/*
 *  pata_sch.c - Intel SCH PATA controllers
 *
 *  Copyright (c) 2008 Alek Du <alek.du@intel.com>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License 2 as published
 *  by the Free Software Foundation.
 *
 *  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.
 *
 */

/*
 *  Supports:
 *    Intel SCH (AF82US15W, AF82US15L, AF82UL11L) chipsets -- see spec at:
 *    http://download.intel.com/design/chipsets/embedded/datashts/319537.pdf
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <scsi/scsi_host.h>
#include <linux/libata.h>
#include <linux/dmi.h>

#define DRV_NAME        "pata_sch"
#define DRV_VERSION     "0.2"

/* see SCH datasheet page 351 */
enum {
        D0TIM   = 0x80,         /* Device 0 Timing Register */
        D1TIM   = 0x84,         /* Device 1 Timing Register */
        PM      = 0x07,         /* PIO Mode Bit Mask */
        MDM     = (0x03 << 8),  /* Multi-word DMA Mode Bit Mask */
        UDM     = (0x07 << 16), /* Ultra DMA Mode Bit Mask */
        PPE     = (1 << 30),    /* Prefetch/Post Enable */
        USD     = (1 << 31),    /* Use Synchronous DMA */
};

static int sch_init_one(struct pci_dev *pdev,
                         const struct pci_device_id *ent);
static void sch_set_piomode(struct ata_port *ap, struct ata_device *adev);
static void sch_set_dmamode(struct ata_port *ap, struct ata_device *adev);

static const struct pci_device_id sch_pci_tbl[] = {
        /* Intel SCH PATA Controller */
        { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_SCH_IDE), 0 },
        { }     /* terminate list */
};

static struct pci_driver sch_pci_driver = {
        .name                   = DRV_NAME,
        .id_table               = sch_pci_tbl,
        .probe                  = sch_init_one,
        .remove                 = ata_pci_remove_one,
#ifdef CONFIG_PM
        .suspend                = ata_pci_device_suspend,
        .resume                 = ata_pci_device_resume,
#endif
};

static struct scsi_host_template sch_sht = {
        ATA_BMDMA_SHT(DRV_NAME),
};

static struct ata_port_operations sch_pata_ops = {
        .inherits               = &ata_bmdma_port_ops,
        .cable_detect           = ata_cable_unknown,
        .set_piomode            = sch_set_piomode,
        .set_dmamode            = sch_set_dmamode,
};

static struct ata_port_info sch_port_info = {
        .flags          = ATA_FLAG_SLAVE_POSS,
        .pio_mask       = ATA_PIO4,
        .mwdma_mask     = ATA_MWDMA2,
        .udma_mask      = ATA_UDMA5,
        .port_ops       = &sch_pata_ops,
};

MODULE_AUTHOR("Alek Du <alek.du@intel.com>");
MODULE_DESCRIPTION("SCSI low-level driver for Intel SCH PATA controllers");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(pci, sch_pci_tbl);
MODULE_VERSION(DRV_VERSION);

/**
 *      sch_set_piomode - Initialize host controller PATA PIO timings
 *      @ap: Port whose timings we are configuring
 *      @adev: ATA device
 *
 *      Set PIO mode for device, in host controller PCI config space.
 *
 *      LOCKING:
 *      None (inherited from caller).
 */

static void sch_set_piomode(struct ata_port *ap, struct ata_device *adev)
{
        unsigned int pio        = adev->pio_mode - XFER_PIO_0;
        struct pci_dev *dev     = to_pci_dev(ap->host->dev);
        unsigned int port       = adev->devno ? D1TIM : D0TIM;
        unsigned int data;

        pci_read_config_dword(dev, port, &data);
        /* see SCH datasheet page 351 */
        /* set PIO mode */
        data &= ~(PM | PPE);
        data |= pio;
        /* enable PPE for block device */
        if (adev->class == ATA_DEV_ATA)
                data |= PPE;
        pci_write_config_dword(dev, port, data);
}

/**
 *      sch_set_dmamode - Initialize host controller PATA DMA timings
 *      @ap: Port whose timings we are configuring
 *      @adev: ATA device
 *
 *      Set MW/UDMA mode for device, in host controller PCI config space.
 *
 *      LOCKING:
 *      None (inherited from caller).
 */

static void sch_set_dmamode(struct ata_port *ap, struct ata_device *adev)
{
        unsigned int dma_mode   = adev->dma_mode;
        struct pci_dev *dev     = to_pci_dev(ap->host->dev);
        unsigned int port       = adev->devno ? D1TIM : D0TIM;
        unsigned int data;

        pci_read_config_dword(dev, port, &data);
        /* see SCH datasheet page 351 */
        if (dma_mode >= XFER_UDMA_0) {
                /* enable Synchronous DMA mode */
                data |= USD;
                data &= ~UDM;
                data |= (dma_mode - XFER_UDMA_0) << 16;
        } else { /* must be MWDMA mode, since we masked SWDMA already */
                data &= ~(USD | MDM);
                data |= (dma_mode - XFER_MW_DMA_0) << 8;
        }
        pci_write_config_dword(dev, port, data);
}

/**
 *      sch_init_one - Register SCH ATA PCI device with kernel services
 *      @pdev: PCI device to register
 *      @ent: Entry in sch_pci_tbl matching with @pdev
 *
 *      LOCKING:
 *      Inherited from PCI layer (may sleep).
 *
 *      RETURNS:
 *      Zero on success, or -ERRNO value.
 */

static int __devinit sch_init_one(struct pci_dev *pdev,
                                   const struct pci_device_id *ent)
{
        static int printed_version;
        const struct ata_port_info *ppi[] = { &sch_port_info, NULL };
        struct ata_host *host;
        int rc;

        if (!printed_version++)
                dev_printk(KERN_DEBUG, &pdev->dev,
                           "version " DRV_VERSION "\n");

        /* enable device and prepare host */
        rc = pcim_enable_device(pdev);
        if (rc)
                return rc;
        rc = ata_pci_sff_prepare_host(pdev, ppi, &host);
        if (rc)
                return rc;
        pci_set_master(pdev);
        return ata_pci_sff_activate_host(host, ata_sff_interrupt, &sch_sht);
}

static int __init sch_init(void)
{
        return pci_register_driver(&sch_pci_driver);
}

static void __exit sch_exit(void)
{
        pci_unregister_driver(&sch_pci_driver);
}

module_init(sch_init);
module_exit(sch_exit);