Use active wait and perform extra toggle if needed. (same as the nrf_pwm)

2 files changed, 98 insertions, 45 deletions

diff --git a/os/hal/ports/NRF5/NRF51822/hal_pwm_lld.c b/os/hal/ports/NRF5/NRF51822/hal_pwm_lld.c
index 378525f..f446fd3 100644
--- a/os/hal/ports/NRF5/NRF51822/hal_pwm_lld.c
+++ b/os/hal/ports/NRF5/NRF51822/hal_pwm_lld.c
@@ -30,6 +30,7 @@
 /* Driver local definitions.                                                 */

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

 

+#define PWM_GPIOTE_PPI_CC 3

 

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

 /* Driver exported variables.                                                */

@@ -63,19 +64,23 @@ PWMDriver PWMD3;
 /* Driver local variables and types.                                         */

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

 

+static const uint8_t pwm_margin_by_prescaler[] = {

+    80, 40, 20, 15, 10, 5, 2, 1, 1, 1

+};

+

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

 /* Driver local functions.                                                   */

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

 

 static void pwm_lld_serve_interrupt(PWMDriver *pwmp) {

-  // Deal with PWM channels     

-  uint8_t n;

-  for (n = 0 ; n < pwmp->channels ; n++) {

-    if (pwmp->timer->EVENTS_COMPARE[n]) {

-      pwmp->timer->EVENTS_COMPARE[n] = 0;

-

-      if (pwmp->config->channels[n].callback != NULL) {

-	pwmp->config->channels[n].callback(pwmp);

+  uint8_t channel;

+  // Deal with PWM channels       

+  for (channel = 0 ; channel < pwmp->channels ; channel++) {

+    if (pwmp->timer->EVENTS_COMPARE[channel]) {

+      pwmp->timer->EVENTS_COMPARE[channel] = 0;

+

+      if (pwmp->config->channels[channel].callback != NULL) {

+	pwmp->config->channels[channel].callback(pwmp);

       }

     }      

   }

@@ -88,7 +93,14 @@ static void pwm_lld_serve_interrupt(PWMDriver *pwmp) {
       pwmp->config->callback(pwmp);

     }

   }

+}

 

+static inline

+bool pwm_within_safe_margins(PWMDriver *pwmp, uint32_t timer, uint32_t width)  {

+    const uint32_t margin = pwm_margin_by_prescaler[pwmp->timer->PRESCALER];

+    return (width <= margin)

+	? ((width <= timer) && (timer < (pwmp->period + width - margin)))

+	: ((width <= timer) || (timer < (width - margin)));

 }

 

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

@@ -245,7 +257,7 @@ void pwm_lld_start(PWMDriver *pwmp) {
  * @notapi

  */

 void pwm_lld_stop(PWMDriver *pwmp) {

-  pwmp->timer->TASKS_STOP = 1;

+  pwmp->timer->TASKS_SHUTDOWN = 1;

 

 #if NRF5_PWM_USE_TIMER0

   if (&PWMD1 == pwmp) {

@@ -284,41 +296,81 @@ void pwm_lld_enable_channel(PWMDriver *pwmp,
                             pwmcnt_t width) {

 #if NRF5_PWM_USE_GPIOTE_PPI

   const PWMChannelConfig *cfg_channel = &pwmp->config->channels[channel];

-

+  const uint8_t  gpiote_channel = cfg_channel->gpiote_channel;

+  const uint8_t *ppi_channel    = cfg_channel->ppi_channel;

+  

   uint32_t outinit;

   switch(cfg_channel->mode & PWM_OUTPUT_MASK) {

-  case PWM_OUTPUT_ACTIVE_LOW:

-    outinit = GPIOTE_CONFIG_OUTINIT_Low;

-    break;

-  case PWM_OUTPUT_ACTIVE_HIGH:

-    outinit = GPIOTE_CONFIG_OUTINIT_High;

-    break;

-  case PWM_OUTPUT_DISABLED:

-  default:

-      goto no_output_config;

+  case PWM_OUTPUT_ACTIVE_LOW : outinit = GPIOTE_CONFIG_OUTINIT_Low;  break;

+  case PWM_OUTPUT_ACTIVE_HIGH: outinit = GPIOTE_CONFIG_OUTINIT_High; break;

+  case PWM_OUTPUT_DISABLED   : /* fall-through */

+  default                    : goto no_output_config;

   }

 

-  const uint32_t gpio_pin       = PAL_PAD(cfg_channel->ioline);

-  const uint8_t  gpiote_channel = cfg_channel->gpiote_channel;

-  const uint8_t *ppi_channel    = cfg_channel->ppi_channel;

-  const uint32_t polarity       = GPIOTE_CONFIG_POLARITY_Toggle;

-

-  // Create GPIO Task

-  NRF_GPIOTE->CONFIG[gpiote_channel] = GPIOTE_CONFIG_MODE_Task |

-      ((gpio_pin << GPIOTE_CONFIG_PSEL_Pos    ) & GPIOTE_CONFIG_PSEL_Msk) |

-      ((polarity << GPIOTE_CONFIG_POLARITY_Pos) & GPIOTE_CONFIG_POLARITY_Msk) |

-      ((outinit  << GPIOTE_CONFIG_OUTINIT_Pos ) & GPIOTE_CONFIG_OUTINIT_Msk);

-

-  // Program tasks (one for duty cycle, one for periode)

-  NRF_PPI->CH[ppi_channel[0]].EEP =

-      (uint32_t)&pwmp->timer->EVENTS_COMPARE[channel];

-  NRF_PPI->CH[ppi_channel[0]].TEP =

-      (uint32_t)&NRF_GPIOTE->TASKS_OUT[gpiote_channel];

-  NRF_PPI->CH[ppi_channel[1]].EEP =

-      (uint32_t)&pwmp->timer->EVENTS_COMPARE[pwmp->channels];

-  NRF_PPI->CH[ppi_channel[1]].TEP =

-      (uint32_t)&NRF_GPIOTE->TASKS_OUT[gpiote_channel];

-  NRF_PPI->CHENSET = ((1 << ppi_channel[0]) | (1 << ppi_channel[1]));

+  // Deal with corner case: 0% and 100%

+  if ((width <= 0) || (width >= pwmp->period)) {

+    // Disable GPIOTE/PPI task

+    NRF_GPIOTE->CONFIG[gpiote_channel] = GPIOTE_CONFIG_MODE_Disabled;

+    NRF_PPI->CHENCLR = ((1 << ppi_channel[0]) | (1 << ppi_channel[1]));

+    // Set Line

+    palWriteLine(cfg_channel->ioline,

+	   ((width <= 0) ^

+	    ((cfg_channel->mode & PWM_OUTPUT_MASK) == PWM_OUTPUT_ACTIVE_HIGH)));

+

+  // Really doing PWM

+  } else {

+    const uint32_t gpio_pin = PAL_PAD(cfg_channel->ioline);

+    const uint32_t polarity = GPIOTE_CONFIG_POLARITY_Toggle;

+

+    // Program tasks (one for duty cycle, one for periode)

+    NRF_PPI->CH[ppi_channel[0]].EEP =

+	  (uint32_t)&pwmp->timer->EVENTS_COMPARE[channel];

+    NRF_PPI->CH[ppi_channel[0]].TEP =

+	  (uint32_t)&NRF_GPIOTE->TASKS_OUT[gpiote_channel];

+    NRF_PPI->CH[ppi_channel[1]].EEP =

+	  (uint32_t)&pwmp->timer->EVENTS_COMPARE[pwmp->channels];

+    NRF_PPI->CH[ppi_channel[1]].TEP =

+	  (uint32_t)&NRF_GPIOTE->TASKS_OUT[gpiote_channel];

+    NRF_PPI->CHENSET = ((1 << ppi_channel[0]) | (1 << ppi_channel[1]));

+

+    // Something Old, something New

+    const uint32_t old_width = pwmp->timer->CC[channel];

+    const uint32_t new_width = width;

+

+    // Check GPIOTE state

+    const bool gpiote = (NRF_GPIOTE->CONFIG[gpiote_channel] &

+		   GPIOTE_CONFIG_MODE_Msk) != GPIOTE_CONFIG_MODE_Disabled;

+

+    // GPIOTE is currently running

+    if (gpiote) {

+      uint32_t current;

+      while (true) {

+	pwmp->timer->TASKS_CAPTURE[PWM_GPIOTE_PPI_CC] = 1;

+	current = pwmp->timer->CC[PWM_GPIOTE_PPI_CC];

+

+	if (pwm_within_safe_margins(pwmp, current, old_width) &&

+	  pwm_within_safe_margins(pwmp, current, new_width))

+	    break;

+      }

+      if (((old_width <= current) && (current < new_width)) ||

+	  ((new_width <= current) && (current < old_width))) {

+	NRF_GPIOTE->TASKS_OUT[gpiote_channel] = 1;

+      }

+

+    // GPIOTE need to be restarted

+    } else {

+      // Create GPIO Task

+      NRF_GPIOTE->CONFIG[gpiote_channel] =

+	(GPIOTE_CONFIG_MODE_Task << GPIOTE_CONFIG_MODE_Pos) |

+	((gpio_pin << GPIOTE_CONFIG_PSEL_Pos    ) & GPIOTE_CONFIG_PSEL_Msk    )|

+	((polarity << GPIOTE_CONFIG_POLARITY_Pos) & GPIOTE_CONFIG_POLARITY_Msk)|

+	((outinit  << GPIOTE_CONFIG_OUTINIT_Pos ) & GPIOTE_CONFIG_OUTINIT_Msk );

+

+      pwmp->timer->TASKS_CAPTURE[PWM_GPIOTE_PPI_CC] = 1;

+      if (pwmp->timer->CC[PWM_GPIOTE_PPI_CC] > width)

+	NRF_GPIOTE->TASKS_OUT[gpiote_channel] = 1;

+    }

+  }

 

  no_output_config:

 #endif

diff --git a/os/hal/ports/NRF5/NRF51822/hal_pwm_lld.h b/os/hal/ports/NRF5/NRF51822/hal_pwm_lld.h
index cd64fa7..2cad6e7 100644
--- a/os/hal/ports/NRF5/NRF51822/hal_pwm_lld.h
+++ b/os/hal/ports/NRF5/NRF51822/hal_pwm_lld.h
@@ -34,8 +34,11 @@
 /**

  * @brief   Number of PWM channels per PWM driver.

  */

+#if NRF5_PWM_USE_GPIOTE_PPI

+#define PWM_CHANNELS                            2

+#else

 #define PWM_CHANNELS                            3

-

+#endif

 

 #define PWM_FREQUENCY_16MHZ  16000000 /** @brief   16MHz */

 #define PWM_FREQUENCY_8MHZ    8000000 /** @brief    8MHz */

@@ -103,7 +106,7 @@
  * @brief   Allow driver to use GPIOTE/PPI to control PAL line

  */

 #if !defined(NRF5_PWM_USE_GPIOTE_PPI)

-#define NRF5_PWM_USE_GPIOTE_PPI FALSE

+#define NRF5_PWM_USE_GPIOTE_PPI TRUE

 #endif

 

 /** @} */

@@ -177,6 +180,7 @@ typedef struct {
   pwmcallback_t             callback;

   /* End of the mandatory fields.*/

 

+#if NRF5_PWM_USE_GPIOTE_PPI || defined(__DOXYGEN__)

   /**

    * @brief PAL line to toggle.

    * @note  Only used if mode is PWM_OUTPUT_HIGH or PWM_OUTPUT_LOW.

@@ -186,17 +190,14 @@ typedef struct {
    */

   ioline_t ioline;

 

-#if NRF5_PWM_USE_GPIOTE_PPI || defined(__DOXYGEN__)

   /**

    * @brief Unique GPIOTE channel to use. (1 channel)

-   * @note  Only used if mode is PWM_OUTPUT_HIGH or PWM_OUTPUT_LOW.

    * @note  Only 4 GPIOTE channels are available on nRF51.

    */

   uint8_t gpiote_channel;

 

   /**

    * @brief Unique PPI channels to use. (2 channels)

-   * @note  Only used if mode is PWM_OUTPUT_HIGH or PWM_OUTPUT_LOW.

    * @note  Only 16 PPI channels are available on nRF51

    *        (When Softdevice is enabled, only channels 0-7 are available)

    */