diff options
author | gdisirio <gdisirio@35acf78f-673a-0410-8e92-d51de3d6d3f4> | 2011-03-31 10:21:52 +0000 |
---|---|---|
committer | gdisirio <gdisirio@35acf78f-673a-0410-8e92-d51de3d6d3f4> | 2011-03-31 10:21:52 +0000 |
commit | a58a524d4c7e58d03a0fa3698f09fb17985a70bc (patch) | |
tree | 561b345be6af1915bff26496f4dab45fdf666c2c /os/hal/include | |
parent | 8cdc7bd8f3987116d89c0a9d1a624127f8652ac0 (diff) | |
download | ChibiOS-a58a524d4c7e58d03a0fa3698f09fb17985a70bc.tar.gz ChibiOS-a58a524d4c7e58d03a0fa3698f09fb17985a70bc.tar.bz2 ChibiOS-a58a524d4c7e58d03a0fa3698f09fb17985a70bc.zip |
Improvements to the PWM driver.
git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@2853 35acf78f-673a-0410-8e92-d51de3d6d3f4
Diffstat (limited to 'os/hal/include')
-rw-r--r-- | os/hal/include/pwm.h | 107 |
1 files changed, 94 insertions, 13 deletions
diff --git a/os/hal/include/pwm.h b/os/hal/include/pwm.h index e63478ca3..7181054e4 100644 --- a/os/hal/include/pwm.h +++ b/os/hal/include/pwm.h @@ -57,13 +57,16 @@ typedef enum { } pwmstate_t;
/**
- * @brief PWM logic mode.
+ * @brief Type of a structure representing a PWM driver.
*/
-typedef enum {
- PWM_OUTPUT_DISABLED = 0, /**< Output not driven, callback only. */
- PWM_OUTPUT_ACTIVE_HIGH = 1, /**< Idle is logic level 0. */
- PWM_OUTPUT_ACTIVE_LOW = 2 /**< Idle is logic level 1. */
-} pwmmode_t;
+typedef struct PWMDriver PWMDriver;
+
+/**
+ * @brief PWM notification callback type.
+ *
+ * @param[in] pwmp pointer to a @p PWMDriver object
+ */
+typedef void (*pwmcallback_t)(PWMDriver *pwmp);
#include "pwm_lld.h"
@@ -72,12 +75,86 @@ typedef enum { /*===========================================================================*/
/**
+ * @brief Converts from fraction to pulse width.
+ * @note Be careful with rounding errors, this is integer math not magic.
+ * You can specify tenths of thousandth but make sure you have the
+ * proper hardware resolution by carefully choosing the clock source
+ * and prescaler settings, see @p PWM_COMPUTE_PSC.
+ *
+ * @param[in] pwmp pointer to a @p PWMDriver object
+ * @param[in] denominator denominator of the fraction
+ * @param[in] numerator numerator of the fraction
+ * @return The pulse width to be passed to @p pwmEnableChannel().
+ *
+ * @api
+ */
+#define PWM_FRACTION_TO_WIDTH(pwmp, denominator, numerator) \
+ ((uint16_t)((((uint32_t)(pwmp)->period) * \
+ (uint32_t)(numerator)) / (uint32_t)(denominator)))
+
+/**
+ * @brief Converts from degrees to pulse width.
+ * @note Be careful with rounding errors, this is integer math not magic.
+ * You can specify hundredths of degrees but make sure you have the
+ * proper hardware resolution by carefully choosing the clock source
+ * and prescaler settings, see @p PWM_COMPUTE_PSC.
+ *
+ * @param[in] pwmp pointer to a @p PWMDriver object
+ * @param[in] degrees degrees as an integer between 0 and 36000
+ * @return The pulse width to be passed to @p pwmEnableChannel().
+ *
+ * @api
+ */
+#define PWM_DEGREES_TO_WIDTH(pwmp, degrees) \
+ PWM_FRACTION_TO_WIDTH(pwmp, 36000, degrees)
+
+/**
+ * @brief Converts from percentage to pulse width.
+ * @note Be careful with rounding errors, this is integer math not magic.
+ * You can specify tenths of thousandth but make sure you have the
+ * proper hardware resolution by carefully choosing the clock source
+ * and prescaler settings, see @p PWM_COMPUTE_PSC.
+ *
+ * @param[in] pwmp pointer to a @p PWMDriver object
+ * @param[in] percentage percentage as an integer between 0 and 10000
+ * @return The pulse width to be passed to @p pwmEnableChannel().
+ *
+ * @api
+ */
+#define PWM_PERCENTAGE_TO_WIDTH(pwmp, percentage) \
+ PWM_FRACTION_TO_WIDTH(pwmp, 10000, percentage)
+
+/**
+ * @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
+ *
+ * @iclass
+ */
+#define pwmChangePeriodI(pwmp, period) { \
+ (pwmp)->period = (period); \
+ pwm_lld_change_period(pwmp, period); \
+}
+
+/**
* @brief Enables a PWM channel.
- * @details Programs (or reprograms) a PWM channel.
- * @note This function has to be invoked from a lock zone.
+ * @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
+ * @param[in] channel PWM channel identifier (0...PWM_CHANNELS-1)
* @param[in] width PWM pulse width as clock pulses number
*
* @iclass
@@ -86,13 +163,16 @@ typedef enum { pwm_lld_enable_channel(pwmp, channel, width)
/**
- * @brief Disables a PWM channel.
- * @details The channel is disabled and its output line returned to the
+ * @brief Disables a PWM channel.
+ * @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 This function has to be invoked from a lock zone.
+ * @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
+ * @param[in] channel PWM channel identifier (0...PWM_CHANNELS-1)
*
* @iclass
*/
@@ -110,6 +190,7 @@ extern "C" { void pwmObjectInit(PWMDriver *pwmp);
void pwmStart(PWMDriver *pwmp, const PWMConfig *config);
void pwmStop(PWMDriver *pwmp);
+ void pwmChangePeriod(PWMDriver *pwmp, pwmcnt_t period);
void pwmEnableChannel(PWMDriver *pwmp,
pwmchannel_t channel,
pwmcnt_t width);
|