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#include <stdlib.h>
#include <stdint.h>
#include "encoding.h"
#include "platform.h"
#include "prci_driver.h"
#include "eos.h"
#include "i2c.h"
void eos_i2c_start(uint32_t baud_rate) {
eos_i2c_set_baud_rate(baud_rate);
GPIO_REG(GPIO_PULLUP_EN) &= ~(1 << IOF_I2C0_SCL);
GPIO_REG(GPIO_OUTPUT_XOR) &= ~(1 << IOF_I2C0_SCL);
GPIO_REG(GPIO_PULLUP_EN) &= ~(1 << IOF_I2C0_SDA);
GPIO_REG(GPIO_OUTPUT_XOR) &= ~(1 << IOF_I2C0_SDA);
GPIO_REG(GPIO_IOF_SEL) &= ~IOF0_I2C0_MASK;
GPIO_REG(GPIO_IOF_EN) |= IOF0_I2C0_MASK;
}
void eos_i2c_stop(void) {
GPIO_REG(GPIO_PULLUP_EN) |= (1 << IOF_I2C0_SCL);
GPIO_REG(GPIO_PULLUP_EN) |= (1 << IOF_I2C0_SDA);
GPIO_REG(GPIO_IOF_EN) &= ~IOF0_I2C0_MASK;
}
void eos_i2c_set_baud_rate(uint32_t baud_rate) {
unsigned long clock_rate = PRCI_get_cpu_freq();
uint16_t prescaler = (clock_rate / (baud_rate * 5)) - 1;
I2C0_REGB(I2C_CONTROL) &= ~I2C_CONTROL_EN;
I2C0_REGB(I2C_PRESCALE_LOW) = prescaler & 0xFF;
I2C0_REGB(I2C_PRESCALE_HIGH) = (prescaler >> 8) & 0xFF;
I2C0_REGB(I2C_CONTROL) |= I2C_CONTROL_EN;
}
static int i2c_addr(uint8_t addr, uint8_t rw_flag) {
I2C0_REGB(I2C_TRANSMIT) = ((addr & 0x7F) << 1) | (rw_flag & 0x1);
I2C0_REGB(I2C_COMMAND) = I2C_CMD_START | I2C_CMD_WRITE;
while (I2C0_REGB(I2C_STATUS) & I2C_STATUS_TIP);
if (I2C0_REGB(I2C_STATUS) & I2C_STATUS_RXACK) return EOS_ERR;
return EOS_OK;
}
static int i2c_reg(uint8_t reg) {
I2C0_REGB(I2C_TRANSMIT) = reg;
I2C0_REGB(I2C_COMMAND) = I2C_CMD_WRITE;
while (I2C0_REGB(I2C_STATUS) & I2C_STATUS_TIP);
if (I2C0_REGB(I2C_STATUS) & I2C_STATUS_RXACK) return EOS_ERR;
return EOS_OK;
}
int eos_i2c_read(uint8_t addr, uint8_t reg, uint8_t *buffer, uint16_t len) {
uint8_t cmd;
int rv;
int i;
rv = i2c_addr(addr, I2C_WRITE);
if (rv) return rv;
rv = i2c_reg(reg);
if (rv) return rv;
rv = i2c_addr(addr, I2C_READ);
if (rv) return rv;
cmd = I2C_CMD_READ;
for (i=0; i<len; i++) {
/* Set NACK to end read, and generate STOP condition */
if (i == (len - 1)) cmd |= I2C_CMD_ACK | I2C_CMD_STOP;
I2C0_REGB(I2C_COMMAND) = cmd;
while (I2C0_REGB(I2C_STATUS) & I2C_STATUS_TIP);
buffer[i] = I2C0_REGB(I2C_RECEIVE);
}
return EOS_OK;
}
int eos_i2c_write(uint8_t addr, uint8_t reg, uint8_t *buffer, uint16_t len) {
uint8_t cmd;
int rv;
int i;
rv = i2c_addr(addr, I2C_WRITE);
if (rv) return rv;
rv = i2c_reg(reg);
if (rv) return rv;
cmd = I2C_CMD_WRITE;
for (i=0; i<len; i++) {
if (i == (len - 1)) cmd |= I2C_CMD_STOP;
I2C0_REGB(I2C_TRANSMIT) = buffer[i];
I2C0_REGB(I2C_COMMAND) = cmd;
while (I2C0_REGB(I2C_STATUS) & I2C_STATUS_TIP);
if (I2C0_REGB(I2C_STATUS) & I2C_STATUS_RXACK) return EOS_ERR;
}
return EOS_OK;
}
int eos_i2c_read8(uint8_t addr, uint8_t reg, uint8_t *data) {
return eos_i2c_read(addr, reg, data, 1);
}
int eos_i2c_write8(uint8_t addr, uint8_t reg, uint8_t data) {
return eos_i2c_write(addr, reg, &data, 1);
}
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