arch/arm/mach-msm/acpuclock-arm11.c

   1 /* arch/arm/mach-msm/acpuclock.c
   2  *
   3  * MSM architecture clock driver
   4  *
   5  * Copyright (C) 2007 Google, Inc.
   6  * Copyright (c) 2007 QUALCOMM Incorporated
   7  * Author: San Mehat <san@android.com>
   8  *
   9  * This software is licensed under the terms of the GNU General Public
  10  * License version 2, as published by the Free Software Foundation, and
  11  * may be copied, distributed, and modified under those terms.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  */
  19
  20 #include <linux/kernel.h>
  21 #include <linux/init.h>
  22 #include <linux/list.h>
  23 #include <linux/errno.h>
  24 #include <linux/string.h>
  25 #include <linux/delay.h>
  26 #include <linux/clk.h>
  27 #include <linux/cpufreq.h>
  28 #include <linux/mutex.h>
  29 #include <linux/io.h>
  30 #include <mach/board.h>
  31 #include <mach/msm_iomap.h>
  32
  33 #include "proc_comm.h"
  34 #include "acpuclock.h"
  35
  36
  37 #define A11S_CLK_CNTL_ADDR (MSM_CSR_BASE + 0x100)
  38 #define A11S_CLK_SEL_ADDR (MSM_CSR_BASE + 0x104)
  39 #define A11S_VDD_SVS_PLEVEL_ADDR (MSM_CSR_BASE + 0x124)
  40
  41 /*
  42  * ARM11 clock configuration for specific ACPU speeds
  43  */
  44
  45 #define ACPU_PLL_TCXO   -1
  46 #define ACPU_PLL_0      0
  47 #define ACPU_PLL_1      1
  48 #define ACPU_PLL_2      2
  49 #define ACPU_PLL_3      3
  50
  51 #define PERF_SWITCH_DEBUG 0
  52 #define PERF_SWITCH_STEP_DEBUG 0
  53
  54 struct clock_state
  55 {
  56         struct clkctl_acpu_speed        *current_speed;
  57         struct mutex                    lock;
  58         uint32_t                        acpu_switch_time_us;
  59         uint32_t                        max_speed_delta_khz;
  60         uint32_t                        vdd_switch_time_us;
  61         unsigned long                   power_collapse_khz;
  62         unsigned long                   wait_for_irq_khz;
  63 };
  64
  65 static struct clk *ebi1_clk;
  66 static struct clock_state drv_state = { 0 };
  67
  68 static void __init acpuclk_init(void);
  69
  70 /* MSM7201A Levels 3-6 all correspond to 1.2V, level 7 corresponds to 1.325V. */
  71 enum {
  72         VDD_0 = 0,
  73         VDD_1 = 1,
  74         VDD_2 = 2,
  75         VDD_3 = 3,
  76         VDD_4 = 3,
  77         VDD_5 = 3,
  78         VDD_6 = 3,
  79         VDD_7 = 7,
  80         VDD_END
  81 };
  82
  83 struct clkctl_acpu_speed {
  84         unsigned int    a11clk_khz;
  85         int             pll;
  86         unsigned int    a11clk_src_sel;
  87         unsigned int    a11clk_src_div;
  88         unsigned int    ahbclk_khz;
  89         unsigned int    ahbclk_div;
  90         int             vdd;
  91         unsigned int    axiclk_khz;
  92         unsigned long   lpj; /* loops_per_jiffy */
  93 /* Index in acpu_freq_tbl[] for steppings. */
  94         short           down;
  95         short           up;
  96 };
  97
  98 /*
  99  * ACPU speed table. Complete table is shown but certain speeds are commented
 100  * out to optimized speed switching. Initialize loops_per_jiffy to 0.
 101  *
 102  * Table stepping up/down is optimized for 256mhz jumps while staying on the
 103  * same PLL.
 104  */
 105 #if (0)
 106 static struct clkctl_acpu_speed  acpu_freq_tbl[] = {
 107         { 19200, ACPU_PLL_TCXO, 0, 0, 19200, 0, VDD_0, 30720, 0, 0, 8 },
 108         { 61440, ACPU_PLL_0,  4, 3, 61440,  0, VDD_0, 30720,  0, 0, 8 },
 109         { 81920, ACPU_PLL_0,  4, 2, 40960,  1, VDD_0, 61440,  0, 0, 8 },
 110         { 96000, ACPU_PLL_1,  1, 7, 48000,  1, VDD_0, 61440,  0, 0, 9 },
 111         { 122880, ACPU_PLL_0, 4, 1, 61440,  1, VDD_3, 61440,  0, 0, 8 },
 112         { 128000, ACPU_PLL_1, 1, 5, 64000,  1, VDD_3, 61440,  0, 0, 12 },
 113         { 176000, ACPU_PLL_2, 2, 5, 88000,  1, VDD_3, 61440,  0, 0, 11 },
 114         { 192000, ACPU_PLL_1, 1, 3, 64000,  2, VDD_3, 61440,  0, 0, 12 },
 115         { 245760, ACPU_PLL_0, 4, 0, 81920,  2, VDD_4, 61440,  0, 0, 12 },
 116         { 256000, ACPU_PLL_1, 1, 2, 128000, 2, VDD_5, 128000, 0, 0, 12 },
 117         { 264000, ACPU_PLL_2, 2, 3, 88000,  2, VDD_5, 128000, 0, 6, 13 },
 118         { 352000, ACPU_PLL_2, 2, 2, 88000,  3, VDD_5, 128000, 0, 6, 13 },
 119         { 384000, ACPU_PLL_1, 1, 1, 128000, 2, VDD_6, 128000, 0, 5, -1 },
 120         { 528000, ACPU_PLL_2, 2, 1, 132000, 3, VDD_7, 128000, 0, 11, -1 },
 121         { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
 122 };
 123 #else /* Table of freq we currently use. */
 124 static struct clkctl_acpu_speed  acpu_freq_tbl[] = {
 125         { 19200, ACPU_PLL_TCXO, 0, 0, 19200, 0, VDD_0, 30720, 0, 0, 4 },
 126         { 122880, ACPU_PLL_0, 4, 1, 61440, 1, VDD_3, 61440, 0, 0, 4 },
 127         { 128000, ACPU_PLL_1, 1, 5, 64000, 1, VDD_3, 61440, 0, 0, 6 },
 128         { 176000, ACPU_PLL_2, 2, 5, 88000, 1, VDD_3, 61440, 0, 0, 5 },
 129         { 245760, ACPU_PLL_0, 4, 0, 81920, 2, VDD_4, 61440, 0, 0, 5 },
 130         { 352000, ACPU_PLL_2, 2, 2, 88000, 3, VDD_5, 128000, 0, 3, 7 },
 131         { 384000, ACPU_PLL_1, 1, 1, 128000, 2, VDD_6, 128000, 0, 2, -1 },
 132         { 528000, ACPU_PLL_2, 2, 1, 132000, 3, VDD_7, 128000, 0, 5, -1 },
 133         { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
 134 };
 135 #endif
 136
 137
 138 #ifdef CONFIG_CPU_FREQ_TABLE
 139 static struct cpufreq_frequency_table freq_table[] = {
 140         { 0, 122880 },
 141         { 1, 128000 },
 142         { 2, 245760 },
 143         { 3, 384000 },
 144         { 4, 528000 },
 145         { 5, CPUFREQ_TABLE_END },
 146 };
 147 #endif
 148
 149 static int pc_pll_request(unsigned id, unsigned on)
 150 {
 151         int res;
 152         on = !!on;
 153
 154 #if PERF_SWITCH_DEBUG
 155         if (on)
 156                 printk(KERN_DEBUG "Enabling PLL %d\n", id);
 157         else
 158                 printk(KERN_DEBUG "Disabling PLL %d\n", id);
 159 #endif
 160
 161         res = msm_proc_comm(PCOM_CLKCTL_RPC_PLL_REQUEST, &id, &on);
 162         if (res < 0)
 163                 return res;
 164
 165 #if PERF_SWITCH_DEBUG
 166         if (on)
 167                 printk(KERN_DEBUG "PLL %d enabled\n", id);
 168         else
 169                 printk(KERN_DEBUG "PLL %d disabled\n", id);
 170 #endif
 171         return res;
 172 }
 173
 174
 175 /*----------------------------------------------------------------------------
 176  * ARM11 'owned' clock control
 177  *---------------------------------------------------------------------------*/
 178
 179 unsigned long acpuclk_power_collapse(void) {
 180         int ret = acpuclk_get_rate();
 181         ret *= 1000;
 182         if (ret > drv_state.power_collapse_khz)
 183                 acpuclk_set_rate(drv_state.power_collapse_khz, 1);
 184         return ret;
 185 }
 186
 187 unsigned long acpuclk_get_wfi_rate(void)
 188 {
 189         return drv_state.wait_for_irq_khz;
 190 }
 191
 192 unsigned long acpuclk_wait_for_irq(void) {
 193         int ret = acpuclk_get_rate();
 194         ret *= 1000;
 195         if (ret > drv_state.wait_for_irq_khz)
 196                 acpuclk_set_rate(drv_state.wait_for_irq_khz, 1);
 197         return ret;
 198 }
 199
 200 static int acpuclk_set_vdd_level(int vdd)
 201 {
 202         uint32_t current_vdd;
 203
 204         current_vdd = readl(A11S_VDD_SVS_PLEVEL_ADDR) & 0x07;
 205
 206 #if PERF_SWITCH_DEBUG
 207         printk(KERN_DEBUG "acpuclock: Switching VDD from %u -> %d\n",
 208                current_vdd, vdd);
 209 #endif
 210         writel((1 << 7) | (vdd << 3), A11S_VDD_SVS_PLEVEL_ADDR);
 211         udelay(drv_state.vdd_switch_time_us);
 212         if ((readl(A11S_VDD_SVS_PLEVEL_ADDR) & 0x7) != vdd) {
 213 #if PERF_SWITCH_DEBUG
 214                 printk(KERN_ERR "acpuclock: VDD set failed\n");
 215 #endif
 216                 return -EIO;
 217         }
 218
 219 #if PERF_SWITCH_DEBUG
 220         printk(KERN_DEBUG "acpuclock: VDD switched\n");
 221 #endif
 222         return 0;
 223 }
 224
 225 /* Set proper dividers for the given clock speed. */
 226 static void acpuclk_set_div(const struct clkctl_acpu_speed *hunt_s) {
 227         uint32_t reg_clkctl, reg_clksel, clk_div;
 228
 229         /* AHB_CLK_DIV */
 230         clk_div = (readl(A11S_CLK_SEL_ADDR) >> 1) & 0x03;
 231         /*
 232          * If the new clock divider is higher than the previous, then
 233          * program the divider before switching the clock
 234          */
 235         if (hunt_s->ahbclk_div > clk_div) {
 236                 reg_clksel = readl(A11S_CLK_SEL_ADDR);
 237                 reg_clksel &= ~(0x3 << 1);
 238                 reg_clksel |= (hunt_s->ahbclk_div << 1);
 239                 writel(reg_clksel, A11S_CLK_SEL_ADDR);
 240         }
 241         if ((readl(A11S_CLK_SEL_ADDR) & 0x01) == 0) {
 242                 /* SRC0 */
 243
 244                 /* Program clock source */
 245                 reg_clkctl = readl(A11S_CLK_CNTL_ADDR);
 246                 reg_clkctl &= ~(0x07 << 4);
 247                 reg_clkctl |= (hunt_s->a11clk_src_sel << 4);
 248                 writel(reg_clkctl, A11S_CLK_CNTL_ADDR);
 249
 250                 /* Program clock divider */
 251                 reg_clkctl = readl(A11S_CLK_CNTL_ADDR);
 252                 reg_clkctl &= ~0xf;
 253                 reg_clkctl |= hunt_s->a11clk_src_div;
 254                 writel(reg_clkctl, A11S_CLK_CNTL_ADDR);
 255
 256                 /* Program clock source selection */
 257                 reg_clksel = readl(A11S_CLK_SEL_ADDR);
 258                 reg_clksel |= 1; /* CLK_SEL_SRC1NO  == SRC1 */
 259                 writel(reg_clksel, A11S_CLK_SEL_ADDR);
 260         } else {
 261                 /* SRC1 */
 262
 263                 /* Program clock source */
 264                 reg_clkctl = readl(A11S_CLK_CNTL_ADDR);
 265                 reg_clkctl &= ~(0x07 << 12);
 266                 reg_clkctl |= (hunt_s->a11clk_src_sel << 12);
 267                 writel(reg_clkctl, A11S_CLK_CNTL_ADDR);
 268
 269                 /* Program clock divider */
 270                 reg_clkctl = readl(A11S_CLK_CNTL_ADDR);
 271                 reg_clkctl &= ~(0xf << 8);
 272                 reg_clkctl |= (hunt_s->a11clk_src_div << 8);
 273                 writel(reg_clkctl, A11S_CLK_CNTL_ADDR);
 274
 275                 /* Program clock source selection */
 276                 reg_clksel = readl(A11S_CLK_SEL_ADDR);
 277                 reg_clksel &= ~1; /* CLK_SEL_SRC1NO  == SRC0 */
 278                 writel(reg_clksel, A11S_CLK_SEL_ADDR);
 279         }
 280
 281         /*
 282          * If the new clock divider is lower than the previous, then
 283          * program the divider after switching the clock
 284          */
 285         if (hunt_s->ahbclk_div < clk_div) {
 286                 reg_clksel = readl(A11S_CLK_SEL_ADDR);
 287                 reg_clksel &= ~(0x3 << 1);
 288                 reg_clksel |= (hunt_s->ahbclk_div << 1);
 289                 writel(reg_clksel, A11S_CLK_SEL_ADDR);
 290         }
 291 }
 292
 293 int acpuclk_set_rate(unsigned long rate, int for_power_collapse)
 294 {
 295         uint32_t reg_clkctl;
 296         struct clkctl_acpu_speed *cur_s, *tgt_s, *strt_s;
 297         int rc = 0;
 298         unsigned int plls_enabled = 0, pll;
 299
 300         strt_s = cur_s = drv_state.current_speed;
 301
 302         WARN_ONCE(cur_s == NULL, "acpuclk_set_rate: not initialized\n");
 303         if (cur_s == NULL)
 304                 return -ENOENT;
 305
 306         if (rate == (cur_s->a11clk_khz * 1000))
 307                 return 0;
 308
 309         for (tgt_s = acpu_freq_tbl; tgt_s->a11clk_khz != 0; tgt_s++) {
 310                 if (tgt_s->a11clk_khz == (rate / 1000))
 311                         break;
 312         }
 313
 314         if (tgt_s->a11clk_khz == 0)
 315                 return -EINVAL;
 316
 317         /* Choose the highest speed speed at or below 'rate' with same PLL. */
 318         if (for_power_collapse && tgt_s->a11clk_khz < cur_s->a11clk_khz) {
 319                 while (tgt_s->pll != ACPU_PLL_TCXO && tgt_s->pll != cur_s->pll)
 320                         tgt_s--;
 321         }
 322
 323         if (strt_s->pll != ACPU_PLL_TCXO)
 324                 plls_enabled |= 1 << strt_s->pll;
 325
 326         if (!for_power_collapse) {
 327                 mutex_lock(&drv_state.lock);
 328                 if (strt_s->pll != tgt_s->pll && tgt_s->pll != ACPU_PLL_TCXO) {
 329                         rc = pc_pll_request(tgt_s->pll, 1);
 330                         if (rc < 0) {
 331                                 pr_err("PLL%d enable failed (%d)\n",
 332                                         tgt_s->pll, rc);
 333                                 goto out;
 334                         }
 335                         plls_enabled |= 1 << tgt_s->pll;
 336                 }
 337                 /* Increase VDD if needed. */
 338                 if (tgt_s->vdd > cur_s->vdd) {
 339                         if ((rc = acpuclk_set_vdd_level(tgt_s->vdd)) < 0) {
 340                                 printk(KERN_ERR "Unable to switch ACPU vdd\n");
 341                                 goto out;
 342                         }
 343                 }
 344         }
 345
 346         /* Set wait states for CPU between frequency changes */
 347         reg_clkctl = readl(A11S_CLK_CNTL_ADDR);
 348         reg_clkctl |= (100 << 16); /* set WT_ST_CNT */
 349         writel(reg_clkctl, A11S_CLK_CNTL_ADDR);
 350
 351 #if PERF_SWITCH_DEBUG
 352         printk(KERN_INFO "acpuclock: Switching from ACPU rate %u -> %u\n",
 353                strt_s->a11clk_khz * 1000, tgt_s->a11clk_khz * 1000);
 354 #endif
 355
 356         while (cur_s != tgt_s) {
 357                 /*
 358                  * Always jump to target freq if within 256mhz, regulardless of
 359                  * PLL. If differnece is greater, use the predefinied
 360                  * steppings in the table.
 361                  */
 362                 int d = abs((int)(cur_s->a11clk_khz - tgt_s->a11clk_khz));
 363                 if (d > drv_state.max_speed_delta_khz) {
 364                         /* Step up or down depending on target vs current. */
 365                         int clk_index = tgt_s->a11clk_khz > cur_s->a11clk_khz ?
 366                                 cur_s->up : cur_s->down;
 367                         if (clk_index < 0) { /* This should not happen. */
 368                                 printk(KERN_ERR "cur:%u target: %u\n",
 369                                         cur_s->a11clk_khz, tgt_s->a11clk_khz);
 370                                 rc = -EINVAL;
 371                                 goto out;
 372                         }
 373                         cur_s = &acpu_freq_tbl[clk_index];
 374                 } else {
 375                         cur_s = tgt_s;
 376                 }
 377 #if PERF_SWITCH_STEP_DEBUG
 378                 printk(KERN_DEBUG "%s: STEP khz = %u, pll = %d\n",
 379                         __func__, cur_s->a11clk_khz, cur_s->pll);
 380 #endif
 381                 if (!for_power_collapse&& cur_s->pll != ACPU_PLL_TCXO
 382                     && !(plls_enabled & (1 << cur_s->pll))) {
 383                         rc = pc_pll_request(cur_s->pll, 1);
 384                         if (rc < 0) {
 385                                 pr_err("PLL%d enable failed (%d)\n",
 386                                         cur_s->pll, rc);
 387                                 goto out;
 388                         }
 389                         plls_enabled |= 1 << cur_s->pll;
 390                 }
 391
 392                 acpuclk_set_div(cur_s);
 393                 drv_state.current_speed = cur_s;
 394                 /* Re-adjust lpj for the new clock speed. */
 395                 loops_per_jiffy = cur_s->lpj;
 396                 udelay(drv_state.acpu_switch_time_us);
 397         }
 398
 399         /* Nothing else to do for power collapse. */
 400         if (for_power_collapse)
 401                 return 0;
 402
 403         /* Disable PLLs we are not using anymore. */
 404         plls_enabled &= ~(1 << tgt_s->pll);
 405         for (pll = ACPU_PLL_0; pll <= ACPU_PLL_2; pll++)
 406                 if (plls_enabled & (1 << pll)) {
 407                         rc = pc_pll_request(pll, 0);
 408                         if (rc < 0) {
 409                                 pr_err("PLL%d disable failed (%d)\n", pll, rc);
 410                                 goto out;
 411                         }
 412                 }
 413
 414         /* Change the AXI bus frequency if we can. */
 415         if (strt_s->axiclk_khz != tgt_s->axiclk_khz) {
 416                 rc = clk_set_rate(ebi1_clk, tgt_s->axiclk_khz * 1000);
 417                 if (rc < 0)
 418                         pr_err("Setting AXI min rate failed!\n");
 419         }
 420
 421         /* Drop VDD level if we can. */
 422         if (tgt_s->vdd < strt_s->vdd) {
 423                 if (acpuclk_set_vdd_level(tgt_s->vdd) < 0)
 424                         printk(KERN_ERR "acpuclock: Unable to drop ACPU vdd\n");
 425         }
 426
 427 #if PERF_SWITCH_DEBUG
 428         printk(KERN_DEBUG "%s: ACPU speed change complete\n", __FUNCTION__);
 429 #endif
 430 out:
 431         if (!for_power_collapse)
 432                 mutex_unlock(&drv_state.lock);
 433         return rc;
 434 }
 435
 436 static void __init acpuclk_init(void)
 437 {
 438         struct clkctl_acpu_speed *speed;
 439         uint32_t div, sel;
 440         int rc;
 441
 442         /*
 443          * Determine the rate of ACPU clock
 444          */
 445
 446         if (!(readl(A11S_CLK_SEL_ADDR) & 0x01)) { /* CLK_SEL_SRC1N0 */
 447                 /* CLK_SRC0_SEL */
 448                 sel = (readl(A11S_CLK_CNTL_ADDR) >> 12) & 0x7;
 449                 /* CLK_SRC0_DIV */
 450                 div = (readl(A11S_CLK_CNTL_ADDR) >> 8) & 0x0f;
 451         } else {
 452                 /* CLK_SRC1_SEL */
 453                 sel = (readl(A11S_CLK_CNTL_ADDR) >> 4) & 0x07;
 454                 /* CLK_SRC1_DIV */
 455                 div = readl(A11S_CLK_CNTL_ADDR) & 0x0f;
 456         }
 457
 458         for (speed = acpu_freq_tbl; speed->a11clk_khz != 0; speed++) {
 459                 if (speed->a11clk_src_sel == sel
 460                  && (speed->a11clk_src_div == div))
 461                         break;
 462         }
 463         if (speed->a11clk_khz == 0) {
 464                 printk(KERN_WARNING "Warning - ACPU clock reports invalid speed\n");
 465                 return;
 466         }
 467
 468         drv_state.current_speed = speed;
 469
 470         rc = clk_set_rate(ebi1_clk, speed->axiclk_khz * 1000);
 471         if (rc < 0)
 472                 pr_err("Setting AXI min rate failed!\n");
 473
 474         printk(KERN_INFO "ACPU running at %d KHz\n", speed->a11clk_khz);
 475 }
 476
 477 unsigned long acpuclk_get_rate(void)
 478 {
 479         WARN_ONCE(drv_state.current_speed == NULL,
 480                   "acpuclk_get_rate: not initialized\n");
 481         if (drv_state.current_speed)
 482                 return drv_state.current_speed->a11clk_khz;
 483         else
 484                 return 0;
 485 }
 486
 487 uint32_t acpuclk_get_switch_time(void)
 488 {
 489         return drv_state.acpu_switch_time_us;
 490 }
 491
 492 /*----------------------------------------------------------------------------
 493  * Clock driver initialization
 494  *---------------------------------------------------------------------------*/
 495
 496 /* Initialize the lpj field in the acpu_freq_tbl. */
 497 static void __init lpj_init(void)
 498 {
 499         int i;
 500         const struct clkctl_acpu_speed *base_clk = drv_state.current_speed;
 501         for (i = 0; acpu_freq_tbl[i].a11clk_khz; i++) {
 502                 acpu_freq_tbl[i].lpj = cpufreq_scale(loops_per_jiffy,
 503                                                 base_clk->a11clk_khz,
 504                                                 acpu_freq_tbl[i].a11clk_khz);
 505         }
 506 }
 507
 508 void __init msm_acpu_clock_init(struct msm_acpu_clock_platform_data *clkdata)
 509 {
 510         pr_info("acpu_clock_init()\n");
 511
 512         ebi1_clk = clk_get(NULL, "ebi1_clk");
 513
 514         mutex_init(&drv_state.lock);
 515         drv_state.acpu_switch_time_us = clkdata->acpu_switch_time_us;
 516         drv_state.max_speed_delta_khz = clkdata->max_speed_delta_khz;
 517         drv_state.vdd_switch_time_us = clkdata->vdd_switch_time_us;
 518         drv_state.power_collapse_khz = clkdata->power_collapse_khz;
 519         drv_state.wait_for_irq_khz = clkdata->wait_for_irq_khz;
 520         acpuclk_init();
 521         lpj_init();
 522 #ifdef CONFIG_CPU_FREQ_TABLE
 523         cpufreq_frequency_table_get_attr(freq_table, smp_processor_id());
 524 #endif
 525 }