linux/drivers/cpufreq/pxa3xx-cpufreq.c
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   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
  41struct 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
  69static 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
  77static 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
  86static unsigned int pxa3xx_freqs_num;
  87static struct pxa3xx_freq_info *pxa3xx_freqs;
  88static struct cpufreq_frequency_table *pxa3xx_freqs_table;
  89
  90static 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 = kcalloc(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        policy->freq_table = table;
 112
 113        return 0;
 114}
 115
 116static void __update_core_freq(struct pxa3xx_freq_info *info)
 117{
 118        uint32_t mask = ACCR_XN_MASK | ACCR_XL_MASK;
 119        uint32_t accr = ACCR;
 120        uint32_t xclkcfg;
 121
 122        accr &= ~(ACCR_XN_MASK | ACCR_XL_MASK | ACCR_XSPCLK_MASK);
 123        accr |= ACCR_XN(info->core_xn) | ACCR_XL(info->core_xl);
 124
 125        /* No clock until core PLL is re-locked */
 126        accr |= ACCR_XSPCLK(XSPCLK_NONE);
 127
 128        xclkcfg = (info->core_xn == 2) ? 0x3 : 0x2;     /* turbo bit */
 129
 130        ACCR = accr;
 131        __asm__("mcr p14, 0, %0, c6, c0, 0\n" : : "r"(xclkcfg));
 132
 133        while ((ACSR & mask) != (accr & mask))
 134                cpu_relax();
 135}
 136
 137static void __update_bus_freq(struct pxa3xx_freq_info *info)
 138{
 139        uint32_t mask;
 140        uint32_t accr = ACCR;
 141
 142        mask = ACCR_SMCFS_MASK | ACCR_SFLFS_MASK | ACCR_HSS_MASK |
 143                ACCR_DMCFS_MASK;
 144
 145        accr &= ~mask;
 146        accr |= ACCR_SMCFS(info->smcfs) | ACCR_SFLFS(info->sflfs) |
 147                ACCR_HSS(info->hss) | ACCR_DMCFS(info->dmcfs);
 148
 149        ACCR = accr;
 150
 151        while ((ACSR & mask) != (accr & mask))
 152                cpu_relax();
 153}
 154
 155static unsigned int pxa3xx_cpufreq_get(unsigned int cpu)
 156{
 157        return pxa3xx_get_clk_frequency_khz(0);
 158}
 159
 160static int pxa3xx_cpufreq_set(struct cpufreq_policy *policy, unsigned int index)
 161{
 162        struct pxa3xx_freq_info *next;
 163        unsigned long flags;
 164
 165        if (policy->cpu != 0)
 166                return -EINVAL;
 167
 168        next = &pxa3xx_freqs[index];
 169
 170        local_irq_save(flags);
 171        __update_core_freq(next);
 172        __update_bus_freq(next);
 173        local_irq_restore(flags);
 174
 175        return 0;
 176}
 177
 178static int pxa3xx_cpufreq_init(struct cpufreq_policy *policy)
 179{
 180        int ret = -EINVAL;
 181
 182        /* set default policy and cpuinfo */
 183        policy->min = policy->cpuinfo.min_freq = 104000;
 184        policy->max = policy->cpuinfo.max_freq =
 185                (cpu_is_pxa320()) ? 806000 : 624000;
 186        policy->cpuinfo.transition_latency = 1000; /* FIXME: 1 ms, assumed */
 187
 188        if (cpu_is_pxa300() || cpu_is_pxa310())
 189                ret = setup_freqs_table(policy, pxa300_freqs,
 190                                        ARRAY_SIZE(pxa300_freqs));
 191
 192        if (cpu_is_pxa320())
 193                ret = setup_freqs_table(policy, pxa320_freqs,
 194                                        ARRAY_SIZE(pxa320_freqs));
 195
 196        if (ret) {
 197                pr_err("failed to setup frequency table\n");
 198                return ret;
 199        }
 200
 201        pr_info("CPUFREQ support for PXA3xx initialized\n");
 202        return 0;
 203}
 204
 205static struct cpufreq_driver pxa3xx_cpufreq_driver = {
 206        .flags          = CPUFREQ_NEED_INITIAL_FREQ_CHECK,
 207        .verify         = cpufreq_generic_frequency_table_verify,
 208        .target_index   = pxa3xx_cpufreq_set,
 209        .init           = pxa3xx_cpufreq_init,
 210        .get            = pxa3xx_cpufreq_get,
 211        .name           = "pxa3xx-cpufreq",
 212};
 213
 214static int __init cpufreq_init(void)
 215{
 216        if (cpu_is_pxa3xx())
 217                return cpufreq_register_driver(&pxa3xx_cpufreq_driver);
 218
 219        return 0;
 220}
 221module_init(cpufreq_init);
 222
 223static void __exit cpufreq_exit(void)
 224{
 225        cpufreq_unregister_driver(&pxa3xx_cpufreq_driver);
 226}
 227module_exit(cpufreq_exit);
 228
 229MODULE_DESCRIPTION("CPU frequency scaling driver for PXA3xx");
 230MODULE_LICENSE("GPL");
 231