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. Returns > 0 if high, 0 if low, or an error
17 * if negative.
18 * @low: drive the CEC pin low.
19 * @high: stop driving the CEC pin. The pull-up will drive the pin
20 * high, unless someone else is driving the pin low.
21 * @enable_irq: optional, enable the interrupt to detect pin voltage changes.
22 * @disable_irq: optional, disable the interrupt.
23 * @free: optional. Free any allocated resources. Called when the
24 * adapter is deleted.
25 * @status: optional, log status information.
26 * @read_hpd: optional. Read the HPD pin. Returns > 0 if high, 0 if low or
27 * an error if negative.
28 * @read_5v: optional. Read the 5V pin. Returns > 0 if high, 0 if low or
29 * an error if negative.
30 * @received: optional. High-level CEC message callback. Allows the driver
31 * to process CEC messages.
32 *
33 * These operations (except for the @received op) are used by the
34 * cec pin framework to manipulate the CEC pin.
35 */
36 struct cec_pin_ops {
37 int (*read)(struct cec_adapter *adap);
38 void (*low)(struct cec_adapter *adap);
39 void (*high)(struct cec_adapter *adap);
40 bool (*enable_irq)(struct cec_adapter *adap);
41 void (*disable_irq)(struct cec_adapter *adap);
42 void (*free)(struct cec_adapter *adap);
43 void (*status)(struct cec_adapter *adap, struct seq_file *file);
44 int (*read_hpd)(struct cec_adapter *adap);
45 int (*read_5v)(struct cec_adapter *adap);
46
47 /* High-level CEC message callback */
48 int (*received)(struct cec_adapter *adap, struct cec_msg *msg);
49 };
50
51 /**
52 * cec_pin_changed() - update pin state from interrupt
53 *
54 * @adap: pointer to the cec adapter
55 * @value: when true the pin is high, otherwise it is low
56 *
57 * If changes of the CEC voltage are detected via an interrupt, then
58 * cec_pin_changed is called from the interrupt with the new value.
59 */
60 void cec_pin_changed(struct cec_adapter *adap, bool value);
61
62 /**
63 * cec_pin_allocate_adapter() - allocate a pin-based cec adapter
64 *
65 * @pin_ops: low-level pin operations
66 * @priv: will be stored in adap->priv and can be used by the adapter ops.
67 * Use cec_get_drvdata(adap) to get the priv pointer.
68 * @name: the name of the CEC adapter. Note: this name will be copied.
69 * @caps: capabilities of the CEC adapter. This will be ORed with
70 * CEC_CAP_MONITOR_ALL and CEC_CAP_MONITOR_PIN.
71 *
72 * Allocate a cec adapter using the cec pin framework.
73 *
74 * Return: a pointer to the cec adapter or an error pointer
75 */
76 struct cec_adapter *cec_pin_allocate_adapter(const struct cec_pin_ops *pin_ops,
77 void *priv, const char *name, u32 caps);
78
79 #endif
80
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