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 */ 32 struct 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 */ 52 void 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 */ 68 struct 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