## ## This file is part of the libsigrokdecode project. ## ## Copyright (C) 2017 Gerhard Sittig ## ## This program 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; either version 2 of the License, or ## (at your option) any later version. ## ## 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; if not, see . ## # This implementation is incomplete. TODO items: # - Support the optional RESET# pin, detect cold and warm reset. # - Split slot values into audio samples of their respective width and # frequency (either on user provided parameters, or from inspection of # decoded register access). import sigrokdecode as srd class ChannelError(Exception): pass class Pins: (SYNC, BIT_CLK, SDATA_OUT, SDATA_IN, RESET) = range(5) class Ann: ( BITS_OUT, BITS_IN, SLOT_OUT_RAW, SLOT_OUT_TAG, SLOT_OUT_ADDR, SLOT_OUT_DATA, SLOT_OUT_03, SLOT_OUT_04, SLOT_OUT_05, SLOT_OUT_06, SLOT_OUT_07, SLOT_OUT_08, SLOT_OUT_09, SLOT_OUT_10, SLOT_OUT_11, SLOT_OUT_IO, SLOT_IN_RAW, SLOT_IN_TAG, SLOT_IN_ADDR, SLOT_IN_DATA, SLOT_IN_03, SLOT_IN_04, SLOT_IN_05, SLOT_IN_06, SLOT_IN_07, SLOT_IN_08, SLOT_IN_09, SLOT_IN_10, SLOT_IN_11, SLOT_IN_IO, WARN, ERROR, ) = range(32) ( BIN_FRAME_OUT, BIN_FRAME_IN, BIN_SLOT_RAW_OUT, BIN_SLOT_RAW_IN, ) = range(4) class Decoder(srd.Decoder): api_version = 3 id = 'ac97' name = "AC '97" longname = "Audio Codec '97" desc = 'Audio and modem control for PC systems.' license = 'gplv2+' inputs = ['logic'] outputs = [] tags = ['Audio', 'PC'] channels = ( {'id': 'sync', 'name': 'SYNC', 'desc': 'Frame synchronization'}, {'id': 'clk', 'name': 'BIT_CLK', 'desc': 'Data bits clock'}, ) optional_channels = ( {'id': 'out', 'name': 'SDATA_OUT', 'desc': 'Data output'}, {'id': 'in', 'name': 'SDATA_IN', 'desc': 'Data input'}, {'id': 'rst', 'name': 'RESET#', 'desc': 'Reset line'}, ) annotations = ( ('bit-out', 'Output bits'), ('bit-in', 'Input bits'), ('slot-out-raw', 'Output raw value'), ('slot-out-tag', 'Output TAG'), ('slot-out-cmd-addr', 'Output command address'), ('slot-out-cmd-data', 'Output command data'), ('slot-out-03', 'Output slot 3'), ('slot-out-04', 'Output slot 4'), ('slot-out-05', 'Output slot 5'), ('slot-out-06', 'Output slot 6'), ('slot-out-07', 'Output slot 7'), ('slot-out-08', 'Output slot 8'), ('slot-out-09', 'Output slot 9'), ('slot-out-10', 'Output slot 10'), ('slot-out-11', 'Output slot 11'), ('slot-out-io-ctrl', 'Output I/O control'), ('slot-in-raw', 'Input raw value'), ('slot-in-tag', 'Input TAG'), ('slot-in-sts-addr', 'Input status address'), ('slot-in-sts-data', 'Input status data'), ('slot-in-03', 'Input slot 3'), ('slot-in-04', 'Input slot 4'), ('slot-in-05', 'Input slot 5'), ('slot-in-06', 'Input slot 6'), ('slot-in-07', 'Input slot 7'), ('slot-in-08', 'Input slot 8'), ('slot-in-09', 'Input slot 9'), ('slot-in-10', 'Input slot 10'), ('slot-in-11', 'Input slot 11'), ('slot-in-io-sts', 'Input I/O status'), # TODO: Add more annotation classes: # TAG: 'ready', 'valid', 'id', 'rsv' # CMD ADDR: 'r/w', 'addr', 'unused' # CMD DATA: 'data', 'unused' # 3-11: 'data', 'unused', 'double data' ('warning', 'Warning'), ('error', 'Error'), ) annotation_rows = ( ('bits-out', 'Output bits', (Ann.BITS_OUT,)), ('slots-out-raw', 'Output numbers', (Ann.SLOT_OUT_RAW,)), ('slots-out', 'Output slots', ( Ann.SLOT_OUT_TAG, Ann.SLOT_OUT_ADDR, Ann.SLOT_OUT_DATA, Ann.SLOT_OUT_03, Ann.SLOT_OUT_04, Ann.SLOT_OUT_05, Ann.SLOT_OUT_06, Ann.SLOT_OUT_07, Ann.SLOT_OUT_08, Ann.SLOT_OUT_09, Ann.SLOT_OUT_10, Ann.SLOT_OUT_11, Ann.SLOT_OUT_IO,)), ('bits-in', 'Input bits', (Ann.BITS_IN,)), ('slots-in-raw', 'Input numbers', (Ann.SLOT_IN_RAW,)), ('slots-in', 'Input slots', ( Ann.SLOT_IN_TAG, Ann.SLOT_IN_ADDR, Ann.SLOT_IN_DATA, Ann.SLOT_IN_03, Ann.SLOT_IN_04, Ann.SLOT_IN_05, Ann.SLOT_IN_06, Ann.SLOT_IN_07, Ann.SLOT_IN_08, Ann.SLOT_IN_09, Ann.SLOT_IN_10, Ann.SLOT_IN_11, Ann.SLOT_IN_IO,)), ('warnings', 'Warnings', (Ann.WARN,)), ('errors', 'Errors', (Ann.ERROR,)), ) binary = ( ('frame-out', 'Frame bits, output data'), ('frame-in', 'Frame bits, input data'), ('slot-raw-out', 'Raw slot bits, output data'), ('slot-raw-in', 'Raw slot bits, input data'), # TODO: Which (other) binary classes to implement? # - Are binary annotations per audio slot useful? # - Assume 20bit per slot, in 24bit units? Or assume 16bit # audio samples? Observe register access and derive width # of the audio data? Dump channels 3-11 or 1-12? ) def putx(self, ss, es, cls, data): self.put(ss, es, self.out_ann, [cls, data]) def putf(self, frombit, bitcount, cls, data): ss = self.frame_ss_list[frombit] es = self.frame_ss_list[frombit + bitcount] self.putx(ss, es, cls, data) def putb(self, frombit, bitcount, cls, data): ss = self.frame_ss_list[frombit] es = self.frame_ss_list[frombit + bitcount] self.put(ss, es, self.out_binary, [cls, data]) def __init__(self): self.out_binary = None self.out_ann = None self.reset() def reset(self): self.frame_ss_list = None self.frame_slot_lens = [0, 16] + [16 + 20 * i for i in range(1, 13)] self.frame_total_bits = self.frame_slot_lens[-1] self.handle_slots = { 0: self.handle_slot_00, 1: self.handle_slot_01, 2: self.handle_slot_02, } def start(self): if not self.out_binary: self.out_binary = self.register(srd.OUTPUT_BINARY) if not self.out_ann: self.out_ann = self.register(srd.OUTPUT_ANN) def metadata(self, key, value): if key == srd.SRD_CONF_SAMPLERATE: self.samplerate = value def bits_to_int(self, bits): # Convert MSB-first bit sequence to integer value. if not bits: return 0 count = len(bits) value = sum([2 ** (count - 1 - i) for i in range(count) if bits[i]]) return value def bits_to_bin_ann(self, bits): # Convert MSB-first bit sequence to binary annotation data. # It's assumed that the number of bits does not (in useful ways) # fit into an integer, and we need to create an array of bytes # from the data afterwards, anyway. Hence the separate routine # and the conversion of eight bits each. out = [] count = len(bits) while count > 0: count -= 8 by, bits = bits[:8], bits[8:] by = self.bits_to_int(by) out.append(by) out = bytes(out) return out def int_to_nibble_text(self, value, bitcount): # Convert number to hex digits for given bit count. digits = (bitcount + 3) // 4 text = '{{:0{:d}x}}'.format(digits).format(value) return text def get_bit_field(self, data, size, off, count): shift = size - off - count data >>= shift mask = (1 << count) - 1 data &= mask return data def flush_frame_bits(self): # Flush raw frame bits to binary annotation. anncls = Ann.BIN_FRAME_OUT data = self.frame_bits_out[:] count = len(data) data = self.bits_to_bin_ann(data) self.putb(0, count, anncls, data) anncls = Ann.BIN_FRAME_IN data = self.frame_bits_in[:] count = len(data) data = self.bits_to_bin_ann(data) self.putb(0, count, anncls, data) def start_frame(self, ss): # Mark the start of a frame. if self.frame_ss_list: # Flush bits if we had a frame before the frame which is # starting here. self.flush_frame_bits() self.frame_ss_list = [ss] self.frame_bits_out = [] self.frame_bits_in = [] self.frame_slot_data_out = [] self.frame_slot_data_in = [] self.have_slots = {True: None, False: None} def handle_slot_dummy(self, slotidx, bitidx, bitcount, is_out, data): # Handle slot x, default/fallback handler. # Only process data of slots 1-12 when slot 0 says "valid". if not self.have_slots[is_out]: return if not self.have_slots[is_out][slotidx]: return # Emit a naive annotation with just the data bits that we saw # for the slot (hex nibbles for density). For audio data this # can be good enough. Slots with special meaning should not end # up calling the dummy handler. text = self.int_to_nibble_text(data, bitcount) anncls = Ann.SLOT_OUT_TAG if is_out else Ann.SLOT_IN_TAG self.putf(bitidx, bitcount, anncls + slotidx, [text]) # Emit binary output for the data that is contained in slots # which end up calling the default handler. This transparently # should translate to "the slots with audio data", as other # slots which contain management data should have their specific # handler routines. In the present form, this approach might be # good enough to get a (header-less) audio stream for typical # setups where only line-in or line-out are in use. # # TODO: Improve this early prototype implementation. For now the # decoder just exports the upper 16 bits of each audio channel # that happens to be valid. For an improved implementation, it # either takes user provided specs or more smarts like observing # register access (if the capture includes it). anncls = Ann.BIN_SLOT_RAW_OUT if is_out else Ann.BIN_SLOT_RAW_IN data_bin = data >> 4 data_bin &= 0xffff data_bin = data_bin.to_bytes(2, byteorder = 'big') self.putb(bitidx, bitcount, anncls, data_bin) def handle_slot_00(self, slotidx, bitidx, bitcount, is_out, data): # Handle slot 0, TAG. slotpos = self.frame_slot_lens[slotidx] fieldoff = 0 anncls = Ann.SLOT_OUT_TAG if is_out else Ann.SLOT_IN_TAG fieldlen = 1 ready = self.get_bit_field(data, bitcount, fieldoff, fieldlen) text = ['READY: 1', 'READY', 'RDY', 'R'] if ready else ['ready: 0', 'rdy', '-'] self.putf(slotpos + fieldoff, fieldlen, anncls, text) fieldoff += fieldlen fieldlen = 12 valid = self.get_bit_field(data, bitcount, fieldoff, fieldlen) text = ['VALID: {:3x}'.format(valid), '{:3x}'.format(valid)] self.putf(slotpos + fieldoff, fieldlen, anncls, text) have_slots = [True] + [False] * 12 for idx in range(12): have_slots[idx + 1] = bool(valid & (1 << (11 - idx))) self.have_slots[is_out] = have_slots fieldoff += fieldlen fieldlen = 1 rsv = self.get_bit_field(data, bitcount, fieldoff, fieldlen) if rsv != 0: text = ['reserved bit error', 'rsv error', 'rsv'] self.putf(slotpos + fieldoff, fieldlen, Ann.ERROR, text) fieldoff += fieldlen # TODO: Will input slot 0 have a Codec ID, or 3 reserved bits? fieldlen = 2 codec = self.get_bit_field(data, bitcount, fieldoff, fieldlen) text = ['CODEC: {:1x}'.format(codec), '{:1x}'.format(codec)] self.putf(slotpos + fieldoff, fieldlen, anncls, text) fieldoff += fieldlen def handle_slot_01(self, slotidx, bitidx, bitcount, is_out, data): # Handle slot 1, command/status address. slotpos = self.frame_slot_lens[slotidx] if not self.have_slots[is_out]: return if not self.have_slots[is_out][slotidx]: return fieldoff = 0 anncls = Ann.SLOT_OUT_TAG if is_out else Ann.SLOT_IN_TAG anncls += slotidx fieldlen = 1 if is_out: is_read = self.get_bit_field(data, bitcount, fieldoff, fieldlen) text = ['READ', 'RD', 'R'] if is_read else ['WRITE', 'WR', 'W'] self.putf(slotpos + fieldoff, fieldlen, anncls, text) # TODO: Check for the "atomic" constraint? Some operations # involve address _and_ data, which cannot be spread across # several frames. Slot 0 and 1 _must_ be provided within the # same frame (the test should occur in the handler for slot # 2 of course, in slot 1 we don't know what will follow). else: rsv = self.get_bit_field(data, bitcount, fieldoff, fieldlen) if rsv != 0: text = ['reserved bit error', 'rsv error', 'rsv'] self.putf(slotpos + fieldoff, fieldlen, Ann.ERROR, text) fieldoff += fieldlen fieldlen = 7 regaddr = self.get_bit_field(data, bitcount, fieldoff, fieldlen) # TODO: Present 0-63 or 0-126 as the address of the 16bit register? text = ['ADDR: {:2x}'.format(regaddr), '{:2x}'.format(regaddr)] self.putf(slotpos + fieldoff, fieldlen, anncls, text) if regaddr & 0x01: text = ['odd register address', 'odd reg addr', 'odd addr', 'odd'] self.putf(slotpos + fieldoff, fieldlen, Ann.ERROR, text) fieldoff += fieldlen # Strictly speaking there are 10 data request bits and 2 reserved # bits for input slots, and 12 reserved bits for output slots. We # test for 10 and 2 bits, to simplify the logic. Only in case of # non-zero reserved bits for outputs this will result in "a little # strange" an annotation. This is a cosmetic issue, we don't mind. fieldlen = 10 reqdata = self.get_bit_field(data, bitcount, fieldoff, fieldlen) if is_out and reqdata != 0: text = ['reserved bit error', 'rsv error', 'rsv'] self.putf(slotpos + fieldoff, fieldlen, Ann.ERROR, text) if not is_out: text = ['REQ: {:3x}'.format(reqdata), '{:3x}'.format(reqdata)] self.putf(slotpos + fieldoff, fieldlen, anncls, text) fieldoff += fieldlen fieldlen = 2 rsv = self.get_bit_field(data, bitcount, fieldoff, fieldlen) if rsv != 0: text = ['reserved bit error', 'rsv error', 'rsv'] self.putf(slotpos + fieldoff, fieldlen, Ann.ERROR, text) fieldoff += fieldlen def handle_slot_02(self, slotidx, bitidx, bitcount, is_out, data): # Handle slot 2, command/status data. slotpos = self.frame_slot_lens[slotidx] if not self.have_slots[is_out]: return if not self.have_slots[is_out][slotidx]: return fieldoff = 0 anncls = Ann.SLOT_OUT_TAG if is_out else Ann.SLOT_IN_TAG anncls += slotidx fieldlen = 16 rwdata = self.get_bit_field(data, bitcount, fieldoff, fieldlen) # TODO: Check for zero output data when the operation is a read. # TODO: Check for the "atomic" constraint. text = ['DATA: {:4x}'.format(rwdata), '{:4x}'.format(rwdata)] self.putf(slotpos + fieldoff, fieldlen, anncls, text) fieldoff += fieldlen fieldlen = 4 rsv = self.get_bit_field(data, bitcount, fieldoff, fieldlen) if rsv != 0: text = ['reserved bits error', 'rsv error', 'rsv'] self.putf(slotpos + fieldoff, fieldlen, Ann.ERROR, text) fieldoff += fieldlen # TODO: Implement other slots. # - 1: cmd/status addr (check status vs command) # - 2: cmd/status data (check status vs command) # - 3-11: audio out/in # - 12: io control/status (modem GPIO(?)) def handle_slot(self, slotidx, data_out, data_in): # Process a received slot of a frame. func = self.handle_slots.get(slotidx, self.handle_slot_dummy) bitidx = self.frame_slot_lens[slotidx] bitcount = self.frame_slot_lens[slotidx + 1] - bitidx if data_out is not None: func(slotidx, bitidx, bitcount, True, data_out) if data_in is not None: func(slotidx, bitidx, bitcount, False, data_in) def handle_bits(self, ss, es, bit_out, bit_in): # Process a received pair of bits. # Emit the bits' annotations. Only interpret the data when we # are in a frame (have seen the start of the frame, and don't # exceed the expected number of bits in a frame). if bit_out is not None: self.putx(ss, es, Ann.BITS_OUT, ['{:d}'.format(bit_out)]) if bit_in is not None: self.putx(ss, es, Ann.BITS_IN, ['{:d}'.format(bit_in)]) if self.frame_ss_list is None: return self.frame_ss_list.append(es) have_len = len(self.frame_ss_list) - 1 if have_len > self.frame_total_bits: return # Accumulate the bits within the frame, until one slot of the # frame has become available. slot_idx = 0 if bit_out is not None: self.frame_bits_out.append(bit_out) slot_idx = len(self.frame_slot_data_out) if bit_in is not None: self.frame_bits_in.append(bit_in) slot_idx = len(self.frame_slot_data_in) want_len = self.frame_slot_lens[slot_idx + 1] if have_len != want_len: return prev_len = self.frame_slot_lens[slot_idx] # Convert bits to integer values. This shall simplify extraction # of bit fields in multiple other locations. slot_data_out = None if bit_out is not None: slot_bits = self.frame_bits_out[prev_len:] slot_data = self.bits_to_int(slot_bits) self.frame_slot_data_out.append(slot_data) slot_data_out = slot_data slot_data_in = None if bit_in is not None: slot_bits = self.frame_bits_in[prev_len:] slot_data = self.bits_to_int(slot_bits) self.frame_slot_data_in.append(slot_data) slot_data_in = slot_data # Emit simple annotations for the integer values, until upper # layer decode stages will be implemented. slot_len = have_len - prev_len slot_ss = self.frame_ss_list[prev_len] slot_es = self.frame_ss_list[have_len] if slot_data_out is not None: slot_text = self.int_to_nibble_text(slot_data_out, slot_len) self.putx(slot_ss, slot_es, Ann.SLOT_OUT_RAW, [slot_text]) if slot_data_in is not None: slot_text = self.int_to_nibble_text(slot_data_in, slot_len) self.putx(slot_ss, slot_es, Ann.SLOT_IN_RAW, [slot_text]) self.handle_slot(slot_idx, slot_data_out, slot_data_in) def decode(self): have_sdo = self.has_channel(Pins.SDATA_OUT) have_sdi = self.has_channel(Pins.SDATA_IN) if not have_sdo and not have_sdi: raise ChannelError('Either SDATA_OUT or SDATA_IN (or both) are required.') have_reset = self.has_channel(Pins.RESET) # Data is sampled at falling CLK edges. Annotations need to span # the period between rising edges. SYNC rises one cycle _before_ # the start of a frame. Grab the earliest SYNC sample we can get # and advance to the start of a bit time. Then keep getting the # samples and the end of all subsequent bit times. prev_sync = [None, None, None] pins = self.wait({Pins.BIT_CLK: 'e'}) if pins[Pins.BIT_CLK] == 0: prev_sync[-1] = pins[Pins.SYNC] pins = self.wait({Pins.BIT_CLK: 'r'}) bit_ss = self.samplenum while True: pins = self.wait({Pins.BIT_CLK: 'f'}) prev_sync.pop(0) prev_sync.append(pins[Pins.SYNC]) self.wait({Pins.BIT_CLK: 'r'}) if prev_sync[0] == 0 and prev_sync[1] == 1: self.start_frame(bit_ss) self.handle_bits(bit_ss, self.samplenum, pins[Pins.SDATA_OUT] if have_sdo else None, pins[Pins.SDATA_IN] if have_sdi else None) bit_ss = self.samplenum