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linux/drivers/auxdisplay/line-display.h
Andy Shevchenko 4ce026d5f4 auxdisplay: linedisp: Allocate buffer for the string
Always allocate a buffer for the currently displayed characters.
It makes the line display API simpler.

Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2024-02-26 18:02:19 +02:00

89 lines
2.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* Character line display core support
*
* Copyright (C) 2016 Imagination Technologies
* Author: Paul Burton <paul.burton@mips.com>
*
* Copyright (C) 2021 Glider bv
*/
#ifndef _LINEDISP_H
#define _LINEDISP_H
#include <linux/device.h>
#include <linux/timer_types.h>
#include <linux/map_to_7segment.h>
#include <linux/map_to_14segment.h>
struct linedisp;
/**
* enum linedisp_map_type - type of the character mapping
* @LINEDISP_MAP_SEG7: Map characters to 7 segment display
* @LINEDISP_MAP_SEG14: Map characters to 14 segment display
*/
enum linedisp_map_type {
LINEDISP_MAP_SEG7,
LINEDISP_MAP_SEG14,
};
/**
* struct linedisp_map - character mapping
* @type: type of the character mapping
* @map: conversion character mapping
* @size: size of the @map
*/
struct linedisp_map {
enum linedisp_map_type type;
union {
struct seg7_conversion_map seg7;
struct seg14_conversion_map seg14;
} map;
unsigned int size;
};
/**
* struct linedisp_ops - character line display operations
* @get_map_type: Function called to get the character mapping, if required
* @update: Function called to update the display. This must not sleep!
*/
struct linedisp_ops {
int (*get_map_type)(struct linedisp *linedisp);
void (*update)(struct linedisp *linedisp);
};
/**
* struct linedisp - character line display private data structure
* @dev: the line display device
* @timer: timer used to implement scrolling
* @ops: character line display operations
* @buf: pointer to the buffer for the string currently displayed
* @message: the full message to display or scroll on the display
* @num_chars: the number of characters that can be displayed
* @message_len: the length of the @message string
* @scroll_pos: index of the first character of @message currently displayed
* @scroll_rate: scroll interval in jiffies
* @id: instance id of this display
*/
struct linedisp {
struct device dev;
struct timer_list timer;
const struct linedisp_ops *ops;
struct linedisp_map *map;
char *buf;
char *message;
unsigned int num_chars;
unsigned int message_len;
unsigned int scroll_pos;
unsigned int scroll_rate;
unsigned int id;
};
int linedisp_register(struct linedisp *linedisp, struct device *parent,
unsigned int num_chars, const struct linedisp_ops *ops);
void linedisp_unregister(struct linedisp *linedisp);
#endif /* LINEDISP_H */