#!/usr/bin/python
#
# Copyright 2014-present Facebook. All Rights Reserved.
#
# This program file is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the
# Free Software Foundation; version 2 of the License.
#
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
# for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program in a file named COPYING; if not, write to the
# Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor,
# Boston, MA 02110-1301 USA
#

from argparse import ArgumentParser
import subprocess
import time

IO_BASE = [ 0x1e660000, 0x1e680000 ]
PHYCR_REG_OFFSET = 0x60
PHYCR_READ_BIT = 0x1 << 26
PHYCR_WRITE_BIT = 0x1 << 27
phycr_reg = lambda mac: IO_BASE[mac - 1] + PHYCR_REG_OFFSET
PHYDATA_REG_OFFSET = 0x64
phydata_reg = lambda mac: IO_BASE[mac - 1] + PHYDATA_REG_OFFSET


devmem_read_cmd = lambda reg: [ 'devmem', hex(reg) ]
devmem_write_cmd = lambda reg, val: [ 'devmem', hex(reg), '32', hex(val)]


def devmem_read(reg):
    cmd = devmem_read_cmd(reg)
    #print('Cmd: {}'.format(cmd))
    out = subprocess.Popen(cmd, stdout=subprocess.PIPE).communicate()[0]
    return int(out, 0)


def devmem_write(reg, val):
    cmd = devmem_write_cmd(reg, val)
    #print('Cmd: {}'.format(cmd))
    subprocess.Popen(cmd, stdout=subprocess.PIPE).communicate()[0]


def wait_for_mdio_done(args):
    reg = phycr_reg(args.mac)
    while devmem_read(reg) & (PHYCR_READ_BIT|PHYCR_WRITE_BIT):
        time.sleep(0.010)       # 10ms


def read_mdio(args):
    reg = phycr_reg(args.mac)
    ctrl = devmem_read(reg)
    ctrl &= 0x3000003f
    ctrl |= (args.phy & 0x1F) << 16
    ctrl |= (args.register & 0x1F) << 21
    ctrl |= PHYCR_READ_BIT
    devmem_write(reg, ctrl)
    wait_for_mdio_done(args)
    val = devmem_read(phydata_reg(args.mac)) >> 16
    print('Read from PHY ({}.{}): {}'
          .format(hex(args.phy), hex(args.register), hex(val)))


def write_mdio(args):
    ctrl_reg = phycr_reg(args.mac)
    ctrl = devmem_read(ctrl_reg)
    ctrl &= 0x3000003f
    ctrl |= (args.phy & 0x1F) << 16
    ctrl |= (args.register & 0x1F) << 21
    ctrl |= PHYCR_WRITE_BIT
    data_reg = phydata_reg(args.mac)
    # write data first
    devmem_write(data_reg, args.value)
    # then ctrl
    devmem_write(ctrl_reg, ctrl)
    wait_for_mdio_done(args)
    print('Write to PHY ({}.{}): {}'
          .format(hex(args.phy), hex(args.register), hex(args.value)))


def auto_int(x):
    return int(x, 0)

if __name__ == '__main__':
    ap = ArgumentParser()
    ap.add_argument('--mac', '-m', type=int, default=2,
                    help='The MAC')
    ap.add_argument('--phy', '-p', type=auto_int, default=0x1f,
                    help='The PHY address')

    subparsers = ap.add_subparsers()

    read_parser = subparsers.add_parser('read',
                                        help='read MDIO')
    read_parser.set_defaults(func=read_mdio)
    read_parser.add_argument('register', type=auto_int,
                             help='The register to read from')

    write_parser = subparsers.add_parser('write',
                                         help='write MDIO')
    write_parser.set_defaults(func=write_mdio)
    write_parser.add_argument('register', type=auto_int,
                              help='The register to write to')
    write_parser.add_argument('value', type=auto_int,
                              help='The value to write to')

    args = ap.parse_args()

    if args.mac != 2 and args.mac != 1:
        print("MAC can only be either 1 or 2.")
        exit(-1)

    if args.phy > 0x1f:
        printf("PHY address must be smaller than 0x1f.")
        exit(-2)

    args.func(args)