Improvements to the PWM driver.

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

9 files changed, 289 insertions, 227 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);

diff --git a/os/hal/platforms/STM32/gpt_lld.c b/os/hal/platforms/STM32/gpt_lld.c
index ffbfe475c..8419cad68 100644
--- a/os/hal/platforms/STM32/gpt_lld.c
+++ b/os/hal/platforms/STM32/gpt_lld.c
@@ -325,6 +325,7 @@ void gpt_lld_stop(GPTDriver *gptp) {
   if (gptp->state == GPT_READY) {

     gptp->tim->CR1  = 0;                    /* Timer disabled.              */

     gptp->tim->DIER = 0;                    /* All IRQs disabled.           */

+    gptp->tim->SR   = 0;                    /* Clear eventual pending IRQs. */

 

 #if STM32_GPT_USE_TIM1

     if (&GPTD1 == gptp) {

diff --git a/os/hal/platforms/STM32/pwm_lld.c b/os/hal/platforms/STM32/pwm_lld.c
index eaf83bd90..6b05b66aa 100644
--- a/os/hal/platforms/STM32/pwm_lld.c
+++ b/os/hal/platforms/STM32/pwm_lld.c
@@ -289,12 +289,15 @@ void pwm_lld_init(void) {
 

 /**

  * @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

  *

  * @notapi

  */

 void pwm_lld_start(PWMDriver *pwmp) {

+  uint32_t clock, psc;

   uint16_t ccer;

 

   /* Reset channels.*/

@@ -311,6 +314,7 @@ void pwm_lld_start(PWMDriver *pwmp) {
                        CORTEX_PRIORITY_MASK(STM32_PWM_TIM1_IRQ_PRIORITY));

       NVICEnableVector(TIM1_CC_IRQn,

                        CORTEX_PRIORITY_MASK(STM32_PWM_TIM1_IRQ_PRIORITY));

+      clock = STM32_TIMCLK2;

     }

 #endif

 #if STM32_PWM_USE_TIM2

@@ -320,6 +324,7 @@ void pwm_lld_start(PWMDriver *pwmp) {
       RCC->APB1RSTR = 0;

       NVICEnableVector(TIM2_IRQn,

                        CORTEX_PRIORITY_MASK(STM32_PWM_TIM2_IRQ_PRIORITY));

+      clock = STM32_TIMCLK1;

     }

 #endif

 #if STM32_PWM_USE_TIM3

@@ -329,6 +334,7 @@ void pwm_lld_start(PWMDriver *pwmp) {
       RCC->APB1RSTR = 0;

       NVICEnableVector(TIM3_IRQn,

                        CORTEX_PRIORITY_MASK(STM32_PWM_TIM3_IRQ_PRIORITY));

+      clock = STM32_TIMCLK1;

     }

 #endif

 #if STM32_PWM_USE_TIM4

@@ -338,6 +344,7 @@ void pwm_lld_start(PWMDriver *pwmp) {
       RCC->APB1RSTR = 0;

       NVICEnableVector(TIM4_IRQn,

                        CORTEX_PRIORITY_MASK(STM32_PWM_TIM4_IRQ_PRIORITY));

+      clock = STM32_TIMCLK1;

     }

 #endif

 

@@ -348,6 +355,7 @@ void pwm_lld_start(PWMDriver *pwmp) {
       RCC->APB1RSTR = 0;

       NVICEnableVector(TIM5_IRQn,

                        CORTEX_PRIORITY_MASK(STM32_PWM_TIM5_IRQ_PRIORITY));

+      clock = STM32_TIMCLK1;

     }

 #endif

 

@@ -364,21 +372,26 @@ void pwm_lld_start(PWMDriver *pwmp) {
   }

   else {

     /* Driver re-configuration scenario, it must be stopped first.*/

-    /* Really required ?????????? */

-    pwmp->tim->CR1  = 0;                    /* Timer stopped.               */

-    pwmp->tim->CR2  = 0;                    /* Timer stopped.               */

-    pwmp->tim->SMCR = 0;                    /* Slave mode disabled.         */

+    pwmp->enabled_channels = 0;             /* All channels disabled.       */

+    pwmp->tim->CR1  = 0;                    /* Timer disabled.              */

+    pwmp->tim->DIER = 0;                    /* All IRQs disabled.           */

+    pwmp->tim->SR   = 0;                    /* Clear eventual pending IRQs. */

     pwmp->tim->CCR1 = 0;                    /* Comparator 1 disabled.       */

     pwmp->tim->CCR2 = 0;                    /* Comparator 2 disabled.       */

     pwmp->tim->CCR3 = 0;                    /* Comparator 3 disabled.       */

     pwmp->tim->CCR4 = 0;                    /* Comparator 4 disabled.       */

-    pwmp->tim->CNT  = 0;

+    pwmp->tim->CNT  = 0;                    /* Counter reset to zero.       */

   }

 

   /* Timer configuration.*/

+  psc = (clock / pwmp->config->frequency) - 1;

+  chDbgAssert((psc <= 0xFFFF) &&

+              ((psc + 1) * pwmp->config->frequency) == clock,

+              "pwm_lld_start(), #1", "invalid frequency");

+  pwmp->tim->PSC  = (uint16_t)psc;

+  pwmp->tim->ARR  = (uint16_t)(pwmp->period - 1);

   pwmp->tim->CR2  = pwmp->config->cr2;

-  pwmp->tim->PSC  = pwmp->config->psc;

-  pwmp->tim->ARR  = pwmp->config->arr;

+

   /* Output enables and polarities setup.*/

   ccer = 0;

   switch (pwmp->config->channels[0].mode) {

@@ -434,17 +447,9 @@ void pwm_lld_stop(PWMDriver *pwmp) {
   /* If in ready state then disables the PWM clock.*/

   if (pwmp->state == PWM_READY) {

     pwmp->enabled_channels = 0;             /* All channels disabled.       */

-    pwmp->tim->CR1   = 0;

-    pwmp->tim->CR2   = 0;

-    pwmp->tim->CCER  = 0;                   /* Outputs disabled.            */

-    pwmp->tim->CCR1  = 0;                   /* Comparator 1 disabled.       */

-    pwmp->tim->CCR2  = 0;                   /* Comparator 2 disabled.       */

-    pwmp->tim->CCR3  = 0;                   /* Comparator 3 disabled.       */

-    pwmp->tim->CCR4  = 0;                   /* Comparator 4 disabled.       */

-    pwmp->tim->BDTR  = 0;

-    pwmp->tim->DIER  = 0;

-    pwmp->tim->SR    = 0;

-    pwmp->tim->EGR   = TIM_EGR_UG;          /* Update event.                */

+    pwmp->tim->CR1  = 0;                    /* Timer disabled.              */

+    pwmp->tim->DIER = 0;                    /* All IRQs disabled.           */

+    pwmp->tim->SR   = 0;                    /* Clear eventual pending IRQs. */

 

 #if STM32_PWM_USE_TIM1

     if (&PWMD1 == pwmp) {

@@ -481,7 +486,38 @@ void pwm_lld_stop(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    The function has effect at the next cycle start.

+ *

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

+ *

+ * @api

+ */

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

+

+  pwmp->enabled_channels = 0;           /* All channels disabled.           */

+  pwmp->tim->DIER &= ~(TIM_DIER_CC1IE |

+                       TIM_DIER_CC2IE |

+                       TIM_DIER_CC3IE |

+                       TIM_DIER_CC4IE); /* Channels sources disabled.       */

+  pwmp->tim->SR    = ~(TIM_SR_CC1IF |

+                       TIM_SR_CC1IF |

+                       TIM_SR_CC1IF |

+                       TIM_SR_CC1IF);   /* Clears eventual pending IRQs.    */

+  pwmp->tim->ARR   = (uint16_t)(period - 1);

+}

+

+/**

  * @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    The function has effect at the next cycle start.

  *

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

  * @param[in] channel   PWM channel identifier (0...PWM_CHANNELS-1)

@@ -508,8 +544,10 @@ 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    The function has effect at the next cycle start.

  *

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

  * @param[in] channel   PWM channel identifier (0...PWM_CHANNELS-1)

diff --git a/os/hal/platforms/STM32/pwm_lld.h b/os/hal/platforms/STM32/pwm_lld.h
index 8c15a3c6f..d8e1754c9 100644
--- a/os/hal/platforms/STM32/pwm_lld.h
+++ b/os/hal/platforms/STM32/pwm_lld.h
@@ -169,16 +169,13 @@ 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.

@@ -202,6 +199,18 @@ 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.

@@ -213,14 +222,6 @@ typedef struct {
   PWMChannelConfig          channels[PWM_CHANNELS];

   /* End of the mandatory fields.*/

   /**

-   * @brief TIM PSC (pre-scaler) register initialization data.

-   */

-  uint16_t                  psc;

-  /**

-   * @brief TIM ARR (auto-reload) register initialization data.

-   */

-  uint16_t                  arr;

-  /**

    * @brief TIM CR2 register initialization data.

    * @note  The value of this field should normally be equal to zero.

    */

@@ -239,6 +240,10 @@ struct PWMDriver {
    * @brief Current driver 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

@@ -257,90 +262,6 @@ struct PWMDriver {
 /* Driver macros.                                                            */

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

 

-/**

- * @brief   PWM clock prescaler initialization utility.

- * @note    The real clock value is rounded to the lower valid value, please

- *          make sure that the source clock frequency is a multiple of the

- *          requested PWM clock frequency.

- * @note    The calculated value must fit into an unsigned 16 bits integer.

- *

- * @param[in] clksrc    clock source frequency, depending on the target timer

- *                      cell it can be one of:

- *                      - STM32_TIMCLK1

- *                      - STM32_TIMCLK2

- *                      .

- *                      Please refer to the STM32 HAL driver documentation

- *                      and/or the STM32 Reference Manual for the right clock

- *                      source.

- * @param[in] pwmclk    PWM clock frequency in cycles

- * @return              The value to be stored in the @p psc field of the

- *                      @p PWMConfig structure.

- */

-#define PWM_COMPUTE_PSC(clksrc, pwmclk)                                     \

-  ((uint16_t)(((clksrc) / (pwmclk)) - 1))

-

-/**

- * @brief   PWM cycle period initialization utility.

- * @note    The calculated value must fit into an unsigned 16 bits integer.

- *

- * @param[in] pwmclk    PWM clock frequency in cycles

- * @param[in] pwmperiod PWM cycle period in nanoseconds

- * @return              The value to be stored in the @p arr field of the

- *                      @p PWMConfig structure.

- */

-#define PWM_COMPUTE_ARR(pwmclk, pwmperiod)                                  \

-  ((uint16_t)(((pwmclk) / (1000000000 / (pwmperiod))) - 1))

-

-/**

- * @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)                 \

-  ((uint16_t)((((uint32_t)(pwmp)->config->arr + 1UL) *                      \

-               (uint32_t)(denominator)) / (uint32_t)(numerator)))

-

-/**

- * @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.                                                    */

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

@@ -371,6 +292,7 @@ extern "C" {
   void pwm_lld_init(void);

   void pwm_lld_start(PWMDriver *pwmp);

   void pwm_lld_stop(PWMDriver *pwmp);

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

   void pwm_lld_enable_channel(PWMDriver *pwmp,

                               pwmchannel_t channel,

                               pwmcnt_t width);

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)

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);

diff --git a/readme.txt b/readme.txt
index ddc7c35f1..b0c085811 100644
--- a/readme.txt
+++ b/readme.txt
@@ -79,7 +79,14 @@
 - FIX: Fixed wrong checks in I/O Queues (bug 3219197)(backported to 2.2.3).

 - FIX: Fixed invalid assertion in adcConvert() (bug 3205410)(backported

   to 2.2.3).

-- NEW: Added new ICU driver model, Input Capture Unit..

+- NEW: Improvements to the PWM driver model:

+  - Easier configuration similar to the GPT driver initializations, macros

+    are no more required.

+  - Added a new function that allows to change the PWM period on the fly,

+    even from within callbacks. Formerly it was required to stop and restart

+    the driver.

+  - Improved driver documentation.

+- NEW: Added new ICU driver model, Input Capture Unit.

 - NEW: ICU driver implementation for STM32.

 - NEW: Implemented stack checking in the Cortex-Mx RVCT port (backported

   to 2.2.3).

diff --git a/testhal/STM32/PWM/main.c b/testhal/STM32/PWM/main.c
index c42b15939..ef08b792c 100644
--- a/testhal/STM32/PWM/main.c
+++ b/testhal/STM32/PWM/main.c
@@ -21,33 +21,21 @@
 #include "ch.h"

 #include "hal.h"

 

-/*

- * Red LEDs blinker thread, times are in milliseconds.

- */

-static WORKING_AREA(waThread1, 128);

-static msg_t Thread1(void *arg) {

-

-  (void)arg;

-  while (TRUE) {

-    palClearPad(IOPORT3, GPIOC_LED);

-    chThdSleepMilliseconds(500);

-    palSetPad(IOPORT3, GPIOC_LED);

-    chThdSleepMilliseconds(500);

-  }

-  return 0;

-}

-

 static void pwmpcb(PWMDriver *pwmp) {

 

   (void)pwmp;

+  palSetPad(IOPORT3, GPIOC_LED);

 }

 

 static void pwmc1cb(PWMDriver *pwmp) {

 

   (void)pwmp;

+  palClearPad(IOPORT3, GPIOC_LED);

 }

 

 static PWMConfig pwmcfg = {

+  10000,                                    /* 10KHz PWM clock frequency.   */

+  10000,                                    /* Initial PWM period 1S.       */

   pwmpcb,

   {

    {PWM_OUTPUT_ACTIVE_HIGH, pwmc1cb},

@@ -55,8 +43,6 @@ static PWMConfig pwmcfg = {
    {PWM_OUTPUT_DISABLED, NULL},

    {PWM_OUTPUT_DISABLED, NULL}

   },

-  PWM_COMPUTE_PSC(STM32_TIMCLK1, 10000),    /* 10KHz PWM clock frequency.   */

-  PWM_COMPUTE_ARR(10000, 1000000),          /* PWM period 1S.               */

   0

 };

 

@@ -76,9 +62,9 @@ int main(void) {
   chSysInit();

 

   /*

-   * Creates the blinker thread.

+   * LED initially off.

    */

-  chThdCreateStatic(waThread1, sizeof(waThread1), NORMALPRIO, Thread1, NULL);

+  palSetPad(IOPORT3, GPIOC_LED);

 

   /*

    * Initializes the PWM driver 1.

@@ -88,9 +74,9 @@ int main(void) {
   chThdSleepMilliseconds(2000);

 

   /*

-   * Starts the channel 0 using 50% duty cycle.

+   * Starts the channel 0 using 25% duty cycle.

    */

-  pwmEnableChannel(&PWMD1, 0, PWM_PERCENTAGE_TO_WIDTH(&PWMD1, 5000));

+  pwmEnableChannel(&PWMD1, 0, PWM_PERCENTAGE_TO_WIDTH(&PWMD1, 2500));

   chThdSleepMilliseconds(5000);

 

   /*

@@ -100,10 +86,18 @@ int main(void) {
   chThdSleepMilliseconds(5000);

 

   /*

+   * Changes PWM period to half second and duty cycle to 50%.

+   */

+  pwmChangePeriod(&PWMD1, 5000);

+  pwmEnableChannel(&PWMD1, 0, PWM_PERCENTAGE_TO_WIDTH(&PWMD1, 5000));

+  chThdSleepMilliseconds(5000);

+

+  /*

    * Disables channel 0.

    */

   pwmDisableChannel(&PWMD1, 0);

-

+  pwmStop(&PWMD1);

+  palSetPad(IOPORT3, GPIOC_LED);

 

   /*

    * Normal main() thread activity, in this demo it does nothing.