b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame^] | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
| 2 | /* |
| 3 | * bcu.c, Bus Control Unit routines for the NEC VR4100 series. |
| 4 | * |
| 5 | * Copyright (C) 2002 MontaVista Software Inc. |
| 6 | * Author: Yoichi Yuasa <source@mvista.com> |
| 7 | * Copyright (C) 2003-2005 Yoichi Yuasa <yuasa@linux-mips.org> |
| 8 | */ |
| 9 | /* |
| 10 | * Changes: |
| 11 | * MontaVista Software Inc. <source@mvista.com> |
| 12 | * - New creation, NEC VR4122 and VR4131 are supported. |
| 13 | * - Added support for NEC VR4111 and VR4121. |
| 14 | * |
| 15 | * Yoichi Yuasa <yuasa@linux-mips.org> |
| 16 | * - Added support for NEC VR4133. |
| 17 | */ |
| 18 | #include <linux/export.h> |
| 19 | #include <linux/kernel.h> |
| 20 | #include <linux/smp.h> |
| 21 | #include <linux/types.h> |
| 22 | |
| 23 | #include <asm/cpu-type.h> |
| 24 | #include <asm/cpu.h> |
| 25 | #include <asm/io.h> |
| 26 | |
| 27 | #define CLKSPEEDREG_TYPE1 (void __iomem *)KSEG1ADDR(0x0b000014) |
| 28 | #define CLKSPEEDREG_TYPE2 (void __iomem *)KSEG1ADDR(0x0f000014) |
| 29 | #define CLKSP(x) ((x) & 0x001f) |
| 30 | #define CLKSP_VR4133(x) ((x) & 0x0007) |
| 31 | |
| 32 | #define DIV2B 0x8000 |
| 33 | #define DIV3B 0x4000 |
| 34 | #define DIV4B 0x2000 |
| 35 | |
| 36 | #define DIVT(x) (((x) & 0xf000) >> 12) |
| 37 | #define DIVVT(x) (((x) & 0x0f00) >> 8) |
| 38 | |
| 39 | #define TDIVMODE(x) (2 << (((x) & 0x1000) >> 12)) |
| 40 | #define VTDIVMODE(x) (((x) & 0x0700) >> 8) |
| 41 | |
| 42 | static unsigned long vr41xx_vtclock; |
| 43 | static unsigned long vr41xx_tclock; |
| 44 | |
| 45 | unsigned long vr41xx_get_vtclock_frequency(void) |
| 46 | { |
| 47 | return vr41xx_vtclock; |
| 48 | } |
| 49 | |
| 50 | EXPORT_SYMBOL_GPL(vr41xx_get_vtclock_frequency); |
| 51 | |
| 52 | unsigned long vr41xx_get_tclock_frequency(void) |
| 53 | { |
| 54 | return vr41xx_tclock; |
| 55 | } |
| 56 | |
| 57 | EXPORT_SYMBOL_GPL(vr41xx_get_tclock_frequency); |
| 58 | |
| 59 | static inline uint16_t read_clkspeed(void) |
| 60 | { |
| 61 | switch (current_cpu_type()) { |
| 62 | case CPU_VR4111: |
| 63 | case CPU_VR4121: return readw(CLKSPEEDREG_TYPE1); |
| 64 | case CPU_VR4122: |
| 65 | case CPU_VR4131: |
| 66 | case CPU_VR4133: return readw(CLKSPEEDREG_TYPE2); |
| 67 | default: |
| 68 | printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n"); |
| 69 | break; |
| 70 | } |
| 71 | |
| 72 | return 0; |
| 73 | } |
| 74 | |
| 75 | static inline unsigned long calculate_pclock(uint16_t clkspeed) |
| 76 | { |
| 77 | unsigned long pclock = 0; |
| 78 | |
| 79 | switch (current_cpu_type()) { |
| 80 | case CPU_VR4111: |
| 81 | case CPU_VR4121: |
| 82 | pclock = 18432000 * 64; |
| 83 | pclock /= CLKSP(clkspeed); |
| 84 | break; |
| 85 | case CPU_VR4122: |
| 86 | pclock = 18432000 * 98; |
| 87 | pclock /= CLKSP(clkspeed); |
| 88 | break; |
| 89 | case CPU_VR4131: |
| 90 | pclock = 18432000 * 108; |
| 91 | pclock /= CLKSP(clkspeed); |
| 92 | break; |
| 93 | case CPU_VR4133: |
| 94 | switch (CLKSP_VR4133(clkspeed)) { |
| 95 | case 0: |
| 96 | pclock = 133000000; |
| 97 | break; |
| 98 | case 1: |
| 99 | pclock = 149000000; |
| 100 | break; |
| 101 | case 2: |
| 102 | pclock = 165900000; |
| 103 | break; |
| 104 | case 3: |
| 105 | pclock = 199100000; |
| 106 | break; |
| 107 | case 4: |
| 108 | pclock = 265900000; |
| 109 | break; |
| 110 | default: |
| 111 | printk(KERN_INFO "Unknown PClock speed for NEC VR4133\n"); |
| 112 | break; |
| 113 | } |
| 114 | break; |
| 115 | default: |
| 116 | printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n"); |
| 117 | break; |
| 118 | } |
| 119 | |
| 120 | printk(KERN_INFO "PClock: %ldHz\n", pclock); |
| 121 | |
| 122 | return pclock; |
| 123 | } |
| 124 | |
| 125 | static inline unsigned long calculate_vtclock(uint16_t clkspeed, unsigned long pclock) |
| 126 | { |
| 127 | unsigned long vtclock = 0; |
| 128 | |
| 129 | switch (current_cpu_type()) { |
| 130 | case CPU_VR4111: |
| 131 | /* The NEC VR4111 doesn't have the VTClock. */ |
| 132 | break; |
| 133 | case CPU_VR4121: |
| 134 | vtclock = pclock; |
| 135 | /* DIVVT == 9 Divide by 1.5 . VTClock = (PClock * 6) / 9 */ |
| 136 | if (DIVVT(clkspeed) == 9) |
| 137 | vtclock = pclock * 6; |
| 138 | /* DIVVT == 10 Divide by 2.5 . VTClock = (PClock * 4) / 10 */ |
| 139 | else if (DIVVT(clkspeed) == 10) |
| 140 | vtclock = pclock * 4; |
| 141 | vtclock /= DIVVT(clkspeed); |
| 142 | printk(KERN_INFO "VTClock: %ldHz\n", vtclock); |
| 143 | break; |
| 144 | case CPU_VR4122: |
| 145 | if(VTDIVMODE(clkspeed) == 7) |
| 146 | vtclock = pclock / 1; |
| 147 | else if(VTDIVMODE(clkspeed) == 1) |
| 148 | vtclock = pclock / 2; |
| 149 | else |
| 150 | vtclock = pclock / VTDIVMODE(clkspeed); |
| 151 | printk(KERN_INFO "VTClock: %ldHz\n", vtclock); |
| 152 | break; |
| 153 | case CPU_VR4131: |
| 154 | case CPU_VR4133: |
| 155 | vtclock = pclock / VTDIVMODE(clkspeed); |
| 156 | printk(KERN_INFO "VTClock: %ldHz\n", vtclock); |
| 157 | break; |
| 158 | default: |
| 159 | printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n"); |
| 160 | break; |
| 161 | } |
| 162 | |
| 163 | return vtclock; |
| 164 | } |
| 165 | |
| 166 | static inline unsigned long calculate_tclock(uint16_t clkspeed, unsigned long pclock, |
| 167 | unsigned long vtclock) |
| 168 | { |
| 169 | unsigned long tclock = 0; |
| 170 | |
| 171 | switch (current_cpu_type()) { |
| 172 | case CPU_VR4111: |
| 173 | if (!(clkspeed & DIV2B)) |
| 174 | tclock = pclock / 2; |
| 175 | else if (!(clkspeed & DIV3B)) |
| 176 | tclock = pclock / 3; |
| 177 | else if (!(clkspeed & DIV4B)) |
| 178 | tclock = pclock / 4; |
| 179 | break; |
| 180 | case CPU_VR4121: |
| 181 | tclock = pclock / DIVT(clkspeed); |
| 182 | break; |
| 183 | case CPU_VR4122: |
| 184 | case CPU_VR4131: |
| 185 | case CPU_VR4133: |
| 186 | tclock = vtclock / TDIVMODE(clkspeed); |
| 187 | break; |
| 188 | default: |
| 189 | printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n"); |
| 190 | break; |
| 191 | } |
| 192 | |
| 193 | printk(KERN_INFO "TClock: %ldHz\n", tclock); |
| 194 | |
| 195 | return tclock; |
| 196 | } |
| 197 | |
| 198 | void vr41xx_calculate_clock_frequency(void) |
| 199 | { |
| 200 | unsigned long pclock; |
| 201 | uint16_t clkspeed; |
| 202 | |
| 203 | clkspeed = read_clkspeed(); |
| 204 | |
| 205 | pclock = calculate_pclock(clkspeed); |
| 206 | vr41xx_vtclock = calculate_vtclock(clkspeed, pclock); |
| 207 | vr41xx_tclock = calculate_tclock(clkspeed, pclock, vr41xx_vtclock); |
| 208 | } |
| 209 | |
| 210 | EXPORT_SYMBOL_GPL(vr41xx_calculate_clock_frequency); |