Hello, Benoît,
On Fri, Dec 13, 2013 at 4:52 AM, Benoît Thébaudeau benoit.thebaudeau@advansee.com wrote:
On Thursday, December 12, 2013 5:46:21 PM, Sergey Alyoshin wrote:
Enable fuse supply gate before fuse programming and disable after.
Signed-off-by: Sergey Alyoshin alyoshin.s@gmail.com Tested-by: Sergey Alyoshin alyoshin.s@gmail.com
Have you also tested without this patch first too? On which SoC?
I have tried to write MAC address in fuse (bank 1) on i.MX53 custom board and 'fuse sense' show no change, reboot show no change either.
I have not tested this on i.MX51, but this register and bit is the same on i.MX51 with exactly the same description. With this patch I have successfully written MAC addresses on several i.MX53 boards.
In Linux 2.6.35 from Freescale this bit is also set for fuse programming, e.g. in arch/arm/mach-mx5/mx51_babbage.c and arch/arm/mach-mx5/mx53_loco.c in mxc_iim_enable_fuse().
My tests had shown that this is not required on i.MX51. It's probably the same on i.MX53. I have not checked if i.MX25 and i.MX35 also have such a bit, but they also work fine as is. This is not even done by Freescale: http://git.freescale.com/git/cgit.cgi/imx/linux-2.6-imx.git/tree/drivers/cha...
In the Reference Manual, nothing says in the IIM / fuse chapters that this bit is needed for proper programming. It is just described in the CCM register map, and nothing refers to it. It is perhaps only useful for test purposes. I'd vote for letting this bit untouched if possible.
Fabio, do you have more information from Freescale about this bit?