allow use of GPIOTE/PPI to drive gpio pin (without callback)

changed value of PAL_NOLINE to -1

os/hal/ports/NRF51/NRF51822/hal_pal_lld.h

@@ -80,7 +80,7 @@
 /**
  * @brief   Value identifying an invalid line.
  */
-#define PAL_NOLINE                      FFU
+#define PAL_NOLINE              ((ioline_t)-1)
 /** @} */
 
 /**

os/hal/ports/NRF51/NRF51822/hal_pwm_lld.c

@@ -68,25 +68,27 @@ PWMDriver PWMD3;
 /*===========================================================================*/
 
 static void pwm_lld_serve_interrupt(PWMDriver *pwmp) {
-  // Deal with PWM period 
-  if (pwmp->timer->EVENTS_COMPARE[pwmp->channels]) {
-    pwmp->timer->EVENTS_COMPARE[pwmp->channels] = 0;
- 
-    if (pwmp->config->callback != NULL) {
-      pwmp->config->callback(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);
       }
     }      
   }
+
+  // Deal with PWM period
+  if (pwmp->timer->EVENTS_COMPARE[pwmp->channels]) {
+    pwmp->timer->EVENTS_COMPARE[pwmp->channels] = 0;
+
+    if (pwmp->config->callback != NULL) {
+      pwmp->config->callback(pwmp);
+    }
+  }
+
 }
 
 /*===========================================================================*/
@@ -280,6 +282,47 @@ void pwm_lld_stop(PWMDriver *pwmp) {
 void pwm_lld_enable_channel(PWMDriver *pwmp,
                             pwmchannel_t channel,
                             pwmcnt_t width) {
+#if NRF51_PWM_USE_GPIOTE_PPI
+  const PWMChannelConfig *cfg_channel = &pwmp->config->channels[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;
+  }
+
+  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]));
+
+ no_output_config:
+#endif
+
   pwmp->timer->CC[channel] = width;
 }
 
@@ -297,6 +340,22 @@ void pwm_lld_enable_channel(PWMDriver *pwmp,
  */
 void pwm_lld_disable_channel(PWMDriver *pwmp, pwmchannel_t channel) {
   pwmp->timer->CC[channel] = 0;
+#if NRF51_PWM_USE_GPIOTE_PPI
+  const PWMChannelConfig *cfg_channel = &pwmp->config->channels[channel];
+  switch(cfg_channel->mode & PWM_OUTPUT_MASK) {
+  case PWM_OUTPUT_ACTIVE_LOW:
+  case PWM_OUTPUT_ACTIVE_HIGH: {
+    const uint8_t  gpiote_channel = cfg_channel->gpiote_channel;
+    const uint8_t *ppi_channel    = cfg_channel->ppi_channel;
+    NRF_PPI->CHENCLR = ((1 << ppi_channel[0]) | (1 << ppi_channel[1]));
+    NRF_GPIOTE->CONFIG[gpiote_channel] = GPIOTE_CONFIG_MODE_Disabled;
+    break;
+  }
+  case PWM_OUTPUT_DISABLED:
+  default:
+    break;
+  }
+#endif
 }
 
 /**

os/hal/ports/NRF51/NRF51822/hal_pwm_lld.h

@@ -52,14 +52,28 @@
 /* Driver pre-compile time settings.                                         */
 /*===========================================================================*/
 
+/**
+ * @name    Configuration options
+ * @{
+ */
+
+/**
+ * @brief   TIMER0 as driver implementation
+ */
 #if !defined(NRF51_PWM_USE_TIMER0)
 #define NRF51_PWM_USE_TIMER0 FALSE
 #endif
 
+/**
+ * @brief   TIMER1 as driver implementation
+ */
 #if !defined(NRF51_PWM_USE_TIMER1)
 #define NRF51_PWM_USE_TIMER1 FALSE
 #endif
 
+/**
+ * @brief   TIMER2 as driver implementation
+ */
 #if !defined(NRF51_PWM_USE_TIMER2)
 #define NRF51_PWM_USE_TIMER2 FALSE
 #endif
@@ -85,12 +99,13 @@
 #define NRF51_PWM_TIMER2_PRIORITY        12
 #endif
 
-/** @} */
-
 /**
- * @name    Configuration options
+ * @brief   Allow driver to use GPIOTE/PPI to control PAL line
- * @{
  */
+#if !defined(NRF51_PWM_USE_GPIOTE_PPI)
+#define NRF51_PWM_USE_GPIOTE_PPI FALSE
+#endif
+
 /** @} */
 
 /*===========================================================================*/
@@ -145,6 +160,32 @@ typedef struct {
    */
   pwmcallback_t             callback;
   /* End of the mandatory fields.*/
+
+  /**
+   * @brief PAL line to toggle.
+   * @note  Only used if mode is PWM_OUTPUT_HIGH or PWM_OUTPUT_LOW.
+   * @note  When NRF51_PWM_USE_GPIOTE_PPI is used and channel enabled,
+   *        it wont be possible to access this PAL line using the PAL
+   *        driver.
+   */
+  ioline_t ioline;
+
+#if NRF51_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)
+   */
+  uint8_t ppi_channel[2];
+#endif
 } PWMChannelConfig;
 
 /**

testhal/NRF51/NRF51822/PWM/main.c

@@ -39,9 +39,15 @@ int main(void) {
     .frequency = PWM_FREQUENCY_31250HZ, 
     .period = 31250,                 
     .callback = pwm_cb_period,
-    { {PWM_OUTPUT_ACTIVE_HIGH, pwm_cb_channel0},
+    { { .mode           = PWM_OUTPUT_DISABLED,
-      {PWM_OUTPUT_DISABLED, NULL},
+	.callback       = pwm_cb_channel0, },
-      {PWM_OUTPUT_DISABLED, NULL}
+      { .mode           = PWM_OUTPUT_ACTIVE_HIGH,
+	.callback       = NULL,
+	.ioline         = LINE_LED2,
+	.gpiote_channel = 0,
+	.ppi_channel    = { 0, 1 } },
+      { .mode           = PWM_OUTPUT_DISABLED,
+	.callback       = NULL, },
     },
   };
 
@@ -62,6 +68,7 @@ int main(void) {
   pwmEnablePeriodicNotification(&PWMD1);
   pwmEnableChannel(&PWMD1, 0, PWM_FRACTION_TO_WIDTH(&PWMD1, 2, 1));
   pwmEnableChannelNotification(&PWMD1, 0);
+  pwmEnableChannel(&PWMD1, 1, PWM_FRACTION_TO_WIDTH(&PWMD1, 4, 3));
 
   while (1) {
     chThdSleepMilliseconds(500);

testhal/NRF51/NRF51822/PWM/mcuconf.h

@@ -25,5 +25,6 @@
 #define NRF51_ST_USE_RTC1                  FALSE
 #define NRF51_ST_USE_TIMER0                FALSE
 #define NRF51_PWM_USE_TIMER0               TRUE
+#define NRF51_PWM_USE_GPIOTE_PPI           TRUE
 
 #endif /* _MCUCONF_H_ */