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

   1/*
   2 * cec-pin.h - low-level CEC pin control
   3 *
   4 * Copyright 2017 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
   5 *
   6 * This program is free software; you may redistribute it and/or modify
   7 * it under the terms of the GNU General Public License as published by
   8 * the Free Software Foundation; version 2 of the License.
   9 *
  10 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  11 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  12 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  13 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  14 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  15 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  16 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  17 * SOFTWARE.
  18 */
  19
  20#ifndef LINUX_CEC_PIN_H
  21#define LINUX_CEC_PIN_H
  22
  23#include <linux/types.h>
  24#include <media/cec.h>
  25
  26/**
  27 * struct cec_pin_ops - low-level CEC pin operations
  28 * @read:       read the CEC pin. Return true if high, false if low.
  29 * @low:        drive the CEC pin low.
  30 * @high:       stop driving the CEC pin. The pull-up will drive the pin
  31 *              high, unless someone else is driving the pin low.
  32 * @enable_irq: optional, enable the interrupt to detect pin voltage changes.
  33 * @disable_irq: optional, disable the interrupt.
  34 * @free:       optional. Free any allocated resources. Called when the
  35 *              adapter is deleted.
  36 * @status:     optional, log status information.
  37 * @read_hpd:   read the HPD pin. Return true if high, false if low or
  38 *              an error if negative. If NULL or -ENOTTY is returned,
  39 *              then this is not supported.
  40 *
  41 * These operations are used by the cec pin framework to manipulate
  42 * the CEC pin.
  43 */
  44struct cec_pin_ops {
  45        bool (*read)(struct cec_adapter *adap);
  46        void (*low)(struct cec_adapter *adap);
  47        void (*high)(struct cec_adapter *adap);
  48        bool (*enable_irq)(struct cec_adapter *adap);
  49        void (*disable_irq)(struct cec_adapter *adap);
  50        void (*free)(struct cec_adapter *adap);
  51        void (*status)(struct cec_adapter *adap, struct seq_file *file);
  52        int  (*read_hpd)(struct cec_adapter *adap);
  53};
  54
  55/**
  56 * cec_pin_changed() - update pin state from interrupt
  57 *
  58 * @adap:       pointer to the cec adapter
  59 * @value:      when true the pin is high, otherwise it is low
  60 *
  61 * If changes of the CEC voltage are detected via an interrupt, then
  62 * cec_pin_changed is called from the interrupt with the new value.
  63 */
  64void cec_pin_changed(struct cec_adapter *adap, bool value);
  65
  66/**
  67 * cec_pin_allocate_adapter() - allocate a pin-based cec adapter
  68 *
  69 * @pin_ops:    low-level pin operations
  70 * @priv:       will be stored in adap->priv and can be used by the adapter ops.
  71 *              Use cec_get_drvdata(adap) to get the priv pointer.
  72 * @name:       the name of the CEC adapter. Note: this name will be copied.
  73 * @caps:       capabilities of the CEC adapter. This will be ORed with
  74 *              CEC_CAP_MONITOR_ALL and CEC_CAP_MONITOR_PIN.
  75 *
  76 * Allocate a cec adapter using the cec pin framework.
  77 *
  78 * Return: a pointer to the cec adapter or an error pointer
  79 */
  80struct cec_adapter *cec_pin_allocate_adapter(const struct cec_pin_ops *pin_ops,
  81                                        void *priv, const char *name, u32 caps);
  82
  83#endif
  84