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 80