xref: /openbmc/linux/drivers/video/fbdev/bt431.h (revision e29f0d55)
1 /*
2  *	linux/drivers/video/bt431.h
3  *
4  *	Copyright 2003  Thiemo Seufer <seufer@csv.ica.uni-stuttgart.de>
5  *	Copyright 2016  Maciej W. Rozycki <macro@linux-mips.org>
6  *
7  *	This file is subject to the terms and conditions of the GNU General
8  *	Public License. See the file COPYING in the main directory of this
9  *	archive for more details.
10  */
11 #include <linux/types.h>
12 
13 #define BT431_CURSOR_SIZE	64
14 
15 /*
16  * Bt431 cursor generator registers, 32-bit aligned.
17  * Two twin Bt431 are used on the DECstation's PMAG-AA.
18  */
19 struct bt431_regs {
20 	volatile u16 addr_lo;
21 	u16 pad0;
22 	volatile u16 addr_hi;
23 	u16 pad1;
24 	volatile u16 addr_cmap;
25 	u16 pad2;
26 	volatile u16 addr_reg;
27 	u16 pad3;
28 };
29 
bt431_set_value(u8 val)30 static inline u16 bt431_set_value(u8 val)
31 {
32 	return ((val << 8) | (val & 0xff)) & 0xffff;
33 }
34 
bt431_get_value(u16 val)35 static inline u8 bt431_get_value(u16 val)
36 {
37 	return val & 0xff;
38 }
39 
40 /*
41  * Additional registers addressed indirectly.
42  */
43 #define BT431_REG_CMD		0x0000
44 #define BT431_REG_CXLO		0x0001
45 #define BT431_REG_CXHI		0x0002
46 #define BT431_REG_CYLO		0x0003
47 #define BT431_REG_CYHI		0x0004
48 #define BT431_REG_WXLO		0x0005
49 #define BT431_REG_WXHI		0x0006
50 #define BT431_REG_WYLO		0x0007
51 #define BT431_REG_WYHI		0x0008
52 #define BT431_REG_WWLO		0x0009
53 #define BT431_REG_WWHI		0x000a
54 #define BT431_REG_WHLO		0x000b
55 #define BT431_REG_WHHI		0x000c
56 
57 #define BT431_REG_CRAM_BASE	0x0000
58 #define BT431_REG_CRAM_END	0x01ff
59 
60 /*
61  * Command register.
62  */
63 #define BT431_CMD_CURS_ENABLE	0x40
64 #define BT431_CMD_XHAIR_ENABLE	0x20
65 #define BT431_CMD_OR_CURSORS	0x10
66 #define BT431_CMD_XOR_CURSORS	0x00
67 #define BT431_CMD_1_1_MUX	0x00
68 #define BT431_CMD_4_1_MUX	0x04
69 #define BT431_CMD_5_1_MUX	0x08
70 #define BT431_CMD_xxx_MUX	0x0c
71 #define BT431_CMD_THICK_1	0x00
72 #define BT431_CMD_THICK_3	0x01
73 #define BT431_CMD_THICK_5	0x02
74 #define BT431_CMD_THICK_7	0x03
75 
bt431_select_reg(struct bt431_regs * regs,int ir)76 static inline void bt431_select_reg(struct bt431_regs *regs, int ir)
77 {
78 	/*
79 	 * The compiler splits the write in two bytes without these
80 	 * helper variables.
81 	 */
82 	volatile u16 *lo = &(regs->addr_lo);
83 	volatile u16 *hi = &(regs->addr_hi);
84 
85 	mb();
86 	*lo = bt431_set_value(ir & 0xff);
87 	wmb();
88 	*hi = bt431_set_value((ir >> 8) & 0xff);
89 }
90 
91 /* Autoincrement read/write. */
bt431_read_reg_inc(struct bt431_regs * regs)92 static inline u8 bt431_read_reg_inc(struct bt431_regs *regs)
93 {
94 	/*
95 	 * The compiler splits the write in two bytes without the
96 	 * helper variable.
97 	 */
98 	volatile u16 *r = &(regs->addr_reg);
99 
100 	mb();
101 	return bt431_get_value(*r);
102 }
103 
bt431_write_reg_inc(struct bt431_regs * regs,u8 value)104 static inline void bt431_write_reg_inc(struct bt431_regs *regs, u8 value)
105 {
106 	/*
107 	 * The compiler splits the write in two bytes without the
108 	 * helper variable.
109 	 */
110 	volatile u16 *r = &(regs->addr_reg);
111 
112 	mb();
113 	*r = bt431_set_value(value);
114 }
115 
bt431_read_reg(struct bt431_regs * regs,int ir)116 static inline u8 bt431_read_reg(struct bt431_regs *regs, int ir)
117 {
118 	bt431_select_reg(regs, ir);
119 	return bt431_read_reg_inc(regs);
120 }
121 
bt431_write_reg(struct bt431_regs * regs,int ir,u8 value)122 static inline void bt431_write_reg(struct bt431_regs *regs, int ir, u8 value)
123 {
124 	bt431_select_reg(regs, ir);
125 	bt431_write_reg_inc(regs, value);
126 }
127 
128 /* Autoincremented read/write for the cursor map. */
bt431_read_cmap_inc(struct bt431_regs * regs)129 static inline u16 bt431_read_cmap_inc(struct bt431_regs *regs)
130 {
131 	/*
132 	 * The compiler splits the write in two bytes without the
133 	 * helper variable.
134 	 */
135 	volatile u16 *r = &(regs->addr_cmap);
136 
137 	mb();
138 	return *r;
139 }
140 
bt431_write_cmap_inc(struct bt431_regs * regs,u16 value)141 static inline void bt431_write_cmap_inc(struct bt431_regs *regs, u16 value)
142 {
143 	/*
144 	 * The compiler splits the write in two bytes without the
145 	 * helper variable.
146 	 */
147 	volatile u16 *r = &(regs->addr_cmap);
148 
149 	mb();
150 	*r = value;
151 }
152 
bt431_read_cmap(struct bt431_regs * regs,int cr)153 static inline u16 bt431_read_cmap(struct bt431_regs *regs, int cr)
154 {
155 	bt431_select_reg(regs, cr);
156 	return bt431_read_cmap_inc(regs);
157 }
158 
bt431_write_cmap(struct bt431_regs * regs,int cr,u16 value)159 static inline void bt431_write_cmap(struct bt431_regs *regs, int cr, u16 value)
160 {
161 	bt431_select_reg(regs, cr);
162 	bt431_write_cmap_inc(regs, value);
163 }
164 
bt431_enable_cursor(struct bt431_regs * regs)165 static inline void bt431_enable_cursor(struct bt431_regs *regs)
166 {
167 	bt431_write_reg(regs, BT431_REG_CMD,
168 			BT431_CMD_CURS_ENABLE | BT431_CMD_OR_CURSORS
169 			| BT431_CMD_4_1_MUX | BT431_CMD_THICK_1);
170 }
171 
bt431_erase_cursor(struct bt431_regs * regs)172 static inline void bt431_erase_cursor(struct bt431_regs *regs)
173 {
174 	bt431_write_reg(regs, BT431_REG_CMD, BT431_CMD_4_1_MUX);
175 }
176 
bt431_position_cursor(struct bt431_regs * regs,u16 x,u16 y)177 static inline void bt431_position_cursor(struct bt431_regs *regs, u16 x, u16 y)
178 {
179 	/*
180 	 * Magic from the MACH sources.
181 	 *
182 	 * Cx = x + D + H - P
183 	 *  P = 37 if 1:1, 52 if 4:1, 57 if 5:1
184 	 *  D = pixel skew between outdata and external data
185 	 *  H = pixels between HSYNCH falling and active video
186 	 *
187 	 * Cy = y + V - 32
188 	 *  V = scanlines between HSYNCH falling, two or more
189 	 *      clocks after VSYNCH falling, and active video
190 	 */
191 	x += 412 - 52;
192 	y += 68 - 32;
193 
194 	/* Use autoincrement. */
195 	bt431_select_reg(regs, BT431_REG_CXLO);
196 	bt431_write_reg_inc(regs, x & 0xff); /* BT431_REG_CXLO */
197 	bt431_write_reg_inc(regs, (x >> 8) & 0x0f); /* BT431_REG_CXHI */
198 	bt431_write_reg_inc(regs, y & 0xff); /* BT431_REG_CYLO */
199 	bt431_write_reg_inc(regs, (y >> 8) & 0x0f); /* BT431_REG_CYHI */
200 }
201 
bt431_set_cursor(struct bt431_regs * regs,const char * data,const char * mask,u16 rop,u16 width,u16 height)202 static inline void bt431_set_cursor(struct bt431_regs *regs,
203 				    const char *data, const char *mask,
204 				    u16 rop, u16 width, u16 height)
205 {
206 	u16 x, y;
207 	int i;
208 
209 	i = 0;
210 	width = DIV_ROUND_UP(width, 8);
211 	bt431_select_reg(regs, BT431_REG_CRAM_BASE);
212 	for (y = 0; y < BT431_CURSOR_SIZE; y++)
213 		for (x = 0; x < BT431_CURSOR_SIZE / 8; x++) {
214 			u16 val = 0;
215 
216 			if (y < height && x < width) {
217 				val = mask[i];
218 				if (rop == ROP_XOR)
219 					val = (val << 8) | (val ^ data[i]);
220 				else
221 					val = (val << 8) | (val & data[i]);
222 				i++;
223 			}
224 			bt431_write_cmap_inc(regs, val);
225 		}
226 }
227 
bt431_init_cursor(struct bt431_regs * regs)228 static inline void bt431_init_cursor(struct bt431_regs *regs)
229 {
230 	/* no crosshair window */
231 	bt431_select_reg(regs, BT431_REG_WXLO);
232 	bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WXLO */
233 	bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WXHI */
234 	bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WYLO */
235 	bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WYHI */
236 	bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WWLO */
237 	bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WWHI */
238 	bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WHLO */
239 	bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WHHI */
240 }
241