1 /*
2 * bcu.c, Bus Control Unit routines for the NEC VR4100 series.
3 *
4 * Copyright (C) 2002 MontaVista Software Inc.
5 * Author: Yoichi Yuasa <yyuasa@mvista.com, or source@mvista.com>
6 * Copyright (C) 2003-2005 Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 */
22 /*
23 * Changes:
24 * MontaVista Software Inc. <yyuasa@mvista.com> or <source@mvista.com>
25 * - New creation, NEC VR4122 and VR4131 are supported.
26 * - Added support for NEC VR4111 and VR4121.
27 *
28 * Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
29 * - Added support for NEC VR4133.
30 */
31 #include <linux/kernel.h>
32 #include <linux/module.h>
33 #include <linux/smp.h>
34 #include <linux/types.h>
35
36 #include <asm/cpu.h>
37 #include <asm/io.h>
38
39 #define CLKSPEEDREG_TYPE1 (void __iomem *)KSEG1ADDR(0x0b000014)
40 #define CLKSPEEDREG_TYPE2 (void __iomem *)KSEG1ADDR(0x0f000014)
41 #define CLKSP(x) ((x) & 0x001f)
42 #define CLKSP_VR4133(x) ((x) & 0x0007)
43
44 #define DIV2B 0x8000
45 #define DIV3B 0x4000
46 #define DIV4B 0x2000
47
48 #define DIVT(x) (((x) & 0xf000) >> 12)
49 #define DIVVT(x) (((x) & 0x0f00) >> 8)
50
51 #define TDIVMODE(x) (2 << (((x) & 0x1000) >> 12))
52 #define VTDIVMODE(x) (((x) & 0x0700) >> 8)
53
54 static unsigned long vr41xx_vtclock;
55 static unsigned long vr41xx_tclock;
56
vr41xx_get_vtclock_frequency(void)57 unsigned long vr41xx_get_vtclock_frequency(void)
58 {
59 return vr41xx_vtclock;
60 }
61
62 EXPORT_SYMBOL_GPL(vr41xx_get_vtclock_frequency);
63
vr41xx_get_tclock_frequency(void)64 unsigned long vr41xx_get_tclock_frequency(void)
65 {
66 return vr41xx_tclock;
67 }
68
69 EXPORT_SYMBOL_GPL(vr41xx_get_tclock_frequency);
70
read_clkspeed(void)71 static inline uint16_t read_clkspeed(void)
72 {
73 switch (current_cpu_type()) {
74 case CPU_VR4111:
75 case CPU_VR4121: return readw(CLKSPEEDREG_TYPE1);
76 case CPU_VR4122:
77 case CPU_VR4131:
78 case CPU_VR4133: return readw(CLKSPEEDREG_TYPE2);
79 default:
80 printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
81 break;
82 }
83
84 return 0;
85 }
86
calculate_pclock(uint16_t clkspeed)87 static inline unsigned long calculate_pclock(uint16_t clkspeed)
88 {
89 unsigned long pclock = 0;
90
91 switch (current_cpu_type()) {
92 case CPU_VR4111:
93 case CPU_VR4121:
94 pclock = 18432000 * 64;
95 pclock /= CLKSP(clkspeed);
96 break;
97 case CPU_VR4122:
98 pclock = 18432000 * 98;
99 pclock /= CLKSP(clkspeed);
100 break;
101 case CPU_VR4131:
102 pclock = 18432000 * 108;
103 pclock /= CLKSP(clkspeed);
104 break;
105 case CPU_VR4133:
106 switch (CLKSP_VR4133(clkspeed)) {
107 case 0:
108 pclock = 133000000;
109 break;
110 case 1:
111 pclock = 149000000;
112 break;
113 case 2:
114 pclock = 165900000;
115 break;
116 case 3:
117 pclock = 199100000;
118 break;
119 case 4:
120 pclock = 265900000;
121 break;
122 default:
123 printk(KERN_INFO "Unknown PClock speed for NEC VR4133\n");
124 break;
125 }
126 break;
127 default:
128 printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
129 break;
130 }
131
132 printk(KERN_INFO "PClock: %ldHz\n", pclock);
133
134 return pclock;
135 }
136
calculate_vtclock(uint16_t clkspeed,unsigned long pclock)137 static inline unsigned long calculate_vtclock(uint16_t clkspeed, unsigned long pclock)
138 {
139 unsigned long vtclock = 0;
140
141 switch (current_cpu_type()) {
142 case CPU_VR4111:
143 /* The NEC VR4111 doesn't have the VTClock. */
144 break;
145 case CPU_VR4121:
146 vtclock = pclock;
147 /* DIVVT == 9 Divide by 1.5 . VTClock = (PClock * 6) / 9 */
148 if (DIVVT(clkspeed) == 9)
149 vtclock = pclock * 6;
150 /* DIVVT == 10 Divide by 2.5 . VTClock = (PClock * 4) / 10 */
151 else if (DIVVT(clkspeed) == 10)
152 vtclock = pclock * 4;
153 vtclock /= DIVVT(clkspeed);
154 printk(KERN_INFO "VTClock: %ldHz\n", vtclock);
155 break;
156 case CPU_VR4122:
157 if(VTDIVMODE(clkspeed) == 7)
158 vtclock = pclock / 1;
159 else if(VTDIVMODE(clkspeed) == 1)
160 vtclock = pclock / 2;
161 else
162 vtclock = pclock / VTDIVMODE(clkspeed);
163 printk(KERN_INFO "VTClock: %ldHz\n", vtclock);
164 break;
165 case CPU_VR4131:
166 case CPU_VR4133:
167 vtclock = pclock / VTDIVMODE(clkspeed);
168 printk(KERN_INFO "VTClock: %ldHz\n", vtclock);
169 break;
170 default:
171 printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
172 break;
173 }
174
175 return vtclock;
176 }
177
calculate_tclock(uint16_t clkspeed,unsigned long pclock,unsigned long vtclock)178 static inline unsigned long calculate_tclock(uint16_t clkspeed, unsigned long pclock,
179 unsigned long vtclock)
180 {
181 unsigned long tclock = 0;
182
183 switch (current_cpu_type()) {
184 case CPU_VR4111:
185 if (!(clkspeed & DIV2B))
186 tclock = pclock / 2;
187 else if (!(clkspeed & DIV3B))
188 tclock = pclock / 3;
189 else if (!(clkspeed & DIV4B))
190 tclock = pclock / 4;
191 break;
192 case CPU_VR4121:
193 tclock = pclock / DIVT(clkspeed);
194 break;
195 case CPU_VR4122:
196 case CPU_VR4131:
197 case CPU_VR4133:
198 tclock = vtclock / TDIVMODE(clkspeed);
199 break;
200 default:
201 printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
202 break;
203 }
204
205 printk(KERN_INFO "TClock: %ldHz\n", tclock);
206
207 return tclock;
208 }
209
vr41xx_calculate_clock_frequency(void)210 void vr41xx_calculate_clock_frequency(void)
211 {
212 unsigned long pclock;
213 uint16_t clkspeed;
214
215 clkspeed = read_clkspeed();
216
217 pclock = calculate_pclock(clkspeed);
218 vr41xx_vtclock = calculate_vtclock(clkspeed, pclock);
219 vr41xx_tclock = calculate_tclock(clkspeed, pclock, vr41xx_vtclock);
220 }
221
222 EXPORT_SYMBOL_GPL(vr41xx_calculate_clock_frequency);
223