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. 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 */
  36struct 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 */
  60void 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 */
  76struct 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