From de8daf30af7b5b699b78d2f3323c963215d41cd7 Mon Sep 17 00:00:00 2001 From: William Breathitt Gray Date: Fri, 27 Aug 2021 12:47:49 +0900 Subject: docs: counter: Update to reflect sysfs internalization The Counter subsystem architecture and driver implementations have changed in order to handle Counter sysfs interactions in a more consistent way. This patch updates the Generic Counter interface documentation to reflect the changes. Reviewed-by: David Lechner Signed-off-by: William Breathitt Gray Link: https://lore.kernel.org/r/91cded13c0145c0d3d0acfe765a2ccb6c9af7c3b.1630031207.git.vilhelm.gray@gmail.com Signed-off-by: Jonathan Cameron --- Documentation/ABI/testing/sysfs-bus-counter | 9 +- Documentation/driver-api/generic-counter.rst | 243 +++++++++++++++++++-------- 2 files changed, 185 insertions(+), 67 deletions(-) (limited to 'Documentation') diff --git a/Documentation/ABI/testing/sysfs-bus-counter b/Documentation/ABI/testing/sysfs-bus-counter index 20fe5afd4f9e..dee79b606847 100644 --- a/Documentation/ABI/testing/sysfs-bus-counter +++ b/Documentation/ABI/testing/sysfs-bus-counter @@ -286,7 +286,14 @@ What: /sys/bus/counter/devices/counterX/signalY/signal KernelVersion: 5.2 Contact: linux-iio@vger.kernel.org Description: - Signal data of Signal Y represented as a string. + Signal level state of Signal Y. The following signal level + states are available: + + low: + Low level state. + + high: + High level state. What: /sys/bus/counter/devices/counterX/signalY/synchronous_mode KernelVersion: 5.2 diff --git a/Documentation/driver-api/generic-counter.rst b/Documentation/driver-api/generic-counter.rst index 64fe7db080e5..f6397218aa4c 100644 --- a/Documentation/driver-api/generic-counter.rst +++ b/Documentation/driver-api/generic-counter.rst @@ -250,8 +250,8 @@ for defining a counter device. .. kernel-doc:: drivers/counter/counter.c :export: -Implementation -============== +Driver Implementation +===================== To support a counter device, a driver must first allocate the available Counter Signals via counter_signal structures. These Signals should @@ -267,25 +267,61 @@ 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. +Driver callbacks must be provided to the counter_device 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/miscellaneous exposure -and 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. +devm_counter_register function may be used if device memory-managed +registration is desired. + +The struct counter_comp structure is used to define counter extensions +for Signals, Synapses, and Counts. + +The "type" member specifies the type of high-level data (e.g. BOOL, +COUNT_DIRECTION, etc.) handled by this extension. The "``*_read``" and +"``*_write``" members can then be set by the counter device driver with +callbacks to handle that data using native C data types (i.e. u8, u64, +etc.). + +Convenience macros such as ``COUNTER_COMP_COUNT_U64`` are provided for +use by driver authors. In particular, driver authors are expected to use +the provided macros for standard Counter subsystem attributes in order +to maintain a consistent interface for userspace. For example, a counter +device driver may define several standard attributes like so:: + + struct counter_comp count_ext[] = { + COUNTER_COMP_DIRECTION(count_direction_read), + COUNTER_COMP_ENABLE(count_enable_read, count_enable_write), + COUNTER_COMP_CEILING(count_ceiling_read, count_ceiling_write), + }; + +This makes it simple to see, add, and modify the attributes that are +supported by this driver ("direction", "enable", and "ceiling") and to +maintain this code without getting lost in a web of struct braces. + +Callbacks must match the function type expected for the respective +component or extension. These function types are defined in the struct +counter_comp structure as the "``*_read``" and "``*_write``" union +members. + +The corresponding callback prototypes for the extensions mentioned in +the previous example above would be:: + + int count_direction_read(struct counter_device *counter, + struct counter_count *count, + enum counter_count_direction *direction); + int count_enable_read(struct counter_device *counter, + struct counter_count *count, u8 *enable); + int count_enable_write(struct counter_device *counter, + struct counter_count *count, u8 enable); + int count_ceiling_read(struct counter_device *counter, + struct counter_count *count, u64 *ceiling); + int count_ceiling_write(struct counter_device *counter, + struct counter_count *count, u64 ceiling); Determining the type of extension to create is a matter of scope. @@ -313,52 +349,127 @@ Determining the type of extension to create is a matter of scope. chip overheated via a device extension called "error_overtemp": /sys/bus/counter/devices/counterX/error_overtemp -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/sysfs-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. +Subsystem Architecture +====================== + +Counter drivers pass and take data natively (i.e. ``u8``, ``u64``, etc.) +and the shared counter module handles the translation between the sysfs +interface. This guarantees a standard userspace interface for all +counter drivers, and enables a Generic Counter chrdev interface via a +generalized device driver ABI. + +A high-level view of how a count value is passed down from a counter +driver is exemplified by the following. The driver callbacks are first +registered to the Counter core component for use by the Counter +userspace interface components:: + + Driver callbacks registration: + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +----------------------------+ + | Counter device driver | + +----------------------------+ + | Processes data from device | + +----------------------------+ + | + ------------------- + / driver callbacks / + ------------------- + | + V + +----------------------+ + | Counter core | + +----------------------+ + | Routes device driver | + | callbacks to the | + | userspace interfaces | + +----------------------+ + | + ------------------- + / driver callbacks / + ------------------- + | + +---------------+ + | + V + +--------------------+ + | Counter sysfs | + +--------------------+ + | Translates to the | + | standard Counter | + | sysfs output | + +--------------------+ + +Thereafter, data can be transferred directly between the Counter device +driver and Counter userspace interface:: + + Count data request: + ~~~~~~~~~~~~~~~~~~~ + ---------------------- + / Counter device \ + +----------------------+ + | Count register: 0x28 | + +----------------------+ + | + ----------------- + / raw count data / + ----------------- + | + V + +----------------------------+ + | Counter device driver | + +----------------------------+ + | Processes data from device | + |----------------------------| + | Type: u64 | + | Value: 42 | + +----------------------------+ + | + ---------- + / u64 / + ---------- + | + +---------------+ + | + V + +--------------------+ + | Counter sysfs | + +--------------------+ + | Translates to the | + | standard Counter | + | sysfs output | + |--------------------| + | Type: const char * | + | Value: "42" | + +--------------------+ + | + --------------- + / const char * / + --------------- + | + V + +--------------------------------------------------+ + | `/sys/bus/counter/devices/counterX/countY/count` | + +--------------------------------------------------+ + \ Count: "42" / + -------------------------------------------------- + +There are three primary components involved: + +Counter device driver +--------------------- +Communicates with the hardware device to read/write data; e.g. counter +drivers for quadrature encoders, timers, etc. + +Counter core +------------ +Registers the counter device driver to the system so that the respective +callbacks are called during userspace interaction. + +Counter sysfs +------------- +Translates counter data to the standard Counter sysfs interface format +and vice versa. + +Please refer to the ``Documentation/ABI/testing/sysfs-bus-counter`` file +for a detailed breakdown of the available Generic Counter interface +sysfs attributes. -- cgit v1.2.3-59-g8ed1b From a8a28737c2c568e55b9fdbe55ab02b5c7c4247b7 Mon Sep 17 00:00:00 2001 From: William Breathitt Gray Date: Wed, 29 Sep 2021 12:16:00 +0900 Subject: docs: counter: Document character device interface This patch adds high-level documentation about the Counter subsystem character device interface. Signed-off-by: William Breathitt Gray Link: https://lore.kernel.org/r/7a71dff2868195901d074ae2ec1b5611838d4b24.1632884256.git.vilhelm.gray@gmail.com Signed-off-by: Jonathan Cameron --- Documentation/driver-api/generic-counter.rst | 177 ++++++++++++++++----- Documentation/userspace-api/ioctl/ioctl-number.rst | 1 + 2 files changed, 137 insertions(+), 41 deletions(-) (limited to 'Documentation') diff --git a/Documentation/driver-api/generic-counter.rst b/Documentation/driver-api/generic-counter.rst index f6397218aa4c..25932dcb6e67 100644 --- a/Documentation/driver-api/generic-counter.rst +++ b/Documentation/driver-api/generic-counter.rst @@ -223,19 +223,6 @@ 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/sysfs-bus-counter 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 ========== @@ -388,16 +375,16 @@ userspace interface components:: / driver callbacks / ------------------- | - +---------------+ - | - V - +--------------------+ - | Counter sysfs | - +--------------------+ - | Translates to the | - | standard Counter | - | sysfs output | - +--------------------+ + +---------------+---------------+ + | | + V V + +--------------------+ +---------------------+ + | Counter sysfs | | Counter chrdev | + +--------------------+ +---------------------+ + | Translates to the | | Translates to the | + | standard Counter | | standard Counter | + | sysfs output | | character device | + +--------------------+ +---------------------+ Thereafter, data can be transferred directly between the Counter device driver and Counter userspace interface:: @@ -428,23 +415,30 @@ driver and Counter userspace interface:: / u64 / ---------- | - +---------------+ - | - V - +--------------------+ - | Counter sysfs | - +--------------------+ - | Translates to the | - | standard Counter | - | sysfs output | - |--------------------| - | Type: const char * | - | Value: "42" | - +--------------------+ - | - --------------- - / const char * / - --------------- + +---------------+---------------+ + | | + V V + +--------------------+ +---------------------+ + | Counter sysfs | | Counter chrdev | + +--------------------+ +---------------------+ + | Translates to the | | Translates to the | + | standard Counter | | standard Counter | + | sysfs output | | character device | + |--------------------| |---------------------| + | Type: const char * | | Type: u64 | + | Value: "42" | | Value: 42 | + +--------------------+ +---------------------+ + | | + --------------- ----------------------- + / const char * / / struct counter_event / + --------------- ----------------------- + | | + | V + | +-----------+ + | | read | + | +-----------+ + | \ Count: 42 / + | ----------- | V +--------------------------------------------------+ @@ -453,7 +447,7 @@ driver and Counter userspace interface:: \ Count: "42" / -------------------------------------------------- -There are three primary components involved: +There are four primary components involved: Counter device driver --------------------- @@ -473,3 +467,104 @@ and vice versa. Please refer to the ``Documentation/ABI/testing/sysfs-bus-counter`` file for a detailed breakdown of the available Generic Counter interface sysfs attributes. + +Counter chrdev +-------------- +Translates Counter events to the standard Counter character device; data +is transferred via standard character device read calls, while Counter +events are configured via ioctl calls. + +Sysfs Interface +=============== + +Several sysfs attributes are generated by the Generic Counter interface, +and reside under the ``/sys/bus/counter/devices/counterX`` directory, +where ``X`` is to the respective counter device id. Please see +``Documentation/ABI/testing/sysfs-bus-counter`` 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. + +Counter Character Device +======================== + +Counter character device nodes are created under the ``/dev`` directory +as ``counterX``, where ``X`` is the respective counter device id. +Defines for the standard Counter data types are exposed via the +userspace ``include/uapi/linux/counter.h`` file. + +Counter events +-------------- +Counter device drivers can support Counter events by utilizing the +``counter_push_event`` function:: + + void counter_push_event(struct counter_device *const counter, const u8 event, + const u8 channel); + +The event id is specified by the ``event`` parameter; the event channel +id is specified by the ``channel`` parameter. When this function is +called, the Counter data associated with the respective event is +gathered, and a ``struct counter_event`` is generated for each datum and +pushed to userspace. + +Counter events can be configured by users to report various Counter +data of interest. This can be conceptualized as a list of Counter +component read calls to perform. For example: + + +------------------------+------------------------+ + | COUNTER_EVENT_OVERFLOW | COUNTER_EVENT_INDEX | + +========================+========================+ + | Channel 0 | Channel 0 | + +------------------------+------------------------+ + | * Count 0 | * Signal 0 | + | * Count 1 | * Signal 0 Extension 0 | + | * Signal 3 | * Extension 4 | + | * Count 4 Extension 2 +------------------------+ + | * Signal 5 Extension 0 | Channel 1 | + | +------------------------+ + | | * Signal 4 | + | | * Signal 4 Extension 0 | + | | * Count 7 | + +------------------------+------------------------+ + +When ``counter_push_event(counter, COUNTER_EVENT_INDEX, 1)`` is called +for example, it will go down the list for the ``COUNTER_EVENT_INDEX`` +event channel 1 and execute the read callbacks for Signal 4, Signal 4 +Extension 0, and Count 7 -- the data returned for each is pushed to a +kfifo as a ``struct counter_event``, which userspace can retrieve via a +standard read operation on the respective character device node. + +Userspace +--------- +Userspace applications can configure Counter events via ioctl operations +on the Counter character device node. There following ioctl codes are +supported and provided by the ``linux/counter.h`` userspace header file: + +* :c:macro:`COUNTER_ADD_WATCH_IOCTL` + +* :c:macro:`COUNTER_ENABLE_EVENTS_IOCTL` + +* :c:macro:`COUNTER_DISABLE_EVENTS_IOCTL` + +To configure events to gather Counter data, users first populate a +``struct counter_watch`` with the relevant event id, event channel id, +and the information for the desired Counter component from which to +read, and then pass it via the ``COUNTER_ADD_WATCH_IOCTL`` ioctl +command. + +Note that an event can be watched without gathering Counter data by +setting the ``component.type`` member equal to +``COUNTER_COMPONENT_NONE``. With this configuration the Counter +character device will simply populate the event timestamps for those +respective ``struct counter_event`` elements and ignore the component +value. + +The ``COUNTER_ADD_WATCH_IOCTL`` command will buffer these Counter +watches. When ready, the ``COUNTER_ENABLE_EVENTS_IOCTL`` ioctl command +may be used to activate these Counter watches. + +Userspace applications can then execute a ``read`` operation (optionally +calling ``poll`` first) on the Counter character device node to retrieve +``struct counter_event`` elements with the desired data. diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst index 2e8134059c87..0ba463be6c58 100644 --- a/Documentation/userspace-api/ioctl/ioctl-number.rst +++ b/Documentation/userspace-api/ioctl/ioctl-number.rst @@ -88,6 +88,7 @@ Code Seq# Include File Comments 0x20 all drivers/cdrom/cm206.h 0x22 all scsi/sg.h +0x3E 00-0F linux/counter.h '!' 00-1F uapi/linux/seccomp.h '#' 00-3F IEEE 1394 Subsystem Block for the entire subsystem -- cgit v1.2.3-59-g8ed1b From bb6264a61de84320e77a22b4b8f4babf240608c4 Mon Sep 17 00:00:00 2001 From: William Breathitt Gray Date: Wed, 29 Sep 2021 12:16:02 +0900 Subject: counter: Implement signalZ_action_component_id sysfs attribute The Generic Counter chrdev interface expects users to supply component IDs in order to select Synapses for requests. In order for users to know what component ID belongs to which Synapse this information must be exposed. The signalZ_action_component_id attribute provides a way for users to discover what component ID belongs to the respective Synapse. Cc: Gwendal Grignou Cc: Dan Carpenter Reviewed-by: David Lechner Signed-off-by: William Breathitt Gray Link: https://lore.kernel.org/r/a6c81b2f1f5d0b8d59b1ebe4f0fed04914b07547.1632884256.git.vilhelm.gray@gmail.com Signed-off-by: Jonathan Cameron --- Documentation/ABI/testing/sysfs-bus-counter | 7 +++++ drivers/counter/counter-sysfs.c | 45 +++++++++++++++++++++++++++++ 2 files changed, 52 insertions(+) (limited to 'Documentation') diff --git a/Documentation/ABI/testing/sysfs-bus-counter b/Documentation/ABI/testing/sysfs-bus-counter index dee79b606847..aa2cd3c10d74 100644 --- a/Documentation/ABI/testing/sysfs-bus-counter +++ b/Documentation/ABI/testing/sysfs-bus-counter @@ -203,6 +203,13 @@ Description: both edges: Any state transition. +What: /sys/bus/counter/devices/counterX/countY/signalZ_action_component_id +KernelVersion: 5.16 +Contact: linux-iio@vger.kernel.org +Description: + Read-only attribute that indicates the component ID of the + respective Synapse of Count Y for Signal Z. + What: /sys/bus/counter/devices/counterX/countY/spike_filter_ns KernelVersion: 5.14 Contact: linux-iio@vger.kernel.org diff --git a/drivers/counter/counter-sysfs.c b/drivers/counter/counter-sysfs.c index 108cbd838eb9..ee7ff1cde454 100644 --- a/drivers/counter/counter-sysfs.c +++ b/drivers/counter/counter-sysfs.c @@ -532,6 +532,46 @@ static int counter_name_attr_create(struct device *const dev, return 0; } +static ssize_t counter_comp_id_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + const size_t id = (size_t)to_counter_attribute(attr)->comp.priv; + + return sprintf(buf, "%zu\n", id); +} + +static int counter_comp_id_attr_create(struct device *const dev, + struct counter_attribute_group *const group, + const char *name, const size_t id) +{ + struct counter_attribute *counter_attr; + + /* Allocate Counter attribute */ + counter_attr = devm_kzalloc(dev, sizeof(*counter_attr), GFP_KERNEL); + if (!counter_attr) + return -ENOMEM; + + /* Generate component ID name */ + name = devm_kasprintf(dev, GFP_KERNEL, "%s_component_id", name); + if (!name) + return -ENOMEM; + + /* Configure Counter attribute */ + counter_attr->comp.priv = (void *)id; + + /* Configure device attribute */ + sysfs_attr_init(&counter_attr->dev_attr.attr); + counter_attr->dev_attr.attr.name = name; + counter_attr->dev_attr.attr.mode = 0444; + counter_attr->dev_attr.show = counter_comp_id_show; + + /* Store list node */ + list_add(&counter_attr->l, &group->attr_list); + group->num_attr++; + + return 0; +} + static struct counter_comp counter_signal_comp = { .type = COUNTER_COMP_SIGNAL_LEVEL, .name = "signal", @@ -626,6 +666,11 @@ static int counter_sysfs_synapses_add(struct counter_device *const counter, COUNTER_SCOPE_COUNT, count); if (err < 0) return err; + + /* Create Synapse component ID attribute */ + err = counter_comp_id_attr_create(dev, group, comp.name, i); + if (err < 0) + return err; } return 0; -- cgit v1.2.3-59-g8ed1b From 4bdec61d927b5db25f75fa377504d4e127c3682b Mon Sep 17 00:00:00 2001 From: William Breathitt Gray Date: Wed, 29 Sep 2021 12:16:03 +0900 Subject: counter: Implement *_component_id sysfs attributes The Generic Counter chrdev interface expects users to supply component IDs in order to select extensions for requests. In order for users to know what component ID belongs to which extension this information must be exposed. The *_component_id attribute provides a way for users to discover what component ID belongs to which respective extension. Cc: David Lechner Cc: Gwendal Grignou Cc: Dan Carpenter Signed-off-by: William Breathitt Gray Link: https://lore.kernel.org/r/8961a11edbb882fc689e468194f5be75f572443e.1632884256.git.vilhelm.gray@gmail.com Signed-off-by: Jonathan Cameron --- Documentation/ABI/testing/sysfs-bus-counter | 16 +++++++++++++- drivers/counter/counter-sysfs.c | 33 +++++++++++++++++++++++------ 2 files changed, 42 insertions(+), 7 deletions(-) (limited to 'Documentation') diff --git a/Documentation/ABI/testing/sysfs-bus-counter b/Documentation/ABI/testing/sysfs-bus-counter index aa2cd3c10d74..0ce16669157e 100644 --- a/Documentation/ABI/testing/sysfs-bus-counter +++ b/Documentation/ABI/testing/sysfs-bus-counter @@ -203,12 +203,26 @@ Description: both edges: Any state transition. +What: /sys/bus/counter/devices/counterX/countY/ceiling_component_id +What: /sys/bus/counter/devices/counterX/countY/floor_component_id +What: /sys/bus/counter/devices/counterX/countY/count_mode_component_id +What: /sys/bus/counter/devices/counterX/countY/direction_component_id +What: /sys/bus/counter/devices/counterX/countY/enable_component_id +What: /sys/bus/counter/devices/counterX/countY/error_noise_component_id +What: /sys/bus/counter/devices/counterX/countY/prescaler_component_id +What: /sys/bus/counter/devices/counterX/countY/preset_component_id +What: /sys/bus/counter/devices/counterX/countY/preset_enable_component_id What: /sys/bus/counter/devices/counterX/countY/signalZ_action_component_id +What: /sys/bus/counter/devices/counterX/signalY/cable_fault_component_id +What: /sys/bus/counter/devices/counterX/signalY/cable_fault_enable_component_id +What: /sys/bus/counter/devices/counterX/signalY/filter_clock_prescaler_component_id +What: /sys/bus/counter/devices/counterX/signalY/index_polarity_component_id +What: /sys/bus/counter/devices/counterX/signalY/synchronous_mode_component_id KernelVersion: 5.16 Contact: linux-iio@vger.kernel.org Description: Read-only attribute that indicates the component ID of the - respective Synapse of Count Y for Signal Z. + respective extension or Synapse. What: /sys/bus/counter/devices/counterX/countY/spike_filter_ns KernelVersion: 5.14 diff --git a/drivers/counter/counter-sysfs.c b/drivers/counter/counter-sysfs.c index ee7ff1cde454..97d8d7c2a2b6 100644 --- a/drivers/counter/counter-sysfs.c +++ b/drivers/counter/counter-sysfs.c @@ -586,6 +586,7 @@ static int counter_signal_attrs_create(struct counter_device *const counter, int err; struct counter_comp comp; size_t i; + struct counter_comp *ext; /* Create main Signal attribute */ comp = counter_signal_comp; @@ -601,8 +602,14 @@ static int counter_signal_attrs_create(struct counter_device *const counter, /* Create an attribute for each extension */ for (i = 0; i < signal->num_ext; i++) { - err = counter_attr_create(dev, cattr_group, signal->ext + i, - scope, signal); + ext = &signal->ext[i]; + + err = counter_attr_create(dev, cattr_group, ext, scope, signal); + if (err < 0) + return err; + + err = counter_comp_id_attr_create(dev, cattr_group, ext->name, + i); if (err < 0) return err; } @@ -693,6 +700,7 @@ static int counter_count_attrs_create(struct counter_device *const counter, int err; struct counter_comp comp; size_t i; + struct counter_comp *ext; /* Create main Count attribute */ comp = counter_count_comp; @@ -717,8 +725,14 @@ static int counter_count_attrs_create(struct counter_device *const counter, /* Create an attribute for each extension */ for (i = 0; i < count->num_ext; i++) { - err = counter_attr_create(dev, cattr_group, count->ext + i, - scope, count); + ext = &count->ext[i]; + + err = counter_attr_create(dev, cattr_group, ext, scope, count); + if (err < 0) + return err; + + err = counter_comp_id_attr_create(dev, cattr_group, ext->name, + i); if (err < 0) return err; } @@ -782,6 +796,7 @@ static int counter_sysfs_attr_add(struct counter_device *const counter, struct device *const dev = &counter->dev; int err; size_t i; + struct counter_comp *ext; /* Add Signals sysfs attributes */ err = counter_sysfs_signals_add(counter, cattr_group); @@ -814,8 +829,14 @@ static int counter_sysfs_attr_add(struct counter_device *const counter, /* Create an attribute for each extension */ for (i = 0; i < counter->num_ext; i++) { - err = counter_attr_create(dev, cattr_group, counter->ext + i, - scope, NULL); + ext = &counter->ext[i]; + + err = counter_attr_create(dev, cattr_group, ext, scope, NULL); + if (err < 0) + return err; + + err = counter_comp_id_attr_create(dev, cattr_group, ext->name, + i); if (err < 0) return err; } -- cgit v1.2.3-59-g8ed1b From feff17a550c7120009d8ba9431426135661a731b Mon Sep 17 00:00:00 2001 From: William Breathitt Gray Date: Wed, 29 Sep 2021 12:16:04 +0900 Subject: counter: Implement events_queue_size sysfs attribute The events_queue_size sysfs attribute provides a way for users to dynamically configure the Counter events queue size for the Counter character device interface. The size is in number of struct counter_event data structures. The number of elements will be rounded-up to a power of 2 due to a requirement of the kfifo_alloc function called during reallocation of the queue. Cc: Oleksij Rempel Signed-off-by: William Breathitt Gray Link: https://lore.kernel.org/r/c914b2db2ea0a2637633bcc3e86ded3c94783f2e.1632884256.git.vilhelm.gray@gmail.com Signed-off-by: Jonathan Cameron --- Documentation/ABI/testing/sysfs-bus-counter | 8 +++++ drivers/counter/counter-sysfs.c | 45 +++++++++++++++++++++++++++++ 2 files changed, 53 insertions(+) (limited to 'Documentation') diff --git a/Documentation/ABI/testing/sysfs-bus-counter b/Documentation/ABI/testing/sysfs-bus-counter index 0ce16669157e..06c2b3e27e0b 100644 --- a/Documentation/ABI/testing/sysfs-bus-counter +++ b/Documentation/ABI/testing/sysfs-bus-counter @@ -233,6 +233,14 @@ Description: shorter or equal to configured value are ignored. Value 0 means filter is disabled. +What: /sys/bus/counter/devices/counterX/events_queue_size +KernelVersion: 5.16 +Contact: linux-iio@vger.kernel.org +Description: + Size of the Counter events queue in number of struct + counter_event data structures. The number of elements will be + rounded-up to a power of 2. + What: /sys/bus/counter/devices/counterX/name KernelVersion: 5.2 Contact: linux-iio@vger.kernel.org diff --git a/drivers/counter/counter-sysfs.c b/drivers/counter/counter-sysfs.c index 97d8d7c2a2b6..1ccd771da25f 100644 --- a/drivers/counter/counter-sysfs.c +++ b/drivers/counter/counter-sysfs.c @@ -3,11 +3,13 @@ * Generic Counter sysfs interface * Copyright (C) 2020 William Breathitt Gray */ +#include #include #include #include #include #include +#include #include #include #include @@ -783,12 +785,49 @@ static int counter_num_counts_read(struct counter_device *counter, u8 *val) return 0; } +static int counter_events_queue_size_read(struct counter_device *counter, + u64 *val) +{ + *val = kfifo_size(&counter->events); + return 0; +} + +static int counter_events_queue_size_write(struct counter_device *counter, + u64 val) +{ + DECLARE_KFIFO_PTR(events, struct counter_event); + int err = 0; + + /* Ensure chrdev is not opened more than 1 at a time */ + if (!atomic_add_unless(&counter->chrdev_lock, 1, 1)) + return -EBUSY; + + /* Allocate new events queue */ + err = kfifo_alloc(&events, val, GFP_KERNEL); + if (err) + goto exit_early; + + /* Swap in new events queue */ + kfifo_free(&counter->events); + counter->events.kfifo = events.kfifo; + +exit_early: + atomic_dec(&counter->chrdev_lock); + + return err; +} + static struct counter_comp counter_num_signals_comp = COUNTER_COMP_DEVICE_U8("num_signals", counter_num_signals_read, NULL); static struct counter_comp counter_num_counts_comp = COUNTER_COMP_DEVICE_U8("num_counts", counter_num_counts_read, NULL); +static struct counter_comp counter_events_queue_size_comp = + COUNTER_COMP_DEVICE_U64("events_queue_size", + counter_events_queue_size_read, + counter_events_queue_size_write); + static int counter_sysfs_attr_add(struct counter_device *const counter, struct counter_attribute_group *cattr_group) { @@ -827,6 +866,12 @@ static int counter_sysfs_attr_add(struct counter_device *const counter, if (err < 0) return err; + /* Create events_queue_size attribute */ + err = counter_attr_create(dev, cattr_group, + &counter_events_queue_size_comp, scope, NULL); + if (err < 0) + return err; + /* Create an attribute for each extension */ for (i = 0; i < counter->num_ext; i++) { ext = &counter->ext[i]; -- cgit v1.2.3-59-g8ed1b From 7110acbdab462b8f2bc30e216c331cbd68c00af9 Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Mon, 4 Oct 2021 22:51:57 -0700 Subject: counter: fix docum. build problems after filename change Fix documentation build warnings due to a source file being renamed. WARNING: kernel-doc '../scripts/kernel-doc -rst -enable-lineno -sphinx-version 1.8.5 -export ../drivers/counter/counter.c' failed with return code 2 Error: Cannot open file ../drivers/counter/counter.c Fixes: aaec1a0f76ec ("counter: Internalize sysfs interface code") Signed-off-by: Randy Dunlap Cc: William Breathitt Gray Cc: linux-iio@vger.kernel.org Cc: Jonathan Cameron Cc: Jonathan Corbet Cc: linux-doc@vger.kernel.org Acked-by: William Breathitt Gray Link: https://lore.kernel.org/r/20211005055157.22937-1-rdunlap@infradead.org Signed-off-by: Jonathan Cameron --- Documentation/driver-api/generic-counter.rst | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'Documentation') diff --git a/Documentation/driver-api/generic-counter.rst b/Documentation/driver-api/generic-counter.rst index 25932dcb6e67..ae9d3c2079f1 100644 --- a/Documentation/driver-api/generic-counter.rst +++ b/Documentation/driver-api/generic-counter.rst @@ -234,7 +234,7 @@ for defining a counter device. .. kernel-doc:: include/linux/counter.h :internal: -.. kernel-doc:: drivers/counter/counter.c +.. kernel-doc:: drivers/counter/counter-core.c :export: Driver Implementation -- cgit v1.2.3-59-g8ed1b From 49af37fc7d3c50ca98143d1f904638a548685622 Mon Sep 17 00:00:00 2001 From: William Breathitt Gray Date: Tue, 5 Oct 2021 15:14:37 +0900 Subject: docs: counter: Include counter-chrdev kernel-doc to generic-counter.rst The counter-chrdev.c file exports the counter_push_event() function. Signed-off-by: William Breathitt Gray Link: https://lore.kernel.org/r/20211005061437.4846-1-vilhelm.gray@gmail.com Signed-off-by: Jonathan Cameron --- Documentation/driver-api/generic-counter.rst | 3 +++ 1 file changed, 3 insertions(+) (limited to 'Documentation') diff --git a/Documentation/driver-api/generic-counter.rst b/Documentation/driver-api/generic-counter.rst index ae9d3c2079f1..1b487a331467 100644 --- a/Documentation/driver-api/generic-counter.rst +++ b/Documentation/driver-api/generic-counter.rst @@ -237,6 +237,9 @@ for defining a counter device. .. kernel-doc:: drivers/counter/counter-core.c :export: +.. kernel-doc:: drivers/counter/counter-chrdev.c + :export: + Driver Implementation ===================== -- cgit v1.2.3-59-g8ed1b