[U-Boot] [PATCH] mxs: fixed battery boot on imx233-olinuxino-micro

[U-Boot] [PATCH] mxs: fixed battery boot on imx233-olinuxino-micro

[Peter Schumann]

This patch makes it possible to boot from battery on olinuxino Boards
from Olimex.

We should not set DOUBLE_FETS in HW_POWER_MINPWR, it makes my system
reset with in seconds while running on battery power.

Also  mxs_power_enable_4p2() should not be called if running from
battery. It switches VDDD and VDDA to LinReg mode and than turns off
the VDDIO DCDC supply. At this point the system resets.
If we run on battery this is no good idea because the LinRegs are
chained behind VDDIO and battery voltage seems not enough to power
the system from LinRegs.
Also is the power system already running on DCDC after BootROM hands
over to u-boot, so no sense in switching back to LinRegs.
---
 arch/arm/cpu/arm926ejs/mxs/spl_power_init.c |    6 ------
 1 file changed, 6 deletions(-)

diff --git a/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c b/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c
index d25019a..0cbb6c4 100644
--- a/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c
+++ b/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c
@@ -237,9 +237,6 @@ static void mxs_src_power_init(void)
 			POWER_LOOPCTRL_RCSCALE_THRESH |
 			POWER_LOOPCTRL_EN_RCSCALE_8X);
 
-	clrsetbits_le32(&power_regs->hw_power_minpwr,
-			POWER_MINPWR_HALFFETS, POWER_MINPWR_DOUBLE_FETS);
-
 	/* 5V to battery handoff ... FIXME */
 	setbits_le32(&power_regs->hw_power_5vctrl, POWER_5VCTRL_DCDC_XFER);
 	early_delay(30);
@@ -631,8 +628,6 @@ static void mxs_batt_boot(void)
 
 	writel(POWER_CTRL_ENIRQ_DCDC4P2_BO, &power_regs->hw_power_ctrl_clr);
 
-	clrsetbits_le32(&power_regs->hw_power_minpwr,
-			POWER_MINPWR_HALFFETS, POWER_MINPWR_DOUBLE_FETS);
 
 	mxs_power_set_linreg();
 
@@ -655,7 +650,6 @@ static void mxs_batt_boot(void)
 		POWER_5VCTRL_CHARGE_4P2_ILIMIT_MASK,
 		0x8 << POWER_5VCTRL_CHARGE_4P2_ILIMIT_OFFSET);
 
-	mxs_power_enable_4p2();
 }
 
 /**
-- 
1.7.10.4

[U-Boot] [PATCH] mxs: fixed battery boot on imx233-olinuxino-micro

[Marek Vasut]

On Wednesday, May 21, 2014 at 04:01:55 AM, Peter Schumann wrote:
> This patch makes it possible to boot from battery on olinuxino Boards
> from Olimex.
> 
> We should not set DOUBLE_FETS in HW_POWER_MINPWR

Please explain how you arrived to this conclusion.

> , it makes my system
> reset with in seconds while running on battery power.
>
> Also  mxs_power_enable_4p2() should not be called if running from
> battery. It switches VDDD and VDDA to LinReg mode and than turns off
> the VDDIO DCDC supply. At this point the system resets.

This has been tested on i.MX28 , can you please check what the differences are 
between these two chips and why it works only on one of them ?

> If we run on battery this is no good idea because the LinRegs are
> chained behind VDDIO and battery voltage seems not enough to power
> the system from LinRegs.
> Also is the power system already running on DCDC after BootROM hands
> over to u-boot, so no sense in switching back to LinRegs.

The BootROM never hands over to U-Boot, so this really makes no sense. Can you 
please explain ? The BootROM handles over to U-Boot SPL, which configures the 
power block.

Also, I find it a very bad idea to depend on the BootROM to actually start the 
DCDC converter. I don't think we can universally say the DCDC converter is 
running when entering U-Boot SPL. I also don't think we can even depend on the 
power block configuration when exiting the BootROM -- for example in JTAG Boot 
Mode, the BootROM halts early in the boot process and will likely not configure 
anything with regards to the power block.

[...]

THanks!

Best regards,
Marek Vasut

[U-Boot] [PATCH] mxs: fixed battery boot on imx233-olinuxino-micro

[Peter Schumann]

Am 24.05.2014 12:44, schrieb Marek Vasut:

> 
> Please explain how you arrived to this conclusion.
> 
Hello Marek,

I started writing an powerblock driver for the i.MX233 to use the imx233
olimex board with a battery.
Short time (instant up to 90 seconds) after the 5v to battery handoff
the system reseted.
The system was running on DCDC prior to the handoff. I suspected that
some of the power rails where droping and trigger
hardware brownouts. But this was not the case. The DCDC got shutdown and
some ms after that the rails begun to drop.
I have some scope pic of this happening i it is of interest.

I than tried out some random bits in the MINPWR register and the reset
problem was gone. Than I track down it to this 1 bit causing the
instability.
> 
> This has been tested on i.MX28 , can you please check what the differences are 
> between these two chips and why it works only on one of them ?
> 

[U-Boot] [PATCH] mxs: fixed battery boot on imx233-olinuxino-micro

[Marek Vasut]

On Wednesday, May 21, 2014 at 04:01:55 AM, Peter Schumann wrote:
> This patch makes it possible to boot from battery on olinuxino Boards
> from Olimex.
> 
> We should not set DOUBLE_FETS in HW_POWER_MINPWR, it makes my system
> reset with in seconds while running on battery power.
> 
> Also  mxs_power_enable_4p2() should not be called if running from
> battery. It switches VDDD and VDDA to LinReg mode and than turns off
> the VDDIO DCDC supply. At this point the system resets.
> If we run on battery this is no good idea because the LinRegs are
> chained behind VDDIO and battery voltage seems not enough to power
> the system from LinRegs.
> Also is the power system already running on DCDC after BootROM hands
> over to u-boot, so no sense in switching back to LinRegs.

Sorry for the late reply, I'm somewhat congested recently. In the meantime, I 
was not able to test this yet. But you're missing Signed-off-by: line, can you 
please re-send this with a proper SoB line [1] ?

[1] http://www.denx.de/wiki/U-Boot/Patches#General_Patch_Submission_Rules

Thanks

Best regards,
Marek Vasut

[U-Boot] [PATCH] mxs: fixed battery boot on imx233-olinuxino-micro

[Marek Vasut]

On Friday, June 06, 2014 at 12:18:09 AM, Marek Vasut wrote:
> On Wednesday, May 21, 2014 at 04:01:55 AM, Peter Schumann wrote:
> > This patch makes it possible to boot from battery on olinuxino Boards
> > from Olimex.
> > 
> > We should not set DOUBLE_FETS in HW_POWER_MINPWR, it makes my system
> > reset with in seconds while running on battery power.
> > 
> > Also  mxs_power_enable_4p2() should not be called if running from
> > battery. It switches VDDD and VDDA to LinReg mode and than turns off
> > the VDDIO DCDC supply. At this point the system resets.
> > If we run on battery this is no good idea because the LinRegs are
> > chained behind VDDIO and battery voltage seems not enough to power
> > the system from LinRegs.
> > Also is the power system already running on DCDC after BootROM hands
> > over to u-boot, so no sense in switching back to LinRegs.
> 
> Sorry for the late reply, I'm somewhat congested recently. In the meantime,
> I was not able to test this yet. But you're missing Signed-off-by: line,
> can you please re-send this with a proper SoB line [1] ?
> 
> [1] http://www.denx.de/wiki/U-Boot/Patches#General_Patch_Submission_Rules

Bump?

Best regards,
Marek Vasut

[U-Boot] [PATCH] mxs: fixed battery boot on imx233-olinuxino-micro

[Peter Schumann]

> 
> Bump?
> 
> Best regards,
> Marek Vasut
> 
Hi Marek,

I am occupied with work at the moment. I will get it done at the weekend.

Best regards,
Peter Schumann

[U-Boot] [PATCH] mxs: fixed battery boot on imx233-olinuxino-micro

[Marek Vasut]

On Friday, June 13, 2014 at 09:36:51 AM, Peter Schumann wrote:
> > Bump?
> > 
> > Best regards,
> > Marek Vasut
> 
> Hi Marek,
> 
> I am occupied with work at the moment. I will get it done at the weekend.

Thanks!

Best regards,
Marek Vasut

[U-Boot] [PATCH v2] mxs: fixed battery boot on imx233-olinuxino-micro

[Peter Schumann]

This patch makes it possible to boot from battery on olinuxino Boards
from Olimex.

We should not set DOUBLE_FETS in HW_POWER_MINPWR, it makes my system
reset with in seconds while running on battery power.

Also  mxs_power_enable_4p2() should not be called if running from
battery. It switches VDDD and VDDA to LinReg mode and than turns off
the VDDIO DCDC supply. At this point the system resets.
If we run on battery this is no good idea because the LinRegs are
chained behind VDDIO and battery voltage seems not enough to power
the system from LinRegs.
Also is the power system already running on DCDC after BootROM hands
over to u-boot, so no sense in switching back to LinRegs.

Signed-off-by: Peter Schumann <peter.schumann@jeepxj.de>
---
 arch/arm/cpu/arm926ejs/mxs/spl_power_init.c |    6 ------
 1 file changed, 6 deletions(-)

diff --git a/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c b/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c
index d25019a..0cbb6c4 100644
--- a/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c
+++ b/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c
@@ -237,9 +237,6 @@ static void mxs_src_power_init(void)
 			POWER_LOOPCTRL_RCSCALE_THRESH |
 			POWER_LOOPCTRL_EN_RCSCALE_8X);
 
-	clrsetbits_le32(&power_regs->hw_power_minpwr,
-			POWER_MINPWR_HALFFETS, POWER_MINPWR_DOUBLE_FETS);
-
 	/* 5V to battery handoff ... FIXME */
 	setbits_le32(&power_regs->hw_power_5vctrl, POWER_5VCTRL_DCDC_XFER);
 	early_delay(30);
@@ -631,8 +628,6 @@ static void mxs_batt_boot(void)
 
 	writel(POWER_CTRL_ENIRQ_DCDC4P2_BO, &power_regs->hw_power_ctrl_clr);
 
-	clrsetbits_le32(&power_regs->hw_power_minpwr,
-			POWER_MINPWR_HALFFETS, POWER_MINPWR_DOUBLE_FETS);
 
 	mxs_power_set_linreg();
 
@@ -655,7 +650,6 @@ static void mxs_batt_boot(void)
 		POWER_5VCTRL_CHARGE_4P2_ILIMIT_MASK,
 		0x8 << POWER_5VCTRL_CHARGE_4P2_ILIMIT_OFFSET);
 
-	mxs_power_enable_4p2();
 }
 
 /**
-- 
1.7.10.4

[U-Boot] [PATCH v2] mxs: fixed battery boot on imx233-olinuxino-micro

[Marek Vasut]

On Sunday, June 15, 2014 at 03:11:56 PM, Peter Schumann wrote:
> This patch makes it possible to boot from battery on olinuxino Boards
> from Olimex.
> 
> We should not set DOUBLE_FETS in HW_POWER_MINPWR, it makes my system
> reset with in seconds while running on battery power.
> 
> Also  mxs_power_enable_4p2() should not be called if running from
> battery. It switches VDDD and VDDA to LinReg mode and than turns off
> the VDDIO DCDC supply. At this point the system resets.
> If we run on battery this is no good idea because the LinRegs are
> chained behind VDDIO and battery voltage seems not enough to power
> the system from LinRegs.
> Also is the power system already running on DCDC after BootROM hands
> over to u-boot, so no sense in switching back to LinRegs.
> 
> Signed-off-by: Peter Schumann <peter.schumann@jeepxj.de>

+CC Fabio, I'd like to see his take on this too.

Best regards,
Marek Vasut

[U-Boot] [PATCH v2] mxs: fixed battery boot on imx233-olinuxino-micro

[Marek Vasut]

On Tuesday, June 17, 2014 at 12:18:55 AM, Marek Vasut wrote:
> On Sunday, June 15, 2014 at 03:11:56 PM, Peter Schumann wrote:
> > This patch makes it possible to boot from battery on olinuxino Boards
> > from Olimex.
> > 
> > We should not set DOUBLE_FETS in HW_POWER_MINPWR, it makes my system
> > reset with in seconds while running on battery power.
> > 
> > Also  mxs_power_enable_4p2() should not be called if running from
> > battery. It switches VDDD and VDDA to LinReg mode and than turns off
> > the VDDIO DCDC supply. At this point the system resets.
> > If we run on battery this is no good idea because the LinRegs are
> > chained behind VDDIO and battery voltage seems not enough to power
> > the system from LinRegs.
> > Also is the power system already running on DCDC after BootROM hands
> > over to u-boot, so no sense in switching back to LinRegs.
> > 
> > Signed-off-by: Peter Schumann <peter.schumann@jeepxj.de>
> 
> +CC Fabio, I'd like to see his take on this too.

Reviewed-by: Marek Vasut <marex@denx.de>

I'd like to get this merged after 2014.07 though, so it can get some proper 
testing. We're too late in the -rc cycle anyway ...

Best regards,
Marek Vasut

[U-Boot] [PATCH v2] mxs: fixed battery boot on imx233-olinuxino-micro

[Stefano Babic]

Hi peter,

On 17/06/2014 00:19, Marek Vasut wrote:
> On Tuesday, June 17, 2014 at 12:18:55 AM, Marek Vasut wrote:
>> On Sunday, June 15, 2014 at 03:11:56 PM, Peter Schumann wrote:
>>> This patch makes it possible to boot from battery on olinuxino Boards
>>> from Olimex.
>>>
>>> We should not set DOUBLE_FETS in HW_POWER_MINPWR, it makes my system
>>> reset with in seconds while running on battery power.
>>>
>>> Also  mxs_power_enable_4p2() should not be called if running from
>>> battery. It switches VDDD and VDDA to LinReg mode and than turns off
>>> the VDDIO DCDC supply. At this point the system resets.
>>> If we run on battery this is no good idea because the LinRegs are
>>> chained behind VDDIO and battery voltage seems not enough to power
>>> the system from LinRegs.
>>> Also is the power system already running on DCDC after BootROM hands
>>> over to u-boot, so no sense in switching back to LinRegs.
>>>
>>> Signed-off-by: Peter Schumann <peter.schumann@jeepxj.de>
>>
>> +CC Fabio, I'd like to see his take on this too.
> 
> Reviewed-by: Marek Vasut <marex@denx.de>
> 
> I'd like to get this merged after 2014.07 though, so it can get some proper 
> testing. We're too late in the -rc cycle anyway ...
> 

Agree. Reason is that this change is for all boards, and without a
proper testing I will avoid to merge it in the release.

Best regards,
Stefano Babic



-- 
=====================================================================
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-53 Fax: +49-8142-66989-80 Email: sbabic at denx.de
=====================================================================

[U-Boot] [PATCH v2] mxs: fixed battery boot on imx233-olinuxino-micro

[Peter Schumann]

Am 17.06.2014 18:00, schrieb Stefano Babic:
> Hi peter,
> ...
> On 17/06/2014 00:19, Marek Vasut wrote:
> Agree. Reason is that this change is for all boards, and without a
> proper testing I will avoid to merge it in the release.
> 
> Best regards,
> Stefano Babic
> 
> 
> 

Hi Stefano,

I've only the imx233 olimex board for testing. The DOUBLE_FETS switch in
HW_POWER_MINPWR is some thing were maybe problems emerge.

I have very little load on the powerrails (imx233 + DRAM), so maybe with
more current demand DOUBLE_FETS is working OK and even more may require
it to be set.

The DOUBLE_FETS and HALF_FETS switches control the switching MOSFET size
in the DCDC Converter. My assumption is that if we have a to big FET
setting and to low current demand we trigger some failsafe mechanism.
Because the required "on time" of the FET is smaller than the minimum
possible "on time" of then DCDC FET control logic.

I don't have an easy way to test this assumption without an adjustable load.

The other change regarding mxs_power_enable_4p2() should be relatively
safe to apply.

If I can help with some testing let me know.

Best regards,
Peter Schumann

[U-Boot] [PATCH v2] mxs: fixed battery boot on imx233-olinuxino-micro

[Marek Vasut]

On Wednesday, June 18, 2014 at 08:17:05 PM, Peter Schumann wrote:
> Am 17.06.2014 18:00, schrieb Stefano Babic:
> > Hi peter,
> > ...
> > On 17/06/2014 00:19, Marek Vasut wrote:
> > Agree. Reason is that this change is for all boards, and without a
> > proper testing I will avoid to merge it in the release.
> > 
> > Best regards,
> > Stefano Babic
> 
> Hi Stefano,
> 
> I've only the imx233 olimex board for testing. The DOUBLE_FETS switch in
> HW_POWER_MINPWR is some thing were maybe problems emerge.
> 
> I have very little load on the powerrails (imx233 + DRAM), so maybe with
> more current demand DOUBLE_FETS is working OK and even more may require
> it to be set.

If that was the case, the problem would manifest even when _not_ booting from 
battery-only supply, correct?

> The DOUBLE_FETS and HALF_FETS switches control the switching MOSFET size
> in the DCDC Converter. My assumption is that if we have a to big FET
> setting and to low current demand we trigger some failsafe mechanism.
> Because the required "on time" of the FET is smaller than the minimum
> possible "on time" of then DCDC FET control logic.
> 
> I don't have an easy way to test this assumption without an adjustable
> load.
> 
> The other change regarding mxs_power_enable_4p2() should be relatively
> safe to apply.

This breaks booting from battery on MX28 for some reason. The DC converter is 
not enabled at that point.

Best regards,
Marek Vasut

[U-Boot] [PATCH v2] mxs: fixed battery boot on imx233-olinuxino-micro

[Stefano Babic]

Hi Peter, hi Marek,

On 19/06/2014 09:12, Marek Vasut wrote:
> On Wednesday, June 18, 2014 at 08:17:05 PM, Peter Schumann wrote:
>> Am 17.06.2014 18:00, schrieb Stefano Babic:
>>> Hi peter,
>>> ...
>>> On 17/06/2014 00:19, Marek Vasut wrote:
>>> Agree. Reason is that this change is for all boards, and without a
>>> proper testing I will avoid to merge it in the release.
>>>
>>> Best regards,
>>> Stefano Babic
>>
>> Hi Stefano,
>>
>> I've only the imx233 olimex board for testing. The DOUBLE_FETS switch in
>> HW_POWER_MINPWR is some thing were maybe problems emerge.
>>
>> I have very little load on the powerrails (imx233 + DRAM), so maybe with
>> more current demand DOUBLE_FETS is working OK and even more may require
>> it to be set.
> 
> If that was the case, the problem would manifest even when _not_ booting from 
> battery-only supply, correct?
> 
>> The DOUBLE_FETS and HALF_FETS switches control the switching MOSFET size
>> in the DCDC Converter. My assumption is that if we have a to big FET
>> setting and to low current demand we trigger some failsafe mechanism.
>> Because the required "on time" of the FET is smaller than the minimum
>> possible "on time" of then DCDC FET control logic.
>>
>> I don't have an easy way to test this assumption without an adjustable
>> load.
>>
>> The other change regarding mxs_power_enable_4p2() should be relatively
>> safe to apply.
> 
> This breaks booting from battery on MX28 for some reason. The DC converter is 
> not enabled at that point.

As I have not (yet) forgotten this patch: current status is that mx28 is
broken after applying this patch. I set the status as "Changes
requested" and it will be not applied.

Best regards,
Stefano Babic




-- 
=====================================================================
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-53 Fax: +49-8142-66989-80 Email: sbabic at denx.de
=====================================================================