/*
 *  acard-ahci.c - ACard AHCI SATA support
 *
 *  Maintained by:  Tejun Heo <tj@kernel.org>
 *                  Please ALWAYS copy linux-ide@vger.kernel.org
 *                  on emails.
 *
 *  Copyright 2010 Red Hat, Inc.
 *
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2, or (at your option)
 *  any later version.
 *
 *  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; see the file COPYING.  If not, write to
 *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 *
 * libata documentation is available via 'make {ps|pdf}docs',
 * as Documentation/driver-api/libata.rst
 *
 * AHCI hardware documentation:
 * http://www.intel.com/technology/serialata/pdf/rev1_0.pdf
 * http://www.intel.com/technology/serialata/pdf/rev1_1.pdf
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/blkdev.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/dma-mapping.h>
#include <linux/device.h>
#include <linux/dmi.h>
#include <linux/gfp.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_cmnd.h>
#include <linux/libata.h>
#include "ahci.h"

#define DRV_NAME        "acard-ahci"
#define DRV_VERSION     "1.0"

/*
  Received FIS structure limited to 80h.
*/

#define ACARD_AHCI_RX_FIS_SZ 128

enum {
        AHCI_PCI_BAR            = 5,
};

enum board_ids {
        board_acard_ahci,
};

struct acard_sg {
        __le32                  addr;
        __le32                  addr_hi;
        __le32                  reserved;
        __le32                  size;    /* bit 31 (EOT) max==0x10000 (64k) */
};

static void acard_ahci_qc_prep(struct ata_queued_cmd *qc);
static bool acard_ahci_qc_fill_rtf(struct ata_queued_cmd *qc);
static int acard_ahci_port_start(struct ata_port *ap);
static int acard_ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent);

#ifdef CONFIG_PM_SLEEP
static int acard_ahci_pci_device_suspend(struct pci_dev *pdev, pm_message_t mesg);
static int acard_ahci_pci_device_resume(struct pci_dev *pdev);
#endif

static struct scsi_host_template acard_ahci_sht = {
        AHCI_SHT("acard-ahci"),
};

static struct ata_port_operations acard_ops = {
        .inherits               = &ahci_ops,
        .qc_prep                = acard_ahci_qc_prep,
        .qc_fill_rtf            = acard_ahci_qc_fill_rtf,
        .port_start             = acard_ahci_port_start,
};

#define AHCI_HFLAGS(flags)      .private_data   = (void *)(flags)

static const struct ata_port_info acard_ahci_port_info[] = {
        [board_acard_ahci] =
        {
                AHCI_HFLAGS     (AHCI_HFLAG_NO_NCQ),
                .flags          = AHCI_FLAG_COMMON,
                .pio_mask       = ATA_PIO4,
                .udma_mask      = ATA_UDMA6,
                .port_ops       = &acard_ops,
        },
};

static const struct pci_device_id acard_ahci_pci_tbl[] = {
        /* ACard */
        { PCI_VDEVICE(ARTOP, 0x000d), board_acard_ahci }, /* ATP8620 */

        { }    /* terminate list */
};

static struct pci_driver acard_ahci_pci_driver = {
        .name                   = DRV_NAME,
        .id_table               = acard_ahci_pci_tbl,
        .probe                  = acard_ahci_init_one,
        .remove                 = ata_pci_remove_one,
#ifdef CONFIG_PM_SLEEP
        .suspend                = acard_ahci_pci_device_suspend,
        .resume                 = acard_ahci_pci_device_resume,
#endif
};

#ifdef CONFIG_PM_SLEEP
static int acard_ahci_pci_device_suspend(struct pci_dev *pdev, pm_message_t mesg)
{
        struct ata_host *host = pci_get_drvdata(pdev);
        struct ahci_host_priv *hpriv = host->private_data;
        void __iomem *mmio = hpriv->mmio;
        u32 ctl;

        if (mesg.event & PM_EVENT_SUSPEND &&
            hpriv->flags & AHCI_HFLAG_NO_SUSPEND) {
                dev_err(&pdev->dev,
                        "BIOS update required for suspend/resume\n");
                return -EIO;
        }

        if (mesg.event & PM_EVENT_SLEEP) {
                /* AHCI spec rev1.1 section 8.3.3:
                 * Software must disable interrupts prior to requesting a
                 * transition of the HBA to D3 state.
                 */
                ctl = readl(mmio + HOST_CTL);
                ctl &= ~HOST_IRQ_EN;
                writel(ctl, mmio + HOST_CTL);
                readl(mmio + HOST_CTL); /* flush */
        }

        return ata_pci_device_suspend(pdev, mesg);
}

static int acard_ahci_pci_device_resume(struct pci_dev *pdev)
{
        struct ata_host *host = pci_get_drvdata(pdev);
        int rc;

        rc = ata_pci_device_do_resume(pdev);
        if (rc)
                return rc;

        if (pdev->dev.power.power_state.event == PM_EVENT_SUSPEND) {
                rc = ahci_reset_controller(host);
                if (rc)
                        return rc;

                ahci_init_controller(host);
        }

        ata_host_resume(host);

        return 0;
}
#endif

static int acard_ahci_configure_dma_masks(struct pci_dev *pdev, int using_dac)
{
        int rc;

        if (using_dac &&
            !dma_set_mask(&pdev->dev, DMA_BIT_MASK(64))) {
                rc = dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(64));
                if (rc) {
                        rc = dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(32));
                        if (rc) {
                                dev_err(&pdev->dev,
                                           "64-bit DMA enable failed\n");
                                return rc;
                        }
                }
        } else {
                rc = dma_set_mask(&pdev->dev, DMA_BIT_MASK(32));
                if (rc) {
                        dev_err(&pdev->dev, "32-bit DMA enable failed\n");
                        return rc;
                }
                rc = dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(32));
                if (rc) {
                        dev_err(&pdev->dev,
                                "32-bit consistent DMA enable failed\n");
                        return rc;
                }
        }
        return 0;
}

static void acard_ahci_pci_print_info(struct ata_host *host)
{
        struct pci_dev *pdev = to_pci_dev(host->dev);
        u16 cc;
        const char *scc_s;

        pci_read_config_word(pdev, 0x0a, &cc);
        if (cc == PCI_CLASS_STORAGE_IDE)
                scc_s = "IDE";
        else if (cc == PCI_CLASS_STORAGE_SATA)
                scc_s = "SATA";
        else if (cc == PCI_CLASS_STORAGE_RAID)
                scc_s = "RAID";
        else
                scc_s = "unknown";

        ahci_print_info(host, scc_s);
}

static unsigned int acard_ahci_fill_sg(struct ata_queued_cmd *qc, void *cmd_tbl)
{
        struct scatterlist *sg;
        struct acard_sg *acard_sg = cmd_tbl + AHCI_CMD_TBL_HDR_SZ;
        unsigned int si, last_si = 0;

        VPRINTK("ENTER\n");

        /*
         * Next, the S/G list.
         */
        for_each_sg(qc->sg, sg, qc->n_elem, si) {
                dma_addr_t addr = sg_dma_address(sg);
                u32 sg_len = sg_dma_len(sg);

                /*
                 * ACard note:
                 * We must set an end-of-table (EOT) bit,
                 * and the segment cannot exceed 64k (0x10000)
                 */
                acard_sg[si].addr = cpu_to_le32(addr & 0xffffffff);
                acard_sg[si].addr_hi = cpu_to_le32((addr >> 16) >> 16);
                acard_sg[si].size = cpu_to_le32(sg_len);
                last_si = si;
        }

        acard_sg[last_si].size |= cpu_to_le32(1 << 31); /* set EOT */

        return si;
}

static void acard_ahci_qc_prep(struct ata_queued_cmd *qc)
{
        struct ata_port *ap = qc->ap;
        struct ahci_port_priv *pp = ap->private_data;
        int is_atapi = ata_is_atapi(qc->tf.protocol);
        void *cmd_tbl;
        u32 opts;
        const u32 cmd_fis_len = 5; /* five dwords */
        unsigned int n_elem;

        /*
         * Fill in command table information.  First, the header,
         * a SATA Register - Host to Device command FIS.
         */
        cmd_tbl = pp->cmd_tbl + qc->tag * AHCI_CMD_TBL_SZ;

        ata_tf_to_fis(&qc->tf, qc->dev->link->pmp, 1, cmd_tbl);
        if (is_atapi) {
                memset(cmd_tbl + AHCI_CMD_TBL_CDB, 0, 32);
                memcpy(cmd_tbl + AHCI_CMD_TBL_CDB, qc->cdb, qc->dev->cdb_len);
        }

        n_elem = 0;
        if (qc->flags & ATA_QCFLAG_DMAMAP)
                n_elem = acard_ahci_fill_sg(qc, cmd_tbl);

        /*
         * Fill in command slot information.
         *
         * ACard note: prd table length not filled in
         */
        opts = cmd_fis_len | (qc->dev->link->pmp << 12);
        if (qc->tf.flags & ATA_TFLAG_WRITE)
                opts |= AHCI_CMD_WRITE;
        if (is_atapi)
                opts |= AHCI_CMD_ATAPI | AHCI_CMD_PREFETCH;

        ahci_fill_cmd_slot(pp, qc->tag, opts);
}

static bool acard_ahci_qc_fill_rtf(struct ata_queued_cmd *qc)
{
        struct ahci_port_priv *pp = qc->ap->private_data;
        u8 *rx_fis = pp->rx_fis;

        if (pp->fbs_enabled)
                rx_fis += qc->dev->link->pmp * ACARD_AHCI_RX_FIS_SZ;

        /*
         * After a successful execution of an ATA PIO data-in command,
         * the device doesn't send D2H Reg FIS to update the TF and
         * the host should take TF and E_Status from the preceding PIO
         * Setup FIS.
         */
        if (qc->tf.protocol == ATA_PROT_PIO && qc->dma_dir == DMA_FROM_DEVICE &&
            !(qc->flags & ATA_QCFLAG_FAILED)) {
                ata_tf_from_fis(rx_fis + RX_FIS_PIO_SETUP, &qc->result_tf);
                qc->result_tf.command = (rx_fis + RX_FIS_PIO_SETUP)[15];
        } else
                ata_tf_from_fis(rx_fis + RX_FIS_D2H_REG, &qc->result_tf);

        return true;
}

static int acard_ahci_port_start(struct ata_port *ap)
{
        struct ahci_host_priv *hpriv = ap->host->private_data;
        struct device *dev = ap->host->dev;
        struct ahci_port_priv *pp;
        void *mem;
        dma_addr_t mem_dma;
        size_t dma_sz, rx_fis_sz;

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

        /* check FBS capability */
        if ((hpriv->cap & HOST_CAP_FBS) && sata_pmp_supported(ap)) {
                void __iomem *port_mmio = ahci_port_base(ap);
                u32 cmd = readl(port_mmio + PORT_CMD);
                if (cmd & PORT_CMD_FBSCP)
                        pp->fbs_supported = true;
                else if (hpriv->flags & AHCI_HFLAG_YES_FBS) {
                        dev_info(dev, "port %d can do FBS, forcing FBSCP\n",
                                 ap->port_no);
                        pp->fbs_supported = true;
                } else
                        dev_warn(dev, "port %d is not capable of FBS\n",
                                 ap->port_no);
        }

        if (pp->fbs_supported) {
                dma_sz = AHCI_PORT_PRIV_FBS_DMA_SZ;
                rx_fis_sz = ACARD_AHCI_RX_FIS_SZ * 16;
        } else {
                dma_sz = AHCI_PORT_PRIV_DMA_SZ;
                rx_fis_sz = ACARD_AHCI_RX_FIS_SZ;
        }

        mem = dmam_alloc_coherent(dev, dma_sz, &mem_dma, GFP_KERNEL);
        if (!mem)
                return -ENOMEM;
        memset(mem, 0, dma_sz);

        /*
         * First item in chunk of DMA memory: 32-slot command table,
         * 32 bytes each in size
         */
        pp->cmd_slot = mem;
        pp->cmd_slot_dma = mem_dma;

        mem += AHCI_CMD_SLOT_SZ;
        mem_dma += AHCI_CMD_SLOT_SZ;

        /*
         * Second item: Received-FIS area
         */
        pp->rx_fis = mem;
        pp->rx_fis_dma = mem_dma;

        mem += rx_fis_sz;
        mem_dma += rx_fis_sz;

        /*
         * Third item: data area for storing a single command
         * and its scatter-gather table
         */
        pp->cmd_tbl = mem;
        pp->cmd_tbl_dma = mem_dma;

        /*
         * Save off initial list of interrupts to be enabled.
         * This could be changed later
         */
        pp->intr_mask = DEF_PORT_IRQ;

        ap->private_data = pp;

        /* engage engines, captain */
        return ahci_port_resume(ap);
}

static int acard_ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
{
        unsigned int board_id = ent->driver_data;
        struct ata_port_info pi = acard_ahci_port_info[board_id];
        const struct ata_port_info *ppi[] = { &pi, NULL };
        struct device *dev = &pdev->dev;
        struct ahci_host_priv *hpriv;
        struct ata_host *host;
        int n_ports, i, rc;

        VPRINTK("ENTER\n");

        WARN_ON((int)ATA_MAX_QUEUE > AHCI_MAX_CMDS);

        ata_print_version_once(&pdev->dev, DRV_VERSION);

        /* acquire resources */
        rc = pcim_enable_device(pdev);
        if (rc)
                return rc;

        /* AHCI controllers often implement SFF compatible interface.
         * Grab all PCI BARs just in case.
         */
        rc = pcim_iomap_regions_request_all(pdev, 1 << AHCI_PCI_BAR, DRV_NAME);
        if (rc == -EBUSY)
                pcim_pin_device(pdev);
        if (rc)
                return rc;

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

        hpriv->irq = pdev->irq;
        hpriv->flags |= (unsigned long)pi.private_data;

        if (!(hpriv->flags & AHCI_HFLAG_NO_MSI))
                pci_enable_msi(pdev);

        hpriv->mmio = pcim_iomap_table(pdev)[AHCI_PCI_BAR];

        /* save initial config */
        ahci_save_initial_config(&pdev->dev, hpriv);

        /* prepare host */
        if (hpriv->cap & HOST_CAP_NCQ)
                pi.flags |= ATA_FLAG_NCQ;

        if (hpriv->cap & HOST_CAP_PMP)
                pi.flags |= ATA_FLAG_PMP;

        ahci_set_em_messages(hpriv, &pi);

        /* CAP.NP sometimes indicate the index of the last enabled
         * port, at other times, that of the last possible port, so
         * determining the maximum port number requires looking at
         * both CAP.NP and port_map.
         */
        n_ports = max(ahci_nr_ports(hpriv->cap), fls(hpriv->port_map));

        host = ata_host_alloc_pinfo(&pdev->dev, ppi, n_ports);
        if (!host)
                return -ENOMEM;
        host->private_data = hpriv;

        if (!(hpriv->cap & HOST_CAP_SSS) || ahci_ignore_sss)
                host->flags |= ATA_HOST_PARALLEL_SCAN;
        else
                printk(KERN_INFO "ahci: SSS flag set, parallel bus scan disabled\n");

        for (i = 0; i < host->n_ports; i++) {
                struct ata_port *ap = host->ports[i];

                ata_port_pbar_desc(ap, AHCI_PCI_BAR, -1, "abar");
                ata_port_pbar_desc(ap, AHCI_PCI_BAR,
                                   0x100 + ap->port_no * 0x80, "port");

                /* set initial link pm policy */
                /*
                ap->pm_policy = NOT_AVAILABLE;
                */
                /* disabled/not-implemented port */
                if (!(hpriv->port_map & (1 << i)))
                        ap->ops = &ata_dummy_port_ops;
        }

        /* initialize adapter */
        rc = acard_ahci_configure_dma_masks(pdev, hpriv->cap & HOST_CAP_64);
        if (rc)
                return rc;

        rc = ahci_reset_controller(host);
        if (rc)
                return rc;

        ahci_init_controller(host);
        acard_ahci_pci_print_info(host);

        pci_set_master(pdev);
        return ahci_host_activate(host, &acard_ahci_sht);
}

module_pci_driver(acard_ahci_pci_driver);

MODULE_AUTHOR("Jeff Garzik");
MODULE_DESCRIPTION("ACard AHCI SATA low-level driver");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(pci, acard_ahci_pci_tbl);
MODULE_VERSION(DRV_VERSION);