1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2 /*
3  * Userspace ABI for Counter character devices
4  * Copyright (C) 2020 William Breathitt Gray
5  */
6 #ifndef _UAPI_COUNTER_H_
7 #define _UAPI_COUNTER_H_
8 
9 #include <linux/ioctl.h>
10 #include <linux/types.h>
11 
12 /* Component type definitions */
13 enum counter_component_type {
14 	COUNTER_COMPONENT_NONE,
15 	COUNTER_COMPONENT_SIGNAL,
16 	COUNTER_COMPONENT_COUNT,
17 	COUNTER_COMPONENT_FUNCTION,
18 	COUNTER_COMPONENT_SYNAPSE_ACTION,
19 	COUNTER_COMPONENT_EXTENSION,
20 };
21 
22 /* Component scope definitions */
23 enum counter_scope {
24 	COUNTER_SCOPE_DEVICE,
25 	COUNTER_SCOPE_SIGNAL,
26 	COUNTER_SCOPE_COUNT,
27 };
28 
29 /**
30  * struct counter_component - Counter component identification
31  * @type: component type (one of enum counter_component_type)
32  * @scope: component scope (one of enum counter_scope)
33  * @parent: parent ID (matching the ID suffix of the respective parent sysfs
34  *          path as described by the ABI documentation file
35  *          Documentation/ABI/testing/sysfs-bus-counter)
36  * @id: component ID (matching the ID provided by the respective *_component_id
37  *      sysfs attribute of the desired component)
38  *
39  * For example, if the Count 2 ceiling extension of Counter device 4 is desired,
40  * set type equal to COUNTER_COMPONENT_EXTENSION, scope equal to
41  * COUNTER_SCOPE_COUNT, parent equal to 2, and id equal to the value provided by
42  * the respective /sys/bus/counter/devices/counter4/count2/ceiling_component_id
43  * sysfs attribute.
44  */
45 struct counter_component {
46 	__u8 type;
47 	__u8 scope;
48 	__u8 parent;
49 	__u8 id;
50 };
51 
52 /* Event type definitions */
53 enum counter_event_type {
54 	/* Count value increased past ceiling */
55 	COUNTER_EVENT_OVERFLOW,
56 	/* Count value decreased past floor */
57 	COUNTER_EVENT_UNDERFLOW,
58 	/* Count value increased past ceiling, or decreased past floor */
59 	COUNTER_EVENT_OVERFLOW_UNDERFLOW,
60 	/* Count value reached threshold */
61 	COUNTER_EVENT_THRESHOLD,
62 	/* Index signal detected */
63 	COUNTER_EVENT_INDEX,
64 	/* State of counter is changed */
65 	COUNTER_EVENT_CHANGE_OF_STATE,
66 	/* Count value captured */
67 	COUNTER_EVENT_CAPTURE,
68 	/* Direction change detected */
69 	COUNTER_EVENT_DIRECTION_CHANGE,
70 };
71 
72 /**
73  * struct counter_watch - Counter component watch configuration
74  * @component: component to watch when event triggers
75  * @event: event that triggers (one of enum counter_event_type)
76  * @channel: event channel (typically 0 unless the device supports concurrent
77  *	     events of the same type)
78  */
79 struct counter_watch {
80 	struct counter_component component;
81 	__u8 event;
82 	__u8 channel;
83 };
84 
85 /*
86  * Queues a Counter watch for the specified event.
87  *
88  * The queued watches will not be applied until COUNTER_ENABLE_EVENTS_IOCTL is
89  * called.
90  */
91 #define COUNTER_ADD_WATCH_IOCTL _IOW(0x3E, 0x00, struct counter_watch)
92 /*
93  * Enables monitoring the events specified by the Counter watches that were
94  * queued by COUNTER_ADD_WATCH_IOCTL.
95  *
96  * If events are already enabled, the new set of watches replaces the old one.
97  * Calling this ioctl also has the effect of clearing the queue of watches added
98  * by COUNTER_ADD_WATCH_IOCTL.
99  */
100 #define COUNTER_ENABLE_EVENTS_IOCTL _IO(0x3E, 0x01)
101 /*
102  * Stops monitoring the previously enabled events.
103  */
104 #define COUNTER_DISABLE_EVENTS_IOCTL _IO(0x3E, 0x02)
105 
106 /**
107  * struct counter_event - Counter event data
108  * @timestamp: best estimate of time of event occurrence, in nanoseconds
109  * @value: component value
110  * @watch: component watch configuration
111  * @status: return status (system error number)
112  */
113 struct counter_event {
114 	__aligned_u64 timestamp;
115 	__aligned_u64 value;
116 	struct counter_watch watch;
117 	__u8 status;
118 };
119 
120 /* Count direction values */
121 enum counter_count_direction {
122 	COUNTER_COUNT_DIRECTION_FORWARD,
123 	COUNTER_COUNT_DIRECTION_BACKWARD,
124 };
125 
126 /* Count mode values */
127 enum counter_count_mode {
128 	COUNTER_COUNT_MODE_NORMAL,
129 	COUNTER_COUNT_MODE_RANGE_LIMIT,
130 	COUNTER_COUNT_MODE_NON_RECYCLE,
131 	COUNTER_COUNT_MODE_MODULO_N,
132 	COUNTER_COUNT_MODE_INTERRUPT_ON_TERMINAL_COUNT,
133 	COUNTER_COUNT_MODE_HARDWARE_RETRIGGERABLE_ONESHOT,
134 	COUNTER_COUNT_MODE_RATE_GENERATOR,
135 	COUNTER_COUNT_MODE_SQUARE_WAVE_MODE,
136 	COUNTER_COUNT_MODE_SOFTWARE_TRIGGERED_STROBE,
137 	COUNTER_COUNT_MODE_HARDWARE_TRIGGERED_STROBE,
138 };
139 
140 /* Count function values */
141 enum counter_function {
142 	COUNTER_FUNCTION_INCREASE,
143 	COUNTER_FUNCTION_DECREASE,
144 	COUNTER_FUNCTION_PULSE_DIRECTION,
145 	COUNTER_FUNCTION_QUADRATURE_X1_A,
146 	COUNTER_FUNCTION_QUADRATURE_X1_B,
147 	COUNTER_FUNCTION_QUADRATURE_X2_A,
148 	COUNTER_FUNCTION_QUADRATURE_X2_B,
149 	COUNTER_FUNCTION_QUADRATURE_X4,
150 };
151 
152 /* Signal values */
153 enum counter_signal_level {
154 	COUNTER_SIGNAL_LEVEL_LOW,
155 	COUNTER_SIGNAL_LEVEL_HIGH,
156 };
157 
158 /* Action mode values */
159 enum counter_synapse_action {
160 	COUNTER_SYNAPSE_ACTION_NONE,
161 	COUNTER_SYNAPSE_ACTION_RISING_EDGE,
162 	COUNTER_SYNAPSE_ACTION_FALLING_EDGE,
163 	COUNTER_SYNAPSE_ACTION_BOTH_EDGES,
164 };
165 
166 /* Signal polarity values */
167 enum counter_signal_polarity {
168 	COUNTER_SIGNAL_POLARITY_POSITIVE,
169 	COUNTER_SIGNAL_POLARITY_NEGATIVE,
170 };
171 
172 #endif /* _UAPI_COUNTER_H_ */
173