[PATCH 1/5] arm: mxs: Provide Kconfig option to to not use VDD5V as IMX28 PMU source

Lukasz Majewski lukma at denx.de
Tue May 9 16:32:39 CEST 2023

This option sets the current limit for 5V source to zero, so all
the PMU outputs are primarily powered from battery source (DCDC_BAT).

This option may be set on systems, where the 5V is NOT supposed to be
in any scenario powering the system - for example on systems where
DCDC_BAT is connected to fixed and regulated 4.2V source (so the
"battery" is not present).

Signed-off-by: Lukasz Majewski <lukma at denx.de>
 arch/arm/cpu/arm926ejs/mxs/spl_power_init.c | 4 ++++
 arch/arm/mach-imx/mxs/Kconfig               | 8 ++++++++
 2 files changed, 12 insertions(+)

diff --git a/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c b/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c
index c33170f06d..9965810ac2 100644
--- a/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c
+++ b/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c
@@ -752,6 +752,10 @@ static void mxs_batt_boot(void)
+		setbits_le32(&power_regs->hw_power_5vctrl,
diff --git a/arch/arm/mach-imx/mxs/Kconfig b/arch/arm/mach-imx/mxs/Kconfig
index b2026a3758..3232b0fb67 100644
--- a/arch/arm/mach-imx/mxs/Kconfig
+++ b/arch/arm/mach-imx/mxs/Kconfig
@@ -51,6 +51,14 @@ endchoice
 config SYS_SOC
 	default "mxs"
+	bool "Force minimal current draw from VDD5V by MX28 PMU"
+	default n
+	help
+	  After setting this option, the current drawn from VDD5V
+	  by the PMU is reduced to zero - the DCDC_BATT is used as
+	  the main power source for PMU.
 source "board/freescale/mx28evk/Kconfig"
 source "board/liebherr/xea/Kconfig"

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