1 /* 2 * Copyright (C) 2008 Marvell International Ltd. 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License as published by 6 * the Free Software Foundation; either version 2 of the License, or 7 * (at your option) any later version. 8 */ 9 10 #include <linux/kernel.h> 11 #include <linux/module.h> 12 #include <linux/sched.h> 13 #include <linux/init.h> 14 #include <linux/cpufreq.h> 15 #include <linux/slab.h> 16 #include <linux/io.h> 17 18 #include <mach/generic.h> 19 #include <mach/pxa3xx-regs.h> 20 21 #define HSS_104M (0) 22 #define HSS_156M (1) 23 #define HSS_208M (2) 24 #define HSS_312M (3) 25 26 #define SMCFS_78M (0) 27 #define SMCFS_104M (2) 28 #define SMCFS_208M (5) 29 30 #define SFLFS_104M (0) 31 #define SFLFS_156M (1) 32 #define SFLFS_208M (2) 33 #define SFLFS_312M (3) 34 35 #define XSPCLK_156M (0) 36 #define XSPCLK_NONE (3) 37 38 #define DMCFS_26M (0) 39 #define DMCFS_260M (3) 40 41 struct pxa3xx_freq_info { 42 unsigned int cpufreq_mhz; 43 unsigned int core_xl : 5; 44 unsigned int core_xn : 3; 45 unsigned int hss : 2; 46 unsigned int dmcfs : 2; 47 unsigned int smcfs : 3; 48 unsigned int sflfs : 2; 49 unsigned int df_clkdiv : 3; 50 51 int vcc_core; /* in mV */ 52 int vcc_sram; /* in mV */ 53 }; 54 55 #define OP(cpufreq, _xl, _xn, _hss, _dmc, _smc, _sfl, _dfi, vcore, vsram) \ 56 { \ 57 .cpufreq_mhz = cpufreq, \ 58 .core_xl = _xl, \ 59 .core_xn = _xn, \ 60 .hss = HSS_##_hss##M, \ 61 .dmcfs = DMCFS_##_dmc##M, \ 62 .smcfs = SMCFS_##_smc##M, \ 63 .sflfs = SFLFS_##_sfl##M, \ 64 .df_clkdiv = _dfi, \ 65 .vcc_core = vcore, \ 66 .vcc_sram = vsram, \ 67 } 68 69 static struct pxa3xx_freq_info pxa300_freqs[] = { 70 /* CPU XL XN HSS DMEM SMEM SRAM DFI VCC_CORE VCC_SRAM */ 71 OP(104, 8, 1, 104, 260, 78, 104, 3, 1000, 1100), /* 104MHz */ 72 OP(208, 16, 1, 104, 260, 104, 156, 2, 1000, 1100), /* 208MHz */ 73 OP(416, 16, 2, 156, 260, 104, 208, 2, 1100, 1200), /* 416MHz */ 74 OP(624, 24, 2, 208, 260, 208, 312, 3, 1375, 1400), /* 624MHz */ 75 }; 76 77 static struct pxa3xx_freq_info pxa320_freqs[] = { 78 /* CPU XL XN HSS DMEM SMEM SRAM DFI VCC_CORE VCC_SRAM */ 79 OP(104, 8, 1, 104, 260, 78, 104, 3, 1000, 1100), /* 104MHz */ 80 OP(208, 16, 1, 104, 260, 104, 156, 2, 1000, 1100), /* 208MHz */ 81 OP(416, 16, 2, 156, 260, 104, 208, 2, 1100, 1200), /* 416MHz */ 82 OP(624, 24, 2, 208, 260, 208, 312, 3, 1375, 1400), /* 624MHz */ 83 OP(806, 31, 2, 208, 260, 208, 312, 3, 1400, 1400), /* 806MHz */ 84 }; 85 86 static unsigned int pxa3xx_freqs_num; 87 static struct pxa3xx_freq_info *pxa3xx_freqs; 88 static struct cpufreq_frequency_table *pxa3xx_freqs_table; 89 90 static int setup_freqs_table(struct cpufreq_policy *policy, 91 struct pxa3xx_freq_info *freqs, int num) 92 { 93 struct cpufreq_frequency_table *table; 94 int i; 95 96 table = kzalloc((num + 1) * sizeof(*table), GFP_KERNEL); 97 if (table == NULL) 98 return -ENOMEM; 99 100 for (i = 0; i < num; i++) { 101 table[i].driver_data = i; 102 table[i].frequency = freqs[i].cpufreq_mhz * 1000; 103 } 104 table[num].driver_data = i; 105 table[num].frequency = CPUFREQ_TABLE_END; 106 107 pxa3xx_freqs = freqs; 108 pxa3xx_freqs_num = num; 109 pxa3xx_freqs_table = table; 110 111 return cpufreq_frequency_table_cpuinfo(policy, table); 112 } 113 114 static void __update_core_freq(struct pxa3xx_freq_info *info) 115 { 116 uint32_t mask = ACCR_XN_MASK | ACCR_XL_MASK; 117 uint32_t accr = ACCR; 118 uint32_t xclkcfg; 119 120 accr &= ~(ACCR_XN_MASK | ACCR_XL_MASK | ACCR_XSPCLK_MASK); 121 accr |= ACCR_XN(info->core_xn) | ACCR_XL(info->core_xl); 122 123 /* No clock until core PLL is re-locked */ 124 accr |= ACCR_XSPCLK(XSPCLK_NONE); 125 126 xclkcfg = (info->core_xn == 2) ? 0x3 : 0x2; /* turbo bit */ 127 128 ACCR = accr; 129 __asm__("mcr p14, 0, %0, c6, c0, 0\n" : : "r"(xclkcfg)); 130 131 while ((ACSR & mask) != (accr & mask)) 132 cpu_relax(); 133 } 134 135 static void __update_bus_freq(struct pxa3xx_freq_info *info) 136 { 137 uint32_t mask; 138 uint32_t accr = ACCR; 139 140 mask = ACCR_SMCFS_MASK | ACCR_SFLFS_MASK | ACCR_HSS_MASK | 141 ACCR_DMCFS_MASK; 142 143 accr &= ~mask; 144 accr |= ACCR_SMCFS(info->smcfs) | ACCR_SFLFS(info->sflfs) | 145 ACCR_HSS(info->hss) | ACCR_DMCFS(info->dmcfs); 146 147 ACCR = accr; 148 149 while ((ACSR & mask) != (accr & mask)) 150 cpu_relax(); 151 } 152 153 static int pxa3xx_cpufreq_verify(struct cpufreq_policy *policy) 154 { 155 return cpufreq_frequency_table_verify(policy, pxa3xx_freqs_table); 156 } 157 158 static unsigned int pxa3xx_cpufreq_get(unsigned int cpu) 159 { 160 return pxa3xx_get_clk_frequency_khz(0); 161 } 162 163 static int pxa3xx_cpufreq_set(struct cpufreq_policy *policy, 164 unsigned int target_freq, 165 unsigned int relation) 166 { 167 struct pxa3xx_freq_info *next; 168 struct cpufreq_freqs freqs; 169 unsigned long flags; 170 int idx; 171 172 if (policy->cpu != 0) 173 return -EINVAL; 174 175 /* Lookup the next frequency */ 176 if (cpufreq_frequency_table_target(policy, pxa3xx_freqs_table, 177 target_freq, relation, &idx)) 178 return -EINVAL; 179 180 next = &pxa3xx_freqs[idx]; 181 182 freqs.old = policy->cur; 183 freqs.new = next->cpufreq_mhz * 1000; 184 185 pr_debug("CPU frequency from %d MHz to %d MHz%s\n", 186 freqs.old / 1000, freqs.new / 1000, 187 (freqs.old == freqs.new) ? " (skipped)" : ""); 188 189 if (freqs.old == target_freq) 190 return 0; 191 192 cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); 193 194 local_irq_save(flags); 195 __update_core_freq(next); 196 __update_bus_freq(next); 197 local_irq_restore(flags); 198 199 cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE); 200 201 return 0; 202 } 203 204 static int pxa3xx_cpufreq_init(struct cpufreq_policy *policy) 205 { 206 int ret = -EINVAL; 207 208 /* set default policy and cpuinfo */ 209 policy->cpuinfo.min_freq = 104000; 210 policy->cpuinfo.max_freq = (cpu_is_pxa320()) ? 806000 : 624000; 211 policy->cpuinfo.transition_latency = 1000; /* FIXME: 1 ms, assumed */ 212 policy->max = pxa3xx_get_clk_frequency_khz(0); 213 policy->cur = policy->min = policy->max; 214 215 if (cpu_is_pxa300() || cpu_is_pxa310()) 216 ret = setup_freqs_table(policy, pxa300_freqs, 217 ARRAY_SIZE(pxa300_freqs)); 218 219 if (cpu_is_pxa320()) 220 ret = setup_freqs_table(policy, pxa320_freqs, 221 ARRAY_SIZE(pxa320_freqs)); 222 223 if (ret) { 224 pr_err("failed to setup frequency table\n"); 225 return ret; 226 } 227 228 pr_info("CPUFREQ support for PXA3xx initialized\n"); 229 return 0; 230 } 231 232 static struct cpufreq_driver pxa3xx_cpufreq_driver = { 233 .verify = pxa3xx_cpufreq_verify, 234 .target = pxa3xx_cpufreq_set, 235 .init = pxa3xx_cpufreq_init, 236 .get = pxa3xx_cpufreq_get, 237 .name = "pxa3xx-cpufreq", 238 }; 239 240 static int __init cpufreq_init(void) 241 { 242 if (cpu_is_pxa3xx()) 243 return cpufreq_register_driver(&pxa3xx_cpufreq_driver); 244 245 return 0; 246 } 247 module_init(cpufreq_init); 248 249 static void __exit cpufreq_exit(void) 250 { 251 cpufreq_unregister_driver(&pxa3xx_cpufreq_driver); 252 } 253 module_exit(cpufreq_exit); 254 255 MODULE_DESCRIPTION("CPU frequency scaling driver for PXA3xx"); 256 MODULE_LICENSE("GPL"); 257