On Mon, Feb 19, 2018 at 9:59 AM, Amelie DELAUNAY <amelie.delaunay@xxxxxx> wrote: > > > On 02/19/2018 12:19 AM, Rob Herring wrote: >> On Thu, Feb 08, 2018 at 03:27:32PM +0100, Amelie Delaunay wrote: >>> This patch adds documentation of device tree bindings for the >>> STMicroelectronics Multi-Function eXpander (MFX). >>> >>> Signed-off-by: Amelie Delaunay <amelie.delaunay@xxxxxx> >>> --- >>> Documentation/devicetree/bindings/mfd/st-mfx.txt | 51 ++++++++++++++++++++++++ >>> 1 file changed, 51 insertions(+) >>> create mode 100644 Documentation/devicetree/bindings/mfd/st-mfx.txt >>> >>> diff --git a/Documentation/devicetree/bindings/mfd/st-mfx.txt b/Documentation/devicetree/bindings/mfd/st-mfx.txt >>> new file mode 100644 >>> index 0000000..423d800 >>> --- /dev/null >>> +++ b/Documentation/devicetree/bindings/mfd/st-mfx.txt >>> @@ -0,0 +1,51 @@ >>> +STMicroelectronics Multi-Function eXpander >>> + >>> +ST Multi-Function eXpander (MFX) is a slave controller using I2C for >>> +communication with the main MCU. Its main features are gpio expansion, main >>> +MCU IDD measurement (IDD is the amount of current that flows through VDD) >>> +and resistive touchscreen controller. >> >> You don't have to implement all the drivers now, but please completely >> describe the device. As is, there is no reason to have a child GPIO >> node. >> > The MFD driver will be abandoned as only GPIO part is used. I'll send a > V2 soon. >>> + >>> +Required properties: >>> +- compatible: must be "st,mfx" >> >> Kind of generic. Only 1 single version ever? >> > "st-mfx" compatible will disappear in V2 (we keep only GPIO driver). MFX > version can be read in MFX FW_VERSION register. So do I keep > "st,mfx-gpio" compatible or you want to see mfx version ? That sounds a bit worrying. The other functions will *never* get accessed? The DT should reflect the h/w including any future needs, not just what you have a driver for today. >>> +- reg: I2C address of the device >>> +- interrupts: interrupt triggered by MFX_IRQ_OUT signal >>> +- interrupt-parent: interrupt controller MFX is connected to >>> +- interrupt-controller: marks the device as an interrupt controller >>> +- #interrupt-cells: should be <1>, index of the interrupt within the >>> + controller, in accordance with the "one cell" variant of >>> + <devicetree/bindings/interrupt-controller/interrupt.txt> >>> + >>> +Optional nodes: >>> + >>> +* GPIO eXpander >>> +MFX provides 16 programmable GPIOs, and it is also possible to recover 8 >>> +alternate GPIOs if the main functions are not used (touchscreen controller and >>> +IDD measurement not enabled). >>> + >>> +Required properties: >>> +- compatible : must be "st,mfx-gpio" >>> +- interrupt-parent : must be <&mfx> >> >> Not necessary. A parent node with 'interrupt-controller' property is the >> interrupt's parent. >> > I will keep it in mind. >>> +- interrupts = must be <0> >>> +- gpio-controller: marks the device node as a GPIO controller >>> +- #gpio-cells: should be <2>, the first cell is the GPIO offset on this GPIO >>> + controller, the second cell is the gpio flags in accordance with >>> + <dt-bindings/gpio/st-mfx-gpio.h>. >> >> Custom flags? Use standard flags. >> >> DT binding headers should be part of this patch. >> > Custom flags because MFX GPIOs have several types: > - Output open drain with internal pull-up resistor > - Output open drain without internal pull-up resistor > - Output push pull without internal pull resistor > - Input with internal pull-up resistor > - Input with internal pull-down resistor > - Input floating > - Input analog. > Standard flags don't have pull up or down information. That's why I am > using custom flags, they overloads standard flags. I'll leave this one to Linus to comment on. > I will add DT bindings header in this patch V2. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
