/*
 * Copyright (C) 2004-2005 Advanced Micro Devices, Inc.
 * Copyright (C)      2007 Bartlomiej Zolnierkiewicz
 *
 * History:
 * 09/20/2005 - Jaya Kumar <jayakumar.ide@gmail.com>
 * - Reworked tuneproc, set_drive, misc mods to prep for mainline
 * - Work was sponsored by CIS (M) Sdn Bhd.
 * Ported to Kernel 2.6.11 on June 26, 2005 by
 *   Wolfgang Zuleger <wolfgang.zuleger@gmx.de>
 *   Alexander Kiausch <alex.kiausch@t-online.de>
 * Originally developed by AMD for 2.4/2.6
 *
 * Development of this chipset driver was funded
 * by the nice folks at National Semiconductor/AMD.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 *
 * Documentation:
 *  CS5535 documentation available from AMD
 */

#include <linux/module.h>
#include <linux/pci.h>
#include <linux/ide.h>

#define DRV_NAME "cs5535"

#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

/* Format I PIO settings. We separate out cmd and data for safer timings */

static unsigned int cs5535_pio_cmd_timings[5] =
{ 0xF7F4, 0x53F3, 0x13F1, 0x5131, 0x1131 };
static unsigned int cs5535_pio_dta_timings[5] =
{ 0xF7F4, 0xF173, 0x8141, 0x5131, 0x1131 };

static unsigned int cs5535_mwdma_timings[3] =
{ 0x7F0FFFF3, 0x7F035352, 0x7f024241 };

static unsigned int cs5535_udma_timings[5] =
{ 0x7F7436A1, 0x7F733481, 0x7F723261, 0x7F713161, 0x7F703061 };

/* Macros to check if the register is the reset value -  reset value is an
   invalid timing and indicates the register has not been set previously */

#define CS5535_BAD_PIO(timings) ( (timings&~0x80000000UL) == 0x00009172 )
#define CS5535_BAD_DMA(timings) ( (timings & 0x000FFFFF) == 0x00077771 )

/****
 *      cs5535_set_speed         -     Configure the chipset to the new speed
 *      @drive: Drive to set up
 *      @speed: desired speed
 *
 *      cs5535_set_speed() configures the chipset to a new speed.
 */
static void cs5535_set_speed(ide_drive_t *drive, const u8 speed)
{
        u32 reg = 0, dummy;
        u8 unit = drive->dn & 1;

        /* Set the PIO timings */
        if (speed < XFER_SW_DMA_0) {
                ide_drive_t *pair = ide_get_pair_dev(drive);
                u8 cmd, pioa;

                cmd = pioa = speed - XFER_PIO_0;

                if (pair) {
                        u8 piob = ide_get_best_pio_mode(pair, 255, 4);

                        if (piob < cmd)
                                cmd = piob;
                }

                /* Write the speed of the current drive */
                reg = (cs5535_pio_cmd_timings[cmd] << 16) |
                        cs5535_pio_dta_timings[pioa];
                wrmsr(unit ? ATAC_CH0D1_PIO : ATAC_CH0D0_PIO, reg, 0);

                /* And if nessesary - change the speed of the other drive */
                rdmsr(unit ?  ATAC_CH0D0_PIO : ATAC_CH0D1_PIO, reg, dummy);

                if (((reg >> 16) & cs5535_pio_cmd_timings[cmd]) !=
                        cs5535_pio_cmd_timings[cmd]) {
                        reg &= 0x0000FFFF;
                        reg |= cs5535_pio_cmd_timings[cmd] << 16;
                        wrmsr(unit ? ATAC_CH0D0_PIO : ATAC_CH0D1_PIO, reg, 0);
                }

                /* Set bit 31 of the DMA register for PIO format 1 timings */
                rdmsr(unit ?  ATAC_CH0D1_DMA : ATAC_CH0D0_DMA, reg, dummy);
                wrmsr(unit ? ATAC_CH0D1_DMA : ATAC_CH0D0_DMA,
                                        reg | 0x80000000UL, 0);
        } else {
                rdmsr(unit ? ATAC_CH0D1_DMA : ATAC_CH0D0_DMA, reg, dummy);

                reg &= 0x80000000UL;  /* Preserve the PIO format bit */

                if (speed >= XFER_UDMA_0 && speed <= XFER_UDMA_4)
                        reg |= cs5535_udma_timings[speed - XFER_UDMA_0];
                else if (speed >= XFER_MW_DMA_0 && speed <= XFER_MW_DMA_2)
                        reg |= cs5535_mwdma_timings[speed - XFER_MW_DMA_0];
                else
                        return;

                wrmsr(unit ? ATAC_CH0D1_DMA : ATAC_CH0D0_DMA, reg, 0);
        }
}

/**
 *      cs5535_set_dma_mode     -       set host controller for DMA mode
 *      @drive: drive
 *      @speed: DMA mode
 *
 *      Programs the chipset for DMA mode.
 */

static void cs5535_set_dma_mode(ide_drive_t *drive, const u8 speed)
{
        cs5535_set_speed(drive, speed);
}

/**
 *      cs5535_set_pio_mode     -       set host controller for PIO mode
 *      @drive: drive
 *      @pio: PIO mode number
 *
 *      A callback from the upper layers for PIO-only tuning.
 */

static void cs5535_set_pio_mode(ide_drive_t *drive, const u8 pio)
{
        cs5535_set_speed(drive, XFER_PIO_0 + pio);
}

static u8 cs5535_cable_detect(ide_hwif_t *hwif)
{
        struct pci_dev *dev = to_pci_dev(hwif->dev);
        u8 bit;

        /* if a 80 wire cable was detected */
        pci_read_config_byte(dev, CS5535_CABLE_DETECT, &bit);

        return (bit & 1) ? ATA_CBL_PATA80 : ATA_CBL_PATA40;
}

static const struct ide_port_ops cs5535_port_ops = {
        .set_pio_mode           = cs5535_set_pio_mode,
        .set_dma_mode           = cs5535_set_dma_mode,
        .cable_detect           = cs5535_cable_detect,
};

static const struct ide_port_info cs5535_chipset __devinitdata = {
        .name           = DRV_NAME,
        .port_ops       = &cs5535_port_ops,
        .host_flags     = IDE_HFLAG_SINGLE | IDE_HFLAG_POST_SET_MODE,
        .pio_mask       = ATA_PIO4,
        .mwdma_mask     = ATA_MWDMA2,
        .udma_mask      = ATA_UDMA4,
};

static int __devinit cs5535_init_one(struct pci_dev *dev,
                                        const struct pci_device_id *id)
{
        return ide_pci_init_one(dev, &cs5535_chipset, NULL);
}

static const struct pci_device_id cs5535_pci_tbl[] = {
        { PCI_VDEVICE(NS, PCI_DEVICE_ID_NS_CS5535_IDE), 0 },
        { 0, },
};

MODULE_DEVICE_TABLE(pci, cs5535_pci_tbl);

static struct pci_driver cs5535_pci_driver = {
        .name           = "CS5535_IDE",
        .id_table       = cs5535_pci_tbl,
        .probe          = cs5535_init_one,
        .remove         = ide_pci_remove,
        .suspend        = ide_pci_suspend,
        .resume         = ide_pci_resume,
};

static int __init cs5535_ide_init(void)
{
        return ide_pci_register_driver(&cs5535_pci_driver);
}

static void __exit cs5535_ide_exit(void)
{
        pci_unregister_driver(&cs5535_pci_driver);
}

module_init(cs5535_ide_init);
module_exit(cs5535_ide_exit);

MODULE_AUTHOR("AMD");
MODULE_DESCRIPTION("PCI driver module for AMD/NS CS5535 IDE");
MODULE_LICENSE("GPL");