static PyObject *py_set_run(PyObject *self, PyObject *args, PyObject *kwargs){
char key[8];
char *channel;
int run = 0;
static char *kwlist[] = {"channel", "run", NULL};
if(!PyArg_ParseTupleAndKeywords(args, kwargs, "s|i", kwlist, &channel, &run))
return NULL;
if (run != 0 && run != 1)
{
PyErr_SetString(PyExc_ValueError, "run must be either 0 or 1");
return NULL;
}
if (!get_pwm_key(channel, key)) {
PyErr_SetString(PyExc_ValueError, "Invalid PWM key or name.");
return NULL;
}
if (pwm_set_run(key, run) == -1) {
PyErr_SetString(PyExc_RuntimeError, "You must start() the PWM channel first");
return NULL;
}
Py_RETURN_NONE;
}
int pwm_disable(PwmChannel_t *pwm)
{
pwm_set_run(pwm, 0);
//close the fds
close(pwm->period_fd);
close(pwm->duty_fd);
close(pwm->polarity_fd);
close(pwm->run_fd);
return 0;
}
int pwm_start(const char *pinName, int exportNumber, char *pwmDir, float duty, float freq, int polarity, PwmChannel_t *pwm)
{
char pwm_control_path[PATHLEN];
char pwm_path[PATHLEN]; //pwm channel control folder
char export[2];
int fd;
strncpy(pwm->key, pinName, KEYLEN);
if (set_pinmux(pinName, "pwm") < 0)
{
return -1;
}
//export pwm channel
if ((fd = open("/sys/class/pwm/export", O_WRONLY)) < 0)
{
LogError("pwm open(/sys/class/pwm/export) fail (%s)\n", strerror(errno));
return -1;
}
snprintf(export, 2, "%i", exportNumber);
write(fd,export,1);
close(fd);
snprintf(pwm_path, sizeof(pwm_path), "/sys/class/pwm/%s", pwmDir);
//create the path for period control
snprintf(pwm_control_path, sizeof(pwm_control_path), "%s/period_ns", pwm_path);
if ((pwm->period_fd = open(pwm_control_path, O_WRONLY)) < 0)
{
LogError("pwm open(%s) fail (%s)\n", pwm_control_path, strerror(errno));
return -1;
}
snprintf(pwm_control_path, sizeof(pwm_control_path), "%s/duty_ns", pwm_path);
if ((pwm->duty_fd = open(pwm_control_path, O_WRONLY)) < 0) {
//error, close already opened period_fd.
LogError("pwm open(%s) fail (%s)\n", pwm_control_path, strerror(errno));
close(pwm->period_fd);
return -1;
}
snprintf(pwm_control_path, sizeof(pwm_control_path), "%s/polarity", pwm_path);
if ((pwm->polarity_fd = open(pwm_control_path, O_WRONLY)) < 0) {
LogError("pwm open(%s) fail (%s)\n", pwm_control_path, strerror(errno));
//error, close already opened period_fd and duty_fd.
close(pwm->period_fd);
close(pwm->duty_fd);
return -1;
}
snprintf(pwm_control_path, sizeof(pwm_control_path), "%s/run", pwm_path);
if ((pwm->run_fd = open(pwm_control_path, O_WRONLY)) < 0) {
LogError("pwm open(%s) fail (%s)\n", pwm_control_path, strerror(errno));
//error, close already opened period_fd and duty_fd.
close(pwm->polarity_fd);
close(pwm->period_fd);
close(pwm->duty_fd);
return -1;
}
pwm_set_frequency(pwm, freq);
pwm_set_polarity(pwm, polarity);
pwm_set_duty_cycle(pwm, duty);
pwm_set_run(pwm, 1);
return 0;
}
