Hi Jorge,
On Thu, Jan 16, 2020 at 5:30 PM Jorge Ramirez-Ortiz, Foundries jorge@foundries.io wrote:
Hi Fabio,
I am trying to enable LDO in an imx7ulp based board but somehow the board locks up as soon I write to PMC1_RUN (using the init_ldo_mode sequence).
Just looked at the i.MX7UL Reference Manual and it says:
"28.5.9.1.1 Using internal LDO regulator After a POR event, when the PMC 0 is running in RUN mode and the PMC 1 is turned off, the process to turn on the PMC 1 using the internal LDO regulator is as follows: • Assert the LDOEN bit (PMC0_CTRL). • Assert the LDOOKDIS bit (PMC0_CTRL) if required. • Assert the PMC1ON bit (PMC0_CTRL)."
So it seems we need to change the order to:
--- a/arch/arm/mach-imx/mx7ulp/soc.c +++ b/arch/arm/mach-imx/mx7ulp/soc.c @@ -122,9 +122,6 @@ static void init_ldo_mode(void) { unsigned int reg;
- /* Set LDOOKDIS */ - setbits_le32(PMC0_BASE_ADDR + PMC0_CTRL, PMC0_CTRL_LDOOKDIS); - /* Set LDOVL to 0.95V in PMC1_RUN */ reg = readl(PMC1_BASE_ADDR + PMC1_RUN); reg &= ~PMC1_LDOVL_MASK; @@ -151,6 +148,9 @@ static void init_ldo_mode(void) /* Set LDOEN bit */ setbits_le32(PMC0_BASE_ADDR + PMC0_CTRL, PMC0_CTRL_LDOEN);
+ /* Set LDOOKDIS */ + setbits_le32(PMC0_BASE_ADDR + PMC0_CTRL, PMC0_CTRL_LDOOKDIS); + /* Set the PMC1ON bit */ setbits_le32(PMC0_BASE_ADDR + PMC0_CTRL, PMC0_CTRL_PMC1ON); }
Does this help?
I think it is interesting that bit PMC0_CTRL_PMC1ON is already set so I am wondering if you think it is possible - in your experience- that ROM might have already configured LDO? or was this also the case - this bit already set- when you tested the feature?
I think it was not set by default. I can confirm tomorrow with a i.MX7ULP Embedded Artists board.
Regards,
Fabio Estevam