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(u16 inst, u16 idx)
  52 {
  53         return readl_relaxed(cm_base + inst + idx);
  54 }
  55
  56 /* Write into a register in a CM */
  57 static inline void am33xx_cm_write_reg(u32 val, u16 inst, u16 idx)
  58 {
  59         writel_relaxed(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 /**
  76  * _clkctrl_idlest - read a CM_*_CLKCTRL register; mask & shift IDLEST bitfield
  77  * @inst: CM instance register offset (*_INST macro)
  78  * @clkctrl_offs: Module clock control register offset (*_CLKCTRL macro)
  79  *
  80  * Return the IDLEST bitfield of a CM_*_CLKCTRL register, shifted down to
  81  * bit 0.
  82  */
  83 static u32 _clkctrl_idlest(u16 inst, u16 clkctrl_offs)
  84 {
  85         u32 v = am33xx_cm_read_reg(inst, clkctrl_offs);
  86         v &= AM33XX_IDLEST_MASK;
  87         v >>= AM33XX_IDLEST_SHIFT;
  88         return v;
  89 }
  90
  91 /**
  92  * _is_module_ready - can module registers be accessed without causing an abort?
  93  * @inst: CM instance register offset (*_INST macro)
  94  * @clkctrl_offs: Module clock control register offset (*_CLKCTRL macro)
  95  *
  96  * Returns true if the module's CM_*_CLKCTRL.IDLEST bitfield is either
  97  * *FUNCTIONAL or *INTERFACE_IDLE; false otherwise.
  98  */
  99 static bool _is_module_ready(u16 inst, u16 clkctrl_offs)
 100 {
 101         u32 v;
 102
 103         v = _clkctrl_idlest(inst, clkctrl_offs);
 104
 105         return (v == CLKCTRL_IDLEST_FUNCTIONAL ||
 106                 v == CLKCTRL_IDLEST_INTERFACE_IDLE) ? true : false;
 107 }
 108
 109 /**
 110  * _clktrctrl_write - write @c to a CM_CLKSTCTRL.CLKTRCTRL register bitfield
 111  * @c: CLKTRCTRL register bitfield (LSB = bit 0, i.e., unshifted)
 112  * @inst: CM instance register offset (*_INST macro)
 113  * @cdoffs: Clockdomain register offset (*_CDOFFS macro)
 114  *
 115  * @c must be the unshifted value for CLKTRCTRL - i.e., this function
 116  * will handle the shift itself.
 117  */
 118 static void _clktrctrl_write(u8 c, u16 inst, u16 cdoffs)
 119 {
 120         u32 v;
 121
 122         v = am33xx_cm_read_reg(inst, cdoffs);
 123         v &= ~AM33XX_CLKTRCTRL_MASK;
 124         v |= c << AM33XX_CLKTRCTRL_SHIFT;
 125         am33xx_cm_write_reg(v, inst, cdoffs);
 126 }
 127
 128 /* Public functions */
 129
 130 /**
 131  * am33xx_cm_is_clkdm_in_hwsup - is a clockdomain in hwsup idle mode?
 132  * @inst: CM instance register offset (*_INST macro)
 133  * @cdoffs: Clockdomain register offset (*_CDOFFS macro)
 134  *
 135  * Returns true if the clockdomain referred to by (@inst, @cdoffs)
 136  * is in hardware-supervised idle mode, or 0 otherwise.
 137  */
 138 static bool am33xx_cm_is_clkdm_in_hwsup(u16 inst, u16 cdoffs)
 139 {
 140         u32 v;
 141
 142         v = am33xx_cm_read_reg(inst, cdoffs);
 143         v &= AM33XX_CLKTRCTRL_MASK;
 144         v >>= AM33XX_CLKTRCTRL_SHIFT;
 145
 146         return (v == OMAP34XX_CLKSTCTRL_ENABLE_AUTO) ? true : false;
 147 }
 148
 149 /**
 150  * am33xx_cm_clkdm_enable_hwsup - put a clockdomain in hwsup-idle mode
 151  * @inst: CM instance register offset (*_INST macro)
 152  * @cdoffs: Clockdomain register offset (*_CDOFFS macro)
 153  *
 154  * Put a clockdomain referred to by (@inst, @cdoffs) into
 155  * hardware-supervised idle mode.  No return value.
 156  */
 157 static void am33xx_cm_clkdm_enable_hwsup(u16 inst, u16 cdoffs)
 158 {
 159         _clktrctrl_write(OMAP34XX_CLKSTCTRL_ENABLE_AUTO, inst, cdoffs);
 160 }
 161
 162 /**
 163  * am33xx_cm_clkdm_disable_hwsup - put a clockdomain in swsup-idle mode
 164  * @inst: CM instance register offset (*_INST macro)
 165  * @cdoffs: Clockdomain register offset (*_CDOFFS macro)
 166  *
 167  * Put a clockdomain referred to by (@inst, @cdoffs) into
 168  * software-supervised idle mode, i.e., controlled manually by the
 169  * Linux OMAP clockdomain code.  No return value.
 170  */
 171 static void am33xx_cm_clkdm_disable_hwsup(u16 inst, u16 cdoffs)
 172 {
 173         _clktrctrl_write(OMAP34XX_CLKSTCTRL_DISABLE_AUTO, inst, cdoffs);
 174 }
 175
 176 /**
 177  * am33xx_cm_clkdm_force_sleep - try to put a clockdomain into idle
 178  * @inst: CM instance register offset (*_INST macro)
 179  * @cdoffs: Clockdomain register offset (*_CDOFFS macro)
 180  *
 181  * Put a clockdomain referred to by (@inst, @cdoffs) into idle
 182  * No return value.
 183  */
 184 static void am33xx_cm_clkdm_force_sleep(u16 inst, u16 cdoffs)
 185 {
 186         _clktrctrl_write(OMAP34XX_CLKSTCTRL_FORCE_SLEEP, inst, cdoffs);
 187 }
 188
 189 /**
 190  * am33xx_cm_clkdm_force_wakeup - try to take a clockdomain out of idle
 191  * @inst: CM instance register offset (*_INST macro)
 192  * @cdoffs: Clockdomain register offset (*_CDOFFS macro)
 193  *
 194  * Take a clockdomain referred to by (@inst, @cdoffs) out of idle,
 195  * waking it up.  No return value.
 196  */
 197 static void am33xx_cm_clkdm_force_wakeup(u16 inst, u16 cdoffs)
 198 {
 199         _clktrctrl_write(OMAP34XX_CLKSTCTRL_FORCE_WAKEUP, inst, cdoffs);
 200 }
 201
 202 /*
 203  *
 204  */
 205
 206 /**
 207  * am33xx_cm_wait_module_ready - wait for a module to be in 'func' state
 208  * @part: PRCM partition, ignored for AM33xx
 209  * @inst: CM instance register offset (*_INST macro)
 210  * @clkctrl_offs: Module clock control register offset (*_CLKCTRL macro)
 211  * @bit_shift: bit shift for the register, ignored for AM33xx
 212  *
 213  * Wait for the module IDLEST to be functional. If the idle state is in any
 214  * the non functional state (trans, idle or disabled), module and thus the
 215  * sysconfig cannot be accessed and will probably lead to an "imprecise
 216  * external abort"
 217  */
 218 static int am33xx_cm_wait_module_ready(u8 part, s16 inst, u16 clkctrl_offs,
 219                                        u8 bit_shift)
 220 {
 221         int i = 0;
 222
 223         omap_test_timeout(_is_module_ready(inst, clkctrl_offs),
 224                           MAX_MODULE_READY_TIME, i);
 225
 226         return (i < MAX_MODULE_READY_TIME) ? 0 : -EBUSY;
 227 }
 228
 229 /**
 230  * am33xx_cm_wait_module_idle - wait for a module to be in 'disabled'
 231  * state
 232  * @part: CM partition, ignored for AM33xx
 233  * @inst: CM instance register offset (*_INST macro)
 234  * @clkctrl_offs: Module clock control register offset (*_CLKCTRL macro)
 235  * @bit_shift: bit shift for the register, ignored for AM33xx
 236  *
 237  * Wait for the module IDLEST to be disabled. Some PRCM transition,
 238  * like reset assertion or parent clock de-activation must wait the
 239  * module to be fully disabled.
 240  */
 241 static int am33xx_cm_wait_module_idle(u8 part, s16 inst, u16 clkctrl_offs,
 242                                       u8 bit_shift)
 243 {
 244         int i = 0;
 245
 246         omap_test_timeout((_clkctrl_idlest(inst, clkctrl_offs) ==
 247                                 CLKCTRL_IDLEST_DISABLED),
 248                                 MAX_MODULE_READY_TIME, i);
 249
 250         return (i < MAX_MODULE_READY_TIME) ? 0 : -EBUSY;
 251 }
 252
 253 /**
 254  * am33xx_cm_module_enable - Enable the modulemode inside CLKCTRL
 255  * @mode: Module mode (SW or HW)
 256  * @part: CM partition, ignored for AM33xx
 257  * @inst: CM instance register offset (*_INST macro)
 258  * @clkctrl_offs: Module clock control register offset (*_CLKCTRL macro)
 259  *
 260  * No return value.
 261  */
 262 static void am33xx_cm_module_enable(u8 mode, u8 part, u16 inst,
 263                                     u16 clkctrl_offs)
 264 {
 265         u32 v;
 266
 267         v = am33xx_cm_read_reg(inst, clkctrl_offs);
 268         v &= ~AM33XX_MODULEMODE_MASK;
 269         v |= mode << AM33XX_MODULEMODE_SHIFT;
 270         am33xx_cm_write_reg(v, inst, clkctrl_offs);
 271 }
 272
 273 /**
 274  * am33xx_cm_module_disable - Disable the module inside CLKCTRL
 275  * @part: CM partition, ignored for AM33xx
 276  * @inst: CM instance register offset (*_INST macro)
 277  * @clkctrl_offs: Module clock control register offset (*_CLKCTRL macro)
 278  *
 279  * No return value.
 280  */
 281 static void am33xx_cm_module_disable(u8 part, u16 inst, u16 clkctrl_offs)
 282 {
 283         u32 v;
 284
 285         v = am33xx_cm_read_reg(inst, clkctrl_offs);
 286         v &= ~AM33XX_MODULEMODE_MASK;
 287         am33xx_cm_write_reg(v, inst, clkctrl_offs);
 288 }
 289
 290 /*
 291  * Clockdomain low-level functions
 292  */
 293
 294 static int am33xx_clkdm_sleep(struct clockdomain *clkdm)
 295 {
 296         am33xx_cm_clkdm_force_sleep(clkdm->cm_inst, clkdm->clkdm_offs);
 297         return 0;
 298 }
 299
 300 static int am33xx_clkdm_wakeup(struct clockdomain *clkdm)
 301 {
 302         am33xx_cm_clkdm_force_wakeup(clkdm->cm_inst, clkdm->clkdm_offs);
 303         return 0;
 304 }
 305
 306 static void am33xx_clkdm_allow_idle(struct clockdomain *clkdm)
 307 {
 308         am33xx_cm_clkdm_enable_hwsup(clkdm->cm_inst, clkdm->clkdm_offs);
 309 }
 310
 311 static void am33xx_clkdm_deny_idle(struct clockdomain *clkdm)
 312 {
 313         am33xx_cm_clkdm_disable_hwsup(clkdm->cm_inst, clkdm->clkdm_offs);
 314 }
 315
 316 static int am33xx_clkdm_clk_enable(struct clockdomain *clkdm)
 317 {
 318         if (clkdm->flags & CLKDM_CAN_FORCE_WAKEUP)
 319                 return am33xx_clkdm_wakeup(clkdm);
 320
 321         return 0;
 322 }
 323
 324 static int am33xx_clkdm_clk_disable(struct clockdomain *clkdm)
 325 {
 326         bool hwsup = false;
 327
 328         hwsup = am33xx_cm_is_clkdm_in_hwsup(clkdm->cm_inst, clkdm->clkdm_offs);
 329
 330         if (!hwsup && (clkdm->flags & CLKDM_CAN_FORCE_SLEEP))
 331                 am33xx_clkdm_sleep(clkdm);
 332
 333         return 0;
 334 }
 335
 336 struct clkdm_ops am33xx_clkdm_operations = {
 337         .clkdm_sleep            = am33xx_clkdm_sleep,
 338         .clkdm_wakeup           = am33xx_clkdm_wakeup,
 339         .clkdm_allow_idle       = am33xx_clkdm_allow_idle,
 340         .clkdm_deny_idle        = am33xx_clkdm_deny_idle,
 341         .clkdm_clk_enable       = am33xx_clkdm_clk_enable,
 342         .clkdm_clk_disable      = am33xx_clkdm_clk_disable,
 343 };
 344
 345 static struct cm_ll_data am33xx_cm_ll_data = {
 346         .wait_module_ready      = &am33xx_cm_wait_module_ready,
 347         .wait_module_idle       = &am33xx_cm_wait_module_idle,
 348         .module_enable          = &am33xx_cm_module_enable,
 349         .module_disable         = &am33xx_cm_module_disable,
 350 };
 351
 352 int __init am33xx_cm_init(const struct omap_prcm_init_data *data)
 353 {
 354         return cm_register(&am33xx_cm_ll_data);
 355 }
 356
 357 static void __exit am33xx_cm_exit(void)
 358 {
 359         cm_unregister(&am33xx_cm_ll_data);
 360 }
 361 __exitcall(am33xx_cm_exit);