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* [PATCH 5/6] mtd: rawnand: ams-delta: use GPIO lookup table
From: Janusz Krzysztofik @ 2018-05-20 15:37 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <CAHp75Ved2nw1JKnXT2Jxnw4XLsby1eVJU6cfBjE2sp4LP4Kwmg@mail.gmail.com>

On Sunday, May 20, 2018 4:44:31 PM CEST Andy Shevchenko wrote:
> On Sun, May 20, 2018 at 12:55 AM, Janusz Krzysztofik
> 
> <jmkrzyszt@gmail.com> wrote:
> > On Saturday, May 19, 2018 8:00:38 PM CEST Andy Shevchenko wrote:
> >> On Sat, May 19, 2018 at 2:15 AM, Janusz Krzysztofik <jmkrzyszt@gmail.com>
> > 
> > wrote:
> >> NULL check in practice discards the _optional part of gpiod_get(). So,
> >> either you use non-optional variant and decide how to handle an
> >> errors, or user _optional w/o NULL check.
> > 
> > OK, I'm going to use something like the below while submitting v2:
> > 
> > -       gpiod_rdy = devm_gpiod_get_optional(&pdev->dev, "rdy", GPIOD_IN);
> > -       if (!IS_ERR_OR_NULL(gpiod_rdy)) {
> > -               this->dev_ready = ams_delta_nand_ready;
> > -       } else {
> > -               this->dev_ready = NULL;
> > -               pr_notice("Couldn't request gpio for Delta NAND
> > ready.\n");
> > +       priv->gpiod_rdy = devm_gpiod_get_optional(&pdev->dev, "rdy",
> > +                                                 GPIOD_IN);
> > +       if (IS_ERR(priv->gpiod_rdy)) {
> > +               err = PTR_ERR(priv->gpiod_nwp);
> > +               dev_warn(&pdev->dev, "RDY GPIO request failed (%d)\n",
> > err); +               goto err_gpiod;
> > 
> >         }
> > 
> > +       if (priv->gpiod_rdy)
> > +               this->dev_ready = ams_delta_nand_ready;
> 
> This makes sense.
> 
> Though, I completely dislike "rdy" name of GPIO. Where is it documented?

No documentation files for Amstrad Delta nor for its NAND driver specifically 
exist under Documentation/. However, there exist some for generic GPIO NAND 
driver where the pin name "rdy" is used explicitly:
Documentation/driver-api/gpio/drivers-on-gpio.rst
Documentation/devicetree/bindings/mtd/gpio-control-nand.txt
You can find that mnemonic used across drivers/mtd/nand/, standalone or as a 
suffix, including the Amstrad Delta NAND driver before the change discussed.

To be honest, I don't like it much either, but I'm just using it instead of 
inventing something new.

Thanks,
Janusz

^ permalink raw reply

* [PATCH v6 3/9] docs: Add Generic Counter interface documentation
From: Jonathan Cameron @ 2018-05-20 15:31 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <aa4d62315bb11ddc66d0e1a685c81b1721ffe624.1526487615.git.vilhelm.gray@gmail.com>

On Wed, 16 May 2018 13:51:06 -0400
William Breathitt Gray <vilhelm.gray@gmail.com> wrote:

> This patch adds high-level documentation about the Generic Counter
> interface.
> 
> Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>

Various comments inline.  I've been doing a lot long reviews recently
(outside of the kernel world) and keep discovering the old rule that
everytime you read a document you'll find something else to
improve :(

Jonathan
> ---
>  Documentation/driver-api/generic-counter.rst | 336 +++++++++++++++++++
>  Documentation/driver-api/index.rst           |   1 +
>  MAINTAINERS                                  |   1 +
>  3 files changed, 338 insertions(+)
>  create mode 100644 Documentation/driver-api/generic-counter.rst
> 
> diff --git a/Documentation/driver-api/generic-counter.rst b/Documentation/driver-api/generic-counter.rst
> new file mode 100644
> index 000000000000..5c6b9c008c06
> --- /dev/null
> +++ b/Documentation/driver-api/generic-counter.rst
> @@ -0,0 +1,336 @@
> +.. SPDX-License-Identifier: GPL-2.0
> +
> +=========================
> +Generic Counter Interface
> +=========================
> +
> +Introduction
> +============
> +
> +Counter devices are prevalent within a diverse spectrum of industries.
> +The ubiquitous presence of these devices necessitates a common interface
> +and standard of interaction and exposure. This driver API attempts to
> +resolve the issue of duplicate code found among existing counter device
> +drivers by introducing a generic counter interface for consumption. The
> +Generic Counter interface enables drivers to support and expose a common
> +set of components and functionality present in counter devices.
> +
> +Theory
> +======
> +
> +Counter devices can vary greatly in design, but regardless of whether
> +some devices are quadrature encoder counters or tally counters, all
> +counter devices consist of a core set of components. This core set of
> +components, shared by all counter devices, is what forms the essence of
> +the Generic Counter interface.
> +
> +There are three core components to a counter:

Enumerate them here.  If people are reading this as a paged document (pdf etc)
then the list of 3 as titles of next few sections may not be clear.

* Count

* Signal

* Synapse 

> +
> +COUNT
> +-----
> +A Count represents the count data for a set of Signals. The Generic
> +Counter interface provides the following available count data types:
> +
> +* COUNT_POSITION_UNSIGNED:
> +  Unsigned integer value representing position.
> +
> +* COUNT_POSITION_SIGNED:
> +  Signed integer value representing position.

Just a thought: As the '0' position is effectively arbitrary is there any
actual difference between signed and unsigned? If we defined all counters
to be unsigned and just offset any signed ones so the range still fitted
would we end up with a simpler interface - there would be no real loss
of meaning that I can see..  I suppose it might not be what people expect
though when they see their counters start at a large positive value...




> +
> +A Count has a count function mode which represents the update behavior
> +for the count data. The Generic Counter interface provides the following
> +available count function modes:
> +
> +* Increase:
> +  Accumulated count is incremented.
> +
> +* Decrease:
> +  Accumulated count is decremented.
> +
> +* Pulse-Direction:
> +  Rising edges on quadrature pair signal A updates the respective count.
> +  The input level of quadrature pair signal B determines direction.
> +
Perhaps group the quadrature modes for the point of view of this document?
Might be slightly easier to read?  

* Quadrature Modes

  - x1 A: etc.

> +* Quadrature x1 A:
> +  If direction is forward, rising edges on quadrature pair signal A
> +  updates the respective count; if the direction is backward, falling
> +  edges on quadrature pair signal A updates the respective count.
> +  Quadrature encoding determines the direction.
> +
> +* Quadrature x1 B:
> +  If direction is forward, rising edges on quadrature pair signal B
> +  updates the respective count; if the direction is backward, falling
> +  edges on quadrature pair signal B updates the respective count.
> +  Quadrature encoding determines the direction.
> +
> +* Quadrature x2 A:
> +  Any state transition on quadrature pair signal A updates the
> +  respective count. Quadrature encoding determines the direction.
> +
> +* Quadrature x2 B:
> +  Any state transition on quadrature pair signal B updates the
> +  respective count. Quadrature encoding determines the direction.
> +
> +* Quadrature x2 Rising:
> +  Rising edges on either quadrature pair signals updates the respective
> +  count. Quadrature encoding determines the direction.

This one I've never met.  Really? There are devices who do this form
of crazy? It gives really uneven counting and I'm failing to see when
it would ever make sense...  References for these odd corner cases
would be good.


__|---|____|-----|____
____|----|____|-----|____

001122222223334444444


> +
> +* Quadrature x2 Falling:
> +  Falling edges on either quadrature pair signals updates the respective
> +  count. Quadrature encoding determines the direction.
> +
> +* Quadrature x4:
> +  Any state transition on either quadrature pair signals updates the
> +  respective count. Quadrature encoding determines the direction.
> +
> +A Count has a set of one or more associated Signals.
> +
> +SIGNAL
> +------
> +A Signal represents a counter input data; this is the input data that is
> +analyzed by the counter to determine the count data; e.g. a quadrature
> +signal output line of a rotary encoder. Not all counter devices provide
> +user access to the Signal data.
> +
> +The Generic Counter interface provides the following available signal
> +data types for when the Signal data is available for user access:
> +
> +* SIGNAL_LEVEL_LOW:
> +  Signal line is in a low state.
> +
> +* SIGNAL_LEVEL_HIGH:
> +  Signal line is in a high state.
> +
> +A Signal may be associated with one or more Counts.
> +
> +SYNAPSE
> +-------
> +A Synapse represents the association of a Signal with a respective
> +Count. Signal data affects respective Count data, and the Synapse
> +represents this relationship.
> +
> +The Synapse action mode specifies the Signal data condition which
> +triggers the respective Count's count function evaluation to update the
> +count data. The Generic Counter interface provides the following
> +available action modes:
> +
> +* None:
> +  Signal does not trigger the count function. In Pulse-Direction count
> +  function mode, this Signal is evaluated as Direction.
> +
> +* Rising Edge:
> +  Low state transitions to high state.
> +
> +* Falling Edge:
> +  High state transitions to low state.
> +
> +* Both Edges:
> +  Any state transition.
> +
> +A counter is defined as a set of input signals associated with count
> +data that are generated by the evaluation of the state of the associated
> +input signals as defined by the respective count functions. Within the
> +context of the Generic Counter interface, a counter consists of Counts
> +each associated with a set of Signals, whose respective Synapse
> +instances represent the count function update conditions for the
> +associated Counts.
> +
> +Paradigm
> +========
> +
> +The most basic counter device may be expressed as a single Count
> +associated with a single Signal via a single Synapse. Take for example
> +a counter device which simply accumulates a count of rising edges on a
> +source input line::
> +
> +                Count                Synapse        Signal
> +                -----                -------        ------
> +        +---------------------+
> +        | Data: Count         |    Rising Edge     ________
> +        | Function: Increase  |  <-------------   / Source \
> +        |                     |                  ____________
> +        +---------------------+
> +
> +In this example, the Signal is a source input line with a pulsing
> +voltage, while the Count is a persistent count value which is repeatedly
> +incremented. The Signal is associated with the respective Count via a
> +Synapse. The increase function is triggered by the Signal data condition
> +specified by the Synapse -- in this case a rising edge condition on the
> +voltage input line. In summary, the counter device existence and
> +behavior is aptly represented by respective Count, Signal, and Synapse
> +components: a rising edge condition triggers an increase function on an
> +accumulating count datum.
> +
> +A counter device is not limited to a single Signal; in fact, in theory
> +many Signals may be associated with even a single Count. For example, a
> +quadrature encoder counter device can keep track of position based on
> +the states of two input lines::
> +
> +                   Count                 Synapse     Signal
> +                   -----                 -------     ------
> +        +-------------------------+
> +        | Data: Position          |    Both Edges     ___
> +        | Function: Quadrature x4 |  <------------   / A \
> +        |                         |                 _______
> +        |                         |
> +        |                         |    Both Edges     ___
> +        |                         |  <------------   / B \
> +        |                         |                 _______
> +        +-------------------------+
> +
> +In this example, two Signals (quadrature encoder lines A and B) are
> +associated with a single Count: a rising or falling edge on either A or
> +B triggers the "Quadrature x4" function which determines the direction
> +of movement and updates the respective position data. The "Quadrature
> +x4" function is likely implemented in the hardware of the quadrature
> +encoder counter device; the Count, Signals, and Synapses simply
> +represent this hardware behavior and functionality.
> +
> +Signals associated with the same Count can have differing Synapse action
> +mode conditions. For example, a quadrature encoder counter device
> +operating in a non-quadrature Pulse-Direction mode could have one input
> +line dedicated for movement and a second input line dedicated for
> +direction::
> +
> +                   Count                   Synapse      Signal
> +                   -----                   -------      ------
> +        +---------------------------+
> +        | Data: Position            |    Rising Edge     ___
> +        | Function: Pulse-Direction |  <-------------   / A \ (Movement)
> +        |                           |                  _______
> +        |                           |
> +        |                           |       None         ___
> +        |                           |  <-------------   / B \ (Direction)
> +        |                           |                  _______
> +        +---------------------------+
> +
> +Only Signal A triggers the "Pulse-Direction" update function, but the
> +instantaneous state of Signal B is still required in order to know the
> +direction so that the position data may be properly updated. Ultimately,
> +both Signals are associated with the same Count via two respective
> +Synapses, but only one Synapse has an active action mode condition which
> +triggers the respective count function while the other is left with a
> +"None" condition action mode to indicate its respective Signal's
> +availability for state evaluation despite its non-triggering mode.
> +
> +Keep in mind that the Signal, Synapse, and Count are abstract
> +representations which do not need to be closely married to their
> +respective physical sources. This allows the user of a counter to
> +divorce themselves from the nuances of physical components (such as
> +whether an input line is differential or single-ended) and instead focus
> +on the core idea of what the data and process represent (e.g. position
> +as interpreted from quadrature encoding data).
> +
> +Userspace Interface
> +===================
> +
> +Several sysfs attributes are generated by the Generic Counter interface,
> +and reside under the /sys/bus/counter/devices/counterX directory, where
> +counterX refers to the respective counter device. Please see
> +Documentation/ABI/testing/sys-bus-counter-generic-sysfs for detailed
> +information on each Generic Counter interface sysfs attribute.
> +
> +Through these sysfs attributes, programs and scripts may interact with
> +the Generic Counter paradigm Counts, Signals, and Synapses of respective
> +counter devices.
> +
> +Driver API
> +==========
> +
> +Driver authors may utilize the Generic Counter interface in their code
> +by including the include/linux/iio/counter.h header file. This header

Didn't this move?

> +file provides several core data structures, function prototypes, and
> +macros for defining a counter device.
> +
> +.. kernel-doc:: include/linux/counter.h
> +   :internal:
> +
> +.. kernel-doc:: drivers/counter/generic-counter.c
> +   :export:
> +
> +Implementation
> +==============
> +
> +To support a counter device, a driver must first allocate the available
> +Counter Signals via counter_signal structures. These Signals should
> +be stored as an array and set to the signals array member of an
> +allocated counter_device structure before the Counter is registered to
> +the system.
> +
> +Counter Counts may be allocated via counter_count structures, and
> +respective Counter Signal associations (Synapses) made via
> +counter_synapse structures. Associated counter_synapse structures are
> +stored as an array and set to the the synapses array member of the
> +respective counter_count structure. These counter_count structures are
> +set to the counts array member of an allocated counter_device structure
> +before the Counter is registered to the system.
> +
> +Driver callbacks should be provided to the counter_device structure via
> +a constant counter_ops structure in order to communicate with the
> +device: to read and write various Signals and Counts, and to set and get
> +the "action mode" and "function mode" for various Synapses and Counts
> +respectively.
> +
> +A defined counter_device structure may be registered to the system by
> +passing it to the counter_register function, and unregistered by passing
> +it to the counter_unregister function. Similarly, the
> +devm_counter_register and devm_counter_unregister functions may be used
> +if device memory-managed registration is desired.
> +
> +Extension sysfs attributes can be created for auxiliary functionality
> +and data by passing in defined counter_device_ext, counter_count_ext,
> +and counter_signal_ext structures. In these cases, the
> +counter_device_ext structure is used for global configuration of the
> +respective Counter device, while the counter_count_ext and
> +counter_signal_ext structures allow for auxiliary exposure and
> +configuration of a specific Count or Signal respectively.
> +
> +Architecture
> +============
> +
> +When the Generic Counter interface counter module is loaded, the
> +counter_init function is called which registers a bus_type named
> +"counter" to the system. Subsequently, when the module is unloaded, the
> +counter_exit function is called which unregisters the bus_type named
> +"counter" from the system.
> +
> +Counter devices are registered to the system via the counter_register
> +function, and later removed via the counter_unregister function. The
> +counter_register function establishes a unique ID for the Counter
> +device and creates a respective sysfs directory, where X is the
> +mentioned unique ID:
> +
> +    /sys/bus/counter/devices/counterX
> +
> +Sysfs attributes are created within the counterX directory to expose
> +functionality, configurations, and data relating to the Counts, Signals,
> +and Synapses of the Counter device, as well as options and information
> +for the Counter device itself.
> +
> +Each Signal has a directory created to house its relevant sysfs
> +attributes, where Y is the unique ID of the respective Signal:
> +
> +    /sys/bus/counter/devices/counterX/signalY
> +
> +Similarly, each Count has a directory created to house its relevant
> +sysfs attributes, where Y is the unique ID of the respective Count:
> +
> +    /sys/bus/counter/devices/counterX/countY
> +
> +For a more detailed breakdown of the available Generic Counter interface
> +sysfs attributes, please refer to the
> +Documentation/ABI/testing/sys-bus-counter file.
> +
> +The Signals and Counts associated with the Counter device are registered
> +to the system as well by the counter_register function. The
> +signal_read/signal_write driver callbacks are associated with their
> +respective Signal attributes, while the count_read/count_write and
> +function_get/function_set driver callbacks are associated with their
> +respective Count attributes; similarly, the same is true for the
> +action_get/action_set driver callbacks and their respective Synapse
> +attributes. If a driver callback is left undefined, then the respective
> +read/write permission is left disabled for the relevant attributes.
> +
> +Similarly, extension sysfs attributes are created for the defined
> +counter_device_ext, counter_count_ext, and counter_signal_ext
> +structures that are passed in.
> diff --git a/Documentation/driver-api/index.rst b/Documentation/driver-api/index.rst
> index 6d8352c0f354..5fd747c4f2ce 100644
> --- a/Documentation/driver-api/index.rst
> +++ b/Documentation/driver-api/index.rst
> @@ -25,6 +25,7 @@ available subsections can be seen below.
>     frame-buffer
>     regulator
>     iio/index
> +   generic-counter
>     input
>     usb/index
>     pci
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 1413e3eb49e5..7a01aa63fb33 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -3674,6 +3674,7 @@ M:	William Breathitt Gray <vilhelm.gray@gmail.com>
>  L:	linux-iio at vger.kernel.org
>  S:	Maintained
>  F:	Documentation/ABI/testing/sysfs-bus-counter*
> +F:	Documentation/driver-api/generic-counter.rst
>  F:	drivers/counter/
>  F:	include/linux/counter.h
>  

^ permalink raw reply

* [PATCH v6 2/9] counter: Documentation: Add Generic Counter sysfs documentation
From: Jonathan Cameron @ 2018-05-20 15:12 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1bf56af37a1d6dab8181ce71f827914acdf5c4f7.1526487615.git.vilhelm.gray@gmail.com>

On Wed, 16 May 2018 13:50:55 -0400
William Breathitt Gray <vilhelm.gray@gmail.com> wrote:

> This patch adds standard documentation for the userspace sysfs
> attributes of the Generic Counter interface.
> 
> Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>

Some really minor stuff inline.  No functional changes.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

> ---
>  Documentation/ABI/testing/sysfs-bus-counter | 241 ++++++++++++++++++++
>  MAINTAINERS                                 |   1 +
>  2 files changed, 242 insertions(+)
>  create mode 100644 Documentation/ABI/testing/sysfs-bus-counter
> 
> diff --git a/Documentation/ABI/testing/sysfs-bus-counter b/Documentation/ABI/testing/sysfs-bus-counter
> new file mode 100644
> index 000000000000..e4a45d231b4f
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-bus-counter
> @@ -0,0 +1,241 @@
> +What:		/sys/bus/counter/devices/counterX/countY/count
> +KernelVersion:	4.18
> +Contact:	linux-iio at vger.kernel.org
> +Description:
> +		Count data of Count Y represented as a string.
> +
> +What:		/sys/bus/counter/devices/counterX/countY/ceiling
> +KernelVersion:	4.18
> +Contact:	linux-iio at vger.kernel.org
> +Description:
> +		Count value ceiling for Count Y. This is the upper limit for the
> +		respective counter.
> +
> +What:		/sys/bus/counter/devices/counterX/countY/floor
> +KernelVersion:	4.18
> +Contact:	linux-iio at vger.kernel.org
> +Description:
> +		Count value floor for Count Y. This is the lower limit for the
> +		respective counter.
> +
> +What:		/sys/bus/counter/devices/counterX/countY/count_mode
> +KernelVersion:	4.18
> +Contact:	linux-iio at vger.kernel.org
> +Description:
> +		Count mode for channel Y. The ceiling and floor values for
> +		Count Y are used by the count mode where required. The following
> +		count modes are available:
> +
> +		Normal:
> +			Counting is continuous in either direction.
> +
> +		Range Limit:
> +			An upper or lower limit is set, mimicking limit switches
> +			in the mechanical counterpart. The upper limit is set to
> +			the Count Y ceiling value, while the lower limit is set
> +			to the Count Y floor value. The counter freezes at
> +			count = ceiling when counting up, and at count = floor
> +			when counting down. At either of these limits, the
> +			counting is resumed only when the count direction is
> +			reversed.
> +
> +		Non-Recycle:
> +			The counter is disabled whenever a counter overflow or
> +			underflow takes place. The counter is re-enabled when a
> +			new count value is loaded to the counter via a preset
> +			operation or direct write.
> +
> +		Modulo-N:
> +			A count value boundary is set between the Count Y floor
> +			value and the Count Y ceiling value. The counter is
> +			reset to the Cunt Y floor value at count = ceiling when
> +			counting up, while the counter is set to the Count Y
> +			ceiling value at count = floor when counting down; the
> +			counter does not freeze at the boundary points, but
> +			counts continuously throughout.
> +
> +What:		/sys/bus/counter/devices/counterX/countY/count_mode_available
> +What:		/sys/bus/counter/devices/counterX/countY/error_noise_available
> +What:		/sys/bus/counter/devices/counterX/countY/function_available
> +What:		/sys/bus/counter/devices/counterX/countY/signalZ_action_available
> +KernelVersion:	4.18
> +Contact:	linux-iio at vger.kernel.org
> +Description:
> +		Discrete set of available values for the respective Count Y
> +		configuration are listed in this file. Values are delineated by
> +		newline characters.
> +
> +What:		/sys/bus/counter/devices/counterX/countY/direction
> +KernelVersion:	4.18
> +Contact:	linux-iio at vger.kernel.org
> +Description:
> +		Read-only attribute that indicates the count direction of Count
> +		Y. Two count directions are available: forward and backward.
> +
> +		Some counter devices are able to determine the direction of
> +		their counting. For example, quadrature encoding counters can
> +		determine the direction of movement by evaluating the leading
> +		phase of the respective A and B quadrature encoding signals.
> +		This attribute exposes such count directions.
> +
> +What:		/sys/bus/counter/devices/counterX/countY/enable
> +KernelVersion:	4.18
> +Contact:	linux-iio at vger.kernel.org
> +Description:
> +		Whether channel Y counter is enabled. Valid attribute values are
> +		boolean.
> +
> +		This attribute is intended to serve as a pause/unpause mechanism
> +		for Count Y. Suppose a counter device is used to count the total
> +		movement of a conveyor belt: this attribute allows an operator
> +		to temporarily pause the counter, service the conveyor belt,
> +		and then finally unpause the counter to continue where it had
> +		left off.
> +
> +What:		/sys/bus/counter/devices/counterX/countY/error_noise
> +KernelVersion:	4.18
> +Contact:	linux-iio at vger.kernel.org
> +Description:
> +		Read-only attribute that indicates whether excessive noise is
> +		present at the channel Y counter inputs.
> +
> +What:		/sys/bus/counter/devices/counterX/countY/function
> +KernelVersion:	4.18
> +Contact:	linux-iio at vger.kernel.org
> +Description:
> +		Count function mode of Count Y; count function evaluation is
> +		triggered by conditions specified by the Count Y signalZ_action
> +		attributes. The following count functions are available:
> +
> +		Increase:
> +			Accumulated count is incremented.
> +
> +		Decrease:
> +			Accumulated count is decremented.
> +
> +		Pulse-Direction:
> +			Rising edges on quadrature pair signal A updates the
> +			respective count. The input level of quadrature pair
> +			signal B determines direction.
> +
> +		Quadrature x1 A:
> +			If direction is forward, rising edges on quadrature pair
> +			signal A updates the respective count; if the direction
> +			is backward, falling edges on quadrature pair signal A
> +			updates the respective count. Quadrature encoding
> +			determines the direction.
> +
> +		Quadrature x1 B:
> +			If direction is forward, rising edges on quadrature pair
> +			signal B updates the respective count; if the direction
> +			is backward, falling edges on quadrature pair signal B
> +			updates the respective count. Quadrature encoding
> +			determines the direction.
> +
> +		Quadrature x2 A:
> +			Any state transition on quadrature pair signal A updates
> +			the respective count. Quadrature encoding determines the
> +			direction.
> +
> +		Quadrature x2 B:
> +			Any state transition on quadrature pair signal B updates
> +			the respective count. Quadrature encoding determines the
> +			direction.
> +
> +		Quadrature x2 Rising:
> +			Rising edges on either quadrature pair signals updates
> +			the respective count. Quadrature encoding determines the
> +			direction.
> +
> +		Quadrature x2 Falling:
> +			Falling edges on either quadrature pair signals updates
> +			the respective count. Quadrature encoding determines the
> +			direction.
> +
> +		Quadrature x4:
> +			Any state transition on either quadrature pair signals
> +			updates	the respective count. Quadrature encoding
> +			determines the direction.
> +
> +What:		/sys/bus/counter/devices/counterX/countY/name
> +KernelVersion:	4.18
> +Contact:	linux-iio at vger.kernel.org
> +Description:
> +		Read-only attribute that indicates the device-specific name of
> +		Count Y. If possible, this should match the name of the
> +		respective channel as it appears in the device datasheet
> +		documentation text.
> +
> +What:		/sys/bus/counter/devices/counterX/countY/preset
> +KernelVersion:	4.18
> +Contact:	linux-iio at vger.kernel.org
> +Description:
> +		If the counter device supports preset registers, the preset
> +		count for channel Y is provided by this attribute.

I would add a small block of text here saying what a "preset" typically is.
It is a term heavily used in encoders etc, but perhaps not some other types
of counter.

> +
> +What:		/sys/bus/counter/devices/counterX/countY/preset_enable
> +KernelVersion:	4.18
> +Contact:	linux-iio at vger.kernel.org
> +Description:
> +		Whether channel Y counter preset operation is enabled. Valid
> +		attribute values are boolean.
> +
> +What:		/sys/bus/counter/devices/counterX/countY/signalZ_action
> +KernelVersion:	4.18
> +Contact:	linux-iio at vger.kernel.org
> +Description:
> +		Action mode of Count Y for Signal Z. This attribute indicates
> +		the condition of Signal Z that triggers the count function
> +		evaluation for Count Y. The following action modes are
> +		available:
> +
> +		None:
> +			Signal does not trigger the count function. In
> +			Pulse-Direction count function mode, this Signal is
> +			evaluated as Direction.
> +
> +		Rising Edge:
> +			Low state transitions to high state.
> +
> +		Falling Edge:
> +			High state transitions to low state.
> +
> +		Both Edges:
> +			Any state transition.
> +
> +What:		/sys/bus/counter/devices/counterX/name
> +KernelVersion:	4.18
> +Contact:	linux-iio at vger.kernel.org
> +Description:
> +		Read-only attribute that indicates the device-specific name of
> +		the Counter. This should match the name of the device as it
> +		appears in its respective datasheet documentation text.

As below, I'm not sure if "documentation text" makes it clearer or less clear..

> +
> +What:		/sys/bus/counter/devices/counterX/num_counts
> +KernelVersion:	4.18
> +Contact:	linux-iio at vger.kernel.org
> +Description:
> +		Read-only attribute that indicates the total number of Counts
> +		belonging to the Counter.
> +
> +What:		/sys/bus/counter/devices/counterX/num_signals
> +KernelVersion:	4.18
> +Contact:	linux-iio at vger.kernel.org
> +Description:
> +		Read-only attribute that indicates the total number of Signals
> +		belonging to the Counter.
> +
> +What:		/sys/bus/counter/devices/counterX/signalY/signal
> +KernelVersion:	4.18
> +Contact:	linux-iio at vger.kernel.org
> +Description:
> +		Signal data of Signal Y represented as a string.
> +
> +What:		/sys/bus/counter/devices/counterX/signalY/name
> +KernelVersion:	4.18
> +Contact:	linux-iio at vger.kernel.org
> +Description:
> +		Read-only attribute that indicates the device-specific name of
> +		Signal Y. If possible, this should match the name of the
> +		respective signal as it appears in the device datasheet
> +		documentation text.

Not sure "documentation text" adds any clarity over the simply "device datasheet"

> diff --git a/MAINTAINERS b/MAINTAINERS
> index 2a016d73ab72..1413e3eb49e5 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -3673,6 +3673,7 @@ COUNTER SUBSYSTEM
>  M:	William Breathitt Gray <vilhelm.gray@gmail.com>
>  L:	linux-iio at vger.kernel.org
>  S:	Maintained
> +F:	Documentation/ABI/testing/sysfs-bus-counter*
>  F:	drivers/counter/
>  F:	include/linux/counter.h
>  

^ permalink raw reply

* [PATCH v6 1/9] counter: Introduce the Generic Counter interface
From: Jonathan Cameron @ 2018-05-20 15:06 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <6e0c93ccc771033f0a8bc08bd92b453a1dacbd1b.1526487615.git.vilhelm.gray@gmail.com>

On Wed, 16 May 2018 13:50:43 -0400
William Breathitt Gray <vilhelm.gray@gmail.com> wrote:

> This patch introduces the Generic Counter interface for supporting
> counter devices.
> 
> In the context of the Generic Counter interface, a counter is defined as
> a device that reports one or more "counts" based on the state changes of
> one or more "signals" as evaluated by a defined "count function."
> 
> Driver callbacks should be provided to communicate with the device: to
> read and write various Signals and Counts, and to set and get the
> "action mode" and "count function" for various Synapses and Counts
> respectively.
> 
> To support a counter device, a driver must first allocate the available
> Counter Signals via counter_signal structures. These Signals should
> be stored as an array and set to the signals array member of an
> allocated counter_device structure before the Counter is registered to
> the system.
> 
> Counter Counts may be allocated via counter_count structures, and
> respective Counter Signal associations (Synapses) made via
> counter_synapse structures. Associated counter_synapse structures are
> stored as an array and set to the the synapses array member of the
> respective counter_count structure. These counter_count structures are
> set to the counts array member of an allocated counter_device structure
> before the Counter is registered to the system.
> 
> A counter device is registered to the system by passing the respective
> initialized counter_device structure to the counter_register function;
> similarly, the counter_unregister function unregisters the respective
> Counter. The devm_counter_register and devm_counter_unregister functions
> serve as device memory-managed versions of the counter_register and
> counter_unregister functions respectively.
> 
> Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>

A few minor comments inline.  I do somewhat wonder if we can cut
back on the huge amount of 'similar' code in here, but there tend to
be just enough small differences to make that really tricky...

Nothing major enough in here that I really plan on reading it again
(though you never know if you change lots ;)

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> ---
>  MAINTAINERS                       |    7 +
>  drivers/Kconfig                   |    2 +
>  drivers/Makefile                  |    1 +
>  drivers/counter/Kconfig           |   18 +
>  drivers/counter/Makefile          |    8 +
>  drivers/counter/generic-counter.c | 1541 +++++++++++++++++++++++++++++
>  include/linux/counter.h           |  554 +++++++++++
>  7 files changed, 2131 insertions(+)
>  create mode 100644 drivers/counter/Kconfig
>  create mode 100644 drivers/counter/Makefile
>  create mode 100644 drivers/counter/generic-counter.c
>  create mode 100644 include/linux/counter.h
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 4b65225d443a..2a016d73ab72 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -3669,6 +3669,13 @@ W:	http://www.fi.muni.cz/~kas/cosa/
>  S:	Maintained
>  F:	drivers/net/wan/cosa*
>  
> +COUNTER SUBSYSTEM
> +M:	William Breathitt Gray <vilhelm.gray@gmail.com>
> +L:	linux-iio at vger.kernel.org
> +S:	Maintained
> +F:	drivers/counter/
> +F:	include/linux/counter.h
> +
>  CPMAC ETHERNET DRIVER
>  M:	Florian Fainelli <f.fainelli@gmail.com>
>  L:	netdev at vger.kernel.org
> diff --git a/drivers/Kconfig b/drivers/Kconfig
> index 95b9ccc08165..70b3cc88dc0b 100644
> --- a/drivers/Kconfig
> +++ b/drivers/Kconfig
> @@ -165,6 +165,8 @@ source "drivers/memory/Kconfig"
>  
>  source "drivers/iio/Kconfig"
>  
> +source "drivers/counter/Kconfig"
> +
Same comment as below.

>  source "drivers/ntb/Kconfig"
>  
>  source "drivers/vme/Kconfig"
> diff --git a/drivers/Makefile b/drivers/Makefile
> index 24cd47014657..5914c78688c3 100644
> --- a/drivers/Makefile
> +++ b/drivers/Makefile
> @@ -165,6 +165,7 @@ obj-$(CONFIG_PM_DEVFREQ)	+= devfreq/
>  obj-$(CONFIG_EXTCON)		+= extcon/
>  obj-$(CONFIG_MEMORY)		+= memory/
>  obj-$(CONFIG_IIO)		+= iio/
> +obj-$(CONFIG_COUNTER)		+= counter/

I can see your logic in putting this here, but I think the convention
is to go at the end rather than grouping.

>  obj-$(CONFIG_VME_BUS)		+= vme/
>  obj-$(CONFIG_IPACK_BUS)		+= ipack/
>  obj-$(CONFIG_NTB)		+= ntb/
> diff --git a/drivers/counter/Kconfig b/drivers/counter/Kconfig
> new file mode 100644
> index 000000000000..65fa92abd5a4
> --- /dev/null
> +++ b/drivers/counter/Kconfig
> @@ -0,0 +1,18 @@
> +#
> +# Counter devices
> +#
> +# When adding new entries keep the list in alphabetical order
> +
> +menuconfig COUNTER
> +	tristate "Counter support"
> +	help
> +	  Provides Generic Counter interface support for counter devices.
> +
> +	  Counter devices are prevalent within a diverse spectrum of industries.
> +	  The ubiquitous presence of these devices necessitates a common
> +	  interface and standard of interaction and exposure. This driver API
> +	  attempts to resolve the issue of duplicate code found among existing
> +	  counter device drivers by providing a generic counter interface for
> +	  consumption. The Generic Counter interface enables drivers to support
> +	  and expose a common set of components and functionality present in
> +	  counter devices.
> diff --git a/drivers/counter/Makefile b/drivers/counter/Makefile
> new file mode 100644
> index 000000000000..ad1ba7109cdc
> --- /dev/null
> +++ b/drivers/counter/Makefile
> @@ -0,0 +1,8 @@
> +#
> +# Makefile for Counter devices
> +#
> +
> +# When adding new entries keep the list in alphabetical order
> +
> +obj-$(CONFIG_COUNTER) += counter.o
> +counter-y := generic-counter.o
> diff --git a/drivers/counter/generic-counter.c b/drivers/counter/generic-counter.c
> new file mode 100644
> index 000000000000..0d83b862453f
> --- /dev/null
> +++ b/drivers/counter/generic-counter.c
> @@ -0,0 +1,1541 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Generic Counter interface
> + * Copyright (C) 2017 William Breathitt Gray
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License, version 2, as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful, but
> + * WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * General Public License for more details.

As below, SPDX and license seems silly.  Unless you are feeling paranoid
just drop the license text.

> + */
> +#include <linux/device.h>
> +#include <linux/err.h>
> +#include <linux/export.h>
> +#include <linux/fs.h>
> +#include <linux/gfp.h>
> +#include <linux/idr.h>
> +#include <linux/init.h>
> +#include <linux/kernel.h>
> +#include <linux/list.h>
> +#include <linux/module.h>
> +#include <linux/printk.h>
> +#include <linux/slab.h>
> +#include <linux/string.h>
> +#include <linux/sysfs.h>
> +#include <linux/types.h>
> +
> +#include <linux/counter.h>
> +
> +const char *const count_direction_str[2] = {
> +	[COUNT_DIRECTION_FORWARD] = "forward",
> +	[COUNT_DIRECTION_BACKWARD] = "backward"
> +};
> +EXPORT_SYMBOL(count_direction_str);
> +
> +const char *const count_mode_str[4] = {
> +	[COUNT_MODE_NORMAL] = "normal",
> +	[COUNT_MODE_RANGE_LIMIT] = "range limit",
> +	[COUNT_MODE_NON_RECYCLE] = "non-recycle",
> +	[COUNT_MODE_MODULO_N] = "modulo-n"
> +};
> +EXPORT_SYMBOL(count_mode_str);
> +
> +ssize_t counter_signal_enum_read(struct counter_device *counter,
> +				 struct counter_signal *signal, void *priv,
> +				 char *buf)
> +{
> +	const struct counter_signal_enum_ext *const e = priv;
> +	int err;
> +	size_t index;
> +
> +	if (!e->get)
> +		return -EINVAL;
> +
> +	err = e->get(counter, signal, &index);
> +	if (err)
> +		return err;
> +
> +	if (index >= e->num_items)
> +		return -EINVAL;
> +
> +	return scnprintf(buf, PAGE_SIZE, "%s\n", e->items[index]);
> +}
> +EXPORT_SYMBOL(counter_signal_enum_read);
> +
> +ssize_t counter_signal_enum_write(struct counter_device *counter,
> +				  struct counter_signal *signal, void *priv,
> +				  const char *buf, size_t len)
> +{
> +	const struct counter_signal_enum_ext *const e = priv;
> +	ssize_t index;
> +	int err;
> +
> +	if (!e->set)
> +		return -EINVAL;
> +
> +	index = __sysfs_match_string(e->items, e->num_items, buf);
> +	if (index < 0)
> +		return index;
> +
> +	err = e->set(counter, signal, index);
> +	if (err)
> +		return err;
> +
> +	return len;
> +}
> +EXPORT_SYMBOL(counter_signal_enum_write);
> +
> +ssize_t counter_signal_enum_available_read(struct counter_device *counter,
> +					   struct counter_signal *signal,
> +					   void *priv, char *buf)
> +{
> +	const struct counter_signal_enum_ext *const e = priv;
> +	size_t i;
> +	size_t len = 0;
> +
> +	if (!e->num_items)
> +		return 0;
> +
> +	for (i = 0; i < e->num_items; i++)
> +		len += scnprintf(buf + len, PAGE_SIZE - len, "%s\n",
> +			e->items[i]);
> +
> +	return len;
> +}
> +EXPORT_SYMBOL(counter_signal_enum_available_read);
> +
> +ssize_t counter_count_enum_read(struct counter_device *counter,
> +				struct counter_count *count, void *priv,
> +				char *buf)
> +{
> +	const struct counter_count_enum_ext *const e = priv;
> +	int err;
> +	size_t index;
> +
> +	if (!e->get)
> +		return -EINVAL;
> +
> +	err = e->get(counter, count, &index);
> +	if (err)
> +		return err;
> +
> +	if (index >= e->num_items)
> +		return -EINVAL;
> +
> +	return scnprintf(buf, PAGE_SIZE, "%s\n", e->items[index]);
> +}
> +EXPORT_SYMBOL(counter_count_enum_read);
> +
> +ssize_t counter_count_enum_write(struct counter_device *counter,
> +				 struct counter_count *count, void *priv,
> +				 const char *buf, size_t len)
> +{
> +	const struct counter_count_enum_ext *const e = priv;
> +	ssize_t index;
> +	int err;
> +
> +	if (!e->set)
> +		return -EINVAL;
> +
> +	index = __sysfs_match_string(e->items, e->num_items, buf);
> +	if (index < 0)
> +		return index;
> +
> +	err = e->set(counter, count, index);
> +	if (err)
> +		return err;
> +
> +	return len;
> +}
> +EXPORT_SYMBOL(counter_count_enum_write);
> +
> +ssize_t counter_count_enum_available_read(struct counter_device *counter,
> +					  struct counter_count *count,
> +					  void *priv, char *buf)
> +{
> +	const struct counter_count_enum_ext *const e = priv;
> +	size_t i;
> +	size_t len = 0;
> +
> +	if (!e->num_items)
> +		return 0;
> +
> +	for (i = 0; i < e->num_items; i++)
> +		len += scnprintf(buf + len, PAGE_SIZE - len, "%s\n",
> +			e->items[i]);
> +
> +	return len;
> +}
> +EXPORT_SYMBOL(counter_count_enum_available_read);
> +
> +ssize_t counter_device_enum_read(struct counter_device *counter, void *priv,
> +				 char *buf)
> +{
> +	const struct counter_device_enum_ext *const e = priv;
> +	int err;
> +	size_t index;
> +
> +	if (!e->get)
> +		return -EINVAL;
> +
> +	err = e->get(counter, &index);
> +	if (err)
> +		return err;
> +
> +	if (index >= e->num_items)
> +		return -EINVAL;
> +
> +	return scnprintf(buf, PAGE_SIZE, "%s\n", e->items[index]);
> +}
> +EXPORT_SYMBOL(counter_device_enum_read);
> +
> +ssize_t counter_device_enum_write(struct counter_device *counter, void *priv,
> +				  const char *buf, size_t len)
> +{
> +	const struct counter_device_enum_ext *const e = priv;
> +	ssize_t index;
> +	int err;
> +
> +	if (!e->set)
> +		return -EINVAL;
> +
> +	index = __sysfs_match_string(e->items, e->num_items, buf);
> +	if (index < 0)
> +		return index;
> +
> +	err = e->set(counter, index);
> +	if (err)
> +		return err;
> +
> +	return len;
> +}
> +EXPORT_SYMBOL(counter_device_enum_write);
> +
> +ssize_t counter_device_enum_available_read(struct counter_device *counter,
> +					   void *priv, char *buf)
> +{
> +	const struct counter_device_enum_ext *const e = priv;
> +	size_t i;
> +	size_t len = 0;
> +
> +	if (!e->num_items)
> +		return 0;
> +
> +	for (i = 0; i < e->num_items; i++)
> +		len += scnprintf(buf + len, PAGE_SIZE - len, "%s\n",
> +			e->items[i]);
> +
> +	return len;
> +}
> +EXPORT_SYMBOL(counter_device_enum_available_read);
> +
> +static const char *const signal_level_str[] = {
> +	[SIGNAL_LEVEL_LOW] = "low",
> +	[SIGNAL_LEVEL_HIGH] = "high"
> +};
> +
> +/**
> + * set_signal_read_value - set signal_read_value data
> + * @val:	signal_read_value structure to set
> + * @type:	property Signal data represents
> + * @data:	Signal data
> + *
> + * This function sets an opaque signal_read_value structure with the provided
> + * Signal data.
> + */
> +void set_signal_read_value(struct signal_read_value *const val,
> +			   const enum signal_value_type type, void *const data)
> +{
> +	if (type == SIGNAL_LEVEL)
> +		val->len = scnprintf(val->buf, PAGE_SIZE, "%s\n",
> +			signal_level_str[*(enum signal_level *)data]);
> +	else
> +		val->len = 0;
> +}
> +EXPORT_SYMBOL(set_signal_read_value);
> +
> +/**
> + * set_count_read_value - set count_read_value data
> + * @val:	count_read_value structure to set
> + * @type:	property Count data represents
> + * @data:	Count data
> + *
> + * This function sets an opaque count_read_value structure with the provided
> + * Count data.
> + */
> +void set_count_read_value(struct count_read_value *const val,
> +			  const enum count_value_type type, void *const data)
> +{
> +	switch (type) {
> +	case COUNT_POSITION_UNSIGNED:
> +		val->len = scnprintf(val->buf, PAGE_SIZE, "%lu\n",
> +				     *(unsigned long *)data);
> +		break;
> +	case COUNT_POSITION_SIGNED:
> +		val->len = scnprintf(val->buf, PAGE_SIZE, "%ld\n",
> +				     *(long *)data);
> +		break;
> +	default:
> +		val->len = 0;
> +	}
> +}
> +EXPORT_SYMBOL(set_count_read_value);
> +
> +/**
> + * get_count_write_value - get count_write_value data
> + * @data:	Count data
> + * @type:	property Count data represents
> + * @val:	count_write_value structure containing data
> + *
> + * This function extracts Count data from the provided opaque count_write_value
> + * structure and stores it at the address provided by @data.
> + *
> + * RETURNS:
> + * 0 on success, negative error number on failure.
> + */
> +int get_count_write_value(void *const data, const enum count_value_type type,
> +			  const struct count_write_value *const val)
> +{
> +	int err;
> +
> +	switch (type) {
> +	case COUNT_POSITION_UNSIGNED:
> +		err = kstrtoul(val->buf, 0, data);
> +		if (err)
> +			return err;
> +		break;
> +	case COUNT_POSITION_SIGNED:
> +		err = kstrtol(val->buf, 0, data);
> +		if (err)
> +			return err;
> +		break;
> +	}
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(get_count_write_value);
> +
> +struct counter_device_attr {
> +	struct device_attribute		dev_attr;
> +	struct list_head		l;
> +	void				*component;
> +};
> +
> +static int counter_attribute_create(
> +	struct counter_device_attr_group *const group,
> +	const char *const prefix,
> +	const char *const name,
> +	ssize_t (*show)(struct device *dev, struct device_attribute *attr,
> +			char *buf),
> +	ssize_t (*store)(struct device *dev, struct device_attribute *attr,
> +			 const char *buf, size_t len),
> +	void *const component)
> +{
> +	struct counter_device_attr *counter_attr;
> +	struct device_attribute *dev_attr;
> +	int err;
> +	struct list_head *const attr_list = &group->attr_list;
> +
> +	/* Allocate a Counter device attribute */
> +	counter_attr = kzalloc(sizeof(*counter_attr), GFP_KERNEL);
> +	if (!counter_attr)
> +		return -ENOMEM;
> +	dev_attr = &counter_attr->dev_attr;
> +
> +	sysfs_attr_init(&dev_attr->attr);
> +
> +	/* Configure device attribute */
> +	dev_attr->attr.name = kasprintf(GFP_KERNEL, "%s%s", prefix, name);
> +	if (!dev_attr->attr.name) {
> +		err = -ENOMEM;
> +		goto err_free_counter_attr;
> +	}
> +	if (show) {
> +		dev_attr->attr.mode |= 0444;
> +		dev_attr->show = show;
> +	}
> +	if (store) {
> +		dev_attr->attr.mode |= 0200;
> +		dev_attr->store = store;
> +	}
> +
> +	/* Store associated Counter component with attribute */
> +	counter_attr->component = component;
> +
> +	/* Keep track of the attribute for later cleanup */
> +	list_add(&counter_attr->l, attr_list);
> +	group->num_attr++;
> +
> +	return 0;
> +
> +err_free_counter_attr:
> +	kfree(counter_attr);
> +	return err;
> +}
> +
> +#define to_counter_attr(_dev_attr) \
> +	container_of(_dev_attr, struct counter_device_attr, dev_attr)
> +
> +struct signal_comp_t {
> +	struct counter_signal	*signal;
> +};
> +
> +static ssize_t counter_signal_show(struct device *dev,
> +				   struct device_attribute *attr, char *buf)
> +{
> +	struct counter_device *const counter = dev_get_drvdata(dev);
> +	const struct counter_device_attr *const devattr = to_counter_attr(attr);
> +	const struct signal_comp_t *const component = devattr->component;
> +	struct counter_signal *const signal = component->signal;
> +	int err;
> +	struct signal_read_value val = { .buf = buf };
> +
> +	err = counter->ops->signal_read(counter, signal, &val);
> +	if (err)
> +		return err;
> +
> +	return val.len;
> +}
> +
> +struct name_comp_t {
> +	const char	*name;
> +};
> +
> +static ssize_t counter_device_attr_name_show(struct device *dev,
> +					     struct device_attribute *attr,
> +					     char *buf)
> +{
> +	const struct name_comp_t *const comp = to_counter_attr(attr)->component;
> +
> +	return scnprintf(buf, PAGE_SIZE, "%s\n", comp->name);
> +}
> +
> +static int counter_name_attribute_create(
> +	struct counter_device_attr_group *const group,
> +	const char *const name)
> +{
> +	struct name_comp_t *name_comp;
> +	int err;
> +
> +	/* Skip if no name */
> +	if (!name)
> +		return 0;
> +
> +	/* Allocate name attribute component */
> +	name_comp = kmalloc(sizeof(*name_comp), GFP_KERNEL);
> +	if (!name_comp)
> +		return -ENOMEM;
> +	name_comp->name = name;
> +
> +	/* Allocate Signal name attribute */
> +	err = counter_attribute_create(group, "", "name",
> +				       counter_device_attr_name_show, NULL,
> +				       name_comp);
> +	if (err)
> +		goto err_free_name_comp;
> +
> +	return 0;
> +
> +err_free_name_comp:
> +	kfree(name_comp);
> +	return err;
> +}
> +
> +struct signal_ext_comp_t {
> +	struct counter_signal		*signal;
> +	const struct counter_signal_ext	*ext;
> +};
> +
> +static ssize_t counter_signal_ext_show(struct device *dev,
> +				       struct device_attribute *attr, char *buf)
> +{
> +	const struct counter_device_attr *const devattr = to_counter_attr(attr);
> +	const struct signal_ext_comp_t *const comp = devattr->component;
> +	const struct counter_signal_ext *const ext = comp->ext;
> +
> +	return ext->read(dev_get_drvdata(dev), comp->signal, ext->priv, buf);
> +}
> +
> +static ssize_t counter_signal_ext_store(struct device *dev,
> +					struct device_attribute *attr,
> +					const char *buf, size_t len)
> +{
> +	const struct counter_device_attr *const devattr = to_counter_attr(attr);
> +	const struct signal_ext_comp_t *const comp = devattr->component;
> +	const struct counter_signal_ext *const ext = comp->ext;
> +
> +	return ext->write(dev_get_drvdata(dev), comp->signal, ext->priv, buf,
> +		len);
> +}
> +
> +static void free_counter_device_attr_list(struct list_head *attr_list)
> +{
> +	struct counter_device_attr *p, *n;
> +
> +	list_for_each_entry_safe(p, n, attr_list, l) {
> +		kfree(p->dev_attr.attr.name);
> +		kfree(p->component);
> +		list_del(&p->l);
> +		kfree(p);
> +	}
> +}
> +
> +static int counter_signal_ext_register(
> +	struct counter_device_attr_group *const group,
> +	struct counter_signal *const signal)
> +{
> +	const size_t num_ext = signal->num_ext;
> +	size_t i;
> +	const struct counter_signal_ext *ext;
> +	struct signal_ext_comp_t *signal_ext_comp;
> +	int err;
> +
> +	/* Create an attribute for each extension */
> +	for (i = 0 ; i < num_ext; i++) {
> +		ext = signal->ext + i;
> +
> +		/* Allocate signal_ext attribute component */
> +		signal_ext_comp = kmalloc(sizeof(*signal_ext_comp), GFP_KERNEL);
> +		if (!signal_ext_comp) {
> +			err = -ENOMEM;
> +			goto err_free_attr_list;
> +		}
> +		signal_ext_comp->signal = signal;
> +		signal_ext_comp->ext = ext;
> +
> +		/* Allocate a Counter device attribute */
> +		err = counter_attribute_create(group, "", ext->name,
> +			(ext->read) ? counter_signal_ext_show : NULL,
> +			(ext->write) ? counter_signal_ext_store : NULL,
> +			signal_ext_comp);
> +		if (err) {
> +			kfree(signal_ext_comp);
> +			goto err_free_attr_list;
> +		}
> +	}
> +
> +	return 0;
> +
> +err_free_attr_list:
> +	free_counter_device_attr_list(&group->attr_list);
> +	return err;
> +}
> +
> +static int counter_signal_attributes_create(
> +	struct counter_device_attr_group *const group,
> +	const struct counter_device *const counter,
> +	struct counter_signal *const signal)
> +{
> +	struct signal_comp_t *signal_comp;
> +	int err;
> +
> +	/* Allocate Signal attribute component */
> +	signal_comp = kmalloc(sizeof(*signal_comp), GFP_KERNEL);
> +	if (!signal_comp)
> +		return -ENOMEM;
> +	signal_comp->signal = signal;
> +
> +	/* Create main Signal attribute */
> +	err = counter_attribute_create(group, "", "signal",
> +		(counter->ops->signal_read) ? counter_signal_show : NULL, NULL,
> +		signal_comp);
> +	if (err) {
> +		kfree(signal_comp);
> +		return err;
> +	}
> +
> +	/* Create Signal name attribute */
> +	err = counter_name_attribute_create(group, signal->name);
> +	if (err)
> +		goto err_free_attr_list;
> +
> +	/* Register Signal extension attributes */
> +	err = counter_signal_ext_register(group, signal);
> +	if (err)
> +		goto err_free_attr_list;
> +
> +	return 0;
> +
> +err_free_attr_list:
> +	free_counter_device_attr_list(&group->attr_list);
> +	return err;
> +}
> +
> +static int counter_signals_register(
> +	struct counter_device_attr_group *const groups_list,
> +	const struct counter_device *const counter)
> +{
> +	const size_t num_signals = counter->num_signals;
> +	size_t i;
> +	struct counter_signal *signal;
> +	const char *name;
> +	int err;
> +
> +	/* Register each Signal */
> +	for (i = 0; i < num_signals; i++) {
> +		signal = counter->signals + i;
> +
> +		/* Generate Signal attribute directory name */
> +		name = kasprintf(GFP_KERNEL, "signal%d", signal->id);
> +		if (!name) {
> +			err = -ENOMEM;
> +			goto err_free_attr_groups;
> +		}
> +		groups_list[i].attr_group.name = name;
> +
> +		/* Create all attributes associated with Signal */
> +		err = counter_signal_attributes_create(groups_list + i, counter,
> +						       signal);
> +		if (err)
> +			goto err_free_attr_groups;
> +	}
> +
> +	return 0;
> +
> +err_free_attr_groups:
> +	do {
> +		kfree(groups_list[i].attr_group.name);
> +		free_counter_device_attr_list(&groups_list[i].attr_list);
> +	} while (i--);
> +	return err;
> +}
> +
> +static const char *const synapse_action_str[] = {
> +	[SYNAPSE_ACTION_NONE] = "none",
> +	[SYNAPSE_ACTION_RISING_EDGE] = "rising edge",
> +	[SYNAPSE_ACTION_FALLING_EDGE] = "falling edge",
> +	[SYNAPSE_ACTION_BOTH_EDGES] = "both edges"
> +};
> +
> +struct action_comp_t {
> +	struct counter_synapse	*synapse;
> +	struct counter_count	*count;
> +};
> +
> +static ssize_t counter_action_show(struct device *dev,
> +				   struct device_attribute *attr, char *buf)
> +{
> +	const struct counter_device_attr *const devattr = to_counter_attr(attr);
> +	int err;
> +	struct counter_device *const counter = dev_get_drvdata(dev);
> +	const struct action_comp_t *const component = devattr->component;
> +	struct counter_count *const count = component->count;
> +	struct counter_synapse *const synapse = component->synapse;
> +	size_t action_index;
> +	enum synapse_action action;
> +
> +	err = counter->ops->action_get(counter, count, synapse, &action_index);
> +	if (err)
> +		return err;
> +
> +	synapse->action = action_index;
> +
> +	action = synapse->actions_list[action_index];
> +	return scnprintf(buf, PAGE_SIZE, "%s\n", synapse_action_str[action]);
> +}
> +
> +static ssize_t counter_action_store(struct device *dev,
> +				    struct device_attribute *attr,
> +				    const char *buf, size_t len)
> +{
> +	const struct counter_device_attr *const devattr = to_counter_attr(attr);
> +	const struct action_comp_t *const component = devattr->component;
> +	struct counter_synapse *const synapse = component->synapse;
> +	size_t action_index;
> +	const size_t num_actions = synapse->num_actions;
> +	enum synapse_action action;
> +	int err;
> +	struct counter_device *const counter = dev_get_drvdata(dev);
> +	struct counter_count *const count = component->count;
> +
> +	/* Find requested action mode */
> +	for (action_index = 0; action_index < num_actions; action_index++) {
> +		action = synapse->actions_list[action_index];
> +		if (sysfs_streq(buf, synapse_action_str[action]))
> +			break;
> +	}
> +	/* If requested action mode not found */
> +	if (action_index >= num_actions)
> +		return -EINVAL;
> +
> +	err = counter->ops->action_set(counter, count, synapse, action_index);
> +	if (err)
> +		return err;
> +
> +	synapse->action = action_index;
> +
> +	return len;
> +}
> +
> +struct action_avail_comp_t {
> +	const enum synapse_action	*actions_list;
> +	size_t				num_actions;
> +};
> +
> +static ssize_t counter_synapse_action_available_show(struct device *dev,
> +	struct device_attribute *attr, char *buf)
> +{
> +	const struct counter_device_attr *const devattr = to_counter_attr(attr);
> +	const struct action_avail_comp_t *const component = devattr->component;
> +	const enum synapse_action *const actions_list = component->actions_list;

I'm not sure this local variable helps much either...

> +	const size_t num_actions = component->num_actions;

Local variable adds nothing as far as I can see..  Just use it inline.


> +	size_t i;
> +	enum synapse_action action;
> +	ssize_t len = 0;
> +
> +	for (i = 0; i < num_actions; i++) {
> +		action = actions_list[i];
> +		len += scnprintf(buf + len, PAGE_SIZE - len, "%s\n",
> +			synapse_action_str[action]);
> +	}
> +
> +	return len;
> +}
> +
> +static int counter_synapses_register(
> +	struct counter_device_attr_group *const group,
> +	const struct counter_device *const counter,
> +	struct counter_count *const count, const char *const count_attr_name)
> +{
> +	const size_t num_synapses = count->num_synapses;

Local variable doesn't add anything. Only used once.

> +	size_t i;
> +	struct counter_synapse *synapse;
> +	const char *prefix;
> +	struct action_comp_t *action_comp;
> +	int err;
> +	struct action_avail_comp_t *avail_comp;
> +
> +	/* Register each Synapse */
> +	for (i = 0; i < num_synapses; i++) {
> +		synapse = count->synapses + i;
> +
> +		/* Generate attribute prefix */
> +		prefix = kasprintf(GFP_KERNEL, "signal%d_",
> +				   synapse->signal->id);
> +		if (!prefix) {
> +			err = -ENOMEM;
> +			goto err_free_attr_list;
> +		}
> +
> +		/* Allocate action attribute component */
> +		action_comp = kmalloc(sizeof(*action_comp), GFP_KERNEL);
> +		if (!action_comp) {
> +			err = -ENOMEM;
> +			goto err_free_prefix;
> +		}
> +		action_comp->synapse = synapse;
> +		action_comp->count = count;
> +
> +		/* Create action attribute */
> +		err = counter_attribute_create(group, prefix, "action",
> +			(counter->ops->action_get) ? counter_action_show : NULL,
> +			(counter->ops->action_set) ? counter_action_store : NULL,
> +			action_comp);
> +		if (err) {
> +			kfree(action_comp);
> +			goto err_free_prefix;
> +		}
> +
> +		/* Allocate action available attribute component */
> +		avail_comp = kmalloc(sizeof(*avail_comp), GFP_KERNEL);
> +		if (!avail_comp) {
> +			err = -ENOMEM;
> +			goto err_free_prefix;
> +		}
> +		avail_comp->actions_list = synapse->actions_list;
> +		avail_comp->num_actions = synapse->num_actions;
> +
> +		/* Create action_available attribute */
> +		err = counter_attribute_create(group, prefix,
> +			"action_available",
> +			counter_synapse_action_available_show, NULL,
> +			avail_comp);
> +		if (err) {
> +			kfree(avail_comp);
> +			goto err_free_prefix;
> +		}
> +
> +		kfree(prefix);
> +	}
> +
> +	return 0;
> +
> +err_free_prefix:
> +	kfree(prefix);
> +err_free_attr_list:
> +	free_counter_device_attr_list(&group->attr_list);
> +	return err;
> +}
> +
> +struct count_comp_t {
> +	struct counter_count	*count;
> +};
> +
> +static ssize_t counter_count_show(struct device *dev,
> +				  struct device_attribute *attr,
> +				  char *buf)
> +{
> +	struct counter_device *const counter = dev_get_drvdata(dev);
> +	const struct counter_device_attr *const devattr = to_counter_attr(attr);
> +	const struct count_comp_t *const component = devattr->component;
> +	struct counter_count *const count = component->count;
> +	int err;
> +	struct count_read_value val = { .buf = buf };
> +
> +	err = counter->ops->count_read(counter, count, &val);
> +	if (err)
> +		return err;
> +
> +	return val.len;
> +}
> +
> +static ssize_t counter_count_store(struct device *dev,
> +				   struct device_attribute *attr,
> +				   const char *buf, size_t len)
> +{
> +	struct counter_device *const counter = dev_get_drvdata(dev);
> +	const struct counter_device_attr *const devattr = to_counter_attr(attr);
> +	const struct count_comp_t *const component = devattr->component;
> +	struct counter_count *const count = component->count;
> +	int err;
> +	struct count_write_value val = { .buf = buf };
> +
> +	err = counter->ops->count_write(counter, count, &val);
> +	if (err)
> +		return err;
> +
> +	return len;
> +}
> +
> +static const char *const count_function_str[] = {
> +	[COUNT_FUNCTION_INCREASE] = "increase",
> +	[COUNT_FUNCTION_DECREASE] = "decrease",
> +	[COUNT_FUNCTION_PULSE_DIRECTION] = "pulse-direction",
> +	[COUNT_FUNCTION_QUADRATURE_X1_A] = "quadrature x1 a",
> +	[COUNT_FUNCTION_QUADRATURE_X1_B] = "quadrature x1 b",
> +	[COUNT_FUNCTION_QUADRATURE_X2_A] = "quadrature x2 a",
> +	[COUNT_FUNCTION_QUADRATURE_X2_B] = "quadrature x2 b",
> +	[COUNT_FUNCTION_QUADRATURE_X2_RISING] = "quadrature x2 rising",
> +	[COUNT_FUNCTION_QUADRATURE_X2_FALLING] = "quadrature x2 falling",
> +	[COUNT_FUNCTION_QUADRATURE_X4] = "quadrature x4"
> +};
> +
> +static ssize_t counter_function_show(struct device *dev,
> +				     struct device_attribute *attr, char *buf)
> +{
> +	int err;
> +	struct counter_device *const counter = dev_get_drvdata(dev);
> +	const struct counter_device_attr *const devattr = to_counter_attr(attr);
> +	const struct count_comp_t *const component = devattr->component;
> +	struct counter_count *const count = component->count;
> +	size_t func_index;
> +	enum count_function function;
> +
> +	err = counter->ops->function_get(counter, count, &func_index);
> +	if (err)
> +		return err;
> +
> +	count->function = func_index;
> +
> +	function = count->functions_list[func_index];
> +	return scnprintf(buf, PAGE_SIZE, "%s\n", count_function_str[function]);
> +}
> +
> +static ssize_t counter_function_store(struct device *dev,
> +				      struct device_attribute *attr,
> +				      const char *buf, size_t len)
> +{
> +	const struct counter_device_attr *const devattr = to_counter_attr(attr);
> +	const struct count_comp_t *const component = devattr->component;
> +	struct counter_count *const count = component->count;
> +	const size_t num_functions = count->num_functions;
> +	size_t func_index;
> +	enum count_function function;
> +	int err;
> +	struct counter_device *const counter = dev_get_drvdata(dev);
> +
> +	/* Find requested Count function mode */
> +	for (func_index = 0; func_index < num_functions; func_index++) {
> +		function = count->functions_list[func_index];
> +		if (sysfs_streq(buf, count_function_str[function]))
> +			break;
> +	}
> +	/* Return error if requested Count function mode not found */
> +	if (func_index >= num_functions)
> +		return -EINVAL;
> +
> +	err = counter->ops->function_set(counter, count, func_index);
> +	if (err)
> +		return err;
> +
> +	count->function = func_index;
> +
> +	return len;
> +}
> +
> +struct count_ext_comp_t {
> +	struct counter_count		*count;
> +	const struct counter_count_ext	*ext;
> +};
> +
> +static ssize_t counter_count_ext_show(struct device *dev,
> +				      struct device_attribute *attr, char *buf)
> +{
> +	const struct counter_device_attr *const devattr = to_counter_attr(attr);
> +	const struct count_ext_comp_t *const comp = devattr->component;
> +	const struct counter_count_ext *const ext = comp->ext;
> +
> +	return ext->read(dev_get_drvdata(dev), comp->count, ext->priv, buf);
> +}
> +
> +static ssize_t counter_count_ext_store(struct device *dev,
> +				       struct device_attribute *attr,
> +				       const char *buf, size_t len)
> +{
> +	const struct counter_device_attr *const devattr = to_counter_attr(attr);
> +	const struct count_ext_comp_t *const comp = devattr->component;
> +	const struct counter_count_ext *const ext = comp->ext;
> +
> +	return ext->write(dev_get_drvdata(dev), comp->count, ext->priv, buf,
> +		len);
> +}
> +
> +static int counter_count_ext_register(
> +	struct counter_device_attr_group *const group,
> +	struct counter_count *const count)
> +{
> +	const size_t num_ext = count->num_ext;

Used in one place, just put it inline?

> +	size_t i;
> +	const struct counter_count_ext *ext;
> +	struct count_ext_comp_t *count_ext_comp;
> +	int err;
> +
> +	/* Create an attribute for each extension */
> +	for (i = 0 ; i < num_ext; i++) {
> +		ext = count->ext + i;
> +
> +		/* Allocate count_ext attribute component */
> +		count_ext_comp = kmalloc(sizeof(*count_ext_comp), GFP_KERNEL);
> +		if (!count_ext_comp) {
> +			err = -ENOMEM;
> +			goto err_free_attr_list;
> +		}
> +		count_ext_comp->count = count;
> +		count_ext_comp->ext = ext;
> +
> +		/* Allocate count_ext attribute */
> +		err = counter_attribute_create(group, "", ext->name,
> +			(ext->read) ? counter_count_ext_show : NULL,
> +			(ext->write) ? counter_count_ext_store : NULL,
> +			count_ext_comp);
> +		if (err) {
> +			kfree(count_ext_comp);
> +			goto err_free_attr_list;
> +		}
> +	}
> +
> +	return 0;
> +
> +err_free_attr_list:
> +	free_counter_device_attr_list(&group->attr_list);
> +	return err;
> +}
> +
> +struct func_avail_comp_t {
> +	const enum count_function	*functions_list;
> +	size_t				num_functions;
> +};
> +
> +static ssize_t counter_count_function_available_show(struct device *dev,
> +	struct device_attribute *attr, char *buf)
> +{
> +	const struct counter_device_attr *const devattr = to_counter_attr(attr);
> +	const struct func_avail_comp_t *const component = devattr->component;
> +	const enum count_function *const func_list = component->functions_list;
> +	const size_t num_functions = component->num_functions;
> +	size_t i;
> +	enum count_function function;
> +	ssize_t len = 0;
> +
> +	for (i = 0; i < num_functions; i++) {
> +		function = func_list[i];
> +		len += scnprintf(buf + len, PAGE_SIZE - len, "%s\n",
> +			count_function_str[function]);
> +	}
> +
> +	return len;
> +}
> +
> +static int counter_count_attributes_create(
> +	struct counter_device_attr_group *const group,
> +	const struct counter_device *const counter,
> +	struct counter_count *const count)
> +{
> +	struct count_comp_t *count_comp;
> +	int err;
> +	struct count_comp_t *func_comp;
> +	struct func_avail_comp_t *avail_comp;
> +
> +	/* Allocate count attribute component */
> +	count_comp = kmalloc(sizeof(*count_comp), GFP_KERNEL);
> +	if (!count_comp)
> +		return -ENOMEM;
> +	count_comp->count = count;
> +
> +	/* Create main Count attribute */
> +	err = counter_attribute_create(group, "", "count",
> +		(counter->ops->count_read) ? counter_count_show : NULL,
> +		(counter->ops->count_write) ? counter_count_store : NULL,
> +		count_comp);
> +	if (err) {
> +		kfree(count_comp);
> +		return err;
> +	}
> +
> +	/* Allocate function attribute component */
> +	func_comp = kmalloc(sizeof(*func_comp), GFP_KERNEL);
> +	if (!func_comp) {
> +		err = -ENOMEM;
> +		goto err_free_attr_list;
> +	}
> +	func_comp->count = count;
> +
> +	/* Create Count function attribute */
> +	err = counter_attribute_create(group, "", "function",
> +		(counter->ops->function_get) ? counter_function_show : NULL,
> +		(counter->ops->function_set) ? counter_function_store : NULL,
> +		func_comp);
> +	if (err) {
> +		kfree(func_comp);
> +		goto err_free_attr_list;
> +	}
> +
> +	/* Allocate function available attribute component */
> +	avail_comp = kmalloc(sizeof(*avail_comp), GFP_KERNEL);
> +	if (!avail_comp) {
> +		err = -ENOMEM;
> +		goto err_free_attr_list;
> +	}
> +	avail_comp->functions_list = count->functions_list;
> +	avail_comp->num_functions = count->num_functions;
> +
> +	/* Create Count function_available attribute */
> +	err = counter_attribute_create(group, "", "function_available",
> +				       counter_count_function_available_show,
> +				       NULL, avail_comp);
> +	if (err) {
> +		kfree(avail_comp);
> +		goto err_free_attr_list;
> +	}
> +
> +	/* Create Count name attribute */
> +	err = counter_name_attribute_create(group, count->name);
> +	if (err)
> +		goto err_free_attr_list;
> +
> +	/* Register Count extension attributes */
> +	err = counter_count_ext_register(group, count);
> +	if (err)
> +		goto err_free_attr_list;
> +
> +	return 0;
> +
> +err_free_attr_list:
> +	free_counter_device_attr_list(&group->attr_list);
> +	return err;
> +}
> +
> +static int counter_counts_register(
> +	struct counter_device_attr_group *const groups_list,
> +	const struct counter_device *const counter)
> +{
> +	const size_t num_counts = counter->num_counts;

I think this is only used on one place.  Not sure having
a local variable is worthwhile.

> +	size_t i;
> +	struct counter_count *count;
> +	const char *name;
> +	int err;
> +
> +	/* Register each Count */
> +	for (i = 0; i < num_counts; i++) {
> +		count = counter->counts + i;
> +
> +		/* Generate Count attribute directory name */
> +		name = kasprintf(GFP_KERNEL, "count%d", count->id);
> +		if (!name) {
> +			err = -ENOMEM;
> +			goto err_free_attr_groups;
> +		}
> +		groups_list[i].attr_group.name = name;
> +
> +		/* Register the Synapses associated with each Count */
> +		err = counter_synapses_register(groups_list + i, counter, count,
> +						name);
> +		if (err)
> +			goto err_free_attr_groups;
> +
> +		/* Create all attributes associated with Count */
> +		err = counter_count_attributes_create(groups_list + i, counter,
> +						      count);
> +		if (err)
> +			goto err_free_attr_groups;
> +	}
> +
> +	return 0;
> +
> +err_free_attr_groups:
> +	do {
> +		kfree(groups_list[i].attr_group.name);
> +		free_counter_device_attr_list(&groups_list[i].attr_list);
> +	} while (i--);
> +	return err;
> +}
> +
> +struct size_comp_t {
> +	size_t size;
> +};
> +
> +static ssize_t counter_device_attr_size_show(struct device *dev,
> +					     struct device_attribute *attr,
> +					     char *buf)
> +{
> +	const struct size_comp_t *const comp = to_counter_attr(attr)->component;
> +
> +	return scnprintf(buf, PAGE_SIZE, "%zu\n", comp->size);
> +}
> +
> +static int counter_size_attribute_create(
> +	struct counter_device_attr_group *const group,
> +	const size_t size, const char *const name)
> +{
> +	struct size_comp_t *size_comp;
> +	int err;
> +
> +	/* Allocate size attribute component */
> +	size_comp = kmalloc(sizeof(*size_comp), GFP_KERNEL);
> +	if (!size_comp)
> +		return -ENOMEM;
> +	size_comp->size = size;
> +
> +	err = counter_attribute_create(group, "", name,
> +				       counter_device_attr_size_show, NULL,
> +				       size_comp);
> +	if (err)
> +		goto err_free_size_comp;
> +
> +	return 0;
> +
> +err_free_size_comp:
> +	kfree(size_comp);
> +	return err;
> +}
> +
> +struct ext_comp_t {
> +	const struct counter_device_ext	*ext;
> +};
> +
> +static ssize_t counter_device_ext_show(struct device *dev,
> +				       struct device_attribute *attr, char *buf)
> +{
> +	const struct counter_device_attr *const devattr = to_counter_attr(attr);
> +	const struct ext_comp_t *const component = devattr->component;
> +	const struct counter_device_ext *const ext = component->ext;
> +
> +	return ext->read(dev_get_drvdata(dev), ext->priv, buf);
> +}
> +
> +static ssize_t counter_device_ext_store(struct device *dev,
> +					struct device_attribute *attr,
> +					const char *buf, size_t len)
> +{
> +	const struct counter_device_attr *const devattr = to_counter_attr(attr);
> +	const struct ext_comp_t *const component = devattr->component;
> +	const struct counter_device_ext *const ext = component->ext;
> +
> +	return ext->write(dev_get_drvdata(dev), ext->priv, buf, len);
> +}
> +
> +static int counter_device_ext_register(
> +	struct counter_device_attr_group *const group,
> +	struct counter_device *const counter)
> +{
> +	const size_t num_ext = counter->num_ext;

num_ext only used in one place so if anything the local variable
is hurting readability.

> +	struct ext_comp_t *ext_comp;
> +	size_t i;
> +	const struct counter_device_ext *ext;
> +	int err;
> +
> +	/* Create an attribute for each extension */
> +	for (i = 0 ; i < num_ext; i++) {
> +		ext = counter->ext + i;

This local variable isn't gaining us much that I can see. Just
use the value directly.

> +
> +		/* Allocate extension attribute component */
> +		ext_comp = kmalloc(sizeof(*ext_comp), GFP_KERNEL);
> +		if (!ext_comp) {
> +			err = -ENOMEM;
> +			goto err_free_attr_list;
> +		}
> +
> +		ext_comp->ext = ext;
> +
> +		/* Allocate extension attribute */
> +		err = counter_attribute_create(group, "", ext->name,
> +			(ext->read) ? counter_device_ext_show : NULL,
> +			(ext->write) ? counter_device_ext_store : NULL,
> +			ext_comp);
> +		if (err) {
> +			kfree(ext_comp);
> +			goto err_free_attr_list;
> +		}
> +	}
> +
> +	return 0;
> +
> +err_free_attr_list:
> +	free_counter_device_attr_list(&group->attr_list);
> +	return err;
> +}
> +
> +static int counter_global_attr_register(
> +	struct counter_device_attr_group *const group,
> +	struct counter_device *const counter)
> +{
> +	int err;
> +
> +	/* Create name attribute */
> +	err = counter_name_attribute_create(group, counter->name);
> +	if (err)
> +		return err;
> +
> +	/* Create num_counts attribute */
> +	err = counter_size_attribute_create(group, counter->num_counts,
> +					    "num_counts");
> +	if (err)
> +		goto err_free_attr_list;
> +
> +	/* Create num_signals attribute */
> +	err = counter_size_attribute_create(group, counter->num_signals,
> +					    "num_signals");
> +	if (err)
> +		goto err_free_attr_list;
> +
> +	/* Register Counter device extension attributes */
> +	err = counter_device_ext_register(group, counter);
> +	if (err)
> +		goto err_free_attr_list;
> +
> +	return 0;
> +
> +err_free_attr_list:
> +	free_counter_device_attr_list(&group->attr_list);
> +	return err;
> +}
> +
> +static void free_counter_device_groups_list(
> +	struct counter_device_attr_group *const groups_list,
> +	const size_t num_groups)
> +{
> +	struct counter_device_attr_group *group;
> +	size_t i;
> +
> +	for (i = 0; i < num_groups; i++) {
> +		group = groups_list + i;
> +

I'd like to see a comment somewhere here on the fact this cleans up both
the registered per counter stuff and the global attributes (that took
a bit of chasing to check it did...)

> +		kfree(group->attr_group.name);
> +		kfree(group->attr_group.attrs);
> +		free_counter_device_attr_list(&group->attr_list);
> +	}
> +
> +	kfree(groups_list);
> +}
> +
> +static int prepare_counter_device_groups_list(
> +	struct counter_device *const counter)
> +{
> +	const size_t total_num_groups =
> +		counter->num_signals + counter->num_counts + 1;
> +	struct counter_device_attr_group *groups_list;
> +	size_t i;
> +	int err;
> +	size_t num_groups = 0;
> +
> +	/* Allocate space for attribute groups (signals. counts, and ext) */
> +	groups_list = kcalloc(total_num_groups, sizeof(*groups_list),
> +			      GFP_KERNEL);
> +	if (!groups_list)
> +		return -ENOMEM;
> +
> +	/* Initialize attribute lists */
> +	for (i = 0; i < total_num_groups; i++)
> +		INIT_LIST_HEAD(&groups_list[i].attr_list);
> +
> +	/* Register Signals */
> +	err = counter_signals_register(groups_list, counter);
> +	if (err)
> +		goto err_free_groups_list;
> +	num_groups += counter->num_signals;
> +
> +	/* Register Counts and respective Synapses */
> +	err = counter_counts_register(groups_list + num_groups, counter);
> +	if (err)
> +		goto err_free_groups_list;
> +	num_groups += counter->num_counts;
> +
> +	/* Register Counter global attributes */
> +	err = counter_global_attr_register(groups_list + num_groups, counter);
> +	if (err)
> +		goto err_free_groups_list;
> +	num_groups++;
> +
> +	/* Store groups_list in device_state */
> +	counter->device_state->groups_list = groups_list;
> +	counter->device_state->num_groups = num_groups;
> +
> +	return 0;
> +
> +err_free_groups_list:
> +	free_counter_device_groups_list(groups_list, num_groups);

Consistent naming would be good.

counter_device_groups_list_free.

I would tidy this up throughout.  I know from experience that
you'll probably end up doing so eventually and it is easier whilst
there isn't too much code.

> +	return err;
> +}
> +
> +static int prepare_counter_device_groups(
> +	struct counter_device_state *const device_state)
> +{
> +	size_t i;
> +	struct counter_device_attr_group *group;
> +	int err;
> +	size_t j;

Tidy this up a little,
size_t i, j;

> +	struct counter_device_attr *p;
> +
> +	/* Allocate attribute groups for association with device */
> +	device_state->groups = kcalloc(device_state->num_groups + 1,
> +				       sizeof(*device_state->groups),
> +				       GFP_KERNEL);
> +	if (!device_state->groups)
> +		return -ENOMEM;
> +
> +	/* Prepare each group of attributes for association */
> +	for (i = 0; i < device_state->num_groups; i++) {
> +		group = device_state->groups_list + i;
> +
> +		/* Allocate space for attribute pointers in attribute group */
> +		group->attr_group.attrs = kcalloc(group->num_attr + 1,
> +			sizeof(*group->attr_group.attrs), GFP_KERNEL);
> +		if (!group->attr_group.attrs) {
> +			err = -ENOMEM;
> +			goto err_free_groups;
> +		}
> +
> +		/* Add attribute pointers to attribute group */
> +		j = 0;
> +		list_for_each_entry(p, &group->attr_list, l)
> +			group->attr_group.attrs[j++] = &p->dev_attr.attr;
> +
> +		/* Group attributes in attribute group */
> +		device_state->groups[i] = &group->attr_group;
> +	}
> +	/* Associate attributes with device */
> +	device_state->dev.groups = device_state->groups;
> +
> +	return 0;
> +
> +err_free_groups:

I'm not convinced this is cleaning up properly.  What about
the kcalloc of group->attr_group.attrs for previous loops?

> +	kfree(device_state->groups);
> +	return err;
> +}
> +
> +/* Provides a unique ID for each counter device */
> +static DEFINE_IDA(counter_ida);
> +
> +static void counter_device_release(struct device *dev)
> +{
> +	struct counter_device *const counter = dev_get_drvdata(dev);
> +	struct counter_device_state *const device_state = counter->device_state;
> +
> +	kfree(device_state->groups);
> +	free_counter_device_groups_list(device_state->groups_list,
> +					device_state->num_groups);
> +	ida_simple_remove(&counter_ida, device_state->id);
> +	kfree(device_state);
> +}
> +
> +static struct device_type counter_device_type = {
> +	.name = "counter_device",
> +	.release = counter_device_release
> +};
> +
> +static struct bus_type counter_bus_type = {
> +	.name = "counter"
> +};
> +
> +/**
> + * counter_register - register Counter to the system
> + * @counter:	pointer to Counter to register
> + *
> + * This function registers a Counter to the system. A sysfs "counter" directory
> + * will be created and populated with sysfs attributes correlating with the
> + * Counter Signals, Synapses, and Counts respectively.
> + */
> +int counter_register(struct counter_device *const counter)
> +{
> +	struct counter_device_state *device_state;
> +	int err;
> +
> +	/* Allocate internal state container for Counter device */
> +	device_state = kzalloc(sizeof(*device_state), GFP_KERNEL);
> +	if (!device_state)
> +		return -ENOMEM;
> +	counter->device_state = device_state;
> +
> +	/* Acquire unique ID */
> +	device_state->id = ida_simple_get(&counter_ida, 0, 0, GFP_KERNEL);
> +	if (device_state->id < 0) {
> +		err = device_state->id;
> +		goto err_free_device_state;
> +	}
> +
> +	/* Configure device structure for Counter */
> +	device_state->dev.type = &counter_device_type;
> +	device_state->dev.bus = &counter_bus_type;
> +	if (counter->parent) {
> +		device_state->dev.parent = counter->parent;
> +		device_state->dev.of_node = counter->parent->of_node;
> +	}
> +	dev_set_name(&device_state->dev, "counter%d", device_state->id);
> +	device_initialize(&device_state->dev);
> +	dev_set_drvdata(&device_state->dev, counter);
> +
> +	/* Prepare device attributes */
> +	err = prepare_counter_device_groups_list(counter);
> +	if (err)
> +		goto err_free_id;
> +
> +	/* Organize device attributes to groups and match to device */
> +	err = prepare_counter_device_groups(device_state);
> +	if (err)
> +		goto err_free_groups_list;
> +
> +	/* Add device to system */
> +	err = device_add(&device_state->dev);
> +	if (err)
> +		goto err_free_groups;
> +
> +	return 0;
> +
> +err_free_groups:
> +	kfree(device_state->groups);
> +err_free_groups_list:
> +	free_counter_device_groups_list(device_state->groups_list,
> +					device_state->num_groups);
> +err_free_id:
> +	ida_simple_remove(&counter_ida, device_state->id);
> +err_free_device_state:
> +	kfree(device_state);
> +	return err;
> +}
> +EXPORT_SYMBOL(counter_register);
> +
> +/**
> + * counter_unregister - unregister Counter from the system
> + * @counter:	pointer to Counter to unregister
> + *
> + * The Counter is unregistered from the system; all allocated memory is freed.
> + */
> +void counter_unregister(struct counter_device *const counter)
> +{
> +	if (counter)
> +		device_del(&counter->device_state->dev);
> +}
> +EXPORT_SYMBOL(counter_unregister);
> +
> +static void devm_counter_unreg(struct device *dev, void *res)
> +{
> +	counter_unregister(*(struct counter_device **)res);
> +}
> +
> +/**
> + * devm_counter_register - Resource-managed counter_register
> + * @dev:	device to allocate counter_device for
> + * @counter:	pointer to Counter to register
> + *
> + * Managed counter_register. The Counter registered with this function is
> + * automatically unregistered on driver detach. This function calls
> + * counter_register internally. Refer to that function for more information.
> + *
> + * If an Counter registered with this function needs to be unregistered
> + * separately, devm_counter_unregister must be used.
> + *
> + * RETURNS:
> + * 0 on success, negative error number on failure.
> + */
> +int devm_counter_register(struct device *dev,
> +			  struct counter_device *const counter)
> +{
> +	struct counter_device **ptr;
> +	int ret;
> +
> +	ptr = devres_alloc(devm_counter_unreg, sizeof(*ptr), GFP_KERNEL);
> +	if (!ptr)
> +		return -ENOMEM;
> +
> +	ret = counter_register(counter);
> +	if (!ret) {
> +		*ptr = counter;
> +		devres_add(dev, ptr);
> +	} else {
> +		devres_free(ptr);
> +	}
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL(devm_counter_register);
> +
> +static int devm_counter_match(struct device *dev, void *res, void *data)
> +{
> +	struct counter_device **r = res;
> +
> +	if (!r || !*r) {
> +		WARN_ON(!r || !*r);
> +		return 0;
> +	}
> +
> +	return *r == data;
> +}
> +
> +/**
> + * devm_counter_unregister - Resource-managed counter_unregister
> + * @dev:	device this counter_device belongs to
> + * @counter:	pointer to Counter associated with the device
> + *
> + * Unregister Counter registered with devm_counter_register.
> + */
> +void devm_counter_unregister(struct device *dev,
> +			     struct counter_device *const counter)
> +{
> +	int rc;
> +
> +	rc = devres_release(dev, devm_counter_unreg, devm_counter_match,
> +			    counter);
> +	WARN_ON(rc);
> +}
> +EXPORT_SYMBOL(devm_counter_unregister);
> +
> +static int __init counter_init(void)
> +{
> +	return bus_register(&counter_bus_type);
> +}
> +
> +static void __exit counter_exit(void)
> +{
> +	bus_unregister(&counter_bus_type);
> +}
> +
> +subsys_initcall(counter_init);
> +module_exit(counter_exit);
> +
> +MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>");
> +MODULE_DESCRIPTION("Generic Counter interface");
> +MODULE_LICENSE("GPL v2");
> diff --git a/include/linux/counter.h b/include/linux/counter.h
> new file mode 100644
> index 000000000000..a0b0349d098a
> --- /dev/null
> +++ b/include/linux/counter.h
> @@ -0,0 +1,554 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Counter interface
> + * Copyright (C) 2017 William Breathitt Gray
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License, version 2, as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful, but
> + * WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * General Public License for more details.

It's a bit controversial, but most people consider SPDX headers equivalent
of the license statement.  As such you normally don't have both and just
go for the SPDK header.

I thought we were also standardising on 
// SPDX-...


> + */
> +#ifndef _COUNTER_H_
> +#define _COUNTER_H_
> +
> +#include <linux/device.h>
> +#include <linux/types.h>
> +
> +enum count_direction {
> +	COUNT_DIRECTION_FORWARD = 0,
> +	COUNT_DIRECTION_BACKWARD
> +};
> +extern const char *const count_direction_str[2];
> +
> +enum count_mode {
> +	COUNT_MODE_NORMAL = 0,
> +	COUNT_MODE_RANGE_LIMIT,
> +	COUNT_MODE_NON_RECYCLE,
> +	COUNT_MODE_MODULO_N
> +};
> +extern const char *const count_mode_str[4];
> +
> +struct counter_device;
> +struct counter_signal;
> +
> +/**
> + * struct counter_signal_ext - Counter Signal extensions
> + * @name:	attribute name
> + * @read:	read callback for this attribute; may be NULL
> + * @write:	write callback for this attribute; may be NULL
> + * @priv:	data private to the driver
> + */
> +struct counter_signal_ext {
> +	const char	*name;
> +	ssize_t		(*read)(struct counter_device *counter,
> +				struct counter_signal *signal, void *priv,
> +				char *buf);
> +	ssize_t		(*write)(struct counter_device *counter,
> +				 struct counter_signal *signal, void *priv,
> +				 const char *buf, size_t len);
> +	void		*priv;
> +};
> +
> +/**
> + * struct counter_signal - Counter Signal node
> + * @id:		unique ID used to identify signal
> + * @name:	device-specific Signal name; ideally, this should match the name
> + *		as it appears in the datasheet documentation
> + * @ext:	optional array of Counter Signal extensions
> + * @num_ext:	number of Counter Signal extensions specified in @ext
> + * @priv:	optional private data supplied by driver
> + */
> +struct counter_signal {
> +	int		id;
> +	const char	*name;
> +
> +	const struct counter_signal_ext	*ext;
> +	size_t				num_ext;
> +
> +	void	*priv;
> +};
> +
> +/**
> + * struct counter_signal_enum_ext - Signal enum extension attribute
> + * @items:	Array of strings
> + * @num_items:	Number of items specified in @items
> + * @set:	Set callback function; may be NULL
> + * @get:	Get callback function; may be NULL
> + *
> + * The counter_signal_enum_ext structure can be used to implement enum style
> + * Signal extension attributes. Enum style attributes are those which have a set
> + * of strings that map to unsigned integer values. The Generic Counter Signal
> + * enum extension helper code takes care of mapping between value and string, as
> + * well as generating a "_available" file which contains a list of all available
> + * items. The get callback is used to query the currently active item; the index
> + * of the item within the respective items array is returned via the 'item'
> + * parameter. The set callback is called when the attribute is updated; the
> + * 'item' parameter contains the index of the newly activated item within the
> + * respective items array.
> + */
> +struct counter_signal_enum_ext {
> +	const char * const	*items;
> +	size_t			num_items;
> +	int			(*get)(struct counter_device *counter,
> +				       struct counter_signal *signal,
> +				       size_t *item);
> +	int			(*set)(struct counter_device *counter,
> +				       struct counter_signal *signal,
> +				       size_t item);
> +};
> +
> +ssize_t counter_signal_enum_read(struct counter_device *counter,
> +				 struct counter_signal *signal, void *priv,
> +				 char *buf);
> +ssize_t counter_signal_enum_write(struct counter_device *counter,
> +				  struct counter_signal *signal, void *priv,
> +				  const char *buf, size_t len);
> +
> +/**
> + * COUNTER_SIGNAL_ENUM() - Initialize Signal enum extension
> + * @_name:	Attribute name
> + * @_e:		Pointer to a counter_count_enum structure
> + *
> + * This should usually be used together with COUNTER_SIGNAL_ENUM_AVAILABLE()
> + */
> +#define COUNTER_SIGNAL_ENUM(_name, _e) \
> +{ \
> +	.name = (_name), \
> +	.read = counter_signal_enum_read, \
> +	.write = counter_signal_enum_write, \
> +	.priv = (_e) \
> +}
> +
> +ssize_t counter_signal_enum_available_read(struct counter_device *counter,
> +					   struct counter_signal *signal,
> +					   void *priv, char *buf);
> +
> +/**
> + * COUNTER_SIGNAL_ENUM_AVAILABLE() - Initialize Signal enum available extension
> + * @_name:	Attribute name ("_available" will be appended to the name)
> + * @_e:		Pointer to a counter_signal_enum structure
> + *
> + * Creates a read only attribute that lists all the available enum items in a
> + * newline separated list. This should usually be used together with
> + * COUNTER_SIGNAL_ENUM()
> + */
> +#define COUNTER_SIGNAL_ENUM_AVAILABLE(_name, _e) \
> +{ \
> +	.name = (_name "_available"), \
> +	.read = counter_signal_enum_available_read, \
> +	.priv = (_e) \
> +}
> +
> +enum synapse_action {
> +	SYNAPSE_ACTION_NONE = 0,
> +	SYNAPSE_ACTION_RISING_EDGE,
> +	SYNAPSE_ACTION_FALLING_EDGE,
> +	SYNAPSE_ACTION_BOTH_EDGES
> +};
> +
> +/**
> + * struct counter_synapse - Counter Synapse node
> + * @action:		index of current action mode
> + * @actions_list:	array of available action modes
> + * @num_actions:	number of action modes specified in @actions_list
> + * @signal:		pointer to associated signal
> + */
> +struct counter_synapse {
> +	size_t					action;
> +	const enum synapse_action		*actions_list;
> +	size_t					num_actions;
> +
> +	struct counter_signal			*signal;
> +};
> +
> +struct counter_count;
> +
> +/**
> + * struct counter_count_ext - Counter Count extension
> + * @name:	attribute name
> + * @read:	read callback for this attribute; may be NULL
> + * @write:	write callback for this attribute; may be NULL
> + * @priv:	data private to the driver
> + */
> +struct counter_count_ext {
> +	const char	*name;
> +	ssize_t		(*read)(struct counter_device *counter,
> +				struct counter_count *count, void *priv,
> +				char *buf);
> +	ssize_t		(*write)(struct counter_device *counter,
> +				 struct counter_count *count, void *priv,
> +				 const char *buf, size_t len);
> +	void		*priv;
> +};
> +
> +enum count_function {
> +	COUNT_FUNCTION_INCREASE = 0,
> +	COUNT_FUNCTION_DECREASE,
> +	COUNT_FUNCTION_PULSE_DIRECTION,
> +	COUNT_FUNCTION_QUADRATURE_X1_A,
> +	COUNT_FUNCTION_QUADRATURE_X1_B,
> +	COUNT_FUNCTION_QUADRATURE_X2_A,
> +	COUNT_FUNCTION_QUADRATURE_X2_B,
> +	COUNT_FUNCTION_QUADRATURE_X2_RISING,
> +	COUNT_FUNCTION_QUADRATURE_X2_FALLING,
> +	COUNT_FUNCTION_QUADRATURE_X4
> +};
> +
> +/**
> + * struct counter_count - Counter Count node
> + * @id:			unique ID used to identify Count
> + * @name:		device-specific Count name; ideally, this should match
> + *			the name as it appears in the datasheet documentation
> + * @function:		index of current function mode
> + * @functions_list:	array available function modes
> + * @num_functions:	number of function modes specified in @functions_list
> + * @synapses:		array of synapses for initialization
> + * @num_synapses:	number of synapses specified in @synapses
> + * @ext:		optional array of Counter Count extensions
> + * @num_ext:		number of Counter Count extensions specified in @ext
> + * @priv:		optional private data supplied by driver
> + */
> +struct counter_count {
> +	int			id;
> +	const char		*name;
> +
> +	size_t					function;
> +	const enum count_function		*functions_list;
> +	size_t					num_functions;

There is a very good illustration here of the issues with using
tabs to pretty print structure elements.  I would drop them entirely as
personally I'm not sure they help readability and you will forever be having
more noise in patches because of the need to change the number of tabs
due to name changes etc.

> +
> +	struct counter_synapse	*synapses;
> +	size_t			num_synapses;
> +
> +	const struct counter_count_ext	*ext;
> +	size_t				num_ext;
> +
> +	void	*priv;
> +};
> +
> +/**
> + * struct counter_count_enum_ext - Count enum extension attribute
> + * @items:	Array of strings
> + * @num_items:	Number of items specified in @items
> + * @set:	Set callback function; may be NULL
> + * @get:	Get callback function; may be NULL
> + *
> + * The counter_count_enum_ext structure can be used to implement enum style
> + * Count extension attributes. Enum style attributes are those which have a set
> + * of strings that map to unsigned integer values. The Generic Counter Count
> + * enum extension helper code takes care of mapping between value and string, as
> + * well as generating a "_available" file which contains a list of all available
> + * items. The get callback is used to query the currently active item; the index
> + * of the item within the respective items array is returned via the 'item'
> + * parameter. The set callback is called when the attribute is updated; the
> + * 'item' parameter contains the index of the newly activated item within the
> + * respective items array.
> + */
> +struct counter_count_enum_ext {
> +	const char * const	*items;
> +	size_t			num_items;
> +	int			(*get)(struct counter_device *counter,
> +				       struct counter_count *count,
> +				       size_t *item);
> +	int			(*set)(struct counter_device *counter,
> +				       struct counter_count *count,
> +				       size_t item);
> +};
> +
> +ssize_t counter_count_enum_read(struct counter_device *counter,
> +				struct counter_count *count, void *priv,
> +				char *buf);
> +ssize_t counter_count_enum_write(struct counter_device *counter,
> +				 struct counter_count *count, void *priv,
> +				 const char *buf, size_t len);
> +
> +/**
> + * COUNTER_COUNT_ENUM() - Initialize Count enum extension
> + * @_name:	Attribute name
> + * @_e:		Pointer to a counter_count_enum structure
> + *
> + * This should usually be used together with COUNTER_COUNT_ENUM_AVAILABLE()
> + */
> +#define COUNTER_COUNT_ENUM(_name, _e) \
> +{ \
> +	.name = (_name), \
> +	.read = counter_count_enum_read, \
> +	.write = counter_count_enum_write, \
> +	.priv = (_e) \
> +}
> +
> +ssize_t counter_count_enum_available_read(struct counter_device *counter,
> +					  struct counter_count *count,
> +					  void *priv, char *buf);
> +
> +/**
> + * COUNTER_COUNT_ENUM_AVAILABLE() - Initialize Count enum available extension
> + * @_name:	Attribute name ("_available" will be appended to the name)
> + * @_e:		Pointer to a counter_count_enum structure
> + *
> + * Creates a read only attribute that lists all the available enum items in a
> + * newline separated list. This should usually be used together with
> + * COUNTER_COUNT_ENUM()
> + */
> +#define COUNTER_COUNT_ENUM_AVAILABLE(_name, _e) \
> +{ \
> +	.name = (_name "_available"), \
> +	.read = counter_count_enum_available_read, \
> +	.priv = (_e) \
> +}
> +
> +/**
> + * struct counter_device_attr_group - internal container for attribute group
> + * @attr_group:	Counter sysfs attributes group
> + * @attr_list:	list to keep track of created Counter sysfs attributes
> + * @num_attr:	number of Counter sysfs attributes
> + */
> +struct counter_device_attr_group {
> +	struct attribute_group	attr_group;
> +	struct list_head	attr_list;
> +	size_t			num_attr;
> +};
> +
> +/**
> + * struct counter_device_state - internal state container for a Counter device
> + * @id:		unique ID used to identify the Counter
> + * @dev:	internal device structure
> + * @groups_list	attribute groups list (groups for Signals, Counts, and ext)

Run kernel-doc script over these files.  You are missing some :s and it would
have told you that.

> + * @num_groups	number of attribute groups containers
> + * @groups:	Counter sysfs attribute groups (used to populate @dev.groups)
> + */
> +struct counter_device_state {
> +	int					id;
> +	struct device				dev;
> +	struct counter_device_attr_group	*groups_list;
> +	size_t					num_groups;
> +	const struct attribute_group		**groups;
> +};
> +
> +/**
> + * struct signal_read_value - Opaque Signal read value
> + * @buf:	string representation of Signal read value
> + * @len:	length of string in @buf
> + */
> +struct signal_read_value {
> +	char	*buf;
> +	size_t	len;
> +};
> +
> +/**
> + * struct count_read_value - Opaque Count read value
> + * @buf:	string representation of Count read value
> + * @len:	length of string in @buf
> + */
> +struct count_read_value {
> +	char	*buf;
> +	size_t	len;
> +};
> +
> +/**
> + * struct count_write_value - Opaque Count write value
> + * @buf:	string representation of Count write value
> + */
> +struct count_write_value {
> +	const char	*buf;
> +};
> +
> +/**
> + * struct counter_ops - Callbacks from driver
> + * @signal_read:	optional read callback for Signal attribute. The read
> + *			value of the respective Signal should be passed back via
> + *			the val parameter. val points to an opaque type which
> + *			should be set only via the set_signal_read_value
> + *			function.

This last part had me a little confused.  I would make it clear that this
set_signal_read_value function should be called to set the value within this
signal_read callback rather than elsewhere...  

> + * @count_read:		optional read callback for Count attribute. The read
> + *			value of the respective Count should be passed back via
> + *			the val parameter. val points to an opaque type which
> + *			should be set only via the set_count_read_value
> + *			function.
> + * @count_write:	optional write callback for Count attribute. The write
> + *			value for the respective Count is passed in via the val
> + *			parameter. val points to an opaque type which should be
> + *			access only via the get_count_write_value function.
> + * @function_get:	function to get the current count function mode. Returns
> + *			0 on success and negative error code on error. The index
> + *			of the respective Count's returned function mode should
> + *			be passed back via the function parameter.
> + * @function_set:	function to set the count function mode. function is the
> + *			index of the requested function mode from the respective
> + *			Count's functions_list array.
> + * @action_get:		function to get the current action mode. Returns 0 on
> + *			success and negative error code on error. The index of
> + *			the respective Signal's returned action mode should be
> + *			passed back via the action parameter.
> + * @action_set:		function to set the action mode. action is the index of
> + *			the requested action mode from the respective Synapse's
> + *			actions_list array.
> + */
> +struct counter_ops {
> +	int	(*signal_read)(struct counter_device *counter,
> +			       struct counter_signal *signal,
> +			       struct signal_read_value *val);
> +	int	(*count_read)(struct counter_device *counter,
> +			      struct counter_count *count,
> +			      struct count_read_value *val);
> +	int	(*count_write)(struct counter_device *counter,
> +			       struct counter_count *count,
> +			       struct count_write_value *val);
> +	int	(*function_get)(struct counter_device *counter,
> +				struct counter_count *count, size_t *function);
> +	int	(*function_set)(struct counter_device *counter,
> +				struct counter_count *count, size_t function);
> +	int	(*action_get)(struct counter_device *counter,
> +			      struct counter_count *count,
> +			      struct counter_synapse *synapse, size_t *action);
> +	int	(*action_set)(struct counter_device *counter,
> +			      struct counter_count *count,
> +			      struct counter_synapse *synapse, size_t action);
> +};
> +
> +/**
> + * struct counter_device_ext - Counter device extension
> + * @name:	attribute name
> + * @read:	read callback for this attribute; may be NULL
> + * @write:	write callback for this attribute; may be NULL
> + * @priv:	data private to the driver
> + */
> +struct counter_device_ext {
> +	const char	*name;
> +	ssize_t		(*read)(struct counter_device *counter, void *priv,
> +				char *buf);
> +	ssize_t		(*write)(struct counter_device *counter, void *priv,
> +				 const char *buf, size_t len);
> +	void		*priv;
> +};
> +
> +/**
> + * struct counter_device_enum_ext - Counter enum extension attribute
> + * @items:	Array of strings
> + * @num_items:	Number of items specified in @items
> + * @set:	Set callback function; may be NULL
> + * @get:	Get callback function; may be NULL
> + *
> + * The counter_device_enum_ext structure can be used to implement enum style
> + * Counter extension attributes. Enum style attributes are those which have a
> + * set of strings that map to unsigned integer values. The Generic Counter enum
> + * extension helper code takes care of mapping between value and string, as well
> + * as generating a "_available" file which contains a list of all available
> + * items. The get callback is used to query the currently active item; the index
> + * of the item within the respective items array is returned via the 'item'
> + * parameter. The set callback is called when the attribute is updated; the
> + * 'item' parameter contains the index of the newly activated item within the
> + * respective items array.
> + */
> +struct counter_device_enum_ext {
> +	const char * const	*items;
> +	size_t			num_items;
> +	int			(*get)(struct counter_device *counter,
> +				       size_t *item);
> +	int			(*set)(struct counter_device *counter,
> +				       size_t item);
> +};
> +
> +ssize_t counter_device_enum_read(struct counter_device *counter, void *priv,
> +				 char *buf);
> +ssize_t counter_device_enum_write(struct counter_device *counter, void *priv,
> +				  const char *buf, size_t len);
> +
> +/**
> + * COUNTER_DEVICE_ENUM() - Initialize Counter enum extension
> + * @_name:	Attribute name
> + * @_e:		Pointer to a counter_device_enum structure
> + *
> + * This should usually be used together with COUNTER_DEVICE_ENUM_AVAILABLE()
> + */
> +#define COUNTER_DEVICE_ENUM(_name, _e) \
> +{ \
> +	.name = (_name), \
> +	.read = counter_device_enum_read, \
> +	.write = counter_device_enum_write, \
> +	.priv = (_e) \
> +}
> +
> +ssize_t counter_device_enum_available_read(struct counter_device *counter,
> +					   void *priv, char *buf);
> +
> +/**
> + * COUNTER_DEVICE_ENUM_AVAILABLE() - Initialize Counter enum available extension
> + * @_name:	Attribute name ("_available" will be appended to the name)
> + * @_e:		Pointer to a counter_device_enum structure
> + *
> + * Creates a read only attribute that lists all the available enum items in a
> + * newline separated list. This should usually be used together with
> + * COUNTER_DEVICE_ENUM()
> + */
> +#define COUNTER_DEVICE_ENUM_AVAILABLE(_name, _e) \
> +{ \
> +	.name = (_name "_available"), \
> +	.read = counter_device_enum_available_read, \
> +	.priv = (_e) \
> +}
> +
> +/**
> + * struct counter_device - Counter data structure
> + * @name:		name of the device as it appears in the datasheet
> + * @parent:		optional parent device providing the counters
> + * @device_state:	internal device state container
> + * @ops:		callbacks from driver
> + * @signals:		array of Signals
> + * @num_signals:	number of Signals specified in @signals
> + * @counts:		array of Counts
> + * @num_counts:		number of Counts specified in @counts
> + * @ext:		optional array of Counter device extensions
> + * @num_ext:		number of Counter device extensions specified in @ext
> + * @priv:		optional private data supplied by driver
> + */
> +struct counter_device {
> +	const char			*name;
> +	struct device			*parent;
> +	struct counter_device_state	*device_state;
> +
> +	const struct counter_ops	*ops;
> +
> +	struct counter_signal	*signals;
> +	size_t			num_signals;
> +	struct counter_count	*counts;
> +	size_t			num_counts;
> +
> +	const struct counter_device_ext	*ext;
> +	size_t				num_ext;
> +
> +	void	*priv;
> +};
> +
> +enum signal_level {
> +	SIGNAL_LEVEL_LOW = 0,
> +	SIGNAL_LEVEL_HIGH
> +};
> +
> +enum signal_value_type {
> +	SIGNAL_LEVEL = 0
> +};
> +
> +enum count_value_type {
> +	COUNT_POSITION_UNSIGNED = 0,
> +	COUNT_POSITION_SIGNED
> +};
> +
> +void set_signal_read_value(struct signal_read_value *const val,
> +			   const enum signal_value_type type, void *const data);
> +void set_count_read_value(struct count_read_value *const val,
> +			  const enum count_value_type type, void *const data);
> +int get_count_write_value(void *const data, const enum count_value_type type,
> +			  const struct count_write_value *const val);

I wonder if naming wise, we would be better sticking to the
noun_verb naming format.

signal_read_value_set
count_read_value_set
count_write_value_get

for example?

> +
> +int counter_register(struct counter_device *const counter);
> +void counter_unregister(struct counter_device *const counter);
> +int devm_counter_register(struct device *dev,
> +			  struct counter_device *const counter);
> +void devm_counter_unregister(struct device *dev,
> +			     struct counter_device *const counter);
> +
> +#endif /* _COUNTER_H_ */

^ permalink raw reply

* [PATCH] MAINTAINERS: Update Layerscape PCIe driver maintainers list
From: Fabio Estevam @ 2018-05-20 15:04 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <CAOMZO5DfHK=2x6+7T1x4n3A4uK5naWkQ_0dmjVt5JyeMAZPGyQ@mail.gmail.com>

Hi Lorenzo,

On Wed, May 2, 2018 at 2:55 PM, Fabio Estevam <festevam@gmail.com> wrote:
> [Adding Lorenzo]
>
> On Wed, Mar 28, 2018 at 10:53 PM, Minghuan Lian <Minghuan.Lian@nxp.com> wrote:
>> Change Layerscape PCIe driver maintainers' email address
>> from freescale to nxp.
>>
>> Signed-off-by: Minghuan Lian <Minghuan.Lian@nxp.com>
>
> Yes, freescale.com emails are no longer reachable, so hopefully this
> one can land into 4.17.

A gentle ping on this one.

^ permalink raw reply

* [GIT PULL 5/5] i.MX defconfig updates for 4.18
From: Shawn Guo @ 2018-05-20 14:58 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1526828281-14664-1-git-send-email-shawnguo@kernel.org>

The following changes since commit 60cc43fc888428bb2f18f08997432d426a243338:

  Linux 4.17-rc1 (2018-04-15 18:24:20 -0700)

are available in the git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/shawnguo/linux.git tags/imx-defconfig-4.18

for you to fetch changes up to 1049167999fc9a078c5914db9f341a275c2376cb:

  ARM: imx_v6_v7_defconfig: Select CONFIG_GPIO_MAX732X by default (2018-05-04 17:03:20 +0800)

----------------------------------------------------------------
i.MX defconfig update for 4.18:
 - Enable i.MX6SLL SoC support.
 - Build in GPIO_MAX732X support as the GPIO expanders are used on
   i.MX6 SabreAuto boards.
 - Enable driver for RN5T618 PMIC and Marvell MWIFIEX support which
   are found on i.MX6/7 Colibri boards.
 - Build in OCOTP NVMEM driver for Vybrid (vf610) SoCs.

----------------------------------------------------------------
Anson Huang (1):
      ARM: imx_v6_v7_defconfig: Select CONFIG_GPIO_MAX732X by default

Bai Ping (1):
      ARM: imx_v6_v7_defconfig: enable imx6sll by default

Stefan Agner (3):
      ARM: imx_v6_v7_defconfig: add RN5T618 PMIC family support
      ARM: imx_v6_v7_defconfig: add mwifiex driver
      ARM: imx_v6_v7_defconfig: enable Vybrid OCOTP driver

 arch/arm/configs/imx_v6_v7_defconfig | 9 +++++++++
 1 file changed, 9 insertions(+)

^ permalink raw reply

* [GIT PULL 4/5] Freescale arm64 device tree updates for 4.18
From: Shawn Guo @ 2018-05-20 14:58 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1526828281-14664-1-git-send-email-shawnguo@kernel.org>

The following changes since commit 60cc43fc888428bb2f18f08997432d426a243338:

  Linux 4.17-rc1 (2018-04-15 18:24:20 -0700)

are available in the git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/shawnguo/linux.git tags/imx-dt64-4.18

for you to fetch changes up to 70ce60431e45ace2a1198d4cf339beaef1de9f8b:

  arm64: dts: fsl-ls1012a: Fix DTC aliases warnings (2018-05-15 14:43:58 +0800)

----------------------------------------------------------------
Freescale arm64 device tree update for 4.18:
 - Add unit address for ls208xa-rdb SPI flash node matching 'reg'
   property to fix DTC warning unit_address_vs_reg.
 - Use hypen instead of underscore in aliases name for fsl-ls1012a to
   fix DTC warning alias_paths.

----------------------------------------------------------------
Fabio Estevam (2):
      arm64: dts: ls208xa-rdb: Pass unit name to SPI flash node
      arm64: dts: fsl-ls1012a: Fix DTC aliases warnings

 arch/arm64/boot/dts/freescale/fsl-ls1012a.dtsi     | 10 +++++-----
 arch/arm64/boot/dts/freescale/fsl-ls208xa-rdb.dtsi |  2 +-
 2 files changed, 6 insertions(+), 6 deletions(-)

^ permalink raw reply

* [GIT PULL 3/5] i.MX device tree updates for 4.18
From: Shawn Guo @ 2018-05-20 14:57 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1526828281-14664-1-git-send-email-shawnguo@kernel.org>

The following changes since commit 60cc43fc888428bb2f18f08997432d426a243338:

  Linux 4.17-rc1 (2018-04-15 18:24:20 -0700)

are available in the git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/shawnguo/linux.git tags/imx-dt-4.18

for you to fetch changes up to 204d9e32b7971ecd187068c3a40c48bac4656cb0:

  ARM: dts: imx28/imx53: enable edt-ft5x06 wakeup source (2018-05-20 21:04:59 +0800)

----------------------------------------------------------------
i.MX device tree update for 4.18:
 - New boards support: BTicino i.MX6DL Mamoj board, DHCOM iMX6 SoM and
   PDK2 board, Engicam i.CoreM6 1.5 Quad/Dual MIPI starter kit,
   Kieback & Peter GmbH iMX6Q TPC board.
 - A series from Anson Huang to add a bunch of devices for i.MX6SX
   SabreAuto board, PMIC, IO expanders, FEC, Watchdog, LED and Touch.
 - Update i.MX7D for cpufreq support, using operating-points-v2
   bindings, correcting cpu supply name for voltage scaling.
 - Clean up unneeded 'codec-handle' property from imx25-pdk and
   imx53-tx53 device tree.
 - Switch SoC dtsi and NXP board dts files to use SPDX identifier.
 - Remove unnecessary '#address-cells/#size-cells' to fix DTC warning
   avoid_unnecessary_addr_size seen with W=1 switch.
 - A series from Rob Herring to fix DTC warning graph_endpoint seen with
   IPU OF graph when W=1 switch is on.
 - Update a few boards to use symbol name instead of hard-coding the
   input codes.
 - Update a number of boards to use IRQ_TYPE specifier instead of the
   raw value.
 - A few updates for i.MX6 RDU2 board: bumping SoC/PU operating points,
   adding assigned clocks for GPU, and enabling eGalax touchscreen.
 - A couple of i.MX51 RDU1 updates: limiting usbh1 to full-speed, and
   cleaning up eMMC device node.
 - Convert Hummingboard audio bindings from imx-audio-sgtl5000 to
   simple-audio-card, so that auxiliary audio devices such as external
   amplifiers can be supported.
 - Replace underscore with hyphen in aliases name to fix DTC warning
   alias_paths with W=1 switch.
 - A couple of updates on i.MX7D SAI and i.MX6ULL UART5 pin defines.
 - Other random and small changes.

----------------------------------------------------------------
Anson Huang (13):
      ARM: dts: imx7d-sdb: add gpio key support
      ARM: dts: imx7s: add anatop vdd1p2 regulator
      ARM: dts: imx6sx-sabreauto: add external 24MHz clock source
      ARM: dts: imx6sx-sabreauto: add PMIC support
      ARM: dts: imx6sx-sabreauto: add max7322 IO expander support
      ARM: dts: imx6sx-sabreauto: add IO expander max7310 support
      ARM: dts: imx6sx-sabreauto: add fec support
      ARM: dts: imx6sx-sabreauto: add wdog external reset
      ARM: dts: imx6sx-sabreauto: add debug LED support
      ARM: dts: imx6sx-sabreauto: add egalax touch screen support
      ARM: dts: imx7d: correct cpu supply name for voltage scaling
      ARM: dts: imx7s-warp: remove unnecessary cpu regulator supply
      ARM: dts: imx7d: use operating-points-v2 for cpu

Daniel Mack (1):
      ARM: dts: imx28/imx53: enable edt-ft5x06 wakeup source

Fabio Estevam (26):
      ARM: dts: imx25-pdk: Remove unneeded 'codec-handle' property
      ARM: dts: imx53-tx53: Remove unneeded 'codec-handle' property
      ARM: dts: imx6qdl-wandboard: Let the codec control MCLK pinctrl
      ARM: dts: imx7: Move tempmon node out of bus
      ARM: dts: imx6qdl-tx6: Remove 'bus-format-override' property
      ARM: dts: imx6ul: Add CAAM support
      ARM: dts: imx6qdl: Remove #address/#size-cells from mipi_dsi
      ARM: dts: imx: Remove #address/#size-cells from switch nodes
      ARM: dts: imx: Remove #address/#size-cells from stmpe nodes
      ARM: dts: imx6qdl-sabre: Remove #address/#size-cells from camera port nodes
      ARM: dts: imx53-ppd: Remove unnecessary #address/#size-cells
      ARM: dts: imx6dl-aristainetos2_4: Remove #address/#size-cells from display0
      ARM: dts: imx6q-b850v3: Remove #address/#size-cells from stdp2690
      ARM: dts: imx6q-utilite-pro: Remove #address/#size-cells from encoder
      ARM: dts: imx6q-var-dt6customboard: Remove #address/#size-cells from gpio-keys
      ARM: dts: imx6q-pistachio: Use 'uart-has-rtscts' property
      ARM: dts: imx6qdl-wandboard: Switch to SPDX identifier
      ARM: dts: imx6qdl-udoo: Switch to SPDX identifier
      ARM: dts: imx28-cfa10049: Remove unnecessary #address/#size-cells
      ARM: dts: imx28-duckbill-2-enocean: Remove unnecessary #address/#size-cells
      ARM: dts: imx: Switch to SPDX identifier
      ARM: dts: imx53-ard: Do not hardcode input codes
      ARM: dts: imx53-smd: Do not hardcode input codes
      ARM: dts: imx6q-gk802: Do not hardcode input codes
      ARM: dts: imx: Switch NXP boards to SPDX identifier
      ARM: dts: imx6/7: Remove unit-address from anatop regulators

Greg Ungerer (1):
      ARM: dts: imx6ull: add UART5 input select register definitions

Hern?n Gonzalez (4):
      ARM: dts: vf-colibri-eval-v3: Use IRQ_TYPE specifier
      ARM: dts: imx53-qsb: Use IRQ_TYPE specifier
      ARM: dts: imx53-voipac-dmm-668: Use IRQ_TYPE specifier
      ARM: dts: imx6qdl-phytec-pfla02: Use IRQ_TYPE specifier

Jagan Teki (4):
      dt-bindings: Add vendor prefix for Bticino
      ARM: dts: i.MX6: Add BTicino i.MX6DL Mamoj initial support
      ARM: dts: imx6q-icore-ofcap12: Switch LVDS timings from panel-simple
      ARM: dts: imx6q: Add Engicam i.CoreM6 1.5 Quad/Dual MIPI starter kit support

Ken Lin (1):
      ARM: dts: imx: ba16: add "mfg" Q7 SPI-NOR partition

Lucas Stach (3):
      ARM: dts: imx6: RDU2: bump SoC/PU operating points by 25mV
      ARM: dts: imx6: RDU2+: add assigned clocks for GPU 3D
      ARM: dts: imx6: RDU2: add eGalax touchscreen

Lukasz Majewski (1):
      ARM: dts: tpc: Device tree description of the iMX6Q TPC board

Marek Vasut (1):
      ARM: dts: imx6q: Add support for the DHCOM iMX6 SoM and PDK2

Matt Porter (1):
      ARM: dts: hummingboard: convert onboard audio to simple-audio-card

Nikita Yushchenko (3):
      ARM: dts: imx51-zii-rdu1: limit usbh1 to full-speed
      ARM: dts: vf610-zii-dev: enable vf610 builtin temp sensor
      ARM: dts: imx51-zii-rdu1: cleanup eMMC node

Rob Herring (3):
      ARM: dts: imx: fix IPU OF graph endpoint node names
      ARM: dts: imx53: Fix LDB OF graph warning
      ARM: dts: imx7: Fix error in coresight TPIU graph connection

Sebastian Reichel (1):
      ARM: dts: imx53-ppd: Use IRQ_TYPE_* constants

Shawn Guo (7):
      ARM: dts: imx6sx-sabreauto: drop 'regulators' container node
      ARM: dts: imx6sx-sabreauto: drop board specific pinctrl container node
      ARM: dts: imx: drop unnecessary #address-cells/#size-cells
      ARM: dts: imx1: move clk32 clock into soc dtsi
      ARM: dts: imx27: use label to override osc26m clock setting
      ARM: dts: imx: drop 'clocks' container for board level clocks
      ARM: dts: imx: replace underscore with hyphen in aliases name

Shengjiu Wang (1):
      ARM: dts: imx7d-pinfunc: update sai select input value

Stefan Wahren (1):
      ARM: dts: imx6ull: add UART5 RTS input select register

 .../devicetree/bindings/vendor-prefixes.txt        |   1 +
 arch/arm/boot/dts/Makefile                         |   4 +
 arch/arm/boot/dts/imx1-ads.dts                     |  11 -
 arch/arm/boot/dts/imx1.dtsi                        |  21 +-
 arch/arm/boot/dts/imx23-evk.dts                    |  13 +-
 arch/arm/boot/dts/imx23.dtsi                       |  13 +-
 arch/arm/boot/dts/imx25-pdk.dts                    |  14 +-
 arch/arm/boot/dts/imx25.dtsi                       |  16 +-
 arch/arm/boot/dts/imx27-apf27.dts                  |  13 +-
 arch/arm/boot/dts/imx27-pdk.dts                    |  13 +-
 arch/arm/boot/dts/imx27.dtsi                       |  18 +-
 arch/arm/boot/dts/imx28-cfa10049.dts               |   2 -
 arch/arm/boot/dts/imx28-duckbill-2-enocean.dts     |   2 -
 arch/arm/boot/dts/imx28-evk.dts                    |  13 +-
 arch/arm/boot/dts/imx28-tx28.dts                   |  14 +-
 arch/arm/boot/dts/imx28.dtsi                       |  13 +-
 arch/arm/boot/dts/imx31.dtsi                       |  13 +-
 arch/arm/boot/dts/imx35-pdk.dts                    |  15 +-
 arch/arm/boot/dts/imx35.dtsi                       |  14 +-
 arch/arm/boot/dts/imx50-evk.dts                    |  17 +-
 arch/arm/boot/dts/imx50.dtsi                       |   3 -
 arch/arm/boot/dts/imx51-babbage.dts                |  15 +-
 arch/arm/boot/dts/imx51-zii-rdu1.dts               |   6 +-
 arch/arm/boot/dts/imx51.dtsi                       |  18 +-
 arch/arm/boot/dts/imx53-ard.dts                    |  11 +-
 arch/arm/boot/dts/imx53-m53.dtsi                   |   2 -
 arch/arm/boot/dts/imx53-ppd.dts                    |  12 +-
 arch/arm/boot/dts/imx53-qsb-common.dtsi            |  15 +-
 arch/arm/boot/dts/imx53-qsb.dts                    |  17 +-
 arch/arm/boot/dts/imx53-qsrb.dts                   |  15 +-
 arch/arm/boot/dts/imx53-smd.dts                    |  20 +-
 arch/arm/boot/dts/imx53-tx53-x03x.dts              |   1 +
 arch/arm/boot/dts/imx53-tx53.dtsi                  |  14 +-
 arch/arm/boot/dts/imx53-voipac-dmm-668.dtsi        |   2 +-
 arch/arm/boot/dts/imx53.dtsi                       |  11 +-
 arch/arm/boot/dts/imx6dl-aristainetos2_4.dts       |   2 -
 arch/arm/boot/dts/imx6dl-colibri-eval-v3.dts       |  15 +-
 arch/arm/boot/dts/imx6dl-mamoj.dts                 | 224 ++++++++++
 arch/arm/boot/dts/imx6dl-sabreauto.dts             |  10 +-
 arch/arm/boot/dts/imx6dl-sabresd.dts               |  10 +-
 arch/arm/boot/dts/imx6dl-udoo.dts                  |   6 +-
 arch/arm/boot/dts/imx6dl-wandboard-revb1.dts       |   6 +-
 arch/arm/boot/dts/imx6dl-wandboard-revd1.dts       |   6 +-
 arch/arm/boot/dts/imx6dl-wandboard.dts             |   6 +-
 arch/arm/boot/dts/imx6dl.dtsi                      |  12 +-
 arch/arm/boot/dts/imx6q-b850v3.dts                 |   4 -
 arch/arm/boot/dts/imx6q-ba16.dtsi                  |   7 +-
 arch/arm/boot/dts/imx6q-bx50v3.dtsi                |  13 +-
 arch/arm/boot/dts/imx6q-dhcom-pdk2.dts             | 151 +++++++
 arch/arm/boot/dts/imx6q-dhcom-som.dtsi             | 476 +++++++++++++++++++++
 arch/arm/boot/dts/imx6q-gk802.dts                  |   3 +-
 arch/arm/boot/dts/imx6q-icore-mipi.dts             |  25 ++
 arch/arm/boot/dts/imx6q-icore-ofcap12.dts          |  31 +-
 arch/arm/boot/dts/imx6q-kp-tpc.dts                 |  22 +
 arch/arm/boot/dts/imx6q-kp.dtsi                    | 432 +++++++++++++++++++
 arch/arm/boot/dts/imx6q-novena.dts                 |   2 -
 arch/arm/boot/dts/imx6q-pistachio.dts              |   2 +-
 arch/arm/boot/dts/imx6q-sabreauto.dts              |  15 +-
 arch/arm/boot/dts/imx6q-sabresd.dts                |  15 +-
 arch/arm/boot/dts/imx6q-udoo.dts                   |   6 +-
 arch/arm/boot/dts/imx6q-utilite-pro.dts            |   2 -
 arch/arm/boot/dts/imx6q-var-dt6customboard.dts     |   2 -
 arch/arm/boot/dts/imx6q-wandboard-revb1.dts        |   6 +-
 arch/arm/boot/dts/imx6q-wandboard-revd1.dts        |   6 +-
 arch/arm/boot/dts/imx6q-wandboard.dts              |   6 +-
 arch/arm/boot/dts/imx6q.dtsi                       |  39 +-
 arch/arm/boot/dts/imx6qdl-apalis.dtsi              |   2 -
 arch/arm/boot/dts/imx6qdl-colibri.dtsi             |   2 -
 arch/arm/boot/dts/imx6qdl-gw5904.dtsi              |   2 -
 arch/arm/boot/dts/imx6qdl-hummingboard.dtsi        |  52 ++-
 arch/arm/boot/dts/imx6qdl-hummingboard2.dtsi       |  47 +-
 arch/arm/boot/dts/imx6qdl-icore.dtsi               |  25 +-
 arch/arm/boot/dts/imx6qdl-phytec-pfla02.dtsi       |   2 +-
 arch/arm/boot/dts/imx6qdl-sabreauto.dtsi           |  15 +-
 arch/arm/boot/dts/imx6qdl-sabrelite.dtsi           |   3 -
 arch/arm/boot/dts/imx6qdl-sabresd.dtsi             |  18 +-
 arch/arm/boot/dts/imx6qdl-tx6-lcd.dtsi             |   1 -
 arch/arm/boot/dts/imx6qdl-tx6-mb7.dtsi             |   3 -
 arch/arm/boot/dts/imx6qdl-tx6.dtsi                 |   6 +-
 arch/arm/boot/dts/imx6qdl-udoo.dtsi                |   6 +-
 arch/arm/boot/dts/imx6qdl-wandboard-revb1.dtsi     |   1 -
 arch/arm/boot/dts/imx6qdl-wandboard-revc1.dtsi     |   1 -
 arch/arm/boot/dts/imx6qdl-wandboard-revd1.dtsi     |   1 -
 arch/arm/boot/dts/imx6qdl-wandboard.dtsi           |  14 +-
 arch/arm/boot/dts/imx6qdl-zii-rdu2.dtsi            |  24 +-
 arch/arm/boot/dts/imx6qdl.dtsi                     |  70 ++-
 arch/arm/boot/dts/imx6qp-sabreauto.dts             |  44 +-
 arch/arm/boot/dts/imx6qp-sabresd.dts               |  44 +-
 arch/arm/boot/dts/imx6qp-wandboard-revd1.dts       |   6 +-
 arch/arm/boot/dts/imx6qp-zii-rdu2.dts              |   5 +
 arch/arm/boot/dts/imx6qp.dtsi                      |  44 +-
 arch/arm/boot/dts/imx6sl-evk.dts                   |  10 +-
 arch/arm/boot/dts/imx6sl.dtsi                      |  34 +-
 arch/arm/boot/dts/imx6sx-nitrogen6sx.dts           |   4 +-
 arch/arm/boot/dts/imx6sx-sabreauto.dts             | 427 ++++++++++++++----
 arch/arm/boot/dts/imx6sx.dtsi                      | 101 ++---
 arch/arm/boot/dts/imx6ul-14x14-evk.dts             |  10 +-
 arch/arm/boot/dts/imx6ul-isiot.dtsi                |   2 -
 arch/arm/boot/dts/imx6ul-tx6ul-mainboard.dts       |   2 +-
 arch/arm/boot/dts/imx6ul-tx6ul.dtsi                |   6 +-
 arch/arm/boot/dts/imx6ul.dtsi                      |  51 ++-
 arch/arm/boot/dts/imx6ull-pinfunc.h                |   9 +
 arch/arm/boot/dts/imx6ull.dtsi                     |   2 +
 arch/arm/boot/dts/imx7d-cl-som-imx7.dts            |   2 +-
 arch/arm/boot/dts/imx7d-nitrogen7.dts              |   6 +-
 arch/arm/boot/dts/imx7d-pinfunc.h                  |   6 +-
 arch/arm/boot/dts/imx7d-sdb-sht11.dts              |  44 +-
 arch/arm/boot/dts/imx7d-sdb.dts                    |  70 ++-
 arch/arm/boot/dts/imx7d.dtsi                       |  71 ++-
 arch/arm/boot/dts/imx7s-warp.dts                   |   4 -
 arch/arm/boot/dts/imx7s.dtsi                       |  88 ++--
 arch/arm/boot/dts/vf-colibri-eval-v3.dtsi          |   2 +-
 arch/arm/boot/dts/vf610-zii-dev-rev-b.dts          |   6 -
 arch/arm/boot/dts/vf610-zii-dev-rev-c.dts          |   4 -
 arch/arm/boot/dts/vf610-zii-dev.dtsi               |   4 +
 arch/arm/boot/dts/vfxxx.dtsi                       |   2 +-
 116 files changed, 2285 insertions(+), 1084 deletions(-)
 create mode 100644 arch/arm/boot/dts/imx6dl-mamoj.dts
 create mode 100644 arch/arm/boot/dts/imx6q-dhcom-pdk2.dts
 create mode 100644 arch/arm/boot/dts/imx6q-dhcom-som.dtsi
 create mode 100644 arch/arm/boot/dts/imx6q-icore-mipi.dts
 create mode 100644 arch/arm/boot/dts/imx6q-kp-tpc.dts
 create mode 100644 arch/arm/boot/dts/imx6q-kp.dtsi

^ permalink raw reply

* [GIT PULL 2/5] i.MX SoC changes for 4.18
From: Shawn Guo @ 2018-05-20 14:57 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1526828281-14664-1-git-send-email-shawnguo@kernel.org>

The following changes since commit 60cc43fc888428bb2f18f08997432d426a243338:

  Linux 4.17-rc1 (2018-04-15 18:24:20 -0700)

are available in the git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/shawnguo/linux.git tags/imx-soc-4.18

for you to fetch changes up to 0e8d1c4b7613399494720e315f99d21793cacb8c:

  ARM: imx: select imx6sll pinctrl when imx6sll enabled (2018-05-02 15:01:32 +0800)

----------------------------------------------------------------
i.MX SoC update for 4.18:
 - A series from Bartosz to convert all i.MX plaform code using
   at24_platform_data to use at24 eeprom generic device properties.
 - Enable pinctrl driver support for i.MX6SLL SoC.
 - Clean up i.MX platform code using spi_imx platform data on outdated
   documentation and chip select array usage.

----------------------------------------------------------------
Bai Ping (1):
      ARM: imx: select imx6sll pinctrl when imx6sll enabled

Bartosz Golaszewski (4):
      ARM: imx: vpr200: drop at24_platform_data
      ARM: imx: pcm043: use device properties for at24 eeprom
      ARM: imx: pca100: use device properties for at24 eeprom
      ARM: imx: pcm037: use device properties for at24 eeprom

Trent Piepho (1):
      ARM: imx: Update spi_imx platform data to reflect current state

 arch/arm/mach-imx/Kconfig             |  1 +
 arch/arm/mach-imx/mach-mx31_3ds.c     | 18 ++----------------
 arch/arm/mach-imx/mach-mx31lilly.c    | 12 ++----------
 arch/arm/mach-imx/mach-mx31lite.c     | 16 ++--------------
 arch/arm/mach-imx/mach-mx31moboard.c  | 17 +++--------------
 arch/arm/mach-imx/mach-pca100.c       | 13 ++++++-------
 arch/arm/mach-imx/mach-pcm037.c       | 13 ++++++-------
 arch/arm/mach-imx/mach-pcm037_eet.c   |  5 +----
 arch/arm/mach-imx/mach-pcm043.c       | 13 ++++++-------
 arch/arm/mach-imx/mach-vpr200.c       |  9 +--------
 include/linux/platform_data/spi-imx.h | 29 +++++++++++++++++------------
 11 files changed, 47 insertions(+), 99 deletions(-)

^ permalink raw reply

* [GIT PULL 1/5] i.MX drivers updates for 4.18
From: Shawn Guo @ 2018-05-20 14:57 UTC (permalink / raw)
  To: linux-arm-kernel

The following changes since commit 60cc43fc888428bb2f18f08997432d426a243338:

  Linux 4.17-rc1 (2018-04-15 18:24:20 -0700)

are available in the git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/shawnguo/linux.git tags/imx-drivers-4.18

for you to fetch changes up to f54e714cfc53b9164d1206f9ee49042195532a51:

  soc: imx: gpc: Do not pass static memory as platform data (2018-04-23 17:03:15 +0800)

----------------------------------------------------------------
i.MX drivers update for 4.18:
 - Use platform_device_add_data() instead of a pointer to a static
   memory in gpc/gpcv2 driver for platform data passing, so that we
   can avoid a BUG() when calling platform_device_put().

----------------------------------------------------------------
Andrey Smirnov (2):
      soc: imx: gpcv2: Do not pass static memory as platform data
      soc: imx: gpc: Do not pass static memory as platform data

 drivers/soc/imx/gpc.c   | 18 +++++++++++++-----
 drivers/soc/imx/gpcv2.c | 22 +++++++++++++++-------
 2 files changed, 28 insertions(+), 12 deletions(-)

^ permalink raw reply

* [PATCH v1 1/5] ARM: trusted_foundations: Implement L2 cache initialization callback
From: Dmitry Osipenko @ 2018-05-20 14:53 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <20180520140805.GL17671@n2100.armlinux.org.uk>

On 20.05.2018 17:08, Russell King - ARM Linux wrote:
> On Sun, May 20, 2018 at 01:15:38PM +0300, Dmitry Osipenko wrote:
>> Implement L2 cache initialization firmware callback that should be invoked
>> early in boot to enable cache HW.
>>
>> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
>> ---
>>  arch/arm/firmware/trusted_foundations.c | 23 +++++++++++++++++++++++
>>  1 file changed, 23 insertions(+)
>>
>> diff --git a/arch/arm/firmware/trusted_foundations.c b/arch/arm/firmware/trusted_foundations.c
>> index 3fb1b5a1dce9..198ce5c75ca0 100644
>> --- a/arch/arm/firmware/trusted_foundations.c
>> +++ b/arch/arm/firmware/trusted_foundations.c
>> @@ -18,8 +18,13 @@
>>  #include <linux/init.h>
>>  #include <linux/of.h>
>>  #include <asm/firmware.h>
>> +#include <asm/outercache.h>
>>  #include <asm/trusted_foundations.h>
>>  
>> +#define TF_CACHE_MAINT		0xfffff100
>> +
>> +#define TF_CACHE_INIT		1
>> +
>>  #define TF_SET_CPU_BOOT_ADDR_SMC 0xfffff200
>>  
>>  #define TF_CPU_PM		0xfffffffc
>> @@ -63,9 +68,27 @@ static int tf_prepare_idle(void)
>>  	return 0;
>>  }
>>  
>> +#ifdef CONFIG_CACHE_L2X0
>> +static void tf_cache_write_sec(unsigned long val, unsigned int reg)
>> +{
>> +	pr_warn("%s: Ignoring write [0x%x]: 0x%08lx\n", __func__, reg, val);
> 
> Why at warning level?  Is this some issue that the user needs to be
> warned about?
> 

If cache-l2x0 code will be changed in the future in a way that it will try to do
something using the secure-registers, then user should be informed about that
incident as we are ignoring the accesses to secure-registers and this may lead
to an undesired consequences. If a such change in cache-l2x0 will happen, then
we will have to take some action by either fixing the invalid accesses or
silencing the warning message if will be appropriate. For now I'd prefer to have
verbosity in the KMSG to masking the potential problems.

^ permalink raw reply

* [PATCH 5/6] mtd: rawnand: ams-delta: use GPIO lookup table
From: Andy Shevchenko @ 2018-05-20 14:44 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <5456625.lDWjtgZygK@z50>

On Sun, May 20, 2018 at 12:55 AM, Janusz Krzysztofik
<jmkrzyszt@gmail.com> wrote:
> On Saturday, May 19, 2018 8:00:38 PM CEST Andy Shevchenko wrote:
>> On Sat, May 19, 2018 at 2:15 AM, Janusz Krzysztofik <jmkrzyszt@gmail.com>
> wrote:

>> NULL check in practice discards the _optional part of gpiod_get(). So,
>> either you use non-optional variant and decide how to handle an
>> errors, or user _optional w/o NULL check.
>
> OK, I'm going to use something like the below while submitting v2:
>
> -       gpiod_rdy = devm_gpiod_get_optional(&pdev->dev, "rdy", GPIOD_IN);
> -       if (!IS_ERR_OR_NULL(gpiod_rdy)) {
> -               this->dev_ready = ams_delta_nand_ready;
> -       } else {
> -               this->dev_ready = NULL;
> -               pr_notice("Couldn't request gpio for Delta NAND ready.\n");
> +       priv->gpiod_rdy = devm_gpiod_get_optional(&pdev->dev, "rdy",
> +                                                 GPIOD_IN);
> +       if (IS_ERR(priv->gpiod_rdy)) {
> +               err = PTR_ERR(priv->gpiod_nwp);
> +               dev_warn(&pdev->dev, "RDY GPIO request failed (%d)\n", err);
> +               goto err_gpiod;
>         }
>
> +       if (priv->gpiod_rdy)
> +               this->dev_ready = ams_delta_nand_ready;

This makes sense.

Though, I completely dislike "rdy" name of GPIO. Where is it documented?

>> >> > +err_gpiod:
>> >> > +       if (err == -ENODEV || err == -ENOENT)
>> >> > +               err = -EPROBE_DEFER;
>> >>
>> >> Hmm...
>> >
>> > Amstrad Delta uses gpio-mmio driver. Unfortunatelty that driver is not
>> > availble before device init phase, unlike other crucial GPIO drivers which
>> > are initialized earlier, e.g. during the postcore or at latetst the
>> > subsys phase. Hence, devices which depend on GPIO pins provided by
>> > gpio-mmio must either be declared late or fail softly so they get another
>> > chance of being probed succesfully.
>> >
>> > I thought of replacing the gpio-mmio platform driver with bgpio functions
>> > it exports but for now I haven't implemented it, not even shared the
>> > idea.
>> >
>> > Does it really hurt to return -EPROBE_DEFER if a GPIO pin can't be
>> > obtained?
>> I'm only concerned if it would be an infinite defer in the case when
>> driver will never appear.
>> But I don't remember the details.
>
> Deferred probes are handled effectively during late_initcall, no risk of
> infinite defer, see drivers/base/dd.c for details.

Yes, but the code you provided in patch looks somehow suspicious. OK,
I let Linus decide whtat to do with that.

-- 
With Best Regards,
Andy Shevchenko

^ permalink raw reply

* [PATCH v1 1/5] ARM: trusted_foundations: Implement L2 cache initialization callback
From: Russell King - ARM Linux @ 2018-05-20 14:08 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <20180520101542.12206-2-digetx@gmail.com>

On Sun, May 20, 2018 at 01:15:38PM +0300, Dmitry Osipenko wrote:
> Implement L2 cache initialization firmware callback that should be invoked
> early in boot to enable cache HW.
> 
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
>  arch/arm/firmware/trusted_foundations.c | 23 +++++++++++++++++++++++
>  1 file changed, 23 insertions(+)
> 
> diff --git a/arch/arm/firmware/trusted_foundations.c b/arch/arm/firmware/trusted_foundations.c
> index 3fb1b5a1dce9..198ce5c75ca0 100644
> --- a/arch/arm/firmware/trusted_foundations.c
> +++ b/arch/arm/firmware/trusted_foundations.c
> @@ -18,8 +18,13 @@
>  #include <linux/init.h>
>  #include <linux/of.h>
>  #include <asm/firmware.h>
> +#include <asm/outercache.h>
>  #include <asm/trusted_foundations.h>
>  
> +#define TF_CACHE_MAINT		0xfffff100
> +
> +#define TF_CACHE_INIT		1
> +
>  #define TF_SET_CPU_BOOT_ADDR_SMC 0xfffff200
>  
>  #define TF_CPU_PM		0xfffffffc
> @@ -63,9 +68,27 @@ static int tf_prepare_idle(void)
>  	return 0;
>  }
>  
> +#ifdef CONFIG_CACHE_L2X0
> +static void tf_cache_write_sec(unsigned long val, unsigned int reg)
> +{
> +	pr_warn("%s: Ignoring write [0x%x]: 0x%08lx\n", __func__, reg, val);

Why at warning level?  Is this some issue that the user needs to be
warned about?

-- 
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line in suburbia: sync at 8.8Mbps down 630kbps up
According to speedtest.net: 8.21Mbps down 510kbps up

^ permalink raw reply

* [PATCH 7/7 v5] arm64: dts: ls208xa: comply with the iommu map binding for fsl_mc
From: Nipun Gupta @ 2018-05-20 13:49 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1526824191-7000-1-git-send-email-nipun.gupta@nxp.com>

fsl-mc bus support the new iommu-map property. Comply to this binding
for fsl_mc bus.

Signed-off-by: Nipun Gupta <nipun.gupta@nxp.com>
Reviewed-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
---
 arch/arm64/boot/dts/freescale/fsl-ls208xa.dtsi | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/freescale/fsl-ls208xa.dtsi b/arch/arm64/boot/dts/freescale/fsl-ls208xa.dtsi
index 137ef4d..6010505 100644
--- a/arch/arm64/boot/dts/freescale/fsl-ls208xa.dtsi
+++ b/arch/arm64/boot/dts/freescale/fsl-ls208xa.dtsi
@@ -184,6 +184,7 @@
 		#address-cells = <2>;
 		#size-cells = <2>;
 		ranges;
+		dma-ranges = <0x0 0x0 0x0 0x0 0x10000 0x00000000>;
 
 		clockgen: clocking at 1300000 {
 			compatible = "fsl,ls2080a-clockgen";
@@ -357,6 +358,8 @@
 			reg = <0x00000008 0x0c000000 0 0x40>,	 /* MC portal base */
 			      <0x00000000 0x08340000 0 0x40000>; /* MC control reg */
 			msi-parent = <&its>;
+			iommu-map = <0 &smmu 0 0>;	/* This is fixed-up by u-boot */
+			dma-coherent;
 			#address-cells = <3>;
 			#size-cells = <1>;
 
@@ -460,6 +463,8 @@
 			compatible = "arm,mmu-500";
 			reg = <0 0x5000000 0 0x800000>;
 			#global-interrupts = <12>;
+			#iommu-cells = <1>;
+			stream-match-mask = <0x7C00>;
 			interrupts = <0 13 4>, /* global secure fault */
 				     <0 14 4>, /* combined secure interrupt */
 				     <0 15 4>, /* global non-secure fault */
@@ -502,7 +507,6 @@
 				     <0 204 4>, <0 205 4>,
 				     <0 206 4>, <0 207 4>,
 				     <0 208 4>, <0 209 4>;
-			mmu-masters = <&fsl_mc 0x300 0>;
 		};
 
 		dspi: dspi at 2100000 {
-- 
1.9.1

^ permalink raw reply related

* [PATCH 6/7 v5] bus: fsl-mc: set coherent dma mask for devices on fsl-mc bus
From: Nipun Gupta @ 2018-05-20 13:49 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1526824191-7000-1-git-send-email-nipun.gupta@nxp.com>

of_dma_configure() API expects coherent_dma_mask to be correctly
set in the devices. This patch does the needful.

Signed-off-by: Nipun Gupta <nipun.gupta@nxp.com>
---
 drivers/bus/fsl-mc/fsl-mc-bus.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/bus/fsl-mc/fsl-mc-bus.c b/drivers/bus/fsl-mc/fsl-mc-bus.c
index fa43c7d..624828b 100644
--- a/drivers/bus/fsl-mc/fsl-mc-bus.c
+++ b/drivers/bus/fsl-mc/fsl-mc-bus.c
@@ -627,6 +627,7 @@ int fsl_mc_device_add(struct fsl_mc_obj_desc *obj_desc,
 		mc_dev->icid = parent_mc_dev->icid;
 		mc_dev->dma_mask = FSL_MC_DEFAULT_DMA_MASK;
 		mc_dev->dev.dma_mask = &mc_dev->dma_mask;
+		mc_dev->dev.coherent_dma_mask = mc_dev->dma_mask;
 		dev_set_msi_domain(&mc_dev->dev,
 				   dev_get_msi_domain(&parent_mc_dev->dev));
 	}
-- 
1.9.1

^ permalink raw reply related

* [PATCH 5/7 v5] bus: fsl-mc: support dma configure for devices on fsl-mc bus
From: Nipun Gupta @ 2018-05-20 13:49 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1526824191-7000-1-git-send-email-nipun.gupta@nxp.com>

This patch adds support of dma configuration for devices on fsl-mc
bus using 'dma_configure' callback for busses. Also, directly calling
arch_setup_dma_ops is removed from the fsl-mc bus.

Signed-off-by: Nipun Gupta <nipun.gupta@nxp.com>
Reviewed-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
---
 drivers/bus/fsl-mc/fsl-mc-bus.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/bus/fsl-mc/fsl-mc-bus.c b/drivers/bus/fsl-mc/fsl-mc-bus.c
index 5d8266c..fa43c7d 100644
--- a/drivers/bus/fsl-mc/fsl-mc-bus.c
+++ b/drivers/bus/fsl-mc/fsl-mc-bus.c
@@ -127,6 +127,16 @@ static int fsl_mc_bus_uevent(struct device *dev, struct kobj_uevent_env *env)
 	return 0;
 }
 
+static int fsl_mc_dma_configure(struct device *dev)
+{
+	struct device *dma_dev = dev;
+
+	while (dev_is_fsl_mc(dma_dev))
+		dma_dev = dma_dev->parent;
+
+	return of_dma_configure(dev, dma_dev->of_node, 0);
+}
+
 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 			     char *buf)
 {
@@ -148,6 +158,7 @@ struct bus_type fsl_mc_bus_type = {
 	.name = "fsl-mc",
 	.match = fsl_mc_bus_match,
 	.uevent = fsl_mc_bus_uevent,
+	.dma_configure  = fsl_mc_dma_configure,
 	.dev_groups = fsl_mc_dev_groups,
 };
 EXPORT_SYMBOL_GPL(fsl_mc_bus_type);
@@ -633,10 +644,6 @@ int fsl_mc_device_add(struct fsl_mc_obj_desc *obj_desc,
 			goto error_cleanup_dev;
 	}
 
-	/* Objects are coherent, unless 'no shareability' flag set. */
-	if (!(obj_desc->flags & FSL_MC_OBJ_FLAG_NO_MEM_SHAREABILITY))
-		arch_setup_dma_ops(&mc_dev->dev, 0, 0, NULL, true);
-
 	/*
 	 * The device-specific probe callback will get invoked by device_add()
 	 */
-- 
1.9.1

^ permalink raw reply related

* [PATCH 4/7 v5] iommu: arm-smmu: Add support for the fsl-mc bus
From: Nipun Gupta @ 2018-05-20 13:49 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1526824191-7000-1-git-send-email-nipun.gupta@nxp.com>

Implement bus specific support for the fsl-mc bus including
registering arm_smmu_ops and bus specific device add operations.

Signed-off-by: Nipun Gupta <nipun.gupta@nxp.com>
---
 drivers/iommu/arm-smmu.c |  7 +++++++
 drivers/iommu/iommu.c    | 21 +++++++++++++++++++++
 include/linux/fsl/mc.h   |  8 ++++++++
 include/linux/iommu.h    |  2 ++
 4 files changed, 38 insertions(+)

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 69e7c60..e1d5090 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -52,6 +52,7 @@
 #include <linux/spinlock.h>
 
 #include <linux/amba/bus.h>
+#include <linux/fsl/mc.h>
 
 #include "io-pgtable.h"
 #include "arm-smmu-regs.h"
@@ -1459,6 +1460,8 @@ static struct iommu_group *arm_smmu_device_group(struct device *dev)
 
 	if (dev_is_pci(dev))
 		group = pci_device_group(dev);
+	else if (dev_is_fsl_mc(dev))
+		group = fsl_mc_device_group(dev);
 	else
 		group = generic_device_group(dev);
 
@@ -2037,6 +2040,10 @@ static void arm_smmu_bus_init(void)
 		bus_set_iommu(&pci_bus_type, &arm_smmu_ops);
 	}
 #endif
+#ifdef CONFIG_FSL_MC_BUS
+	if (!iommu_present(&fsl_mc_bus_type))
+		bus_set_iommu(&fsl_mc_bus_type, &arm_smmu_ops);
+#endif
 }
 
 static int arm_smmu_device_probe(struct platform_device *pdev)
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index d2aa2320..6d4ce35 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -32,6 +32,7 @@
 #include <linux/pci.h>
 #include <linux/bitops.h>
 #include <linux/property.h>
+#include <linux/fsl/mc.h>
 #include <trace/events/iommu.h>
 
 static struct kset *iommu_group_kset;
@@ -987,6 +988,26 @@ struct iommu_group *pci_device_group(struct device *dev)
 	return iommu_group_alloc();
 }
 
+/* Get the IOMMU group for device on fsl-mc bus */
+struct iommu_group *fsl_mc_device_group(struct device *dev)
+{
+	struct device *cont_dev = fsl_mc_cont_dev(dev);
+	struct iommu_group *group;
+
+	/* Container device is responsible for creating the iommu group */
+	if (fsl_mc_is_cont_dev(dev)) {
+		group = iommu_group_alloc();
+		if (IS_ERR(group))
+			return NULL;
+	} else {
+		get_device(cont_dev);
+		group = iommu_group_get(cont_dev);
+		put_device(cont_dev);
+	}
+
+	return group;
+}
+
 /**
  * iommu_group_get_for_dev - Find or create the IOMMU group for a device
  * @dev: target device
diff --git a/include/linux/fsl/mc.h b/include/linux/fsl/mc.h
index f27cb14..dddaca1 100644
--- a/include/linux/fsl/mc.h
+++ b/include/linux/fsl/mc.h
@@ -351,6 +351,14 @@ struct fsl_mc_io {
 #define dev_is_fsl_mc(_dev) (0)
 #endif
 
+/* Macro to check if a device is a container device */
+#define fsl_mc_is_cont_dev(_dev) (to_fsl_mc_device(_dev)->flags & \
+	FSL_MC_IS_DPRC)
+
+/* Macro to get the container device of a MC device */
+#define fsl_mc_cont_dev(_dev) (fsl_mc_is_cont_dev(_dev) ? \
+	(_dev) : (_dev)->parent)
+
 /*
  * module_fsl_mc_driver() - Helper macro for drivers that don't do
  * anything special in module init/exit.  This eliminates a lot of
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 19938ee..2981200 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -389,6 +389,8 @@ static inline size_t iommu_map_sg(struct iommu_domain *domain,
 extern struct iommu_group *pci_device_group(struct device *dev);
 /* Generic device grouping function */
 extern struct iommu_group *generic_device_group(struct device *dev);
+/* FSL-MC device grouping function */
+struct iommu_group *fsl_mc_device_group(struct device *dev);
 
 /**
  * struct iommu_fwspec - per-device IOMMU instance data
-- 
1.9.1

^ permalink raw reply related

* [PATCH 3/7 v5] iommu: support iommu configuration for fsl-mc devices
From: Nipun Gupta @ 2018-05-20 13:49 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1526824191-7000-1-git-send-email-nipun.gupta@nxp.com>

With of_pci_map_rid available for all the busses, use the function
for configuration of devices on fsl-mc bus

Signed-off-by: Nipun Gupta <nipun.gupta@nxp.com>
---
 drivers/iommu/of_iommu.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
index 811e160..284474d 100644
--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c
@@ -24,6 +24,7 @@
 #include <linux/of_iommu.h>
 #include <linux/of_pci.h>
 #include <linux/slab.h>
+#include <linux/fsl/mc.h>
 
 #define NO_IOMMU	1
 
@@ -159,6 +160,23 @@ static int of_pci_iommu_init(struct pci_dev *pdev, u16 alias, void *data)
 	return err;
 }
 
+static int of_fsl_mc_iommu_init(struct fsl_mc_device *mc_dev,
+				struct device_node *master_np)
+{
+	struct of_phandle_args iommu_spec = { .args_count = 1 };
+	int err;
+
+	err = of_map_rid(master_np, mc_dev->icid, "iommu-map",
+			 "iommu-map-mask", &iommu_spec.np,
+			 iommu_spec.args);
+	if (err)
+		return err == -ENODEV ? NO_IOMMU : err;
+
+	err = of_iommu_xlate(&mc_dev->dev, &iommu_spec);
+	of_node_put(iommu_spec.np);
+	return err;
+}
+
 const struct iommu_ops *of_iommu_configure(struct device *dev,
 					   struct device_node *master_np)
 {
@@ -190,6 +208,8 @@ const struct iommu_ops *of_iommu_configure(struct device *dev,
 
 		err = pci_for_each_dma_alias(to_pci_dev(dev),
 					     of_pci_iommu_init, &info);
+	} else if (dev_is_fsl_mc(dev)) {
+		err = of_fsl_mc_iommu_init(to_fsl_mc_device(dev), master_np);
 	} else {
 		struct of_phandle_args iommu_spec;
 		int idx = 0;
-- 
1.9.1

^ permalink raw reply related

* [PATCH 2/7 v5] iommu: of: make of_pci_map_rid() available for other devices too
From: Nipun Gupta @ 2018-05-20 13:49 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1526824191-7000-1-git-send-email-nipun.gupta@nxp.com>

iommu-map property is also used by devices with fsl-mc. This
patch moves the of_pci_map_rid to generic location, so that it
can be used by other busses too.

'of_pci_map_rid' is renamed here to 'of_map_rid' and there is no
functional change done in the API.

Signed-off-by: Nipun Gupta <nipun.gupta@nxp.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
---
 drivers/iommu/of_iommu.c |   5 +--
 drivers/of/base.c        | 102 +++++++++++++++++++++++++++++++++++++++++++++++
 drivers/of/irq.c         |   5 +--
 drivers/pci/of.c         | 101 ----------------------------------------------
 include/linux/of.h       |  11 +++++
 include/linux/of_pci.h   |  10 -----
 6 files changed, 117 insertions(+), 117 deletions(-)

diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
index 5c36a8b..811e160 100644
--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c
@@ -149,9 +149,8 @@ static int of_pci_iommu_init(struct pci_dev *pdev, u16 alias, void *data)
 	struct of_phandle_args iommu_spec = { .args_count = 1 };
 	int err;
 
-	err = of_pci_map_rid(info->np, alias, "iommu-map",
-			     "iommu-map-mask", &iommu_spec.np,
-			     iommu_spec.args);
+	err = of_map_rid(info->np, alias, "iommu-map", "iommu-map-mask",
+			 &iommu_spec.np, iommu_spec.args);
 	if (err)
 		return err == -ENODEV ? NO_IOMMU : err;
 
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 848f549..c7aac81 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -1995,3 +1995,105 @@ int of_find_last_cache_level(unsigned int cpu)
 
 	return cache_level;
 }
+
+/**
+ * of_map_rid - Translate a requester ID through a downstream mapping.
+ * @np: root complex device node.
+ * @rid: device requester ID to map.
+ * @map_name: property name of the map to use.
+ * @map_mask_name: optional property name of the mask to use.
+ * @target: optional pointer to a target device node.
+ * @id_out: optional pointer to receive the translated ID.
+ *
+ * Given a device requester ID, look up the appropriate implementation-defined
+ * platform ID and/or the target device which receives transactions on that
+ * ID, as per the "iommu-map" and "msi-map" bindings. Either of @target or
+ * @id_out may be NULL if only the other is required. If @target points to
+ * a non-NULL device node pointer, only entries targeting that node will be
+ * matched; if it points to a NULL value, it will receive the device node of
+ * the first matching target phandle, with a reference held.
+ *
+ * Return: 0 on success or a standard error code on failure.
+ */
+int of_map_rid(struct device_node *np, u32 rid,
+	       const char *map_name, const char *map_mask_name,
+	       struct device_node **target, u32 *id_out)
+{
+	u32 map_mask, masked_rid;
+	int map_len;
+	const __be32 *map = NULL;
+
+	if (!np || !map_name || (!target && !id_out))
+		return -EINVAL;
+
+	map = of_get_property(np, map_name, &map_len);
+	if (!map) {
+		if (target)
+			return -ENODEV;
+		/* Otherwise, no map implies no translation */
+		*id_out = rid;
+		return 0;
+	}
+
+	if (!map_len || map_len % (4 * sizeof(*map))) {
+		pr_err("%pOF: Error: Bad %s length: %d\n", np,
+			map_name, map_len);
+		return -EINVAL;
+	}
+
+	/* The default is to select all bits. */
+	map_mask = 0xffffffff;
+
+	/*
+	 * Can be overridden by "{iommu,msi}-map-mask" property.
+	 * If of_property_read_u32() fails, the default is used.
+	 */
+	if (map_mask_name)
+		of_property_read_u32(np, map_mask_name, &map_mask);
+
+	masked_rid = map_mask & rid;
+	for ( ; map_len > 0; map_len -= 4 * sizeof(*map), map += 4) {
+		struct device_node *phandle_node;
+		u32 rid_base = be32_to_cpup(map + 0);
+		u32 phandle = be32_to_cpup(map + 1);
+		u32 out_base = be32_to_cpup(map + 2);
+		u32 rid_len = be32_to_cpup(map + 3);
+
+		if (rid_base & ~map_mask) {
+			pr_err("%pOF: Invalid %s translation - %s-mask (0x%x) ignores rid-base (0x%x)\n",
+				np, map_name, map_name,
+				map_mask, rid_base);
+			return -EFAULT;
+		}
+
+		if (masked_rid < rid_base || masked_rid >= rid_base + rid_len)
+			continue;
+
+		phandle_node = of_find_node_by_phandle(phandle);
+		if (!phandle_node)
+			return -ENODEV;
+
+		if (target) {
+			if (*target)
+				of_node_put(phandle_node);
+			else
+				*target = phandle_node;
+
+			if (*target != phandle_node)
+				continue;
+		}
+
+		if (id_out)
+			*id_out = masked_rid - rid_base + out_base;
+
+		pr_debug("%pOF: %s, using mask %08x, rid-base: %08x, out-base: %08x, length: %08x, rid: %08x -> %08x\n",
+			np, map_name, map_mask, rid_base, out_base,
+			rid_len, rid, masked_rid - rid_base + out_base);
+		return 0;
+	}
+
+	pr_err("%pOF: Invalid %s translation - no match for rid 0x%x on %pOF\n",
+		np, map_name, rid, target && *target ? *target : NULL);
+	return -EFAULT;
+}
+EXPORT_SYMBOL_GPL(of_map_rid);
diff --git a/drivers/of/irq.c b/drivers/of/irq.c
index 02ad93a..e1f6f39 100644
--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c
@@ -22,7 +22,6 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_irq.h>
-#include <linux/of_pci.h>
 #include <linux/string.h>
 #include <linux/slab.h>
 
@@ -588,8 +587,8 @@ static u32 __of_msi_map_rid(struct device *dev, struct device_node **np,
 	 * "msi-map" property.
 	 */
 	for (parent_dev = dev; parent_dev; parent_dev = parent_dev->parent)
-		if (!of_pci_map_rid(parent_dev->of_node, rid_in, "msi-map",
-				    "msi-map-mask", np, &rid_out))
+		if (!of_map_rid(parent_dev->of_node, rid_in, "msi-map",
+				"msi-map-mask", np, &rid_out))
 			break;
 	return rid_out;
 }
diff --git a/drivers/pci/of.c b/drivers/pci/of.c
index a28355c..d2cebbe 100644
--- a/drivers/pci/of.c
+++ b/drivers/pci/of.c
@@ -362,107 +362,6 @@ int of_pci_get_host_bridge_resources(struct device_node *dev,
 EXPORT_SYMBOL_GPL(of_pci_get_host_bridge_resources);
 #endif /* CONFIG_OF_ADDRESS */
 
-/**
- * of_pci_map_rid - Translate a requester ID through a downstream mapping.
- * @np: root complex device node.
- * @rid: PCI requester ID to map.
- * @map_name: property name of the map to use.
- * @map_mask_name: optional property name of the mask to use.
- * @target: optional pointer to a target device node.
- * @id_out: optional pointer to receive the translated ID.
- *
- * Given a PCI requester ID, look up the appropriate implementation-defined
- * platform ID and/or the target device which receives transactions on that
- * ID, as per the "iommu-map" and "msi-map" bindings. Either of @target or
- * @id_out may be NULL if only the other is required. If @target points to
- * a non-NULL device node pointer, only entries targeting that node will be
- * matched; if it points to a NULL value, it will receive the device node of
- * the first matching target phandle, with a reference held.
- *
- * Return: 0 on success or a standard error code on failure.
- */
-int of_pci_map_rid(struct device_node *np, u32 rid,
-		   const char *map_name, const char *map_mask_name,
-		   struct device_node **target, u32 *id_out)
-{
-	u32 map_mask, masked_rid;
-	int map_len;
-	const __be32 *map = NULL;
-
-	if (!np || !map_name || (!target && !id_out))
-		return -EINVAL;
-
-	map = of_get_property(np, map_name, &map_len);
-	if (!map) {
-		if (target)
-			return -ENODEV;
-		/* Otherwise, no map implies no translation */
-		*id_out = rid;
-		return 0;
-	}
-
-	if (!map_len || map_len % (4 * sizeof(*map))) {
-		pr_err("%pOF: Error: Bad %s length: %d\n", np,
-			map_name, map_len);
-		return -EINVAL;
-	}
-
-	/* The default is to select all bits. */
-	map_mask = 0xffffffff;
-
-	/*
-	 * Can be overridden by "{iommu,msi}-map-mask" property.
-	 * If of_property_read_u32() fails, the default is used.
-	 */
-	if (map_mask_name)
-		of_property_read_u32(np, map_mask_name, &map_mask);
-
-	masked_rid = map_mask & rid;
-	for ( ; map_len > 0; map_len -= 4 * sizeof(*map), map += 4) {
-		struct device_node *phandle_node;
-		u32 rid_base = be32_to_cpup(map + 0);
-		u32 phandle = be32_to_cpup(map + 1);
-		u32 out_base = be32_to_cpup(map + 2);
-		u32 rid_len = be32_to_cpup(map + 3);
-
-		if (rid_base & ~map_mask) {
-			pr_err("%pOF: Invalid %s translation - %s-mask (0x%x) ignores rid-base (0x%x)\n",
-				np, map_name, map_name,
-				map_mask, rid_base);
-			return -EFAULT;
-		}
-
-		if (masked_rid < rid_base || masked_rid >= rid_base + rid_len)
-			continue;
-
-		phandle_node = of_find_node_by_phandle(phandle);
-		if (!phandle_node)
-			return -ENODEV;
-
-		if (target) {
-			if (*target)
-				of_node_put(phandle_node);
-			else
-				*target = phandle_node;
-
-			if (*target != phandle_node)
-				continue;
-		}
-
-		if (id_out)
-			*id_out = masked_rid - rid_base + out_base;
-
-		pr_debug("%pOF: %s, using mask %08x, rid-base: %08x, out-base: %08x, length: %08x, rid: %08x -> %08x\n",
-			np, map_name, map_mask, rid_base, out_base,
-			rid_len, rid, masked_rid - rid_base + out_base);
-		return 0;
-	}
-
-	pr_err("%pOF: Invalid %s translation - no match for rid 0x%x on %pOF\n",
-		np, map_name, rid, target && *target ? *target : NULL);
-	return -EFAULT;
-}
-
 #if IS_ENABLED(CONFIG_OF_IRQ)
 /**
  * of_irq_parse_pci - Resolve the interrupt for a PCI device
diff --git a/include/linux/of.h b/include/linux/of.h
index 4d25e4f..f4251c3 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -545,6 +545,10 @@ const __be32 *of_prop_next_u32(struct property *prop, const __be32 *cur,
 
 extern int of_cpu_node_to_id(struct device_node *np);
 
+int of_map_rid(struct device_node *np, u32 rid,
+	       const char *map_name, const char *map_mask_name,
+	       struct device_node **target, u32 *id_out);
+
 #else /* CONFIG_OF */
 
 static inline void of_core_init(void)
@@ -931,6 +935,13 @@ static inline int of_cpu_node_to_id(struct device_node *np)
 	return -ENODEV;
 }
 
+static inline int of_map_rid(struct device_node *np, u32 rid,
+			     const char *map_name, const char *map_mask_name,
+			     struct device_node **target, u32 *id_out)
+{
+	return -EINVAL;
+}
+
 #define of_match_ptr(_ptr)	NULL
 #define of_match_node(_matches, _node)	NULL
 #endif /* CONFIG_OF */
diff --git a/include/linux/of_pci.h b/include/linux/of_pci.h
index 091033a..a23b44a 100644
--- a/include/linux/of_pci.h
+++ b/include/linux/of_pci.h
@@ -17,9 +17,6 @@ struct device_node *of_pci_find_child_device(struct device_node *parent,
 int of_get_pci_domain_nr(struct device_node *node);
 int of_pci_get_max_link_speed(struct device_node *node);
 void of_pci_check_probe_only(void);
-int of_pci_map_rid(struct device_node *np, u32 rid,
-		   const char *map_name, const char *map_mask_name,
-		   struct device_node **target, u32 *id_out);
 #else
 static inline struct device_node *of_pci_find_child_device(struct device_node *parent,
 					     unsigned int devfn)
@@ -44,13 +41,6 @@ static inline int of_pci_get_devfn(struct device_node *np)
 	return -1;
 }
 
-static inline int of_pci_map_rid(struct device_node *np, u32 rid,
-			const char *map_name, const char *map_mask_name,
-			struct device_node **target, u32 *id_out)
-{
-	return -EINVAL;
-}
-
 static inline int
 of_pci_get_max_link_speed(struct device_node *node)
 {
-- 
1.9.1

^ permalink raw reply related

* [PATCH 1/7 v5] Docs: dt: add fsl-mc iommu-map device-tree binding
From: Nipun Gupta @ 2018-05-20 13:49 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1526824191-7000-1-git-send-email-nipun.gupta@nxp.com>

The existing IOMMU bindings cannot be used to specify the relationship
between fsl-mc devices and IOMMUs. This patch adds a generic binding for
mapping fsl-mc devices to IOMMUs, using iommu-map property.

Signed-off-by: Nipun Gupta <nipun.gupta@nxp.com>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 .../devicetree/bindings/misc/fsl,qoriq-mc.txt      | 39 ++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/Documentation/devicetree/bindings/misc/fsl,qoriq-mc.txt b/Documentation/devicetree/bindings/misc/fsl,qoriq-mc.txt
index 6611a7c..8cbed4f 100644
--- a/Documentation/devicetree/bindings/misc/fsl,qoriq-mc.txt
+++ b/Documentation/devicetree/bindings/misc/fsl,qoriq-mc.txt
@@ -9,6 +9,25 @@ blocks that can be used to create functional hardware objects/devices
 such as network interfaces, crypto accelerator instances, L2 switches,
 etc.
 
+For an overview of the DPAA2 architecture and fsl-mc bus see:
+drivers/staging/fsl-mc/README.txt
+
+As described in the above overview, all DPAA2 objects in a DPRC share the
+same hardware "isolation context" and a 10-bit value called an ICID
+(isolation context id) is expressed by the hardware to identify
+the requester.
+
+The generic 'iommus' property is insufficient to describe the relationship
+between ICIDs and IOMMUs, so an iommu-map property is used to define
+the set of possible ICIDs under a root DPRC and how they map to
+an IOMMU.
+
+For generic IOMMU bindings, see
+Documentation/devicetree/bindings/iommu/iommu.txt.
+
+For arm-smmu binding, see:
+Documentation/devicetree/bindings/iommu/arm,smmu.txt.
+
 Required properties:
 
     - compatible
@@ -88,14 +107,34 @@ Sub-nodes:
               Value type: <phandle>
               Definition: Specifies the phandle to the PHY device node associated
                           with the this dpmac.
+Optional properties:
+
+- iommu-map: Maps an ICID to an IOMMU and associated iommu-specifier
+  data.
+
+  The property is an arbitrary number of tuples of
+  (icid-base,iommu,iommu-base,length).
+
+  Any ICID i in the interval [icid-base, icid-base + length) is
+  associated with the listed IOMMU, with the iommu-specifier
+  (i - icid-base + iommu-base).
 
 Example:
 
+        smmu: iommu at 5000000 {
+               compatible = "arm,mmu-500";
+               #iommu-cells = <2>;
+               stream-match-mask = <0x7C00>;
+               ...
+        };
+
         fsl_mc: fsl-mc at 80c000000 {
                 compatible = "fsl,qoriq-mc";
                 reg = <0x00000008 0x0c000000 0 0x40>,    /* MC portal base */
                       <0x00000000 0x08340000 0 0x40000>; /* MC control reg */
                 msi-parent = <&its>;
+                /* define map for ICIDs 23-64 */
+                iommu-map = <23 &smmu 23 41>;
                 #address-cells = <3>;
                 #size-cells = <1>;
 
-- 
1.9.1

^ permalink raw reply related

* [PATCH 0/7 v5] Support for fsl-mc bus and its devices in SMMU
From: Nipun Gupta @ 2018-05-20 13:49 UTC (permalink / raw)
  To: linux-arm-kernel

This patchset defines IOMMU DT binding for fsl-mc bus and adds
support in SMMU for fsl-mc bus.

The patch series is based on top of dma-mapping tree (for-next branch):
http://git.infradead.org/users/hch/dma-mapping.git

These patches
  - Define property 'iommu-map' for fsl-mc bus (patch 1)
  - Integrates the fsl-mc bus with the SMMU using this
    IOMMU binding (patch 2,3,4)
  - Adds the dma configuration support for fsl-mc bus (patch 5, 6)
  - Updates the fsl-mc device node with iommu/dma related changes (patch 7)

Changes in v2:
  - use iommu-map property for fsl-mc bus
  - rebase over patchset https://patchwork.kernel.org/patch/10317337/
    and make corresponding changes for dma configuration of devices on
    fsl-mc bus

Changes in v3:
  - move of_map_rid in drivers/of/address.c

Changes in v4:
  - move of_map_rid in drivers/of/base.c

Changes in v5:
  - break patch 5 in two separate patches (now patch 5/7 and patch 6/7)
  - add changelog text in patch 3/7 and patch 5/7
  - typo fix

Nipun Gupta (7):
  Docs: dt: add fsl-mc iommu-map device-tree binding
  iommu: of: make of_pci_map_rid() available for other devices too
  iommu: support iommu configuration for fsl-mc devices
  iommu: arm-smmu: Add support for the fsl-mc bus
  bus: fsl-mc: support dma configure for devices on fsl-mc bus
  bus: fsl-mc: set coherent dma mask for devices on fsl-mc bus
  arm64: dts: ls208xa: comply with the iommu map binding for fsl_mc

 .../devicetree/bindings/misc/fsl,qoriq-mc.txt      |  39 ++++++++
 arch/arm64/boot/dts/freescale/fsl-ls208xa.dtsi     |   6 +-
 drivers/bus/fsl-mc/fsl-mc-bus.c                    |  16 +++-
 drivers/iommu/arm-smmu.c                           |   7 ++
 drivers/iommu/iommu.c                              |  21 +++++
 drivers/iommu/of_iommu.c                           |  25 ++++-
 drivers/of/base.c                                  | 102 +++++++++++++++++++++
 drivers/of/irq.c                                   |   5 +-
 drivers/pci/of.c                                   | 101 --------------------
 include/linux/fsl/mc.h                             |   8 ++
 include/linux/iommu.h                              |   2 +
 include/linux/of.h                                 |  11 +++
 include/linux/of_pci.h                             |  10 --
 13 files changed, 231 insertions(+), 122 deletions(-)

-- 
1.9.1

^ permalink raw reply

* [PULL v8] KVM: arm64: Optimise FPSIMD context switching
From: Marc Zyngier @ 2018-05-20 13:14 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <20180516104942.GS7753@e103592.cambridge.arm.com>

On Wed, 16 May 2018 11:49:42 +0100
Dave Martin <Dave.Martin@arm.com> wrote:

Hi Dave,

> Hi Marc,
> 
> This is a trivial update to the previously posted v7 [1].  The only
> changes are a couple of minor cosmetic changes requested by reviewers,
> on-list and the addition of Acked-by/Reviewed-by tags received since the
> series was posted.
> 
> Let me know if you need anything else on this.

So I've taken this, merged in Linus' top of tree, started a guest on a
dual A53 board, and immediately hit the following:

root at sy-borg:~# [  287.226184] Unable to handle kernel NULL pointer dereference at virtual address 00000000
[  287.231672] Mem abort info:
[  287.234537]   ESR = 0x96000044
[  287.237674]   Exception class = DABT (current EL), IL = 32 bits
[  287.243765]   SET = 0, FnV = 0
[  287.246900]   EA = 0, S1PTW = 0
[  287.250126] Data abort info:
[  287.253083]   ISV = 0, ISS = 0x00000044
[  287.257025]   CM = 0, WnR = 1
[  287.260076] user pgtable: 4k pages, 48-bit VAs, pgdp = 00000000b8483f75
[  287.266882] [0000000000000000] pgd=0000000000000000
[  287.271903] Internal error: Oops: 96000044 [#1] PREEMPT SMP
[  287.277636] Modules linked in:
[  287.280776] CPU: 1 PID: 3098 Comm: kworker/u4:3 Not tainted 4.17.0-rc5-00166-gd84e81cca249 #136
[  287.289730] Hardware name: Globalscale Marvell ESPRESSOBin Board (DT)
[  287.296364] pstate: 40000085 (nZcv daIf -PAN -UAO)
[  287.301301] pc : fpsimd_save_state+0x0/0x54
[  287.305595] lr : fpsimd_save+0x50/0x100
[  287.309531] sp : ffff00000dde3af0
[  287.312936] x29: ffff00000dde3af0 x28: ffff000008cd565c 
[  287.318401] x27: ffff800078ee9c80 x26: ffff80007b207628 
[  287.323867] x25: ffff0000093f9000 x24: 0000000000000001 
[  287.329333] x23: ffff0000093d4000 x22: ffff80007b207000 
[  287.334798] x21: ffff80007efd7d80 x20: ffff80007b207000 
[  287.340264] x19: 0000000000000000 x18: 0000000000040f0b 
[  287.345729] x17: 0000ffffb70752b8 x16: 0000ffffb708e008 
[  287.351195] x15: 0000000000000000 x14: 0000000000000400 
[  287.356661] x13: 0000000000000001 x12: 0000000000000001 
[  287.362127] x11: 0000000000000001 x10: 0000000000000000 
[  287.367592] x9 : 0000000000000253 x8 : ffff80007b207200 
[  287.373057] x7 : ffff80007b207100 x6 : ffff80007c378f18 
[  287.378523] x5 : 00000042c2094c00 x4 : 0000000000000000 
[  287.383990] x3 : 00000042e0033450 x2 : 0000000000000000 
[  287.389454] x1 : 0000800075bf6000 x0 : 0000000000000000 
[  287.394922] Process kworker/u4:3 (pid: 3098, stack limit = 0x00000000ca0dd8c6)
[  287.402358] Call trace:
[  287.404873]  fpsimd_save_state+0x0/0x54
[  287.408813]  fpsimd_thread_switch+0x28/0xa0
[  287.413114]  __switch_to+0x1c/0xd0
[  287.416609]  __schedule+0x1b8/0x730
[  287.420191]  preempt_schedule_common+0x24/0x48
[  287.424760]  preempt_schedule.part.23+0x1c/0x28
[  287.429419]  preempt_schedule+0x1c/0x28
[  287.433363]  _raw_spin_unlock+0x34/0x48
[  287.437308]  flush_old_exec+0x45c/0x6a0
[  287.441250]  load_elf_binary+0x324/0x1198
[  287.445372]  search_binary_handler+0xac/0x230
[  287.449851]  do_execveat_common.isra.14+0x508/0x6e0
[  287.454867]  do_execve+0x28/0x30
[  287.458185]  call_usermodehelper_exec_async+0xdc/0x140
[  287.463468]  ret_from_fork+0x10/0x18
[  287.467143] Code: a9425bf5 a8c37bfd d65f03c0 d65f03c0 (ad000400) 
[  287.473414] ---[ end trace c4346b99cc877f8e ]---

It happened just after having loaded the guest kernel, so I presume
we're missing some kind of initialization. I couldn't subsequently
reproduce it  on the same machine, and the same kernel is doing
absolutely fine on a Seattle box.

I can't immediately see how st would be NULL, unless we somehow are
missing some state tracking somewhere...

Any idea?

	M.
-- 
Without deviation from the norm, progress is not possible.

^ permalink raw reply

* [PATCH v2 3/3] ARM: dts: imx28/imx53: enable edt-ft5x06 wakeup source
From: Shawn Guo @ 2018-05-20 13:05 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <20180517090552.5704-4-daniel@zonque.org>

On Thu, May 17, 2018 at 11:05:52AM +0200, Daniel Mack wrote:
> The touchscreen driver no longer configures the device as wakeup source by
> default. A "wakeup-source" property is needed.
> 
> To avoid regressions, this patch changes the DTS files for the only two
> users of this driver that didn't have this property yet.
> 
> Signed-off-by: Daniel Mack <daniel@zonque.org>
> Cc: Shawn Guo <shawnguo@kernel.org>
> Cc: Sascha Hauer <kernel@pengutronix.de>
> Cc: Fabio Estevam <fabio.estevam@nxp.com>
> Cc: Rob Herring <robh+dt@kernel.org>

Applied this one, thanks.

^ permalink raw reply

* [PATCH] clk: imx6sl: correct ocram_podf clock type
From: Shawn Guo @ 2018-05-20 13:02 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1526533248-21990-2-git-send-email-Anson.Huang@nxp.com>

On Thu, May 17, 2018 at 01:00:48PM +0800, Anson Huang wrote:
> IMX6SL_CLK_OCRAM_PODF is a busy divider, its name in
> CCM_CDHIPR register of Reference Manual CCM chapter
> is axi_podf_busy, correct its clock type.
> 
> Signed-off-by: Anson Huang <Anson.Huang@nxp.com>

Acked-by: Shawn Guo <shawnguo@kernel.org>

^ permalink raw reply

* [PATCH] clk: imx6sx: disable unnecessary clocks during clock initialization
From: Shawn Guo @ 2018-05-20 13:01 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1526533248-21990-1-git-send-email-Anson.Huang@nxp.com>

On Thu, May 17, 2018 at 01:00:47PM +0800, Anson Huang wrote:
> Disable those unnecessary clocks during kernel boot up to save power,
> those modules clock should be managed by modules driver in runtime.
> 
> Signed-off-by: Anson Huang <Anson.Huang@nxp.com>

Acked-by: Shawn Guo <shawnguo@kernel.org>

^ permalink raw reply


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