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Diffstat (limited to 'os/hal/ports/NRF5/NRF51822/hal_pwm_lld.c')
-rw-r--r--os/hal/ports/NRF5/NRF51822/hal_pwm_lld.c195
1 files changed, 131 insertions, 64 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..e2b4b6b 100644
--- a/os/hal/ports/NRF5/NRF51822/hal_pwm_lld.c
+++ b/os/hal/ports/NRF5/NRF51822/hal_pwm_lld.c
@@ -18,6 +18,11 @@
* @file hal_pwm_lld.c
* @brief NRF51 PWM subsystem low level driver source.
*
+ * @note Using the method described in nrf51-pwm-library to correctly
+ * handle toggling of the pin with GPIOTE when changing period.
+ * It means it is generally unsafe to use GPIOTE with a period
+ * less than (2 * PWM_GPIOTE_DECISION_TIME / 16MHz)
+ *
* @addtogroup PWM
* @{
*/
@@ -30,6 +35,8 @@
/* Driver local definitions. */
/*===========================================================================*/
+#define PWM_GPIOTE_PPI_CC 3
+#define PWM_GPIOTE_DECISION_TIME 160
/*===========================================================================*/
/* Driver exported variables. */
@@ -63,24 +70,39 @@ PWMDriver PWMD3;
/* Driver local variables and types. */
/*===========================================================================*/
+static const uint8_t pwm_margin_by_prescaler[] = {
+ (PWM_GPIOTE_DECISION_TIME + 0) >> 0,
+ (PWM_GPIOTE_DECISION_TIME + 1) >> 1,
+ (PWM_GPIOTE_DECISION_TIME + 3) >> 2,
+ (PWM_GPIOTE_DECISION_TIME + 7) >> 3,
+ (PWM_GPIOTE_DECISION_TIME + 15) >> 4,
+ (PWM_GPIOTE_DECISION_TIME + 31) >> 5,
+ (PWM_GPIOTE_DECISION_TIME + 63) >> 6,
+ (PWM_GPIOTE_DECISION_TIME + 127) >> 7,
+ (PWM_GPIOTE_DECISION_TIME + 255) >> 8,
+ (PWM_GPIOTE_DECISION_TIME + 511) >> 9
+};
+
/*===========================================================================*/
/* 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);
}
}
}
- // Deal with PWM period
+ /* Deal with PWM period
+ */
if (pwmp->timer->EVENTS_COMPARE[pwmp->channels]) {
pwmp->timer->EVENTS_COMPARE[pwmp->channels] = 0;
@@ -88,7 +110,14 @@ 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)));
}
/*===========================================================================*/
@@ -174,47 +203,45 @@ void pwm_lld_init(void) {
* @notapi
*/
void pwm_lld_start(PWMDriver *pwmp) {
- // Prescaler value calculation: ftimer = 16MHz / 2^PRESCALER
+ /* Prescaler value calculation: ftimer = 16MHz / 2^PRESCALER */
uint16_t psc_ratio = NRF5_HFCLK_FREQUENCY / pwmp->config->frequency;
- // Prescaler ratio must be between 1 and 512, and a power of two.
+ /* Prescaler ratio must be between 1 and 512, and a power of two. */
osalDbgAssert(psc_ratio <= 512 && !(psc_ratio & (psc_ratio - 1)),
- "invalid frequency");
- // Prescaler value as a power of 2, must be 0..9
+ "invalid frequency");
+ /* Prescaler value as a power of 2, must be 0..9 */
uint32_t psc_value;
for (psc_value = 0; psc_value < 10; psc_value++)
- if (psc_ratio == (unsigned)(1 << psc_value))
- break;
+ if (psc_ratio == (unsigned)(1 << psc_value))
+ break;
-
- // Configure as 16bits timer (only TIMER0 support 32bits)
+ /* Configure as 16bits timer (only TIMER0 support 32bits) */
pwmp->timer->BITMODE = TIMER_BITMODE_BITMODE_16Bit;
pwmp->timer->MODE = TIMER_MODE_MODE_Timer;
- // With clear shortcuts for period
+ /* With clear shortcuts for period */
pwmp->timer->SHORTS =
- 0x1UL << (TIMER_SHORTS_COMPARE0_CLEAR_Pos + pwmp->channels);
+ 0x1UL << (TIMER_SHORTS_COMPARE0_CLEAR_Pos + pwmp->channels);
- // Disable and reset interrupts for compare events
+ /* Disable and reset interrupts for compare events */
pwmp->timer->INTENCLR = (TIMER_INTENCLR_COMPARE0_Msk |
- TIMER_INTENCLR_COMPARE1_Msk |
- TIMER_INTENCLR_COMPARE2_Msk |
- TIMER_INTENCLR_COMPARE3_Msk );
+ TIMER_INTENCLR_COMPARE1_Msk |
+ TIMER_INTENCLR_COMPARE2_Msk |
+ TIMER_INTENCLR_COMPARE3_Msk );
pwmp->timer->EVENTS_COMPARE[0] = 0;
pwmp->timer->EVENTS_COMPARE[1] = 0;
pwmp->timer->EVENTS_COMPARE[2] = 0;
pwmp->timer->EVENTS_COMPARE[3] = 0;
- // Set prescaler
+ /* Set prescaler */
pwmp->timer->PRESCALER = psc_value;
- // Set period
+ /* Set period */
pwmp->timer->CC[pwmp->channels] = pwmp->period;
- // Clear everything
+ /* Clear everything */
pwmp->timer->TASKS_CLEAR = 1;
-
- // Enable interrupt
+ /* Enable interrupt */
#if NRF5_PWM_USE_TIMER0
if (&PWMD1 == pwmp) {
nvicEnableVector(TIMER0_IRQn, NRF5_PWM_TIMER0_PRIORITY);
@@ -233,7 +260,7 @@ void pwm_lld_start(PWMDriver *pwmp) {
}
#endif
- // Start timer
+ /* Start timer */
pwmp->timer->TASKS_START = 1;
}
@@ -245,7 +272,7 @@ 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 +311,81 @@ 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 =
+ /* 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 =
+ NRF_PPI->CH[ppi_channel[0]].TEP =
(uint32_t)&NRF_GPIOTE->TASKS_OUT[gpiote_channel];
- NRF_PPI->CH[ppi_channel[1]].EEP =
+ NRF_PPI->CH[ppi_channel[1]].EEP =
(uint32_t)&pwmp->timer->EVENTS_COMPARE[pwmp->channels];
- NRF_PPI->CH[ppi_channel[1]].TEP =
+ 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]));
+ 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
@@ -369,7 +436,7 @@ void pwm_lld_disable_channel(PWMDriver *pwmp, pwmchannel_t channel) {
*/
void pwm_lld_enable_periodic_notification(PWMDriver *pwmp) {
pwmp->timer->INTENSET =
- 0x1UL << (TIMER_INTENSET_COMPARE0_Pos + pwmp->channels);
+ 0x1UL << (TIMER_INTENSET_COMPARE0_Pos + pwmp->channels);
}
/**
@@ -383,7 +450,7 @@ void pwm_lld_enable_periodic_notification(PWMDriver *pwmp) {
*/
void pwm_lld_disable_periodic_notification(PWMDriver *pwmp) {
pwmp->timer->INTENCLR =
- 0x1UL << (TIMER_INTENCLR_COMPARE0_Pos + pwmp->channels);
+ 0x1UL << (TIMER_INTENCLR_COMPARE0_Pos + pwmp->channels);
}
/**
@@ -400,7 +467,7 @@ void pwm_lld_disable_periodic_notification(PWMDriver *pwmp) {
void pwm_lld_enable_channel_notification(PWMDriver *pwmp,
pwmchannel_t channel) {
pwmp->timer->INTENSET =
- 0x1UL << (TIMER_INTENSET_COMPARE0_Pos + channel);
+ 0x1UL << (TIMER_INTENSET_COMPARE0_Pos + channel);
}
/**
@@ -409,15 +476,15 @@ void pwm_lld_enable_channel_notification(PWMDriver *pwmp,
* @pre The channel must have been activated using @p pwmEnableChannel().
* @note If the notification is already disabled then the call has no effect.
*
- * @param[in] pwmp pointer to a @p PWMDriver object
- * @param[in] channel PWM channel identifier (0...channels-1)
+ * @param[in] pwmp pointer to a @p PWMDriver object
+ * @param[in] channel PWM channel identifier (0...channels-1)
*
* @notapi
*/
void pwm_lld_disable_channel_notification(PWMDriver *pwmp,
- pwmchannel_t channel) {
+ pwmchannel_t channel) {
pwmp->timer->INTENCLR =
- 0x1UL << (TIMER_INTENCLR_COMPARE0_Pos + channel);
+ 0x1UL << (TIMER_INTENCLR_COMPARE0_Pos + channel);
}
#endif /* HAL_USE_PWM */
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-01 03:31:16 +0000