int i2c_init_master(i2c_t dev, i2c_speed_t speed)
{
I2C_TypeDef *i2c;
gpio_t pin_scl, pin_sda;
int ccr;
/* read speed configuration */
switch (speed) {
case I2C_SPEED_NORMAL:
ccr = I2C_APBCLK / 200000;
break;
case I2C_SPEED_FAST:
ccr = I2C_APBCLK / 800000;
break;
default:
return -2;
}
/* read static device configuration */
switch (dev) {
#if I2C_0_EN
case I2C_0:
i2c = I2C_0_DEV;
pin_scl = I2C_0_SCL_PIN;
pin_sda = I2C_0_SDA_PIN;
I2C_0_CLKEN();
NVIC_SetPriority(I2C_0_ERR_IRQ, I2C_IRQ_PRIO);
NVIC_EnableIRQ(I2C_0_ERR_IRQ);
break;
#endif
default:
return -1;
}
/* configure pins */
_pin_config(pin_scl, pin_sda);
/* configure device */
_i2c_init(i2c, ccr);
/* make sure the analog filters don't hang -> see errata sheet 2.14.7 */
if (i2c->SR2 & I2C_SR2_BUSY) {
DEBUG("LINE BUSY AFTER RESET -> toggle pins now\n");
/* disable peripheral */
i2c->CR1 &= ~I2C_CR1_PE;
/* re-run pin config to toggle and re-configure pins */
_pin_config(pin_scl, pin_sda);
/* make peripheral soft reset */
i2c->CR1 |= I2C_CR1_SWRST;
i2c->CR1 &= ~I2C_CR1_SWRST;
/* enable device */
_i2c_init(i2c, ccr);
}
return 0;
}
mp_obj_t pyb_I2C(mp_obj_t i2c_id, mp_obj_t i2c_addr) {
pyb_i2c_t i2c_port;
switch(mp_obj_get_int(i2c_id)) {
case 0: i2c_port = PYB_I2C_1; break;
case 1: i2c_port = PYB_I2C_2; break;
default: return mp_const_none;
}
if (_i2c_init(i2c_port) == false) {
return mp_const_none;
}
pyb_i2c_obj_t *o = m_new_obj(pyb_i2c_obj_t);
o->base.type = &i2c_obj_type;
o->i2c_port = i2c_port;
o->i2c_addr = mp_obj_get_int(i2c_addr);
o->i2c_state = I2C_STATE_IDLE;
return o;
}
int i2c_init_master(i2c_t dev, i2c_speed_t speed)
{
int ccr;
if ((unsigned int)dev >= I2C_NUMOF) {
return -1;
}
/* read speed configuration */
switch (speed) {
case I2C_SPEED_NORMAL:
ccr = I2C_APBCLK / 200000;
break;
case I2C_SPEED_FAST:
ccr = I2C_APBCLK / 800000;
break;
default:
return -2;
}
I2C_TypeDef *i2c = i2c_config[dev].dev;
/* enable I2C clock */
i2c_poweron(dev);
/* set IRQn priority */
NVIC_SetPriority(i2c_config[dev].er_irqn, I2C_IRQ_PRIO);
/* enable IRQn */
NVIC_EnableIRQ(i2c_config[dev].er_irqn);
/* configure pins */
gpio_init(i2c_config[dev].scl, GPIO_DIR_OUT, GPIO_PULLUP);
gpio_init_af(i2c_config[dev].scl, i2c_config[dev].af);
gpio_init(i2c_config[dev].sda, GPIO_DIR_OUT, GPIO_PULLUP);
gpio_init_af(i2c_config[dev].sda, i2c_config[dev].af);
/* configure device */
_i2c_init(i2c, ccr);
return 0;
}
void i2c_init(i2c_t dev)
{
assert(dev < I2C_NUMOF);
DEBUG("[i2c] init: initializing device\n");
mutex_init(&locks[dev]);
I2C_TypeDef *i2c = i2c_config[dev].dev;
periph_clk_en(i2c_config[dev].bus, i2c_config[dev].rcc_mask);
NVIC_SetPriority(i2c_config[dev].irqn, I2C_IRQ_PRIO);
NVIC_EnableIRQ(i2c_config[dev].irqn);
#if defined(CPU_FAM_STM32F0) || defined(CPU_FAM_STM32F3)
/* Set I2CSW bits to enable I2C clock source */
RCC->CFGR3 |= i2c_config[dev].rcc_sw_mask;
#endif
DEBUG("[i2c] init: configuring pins\n");
/* configure pins */
gpio_init(i2c_config[dev].scl_pin, GPIO_OD_PU);
gpio_init_af(i2c_config[dev].scl_pin, i2c_config[dev].scl_af);
gpio_init(i2c_config[dev].sda_pin, GPIO_OD_PU);
gpio_init_af(i2c_config[dev].sda_pin, i2c_config[dev].sda_af);
DEBUG("[i2c] init: configuring device\n");
/* set the timing register value from predefined values */
i2c_timing_param_t tp = timing_params[i2c_config[dev].speed];
uint32_t timing = (( (uint32_t)tp.presc << I2C_TIMINGR_PRESC_Pos) |
( (uint32_t)tp.scldel << I2C_TIMINGR_SCLDEL_Pos) |
( (uint32_t)tp.sdadel << I2C_TIMINGR_SDADEL_Pos) |
( (uint16_t)tp.sclh << I2C_TIMINGR_SCLH_Pos) |
tp.scll);
_i2c_init(i2c, timing);
}
void i2c_init(i2c_t dev)
{
assert(dev < I2C_NUMOF);
mutex_init(&locks[dev]);
I2C_TypeDef *i2c = i2c_config[dev].dev;
assert(i2c != NULL);
uint32_t ccr;
/* read speed configuration */
switch (i2c_config[dev].speed) {
case I2C_SPEED_LOW:
/* 10Kbit/s */
ccr = i2c_config[dev].clk / 20000;
break;
case I2C_SPEED_NORMAL:
/* 100Kbit/s */
ccr = i2c_config[dev].clk / 200000;
break;
case I2C_SPEED_FAST:
ccr = i2c_config[dev].clk / 800000;
break;
default:
return;
}
periph_clk_en(i2c_config[dev].bus, i2c_config[dev].rcc_mask);
NVIC_SetPriority(i2c_config[dev].irqn, I2C_IRQ_PRIO);
NVIC_EnableIRQ(i2c_config[dev].irqn);
/* configure pins */
gpio_init(i2c_config[dev].scl_pin, GPIO_OD_PU);
gpio_init(i2c_config[dev].sda_pin, GPIO_OD_PU);
#ifdef CPU_FAM_STM32F1
/* This is needed in case the remapped pins are used */
if (i2c_config[dev].scl_pin == GPIO_PIN(PORT_B, 8) ||
i2c_config[dev].sda_pin == GPIO_PIN(PORT_B, 9)) {
/* The remapping periph clock must first be enabled */
RCC->APB2ENR |= RCC_APB2ENR_AFIOEN;
/* Then the remap can occur */
AFIO->MAPR |= AFIO_MAPR_I2C1_REMAP;
}
gpio_init_af(i2c_config[dev].scl_pin, GPIO_AF_OUT_OD);
gpio_init_af(i2c_config[dev].sda_pin, GPIO_AF_OUT_OD);
#else
gpio_init_af(i2c_config[dev].scl_pin, i2c_config[dev].scl_af);
gpio_init_af(i2c_config[dev].sda_pin, i2c_config[dev].sda_af);
#endif
/* configure device */
_i2c_init(i2c, i2c_config[dev].clk, ccr);
#if defined(CPU_FAM_STM32F4)
/* make sure the analog filters don't hang -> see errata sheet 2.14.7 */
if (i2c->SR2 & I2C_SR2_BUSY) {
/* disable peripheral */
i2c->CR1 &= ~I2C_CR1_PE;
/* toggle both pins to reset analog filter */
gpio_init(i2c_config[dev].scl_pin, GPIO_OD);
gpio_init(i2c_config[dev].sda_pin, GPIO_OD);
gpio_set(i2c_config[dev].sda_pin);
gpio_set(i2c_config[dev].scl_pin);
gpio_clear(i2c_config[dev].sda_pin);
gpio_clear(i2c_config[dev].scl_pin);
gpio_set(i2c_config[dev].sda_pin);
gpio_set(i2c_config[dev].scl_pin);
/* reset pins for alternate function */
gpio_init(i2c_config[dev].scl_pin, GPIO_OD_PU);
gpio_init(i2c_config[dev].sda_pin, GPIO_OD_PU);
gpio_init_af(i2c_config[dev].scl_pin, i2c_config[dev].scl_af);
gpio_init_af(i2c_config[dev].sda_pin, i2c_config[dev].sda_af);
/* make peripheral soft reset */
i2c->CR1 |= I2C_CR1_SWRST;
i2c->CR1 &= ~I2C_CR1_SWRST;
/* enable device */
_i2c_init(i2c, i2c_config[dev].clk, ccr);
}
#endif
}
