#!/usr/bin/env python3
# -*- coding: utf-8 -*-
#
# Copyright (C) 2017-2020  The Project X-Ray Authors.
#
# Use of this source code is governed by a ISC-style
# license that can be found in the LICENSE file or at
# https://opensource.org/licenses/ISC
#
# SPDX-License-Identifier: ISC
import argparse

REGISTER_LAYOUT = {
    'CLKOUT1': [
        ('LOW_TIME', 6),
        ('HIGH_TIME', 6),
        ('OUTPUT_ENABLE', 1),
        ('PHASE_MUX', 3),
    ],
    'CLKOUT2': [
        ('DELAY_TIME', 6),
        ('NO_COUNT', 1),
        ('EDGE', 1),
        ('MX', 2),
        ('FRAC_WF_R', 1),
        ('FRAC_EN', 1),
        ('FRAC', 3),
        ('RESERVED', 1),
    ],
    'CLKOUT2_FRACTIONAL': [
        ('DELAY_TIME', 6),
        ('NO_COUNT', 1),
        ('EDGE', 1),
        ('MX', 2),
        ('FRAC_WF_F', 1),
        ('PHASE_MUX_F', 3),
        ('RESERVED', 2),
    ],
    'DIVCLK': [
        ('LOW_TIME', 6),
        ('HIGH_TIME', 6),
        ('NO_COUNT', 1),
        ('EDGE', 1),
        ('RESERVED', 2),
    ],
    'LOCKREG1': [
        ('LKTABLE', 10, 20),
        ('LOCKREG1_RESERVED', 6, 0),
    ],
    'LOCKREG2': [
        ('LKTABLE', 10, 0),
        ('LKTABLE', 5, 30),
        ('LOCKREG2_RESERVED', 1, 0),
    ],
    'LOCKREG3': [
        ('LKTABLE', 10, 10),
        ('LKTABLE', 5, 35),
        ('LOCKREG3_RESERVED', 1, 0),
    ],
    'FILTREG1': [
        ('FILTREG1_RESERVED', 8, 0),
        ('TABLE', 1, 6),
        ('FILTREG1_RESERVED', 2, 8),
        ('TABLE', 2, 7),
        ('FILTREG1_RESERVED', 2, 10),
        ('TABLE', 1, 9),
    ],
    'FILTREG2': [
        ('FILTREG2_RESERVED', 4, 0),
        ('TABLE', 1, 0),
        ('FILTREG2_RESERVED', 2, 4),
        ('TABLE', 2, 1),
        ('FILTREG2_RESERVED', 2, 6),
        ('TABLE', 2, 3),
        ('FILTREG2_RESERVED', 2, 8),
        ('TABLE', 1, 5),
    ],
    'POWER_REG': [
        ('POWER_REG', 16),
    ],
}

BASE_OFFSET = 0x00
REGISTER_MAP = []

REGISTER_MAP.append(None)
REGISTER_MAP.append(None)

for idx in range(3):
    REGISTER_MAP.append(None)

REGISTER_MAP.append(None)

# 0x06 - 0x15
for output in ['CLKOUT5', 'CLKOUT0', 'CLKOUT1', 'CLKOUT2', 'CLKOUT3',
               'CLKOUT4', 'CLKOUT6', 'CLKFBOUT']:
    if output is not None:
        REGISTER_MAP.append(('CLKOUT1', output))
        if output in ['CLKOUT5', 'CLKOUT6']:
            # CLKOUT5 CLKOUT2 register actually controls the fractional of
            # CLKOUT0.
            # CLKOUT6 CLKOUT2 register actually controls the fractional of
            # CLKFBOUT.
            REGISTER_MAP.append(('CLKOUT2_FRACTIONAL', output))
        else:
            REGISTER_MAP.append(('CLKOUT2', output))
    else:
        REGISTER_MAP.append(None)
        REGISTER_MAP.append(None)

# 0x16
REGISTER_MAP.append(('DIVCLK', 'DIVCLK'))
# 0x17
REGISTER_MAP.append(None)
# 0x18-0x1A
REGISTER_MAP.append(('LOCKREG1', 'LOCKREG1'))
REGISTER_MAP.append(('LOCKREG2', 'LOCKREG2'))
REGISTER_MAP.append(('LOCKREG3', 'LOCKREG3'))

for _ in range(0x28 - 0x1A - 1):
    REGISTER_MAP.append(None)

REGISTER_MAP.append(('POWER_REG', 'POWER_REG'))

for _ in range(0x4E - 0x28 - 1):
    REGISTER_MAP.append(None)

# 0x4E - 0x4F
REGISTER_MAP.append(('FILTREG1', 'FILTREG1'))
REGISTER_MAP.append(('FILTREG2', 'FILTREG2'))

for _ in range(0x20):
    REGISTER_MAP.append(None)


class RegisterAddress(object):
    def __init__(self, frame_offsets, bit_offset, reverse=False):
        self.frame_index = 0
        self.frame_offsets = frame_offsets
        self.bit_offset = bit_offset
        self.bits_used = set()
        self.reverse = reverse

    def next_bit(self, used=True):
        output = '{}_{}'.format(
            self.frame_offsets[self.frame_index], self.bit_offset)

        if used:
            self.bits_used.add(output)

        self.frame_index += 1
        if self.frame_index >= len(self.frame_offsets):
            self.frame_index = 0
            if self.reverse:
                self.bit_offset -= 1
            else:
                self.bit_offset += 1

        return output


def passthrough_non_register_segbits(seg_in):
    """ Filter input segbits file and capture register base offset.

    Some MMCM bit ranges are documented registers in the PLL/MMCM dynamic
    reconfiguration iterface.  These features will be generated in
    output_registers.  In order for output_registers to function, it needs
    the starting bit offset of the register space, which is based off of
    base_offset_register segbit definition.

    Other features generated in fuzzing are passed through.

    """
    base_offset_register = 'CMT_LOWER_B.MMCME2_ADV.CLKOUT5_DIVIDE[1]'

    bit_offset = None
    in_use = None
    with open(seg_in, 'r') as f:
        for l in f:
            if l.startswith(base_offset_register):
                parts = l.split()
                assert len(parts) == 2
                assert parts[0] == base_offset_register
                frame_offset, bit_index = map(int, parts[1].split('_'))

                assert frame_offset == 29
                assert bit_index > 3
                bit_offset = bit_index + 3 + 3 * 16

                continue

            if 'IN_USE' in l:
                assert in_use is None
                in_use = l.strip()
                continue

            parts = l.split()
            feature_parts = parts[0].split('.')

            if len(feature_parts) < 3:
                print(l.strip())
                continue

            if feature_parts[2] == 'BANDWIDTH':
                continue

            if '[' not in feature_parts[2]:
                print(l.strip())
                continue

            base_feature = feature_parts[2].split('[')

            if base_feature[0] in [
                    'CLKOUT0_DIVIDE_F',
                    'CLKOUT1_DIVIDE',
                    'CLKOUT2_DIVIDE',
                    'CLKOUT3_DIVIDE',
                    'CLKOUT4_DIVIDE',
                    'CLKOUT5_DIVIDE',
                    'CLKOUT6_DIVIDE',
                    'DIVCLK_DIVIDE',
                    'CLKFBOUT_MULT_F',
                    'CLKOUT0_DUTY_CYCLE',
            ]:
                # These features are MMCM registers, so ignore the base
                continue

            print(l.strip())

    assert bit_offset is not None
    assert in_use is not None
    return bit_offset, in_use


def output_registers(bit_offset, in_use):
    """ Output segbits for the known MMCM register space.

    The first bit offset in the register space is required to generate this
    output.

    """
    reg = RegisterAddress(
        frame_offsets=[29, 28], bit_offset=bit_offset, reverse=True)

    for idx, register in enumerate(REGISTER_MAP):
        if register is None:
            for _ in range(16):
                reg.next_bit(used=False)
            continue

        layout, register_name = register

        layout_bits = REGISTER_LAYOUT[layout]

        simple_layout = len(layout_bits[0]) == 2

        if True:
            bit_count = 0
            if simple_layout:
                for field, width in layout_bits:
                    for bit in range(width):
                        bit_count += 1

                        if field is None:
                            reg.next_bit(used=False)
                            continue

                        print(
                            'CMT_LOWER_B.MMCME2_ADV.{}_{}_{}[{}] {}'.format(
                                register_name, layout, field, bit,
                                reg.next_bit()))
            else:
                for field, width, start_bit in layout_bits:
                    for bit in range(width):
                        bit_count += 1

                        if field is None:
                            reg.next_bit(used=False)
                            continue

                        print(
                            'CMT_LOWER_B.MMCME2_ADV.{}[{}] {}'.format(
                                field, start_bit + bit, reg.next_bit()))

            assert bit_count == 16
        else:
            for bit in range(16):
                if register_name != layout or layout in ['CLKOUT1', 'CLKOUT2']:
                    print(
                        'CMT_LOWER_B.MMCME2_ADV.{}_{}[{}] {}'.format(
                            register_name, layout, bit, reg.next_bit()))
                else:
                    print(
                        'CMT_LOWER_B.MMCME2_ADV.{}[{}] {}'.format(
                            register_name, bit, reg.next_bit()))

    parts = in_use.split()
    feature = parts[0]
    bits = [p for p in parts[1:] if p not in reg.bits_used]
    print('{} {}'.format(feature, ' '.join(bits)))


def main():
    parser = argparse.ArgumentParser(description="")

    parser.add_argument('--seg_in')

    args = parser.parse_args()

    bit_offset, in_use = passthrough_non_register_segbits(args.seg_in)

    output_registers(bit_offset, in_use)


if __name__ == "__main__":
    main()