xref: /openbmc/linux/drivers/video/fbdev/bt455.h (revision d2168146)
1 /*
2  *	linux/drivers/video/bt455.h
3  *
4  *	Copyright 2003  Thiemo Seufer <seufer@csv.ica.uni-stuttgart.de>
5  *
6  *	This file is subject to the terms and conditions of the GNU General
7  *	Public License. See the file COPYING in the main directory of this
8  *	archive for more details.
9  */
10 #include <linux/types.h>
11 
12 /*
13  * Bt455 byte-wide registers, 32-bit aligned.
14  */
15 struct bt455_regs {
16 	volatile u8 addr_cmap;
17 	u8 pad0[3];
18 	volatile u8 addr_cmap_data;
19 	u8 pad1[3];
20 	volatile u8 addr_clr;
21 	u8 pad2[3];
22 	volatile u8 addr_ovly;
23 	u8 pad3[3];
24 };
25 
26 static inline void bt455_select_reg(struct bt455_regs *regs, int ir)
27 {
28 	mb();
29 	regs->addr_cmap = ir & 0x0f;
30 }
31 
32 /*
33  * Read/write to a Bt455 color map register.
34  */
35 static inline void bt455_read_cmap_entry(struct bt455_regs *regs, int cr,
36 					 u8* red, u8* green, u8* blue)
37 {
38 	bt455_select_reg(regs, cr);
39 	mb();
40 	*red = regs->addr_cmap_data & 0x0f;
41 	rmb();
42 	*green = regs->addr_cmap_data & 0x0f;
43 	rmb();
44 	*blue = regs->addr_cmap_data & 0x0f;
45 }
46 
47 static inline void bt455_write_cmap_entry(struct bt455_regs *regs, int cr,
48 					  u8 red, u8 green, u8 blue)
49 {
50 	bt455_select_reg(regs, cr);
51 	wmb();
52 	regs->addr_cmap_data = red & 0x0f;
53 	wmb();
54 	regs->addr_cmap_data = green & 0x0f;
55 	wmb();
56 	regs->addr_cmap_data = blue & 0x0f;
57 }
58 
59 static inline void bt455_write_ovly_entry(struct bt455_regs *regs, int cr,
60 					  u8 red, u8 green, u8 blue)
61 {
62 	bt455_select_reg(regs, cr);
63 	wmb();
64 	regs->addr_ovly = red & 0x0f;
65 	wmb();
66 	regs->addr_ovly = green & 0x0f;
67 	wmb();
68 	regs->addr_ovly = blue & 0x0f;
69 }
70 
71 static inline void bt455_set_cursor(struct bt455_regs *regs)
72 {
73 	mb();
74 	regs->addr_ovly = 0x0f;
75 	wmb();
76 	regs->addr_ovly = 0x0f;
77 	wmb();
78 	regs->addr_ovly = 0x0f;
79 }
80 
81 static inline void bt455_erase_cursor(struct bt455_regs *regs)
82 {
83 	/* bt455_write_cmap_entry(regs, 8, 0x00, 0x00, 0x00); */
84 	/* bt455_write_cmap_entry(regs, 9, 0x00, 0x00, 0x00); */
85 	bt455_write_ovly_entry(regs, 8, 0x03, 0x03, 0x03);
86 	bt455_write_ovly_entry(regs, 9, 0x07, 0x07, 0x07);
87 
88 	wmb();
89 	regs->addr_ovly = 0x09;
90 	wmb();
91 	regs->addr_ovly = 0x09;
92 	wmb();
93 	regs->addr_ovly = 0x09;
94 }
95