arch/arm/mach-omap1/clock.c

   1 /*
   2  *  linux/arch/arm/mach-omap1/clock.c
   3  *
   4  *  Copyright (C) 2004 - 2005, 2009-2010 Nokia Corporation
   5  *  Written by Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>
   6  *
   7  *  Modified to use omap shared clock framework by
   8  *  Tony Lindgren <tony@atomide.com>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  */
  14 #include <linux/kernel.h>
  15 #include <linux/list.h>
  16 #include <linux/errno.h>
  17 #include <linux/err.h>
  18 #include <linux/io.h>
  19 #include <linux/clk.h>
  20 #include <linux/clkdev.h>
  21
  22 #include <asm/mach-types.h>
  23
  24 #include <plat/cpu.h>
  25 #include <plat/usb.h>
  26 #include <plat/clock.h>
  27 #include <plat/sram.h>
  28 #include <plat/clkdev_omap.h>
  29
  30 #include <mach/hardware.h>
  31
  32 #include "iomap.h"
  33 #include "clock.h"
  34 #include "opp.h"
  35
  36 __u32 arm_idlect1_mask;
  37 struct clk *api_ck_p, *ck_dpll1_p, *ck_ref_p;
  38
  39 /*
  40  * Omap1 specific clock functions
  41  */
  42
  43 unsigned long omap1_uart_recalc(struct clk *clk)
  44 {
  45         unsigned int val = __raw_readl(clk->enable_reg);
  46         return val & clk->enable_bit ? 48000000 : 12000000;
  47 }
  48
  49 unsigned long omap1_sossi_recalc(struct clk *clk)
  50 {
  51         u32 div = omap_readl(MOD_CONF_CTRL_1);
  52
  53         div = (div >> 17) & 0x7;
  54         div++;
  55
  56         return clk->parent->rate / div;
  57 }
  58
  59 static void omap1_clk_allow_idle(struct clk *clk)
  60 {
  61         struct arm_idlect1_clk * iclk = (struct arm_idlect1_clk *)clk;
  62
  63         if (!(clk->flags & CLOCK_IDLE_CONTROL))
  64                 return;
  65
  66         if (iclk->no_idle_count > 0 && !(--iclk->no_idle_count))
  67                 arm_idlect1_mask |= 1 << iclk->idlect_shift;
  68 }
  69
  70 static void omap1_clk_deny_idle(struct clk *clk)
  71 {
  72         struct arm_idlect1_clk * iclk = (struct arm_idlect1_clk *)clk;
  73
  74         if (!(clk->flags & CLOCK_IDLE_CONTROL))
  75                 return;
  76
  77         if (iclk->no_idle_count++ == 0)
  78                 arm_idlect1_mask &= ~(1 << iclk->idlect_shift);
  79 }
  80
  81 static __u16 verify_ckctl_value(__u16 newval)
  82 {
  83         /* This function checks for following limitations set
  84          * by the hardware (all conditions must be true):
  85          * DSPMMU_CK == DSP_CK  or  DSPMMU_CK == DSP_CK/2
  86          * ARM_CK >= TC_CK
  87          * DSP_CK >= TC_CK
  88          * DSPMMU_CK >= TC_CK
  89          *
  90          * In addition following rules are enforced:
  91          * LCD_CK <= TC_CK
  92          * ARMPER_CK <= TC_CK
  93          *
  94          * However, maximum frequencies are not checked for!
  95          */
  96         __u8 per_exp;
  97         __u8 lcd_exp;
  98         __u8 arm_exp;
  99         __u8 dsp_exp;
 100         __u8 tc_exp;
 101         __u8 dspmmu_exp;
 102
 103         per_exp = (newval >> CKCTL_PERDIV_OFFSET) & 3;
 104         lcd_exp = (newval >> CKCTL_LCDDIV_OFFSET) & 3;
 105         arm_exp = (newval >> CKCTL_ARMDIV_OFFSET) & 3;
 106         dsp_exp = (newval >> CKCTL_DSPDIV_OFFSET) & 3;
 107         tc_exp = (newval >> CKCTL_TCDIV_OFFSET) & 3;
 108         dspmmu_exp = (newval >> CKCTL_DSPMMUDIV_OFFSET) & 3;
 109
 110         if (dspmmu_exp < dsp_exp)
 111                 dspmmu_exp = dsp_exp;
 112         if (dspmmu_exp > dsp_exp+1)
 113                 dspmmu_exp = dsp_exp+1;
 114         if (tc_exp < arm_exp)
 115                 tc_exp = arm_exp;
 116         if (tc_exp < dspmmu_exp)
 117                 tc_exp = dspmmu_exp;
 118         if (tc_exp > lcd_exp)
 119                 lcd_exp = tc_exp;
 120         if (tc_exp > per_exp)
 121                 per_exp = tc_exp;
 122
 123         newval &= 0xf000;
 124         newval |= per_exp << CKCTL_PERDIV_OFFSET;
 125         newval |= lcd_exp << CKCTL_LCDDIV_OFFSET;
 126         newval |= arm_exp << CKCTL_ARMDIV_OFFSET;
 127         newval |= dsp_exp << CKCTL_DSPDIV_OFFSET;
 128         newval |= tc_exp << CKCTL_TCDIV_OFFSET;
 129         newval |= dspmmu_exp << CKCTL_DSPMMUDIV_OFFSET;
 130
 131         return newval;
 132 }
 133
 134 static int calc_dsor_exp(struct clk *clk, unsigned long rate)
 135 {
 136         /* Note: If target frequency is too low, this function will return 4,
 137          * which is invalid value. Caller must check for this value and act
 138          * accordingly.
 139          *
 140          * Note: This function does not check for following limitations set
 141          * by the hardware (all conditions must be true):
 142          * DSPMMU_CK == DSP_CK  or  DSPMMU_CK == DSP_CK/2
 143          * ARM_CK >= TC_CK
 144          * DSP_CK >= TC_CK
 145          * DSPMMU_CK >= TC_CK
 146          */
 147         unsigned long realrate;
 148         struct clk * parent;
 149         unsigned  dsor_exp;
 150
 151         parent = clk->parent;
 152         if (unlikely(parent == NULL))
 153                 return -EIO;
 154
 155         realrate = parent->rate;
 156         for (dsor_exp=0; dsor_exp<4; dsor_exp++) {
 157                 if (realrate <= rate)
 158                         break;
 159
 160                 realrate /= 2;
 161         }
 162
 163         return dsor_exp;
 164 }
 165
 166 unsigned long omap1_ckctl_recalc(struct clk *clk)
 167 {
 168         /* Calculate divisor encoded as 2-bit exponent */
 169         int dsor = 1 << (3 & (omap_readw(ARM_CKCTL) >> clk->rate_offset));
 170
 171         return clk->parent->rate / dsor;
 172 }
 173
 174 unsigned long omap1_ckctl_recalc_dsp_domain(struct clk *clk)
 175 {
 176         int dsor;
 177
 178         /* Calculate divisor encoded as 2-bit exponent
 179          *
 180          * The clock control bits are in DSP domain,
 181          * so api_ck is needed for access.
 182          * Note that DSP_CKCTL virt addr = phys addr, so
 183          * we must use __raw_readw() instead of omap_readw().
 184          */
 185         omap1_clk_enable(api_ck_p);
 186         dsor = 1 << (3 & (__raw_readw(DSP_CKCTL) >> clk->rate_offset));
 187         omap1_clk_disable(api_ck_p);
 188
 189         return clk->parent->rate / dsor;
 190 }
 191
 192 /* MPU virtual clock functions */
 193 int omap1_select_table_rate(struct clk *clk, unsigned long rate)
 194 {
 195         /* Find the highest supported frequency <= rate and switch to it */
 196         struct mpu_rate * ptr;
 197         unsigned long ref_rate;
 198
 199         ref_rate = ck_ref_p->rate;
 200
 201         for (ptr = omap1_rate_table; ptr->rate; ptr++) {
 202                 if (!(ptr->flags & cpu_mask))
 203                         continue;
 204
 205                 if (ptr->xtal != ref_rate)
 206                         continue;
 207
 208                 /* Can check only after xtal frequency check */
 209                 if (ptr->rate <= rate)
 210                         break;
 211         }
 212
 213         if (!ptr->rate)
 214                 return -EINVAL;
 215
 216         /*
 217          * In most cases we should not need to reprogram DPLL.
 218          * Reprogramming the DPLL is tricky, it must be done from SRAM.
 219          */
 220         omap_sram_reprogram_clock(ptr->dpllctl_val, ptr->ckctl_val);
 221
 222         /* XXX Do we need to recalculate the tree below DPLL1 at this point? */
 223         ck_dpll1_p->rate = ptr->pll_rate;
 224
 225         return 0;
 226 }
 227
 228 int omap1_clk_set_rate_dsp_domain(struct clk *clk, unsigned long rate)
 229 {
 230         int dsor_exp;
 231         u16 regval;
 232
 233         dsor_exp = calc_dsor_exp(clk, rate);
 234         if (dsor_exp > 3)
 235                 dsor_exp = -EINVAL;
 236         if (dsor_exp < 0)
 237                 return dsor_exp;
 238
 239         regval = __raw_readw(DSP_CKCTL);
 240         regval &= ~(3 << clk->rate_offset);
 241         regval |= dsor_exp << clk->rate_offset;
 242         __raw_writew(regval, DSP_CKCTL);
 243         clk->rate = clk->parent->rate / (1 << dsor_exp);
 244
 245         return 0;
 246 }
 247
 248 long omap1_clk_round_rate_ckctl_arm(struct clk *clk, unsigned long rate)
 249 {
 250         int dsor_exp = calc_dsor_exp(clk, rate);
 251         if (dsor_exp < 0)
 252                 return dsor_exp;
 253         if (dsor_exp > 3)
 254                 dsor_exp = 3;
 255         return clk->parent->rate / (1 << dsor_exp);
 256 }
 257
 258 int omap1_clk_set_rate_ckctl_arm(struct clk *clk, unsigned long rate)
 259 {
 260         int dsor_exp;
 261         u16 regval;
 262
 263         dsor_exp = calc_dsor_exp(clk, rate);
 264         if (dsor_exp > 3)
 265                 dsor_exp = -EINVAL;
 266         if (dsor_exp < 0)
 267                 return dsor_exp;
 268
 269         regval = omap_readw(ARM_CKCTL);
 270         regval &= ~(3 << clk->rate_offset);
 271         regval |= dsor_exp << clk->rate_offset;
 272         regval = verify_ckctl_value(regval);
 273         omap_writew(regval, ARM_CKCTL);
 274         clk->rate = clk->parent->rate / (1 << dsor_exp);
 275         return 0;
 276 }
 277
 278 long omap1_round_to_table_rate(struct clk *clk, unsigned long rate)
 279 {
 280         /* Find the highest supported frequency <= rate */
 281         struct mpu_rate * ptr;
 282         long highest_rate;
 283         unsigned long ref_rate;
 284
 285         ref_rate = ck_ref_p->rate;
 286
 287         highest_rate = -EINVAL;
 288
 289         for (ptr = omap1_rate_table; ptr->rate; ptr++) {
 290                 if (!(ptr->flags & cpu_mask))
 291                         continue;
 292
 293                 if (ptr->xtal != ref_rate)
 294                         continue;
 295
 296                 highest_rate = ptr->rate;
 297
 298                 /* Can check only after xtal frequency check */
 299                 if (ptr->rate <= rate)
 300                         break;
 301         }
 302
 303         return highest_rate;
 304 }
 305
 306 static unsigned calc_ext_dsor(unsigned long rate)
 307 {
 308         unsigned dsor;
 309
 310         /* MCLK and BCLK divisor selection is not linear:
 311          * freq = 96MHz / dsor
 312          *
 313          * RATIO_SEL range: dsor <-> RATIO_SEL
 314          * 0..6: (RATIO_SEL+2) <-> (dsor-2)
 315          * 6..48:  (8+(RATIO_SEL-6)*2) <-> ((dsor-8)/2+6)
 316          * Minimum dsor is 2 and maximum is 96. Odd divisors starting from 9
 317          * can not be used.
 318          */
 319         for (dsor = 2; dsor < 96; ++dsor) {
 320                 if ((dsor & 1) && dsor > 8)
 321                         continue;
 322                 if (rate >= 96000000 / dsor)
 323                         break;
 324         }
 325         return dsor;
 326 }
 327
 328 /* XXX Only needed on 1510 */
 329 int omap1_set_uart_rate(struct clk *clk, unsigned long rate)
 330 {
 331         unsigned int val;
 332
 333         val = __raw_readl(clk->enable_reg);
 334         if (rate == 12000000)
 335                 val &= ~(1 << clk->enable_bit);
 336         else if (rate == 48000000)
 337                 val |= (1 << clk->enable_bit);
 338         else
 339                 return -EINVAL;
 340         __raw_writel(val, clk->enable_reg);
 341         clk->rate = rate;
 342
 343         return 0;
 344 }
 345
 346 /* External clock (MCLK & BCLK) functions */
 347 int omap1_set_ext_clk_rate(struct clk *clk, unsigned long rate)
 348 {
 349         unsigned dsor;
 350         __u16 ratio_bits;
 351
 352         dsor = calc_ext_dsor(rate);
 353         clk->rate = 96000000 / dsor;
 354         if (dsor > 8)
 355                 ratio_bits = ((dsor - 8) / 2 + 6) << 2;
 356         else
 357                 ratio_bits = (dsor - 2) << 2;
 358
 359         ratio_bits |= __raw_readw(clk->enable_reg) & ~0xfd;
 360         __raw_writew(ratio_bits, clk->enable_reg);
 361
 362         return 0;
 363 }
 364
 365 int omap1_set_sossi_rate(struct clk *clk, unsigned long rate)
 366 {
 367         u32 l;
 368         int div;
 369         unsigned long p_rate;
 370
 371         p_rate = clk->parent->rate;
 372         /* Round towards slower frequency */
 373         div = (p_rate + rate - 1) / rate;
 374         div--;
 375         if (div < 0 || div > 7)
 376                 return -EINVAL;
 377
 378         l = omap_readl(MOD_CONF_CTRL_1);
 379         l &= ~(7 << 17);
 380         l |= div << 17;
 381         omap_writel(l, MOD_CONF_CTRL_1);
 382
 383         clk->rate = p_rate / (div + 1);
 384
 385         return 0;
 386 }
 387
 388 long omap1_round_ext_clk_rate(struct clk *clk, unsigned long rate)
 389 {
 390         return 96000000 / calc_ext_dsor(rate);
 391 }
 392
 393 void omap1_init_ext_clk(struct clk *clk)
 394 {
 395         unsigned dsor;
 396         __u16 ratio_bits;
 397
 398         /* Determine current rate and ensure clock is based on 96MHz APLL */
 399         ratio_bits = __raw_readw(clk->enable_reg) & ~1;
 400         __raw_writew(ratio_bits, clk->enable_reg);
 401
 402         ratio_bits = (ratio_bits & 0xfc) >> 2;
 403         if (ratio_bits > 6)
 404                 dsor = (ratio_bits - 6) * 2 + 8;
 405         else
 406                 dsor = ratio_bits + 2;
 407
 408         clk-> rate = 96000000 / dsor;
 409 }
 410
 411 int omap1_clk_enable(struct clk *clk)
 412 {
 413         int ret = 0;
 414
 415         if (clk->usecount++ == 0) {
 416                 if (clk->parent) {
 417                         ret = omap1_clk_enable(clk->parent);
 418                         if (ret)
 419                                 goto err;
 420
 421                         if (clk->flags & CLOCK_NO_IDLE_PARENT)
 422                                 omap1_clk_deny_idle(clk->parent);
 423                 }
 424
 425                 ret = clk->ops->enable(clk);
 426                 if (ret) {
 427                         if (clk->parent)
 428                                 omap1_clk_disable(clk->parent);
 429                         goto err;
 430                 }
 431         }
 432         return ret;
 433
 434 err:
 435         clk->usecount--;
 436         return ret;
 437 }
 438
 439 void omap1_clk_disable(struct clk *clk)
 440 {
 441         if (clk->usecount > 0 && !(--clk->usecount)) {
 442                 clk->ops->disable(clk);
 443                 if (likely(clk->parent)) {
 444                         omap1_clk_disable(clk->parent);
 445                         if (clk->flags & CLOCK_NO_IDLE_PARENT)
 446                                 omap1_clk_allow_idle(clk->parent);
 447                 }
 448         }
 449 }
 450
 451 static int omap1_clk_enable_generic(struct clk *clk)
 452 {
 453         __u16 regval16;
 454         __u32 regval32;
 455
 456         if (unlikely(clk->enable_reg == NULL)) {
 457                 printk(KERN_ERR "clock.c: Enable for %s without enable code\n",
 458                        clk->name);
 459                 return -EINVAL;
 460         }
 461
 462         if (clk->flags & ENABLE_REG_32BIT) {
 463                 regval32 = __raw_readl(clk->enable_reg);
 464                 regval32 |= (1 << clk->enable_bit);
 465                 __raw_writel(regval32, clk->enable_reg);
 466         } else {
 467                 regval16 = __raw_readw(clk->enable_reg);
 468                 regval16 |= (1 << clk->enable_bit);
 469                 __raw_writew(regval16, clk->enable_reg);
 470         }
 471
 472         return 0;
 473 }
 474
 475 static void omap1_clk_disable_generic(struct clk *clk)
 476 {
 477         __u16 regval16;
 478         __u32 regval32;
 479
 480         if (clk->enable_reg == NULL)
 481                 return;
 482
 483         if (clk->flags & ENABLE_REG_32BIT) {
 484                 regval32 = __raw_readl(clk->enable_reg);
 485                 regval32 &= ~(1 << clk->enable_bit);
 486                 __raw_writel(regval32, clk->enable_reg);
 487         } else {
 488                 regval16 = __raw_readw(clk->enable_reg);
 489                 regval16 &= ~(1 << clk->enable_bit);
 490                 __raw_writew(regval16, clk->enable_reg);
 491         }
 492 }
 493
 494 const struct clkops clkops_generic = {
 495         .enable         = omap1_clk_enable_generic,
 496         .disable        = omap1_clk_disable_generic,
 497 };
 498
 499 static int omap1_clk_enable_dsp_domain(struct clk *clk)
 500 {
 501         int retval;
 502
 503         retval = omap1_clk_enable(api_ck_p);
 504         if (!retval) {
 505                 retval = omap1_clk_enable_generic(clk);
 506                 omap1_clk_disable(api_ck_p);
 507         }
 508
 509         return retval;
 510 }
 511
 512 static void omap1_clk_disable_dsp_domain(struct clk *clk)
 513 {
 514         if (omap1_clk_enable(api_ck_p) == 0) {
 515                 omap1_clk_disable_generic(clk);
 516                 omap1_clk_disable(api_ck_p);
 517         }
 518 }
 519
 520 const struct clkops clkops_dspck = {
 521         .enable         = omap1_clk_enable_dsp_domain,
 522         .disable        = omap1_clk_disable_dsp_domain,
 523 };
 524
 525 /* XXX SYSC register handling does not belong in the clock framework */
 526 static int omap1_clk_enable_uart_functional_16xx(struct clk *clk)
 527 {
 528         int ret;
 529         struct uart_clk *uclk;
 530
 531         ret = omap1_clk_enable_generic(clk);
 532         if (ret == 0) {
 533                 /* Set smart idle acknowledgement mode */
 534                 uclk = (struct uart_clk *)clk;
 535                 omap_writeb((omap_readb(uclk->sysc_addr) & ~0x10) | 8,
 536                             uclk->sysc_addr);
 537         }
 538
 539         return ret;
 540 }
 541
 542 /* XXX SYSC register handling does not belong in the clock framework */
 543 static void omap1_clk_disable_uart_functional_16xx(struct clk *clk)
 544 {
 545         struct uart_clk *uclk;
 546
 547         /* Set force idle acknowledgement mode */
 548         uclk = (struct uart_clk *)clk;
 549         omap_writeb((omap_readb(uclk->sysc_addr) & ~0x18), uclk->sysc_addr);
 550
 551         omap1_clk_disable_generic(clk);
 552 }
 553
 554 /* XXX SYSC register handling does not belong in the clock framework */
 555 const struct clkops clkops_uart_16xx = {
 556         .enable         = omap1_clk_enable_uart_functional_16xx,
 557         .disable        = omap1_clk_disable_uart_functional_16xx,
 558 };
 559
 560 long omap1_clk_round_rate(struct clk *clk, unsigned long rate)
 561 {
 562         if (clk->round_rate != NULL)
 563                 return clk->round_rate(clk, rate);
 564
 565         return clk->rate;
 566 }
 567
 568 int omap1_clk_set_rate(struct clk *clk, unsigned long rate)
 569 {
 570         int  ret = -EINVAL;
 571
 572         if (clk->set_rate)
 573                 ret = clk->set_rate(clk, rate);
 574         return ret;
 575 }
 576
 577 /*
 578  * Omap1 clock reset and init functions
 579  */
 580
 581 #ifdef CONFIG_OMAP_RESET_CLOCKS
 582
 583 void omap1_clk_disable_unused(struct clk *clk)
 584 {
 585         __u32 regval32;
 586
 587         /* Clocks in the DSP domain need api_ck. Just assume bootloader
 588          * has not enabled any DSP clocks */
 589         if (clk->enable_reg == DSP_IDLECT2) {
 590                 printk(KERN_INFO "Skipping reset check for DSP domain "
 591                        "clock \"%s\"\n", clk->name);
 592                 return;
 593         }
 594
 595         /* Is the clock already disabled? */
 596         if (clk->flags & ENABLE_REG_32BIT)
 597                 regval32 = __raw_readl(clk->enable_reg);
 598         else
 599                 regval32 = __raw_readw(clk->enable_reg);
 600
 601         if ((regval32 & (1 << clk->enable_bit)) == 0)
 602                 return;
 603
 604         printk(KERN_INFO "Disabling unused clock \"%s\"... ", clk->name);
 605         clk->ops->disable(clk);
 606         printk(" done\n");
 607 }
 608
 609 #endif