LXR linux/include/media/cec-pin.h

   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 *
  29 * These operations are used by the cec pin framework to manipulate
  30 * the CEC pin.
  31 */
  32struct cec_pin_ops {
  33        bool (*read)(struct cec_adapter *adap);
  34        void (*low)(struct cec_adapter *adap);
  35        void (*high)(struct cec_adapter *adap);
  36        bool (*enable_irq)(struct cec_adapter *adap);
  37        void (*disable_irq)(struct cec_adapter *adap);
  38        void (*free)(struct cec_adapter *adap);
  39        void (*status)(struct cec_adapter *adap, struct seq_file *file);
  40        int  (*read_hpd)(struct cec_adapter *adap);
  41};
  42
  43/**
  44 * cec_pin_changed() - update pin state from interrupt
  45 *
  46 * @adap:       pointer to the cec adapter
  47 * @value:      when true the pin is high, otherwise it is low
  48 *
  49 * If changes of the CEC voltage are detected via an interrupt, then
  50 * cec_pin_changed is called from the interrupt with the new value.
  51 */
  52void cec_pin_changed(struct cec_adapter *adap, bool value);
  53
  54/**
  55 * cec_pin_allocate_adapter() - allocate a pin-based cec adapter
  56 *
  57 * @pin_ops:    low-level pin operations
  58 * @priv:       will be stored in adap->priv and can be used by the adapter ops.
  59 *              Use cec_get_drvdata(adap) to get the priv pointer.
  60 * @name:       the name of the CEC adapter. Note: this name will be copied.
  61 * @caps:       capabilities of the CEC adapter. This will be ORed with
  62 *              CEC_CAP_MONITOR_ALL and CEC_CAP_MONITOR_PIN.
  63 *
  64 * Allocate a cec adapter using the cec pin framework.
  65 *
  66 * Return: a pointer to the cec adapter or an error pointer
  67 */
  68struct cec_adapter *cec_pin_allocate_adapter(const struct cec_pin_ops *pin_ops,
  69                                        void *priv, const char *name, u32 caps);
  70
  71#endif
  72