* [PATCH v2 15/18] drivers/fsi: Add documentation for GPIO based FSI master
@ 2017-01-12 22:35 christopher.lee.bostic
2017-01-18 21:57 ` Rob Herring
0 siblings, 1 reply; 5+ messages in thread
From: christopher.lee.bostic @ 2017-01-12 22:35 UTC (permalink / raw)
To: robh+dt, mark.rutland, linux, gregkh, mturquette, geert+renesas,
devicetree, linux-arm-kernel, joel, jk, linux-kernel, andrew,
alistair, benh
Cc: Chris Bostic
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"
+
+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>;
+}
--
1.8.2.2
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH v2 15/18] drivers/fsi: Add documentation for GPIO based FSI master
2017-01-12 22:35 [PATCH v2 15/18] drivers/fsi: Add documentation for GPIO based FSI master christopher.lee.bostic
@ 2017-01-18 21:57 ` Rob Herring
2017-01-19 2:11 ` Jeremy Kerr
2017-02-01 17:17 ` Christopher Bostic
0 siblings, 2 replies; 5+ messages in thread
From: Rob Herring @ 2017-01-18 21:57 UTC (permalink / raw)
To: christopher.lee.bostic
Cc: mark.rutland, linux, gregkh, mturquette, geert+renesas,
devicetree, linux-arm-kernel, joel, jk, linux-kernel, andrew,
alistair, benh, Chris Bostic
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
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v2 15/18] drivers/fsi: Add documentation for GPIO based FSI master
2017-01-18 21:57 ` Rob Herring
@ 2017-01-19 2:11 ` Jeremy Kerr
2017-02-01 17:09 ` Christopher Bostic
2017-02-01 17:17 ` Christopher Bostic
1 sibling, 1 reply; 5+ messages in thread
From: Jeremy Kerr @ 2017-01-19 2:11 UTC (permalink / raw)
To: Rob Herring, christopher.lee.bostic
Cc: mark.rutland, linux, gregkh, mturquette, geert+renesas,
devicetree, linux-arm-kernel, joel, linux-kernel, andrew,
alistair, benh, Chris Bostic
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
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v2 15/18] drivers/fsi: Add documentation for GPIO based FSI master
2017-01-19 2:11 ` Jeremy Kerr
@ 2017-02-01 17:09 ` Christopher Bostic
0 siblings, 0 replies; 5+ messages in thread
From: Christopher Bostic @ 2017-02-01 17:09 UTC (permalink / raw)
To: Jeremy Kerr
Cc: Rob Herring, Mark Rutland, linux, Greg KH, Michael Turquette,
geert+renesas, Open List OF Flattened dev tree bindings,
Moderated list: ARM PORT, Joel Stanley, Linux open list,
Andrew Jeffery, Alistair Popple, Benjamin Herrenschmidt,
Chris Bostic
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
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v2 15/18] drivers/fsi: Add documentation for GPIO based FSI master
2017-01-18 21:57 ` Rob Herring
2017-01-19 2:11 ` Jeremy Kerr
@ 2017-02-01 17:17 ` Christopher Bostic
1 sibling, 0 replies; 5+ messages in thread
From: Christopher Bostic @ 2017-02-01 17:17 UTC (permalink / raw)
To: Rob Herring
Cc: Mark Rutland, linux, Greg KH, Michael Turquette, geert+renesas,
Open List OF Flattened dev tree bindings,
Moderated list: ARM PORT, Joel Stanley, Jeremy Kerr,
Linux open list, Andrew Jeffery, Alistair Popple,
Benjamin Herrenschmidt, Chris Bostic
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
>>
^ permalink raw reply [flat|nested] 5+ messages in thread
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2017-01-12 22:35 [PATCH v2 15/18] drivers/fsi: Add documentation for GPIO based FSI master christopher.lee.bostic
2017-01-18 21:57 ` Rob Herring
2017-01-19 2:11 ` Jeremy Kerr
2017-02-01 17:09 ` Christopher Bostic
2017-02-01 17:17 ` Christopher Bostic
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