drivers/clk/ti/apll.c

   1 /*
   2  * OMAP APLL clock support
   3  *
   4  * Copyright (C) 2013 Texas Instruments, Inc.
   5  *
   6  * J Keerthy <j-keerthy@ti.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  *
  12  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
  13  * kind, whether express or implied; without even the implied warranty
  14  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  */
  17
  18 #include <linux/clk.h>
  19 #include <linux/clk-provider.h>
  20 #include <linux/module.h>
  21 #include <linux/slab.h>
  22 #include <linux/io.h>
  23 #include <linux/err.h>
  24 #include <linux/string.h>
  25 #include <linux/log2.h>
  26 #include <linux/of.h>
  27 #include <linux/of_address.h>
  28 #include <linux/clk/ti.h>
  29 #include <linux/delay.h>
  30
  31 #include "clock.h"
  32
  33 #define APLL_FORCE_LOCK 0x1
  34 #define APLL_AUTO_IDLE  0x2
  35 #define MAX_APLL_WAIT_TRIES             1000000
  36
  37 #undef pr_fmt
  38 #define pr_fmt(fmt) "%s: " fmt, __func__
  39
  40 static int dra7_apll_enable(struct clk_hw *hw)
  41 {
  42         struct clk_hw_omap *clk = to_clk_hw_omap(hw);
  43         int r = 0, i = 0;
  44         struct dpll_data *ad;
  45         const char *clk_name;
  46         u8 state = 1;
  47         u32 v;
  48
  49         ad = clk->dpll_data;
  50         if (!ad)
  51                 return -EINVAL;
  52
  53         clk_name = clk_hw_get_name(&clk->hw);
  54
  55         state <<= __ffs(ad->idlest_mask);
  56
  57         /* Check is already locked */
  58         v = ti_clk_ll_ops->clk_readl(&ad->idlest_reg);
  59
  60         if ((v & ad->idlest_mask) == state)
  61                 return r;
  62
  63         v = ti_clk_ll_ops->clk_readl(&ad->control_reg);
  64         v &= ~ad->enable_mask;
  65         v |= APLL_FORCE_LOCK << __ffs(ad->enable_mask);
  66         ti_clk_ll_ops->clk_writel(v, &ad->control_reg);
  67
  68         state <<= __ffs(ad->idlest_mask);
  69
  70         while (1) {
  71                 v = ti_clk_ll_ops->clk_readl(&ad->idlest_reg);
  72                 if ((v & ad->idlest_mask) == state)
  73                         break;
  74                 if (i > MAX_APLL_WAIT_TRIES)
  75                         break;
  76                 i++;
  77                 udelay(1);
  78         }
  79
  80         if (i == MAX_APLL_WAIT_TRIES) {
  81                 pr_warn("clock: %s failed transition to '%s'\n",
  82                         clk_name, (state) ? "locked" : "bypassed");
  83                 r = -EBUSY;
  84         } else
  85                 pr_debug("clock: %s transition to '%s' in %d loops\n",
  86                          clk_name, (state) ? "locked" : "bypassed", i);
  87
  88         return r;
  89 }
  90
  91 static void dra7_apll_disable(struct clk_hw *hw)
  92 {
  93         struct clk_hw_omap *clk = to_clk_hw_omap(hw);
  94         struct dpll_data *ad;
  95         u8 state = 1;
  96         u32 v;
  97
  98         ad = clk->dpll_data;
  99
 100         state <<= __ffs(ad->idlest_mask);
 101
 102         v = ti_clk_ll_ops->clk_readl(&ad->control_reg);
 103         v &= ~ad->enable_mask;
 104         v |= APLL_AUTO_IDLE << __ffs(ad->enable_mask);
 105         ti_clk_ll_ops->clk_writel(v, &ad->control_reg);
 106 }
 107
 108 static int dra7_apll_is_enabled(struct clk_hw *hw)
 109 {
 110         struct clk_hw_omap *clk = to_clk_hw_omap(hw);
 111         struct dpll_data *ad;
 112         u32 v;
 113
 114         ad = clk->dpll_data;
 115
 116         v = ti_clk_ll_ops->clk_readl(&ad->control_reg);
 117         v &= ad->enable_mask;
 118
 119         v >>= __ffs(ad->enable_mask);
 120
 121         return v == APLL_AUTO_IDLE ? 0 : 1;
 122 }
 123
 124 static u8 dra7_init_apll_parent(struct clk_hw *hw)
 125 {
 126         return 0;
 127 }
 128
 129 static const struct clk_ops apll_ck_ops = {
 130         .enable         = &dra7_apll_enable,
 131         .disable        = &dra7_apll_disable,
 132         .is_enabled     = &dra7_apll_is_enabled,
 133         .get_parent     = &dra7_init_apll_parent,
 134 };
 135
 136 static void __init omap_clk_register_apll(void *user,
 137                                           struct device_node *node)
 138 {
 139         struct clk_hw *hw = user;
 140         struct clk_hw_omap *clk_hw = to_clk_hw_omap(hw);
 141         struct dpll_data *ad = clk_hw->dpll_data;
 142         struct clk *clk;
 143
 144         clk = of_clk_get(node, 0);
 145         if (IS_ERR(clk)) {
 146                 pr_debug("clk-ref for %pOFn not ready, retry\n",
 147                          node);
 148                 if (!ti_clk_retry_init(node, hw, omap_clk_register_apll))
 149                         return;
 150
 151                 goto cleanup;
 152         }
 153
 154         ad->clk_ref = __clk_get_hw(clk);
 155
 156         clk = of_clk_get(node, 1);
 157         if (IS_ERR(clk)) {
 158                 pr_debug("clk-bypass for %pOFn not ready, retry\n",
 159                          node);
 160                 if (!ti_clk_retry_init(node, hw, omap_clk_register_apll))
 161                         return;
 162
 163                 goto cleanup;
 164         }
 165
 166         ad->clk_bypass = __clk_get_hw(clk);
 167
 168         clk = ti_clk_register(NULL, &clk_hw->hw, node->name);
 169         if (!IS_ERR(clk)) {
 170                 of_clk_add_provider(node, of_clk_src_simple_get, clk);
 171                 kfree(clk_hw->hw.init->parent_names);
 172                 kfree(clk_hw->hw.init);
 173                 return;
 174         }
 175
 176 cleanup:
 177         kfree(clk_hw->dpll_data);
 178         kfree(clk_hw->hw.init->parent_names);
 179         kfree(clk_hw->hw.init);
 180         kfree(clk_hw);
 181 }
 182
 183 static void __init of_dra7_apll_setup(struct device_node *node)
 184 {
 185         struct dpll_data *ad = NULL;
 186         struct clk_hw_omap *clk_hw = NULL;
 187         struct clk_init_data *init = NULL;
 188         const char **parent_names = NULL;
 189         int ret;
 190
 191         ad = kzalloc(sizeof(*ad), GFP_KERNEL);
 192         clk_hw = kzalloc(sizeof(*clk_hw), GFP_KERNEL);
 193         init = kzalloc(sizeof(*init), GFP_KERNEL);
 194         if (!ad || !clk_hw || !init)
 195                 goto cleanup;
 196
 197         clk_hw->dpll_data = ad;
 198         clk_hw->hw.init = init;
 199
 200         init->name = node->name;
 201         init->ops = &apll_ck_ops;
 202
 203         init->num_parents = of_clk_get_parent_count(node);
 204         if (init->num_parents < 1) {
 205                 pr_err("dra7 apll %pOFn must have parent(s)\n", node);
 206                 goto cleanup;
 207         }
 208
 209         parent_names = kcalloc(init->num_parents, sizeof(char *), GFP_KERNEL);
 210         if (!parent_names)
 211                 goto cleanup;
 212
 213         of_clk_parent_fill(node, parent_names, init->num_parents);
 214
 215         init->parent_names = parent_names;
 216
 217         ret = ti_clk_get_reg_addr(node, 0, &ad->control_reg);
 218         ret |= ti_clk_get_reg_addr(node, 1, &ad->idlest_reg);
 219
 220         if (ret)
 221                 goto cleanup;
 222
 223         ad->idlest_mask = 0x1;
 224         ad->enable_mask = 0x3;
 225
 226         omap_clk_register_apll(&clk_hw->hw, node);
 227         return;
 228
 229 cleanup:
 230         kfree(parent_names);
 231         kfree(ad);
 232         kfree(clk_hw);
 233         kfree(init);
 234 }
 235 CLK_OF_DECLARE(dra7_apll_clock, "ti,dra7-apll-clock", of_dra7_apll_setup);
 236
 237 #define OMAP2_EN_APLL_LOCKED    0x3
 238 #define OMAP2_EN_APLL_STOPPED   0x0
 239
 240 static int omap2_apll_is_enabled(struct clk_hw *hw)
 241 {
 242         struct clk_hw_omap *clk = to_clk_hw_omap(hw);
 243         struct dpll_data *ad = clk->dpll_data;
 244         u32 v;
 245
 246         v = ti_clk_ll_ops->clk_readl(&ad->control_reg);
 247         v &= ad->enable_mask;
 248
 249         v >>= __ffs(ad->enable_mask);
 250
 251         return v == OMAP2_EN_APLL_LOCKED ? 1 : 0;
 252 }
 253
 254 static unsigned long omap2_apll_recalc(struct clk_hw *hw,
 255                                        unsigned long parent_rate)
 256 {
 257         struct clk_hw_omap *clk = to_clk_hw_omap(hw);
 258
 259         if (omap2_apll_is_enabled(hw))
 260                 return clk->fixed_rate;
 261
 262         return 0;
 263 }
 264
 265 static int omap2_apll_enable(struct clk_hw *hw)
 266 {
 267         struct clk_hw_omap *clk = to_clk_hw_omap(hw);
 268         struct dpll_data *ad = clk->dpll_data;
 269         u32 v;
 270         int i = 0;
 271
 272         v = ti_clk_ll_ops->clk_readl(&ad->control_reg);
 273         v &= ~ad->enable_mask;
 274         v |= OMAP2_EN_APLL_LOCKED << __ffs(ad->enable_mask);
 275         ti_clk_ll_ops->clk_writel(v, &ad->control_reg);
 276
 277         while (1) {
 278                 v = ti_clk_ll_ops->clk_readl(&ad->idlest_reg);
 279                 if (v & ad->idlest_mask)
 280                         break;
 281                 if (i > MAX_APLL_WAIT_TRIES)
 282                         break;
 283                 i++;
 284                 udelay(1);
 285         }
 286
 287         if (i == MAX_APLL_WAIT_TRIES) {
 288                 pr_warn("%s failed to transition to locked\n",
 289                         clk_hw_get_name(&clk->hw));
 290                 return -EBUSY;
 291         }
 292
 293         return 0;
 294 }
 295
 296 static void omap2_apll_disable(struct clk_hw *hw)
 297 {
 298         struct clk_hw_omap *clk = to_clk_hw_omap(hw);
 299         struct dpll_data *ad = clk->dpll_data;
 300         u32 v;
 301
 302         v = ti_clk_ll_ops->clk_readl(&ad->control_reg);
 303         v &= ~ad->enable_mask;
 304         v |= OMAP2_EN_APLL_STOPPED << __ffs(ad->enable_mask);
 305         ti_clk_ll_ops->clk_writel(v, &ad->control_reg);
 306 }
 307
 308 static const struct clk_ops omap2_apll_ops = {
 309         .enable         = &omap2_apll_enable,
 310         .disable        = &omap2_apll_disable,
 311         .is_enabled     = &omap2_apll_is_enabled,
 312         .recalc_rate    = &omap2_apll_recalc,
 313 };
 314
 315 static void omap2_apll_set_autoidle(struct clk_hw_omap *clk, u32 val)
 316 {
 317         struct dpll_data *ad = clk->dpll_data;
 318         u32 v;
 319
 320         v = ti_clk_ll_ops->clk_readl(&ad->autoidle_reg);
 321         v &= ~ad->autoidle_mask;
 322         v |= val << __ffs(ad->autoidle_mask);
 323         ti_clk_ll_ops->clk_writel(v, &ad->control_reg);
 324 }
 325
 326 #define OMAP2_APLL_AUTOIDLE_LOW_POWER_STOP      0x3
 327 #define OMAP2_APLL_AUTOIDLE_DISABLE             0x0
 328
 329 static void omap2_apll_allow_idle(struct clk_hw_omap *clk)
 330 {
 331         omap2_apll_set_autoidle(clk, OMAP2_APLL_AUTOIDLE_LOW_POWER_STOP);
 332 }
 333
 334 static void omap2_apll_deny_idle(struct clk_hw_omap *clk)
 335 {
 336         omap2_apll_set_autoidle(clk, OMAP2_APLL_AUTOIDLE_DISABLE);
 337 }
 338
 339 static const struct clk_hw_omap_ops omap2_apll_hwops = {
 340         .allow_idle     = &omap2_apll_allow_idle,
 341         .deny_idle      = &omap2_apll_deny_idle,
 342 };
 343
 344 static void __init of_omap2_apll_setup(struct device_node *node)
 345 {
 346         struct dpll_data *ad = NULL;
 347         struct clk_hw_omap *clk_hw = NULL;
 348         struct clk_init_data *init = NULL;
 349         struct clk *clk;
 350         const char *parent_name;
 351         u32 val;
 352         int ret;
 353
 354         ad = kzalloc(sizeof(*ad), GFP_KERNEL);
 355         clk_hw = kzalloc(sizeof(*clk_hw), GFP_KERNEL);
 356         init = kzalloc(sizeof(*init), GFP_KERNEL);
 357
 358         if (!ad || !clk_hw || !init)
 359                 goto cleanup;
 360
 361         clk_hw->dpll_data = ad;
 362         clk_hw->hw.init = init;
 363         init->ops = &omap2_apll_ops;
 364         init->name = node->name;
 365         clk_hw->ops = &omap2_apll_hwops;
 366
 367         init->num_parents = of_clk_get_parent_count(node);
 368         if (init->num_parents != 1) {
 369                 pr_err("%pOFn must have one parent\n", node);
 370                 goto cleanup;
 371         }
 372
 373         parent_name = of_clk_get_parent_name(node, 0);
 374         init->parent_names = &parent_name;
 375
 376         if (of_property_read_u32(node, "ti,clock-frequency", &val)) {
 377                 pr_err("%pOFn missing clock-frequency\n", node);
 378                 goto cleanup;
 379         }
 380         clk_hw->fixed_rate = val;
 381
 382         if (of_property_read_u32(node, "ti,bit-shift", &val)) {
 383                 pr_err("%pOFn missing bit-shift\n", node);
 384                 goto cleanup;
 385         }
 386
 387         clk_hw->enable_bit = val;
 388         ad->enable_mask = 0x3 << val;
 389         ad->autoidle_mask = 0x3 << val;
 390
 391         if (of_property_read_u32(node, "ti,idlest-shift", &val)) {
 392                 pr_err("%pOFn missing idlest-shift\n", node);
 393                 goto cleanup;
 394         }
 395
 396         ad->idlest_mask = 1 << val;
 397
 398         ret = ti_clk_get_reg_addr(node, 0, &ad->control_reg);
 399         ret |= ti_clk_get_reg_addr(node, 1, &ad->autoidle_reg);
 400         ret |= ti_clk_get_reg_addr(node, 2, &ad->idlest_reg);
 401
 402         if (ret)
 403                 goto cleanup;
 404
 405         clk = clk_register(NULL, &clk_hw->hw);
 406         if (!IS_ERR(clk)) {
 407                 of_clk_add_provider(node, of_clk_src_simple_get, clk);
 408                 kfree(init);
 409                 return;
 410         }
 411 cleanup:
 412         kfree(ad);
 413         kfree(clk_hw);
 414         kfree(init);
 415 }
 416 CLK_OF_DECLARE(omap2_apll_clock, "ti,omap2-apll-clock",
 417                of_omap2_apll_setup);