djsundog/circuitpython
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Merge pull request #7212 from dhalbert/stm-pwm-fix

Browse Source 
STM: off-by-one TIMx reference; other code cleanup and minor fixes
This commit is contained in:
Scott Shawcroft 2022-11-15 11:50:53 -08:00 committed by GitHub
commit b8a2d3ffdc
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
4 changed files with 100 additions and 64 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
ports/stm/common-hal/pulseio/PulseIn.c
View File

@ -106,7 +106,8 @@ void pulsein_reset(void) {
memset(callback_obj_ref, 0, sizeof(callback_obj_ref));
HAL_TIM_Base_DeInit(&tim_handle);
tim_clock_disable(stm_peripherals_timer_get_index(tim_handle.Instance));
// tim_clock_disable() takes a bitmask of timers.
tim_clock_disable(1 << stm_peripherals_timer_get_index(tim_handle.Instance));
memset(&tim_handle, 0, sizeof(tim_handle));
refcount = 0;
}

97
ports/stm/common-hal/pwmio/PWMOut.c
View File

@ -36,23 +36,24 @@
#include "timers.h"
#define ALL_CLOCKS 0xFFFF
STATIC uint8_t reserved_tim[TIM_BANK_ARRAY_LEN];
// Bitmask of channels taken.
STATIC uint8_t tim_channels_taken[TIM_BANK_ARRAY_LEN];
// Initial frequency timer is set to.
STATIC uint32_t tim_frequencies[TIM_BANK_ARRAY_LEN];
STATIC bool never_reset_tim[TIM_BANK_ARRAY_LEN];
STATIC uint32_t timer_get_internal_duty(uint16_t duty, uint32_t period) {
// duty cycle is duty/0xFFFF fraction x (number of pulses per period)
return (duty * period) / ((1 << 16) - 1);
return (duty * period) / 0xffff;
}
STATIC bool timer_get_optimal_divisors(uint32_t *period, uint32_t *prescaler,
uint32_t frequency, uint32_t source_freq) {
// Find the largest possible period supported by this frequency
for (int i = 0; i < (1 << 16); i++) {
*prescaler = 0;
for (uint32_t i = 1; i <= 0xffff; i++) {
*period = source_freq / (i * frequency);
if (*period < (1 << 16) && *period >= 2) {
if (*period <= 0xffff && *period >= 2) {
*prescaler = i;
break;
}
@ -62,13 +63,10 @@ STATIC bool timer_get_optimal_divisors(uint32_t *period, uint32_t *prescaler,
}
void pwmout_reset(void) {
uint16_t never_reset_mask = 0x00;
for (int i = 0; i < TIM_BANK_ARRAY_LEN; i++) {
if (!never_reset_tim[i]) {
reserved_tim[i] = 0x00;
tim_frequencies[i] = 0x00;
} else {
never_reset_mask |= 1 << i;
tim_channels_taken[i] = 0x00;
tim_frequencies[i] = 0;
}
}
}
@ -78,73 +76,69 @@ pwmout_result_t common_hal_pwmio_pwmout_construct(pwmio_pwmout_obj_t *self,
uint16_t duty,
uint32_t frequency,
bool variable_frequency) {
TIM_TypeDef *TIMx;
uint8_t tim_num = MP_ARRAY_SIZE(mcu_tim_pin_list);
bool tim_taken_internal = false;
bool tim_chan_taken = false;
bool tim_taken_f_mismatch = false;
bool var_freq_mismatch = false;
// Default error is no timer at all on pin.
pwmout_result_t last_failure = PWMOUT_INVALID_PIN;
bool first_time_setup = true;
for (uint i = 0; i < tim_num; i++) {
const mcu_tim_pin_obj_t *l_tim = &mcu_tim_pin_list[i];
uint8_t l_tim_index = l_tim->tim_index;
uint8_t l_tim_channel = l_tim->channel_index;
uint8_t tim_index;
uint8_t tim_channel_index;
self->tim = NULL;
for (uint i = 0; i < MP_ARRAY_SIZE(mcu_tim_pin_list); i++) {
const mcu_tim_pin_obj_t *tim = &mcu_tim_pin_list[i];
tim_index = tim->tim_index;
tim_channel_index = tim->channel_index;
// if pin is same
if (l_tim->pin == pin) {
if (tim->pin == pin) {
// check if the timer has a channel active, or is reserved by main timer system
if (l_tim_index < TIM_BANK_ARRAY_LEN && reserved_tim[l_tim_index] != 0) {
if (tim_index < TIM_BANK_ARRAY_LEN && tim_channels_taken[tim_index] != 0) {
// Timer has already been reserved by an internal module
if (stm_peripherals_timer_is_reserved(mcu_tim_banks[l_tim_index])) {
tim_taken_internal = true;
if (stm_peripherals_timer_is_reserved(mcu_tim_banks[tim_index])) {
last_failure = PWMOUT_ALL_TIMERS_ON_PIN_IN_USE;
continue; // keep looking
}
// is it the same channel? (or all channels reserved by a var-freq)
if (reserved_tim[l_tim_index] & 1 << (l_tim_channel)) {
tim_chan_taken = true;
if (tim_channels_taken[tim_index] & (1 << tim_channel_index)) {
last_failure = PWMOUT_ALL_TIMERS_ON_PIN_IN_USE;
continue; // keep looking, might be another viable option
}
// If the frequencies are the same it's ok
if (tim_frequencies[l_tim_index] != frequency) {
tim_taken_f_mismatch = true;
if (tim_frequencies[tim_index] != frequency) {
last_failure = PWMOUT_INVALID_FREQUENCY_ON_PIN;
continue; // keep looking
}
// you can't put a variable frequency on a partially reserved timer
if (variable_frequency) {
var_freq_mismatch = true;
last_failure = PWMOUT_VARIABLE_FREQUENCY_NOT_AVAILABLE;
continue; // keep looking
}
first_time_setup = false; // skip setting up the timer
}
// No problems taken, so set it up
self->tim = l_tim;
self->tim = tim;
break;
}
}
TIM_TypeDef *TIMx;
// handle valid/invalid timer instance
if (self->tim != NULL) {
// create instance
TIMx = mcu_tim_banks[self->tim->tim_index];
TIMx = mcu_tim_banks[tim_index];
// reserve timer/channel
if (variable_frequency) {
reserved_tim[self->tim->tim_index] = 0x0F;
// Take all the channels.
tim_channels_taken[tim_index] = 0x0F;
} else {
reserved_tim[self->tim->tim_index] |= 1 << self->tim->channel_index;
tim_channels_taken[tim_index] |= 1 << tim_channel_index;
}
tim_frequencies[self->tim->tim_index] = frequency;
tim_frequencies[tim_index] = frequency;
stm_peripherals_timer_reserve(TIMx);
} else { // no match found
if (tim_chan_taken || tim_taken_internal) {
return PWMOUT_ALL_TIMERS_ON_PIN_IN_USE;
} else if (tim_taken_f_mismatch) {
return PWMOUT_INVALID_FREQUENCY_ON_PIN;
} else if (var_freq_mismatch) {
return PWMOUT_VARIABLE_FREQUENCY_NOT_AVAILABLE;
} else {
return PWMOUT_INVALID_PIN;
}
} else {
// no match found
return last_failure;
}
uint32_t prescaler = 0; // prescaler is 15 bit
@ -163,10 +157,10 @@ pwmout_result_t common_hal_pwmio_pwmout_construct(pwmio_pwmout_obj_t *self,
HAL_GPIO_Init(pin_port(pin->port), &GPIO_InitStruct);
self->pin = pin;
tim_clock_enable(1 << (self->tim->tim_index));
tim_clock_enable(1 << tim_index);
// translate channel into handle value
self->channel = 4 * self->tim->channel_index;
// translate channel into handle value: TIM_CHANNEL_1, _2, _3, _4.
self->channel = 4 * tim_channel_index;
// Timer init
self->handle.Instance = TIMx;
@ -175,6 +169,7 @@ pwmout_result_t common_hal_pwmio_pwmout_construct(pwmio_pwmout_obj_t *self,
self->handle.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
self->handle.Init.CounterMode = TIM_COUNTERMODE_UP;
self->handle.Init.RepetitionCounter = 0;
self->handle.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
// only run init if this is the first instance of this timer
if (first_time_setup) {
@ -232,15 +227,15 @@ void common_hal_pwmio_pwmout_deinit(pwmio_pwmout_obj_t *self) {
}
// var freq shuts down entire timer, others just their channel
if (self->variable_frequency) {
reserved_tim[self->tim->tim_index] = 0x00;
tim_channels_taken[self->tim->tim_index] = 0x00;
} else {
reserved_tim[self->tim->tim_index] &= ~(1 << self->tim->channel_index);
tim_channels_taken[self->tim->tim_index] &= ~(1 << self->tim->channel_index);
HAL_TIM_PWM_Stop(&self->handle, self->channel);
}
common_hal_reset_pin(self->pin);
// if reserved timer has no active channels, we can disable it
if (reserved_tim[self->tim->tim_index] == 0) {
if (tim_channels_taken[self->tim->tim_index] == 0) {
tim_frequencies[self->tim->tim_index] = 0x00;
stm_peripherals_timer_free(self->handle.Instance);
}

6
ports/stm/common-hal/pwmio/PWMOut.h
View File

@ -39,12 +39,12 @@ typedef struct {
TIM_HandleTypeDef handle;
TIM_OC_InitTypeDef chan_handle;
const mcu_tim_pin_obj_t *tim;
uint8_t channel : 7;
bool variable_frequency : 1;
uint16_t duty_cycle;
uint32_t frequency;
uint32_t period;
const mcu_pin_obj_t *pin;
uint16_t duty_cycle;
uint8_t channel;
bool variable_frequency;
} pwmio_pwmout_obj_t;
void pwmout_reset(void);

58
ports/stm/peripherals/timers.c
View File

@ -150,26 +150,65 @@ static size_t irq_map[] = {
};
// Get the frequency (in Hz) of the source clock for the given timer.
// On STM32F405/407/415/417 there are 2 cases for how the clock freq is set.
// If the APB prescaler is 1, then the timer clock is equal to its respective
// APB clock. Otherwise (APB prescaler > 1) the timer clock is twice its
// respective APB clock. See DM00031020 Rev 4, page 115.
//
// From STM ref manual: DM00031020 Rev 19, section 7.2, page 217:
//
// The timer clock frequencies for STM32F405xx/07xx and STM32F415xx/17xx are
// automatically set by hardware. There are two cases:
// 1. If the APB prescaler is 1, the timer clock frequencies are set to the same frequency as
// that of the APB domain to which the timers are connected.
// 2. Otherwise, they are set to twice (×2) the frequency of the APB domain to which the
// timers are connected.
// From STM ref manual: DM00031020 Rev 19, section 6.2, page 153:
//
// The timer clock frequencies for STM32F42xxx and STM32F43xxx are automatically set by
// hardware. There are two cases depending on the value of TIMPRE bit in RCC_CFGR [sic - should be RCC_DKCFGR]
// register:
// * If TIMPRE bit in RCC_DKCFGR register is reset:
// If the APB prescaler is configured to a division factor of 1, the timer clock frequencies
// (TIMxCLK) are set to PCLKx. Otherwise, the timer clock frequencies are twice the
// frequency of the APB domain to which the timers are connected: TIMxCLK = 2xPCLKx.
// * If TIMPRE bit in RCC_DKCFGR register is set:
// If the APB prescaler is configured to a division factor of 1, 2 or 4, the timer clock
// frequencies (TIMxCLK) are set to HCLK. Otherwise, the timer clock frequencies is four
// times the frequency of the APB domain to which the timers are connected: TIMxCLK = 4xPCLKx.
uint32_t stm_peripherals_timer_get_source_freq(TIM_TypeDef *timer) {
size_t tim_id = stm_peripherals_timer_get_index(timer);
// The timer index starts at 0, but the timer numbers start at TIM1.
size_t tim_id = stm_peripherals_timer_get_index(timer) + 1;
uint32_t source, clk_div;
if (tim_id == 1 || (8 <= tim_id && tim_id <= 11)) {
// TIM{1,8,9,10,11} are on APB2
source = HAL_RCC_GetPCLK2Freq();
clk_div = RCC->CFGR & RCC_CFGR_PPRE2;
// 0b0xx means not divided; 0b100 is divide by 2; 0b101 by 4; 0b110 by 8; 0b111 by 16.
clk_div = (RCC->CFGR & RCC_CFGR_PPRE2) >> RCC_CFGR_PPRE2_Pos;
} else {
// TIM{2,3,4,5,6,7,12,13,14} are on APB1
source = HAL_RCC_GetPCLK1Freq();
clk_div = RCC->CFGR & RCC_CFGR_PPRE1;
// 0b0xx means not divided; 0b100 is divide by 2; 0b101 by 4; 0b110 by 8; 0b111 by 16.
clk_div = (RCC->CFGR & RCC_CFGR_PPRE1) >> RCC_CFGR_PPRE1_Pos;
}
if (clk_div != 0) {
// APB prescaler for this timer is > 1
// Only some STM32's have TIMPRE.
#if defined(RCC_CFGR_TIMPRE)
uint32_t timpre = RCC->DCKCFGR & RCC_CFGR_TIMPRE;
if (timpre == 0) {
if (clk_div >= 0b100) {
source *= 2;
}
} else {
if (clk_div > 0b101) {
source *= 4;
} else {
source = HAL_RCC_GetHCLKFreq();
}
}
#else
if (clk_div >= 0b100) {
source *= 2;
}
#endif
return source;
}
@ -271,6 +310,7 @@ bool stm_peripherals_timer_is_reserved(TIM_TypeDef *instance) {
return stm_timer_reserved[tim_idx];
}
// Note this returns a timer index starting at zero, corresponding to TIM1.
size_t stm_peripherals_timer_get_index(TIM_TypeDef *instance) {
for (size_t i = 0; i < MP_ARRAY_SIZE(mcu_tim_banks); i++) {
if (instance == mcu_tim_banks[i]) {