| Message ID | 20220115023135.234667-4-dmanti@microsoft.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Add spi-hid, transport for HID over SPI bus | expand |
On Fri, Jan 14, 2022 at 06:31:33PM -0800, Dmitry Antipov wrote: > From: Dmitry Antipov <dmanti@microsoft.com> > > Added documentation describes the required properties for implementing > Device Tree for a device supporting HID over SPI and also provides an > example. Bindings are in DT schema format now. > > Signed-off-by: Dmitry Antipov <dmanti@microsoft.com> > --- > .../bindings/input/hid-over-spi.txt | 43 +++++++++++++++++++ > 1 file changed, 43 insertions(+) > create mode 100755 Documentation/devicetree/bindings/input/hid-over-spi.txt > > diff --git a/Documentation/devicetree/bindings/input/hid-over-spi.txt b/Documentation/devicetree/bindings/input/hid-over-spi.txt > new file mode 100755 > index 000000000000..5eba95b5724e > --- /dev/null > +++ b/Documentation/devicetree/bindings/input/hid-over-spi.txt > @@ -0,0 +1,43 @@ > +* HID over SPI Device-Tree bindings > + > +HID over SPI provides support for Human Interface Devices over the SPI bus. HID > +Over SPI Protocol Specification 1.0 was written by Microsoft and is available at > +https://www.microsoft.com/en-us/download/details.aspx?id=103325. > + > +If this binding is used, the kernel module spi-hid will handle the communication What's a kernel module? ;) Bindings are OS independent (or supposed to be), so kernel details do not belong here. > +with the device and the generic hid core layer will handle the protocol. > + > +Required properties: > +- compatible: must be "hid-over-spi" Bindings describe devices, not protocols. There is no such 'hid-over-spi' device. Please see the existing hid-over-i2c binding. It's fine to have this compatible, but only as a fallback compatible. > +- interrupts: interrupt line > +- vdd-supply: phandle of the regulator that provides the supply voltage What happens when the device has 2 supplies? And there's some timing requirement between them? > +- reset_gpio-gpios: gpio wired to the device reset line 'reset-gpios' is the standard name. > +- post-power-on-delay-ms: time required by the device after enabling its > +regulators or powering it on, before it is ready for communication > +- minimal-reset-delay-ms: minimum amount of time that device needs to be in > +reset state for the reset to take effect These properties are what happens when we try to do generic bindings. It's a never-ending addition of more properties to try to describe (poorly) the power sequencing requirements. > +- input-report-header-address: this property and the rest are described in HID > +Over SPI Protocol Spec 1.0 > +- input-report-body-address > +- output-report-address > +- read-opcode > +- write-opcode > +- flags A bit too generic. We generally want to avoid having a property name with 2 different types/meaning. It's not something we check for yet, but I plan to at some point. > + > +Example: > + spi-hid-dev0 { > + compatible = "hid-over-spi"; > + reg = <0>; > + interrupts-extended = <&tlmm 42 IRQ_TYPE_EDGE_FALLING>; > + vdd-supply = <&pm8350c_l3>; > + input-report-header-address = <0x1000>; > + input-report-body-address = <0x1004>; > + output-report-address = <0x2000>; > + read-opcode = <0x0b>; > + write-opcode = <0x02>; > + flags = <0x00>; > + reset_gpio-gpios = <&tlmm 25 GPIO_ACTIVE_LOW>; > + post-power-on-delay-ms = <5>; > + minimal-reset-delay-ms = <5>; > + > + }; > -- > 2.25.1 > >
Dmitry Antipov <daantipov@gmail.com> writes: > From: Dmitry Antipov <dmanti@microsoft.com> > > Added documentation describes the required properties for implementing > Device Tree for a device supporting HID over SPI and also provides an > example. > > Signed-off-by: Dmitry Antipov <dmanti@microsoft.com> > --- > .../bindings/input/hid-over-spi.txt | 43 +++++++++++++++++++ > 1 file changed, 43 insertions(+) > create mode 100755 Documentation/devicetree/bindings/input/hid-over-spi.txt > > diff --git a/Documentation/devicetree/bindings/input/hid-over-spi.txt b/Documentation/devicetree/bindings/input/hid-over-spi.txt > new file mode 100755 > index 000000000000..5eba95b5724e > --- /dev/null > +++ b/Documentation/devicetree/bindings/input/hid-over-spi.txt > @@ -0,0 +1,43 @@ > +* HID over SPI Device-Tree bindings > + Some windows-style line endings leaked here. Perhaps run dos2unix on the file?
Hello Rob, I just submitted patch v4 that addresses most of your feedback. On Thu, Jan 20, 2022 at 12:07 PM,Rob Herring wrote: > From: Rob Herring <robh@kernel.org> > > On Fri, Jan 14, 2022 at 06:31:33PM -0800, Dmitry Antipov wrote: > > From: Dmitry Antipov <dmanti@microsoft.com> > > > > Added documentation describes the required properties for implementing > > Device Tree for a device supporting HID over SPI and also provides an > > example. > > Bindings are in DT schema format now. > > > > > Signed-off-by: Dmitry Antipov <dmanti@microsoft.com> > > --- > > .../bindings/input/hid-over-spi.txt | 43 +++++++++++++++++++ > > 1 file changed, 43 insertions(+) > > create mode 100755 > > Documentation/devicetree/bindings/input/hid-over-spi.txt > > > > diff --git a/Documentation/devicetree/bindings/input/hid-over-spi.txt > > b/Documentation/devicetree/bindings/input/hid-over-spi.txt > > new file mode 100755 > > index 000000000000..5eba95b5724e > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/input/hid-over-spi.txt > > @@ -0,0 +1,43 @@ > > +* HID over SPI Device-Tree bindings > > + > > +HID over SPI provides support for Human Interface Devices over the > > +SPI bus. HID Over SPI Protocol Specification 1.0 was written by > > +Microsoft and is available at > https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.m > icrosoft.com%2Fen- > us%2Fdownload%2Fdetails.aspx%3Fid%3D103325&data=04%7C01%7Cd > manti%40microsoft.com%7Cb0b84680fa2c45bc2f3a08d9dc5063f6%7C72f988 > bf86f141af91ab2d7cd011db47%7C1%7C0%7C637783060144589082%7CUnkn > own%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1h > aWwiLCJXVCI6Mn0%3D%7C3000&sdata=bWGZDRYtVovy3XYlpDsZ8xR2AL > be5YoP0iSZ8xORSyA%3D&reserved=0. > > + > > +If this binding is used, the kernel module spi-hid will handle the > > +communication > > What's a kernel module? ;) Bindings are OS independent (or supposed to be), so > kernel details do not belong here. > > > +with the device and the generic hid core layer will handle the protocol. > > + > > +Required properties: > > +- compatible: must be "hid-over-spi" > > Bindings describe devices, not protocols. There is no such 'hid-over-spi' device. > Please see the existing hid-over-i2c binding. > It's fine to have this compatible, but only as a fallback compatible. In the v4 patch the yaml file expects the device-specific compatible string, but also 'hid-over-spi'. > > > +- interrupts: interrupt line > > +- vdd-supply: phandle of the regulator that provides the supply > > +voltage > > What happens when the device has 2 supplies? And there's some timing > requirement between them? I am not sure if there is a way to account for all possible scenarios. Our device only has one power regulator and the binding is now device-specific. > > > +- reset_gpio-gpios: gpio wired to the device reset line > > 'reset-gpios' is the standard name. > > > +- post-power-on-delay-ms: time required by the device after enabling > > +its regulators or powering it on, before it is ready for > > +communication > > +- minimal-reset-delay-ms: minimum amount of time that device needs to > > +be in reset state for the reset to take effect > > These properties are what happens when we try to do generic bindings. > It's a never-ending addition of more properties to try to describe > (poorly) the power sequencing requirements. I have made these optional in the v4 patch. > > > +- input-report-header-address: this property and the rest are > > +described in HID Over SPI Protocol Spec 1.0 > > +- input-report-body-address > > +- output-report-address > > +- read-opcode > > +- write-opcode > > +- flags > > A bit too generic. We generally want to avoid having a property name with 2 > different types/meaning. It's not something we check for yet, but I plan to at > some point. I've made "flags" more specific in the v4 patch. > > > + > > +Example: > > + spi-hid-dev0 { > > + compatible = "hid-over-spi"; > > + reg = <0>; > > + interrupts-extended = <&tlmm 42 IRQ_TYPE_EDGE_FALLING>; > > + vdd-supply = <&pm8350c_l3>; > > + input-report-header-address = <0x1000>; > > + input-report-body-address = <0x1004>; > > + output-report-address = <0x2000>; > > + read-opcode = <0x0b>; > > + write-opcode = <0x02>; > > + flags = <0x00>; > > + reset_gpio-gpios = <&tlmm 25 GPIO_ACTIVE_LOW>; > > + post-power-on-delay-ms = <5>; > > + minimal-reset-delay-ms = <5>; > > + > > + }; > > -- > > 2.25.1 > > > >
diff --git a/Documentation/devicetree/bindings/input/hid-over-spi.txt b/Documentation/devicetree/bindings/input/hid-over-spi.txt new file mode 100755 index 000000000000..5eba95b5724e --- /dev/null +++ b/Documentation/devicetree/bindings/input/hid-over-spi.txt @@ -0,0 +1,43 @@ +* HID over SPI Device-Tree bindings + +HID over SPI provides support for Human Interface Devices over the SPI bus. HID +Over SPI Protocol Specification 1.0 was written by Microsoft and is available at +https://www.microsoft.com/en-us/download/details.aspx?id=103325. + +If this binding is used, the kernel module spi-hid will handle the communication +with the device and the generic hid core layer will handle the protocol. + +Required properties: +- compatible: must be "hid-over-spi" +- interrupts: interrupt line +- vdd-supply: phandle of the regulator that provides the supply voltage +- reset_gpio-gpios: gpio wired to the device reset line +- post-power-on-delay-ms: time required by the device after enabling its +regulators or powering it on, before it is ready for communication +- minimal-reset-delay-ms: minimum amount of time that device needs to be in +reset state for the reset to take effect +- input-report-header-address: this property and the rest are described in HID +Over SPI Protocol Spec 1.0 +- input-report-body-address +- output-report-address +- read-opcode +- write-opcode +- flags + +Example: + spi-hid-dev0 { + compatible = "hid-over-spi"; + reg = <0>; + interrupts-extended = <&tlmm 42 IRQ_TYPE_EDGE_FALLING>; + vdd-supply = <&pm8350c_l3>; + input-report-header-address = <0x1000>; + input-report-body-address = <0x1004>; + output-report-address = <0x2000>; + read-opcode = <0x0b>; + write-opcode = <0x02>; + flags = <0x00>; + reset_gpio-gpios = <&tlmm 25 GPIO_ACTIVE_LOW>; + post-power-on-delay-ms = <5>; + minimal-reset-delay-ms = <5>; + + };