drivers/cpufreq/exynos4210-cpufreq.c

   1 /*
   2  * Copyright (c) 2010-2011 Samsung Electronics Co., Ltd.
   3  *              http://www.samsung.com
   4  *
   5  * EXYNOS4210 - CPU frequency scaling support
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10 */
  11
  12 #include <linux/module.h>
  13 #include <linux/kernel.h>
  14 #include <linux/err.h>
  15 #include <linux/clk.h>
  16 #include <linux/io.h>
  17 #include <linux/slab.h>
  18 #include <linux/cpufreq.h>
  19
  20 #include <mach/regs-clock.h>
  21 #include <mach/cpufreq.h>
  22
  23 #define CPUFREQ_LEVEL_END       L5
  24
  25 static int max_support_idx = L0;
  26 static int min_support_idx = (CPUFREQ_LEVEL_END - 1);
  27
  28 static struct clk *cpu_clk;
  29 static struct clk *moutcore;
  30 static struct clk *mout_mpll;
  31 static struct clk *mout_apll;
  32
  33 struct cpufreq_clkdiv {
  34         unsigned int index;
  35         unsigned int clkdiv;
  36 };
  37
  38 static unsigned int exynos4210_volt_table[CPUFREQ_LEVEL_END] = {
  39         1250000, 1150000, 1050000, 975000, 950000,
  40 };
  41
  42
  43 static struct cpufreq_clkdiv exynos4210_clkdiv_table[CPUFREQ_LEVEL_END];
  44
  45 static struct cpufreq_frequency_table exynos4210_freq_table[] = {
  46         {L0, 1200*1000},
  47         {L1, 1000*1000},
  48         {L2, 800*1000},
  49         {L3, 500*1000},
  50         {L4, 200*1000},
  51         {0, CPUFREQ_TABLE_END},
  52 };
  53
  54 static unsigned int clkdiv_cpu0[CPUFREQ_LEVEL_END][7] = {
  55         /*
  56          * Clock divider value for following
  57          * { DIVCORE, DIVCOREM0, DIVCOREM1, DIVPERIPH,
  58          *              DIVATB, DIVPCLK_DBG, DIVAPLL }
  59          */
  60
  61         /* ARM L0: 1200MHz */
  62         { 0, 3, 7, 3, 4, 1, 7 },
  63
  64         /* ARM L1: 1000MHz */
  65         { 0, 3, 7, 3, 4, 1, 7 },
  66
  67         /* ARM L2: 800MHz */
  68         { 0, 3, 7, 3, 3, 1, 7 },
  69
  70         /* ARM L3: 500MHz */
  71         { 0, 3, 7, 3, 3, 1, 7 },
  72
  73         /* ARM L4: 200MHz */
  74         { 0, 1, 3, 1, 3, 1, 0 },
  75 };
  76
  77 static unsigned int clkdiv_cpu1[CPUFREQ_LEVEL_END][2] = {
  78         /*
  79          * Clock divider value for following
  80          * { DIVCOPY, DIVHPM }
  81          */
  82
  83         /* ARM L0: 1200MHz */
  84         { 5, 0 },
  85
  86         /* ARM L1: 1000MHz */
  87         { 4, 0 },
  88
  89         /* ARM L2: 800MHz */
  90         { 3, 0 },
  91
  92         /* ARM L3: 500MHz */
  93         { 3, 0 },
  94
  95         /* ARM L4: 200MHz */
  96         { 3, 0 },
  97 };
  98
  99 static unsigned int exynos4210_apll_pms_table[CPUFREQ_LEVEL_END] = {
 100         /* APLL FOUT L0: 1200MHz */
 101         ((150 << 16) | (3 << 8) | 1),
 102
 103         /* APLL FOUT L1: 1000MHz */
 104         ((250 << 16) | (6 << 8) | 1),
 105
 106         /* APLL FOUT L2: 800MHz */
 107         ((200 << 16) | (6 << 8) | 1),
 108
 109         /* APLL FOUT L3: 500MHz */
 110         ((250 << 16) | (6 << 8) | 2),
 111
 112         /* APLL FOUT L4: 200MHz */
 113         ((200 << 16) | (6 << 8) | 3),
 114 };
 115
 116 static void exynos4210_set_clkdiv(unsigned int div_index)
 117 {
 118         unsigned int tmp;
 119
 120         /* Change Divider - CPU0 */
 121
 122         tmp = exynos4210_clkdiv_table[div_index].clkdiv;
 123
 124         __raw_writel(tmp, S5P_CLKDIV_CPU);
 125
 126         do {
 127                 tmp = __raw_readl(S5P_CLKDIV_STATCPU);
 128         } while (tmp & 0x1111111);
 129
 130         /* Change Divider - CPU1 */
 131
 132         tmp = __raw_readl(S5P_CLKDIV_CPU1);
 133
 134         tmp &= ~((0x7 << 4) | 0x7);
 135
 136         tmp |= ((clkdiv_cpu1[div_index][0] << 4) |
 137                 (clkdiv_cpu1[div_index][1] << 0));
 138
 139         __raw_writel(tmp, S5P_CLKDIV_CPU1);
 140
 141         do {
 142                 tmp = __raw_readl(S5P_CLKDIV_STATCPU1);
 143         } while (tmp & 0x11);
 144 }
 145
 146 static void exynos4210_set_apll(unsigned int index)
 147 {
 148         unsigned int tmp;
 149
 150         /* 1. MUX_CORE_SEL = MPLL, ARMCLK uses MPLL for lock time */
 151         clk_set_parent(moutcore, mout_mpll);
 152
 153         do {
 154                 tmp = (__raw_readl(S5P_CLKMUX_STATCPU)
 155                         >> S5P_CLKSRC_CPU_MUXCORE_SHIFT);
 156                 tmp &= 0x7;
 157         } while (tmp != 0x2);
 158
 159         /* 2. Set APLL Lock time */
 160         __raw_writel(S5P_APLL_LOCKTIME, S5P_APLL_LOCK);
 161
 162         /* 3. Change PLL PMS values */
 163         tmp = __raw_readl(S5P_APLL_CON0);
 164         tmp &= ~((0x3ff << 16) | (0x3f << 8) | (0x7 << 0));
 165         tmp |= exynos4210_apll_pms_table[index];
 166         __raw_writel(tmp, S5P_APLL_CON0);
 167
 168         /* 4. wait_lock_time */
 169         do {
 170                 tmp = __raw_readl(S5P_APLL_CON0);
 171         } while (!(tmp & (0x1 << S5P_APLLCON0_LOCKED_SHIFT)));
 172
 173         /* 5. MUX_CORE_SEL = APLL */
 174         clk_set_parent(moutcore, mout_apll);
 175
 176         do {
 177                 tmp = __raw_readl(S5P_CLKMUX_STATCPU);
 178                 tmp &= S5P_CLKMUX_STATCPU_MUXCORE_MASK;
 179         } while (tmp != (0x1 << S5P_CLKSRC_CPU_MUXCORE_SHIFT));
 180 }
 181
 182 bool exynos4210_pms_change(unsigned int old_index, unsigned int new_index)
 183 {
 184         unsigned int old_pm = (exynos4210_apll_pms_table[old_index] >> 8);
 185         unsigned int new_pm = (exynos4210_apll_pms_table[new_index] >> 8);
 186
 187         return (old_pm == new_pm) ? 0 : 1;
 188 }
 189
 190 static void exynos4210_set_frequency(unsigned int old_index,
 191                                      unsigned int new_index)
 192 {
 193         unsigned int tmp;
 194
 195         if (old_index > new_index) {
 196                 if (!exynos4210_pms_change(old_index, new_index)) {
 197                         /* 1. Change the system clock divider values */
 198                         exynos4210_set_clkdiv(new_index);
 199
 200                         /* 2. Change just s value in apll m,p,s value */
 201                         tmp = __raw_readl(S5P_APLL_CON0);
 202                         tmp &= ~(0x7 << 0);
 203                         tmp |= (exynos4210_apll_pms_table[new_index] & 0x7);
 204                         __raw_writel(tmp, S5P_APLL_CON0);
 205                 } else {
 206                         /* Clock Configuration Procedure */
 207                         /* 1. Change the system clock divider values */
 208                         exynos4210_set_clkdiv(new_index);
 209                         /* 2. Change the apll m,p,s value */
 210                         exynos4210_set_apll(new_index);
 211                 }
 212         } else if (old_index < new_index) {
 213                 if (!exynos4210_pms_change(old_index, new_index)) {
 214                         /* 1. Change just s value in apll m,p,s value */
 215                         tmp = __raw_readl(S5P_APLL_CON0);
 216                         tmp &= ~(0x7 << 0);
 217                         tmp |= (exynos4210_apll_pms_table[new_index] & 0x7);
 218                         __raw_writel(tmp, S5P_APLL_CON0);
 219
 220                         /* 2. Change the system clock divider values */
 221                         exynos4210_set_clkdiv(new_index);
 222                 } else {
 223                         /* Clock Configuration Procedure */
 224                         /* 1. Change the apll m,p,s value */
 225                         exynos4210_set_apll(new_index);
 226                         /* 2. Change the system clock divider values */
 227                         exynos4210_set_clkdiv(new_index);
 228                 }
 229         }
 230 }
 231
 232 int exynos4210_cpufreq_init(struct exynos_dvfs_info *info)
 233 {
 234         int i;
 235         unsigned int tmp;
 236         unsigned long rate;
 237
 238         cpu_clk = clk_get(NULL, "armclk");
 239         if (IS_ERR(cpu_clk))
 240                 return PTR_ERR(cpu_clk);
 241
 242         moutcore = clk_get(NULL, "moutcore");
 243         if (IS_ERR(moutcore))
 244                 goto err_moutcore;
 245
 246         mout_mpll = clk_get(NULL, "mout_mpll");
 247         if (IS_ERR(mout_mpll))
 248                 goto err_mout_mpll;
 249
 250         rate = clk_get_rate(mout_mpll) / 1000;
 251
 252         mout_apll = clk_get(NULL, "mout_apll");
 253         if (IS_ERR(mout_apll))
 254                 goto err_mout_apll;
 255
 256         tmp = __raw_readl(S5P_CLKDIV_CPU);
 257
 258         for (i = L0; i <  CPUFREQ_LEVEL_END; i++) {
 259                 tmp &= ~(S5P_CLKDIV_CPU0_CORE_MASK |
 260                         S5P_CLKDIV_CPU0_COREM0_MASK |
 261                         S5P_CLKDIV_CPU0_COREM1_MASK |
 262                         S5P_CLKDIV_CPU0_PERIPH_MASK |
 263                         S5P_CLKDIV_CPU0_ATB_MASK |
 264                         S5P_CLKDIV_CPU0_PCLKDBG_MASK |
 265                         S5P_CLKDIV_CPU0_APLL_MASK);
 266
 267                 tmp |= ((clkdiv_cpu0[i][0] << S5P_CLKDIV_CPU0_CORE_SHIFT) |
 268                         (clkdiv_cpu0[i][1] << S5P_CLKDIV_CPU0_COREM0_SHIFT) |
 269                         (clkdiv_cpu0[i][2] << S5P_CLKDIV_CPU0_COREM1_SHIFT) |
 270                         (clkdiv_cpu0[i][3] << S5P_CLKDIV_CPU0_PERIPH_SHIFT) |
 271                         (clkdiv_cpu0[i][4] << S5P_CLKDIV_CPU0_ATB_SHIFT) |
 272                         (clkdiv_cpu0[i][5] << S5P_CLKDIV_CPU0_PCLKDBG_SHIFT) |
 273                         (clkdiv_cpu0[i][6] << S5P_CLKDIV_CPU0_APLL_SHIFT));
 274
 275                 exynos4210_clkdiv_table[i].clkdiv = tmp;
 276         }
 277
 278         info->mpll_freq_khz = rate;
 279         info->pm_lock_idx = L2;
 280         info->pll_safe_idx = L2;
 281         info->max_support_idx = max_support_idx;
 282         info->min_support_idx = min_support_idx;
 283         info->cpu_clk = cpu_clk;
 284         info->volt_table = exynos4210_volt_table;
 285         info->freq_table = exynos4210_freq_table;
 286         info->set_freq = exynos4210_set_frequency;
 287         info->need_apll_change = exynos4210_pms_change;
 288
 289         return 0;
 290
 291 err_mout_apll:
 292         if (!IS_ERR(mout_mpll))
 293                 clk_put(mout_mpll);
 294 err_mout_mpll:
 295         if (!IS_ERR(moutcore))
 296                 clk_put(moutcore);
 297 err_moutcore:
 298         if (!IS_ERR(cpu_clk))
 299                 clk_put(cpu_clk);
 300
 301         pr_debug("%s: failed initialization\n", __func__);
 302         return -EINVAL;
 303 }
 304 EXPORT_SYMBOL(exynos4210_cpufreq_init);