1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * Character line display core support
4 *
5 * Copyright (C) 2016 Imagination Technologies
6 * Author: Paul Burton <paul.burton@mips.com>
7 *
8 * Copyright (C) 2021 Glider bv
9 */
10
11#ifndef _LINEDISP_H
12#define _LINEDISP_H
13
14#include <linux/device.h>
15#include <linux/timer_types.h>
16
17#include <linux/map_to_7segment.h>
18#include <linux/map_to_14segment.h>
19
20struct linedisp;
21
22/**
23 * enum linedisp_map_type - type of the character mapping
24 * @LINEDISP_MAP_SEG7: Map characters to 7 segment display
25 * @LINEDISP_MAP_SEG14: Map characters to 14 segment display
26 */
27enum linedisp_map_type {
28	LINEDISP_MAP_SEG7,
29	LINEDISP_MAP_SEG14,
30};
31
32/**
33 * struct linedisp_map - character mapping
34 * @type: type of the character mapping
35 * @map: conversion character mapping
36 * @size: size of the @map
37 */
38struct linedisp_map {
39	enum linedisp_map_type type;
40	union {
41		struct seg7_conversion_map seg7;
42		struct seg14_conversion_map seg14;
43	} map;
44	unsigned int size;
45};
46
47/**
48 * struct linedisp_ops - character line display operations
49 * @get_map_type: Function called to get the character mapping, if required
50 * @update: Function called to update the display. This must not sleep!
51 */
52struct linedisp_ops {
53	int (*get_map_type)(struct linedisp *linedisp);
54	void (*update)(struct linedisp *linedisp);
55};
56
57/**
58 * struct linedisp - character line display private data structure
59 * @dev: the line display device
60 * @timer: timer used to implement scrolling
61 * @ops: character line display operations
62 * @buf: pointer to the buffer for the string currently displayed
63 * @message: the full message to display or scroll on the display
64 * @num_chars: the number of characters that can be displayed
65 * @message_len: the length of the @message string
66 * @scroll_pos: index of the first character of @message currently displayed
67 * @scroll_rate: scroll interval in jiffies
68 * @id: instance id of this display
69 */
70struct linedisp {
71	struct device dev;
72	struct timer_list timer;
73	const struct linedisp_ops *ops;
74	struct linedisp_map *map;
75	char *buf;
76	char *message;
77	unsigned int num_chars;
78	unsigned int message_len;
79	unsigned int scroll_pos;
80	unsigned int scroll_rate;
81	unsigned int id;
82};
83
84int linedisp_register(struct linedisp *linedisp, struct device *parent,
85		      unsigned int num_chars, const struct linedisp_ops *ops);
86void linedisp_unregister(struct linedisp *linedisp);
87
88#endif /* LINEDISP_H */
89