From: William Breathitt Gray Date: Wed, 29 Sep 2021 03:16:02 +0000 (+0900) Subject: counter: Implement signalZ_action_component_id sysfs attribute X-Git-Tag: v5.16-rc1~119^2~29^2~7 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=bb6264a61de84320e77a22b4b8f4babf240608c4;p=thirdparty%2Fkernel%2Flinux.git 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 --- diff --git a/Documentation/ABI/testing/sysfs-bus-counter b/Documentation/ABI/testing/sysfs-bus-counter index dee79b606847d..aa2cd3c10d74e 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 108cbd838eb92..ee7ff1cde4549 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;