| Message ID | 1484260543-80300-1-git-send-email-christopher.lee.bostic@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Jan 12, 2017 at 04:35:43PM -0600, christopher.lee.bostic@gmail.com wrote: > From: Chris Bostic <cbostic@us.ibm.com> > > Define the device tree bindings for the GPIO master type. > > Signed-off-by: Chris Bostic <cbostic@us.ibm.com> > > --- > > V2 - Break out this documentation update from the code implementing > The GPIO master function. > > - Move the documentation to an earlier patch than the code > implementing the function. > > - Document all 'compatible' strings used in the series. > > - Write binding document in terms of hardware, not software. > > - Elaborate on what a GPIO based FSI master is versus a non > GPIO based master. > > - Give a more detailed description of what each pin in the GPIO > FSI master is to be used for. > > - Re-order compatible strings in example so that most specific > comes first. > > - Indicate the proper order each pin should be initialized. > > - Fix an unmatched '>' bracket in the example for binding. > > - Bracket each element of the example list items individually. > --- > .../devicetree/bindings/fsi/fsi-master-gpio.txt | 71 ++++++++++++++++++++++ > 1 file changed, 71 insertions(+) > create mode 100644 Documentation/devicetree/bindings/fsi/fsi-master-gpio.txt > > diff --git a/Documentation/devicetree/bindings/fsi/fsi-master-gpio.txt b/Documentation/devicetree/bindings/fsi/fsi-master-gpio.txt > new file mode 100644 > index 0000000..5d589bf > --- /dev/null > +++ b/Documentation/devicetree/bindings/fsi/fsi-master-gpio.txt > @@ -0,0 +1,71 @@ > +Device-tree bindings for FSI master implemented with GPIO > +--------------------------------------------------------- > + > +Typically a FSI master is defined in hardware with output control > +lines designated for Enable, Data, Clock, etc.. In the case of > +a 'GPIO FSI master', however, it may be the case that there is no > +such master defined in hardware and must be implemented in standard > +GPIO to interact with its slaves. In this 'virtual' FSI master > +case the GPIO pins representing clk and data are directly > +connected to the slaves. > + > +The GPIO FSI master node > +------------------------- > +This node describes a FSI master implmented with GPIO. > +Required property: > + compatible = "ibm,fsi-master-gpio" Generally, we don't have a vendor prefix for GPIO based implementations. > + > +The standard FSI master node > +---------------------------- > +This node describes a FSI master implmemented fully in hardware > +with dedicated input/output pins required for its function (i.e. > +not using generic GPIO pins). > +Required property: > + compatible = "ibm,fsi-master" This and GPIO binding should be in 2 docs. > + > + > +GPIO FSI master property/pin descriptions > +------------------------------------------ > +clk - The master controlled clock line that indicates to the > + slave when to read in or send out new data - required. > +data - The serial data line containing information to be sent or > + received by the master. This line is bi-directional. During > + command phase the master controls the line and when a response > + is required the slave takes control - required. > +enable - Controls power state of data line - optional. > +trans - Voltage translator control. In some applications the data line > + must have its signal levels altered by a translator. If this is > + necessary then control of signal direction is managed via this > + line - optional. > +mux - Multiplexor control. This activates/deactivates the data line > + in cases where it is one of many possible selections via mux - > + optional. Combine these descriptions and the property names, grouped as below. > + > +Required properties: > + - compatible = "ibm,fsi-master-gpio"; > + - clk-gpios; > + - data-gpios; > + > +Optional properties: > + - enable-gpios; > + - trans-gpios; > + - mux-gpios; > + > +Order of property activation: > +1. clk > +2. data > +3. trans > +4. enable > +5. mux > + > + > +Example: > + > +fsi-master { > + compatible = "ibm,fsi-master-gpio", "ibm,fsi-master"; From the description, these should be mutually exclusive. > + clk-gpios = <&gpio 0>, <&gpio 6>; > + data-gpios = <&gpio 1>, <&gpio 7>; > + enable-gpios = <&gpio 2>, <&gpio 8>; > + trans-gpios = <&gpio 3>, <&gpio 9>; > + mux-gpios = <&gpio 4>, <&gpio 10>; > +} > -- > 1.8.2.2 >
Hi Chris, From this: >> + >> +The standard FSI master node >> +---------------------------- >> +This node describes a FSI master implmemented fully in hardware >> +with dedicated input/output pins required for its function (i.e. >> +not using generic GPIO pins). >> +Required property: >> + compatible = "ibm,fsi-master" and this: >> +Example: >> + >> +fsi-master { >> + compatible = "ibm,fsi-master-gpio", "ibm,fsi-master"; > > From the description, these should be mutually exclusive. I agree with Rob here. The intention is for "ibm,fsi-master" to be an abstract master -- simply indicating that this node describes a master, with no specific implementation, and "ibm,fsi-master-gpio" to be a GPIO-based implementation. A hardware-based FSI master would have a different compatible value, based on the hardware. We should remove references to implementations in the "The standard FSI master node" section, because this is independent of implementation. >> + clk-gpios = <&gpio 0>, <&gpio 6>; >> + data-gpios = <&gpio 1>, <&gpio 7>; >> + enable-gpios = <&gpio 2>, <&gpio 8>; >> + trans-gpios = <&gpio 3>, <&gpio 9>; >> + mux-gpios = <&gpio 4>, <&gpio 10>; Do we support multiple-link masters? This example implies a 2-link master. Cheers, Jeremy
On Wed, Jan 18, 2017 at 8:11 PM, Jeremy Kerr <jk@ozlabs.org> wrote: > Hi Chris, > > From this: > >>> + >>> +The standard FSI master node >>> +---------------------------- >>> +This node describes a FSI master implmemented fully in hardware >>> +with dedicated input/output pins required for its function (i.e. >>> +not using generic GPIO pins). >>> +Required property: >>> + compatible = "ibm,fsi-master" > > and this: > >>> +Example: >>> + >>> +fsi-master { >>> + compatible = "ibm,fsi-master-gpio", "ibm,fsi-master"; >> >> From the description, these should be mutually exclusive. > > I agree with Rob here. The intention is for "ibm,fsi-master" to be an > abstract master -- simply indicating that this node describes a master, > with no specific implementation, and "ibm,fsi-master-gpio" to be a > GPIO-based implementation. A hardware-based FSI master would have a > different compatible value, based on the hardware. > > We should remove references to implementations in the "The standard FSI > master node" section, because this is independent of implementation. > Hi, OK will make that change for version 4. >>> + clk-gpios = <&gpio 0>, <&gpio 6>; >>> + data-gpios = <&gpio 1>, <&gpio 7>; >>> + enable-gpios = <&gpio 2>, <&gpio 8>; >>> + trans-gpios = <&gpio 3>, <&gpio 9>; >>> + mux-gpios = <&gpio 4>, <&gpio 10>; > > Do we support multiple-link masters? This example implies a 2-link > master. > Should we start with a single link in this case? To start off with only one link is supported by the master. Thanks > Cheers, > > > Jeremy
On Wed, Jan 18, 2017 at 3:57 PM, Rob Herring <robh@kernel.org> wrote: > On Thu, Jan 12, 2017 at 04:35:43PM -0600, christopher.lee.bostic@gmail.com wrote: >> From: Chris Bostic <cbostic@us.ibm.com> >> >> Define the device tree bindings for the GPIO master type. >> >> Signed-off-by: Chris Bostic <cbostic@us.ibm.com> >> >> --- >> >> V2 - Break out this documentation update from the code implementing >> The GPIO master function. >> >> - Move the documentation to an earlier patch than the code >> implementing the function. >> >> - Document all 'compatible' strings used in the series. >> >> - Write binding document in terms of hardware, not software. >> >> - Elaborate on what a GPIO based FSI master is versus a non >> GPIO based master. >> >> - Give a more detailed description of what each pin in the GPIO >> FSI master is to be used for. >> >> - Re-order compatible strings in example so that most specific >> comes first. >> >> - Indicate the proper order each pin should be initialized. >> >> - Fix an unmatched '>' bracket in the example for binding. >> >> - Bracket each element of the example list items individually. >> --- >> .../devicetree/bindings/fsi/fsi-master-gpio.txt | 71 ++++++++++++++++++++++ >> 1 file changed, 71 insertions(+) >> create mode 100644 Documentation/devicetree/bindings/fsi/fsi-master-gpio.txt >> >> diff --git a/Documentation/devicetree/bindings/fsi/fsi-master-gpio.txt b/Documentation/devicetree/bindings/fsi/fsi-master-gpio.txt >> new file mode 100644 >> index 0000000..5d589bf >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/fsi/fsi-master-gpio.txt >> @@ -0,0 +1,71 @@ >> +Device-tree bindings for FSI master implemented with GPIO >> +--------------------------------------------------------- >> + >> +Typically a FSI master is defined in hardware with output control >> +lines designated for Enable, Data, Clock, etc.. In the case of >> +a 'GPIO FSI master', however, it may be the case that there is no >> +such master defined in hardware and must be implemented in standard >> +GPIO to interact with its slaves. In this 'virtual' FSI master >> +case the GPIO pins representing clk and data are directly >> +connected to the slaves. >> + >> +The GPIO FSI master node >> +------------------------- >> +This node describes a FSI master implmented with GPIO. >> +Required property: >> + compatible = "ibm,fsi-master-gpio" > > Generally, we don't have a vendor prefix for GPIO based implementations. > Hi Rob Will make the change in the next revision (v4). >> + >> +The standard FSI master node >> +---------------------------- >> +This node describes a FSI master implmemented fully in hardware >> +with dedicated input/output pins required for its function (i.e. >> +not using generic GPIO pins). >> +Required property: >> + compatible = "ibm,fsi-master" > > This and GPIO binding should be in 2 docs. > Will separate out. >> + >> + >> +GPIO FSI master property/pin descriptions >> +------------------------------------------ >> +clk - The master controlled clock line that indicates to the >> + slave when to read in or send out new data - required. >> +data - The serial data line containing information to be sent or >> + received by the master. This line is bi-directional. During >> + command phase the master controls the line and when a response >> + is required the slave takes control - required. >> +enable - Controls power state of data line - optional. >> +trans - Voltage translator control. In some applications the data line >> + must have its signal levels altered by a translator. If this is >> + necessary then control of signal direction is managed via this >> + line - optional. >> +mux - Multiplexor control. This activates/deactivates the data line >> + in cases where it is one of many possible selections via mux - >> + optional. > > Combine these descriptions and the property names, grouped as below. > Will update. >> + >> +Required properties: >> + - compatible = "ibm,fsi-master-gpio"; >> + - clk-gpios; >> + - data-gpios; >> + >> +Optional properties: >> + - enable-gpios; >> + - trans-gpios; >> + - mux-gpios; >> + >> +Order of property activation: >> +1. clk >> +2. data >> +3. trans >> +4. enable >> +5. mux >> + >> + >> +Example: >> + >> +fsi-master { >> + compatible = "ibm,fsi-master-gpio", "ibm,fsi-master"; > > From the description, these should be mutually exclusive. Will change. Thanks for your input. > >> + clk-gpios = <&gpio 0>, <&gpio 6>; >> + data-gpios = <&gpio 1>, <&gpio 7>; >> + enable-gpios = <&gpio 2>, <&gpio 8>; >> + trans-gpios = <&gpio 3>, <&gpio 9>; >> + mux-gpios = <&gpio 4>, <&gpio 10>; >> +} >> -- >> 1.8.2.2 >>
diff --git a/Documentation/devicetree/bindings/fsi/fsi-master-gpio.txt b/Documentation/devicetree/bindings/fsi/fsi-master-gpio.txt new file mode 100644 index 0000000..5d589bf --- /dev/null +++ b/Documentation/devicetree/bindings/fsi/fsi-master-gpio.txt @@ -0,0 +1,71 @@ +Device-tree bindings for FSI master implemented with GPIO +--------------------------------------------------------- + +Typically a FSI master is defined in hardware with output control +lines designated for Enable, Data, Clock, etc.. In the case of +a 'GPIO FSI master', however, it may be the case that there is no +such master defined in hardware and must be implemented in standard +GPIO to interact with its slaves. In this 'virtual' FSI master +case the GPIO pins representing clk and data are directly +connected to the slaves. + +The GPIO FSI master node +------------------------- +This node describes a FSI master implmented with GPIO. +Required property: + compatible = "ibm,fsi-master-gpio" + +The standard FSI master node +---------------------------- +This node describes a FSI master implmemented fully in hardware +with dedicated input/output pins required for its function (i.e. +not using generic GPIO pins). +Required property: + compatible = "ibm,fsi-master" + + +GPIO FSI master property/pin descriptions +------------------------------------------ +clk - The master controlled clock line that indicates to the + slave when to read in or send out new data - required. +data - The serial data line containing information to be sent or + received by the master. This line is bi-directional. During + command phase the master controls the line and when a response + is required the slave takes control - required. +enable - Controls power state of data line - optional. +trans - Voltage translator control. In some applications the data line + must have its signal levels altered by a translator. If this is + necessary then control of signal direction is managed via this + line - optional. +mux - Multiplexor control. This activates/deactivates the data line + in cases where it is one of many possible selections via mux - + optional. + +Required properties: + - compatible = "ibm,fsi-master-gpio"; + - clk-gpios; + - data-gpios; + +Optional properties: + - enable-gpios; + - trans-gpios; + - mux-gpios; + +Order of property activation: +1. clk +2. data +3. trans +4. enable +5. mux + + +Example: + +fsi-master { + compatible = "ibm,fsi-master-gpio", "ibm,fsi-master"; + clk-gpios = <&gpio 0>, <&gpio 6>; + data-gpios = <&gpio 1>, <&gpio 7>; + enable-gpios = <&gpio 2>, <&gpio 8>; + trans-gpios = <&gpio 3>, <&gpio 9>; + mux-gpios = <&gpio 4>, <&gpio 10>; +}