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Nishanth Menon 3acb553439 OMAP4460: TPS Ensure SET1 is selected after voltage configuration 
TPS SET0/SET1 register is selected by a GPIO pin on OMAP4460 platforms.
Currently we control this pin with a mux configuration as part of
boot sequence.
Current configuration results in the following voltage waveform:
                           |---------------| (SET1 default 1.4V)
                           |               --------(programmed voltage)
                           | <- (This switch happens on mux7,pullup)
vdd_mpu(TPS)         -----/ (OPP boot voltage)
                                             --------- (programmed voltage)
vdd_core(TWL6030)    -----------------------/ (OPP boot voltage)
Problem 1)                |<----- Tx ------>|
   timing violation for a duration Tx close to few milliseconds.
Problem 2) voltage of MPU goes beyond spec for even the highest of MPU OPP.

By using GPIO as recommended as standard procedure by TI, the sequence
changes to:
                                  -------- (programmed voltage)
vdd_mpu(TPS)         ------------/ (Opp boot voltage)
                                   --------- (programmed voltage)
vdd_core(TWL6030)    -------------/ (OPP boot voltage)

NOTE: This does not attempt to address OMAP5 - Aneesh please confirm

Reported-by: Isabelle Gros <i-gros@ti.com>
Reported-by: Jerome Angeloni <j-angeloni@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
2012-05-15 08:31:22 +02:00
..
arm720t arm: Use common .lds file where possible 2012-03-30 07:43:47 +02:00
arm920t arm: Use common .lds file where possible 2012-03-30 07:43:47 +02:00
arm925t arm: Use common .lds file where possible 2012-03-30 07:43:47 +02:00
arm926ejs arm926ejs: add NXP LPC32x0 cpu series support 2012-05-15 08:31:21 +02:00
arm946es arm: Use common .lds file where possible 2012-03-30 07:43:47 +02:00
arm1136 ARM1136: MX35: Make asm routines volatile in cache ops 2012-04-16 14:53:59 +02:00
arm1176 arm: Use common .lds file where possible 2012-03-30 07:43:47 +02:00
arm_intcm arm: Use common .lds file where possible 2012-03-30 07:43:47 +02:00
armv7 OMAP4460: TPS Ensure SET1 is selected after voltage configuration 2012-05-15 08:31:22 +02:00
ixp IXP: Squash warnings in IXP NPE 2012-03-26 23:09:26 +02:00
lh7a40x arm: Use common .lds file where possible 2012-03-30 07:43:47 +02:00
pxa arm: Use common .lds file where possible 2012-03-30 07:43:47 +02:00
s3c44b0 arm: Use common .lds file where possible 2012-03-30 07:43:47 +02:00
sa1100 arm: Use common .lds file where possible 2012-03-30 07:43:47 +02:00
u-boot.lds arm: add a common .lds link script 2012-03-30 07:43:44 +02:00