Commit 650ae67b authored by William Breathitt Gray's avatar William Breathitt Gray Committed by Greg Kroah-Hartman
Browse files

counter: Introduce the Signal polarity component 

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@baylibre.com>
Link: https://lore.kernel.org/r/8f47d6e1db71a11bb1e2666f8e2a6e9d256d4131.1664204990.git.william.gray@linaro.org/


Signed-off-by: default avatarWilliam Breathitt Gray <william.gray@linaro.org>
Link: https://lore.kernel.org/r/b6e53438badcb6318997d13dd2fc052f97d808ac.1664318353.git.william.gray@linaro.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 7bbf842c

Documentation/ABI/testing/sysfs-bus-counter

+14 −0
Original line number Diff line number Diff line
@@ -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@vger.kernel.org
@@ -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@vger.kernel.org

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@vger.kernel.org

drivers/counter/counter-chrdev.c

+1 −0
Original line number Diff line number Diff line
@@ -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);

drivers/counter/counter-sysfs.c

+12 −0
Original line number Diff line number Diff line
@@ -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;

include/linux/counter.h

+10 −0
Original line number Diff line number Diff line
@@ -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)

include/uapi/linux/counter.h

+6 −0
Original line number Diff line number Diff line
@@ -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_ */