Add startup time to LDO regulators of S2MPS11 PMIC on Odroid XU3/XU4/HC1 family of boards to be sure the voltage is proper before relying on the regulator.
The datasheet for all the S2MPS1x family is inconsistent here and does not specify unambiguously the value of ramp delay for LDO. It mentions 30 mV/us in one timing diagram but then omits it completely in LDO regulator characteristics table (it is specified for bucks).
However the vendor kernels for Galaxy S5 and Odroid XU3 use values of 12 mV/us or 24 mV/us.
Without the ramp delay value the consumers do not wait for voltage settle after changing it. Although the proper value of ramp delay for LDOs is unknown, it seems safer to use at least some value from reference kernel than to leave it unset.
Signed-off-by: Krzysztof Kozlowski krzk@kernel.org --- arch/arm/dts/exynos5422-odroidxu3.dts | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+)
diff --git a/arch/arm/dts/exynos5422-odroidxu3.dts b/arch/arm/dts/exynos5422-odroidxu3.dts index 9dfae90667cf..04ecc404f907 100644 --- a/arch/arm/dts/exynos5422-odroidxu3.dts +++ b/arch/arm/dts/exynos5422-odroidxu3.dts @@ -45,6 +45,7 @@ regulator-name = "vdd_ldo1"; regulator-min-microvolt = <1000000>; regulator-max-microvolt = <1000000>; + regulator-ramp-delay = <12000>; regulator-always-on; };
@@ -52,18 +53,21 @@ regulator-name = "vddq_mmc0"; regulator-min-microvolt = <1800000>; regulator-max-microvolt = <1800000>; + regulator-ramp-delay = <12000>; };
ldo4_reg: LDO4 { regulator-name = "vdd_adc"; regulator-min-microvolt = <1800000>; regulator-max-microvolt = <1800000>; + regulator-ramp-delay = <12000>; };
ldo5_reg: LDO5 { regulator-name = "vdd_ldo5"; regulator-min-microvolt = <1800000>; regulator-max-microvolt = <1800000>; + regulator-ramp-delay = <12000>; regulator-always-on; };
@@ -71,6 +75,7 @@ regulator-name = "vdd_ldo6"; regulator-min-microvolt = <1000000>; regulator-max-microvolt = <1000000>; + regulator-ramp-delay = <12000>; regulator-always-on; };
@@ -78,6 +83,7 @@ regulator-name = "vdd_ldo7"; regulator-min-microvolt = <1800000>; regulator-max-microvolt = <1800000>; + regulator-ramp-delay = <12000>; regulator-always-on; };
@@ -85,6 +91,7 @@ regulator-name = "vdd_ldo8"; regulator-min-microvolt = <1800000>; regulator-max-microvolt = <1800000>; + regulator-ramp-delay = <12000>; regulator-always-on; };
@@ -92,6 +99,7 @@ regulator-name = "vdd_ldo9"; regulator-min-microvolt = <3000000>; regulator-max-microvolt = <3000000>; + regulator-ramp-delay = <12000>; regulator-always-on; };
@@ -99,6 +107,7 @@ regulator-name = "vdd_ldo10"; regulator-min-microvolt = <1800000>; regulator-max-microvolt = <1800000>; + regulator-ramp-delay = <12000>; regulator-always-on; };
@@ -106,6 +115,7 @@ regulator-name = "vdd_ldo11"; regulator-min-microvolt = <1000000>; regulator-max-microvolt = <1000000>; + regulator-ramp-delay = <12000>; regulator-always-on; };
@@ -113,6 +123,7 @@ regulator-name = "vdd_ldo12"; regulator-min-microvolt = <1800000>; regulator-max-microvolt = <1800000>; + regulator-ramp-delay = <12000>; regulator-always-on; };
@@ -120,12 +131,14 @@ regulator-name = "vddq_mmc2"; regulator-min-microvolt = <2800000>; regulator-max-microvolt = <2800000>; + regulator-ramp-delay = <12000>; };
ldo15_reg: LDO15 { regulator-name = "vdd_ldo15"; regulator-min-microvolt = <3300000>; regulator-max-microvolt = <3300000>; + regulator-ramp-delay = <12000>; regulator-always-on; };
@@ -133,6 +146,7 @@ regulator-name = "vdd_ldo16"; regulator-min-microvolt = <2200000>; regulator-max-microvolt = <2200000>; + regulator-ramp-delay = <12000>; regulator-always-on; };
@@ -140,6 +154,7 @@ regulator-name = "vdd_ldo17"; regulator-min-microvolt = <3300000>; regulator-max-microvolt = <3300000>; + regulator-ramp-delay = <12000>; regulator-always-on; };
@@ -147,18 +162,21 @@ regulator-name = "vdd_emmc_1V8"; regulator-min-microvolt = <1800000>; regulator-max-microvolt = <1800000>; + regulator-ramp-delay = <12000>; };
ldo19_reg: LDO19 { regulator-name = "vdd_sd"; regulator-min-microvolt = <2800000>; regulator-max-microvolt = <2800000>; + regulator-ramp-delay = <12000>; };
ldo24_reg: LDO24 { regulator-name = "tsp_io"; regulator-min-microvolt = <2800000>; regulator-max-microvolt = <2800000>; + regulator-ramp-delay = <12000>; regulator-always-on; };
@@ -166,6 +184,7 @@ regulator-name = "vdd_ldo26"; regulator-min-microvolt = <3000000>; regulator-max-microvolt = <3000000>; + regulator-ramp-delay = <12000>; regulator-always-on; };