X-Git-Url: https://git.ayoreis.com/Adafruit_Blinka-hackapet.git/blobdiff_plain/e7c4fe7ee943f868421452be4d797c01cb0bf767..refs/heads/revert-863-do-not-upload-bdist:/src/adafruit_blinka/microcontroller/rockchip/PWMOut.py diff --git a/src/adafruit_blinka/microcontroller/rockchip/PWMOut.py b/src/adafruit_blinka/microcontroller/rockchip/PWMOut.py index abff5d1..1e5d6e4 100644 --- a/src/adafruit_blinka/microcontroller/rockchip/PWMOut.py +++ b/src/adafruit_blinka/microcontroller/rockchip/PWMOut.py @@ -1,3 +1,12 @@ +# SPDX-FileCopyrightText: 2021 Melissa LeBlanc-Williams for Adafruit Industries +# +# SPDX-License-Identifier: MIT +""" +Much code from https://github.com/vsergeev/python-periphery/blob/master/periphery/pwm.py +Copyright (c) 2015-2016 vsergeev / Ivan (Vanya) A. Sergeev +License: MIT +""" + import os from time import sleep from errno import EACCES @@ -8,12 +17,18 @@ except ImportError: raise RuntimeError("No PWM outputs defined for this board.") from ImportError +# pylint: disable=unnecessary-pass, too-many-instance-attributes + + class PWMError(IOError): """Base class for PWM errors.""" pass +# pylint: enable=unnecessary-pass + + class PWMOut: """Pulse Width Modulation Output Class""" @@ -23,20 +38,9 @@ class PWMOut: PWM_STAT_DELAY = 0.1 # Sysfs paths - _sysfs_path = "/sys/class/pwm" _chip_path = "pwmchip{}" _channel_path = "pwm{}" - # Sysfs commands - _export = "export" - _unexport = "unexport" - - # Pin commands - _pin_period = "period" - _pin_duty_cycle = "duty_cycle" - _pin_polarity = "polarity" - _pin_enable = "enable" - def __init__(self, pwm, *, frequency=500, duty_cycle=0, variable_frequency=False): """Instantiate a PWM object and open the sysfs PWM corresponding to the specified chip and channel. @@ -74,10 +78,15 @@ class PWMOut: self._chip = pwmout[0][0] self._channel = pwmout[0][1] - self._pwm = pwm + self._chip_path = os.path.join( + "/sys/class/pwm", self._chip_path.format(self._chip) + ) + self._channel_path = os.path.join( + self._chip_path, self._channel_path.format(self._channel) + ) - self._chip_path = os.path.join(self._sysfs_path, self._chip_path.format(self._chip)) - self._channel_path = os.path.join(self._chip_path, self._channel_path.format(self._channel)) + if variable_frequency: + print("Variable Frequency is not supported, continuing without it...") if not os.path.isdir(self._chip_path): raise LookupError("Opening PWM: PWM chip {} not found.".format(self._chip)) @@ -85,10 +94,14 @@ class PWMOut: if not os.path.isdir(self._channel_path): # Exporting the PWM. try: - with open(os.path.join(self._chip_path, self._export), "w") as f_export: + with open( + os.path.join(self._chip_path, "export"), "w", encoding="utf-8" + ) as f_export: f_export.write("{:d}\n".format(self._channel)) except IOError as e: - raise PWMError(e.errno, "Exporting PWM channel: " + e.strerror) + raise PWMError( + e.errno, "Exporting PWM channel: " + e.strerror + ) from IOError # Loop until PWM is exported exported = False @@ -100,23 +113,37 @@ class PWMOut: sleep(PWMOut.PWM_STAT_DELAY) if not exported: - raise TimeoutError("Exporting PWM: waiting for \"{:s}\" timed out.".format(self._channel_path)) + raise TimeoutError( + 'Exporting PWM: waiting for "{:s}" timed out.'.format( + self._channel_path + ) + ) # Loop until 'period' is writable, This could take some time after # export as application of the udev rules after export is asynchronous. # Without this loop, the following properties may not be writable yet. for i in range(PWMOut.PWM_STAT_RETRIES): try: - with open(os.path.join(self._channel_path, "period"), "w",): + with open( + os.path.join(self._channel_path, "period"), + "w", + encoding="utf-8", + ): break except IOError as e: - if e.errno != EACCES or (e.errno == EACCES and i == PWMOut.PWM_STAT_RETRIES - 1): - raise PWMError(e.errno, "Opening PWM period: " + e.strerror) from IOError + if e.errno != EACCES or ( + e.errno == EACCES and i == PWMOut.PWM_STAT_RETRIES - 1 + ): + raise PWMError( + e.errno, "Opening PWM period: " + e.strerror + ) from IOError sleep(PWMOut.PWM_STAT_DELAY) self.frequency = frequency self.duty_cycle = duty_cycle + self.polarity = "normal" + self.enable() # Cache the period for fast duty cycle updates self._period_ns = self._get_period_ns() @@ -126,31 +153,37 @@ class PWMOut: if self._channel is not None: # Unexporting the PWM channel try: - unexport_fd = os.open(os.path.join(self._chip_path, self._unexport), os.O_WRONLY) + unexport_fd = os.open( + os.path.join(self._chip_path, "unexport"), os.O_WRONLY + ) os.write(unexport_fd, "{:d}\n".format(self._channel).encode()) os.close(unexport_fd) except OSError as e: - raise PWMError(e.errno, "Unexporting PWM: " + e.strerror) + raise PWMError(e.errno, "Unexporting PWM: " + e.strerror) from OSError self._chip = None self._channel = None def _write_channel_attr(self, attr, value): - with open(os.path.join(self._channel_path, attr), 'w') as f_attr: + with open( + os.path.join(self._channel_path, attr), "w", encoding="utf-8" + ) as f_attr: f_attr.write(value + "\n") def _read_channel_attr(self, attr): - with open(os.path.join(self._channel_path, attr), 'r') as f_attr: + with open( + os.path.join(self._channel_path, attr), "r", encoding="utf-8" + ) as f_attr: return f_attr.read().strip() # Methods def enable(self): - """Enable the PWM outout.""" + """Enable the PWM output.""" self.enabled = True def disable(self): - """Diable the PWM output.""" + """Disable the PWM output.""" self.enabled = False # Mutable properties @@ -166,11 +199,11 @@ class PWMOut: period = property(_get_period, _set_period) """Get or set the PWM's output period in seconds. - + Raises: PWMError: if an I/O or OS error occurs. TypeError: if value type is not int. - + :type: int, float """ @@ -184,11 +217,11 @@ class PWMOut: period_ms = property(_get_period_ms, _set_period_ms) """Get or set the PWM's output period in milliseconds. - + Raises: PWMError: if an I/O or OS error occurs. TypeError: if value type is not int. - + :type: int, float """ @@ -203,20 +236,22 @@ class PWMOut: period_us = property(_get_period_us, _set_period_us) """Get or set the PWM's output period in microseconds. - + Raises: PWMError: if an I/O or OS error occurs. TypeError: if value type is not int. - + :type: int """ def _get_period_ns(self): - period_ns = self._read_channel_attr(self._pin_period) + period_ns = self._read_channel_attr("period") try: period_ns = int(period_ns) except ValueError: - raise PWMError(None, "Unknown period value: \"%s\"." % period_ns) from ValueError + raise PWMError( + None, 'Unknown period value: "%s".' % period_ns + ) from ValueError self._period_ns = period_ns @@ -233,11 +268,11 @@ class PWMOut: period_ns = property(_get_period_ns, _set_period_ns) """Get or set the PWM's output period in nanoseconds. - + Raises: PWMError: if an I/O or OS error occurs. TypeError: if value type is not int. - + :type: int """ @@ -247,7 +282,9 @@ class PWMOut: try: duty_cycle_ns = int(duty_cycle_ns_str) except ValueError: - raise PWMError(None, "Unknown duty cycle value: \"{:s}\"".format(duty_cycle_ns_str)) + raise PWMError( + None, 'Unknown duty cycle value: "{:s}"'.format(duty_cycle_ns_str) + ) from ValueError return duty_cycle_ns @@ -259,11 +296,11 @@ class PWMOut: duty_cycle_ns = property(_get_duty_cycle_ns, _set_duty_cycle_ns) """Get or set the PWM's output duty cycle in nanoseconds. - + Raises: PWMError: if an I/O or OS error occurs. TypeError: if value type is not int. - + :type: int """ @@ -273,7 +310,8 @@ class PWMOut: def _set_duty_cycle(self, duty_cycle): if not isinstance(duty_cycle, (int, float)): raise TypeError("Invalid duty cycle type, should be int or float.") - elif not 0.0 <= duty_cycle <= 1.0: + + if not 0.0 <= duty_cycle <= 1.0: raise ValueError("Invalid duty cycle value, should be between 0.0 and 1.0.") # Convert duty cycle from ratio to nanoseconds @@ -311,8 +349,9 @@ class PWMOut: def _set_polarity(self, polarity): if not isinstance(polarity, str): raise TypeError("Invalid polarity type, should be str.") - elif polarity.lower() not in ["normal", "inversed"]: - raise ValueError("Invalid polarity, can be: \"normal\" or \"inversed\".") + + if polarity.lower() not in ["normal", "inversed"]: + raise ValueError('Invalid polarity, can be: "normal" or "inversed".') self._write_channel_attr("polarity", polarity.lower()) @@ -330,10 +369,10 @@ class PWMOut: if enabled == "1": return True - elif enabled == "0": + if enabled == "0": return False - raise PWMError(None, "Unknown enabled value: \"{:s}\"".format(enabled)) + raise PWMError(None, 'Unknown enabled value: "{:s}"'.format(enabled)) def _set_enabled(self, value): if not isinstance(value, bool): @@ -352,5 +391,14 @@ class PWMOut: # String representation def __str__(self): - return "PWM {:d}, chip {:d} (period={:f} sec, duty_cycle={:f}%, polarity={:s}, enabled={:s})" \ - .format(self._channel, self._chip, self.period, self.duty_cycle * 100, self.polarity, str(self.enabled)) \ No newline at end of file + return ( + "PWM {:d}, chip {:d} (period={:f} sec, duty_cycle={:f}%," + " polarity={:s}, enabled={:s})".format( + self._channel, + self._chip, + self.period, + self.duty_cycle * 100, + self.polarity, + str(self.enabled), + ) + )