When buffer_setup is run we start the TS initialization: set SAA7134_TS_STOPPED.
When all buffers are prepared we write data into DMA register and set
SAA7134_TS_BUFF_DONE.
When the first buffer is active start TS and set SAA7134_TS_STARTED.
When ts_release is called stop TS and set SAA7134_TS_STOPPED.