drivers/cpufreq/pxa3xx-cpufreq.c

   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_table_validate_and_show(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 unsigned int pxa3xx_cpufreq_get(unsigned int cpu)
 154 {
 155         return pxa3xx_get_clk_frequency_khz(0);
 156 }
 157
 158 static int pxa3xx_cpufreq_set(struct cpufreq_policy *policy, unsigned int index)
 159 {
 160         struct pxa3xx_freq_info *next;
 161         unsigned long flags;
 162
 163         if (policy->cpu != 0)
 164                 return -EINVAL;
 165
 166         next = &pxa3xx_freqs[index];
 167
 168         local_irq_save(flags);
 169         __update_core_freq(next);
 170         __update_bus_freq(next);
 171         local_irq_restore(flags);
 172
 173         return 0;
 174 }
 175
 176 static int pxa3xx_cpufreq_init(struct cpufreq_policy *policy)
 177 {
 178         int ret = -EINVAL;
 179
 180         /* set default policy and cpuinfo */
 181         policy->min = policy->cpuinfo.min_freq = 104000;
 182         policy->max = policy->cpuinfo.max_freq =
 183                 (cpu_is_pxa320()) ? 806000 : 624000;
 184         policy->cpuinfo.transition_latency = 1000; /* FIXME: 1 ms, assumed */
 185
 186         if (cpu_is_pxa300() || cpu_is_pxa310())
 187                 ret = setup_freqs_table(policy, pxa300_freqs,
 188                                         ARRAY_SIZE(pxa300_freqs));
 189
 190         if (cpu_is_pxa320())
 191                 ret = setup_freqs_table(policy, pxa320_freqs,
 192                                         ARRAY_SIZE(pxa320_freqs));
 193
 194         if (ret) {
 195                 pr_err("failed to setup frequency table\n");
 196                 return ret;
 197         }
 198
 199         pr_info("CPUFREQ support for PXA3xx initialized\n");
 200         return 0;
 201 }
 202
 203 static struct cpufreq_driver pxa3xx_cpufreq_driver = {
 204         .verify         = cpufreq_generic_frequency_table_verify,
 205         .target_index   = pxa3xx_cpufreq_set,
 206         .init           = pxa3xx_cpufreq_init,
 207         .exit           = cpufreq_generic_exit,
 208         .get            = pxa3xx_cpufreq_get,
 209         .name           = "pxa3xx-cpufreq",
 210 };
 211
 212 static int __init cpufreq_init(void)
 213 {
 214         if (cpu_is_pxa3xx())
 215                 return cpufreq_register_driver(&pxa3xx_cpufreq_driver);
 216
 217         return 0;
 218 }
 219 module_init(cpufreq_init);
 220
 221 static void __exit cpufreq_exit(void)
 222 {
 223         cpufreq_unregister_driver(&pxa3xx_cpufreq_driver);
 224 }
 225 module_exit(cpufreq_exit);
 226
 227 MODULE_DESCRIPTION("CPU frequency scaling driver for PXA3xx");
 228 MODULE_LICENSE("GPL");