gpiocmds: Add soft-pwm frequency modulation support

Signed-off-by: Guy Shapira <gayuha@gmail.com>
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

3 files changed, 35 insertions, 27 deletions

diff --git a/docs/MCU_Commands.md b/docs/MCU_Commands.md
index 921f402a..79425a2e 100644
--- a/docs/MCU_Commands.md
+++ b/docs/MCU_Commands.md
@@ -133,15 +133,13 @@ This section lists some commonly used config commands.
   see the description of the 'set_pwm_out' and 'config_digital_out'
   commands for parameter description.
 
-* `config_soft_pwm_out oid=%c pin=%u cycle_ticks=%u value=%c
+* `config_soft_pwm_out oid=%c pin=%u value=%c
   default_value=%c max_duration=%u` : This command creates an internal
   micro-controller object for software implemented PWM. Unlike
   hardware pwm pins, a software pwm object does not require any
   special hardware support (other than the ability to configure the
-  pin as a digital output GPIO). Because the output switching is
-  implemented in the micro-controller software, it is recommended that
-  the cycle_ticks parameter correspond to a time of 10ms or greater.
-  See the description of the 'set_pwm_out' and 'config_digital_out'
+  pin as a digital output GPIO).  See the description of
+  the 'set_pwm_out' and 'config_digital_out'
   commands for parameter description.
 
 * `config_analog_in oid=%c pin=%u` : This command is used to configure
@@ -203,9 +201,13 @@ only of interest to developers looking to gain insight into Klipper.
   a hardware PWM output pin. See the 'schedule_digital_out' and
   'config_pwm_out' commands for more info.
 
-* `schedule_soft_pwm_out oid=%c clock=%u on_ticks=%u` : Schedules a
-  change to a software PWM output pin. See the 'schedule_digital_out'
-  and 'config_soft_pwm_out' commands for more info.
+* `schedule_soft_pwm_out oid=%c clock=%u on_ticks=%u off_ticks=%u` : Schedules a
+  change to a software PWM output pin. The parameters 'on_ticks' and 'off_ticks'
+  define for how many ticks the pin will be on and off, respectively.
+  Because the output switching is implemented in the micro-controller software,
+  it is recommended that the sum of on_ticks and off_ticks parameters
+  corresponds to a time of 10ms or greater. See the 'schedule_digital_out' and
+  'config_soft_pwm_out' commands for more info.
 
 * `query_analog_in oid=%c clock=%u sample_ticks=%u sample_count=%c
   rest_ticks=%u min_value=%hu max_value=%hu` : This command sets up a
diff --git a/klippy/mcu.py b/klippy/mcu.py
index c919d88e..70e6b969 100644
--- a/klippy/mcu.py
+++ b/klippy/mcu.py
@@ -233,28 +233,35 @@ class MCU_pwm:
             return
         self._oid = self._mcu.create_oid()
         self._mcu.add_config_cmd(
-            "config_soft_pwm_out oid=%d pin=%s cycle_ticks=%d value=%d"
+            "config_soft_pwm_out oid=%d pin=%s value=%d"
             " default_value=%d max_duration=%d"
-            % (self._oid, self._pin, cycle_ticks,
-               self._start_value >= 1.0, self._shutdown_value >= 0.5,
+            % (self._oid, self._pin, self._start_value >= 1.0,
+               self._shutdown_value >= 0.5,
                self._mcu.seconds_to_clock(self._max_duration)))
         curtime = self._mcu.get_printer().get_reactor().monotonic()
         printtime = self._mcu.estimated_print_time(curtime)
         self._last_clock = self._mcu.print_time_to_clock(printtime + 0.100)
         svalue = int(self._start_value * self._pwm_max + 0.5)
         self._mcu.add_config_cmd(
-            "schedule_soft_pwm_out oid=%d clock=%d on_ticks=%d"
-            % (self._oid, self._last_clock, svalue), is_init=True)
+            "schedule_soft_pwm_out oid=%d clock=%d on_ticks=%d off_ticks=%d"
+            % (self._oid, self._last_clock, svalue, cycle_ticks - svalue),
+            is_init=True)
         self._set_cmd = self._mcu.lookup_command(
-            "schedule_soft_pwm_out oid=%c clock=%u on_ticks=%u",
+            "schedule_soft_pwm_out oid=%c clock=%u on_ticks=%u off_ticks=%u",
             cq=cmd_queue)
     def set_pwm(self, print_time, value):
+        cycle_ticks = self._mcu.seconds_to_clock(self._cycle_time)
         clock = self._mcu.print_time_to_clock(print_time)
         if self._invert:
             value = 1. - value
-        value = int(max(0., min(1., value)) * self._pwm_max + 0.5)
-        self._set_cmd.send([self._oid, clock, value],
-                           minclock=self._last_clock, reqclock=clock)
+        on_ticks = int(max(0., min(1., value)) * float(cycle_ticks) + 0.5)
+        if self._hardware_pwm:
+            self._set_cmd.send([self._oid, clock, on_ticks],
+                               minclock=self._last_clock, reqclock=clock)
+        else:
+            off_ticks = cycle_ticks - on_ticks
+            self._set_cmd.send([self._oid, clock, on_ticks, off_ticks],
+                               minclock=self._last_clock, reqclock=clock)
         self._last_clock = clock
 
 class MCU_adc:
diff --git a/src/gpiocmds.c b/src/gpiocmds.c
index 91d97b75..e6bf4671 100644
--- a/src/gpiocmds.c
+++ b/src/gpiocmds.c
@@ -110,7 +110,7 @@ struct soft_pwm_s {
     struct timer timer;
     uint32_t on_duration, off_duration, end_time;
     uint32_t next_on_duration, next_off_duration;
-    uint32_t max_duration, cycle_time;
+    uint32_t max_duration;
     struct gpio_out pin;
     uint8_t default_value, flags;
 };
@@ -172,32 +172,31 @@ soft_pwm_load_event(struct timer *timer)
 void
 command_config_soft_pwm_out(uint32_t *args)
 {
-    struct gpio_out pin = gpio_out_setup(args[1], !!args[3]);
+    struct gpio_out pin = gpio_out_setup(args[1], !!args[2]);
     struct soft_pwm_s *s = oid_alloc(args[0], command_config_soft_pwm_out
                                      , sizeof(*s));
     s->pin = pin;
-    s->cycle_time = args[2];
-    s->default_value = !!args[4];
-    s->max_duration = args[5];
+    s->default_value = !!args[3];
+    s->max_duration = args[4];
     s->flags = s->default_value ? SPF_ON : 0;
 }
 DECL_COMMAND(command_config_soft_pwm_out,
-             "config_soft_pwm_out oid=%c pin=%u cycle_ticks=%u value=%c"
+             "config_soft_pwm_out oid=%c pin=%u value=%c"
              " default_value=%c max_duration=%u");
 
 void
 command_schedule_soft_pwm_out(uint32_t *args)
 {
     struct soft_pwm_s *s = oid_lookup(args[0], command_config_soft_pwm_out);
-    uint32_t time = args[1], next_on_duration = args[2], next_off_duration;
+    uint32_t time = args[1], next_on_duration = args[2],
+        next_off_duration = args[3];
     uint8_t next_flags = SPF_CHECK_END | SPF_HAVE_NEXT;
-    if (next_on_duration == 0 || next_on_duration >= s->cycle_time) {
+    if (next_on_duration == 0 || next_off_duration == 0) {
         next_flags |= next_on_duration ? SPF_NEXT_ON : 0;
         if (!!next_on_duration != s->default_value && s->max_duration)
             next_flags |= SPF_NEXT_CHECK_END;
         next_on_duration = next_off_duration = 0;
     } else {
-        next_off_duration = s->cycle_time - next_on_duration;
         next_flags |= SPF_NEXT_ON | SPF_NEXT_TOGGLING;
         if (s->max_duration)
             next_flags |= SPF_NEXT_CHECK_END;
@@ -221,7 +220,7 @@ command_schedule_soft_pwm_out(uint32_t *args)
     irq_enable();
 }
 DECL_COMMAND(command_schedule_soft_pwm_out,
-             "schedule_soft_pwm_out oid=%c clock=%u on_ticks=%u");
+             "schedule_soft_pwm_out oid=%c clock=%u on_ticks=%u off_ticks=%u");
 
 void
 soft_pwm_shutdown(void)