add PWM.set_period_ns and PWM.set_pulse_width_ns

source/c_pwm.c

@@ -126,6 +126,33 @@ int pwm_set_frequency(const char *key, float freq) {
     return 1;
 }
 
+int pwm_set_period_ns(const char *key, unsigned long period_ns) {
+    int len;
+    char buffer[80];
+    unsigned long period_ns;
+    struct pwm_exp *pwm;
+
+    if (freq <= 0.0)
+        return -1;
+
+    pwm = lookup_exported_pwm(key);
+
+    if (pwm == NULL) {
+        return -1;
+    }
+
+    //period_ns = (unsigned long)(1e9 / freq);
+
+    if (period_ns != pwm->period_ns) {
+        pwm->period_ns = period_ns;
+
+        len = snprintf(buffer, sizeof(buffer), "%lu", period_ns); BUF2SMALL(buffer);
+        ssize_t s = write(pwm->period_fd, buffer, len);  ASSRT(s == len);
+    }
+
+    return 1;
+}
+
 int pwm_set_polarity(const char *key, int polarity) {
     int len;
     char buffer[80];
@@ -175,6 +202,28 @@ int pwm_set_duty_cycle(const char *key, float duty) {
     return 0;
 }
 
+int pwm_set_pulse_width_ns(const char *key, unsigned long pulse_width_ns) {
+    int len;
+    char buffer[80];
+    struct pwm_exp *pwm;
+
+    pwm = lookup_exported_pwm(key);
+
+    if (pwm == NULL) {
+        return -1;
+    }
+
+    if (pulse_width_ns < 0 || pulse_width_ns > pwm->period_ns)
+        return -1;
+
+    pwm->duty = pulse_width_ns //(unsigned long)(pwm->period_ns * (duty / 100.0));
+
+    len = snprintf(buffer, sizeof(buffer), "%lu", pwm->duty); BUF2SMALL(buffer);
+    ssize_t s = write(pwm->duty_fd, buffer, len);  ASSRT(s == len);
+
+    return 0;
+}
+
 int pwm_set_enable(const char *key, int enable)
 {
     int len;

source/c_pwm.h

@@ -32,6 +32,8 @@ SOFTWARE.
 int pwm_start(const char *key, float duty, float freq, int polarity);
 int pwm_disable(const char *key);
 int pwm_set_frequency(const char *key, float freq);
+int pwm_set_period_ns(const char *key, unsigned long period_ns);
 int pwm_set_duty_cycle(const char *key, float duty);
+int pwm_set_pulse_width_ns(const char *key, unsigned long pulse_width_ns);
 int pwm_set_enable(const char *key, int enable);
 void pwm_cleanup(void);

source/py_pwm.c

@@ -134,6 +134,38 @@ static PyObject *py_set_duty_cycle(PyObject *self, PyObject *args, PyObject *kwa
     Py_RETURN_NONE;
 }
 
+// python method PWM.set_pulse_width(channel, pulse_width_ns)
+static PyObject *py_set_pulse_width_ns(PyObject *self, PyObject *args, PyObject *kwargs)
+{
+    char key[8];
+    char *channel;
+    unsigned long pulse_width_ns = 0.0;
+    static char *kwlist[] = {"channel", "pulse_width_ns", NULL};
+
+    if (!PyArg_ParseTupleAndKeywords(args, kwargs, "s|k", kwlist, &channel, &pulse_width_ns))
+        return NULL;
+
+    pwm = lookup_exported_pwm(key);
+
+    if (pwm == NULL) {
+        PyErr_SetString(PyExc_ValueError, "Invalid PWM key or name.");
+        return NULL;
+    }
+
+	if (pulse_width_ns < 0.0 || pulse_width_ns > pwm->period_ns)
+    {
+        PyErr_SetString(PyExc_ValueError, "pulse width must have a value from 0 to period");
+        return NULL;
+    }
+
+    if (pwm_set_pulse_width_ns(key, duty_cycle) == -1) {
+        PyErr_SetString(PyExc_RuntimeError, "You must start() the PWM channel first");
+        return NULL;
+    }
+
+    Py_RETURN_NONE;
+}
+
 // python method PWM.set_frequency(channel, frequency)
 static PyObject *py_set_frequency(PyObject *self, PyObject *args, PyObject *kwargs)
 {
@@ -164,6 +196,35 @@ static PyObject *py_set_frequency(PyObject *self, PyObject *args, PyObject *kwar
     Py_RETURN_NONE;
 }
 
+// python method PWM.set_period_ns(channel, period_ns)
+static PyObject *py_set_period_ns(PyObject *self, PyObject *args, PyObject *kwargs)
+{
+    char key[8];
+    char *channel;
+    unsigned long period_ns = 2e6;
+    static char *kwlist[] = {"channel", "period_ns", NULL};
+
+    if (!PyArg_ParseTupleAndKeywords(args, kwargs, "s|k", kwlist, &channel, &period_ns))
+        return NULL;
+
+    if (period_ns <= 0)
+    {
+        PyErr_SetString(PyExc_ValueError, "period must be greater than 0ns");
+        return NULL;
+    }
+
+    if (!get_pwm_key(channel, key)) {
+        PyErr_SetString(PyExc_ValueError, "Invalid PWM key or name.");
+        return NULL;
+    }
+
+    if (pwm_set_period_ns(key, period_ns) == -1) {
+        PyErr_SetString(PyExc_RuntimeError, "You must start() the PWM channel first");
+        return NULL;
+    }
+
+    Py_RETURN_NONE;
+}
 
 static const char moduledocstring[] = "Hardware PWM functionality of a CHIP using Python";
 
@@ -172,6 +233,8 @@ PyMethodDef pwm_methods[] = {
     {"stop", (PyCFunction)py_stop_channel, METH_VARARGS | METH_KEYWORDS, "Stop the PWM channel.  channel can be in the form of 'PWM0', or 'U13_18'"},
     { "set_duty_cycle", (PyCFunction)py_set_duty_cycle, METH_VARARGS, "Change the duty cycle\ndutycycle - between 0.0 and 100.0" },
     { "set_frequency", (PyCFunction)py_set_frequency, METH_VARARGS, "Change the frequency\nfrequency - frequency in Hz (freq > 0.0)" },
+    { "set_period_ns", (PyCFunction)py_set_period_ns, METH_VARARGS, "Change the period\nperiod_ns - period in nanoseconds" },
+    { "set_pulse_width_ns", (PyCFunction)py_set_pulse_width_ns, METH_VARARGS, "Change the period\npulse_width_ns - pulse width in nanoseconds" },
     {"cleanup", py_cleanup, METH_VARARGS, "Clean up by resetting all GPIO channels that have been used by this program to INPUT with no pullup/pulldown and no event detection"},
     //{"setwarnings", py_setwarnings, METH_VARARGS, "Enable or disable warning messages"},
     {NULL, NULL, 0, NULL}