Python client for GEX
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gex-client-py/gex/units/I2C.py

72 lines
2.2 KiB

import gex
class I2C(gex.Unit):
"""
I2C master direct access
"""
def _type(self):
return 'I2C'
def _begin_i2c_pld(self, address:int, a10bit:bool=False):
pb = gex.PayloadBuilder()
if a10bit: address |= 0x8000
pb.u16(address)
return pb
def write(self, address:int, payload, a10bit:bool=False):
"""
Write to an address
"""
pb = self._begin_i2c_pld(address, a10bit)
pb.blob(payload) # payload to write
self._query(0x80, pb.close())
def read(self, address:int, count, a10bit:bool=False):
"""
Read from an address
"""
pb = self._begin_i2c_pld(address, a10bit)
pb.u16(count) # number of bytes to read
self._query(0x01, pb.close())
def read_reg(self, address:int, reg, width:int=1, a10bit:bool=False, endian='little'):
"""
Read a single register
"""
return self.read_regs(address, reg, count=1, width=width, a10bit=a10bit, endian=endian)[0]
def read_regs(self, address:int, reg, count:int, width:int=1, a10bit:bool=False, endian='little'):
"""
Read multiple registers from an address
"""
pb = self._begin_i2c_pld(address, a10bit)
pb.u8(reg)
pb.u16(width*count) # we assume the device will auto-increment (most do)
resp = self._query(0x03, pb.close())
fields = []
pp = gex.PayloadParser(resp.data, endian=endian)
for i in range(0, count):
if width==1: fields.append(pp.u8())
elif width==2: fields.append(pp.u16())
elif width==3: fields.append(pp.u24())
elif width==4: fields.append(pp.u32())
else: raise Exception("Bad width")
return fields
def write_reg(self, address:int, reg, value:int, width:int=1, a10bit:bool=False, endian='little'):
"""
Write a to a single register
"""
pb = self._begin_i2c_pld(address, a10bit)
pb.u8(reg)
pb.endian = endian
if width == 1: pb.u8(value)
elif width == 2: pb.u16(value)
elif width == 3: pb.u24(value)
elif width == 4: pb.u32(value)
else: raise Exception("Bad width")
self._query(0x82, pb.close())