PX4-Autopilot/src/drivers/stm32/drv_led_pwm.cpp

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/**
* @file drv_led_pwm.cpp
*
*
*/

#include <nuttx/config.h>


#include <sys/types.h>
#include <stdint.h>
#include <string.h>
#include <stdlib.h>
#include <stdbool.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
#include <ctype.h>


#include <systemlib/perf_counter.h>
#include <systemlib/err.h>
#include <systemlib/systemlib.h>
#include <systemlib/px4_macros.h>

#include <drivers/drv_pwm_output.h>
#include <drivers/stm32/drv_io_timer.h>


#include <board_config.h>

#if defined(BOARD_HAS_LED_PWM)
#define REG(_tmr, _reg) (*(volatile uint32_t *)(led_pwm_timers[_tmr].base + _reg))

#define rCR1(_tmr)      REG(_tmr, STM32_GTIM_CR1_OFFSET)
#define rCR2(_tmr)      REG(_tmr, STM32_GTIM_CR2_OFFSET)
#define rSMCR(_tmr)     REG(_tmr, STM32_GTIM_SMCR_OFFSET)
#define rDIER(_tmr)     REG(_tmr, STM32_GTIM_DIER_OFFSET)
#define rSR(_tmr)       REG(_tmr, STM32_GTIM_SR_OFFSET)
#define rEGR(_tmr)      REG(_tmr, STM32_GTIM_EGR_OFFSET)
#define rCCMR1(_tmr)    REG(_tmr, STM32_GTIM_CCMR1_OFFSET)
#define rCCMR2(_tmr)    REG(_tmr, STM32_GTIM_CCMR2_OFFSET)
#define rCCER(_tmr)     REG(_tmr, STM32_GTIM_CCER_OFFSET)
#define rCNT(_tmr)      REG(_tmr, STM32_GTIM_CNT_OFFSET)
#define rPSC(_tmr)      REG(_tmr, STM32_GTIM_PSC_OFFSET)
#define rARR(_tmr)      REG(_tmr, STM32_GTIM_ARR_OFFSET)
#define rCCR1(_tmr)     REG(_tmr, STM32_GTIM_CCR1_OFFSET)
#define rCCR2(_tmr)     REG(_tmr, STM32_GTIM_CCR2_OFFSET)
#define rCCR3(_tmr)     REG(_tmr, STM32_GTIM_CCR3_OFFSET)
#define rCCR4(_tmr)     REG(_tmr, STM32_GTIM_CCR4_OFFSET)
#define rDCR(_tmr)      REG(_tmr, STM32_GTIM_DCR_OFFSET)
#define rDMAR(_tmr)     REG(_tmr, STM32_GTIM_DMAR_OFFSET)
#define rBDTR(_tmr)     REG(_tmr, STM32_ATIM_BDTR_OFFSET)

static void             led_pwm_timer_init(unsigned timer);
static void             led_pwm_timer_set_rate(unsigned timer, unsigned rate);
static void             led_pwm_channel_init(unsigned channel);

int led_pwm_servo_set(unsigned channel, uint8_t  value);
unsigned led_pwm_servo_get(unsigned channel);
int led_pwm_servo_init(void);
void led_pwm_servo_deinit(void);
void led_pwm_servo_arm(bool armed);
unsigned led_pwm_timer_get_period(unsigned timer);


static void
led_pwm_timer_init(unsigned timer)
{
	/* valid Timer */

	if (led_pwm_timers[timer].base != 0) {

		/* enable the timer clock before we try to talk to it */

		modifyreg32(led_pwm_timers[timer].clock_register, 0, led_pwm_timers[timer].clock_bit);

		/* disable and configure the timer */
		rCR1(timer) = 0;
		rCR2(timer) = 0;
		rSMCR(timer) = 0;
		rDIER(timer) = 0;
		rCCER(timer) = 0;
		rCCMR1(timer) = 0;
		rCCMR2(timer) = 0;
		rCCER(timer) = 0;
		rDCR(timer) = 0;

		if ((led_pwm_timers[timer].base == STM32_TIM1_BASE) || (led_pwm_timers[timer].base == STM32_TIM8_BASE)) {
			/* master output enable = on */
			rBDTR(timer) = ATIM_BDTR_MOE;
		}

		/* configure the timer to free-run at 1MHz */
		rPSC(timer) = (led_pwm_timers[timer].clock_freq / 1000000) - 1;

		/* default to updating at 50Hz */
		led_pwm_timer_set_rate(timer, 50);

		/* note that the timer is left disabled - arming is performed separately */
	}
}
unsigned
led_pwm_timer_get_period(unsigned timer)
{
	return (rARR(timer));
}
static void
led_pwm_timer_set_rate(unsigned timer, unsigned rate)
{
	/* configure the timer to update at the desired rate */
	rARR(timer) = 1000000 / rate;

	/* generate an update event; reloads the counter and all registers */
	rEGR(timer) = GTIM_EGR_UG;
}


static void
led_pwm_channel_init(unsigned channel)
{
	unsigned timer = led_pwm_channels[channel].timer_index;

	/* configure the GPIO first */

	px4_arch_configgpio(led_pwm_channels[channel].gpio_out);

	/* configure the channel */
	switch (led_pwm_channels[channel].timer_channel) {
	case 1:
		rCCMR1(timer) |= (GTIM_CCMR_MODE_PWM1 << GTIM_CCMR1_OC1M_SHIFT) | GTIM_CCMR1_OC1PE;
		rCCER(timer) |= GTIM_CCER_CC1E;
		break;

	case 2:
		rCCMR1(timer) |= (GTIM_CCMR_MODE_PWM1 << GTIM_CCMR1_OC2M_SHIFT) | GTIM_CCMR1_OC2PE;
		rCCER(timer) |= GTIM_CCER_CC2E;
		break;

	case 3:
		rCCMR2(timer) |= (GTIM_CCMR_MODE_PWM1 << GTIM_CCMR2_OC3M_SHIFT) | GTIM_CCMR2_OC3PE;
		rCCER(timer) |= GTIM_CCER_CC3E;
		break;

	case 4:
		rCCMR2(timer) |= (GTIM_CCMR_MODE_PWM1 << GTIM_CCMR2_OC4M_SHIFT) | GTIM_CCMR2_OC4PE;
		rCCER(timer) |= GTIM_CCER_CC4E;
		break;
	}
}

int
led_pwm_servo_set(unsigned channel, uint8_t  cvalue)
{
	if (channel >= arraySize(led_pwm_channels)) {
		return -1;
	}

	unsigned timer = led_pwm_channels[channel].timer_index;

	/* test timer for validity */
	if ((led_pwm_timers[timer].base == 0) ||
	    (led_pwm_channels[channel].gpio_out == 0)) {
		return -1;
	}

	unsigned period = led_pwm_timer_get_period(timer);

#if defined(BOARD_LED_PWM_DRIVE_ACTIVE_LOW)
	unsigned value = period - (unsigned)cvalue * period / 255;
#else
	unsigned value = (unsigned)cvalue * period / 255;
#endif

	/* configure the channel */
	if (value > 0) {
		value--;
	}


	switch (led_pwm_channels[channel].timer_channel) {
	case 1:
		rCCR1(timer) = value;
		break;

	case 2:
		rCCR2(timer) = value;
		break;

	case 3:
		rCCR3(timer) = value;
		break;

	case 4:
		rCCR4(timer) = value;
		break;

	default:
		return -1;
	}

	return 0;
}
unsigned
led_pwm_servo_get(unsigned channel)
{
	if (channel >= 3) {
		return 0;
	}

	unsigned timer = led_pwm_channels[channel].timer_index;
	servo_position_t value = 0;

	/* test timer for validity */
	if ((led_pwm_timers[timer].base == 0) ||
	    (led_pwm_channels[channel].timer_channel == 0)) {
		return 0;
	}

	/* configure the channel */
	switch (led_pwm_channels[channel].timer_channel) {
	case 1:
		value = rCCR1(timer);
		break;

	case 2:
		value = rCCR2(timer);
		break;

	case 3:
		value = rCCR3(timer);
		break;

	case 4:
		value = rCCR4(timer);
		break;
	}

	unsigned period = led_pwm_timer_get_period(timer);
	return ((value + 1) * 255 / period);
}
int
led_pwm_servo_init(void)
{
	/* do basic timer initialisation first */
	for (unsigned i = 0; i < arraySize(led_pwm_timers); i++) {
		led_pwm_timer_init(i);
	}

	/* now init channels */
	for (unsigned i = 0; i < arraySize(led_pwm_channels); i++) {
		led_pwm_channel_init(i);
	}

	led_pwm_servo_arm(true);
	return OK;
}

void
led_pwm_servo_deinit(void)
{
	/* disable the timers */
	led_pwm_servo_arm(false);
}
void
led_pwm_servo_arm(bool armed)
{
	/* iterate timers and arm/disarm appropriately */
	for (unsigned i = 0; i < arraySize(led_pwm_timers); i++) {
		if (led_pwm_timers[i].base != 0) {
			if (armed) {
				/* force an update to preload all registers */
				rEGR(i) = GTIM_EGR_UG;

				/* arm requires the timer be enabled */
				rCR1(i) |= GTIM_CR1_CEN | GTIM_CR1_ARPE;

			} else {
				rCR1(i) = 0;
			}
		}
	}
}

#endif // BOARD_HAS_LED_PWM