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RIOT/cpu/esp32/periph/pwm.c
Marian Buschsieweke 64f4f9a9be
cpu/esp32/periph/pwm.c: fix format specifier 
Use %u to print `unsigned`.
2023-05-10 13:02:47 +02:00

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/*
* Copyright (C) 2018 Gunar Schorcht
*
* This file is subject to the terms and conditions of the GNU Lesser
* General Public License v2.1. See the file LICENSE in the top level
* directory for more details.
*/
/**
* @ingroup cpu_esp32
* @ingroup drivers_periph_pwm
* @{
*
* @file
* @brief Low-level PWM driver implementation
*
* @author Gunar Schorcht <gunar@schorcht.net>
* @}
*/
#include "bitarithm.h"
#include "board.h"
#include "cpu.h"
#include "gpio_arch.h"
#include "kernel_defines.h"
#include "log.h"
#include "irq_arch.h"
#include "periph/pwm.h"
#include "periph/gpio.h"
#include "driver/periph_ctrl.h"
#include "esp_common.h"
#include "esp_rom_gpio.h"
#include "hal/ledc_hal.h"
#include "soc/ledc_struct.h"
#include "soc/rtc.h"
#define ENABLE_DEBUG 0
#include "debug.h"
#if defined(PWM0_GPIOS) || defined(PWM1_GPIOS) || defined(PWM2_GPIOS) || defined(PWM3_GPIOS)
/* Ensure that the SPIn_* symbols define SPI_DEV(n) */
#if defined(PWM1_GPIOS) && !defined(PWM0_GPIOS)
#error "PWM1_GPIOS is used but PWM0_GPIOS is not defined"
#elif defined(PWM2_GPIOS) && !defined(PWM1_GPIOS)
#error "PWM2_GPIOS is used but PWM1_GPIOS is not defined"
#elif defined(PWM3_GPIOS) && !defined(PWM2_GPIOS)
#error "PWM3_GPIOS is used but PWM2_GPIOS is not defined"
#endif
#define SOC_LEDC_CLK_DIV_BIT_NUM 18
#define SOC_LEDC_CLK_DIV_INT_BIT_NUM 10 /* integral part of CLK divider */
#define SOC_LEDC_CLK_DIV_FRAC_BIT_NUM 8 /* fractional part of CLK divider */
#define PWM_HW_RES_MAX ((uint32_t)1 << SOC_LEDC_TIMER_BIT_WIDE_NUM)
#define PWM_HW_RES_MIN ((uint32_t)1 << 1)
#define _DEV _pwm_dev[pwm] /* shortcut for PWM device descriptor */
#define _CFG pwm_config[pwm] /* shortcut for PWM device configuration */
/* data structure for dynamic channel parameters */
typedef struct {
uint32_t duty; /* actual duty value */
uint32_t hpoint; /* actual hpoing value */
bool used; /* true if the channel is set by pwm_set */
uint8_t ch; /* actual channel index within used channel group */
} _pwm_ch_t;
/* data structure for device handling at runtime */
typedef struct {
uint32_t freq; /* specified frequency parameter */
uint32_t res; /* specified resolution parameter */
uint32_t hw_freq; /* used hardware frequency */
uint32_t hw_res; /* used hardware resolution */
uint32_t hw_clk_div; /* used hardware clock divider */
_pwm_ch_t ch[PWM_CH_NUMOF_MAX]; /* dynamic channel parameters at runtime */
ledc_hal_context_t hw; /* used hardware device context */
pwm_mode_t mode; /* specified mode */
ledc_timer_bit_t hw_res_bit; /* used hardware resolution in bit */
bool enabled; /* true if the device is used (powered on) */
} _pwm_dev_t;
static _pwm_dev_t _pwm_dev[PWM_NUMOF] = { };
/* if pwm_init is called first time, it checks the pwm configuration */
static bool _pwm_initialized = false;
/* static configuration checks and initialization on first pwm_init */
static bool _pwm_initialize(void);
/* Initialize PWM device */
uint32_t pwm_init(pwm_t pwm, pwm_mode_t mode, uint32_t freq, uint16_t res)
{
_Static_assert(PWM_NUMOF <= PWM_NUMOF_MAX, "Too many PWM devices defined");
if (!_pwm_initialized) {
if (!_pwm_initialize()) {
return 0;
}
_pwm_initialized = true;
}
assert(pwm < PWM_NUMOF);
assert(freq > 0);
_DEV.enabled = true;
_DEV.res = res;
_DEV.freq = freq;
_DEV.mode = mode;
if ((res < PWM_HW_RES_MIN) || (_DEV.res > PWM_HW_RES_MAX)) {
LOG_TAG_ERROR("pwm", "Resolution of PWM device %u to be in "
"range [%"PRIu32", %"PRIu32"]\n",
pwm, PWM_HW_RES_MIN, PWM_HW_RES_MAX);
return 0;
}
/*
* The hardware resolution must be a power of two, so we determine the
* next power of two, which covers the desired resolution
*/
ledc_timer_bit_t hw_res_bit = bitarithm_msb(res - 1);
if (hw_res_bit < SOC_LEDC_TIMER_BIT_WIDE_NUM) {
hw_res_bit++;
}
uint32_t hw_res = 1 << hw_res_bit;
uint32_t hw_ticks_max = rtc_clk_apb_freq_get();
uint32_t hw_ticks_min = hw_ticks_max / (1 << SOC_LEDC_CLK_DIV_INT_BIT_NUM);
uint32_t hw_freq_min = hw_ticks_min / (1 << SOC_LEDC_TIMER_BIT_WIDE_NUM) + 1;
if (freq < hw_freq_min) {
LOG_TAG_ERROR("pwm", "Frequency of %"PRIu32" Hz is too less, minimum "
"frequency is %"PRIu32" Hz\n", freq, hw_freq_min);
return 0;
}
/* number of hardware ticks required, at maximum it can be APB clock */
uint32_t hw_ticks = MIN(freq * hw_res, rtc_clk_apb_freq_get());
/*
* if the number of required ticks is less than minimum ticks supported by
* the hardware supports, we have to increase the resolution.
*/
while (hw_ticks < hw_ticks_min) {
hw_res_bit++;
hw_res = 1 << hw_res_bit;
hw_ticks = freq * hw_res;
}
/* LEDC_CLK_DIV is given in Q10.8 format */
uint32_t hw_clk_div =
((uint64_t)rtc_clk_apb_freq_get() << SOC_LEDC_CLK_DIV_FRAC_BIT_NUM) / hw_ticks;
_DEV.freq = freq;
_DEV.res = res;
_DEV.hw_freq = hw_ticks / hw_res;
_DEV.hw_res = hw_res;
_DEV.hw_res_bit = hw_res_bit;
_DEV.hw_clk_div = hw_clk_div;
DEBUG("%s hw_freq=%"PRIu32" hw_res=%"PRIu32" hw_ticks=%"PRIu32
" hw_clk_div=%"PRIu32"\n", __func__,
_DEV.hw_freq, _DEV.hw_res, hw_ticks, _DEV.hw_clk_div);
for (int i = 0; i < _CFG.ch_numof; i++) {
/* initialize channel data */
_DEV.ch[i].used = false;
_DEV.ch[i].duty = 0;
/* reset GPIO usage type if the pins were used already for PWM before
to make it possible to reinitialize PWM with new parameters */
if (gpio_get_pin_usage(_CFG.gpios[i]) == _PWM) {
gpio_set_pin_usage(_CFG.gpios[i], _GPIO);
}
if (gpio_get_pin_usage(_CFG.gpios[i]) != _GPIO) {
LOG_TAG_ERROR("pwm", "GPIO%d is used for %s and cannot be used as "
"PWM output\n",
i, gpio_get_pin_usage_str(_CFG.gpios[i]));
return 0;
}
/* initialize the GPIOs and route the PWM signal output to the GPIO */
if (gpio_init(_CFG.gpios[i], GPIO_OUT) < 0) {
return 0;
}
gpio_set_pin_usage(_CFG.gpios[i], _PWM);
gpio_clear(_CFG.gpios[i]);
esp_rom_gpio_connect_out_signal(
_CFG.gpios[i],
ledc_periph_signal[_CFG.group].sig_out0_idx + _DEV.ch[i].ch, 0, 0);
}
pwm_poweron(pwm);
return _DEV.hw_freq;
}
uint8_t pwm_channels(pwm_t pwm)
{
assert(pwm < PWM_NUMOF);
return _CFG.ch_numof;
}
void pwm_set(pwm_t pwm, uint8_t channel, uint16_t value)
{
DEBUG("%s pwm=%u channel=%u value=%u\n", __func__, pwm, channel, value);
assert(pwm < PWM_NUMOF);
assert(channel < _CFG.ch_numof);
value = MIN(value, _DEV.res);
_DEV.ch[channel].used = true;
_DEV.ch[channel].duty = value * _DEV.hw_res / _DEV.res;
_DEV.ch[channel].hpoint = 0;
switch (_DEV.mode) {
case PWM_LEFT:
_DEV.ch[channel].hpoint = 0;
break;
case PWM_RIGHT:
_DEV.ch[channel].hpoint = _DEV.hw_res - 1 - _DEV.ch[channel].duty;
break;
case PWM_CENTER:
_DEV.ch[channel].hpoint = (_DEV.hw_res - _DEV.ch[channel].duty) >> 1;
break;
}
DEBUG("%s pwm=%u duty=%"PRIu32" hpoint=%"PRIu32"\n",
__func__, pwm, _DEV.ch[channel].duty, _DEV.ch[channel].hpoint);
unsigned ch = _DEV.ch[channel].ch; /* internal channel mapping */
critical_enter();
ledc_hal_set_duty_int_part(&_DEV.hw, ch, _DEV.ch[channel].duty);
ledc_hal_set_hpoint(&_DEV.hw, ch, _DEV.ch[channel].hpoint);
ledc_hal_set_sig_out_en(&_DEV.hw, ch, true);
ledc_hal_ls_channel_update(&_DEV.hw, ch);
ledc_hal_set_duty_start(&_DEV.hw, ch, true);
critical_exit();
}
void pwm_poweron(pwm_t pwm)
{
DEBUG("%s pwm=%u\n", __func__, pwm);
/* enable and init the module and select the right clock source */
periph_module_enable(_CFG.module);
ledc_hal_init(&_DEV.hw, _CFG.group);
ledc_hal_set_slow_clk_sel(&_DEV.hw, LEDC_SLOW_CLK_APB);
ledc_hal_set_clock_source(&_DEV.hw, _CFG.timer, LEDC_APB_CLK);
/* update the timer according to determined parameters */
ledc_hal_set_clock_divider(&_DEV.hw, _CFG.timer, _DEV.hw_clk_div);
ledc_hal_set_duty_resolution(&_DEV.hw, _CFG.timer, _DEV.hw_res_bit);
ledc_hal_ls_timer_update(&_DEV.hw, _CFG.timer);
ledc_hal_timer_rst(&_DEV.hw, _CFG.timer);
critical_enter();
for (unsigned i = 0; i < _CFG.ch_numof; i++) {
/* static configuration of the channel, no fading */
ledc_hal_set_duty_direction(&_DEV.hw, _DEV.ch[i].ch, 1);
ledc_hal_set_duty_num(&_DEV.hw, _DEV.ch[i].ch, 1);
ledc_hal_set_duty_cycle(&_DEV.hw, _DEV.ch[i].ch, 1);
ledc_hal_set_duty_scale(&_DEV.hw, _DEV.ch[i].ch, 0);
ledc_hal_set_fade_end_intr(&_DEV.hw, _DEV.ch[i].ch, 0);
/* bind the channel to the timer and disable the output for now */
ledc_hal_bind_channel_timer(&_DEV.hw, _DEV.ch[i].ch, _CFG.timer);
/* restore used parameters */
ledc_hal_set_duty_int_part(&_DEV.hw, _DEV.ch[i].ch, _DEV.ch[i].duty);
ledc_hal_set_hpoint(&_DEV.hw, _DEV.ch[i].ch, _DEV.ch[i].hpoint);
ledc_hal_set_sig_out_en(&_DEV.hw, _DEV.ch[i].ch, _DEV.ch[i].used);
ledc_hal_ls_channel_update(&_DEV.hw, _DEV.ch[i].ch);
ledc_hal_set_duty_start(&_DEV.hw, _DEV.ch[i].ch, _DEV.ch[i].used);
}
_DEV.enabled = true;
critical_exit();
}
void pwm_poweroff(pwm_t pwm)
{
DEBUG("%s pwm=%u\n", __func__, pwm);
if (!_pwm_dev[pwm].enabled) {
return;
}
unsigned i;
/* disable the signal of all channels */
critical_enter();
for (i = 0; i < _CFG.ch_numof; i++) {
ledc_hal_set_idle_level(&_DEV.hw, _DEV.ch[i].ch, 0);
ledc_hal_set_sig_out_en(&_DEV.hw, _DEV.ch[i].ch, false);
ledc_hal_set_duty_start(&_DEV.hw, _DEV.ch[i].ch, false);
ledc_hal_ls_channel_update(&_DEV.hw, _DEV.ch[i].ch);
}
_DEV.enabled = false;
critical_exit();
/* check whether all devices of the same hardware module are disabled */
for (i = 0; i < PWM_NUMOF; i++) {
if ((_CFG.module == pwm_config[i].module) && _pwm_dev[i].enabled) {
break;
}
}
/* if all devices of the same hardware module are disable, it is powered off */
if (i == PWM_NUMOF) {
periph_module_disable(_CFG.module);
}
}
void pwm_print_config(void)
{
for (unsigned pwm = 0; pwm < PWM_NUMOF; pwm++) {
printf("\tPWM_DEV(%u)\tchannels=[ ", pwm);
for (int i = 0; i < _CFG.ch_numof; i++) {
printf("%d ", _CFG.gpios[i]);
}
printf("]\n");
}
}
/* do static configuration checks */
static bool _pwm_initialize(void)
{
unsigned ch_numof[2] = {};
for (unsigned pwm = 0; pwm < PWM_NUMOF; pwm++) {
/* compute the channel indices */
for (unsigned i = 0; i < _CFG.ch_numof; i++) {
_pwm_dev[pwm].ch[i].ch = ch_numof[_CFG.group] + i;
}
ch_numof[_CFG.group] += _CFG.ch_numof;
if (_CFG.ch_numof > PWM_CH_NUMOF_MAX) {
LOG_TAG_ERROR("pwm", "Number of PWM channels of device %d is %d, "
"only %d channels per PWM device are supported\n",
pwm, _CFG.ch_numof, PWM_CH_NUMOF_MAX);
return false;
}
}
unsigned total_ch_numof = ch_numof[0] + ch_numof[1];
if (total_ch_numof > (SOC_LEDC_CHANNEL_NUM * ARRAY_SIZE(ledc_periph_signal))) {
LOG_TAG_ERROR("pwm", "Total number of PWM channels is %d, only "
"%d channels are supported at maximum\n", total_ch_numof,
PWM_CH_NUMOF_MAX * ARRAY_SIZE(ledc_periph_signal));
return false;
}
bool multiple_used = false;
for (unsigned pi = 0; pi < PWM_NUMOF; pi++) {
for (unsigned ci = 0; ci < pwm_config[pi].ch_numof; ci++) {
for (unsigned pj = 0; pj < PWM_NUMOF; pj++) {
if (pi == pj) {
continue;
}
for (unsigned cj = 0; cj < pwm_config[pj].ch_numof; cj++) {
if (pwm_config[pi].gpios[ci] == pwm_config[pj].gpios[cj]) {
LOG_TAG_ERROR("pwm", "GPIO%d is used multiple times in "
"PWM devices %d and %d\n",
pwm_config[pi].gpios[ci], pi, pj);
multiple_used = true;
}
}
}
}
}
if (multiple_used) {
return false;
}
return true;
}
#else
void pwm_print_config(void)
{
LOG_TAG_INFO("pwm", "no PWM devices\n");
}
#endif
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