xref: /linux/drivers/auxdisplay/charlcd.h (revision 9e56ff53b4115875667760445b028357848b4748)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * Character LCD driver for Linux
4  *
5  * Copyright (C) 2000-2008, Willy Tarreau <w@1wt.eu>
6  * Copyright (C) 2016-2017 Glider bvba
7  */
8 
9 #ifndef _CHARLCD_H
10 #define _CHARLCD_H
11 
12 #define LCD_FLAG_B		0x0004	/* Blink on */
13 #define LCD_FLAG_C		0x0008	/* Cursor on */
14 #define LCD_FLAG_D		0x0010	/* Display on */
15 #define LCD_FLAG_F		0x0020	/* Large font mode */
16 #define LCD_FLAG_N		0x0040	/* 2-rows mode */
17 #define LCD_FLAG_L		0x0080	/* Backlight enabled */
18 
19 enum charlcd_onoff {
20 	CHARLCD_OFF = 0,
21 	CHARLCD_ON,
22 };
23 
24 enum charlcd_shift_dir {
25 	CHARLCD_SHIFT_LEFT,
26 	CHARLCD_SHIFT_RIGHT,
27 };
28 
29 enum charlcd_fontsize {
30 	CHARLCD_FONTSIZE_SMALL,
31 	CHARLCD_FONTSIZE_LARGE,
32 };
33 
34 enum charlcd_lines {
35 	CHARLCD_LINES_1,
36 	CHARLCD_LINES_2,
37 };
38 
39 struct charlcd {
40 	const struct charlcd_ops *ops;
41 	const unsigned char *char_conv;	/* Optional */
42 
43 	int height;
44 	int width;
45 
46 	/* Contains the LCD X and Y offset */
47 	struct {
48 		unsigned long x;
49 		unsigned long y;
50 	} addr;
51 
52 	void *drvdata;
53 };
54 
55 /**
56  * struct charlcd_ops - Functions used by charlcd. Drivers have to implement
57  * these.
58  * @backlight: Turn backlight on or off. Optional.
59  * @print: Print one character to the display at current cursor position.
60  * The buffered cursor position is advanced by charlcd. The cursor should not
61  * wrap to the next line at the end of a line.
62  * @gotoxy: Set cursor to x, y. The x and y values to set the cursor to are
63  * previously set in addr.x and addr.y by charlcd.
64  * @home: Set cursor to 0, 0. The values in addr.x and addr.y are set to 0, 0 by
65  * charlcd prior to calling this function.
66  * @clear_display: Clear the whole display and set the cursor to 0, 0. The
67  * values in addr.x and addr.y are set to 0, 0 by charlcd after to calling this
68  * function.
69  * @init_display: Initialize the display.
70  * @shift_cursor: Shift cursor left or right one position.
71  * @shift_display: Shift whole display content left or right.
72  * @display: Turn display on or off.
73  * @cursor: Turn cursor on or off.
74  * @blink: Turn cursor blink on or off.
75  * @lines: One or two lines.
76  * @redefine_char: Redefine the actual pixel matrix of character.
77  */
78 struct charlcd_ops {
79 	void (*backlight)(struct charlcd *lcd, enum charlcd_onoff on);
80 	int (*print)(struct charlcd *lcd, int c);
81 	int (*gotoxy)(struct charlcd *lcd, unsigned int x, unsigned int y);
82 	int (*home)(struct charlcd *lcd);
83 	int (*clear_display)(struct charlcd *lcd);
84 	int (*init_display)(struct charlcd *lcd);
85 	int (*shift_cursor)(struct charlcd *lcd, enum charlcd_shift_dir dir);
86 	int (*shift_display)(struct charlcd *lcd, enum charlcd_shift_dir dir);
87 	int (*display)(struct charlcd *lcd, enum charlcd_onoff on);
88 	int (*cursor)(struct charlcd *lcd, enum charlcd_onoff on);
89 	int (*blink)(struct charlcd *lcd, enum charlcd_onoff on);
90 	int (*fontsize)(struct charlcd *lcd, enum charlcd_fontsize size);
91 	int (*lines)(struct charlcd *lcd, enum charlcd_lines lines);
92 	int (*redefine_char)(struct charlcd *lcd, char *esc);
93 };
94 
95 void charlcd_backlight(struct charlcd *lcd, enum charlcd_onoff on);
96 struct charlcd *charlcd_alloc(void);
97 void charlcd_free(struct charlcd *lcd);
98 
99 int charlcd_register(struct charlcd *lcd);
100 int charlcd_unregister(struct charlcd *lcd);
101 
102 void charlcd_poke(struct charlcd *lcd);
103 
104 #endif /* CHARLCD_H */
105