Help with configuring adau1450 registers using I2C

I want to use the STM32 microcontroller to configure the ADAU1450 DSP registers using I2C. I have tried to follow the steps for configuring this DSP registers as explained in Table 27 of the ADAU1450/1452 datasheet, but I am not getting any response from the ADAU1450. I don't know where I could be going wrong.

here are my header and source files...

#ifndef I2C_H_
#define I2C_H_

#include "stm32.h"
#include <stdint.h>

void I2C1_Init(void);
void I2C1_Write(uint8_t saddr, uint16_t reg, const uint8_t *data, uint16_t len);
void I2C1_Read(uint8_t saddr, uint16_t reg, uint8_t *data, uint16_t len);

#include "i2c.h"

#define I2C_SPEED      40      // ~100kHz for 8 MHz APB1
#define I2C_TRISE      9
#define I2C1_EN        (1U << 21)
#define GPIOB_EN       (1U << 3)

void I2C1_Init(void)
{
    RCC->APB2ENR |= GPIOB_EN;
    RCC->APB1ENR |= I2C1_EN;

    // PB6, PB7 Alternate function open-drain
    GPIOB->CRL &= ~((0xF << 24) | (0xF << 28));
    GPIOB->CRL |=  ((0xB << 24) | (0xB << 28));  // MODE=11 (50MHz), CNF=10 (AF open-drain)

    // Software reset
    I2C1->CR1 |= (1 << 15);
    I2C1->CR1 &= ~(1 << 15);

    I2C1->CR2 = 8;              // APB1 = 8 MHz
    I2C1->CCR = I2C_SPEED;
    I2C1->TRISE = I2C_TRISE;

    I2C1->CR1 |= (1 << 0);      // Enable I2C1
}

void I2C1_Write(uint8_t saddr, uint16_t reg, const uint8_t *data, uint16_t len)
{
    volatile int tmp;

    while (I2C1->SR2 & (1 << 1)); // Wait if busy

    I2C1->CR1 |= (1 << 8);        // START
    while (!(I2C1->SR1 & (1 << 0))); // SB

    I2C1->DR = saddr << 1;        // Write address
    while (!(I2C1->SR1 & (1 << 1))); // ADDR
    tmp = I2C1->SR2;

    // Send 16-bit register address
    while (!(I2C1->SR1 & (1 << 7)));
    I2C1->DR = (reg >> 8) & 0xFF;
    while (!(I2C1->SR1 & (1 << 7)));
    I2C1->DR = reg & 0xFF;

    // Send data
    for (uint16_t i = 0; i < len; i++)
    {
        while (!(I2C1->SR1 & (1 << 7)));
        I2C1->DR = data[i];
    }

    while (!(I2C1->SR1 & (1 << 2))); // BTF
    I2C1->CR1 |= (1 << 9);           // STOP
}

void I2C1_Read(uint8_t saddr, uint16_t reg, uint8_t *data, uint16_t len)
{
    volatile int tmp;

    while (I2C1->SR2 & (1 << 1)); // Busy

    I2C1->CR1 |= (1 << 8);        // START
    while (!(I2C1->SR1 & (1 << 0)));

    I2C1->DR = saddr << 1;        // Write mode
    while (!(I2C1->SR1 & (1 << 1)));
    tmp = I2C1->SR2;

    while (!(I2C1->SR1 & (1 << 7)));
    I2C1->DR = (reg >> 8) & 0xFF;
    while (!(I2C1->SR1 & (1 << 7)));
    I2C1->DR = reg & 0xFF;
    while (!(I2C1->SR1 & (1 << 7)));

    I2C1->CR1 |= (1 << 8);        // Re-START
    while (!(I2C1->SR1 & (1 << 0)));

    I2C1->DR = (saddr << 1) | 1;  // Read mode
    while (!(I2C1->SR1 & (1 << 1)));
    tmp = I2C1->SR2;

    if (len == 1)
    {
        I2C1->CR1 &= ~(1 << 10); // ACK = 0
        I2C1->CR1 |= (1 << 9);   // STOP
        while (!(I2C1->SR1 & (1 << 6)));
        data[0] = I2C1->DR;
    }
    else
    {
        I2C1->CR1 |= (1 << 10); // ACK
        for (uint16_t i = 0; i < len; i++)
        {
            if (i == len - 2)
                I2C1->CR1 &= ~(1 << 10); // NACK before last byte
            if (i == len - 1)
                I2C1->CR1 |= (1 << 9);   // STOP

            while (!(I2C1->SR1 & (1 << 6)));
            data[i] = I2C1->DR;
        }
    }
}

#ifndef ADAU1450_H_
#define ADAU1450_H_

#include <stdint.h>

#define ADAU1450_I2C_ADDR    0x38  // Make sure ADDR0 and ADDR1 = 0

#define PLL_CTRL0            0xF000
#define PLL_CTRL1            0xF001
#define PLL_CLK_SRC          0xF002
#define PLL_ENABLE           0xF003
#define PLL_LOCK             0xF004
#define MCLK_OUT_ENABLE      0xF005
#define SOFT_RESET           0xF890
#define HIBERNATE            0xF400
#define KILL_CORE            0xF403
#define START_CORE           0xF402
#define SYS_PWR              0xF050
#define SYS_DISABLE          0xF051

void adau1450_init(void);
void adau1450_write(uint16_t reg, uint8_t val);
uint8_t adau1450_read(uint16_t reg);
uint8_t adau1450_check_pll_lock(void);

#include "i2c.h"
#include "adau1450.h"

int main(void)
{
    I2C1_Init();
    adau1450_init();

    uint8_t pll_val;

    while (1)
    {
        pll_val = adau1450_read(PLL_CTRL0);
        for (volatile int i = 0; i < 100000; i++);
    }
}