The Signal polarity component represents the active level of a respective Signal. There are two possible states: positive (rising edge) and negative (falling edge); enum counter_signal_polarity represents these states. A convenience macro COUNTER_COMP_POLARITY() is provided for driver authors to declare a Signal polarity component. Cc: Julien Panis <jpanis@xxxxxxxxxxxx> Link: https://lore.kernel.org/r/8f47d6e1db71a11bb1e2666f8e2a6e9d256d4131.1664204990.git.william.gray@xxxxxxxxxx/ Signed-off-by: William Breathitt Gray <william.gray@xxxxxxxxxx> --- Documentation/ABI/testing/sysfs-bus-counter | 14 ++++++++++++++ drivers/counter/counter-chrdev.c | 1 + drivers/counter/counter-sysfs.c | 12 ++++++++++++ include/linux/counter.h | 10 ++++++++++ include/uapi/linux/counter.h | 6 ++++++ 5 files changed, 43 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-bus-counter b/Documentation/ABI/testing/sysfs-bus-counter index 06c2b3e27e0b..2a996deabe9e 100644 --- a/Documentation/ABI/testing/sysfs-bus-counter +++ b/Documentation/ABI/testing/sysfs-bus-counter @@ -217,6 +217,7 @@ 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/polarity_component_id What: /sys/bus/counter/devices/counterX/signalY/synchronous_mode_component_id KernelVersion: 5.16 Contact: linux-iio@xxxxxxxxxxxxxxx @@ -303,6 +304,19 @@ Description: Discrete set of available values for the respective Signal Y configuration are listed in this file. +What: /sys/bus/counter/devices/counterX/signalY/polarity +KernelVersion: 6.1 +Contact: linux-iio@xxxxxxxxxxxxxxx +Description: + Active level of Signal Y. The following polarity values are + available: + + positive: + Signal high state considered active level (rising edge). + + negative: + Signal low state considered active level (falling edge). + What: /sys/bus/counter/devices/counterX/signalY/name KernelVersion: 5.2 Contact: linux-iio@xxxxxxxxxxxxxxx diff --git a/drivers/counter/counter-chrdev.c b/drivers/counter/counter-chrdev.c index 4e71a19d7e6a..120879ee2e87 100644 --- a/drivers/counter/counter-chrdev.c +++ b/drivers/counter/counter-chrdev.c @@ -487,6 +487,7 @@ static int counter_get_data(struct counter_device *const counter, case COUNTER_COMP_ENUM: case COUNTER_COMP_COUNT_DIRECTION: case COUNTER_COMP_COUNT_MODE: + case COUNTER_COMP_SIGNAL_POLARITY: switch (comp_node->component.scope) { case COUNTER_SCOPE_DEVICE: ret = comp->device_u32_read(counter, &value_u32); diff --git a/drivers/counter/counter-sysfs.c b/drivers/counter/counter-sysfs.c index 04eac41dad33..e5dd36e1a45f 100644 --- a/drivers/counter/counter-sysfs.c +++ b/drivers/counter/counter-sysfs.c @@ -91,6 +91,11 @@ static const char *const counter_count_mode_str[] = { [COUNTER_COUNT_MODE_MODULO_N] = "modulo-n" }; +static const char *const counter_signal_polarity_str[] = { + [COUNTER_SIGNAL_POLARITY_POSITIVE] = "positive", + [COUNTER_SIGNAL_POLARITY_NEGATIVE] = "negative" +}; + static ssize_t counter_comp_u8_show(struct device *dev, struct device_attribute *attr, char *buf) { @@ -201,6 +206,8 @@ static ssize_t counter_comp_u32_show(struct device *dev, return sysfs_emit(buf, "%s\n", counter_count_direction_str[data]); case COUNTER_COMP_COUNT_MODE: return sysfs_emit(buf, "%s\n", counter_count_mode_str[data]); + case COUNTER_COMP_SIGNAL_POLARITY: + return sysfs_emit(buf, "%s\n", counter_signal_polarity_str[data]); default: return sysfs_emit(buf, "%u\n", (unsigned int)data); } @@ -252,6 +259,10 @@ static ssize_t counter_comp_u32_store(struct device *dev, err = counter_find_enum(&data, avail->enums, avail->num_items, buf, counter_count_mode_str); break; + case COUNTER_COMP_SIGNAL_POLARITY: + err = counter_find_enum(&data, avail->enums, avail->num_items, + buf, counter_signal_polarity_str); + break; default: err = kstrtou32(buf, 0, &data); break; @@ -469,6 +480,7 @@ static int counter_attr_create(struct device *const dev, case COUNTER_COMP_ENUM: case COUNTER_COMP_COUNT_DIRECTION: case COUNTER_COMP_COUNT_MODE: + case COUNTER_COMP_SIGNAL_POLARITY: if (comp->device_u32_read) { dev_attr->attr.mode |= 0444; dev_attr->show = counter_comp_u32_show; diff --git a/include/linux/counter.h b/include/linux/counter.h index a81234bc8ea8..b3fb6b68881a 100644 --- a/include/linux/counter.h +++ b/include/linux/counter.h @@ -31,6 +31,7 @@ enum counter_comp_type { COUNTER_COMP_ENUM, COUNTER_COMP_COUNT_DIRECTION, COUNTER_COMP_COUNT_MODE, + COUNTER_COMP_SIGNAL_POLARITY, }; /** @@ -477,6 +478,15 @@ struct counter_available { #define COUNTER_COMP_FLOOR(_read, _write) \ COUNTER_COMP_COUNT_U64("floor", _read, _write) +#define COUNTER_COMP_POLARITY(_read, _write, _available) \ +{ \ + .type = COUNTER_COMP_SIGNAL_POLARITY, \ + .name = "polarity", \ + .signal_u32_read = (_read), \ + .signal_u32_write = (_write), \ + .priv = &(_available), \ +} + #define COUNTER_COMP_PRESET(_read, _write) \ COUNTER_COMP_COUNT_U64("preset", _read, _write) diff --git a/include/uapi/linux/counter.h b/include/uapi/linux/counter.h index 96c5ffd368ad..e9610e1944dc 100644 --- a/include/uapi/linux/counter.h +++ b/include/uapi/linux/counter.h @@ -153,4 +153,10 @@ enum counter_synapse_action { COUNTER_SYNAPSE_ACTION_BOTH_EDGES, }; +/* Signal polarity values */ +enum counter_signal_polarity { + COUNTER_SIGNAL_POLARITY_POSITIVE, + COUNTER_SIGNAL_POLARITY_NEGATIVE, +}; + #endif /* _UAPI_COUNTER_H_ */ -- 2.37.3
