xref: /linux/drivers/video/fbdev/geode/display_gx.c (revision e47a324d6f07c9ef252cfce1f14cfa5110cbed99)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Geode GX display controller.
4  *
5  *   Copyright (C) 2005 Arcom Control Systems Ltd.
6  *
7  *   Portions from AMD's original 2.4 driver:
8  *     Copyright (C) 2004 Advanced Micro Devices, Inc.
9  */
10 #include <linux/spinlock.h>
11 #include <linux/fb.h>
12 #include <linux/delay.h>
13 #include <asm/io.h>
14 #include <asm/div64.h>
15 #include <asm/delay.h>
16 #include <asm/msr.h>
17 #include <linux/cs5535.h>
18 
19 #include "gxfb.h"
20 
21 unsigned int gx_frame_buffer_size(void)
22 {
23 	unsigned int val;
24 
25 	if (!cs5535_has_vsa2()) {
26 		uint32_t hi, lo;
27 
28 		/* The number of pages is (PMAX - PMIN)+1 */
29 		rdmsr(MSR_GLIU_P2D_RO0, lo, hi);
30 
31 		/* PMAX */
32 		val = ((hi & 0xff) << 12) | ((lo & 0xfff00000) >> 20);
33 		/* PMIN */
34 		val -= (lo & 0x000fffff);
35 		val += 1;
36 
37 		/* The page size is 4k */
38 		return (val << 12);
39 	}
40 
41 	/* FB size can be obtained from the VSA II */
42 	/* Virtual register class = 0x02 */
43 	/* VG_MEM_SIZE(512Kb units) = 0x00 */
44 
45 	outw(VSA_VR_UNLOCK, VSA_VRC_INDEX);
46 	outw(VSA_VR_MEM_SIZE, VSA_VRC_INDEX);
47 
48 	val = (unsigned int)(inw(VSA_VRC_DATA)) & 0xFFl;
49 	return (val << 19);
50 }
51 
52 int gx_line_delta(int xres, int bpp)
53 {
54 	/* Must be a multiple of 8 bytes. */
55 	return (xres * (bpp >> 3) + 7) & ~0x7;
56 }
57 
58 void gx_set_mode(struct fb_info *info)
59 {
60 	struct gxfb_par *par = info->par;
61 	u32 gcfg, dcfg;
62 	int hactive, hblankstart, hsyncstart, hsyncend, hblankend, htotal;
63 	int vactive, vblankstart, vsyncstart, vsyncend, vblankend, vtotal;
64 
65 	/* Unlock the display controller registers. */
66 	write_dc(par, DC_UNLOCK, DC_UNLOCK_UNLOCK);
67 
68 	gcfg = read_dc(par, DC_GENERAL_CFG);
69 	dcfg = read_dc(par, DC_DISPLAY_CFG);
70 
71 	/* Disable the timing generator. */
72 	dcfg &= ~DC_DISPLAY_CFG_TGEN;
73 	write_dc(par, DC_DISPLAY_CFG, dcfg);
74 
75 	/* Wait for pending memory requests before disabling the FIFO load. */
76 	udelay(100);
77 
78 	/* Disable FIFO load and compression. */
79 	gcfg &= ~(DC_GENERAL_CFG_DFLE | DC_GENERAL_CFG_CMPE |
80 			DC_GENERAL_CFG_DECE);
81 	write_dc(par, DC_GENERAL_CFG, gcfg);
82 
83 	/* Setup DCLK and its divisor. */
84 	gx_set_dclk_frequency(info);
85 
86 	/*
87 	 * Setup new mode.
88 	 */
89 
90 	/* Clear all unused feature bits. */
91 	gcfg &= DC_GENERAL_CFG_YUVM | DC_GENERAL_CFG_VDSE;
92 	dcfg = 0;
93 
94 	/* Set FIFO priority (default 6/5) and enable. */
95 	/* FIXME: increase fifo priority for 1280x1024 and higher modes? */
96 	gcfg |= (6 << DC_GENERAL_CFG_DFHPEL_SHIFT) |
97 		(5 << DC_GENERAL_CFG_DFHPSL_SHIFT) | DC_GENERAL_CFG_DFLE;
98 
99 	/* Framebuffer start offset. */
100 	write_dc(par, DC_FB_ST_OFFSET, 0);
101 
102 	/* Line delta and line buffer length. */
103 	write_dc(par, DC_GFX_PITCH, info->fix.line_length >> 3);
104 	write_dc(par, DC_LINE_SIZE,
105 		((info->var.xres * info->var.bits_per_pixel/8) >> 3) + 2);
106 
107 
108 	/* Enable graphics and video data and unmask address lines. */
109 	dcfg |= DC_DISPLAY_CFG_GDEN | DC_DISPLAY_CFG_VDEN |
110 		DC_DISPLAY_CFG_A20M | DC_DISPLAY_CFG_A18M;
111 
112 	/* Set pixel format. */
113 	switch (info->var.bits_per_pixel) {
114 	case 8:
115 		dcfg |= DC_DISPLAY_CFG_DISP_MODE_8BPP;
116 		break;
117 	case 16:
118 		dcfg |= DC_DISPLAY_CFG_DISP_MODE_16BPP;
119 		break;
120 	case 32:
121 		dcfg |= DC_DISPLAY_CFG_DISP_MODE_24BPP;
122 		dcfg |= DC_DISPLAY_CFG_PALB;
123 		break;
124 	}
125 
126 	/* Enable timing generator. */
127 	dcfg |= DC_DISPLAY_CFG_TGEN;
128 
129 	/* Horizontal and vertical timings. */
130 	hactive = info->var.xres;
131 	hblankstart = hactive;
132 	hsyncstart = hblankstart + info->var.right_margin;
133 	hsyncend =  hsyncstart + info->var.hsync_len;
134 	hblankend = hsyncend + info->var.left_margin;
135 	htotal = hblankend;
136 
137 	vactive = info->var.yres;
138 	vblankstart = vactive;
139 	vsyncstart = vblankstart + info->var.lower_margin;
140 	vsyncend =  vsyncstart + info->var.vsync_len;
141 	vblankend = vsyncend + info->var.upper_margin;
142 	vtotal = vblankend;
143 
144 	write_dc(par, DC_H_ACTIVE_TIMING, (hactive - 1)    |
145 			((htotal - 1) << 16));
146 	write_dc(par, DC_H_BLANK_TIMING, (hblankstart - 1) |
147 			((hblankend - 1) << 16));
148 	write_dc(par, DC_H_SYNC_TIMING, (hsyncstart - 1)   |
149 			((hsyncend - 1) << 16));
150 
151 	write_dc(par, DC_V_ACTIVE_TIMING, (vactive - 1)    |
152 			((vtotal - 1) << 16));
153 	write_dc(par, DC_V_BLANK_TIMING, (vblankstart - 1) |
154 			((vblankend - 1) << 16));
155 	write_dc(par, DC_V_SYNC_TIMING, (vsyncstart - 1)   |
156 			((vsyncend - 1) << 16));
157 
158 	/* Write final register values. */
159 	write_dc(par, DC_DISPLAY_CFG, dcfg);
160 	write_dc(par, DC_GENERAL_CFG, gcfg);
161 
162 	gx_configure_display(info);
163 
164 	/* Relock display controller registers */
165 	write_dc(par, DC_UNLOCK, DC_UNLOCK_LOCK);
166 }
167 
168 void gx_set_hw_palette_reg(struct fb_info *info, unsigned regno,
169 		unsigned red, unsigned green, unsigned blue)
170 {
171 	struct gxfb_par *par = info->par;
172 	int val;
173 
174 	/* Hardware palette is in RGB 8-8-8 format. */
175 	val  = (red   << 8) & 0xff0000;
176 	val |= (green)      & 0x00ff00;
177 	val |= (blue  >> 8) & 0x0000ff;
178 
179 	write_dc(par, DC_PAL_ADDRESS, regno);
180 	write_dc(par, DC_PAL_DATA, val);
181 }
182