/*
 * ice1usb_proto.h
 *
 * Copyright (C) 2020  Harald Welte <laforge@osmocom.org>
 * SPDX-License-Identifier: MIT
 *
 * Header file describing the USB protocol between the icE1usb firmware and the host
 * software (currently really only osmo-e1d)
 */

#pragma once

/***********************************************************************
 * Control Endpoint / Device Requests
 ***********************************************************************/

/*! returns a bit-mask of optional device capabilities (see enum e1usb_dev_capability) */
#define ICE1USB_DEV_GET_CAPABILITIES	0x01

/*! returns a string describing the firmware version */
#define ICE1USB_DEV_GET_FW_BUILD	0x02

/*! performs an I2C register access (read/write depends on direction) */
#define ICE1USB_DEV_I2C_REG_ACCESS	0x10


enum e1usb_dev_capability {
	/*! Does this board have a GPS-DO */
	ICE1USB_DEV_CAP_GPSDO,
};

/***********************************************************************
 * Control Endpoint / GPS-DO Interface Requests
 ***********************************************************************/

#define ICE1USB_INTF_GET_GPSDO_STATUS	0x10
#define ICE1USB_INTF_GET_GPSDO_MODE	0x12	/*!< uint8_t */
#define ICE1USB_INTF_SET_GPSDO_MODE	0x13	/*!< wValue = mode */
#define ICE1USB_INTF_GET_GPSDO_TUNE	0x14	/*!< data   = struct e1usb_gpsdo_tune */
#define ICE1USB_INTF_SET_GPSDO_TUNE	0x15	/*!< data   = struct e1usb_gpsdo_tune */

enum ice1usb_gpsdo_mode {
	ICE1USB_GPSDO_MODE_DISABLED	= 0,
	ICE1USB_GPSDO_MODE_AUTO		= 1,
};

enum ice1usb_gpsdo_antenna_state {
	ICE1USB_GPSDO_ANT_UNKNOWN	= 0,
	ICE1USB_GPSDO_ANT_OK		= 1,
	ICE1USB_GPSDO_ANT_OPEN		= 2,
	ICE1USB_GPSDO_ANT_SHORT		= 3,
};

enum ice1usb_gpsdo_state {
	ICE1USB_GPSDO_STATE_DISABLED	= 0,
	ICE1USB_GPSDO_STATE_CALIBRATE	= 1,
	ICE1USB_GPSDO_STATE_HOLD_OVER	= 2,
	ICE1USB_GPSDO_STATE_TUNE_COARSE	= 3,
	ICE1USB_GPSDO_STATE_TUNE_FINE	= 4,
};

struct e1usb_gpsdo_tune {
	uint16_t coarse;
	uint16_t fine;
} __attribute__((packed));

struct e1usb_gpsdo_status {
	uint8_t state;
	uint8_t antenna_state;		/*!< Antenna state */
	uint8_t valid_fix;		/*!< Valid GPS Fix (0/1) */
	uint8_t mode;			/*!< Current configured operating mode */
	struct e1usb_gpsdo_tune tune;	/*!< Current VCXO tuning values */
	uint32_t freq_est;		/*!< Latest frequency estimate measurement */
	int16_t  err_acc;		/*!< Accumulated error */
} __attribute__((packed));


/***********************************************************************
 * Control Endpoint / E1 Interface Requests
 ***********************************************************************/

/*! returns a bit-mask of optional device capabilities (see enum e1usb_intf_capability) */
#define ICE1USB_INTF_GET_CAPABILITIES	0x01
#define ICE1USB_INTF_SET_TX_CFG		0x02	/*!< struct ice1usb_tx_config */
#define ICE1USB_INTF_GET_TX_CFG		0x03	/*!< struct ice1usb_tx_config */
#define ICE1USB_INTF_SET_RX_CFG		0x04	/*!< struct ice1usb_rx_config */
#define ICE1USB_INTF_GET_RX_CFG		0x05	/*!< struct ice1usb_rx_config */
#define ICE1USB_INTF_GET_ERRORS		0x06	/*!< struct ice1usb_irq_err */

//enum e1usb_intf_capability { };

enum ice1usb_tx_mode {
	ICE1USB_TX_MODE_TRANSP		= 0,
	ICE1USB_TX_MODE_TS0		= 1,
	ICE1USB_TX_MODE_TS0_CRC4	= 2,
	ICE1USB_TX_MODE_TS0_CRC4_E	= 3,
};

enum ice1usb_tx_timing {
	ICE1USB_TX_TIME_SRC_LOCAL	= 0,
	ICE1USB_TX_TIME_SRC_REMOTE	= 1,
};

enum ice1usb_tx_ext_loopback {
	ICE1USB_TX_EXT_LOOPBACK_OFF	= 0,
	ICE1USB_TX_EXT_LOOPBACK_SAME	= 1,
	ICE1USB_TX_EXT_LOOPBACK_CROSS	= 2,
};

/* ICE1USB_INTF_{GET,SET}_TX_CFG */
struct ice1usb_tx_config {
	uint8_t mode;		/*!< enum ice1usb_tx_mode */
	uint8_t timing;		/*!< enum ice1usb_tx_timing */
	uint8_t ext_loopback;	/*!< enum ice1usb_tx_ext_loopback */
	uint8_t alarm;		/*!< 1 = transmit alarm; 0 = don't */
} __attribute__((packed));


enum ice1usb_rx_mode {
	/*! transparent, unaligned bitstream */
	ICE1USB_RX_MODE_TRANSP		= 0,
	/*! alignment to E1 frame */
	ICE1USB_RX_MODE_FRAME		= 2,
	/*! alignment to E1 multiframe */
	ICE1USB_RX_MODE_MULTIFRAME	= 3,
};

/* ICE1USB_INTF_{GET,SET}_RX_CFG */
struct ice1usb_rx_config {
	uint8_t mode;		/*!< enum ice1usb_rx_mode */
} __attribute__((packed));


/***********************************************************************
 * Interrupt Endpoint
 ***********************************************************************/

enum ice1usb_irq_type {
	ICE1USB_IRQ_T_ERRCNT		= 1,
};

/* Ensue to keep those in sync with e1.h */
#define ICE1USB_ERR_F_ALIGN_ERR	0x01
#define ICE1USB_ERR_F_LOS	0x02
#define ICE1USB_ERR_F_RAI	0x04

struct ice1usb_irq_err {
	/* 16-bit little-endian counters */
	uint16_t crc;
	uint16_t align;
	uint16_t ovfl;
	uint16_t unfl;
	uint8_t flags;
} __attribute__((packed));

struct ice1usb_irq {
	uint8_t type; 		/*!< enum ice1usb_irq_type */
	union {
		struct ice1usb_irq_err errors;
	} u;
} __attribute__((packed));