tms9914.h

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

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

#ifndef _TMS9914_H
#define _TMS9914_H

#include <linux/types.h>
#include <linux/interrupt.h>
#include "gpib_state_machines.h"
#include "gpib_types.h"

enum tms9914_holdoff_mode {
	TMS9914_HOLDOFF_NONE,
	TMS9914_HOLDOFF_EOI,
	TMS9914_HOLDOFF_ALL,
};

/* struct used to provide variables local to a tms9914 chip */
struct tms9914_priv {
#ifdef CONFIG_HAS_IOPORT
	u32 iobase;
#endif
	void __iomem *mmiobase;
	unsigned int offset;	// offset between successive tms9914 io addresses
	unsigned int dma_channel;
	// software copy of bits written to interrupt mask registers
	u8 imr0_bits, imr1_bits;
	// bits written to address mode register
	u8 admr_bits;
	u8 auxa_bits;		// bits written to auxiliary register A
	// used to keep track of board's state, bit definitions given below
	unsigned long state;
	u8 eos;			// eos character
	short eos_flags;
	u8 spoll_status;
	enum tms9914_holdoff_mode holdoff_mode;
	unsigned int ppoll_line;
	enum talker_function_state talker_state;
	enum listener_function_state listener_state;
	unsigned ppoll_sense : 1;
	unsigned ppoll_enable : 1;
	unsigned ppoll_configure_state : 1;
	unsigned primary_listen_addressed : 1;
	unsigned primary_talk_addressed : 1;
	unsigned holdoff_on_end : 1;
	unsigned holdoff_on_all : 1;
	unsigned holdoff_active : 1;
	// wrappers for outb, inb, readb, or writeb
	u8 (*read_byte)(struct tms9914_priv *priv, unsigned int register_number);
	void (*write_byte)(struct tms9914_priv *priv, u8 byte, unsigned int
			   register_number);
};

// slightly shorter way to access read_byte and write_byte
static inline u8 read_byte(struct tms9914_priv *priv, unsigned int register_number)
{
	return priv->read_byte(priv, register_number);
}

static inline void write_byte(struct tms9914_priv *priv, u8 byte, unsigned int register_number)
{
	priv->write_byte(priv, byte, register_number);
}

// struct tms9914_priv.state bit numbers
enum {
	PIO_IN_PROGRESS_BN,		// pio transfer in progress
	DMA_READ_IN_PROGRESS_BN,	// dma read transfer in progress
	DMA_WRITE_IN_PROGRESS_BN,	// dma write transfer in progress
	READ_READY_BN,			// board has data byte available to read
	WRITE_READY_BN,			// board is ready to send a data byte
	COMMAND_READY_BN,		// board is ready to send a command byte
	RECEIVED_END_BN,		// received END
	BUS_ERROR_BN,			// bus error
	DEV_CLEAR_BN,			// device clear received
};

// interface functions
int tms9914_read(struct gpib_board *board, struct tms9914_priv *priv, u8 *buffer,
		 size_t length, int *end, size_t *bytes_read);
int tms9914_write(struct gpib_board *board, struct tms9914_priv *priv, u8 *buffer,
		  size_t length, int send_eoi, size_t *bytes_written);
int tms9914_command(struct gpib_board *board, struct tms9914_priv *priv, u8 *buffer,
		    size_t length, size_t *bytes_written);
int tms9914_take_control(struct gpib_board *board, struct tms9914_priv *priv, int syncronous);
/*
 * alternate version of tms9914_take_control which works around buggy tcs
 * implementation.
 */
int tms9914_take_control_workaround(struct gpib_board *board, struct tms9914_priv *priv,
				    int syncronous);
int tms9914_go_to_standby(struct gpib_board *board, struct tms9914_priv *priv);
int tms9914_request_system_control(struct gpib_board *board, struct tms9914_priv *priv,
				   int request_control);
void tms9914_interface_clear(struct gpib_board *board, struct tms9914_priv *priv, int assert);
void tms9914_remote_enable(struct gpib_board *board, struct tms9914_priv *priv, int enable);
int tms9914_enable_eos(struct gpib_board *board, struct tms9914_priv *priv, u8 eos_bytes,
		       int compare_8_bits);
void tms9914_disable_eos(struct gpib_board *board, struct tms9914_priv *priv);
unsigned int tms9914_update_status(struct gpib_board *board, struct tms9914_priv *priv,
				   unsigned int clear_mask);
int tms9914_primary_address(struct gpib_board *board,
			    struct tms9914_priv *priv, unsigned int address);
int tms9914_secondary_address(struct gpib_board *board, struct tms9914_priv *priv,
			      unsigned int address, int enable);
int tms9914_parallel_poll(struct gpib_board *board, struct tms9914_priv *priv, u8 *result);
void tms9914_parallel_poll_configure(struct gpib_board *board,
				     struct tms9914_priv *priv, u8 config);
void tms9914_parallel_poll_response(struct gpib_board *board,
				    struct tms9914_priv *priv, int ist);
void tms9914_serial_poll_response(struct gpib_board *board,
				  struct tms9914_priv *priv, u8 status);
u8 tms9914_serial_poll_status(struct gpib_board *board, struct tms9914_priv *priv);
int tms9914_line_status(const struct gpib_board *board, struct tms9914_priv *priv);
unsigned int tms9914_t1_delay(struct gpib_board *board, struct tms9914_priv *priv,
			      unsigned int nano_sec);
void tms9914_return_to_local(const struct gpib_board *board, struct tms9914_priv *priv);

// utility functions
void tms9914_board_reset(struct tms9914_priv *priv);
void tms9914_online(struct gpib_board *board, struct tms9914_priv *priv);
void tms9914_release_holdoff(struct tms9914_priv *priv);
void tms9914_set_holdoff_mode(struct tms9914_priv *priv, enum tms9914_holdoff_mode mode);

// wrappers for io functions
u8 tms9914_ioport_read_byte(struct tms9914_priv *priv, unsigned int register_num);
void tms9914_ioport_write_byte(struct tms9914_priv *priv, u8 data, unsigned int register_num);
u8 tms9914_iomem_read_byte(struct tms9914_priv *priv, unsigned int register_num);
void tms9914_iomem_write_byte(struct tms9914_priv *priv, u8 data, unsigned int register_num);

// interrupt service routine
irqreturn_t tms9914_interrupt(struct gpib_board *board, struct tms9914_priv *priv);
irqreturn_t tms9914_interrupt_have_status(struct gpib_board *board, struct tms9914_priv *priv,
					  int status1,	int status2);

// tms9914 has 8 registers
enum {
	ms9914_num_registers = 8,
};

/*
 * tms9914 register numbers (might need to be multiplied by
 * a board-dependent offset to get actually io address offset)
 */
// write registers
enum {
	IMR0 = 0,	/* interrupt mask 0          */
	IMR1 = 1,	/* interrupt mask 1          */
	AUXCR = 3,	/* auxiliary command         */
	ADR = 4,	/* address register	     */
	SPMR = 5,	/* serial poll mode register */
	PPR = 6,	/* parallel poll             */
	CDOR = 7,	/* data out register         */
};

// read registers
enum {
	ISR0 = 0,	/* interrupt status 0	     */
	ISR1 = 1,	/* interrupt status 1	     */
	ADSR = 2,	/* address status	     */
	BSR = 3,	/* bus status		     */
	CPTR = 6,	/* command pass thru	     */
	DIR = 7,	/* data in register          */
};

// bit definitions common to tms9914 compatible registers

/* ISR0   - Register bits */
enum isr0_bits {
	HR_MAC = (1 << 0),   /* My Address Change           */
	HR_RLC = (1 << 1),   /* Remote/Local change         */
	HR_SPAS = (1 << 2),   /* Serial Poll active State    */
	HR_END = (1 << 3),   /* END (EOI or EOS)            */
	HR_BO = (1 << 4),   /* Byte Out                    */
	HR_BI = (1 << 5),   /* Byte In                     */
};

/* IMR0   - Register bits */
enum imr0_bits {
	HR_MACIE = (1 << 0),   /*        */
	HR_RLCIE = (1 << 1),   /*        */
	HR_SPASIE = (1 << 2),   /*        */
	HR_ENDIE = (1 << 3),   /*        */
	HR_BOIE = (1 << 4),   /*        */
	HR_BIIE = (1 << 5),   /*        */
};

/* ISR1   - Register bits */
enum isr1_bits {
	HR_IFC = (1 << 0),   /* IFC asserted                */
	HR_SRQ = (1 << 1),   /* SRQ asserted                */
	HR_MA = (1 << 2),    /* My Address                  */
	HR_DCAS = (1 << 3),  /* Device Clear active State   */
	HR_APT = (1 << 4),   /* Address pass Through        */
	HR_UNC = (1 << 5),   /* Unrecognized Command        */
	HR_ERR = (1 << 6),   /* Data Transmission Error     */
	HR_GET = (1 << 7),   /* Group execute Trigger       */
};

/* IMR1   - Register bits */
enum imr1_bits {
	HR_IFCIE = (1 << 0),   /*        */
	HR_SRQIE = (1 << 1),   /*        */
	HR_MAIE = (1 << 2),    /*        */
	HR_DCASIE = (1 << 3),  /*        */
	HR_APTIE = (1 << 4),   /*        */
	HR_UNCIE = (1 << 5),   /*        */
	HR_ERRIE = (1 << 6),   /*        */
	HR_GETIE = (1 << 7),   /*        */
};

/* ADSR   - Register bits */
enum adsr_bits {
	HR_ULPA = (1 << 0),   /* Store last address LSB       */
	HR_TA = (1 << 1),     /* Talker Adressed              */
	HR_LA = (1 << 2),     /* Listener adressed            */
	HR_TPAS = (1 << 3),   /* talker primary address state */
	HR_LPAS = (1 << 4),   /* listener    "                */
	HR_ATN = (1 << 5),    /* ATN active                   */
	HR_LLO = (1 << 6),    /* LLO active                   */
	HR_REM = (1 << 7),    /* REM active                   */
};

/* ADR   - Register bits */
enum adr_bits {
	ADDRESS_MASK = 0x1f,	/* mask to specify lower 5 bits for ADR */
	HR_DAT = (1 << 5),      /* disable talker */
	HR_DAL = (1 << 6),      /* disable listener */
	HR_EDPA = (1 << 7),     /* enable dual primary addressing */
};

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

/*---------------------------------------------------------*/
/* TMS 9914 Auxiliary Commands                             */
/*---------------------------------------------------------*/

enum aux_cmd_bits {
	AUX_CS = 0x80,			/* set bit instead of clearing it, used with commands marked 'd' below */
	AUX_CHIP_RESET = 0x0,		/* d Chip reset                   */
	AUX_INVAL = 0x1,		/* release dac holdoff, invalid command byte */
	AUX_VAL = (AUX_INVAL | AUX_CS),	/* release dac holdoff, valid command byte   */
	AUX_RHDF = 0x2,			/* X Release RFD holdoff          */
	AUX_HLDA = 0x3,			/* d holdoff on all data          */
	AUX_HLDE = 0x4,			/* d holdoff on EOI only          */
	AUX_NBAF = 0x5,			/* X Set new byte available false */
	AUX_FGET = 0x6,			/* d force GET                    */
	AUX_RTL = 0x7,			/* d return to local              */
	AUX_SEOI = 0x8,			/* X send EOI with next byte      */
	AUX_LON = 0x9,			/* d Listen only                  */
	AUX_TON = 0xa,			/* d Talk only                    */
	AUX_GTS = 0xb,			/* X goto standby                 */
	AUX_TCA = 0xc,			/* X take control asynchronously  */
	AUX_TCS = 0xd,			/* X take    "     synchronously  */
	AUX_RPP = 0xe,			/* d Request parallel poll        */
	AUX_SIC = 0xf,			/* d send interface clear         */
	AUX_SRE = 0x10,			/* d send remote enable           */
	AUX_RQC = 0x11,			/* X request control              */
	AUX_RLC = 0x12,			/* X release control              */
	AUX_DAI = 0x13,			/* d disable all interrupts       */
	AUX_PTS = 0x14,			/* X pass through next secondary  */
	AUX_STDL = 0x15,		/* d short T1 delay		  */
	AUX_SHDW = 0x16,		/* d shadow handshake             */
	AUX_VSTDL = 0x17,		/* d very short T1 delay (smj9914 extension)   */
	AUX_RSV2 = 0x18,		/* d request service bit 2 (smj9914 extension) */
};

#endif	//_TMS9914_H