Dear Olimex
I would like to output a 6MHz clock on the above port and as far as I understand it should be possible.
The documentation on the FEX is quite long and I cannot find a reference on how to do the above.
A solution would be good, actually great !
If there is nothing ready for the above could you point out to some documentation ?
I have looked at
https://www.olimex.com/wiki/How_to_edit_board_configurations_and_definitions_in_the_official_Debian_Linux
http://linux-sunxi.org/GPIO
http://linux-sunxi.org/Talk:Fex_Guide
Thanks, Damiano
Quote from: engidea on September 29, 2015, 02:21:30 PM
I would like to output a 6MHz clock on the above port and as far as I understand it should be possible.
The documentation on the FEX is quite long and I cannot find a reference on how to do the above.
In Linux 4.3, have a driver get the clock "clk_out_a" using clk_get. Technically, for this, the device that needs the clock needs to be in the device tree (dts) file. But for the quick and dirty way see below.
No idea how it works on older kernels.
struct clk* clk1;
unsigned long rounded_rate;
clk1 = clk_get(NULL, "clk_out_a");
rounded_rate = clk_round_rate(clk1, 600000000U);
ret = clk_set_rate(clk, rounded_rate);
There is a "discussion" on sunxy group that is quite extensive
https://groups.google.com/forum/#!topic/linux-sunxi/zDOxAP_JJIc
Long story short, you also need a pullup...