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  */
  44 struct 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  */
  64 void 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  */
  80 struct cec_adapter *cec_pin_allocate_adapter(const struct cec_pin_ops *pin_ops,
  81                                         void *priv, const char *name, u32 caps);
  82
  83 #endif