[PATCHv5 2/5] ARM: dts: Odroid-XU3 Enable TMU at Exynos5422 base

Krzysztof Kozlowski k.kozlowski at samsung.com
Sat May 23 21:33:38 PDT 2015


2015-05-24 2:35 GMT+09:00 Anand Moon <linux.amoon at gmail.com>:
> Hi Krzysztof,
>
> I did some debugging on the this using powerdebug utility.
> Using  LDO7 to control TMU seams to me correct option compared to BUCK3.
>
> Setting LDO7 to control TMU I observed  following output on powerdebug.
> I observed that the power drawn by the board on Odroid show is much
> less compare to BUCK3 on the same setup.
> I can see the HDMI output on Odroid-V2 display screen.
> I have done some stress testing on this configuration and It worked correctly.
>
> Powerdebug output using LDO7
> ---------------------------------------------------------------------------------------------------------------
> PowerDebug 0.7.3     Clocks  Regulators  Sensors  Gpio
> Name        Status      State       Type        Users       Microvolts
>  Min u-volts Max u-volts
> phy                                             0           0
>  0           0
> phy                                             0           0
>  0           0
> vdd_ldo1                enabled     voltage     0           1000000
>  1000000     1000000
> LDO1                                            0           0
>  0           0
> LDO2                    enabled     voltage     0           1800000
>  0           0
> vdd_ldo3                enabled     voltage     0           1800000
>  1800000     1800000
> LDO3                                            0           0
>  0           0
> LDO4                    enabled     voltage     0           1800000
>  0           0
> vdd_ldo5                enabled     voltage     0           1800000
>  1800000     1800000
> LDO5                                            0           0
>  0           0
> vdd_ldo6                enabled     voltage     0           1000000
>  1000000     1000000
> hdmi        okay                                0           0
>  0           0
> hdmi        okay                                0           0
>  0           0
> LDO6                                            0           0
>  0           0
> vdd_ldo7                enabled     voltage     0           1800000
>  1800000     1800000
> hdmi        okay                                0           0
>  0           0
> tmu         okay                                0           0
>  0           0
> tmu         okay                                0           0
>  0           0
> tmu         okay                                0           0
>  0           0
> tmu         okay                                0           0
>  0           0
> tmu         okay                                0           0
>  0           0
> LDO7                                            0           0
>  0           0
> vdd_ldo8                enabled     voltage     0           1800000
>  1800000     1800000
> LDO8                                            0           0
>  0           0
> vdd_ldo9                enabled     voltage     0           3000000
>  3000000     3000000
> LDO9                                            0           0
>  0           0
>
> Powerdebug output using BUCK3.
> --------------------------------------------------------------------------------------------------------------------------
> PowerDebug 0.7.3     Clocks  Regulators  Sensors  Gpio
> Name        Status      State       Type        Users       Microvolts
>  Min u-volts Max u-volts
> LDO21                   disabled    voltage     0           1800000
>  0           0
> LDO22                   disabled    voltage     0           1200000
>  0           0
> LDO23                   enabled     voltage     0           1100000
>  0           0
> tsp_io                  enabled     voltage     0           2800000
>  2800000     2800000
> LDO24                                           0           0
>  0           0
> LDO25                   disabled    voltage     0           1800000
>  0           0
> vdd_ldo26               enabled     voltage     0           3000000
>  3000000     3000000
> LDO26                                           0           0
>  0           0
> LDO27                   enabled     voltage     0           1000000
>  0           0
> LDO28                   disabled    voltage     0           3300000
>  0           0
> LDO29                   disabled    voltage     0           1800000
>  0           0
> LDO30                   disabled    voltage     0           1800000
>  0           0
> LDO31                   disabled    voltage     0           1800000
>  0           0
> LDO32                   disabled    voltage     0           1800000
>  0           0
> LDO33                   disabled    voltage     0           1800000
>  0           0
> LDO34                   disabled    voltage     0           3000000
>  0           0
> LDO35                   disabled    voltage     0           1600000
>  0           0
> LDO36                   disabled    voltage     0           1800000
>  0           0
> LDO37                   disabled    voltage     0           1800000
>  0           0
> LDO38                   disabled    voltage     0           2800000
>  0           0
> vdd_mif                 enabled     voltage     0           1100000
>  800000      1300000
> BUCK1                                           0           0
>  0           0
> vdd_arm                 enabled     voltage     0           1000000
>  800000      1500000
> BUCK2                                           0           0
>  0           0
> vdd_int                 enabled     voltage     0           1000000
>  800000      1400000
> tmu         okay                                0           0
>  0           0
> tmu         okay                                0           0
>  0           0
> tmu         okay                                0           0
>  0           0
> tmu         okay                                0           0
>  0           0
> tmu         okay                                0           0
>  0           0
> BUCK3                                           0           0
>  0           0
> vdd_g3d                 enabled     voltage     0           1000000
>  800000      1400000
> BUCK4                                           0           0
>  0           0
> vdd_mem                 enabled     voltage     0           1200000
>  800000      1400000
> BUCK5                                           0           0
>  0           0
> vdd_kfc                 enabled     voltage     0           1025000
>  800000      1500000
>
> So I would like to go with LDO7.
>
> Please share your thoughts.

I don't understand how grepping through /sys/class/regulator helps in
making this decision. I just don't get it. Can you please explain it
to me?

Best regards,
Krzysztof



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