2015-09-01 11:10 GMT+09:00 Andreas Dannenberg <dannenberg@xxxxxx>:
> Extend the bq24257 charger's device tree documentation to cover the
> bq24250 and bq24257 devices as well as recent feature additions.
>
> Signed-off-by: Andreas Dannenberg <dannenberg@xxxxxx>
> ---
> .../devicetree/bindings/power/bq24257.txt | 59 ++++++++++++++++++++--
> 1 file changed, 55 insertions(+), 4 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/power/bq24257.txt b/Documentation/devicetree/bindings/power/bq24257.txt
> index 5c9d394..36b115c 100644
> --- a/Documentation/devicetree/bindings/power/bq24257.txt
> +++ b/Documentation/devicetree/bindings/power/bq24257.txt
> @@ -2,20 +2,71 @@ Binding for TI bq24257 Li-Ion Charger
>
> Required properties:
> - compatible: Should contain one of the following:
> + * "ti,bq24250"
> + * "ti,bq24251"
> * "ti,bq24257"
> -- reg: integer, i2c address of the device.
> +- reg: integer, i2c address of the device.
> +- stat-gpio: GPIO used for the devices STAT_IN pin. Alternatively the pin can
> + also be defined through the standard interrupt definition properties (see
> + optional properties section below). Only use one method.
Preferred suffix should be "gpios":
Documentation/devicetree/bindings/gpio/gpio.txt
> +- pg-gpio: GPIO used for the device PG (Power Good) pin. This pin is not
> + available on all devices and therefore only required on applicable devices.
> + However it is also possible to explicitly disable the use of this pin
> + through the optional property "ti,pg-gpio-disable" (see below) if desired.
> + In this case the "pg-gpio" property is no longer required.
> - ti,battery-regulation-voltage: integer, maximum charging voltage in uV.
> -- ti,charge-current: integer, maximum charging current in uA.
> -- ti,termination-current: integer, charge will be terminated when current in
> - constant-voltage phase drops below this value (in uA).
> +- ti,charge-current: integer, maximum charging current in uA.
> +- ti,termination-current: integer, charge will be terminated when current in
> + constant-voltage phase drops below this value (in uA).
> +
> +Optional properties:
> +- ti,in-ilimit-autoset-disable: If this boolean property is present it disables
I thought "ilimit" is a typo but apparently not :) . The names of this
property and "ti,in-limit-current" below are quite obfuscated. I am
thinking about different names but first I would like to understand
the feature: what do you mean by "automatic setting of the input
current limit"? Like adjusting the limit of possible current to given
charger type?
> + the automatic setting of the input current limit. This property is also set
> + implicitly on devices without charger type detection. If this property is
> + provided the input current limit should be set manually through
> + "ti,in-limit-current".
> +- ti,in-limit-current: The maximum current to be drawn from the charger's input
> + (in uA). Use this for devices that don't have charger type detection or if
> + you have have set "ti,in-ilimit-autoset-disable".
> +- ti,vovp-voltage: Configures the over voltage protection voltage (in uV).
> +- ti,vindpm-voltage: Configures the threshold input voltage for the dynamic
> + power path management (in uV).
I think the leading 'v' could be removed, so "ti,ovp-voltage" and
"ti,in-dpm-voltage"?
> +- ti,pg-gpio-disable: If this boolean property is provided a software-based
> + approach for power good determination is used. Note that the PG-pin based
> + approach is generally preferable.
That's confusing. If someone does not want to use pg-gpio then he
could just skip the "pg-gpio" property?
> +- ti,timer-2x-enable: If this boolean property is provided the device's safety
> + timer is extended by a factor of two.
Boolean properties like this have disadvantage - they cannot be
overridden. Also extending them is difficult (e.g. for some next
device the timer could have value of 4). Usually it is better to have
a value-based property with "0" meaning default or disabled.
Also please look at existing bindings:
$ git grep "ti," Documentation/devicetree/bindings/power
Maybe you could reuse some? Each of these existing and new bindings
are made generic (not device specific) so they should be reused.
Best regards,
Krzysztof
> +- interrupt-parent: Should be the phandle for the interrupt controller. Use in
> + conjunction with "interrupts" and only in case "stat-gpio" is not used.
> +- interrupts: Interrupt mapping for GPIO IRQ (configure for both edges). Use in
> + conjunction with "interrupt-parent" and only in case "stat-gpio" is not
> + used.
>
> Example:
>
> bq24257 {
> compatible = "ti,bq24257";
> reg = <0x6a>;
> + stat-gpio = <&gpio1 16 GPIO_ACTIVE_HIGH>;
> + pg-gpio = <&gpio1 28 GPIO_ACTIVE_HIGH>;
>
> ti,battery-regulation-voltage = <4200000>;
> ti,charge-current = <1000000>;
> ti,termination-current = <50000>;
> };
> +
> +Example:
> +
> +bq24250 {
> + compatible = "ti,bq24250";
> + reg = <0x6a>;
> + interrupt-parent = <&gpio1>;
> + interrupts = <16 IRQ_TYPE_EDGE_BOTH>;
> +
> + ti,battery-regulation-voltage = <4200000>;
> + ti,charge-current = <500000>;
> + ti,termination-current = <50000>;
> + ti,in-limit-current = <900000>;
> + ti,vovp-voltage = <9500000>;
> + ti,vindpm-voltage = <4440000>;
> +};
> --
> 1.9.1
>
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