You need 2 DMA channels.
If Timer 4 is triggering a EDMA event, you have to RESET this event. If the event is not reset, there is only 1 trigger. But you want N triggers. So you have to reset the event source. You need a DMA channel for this. You have to clear 2 registers of the timer. The channel is set up: source = memory filled with the required values (0x07, 0). And the destination increment is set up to be the difference of the register addresses.
If you do it right, you will have a continous stream of trigger events from the timer to the EDMA.
And for doing the "real work", you use DMA chaining to another channel.
My "test code" is a very complex DMA machine, doing LED pwm, SPI, and keyboard scanning all by DMA. It's confusing.
regards
Wolfgang