/*      $NetBSD: pcf8584reg.h,v 1.5 2026/07/12 20:51:00 thorpej Exp $ */

#ifndef _DEV_IC_PCF8584REG_H_
#define _DEV_IC_PCF8584REG_H_

/* Written by Tobias Nygren. Released into the public domain. */

/* SCL clock frequency */
#define PCF8584_SCL_90          0       /* 90 kHz */
#define PCF8584_SCL_45          1       /* 45 kHz */
#define PCF8584_SCL_11          2       /* 11 kHz */
#define PCF8584_SCL_1_5         3       /* 1.5 kHz */

/* Internal clock frequency */
#define PCF8584_CLK_3           0       /* 3 MHz */
#define PCF8584_CLK_4_43        0x10    /* 4.43 MHz */
#define PCF8584_CLK_6           0x14    /* 6 MHz */
#define PCF8584_CLK_8           0x18    /* 8 MHz */
#define PCF8584_CLK_12          0x1C    /* 12 MHz */

/* Control register bits (write only) */
#define PCF8584_CTRL_ACK        (1<<0)  /* send ACK */
#define PCF8584_CTRL_STO        (1<<1)  /* send STOP */
#define PCF8584_CTRL_STA        (1<<2)  /* send START */
#define PCF8584_CTRL_ENI        (1<<3)  /* Enable Interrupt */
#define PCF8584_CTRL_ES2        (1<<4)  /* alternate register selection */
#define PCF8584_CTRL_ES1        (1<<5)  /* alternate register selection */
#define PCF8584_CTRL_ESO        (1<<6)  /* Enable Serial Output */
#define PCF8584_CTRL_PIN        (1<<7)  /* Pending Interrupt Not */

/* Status register bits (read only) */
#define PCF8584_STATUS_BBN      (1<<0)  /* Bus Busy Not */
#define PCF8584_STATUS_LAB      (1<<1)  /* Lost Arbitration */
#define PCF8584_STATUS_AAS      (1<<2)  /* Addressed As Slave */
#define PCF8584_STATUS_LRB      (1<<3)  /* Last Received Bit (NAK+bcast det.) */
#define PCF8584_STATUS_BER      (1<<4)  /* Bus error */
#define PCF8584_STATUS_STS      (1<<5)  /* external STOP condition detected */
#define PCF8584_STATUS_INI      (1<<6)  /* 0 if initialized */
#define PCF8584_STATUS_PIN      (1<<7)  /* Pending Interrupt Not */

#define PCF8584_REG_S0_         0                       /* S0' own address */
#define PCF8584_REG_S2          PCF8584_CTRL_ES1        /* clock register */
#define PCF8584_REG_S3          PCF8584_CTRL_ES2        /* Interrupt vector */

#define PCF8584_CMD_START       (PCF8584_CTRL_PIN | PCF8584_CTRL_ESO | \
                                 PCF8584_CTRL_STA | PCF8584_CTRL_ACK)

#define PCF8584_CMD_STOP        (PCF8584_CTRL_PIN | PCF8584_CTRL_ESO | \
                                 PCF8584_CTRL_STO | PCF8584_CTRL_ACK)

#define PCF8584_CMD_REPSTART    (PCF8584_CTRL_ESO | PCF8584_CTRL_STA | \
                                 PCF8584_CTRL_ACK)

#define PCF8584_CMD_IDLE        (PCF8584_CTRL_PIN | PCF8584_CTRL_ESO | \
                                 PCF8584_CTRL_ACK)

#define PCF8584_CMD_NAK         (PCF8584_CTRL_ESO)

#endif /* _DEV_IC_PCF8584REG_H_ */