int i2c_init_master(i2c_t dev, i2c_speed_t speed)
{
I2C_TypeDef *i2c;
GPIO_TypeDef *port_scl;
GPIO_TypeDef *port_sda;
int pin_scl = 0, pin_sda = 0;
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;
port_scl = I2C_0_SCL_PORT;
pin_scl = I2C_0_SCL_PIN;
port_sda = I2C_0_SDA_PORT;
pin_sda = I2C_0_SDA_PIN;
I2C_0_CLKEN();
I2C_0_SCL_CLKEN();
I2C_0_SDA_CLKEN();
NVIC_SetPriority(I2C_0_ERR_IRQ, I2C_IRQ_PRIO);
NVIC_EnableIRQ(I2C_0_ERR_IRQ);
break;
#endif
#if I2C_1_EN
case I2C_1:
i2c = I2C_1_DEV;
port_scl = I2C_1_SCL_PORT;
pin_scl = I2C_1_SCL_PIN;
port_sda = I2C_1_SDA_PORT;
pin_sda = I2C_1_SDA_PIN;
I2C_1_CLKEN();
I2C_1_SCL_CLKEN();
I2C_1_SDA_CLKEN();
NVIC_SetPriority(I2C_1_ERR_IRQ, I2C_IRQ_PRIO);
NVIC_EnableIRQ(I2C_1_ERR_IRQ);
break;
#endif
default:
return -1;
}
/* configure pins */
_pin_config(port_scl, port_sda, 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;
/* toggle both pins to reset analog filter */
_toggle_pins(port_scl, port_sda, pin_scl, pin_sda);
/* reset pins for alternate function */
_pin_config(port_scl, port_sda, 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;
}
int i2c_init_master(i2c_t dev, i2c_speed_t speed)
{
I2C_TypeDef *i2c;
GPIO_TypeDef *port_scl;
GPIO_TypeDef *port_sda;
int 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;
port_scl = I2C_0_SCL_PORT;
pin_scl = I2C_0_SCL_PIN;
port_sda = I2C_0_SDA_PORT;
pin_sda = I2C_0_SDA_PIN;
I2C_0_CLKEN();
I2C_0_SCL_CLKEN();
I2C_0_SDA_CLKEN();
break;
#endif
default:
return -1;
}
/* configure pins, alternate output, open-drain, output mode with 50MHz */
if (pin_scl < 8) {
port_scl->CRL |= (0xf << (pin_scl * 4));
}
else {
port_scl->CRH |= (0xf << ((pin_scl - 8) * 4));
}
if (pin_sda < 8) {
port_sda->CRL |= (0xf << (pin_sda * 4));
}
else {
port_sda->CRH |= (0xf << ((pin_sda - 8) * 4));
}
/* disable device and set ACK bit */
i2c->CR1 = I2C_CR1_ACK;
/* configure I2C clock */
i2c->CR2 = (I2C_APBCLK / 1000000);
i2c->CCR = ccr;
i2c->TRISE = (I2C_APBCLK / 1000000) + 1;
/* configure device */
i2c->OAR1 = 0; /* makes sure we are in 7-bit address mode */
/* enable device */
i2c->CR1 |= I2C_CR1_PE;
return 0;
}
