Changes in v4:
- Handle COUNTER_COMP_SIGNAL_POLARITY type in counter_attr_create() and
counter_get_data(); previously was incorrectly treating as invalid
- Replace DEFINE_COUNTER_ARRAY macro with DEFINE_COUNTER_ARRAY_U64 and
DEFINE_COUNTER_ARRAY_POLARITY macros
The COUNTER_COMP_ARRAY Counter component type is introduced to enable
support for Counter array components. With Counter array components,
exposure for buffers on counter devices can be defined via new Counter
array component macros. This should simplify code for driver authors who
would otherwise need to define individual Counter components for each
array element.
Six Counter array component macros are introduced::
DEFINE_COUNTER_ARRAY_U64(_name, _length)
DEFINE_COUNTER_ARRAY_POLARITY(_name, _enums, _length)
COUNTER_COMP_DEVICE_ARRAY_U64(_name, _read, _write, _array)
COUNTER_COMP_COUNT_ARRAY_U64(_name, _read, _write, _array)
COUNTER_COMP_SIGNAL_ARRAY_U64(_name, _read, _write, _array)
COUNTER_COMP_ARRAY_POLARITY(_read, _write, _array)
Eight Counter array callbacks are introduced as well::
int (*signal_array_u32_read)(struct counter_device *counter,
struct counter_signal *signal,
size_t idx, u32 *val);
int (*signal_array_u32_write)(struct counter_device *counter,
struct counter_signal *signal,
size_t idx, u32 val);
int (*device_array_u64_read)(struct counter_device *counter,
size_t idx, u64 *val);
int (*count_array_u64_read)(struct counter_device *counter,
struct counter_count *count,
size_t idx, u64 *val);
int (*signal_array_u64_read)(struct counter_device *counter,
struct counter_signal *signal,
size_t idx, u64 *val);
int (*device_array_u64_write)(struct counter_device *counter,
size_t idx, u64 val);
int (*count_array_u64_write)(struct counter_device *counter,
struct counter_count *count,
size_t idx, u64 val);
int (*signal_array_u64_write)(struct counter_device *counter,
struct counter_signal *signal,
size_t idx, u64 val);
Driver authors can handle reads/writes for an array component by
receiving an element index via the `idx` parameter and processing the
respective value via the `val` parameter.
For example, suppose a driver wants to expose a Count's read-only
capture buffer of four elements using a callback
`foobar_capture_read()`::
DEFINE_COUNTER_ARRAY_U64(foobar_capture_array, 4);
COUNTER_COMP_COUNT_ARRAY_U64("capture", foobar_capture_read,
NULL, foobar_capture_array)
Respective sysfs attributes for each array element would appear for the
respective Count:
* /sys/bus/counter/devices/counterX/countY/capture0
* /sys/bus/counter/devices/counterX/countY/capture1
* /sys/bus/counter/devices/counterX/countY/capture2
* /sys/bus/counter/devices/counterX/countY/capture3
If a user tries to read _capture2_ for example, `idx` will be `2` when
passed to the `foobar_capture_read()` callback, and thus the driver
knows which array element to handle.
In addition, this patchset introduces the Signal polarity component,
which represents the active level of a respective Signal. There are two
possible states: positive (rising edge) and negative (falling edge). The
104-quad-8 driver is updated to expose its index_polarity functionality
via this new polarity component.
Counter arrays for polarity elements can be defined in a similar
manner as u64 elements::
const enum counter_signal_polarity foobar_polarity_states[] = {
COUNTER_SIGNAL_POLARITY_POSITIVE,
COUNTER_SIGNAL_POLARITY_NEGATIVE,
};
DEFINE_COUNTER_ARRAY_POLARITY(foobar_polarity_array,
foobar_polarity_states, 4);
COUNTER_COMP_ARRAY_POLARITY(foobar_polarity_read,
foobar_polarity_write,
foobar_polarity_array)
The only component types supported for Counter arrays currently are
COUNTER_COMP_U64 and COUNTER_COMP_SIGNAL_POLARITY.
William Breathitt Gray (4):
counter: Introduce the Signal polarity component
counter: 104-quad-8: Add Signal polarity component
counter: Consolidate Counter extension sysfs attribute creation
counter: Introduce the COUNTER_COMP_ARRAY component type
Documentation/ABI/testing/sysfs-bus-counter | 13 +
drivers/counter/104-quad-8.c | 35 +++
drivers/counter/counter-chrdev.c | 48 +++-
drivers/counter/counter-sysfs.c | 304 ++++++++++++++++----
include/linux/counter.h | 138 +++++++++
include/uapi/linux/counter.h | 6 +
6 files changed, 492 insertions(+), 52 deletions(-)
base-commit: f95ec98139dc58db72e4bd0df049a3097990a8e7
--
2.37.3
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 <[email protected]>
Signed-off-by: William Breathitt Gray <[email protected]>
---
Documentation/ABI/testing/sysfs-bus-counter | 13 +++++++++++++
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, 42 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-bus-counter b/Documentation/ABI/testing/sysfs-bus-counter
index 06c2b3e27e0b..a234022f9add 100644
--- a/Documentation/ABI/testing/sysfs-bus-counter
+++ b/Documentation/ABI/testing/sysfs-bus-counter
@@ -303,6 +303,19 @@ 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: [email protected]
+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: [email protected]
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 1fe17f5adb09..d508b260aaca 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,
};
/**
@@ -483,4 +484,13 @@ struct counter_available {
#define COUNTER_COMP_PRESET_ENABLE(_read, _write) \
COUNTER_COMP_COUNT_BOOL("preset_enable", _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), \
+}
+
#endif /* _COUNTER_H_ */
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