10 Feb
2015
10 Feb
'15
12:57 p.m.
On 25/01/2015 02:07, Graeme Russ wrote:
Section 4.1.2 of Freescale Application Note AN4199 describes the configuration required to operate the mx28 from a 5V source without a battery.
This patch changes the behaviour of the dropout control of the DC-DC converter (refer to section 11.12.9 of the mx28 Application Processor Reference Manual - Document Number: MCIMX28RM, Rev 2, 08/2013) to the following:
- Always use 4P2 Linear Regulator if CONFIG_SYS_MXS_VDD5V_ONLY is defined
- Switch between 4P2 Linear Regulator and Battery, using whichever has the highest voltage if CONFIG_SYS_MXS_VDD5V_ONLY isnot set (this is the same as the pre-patch behaviour)
Signed-off-by: Graeme Russ gruss@tss-engineering.com Signed-off-by: Damien Gotfroi dgotfroi@greenwatch.be
Changes in v2
- Implemented Damien Gotfroi's simplified version
Changes in v3
- Updated commit message
- Explicitly use POWER_DCDC4P2_DROPOUT_CTRL_SRC_4P2 for the DCDC4P2_DROPOUT_CONFIG define (it is 0x0 so it make no functional difference)
Applied to u-boot-imx, thanks !
Best regards, Stefano Babic
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