static void pwm_dump(FAR const char *msg, FAR const struct pwm_info_s *info, bool started) { #ifdef CONFIG_PWM_MULTICHAN int i; #endif pwminfo("%s: frequency: %d", msg, info->frequency); #ifdef CONFIG_PWM_MULTICHAN for (i = 0; i < CONFIG_PWM_NCHANNELS; i++) { pwminfo(" channel: %d duty: %08x", info->channels[i].channel, info->channels[i].duty); } #else pwminfo(" duty: %08x", info->duty); #endif #ifdef CONFIG_PWM_PULSECOUNT pwminfo(" count: %d\n", info->count); #endif pwminfo(" started: %d\n", started); }
static int pwm_open(FAR struct file *filep) { FAR struct inode *inode = filep->f_inode; FAR struct pwm_upperhalf_s *upper = inode->i_private; uint8_t tmp; int ret; pwminfo("crefs: %d\n", upper->crefs); /* Get exclusive access to the device structures */ ret = nxsem_wait(&upper->exclsem); if (ret < 0) { goto errout; } /* Increment the count of references to the device. If this the first * time that the driver has been opened for this device, then initialize * the device. */ tmp = upper->crefs + 1; if (tmp == 0) { /* More than 255 opens; uint8_t overflows to zero */ ret = -EMFILE; goto errout_with_sem; } /* Check if this is the first time that the driver has been opened. */ if (tmp == 1) { FAR struct pwm_lowerhalf_s *lower = upper->dev; /* Yes.. perform one time hardware initialization. */ DEBUGASSERT(lower->ops->setup != NULL); pwminfo("calling setup\n"); ret = lower->ops->setup(lower); if (ret < 0) { goto errout_with_sem; } } /* Save the new open count on success */ upper->crefs = tmp; ret = OK; errout_with_sem: nxsem_post(&upper->exclsem); errout: return ret; }
static int pwm_close(FAR struct file *filep) { FAR struct inode *inode = filep->f_inode; FAR struct pwm_upperhalf_s *upper = inode->i_private; int ret; pwminfo("crefs: %d\n", upper->crefs); /* Get exclusive access to the device structures */ ret = sem_wait(&upper->exclsem); if (ret < 0) { ret = -get_errno(); goto errout; } /* Decrement the references to the driver. If the reference count will * decrement to 0, then uninitialize the driver. */ if (upper->crefs > 1) { upper->crefs--; } else { FAR struct pwm_lowerhalf_s *lower = upper->dev; /* There are no more references to the port */ upper->crefs = 0; /* Disable the PWM device */ DEBUGASSERT(lower->ops->shutdown != NULL); pwminfo("calling shutdown: %d\n"); lower->ops->shutdown(lower); } ret = OK; //errout_with_sem: sem_post(&upper->exclsem); errout: return ret; }
void pwm_expired(FAR void *handle) { FAR struct pwm_upperhalf_s *upper = (FAR struct pwm_upperhalf_s *)handle; pwminfo("started: %d waiting: %d\n", upper->started, upper->waiting); /* Make sure that the PWM is started */ if (upper->started) { /* Is there a thread waiting for the pulse train to complete? */ if (upper->waiting) { /* Yes.. clear the waiting flag and awakened the waiting thread */ upper->waiting = false; sem_post(&upper->waitsem); } /* The PWM is now stopped */ upper->started = false; } }
int pwm_register(FAR const char *path, FAR struct pwm_lowerhalf_s *dev) { FAR struct pwm_upperhalf_s *upper; /* Allocate the upper-half data structure */ upper = (FAR struct pwm_upperhalf_s *)kmm_zalloc(sizeof(struct pwm_upperhalf_s)); if (!upper) { pwmerr("Allocation failed\n"); return -ENOMEM; } /* Initialize the PWM device structure (it was already zeroed by kmm_zalloc()) */ sem_init(&upper->exclsem, 0, 1); #ifdef CONFIG_PWM_PULSECOUNT sem_init(&upper->waitsem, 0, 0); #endif upper->dev = dev; /* Register the PWM device */ pwminfo("Registering %s\n", path); return register_driver(path, &g_pwmops, 0666, upper); }
int pwm_register(FAR const char *path, FAR struct pwm_lowerhalf_s *dev) { FAR struct pwm_upperhalf_s *upper; /* Allocate the upper-half data structure */ upper = (FAR struct pwm_upperhalf_s *)kmm_zalloc(sizeof(struct pwm_upperhalf_s)); if (!upper) { pwmerr("Allocation failed\n"); return -ENOMEM; } /* Initialize the PWM device structure (it was already zeroed by kmm_zalloc()) */ sem_init(&upper->exclsem, 0, 1); #ifdef CONFIG_PWM_PULSECOUNT sem_init(&upper->waitsem, 0, 0); /* The wait semaphore is used for signaling and, hence, should not have priority * inheritance enabled. */ sem_setprotocol(&upper->waitsem, SEM_PRIO_NONE); #endif upper->dev = dev; /* Register the PWM device */ pwminfo("Registering %s\n", path); return register_driver(path, &g_pwmops, 0666, upper); }
static int pwm_ioctl(FAR struct file *filep, int cmd, unsigned long arg) { FAR struct inode *inode = filep->f_inode; FAR struct pwm_upperhalf_s *upper = inode->i_private; FAR struct pwm_lowerhalf_s *lower = upper->dev; int ret; pwminfo("cmd: %d arg: %ld\n", cmd, arg); /* Get exclusive access to the device structures */ ret = sem_wait(&upper->exclsem); if (ret < 0) { return ret; } /* Handle built-in ioctl commands */ switch (cmd) { /* PWMIOC_SETCHARACTERISTICS - Set the characteristics of the next pulsed * output. This command will neither start nor stop the pulsed output. * It will either setup the configuration that will be used when the * output is started; or it will change the characteristics of the pulsed * output on the fly if the timer is already started. * * ioctl argument: A read-only reference to struct pwm_info_s that provides * the characteristics of the pulsed output. */ case PWMIOC_SETCHARACTERISTICS: { FAR const struct pwm_info_s *info = (FAR const struct pwm_info_s *)((uintptr_t)arg); DEBUGASSERT(info != NULL && lower->ops->start != NULL); pwm_dump("PWMIOC_SETCHARACTERISTICS", info, upper->started); /* Save the pulse train characteristics */ memcpy(&upper->info, info, sizeof(struct pwm_info_s)); /* If PWM is already running, then re-start it with the new characteristics */ if (upper->started) { #ifdef CONFIG_PWM_PULSECOUNT ret = lower->ops->start(lower, &upper->info, upper); #else ret = lower->ops->start(lower, &upper->info); #endif } } break; /* PWMIOC_GETCHARACTERISTICS - Get the currently selected characteristics of * the pulsed output (independent of whether the output is start or stopped). * * ioctl argument: A reference to struct pwm_info_s to receive the * characteristics of the pulsed output. */ case PWMIOC_GETCHARACTERISTICS: { FAR struct pwm_info_s *info = (FAR struct pwm_info_s *)((uintptr_t)arg); DEBUGASSERT(info != NULL); memcpy(info, &upper->info, sizeof(struct pwm_info_s)); pwm_dump("PWMIOC_GETCHARACTERISTICS", info, upper->started); } break; /* PWMIOC_START - Start the pulsed output. The PWMIOC_SETCHARACTERISTICS * command must have previously been sent. * * ioctl argument: None */ case PWMIOC_START: { pwm_dump("PWMIOC_START", &upper->info, upper->started); DEBUGASSERT(lower->ops->start != NULL); /* Start the pulse train */ ret = pwm_start(upper, filep->f_oflags); } break; /* PWMIOC_STOP - Stop the pulsed output. * * ioctl argument: None */ case PWMIOC_STOP: { pwminfo("PWMIOC_STOP: started: %d\n", upper->started); DEBUGASSERT(lower->ops->stop != NULL); if (upper->started) { ret = lower->ops->stop(lower); upper->started = false; #ifdef CONFIG_PWM_PULSECOUNT if (upper->waiting) { upper->waiting = false; } #endif } } break; /* Any unrecognized IOCTL commands might be platform-specific ioctl commands */ default: { pwminfo("Forwarding unrecognized cmd: %d arg: %ld\n", cmd, arg); DEBUGASSERT(lower->ops->ioctl != NULL); ret = lower->ops->ioctl(lower, cmd, arg); } break; } sem_post(&upper->exclsem); return ret; }
static int pwm_start(FAR struct pwm_upperhalf_s *upper, unsigned int oflags) { FAR struct pwm_lowerhalf_s *lower = upper->dev; irqstate_t flags; int ret = OK; DEBUGASSERT(upper != NULL && lower->ops->start != NULL); /* Verify that the PWM is not already running */ if (!upper->started) { /* Disable interrupts to avoid race conditions */ flags = enter_critical_section(); /* Indicate that if will be waiting for the pulse count to complete. * Note that we will only wait if a non-zero pulse count is specified * and if the PWM driver was opened in normal, blocking mode. Also * assume for now that the pulse train will be successfully started. * * We do these things before starting the PWM to avoid race conditions. */ upper->waiting = (upper->info.count > 0) && ((oflags & O_NONBLOCK) == 0); upper->started = true; /* Invoke the bottom half method to start the pulse train */ ret = lower->ops->start(lower, &upper->info, upper); /* A return value of zero means that the pulse train was started * successfully. */ if (ret == OK) { /* Should we wait for the pulse output to complete? Loop in * in case the wakeup form sem_wait() is a false alarm. */ while (upper->waiting) { /* Wait until we are awakened by pwm_expired(). When * pwm_expired is called, it will post the waitsem and * clear the waiting flag. */ int tmp = sem_wait(&upper->waitsem); DEBUGASSERT(tmp == OK || get_errno() == EINTR); } } else { /* Looks like we won't be waiting after all */ pwminfo("start failed: %d\n", ret); upper->started = false; upper->waiting = false; } leave_critical_section(flags); } return ret; }