] = { 0 };
        u16 *id;
        u64 n_sectors;
        struct ahci_probe_ent *probe_ent =
                (struct ahci_probe_ent *)sata_dev_desc[dev].priv;
        u8 port = probe_ent->hard_port_no;
        block_dev_desc_t *pdev = &(sata_dev_desc[dev]);

        id = (u16 *)malloc(ATA_ID_WORDS * 2);
        if (!id) {
                printf("id malloc failed\n\r");
                return -1;
        }

        /* Identify device to get information */
        dwc_ahsata_identify(dev, id);

        /* Serial number */
        ata_id_c_string(id, serial, ATA_ID_SERNO, sizeof(serial));
        memcpy(pdev->product, serial, sizeof(serial));

        /* Firmware version */
        ata_id_c_string(id, firmware, ATA_ID_FW_REV, sizeof(firmware));
        memcpy(pdev->revision, firmware, sizeof(firmware));

        /* Product model */
        ata_id_c_string(id, product, ATA_ID_PROD, sizeof(product));
        memcpy(pdev->vendor, product, sizeof(product));

        /* Totoal sectors */
        n_sectors = ata_id_n_sectors(id);
        pdev->lba = (u32)n_sectors;

        pdev->type = DEV_TYPE_HARDDISK;
        pdev->blksz = ATA_SECT_SIZE;
        pdev->lun = 0 ;

        /* Check if support LBA48 */
        if (ata_id_has_lba48(id)) {
                pdev->lba48 = 1;
                debug("Device support LBA48\n\r");
        }

        /* Get the NCQ queue depth from device */
        probe_ent->flags &= (~SATA_FLAG_Q_DEP_MASK);
        probe_ent->flags |= ata_id_queue_depth(id);

        /* Get the xfer mode from device */
        dwc_ahsata_xfer_mode(dev, id);

        /* Get the write cache status from device */
        dwc_ahsata_init_wcache(dev, id);

        /* Set the xfer mode to highest speed */
        ahci_set_feature(dev, port);

        free((void *)id);

        dwc_ahsata_print_info(dev);

        is_ready = 1;

        return 0;
}