1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * cec-pin.h - low-level CEC pin control
4 *
5 * Copyright 2017 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
6 */
7
8 #ifndef LINUX_CEC_PIN_H
9 #define LINUX_CEC_PIN_H
10
11 #include <linux/types.h>
12 #include <media/cec.h>
13
14 /**
15 * struct cec_pin_ops - low-level CEC pin operations
16 * @read: read the CEC pin. Return true if high, false if low.
17 * @low: drive the CEC pin low.
18 * @high: stop driving the CEC pin. The pull-up will drive the pin
19 * high, unless someone else is driving the pin low.
20 * @enable_irq: optional, enable the interrupt to detect pin voltage changes.
21 * @disable_irq: optional, disable the interrupt.
22 * @free: optional. Free any allocated resources. Called when the
23 * adapter is deleted.
24 * @status: optional, log status information.
25 * @read_hpd: read the HPD pin. Return true if high, false if low or
26 * an error if negative. If NULL or -ENOTTY is returned,
27 * then this is not supported.
28 * @read_5v: read the 5V pin. Return true if high, false if low or
29 * an error if negative. If NULL or -ENOTTY is returned,
30 * then this is not supported.
31 *
32 * These operations are used by the cec pin framework to manipulate
33 * the CEC pin.
34 */
35 struct cec_pin_ops {
36 bool (*read)(struct cec_adapter *adap);
37 void (*low)(struct cec_adapter *adap);
38 void (*high)(struct cec_adapter *adap);
39 bool (*enable_irq)(struct cec_adapter *adap);
40 void (*disable_irq)(struct cec_adapter *adap);
41 void (*free)(struct cec_adapter *adap);
42 void (*status)(struct cec_adapter *adap, struct seq_file *file);
43 int (*read_hpd)(struct cec_adapter *adap);
44 int (*read_5v)(struct cec_adapter *adap);
45 };
46
47 /**
48 * cec_pin_changed() - update pin state from interrupt
49 *
50 * @adap: pointer to the cec adapter
51 * @value: when true the pin is high, otherwise it is low
52 *
53 * If changes of the CEC voltage are detected via an interrupt, then
54 * cec_pin_changed is called from the interrupt with the new value.
55 */
56 void cec_pin_changed(struct cec_adapter *adap, bool value);
57
58 /**
59 * cec_pin_allocate_adapter() - allocate a pin-based cec adapter
60 *
61 * @pin_ops: low-level pin operations
62 * @priv: will be stored in adap->priv and can be used by the adapter ops.
63 * Use cec_get_drvdata(adap) to get the priv pointer.
64 * @name: the name of the CEC adapter. Note: this name will be copied.
65 * @caps: capabilities of the CEC adapter. This will be ORed with
66 * CEC_CAP_MONITOR_ALL and CEC_CAP_MONITOR_PIN.
67 *
68 * Allocate a cec adapter using the cec pin framework.
69 *
70 * Return: a pointer to the cec adapter or an error pointer
71 */
72 struct cec_adapter *cec_pin_allocate_adapter(const struct cec_pin_ops *pin_ops,
73 void *priv, const char *name, u32 caps);
74
75 #endif