/* SPDX-License-Identifier: GPL-2.0 */

/***************************************************************************
 *    copyright            : (C) 2002 by Frank Mori Hess
 ***************************************************************************/

#include "nec7210.h"
#include "gpibP.h"
#include "amccs5933.h"

#include <linux/delay.h>
#include <linux/interrupt.h>

enum {
        PCI_DEVICE_ID_CBOARDS_PCI_GPIB = 0x6,
        PCI_DEVICE_ID_CBOARDS_CPCI_GPIB = 0xe,
};

enum pci_chip {
        PCI_CHIP_NONE = 0,
        PCI_CHIP_AMCC_S5933,
        PCI_CHIP_QUANCOM
};

// struct which defines private_data for cb7210 boards
struct cb7210_priv {
        struct nec7210_priv nec7210_priv;
        struct pci_dev *pci_device;
        // base address of amccs5933 pci chip
        unsigned long amcc_iobase;
        unsigned long fifo_iobase;
        unsigned int irq;
        enum pci_chip pci_chip;
        u8 hs_mode_bits;
        unsigned out_fifo_half_empty : 1;
        unsigned in_fifo_half_full : 1;
};

// pci-gpib register offset
static const int cb7210_reg_offset = 1;

// uses 10 ioports
static const int cb7210_iosize = 10;

// fifo size in bytes
static const int cb7210_fifo_size = 2048;
static const int cb7210_fifo_width = 2;

// cb7210 specific registers and bits
enum cb7210_regs {
        BUS_STATUS = 0x7,
};

enum cb7210_page_in {
        BUS_STATUS_PAGE = 1,
};

enum hs_regs {
        // write registers
        HS_MODE = 0x8,  /* HS_MODE register */
        HS_INT_LEVEL = 0x9,     /* HS_INT_LEVEL register */
        // read registers
        HS_STATUS = 0x8,        /* HS_STATUS register */
};

static inline u32 nec7210_iobase(const struct cb7210_priv *cb_priv)
{
        return cb_priv->nec7210_priv.iobase;
}

static inline int cb7210_page_in_bits(unsigned int page)
{
        return 0x50 | (page & 0xf);
}

static inline u8 cb7210_paged_read_byte(struct cb7210_priv *cb_priv,
                                        unsigned int register_num, unsigned int page)
{
        struct nec7210_priv *nec_priv = &cb_priv->nec7210_priv;
        u8 retval;
        unsigned long flags;

        spin_lock_irqsave(&nec_priv->register_page_lock, flags);
        outb(cb7210_page_in_bits(page), nec7210_iobase(cb_priv) + AUXMR * nec_priv->offset);
        udelay(1);
        retval = inb(nec7210_iobase(cb_priv) + register_num * nec_priv->offset);
        spin_unlock_irqrestore(&nec_priv->register_page_lock, flags);
        return retval;
}

// don't use for register_num < 8, since it doesn't lock
static inline u8 cb7210_read_byte(const struct cb7210_priv *cb_priv,
                                  enum hs_regs register_num)
{
        const struct nec7210_priv *nec_priv = &cb_priv->nec7210_priv;
        u8 retval;

        retval = inb(nec7210_iobase(cb_priv) + register_num * nec_priv->offset);
        return retval;
}

static inline void cb7210_paged_write_byte(struct cb7210_priv *cb_priv, u8 data,
                                           unsigned int register_num, unsigned int page)
{
        struct nec7210_priv *nec_priv = &cb_priv->nec7210_priv;
        unsigned long flags;

        spin_lock_irqsave(&nec_priv->register_page_lock, flags);
        outb(cb7210_page_in_bits(page), nec7210_iobase(cb_priv) + AUXMR * nec_priv->offset);
        udelay(1);
        outb(data, nec7210_iobase(cb_priv) + register_num * nec_priv->offset);
        spin_unlock_irqrestore(&nec_priv->register_page_lock, flags);
}

// don't use for register_num < 8, since it doesn't lock
static inline void cb7210_write_byte(const struct cb7210_priv *cb_priv, u8 data,
                                     enum hs_regs register_num)
{
        const struct nec7210_priv *nec_priv = &cb_priv->nec7210_priv;

        outb(data, nec7210_iobase(cb_priv) + register_num * nec_priv->offset);
}

enum bus_status_bits {
        BSR_ATN_BIT = 0x1,
        BSR_EOI_BIT = 0x2,
        BSR_SRQ_BIT = 0x4,
        BSR_IFC_BIT = 0x8,
        BSR_REN_BIT = 0x10,
        BSR_DAV_BIT = 0x20,
        BSR_NRFD_BIT = 0x40,
        BSR_NDAC_BIT = 0x80,
};

/* CBI 488.2 HS control */

/*
 * when both bit 0 and 1 are set, it
 *   1 clears the transmit state machine to an initial condition
 *   2 clears any residual interrupts left latched on cbi488.2
 *   3 resets all control bits in HS_MODE to zero
 *   4 enables TX empty interrupts
 * when both bit 0 and 1 are zero, then the high speed mode is disabled
 */
enum hs_mode_bits {
        HS_ENABLE_MASK = 0x3,
        HS_TX_ENABLE = (1 << 0),
        HS_RX_ENABLE = (1 << 1),
        HS_HF_INT_EN = (1 << 3),
        HS_CLR_SRQ_INT = (1 << 4),
        HS_CLR_EOI_EMPTY_INT = (1 << 5),
        HS_CLR_HF_INT = (1 << 6),
        HS_SYS_CONTROL = (1 << 7),
};

/* CBI 488.2 status */
enum hs_status_bits {
        HS_FIFO_FULL = (1 << 0),
        HS_HALF_FULL = (1 << 1),
        HS_SRQ_INT = (1 << 2),
        HS_EOI_INT = (1 << 3),
        HS_TX_MSB_NOT_EMPTY = (1 << 4),
        HS_RX_MSB_NOT_EMPTY = (1 << 5),
        HS_TX_LSB_NOT_EMPTY = (1 << 6),
        HS_RX_LSB_NOT_EMPTY = (1 << 7),
};

/* CBI488.2 hs_int_level register */
enum hs_int_level_bits {
        HS_RESET7210 = (1 << 7),
};

static inline unsigned int irq_bits(unsigned int irq)
{
        switch (irq) {
        case 2:
        case 3:
        case 4:
        case 5:
                return irq - 1;
        case 7:
                return 0x5;
        case 10:
                return 0x6;
        case 11:
                return 0x7;
        default:
                return 0;
        }
}

enum cb7210_aux_cmds {
/*
 * AUX_RTL2 is an undocumented aux command which causes cb7210 to assert
 * (and keep asserted) local rtl message.  This is used in conjunction
 * with the (stupid) cb7210 implementation
 * of the normal nec7210 AUX_RTL aux command, which
 * causes the rtl message to toggle between on and off.
 */
        AUX_RTL2 = 0xd,
        AUX_LO_SPEED = 0x40,
        AUX_HI_SPEED = 0x41,
};