// SPDX-License-Identifier: GPL-2.0-only
/*
 * pata_cmd64x.c        - CMD64x PATA for new ATA layer
 *                        (C) 2005 Red Hat Inc
 *                        Alan Cox <alan@lxorguk.ukuu.org.uk>
 *                        (C) 2009-2010 Bartlomiej Zolnierkiewicz
 *                        (C) 2012 MontaVista Software, LLC <source@mvista.com>
 *
 * Based upon
 * linux/drivers/ide/pci/cmd64x.c               Version 1.30    Sept 10, 2002
 *
 * cmd64x.c: Enable interrupts at initialization time on Ultra/PCI machines.
 *           Note, this driver is not used at all on other systems because
 *           there the "BIOS" has done all of the following already.
 *           Due to massive hardware bugs, UltraDMA is only supported
 *           on the 646U2 and not on the 646U.
 *
 * Copyright (C) 1998           Eddie C. Dost  (ecd@skynet.be)
 * Copyright (C) 1998           David S. Miller (davem@redhat.com)
 *
 * Copyright (C) 1999-2002      Andre Hedrick <andre@linux-ide.org>
 *
 * TODO
 *      Testing work
 */

#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_cmd64x"
#define DRV_VERSION "0.2.18"

/*
 * CMD64x specific registers definition.
 */

enum {
        CFR             = 0x50,
                CFR_INTR_CH0  = 0x04,
        CNTRL           = 0x51,
                CNTRL_CH0     = 0x04,
                CNTRL_CH1     = 0x08,
        CMDTIM          = 0x52,
        ARTTIM0         = 0x53,
        DRWTIM0         = 0x54,
        ARTTIM1         = 0x55,
        DRWTIM1         = 0x56,
        ARTTIM23        = 0x57,
                ARTTIM23_DIS_RA2  = 0x04,
                ARTTIM23_DIS_RA3  = 0x08,
                ARTTIM23_INTR_CH1 = 0x10,
        DRWTIM2         = 0x58,
        BRST            = 0x59,
        DRWTIM3         = 0x5b,
        BMIDECR0        = 0x70,
        MRDMODE         = 0x71,
                MRDMODE_INTR_CH0 = 0x04,
                MRDMODE_INTR_CH1 = 0x08,
        BMIDESR0        = 0x72,
        UDIDETCR0       = 0x73,
        DTPR0           = 0x74,
        BMIDECR1        = 0x78,
        BMIDECSR        = 0x79,
        UDIDETCR1       = 0x7B,
        DTPR1           = 0x7C
};

static int cmd648_cable_detect(struct ata_port *ap)
{
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);
        u8 r;

        /* Check cable detect bits */
        pci_read_config_byte(pdev, BMIDECSR, &r);
        if (r & (1 << ap->port_no))
                return ATA_CBL_PATA80;
        return ATA_CBL_PATA40;
}

/**
 *      cmd64x_set_timing       -       set PIO and MWDMA timing
 *      @ap: ATA interface
 *      @adev: ATA device
 *      @mode: mode
 *
 *      Called to do the PIO and MWDMA mode setup.
 */

static void cmd64x_set_timing(struct ata_port *ap, struct ata_device *adev, u8 mode)
{
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);
        struct ata_timing t;
        const unsigned long T = 1000000 / 33;
        const u8 setup_data[] = { 0x40, 0x40, 0x40, 0x80, 0x00 };

        u8 reg;

        /* Port layout is not logical so use a table */
        const u8 arttim_port[2][2] = {
                { ARTTIM0, ARTTIM1 },
                { ARTTIM23, ARTTIM23 }
        };
        const u8 drwtim_port[2][2] = {
                { DRWTIM0, DRWTIM1 },
                { DRWTIM2, DRWTIM3 }
        };

        int arttim = arttim_port[ap->port_no][adev->devno];
        int drwtim = drwtim_port[ap->port_no][adev->devno];

        /* ata_timing_compute is smart and will produce timings for MWDMA
           that don't violate the drives PIO capabilities. */
        if (ata_timing_compute(adev, mode, &t, T, 0) < 0) {
                ata_dev_err(adev, DRV_NAME ": mode computation failed.\n");
                return;
        }
        if (ap->port_no) {
                /* Slave has shared address setup */
                struct ata_device *pair = ata_dev_pair(adev);

                if (pair) {
                        struct ata_timing tp;
                        ata_timing_compute(pair, pair->pio_mode, &tp, T, 0);
                        ata_timing_merge(&t, &tp, &t, ATA_TIMING_SETUP);
                }
        }

        ata_dev_dbg(adev, DRV_NAME ": active %d recovery %d setup %d.\n",
                t.active, t.recover, t.setup);
        if (t.recover > 16) {
                t.active += t.recover - 16;
                t.recover = 16;
        }
        if (t.active > 16)
                t.active = 16;

        /* Now convert the clocks into values we can actually stuff into
           the chip */

        if (t.recover == 16)
                t.recover = 0;
        else if (t.recover > 1)
                t.recover--;
        else
                t.recover = 15;

        if (t.setup > 4)
                t.setup = 0xC0;
        else
                t.setup = setup_data[t.setup];

        t.active &= 0x0F;       /* 0 = 16 */

        /* Load setup timing */
        pci_read_config_byte(pdev, arttim, &reg);
        reg &= 0x3F;
        reg |= t.setup;
        pci_write_config_byte(pdev, arttim, reg);

        /* Load active/recovery */
        pci_write_config_byte(pdev, drwtim, (t.active << 4) | t.recover);
}

/**
 *      cmd64x_set_piomode      -       set initial PIO mode data
 *      @ap: ATA interface
 *      @adev: ATA device
 *
 *      Used when configuring the devices ot set the PIO timings. All the
 *      actual work is done by the PIO/MWDMA setting helper
 */

static void cmd64x_set_piomode(struct ata_port *ap, struct ata_device *adev)
{
        cmd64x_set_timing(ap, adev, adev->pio_mode);
}

/**
 *      cmd64x_set_dmamode      -       set initial DMA mode data
 *      @ap: ATA interface
 *      @adev: ATA device
 *
 *      Called to do the DMA mode setup.
 */

static void cmd64x_set_dmamode(struct ata_port *ap, struct ata_device *adev)
{
        static const u8 udma_data[] = {
                0x30, 0x20, 0x10, 0x20, 0x10, 0x00
        };

        struct pci_dev *pdev = to_pci_dev(ap->host->dev);
        u8 regU, regD;

        int pciU = UDIDETCR0 + 8 * ap->port_no;
        int pciD = BMIDESR0 + 8 * ap->port_no;
        int shift = 2 * adev->devno;

        pci_read_config_byte(pdev, pciD, &regD);
        pci_read_config_byte(pdev, pciU, &regU);

        /* DMA bits off */
        regD &= ~(0x20 << adev->devno);
        /* DMA control bits */
        regU &= ~(0x30 << shift);
        /* DMA timing bits */
        regU &= ~(0x05 << adev->devno);

        if (adev->dma_mode >= XFER_UDMA_0) {
                /* Merge the timing value */
                regU |= udma_data[adev->dma_mode - XFER_UDMA_0] << shift;
                /* Merge the control bits */
                regU |= 1 << adev->devno; /* UDMA on */
                if (adev->dma_mode > XFER_UDMA_2) /* 15nS timing */
                        regU |= 4 << adev->devno;
        } else {
                regU &= ~ (1 << adev->devno);   /* UDMA off */
                cmd64x_set_timing(ap, adev, adev->dma_mode);
        }

        regD |= 0x20 << adev->devno;

        pci_write_config_byte(pdev, pciU, regU);
        pci_write_config_byte(pdev, pciD, regD);
}

/**
 *      cmd64x_sff_irq_check    -       check IDE interrupt
 *      @ap: ATA interface
 *
 *      Check IDE interrupt in CFR/ARTTIM23 registers.
 */

static bool cmd64x_sff_irq_check(struct ata_port *ap)
{
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);
        int irq_mask = ap->port_no ? ARTTIM23_INTR_CH1 : CFR_INTR_CH0;
        int irq_reg  = ap->port_no ? ARTTIM23 : CFR;
        u8 irq_stat;

        /* NOTE: reading the register should clear the interrupt */
        pci_read_config_byte(pdev, irq_reg, &irq_stat);

        return irq_stat & irq_mask;
}

/**
 *      cmd64x_sff_irq_clear    -       clear IDE interrupt
 *      @ap: ATA interface
 *
 *      Clear IDE interrupt in CFR/ARTTIM23 and DMA status registers.
 */

static void cmd64x_sff_irq_clear(struct ata_port *ap)
{
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);
        int irq_reg = ap->port_no ? ARTTIM23 : CFR;
        u8 irq_stat;

        ata_bmdma_irq_clear(ap);

        /* Reading the register should be enough to clear the interrupt */
        pci_read_config_byte(pdev, irq_reg, &irq_stat);
}

/**
 *      cmd648_sff_irq_check    -       check IDE interrupt
 *      @ap: ATA interface
 *
 *      Check IDE interrupt in MRDMODE register.
 */

static bool cmd648_sff_irq_check(struct ata_port *ap)
{
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);
        unsigned long base = pci_resource_start(pdev, 4);
        int irq_mask = ap->port_no ? MRDMODE_INTR_CH1 : MRDMODE_INTR_CH0;
        u8 mrdmode = inb(base + 1);

        return mrdmode & irq_mask;
}

/**
 *      cmd648_sff_irq_clear    -       clear IDE interrupt
 *      @ap: ATA interface
 *
 *      Clear IDE interrupt in MRDMODE and DMA status registers.
 */

static void cmd648_sff_irq_clear(struct ata_port *ap)
{
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);
        unsigned long base = pci_resource_start(pdev, 4);
        int irq_mask = ap->port_no ? MRDMODE_INTR_CH1 : MRDMODE_INTR_CH0;
        u8 mrdmode;

        ata_bmdma_irq_clear(ap);

        /* Clear this port's interrupt bit (leaving the other port alone) */
        mrdmode  = inb(base + 1);
        mrdmode &= ~(MRDMODE_INTR_CH0 | MRDMODE_INTR_CH1);
        outb(mrdmode | irq_mask, base + 1);
}

/**
 *      cmd646r1_bmdma_stop     -       DMA stop callback
 *      @qc: Command in progress
 *
 *      Stub for now while investigating the r1 quirk in the old driver.
 */

static void cmd646r1_bmdma_stop(struct ata_queued_cmd *qc)
{
        ata_bmdma_stop(qc);
}

static const struct scsi_host_template cmd64x_sht = {
        ATA_BMDMA_SHT(DRV_NAME),
};

static const struct ata_port_operations cmd64x_base_ops = {
        .inherits       = &ata_bmdma_port_ops,
        .set_piomode    = cmd64x_set_piomode,
        .set_dmamode    = cmd64x_set_dmamode,
};

static struct ata_port_operations cmd64x_port_ops = {
        .inherits       = &cmd64x_base_ops,
        .sff_irq_check  = cmd64x_sff_irq_check,
        .sff_irq_clear  = cmd64x_sff_irq_clear,
        .cable_detect   = ata_cable_40wire,
};

static struct ata_port_operations cmd646r1_port_ops = {
        .inherits       = &cmd64x_base_ops,
        .sff_irq_check  = cmd64x_sff_irq_check,
        .sff_irq_clear  = cmd64x_sff_irq_clear,
        .bmdma_stop     = cmd646r1_bmdma_stop,
        .cable_detect   = ata_cable_40wire,
};

static struct ata_port_operations cmd646r3_port_ops = {
        .inherits       = &cmd64x_base_ops,
        .sff_irq_check  = cmd648_sff_irq_check,
        .sff_irq_clear  = cmd648_sff_irq_clear,
        .cable_detect   = ata_cable_40wire,
};

static struct ata_port_operations cmd648_port_ops = {
        .inherits       = &cmd64x_base_ops,
        .sff_irq_check  = cmd648_sff_irq_check,
        .sff_irq_clear  = cmd648_sff_irq_clear,
        .cable_detect   = cmd648_cable_detect,
};

static void cmd64x_fixup(struct pci_dev *pdev)
{
        u8 mrdmode;

        pci_write_config_byte(pdev, PCI_LATENCY_TIMER, 64);
        pci_read_config_byte(pdev, MRDMODE, &mrdmode);
        mrdmode &= ~0x30;       /* IRQ set up */
        mrdmode |= 0x02;        /* Memory read line enable */
        pci_write_config_byte(pdev, MRDMODE, mrdmode);

        /* PPC specific fixup copied from old driver */
#ifdef CONFIG_PPC
        pci_write_config_byte(pdev, UDIDETCR0, 0xF0);
#endif
}

static int cmd64x_init_one(struct pci_dev *pdev, const struct pci_device_id *id)
{
        static const struct ata_port_info cmd_info[7] = {
                {       /* CMD 643 - no UDMA */
                        .flags = ATA_FLAG_SLAVE_POSS,
                        .pio_mask = ATA_PIO4,
                        .mwdma_mask = ATA_MWDMA2,
                        .port_ops = &cmd64x_port_ops
                },
                {       /* CMD 646 with broken UDMA */
                        .flags = ATA_FLAG_SLAVE_POSS,
                        .pio_mask = ATA_PIO4,
                        .mwdma_mask = ATA_MWDMA2,
                        .port_ops = &cmd64x_port_ops
                },
                {       /* CMD 646U with broken UDMA */
                        .flags = ATA_FLAG_SLAVE_POSS,
                        .pio_mask = ATA_PIO4,
                        .mwdma_mask = ATA_MWDMA2,
                        .port_ops = &cmd646r3_port_ops
                },
                {       /* CMD 646U2 with working UDMA */
                        .flags = ATA_FLAG_SLAVE_POSS,
                        .pio_mask = ATA_PIO4,
                        .mwdma_mask = ATA_MWDMA2,
                        .udma_mask = ATA_UDMA2,
                        .port_ops = &cmd646r3_port_ops
                },
                {       /* CMD 646 rev 1  */
                        .flags = ATA_FLAG_SLAVE_POSS,
                        .pio_mask = ATA_PIO4,
                        .mwdma_mask = ATA_MWDMA2,
                        .port_ops = &cmd646r1_port_ops
                },
                {       /* CMD 648 */
                        .flags = ATA_FLAG_SLAVE_POSS,
                        .pio_mask = ATA_PIO4,
                        .mwdma_mask = ATA_MWDMA2,
                        .udma_mask = ATA_UDMA4,
                        .port_ops = &cmd648_port_ops
                },
                {       /* CMD 649 */
                        .flags = ATA_FLAG_SLAVE_POSS,
                        .pio_mask = ATA_PIO4,
                        .mwdma_mask = ATA_MWDMA2,
                        .udma_mask = ATA_UDMA5,
                        .port_ops = &cmd648_port_ops
                }
        };
        const struct ata_port_info *ppi[] = {
                &cmd_info[id->driver_data],
                &cmd_info[id->driver_data],
                NULL
        };
        u8 reg;
        int rc;
        struct pci_dev *bridge = pdev->bus->self;
        /* mobility split bridges don't report enabled ports correctly */
        int port_ok = !(bridge && bridge->vendor ==
                        PCI_VENDOR_ID_MOBILITY_ELECTRONICS);
        /* all (with exceptions below) apart from 643 have CNTRL_CH0 bit */
        int cntrl_ch0_ok = (id->driver_data != 0);

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

        if (id->driver_data == 0)       /* 643 */
                ata_pci_bmdma_clear_simplex(pdev);

        if (pdev->device == PCI_DEVICE_ID_CMD_646)
                switch (pdev->revision) {
                /* UDMA works since rev 5 */
                default:
                        ppi[0] = &cmd_info[3];
                        ppi[1] = &cmd_info[3];
                        break;
                /* Interrupts in MRDMODE since rev 3 */
                case 3:
                case 4:
                        ppi[0] = &cmd_info[2];
                        ppi[1] = &cmd_info[2];
                        break;
                /* Rev 1 with other problems? */
                case 1:
                        ppi[0] = &cmd_info[4];
                        ppi[1] = &cmd_info[4];
                        fallthrough;
                /* Early revs have no CNTRL_CH0 */
                case 2:
                case 0:
                        cntrl_ch0_ok = 0;
                        break;
                }

        cmd64x_fixup(pdev);

        /* check for enabled ports */
        pci_read_config_byte(pdev, CNTRL, &reg);
        if (!port_ok)
                dev_notice(&pdev->dev, "Mobility Bridge detected, ignoring CNTRL port enable/disable\n");
        if (port_ok && cntrl_ch0_ok && !(reg & CNTRL_CH0)) {
                dev_notice(&pdev->dev, "Primary port is disabled\n");
                ppi[0] = &ata_dummy_port_info;

        }
        if (port_ok && !(reg & CNTRL_CH1)) {
                dev_notice(&pdev->dev, "Secondary port is disabled\n");
                ppi[1] = &ata_dummy_port_info;
        }

        return ata_pci_bmdma_init_one(pdev, ppi, &cmd64x_sht, NULL, 0);
}

#ifdef CONFIG_PM_SLEEP
static int cmd64x_reinit_one(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;

        cmd64x_fixup(pdev);

        ata_host_resume(host);
        return 0;
}
#endif

static const struct pci_device_id cmd64x[] = {
        { PCI_VDEVICE(CMD, PCI_DEVICE_ID_CMD_643), 0 },
        { PCI_VDEVICE(CMD, PCI_DEVICE_ID_CMD_646), 1 },
        { PCI_VDEVICE(CMD, PCI_DEVICE_ID_CMD_648), 5 },
        { PCI_VDEVICE(CMD, PCI_DEVICE_ID_CMD_649), 6 },

        { },
};

static struct pci_driver cmd64x_pci_driver = {
        .name           = DRV_NAME,
        .id_table       = cmd64x,
        .probe          = cmd64x_init_one,
        .remove         = ata_pci_remove_one,
#ifdef CONFIG_PM_SLEEP
        .suspend        = ata_pci_device_suspend,
        .resume         = cmd64x_reinit_one,
#endif
};

module_pci_driver(cmd64x_pci_driver);

MODULE_AUTHOR("Alan Cox");
MODULE_DESCRIPTION("low-level driver for CMD64x series PATA controllers");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(pci, cmd64x);
MODULE_VERSION(DRV_VERSION);