linux/include/media/cec-pin.h
Hans Verkuil e5ad7db4b2 media: cec-gpio: handle gpiod_get_value errors correctly
gpiod_get_value() can return negative values if an error occurs.
In several places this error code was ignored.

Ensure that errors codes are handled correctly throughout the CEC
pin framework and CEC pin drivers.

The return code of the cec_pin_ops read() callback had to be changed
from 'bool' to 'int', which mean the prototype of that callback in the
sun4i drm driver also had to be changed.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-04-29 12:04:38 +02:00

80 lines
2.8 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* cec-pin.h - low-level CEC pin control
*
* Copyright 2017 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
*/
#ifndef LINUX_CEC_PIN_H
#define LINUX_CEC_PIN_H
#include <linux/types.h>
#include <media/cec.h>
/**
* struct cec_pin_ops - low-level CEC pin operations
* @read: read the CEC pin. Returns > 0 if high, 0 if low, or an error
* if negative.
* @low: drive the CEC pin low.
* @high: stop driving the CEC pin. The pull-up will drive the pin
* high, unless someone else is driving the pin low.
* @enable_irq: optional, enable the interrupt to detect pin voltage changes.
* @disable_irq: optional, disable the interrupt.
* @free: optional. Free any allocated resources. Called when the
* adapter is deleted.
* @status: optional, log status information.
* @read_hpd: optional. Read the HPD pin. Returns > 0 if high, 0 if low or
* an error if negative.
* @read_5v: optional. Read the 5V pin. Returns > 0 if high, 0 if low or
* an error if negative.
* @received: optional. High-level CEC message callback. Allows the driver
* to process CEC messages.
*
* These operations (except for the @received op) are used by the
* cec pin framework to manipulate the CEC pin.
*/
struct cec_pin_ops {
int (*read)(struct cec_adapter *adap);
void (*low)(struct cec_adapter *adap);
void (*high)(struct cec_adapter *adap);
bool (*enable_irq)(struct cec_adapter *adap);
void (*disable_irq)(struct cec_adapter *adap);
void (*free)(struct cec_adapter *adap);
void (*status)(struct cec_adapter *adap, struct seq_file *file);
int (*read_hpd)(struct cec_adapter *adap);
int (*read_5v)(struct cec_adapter *adap);
/* High-level CEC message callback */
int (*received)(struct cec_adapter *adap, struct cec_msg *msg);
};
/**
* cec_pin_changed() - update pin state from interrupt
*
* @adap: pointer to the cec adapter
* @value: when true the pin is high, otherwise it is low
*
* If changes of the CEC voltage are detected via an interrupt, then
* cec_pin_changed is called from the interrupt with the new value.
*/
void cec_pin_changed(struct cec_adapter *adap, bool value);
/**
* cec_pin_allocate_adapter() - allocate a pin-based cec adapter
*
* @pin_ops: low-level pin operations
* @priv: will be stored in adap->priv and can be used by the adapter ops.
* Use cec_get_drvdata(adap) to get the priv pointer.
* @name: the name of the CEC adapter. Note: this name will be copied.
* @caps: capabilities of the CEC adapter. This will be ORed with
* CEC_CAP_MONITOR_ALL and CEC_CAP_MONITOR_PIN.
*
* Allocate a cec adapter using the cec pin framework.
*
* Return: a pointer to the cec adapter or an error pointer
*/
struct cec_adapter *cec_pin_allocate_adapter(const struct cec_pin_ops *pin_ops,
void *priv, const char *name, u32 caps);
#endif