HSI2C_RXCHON
val = readl(i2c->regs + HSI2C_CTL) | HSI2C_RXCHON;
val = readl(i2c->regs + HSI2C_CTL) & ~HSI2C_RXCHON;
i2c_ctl &= ~(HSI2C_TXCHON | HSI2C_RXCHON);
i2c_ctl |= HSI2C_RXCHON;