/*-
 * SPDX-License-Identifier: BSD-4-Clause
 *
 * Copyright (c) 1997, 1998, 1999
 *      Bill Paul <wpaul@ee.columbia.edu>.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Bill Paul.
 * 4. Neither the name of the author nor the names of any co-contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY Bill Paul AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL Bill Paul OR THE VOICES IN HIS HEAD
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * Register definitions for the SiS 900 and SiS 7016 chipsets. The
 * 7016 is actually an older chip and some of its registers differ
 * from the 900, however the core operational registers are the same:
 * the differences lie in the OnNow/Wake on LAN stuff which we don't
 * use anyway. The 7016 needs an external MII compliant PHY while the
 * SiS 900 has one built in. All registers are 32-bits wide.
 */

/* Registers common to SiS 900 and SiS 7016 */
#define SIS_CSR                 0x00
#define SIS_CFG                 0x04
#define SIS_EECTL               0x08
#define SIS_PCICTL              0x0C
#define SIS_ISR                 0x10
#define SIS_IMR                 0x14
#define SIS_IER                 0x18
#define SIS_PHYCTL              0x1C
#define SIS_TX_LISTPTR          0x20
#define SIS_TX_CFG              0x24
#define SIS_RX_LISTPTR          0x30
#define SIS_RX_CFG              0x34
#define SIS_FLOWCTL             0x38
#define SIS_RXFILT_CTL          0x48
#define SIS_RXFILT_DATA         0x4C
#define SIS_PWRMAN_CTL          0xB0
#define SIS_PWERMAN_WKUP_EVENT  0xB4
#define SIS_WKUP_FRAME_CRC      0xBC
#define SIS_WKUP_FRAME_MASK0    0xC0
#define SIS_WKUP_FRAME_MASKXX   0xEC

/* SiS 7016 specific registers */
#define SIS_SILICON_REV         0x5C
#define SIS_MIB_CTL0            0x60
#define SIS_MIB_CTL1            0x64
#define SIS_MIB_CTL2            0x68
#define SIS_MIB_CTL3            0x6C
#define SIS_MIB                 0x80
#define SIS_LINKSTS             0xA0
#define SIS_TIMEUNIT            0xA4
#define SIS_GPIO                0xB8

/* NS DP83815/6 registers */
#define NS_IHR                  0x1C
#define NS_CLKRUN               0x3C
#define NS_WCSR                 0x40
#define NS_SRR                  0x58
#define NS_BMCR                 0x80
#define NS_BMSR                 0x84
#define NS_PHYIDR1              0x88
#define NS_PHYIDR2              0x8C
#define NS_ANAR                 0x90
#define NS_ANLPAR               0x94
#define NS_ANER                 0x98
#define NS_ANNPTR               0x9C

#define NS_PHY_CR               0xE4
#define NS_PHY_10BTSCR          0xE8
#define NS_PHY_PAGE             0xCC
#define NS_PHY_EXTCFG           0xF0
#define NS_PHY_DSPCFG           0xF4
#define NS_PHY_SDCFG            0xF8
#define NS_PHY_TDATA            0xFC

#define NS_CLKRUN_PMESTS        0x00008000
#define NS_CLKRUN_PMEENB        0x00000100
#define NS_CLNRUN_CLKRUN_ENB    0x00000001

#define NS_WCSR_WAKE_PHYINTR    0x00000001
#define NS_WCSR_WAKE_UCAST      0x00000002
#define NS_WCSR_WAKE_MCAST      0x00000004
#define NS_WCSR_WAKE_BCAST      0x00000008
#define NS_WCSR_WAKE_ARP        0x00000010
#define NS_WCSR_WAKE_PATTERN0   0x00000020
#define NS_WCSR_WAKE_PATTERN1   0x00000040
#define NS_WCSR_WAKE_PATTERN2   0x00000080
#define NS_WCSR_WAKE_PATTERN3   0x00000100
#define NS_WCSR_WAKE_MAGIC      0x00000200
#define NS_WCSR_WAKE_MAGIC_SEC  0x00000400
#define NS_WCSR_DET_MAGIC_SECH  0x00100000
#define NS_WCSR_DET_PHYINTR     0x00400000
#define NS_WCSR_DET_UCAST       0x00800000
#define NS_WCSR_DET_MCAST       0x01000000
#define NS_WCSR_DET_BCAST       0x02000000
#define NS_WCSR_DET_ARP         0x04000000
#define NS_WCSR_DET_PATTERN0    0x08000000
#define NS_WCSR_DET_PATTERN1    0x10000000
#define NS_WCSR_DET_PATTERN2    0x20000000
#define NS_WCSR_DET_PATTERN3    0x40000000
#define NS_WCSR_DET_MAGIC       0x80000000

/* NS silicon revisions */
#define NS_SRR_15C              0x302
#define NS_SRR_15D              0x403
#define NS_SRR_16A              0x505

#define SIS_CSR_TX_ENABLE       0x00000001
#define SIS_CSR_TX_DISABLE      0x00000002
#define SIS_CSR_RX_ENABLE       0x00000004
#define SIS_CSR_RX_DISABLE      0x00000008
#define SIS_CSR_TX_RESET        0x00000010
#define SIS_CSR_RX_RESET        0x00000020
#define SIS_CSR_SOFTINTR        0x00000080
#define SIS_CSR_RESET           0x00000100
#define SIS_CSR_ACCESS_MODE     0x00000200
#define SIS_CSR_RELOAD          0x00000400

#define SIS_CFG_BIGENDIAN       0x00000001
#define SIS_CFG_PERR_DETECT     0x00000008
#define SIS_CFG_DEFER_DISABLE   0x00000010
#define SIS_CFG_OUTOFWIN_TIMER  0x00000020
#define SIS_CFG_SINGLE_BACKOFF  0x00000040
#define SIS_CFG_PCIREQ_ALG      0x00000080
#define SIS_CFG_FAIR_BACKOFF    0x00000200 /* 635 & 900B Specific */
#define SIS_CFG_RND_CNT 0x00000400 /* 635 & 900B Specific */
#define SIS_CFG_EDB_MASTER_EN   0x00002000

#define SIS_EECTL_DIN           0x00000001
#define SIS_EECTL_DOUT          0x00000002
#define SIS_EECTL_CLK           0x00000004
#define SIS_EECTL_CSEL          0x00000008

#define SIS_MII_CLK             0x00000040
#define SIS_MII_DIR             0x00000020
#define SIS_MII_DATA            0x00000010

#define SIS_EECMD_WRITE         0x140
#define SIS_EECMD_READ          0x180
#define SIS_EECMD_ERASE         0x1c0

/*
 * EEPROM Commands for SiS96x
 * chipsets.
 */
#define SIS_EECMD_REQ           0x00000400
#define SIS_EECMD_DONE          0x00000200
#define SIS_EECMD_GNT           0x00000100

#define SIS_EE_NODEADDR         0x8
#define NS_EE_NODEADDR          0x6

#define SIS_PCICTL_SRAMADDR     0x0000001F
#define SIS_PCICTL_RAMTSTENB    0x00000020
#define SIS_PCICTL_TXTSTENB     0x00000040
#define SIS_PCICTL_RXTSTENB     0x00000080
#define SIS_PCICTL_BMTSTENB     0x00000200
#define SIS_PCICTL_RAMADDR      0x001F0000
#define SIS_PCICTL_ROMTIME      0x0F000000
#define SIS_PCICTL_DISCTEST     0x40000000

#define SIS_ISR_RX_OK           0x00000001
#define SIS_ISR_RX_DESC_OK      0x00000002
#define SIS_ISR_RX_ERR          0x00000004
#define SIS_ISR_RX_EARLY        0x00000008
#define SIS_ISR_RX_IDLE         0x00000010
#define SIS_ISR_RX_OFLOW        0x00000020
#define SIS_ISR_TX_OK           0x00000040
#define SIS_ISR_TX_DESC_OK      0x00000080
#define SIS_ISR_TX_ERR          0x00000100
#define SIS_ISR_TX_IDLE         0x00000200
#define SIS_ISR_TX_UFLOW        0x00000400
#define SIS_ISR_SOFTINTR        0x00000800
#define SIS_ISR_HIBITS          0x00008000
#define SIS_ISR_RX_FIFO_OFLOW   0x00010000
#define SIS_ISR_TGT_ABRT        0x00100000
#define SIS_ISR_BM_ABRT         0x00200000
#define SIS_ISR_SYSERR          0x00400000
#define SIS_ISR_PARITY_ERR      0x00800000
#define SIS_ISR_RX_RESET_DONE   0x01000000
#define SIS_ISR_TX_RESET_DONE   0x02000000
#define SIS_ISR_TX_PAUSE_START  0x04000000
#define SIS_ISR_TX_PAUSE_DONE   0x08000000
#define SIS_ISR_WAKE_EVENT      0x10000000

#define SIS_IMR_RX_OK           0x00000001
#define SIS_IMR_RX_DESC_OK      0x00000002
#define SIS_IMR_RX_ERR          0x00000004
#define SIS_IMR_RX_EARLY        0x00000008
#define SIS_IMR_RX_IDLE         0x00000010
#define SIS_IMR_RX_OFLOW        0x00000020
#define SIS_IMR_TX_OK           0x00000040
#define SIS_IMR_TX_DESC_OK      0x00000080
#define SIS_IMR_TX_ERR          0x00000100
#define SIS_IMR_TX_IDLE         0x00000200
#define SIS_IMR_TX_UFLOW        0x00000400
#define SIS_IMR_SOFTINTR        0x00000800
#define SIS_IMR_HIBITS          0x00008000
#define SIS_IMR_RX_FIFO_OFLOW   0x00010000
#define SIS_IMR_TGT_ABRT        0x00100000
#define SIS_IMR_BM_ABRT         0x00200000
#define SIS_IMR_SYSERR          0x00400000
#define SIS_IMR_PARITY_ERR      0x00800000
#define SIS_IMR_RX_RESET_DONE   0x01000000
#define SIS_IMR_TX_RESET_DONE   0x02000000
#define SIS_IMR_TX_PAUSE_START  0x04000000
#define SIS_IMR_TX_PAUSE_DONE   0x08000000
#define SIS_IMR_WAKE_EVENT      0x10000000

#define SIS_INTRS       \
        (SIS_IMR_RX_OFLOW|SIS_IMR_TX_UFLOW|SIS_IMR_TX_OK|\
         SIS_IMR_TX_IDLE|SIS_IMR_RX_OK|SIS_IMR_RX_ERR|\
         SIS_IMR_RX_IDLE|\
         SIS_IMR_SYSERR)

#define SIS_IER_INTRENB         0x00000001

#define SIS_PHYCTL_ACCESS       0x00000010
#define SIS_PHYCTL_OP           0x00000020
#define SIS_PHYCTL_REGADDR      0x000007C0
#define SIS_PHYCTL_PHYADDR      0x0000F800
#define SIS_PHYCTL_PHYDATA      0xFFFF0000

#define SIS_PHYOP_READ          0x00000020
#define SIS_PHYOP_WRITE         0x00000000

#define SIS_TXCFG_DRAIN_THRESH  0x0000003F /* 32-byte units */
#define SIS_TXCFG_FILL_THRESH   0x00003F00 /* 32-byte units */
#define SIS_TXCFG_DMABURST      0x00700000
#define SIS_TXCFG_AUTOPAD       0x10000000
#define SIS_TXCFG_LOOPBK        0x20000000
#define SIS_TXCFG_IGN_HBEAT     0x40000000
#define SIS_TXCFG_IGN_CARR      0x80000000

#define SIS_TXCFG_DRAIN(x)      (((x) >> 5) & SIS_TXCFG_DRAIN_THRESH)
#define SIS_TXCFG_FILL(x)       ((((x) >> 5) << 8) & SIS_TXCFG_FILL_THRESH)

#define SIS_TXDMA_512BYTES      0x00000000
#define SIS_TXDMA_4BYTES        0x00100000
#define SIS_TXDMA_8BYTES        0x00200000
#define SIS_TXDMA_16BYTES       0x00300000
#define SIS_TXDMA_32BYTES       0x00400000
#define SIS_TXDMA_64BYTES       0x00500000
#define SIS_TXDMA_128BYTES      0x00600000
#define SIS_TXDMA_256BYTES      0x00700000

#define SIS_TXCFG_100   \
        (SIS_TXDMA_64BYTES|SIS_TXCFG_AUTOPAD|\
         SIS_TXCFG_FILL(64)|SIS_TXCFG_DRAIN(1536))

#define SIS_TXCFG_10    \
        (SIS_TXDMA_32BYTES|SIS_TXCFG_AUTOPAD|\
         SIS_TXCFG_FILL(64)|SIS_TXCFG_DRAIN(1536))

#define SIS_RXCFG_DRAIN_THRESH  0x0000003E /* 8-byte units */
#define SIS_TXCFG_MPII03D       0x00040000 /* "Must be 1" */
#define SIS_RXCFG_DMABURST      0x00700000
#define SIS_RXCFG_RX_JABBER     0x08000000
#define SIS_RXCFG_RX_TXPKTS     0x10000000
#define SIS_RXCFG_RX_RUNTS      0x40000000
#define SIS_RXCFG_RX_GIANTS     0x80000000

#define SIS_RXCFG_DRAIN(x)      ((((x) >> 3) << 1) & SIS_RXCFG_DRAIN_THRESH)

#define SIS_RXDMA_512BYTES      0x00000000
#define SIS_RXDMA_4BYTES        0x00100000
#define SIS_RXDMA_8BYTES        0x00200000
#define SIS_RXDMA_16BYTES       0x00300000
#define SIS_RXDMA_32BYTES       0x00400000
#define SIS_RXDMA_64BYTES       0x00500000
#define SIS_RXDMA_128BYTES      0x00600000
#define SIS_RXDMA_256BYTES      0x00700000

#define SIS_RXCFG256 \
        (SIS_RXCFG_DRAIN(64)|SIS_RXDMA_256BYTES)
#define SIS_RXCFG64 \
        (SIS_RXCFG_DRAIN(64)|SIS_RXDMA_64BYTES)

#define SIS_RXFILTCTL_ADDR      0x000F0000
#define NS_RXFILTCTL_MCHASH     0x00200000
#define NS_RXFILTCTL_ARP        0x00400000
#define NS_RXFILTCTL_PERFECT    0x08000000
#define SIS_RXFILTCTL_ALLPHYS   0x10000000
#define SIS_RXFILTCTL_ALLMULTI  0x20000000
#define SIS_RXFILTCTL_BROAD     0x40000000
#define SIS_RXFILTCTL_ENABLE    0x80000000

#define SIS_FILTADDR_PAR0       0x00000000
#define SIS_FILTADDR_PAR1       0x00010000
#define SIS_FILTADDR_PAR2       0x00020000
#define SIS_FILTADDR_MAR0       0x00040000
#define SIS_FILTADDR_MAR1       0x00050000
#define SIS_FILTADDR_MAR2       0x00060000
#define SIS_FILTADDR_MAR3       0x00070000
#define SIS_FILTADDR_MAR4       0x00080000
#define SIS_FILTADDR_MAR5       0x00090000
#define SIS_FILTADDR_MAR6       0x000A0000
#define SIS_FILTADDR_MAR7       0x000B0000

#define NS_FILTADDR_PAR0        0x00000000
#define NS_FILTADDR_PAR1        0x00000002
#define NS_FILTADDR_PAR2        0x00000004

#define NS_FILTADDR_FMEM_LO     0x00000200
#define NS_FILTADDR_FMEM_HI     0x000003FE

#define SIS_PWRMAN_WOL_LINK_OFF 0x00000001
#define SIS_PWRMAN_WOL_LINK_ON  0x00000002
#define SIS_PWRMAN_WOL_MAGIC    0x00000400

/*
 * TX/RX DMA descriptor structures.
 */
struct sis_desc {
        /* SiS hardware descriptor section */
        uint32_t                sis_next;
        volatile uint32_t       sis_cmdsts;
        volatile uint32_t       sis_ptr;
};

#define SIS_CMDSTS_BUFLEN       0x00000FFF
#define SIS_CMDSTS_PKT_OK       0x08000000
#define SIS_CMDSTS_CRC          0x10000000
#define SIS_CMDSTS_INTR         0x20000000
#define SIS_CMDSTS_MORE         0x40000000
#define SIS_CMDSTS_OWN          0x80000000

#define SIS_RXSTAT_COLL         0x00010000
#define SIS_RXSTAT_LOOPBK       0x00020000
#define SIS_RXSTAT_ALIGNERR     0x00040000
#define SIS_RXSTAT_CRCERR       0x00080000
#define SIS_RXSTAT_SYMBOLERR    0x00100000
#define SIS_RXSTAT_RUNT         0x00200000
#define SIS_RXSTAT_GIANT        0x00400000
#define SIS_RXSTAT_DSTCLASS     0x01800000
#define SIS_RXSTAT_OVERRUN      0x02000000
#define SIS_RXSTAT_RX_ABORT     0x04000000

#define SIS_RXSTAT_ERROR(x)                                             \
        ((x) & (SIS_RXSTAT_RX_ABORT | SIS_RXSTAT_OVERRUN |              \
        SIS_RXSTAT_GIANT | SIS_RXSTAT_SYMBOLERR | SIS_RXSTAT_RUNT |     \
        SIS_RXSTAT_CRCERR | SIS_RXSTAT_ALIGNERR))

#define SIS_DSTCLASS_REJECT     0x00000000
#define SIS_DSTCLASS_UNICAST    0x00800000
#define SIS_DSTCLASS_MULTICAST  0x01000000
#define SIS_DSTCLASS_BROADCAST  0x02000000

#define SIS_TXSTAT_COLLCNT      0x000F0000
#define SIS_TXSTAT_EXCESSCOLLS  0x00100000
#define SIS_TXSTAT_OUTOFWINCOLL 0x00200000
#define SIS_TXSTAT_EXCESS_DEFER 0x00400000
#define SIS_TXSTAT_DEFERED      0x00800000
#define SIS_TXSTAT_CARR_LOST    0x01000000
#define SIS_TXSTAT_UNDERRUN     0x02000000
#define SIS_TXSTAT_TX_ABORT     0x04000000

#define SIS_DESC_ALIGN          16
#define SIS_RX_BUF_ALIGN        4
#define SIS_MAXTXSEGS           16
#define SIS_RX_LIST_CNT         64
#define SIS_TX_LIST_CNT         128

#define SIS_RX_LIST_SZ          SIS_RX_LIST_CNT * sizeof(struct sis_desc)
#define SIS_TX_LIST_SZ          SIS_TX_LIST_CNT * sizeof(struct sis_desc)

#define SIS_ADDR_LO(x)          ((uint64_t) (x) & 0xffffffff)
#define SIS_ADDR_HI(x)          ((uint64_t) (x) >> 32)

#define SIS_RX_RING_ADDR(sc, i) \
        ((sc)->sis_rx_paddr + sizeof(struct sis_desc) * (i))
#define SIS_TX_RING_ADDR(sc, i) \
        ((sc)->sis_tx_paddr + sizeof(struct sis_desc) * (i))

#define SIS_INC(x, y)           (x) = (x + 1) % (y)

/*
 * SiS PCI vendor ID.
 */
#define SIS_VENDORID            0x1039

/*
 * SiS PCI device IDs
 */
#define SIS_DEVICEID_900        0x0900
#define SIS_DEVICEID_7016       0x7016

/*
 * SiS 900 PCI revision codes.
 */
#define SIS_REV_900B            0x0003
#define SIS_REV_630A            0x0080
#define SIS_REV_630E            0x0081
#define SIS_REV_630S            0x0082
#define SIS_REV_630EA1          0x0083
#define SIS_REV_630ET           0x0084
#define SIS_REV_635             0x0090
#define SIS_REV_96x             0x0091

/*
 * NatSemi vendor ID
 */
#define NS_VENDORID             0x100B

/*
 * DP83815 device ID
 */
#define NS_DEVICEID_DP83815     0x0020

struct sis_type {
        uint16_t                sis_vid;
        uint16_t                sis_did;
        const char              *sis_name;
};

#define SIS_TYPE_900    1
#define SIS_TYPE_7016   2
#define SIS_TYPE_83815  3

struct sis_txdesc {
        struct mbuf             *tx_m;
        bus_dmamap_t            tx_dmamap;
};

struct sis_rxdesc {
        struct mbuf             *rx_m;
        bus_dmamap_t            rx_dmamap;
        struct sis_desc         *rx_desc;
};

struct sis_softc {
        if_t                    sis_ifp;        /* interface info */
        struct resource         *sis_res[2];
        void                    *sis_intrhand;
        device_t                sis_dev;
        device_t                sis_miibus;
        uint8_t                 sis_type;
        uint8_t                 sis_rev;
        uint32_t                sis_flags;
#define SIS_FLAG_MANUAL_PAD     0x0800
#define SIS_FLAG_LINK           0x8000
        int                     sis_manual_pad;
        uint32_t                sis_srr;
        struct sis_desc         *sis_rx_list;
        struct sis_desc         *sis_tx_list;
        bus_dma_tag_t           sis_rx_list_tag;
        bus_dmamap_t            sis_rx_list_map;
        bus_dma_tag_t           sis_tx_list_tag;
        bus_dmamap_t            sis_tx_list_map;
        bus_dma_tag_t           sis_parent_tag;
        bus_dma_tag_t           sis_rx_tag;
        bus_dmamap_t            sis_rx_sparemap;
        bus_dma_tag_t           sis_tx_tag;
        struct sis_rxdesc       sis_rxdesc[SIS_RX_LIST_CNT];
        struct sis_txdesc       sis_txdesc[SIS_TX_LIST_CNT];
        int                     sis_tx_prod;
        int                     sis_tx_cons;
        int                     sis_tx_cnt;
        int                     sis_rx_cons;
        bus_addr_t              sis_rx_paddr;
        bus_addr_t              sis_tx_paddr;
        struct callout          sis_stat_ch;
        int                     sis_watchdog_timer;
        int                     sis_if_flags;
#ifdef DEVICE_POLLING
        int                     rxcycles;
#endif
        struct mtx              sis_mtx;
};

#define SIS_TIMEOUT             1000
#define ETHER_ALIGN             2
#define SIS_RXLEN               1536
#define SIS_MIN_FRAMELEN        60

/*
 * PCI low memory base and low I/O base register, and
 * other PCI registers.
 */

#define SIS_PCI_VENDOR_ID       0x00
#define SIS_PCI_DEVICE_ID       0x02
#define SIS_PCI_COMMAND         0x04
#define SIS_PCI_STATUS          0x06
#define SIS_PCI_REVID           0x08
#define SIS_PCI_CLASSCODE       0x09
#define SIS_PCI_CACHELEN        0x0C
#define SIS_PCI_LATENCY_TIMER   0x0D
#define SIS_PCI_HEADER_TYPE     0x0E
#define SIS_PCI_LOIO            0x10
#define SIS_PCI_LOMEM           0x14
#define SIS_PCI_BIOSROM         0x30
#define SIS_PCI_INTLINE         0x3C
#define SIS_PCI_INTPIN          0x3D
#define SIS_PCI_MINGNT          0x3E
#define SIS_PCI_MINLAT          0x0F
#define SIS_PCI_RESETOPT        0x48
#define SIS_PCI_EEPROM_DATA     0x4C

/* power management registers */
#define SIS_PCI_CAPID           0x50 /* 8 bits */
#define SIS_PCI_NEXTPTR         0x51 /* 8 bits */
#define SIS_PCI_PWRMGMTCAP      0x52 /* 16 bits */
#define SIS_PCI_PWRMGMTCTRL     0x54 /* 16 bits */

#define SIS_PSTATE_MASK         0x0003
#define SIS_PSTATE_D0           0x0000
#define SIS_PSTATE_D1           0x0001
#define SIS_PSTATE_D2           0x0002
#define SIS_PSTATE_D3           0x0003
#define SIS_PME_EN              0x0010
#define SIS_PME_STATUS          0x8000