drivers/auxdisplay/line-display.h

0001 /* SPDX-License-Identifier: GPL-2.0-or-later */
0002 /*
0003  * Character line display core support
0004  *
0005  * Copyright (C) 2016 Imagination Technologies
0006  * Author: Paul Burton <paul.burton@mips.com>
0007  *
0008  * Copyright (C) 2021 Glider bv
0009  */
0010
0011 #ifndef _LINEDISP_H
0012 #define _LINEDISP_H
0013
0014 /**
0015  * struct linedisp - character line display private data structure
0016  * @dev: the line display device
0017  * @timer: timer used to implement scrolling
0018  * @update: function called to update the display
0019  * @buf: pointer to the buffer for the string currently displayed
0020  * @message: the full message to display or scroll on the display
0021  * @num_chars: the number of characters that can be displayed
0022  * @message_len: the length of the @message string
0023  * @scroll_pos: index of the first character of @message currently displayed
0024  * @scroll_rate: scroll interval in jiffies
0025  */
0026 struct linedisp {
0027     struct device dev;
0028     struct timer_list timer;
0029     void (*update)(struct linedisp *linedisp);
0030     char *buf;
0031     char *message;
0032     unsigned int num_chars;
0033     unsigned int message_len;
0034     unsigned int scroll_pos;
0035     unsigned int scroll_rate;
0036 };
0037
0038 int linedisp_register(struct linedisp *linedisp, struct device *parent,
0039               unsigned int num_chars, char *buf,
0040               void (*update)(struct linedisp *linedisp));
0041 void linedisp_unregister(struct linedisp *linedisp);
0042
0043 #endif /* LINEDISP_H */