include/media/cec-pin.h

0001 /* SPDX-License-Identifier: GPL-2.0-only */
0002 /*
0003  * cec-pin.h - low-level CEC pin control
0004  *
0005  * Copyright 2017 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
0006  */
0007
0008 #ifndef LINUX_CEC_PIN_H
0009 #define LINUX_CEC_PIN_H
0010
0011 #include <linux/types.h>
0012 #include <media/cec.h>
0013
0014 /**
0015  * struct cec_pin_ops - low-level CEC pin operations
0016  * @read:   read the CEC pin. Returns > 0 if high, 0 if low, or an error
0017  *      if negative.
0018  * @low:    drive the CEC pin low.
0019  * @high:   stop driving the CEC pin. The pull-up will drive the pin
0020  *      high, unless someone else is driving the pin low.
0021  * @enable_irq: optional, enable the interrupt to detect pin voltage changes.
0022  * @disable_irq: optional, disable the interrupt.
0023  * @free:   optional. Free any allocated resources. Called when the
0024  *      adapter is deleted.
0025  * @status: optional, log status information.
0026  * @read_hpd:   optional. Read the HPD pin. Returns > 0 if high, 0 if low or
0027  *      an error if negative.
0028  * @read_5v:    optional. Read the 5V pin. Returns > 0 if high, 0 if low or
0029  *      an error if negative.
0030  * @received:   optional. High-level CEC message callback. Allows the driver
0031  *      to process CEC messages.
0032  *
0033  * These operations (except for the @received op) are used by the
0034  * cec pin framework to manipulate the CEC pin.
0035  */
0036 struct cec_pin_ops {
0037     int  (*read)(struct cec_adapter *adap);
0038     void (*low)(struct cec_adapter *adap);
0039     void (*high)(struct cec_adapter *adap);
0040     bool (*enable_irq)(struct cec_adapter *adap);
0041     void (*disable_irq)(struct cec_adapter *adap);
0042     void (*free)(struct cec_adapter *adap);
0043     void (*status)(struct cec_adapter *adap, struct seq_file *file);
0044     int  (*read_hpd)(struct cec_adapter *adap);
0045     int  (*read_5v)(struct cec_adapter *adap);
0046
0047     /* High-level CEC message callback */
0048     int (*received)(struct cec_adapter *adap, struct cec_msg *msg);
0049 };
0050
0051 /**
0052  * cec_pin_changed() - update pin state from interrupt
0053  *
0054  * @adap:   pointer to the cec adapter
0055  * @value:  when true the pin is high, otherwise it is low
0056  *
0057  * If changes of the CEC voltage are detected via an interrupt, then
0058  * cec_pin_changed is called from the interrupt with the new value.
0059  */
0060 void cec_pin_changed(struct cec_adapter *adap, bool value);
0061
0062 /**
0063  * cec_pin_allocate_adapter() - allocate a pin-based cec adapter
0064  *
0065  * @pin_ops:    low-level pin operations
0066  * @priv:   will be stored in adap->priv and can be used by the adapter ops.
0067  *      Use cec_get_drvdata(adap) to get the priv pointer.
0068  * @name:   the name of the CEC adapter. Note: this name will be copied.
0069  * @caps:   capabilities of the CEC adapter. This will be ORed with
0070  *      CEC_CAP_MONITOR_ALL and CEC_CAP_MONITOR_PIN.
0071  *
0072  * Allocate a cec adapter using the cec pin framework.
0073  *
0074  * Return: a pointer to the cec adapter or an error pointer
0075  */
0076 struct cec_adapter *cec_pin_allocate_adapter(const struct cec_pin_ops *pin_ops,
0077                     void *priv, const char *name, u32 caps);
0078
0079 #endif