topic Re: i.MX28 u-boot vs. bootlets - VDD5V Source Only in i.MX Processors

i.MX28 u-boot vs. bootlets - VDD5V Source Only

rabryn — Fri, 19 Apr 2013 15:14:08 GMT

I'm bringing up a custom i.MX283 based board. I'm having trouble with random lockups anywhere from 1 or 2 seconds to several minutes after applying power. I believe the issue is power related. I've implemented the design detailed in section 4.1.2.1 (VDD5V source only) of application note AN4199:

http://www.freescale.com/files/32bit/doc/app_note/AN4199.pdf

After researching the problem I came across this patch on the Freescale website:

Linux patch to add more robust support for a VDD5V or DCDC_BATT only

Currently, I'm using mainline kernel version 3.8.3 with u-boot version v2012.10.

Are the fixes described in the bootlet patch implemented in mainline u-boot? Can u-boot be configured for VDD5V only? I've looked into the u-boot and bootlet code, but the code is seemingly quite different...

Thanks,

Ryan

Re: i.MX28 u-boot vs. bootlets - VDD5V Source Only

rabryn — Mon, 22 Apr 2013 16:01:36 GMT

I have more information about this issue. I've come to the conclusion that u-boot is broken for iMX28 designs that implement section 4.1.2.1 of AN4199 (see my first post for more info). If I apply the previously mentioned patch to the Freescale bootlet code I see a solid 1V8 rail on my DDR for instance, u-boot does not properly initialize the rail voltages in this configuration. Here's an oscope screen shot of the 1V8 when u-boot initializes the power supply...

I've modified u-boot/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c to force the iMX28 to use the 5V supply like the following but no luck (removed battery check and battery brown out initialization).

static void mxs_power_configure_power_source(void)

{

struct mxs_power_regs *power_regs =

(struct mxs_power_regs *)MXS_POWER_BASE;

struct mxs_lradc_regs *lradc_regs =

(struct mxs_lradc_regs *)MXS_LRADC_BASE;

mxs_src_power_init();

/* 5V source detected, bad battery detected. */

writel(LRADC_CONVERSION_AUTOMATIC,

&lradc_regs->hw_lradc_conversion_clr);

clrbits_le32(&power_regs->hw_power_battmonitor,

POWER_BATTMONITOR_BATT_VAL_MASK);

mxs_5v_boot();

mxs_power_clock2pll();

mxs_switch_vddd_to_dcdc_source();

}

If anyone has any suggestions as to how to fix this issue I'd be happy to try them.

Re: i.MX28 u-boot vs. bootlets - VDD5V Source Only

LeonardoSandova — Mon, 22 Apr 2013 22:14:10 GMT

Hi Ryan, Are you using LTIB for your development? Also, Try to do your changes using the latest BSP (L2.6.35_1.1.0_130130).

Leo

Re: i.MX28 u-boot vs. bootlets - VDD5V Source Only

fabio_estevam — Tue, 23 Apr 2013 16:45:53 GMT

Hi Ryan,

Could this also be DDR settings related?

When I run kernel 3.8 with mainline U-boot I do not experience the random lockups.

Would you have access to a mx28evk to compare the behaviour against your hardware?

Regards,

Fabio Estevam

Re: i.MX28 u-boot vs. bootlets - VDD5V Source Only

fabio_estevam — Tue, 23 Apr 2013 16:59:38 GMT

Ryan,

Just to make sure I understand: if you apply the 5V patches into the bootlets code, and then launch the kernel via bootlets: you don't see any lockups in this case?

Re: i.MX28 u-boot vs. bootlets - VDD5V Source Only

rabryn — Tue, 23 Apr 2013 17:00:25 GMT

Hi Fabio,

The problem is u-boot's configuration of the low-level blocks of the power management unit in a 5V only scenario as defined in section 4.1.2 of the application note linked to in the original post. Late yesterday I was able to prove this by porting over the patched bootlet code into u-boot. It appears u-boot's SPL implementation is based on Freescale's original bootlet code. However, Freescale has released a 5V only patch to the bootlet code that has never made it into u-boot.

I now have a working system. Over time I'll try and clean up my modifications to u-boot and get some kind of patch together.

Thanks,

Ryan

Re: i.MX28 u-boot vs. bootlets - VDD5V Source Only

fabio_estevam — Tue, 23 Apr 2013 17:04:50 GMT

Thanks, Ryan.

I will be glad to help you to fix mainline U-boot.

When you have a chance, please generate the patches against 2013.04 version and submit them to the U-boot list.

Regards,

Fabio Estevam

Re: i.MX28 u-boot vs. bootlets - VDD5V Source Only

rabryn — Tue, 23 Apr 2013 18:37:29 GMT

Fabio,

Yes, you are correct. More importantly though, if I apply the patch to the bootlet code I see a solid 1V8 on my DDR2 rail... the thrashing you see in the oscope screenshot above is gone.

Ryan

Re: i.MX28 u-boot vs. bootlets - VDD5V Source Only

rabryn — Tue, 23 Apr 2013 18:43:45 GMT

Fabio,

I will generate a patch, but it will take some time. I basically replaced u-boot-2013.04/arch/arm/cpu/arm926ejs/mxs/{spl_power_init.c, spl_mem_init.c} with the bootlet's power_prep.c and init-mx28.c respectively. A brute force approach if you will. I'm going to narrow down the changes and try to find specifically what's needed.

Ryan

Re: i.MX28 u-boot vs. bootlets - VDD5V Source Only

B_K_Ankur — Mon, 07 Apr 2014 07:10:48 GMT

Hello Ryan,

I am facing similar issue with VDD5V only mode using U-Boot. Could you please share the patch in case if you have created for u-boot with VDD5v only mode or share the code you modified esp. spl_power_init.c ?

Thank you in Advance.

Regards,

Ankur

Re: i.MX28 u-boot vs. bootlets - VDD5V Source Only

B_K_Ankur — Mon, 07 Apr 2014 08:21:33 GMT

Hello Friends,

I have made changes to u-boot code similar to bootlets source (with Patch L2.6.35_10.12_SDK_5V_SUPPLY_PATCH.tar.gz). Please find the attached u-boot patch for VDD5V, which is not working for me.

Can anyone suggest, what's missing in the patch?

U-Boot Console Output:

Configured for 5v only power source. Battery powered operation disabled.

mxs_power_init_dcdc

Regards,

Ankur

Re: i.MX28 u-boot vs. bootlets - VDD5V Source Only

B_K_Ankur — Tue, 08 Apr 2014 00:24:05 GMT

Find Missing Patch: From above post. [C] Ankur Patel - Pastebin.com

Regards,

Ankur

Re: i.MX28 u-boot vs. bootlets - VDD5V Source Only

fabio_estevam — Tue, 08 Apr 2014 00:44:44 GMT

Ankur,

Please post your patch to the U-boot list so that people can review it and help you there.

Regards,

Fabio Estevam

Re: i.MX28 u-boot vs. bootlets - VDD5V Source Only

B_K_Ankur — Tue, 08 Apr 2014 01:32:07 GMT

Sure, Let me give it a try to post it on u-boot list.

I appreciate your kind response.

Thank you,

Regards,

Ankur.

Re: i.MX28 u-boot vs. bootlets - VDD5V Source Only

B_K_Ankur — Thu, 17 Apr 2014 07:16:23 GMT

Thanks All.

Atlast, I have working u-boot with VDD5V powersupply. As done by Ryan, I have ported the power related code from Powerprep to spl_power_init.c and it worked.

Regards,

Ankur

Re: i.MX28 u-boot vs. bootlets - VDD5V Source Only

fabio_estevam — Thu, 17 Apr 2014 12:47:12 GMT

Ankur,

This is great news!

Care to share your patch? Are you familar with submitting it to the U-boot list, so that it could be reviewed and applied to the official project?

Thanks,

Fabio Estevam

Re: i.MX28 u-boot vs. bootlets - VDD5V Source Only

B_K_Ankur — Tue, 06 May 2014 05:08:21 GMT

Sure.. Let me create a patch for u-boot. I am not sure if its been accepted by u-boot as I have used some API's of powerlet bootlet bootloader.

Thank you,

Ankur

Re: Re: i.MX28 u-boot vs. bootlets - VDD5V Source Only

gonfer — Thu, 16 Oct 2014 12:42:43 GMT

Does anybody know if this issue has been finally solved in mainline U-Boot?? I've been looking for a patch but didn't find one.

U-Boot v2014.07 on my custom hardware (VDD5V only / no battery) doesn't boot up. I get this message non stop:

PowerPrep start initialize power...

Battery Voltage = 3.09VHTLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLFLC

PowerPrep start initialize power...

Battery Voltage = 3.10VHTLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLFLC

Can someone help me on this?

BR,

Gonzalo.

Re: Re: i.MX28 u-boot vs. bootlets - VDD5V Source Only

fabio_estevam — Thu, 16 Oct 2014 13:45:15 GMT

Hi Gonzalo,

Not sure whether Ryan or Ankur have submitted the patches to the U-boot list.

About your error messages: it looks like you are still using the bootlets. When you use mainline U-boot you should not have the "PowerPrep" related messages as you show. In mainline U-boot the bootlets code are built-in in U-boot, so you only need to flash U-boot in to your hardware.

Re: Re: Re: i.MX28 u-boot vs. bootlets - VDD5V Source Only

gonfer — Fri, 17 Oct 2014 11:37:44 GMT

Hi Fabio,

thanks for pointing that. I just burned U-Boot in a SD card I use with my iMX28evk. Maybe SD card partitioning was incorrect? So I've partitioned the SD card as described in U-Boot documentation, and now it woks but in a weird way.

HTLLCL0x80206008

0x8020a012

0x80502008

and 15 to 20 seconds later:

HTLLCLLC

U-Boot 2014.07-dirty (Oct 17 2014 - 13:07:42)

CPU: Freescale i.MX28 rev1.2 at 454 MHz

BOOT: SSP SD/MMC #0, 3V3

SPI: ready

DRAM: 128 MiB

NAND: 128 MiB

MMC: MXS MMC: 0

*** Warning - bad CRC, using default environment

Video: MXSFB: 'videomode' variable not set!

In: serial

Out: serial

Err: serial

Net: FEC0 [PRIME], FEC1

Warning: FEC1 using MAC address from net device

Hit any key to stop autoboot: 0

switch to partitions #0, OK

mmc0 is current device

** Invalid partition 2 **

** Invalid partition 2 **

Booting from net ...

FEC0: Autonegotiation timeout

BOOTP broadcast 1

BOOTP broadcast 2

BOOTP broadcast 3

It looks first attempt to boot from SD fails, while second try is successful.

What's the reason for this behaviour? If I burn the same SD card with bootlets using the mk_mx28_image script, the board boots fine all the times. I've done this using 2 different SD cards with the same results.

Thanks,

Gonzalo.

Edit: using these SD cards with U-Boot on my custom board leads to a non stop HTLLCHTLLCHTLLCHTLLCHTLLC

How can I make U-Boot more verbose?