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i2c fallback driver: speedup and conform to i2c specs #445

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i2c fallback driver: speedup and conform to i2c specs #445

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47f150b
i2c fallback driver: speedup and conform to i2c specs
dexter93 Jul 8, 2026
f6b6e80
ports: switch to contrib level i2c fallback
dexter93 Jul 8, 2026
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37 changes: 19 additions & 18 deletions os/hal/lib/fallback/I2C/hal_i2c_lld.c
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Original file line number Diff line number Diff line change
Expand Up @@ -95,17 +95,10 @@ static inline void i2c_delay(I2CDriver *i2cp) {
}

static inline msg_t i2c_check_arbitration(I2CDriver *i2cp) {
#if (SW_I2C_USE_OPENDRAIN == FALSE)
palSetLineMode(i2cp->config->sda, PAL_MODE_INPUT);
#endif
i2c_delay(i2cp);
if (palReadLine(i2cp->config->sda) == PAL_LOW) {
i2cp->errors |= I2C_ARBITRATION_LOST;
return MSG_RESET;
}
#if (SW_I2C_USE_OPENDRAIN == FALSE)
palSetLineMode(i2cp->config->sda, PAL_MODE_OUTPUT_PUSHPULL);
#endif
return MSG_OK;
}

Expand All @@ -121,9 +114,6 @@ static inline msg_t i2c_check_timeout(I2CDriver *i2cp) {
}

static msg_t i2c_wait_clock(I2CDriver *i2cp) {
#if (SW_I2C_USE_OPENDRAIN == FALSE)
palSetLineMode(i2cp->config->scl, PAL_MODE_INPUT);
#endif
i2c_delay(i2cp);

while (palReadLine(i2cp->config->scl) == PAL_LOW) {
Expand All @@ -133,9 +123,6 @@ static msg_t i2c_wait_clock(I2CDriver *i2cp) {
}
i2c_delay(i2cp);
}
#if (SW_I2C_USE_OPENDRAIN == FALSE)
palSetLineMode(i2cp->config->scl, PAL_MODE_OUTPUT_PUSHPULL);
#endif
return MSG_OK;
}

Expand Down Expand Up @@ -213,7 +200,9 @@ static msg_t i2c_write_bit(I2CDriver *i2cp, unsigned bit) {
static msg_t i2c_read_bit(I2CDriver *i2cp) {
msg_t bit;
#if (SW_I2C_USE_OPENDRAIN == FALSE)
palSetLineMode(i2cp->config->sda, PAL_MODE_INPUT);
palSetLineMode(i2cp->config->sda, PAL_MODE_INPUT_PULLUP);
#else
palSetLine(i2cp->config->sda);
#endif
i2c_delay(i2cp);
palSetLine(i2cp->config->scl);
Expand All @@ -225,10 +214,12 @@ static msg_t i2c_read_bit(I2CDriver *i2cp) {

bit = palReadLine(i2cp->config->sda);
#if (SW_I2C_USE_OPENDRAIN == FALSE)
palClearLine(i2cp->config->scl);
palClearLine(i2cp->config->sda); /* Pre-set output register low */
palSetLineMode(i2cp->config->sda, PAL_MODE_OUTPUT_PUSHPULL);
#endif
#else
palClearLine(i2cp->config->scl);
i2c_delay(i2cp);
#endif

return bit;
}
Expand Down Expand Up @@ -347,8 +338,18 @@ void i2c_lld_init(void) {
*/
void i2c_lld_start(I2CDriver *i2cp) {

/* Does nothing.*/
(void)i2cp;
#if (SW_I2C_USE_OPENDRAIN == FALSE)
/* Push-pull mode with INPUT switching */
palSetLine(i2cp->config->sda);
palSetLine(i2cp->config->scl);
palSetLineMode(i2cp->config->sda, PAL_MODE_OUTPUT_PUSHPULL);
palSetLineMode(i2cp->config->scl, PAL_MODE_OUTPUT_PUSHPULL);
#else
palSetLine(i2cp->config->sda);
palSetLine(i2cp->config->scl);
palSetLineMode(i2cp->config->sda, PAL_MODE_OUTPUT_OPENDRAIN);
palSetLineMode(i2cp->config->scl, PAL_MODE_OUTPUT_OPENDRAIN);
#endif
}

/**
Expand Down
6 changes: 3 additions & 3 deletions os/hal/ports/GD/GD32VF103/I2Cv1/driver.mk
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Original file line number Diff line number Diff line change
Expand Up @@ -2,12 +2,12 @@ ifeq ($(USE_HAL_I2C_FALLBACK),yes)
# Fallback SW driver.
ifeq ($(USE_SMART_BUILD),yes)
ifneq ($(findstring HAL_USE_I2C TRUE,$(HALCONF)),)
PLATFORMSRC_CONTRIB += $(CHIBIOS)/os/hal/lib/fallback/I2C/hal_i2c_lld.c
PLATFORMSRC_CONTRIB += $(CHIBIOS_CONTRIB)/os/hal/lib/fallback/I2C/hal_i2c_lld.c
endif
else
PLATFORMSRC_CONTRIB += $(CHIBIOS)/os/hal/lib/fallback/I2C/hal_i2c_lld.c
PLATFORMSRC_CONTRIB += $(CHIBIOS_CONTRIB)/os/hal/lib/fallback/I2C/hal_i2c_lld.c
endif
PLATFORMINC_CONTRIB += $(CHIBIOS)/os/hal/lib/fallback/I2C
PLATFORMINC_CONTRIB += $(CHIBIOS_CONTRIB)/os/hal/lib/fallback/I2C
else
# Default HW driver.
ifeq ($(USE_SMART_BUILD),yes)
Expand Down
6 changes: 3 additions & 3 deletions os/hal/ports/KINETIS/LLD/I2Cv1/driver.mk
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Original file line number Diff line number Diff line change
Expand Up @@ -2,12 +2,12 @@ ifeq ($(USE_HAL_I2C_FALLBACK),yes)
# Fallback SW driver.
ifeq ($(USE_SMART_BUILD),yes)
ifneq ($(findstring HAL_USE_I2C TRUE,$(HALCONF)),)
PLATFORMSRC_CONTRIB += $(CHIBIOS)/os/hal/lib/fallback/I2C/hal_i2c_lld.c
PLATFORMSRC_CONTRIB += $(CHIBIOS_CONTRIB)/os/hal/lib/fallback/I2C/hal_i2c_lld.c
endif
else
PLATFORMSRC_CONTRIB += $(CHIBIOS)/os/hal/lib/fallback/I2C/hal_i2c_lld.c
PLATFORMSRC_CONTRIB += $(CHIBIOS_CONTRIB)/os/hal/lib/fallback/I2C/hal_i2c_lld.c
endif
PLATFORMINC_CONTRIB += $(CHIBIOS)/os/hal/lib/fallback/I2C
PLATFORMINC_CONTRIB += $(CHIBIOS_CONTRIB)/os/hal/lib/fallback/I2C
else
ifeq ($(USE_SMART_BUILD),yes)
ifneq ($(findstring HAL_USE_I2C TRUE,$(HALCONF)),)
Expand Down
6 changes: 3 additions & 3 deletions os/hal/ports/NUMICRO/LLD/I2Cv1/driver.mk
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Original file line number Diff line number Diff line change
Expand Up @@ -2,12 +2,12 @@ ifeq ($(USE_HAL_I2C_FALLBACK),yes)
# Fallback SW driver.
ifeq ($(USE_SMART_BUILD),yes)
ifneq ($(findstring HAL_USE_I2C TRUE,$(HALCONF)),)
PLATFORMSRC += $(CHIBIOS)/os/hal/lib/fallback/I2C/hal_i2c_lld.c
PLATFORMSRC += $(CHIBIOS_CONTRIB)/os/hal/lib/fallback/I2C/hal_i2c_lld.c
endif
else
PLATFORMSRC += $(CHIBIOS)/os/hal/lib/fallback/I2C/hal_i2c_lld.c
PLATFORMSRC += $(CHIBIOS_CONTRIB)/os/hal/lib/fallback/I2C/hal_i2c_lld.c
endif
PLATFORMINC += $(CHIBIOS)/os/hal/lib/fallback/I2C
PLATFORMINC += $(CHIBIOS_CONTRIB)/os/hal/lib/fallback/I2C
else
ifeq ($(USE_SMART_BUILD),yes)
ifneq ($(findstring HAL_USE_I2C TRUE,$(HALCONF)),)
Expand Down
6 changes: 3 additions & 3 deletions os/hal/ports/RP/LLD/I2Cv1/driver.mk
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Original file line number Diff line number Diff line change
Expand Up @@ -2,12 +2,12 @@ ifeq ($(USE_HAL_I2C_FALLBACK),yes)
# Fallback SW driver.
ifeq ($(USE_SMART_BUILD),yes)
ifneq ($(findstring HAL_USE_I2C TRUE,$(HALCONF)),)
PLATFORMSRC += $(CHIBIOS)/os/hal/lib/fallback/I2C/hal_i2c_lld.c
PLATFORMSRC += $(CHIBIOS_CONTRIB)/os/hal/lib/fallback/I2C/hal_i2c_lld.c
endif
else
PLATFORMSRC += $(CHIBIOS)/os/hal/lib/fallback/I2C/hal_i2c_lld.c
PLATFORMSRC += $(CHIBIOS_CONTRIB)/os/hal/lib/fallback/I2C/hal_i2c_lld.c
endif
PLATFORMINC += $(CHIBIOS)/os/hal/lib/fallback/I2C
PLATFORMINC += $(CHIBIOS_CONTRIB)/os/hal/lib/fallback/I2C
else
ifeq ($(USE_SMART_BUILD),yes)
ifneq ($(findstring HAL_USE_I2C TRUE,$(HALCONF)),)
Expand Down
6 changes: 3 additions & 3 deletions os/hal/ports/TIVA/LLD/I2C/driver.mk
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Original file line number Diff line number Diff line change
Expand Up @@ -2,12 +2,12 @@ ifeq ($(USE_HAL_I2C_FALLBACK),yes)
# Fallback SW driver.
ifeq ($(USE_SMART_BUILD),yes)
ifneq ($(findstring HAL_USE_I2C TRUE,$(HALCONF)),)
PLATFORMSRC += $(CHIBIOS)/os/hal/lib/fallback/I2C/hal_i2c_lld.c
PLATFORMSRC += $(CHIBIOS_CONTRIB)/os/hal/lib/fallback/I2C/hal_i2c_lld.c
endif
else
PLATFORMSRC += $(CHIBIOS)/os/hal/lib/fallback/I2C/hal_i2c_lld.c
PLATFORMSRC += $(CHIBIOS_CONTRIB)/os/hal/lib/fallback/I2C/hal_i2c_lld.c
endif
PLATFORMINC += $(CHIBIOS)/os/hal/lib/fallback/I2C
PLATFORMINC += $(CHIBIOS_CONTRIB)/os/hal/lib/fallback/I2C
else
ifeq ($(USE_SMART_BUILD),yes)
ifneq ($(findstring HAL_USE_I2C TRUE,$(HALCONF)),)
Expand Down
6 changes: 3 additions & 3 deletions os/hal/ports/WB32/LLD/I2Cv1/driver.mk
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Original file line number Diff line number Diff line change
Expand Up @@ -2,12 +2,12 @@ ifeq ($(USE_HAL_I2C_FALLBACK),yes)
# Fallback SW driver.
ifeq ($(USE_SMART_BUILD),yes)
ifneq ($(findstring HAL_USE_I2C TRUE,$(HALCONF)),)
PLATFORMSRC_CONTRIB += $(CHIBIOS)/os/hal/lib/fallback/I2C/hal_i2c_lld.c
PLATFORMSRC_CONTRIB += $(CHIBIOS_CONTRIB)/os/hal/lib/fallback/I2C/hal_i2c_lld.c
endif
else
PLATFORMSRC_CONTRIB += $(CHIBIOS)/os/hal/lib/fallback/I2C/hal_i2c_lld.c
PLATFORMSRC_CONTRIB += $(CHIBIOS_CONTRIB)/os/hal/lib/fallback/I2C/hal_i2c_lld.c
endif
PLATFORMINC_CONTRIB += $(CHIBIOS)/os/hal/lib/fallback/I2C
PLATFORMINC_CONTRIB += $(CHIBIOS_CONTRIB)/os/hal/lib/fallback/I2C
else
# Default HW driver.
ifeq ($(USE_SMART_BUILD),yes)
Expand Down
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