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fix OneWire timing and DigitalInOut.switch_to_input()

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This commit is contained in:
Dan Halbert 2018-06-28 23:06:08 -04:00
parent 6908eed7ef
commit 52a11547cb
7 changed files with 74 additions and 25 deletions
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34
ports/atmel-samd/common-hal/digitalio/DigitalInOut.c
View File

@ -60,7 +60,7 @@ void common_hal_digitalio_digitalinout_deinit(digitalio_digitalinout_obj_t* self
void common_hal_digitalio_digitalinout_switch_to_input(
digitalio_digitalinout_obj_t* self, digitalio_pull_t pull) {
self->output = false;
// This also sets direction to input.
common_hal_digitalio_digitalinout_set_pull(self, pull);
}
@ -69,13 +69,13 @@ void common_hal_digitalio_digitalinout_switch_to_output(
digitalio_drive_mode_t drive_mode) {
const uint8_t pin = self->pin->pin;
gpio_set_pin_pull_mode(pin, GPIO_PULL_OFF);
gpio_set_pin_direction(pin, GPIO_DIRECTION_OUT);
// Turn on "strong" pin driving (more current available). See DRVSTR doc in datasheet.
hri_port_set_PINCFG_DRVSTR_bit(PORT, (enum gpio_port)GPIO_PORT(pin), GPIO_PIN(pin));
self->output = true;
self->open_drain = drive_mode == DRIVE_MODE_OPEN_DRAIN;
// Direction is set in set_value. We don't need to do it here.
common_hal_digitalio_digitalinout_set_value(self, value);
}
@ -86,16 +86,22 @@ digitalio_direction_t common_hal_digitalio_digitalinout_get_direction(
void common_hal_digitalio_digitalinout_set_value(
digitalio_digitalinout_obj_t* self, bool value) {
const uint8_t pin = self->pin->pin;
const uint8_t port = GPIO_PORT(pin);
const uint32_t pin_mask = 1U << GPIO_PIN(pin);
if (value) {
if (self->open_drain) {
gpio_set_pin_direction(self->pin->pin, GPIO_DIRECTION_IN);
// Assertion: pull is off, so the pin is floating in this case.
// We do open-drain high output (no sinking of current)
// by changing the direction to input with no pulls.
hri_port_clear_DIR_DIR_bf(PORT, port, pin_mask);
} else {
gpio_set_pin_level(self->pin->pin, true);
gpio_set_pin_direction(self->pin->pin, GPIO_DIRECTION_OUT);
hri_port_set_DIR_DIR_bf(PORT, port, pin_mask);
hri_port_set_OUT_OUT_bf(PORT, port, pin_mask);
}
} else {
gpio_set_pin_level(self->pin->pin, false);
gpio_set_pin_direction(self->pin->pin, GPIO_DIRECTION_OUT);
hri_port_set_DIR_DIR_bf(PORT, port, pin_mask);
hri_port_clear_OUT_OUT_bf(PORT,port, pin_mask);
}
}
@ -105,10 +111,10 @@ bool common_hal_digitalio_digitalinout_get_value(
if (!self->output) {
return gpio_get_pin_level(pin);
} else {
if (self->open_drain && hri_port_get_DIR_reg(PORT, (enum gpio_port)GPIO_PORT(pin), 1U << GPIO_PIN(pin)) == 0) {
if (self->open_drain && hri_port_get_DIR_reg(PORT, GPIO_PORT(pin), 1U << GPIO_PIN(pin)) == 0) {
return true;
} else {
return hri_port_get_OUT_reg(PORT, (enum gpio_port)GPIO_PORT(pin), 1U << GPIO_PIN(pin));
return hri_port_get_OUT_reg(PORT, GPIO_PORT(pin), 1U << GPIO_PIN(pin));
}
}
}
@ -119,7 +125,7 @@ void common_hal_digitalio_digitalinout_set_drive_mode(
bool value = common_hal_digitalio_digitalinout_get_value(self);
self->open_drain = drive_mode == DRIVE_MODE_OPEN_DRAIN;
// True is implemented differently between modes so reset the value to make
// sure its correct for the new mode.
// sure it's correct for the new mode.
if (value) {
common_hal_digitalio_digitalinout_set_value(self, value);
}
@ -148,7 +154,9 @@ void common_hal_digitalio_digitalinout_set_pull(
default:
break;
}
// Set pull first to avoid glitches.
gpio_set_pin_pull_mode(self->pin->pin, asf_pull);
gpio_set_pin_direction(self->pin->pin, GPIO_DIRECTION_IN);
}
digitalio_pull_t common_hal_digitalio_digitalinout_get_pull(
@ -158,9 +166,9 @@ digitalio_pull_t common_hal_digitalio_digitalinout_get_pull(
mp_raise_AttributeError("Cannot get pull while in output mode");
return PULL_NONE;
} else {
if (hri_port_get_PINCFG_PULLEN_bit(PORT, (enum gpio_port)GPIO_PORT(pin), GPIO_PIN(pin)) == 0) {
if (hri_port_get_PINCFG_PULLEN_bit(PORT, GPIO_PORT(pin), GPIO_PIN(pin)) == 0) {
return PULL_NONE;
} if (hri_port_get_OUT_reg(PORT, (enum gpio_port)GPIO_PORT(pin), 1U << GPIO_PIN(pin)) > 0) {
} if (hri_port_get_OUT_reg(PORT, GPIO_PORT(pin), 1U << GPIO_PIN(pin)) > 0) {
return PULL_UP;
} else {
return PULL_DOWN;

20
ports/atmel-samd/mphalport.c
View File

@ -14,6 +14,7 @@
#include "hal/include/hal_delay.h"
#include "hal/include/hal_gpio.h"
#include "hal/include/hal_sleep.h"
#include "sam.h"
#include "mpconfigboard.h"
#include "mphalport.h"
@ -22,6 +23,7 @@
#include "usb.h"
extern struct usart_module usart_instance;
extern uint32_t common_hal_mcu_processor_get_frequency(void);
int mp_hal_stdin_rx_chr(void) {
for (;;) {
@ -75,6 +77,24 @@ void mp_hal_delay_us(mp_uint_t delay) {
tick_delay(delay);
}
// Do a simple timing loop to wait for a certain number of microseconds.
// Can be used when interrupts are disabled, which makes tick_delay() unreliable.
//
// Testing done at 48 MHz on SAMD21 and 120 MHz on SAMD51, multiplication and division cancel out.
// But get the frequency just in case.
#ifdef SAMD21
#define DELAY_LOOP_ITERATIONS_PER_US ( (10U*48000000U) / common_hal_mcu_processor_get_frequency())
#endif
#ifdef SAMD51
#define DELAY_LOOP_ITERATIONS_PER_US ( (30U*120000000U) / common_hal_mcu_processor_get_frequency())
#endif
void mp_hal_delay_us_loop(uint32_t us) {
for (uint32_t i = us*DELAY_LOOP_ITERATIONS_PER_US; i > 0; i--) {
asm volatile("nop");
}
}
void mp_hal_disable_all_interrupts(void) {
common_hal_mcu_disable_interrupts();
}

3
ports/atmel-samd/mphalport.h
View File

@ -48,7 +48,8 @@ int receive_usb(void);
void mp_hal_set_interrupt_char(int c);
void mp_hal_disable_all_interrupts(void);
void mp_hal_enable_all_interrupts(void);
void mp_hal_delay_us_loop(uint32_t us);
#endif // MICROPY_INCLUDED_ATMEL_SAMD_MPHALPORT_H

4
ports/atmel-samd/tick.c
View File

@ -64,8 +64,8 @@ void tick_init() {
for (uint16_t i = 0; i < PERIPH_COUNT_IRQn; i++) {
NVIC_SetPriority(i, (1UL << __NVIC_PRIO_BITS) - 1UL);
}
// Bump up the systick interrupt.
NVIC_SetPriority(SysTick_IRQn, 1);
// Bump up the systick interrupt so nothing else interferes with timekeeping.
NVIC_SetPriority(SysTick_IRQn, 0);
#ifdef SAMD21
NVIC_SetPriority(USB_IRQn, 1);
#endif

14
ports/nrf/mphalport.c
View File

@ -83,3 +83,17 @@ void mp_hal_stdout_tx_strn_cooked(const char *str, mp_uint_t len) {
void mp_hal_stdout_tx_str(const char *str) {
mp_hal_stdout_tx_strn(str, strlen(str));
}
// Do a simple timing loop to wait for a certain number of microseconds.
// Can be used when interrupts are disabled, which makes tick_delay() unreliable.
//
// Testing done at 48 MHz on SAMD21 and 120 MHz on SAMD51 (cache on).
// TODO: Test on NRF. For now, use SAMD51 calibration, even though nRF52 runs slower.
// Fraction should compensate.
#define DELAY_LOOP_ITERATIONS_PER_US (30U*120000000U) / common_hal_mcu_processor_get_frequency())
void mp_hal_delay_us_loop(uint32_t us) {
for (uint32_t i = us*DELAY_LOOP_ITERATIONS_PER_US; i > 0; i--) {
asm volatile("nop");
}
}

3
ports/nrf/mphalport.h
View File

@ -52,6 +52,7 @@ static inline uint32_t hal_tick_fake(void) {
extern const unsigned char mp_hal_status_to_errno_table[4];
NORETURN void mp_hal_raise(HAL_StatusTypeDef status);
void mp_hal_set_interrupt_char(int c); // -1 to disable
@ -69,6 +70,7 @@ bool mp_hal_stdin_any(void);
#define mp_hal_pin_od_high(p) mp_hal_pin_high(p)
#define mp_hal_pin_open_drain(p) hal_gpio_cfg_pin(p->port, p->pin, HAL_GPIO_MODE_INPUT, HAL_GPIO_PULL_DISABLED)
void mp_hal_delay_us_loop(uint32_t us);
// TODO: empty implementation for now. Used by machine_spi.c:69
#define mp_hal_delay_us_fast(p)
@ -76,4 +78,3 @@ bool mp_hal_stdin_any(void);
#define mp_hal_ticks_cpu() (0)
#endif

21
shared-module/bitbangio/OneWire.c
View File

@ -24,6 +24,8 @@
* THE SOFTWARE.
*/
#include "mphalport.h"
#include "common-hal/microcontroller/Pin.h"
#include "shared-bindings/bitbangio/OneWire.h"
#include "shared-bindings/microcontroller/__init__.h"
@ -49,14 +51,17 @@ void shared_module_bitbangio_onewire_deinit(bitbangio_onewire_obj_t* self) {
common_hal_digitalio_digitalinout_deinit(&self->pin);
}
// We can't use common_hal_mcu_delay_us() here because it needs interrupts to be accurate
// due to SysTick rollover checking, done by an interrupt.
bool shared_module_bitbangio_onewire_reset(bitbangio_onewire_obj_t* self) {
common_hal_mcu_disable_interrupts();
common_hal_digitalio_digitalinout_switch_to_output(&self->pin, false, DRIVE_MODE_OPEN_DRAIN);
common_hal_mcu_delay_us(480);
mp_hal_delay_us_loop(480);
common_hal_digitalio_digitalinout_switch_to_input(&self->pin, PULL_NONE);
common_hal_mcu_delay_us(70);
mp_hal_delay_us_loop(70);
bool value = common_hal_digitalio_digitalinout_get_value(&self->pin);
common_hal_mcu_delay_us(410);
mp_hal_delay_us_loop(410);
common_hal_mcu_enable_interrupts();
return value;
}
@ -64,14 +69,14 @@ bool shared_module_bitbangio_onewire_reset(bitbangio_onewire_obj_t* self) {
bool shared_module_bitbangio_onewire_read_bit(bitbangio_onewire_obj_t* self) {
common_hal_mcu_disable_interrupts();
common_hal_digitalio_digitalinout_switch_to_output(&self->pin, false, DRIVE_MODE_OPEN_DRAIN);
common_hal_mcu_delay_us(6);
mp_hal_delay_us_loop(6);
common_hal_digitalio_digitalinout_switch_to_input(&self->pin, PULL_NONE);
// TODO(tannewt): Test with more devices and maybe make the delays
// configurable. This should be 9 by the datasheet but all bits read as 1
// then.
common_hal_mcu_delay_us(6);
mp_hal_delay_us_loop(6);
bool value = common_hal_digitalio_digitalinout_get_value(&self->pin);
common_hal_mcu_delay_us(55);
mp_hal_delay_us_loop(55);
common_hal_mcu_enable_interrupts();
return value;
}
@ -80,8 +85,8 @@ void shared_module_bitbangio_onewire_write_bit(bitbangio_onewire_obj_t* self,
bool bit) {
common_hal_mcu_disable_interrupts();
common_hal_digitalio_digitalinout_switch_to_output(&self->pin, false, DRIVE_MODE_OPEN_DRAIN);
common_hal_mcu_delay_us(bit? 6 : 60);
mp_hal_delay_us_loop(bit? 6 : 60);
common_hal_digitalio_digitalinout_switch_to_input(&self->pin, PULL_NONE);
common_hal_mcu_delay_us(bit? 64 : 10);
mp_hal_delay_us_loop(bit? 64 : 10);
common_hal_mcu_enable_interrupts();
}