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  */
  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