Thanks, but I am afraid I do not understand. My question was not about BCLK (the I2S bitclock), but about MCLK - the integer multiple of BCLK/LRCLK which is parent of the I2S clock tree. Typically MCLK is 64 - 1024 x fs (=LRCLK).
The source code talks about parents of the I2S clock being GP1 - GP5 https://github.com/raspberrypi/linux/bl ... 2030-L2050 . IIUC that would hint that the I2S controller can be clocked from external clock via one of the GPCLKs - very handy. The GPCLK sources seem to be defined https://github.com/raspberrypi/linux/bl ... 1267-L1327
The other direction would be MCLK output - the GPCLK0 has clk_i2s as one of its parents https://github.com/raspberrypi/linux/bl ... 2145-L2173 - does it mean GPCLK0 could be configured to output clk_i2s? Thanks!
The source code talks about parents of the I2S clock being GP1 - GP5 https://github.com/raspberrypi/linux/bl ... 2030-L2050 . IIUC that would hint that the I2S controller can be clocked from external clock via one of the GPCLKs - very handy. The GPCLK sources seem to be defined https://github.com/raspberrypi/linux/bl ... 1267-L1327
The other direction would be MCLK output - the GPCLK0 has clk_i2s as one of its parents https://github.com/raspberrypi/linux/bl ... 2145-L2173 - does it mean GPCLK0 could be configured to output clk_i2s? Thanks!
Statistics: Posted by phofman — Fri Nov 14, 2025 8:00 am