drivers/cpufreq/s5pv210-cpufreq.c

   1 /*
   2  * Copyright (c) 2010 Samsung Electronics Co., Ltd.
   3  *              http://www.samsung.com
   4  *
   5  * CPU frequency scaling for S5PC110/S5PV210
   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/types.h>
  13 #include <linux/kernel.h>
  14 #include <linux/init.h>
  15 #include <linux/err.h>
  16 #include <linux/clk.h>
  17 #include <linux/io.h>
  18 #include <linux/cpufreq.h>
  19 #include <linux/reboot.h>
  20 #include <linux/regulator/consumer.h>
  21 #include <linux/suspend.h>
  22
  23 #include <mach/map.h>
  24 #include <mach/regs-clock.h>
  25
  26 static struct clk *cpu_clk;
  27 static struct clk *dmc0_clk;
  28 static struct clk *dmc1_clk;
  29 static struct cpufreq_freqs freqs;
  30 static DEFINE_MUTEX(set_freq_lock);
  31
  32 /* APLL M,P,S values for 1G/800Mhz */
  33 #define APLL_VAL_1000   ((1 << 31) | (125 << 16) | (3 << 8) | 1)
  34 #define APLL_VAL_800    ((1 << 31) | (100 << 16) | (3 << 8) | 1)
  35
  36 /* Use 800MHz when entering sleep mode */
  37 #define SLEEP_FREQ      (800 * 1000)
  38
  39 /*
  40  * relation has an additional symantics other than the standard of cpufreq
  41  * DISALBE_FURTHER_CPUFREQ: disable further access to target
  42  * ENABLE_FURTUER_CPUFREQ: enable access to target
  43  */
  44 enum cpufreq_access {
  45         DISABLE_FURTHER_CPUFREQ = 0x10,
  46         ENABLE_FURTHER_CPUFREQ = 0x20,
  47 };
  48
  49 static bool no_cpufreq_access;
  50
  51 /*
  52  * DRAM configurations to calculate refresh counter for changing
  53  * frequency of memory.
  54  */
  55 struct dram_conf {
  56         unsigned long freq;     /* HZ */
  57         unsigned long refresh;  /* DRAM refresh counter * 1000 */
  58 };
  59
  60 /* DRAM configuration (DMC0 and DMC1) */
  61 static struct dram_conf s5pv210_dram_conf[2];
  62
  63 enum perf_level {
  64         L0, L1, L2, L3, L4,
  65 };
  66
  67 enum s5pv210_mem_type {
  68         LPDDR   = 0x1,
  69         LPDDR2  = 0x2,
  70         DDR2    = 0x4,
  71 };
  72
  73 enum s5pv210_dmc_port {
  74         DMC0 = 0,
  75         DMC1,
  76 };
  77
  78 static struct cpufreq_frequency_table s5pv210_freq_table[] = {
  79         {L0, 1000*1000},
  80         {L1, 800*1000},
  81         {L2, 400*1000},
  82         {L3, 200*1000},
  83         {L4, 100*1000},
  84         {0, CPUFREQ_TABLE_END},
  85 };
  86
  87 static struct regulator *arm_regulator;
  88 static struct regulator *int_regulator;
  89
  90 struct s5pv210_dvs_conf {
  91         int arm_volt;   /* uV */
  92         int int_volt;   /* uV */
  93 };
  94
  95 static const int arm_volt_max = 1350000;
  96 static const int int_volt_max = 1250000;
  97
  98 static struct s5pv210_dvs_conf dvs_conf[] = {
  99         [L0] = {
 100                 .arm_volt       = 1250000,
 101                 .int_volt       = 1100000,
 102         },
 103         [L1] = {
 104                 .arm_volt       = 1200000,
 105                 .int_volt       = 1100000,
 106         },
 107         [L2] = {
 108                 .arm_volt       = 1050000,
 109                 .int_volt       = 1100000,
 110         },
 111         [L3] = {
 112                 .arm_volt       = 950000,
 113                 .int_volt       = 1100000,
 114         },
 115         [L4] = {
 116                 .arm_volt       = 950000,
 117                 .int_volt       = 1000000,
 118         },
 119 };
 120
 121 static u32 clkdiv_val[5][11] = {
 122         /*
 123          * Clock divider value for following
 124          * { APLL, A2M, HCLK_MSYS, PCLK_MSYS,
 125          *   HCLK_DSYS, PCLK_DSYS, HCLK_PSYS, PCLK_PSYS,
 126          *   ONEDRAM, MFC, G3D }
 127          */
 128
 129         /* L0 : [1000/200/100][166/83][133/66][200/200] */
 130         {0, 4, 4, 1, 3, 1, 4, 1, 3, 0, 0},
 131
 132         /* L1 : [800/200/100][166/83][133/66][200/200] */
 133         {0, 3, 3, 1, 3, 1, 4, 1, 3, 0, 0},
 134
 135         /* L2 : [400/200/100][166/83][133/66][200/200] */
 136         {1, 3, 1, 1, 3, 1, 4, 1, 3, 0, 0},
 137
 138         /* L3 : [200/200/100][166/83][133/66][200/200] */
 139         {3, 3, 1, 1, 3, 1, 4, 1, 3, 0, 0},
 140
 141         /* L4 : [100/100/100][83/83][66/66][100/100] */
 142         {7, 7, 0, 0, 7, 0, 9, 0, 7, 0, 0},
 143 };
 144
 145 /*
 146  * This function set DRAM refresh counter
 147  * accoriding to operating frequency of DRAM
 148  * ch: DMC port number 0 or 1
 149  * freq: Operating frequency of DRAM(KHz)
 150  */
 151 static void s5pv210_set_refresh(enum s5pv210_dmc_port ch, unsigned long freq)
 152 {
 153         unsigned long tmp, tmp1;
 154         void __iomem *reg = NULL;
 155
 156         if (ch == DMC0) {
 157                 reg = (S5P_VA_DMC0 + 0x30);
 158         } else if (ch == DMC1) {
 159                 reg = (S5P_VA_DMC1 + 0x30);
 160         } else {
 161                 printk(KERN_ERR "Cannot find DMC port\n");
 162                 return;
 163         }
 164
 165         /* Find current DRAM frequency */
 166         tmp = s5pv210_dram_conf[ch].freq;
 167
 168         do_div(tmp, freq);
 169
 170         tmp1 = s5pv210_dram_conf[ch].refresh;
 171
 172         do_div(tmp1, tmp);
 173
 174         __raw_writel(tmp1, reg);
 175 }
 176
 177 static unsigned int s5pv210_getspeed(unsigned int cpu)
 178 {
 179         if (cpu)
 180                 return 0;
 181
 182         return clk_get_rate(cpu_clk) / 1000;
 183 }
 184
 185 static int s5pv210_target(struct cpufreq_policy *policy,
 186                           unsigned int target_freq,
 187                           unsigned int relation)
 188 {
 189         unsigned long reg;
 190         unsigned int index, priv_index;
 191         unsigned int pll_changing = 0;
 192         unsigned int bus_speed_changing = 0;
 193         int arm_volt, int_volt;
 194         int ret = 0;
 195
 196         mutex_lock(&set_freq_lock);
 197
 198         if (relation & ENABLE_FURTHER_CPUFREQ)
 199                 no_cpufreq_access = false;
 200
 201         if (no_cpufreq_access) {
 202 #ifdef CONFIG_PM_VERBOSE
 203                 pr_err("%s:%d denied access to %s as it is disabled"
 204                                 "temporarily\n", __FILE__, __LINE__, __func__);
 205 #endif
 206                 ret = -EINVAL;
 207                 goto exit;
 208         }
 209
 210         if (relation & DISABLE_FURTHER_CPUFREQ)
 211                 no_cpufreq_access = true;
 212
 213         relation &= ~(ENABLE_FURTHER_CPUFREQ | DISABLE_FURTHER_CPUFREQ);
 214
 215         freqs.old = s5pv210_getspeed(0);
 216
 217         if (cpufreq_frequency_table_target(policy, s5pv210_freq_table,
 218                                            target_freq, relation, &index)) {
 219                 ret = -EINVAL;
 220                 goto exit;
 221         }
 222
 223         freqs.new = s5pv210_freq_table[index].frequency;
 224
 225         if (freqs.new == freqs.old)
 226                 goto exit;
 227
 228         /* Finding current running level index */
 229         if (cpufreq_frequency_table_target(policy, s5pv210_freq_table,
 230                                            freqs.old, relation, &priv_index)) {
 231                 ret = -EINVAL;
 232                 goto exit;
 233         }
 234
 235         arm_volt = dvs_conf[index].arm_volt;
 236         int_volt = dvs_conf[index].int_volt;
 237
 238         if (freqs.new > freqs.old) {
 239                 ret = regulator_set_voltage(arm_regulator,
 240                                 arm_volt, arm_volt_max);
 241                 if (ret)
 242                         goto exit;
 243
 244                 ret = regulator_set_voltage(int_regulator,
 245                                 int_volt, int_volt_max);
 246                 if (ret)
 247                         goto exit;
 248         }
 249
 250         cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
 251
 252         /* Check if there need to change PLL */
 253         if ((index == L0) || (priv_index == L0))
 254                 pll_changing = 1;
 255
 256         /* Check if there need to change System bus clock */
 257         if ((index == L4) || (priv_index == L4))
 258                 bus_speed_changing = 1;
 259
 260         if (bus_speed_changing) {
 261                 /*
 262                  * Reconfigure DRAM refresh counter value for minimum
 263                  * temporary clock while changing divider.
 264                  * expected clock is 83Mhz : 7.8usec/(1/83Mhz) = 0x287
 265                  */
 266                 if (pll_changing)
 267                         s5pv210_set_refresh(DMC1, 83000);
 268                 else
 269                         s5pv210_set_refresh(DMC1, 100000);
 270
 271                 s5pv210_set_refresh(DMC0, 83000);
 272         }
 273
 274         /*
 275          * APLL should be changed in this level
 276          * APLL -> MPLL(for stable transition) -> APLL
 277          * Some clock source's clock API are not prepared.
 278          * Do not use clock API in below code.
 279          */
 280         if (pll_changing) {
 281                 /*
 282                  * 1. Temporary Change divider for MFC and G3D
 283                  * SCLKA2M(200/1=200)->(200/4=50)Mhz
 284                  */
 285                 reg = __raw_readl(S5P_CLK_DIV2);
 286                 reg &= ~(S5P_CLKDIV2_G3D_MASK | S5P_CLKDIV2_MFC_MASK);
 287                 reg |= (3 << S5P_CLKDIV2_G3D_SHIFT) |
 288                         (3 << S5P_CLKDIV2_MFC_SHIFT);
 289                 __raw_writel(reg, S5P_CLK_DIV2);
 290
 291                 /* For MFC, G3D dividing */
 292                 do {
 293                         reg = __raw_readl(S5P_CLKDIV_STAT0);
 294                 } while (reg & ((1 << 16) | (1 << 17)));
 295
 296                 /*
 297                  * 2. Change SCLKA2M(200Mhz)to SCLKMPLL in MFC_MUX, G3D MUX
 298                  * (200/4=50)->(667/4=166)Mhz
 299                  */
 300                 reg = __raw_readl(S5P_CLK_SRC2);
 301                 reg &= ~(S5P_CLKSRC2_G3D_MASK | S5P_CLKSRC2_MFC_MASK);
 302                 reg |= (1 << S5P_CLKSRC2_G3D_SHIFT) |
 303                         (1 << S5P_CLKSRC2_MFC_SHIFT);
 304                 __raw_writel(reg, S5P_CLK_SRC2);
 305
 306                 do {
 307                         reg = __raw_readl(S5P_CLKMUX_STAT1);
 308                 } while (reg & ((1 << 7) | (1 << 3)));
 309
 310                 /*
 311                  * 3. DMC1 refresh count for 133Mhz if (index == L4) is
 312                  * true refresh counter is already programed in upper
 313                  * code. 0x287@83Mhz
 314                  */
 315                 if (!bus_speed_changing)
 316                         s5pv210_set_refresh(DMC1, 133000);
 317
 318                 /* 4. SCLKAPLL -> SCLKMPLL */
 319                 reg = __raw_readl(S5P_CLK_SRC0);
 320                 reg &= ~(S5P_CLKSRC0_MUX200_MASK);
 321                 reg |= (0x1 << S5P_CLKSRC0_MUX200_SHIFT);
 322                 __raw_writel(reg, S5P_CLK_SRC0);
 323
 324                 do {
 325                         reg = __raw_readl(S5P_CLKMUX_STAT0);
 326                 } while (reg & (0x1 << 18));
 327
 328         }
 329
 330         /* Change divider */
 331         reg = __raw_readl(S5P_CLK_DIV0);
 332
 333         reg &= ~(S5P_CLKDIV0_APLL_MASK | S5P_CLKDIV0_A2M_MASK |
 334                 S5P_CLKDIV0_HCLK200_MASK | S5P_CLKDIV0_PCLK100_MASK |
 335                 S5P_CLKDIV0_HCLK166_MASK | S5P_CLKDIV0_PCLK83_MASK |
 336                 S5P_CLKDIV0_HCLK133_MASK | S5P_CLKDIV0_PCLK66_MASK);
 337
 338         reg |= ((clkdiv_val[index][0] << S5P_CLKDIV0_APLL_SHIFT) |
 339                 (clkdiv_val[index][1] << S5P_CLKDIV0_A2M_SHIFT) |
 340                 (clkdiv_val[index][2] << S5P_CLKDIV0_HCLK200_SHIFT) |
 341                 (clkdiv_val[index][3] << S5P_CLKDIV0_PCLK100_SHIFT) |
 342                 (clkdiv_val[index][4] << S5P_CLKDIV0_HCLK166_SHIFT) |
 343                 (clkdiv_val[index][5] << S5P_CLKDIV0_PCLK83_SHIFT) |
 344                 (clkdiv_val[index][6] << S5P_CLKDIV0_HCLK133_SHIFT) |
 345                 (clkdiv_val[index][7] << S5P_CLKDIV0_PCLK66_SHIFT));
 346
 347         __raw_writel(reg, S5P_CLK_DIV0);
 348
 349         do {
 350                 reg = __raw_readl(S5P_CLKDIV_STAT0);
 351         } while (reg & 0xff);
 352
 353         /* ARM MCS value changed */
 354         reg = __raw_readl(S5P_ARM_MCS_CON);
 355         reg &= ~0x3;
 356         if (index >= L3)
 357                 reg |= 0x3;
 358         else
 359                 reg |= 0x1;
 360
 361         __raw_writel(reg, S5P_ARM_MCS_CON);
 362
 363         if (pll_changing) {
 364                 /* 5. Set Lock time = 30us*24Mhz = 0x2cf */
 365                 __raw_writel(0x2cf, S5P_APLL_LOCK);
 366
 367                 /*
 368                  * 6. Turn on APLL
 369                  * 6-1. Set PMS values
 370                  * 6-2. Wait untile the PLL is locked
 371                  */
 372                 if (index == L0)
 373                         __raw_writel(APLL_VAL_1000, S5P_APLL_CON);
 374                 else
 375                         __raw_writel(APLL_VAL_800, S5P_APLL_CON);
 376
 377                 do {
 378                         reg = __raw_readl(S5P_APLL_CON);
 379                 } while (!(reg & (0x1 << 29)));
 380
 381                 /*
 382                  * 7. Change souce clock from SCLKMPLL(667Mhz)
 383                  * to SCLKA2M(200Mhz) in MFC_MUX and G3D MUX
 384                  * (667/4=166)->(200/4=50)Mhz
 385                  */
 386                 reg = __raw_readl(S5P_CLK_SRC2);
 387                 reg &= ~(S5P_CLKSRC2_G3D_MASK | S5P_CLKSRC2_MFC_MASK);
 388                 reg |= (0 << S5P_CLKSRC2_G3D_SHIFT) |
 389                         (0 << S5P_CLKSRC2_MFC_SHIFT);
 390                 __raw_writel(reg, S5P_CLK_SRC2);
 391
 392                 do {
 393                         reg = __raw_readl(S5P_CLKMUX_STAT1);
 394                 } while (reg & ((1 << 7) | (1 << 3)));
 395
 396                 /*
 397                  * 8. Change divider for MFC and G3D
 398                  * (200/4=50)->(200/1=200)Mhz
 399                  */
 400                 reg = __raw_readl(S5P_CLK_DIV2);
 401                 reg &= ~(S5P_CLKDIV2_G3D_MASK | S5P_CLKDIV2_MFC_MASK);
 402                 reg |= (clkdiv_val[index][10] << S5P_CLKDIV2_G3D_SHIFT) |
 403                         (clkdiv_val[index][9] << S5P_CLKDIV2_MFC_SHIFT);
 404                 __raw_writel(reg, S5P_CLK_DIV2);
 405
 406                 /* For MFC, G3D dividing */
 407                 do {
 408                         reg = __raw_readl(S5P_CLKDIV_STAT0);
 409                 } while (reg & ((1 << 16) | (1 << 17)));
 410
 411                 /* 9. Change MPLL to APLL in MSYS_MUX */
 412                 reg = __raw_readl(S5P_CLK_SRC0);
 413                 reg &= ~(S5P_CLKSRC0_MUX200_MASK);
 414                 reg |= (0x0 << S5P_CLKSRC0_MUX200_SHIFT);
 415                 __raw_writel(reg, S5P_CLK_SRC0);
 416
 417                 do {
 418                         reg = __raw_readl(S5P_CLKMUX_STAT0);
 419                 } while (reg & (0x1 << 18));
 420
 421                 /*
 422                  * 10. DMC1 refresh counter
 423                  * L4 : DMC1 = 100Mhz 7.8us/(1/100) = 0x30c
 424                  * Others : DMC1 = 200Mhz 7.8us/(1/200) = 0x618
 425                  */
 426                 if (!bus_speed_changing)
 427                         s5pv210_set_refresh(DMC1, 200000);
 428         }
 429
 430         /*
 431          * L4 level need to change memory bus speed, hence onedram clock divier
 432          * and memory refresh parameter should be changed
 433          */
 434         if (bus_speed_changing) {
 435                 reg = __raw_readl(S5P_CLK_DIV6);
 436                 reg &= ~S5P_CLKDIV6_ONEDRAM_MASK;
 437                 reg |= (clkdiv_val[index][8] << S5P_CLKDIV6_ONEDRAM_SHIFT);
 438                 __raw_writel(reg, S5P_CLK_DIV6);
 439
 440                 do {
 441                         reg = __raw_readl(S5P_CLKDIV_STAT1);
 442                 } while (reg & (1 << 15));
 443
 444                 /* Reconfigure DRAM refresh counter value */
 445                 if (index != L4) {
 446                         /*
 447                          * DMC0 : 166Mhz
 448                          * DMC1 : 200Mhz
 449                          */
 450                         s5pv210_set_refresh(DMC0, 166000);
 451                         s5pv210_set_refresh(DMC1, 200000);
 452                 } else {
 453                         /*
 454                          * DMC0 : 83Mhz
 455                          * DMC1 : 100Mhz
 456                          */
 457                         s5pv210_set_refresh(DMC0, 83000);
 458                         s5pv210_set_refresh(DMC1, 100000);
 459                 }
 460         }
 461
 462         cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
 463
 464         if (freqs.new < freqs.old) {
 465                 regulator_set_voltage(int_regulator,
 466                                 int_volt, int_volt_max);
 467
 468                 regulator_set_voltage(arm_regulator,
 469                                 arm_volt, arm_volt_max);
 470         }
 471
 472         printk(KERN_DEBUG "Perf changed[L%d]\n", index);
 473
 474 exit:
 475         mutex_unlock(&set_freq_lock);
 476         return ret;
 477 }
 478
 479 #ifdef CONFIG_PM
 480 static int s5pv210_cpufreq_suspend(struct cpufreq_policy *policy)
 481 {
 482         return 0;
 483 }
 484
 485 static int s5pv210_cpufreq_resume(struct cpufreq_policy *policy)
 486 {
 487         return 0;
 488 }
 489 #endif
 490
 491 static int check_mem_type(void __iomem *dmc_reg)
 492 {
 493         unsigned long val;
 494
 495         val = __raw_readl(dmc_reg + 0x4);
 496         val = (val & (0xf << 8));
 497
 498         return val >> 8;
 499 }
 500
 501 static int __init s5pv210_cpu_init(struct cpufreq_policy *policy)
 502 {
 503         unsigned long mem_type;
 504         int ret;
 505
 506         cpu_clk = clk_get(NULL, "armclk");
 507         if (IS_ERR(cpu_clk))
 508                 return PTR_ERR(cpu_clk);
 509
 510         dmc0_clk = clk_get(NULL, "sclk_dmc0");
 511         if (IS_ERR(dmc0_clk)) {
 512                 ret = PTR_ERR(dmc0_clk);
 513                 goto out_dmc0;
 514         }
 515
 516         dmc1_clk = clk_get(NULL, "hclk_msys");
 517         if (IS_ERR(dmc1_clk)) {
 518                 ret = PTR_ERR(dmc1_clk);
 519                 goto out_dmc1;
 520         }
 521
 522         if (policy->cpu != 0) {
 523                 ret = -EINVAL;
 524                 goto out_dmc1;
 525         }
 526
 527         /*
 528          * check_mem_type : This driver only support LPDDR & LPDDR2.
 529          * other memory type is not supported.
 530          */
 531         mem_type = check_mem_type(S5P_VA_DMC0);
 532
 533         if ((mem_type != LPDDR) && (mem_type != LPDDR2)) {
 534                 printk(KERN_ERR "CPUFreq doesn't support this memory type\n");
 535                 ret = -EINVAL;
 536                 goto out_dmc1;
 537         }
 538
 539         /* Find current refresh counter and frequency each DMC */
 540         s5pv210_dram_conf[0].refresh = (__raw_readl(S5P_VA_DMC0 + 0x30) * 1000);
 541         s5pv210_dram_conf[0].freq = clk_get_rate(dmc0_clk);
 542
 543         s5pv210_dram_conf[1].refresh = (__raw_readl(S5P_VA_DMC1 + 0x30) * 1000);
 544         s5pv210_dram_conf[1].freq = clk_get_rate(dmc1_clk);
 545
 546         return cpufreq_generic_init(policy, s5pv210_freq_table, 40000);
 547
 548 out_dmc1:
 549         clk_put(dmc0_clk);
 550 out_dmc0:
 551         clk_put(cpu_clk);
 552         return ret;
 553 }
 554
 555 static int s5pv210_cpufreq_notifier_event(struct notifier_block *this,
 556                                           unsigned long event, void *ptr)
 557 {
 558         int ret;
 559
 560         switch (event) {
 561         case PM_SUSPEND_PREPARE:
 562                 ret = cpufreq_driver_target(cpufreq_cpu_get(0), SLEEP_FREQ,
 563                                             DISABLE_FURTHER_CPUFREQ);
 564                 if (ret < 0)
 565                         return NOTIFY_BAD;
 566
 567                 return NOTIFY_OK;
 568         case PM_POST_RESTORE:
 569         case PM_POST_SUSPEND:
 570                 cpufreq_driver_target(cpufreq_cpu_get(0), SLEEP_FREQ,
 571                                       ENABLE_FURTHER_CPUFREQ);
 572
 573                 return NOTIFY_OK;
 574         }
 575
 576         return NOTIFY_DONE;
 577 }
 578
 579 static int s5pv210_cpufreq_reboot_notifier_event(struct notifier_block *this,
 580                                                  unsigned long event, void *ptr)
 581 {
 582         int ret;
 583
 584         ret = cpufreq_driver_target(cpufreq_cpu_get(0), SLEEP_FREQ,
 585                                     DISABLE_FURTHER_CPUFREQ);
 586         if (ret < 0)
 587                 return NOTIFY_BAD;
 588
 589         return NOTIFY_DONE;
 590 }
 591
 592 static struct cpufreq_driver s5pv210_driver = {
 593         .flags          = CPUFREQ_STICKY,
 594         .verify         = cpufreq_generic_frequency_table_verify,
 595         .target         = s5pv210_target,
 596         .get            = s5pv210_getspeed,
 597         .init           = s5pv210_cpu_init,
 598         .name           = "s5pv210",
 599 #ifdef CONFIG_PM
 600         .suspend        = s5pv210_cpufreq_suspend,
 601         .resume         = s5pv210_cpufreq_resume,
 602 #endif
 603 };
 604
 605 static struct notifier_block s5pv210_cpufreq_notifier = {
 606         .notifier_call = s5pv210_cpufreq_notifier_event,
 607 };
 608
 609 static struct notifier_block s5pv210_cpufreq_reboot_notifier = {
 610         .notifier_call = s5pv210_cpufreq_reboot_notifier_event,
 611 };
 612
 613 static int __init s5pv210_cpufreq_init(void)
 614 {
 615         arm_regulator = regulator_get(NULL, "vddarm");
 616         if (IS_ERR(arm_regulator)) {
 617                 pr_err("failed to get regulator vddarm");
 618                 return PTR_ERR(arm_regulator);
 619         }
 620
 621         int_regulator = regulator_get(NULL, "vddint");
 622         if (IS_ERR(int_regulator)) {
 623                 pr_err("failed to get regulator vddint");
 624                 regulator_put(arm_regulator);
 625                 return PTR_ERR(int_regulator);
 626         }
 627
 628         register_pm_notifier(&s5pv210_cpufreq_notifier);
 629         register_reboot_notifier(&s5pv210_cpufreq_reboot_notifier);
 630
 631         return cpufreq_register_driver(&s5pv210_driver);
 632 }
 633
 634 late_initcall(s5pv210_cpufreq_init);