diff options
Diffstat (limited to 'meta-facebook/meta-yosemite/recipes-yosemite/fbutils/files/at93c46.py')
| -rw-r--r-- | meta-facebook/meta-yosemite/recipes-yosemite/fbutils/files/at93c46.py | 276 |
1 files changed, 0 insertions, 276 deletions
diff --git a/meta-facebook/meta-yosemite/recipes-yosemite/fbutils/files/at93c46.py b/meta-facebook/meta-yosemite/recipes-yosemite/fbutils/files/at93c46.py deleted file mode 100644 index 9fa9f05..0000000 --- a/meta-facebook/meta-yosemite/recipes-yosemite/fbutils/files/at93c46.py +++ /dev/null @@ -1,276 +0,0 @@ -# Copyright 2004-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 -# - -import subprocess -import struct -import sys - -class VerboseLogger: - def __init__(self, verbose=False): - self.verbose = verbose - - def _verbose_print(self, caption, bytestream=None): - ''' - Print a bytestream to stdout if verbose is enabled. - ''' - if self.verbose: - if bytestream is not None: - sys.stderr.write("{}: {}\n".format(caption, " ".join(['{:02X}'.format(ord(x)) for x in bytestream]))) - else: - sys.stderr.write("{}\n".format(caption)) - -class AT93C46SPI(VerboseLogger): - '''The class to access AT93C46 through SPI intf''' - SPI_CMD = 'spi-bb' - - def __init__(self, bus_width, gpio_cs, gpio_ck, gpio_do, gpio_di, - verbose=False): - if bus_width != 8 and bus_width != 16: - raise Exception("Invalid bus width for AT93C46!") - - self.bus_width = bus_width - self.gpio_cs = gpio_cs - self.gpio_ck = gpio_ck - self.gpio_do = gpio_do - self.gpio_di = gpio_di - self.verbose = verbose - - self.addr_bits = 6 if self.bus_width == 16 else 7 - self.addr_mask = 0x3F if self.bus_width == 16 else 0x7F - - def __shift(self, bytestream, value): - ''' - Shift an entire byte stream by value bits. - ''' - binary = "".join(['{:08b}'.format(ord(x)) for x in bytestream]) - if value > 0: - binary = binary[value:] + '0' * value - else: - binary = '0' * (-value) + binary[:value] - return "".join([chr(int(binary[x:x+8],2)) for x in range(0, len(binary), 8)]) - - def __io(self, op, addr, data=None): - ''' - Perform an IO operation against the EEPROM - ''' - write_bits = self.addr_bits + 3 - if data is not None: - # If giving data, we are doing a write command so - # no need to read any data. - write_bits = write_bits + self.bus_width - read_bits = 0 - else: - # If not giving data, we are doing either a read - # command or a set command, so read the result. - # We pad with an extra bit due to a dummy bit introduced - # by a delay for address decoding on chip. - read_bits = self.addr_bits + 4 + self.bus_width - - # Format the command itself - cmd_loc = 6 if self.bus_width == 16 else 7 - instruction = addr & self.addr_mask - instruction = instruction | ((0x4 | (op & 0x3)) << cmd_loc) - if data is not None: - if self.bus_width == 16: - write_data = struct.pack(">HH", instruction, data & 0xFFFF) - else: - write_data = struct.pack(">HB", instruction, data & 0xFF) - else: - write_data = struct.pack(">H", instruction) - write_data = self.__shift(write_data, 16 - (cmd_loc + 3)) - - self._verbose_print("Write data", write_data) - - # Run the command with the bitbang driver - if read_bits > 0: - data_portion = "-r {} -w {}".format(read_bits, write_bits) - else: - data_portion = "-w {}".format(write_bits) - - cmd = "{} -s {} -c {} -o {} -i {} -b {}".format( - self.SPI_CMD, self.gpio_cs, self.gpio_ck, self.gpio_do, - self.gpio_di, data_portion - ) - - self._verbose_print("Command: {}".format(cmd)) - - out = subprocess.Popen(cmd.split(), - stdout=subprocess.PIPE, - stdin = subprocess.PIPE)\ - .communicate(input=write_data) - - # Format the response - read_data = self.__shift(out[0], cmd_loc + 4) - if self.bus_width == 16: - read_data = read_data[:2] - self._verbose_print("Read data", read_data) - return struct.unpack(">H", read_data)[0] - else: - read_data = read_data[:1] - self._verbose_print("Read data", read_data) - return struct.unpack(">B", read_data)[0] - - def read(self, addr): - return self.__io(0x2, addr) - - def ewen(self): - self.__io(0x0, 0x3 << (self.addr_bits - 2)) - - def erase(self, addr): - self.__io(0x3, addr) - - def write(self, addr, data): - self.__io(0x1, addr, data) - - def eral(self): - self.__io(0x0, 0x2 << (self.addr_bits - 2)) - - def wral(self, data): - self.__io(0x0, 0x1 << (self.addr_bits - 2), data) - - def ewds(self): - self.__io(0x0, 0x0) - -class AT93C46(VerboseLogger): - ''' - The class which handles accessing memory on the AT93C46 chip. - ''' - AT93C46_MEMORY_SIZE = 128 - - def __init__(self, bus_width, gpio_cs, gpio_ck, gpio_do, gpio_di, - byte_swap, verbose=False): - self.bus_width = bus_width - self.verbose = verbose - self.byte_swap = byte_swap - - self.spi = AT93C46SPI(bus_width=bus_width, gpio_cs=gpio_cs, - gpio_ck=gpio_ck, gpio_do=gpio_do, - gpio_di=gpio_di, verbose=verbose) - - def __swap(self, value): - ''' - Swap bytes for a 16-bit integer if instructed to do so. - ''' - if self.bus_width == 16: - if self.byte_swap: - return ((value >> 8) & 0xFF) | ((value << 8) & 0xFF00) - else: - return value - else: - return value - - def erase(self, offset=None, limit=None): - ''' - Erase the chip. - ''' - if offset is None: - offset = 0 - if limit is None: - limit = self.AT93C46_MEMORY_SIZE - - if offset < 0 or offset + limit > self.AT93C46_MEMORY_SIZE: - raise Exception("Erase would be out of bounds!") - if self.bus_width == 16 and \ - ((offset & 1) != 0 or ((offset + limit) & 1) != 0): - raise Exception("Erase can't start or end on odd boundary in 16-bit mode!") - - if offset == 0 and limit == self.AT93C46_MEMORY_SIZE: - # Special case when we are erasing the entire chip - self.spi.ewen() - self.spi.eral() - self.spi.ewds() - - self._verbose_print("Erased entire chip") - else: - # Regular case - if self.bus_width == 16: - real_offset = offset / 2 - real_limit = limit / 2 - else: - real_offset = offset - real_limit = limit - - self.spi.ewen() - for addr in range(real_offset, real_offset + real_limit): - self.spi.erase(addr) - self.spi.ewds() - - self._verbose_print("Erased {} bytes from offset {}".format(limit, offset)) - - def read(self, offset=None, limit=None): - ''' - Read the chip into a memory buffer. - ''' - if offset is None: - offset = 0 - if limit is None: - limit = self.AT93C46_MEMORY_SIZE - - if offset < 0 or offset + limit > self.AT93C46_MEMORY_SIZE: - raise Exception("Read would be out of bounds!") - if self.bus_width == 16 and \ - ((offset & 1) != 0 or ((offset + limit) & 1) != 0): - raise Exception("Read can't start or end on odd boundary in 16-bit mode!") - - output = "" - if self.bus_width == 16: - real_offset = offset / 2 - real_limit = limit / 2 - pack_instruction = "=H" - else: - real_offset = offset - real_offset - pack_instruction = "=B" - - for addr in range(real_offset, real_offset + real_limit): - output = output + struct.pack(pack_instruction, self.__swap(self.spi.read(addr))) - - self._verbose_print("Read {} bytes from offset {}".format(limit, offset), output) - - return output - - def write(self, data, offset=None): - ''' - Write a memory buffer to the chip. - ''' - if offset is None: - offset = 0 - - if offset < 0 or offset + len(data) > self.AT93C46_MEMORY_SIZE: - raise Exception("Write would be out of bounds!") - if self.bus_width == 16 and \ - ((offset & 1) != 0 or ((offset + len(data)) & 1) != 0): - raise Exception("Write can't start or end on odd boundary in 16-bit mode!") - - if self.bus_width == 16: - offset_divisor = 2 - pack_instruction = "=H" - else: - offset_divisor = 1 - pack_instruction = "=B" - - self.spi.ewen() - for addr in range(offset, offset + len(data), offset_divisor): - actual_addr = addr / offset_divisor - value = self.__swap(struct.unpack(pack_instruction, data[(addr - offset):(addr - offset) + offset_divisor])[0]) - - self.spi.erase(actual_addr) - self.spi.write(actual_addr, value) - self.spi.ewds() - - self._verbose_print("Wrote {} bytes from offset {}".format(len(data), offset), data) |
