__HAL_RCC_GET_I2S_APB1_SOURCE macro

The clock source can be one of the following values: @arg RCC_I2SAPB1CLKSOURCE_PLLI2S: PLLI2S VCO output clock divided by PLLI2SR used as I2S clock. @arg RCC_I2SAPB1CLKSOURCE_EXT: External clock mapped on the I2S_CKIN pin used as I2S APB1 clock. @arg RCC_I2SAPB1CLKSOURCE_PLLR: PLL VCO Output divided by PLLR used as I2S APB1 clock. @arg RCC_I2SAPB1CLKSOURCE_PLLSRC: HSI or HSE depending from PLL source Clock.