// SPDX-License-Identifier: GPL-2.0-only
/*
 * pata-cs5535.c        - CS5535 PATA for new ATA layer
 *                        (C) 2005-2006 Red Hat Inc
 *                        Alan Cox <alan@lxorguk.ukuu.org.uk>
 *
 * based upon cs5535.c from AMD <Jens.Altmann@amd.com> as cleaned up and
 * made readable and Linux style by Wolfgang Zuleger <wolfgang.zuleger@gmx.de>
 * and Alexander Kiausch <alex.kiausch@t-online.de>
 *
 * Loosely based on the piix & svwks drivers.
 *
 * Documentation:
 *      Available from AMD web site.
 * TODO
 *      Review errata to see if serializing is necessary
 */

#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>
#include <asm/msr.h>

#define DRV_NAME        "pata_cs5535"
#define DRV_VERSION     "0.2.12"

/*
 *      The Geode (Aka Athlon GX now) uses an internal MSR based
 *      bus system for control. Demented but there you go.
 */

#define MSR_ATAC_BASE           0x51300000
#define ATAC_GLD_MSR_CAP        (MSR_ATAC_BASE+0)
#define ATAC_GLD_MSR_CONFIG    (MSR_ATAC_BASE+0x01)
#define ATAC_GLD_MSR_SMI       (MSR_ATAC_BASE+0x02)
#define ATAC_GLD_MSR_ERROR     (MSR_ATAC_BASE+0x03)
#define ATAC_GLD_MSR_PM        (MSR_ATAC_BASE+0x04)
#define ATAC_GLD_MSR_DIAG      (MSR_ATAC_BASE+0x05)
#define ATAC_IO_BAR            (MSR_ATAC_BASE+0x08)
#define ATAC_RESET             (MSR_ATAC_BASE+0x10)
#define ATAC_CH0D0_PIO         (MSR_ATAC_BASE+0x20)
#define ATAC_CH0D0_DMA         (MSR_ATAC_BASE+0x21)
#define ATAC_CH0D1_PIO         (MSR_ATAC_BASE+0x22)
#define ATAC_CH0D1_DMA         (MSR_ATAC_BASE+0x23)
#define ATAC_PCI_ABRTERR       (MSR_ATAC_BASE+0x24)

#define ATAC_BM0_CMD_PRIM      0x00
#define ATAC_BM0_STS_PRIM      0x02
#define ATAC_BM0_PRD           0x04

#define CS5535_CABLE_DETECT    0x48

/**
 *      cs5535_cable_detect     -       detect cable type
 *      @ap: Port to detect on
 *
 *      Perform cable detection for ATA66 capable cable. Return a libata
 *      cable type.
 */

static int cs5535_cable_detect(struct ata_port *ap)
{
        u8 cable;
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);

        pci_read_config_byte(pdev, CS5535_CABLE_DETECT, &cable);
        if (cable & 1)
                return ATA_CBL_PATA80;
        else
                return ATA_CBL_PATA40;
}

/**
 *      cs5535_set_piomode              -       PIO setup
 *      @ap: ATA interface
 *      @adev: device on the interface
 *
 *      Set our PIO requirements. The CS5535 is pretty clean about all this
 */

static void cs5535_set_piomode(struct ata_port *ap, struct ata_device *adev)
{
        static const u16 pio_timings[5] = {
                0xF7F4, 0xF173, 0x8141, 0x5131, 0x1131
        };
        static const u16 pio_cmd_timings[5] = {
                0xF7F4, 0x53F3, 0x13F1, 0x5131, 0x1131
        };
        u32 reg, __maybe_unused dummy;
        struct ata_device *pair = ata_dev_pair(adev);

        int mode = adev->pio_mode - XFER_PIO_0;
        int cmdmode = mode;

        /* Command timing has to be for the lowest of the pair of devices */
        if (pair) {
                int pairmode = pair->pio_mode - XFER_PIO_0;
                cmdmode = min(mode, pairmode);
                /* Write the other drive timing register if it changed */
                if (cmdmode < pairmode)
                        wrmsr(ATAC_CH0D0_PIO + 2 * pair->devno,
                                pio_cmd_timings[cmdmode] << 16 | pio_timings[pairmode], 0);
        }
        /* Write the drive timing register */
        wrmsr(ATAC_CH0D0_PIO + 2 * adev->devno,
                pio_cmd_timings[cmdmode] << 16 | pio_timings[mode], 0);

        /* Set the PIO "format 1" bit in the DMA timing register */
        rdmsr(ATAC_CH0D0_DMA + 2 * adev->devno, reg, dummy);
        wrmsr(ATAC_CH0D0_DMA + 2 * adev->devno, reg | 0x80000000UL, 0);
}

/**
 *      cs5535_set_dmamode              -       DMA timing setup
 *      @ap: ATA interface
 *      @adev: Device being configured
 *
 */

static void cs5535_set_dmamode(struct ata_port *ap, struct ata_device *adev)
{
        static const u32 udma_timings[5] = {
                0x7F7436A1, 0x7F733481, 0x7F723261, 0x7F713161, 0x7F703061
        };
        static const u32 mwdma_timings[3] = {
                0x7F0FFFF3, 0x7F035352, 0x7F024241
        };
        u32 reg, __maybe_unused dummy;
        int mode = adev->dma_mode;

        rdmsr(ATAC_CH0D0_DMA + 2 * adev->devno, reg, dummy);
        reg &= 0x80000000UL;
        if (mode >= XFER_UDMA_0)
                reg |= udma_timings[mode - XFER_UDMA_0];
        else
                reg |= mwdma_timings[mode - XFER_MW_DMA_0];
        wrmsr(ATAC_CH0D0_DMA + 2 * adev->devno, reg, 0);
}

static const struct scsi_host_template cs5535_sht = {
        ATA_BMDMA_SHT(DRV_NAME),
};

static struct ata_port_operations cs5535_port_ops = {
        .inherits       = &ata_bmdma_port_ops,
        .cable_detect   = cs5535_cable_detect,
        .set_piomode    = cs5535_set_piomode,
        .set_dmamode    = cs5535_set_dmamode,
};

/**
 *      cs5535_init_one         -       Initialise a CS5530
 *      @dev: PCI device
 *      @id: Entry in match table
 *
 *      Install a driver for the newly found CS5530 companion chip. Most of
 *      this is just housekeeping. We have to set the chip up correctly and
 *      turn off various bits of emulation magic.
 */

static int cs5535_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,
                .udma_mask = ATA_UDMA4,
                .port_ops = &cs5535_port_ops
        };
        const struct ata_port_info *ppi[] = { &info, &ata_dummy_port_info };

        return ata_pci_bmdma_init_one(dev, ppi, &cs5535_sht, NULL, 0);
}

static const struct pci_device_id cs5535[] = {
        { PCI_VDEVICE(NS, PCI_DEVICE_ID_NS_CS5535_IDE), },
        { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_CS5535_IDE), },

        { },
};

static struct pci_driver cs5535_pci_driver = {
        .name           = DRV_NAME,
        .id_table       = cs5535,
        .probe          = cs5535_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(cs5535_pci_driver);

MODULE_AUTHOR("Alan Cox, Jens Altmann, Wolfgan Zuleger, Alexander Kiausch");
MODULE_DESCRIPTION("low-level driver for the NS/AMD 5535");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(pci, cs5535);
MODULE_VERSION(DRV_VERSION);