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

#ifndef _GPIB_CMD_H
#define _GPIB_CMD_H

#include <linux/types.h>

/* Command byte definitions tests and functions */

/* mask of bits that actually matter in a command byte */
enum {
        gpib_command_mask = 0x7f,
};

/* Possible GPIB command messages */

enum cmd_byte {
        GTL = 0x1,      /* go to local                  */
        SDC = 0x4,      /* selected device clear        */
        PP_CONFIG = 0x5,
        GET = 0x8,      /* group execute trigger        */
        TCT = 0x9,      /* take control                 */
        LLO = 0x11,     /* local lockout                */
        DCL = 0x14,     /* device clear                 */
        PPU = 0x15,     /* parallel poll unconfigure    */
        SPE = 0x18,     /* serial poll enable           */
        SPD = 0x19,     /* serial poll disable          */
        CFE = 0x1f,     /* configure enable */
        LAD = 0x20,     /* value to be 'ored' in to obtain listen address */
        UNL = 0x3F,     /* unlisten                     */
        TAD = 0x40,     /* value to be 'ored' in to obtain talk address   */
        UNT = 0x5F,     /* untalk                       */
        SAD = 0x60,     /* my secondary address (base) */
        PPE = 0x60,     /* parallel poll enable (base)  */
        PPD = 0x70      /* parallel poll disable        */
};

/* confine address to range 0 to 30. */
static inline unsigned int gpib_address_restrict(u32 addr)
{
        addr &= 0x1f;
        if (addr == 0x1f)
                addr = 0;
        return addr;
}

static inline u8 MLA(u32 addr)
{
        return gpib_address_restrict(addr) | LAD;
}

static inline u8 MTA(u32 addr)
{
        return gpib_address_restrict(addr) | TAD;
}

static inline u8 MSA(u32 addr)
{
        return (addr & 0x1f) | SAD;
}

static inline s32 gpib_address_equal(u32 pad1, s32 sad1, u32 pad2, s32 sad2)
{
        if (pad1 == pad2) {
                if (sad1 == sad2)
                        return 1;
                if (sad1 < 0 && sad2 < 0)
                        return 1;
        }

        return 0;
}

static inline s32 is_PPE(u8 command)
{
        return (command & 0x70) == 0x60;
}

static inline s32 is_PPD(u8 command)
{
        return (command & 0x70) == 0x70;
}

static inline s32 in_addressed_command_group(u8 command)
{
        return (command & 0x70) == 0x0;
}

static inline s32 in_universal_command_group(u8 command)
{
        return (command & 0x70) == 0x10;
}

static inline s32 in_listen_address_group(u8 command)
{
        return (command & 0x60) == 0x20;
}

static inline s32 in_talk_address_group(u8 command)
{
        return (command & 0x60) == 0x40;
}

static inline s32 in_primary_command_group(u8 command)
{
        return in_addressed_command_group(command) ||
                in_universal_command_group(command) ||
                in_listen_address_group(command) ||
                in_talk_address_group(command);
}

#endif /* _GPIB_CMD_H */