arch/arm/mach-omap2/prm33xx.c

   1 /*
   2  * AM33XX PRM functions
   3  *
   4  * Copyright (C) 2011-2012 Texas Instruments Incorporated - https://www.ti.com/
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License as
   8  * published by the Free Software Foundation version 2.
   9  *
  10  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
  11  * kind, whether express or implied; without even the implied warranty
  12  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  */
  15
  16 #include <linux/kernel.h>
  17 #include <linux/types.h>
  18 #include <linux/errno.h>
  19 #include <linux/err.h>
  20 #include <linux/io.h>
  21
  22 #include "powerdomain.h"
  23 #include "prm33xx.h"
  24 #include "prm-regbits-33xx.h"
  25
  26 #define AM33XX_PRM_RSTCTRL_OFFSET               0x0000
  27
  28 #define AM33XX_RST_GLOBAL_WARM_SW_MASK          (1 << 0)
  29
  30 /* Read a register in a PRM instance */
  31 static u32 am33xx_prm_read_reg(s16 inst, u16 idx)
  32 {
  33         return readl_relaxed(prm_base.va + inst + idx);
  34 }
  35
  36 /* Write into a register in a PRM instance */
  37 static void am33xx_prm_write_reg(u32 val, s16 inst, u16 idx)
  38 {
  39         writel_relaxed(val, prm_base.va + inst + idx);
  40 }
  41
  42 /* Read-modify-write a register in PRM. Caller must lock */
  43 static u32 am33xx_prm_rmw_reg_bits(u32 mask, u32 bits, s16 inst, s16 idx)
  44 {
  45         u32 v;
  46
  47         v = am33xx_prm_read_reg(inst, idx);
  48         v &= ~mask;
  49         v |= bits;
  50         am33xx_prm_write_reg(v, inst, idx);
  51
  52         return v;
  53 }
  54
  55 /**
  56  * am33xx_prm_is_hardreset_asserted - read the HW reset line state of
  57  * submodules contained in the hwmod module
  58  * @shift: register bit shift corresponding to the reset line to check
  59  * @part: PRM partition, ignored for AM33xx
  60  * @inst: CM instance register offset (*_INST macro)
  61  * @rstctrl_offs: RM_RSTCTRL register address offset for this module
  62  *
  63  * Returns 1 if the (sub)module hardreset line is currently asserted,
  64  * 0 if the (sub)module hardreset line is not currently asserted, or
  65  * -EINVAL upon parameter error.
  66  */
  67 static int am33xx_prm_is_hardreset_asserted(u8 shift, u8 part, s16 inst,
  68                                             u16 rstctrl_offs)
  69 {
  70         u32 v;
  71
  72         v = am33xx_prm_read_reg(inst, rstctrl_offs);
  73         v &= 1 << shift;
  74         v >>= shift;
  75
  76         return v;
  77 }
  78
  79 /**
  80  * am33xx_prm_assert_hardreset - assert the HW reset line of a submodule
  81  * @shift: register bit shift corresponding to the reset line to assert
  82  * @part: CM partition, ignored for AM33xx
  83  * @inst: CM instance register offset (*_INST macro)
  84  * @rstctrl_reg: RM_RSTCTRL register address for this module
  85  *
  86  * Some IPs like dsp, ipu or iva contain processors that require an HW
  87  * reset line to be asserted / deasserted in order to fully enable the
  88  * IP.  These modules may have multiple hard-reset lines that reset
  89  * different 'submodules' inside the IP block.  This function will
  90  * place the submodule into reset.  Returns 0 upon success or -EINVAL
  91  * upon an argument error.
  92  */
  93 static int am33xx_prm_assert_hardreset(u8 shift, u8 part, s16 inst,
  94                                        u16 rstctrl_offs)
  95 {
  96         u32 mask = 1 << shift;
  97
  98         am33xx_prm_rmw_reg_bits(mask, mask, inst, rstctrl_offs);
  99
 100         return 0;
 101 }
 102
 103 /**
 104  * am33xx_prm_deassert_hardreset - deassert a submodule hardreset line and
 105  * wait
 106  * @shift: register bit shift corresponding to the reset line to deassert
 107  * @st_shift: reset status register bit shift corresponding to the reset line
 108  * @part: PRM partition, not used for AM33xx
 109  * @inst: CM instance register offset (*_INST macro)
 110  * @rstctrl_reg: RM_RSTCTRL register address for this module
 111  * @rstst_reg: RM_RSTST register address for this module
 112  *
 113  * Some IPs like dsp, ipu or iva contain processors that require an HW
 114  * reset line to be asserted / deasserted in order to fully enable the
 115  * IP.  These modules may have multiple hard-reset lines that reset
 116  * different 'submodules' inside the IP block.  This function will
 117  * take the submodule out of reset and wait until the PRCM indicates
 118  * that the reset has completed before returning.  Returns 0 upon success or
 119  * -EINVAL upon an argument error, -EEXIST if the submodule was already out
 120  * of reset, or -EBUSY if the submodule did not exit reset promptly.
 121  */
 122 static int am33xx_prm_deassert_hardreset(u8 shift, u8 st_shift, u8 part,
 123                                          s16 inst, u16 rstctrl_offs,
 124                                          u16 rstst_offs)
 125 {
 126         int c;
 127         u32 mask = 1 << st_shift;
 128
 129         /* Check the current status to avoid  de-asserting the line twice */
 130         if (am33xx_prm_is_hardreset_asserted(shift, 0, inst, rstctrl_offs) == 0)
 131                 return -EEXIST;
 132
 133         /* Clear the reset status by writing 1 to the status bit */
 134         am33xx_prm_rmw_reg_bits(0xffffffff, mask, inst, rstst_offs);
 135
 136         /* de-assert the reset control line */
 137         mask = 1 << shift;
 138
 139         am33xx_prm_rmw_reg_bits(mask, 0, inst, rstctrl_offs);
 140
 141         /* wait the status to be set */
 142         omap_test_timeout(am33xx_prm_is_hardreset_asserted(st_shift, 0, inst,
 143                                                            rstst_offs),
 144                           MAX_MODULE_HARDRESET_WAIT, c);
 145
 146         return (c == MAX_MODULE_HARDRESET_WAIT) ? -EBUSY : 0;
 147 }
 148
 149 static int am33xx_pwrdm_set_next_pwrst(struct powerdomain *pwrdm, u8 pwrst)
 150 {
 151         am33xx_prm_rmw_reg_bits(OMAP_POWERSTATE_MASK,
 152                                 (pwrst << OMAP_POWERSTATE_SHIFT),
 153                                 pwrdm->prcm_offs, pwrdm->pwrstctrl_offs);
 154         return 0;
 155 }
 156
 157 static int am33xx_pwrdm_read_next_pwrst(struct powerdomain *pwrdm)
 158 {
 159         u32 v;
 160
 161         v = am33xx_prm_read_reg(pwrdm->prcm_offs,  pwrdm->pwrstctrl_offs);
 162         v &= OMAP_POWERSTATE_MASK;
 163         v >>= OMAP_POWERSTATE_SHIFT;
 164
 165         return v;
 166 }
 167
 168 static int am33xx_pwrdm_read_pwrst(struct powerdomain *pwrdm)
 169 {
 170         u32 v;
 171
 172         v = am33xx_prm_read_reg(pwrdm->prcm_offs, pwrdm->pwrstst_offs);
 173         v &= OMAP_POWERSTATEST_MASK;
 174         v >>= OMAP_POWERSTATEST_SHIFT;
 175
 176         return v;
 177 }
 178
 179 static int am33xx_pwrdm_set_lowpwrstchange(struct powerdomain *pwrdm)
 180 {
 181         am33xx_prm_rmw_reg_bits(AM33XX_LOWPOWERSTATECHANGE_MASK,
 182                                 (1 << AM33XX_LOWPOWERSTATECHANGE_SHIFT),
 183                                 pwrdm->prcm_offs, pwrdm->pwrstctrl_offs);
 184         return 0;
 185 }
 186
 187 static int am33xx_pwrdm_clear_all_prev_pwrst(struct powerdomain *pwrdm)
 188 {
 189         am33xx_prm_rmw_reg_bits(AM33XX_LASTPOWERSTATEENTERED_MASK,
 190                                 AM33XX_LASTPOWERSTATEENTERED_MASK,
 191                                 pwrdm->prcm_offs, pwrdm->pwrstst_offs);
 192         return 0;
 193 }
 194
 195 static int am33xx_pwrdm_set_logic_retst(struct powerdomain *pwrdm, u8 pwrst)
 196 {
 197         u32 m;
 198
 199         m = pwrdm->logicretstate_mask;
 200         if (!m)
 201                 return -EINVAL;
 202
 203         am33xx_prm_rmw_reg_bits(m, (pwrst << __ffs(m)),
 204                                 pwrdm->prcm_offs, pwrdm->pwrstctrl_offs);
 205
 206         return 0;
 207 }
 208
 209 static int am33xx_pwrdm_read_logic_pwrst(struct powerdomain *pwrdm)
 210 {
 211         u32 v;
 212
 213         v = am33xx_prm_read_reg(pwrdm->prcm_offs, pwrdm->pwrstst_offs);
 214         v &= AM33XX_LOGICSTATEST_MASK;
 215         v >>= AM33XX_LOGICSTATEST_SHIFT;
 216
 217         return v;
 218 }
 219
 220 static int am33xx_pwrdm_read_logic_retst(struct powerdomain *pwrdm)
 221 {
 222         u32 v, m;
 223
 224         m = pwrdm->logicretstate_mask;
 225         if (!m)
 226                 return -EINVAL;
 227
 228         v = am33xx_prm_read_reg(pwrdm->prcm_offs, pwrdm->pwrstctrl_offs);
 229         v &= m;
 230         v >>= __ffs(m);
 231
 232         return v;
 233 }
 234
 235 static int am33xx_pwrdm_set_mem_onst(struct powerdomain *pwrdm, u8 bank,
 236                 u8 pwrst)
 237 {
 238         u32 m;
 239
 240         m = pwrdm->mem_on_mask[bank];
 241         if (!m)
 242                 return -EINVAL;
 243
 244         am33xx_prm_rmw_reg_bits(m, (pwrst << __ffs(m)),
 245                                 pwrdm->prcm_offs, pwrdm->pwrstctrl_offs);
 246
 247         return 0;
 248 }
 249
 250 static int am33xx_pwrdm_set_mem_retst(struct powerdomain *pwrdm, u8 bank,
 251                                         u8 pwrst)
 252 {
 253         u32 m;
 254
 255         m = pwrdm->mem_ret_mask[bank];
 256         if (!m)
 257                 return -EINVAL;
 258
 259         am33xx_prm_rmw_reg_bits(m, (pwrst << __ffs(m)),
 260                                 pwrdm->prcm_offs, pwrdm->pwrstctrl_offs);
 261
 262         return 0;
 263 }
 264
 265 static int am33xx_pwrdm_read_mem_pwrst(struct powerdomain *pwrdm, u8 bank)
 266 {
 267         u32 m, v;
 268
 269         m = pwrdm->mem_pwrst_mask[bank];
 270         if (!m)
 271                 return -EINVAL;
 272
 273         v = am33xx_prm_read_reg(pwrdm->prcm_offs, pwrdm->pwrstst_offs);
 274         v &= m;
 275         v >>= __ffs(m);
 276
 277         return v;
 278 }
 279
 280 static int am33xx_pwrdm_read_mem_retst(struct powerdomain *pwrdm, u8 bank)
 281 {
 282         u32 m, v;
 283
 284         m = pwrdm->mem_retst_mask[bank];
 285         if (!m)
 286                 return -EINVAL;
 287
 288         v = am33xx_prm_read_reg(pwrdm->prcm_offs, pwrdm->pwrstctrl_offs);
 289         v &= m;
 290         v >>= __ffs(m);
 291
 292         return v;
 293 }
 294
 295 static int am33xx_pwrdm_wait_transition(struct powerdomain *pwrdm)
 296 {
 297         u32 c = 0;
 298
 299         /*
 300          * REVISIT: pwrdm_wait_transition() may be better implemented
 301          * via a callback and a periodic timer check -- how long do we expect
 302          * powerdomain transitions to take?
 303          */
 304
 305         /* XXX Is this udelay() value meaningful? */
 306         while ((am33xx_prm_read_reg(pwrdm->prcm_offs, pwrdm->pwrstst_offs)
 307                         & OMAP_INTRANSITION_MASK) &&
 308                         (c++ < PWRDM_TRANSITION_BAILOUT))
 309                 udelay(1);
 310
 311         if (c > PWRDM_TRANSITION_BAILOUT) {
 312                 pr_err("powerdomain: %s: waited too long to complete transition\n",
 313                        pwrdm->name);
 314                 return -EAGAIN;
 315         }
 316
 317         pr_debug("powerdomain: completed transition in %d loops\n", c);
 318
 319         return 0;
 320 }
 321
 322 static int am33xx_check_vcvp(void)
 323 {
 324         /* No VC/VP on am33xx devices */
 325         return 0;
 326 }
 327
 328 /**
 329  * am33xx_prm_global_warm_sw_reset - reboot the device via warm reset
 330  *
 331  * Immediately reboots the device through warm reset.
 332  */
 333 static void am33xx_prm_global_warm_sw_reset(void)
 334 {
 335         am33xx_prm_rmw_reg_bits(AM33XX_RST_GLOBAL_WARM_SW_MASK,
 336                                 AM33XX_RST_GLOBAL_WARM_SW_MASK,
 337                                 AM33XX_PRM_DEVICE_MOD,
 338                                 AM33XX_PRM_RSTCTRL_OFFSET);
 339
 340         /* OCP barrier */
 341         (void)am33xx_prm_read_reg(AM33XX_PRM_DEVICE_MOD,
 342                                   AM33XX_PRM_RSTCTRL_OFFSET);
 343 }
 344
 345 static void am33xx_pwrdm_save_context(struct powerdomain *pwrdm)
 346 {
 347         pwrdm->context = am33xx_prm_read_reg(pwrdm->prcm_offs,
 348                                                 pwrdm->pwrstctrl_offs);
 349         /*
 350          * Do not save LOWPOWERSTATECHANGE, writing a 1 indicates a request,
 351          * reading back a 1 indicates a request in progress.
 352          */
 353         pwrdm->context &= ~AM33XX_LOWPOWERSTATECHANGE_MASK;
 354 }
 355
 356 static void am33xx_pwrdm_restore_context(struct powerdomain *pwrdm)
 357 {
 358         int st, ctrl;
 359
 360         st = am33xx_prm_read_reg(pwrdm->prcm_offs,
 361                                  pwrdm->pwrstst_offs);
 362
 363         am33xx_prm_write_reg(pwrdm->context, pwrdm->prcm_offs,
 364                              pwrdm->pwrstctrl_offs);
 365
 366         /* Make sure we only wait for a transition if there is one */
 367         st &= OMAP_POWERSTATEST_MASK;
 368         ctrl = OMAP_POWERSTATEST_MASK & pwrdm->context;
 369
 370         if (st != ctrl)
 371                 am33xx_pwrdm_wait_transition(pwrdm);
 372 }
 373
 374 struct pwrdm_ops am33xx_pwrdm_operations = {
 375         .pwrdm_set_next_pwrst           = am33xx_pwrdm_set_next_pwrst,
 376         .pwrdm_read_next_pwrst          = am33xx_pwrdm_read_next_pwrst,
 377         .pwrdm_read_pwrst               = am33xx_pwrdm_read_pwrst,
 378         .pwrdm_set_logic_retst          = am33xx_pwrdm_set_logic_retst,
 379         .pwrdm_read_logic_pwrst         = am33xx_pwrdm_read_logic_pwrst,
 380         .pwrdm_read_logic_retst         = am33xx_pwrdm_read_logic_retst,
 381         .pwrdm_clear_all_prev_pwrst     = am33xx_pwrdm_clear_all_prev_pwrst,
 382         .pwrdm_set_lowpwrstchange       = am33xx_pwrdm_set_lowpwrstchange,
 383         .pwrdm_read_mem_pwrst           = am33xx_pwrdm_read_mem_pwrst,
 384         .pwrdm_read_mem_retst           = am33xx_pwrdm_read_mem_retst,
 385         .pwrdm_set_mem_onst             = am33xx_pwrdm_set_mem_onst,
 386         .pwrdm_set_mem_retst            = am33xx_pwrdm_set_mem_retst,
 387         .pwrdm_wait_transition          = am33xx_pwrdm_wait_transition,
 388         .pwrdm_has_voltdm               = am33xx_check_vcvp,
 389         .pwrdm_save_context             = am33xx_pwrdm_save_context,
 390         .pwrdm_restore_context          = am33xx_pwrdm_restore_context,
 391 };
 392
 393 static struct prm_ll_data am33xx_prm_ll_data = {
 394         .assert_hardreset               = am33xx_prm_assert_hardreset,
 395         .deassert_hardreset             = am33xx_prm_deassert_hardreset,
 396         .is_hardreset_asserted          = am33xx_prm_is_hardreset_asserted,
 397         .reset_system                   = am33xx_prm_global_warm_sw_reset,
 398 };
 399
 400 int __init am33xx_prm_init(const struct omap_prcm_init_data *data)
 401 {
 402         return prm_register(&am33xx_prm_ll_data);
 403 }
 404
 405 static void __exit am33xx_prm_exit(void)
 406 {
 407         prm_unregister(&am33xx_prm_ll_data);
 408 }
 409 __exitcall(am33xx_prm_exit);