Re: [PATCH V7 1/8] mfd: add device-tree binding doc for PMIC max77620/max20024

From: Lee Jones
Date: Tue Feb 09 2016 - 10:42:26 EST


On Sat, 30 Jan 2016, Laxman Dewangan wrote:

> The MAXIM PMIC MAX77620 and MAX20024 are power management IC
> which supports RTC, GPIO, DCDC/LDO regulators, interrupt,
> watchdog etc.
>
> Add DT binding document for the different functionality of
> this device.
>
> Signed-off-by: Laxman Dewangan <ldewangan@xxxxxxxxxx>
> Acked-by: Rob Herring <robh@xxxxxxxxxx>
> ---
> Changes from V1:
> - Added units in some of properties.
> - Change the boolean property to tristate type and detail some of
> properties.
>
> Change from V2:
> - added unit in period related dt property.
>
> Change from V3: None
> - Added Rob's ack.
>
> Changes from V4:
> - A- Provide more details in the dt binding doc.
> - Take care of fps nodes.
> - Split the submodule's DT binding doc on respective folder.
> - Drop the battery charger and low battery binding and related code as
> it need to go on power driver.
>
> Change from V5:
> - None
>
> Change from V6:
> -start the patch title with mfd instead of DT: mfd:
>
> Documentation/devicetree/bindings/mfd/max77620.txt | 118 +++++++++++++++++++++
> include/dt-bindings/mfd/max77620.h | 35 ++++++
> 2 files changed, 153 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/mfd/max77620.txt
> create mode 100644 include/dt-bindings/mfd/max77620.h
>
> diff --git a/Documentation/devicetree/bindings/mfd/max77620.txt b/Documentation/devicetree/bindings/mfd/max77620.txt
> new file mode 100644
> index 0000000..f258ce4
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mfd/max77620.txt
> @@ -0,0 +1,118 @@
> +MAX77620 Power management IC from Maxim Semiconductor.
> +
> +Required properties:
> +-------------------
> +- compatible: Must be one of
> + "maxim,max77620"
> + "maxim,max20024".
> +- reg: I2C device address.
> +
> +Optional properties:
> +-------------------
> +- interrupts: the interrupt on the parent the controller is
> + connected to

Nit: Sometimes you use full-stops and sometimes you don't.

> +- interrupt-controller: Marks the device node as an interrupt controller.
> +- #interrupt-cells: is <2> and their usage is compliant to the 2 cells
> + variant of <../interrupt-controller/interrupts.txt>
> + IRQ numbers for different interrupt source of MAX77620
> + are defined at dt-bindings/mfd/max77620.h.
> +
> +Optional subnodes and their properties:
> +=======================================
> +
> +Flexible power sequence configurations:
> +--------------------------------------
> +The PMIC has multiple control mode:

s/mode/modes/

> + Normal mode also called as active mode on which all step-down
> + regulators, all linear regulators, GPIOs, and the 32kHz
> + oscillator are in normal active mode.
> + sleep mode: Regulators/GPIOs/clock can go on OFF state based on

"can go on OFF state"?

> + their configurations.
> + Global Low power mode (GLPM): In this mode, step-down regulators, linear
> + regulators, and the 32kHz oscillator are in low-power modes.

Again, please standardise your formatting. Sometimes you use
uppercase characters, sometimes you don't. Sometimes you use ':'
after the mode, sometimes you don't. Etc.

I suggest the following format would read better:

Normal mode: Also called as active mode on which all step-down
regulators, all linear regulators, GPIOs, and the 32kHz
oscillator are in normal active mode.
Sleep mode: Regulators/GPIOs/clock can go on OFF state based on
their configurations.
Global Low Power mode: In GLPM, step-down regulators, linear
regulators, and the 32kHz oscillator are in low-power modes.

> + Different modes of regulators/clock/GPIOs are controlled by the their
> +FPS configurations. There is different configuration registers for each of
> +these resources. Typical configurations per resource are:
> + FPS source: Attach the resource to required FPS source. When
> + resources are attached to one of FPS source then
> + resournce can be enable/disable when related FPS

Have you used spell check? I suggest you do.

> + source gets the control signal for ON and OFF.
> + Power on slot: Slot number on which resource is ON once FPS source
> + get ON signal.

Can you find another way of explaining this please?

> + Power down slot Slot number on which resource is OFF once FPS source

Please read what you wrote to see if it makes sense before
submitting.

> + get OFF signal.
> +
> +There is three FPS source for resources called FPS0, FPS1 and FPS2. All

s/is/are/
s/source/sources/

> +resources need to attached to one of these FPS. It can alsoi be set

Please spell check the entire document.

> +FPS source to NONE, and on this case, it is completely controlled by

s/on/in/

> +the register control rather than external input control to PMIC.
> +
> +The configuration parameters of FPS is provided through subnode "fps"
> +and their child for FPS specific.
> +The node name for FPS child are defined as "fps0", "fps1", and "fps2" for
> +the FPS0, FPS1 and FPS2 respectively.
> +
> +There is need for different FPS configuration parameters based on system
> +state like when system state changed from active to suspend or active to
> +power off (shutdown).
> +
> +Optinal properties:
> +-------------------
> +-maxim,fps-control: u32, FPS control source like external control input
> + to PMIC i.e. EN0, EN1 or software (SW). The macros
> + are defined on dt-bindings/mfd/max77620.h for
> + different control source.
> + FPS_CONTROL_SRC_EN0 for PMIC external input EN0.
> + FPS_CONTROL_SRC_EN1 for PMIC external input EN1.
> + FPS_CONTROL_SRC_SW for software control.
> +
> +-maxim,shutdown-fps-time-period-us: u32, FPS time period in microseconds
> + when system enters to shutdown state.
> +-maxim,suspend-fps-time-period-us: u32, FPS time period in microseconds
> + when system enters to suspend state.
> +
> +-maxim,enable-sleep: Boolean, enable sleep state of PMIC

We already have bindings for sleeping. Please use a generic one.

> + when the FPS control input become active.
> +-maxim,enable-global-lpm: Boolean, enable Global Low Power Mode (GLPM)
> + of PMIC when the FPS control input become
> + active.
> +
> +Here supported time periods by device in microseconds are as follows:
> +MAX77620 supports 40, 80, 160, 320, 640, 1280, 2560 and 5120 microseconds.
> +MAX20024 supports 20, 40, 80, 160, 320, 640, 1280 and 2540 microseconds.
> +
> +For different sub modules like GPIO, pincontrol, regulator, power, please refer
> +respected device-tree binding document on respective directories.
> +
> +Example:
> +--------
> +#include <dt-bindings/mfd/max77620.h>
> +
> +max77620@3c {
> + compatible = "maxim,max77620";
> + reg = <0x3c>;
> +
> + interrupt-parent = <&intc>;
> + interrupts = <0 86 IRQ_TYPE_NONE>;
> +
> + interrupt-controller;
> + #interrupt-cells = <2>;
> +
> + fps {
> + fps0 {
> + maxim,shutdown-fps-time-period-us = <1280>;
> + maxim,fps-control = <FPS_CONTROL_SRC_EN1>;
> + };
> +
> + fps1 {
> + maxim,shutdown-fps-time-period-us = <1280>;
> + maxim,fps-control = <FPS_CONTROL_SRC_EN0>;
> + };
> +
> + fps2 {
> + maxim,shutdown-fps-time-period-us = <1280>;
> + maxim,fps-control = <FPS_CONTROL_SRC_SW>;
> + };
> + };
> +};
> diff --git a/include/dt-bindings/mfd/max77620.h b/include/dt-bindings/mfd/max77620.h
> new file mode 100644
> index 0000000..1b571d7
> --- /dev/null
> +++ b/include/dt-bindings/mfd/max77620.h
> @@ -0,0 +1,35 @@
> +/*
> + * This header provides macros for MAXIM MAX77620 device bindings.
> + *
> + * Copyright (c) 2016, NVIDIA Corporation.
> + * Author: Laxman Dewangan <ldewangan@xxxxxxxxxx>
> + */
> +
> +#ifndef _DT_BINDINGS_MFD_MAX77620_H
> +#define _DT_BINDINGS_MFD_MAX77620_H
> +
> +/* MAX77620 interrupts */
> +#define MAX77620_IRQ_TOP_GLBL 0 /* Low-Battery */
> +#define MAX77620_IRQ_TOP_SD 1 /* SD power fail */
> +#define MAX77620_IRQ_TOP_LDO 2 /* LDO power fail */
> +#define MAX77620_IRQ_TOP_GPIO 3 /* GPIO internal int to MAX77620 */
> +#define MAX77620_IRQ_TOP_RTC 4 /* RTC */
> +#define MAX77620_IRQ_TOP_32K 5 /* 32kHz oscillator */
> +#define MAX77620_IRQ_TOP_ONOFF 6 /* ON/OFF oscillator */
> +#define MAX77620_IRQ_LBT_MBATLOW 7 /* Thermal alarm status, > 120C */
> +#define MAX77620_IRQ_LBT_TJALRM1 8 /* Thermal alarm status, > 120C */
> +#define MAX77620_IRQ_LBT_TJALRM2 9 /* Thermal alarm status, > 140C */
> +
> +/* FPS control inputs */
> +#define FPS_CONTROL_SRC_EN0 0
> +#define FPS_CONTROL_SRC_EN1 1
> +#define FPS_CONTROL_SRC_SW 2
> +
> +/* FPS source */
> +#define FPS_SRC_0 0
> +#define FPS_SRC_1 1
> +#define FPS_SRC_2 2
> +#define FPS_SRC_NONE 3
> +#define FPS_SRC_DEF 4
> +
> +#endif

--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org â Open source software for ARM SoCs
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