arch/arm/mach-omap2/cm33xx.c

   1 /*
   2  * AM33XX CM functions
   3  *
   4  * Copyright (C) 2011-2012 Texas Instruments Incorporated - http://www.ti.com/
   5  * Vaibhav Hiremath <hvaibhav@ti.com>
   6  *
   7  * Reference taken from from OMAP4 cminst44xx.c
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License as
  11  * published by the Free Software Foundation version 2.
  12  *
  13  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
  14  * kind, whether express or implied; without even the implied warranty
  15  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  */
  18
  19 #include <linux/kernel.h>
  20 #include <linux/types.h>
  21 #include <linux/errno.h>
  22 #include <linux/err.h>
  23 #include <linux/io.h>
  24
  25 #include "clockdomain.h"
  26 #include "cm.h"
  27 #include "cm33xx.h"
  28 #include "cm-regbits-34xx.h"
  29 #include "cm-regbits-33xx.h"
  30 #include "prm33xx.h"
  31
  32 /*
  33  * CLKCTRL_IDLEST_*: possible values for the CM_*_CLKCTRL.IDLEST bitfield:
  34  *
  35  *   0x0 func:     Module is fully functional, including OCP
  36  *   0x1 trans:    Module is performing transition: wakeup, or sleep, or sleep
  37  *                 abortion
  38  *   0x2 idle:     Module is in Idle mode (only OCP part). It is functional if
  39  *                 using separate functional clock
  40  *   0x3 disabled: Module is disabled and cannot be accessed
  41  *
  42  */
  43 #define CLKCTRL_IDLEST_FUNCTIONAL               0x0
  44 #define CLKCTRL_IDLEST_INTRANSITION             0x1
  45 #define CLKCTRL_IDLEST_INTERFACE_IDLE           0x2
  46 #define CLKCTRL_IDLEST_DISABLED                 0x3
  47
  48 /* Private functions */
  49
  50 /* Read a register in a CM instance */
  51 static inline u32 am33xx_cm_read_reg(s16 inst, u16 idx)
  52 {
  53         return __raw_readl(cm_base + inst + idx);
  54 }
  55
  56 /* Write into a register in a CM */
  57 static inline void am33xx_cm_write_reg(u32 val, s16 inst, u16 idx)
  58 {
  59         __raw_writel(val, cm_base + inst + idx);
  60 }
  61
  62 /* Read-modify-write a register in CM */
  63 static inline u32 am33xx_cm_rmw_reg_bits(u32 mask, u32 bits, s16 inst, s16 idx)
  64 {
  65         u32 v;
  66
  67         v = am33xx_cm_read_reg(inst, idx);
  68         v &= ~mask;
  69         v |= bits;
  70         am33xx_cm_write_reg(v, inst, idx);
  71
  72         return v;
  73 }
  74
  75 static inline u32 am33xx_cm_set_reg_bits(u32 bits, s16 inst, s16 idx)
  76 {
  77         return am33xx_cm_rmw_reg_bits(bits, bits, inst, idx);
  78 }
  79
  80 static inline u32 am33xx_cm_clear_reg_bits(u32 bits, s16 inst, s16 idx)
  81 {
  82         return am33xx_cm_rmw_reg_bits(bits, 0x0, inst, idx);
  83 }
  84
  85 static inline u32 am33xx_cm_read_reg_bits(u16 inst, s16 idx, u32 mask)
  86 {
  87         u32 v;
  88
  89         v = am33xx_cm_read_reg(inst, idx);
  90         v &= mask;
  91         v >>= __ffs(mask);
  92
  93         return v;
  94 }
  95
  96 /**
  97  * _clkctrl_idlest - read a CM_*_CLKCTRL register; mask & shift IDLEST bitfield
  98  * @inst: CM instance register offset (*_INST macro)
  99  * @cdoffs: Clockdomain register offset (*_CDOFFS macro)
 100  * @clkctrl_offs: Module clock control register offset (*_CLKCTRL macro)
 101  *
 102  * Return the IDLEST bitfield of a CM_*_CLKCTRL register, shifted down to
 103  * bit 0.
 104  */
 105 static u32 _clkctrl_idlest(u16 inst, s16 cdoffs, u16 clkctrl_offs)
 106 {
 107         u32 v = am33xx_cm_read_reg(inst, clkctrl_offs);
 108         v &= AM33XX_IDLEST_MASK;
 109         v >>= AM33XX_IDLEST_SHIFT;
 110         return v;
 111 }
 112
 113 /**
 114  * _is_module_ready - can module registers be accessed without causing an abort?
 115  * @inst: CM instance register offset (*_INST macro)
 116  * @cdoffs: Clockdomain register offset (*_CDOFFS macro)
 117  * @clkctrl_offs: Module clock control register offset (*_CLKCTRL macro)
 118  *
 119  * Returns true if the module's CM_*_CLKCTRL.IDLEST bitfield is either
 120  * *FUNCTIONAL or *INTERFACE_IDLE; false otherwise.
 121  */
 122 static bool _is_module_ready(u16 inst, s16 cdoffs, u16 clkctrl_offs)
 123 {
 124         u32 v;
 125
 126         v = _clkctrl_idlest(inst, cdoffs, clkctrl_offs);
 127
 128         return (v == CLKCTRL_IDLEST_FUNCTIONAL ||
 129                 v == CLKCTRL_IDLEST_INTERFACE_IDLE) ? true : false;
 130 }
 131
 132 /**
 133  * _clktrctrl_write - write @c to a CM_CLKSTCTRL.CLKTRCTRL register bitfield
 134  * @c: CLKTRCTRL register bitfield (LSB = bit 0, i.e., unshifted)
 135  * @inst: CM instance register offset (*_INST macro)
 136  * @cdoffs: Clockdomain register offset (*_CDOFFS macro)
 137  *
 138  * @c must be the unshifted value for CLKTRCTRL - i.e., this function
 139  * will handle the shift itself.
 140  */
 141 static void _clktrctrl_write(u8 c, s16 inst, u16 cdoffs)
 142 {
 143         u32 v;
 144
 145         v = am33xx_cm_read_reg(inst, cdoffs);
 146         v &= ~AM33XX_CLKTRCTRL_MASK;
 147         v |= c << AM33XX_CLKTRCTRL_SHIFT;
 148         am33xx_cm_write_reg(v, inst, cdoffs);
 149 }
 150
 151 /* Public functions */
 152
 153 /**
 154  * am33xx_cm_is_clkdm_in_hwsup - is a clockdomain in hwsup idle mode?
 155  * @inst: CM instance register offset (*_INST macro)
 156  * @cdoffs: Clockdomain register offset (*_CDOFFS macro)
 157  *
 158  * Returns true if the clockdomain referred to by (@inst, @cdoffs)
 159  * is in hardware-supervised idle mode, or 0 otherwise.
 160  */
 161 bool am33xx_cm_is_clkdm_in_hwsup(s16 inst, u16 cdoffs)
 162 {
 163         u32 v;
 164
 165         v = am33xx_cm_read_reg(inst, cdoffs);
 166         v &= AM33XX_CLKTRCTRL_MASK;
 167         v >>= AM33XX_CLKTRCTRL_SHIFT;
 168
 169         return (v == OMAP34XX_CLKSTCTRL_ENABLE_AUTO) ? true : false;
 170 }
 171
 172 /**
 173  * am33xx_cm_clkdm_enable_hwsup - put a clockdomain in hwsup-idle mode
 174  * @inst: CM instance register offset (*_INST macro)
 175  * @cdoffs: Clockdomain register offset (*_CDOFFS macro)
 176  *
 177  * Put a clockdomain referred to by (@inst, @cdoffs) into
 178  * hardware-supervised idle mode.  No return value.
 179  */
 180 void am33xx_cm_clkdm_enable_hwsup(s16 inst, u16 cdoffs)
 181 {
 182         _clktrctrl_write(OMAP34XX_CLKSTCTRL_ENABLE_AUTO, inst, cdoffs);
 183 }
 184
 185 /**
 186  * am33xx_cm_clkdm_disable_hwsup - put a clockdomain in swsup-idle mode
 187  * @inst: CM instance register offset (*_INST macro)
 188  * @cdoffs: Clockdomain register offset (*_CDOFFS macro)
 189  *
 190  * Put a clockdomain referred to by (@inst, @cdoffs) into
 191  * software-supervised idle mode, i.e., controlled manually by the
 192  * Linux OMAP clockdomain code.  No return value.
 193  */
 194 void am33xx_cm_clkdm_disable_hwsup(s16 inst, u16 cdoffs)
 195 {
 196         _clktrctrl_write(OMAP34XX_CLKSTCTRL_DISABLE_AUTO, inst, cdoffs);
 197 }
 198
 199 /**
 200  * am33xx_cm_clkdm_force_sleep - try to put a clockdomain into idle
 201  * @inst: CM instance register offset (*_INST macro)
 202  * @cdoffs: Clockdomain register offset (*_CDOFFS macro)
 203  *
 204  * Put a clockdomain referred to by (@inst, @cdoffs) into idle
 205  * No return value.
 206  */
 207 void am33xx_cm_clkdm_force_sleep(s16 inst, u16 cdoffs)
 208 {
 209         _clktrctrl_write(OMAP34XX_CLKSTCTRL_FORCE_SLEEP, inst, cdoffs);
 210 }
 211
 212 /**
 213  * am33xx_cm_clkdm_force_wakeup - try to take a clockdomain out of idle
 214  * @inst: CM instance register offset (*_INST macro)
 215  * @cdoffs: Clockdomain register offset (*_CDOFFS macro)
 216  *
 217  * Take a clockdomain referred to by (@inst, @cdoffs) out of idle,
 218  * waking it up.  No return value.
 219  */
 220 void am33xx_cm_clkdm_force_wakeup(s16 inst, u16 cdoffs)
 221 {
 222         _clktrctrl_write(OMAP34XX_CLKSTCTRL_FORCE_WAKEUP, inst, cdoffs);
 223 }
 224
 225 /*
 226  *
 227  */
 228
 229 /**
 230  * am33xx_cm_wait_module_ready - wait for a module to be in 'func' state
 231  * @inst: CM instance register offset (*_INST macro)
 232  * @cdoffs: Clockdomain register offset (*_CDOFFS macro)
 233  * @clkctrl_offs: Module clock control register offset (*_CLKCTRL macro)
 234  *
 235  * Wait for the module IDLEST to be functional. If the idle state is in any
 236  * the non functional state (trans, idle or disabled), module and thus the
 237  * sysconfig cannot be accessed and will probably lead to an "imprecise
 238  * external abort"
 239  */
 240 int am33xx_cm_wait_module_ready(u16 inst, s16 cdoffs, u16 clkctrl_offs)
 241 {
 242         int i = 0;
 243
 244         if (!clkctrl_offs)
 245                 return 0;
 246
 247         omap_test_timeout(_is_module_ready(inst, cdoffs, clkctrl_offs),
 248                           MAX_MODULE_READY_TIME, i);
 249
 250         return (i < MAX_MODULE_READY_TIME) ? 0 : -EBUSY;
 251 }
 252
 253 /**
 254  * am33xx_cm_wait_module_idle - wait for a module to be in 'disabled'
 255  * state
 256  * @inst: CM instance register offset (*_INST macro)
 257  * @cdoffs: Clockdomain register offset (*_CDOFFS macro)
 258  * @clkctrl_offs: Module clock control register offset (*_CLKCTRL macro)
 259  *
 260  * Wait for the module IDLEST to be disabled. Some PRCM transition,
 261  * like reset assertion or parent clock de-activation must wait the
 262  * module to be fully disabled.
 263  */
 264 int am33xx_cm_wait_module_idle(u16 inst, s16 cdoffs, u16 clkctrl_offs)
 265 {
 266         int i = 0;
 267
 268         if (!clkctrl_offs)
 269                 return 0;
 270
 271         omap_test_timeout((_clkctrl_idlest(inst, cdoffs, clkctrl_offs) ==
 272                                 CLKCTRL_IDLEST_DISABLED),
 273                                 MAX_MODULE_READY_TIME, i);
 274
 275         return (i < MAX_MODULE_READY_TIME) ? 0 : -EBUSY;
 276 }
 277
 278 /**
 279  * am33xx_cm_module_enable - Enable the modulemode inside CLKCTRL
 280  * @mode: Module mode (SW or HW)
 281  * @inst: CM instance register offset (*_INST macro)
 282  * @cdoffs: Clockdomain register offset (*_CDOFFS macro)
 283  * @clkctrl_offs: Module clock control register offset (*_CLKCTRL macro)
 284  *
 285  * No return value.
 286  */
 287 void am33xx_cm_module_enable(u8 mode, u16 inst, s16 cdoffs, u16 clkctrl_offs)
 288 {
 289         u32 v;
 290
 291         v = am33xx_cm_read_reg(inst, clkctrl_offs);
 292         v &= ~AM33XX_MODULEMODE_MASK;
 293         v |= mode << AM33XX_MODULEMODE_SHIFT;
 294         am33xx_cm_write_reg(v, inst, clkctrl_offs);
 295 }
 296
 297 /**
 298  * am33xx_cm_module_disable - Disable the module inside CLKCTRL
 299  * @inst: CM instance register offset (*_INST macro)
 300  * @cdoffs: Clockdomain register offset (*_CDOFFS macro)
 301  * @clkctrl_offs: Module clock control register offset (*_CLKCTRL macro)
 302  *
 303  * No return value.
 304  */
 305 void am33xx_cm_module_disable(u16 inst, s16 cdoffs, u16 clkctrl_offs)
 306 {
 307         u32 v;
 308
 309         v = am33xx_cm_read_reg(inst, clkctrl_offs);
 310         v &= ~AM33XX_MODULEMODE_MASK;
 311         am33xx_cm_write_reg(v, inst, clkctrl_offs);
 312 }
 313
 314 /*
 315  * Clockdomain low-level functions
 316  */
 317
 318 static int am33xx_clkdm_sleep(struct clockdomain *clkdm)
 319 {
 320         am33xx_cm_clkdm_force_sleep(clkdm->cm_inst, clkdm->clkdm_offs);
 321         return 0;
 322 }
 323
 324 static int am33xx_clkdm_wakeup(struct clockdomain *clkdm)
 325 {
 326         am33xx_cm_clkdm_force_wakeup(clkdm->cm_inst, clkdm->clkdm_offs);
 327         return 0;
 328 }
 329
 330 static void am33xx_clkdm_allow_idle(struct clockdomain *clkdm)
 331 {
 332         am33xx_cm_clkdm_enable_hwsup(clkdm->cm_inst, clkdm->clkdm_offs);
 333 }
 334
 335 static void am33xx_clkdm_deny_idle(struct clockdomain *clkdm)
 336 {
 337         am33xx_cm_clkdm_disable_hwsup(clkdm->cm_inst, clkdm->clkdm_offs);
 338 }
 339
 340 static int am33xx_clkdm_clk_enable(struct clockdomain *clkdm)
 341 {
 342         if (clkdm->flags & CLKDM_CAN_FORCE_WAKEUP)
 343                 return am33xx_clkdm_wakeup(clkdm);
 344
 345         return 0;
 346 }
 347
 348 static int am33xx_clkdm_clk_disable(struct clockdomain *clkdm)
 349 {
 350         bool hwsup = false;
 351
 352         hwsup = am33xx_cm_is_clkdm_in_hwsup(clkdm->cm_inst, clkdm->clkdm_offs);
 353
 354         if (!hwsup && (clkdm->flags & CLKDM_CAN_FORCE_SLEEP))
 355                 am33xx_clkdm_sleep(clkdm);
 356
 357         return 0;
 358 }
 359
 360 struct clkdm_ops am33xx_clkdm_operations = {
 361         .clkdm_sleep            = am33xx_clkdm_sleep,
 362         .clkdm_wakeup           = am33xx_clkdm_wakeup,
 363         .clkdm_allow_idle       = am33xx_clkdm_allow_idle,
 364         .clkdm_deny_idle        = am33xx_clkdm_deny_idle,
 365         .clkdm_clk_enable       = am33xx_clkdm_clk_enable,
 366         .clkdm_clk_disable      = am33xx_clkdm_clk_disable,
 367 };