From mboxrd@z Thu Jan 1 00:00:00 1970 From: bonbons@linux-vserver.org (Bruno =?UTF-8?B?UHLDqW1vbnQ=?=) Date: Mon, 3 Nov 2014 21:02:44 +0100 Subject: [RFC Patch 1/4] mfd: AXP20x: Add power supply bindings documentation In-Reply-To: <20141021191905.GR21108@lukather> References: <20141020221959.2f312906@neptune.home> <20141020223314.0484f795@neptune.home> <20141021101503.GE26842@x1> <20141021180916.432f02e1@neptune.home> <20141021191905.GR21108@lukather> Message-ID: <20141103210244.1425e0c7@neptune.home> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Maxime, On Tue, 21 October 2014 Maxime Ripard wrote: > On Tue, Oct 21, 2014 at 06:09:16PM +0200, Bruno Pr?mont wrote: > > On Tue, 21 October 2014 Lee Jones wrote: > > > On Mon, 20 Oct 2014, Bruno Pr?mont wrote: > > > > --- > > > > Note: the OCV values seem to have some defaults build into the > > > > PMIC though may need adjustment if the used battery has a different > > > > open circuit voltage curve. > > > > As far as understood (these values are set in vendor driver but not > > > > mentioned in chip documentation) they represent charge percentage > > > > for some predefined voltages. > > > > > > > > If prefixing these values with "x-power," is preferred the following > > > > patch should becomes a dependency: > > > > http://lists.infradead.org/pipermail/linux-arm-kernel/2014-June/267606.html > > > > and users in patch 2/4, 4/4 need adjusting. > > > > > > > > > > > > Documentation/devicetree/bindings/mfd/axp20x.txt | 20 + > > > > 1 files changed, 20 insertions(+), 0 deletion(-) > > > > > > > > diff --git a/Documentation/devicetree/bindings/mfd/axp20x.txt b/Documentation/devicetree/bindings/mfd/axp20x.txt > > > > index cc9e01b..8ea681c 100644 > > > > --- a/Documentation/devicetree/bindings/mfd/axp20x.txt > > > > +++ b/Documentation/devicetree/bindings/mfd/axp20x.txt > > > > @@ -28,6 +28,20 @@ Required properties: > > > > (range: 750-1875). Default: 1.5MHz > > > > > > > > Optional properties for DCDCs: > > > > +- backup: Settings for backup/RTC battery charger > > > > + (Voltage in ?V, current in ?A) > > > > + If not present, charger will be left untouched > > > > +- battery.ocv: OCV capacity curve points (16 data values) > > > > +- battery.resistance: internal battery resistance in m? > > > > + (defaults to 100m?) > > > > +- battery.capacity: Battery capacity in mAh > > > > + If this attribute is missing, charger will be disabled > > > > + unless there is a battery connected. > > > > +- battery.temp_sensor: Description of temperautre sensor, 3 values > > > > + - driver current (20?A, 40?A, 60?A or 80?A) > > > > + - low temperature warning level (in ?V) > > > > + - high temperature warning level (in ?V) > > > > + If missing, temperature sensor gets disabled > > > > - x-powers,dcdc-workmode: 1 for PWM mode, 0 for AUTO mode > > > > Default: AUTO mode > > > > > > > > @@ -49,6 +63,12 @@ axp209: pmic at 34 { > > > > ldo3in-supply = <&axp_ipsout_reg>; > > > > ldo5in-supply = <&axp_ipsout_reg>; > > > > > > > > + backup = <3000000 200>; > > > > + battery.ocv = <0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0>; > > > > + battery.resistance = <0>; > > > > + battery.capacity = <2000>; > > > > + battery.temp_sensor = <20 1000000 4000000>; > > > > > > Since when do we use '.'s in property names? > > > > I've not found guidelines on this, but whatever is the right way to > > name them, I'm open for suggestions. > > You can take a look at the ePAPR specs. Even if it's quite outdated, > it still puts you in the right mindset. There seems to be some kind of e-mail wall in front of this document. > That being said, since they are driver-specific properties, they > should be prefixed by the vendor name (here x-powers). > > And I think they all belong in a sub-node, just like what's been done > for the regulators. Doing something like this?: --- a/arch/arm/boot/dts/sun7i-a20-cubietruck.dts +++ b/arch/arm/boot/dts/sun7i-a20-cubietruck.dts @@ -126,9 +126,11 @@ interrupt-controller; #interrupt-cells = <1>; - backup = <3000000 200>; - battery.resistance = <100>; - battery.capacity = <2000>; + x-powers,backup = <3000000 200>; + battery: battery at 0 { + x-powers,resistance = <100>; + x-powers,capacity = <2000>; + }; }; }; What are the rules to define the label after the colon? Looking at the existing nodes it's either some address or a number... and then the following in driver code (also adjusting the other property names accessed)?: @@ -678,11 +677,11 @@ static int axp20x_battery_config(struct platform_device *pdev, if (ret) return ret; - np = of_node_get(axp20x->dev->of_node); + np = of_find_node_by_name(axp20x->dev->of_node, "battery"); if (!np) return -ENODEV; - ret = of_property_read_u32_array(np, "battery.ocv", ocv, 16); + ret = of_property_read_u32_array(np, "x-powers,ocv", ocv, 16); for (i = 0; ret == 0 && i < ARRAY_SIZE(ocv); i++) if (ocv[i] > 100) { dev_warn(&pdev->dev, "OCV[%d] %u > 100\n", i, ocv[i]); Bruno