Re: [PATCH v2 15/18] drivers/fsi: Add documentation for GPIO based FSI master

[Christopher Bostic]

On Wed, Jan 18, 2017 at 3:57 PM, Rob Herring  wrote:
> On Thu, Jan 12, 2017 at 04:35:43PM -0600, christopher.lee.bos...@gmail.com 
> wrote:
>> From: Chris Bostic 
>>
>> Define the device tree bindings for the GPIO master type.
>>
>> Signed-off-by: Chris Bostic 
>>
>> ---
>>
>> 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 000..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 = < 0>, < 6>;
>> + data-gpios = < 1>, < 7>;
>> + enable-gpios = < 2>, < 8>;
>> + trans-gpios = < 3>, < 9>;
>> + mux-gpios = < 4>, < 10>;
>> +}
>> --
>> 1.8.2.2
>>

Re: [PATCH v2 15/18] drivers/fsi: Add documentation for GPIO based FSI master

[Christopher Bostic]

On Wed, Jan 18, 2017 at 3:57 PM, Rob Herring  wrote:
> On Thu, Jan 12, 2017 at 04:35:43PM -0600, christopher.lee.bos...@gmail.com 
> wrote:
>> From: Chris Bostic 
>>
>> Define the device tree bindings for the GPIO master type.
>>
>> Signed-off-by: Chris Bostic 
>>
>> ---
>>
>> 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 000..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 = < 0>, < 6>;
>> + data-gpios = < 1>, < 7>;
>> + enable-gpios = < 2>, < 8>;
>> + trans-gpios = < 3>, < 9>;
>> + mux-gpios = < 4>, < 10>;
>> +}
>> --
>> 1.8.2.2
>>

Re: [PATCH v2 15/18] drivers/fsi: Add documentation for GPIO based FSI master

[Christopher Bostic]

On Wed, Jan 18, 2017 at 8:11 PM, Jeremy Kerr  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 = < 0>, < 6>;
>>> +data-gpios = < 1>, < 7>;
>>> +enable-gpios = < 2>, < 8>;
>>> +trans-gpios = < 3>, < 9>;
>>> +mux-gpios = < 4>, < 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

Re: [PATCH v2 15/18] drivers/fsi: Add documentation for GPIO based FSI master

[Christopher Bostic]

On Wed, Jan 18, 2017 at 8:11 PM, Jeremy Kerr  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 = < 0>, < 6>;
>>> +data-gpios = < 1>, < 7>;
>>> +enable-gpios = < 2>, < 8>;
>>> +trans-gpios = < 3>, < 9>;
>>> +mux-gpios = < 4>, < 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

Re: [PATCH v2 15/18] drivers/fsi: Add documentation for GPIO based FSI master

[Jeremy Kerr]

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 = < 0>, < 6>;
>> +data-gpios = < 1>, < 7>;
>> +enable-gpios = < 2>, < 8>;
>> +trans-gpios = < 3>, < 9>;
>> +mux-gpios = < 4>, < 10>;

Do we support multiple-link masters? This example implies a 2-link
master.

Cheers,


Jeremy

Re: [PATCH v2 15/18] drivers/fsi: Add documentation for GPIO based FSI master

[Jeremy Kerr]

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 = < 0>, < 6>;
>> +data-gpios = < 1>, < 7>;
>> +enable-gpios = < 2>, < 8>;
>> +trans-gpios = < 3>, < 9>;
>> +mux-gpios = < 4>, < 10>;

Do we support multiple-link masters? This example implies a 2-link
master.

Cheers,


Jeremy

Re: [PATCH v2 15/18] drivers/fsi: Add documentation for GPIO based FSI master

[Rob Herring]

On Thu, Jan 12, 2017 at 04:35:43PM -0600, christopher.lee.bos...@gmail.com 
wrote:
> From: Chris Bostic 
> 
> Define the device tree bindings for the GPIO master type.
> 
> Signed-off-by: Chris Bostic 
> 
> ---
> 
> 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 000..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 = < 0>, < 6>;
> + data-gpios = < 1>, < 7>;
> + enable-gpios = < 2>, < 8>;
> + trans-gpios = < 3>, < 9>;
> + mux-gpios = < 4>, < 10>;
> +}
> -- 
> 1.8.2.2
> 

Re: [PATCH v2 15/18] drivers/fsi: Add documentation for GPIO based FSI master

[Rob Herring]

On Thu, Jan 12, 2017 at 04:35:43PM -0600, christopher.lee.bos...@gmail.com 
wrote:
> From: Chris Bostic 
> 
> Define the device tree bindings for the GPIO master type.
> 
> Signed-off-by: Chris Bostic 
> 
> ---
> 
> 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 000..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 = < 0>, < 6>;
> + data-gpios = < 1>, < 7>;
> + enable-gpios = < 2>, < 8>;
> + trans-gpios = < 3>, < 9>;
> + mux-gpios = < 4>, < 10>;
> +}
> -- 
> 1.8.2.2
> 

[PATCH v2 15/18] drivers/fsi: Add documentation for GPIO based FSI master

[christopher . lee . bostic]

From: Chris Bostic 

Define the device tree bindings for the GPIO master type.

Signed-off-by: Chris Bostic 

---

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 000..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 = < 0>, < 6>;
+   data-gpios = < 1>, < 7>;
+   enable-gpios = < 2>, < 8>;
+   trans-gpios = < 3>, < 9>;
+   mux-gpios = < 4>, < 10>;
+}
-- 
1.8.2.2

[PATCH v2 15/18] drivers/fsi: Add documentation for GPIO based FSI master

[christopher . lee . bostic]

From: Chris Bostic 

Define the device tree bindings for the GPIO master type.

Signed-off-by: Chris Bostic 

---

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 000..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 = < 0>, < 6>;
+   data-gpios = < 1>, < 7>;
+   enable-gpios = < 2>, < 8>;
+   trans-gpios = < 3>, < 9>;
+   mux-gpios = < 4>, < 10>;
+}
-- 
1.8.2.2