// SPDX-License-Identifier: GPL-2.0-only
/*
 * pata_triflex.c       - Compaq PATA for new ATA layer
 *                        (C) 2005 Red Hat Inc
 *                        Alan Cox <alan@lxorguk.ukuu.org.uk>
 *
 * based upon
 *
 * triflex.c
 *
 * IDE Chipset driver for the Compaq TriFlex IDE controller.
 *
 * Known to work with the Compaq Workstation 5x00 series.
 *
 * Copyright (C) 2002 Hewlett-Packard Development Group, L.P.
 * Author: Torben Mathiasen <torben.mathiasen@hp.com>
 *
 * Loosely based on the piix & svwks drivers.
 *
 * Documentation:
 *      Not publicly available.
 */

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

#define DRV_NAME "pata_triflex"
#define DRV_VERSION "0.2.8"

/**
 *      triflex_prereset                -       probe begin
 *      @link: ATA link
 *      @deadline: deadline jiffies for the operation
 *
 *      Set up cable type and use generic probe init
 */

static int triflex_prereset(struct ata_link *link, unsigned long deadline)
{
        static const struct pci_bits triflex_enable_bits[] = {
                { 0x80, 1, 0x01, 0x01 },
                { 0x80, 1, 0x02, 0x02 }
        };

        struct ata_port *ap = link->ap;
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);

        if (!pci_test_config_bits(pdev, &triflex_enable_bits[ap->port_no]))
                return -ENOENT;

        return ata_sff_prereset(link, deadline);
}



/**
 *      triflex_load_timing             -       timing configuration
 *      @ap: ATA interface
 *      @adev: Device on the bus
 *      @speed: speed to configure
 *
 *      The Triflex has one set of timings per device per channel. This
 *      means we must do some switching. As the PIO and DMA timings don't
 *      match we have to do some reloading unlike PIIX devices where tuning
 *      tricks can avoid it.
 */

static void triflex_load_timing(struct ata_port *ap, struct ata_device *adev, int speed)
{
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);
        u32 timing = 0;
        u32 triflex_timing, old_triflex_timing;
        int channel_offset = ap->port_no ? 0x74: 0x70;
        unsigned int is_slave   = (adev->devno != 0);


        pci_read_config_dword(pdev, channel_offset, &old_triflex_timing);
        triflex_timing = old_triflex_timing;

        switch(speed)
        {
                case XFER_MW_DMA_2:
                        timing = 0x0103;break;
                case XFER_MW_DMA_1:
                        timing = 0x0203;break;
                case XFER_MW_DMA_0:
                        timing = 0x0808;break;
                case XFER_SW_DMA_2:
                case XFER_SW_DMA_1:
                case XFER_SW_DMA_0:
                        timing = 0x0F0F;break;
                case XFER_PIO_4:
                        timing = 0x0202;break;
                case XFER_PIO_3:
                        timing = 0x0204;break;
                case XFER_PIO_2:
                        timing = 0x0404;break;
                case XFER_PIO_1:
                        timing = 0x0508;break;
                case XFER_PIO_0:
                        timing = 0x0808;break;
                default:
                        BUG();
        }
        triflex_timing &= ~ (0xFFFF << (16 * is_slave));
        triflex_timing |= (timing << (16 * is_slave));

        if (triflex_timing != old_triflex_timing)
                pci_write_config_dword(pdev, channel_offset, triflex_timing);
}

/**
 *      triflex_set_piomode     -       set initial PIO mode data
 *      @ap: ATA interface
 *      @adev: ATA device
 *
 *      Use the timing loader to set up the PIO mode. We have to do this
 *      because DMA start/stop will only be called once DMA occurs. If there
 *      has been no DMA then the PIO timings are still needed.
 */
static void triflex_set_piomode(struct ata_port *ap, struct ata_device *adev)
{
        triflex_load_timing(ap, adev, adev->pio_mode);
}

/**
 *      triflex_bmdma_start     -       DMA start callback
 *      @qc: Command in progress
 *
 *      Usually drivers set the DMA timing at the point the set_dmamode call
 *      is made. Triflex however requires we load new timings on the
 *      transition or keep matching PIO/DMA pairs (ie MWDMA2/PIO4 etc).
 *      We load the DMA timings just before starting DMA and then restore
 *      the PIO timing when the DMA is finished.
 */

static void triflex_bmdma_start(struct ata_queued_cmd *qc)
{
        triflex_load_timing(qc->ap, qc->dev, qc->dev->dma_mode);
        ata_bmdma_start(qc);
}

/**
 *      triflex_bmdma_stop      -       DMA stop callback
 *      @qc: ATA command
 *
 *      We loaded new timings in dma_start, as a result we need to restore
 *      the PIO timings in dma_stop so that the next command issue gets the
 *      right clock values.
 */

static void triflex_bmdma_stop(struct ata_queued_cmd *qc)
{
        ata_bmdma_stop(qc);
        triflex_load_timing(qc->ap, qc->dev, qc->dev->pio_mode);
}

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

static struct ata_port_operations triflex_port_ops = {
        .inherits       = &ata_bmdma_port_ops,
        .bmdma_start    = triflex_bmdma_start,
        .bmdma_stop     = triflex_bmdma_stop,
        .cable_detect   = ata_cable_40wire,
        .set_piomode    = triflex_set_piomode,
        .reset.prereset = triflex_prereset,
};

static int triflex_init_one(struct pci_dev *dev, const struct pci_device_id *id)
{
        static const struct ata_port_info info = {
                .flags = ATA_FLAG_SLAVE_POSS,
                .pio_mask = ATA_PIO4,
                .mwdma_mask = ATA_MWDMA2,
                .port_ops = &triflex_port_ops
        };
        const struct ata_port_info *ppi[] = { &info, NULL };

        ata_print_version_once(&dev->dev, DRV_VERSION);

        return ata_pci_bmdma_init_one(dev, ppi, &triflex_sht, NULL, 0);
}

static const struct pci_device_id triflex[] = {
        { PCI_VDEVICE(COMPAQ, PCI_DEVICE_ID_COMPAQ_TRIFLEX_IDE), },

        { },
};

#ifdef CONFIG_PM_SLEEP
static int triflex_ata_pci_device_suspend(struct pci_dev *pdev, pm_message_t mesg)
{
        struct ata_host *host = pci_get_drvdata(pdev);

        ata_host_suspend(host, mesg);

        /*
         * We must not disable or powerdown the device.
         * APM bios refuses to suspend if IDE is not accessible.
         */
        pci_save_state(pdev);

        return 0;
}

#endif

static struct pci_driver triflex_pci_driver = {
        .name           = DRV_NAME,
        .id_table       = triflex,
        .probe          = triflex_init_one,
        .remove         = ata_pci_remove_one,
#ifdef CONFIG_PM_SLEEP
        .suspend        = triflex_ata_pci_device_suspend,
        .resume         = ata_pci_device_resume,
#endif
};

module_pci_driver(triflex_pci_driver);

MODULE_AUTHOR("Alan Cox");
MODULE_DESCRIPTION("low-level driver for Compaq Triflex");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(pci, triflex);
MODULE_VERSION(DRV_VERSION);