arm: mxs: Provide Kconfig option to to not use VDD5V as IMX28 PMU source

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@denx.de>

diff --git a/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c b/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c
index c33170f06d350f778f017b49c6b1dd95f56f294f..9965810ac271eabf1d6db1bf9527c628049e470d 100644 (file)
--- 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)
                POWER_5VCTRL_CHARGE_4P2_ILIMIT_MASK,
                0x8 << POWER_5VCTRL_CHARGE_4P2_ILIMIT_OFFSET);
 
+       if (CONFIG_IS_ENABLED(MXS_PMU_MINIMAL_VDD5V_CURRENT))
+               setbits_le32(&power_regs->hw_power_5vctrl,
+                            POWER_5VCTRL_ILIMIT_EQ_ZERO);
+
        mxs_power_enable_4p2();
 }
 

diff --git a/arch/arm/mach-imx/mxs/Kconfig b/arch/arm/mach-imx/mxs/Kconfig
index b2026a3758a5d921849550e982e3437e3f47ed8d..3232b0fb677ccda4760f85abaa89e3546f492f4d 100644 (file)
--- a/arch/arm/mach-imx/mxs/Kconfig
+++ b/arch/arm/mach-imx/mxs/Kconfig
@@ -51,6 +51,14 @@ endchoice
 config SYS_SOC
        default "mxs"
 
+config SPL_MXS_PMU_MINIMAL_VDD5V_CURRENT
+       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"