Improvements to the PWM driver.

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@2853 35acf78f-673a-0410-8e92-d51de3d6d3f4

2 files changed, 48 insertions, 68 deletions

diff --git a/os/hal/templates/pwm_lld.c b/os/hal/templates/pwm_lld.c
index 507ba1294..295b0dcb4 100644
--- a/os/hal/templates/pwm_lld.c
+++ b/os/hal/templates/pwm_lld.c
@@ -87,23 +87,32 @@ void pwm_lld_stop(PWMDriver *pwmp) {
 }

 

 /**

- * @brief   Determines whatever the PWM channel is already enabled.

+ * @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 the @p PWMDriver object

- * @param[in] channel   PWM channel identifier

- * @return              The PWM channel status.

- * @retval FALSE        the channel is not enabled.

- * @retval TRUE         the channel is enabled.

+ * @param[in] pwmp      pointer to a @p PWMDriver object

  *

- * @notapi

+ * @api

  */

-bool_t pwm_lld_is_enabled(PWMDriver *pwmp, pwmchannel_t channel) {

+void pwm_lld_change_period(PWMDriver *pwmp, pwmcnt_t period) {

 

-  return FALSE;

 }

 

 /**

  * @brief   Enables 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)

@@ -119,11 +128,17 @@ void pwm_lld_enable_channel(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)

+ *

+ * @notapi

  */

 void pwm_lld_disable_channel(PWMDriver *pwmp, pwmchannel_t channel) {

 

diff --git a/os/hal/templates/pwm_lld.h b/os/hal/templates/pwm_lld.h
index bee00c073..9ef7a9853 100644
--- a/os/hal/templates/pwm_lld.h
+++ b/os/hal/templates/pwm_lld.h
@@ -65,16 +65,13 @@ typedef uint8_t pwmchannel_t;
 typedef uint16_t pwmcnt_t;

 

 /**

- * @brief   Type of a structure representing an PWM driver.

+ * @brief PWM logic mode.

  */

-typedef struct PWMDriver PWMDriver;

-

-/**

- * @brief   PWM notification callback type.

- *

- * @param[in] pwmp      pointer to a @p PWMDriver object

- */

-typedef void (*pwmcallback_t)(PWMDriver *pwmp);

+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;

 

 /**

  * @brief   PWM driver channel configuration structure.

@@ -102,6 +99,18 @@ typedef struct {
  */

 typedef struct {

   /**

+   * @brief   Timer clock in Hz.

+   * @note    The low level can use assertions in order to catch invalid

+   *          frequency specifications.

+   */

+  uint32_t                  frequency;

+  /**

+   * @brief   PWM period in ticks.

+   * @note    The low level can use assertions in order to catch invalid

+   *          period specifications.

+   */

+  pwmcnt_t                  period;

+  /**

    * @brief Periodic callback pointer.

    * @note  This callback is invoked on PWM counter reset. If set to

    *        @p NULL then the callback is disabled.

@@ -128,6 +137,10 @@ struct PWMDriver {
    * @brief Current configuration data.

    */

   const PWMConfig           *config;

+  /**

+   * @brief   Current PWM period in ticks.

+   */

+  pwmcnt_t                  period;

 #if defined(PWM_DRIVER_EXT_FIELDS)

   PWM_DRIVER_EXT_FIELDS

 #endif

@@ -138,54 +151,6 @@ struct PWMDriver {
 /* Driver macros.                                                            */

 /*===========================================================================*/

 

-/**

- * @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] numerator numerator of the fraction

- * @param[in] denominator percentage as an integer between 0 and numerator

- * @return              The pulse width to be passed to @p pwmEnableChannel().

- *

- * @api

- */

-#define PWM_FRACTION_TO_WIDTH(pwmp, numerator, denominator) 0

-

-/**

- * @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)

-

 /*===========================================================================*/

 /* External declarations.                                                    */

 /*===========================================================================*/

@@ -196,7 +161,7 @@ extern "C" {
   void pwm_lld_init(void);

   void pwm_lld_start(PWMDriver *pwmp);

   void pwm_lld_stop(PWMDriver *pwmp);

-  bool_t pwm_lld_is_enabled(PWMDriver *pwmp, pwmchannel_t channel);

+  void pwm_lld_change_period(PWMDriver *pwmp, pwmcnt_t period);

   void pwm_lld_enable_channel(PWMDriver *pwmp,

                               pwmchannel_t channel,

                               pwmcnt_t width);