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Commit 3692db3a authored by Laxman Dewangan's avatar Laxman Dewangan Committed by Mark Brown
Browse files

regulator: max8973: add support to configure ETR from DT 



The MAX8973/MAX77621 feature an Enhanced Transient Response(ETR)
circuit that is enabled through software. The enhanced transient
response reduces the voltage droop during large load steps by
temporarily allowing all three phases to fire in unison, slewing
total inductor current faster than would normally be possible if
all three phases continued to operate 120deg out of phase. The
enhanced transient response detector features two selectable
sensitivity settings, which select the output voltage slew rate
during load transients that triggers the ETR circuit. The sensitivity
of the ETR detector is set by the CKADV[1:0] bits in the CONTROL2
register.

Add support to configure the ETR through platform data from DT.
Update the DT binding document accordingly.

Signed-off-by: default avatarLaxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 127e1062

Documentation/devicetree/bindings/regulator/max8973-regulator.txt

+6 −0
Original line number Original line Diff line number Diff line
@@ -25,6 +25,12 @@ Optional properties: 
-maxim,enable-frequency-shift: boolean, enable 9% frequency shift.

-maxim,enable-frequency-shift: boolean, enable 9% frequency shift.

-maxim,enable-bias-control: boolean, enable bias control. By enabling this

-maxim,enable-bias-control: boolean, enable bias control. By enabling this

		startup delay can be reduce to 20us from 220us.

		startup delay can be reduce to 20us from 220us.

-maxim,enable-etr: boolean, enable Enhanced Transient Response.

-maxim,enable-high-etr-sensitivity: boolean, Enhanced transient response

		circuit is enabled and set for high sensitivity. If this

		property is available then etr will be enable default.



Enhanced transient response (ETR) will affect the configuration of CKADV.





Example:

Example:

drivers/regulator/max8973-regulator.c

+19 −0
Original line number Original line Diff line number Diff line
@@ -421,6 +421,8 @@ static struct max8973_regulator_platform_data *max8973_parse_dt( 
	struct device_node *np = dev->of_node;

	struct device_node *np = dev->of_node;

	int ret;

	int ret;

	u32 pval;

	u32 pval;

	bool etr_enable;

	bool etr_sensitivity_high;





	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);

	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);

	if (!pdata)

	if (!pdata)
@@ -452,6 +454,23 @@ static struct max8973_regulator_platform_data *max8973_parse_dt( 
	if (of_property_read_bool(np, "maxim,enable-bias-control"))

	if (of_property_read_bool(np, "maxim,enable-bias-control"))

		pdata->control_flags  |= MAX8973_CONTROL_BIAS_ENABLE;

		pdata->control_flags  |= MAX8973_CONTROL_BIAS_ENABLE;





	etr_enable = of_property_read_bool(np, "maxim,enable-etr");

	etr_sensitivity_high = of_property_read_bool(np,

				"maxim,enable-high-etr-sensitivity");

	if (etr_sensitivity_high)

		etr_enable = true;



	if (etr_enable) {

		if (etr_sensitivity_high)

			pdata->control_flags |=

				MAX8973_CONTROL_CLKADV_TRIP_75mV_PER_US;

		else

			pdata->control_flags |=

				MAX8973_CONTROL_CLKADV_TRIP_150mV_PER_US;

	} else {

		pdata->control_flags |= MAX8973_CONTROL_CLKADV_TRIP_DISABLED;

	}



	return pdata;

	return pdata;

}

}