// SPDX-License-Identifier: GPL-2.0-only
/*
 * pata_cypress.c       - Cypress PATA for new ATA layer
 *                        (C) 2006 Red Hat Inc
 *                        Alan Cox
 *
 * Based heavily on
 * linux/drivers/ide/pci/cy82c693.c             Version 0.40    Sep. 10, 2002
 *
 */

#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_cypress"
#define DRV_VERSION "0.1.5"

/* here are the offset definitions for the registers */

enum {
        CY82_IDE_CMDREG         = 0x04,
        CY82_IDE_ADDRSETUP      = 0x48,
        CY82_IDE_MASTER_IOR     = 0x4C,
        CY82_IDE_MASTER_IOW     = 0x4D,
        CY82_IDE_SLAVE_IOR      = 0x4E,
        CY82_IDE_SLAVE_IOW      = 0x4F,
        CY82_IDE_MASTER_8BIT    = 0x50,
        CY82_IDE_SLAVE_8BIT     = 0x51,

        CY82_INDEX_PORT         = 0x22,
        CY82_DATA_PORT          = 0x23,

        CY82_INDEX_CTRLREG1     = 0x01,
        CY82_INDEX_CHANNEL0     = 0x30,
        CY82_INDEX_CHANNEL1     = 0x31,
        CY82_INDEX_TIMEOUT      = 0x32
};

static bool enable_dma = true;
module_param(enable_dma, bool, 0);
MODULE_PARM_DESC(enable_dma, "Enable bus master DMA operations");

/**
 *      cy82c693_set_piomode    -       set initial PIO mode data
 *      @ap: ATA interface
 *      @adev: ATA device
 *
 *      Called to do the PIO mode setup.
 */

static void cy82c693_set_piomode(struct ata_port *ap, struct ata_device *adev)
{
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);
        struct ata_timing t;
        const unsigned long T = 1000000 / 33;
        short time_16, time_8;
        u32 addr;

        if (ata_timing_compute(adev, adev->pio_mode, &t, T, 1) < 0) {
                ata_dev_err(adev, DRV_NAME ": mode computation failed.\n");
                return;
        }

        time_16 = clamp_val(t.recover - 1, 0, 15) |
                  (clamp_val(t.active - 1, 0, 15) << 4);
        time_8 = clamp_val(t.act8b - 1, 0, 15) |
                 (clamp_val(t.rec8b - 1, 0, 15) << 4);

        if (adev->devno == 0) {
                pci_read_config_dword(pdev, CY82_IDE_ADDRSETUP, &addr);

                addr &= ~0x0F;  /* Mask bits */
                addr |= clamp_val(t.setup - 1, 0, 15);

                pci_write_config_dword(pdev, CY82_IDE_ADDRSETUP, addr);
                pci_write_config_byte(pdev, CY82_IDE_MASTER_IOR, time_16);
                pci_write_config_byte(pdev, CY82_IDE_MASTER_IOW, time_16);
                pci_write_config_byte(pdev, CY82_IDE_MASTER_8BIT, time_8);
        } else {
                pci_read_config_dword(pdev, CY82_IDE_ADDRSETUP, &addr);

                addr &= ~0xF0;  /* Mask bits */
                addr |= (clamp_val(t.setup - 1, 0, 15) << 4);

                pci_write_config_dword(pdev, CY82_IDE_ADDRSETUP, addr);
                pci_write_config_byte(pdev, CY82_IDE_SLAVE_IOR, time_16);
                pci_write_config_byte(pdev, CY82_IDE_SLAVE_IOW, time_16);
                pci_write_config_byte(pdev, CY82_IDE_SLAVE_8BIT, time_8);
        }
}

/**
 *      cy82c693_set_dmamode    -       set initial DMA mode data
 *      @ap: ATA interface
 *      @adev: ATA device
 *
 *      Called to do the DMA mode setup.
 */

static void cy82c693_set_dmamode(struct ata_port *ap, struct ata_device *adev)
{
        int reg = CY82_INDEX_CHANNEL0 + ap->port_no;

        /* Be afraid, be very afraid. Magic registers  in low I/O space */
        outb(reg, 0x22);
        outb(adev->dma_mode - XFER_MW_DMA_0, 0x23);

        /* 0x50 gives the best behaviour on the Alpha's using this chip */
        outb(CY82_INDEX_TIMEOUT, 0x22);
        outb(0x50, 0x23);
}

static const struct scsi_host_template cy82c693_sht = {
        ATA_BMDMA_SHT(DRV_NAME),
};

static struct ata_port_operations cy82c693_port_ops = {
        .inherits       = &ata_bmdma_port_ops,
        .cable_detect   = ata_cable_40wire,
        .set_piomode    = cy82c693_set_piomode,
        .set_dmamode    = cy82c693_set_dmamode,
};

static int cy82c693_init_one(struct pci_dev *pdev, const struct pci_device_id *id)
{
        static struct ata_port_info info = {
                .flags = ATA_FLAG_SLAVE_POSS,
                .pio_mask = ATA_PIO4,
                .port_ops = &cy82c693_port_ops
        };
        const struct ata_port_info *ppi[] = { &info, &ata_dummy_port_info };

        if (enable_dma)
                info.mwdma_mask = ATA_MWDMA2;

        /* Devfn 1 is the ATA primary. The secondary is magic and on devfn2.
           For the moment we don't handle the secondary. FIXME */

        if (PCI_FUNC(pdev->devfn) != 1)
                return -ENODEV;

        return ata_pci_bmdma_init_one(pdev, ppi, &cy82c693_sht, NULL, 0);
}

static const struct pci_device_id cy82c693[] = {
        { PCI_VDEVICE(CONTAQ, PCI_DEVICE_ID_CONTAQ_82C693), },

        { },
};

static struct pci_driver cy82c693_pci_driver = {
        .name           = DRV_NAME,
        .id_table       = cy82c693,
        .probe          = cy82c693_init_one,
        .remove         = ata_pci_remove_one,
#ifdef CONFIG_PM_SLEEP
        .suspend        = ata_pci_device_suspend,
        .resume         = ata_pci_device_resume,
#endif
};

module_pci_driver(cy82c693_pci_driver);

MODULE_AUTHOR("Alan Cox");
MODULE_DESCRIPTION("low-level driver for the CY82C693 PATA controller");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(pci, cy82c693);
MODULE_VERSION(DRV_VERSION);