diff options
Diffstat (limited to 'os/hal/src/pwm.c')
| -rw-r--r-- | os/hal/src/pwm.c | 43 |
1 files changed, 41 insertions, 2 deletions
diff --git a/os/hal/src/pwm.c b/os/hal/src/pwm.c index e510ba180..eaa49bc56 100644 --- a/os/hal/src/pwm.c +++ b/os/hal/src/pwm.c @@ -77,6 +77,8 @@ void pwmObjectInit(PWMDriver *pwmp) { /**
* @brief Configures and activates the PWM peripheral.
+ * @note Starting a driver that is already in the @p PWM_READY state
+ * disables all the active channels.
*
* @param[in] pwmp pointer to a @p PWMDriver object
* @param[in] config pointer to a @p PWMConfig object
@@ -91,6 +93,7 @@ void pwmStart(PWMDriver *pwmp, const PWMConfig *config) { chDbgAssert((pwmp->state == PWM_STOP) || (pwmp->state == PWM_READY),
"pwmStart(), #1", "invalid state");
pwmp->config = config;
+ pwmp->period = config->period;
pwm_lld_start(pwmp);
pwmp->state = PWM_READY;
chSysUnlock();
@@ -116,8 +119,40 @@ void pwmStop(PWMDriver *pwmp) { }
/**
+ * @brief Changes the period the PWM peripheral.
+ * @details This function changes the period of a PWM unit that has already
+ * been activated using @p pwmStart().
+ * @pre The PWM unit must have been activated using @p pwmStart().
+ * @post The PWM unit period is changed to the new value.
+ * @post Any active channel is disabled by this function and must be
+ * activated explicitly using @p pwmEnableChannel().
+ * @note Depending on the hardware implementation this function has
+ * effect starting on the next cycle (recommended implementation)
+ * or immediately (fallback implementation).
+ *
+ * @param[in] pwmp pointer to a @p PWMDriver object
+ *
+ * @api
+ */
+void pwmChangePeriod(PWMDriver *pwmp, pwmcnt_t period) {
+
+ chDbgCheck(pwmp != NULL, "pwmChangePeriod");
+
+ chSysLock();
+ chDbgAssert(pwmp->state == PWM_READY,
+ "pwmChangePeriod(), #1", "invalid state");
+ pwmp->period = period;
+ pwm_lld_change_period(pwmp, period);
+ chSysUnlock();
+}
+
+/**
* @brief Enables a PWM channel.
- * @details Programs (or reprograms) a PWM channel.
+ * @pre The PWM unit must have been activated using @p pwmStart().
+ * @post The channel is active using the specified configuration.
+ * @note Depending on the hardware implementation this function has
+ * effect starting on the next cycle (recommended implementation)
+ * or immediately (fallback implementation).
*
* @param[in] pwmp pointer to a @p PWMDriver object
* @param[in] channel PWM channel identifier (0...PWM_CHANNELS-1)
@@ -141,8 +176,12 @@ void pwmEnableChannel(PWMDriver *pwmp, /**
* @brief Disables a PWM channel.
- * @details The channel is disabled and its output line returned to the
+ * @pre The PWM unit must have been activated using @p pwmStart().
+ * @post The channel is disabled and its output line returned to the
* idle state.
+ * @note Depending on the hardware implementation this function has
+ * effect starting on the next cycle (recommended implementation)
+ * or immediately (fallback implementation).
*
* @param[in] pwmp pointer to a @p PWMDriver object
* @param[in] channel PWM channel identifier (0...PWM_CHANNELS-1)
|