diff --git a/source/c_softpwm.c b/source/c_softpwm.c index 54347dc..b6915a5 100644 --- a/source/c_softpwm.c +++ b/source/c_softpwm.c @@ -31,6 +31,7 @@ SOFTWARE. #include #include +#include #include #include #include @@ -43,6 +44,8 @@ SOFTWARE. #define KEYLEN 7 +#define NOTCHIPHW + #define PERIOD 0 #define DUTY 1 @@ -52,10 +55,14 @@ int pwm_initialized = 0; struct softpwm { char key[KEYLEN+1]; /* leave room for terminating NUL byte */ - unsigned long on_ns; - unsigned long off_ns; + + float duty; + float freq; pthread_t thread; struct softpwm *next; + bool enabled; + bool stop_flag; + int polarity; }; struct softpwm *exported_pwms = NULL; @@ -75,9 +82,6 @@ struct softpwm *lookup_exported_pwm(const char *key) } int softpwm_set_frequency(const char *key, float freq) { - int len; - char buffer[20]; - unsigned long period_ns; struct softpwm *pwm; if (freq <= 0.0) @@ -89,21 +93,12 @@ int softpwm_set_frequency(const char *key, float freq) { 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); - write(pwm->period_fd, buffer, len); - } + pwm->freq = freq; return 1; } int softpwm_set_polarity(const char *key, int polarity) { - int len; - char buffer[9]; /* allow room for trailing NUL byte */ struct softpwm *pwm; pwm = lookup_exported_pwm(key); @@ -116,21 +111,12 @@ int softpwm_set_polarity(const char *key, int polarity) { return -1; } - if (polarity == 0) { - len = snprintf(buffer, sizeof(buffer), "%s", "normal"); - } - else - { - len = snprintf(buffer, sizeof(buffer), "%s", "inverted"); - } - write(pwm->polarity_fd, buffer, len); + pwm->polarity = polarity; return 0; } -int softpwm_set_duty_cycle(const char *key, float duty) { - int len; - char buffer[20]; +int softpwm_set_duty_cycle(const char *key, float duty) {; struct softpwm *pwm; if (duty < 0.0 || duty > 100.0) @@ -142,59 +128,93 @@ int softpwm_set_duty_cycle(const char *key, float duty) { return -1; } - pwm->duty = (unsigned long)(pwm->period_ns * (duty / 100.0)); - - len = snprintf(buffer, sizeof(buffer), "%lu", pwm->duty); - write(pwm->duty_fd, buffer, len); + pwm->duty = duty; return 0; } -int softpwm_set_enable(const char *key, int enable) -{ - int len; - char buffer[20]; - struct softpwm *pwm; - - if (enable != 0 || enable != 1) - return -1; - - pwm = lookup_exported_pwm(key); - - if (pwm == NULL) { - return -1; - } - - pwm->enable = enable; - - len = snprintf(buffer, sizeof(buffer), "%d", pwm->enable); - write(pwm->enable_fd, buffer, len); - - return 0; -} - -void* softpwm_toggle(void *key) +void* softpwm_thread_toggle(void *key) { struct softpwm *pwm; unsigned int gpio; - struct timespec tim; + struct timespec tim_on; + struct timespec tim_off; unsigned int sec; + unsigned int period_ns; + unsigned int on_ns; + unsigned int off_ns; + + /* Used to determine if something has + * has changed + */ + unsigned int freq_local = 0; + unsigned int duty_local = 0; get_gpio_number(key, &gpio); pwm = lookup_exported_pwm((char*)key); - while (1) { - sec = (unsigned int)(pwm->on_ns/1e9); - tim.tv_sec = sec; - tim.tv_nsec = pwm->on_ns - (sec*1e9); - gpio_set_value(gpio, HIGH); - nanosleep(&tim, NULL); - sec = (unsigned int)(pwm->off_ns/1e9); - tim.tv_sec = sec; - tim.tv_nsec = pwm->off_ns - (sec*1e9); - gpio_set_value(gpio, LOW); - nanosleep(&tim, NULL); + while (pwm->enabled) { + /* If freq or duty has been changed, update the + * sleep times + */ + if ((freq_local != pwm->freq) || (duty_local != pwm->duty)) { + period_ns = (unsigned long)(1e9 / pwm->freq); + on_ns = (unsigned long)(period_ns * (pwm->duty/100)); + off_ns = period_ns - on_ns; + sec = (unsigned int)(on_ns/1e9); /* Intentional truncation */ + tim_on.tv_sec = sec; + tim_on.tv_nsec = on_ns - (sec*1e9); + sec = (unsigned int)(off_ns/1e9); /* Intentional truncation */ + tim_off.tv_sec = sec; + tim_off.tv_nsec = off_ns - (sec*1e9); + freq_local = pwm->freq; + duty_local = pwm->duty; + } + + /* Set gpio */ + if (pwm->polarity) + { +#ifdef NOTCHIPHW + printf("Setting gpio high"); +#else + gpio_set_value(gpio, HIGH); +#endif + + } + else + { +#ifdef NOTCHIPHW + printf("Setting gpio low"); +#else + //gpio_set_value(gpio, LOW); +#endif + } + + nanosleep(&tim_on, NULL); + + /* Unset gpio */ + if (pwm->polarity) + { +#ifdef NOTCHIPHW + printf("Setting gpio low"); +#else + gpio_set_value(gpio, LOW); +#endif + } + else + { +#ifdef NOTCHIPHW + printf("Setting gpio high"); +#else + gpio_set_value(gpio, HIGH); +#endif + } + + nanosleep(&tim_off, NULL); } + + /* This pwm has been disabled */ + pthread_exit(NULL); } int softpwm_start(const char *key, float duty, float freq, int polarity) @@ -202,13 +222,13 @@ int softpwm_start(const char *key, float duty, float freq, int polarity) struct softpwm *new_pwm, *pwm; pthread_t *new_thread; unsigned int gpio; - unsigned long period_ns; - unsigned long on_ns; int ret; get_gpio_number(key, &gpio); +#ifndef NOTCHIPHW gpio_export(gpio); gpio_set_direction(gpio, OUTPUT); +#endif // add to list new_pwm = malloc(sizeof(struct softpwm)); @@ -216,22 +236,10 @@ int softpwm_start(const char *key, float duty, float freq, int polarity) return -1; // out of memory } - // calculate period and on time from freq - period_ns = (unsigned long)(1e9 / freq); - on_ns = (unsigned long)(period_ns * (duty/100)); - - // create thread for pwm - ret = pthread_create(new_thread, NULL, softpwm_toggle, (void *)key); - if (ret){ - printf("ERROR; return code from pthread_create() is %d\n", ret); - exit(-1); - } - strncpy(new_pwm->key, key, KEYLEN); /* can leave string unterminated */ new_pwm->key[KEYLEN] = '\0'; /* terminate string */ - new_pwm->on_ns = on_ns; - new_pwm->off_ns = period_ns - on_ns; - new_pwm->thread = *new_thread; + new_pwm->enabled = false; + new_pwm->stop_flag = false; new_pwm->next = NULL; if (exported_pwms == NULL) @@ -246,47 +254,43 @@ int softpwm_start(const char *key, float duty, float freq, int polarity) pwm->next = new_pwm; } + softpwm_set_duty_cycle(key, duty); + softpwm_set_frequency(key, freq); softpwm_set_polarity(key, polarity); + // create thread for pwm + ret = pthread_create(new_thread, NULL, softpwm_thread_toggle, (void *)key); + if (ret) { + printf("ERROR; return code from pthread_create() is %d\n", ret); + exit(-1); + } + new_pwm->thread = *new_thread; + new_pwm->enabled = true; + return 1; } int softpwm_disable(const char *key) { struct softpwm *pwm, *temp, *prev_pwm = NULL; - char fragment[18]; - - int fd, len; - char str_gpio[2]; - // Per https://github.com/NextThingCo/CHIP-linux/pull/4 - // we need to export 0 here to enable pwm0 - int gpio = 0; + unsigned int gpio = 0; // Disable the PWM softpwm_set_frequency(key, 0); softpwm_set_polarity(key, 0); - softpwm_set_enable(key, 0); softpwm_set_duty_cycle(key, 0); - if ((fd = open("/sys/class/pwm/pwmchip0/unexport", O_WRONLY)) < 0) - { - return -1; - } - len = snprintf(str_gpio, sizeof(str_gpio), "%d", gpio); - write(fd, str_gpio, len); - close(fd); - // remove from list pwm = exported_pwms; while (pwm != NULL) { if (strcmp(pwm->key, key) == 0) { - //close the fd - close(pwm->enable_fd); - close(pwm->period_fd); - close(pwm->duty_fd); - close(pwm->polarity_fd); + pwm->stop_flag = true; + get_gpio_number(key, &gpio); +#ifndef NOTCHIPHW + gpio_unexport(gpio); +#endif if (prev_pwm == NULL) { diff --git a/source/py_softpwm.c b/source/py_softpwm.c index f25ef69..f99e343 100644 --- a/source/py_softpwm.c +++ b/source/py_softpwm.c @@ -53,6 +53,8 @@ static PyObject *py_start_channel(PyObject *self, PyObject *args, PyObject *kwar int polarity = 0; static char *kwlist[] = {"channel", "duty_cycle", "frequency", "polarity", NULL}; + printf("Made it to CHIPIO softpwm start"); + if (!PyArg_ParseTupleAndKeywords(args, kwargs, "s|ffi", kwlist, &channel, &duty_cycle, &frequency, &polarity)) { return NULL; } @@ -156,7 +158,7 @@ static PyObject *py_set_frequency(PyObject *self, PyObject *args, PyObject *kwar return NULL; } - if (pwm_set_frequency(key, frequency) == -1) { + if (softpwm_set_frequency(key, frequency) == -1) { PyErr_SetString(PyExc_RuntimeError, "You must start() the PWM channel first"); return NULL; }