xref: /linux/drivers/video/fbdev/kyro/STG4000Ramdac.c (revision 48dea9a700c8728cc31a1dd44588b97578de86ee)
1 /*
2  *  linux/drivers/video/kyro/STG4000Ramdac.c
3  *
4  *  Copyright (C) 2002 STMicroelectronics
5  *
6  * This file is subject to the terms and conditions of the GNU General Public
7  * License.  See the file COPYING in the main directory of this archive
8  * for more details.
9  */
10 
11 #include <linux/kernel.h>
12 #include <linux/errno.h>
13 #include <linux/types.h>
14 #include <video/kyro.h>
15 
16 #include "STG4000Reg.h"
17 #include "STG4000Interface.h"
18 
19 static u32 STG_PIXEL_BUS_WIDTH = 128;	/* 128 bit bus width      */
20 static u32 REF_CLOCK = 14318;
21 
22 int InitialiseRamdac(volatile STG4000REG __iomem * pSTGReg,
23 		     u32 displayDepth,
24 		     u32 displayWidth,
25 		     u32 displayHeight,
26 		     s32 HSyncPolarity,
27 		     s32 VSyncPolarity, u32 * pixelClock)
28 {
29 	u32 tmp = 0;
30 	u32 F = 0, R = 0, P = 0;
31 	u32 stride = 0;
32 	u32 ulPdiv = 0;
33 	u32 physicalPixelDepth = 0;
34 	/* Make sure DAC is in Reset */
35 	tmp = STG_READ_REG(SoftwareReset);
36 
37 	if (tmp & 0x1) {
38 		CLEAR_BIT(1);
39 		STG_WRITE_REG(SoftwareReset, tmp);
40 	}
41 
42 	/* Set Pixel Format */
43 	tmp = STG_READ_REG(DACPixelFormat);
44 	CLEAR_BITS_FRM_TO(0, 2);
45 
46 	/* Set LUT not used from 16bpp to 32 bpp ??? */
47 	CLEAR_BITS_FRM_TO(8, 9);
48 
49 	switch (displayDepth) {
50 	case 16:
51 		{
52 			physicalPixelDepth = 16;
53 			tmp |= _16BPP;
54 			break;
55 		}
56 	case 32:
57 		{
58 			/* Set for 32 bits per pixel */
59 			physicalPixelDepth = 32;
60 			tmp |= _32BPP;
61 			break;
62 		}
63 	default:
64 		return -EINVAL;
65 	}
66 
67 	STG_WRITE_REG(DACPixelFormat, tmp);
68 
69 	/* Workout Bus transfer bandwidth according to pixel format */
70 	ulPdiv = STG_PIXEL_BUS_WIDTH / physicalPixelDepth;
71 
72 	/* Get Screen Stride in pixels */
73 	stride = displayWidth;
74 
75 	/* Set Primary size info */
76 	tmp = STG_READ_REG(DACPrimSize);
77 	CLEAR_BITS_FRM_TO(0, 10);
78 	CLEAR_BITS_FRM_TO(12, 31);
79 	tmp |=
80 	    ((((displayHeight - 1) << 12) | (((displayWidth / ulPdiv) -
81 					      1) << 23))
82 	     | (stride / ulPdiv));
83 	STG_WRITE_REG(DACPrimSize, tmp);
84 
85 
86 	/* Set Pixel Clock */
87 	*pixelClock = ProgramClock(REF_CLOCK, *pixelClock, &F, &R, &P);
88 
89 	/* Set DAC PLL Mode */
90 	tmp = STG_READ_REG(DACPLLMode);
91 	CLEAR_BITS_FRM_TO(0, 15);
92 	/* tmp |= ((P-1) | ((F-2) << 2) | ((R-2) << 11)); */
93 	tmp |= ((P) | ((F - 2) << 2) | ((R - 2) << 11));
94 	STG_WRITE_REG(DACPLLMode, tmp);
95 
96 	/* Set Prim Address */
97 	tmp = STG_READ_REG(DACPrimAddress);
98 	CLEAR_BITS_FRM_TO(0, 20);
99 	CLEAR_BITS_FRM_TO(20, 31);
100 	STG_WRITE_REG(DACPrimAddress, tmp);
101 
102 	/* Set Cursor details with HW Cursor disabled */
103 	tmp = STG_READ_REG(DACCursorCtrl);
104 	tmp &= ~SET_BIT(31);
105 	STG_WRITE_REG(DACCursorCtrl, tmp);
106 
107 	tmp = STG_READ_REG(DACCursorAddr);
108 	CLEAR_BITS_FRM_TO(0, 20);
109 	STG_WRITE_REG(DACCursorAddr, tmp);
110 
111 	/* Set Video Window */
112 	tmp = STG_READ_REG(DACVidWinStart);
113 	CLEAR_BITS_FRM_TO(0, 10);
114 	CLEAR_BITS_FRM_TO(16, 26);
115 	STG_WRITE_REG(DACVidWinStart, tmp);
116 
117 	tmp = STG_READ_REG(DACVidWinEnd);
118 	CLEAR_BITS_FRM_TO(0, 10);
119 	CLEAR_BITS_FRM_TO(16, 26);
120 	STG_WRITE_REG(DACVidWinEnd, tmp);
121 
122 	/* Set DAC Border Color to default */
123 	tmp = STG_READ_REG(DACBorderColor);
124 	CLEAR_BITS_FRM_TO(0, 23);
125 	STG_WRITE_REG(DACBorderColor, tmp);
126 
127 	/* Set Graphics and Overlay Burst Control */
128 	STG_WRITE_REG(DACBurstCtrl, 0x0404);
129 
130 	/* Set CRC Trigger to default */
131 	tmp = STG_READ_REG(DACCrcTrigger);
132 	CLEAR_BIT(0);
133 	STG_WRITE_REG(DACCrcTrigger, tmp);
134 
135 	/* Set Video Port Control to default */
136 	tmp = STG_READ_REG(DigVidPortCtrl);
137 	CLEAR_BIT(8);
138 	CLEAR_BITS_FRM_TO(16, 27);
139 	CLEAR_BITS_FRM_TO(1, 3);
140 	CLEAR_BITS_FRM_TO(10, 11);
141 	STG_WRITE_REG(DigVidPortCtrl, tmp);
142 
143 	return 0;
144 }
145 
146 /* Ramdac control, turning output to the screen on and off */
147 void DisableRamdacOutput(volatile STG4000REG __iomem * pSTGReg)
148 {
149 	u32 tmp;
150 
151 	/* Disable DAC for Graphics Stream Control */
152 	tmp = (STG_READ_REG(DACStreamCtrl)) & ~SET_BIT(0);
153 	STG_WRITE_REG(DACStreamCtrl, tmp);
154 }
155 
156 void EnableRamdacOutput(volatile STG4000REG __iomem * pSTGReg)
157 {
158 	u32 tmp;
159 
160 	/* Enable DAC for Graphics Stream Control */
161 	tmp = (STG_READ_REG(DACStreamCtrl)) | SET_BIT(0);
162 	STG_WRITE_REG(DACStreamCtrl, tmp);
163 }
164