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