replicape: add support for Linux hardware PWM (#1443)

The servo pins (P9_14/P9_16) are muxed to the SOCs hardware PWM unit
driven by a 13MHz GP timer. They have to be driven by the linux host
mcu. This commits adds hardware PWM support using the linux sysfs
user space interface.

The servo pins can be specified as "replicape:servo0" and
"replicape:servo1". Removes the "servo0_enable", "servo1_enable"
configuration parameters.
Fixes #1105.

Signed-off-by: Janne Grunau <janne-3d@jannau.net>

1 files changed, 41 insertions, 10 deletions

diff --git a/klippy/extras/replicape.py b/klippy/extras/replicape.py
index 387c4764..12eb1454 100644
--- a/klippy/extras/replicape.py
+++ b/klippy/extras/replicape.py
@@ -108,6 +108,32 @@ class ReplicapeDACEnable:
         else:
             self.pwm.set_pwm(print_time, 0.)
 
+SERVO_PINS = {
+    "servo0": ("pwmchip0/pwm0", "gpio0_30", "gpio1_18"), # P9_11, P9_14
+    "servo1": ("pwmchip0/pwm1", "gpio3_17", "gpio1_19"), # P9_28, P9_16
+}
+
+class servo_pwm:
+    def __init__(self, replicape, pin_params):
+        config_name = pin_params['pin']
+        pwm_pin, resv1, resv2 = SERVO_PINS[config_name]
+        pin_params = dict(pin_params)
+        pin_params['pin'] = pwm_pin
+        # Setup actual pwm pin using linux hardware pwm on host
+        self.mcu_pwm = replicape.host_mcu.setup_pin("pwm", pin_params)
+        self.get_mcu = self.mcu_pwm.get_mcu
+        self.setup_max_duration = self.mcu_pwm.setup_max_duration
+        self.setup_start_value = self.mcu_pwm.setup_start_value
+        self.set_pwm = self.mcu_pwm.set_pwm
+        # Reserve pins to warn user of conflicts
+        pru_mcu = replicape.mcu_pwm_enable.get_mcu()
+        printer = pru_mcu.get_printer()
+        ppins = printer.lookup_object('pins')
+        ppins.reserve_pin(pru_mcu.get_name(), resv1, config_name)
+        ppins.reserve_pin(pru_mcu.get_name(), resv2, config_name)
+    def setup_cycle_time(self, cycle_time, hardware_pwm=False):
+        self.mcu_pwm.setup_cycle_time(cycle_time, True);
+
 ReplicapeStepConfig = {
     'disable': None,
     '1': (1<<7)|(1<<5), '2': (1<<7)|(1<<5)|(1<<6), 'spread2': (1<<5),
@@ -135,6 +161,8 @@ class Replicape:
             "power_hotbed": (pca9685_pwm, 4),
             "power_fan0": (pca9685_pwm, 7), "power_fan1": (pca9685_pwm, 8),
             "power_fan2": (pca9685_pwm, 9), "power_fan3": (pca9685_pwm, 10) }
+        self.servo_pins = {
+            "servo0": 3, "servo1": 2 }
         # Setup stepper config
         self.last_stepper_time = 0.
         self.stepper_dacs = {}
@@ -159,11 +187,7 @@ class Replicape:
             self.stepper_dacs[channel] = cur / REPLICAPE_MAX_CURRENT
             self.pins[prefix + 'enable'] = (ReplicapeDACEnable, channel)
         self.enabled_channels = {ch: False for cl, ch in self.pins.values()}
-        if config.getboolean('servo0_enable', False):
-            shift_registers[1] |= 1
-        if config.getboolean('servo1_enable', False):
-            shift_registers[2] |= 1
-        self.sr_disabled = tuple(reversed(shift_registers))
+        self.sr_disabled = list(reversed(shift_registers))
         if [i for i in [0, 1, 2] if 11+i in self.stepper_dacs]:
             # Enable xyz steppers
             shift_registers[0] &= ~1
@@ -173,7 +197,7 @@ class Replicape:
         if (config.getboolean('standstill_power_down', False)
             and self.stepper_dacs):
             shift_registers[4] &= ~1
-        self.sr_enabled = tuple(reversed(shift_registers))
+        self.sr_enabled = list(reversed(shift_registers))
         self.sr_spi = bus.MCU_SPI(self.host_mcu, REPLICAPE_SHIFT_REGISTER_BUS,
                                   None, 0, 50000000, self.sr_disabled)
         self.sr_spi.spi_send(self.sr_disabled)
@@ -211,10 +235,17 @@ class Replicape:
         self.sr_spi.spi_send(sr, minclock=clock, reqclock=clock)
     def setup_pin(self, pin_type, pin_params):
         pin = pin_params['pin']
-        if pin not in self.pins:
-            raise pins.error("Unknown replicape pin %s" % (pin,))
-        pclass, channel = self.pins[pin]
-        return pclass(self, channel, pin_type, pin_params)
+        if pin in self.pins:
+            pclass, channel = self.pins[pin]
+            return pclass(self, channel, pin_type, pin_params)
+        elif pin in self.servo_pins:
+            # enable servo pins via shift registers
+            index = self.servo_pins[pin]
+            self.sr_enabled[index] |= 1
+            self.sr_disabled[index] |= 1
+            self.sr_spi.spi_send(self.sr_disabled)
+            return servo_pwm(self, pin_params)
+        raise pins.error("Unknown replicape pin %s" % (pin,))
 
 def load_config(config):
     return Replicape(config)