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 84