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 <[email protected]>
Cc: Dan Carpenter <[email protected]>
Reviewed-by: David Lechner <[email protected]>
Signed-off-by: William Breathitt Gray <[email protected]>
---
Documentation/ABI/testing/sysfs-bus-counter | 7 ++++
drivers/counter/counter-sysfs.c | 45 +++++++++++++++++++++
2 files changed, 52 insertions(+)
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: [email protected]
+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: [email protected]
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;
--
2.33.0
On Wed, Sep 29, 2021 at 12:16:02PM +0900, William Breathitt Gray wrote:
> +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);
sysfs_emit()?
> +}
> +