drivers/clk/at91/sckc.c

   1 /*
   2  * drivers/clk/at91/sckc.c
   3  *
   4  *  Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  */
  12
  13 #include <linux/clk-provider.h>
  14 #include <linux/clkdev.h>
  15 #include <linux/delay.h>
  16 #include <linux/of.h>
  17 #include <linux/of_address.h>
  18 #include <linux/io.h>
  19
  20 #define SLOW_CLOCK_FREQ         32768
  21 #define SLOWCK_SW_CYCLES        5
  22 #define SLOWCK_SW_TIME_USEC     ((SLOWCK_SW_CYCLES * USEC_PER_SEC) / \
  23                                  SLOW_CLOCK_FREQ)
  24
  25 #define AT91_SCKC_CR                    0x00
  26 #define         AT91_SCKC_RCEN          (1 << 0)
  27 #define         AT91_SCKC_OSC32EN       (1 << 1)
  28 #define         AT91_SCKC_OSC32BYP      (1 << 2)
  29 #define         AT91_SCKC_OSCSEL        (1 << 3)
  30
  31 struct clk_slow_osc {
  32         struct clk_hw hw;
  33         void __iomem *sckcr;
  34         unsigned long startup_usec;
  35 };
  36
  37 #define to_clk_slow_osc(hw) container_of(hw, struct clk_slow_osc, hw)
  38
  39 struct clk_sama5d4_slow_osc {
  40         struct clk_hw hw;
  41         void __iomem *sckcr;
  42         unsigned long startup_usec;
  43         bool prepared;
  44 };
  45
  46 #define to_clk_sama5d4_slow_osc(hw) container_of(hw, struct clk_sama5d4_slow_osc, hw)
  47
  48 struct clk_slow_rc_osc {
  49         struct clk_hw hw;
  50         void __iomem *sckcr;
  51         unsigned long frequency;
  52         unsigned long accuracy;
  53         unsigned long startup_usec;
  54 };
  55
  56 #define to_clk_slow_rc_osc(hw) container_of(hw, struct clk_slow_rc_osc, hw)
  57
  58 struct clk_sam9x5_slow {
  59         struct clk_hw hw;
  60         void __iomem *sckcr;
  61         u8 parent;
  62 };
  63
  64 #define to_clk_sam9x5_slow(hw) container_of(hw, struct clk_sam9x5_slow, hw)
  65
  66 static int clk_slow_osc_prepare(struct clk_hw *hw)
  67 {
  68         struct clk_slow_osc *osc = to_clk_slow_osc(hw);
  69         void __iomem *sckcr = osc->sckcr;
  70         u32 tmp = readl(sckcr);
  71
  72         if (tmp & (AT91_SCKC_OSC32BYP | AT91_SCKC_OSC32EN))
  73                 return 0;
  74
  75         writel(tmp | AT91_SCKC_OSC32EN, sckcr);
  76
  77         if (system_state < SYSTEM_RUNNING)
  78                 udelay(osc->startup_usec);
  79         else
  80                 usleep_range(osc->startup_usec, osc->startup_usec + 1);
  81
  82         return 0;
  83 }
  84
  85 static void clk_slow_osc_unprepare(struct clk_hw *hw)
  86 {
  87         struct clk_slow_osc *osc = to_clk_slow_osc(hw);
  88         void __iomem *sckcr = osc->sckcr;
  89         u32 tmp = readl(sckcr);
  90
  91         if (tmp & AT91_SCKC_OSC32BYP)
  92                 return;
  93
  94         writel(tmp & ~AT91_SCKC_OSC32EN, sckcr);
  95 }
  96
  97 static int clk_slow_osc_is_prepared(struct clk_hw *hw)
  98 {
  99         struct clk_slow_osc *osc = to_clk_slow_osc(hw);
 100         void __iomem *sckcr = osc->sckcr;
 101         u32 tmp = readl(sckcr);
 102
 103         if (tmp & AT91_SCKC_OSC32BYP)
 104                 return 1;
 105
 106         return !!(tmp & AT91_SCKC_OSC32EN);
 107 }
 108
 109 static const struct clk_ops slow_osc_ops = {
 110         .prepare = clk_slow_osc_prepare,
 111         .unprepare = clk_slow_osc_unprepare,
 112         .is_prepared = clk_slow_osc_is_prepared,
 113 };
 114
 115 static struct clk_hw * __init
 116 at91_clk_register_slow_osc(void __iomem *sckcr,
 117                            const char *name,
 118                            const char *parent_name,
 119                            unsigned long startup,
 120                            bool bypass)
 121 {
 122         struct clk_slow_osc *osc;
 123         struct clk_hw *hw;
 124         struct clk_init_data init;
 125         int ret;
 126
 127         if (!sckcr || !name || !parent_name)
 128                 return ERR_PTR(-EINVAL);
 129
 130         osc = kzalloc(sizeof(*osc), GFP_KERNEL);
 131         if (!osc)
 132                 return ERR_PTR(-ENOMEM);
 133
 134         init.name = name;
 135         init.ops = &slow_osc_ops;
 136         init.parent_names = &parent_name;
 137         init.num_parents = 1;
 138         init.flags = CLK_IGNORE_UNUSED;
 139
 140         osc->hw.init = &init;
 141         osc->sckcr = sckcr;
 142         osc->startup_usec = startup;
 143
 144         if (bypass)
 145                 writel((readl(sckcr) & ~AT91_SCKC_OSC32EN) | AT91_SCKC_OSC32BYP,
 146                        sckcr);
 147
 148         hw = &osc->hw;
 149         ret = clk_hw_register(NULL, &osc->hw);
 150         if (ret) {
 151                 kfree(osc);
 152                 hw = ERR_PTR(ret);
 153         }
 154
 155         return hw;
 156 }
 157
 158 static void __init
 159 of_at91sam9x5_clk_slow_osc_setup(struct device_node *np, void __iomem *sckcr)
 160 {
 161         struct clk_hw *hw;
 162         const char *parent_name;
 163         const char *name = np->name;
 164         u32 startup;
 165         bool bypass;
 166
 167         parent_name = of_clk_get_parent_name(np, 0);
 168         of_property_read_string(np, "clock-output-names", &name);
 169         of_property_read_u32(np, "atmel,startup-time-usec", &startup);
 170         bypass = of_property_read_bool(np, "atmel,osc-bypass");
 171
 172         hw = at91_clk_register_slow_osc(sckcr, name, parent_name, startup,
 173                                          bypass);
 174         if (IS_ERR(hw))
 175                 return;
 176
 177         of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw);
 178 }
 179
 180 static unsigned long clk_slow_rc_osc_recalc_rate(struct clk_hw *hw,
 181                                                  unsigned long parent_rate)
 182 {
 183         struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
 184
 185         return osc->frequency;
 186 }
 187
 188 static unsigned long clk_slow_rc_osc_recalc_accuracy(struct clk_hw *hw,
 189                                                      unsigned long parent_acc)
 190 {
 191         struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
 192
 193         return osc->accuracy;
 194 }
 195
 196 static int clk_slow_rc_osc_prepare(struct clk_hw *hw)
 197 {
 198         struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
 199         void __iomem *sckcr = osc->sckcr;
 200
 201         writel(readl(sckcr) | AT91_SCKC_RCEN, sckcr);
 202
 203         if (system_state < SYSTEM_RUNNING)
 204                 udelay(osc->startup_usec);
 205         else
 206                 usleep_range(osc->startup_usec, osc->startup_usec + 1);
 207
 208         return 0;
 209 }
 210
 211 static void clk_slow_rc_osc_unprepare(struct clk_hw *hw)
 212 {
 213         struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
 214         void __iomem *sckcr = osc->sckcr;
 215
 216         writel(readl(sckcr) & ~AT91_SCKC_RCEN, sckcr);
 217 }
 218
 219 static int clk_slow_rc_osc_is_prepared(struct clk_hw *hw)
 220 {
 221         struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
 222
 223         return !!(readl(osc->sckcr) & AT91_SCKC_RCEN);
 224 }
 225
 226 static const struct clk_ops slow_rc_osc_ops = {
 227         .prepare = clk_slow_rc_osc_prepare,
 228         .unprepare = clk_slow_rc_osc_unprepare,
 229         .is_prepared = clk_slow_rc_osc_is_prepared,
 230         .recalc_rate = clk_slow_rc_osc_recalc_rate,
 231         .recalc_accuracy = clk_slow_rc_osc_recalc_accuracy,
 232 };
 233
 234 static struct clk_hw * __init
 235 at91_clk_register_slow_rc_osc(void __iomem *sckcr,
 236                               const char *name,
 237                               unsigned long frequency,
 238                               unsigned long accuracy,
 239                               unsigned long startup)
 240 {
 241         struct clk_slow_rc_osc *osc;
 242         struct clk_hw *hw;
 243         struct clk_init_data init;
 244         int ret;
 245
 246         if (!sckcr || !name)
 247                 return ERR_PTR(-EINVAL);
 248
 249         osc = kzalloc(sizeof(*osc), GFP_KERNEL);
 250         if (!osc)
 251                 return ERR_PTR(-ENOMEM);
 252
 253         init.name = name;
 254         init.ops = &slow_rc_osc_ops;
 255         init.parent_names = NULL;
 256         init.num_parents = 0;
 257         init.flags = CLK_IGNORE_UNUSED;
 258
 259         osc->hw.init = &init;
 260         osc->sckcr = sckcr;
 261         osc->frequency = frequency;
 262         osc->accuracy = accuracy;
 263         osc->startup_usec = startup;
 264
 265         hw = &osc->hw;
 266         ret = clk_hw_register(NULL, &osc->hw);
 267         if (ret) {
 268                 kfree(osc);
 269                 hw = ERR_PTR(ret);
 270         }
 271
 272         return hw;
 273 }
 274
 275 static void __init
 276 of_at91sam9x5_clk_slow_rc_osc_setup(struct device_node *np, void __iomem *sckcr)
 277 {
 278         struct clk_hw *hw;
 279         u32 frequency = 0;
 280         u32 accuracy = 0;
 281         u32 startup = 0;
 282         const char *name = np->name;
 283
 284         of_property_read_string(np, "clock-output-names", &name);
 285         of_property_read_u32(np, "clock-frequency", &frequency);
 286         of_property_read_u32(np, "clock-accuracy", &accuracy);
 287         of_property_read_u32(np, "atmel,startup-time-usec", &startup);
 288
 289         hw = at91_clk_register_slow_rc_osc(sckcr, name, frequency, accuracy,
 290                                             startup);
 291         if (IS_ERR(hw))
 292                 return;
 293
 294         of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw);
 295 }
 296
 297 static int clk_sam9x5_slow_set_parent(struct clk_hw *hw, u8 index)
 298 {
 299         struct clk_sam9x5_slow *slowck = to_clk_sam9x5_slow(hw);
 300         void __iomem *sckcr = slowck->sckcr;
 301         u32 tmp;
 302
 303         if (index > 1)
 304                 return -EINVAL;
 305
 306         tmp = readl(sckcr);
 307
 308         if ((!index && !(tmp & AT91_SCKC_OSCSEL)) ||
 309             (index && (tmp & AT91_SCKC_OSCSEL)))
 310                 return 0;
 311
 312         if (index)
 313                 tmp |= AT91_SCKC_OSCSEL;
 314         else
 315                 tmp &= ~AT91_SCKC_OSCSEL;
 316
 317         writel(tmp, sckcr);
 318
 319         if (system_state < SYSTEM_RUNNING)
 320                 udelay(SLOWCK_SW_TIME_USEC);
 321         else
 322                 usleep_range(SLOWCK_SW_TIME_USEC, SLOWCK_SW_TIME_USEC + 1);
 323
 324         return 0;
 325 }
 326
 327 static u8 clk_sam9x5_slow_get_parent(struct clk_hw *hw)
 328 {
 329         struct clk_sam9x5_slow *slowck = to_clk_sam9x5_slow(hw);
 330
 331         return !!(readl(slowck->sckcr) & AT91_SCKC_OSCSEL);
 332 }
 333
 334 static const struct clk_ops sam9x5_slow_ops = {
 335         .set_parent = clk_sam9x5_slow_set_parent,
 336         .get_parent = clk_sam9x5_slow_get_parent,
 337 };
 338
 339 static struct clk_hw * __init
 340 at91_clk_register_sam9x5_slow(void __iomem *sckcr,
 341                               const char *name,
 342                               const char **parent_names,
 343                               int num_parents)
 344 {
 345         struct clk_sam9x5_slow *slowck;
 346         struct clk_hw *hw;
 347         struct clk_init_data init;
 348         int ret;
 349
 350         if (!sckcr || !name || !parent_names || !num_parents)
 351                 return ERR_PTR(-EINVAL);
 352
 353         slowck = kzalloc(sizeof(*slowck), GFP_KERNEL);
 354         if (!slowck)
 355                 return ERR_PTR(-ENOMEM);
 356
 357         init.name = name;
 358         init.ops = &sam9x5_slow_ops;
 359         init.parent_names = parent_names;
 360         init.num_parents = num_parents;
 361         init.flags = 0;
 362
 363         slowck->hw.init = &init;
 364         slowck->sckcr = sckcr;
 365         slowck->parent = !!(readl(sckcr) & AT91_SCKC_OSCSEL);
 366
 367         hw = &slowck->hw;
 368         ret = clk_hw_register(NULL, &slowck->hw);
 369         if (ret) {
 370                 kfree(slowck);
 371                 hw = ERR_PTR(ret);
 372         }
 373
 374         return hw;
 375 }
 376
 377 static void __init
 378 of_at91sam9x5_clk_slow_setup(struct device_node *np, void __iomem *sckcr)
 379 {
 380         struct clk_hw *hw;
 381         const char *parent_names[2];
 382         unsigned int num_parents;
 383         const char *name = np->name;
 384
 385         num_parents = of_clk_get_parent_count(np);
 386         if (num_parents == 0 || num_parents > 2)
 387                 return;
 388
 389         of_clk_parent_fill(np, parent_names, num_parents);
 390
 391         of_property_read_string(np, "clock-output-names", &name);
 392
 393         hw = at91_clk_register_sam9x5_slow(sckcr, name, parent_names,
 394                                             num_parents);
 395         if (IS_ERR(hw))
 396                 return;
 397
 398         of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw);
 399 }
 400
 401 static const struct of_device_id sckc_clk_ids[] __initconst = {
 402         /* Slow clock */
 403         {
 404                 .compatible = "atmel,at91sam9x5-clk-slow-osc",
 405                 .data = of_at91sam9x5_clk_slow_osc_setup,
 406         },
 407         {
 408                 .compatible = "atmel,at91sam9x5-clk-slow-rc-osc",
 409                 .data = of_at91sam9x5_clk_slow_rc_osc_setup,
 410         },
 411         {
 412                 .compatible = "atmel,at91sam9x5-clk-slow",
 413                 .data = of_at91sam9x5_clk_slow_setup,
 414         },
 415         { /*sentinel*/ }
 416 };
 417
 418 static void __init of_at91sam9x5_sckc_setup(struct device_node *np)
 419 {
 420         struct device_node *childnp;
 421         void (*clk_setup)(struct device_node *, void __iomem *);
 422         const struct of_device_id *clk_id;
 423         void __iomem *regbase = of_iomap(np, 0);
 424
 425         if (!regbase)
 426                 return;
 427
 428         for_each_child_of_node(np, childnp) {
 429                 clk_id = of_match_node(sckc_clk_ids, childnp);
 430                 if (!clk_id)
 431                         continue;
 432                 clk_setup = clk_id->data;
 433                 clk_setup(childnp, regbase);
 434         }
 435 }
 436 CLK_OF_DECLARE(at91sam9x5_clk_sckc, "atmel,at91sam9x5-sckc",
 437                of_at91sam9x5_sckc_setup);
 438
 439 static int clk_sama5d4_slow_osc_prepare(struct clk_hw *hw)
 440 {
 441         struct clk_sama5d4_slow_osc *osc = to_clk_sama5d4_slow_osc(hw);
 442
 443         if (osc->prepared)
 444                 return 0;
 445
 446         /*
 447          * Assume that if it has already been selected (for example by the
 448          * bootloader), enough time has aready passed.
 449          */
 450         if ((readl(osc->sckcr) & AT91_SCKC_OSCSEL)) {
 451                 osc->prepared = true;
 452                 return 0;
 453         }
 454
 455         if (system_state < SYSTEM_RUNNING)
 456                 udelay(osc->startup_usec);
 457         else
 458                 usleep_range(osc->startup_usec, osc->startup_usec + 1);
 459         osc->prepared = true;
 460
 461         return 0;
 462 }
 463
 464 static int clk_sama5d4_slow_osc_is_prepared(struct clk_hw *hw)
 465 {
 466         struct clk_sama5d4_slow_osc *osc = to_clk_sama5d4_slow_osc(hw);
 467
 468         return osc->prepared;
 469 }
 470
 471 static const struct clk_ops sama5d4_slow_osc_ops = {
 472         .prepare = clk_sama5d4_slow_osc_prepare,
 473         .is_prepared = clk_sama5d4_slow_osc_is_prepared,
 474 };
 475
 476 static void __init of_sama5d4_sckc_setup(struct device_node *np)
 477 {
 478         void __iomem *regbase = of_iomap(np, 0);
 479         struct clk_hw *hw;
 480         struct clk_sama5d4_slow_osc *osc;
 481         struct clk_init_data init;
 482         const char *xtal_name;
 483         const char *parent_names[2] = { "slow_rc_osc", "slow_osc" };
 484         bool bypass;
 485         int ret;
 486
 487         if (!regbase)
 488                 return;
 489
 490         hw = clk_hw_register_fixed_rate_with_accuracy(NULL, parent_names[0],
 491                                                       NULL, 0, 32768,
 492                                                       250000000);
 493         if (IS_ERR(hw))
 494                 return;
 495
 496         xtal_name = of_clk_get_parent_name(np, 0);
 497
 498         bypass = of_property_read_bool(np, "atmel,osc-bypass");
 499
 500         osc = kzalloc(sizeof(*osc), GFP_KERNEL);
 501         if (!osc)
 502                 return;
 503
 504         init.name = parent_names[1];
 505         init.ops = &sama5d4_slow_osc_ops;
 506         init.parent_names = &xtal_name;
 507         init.num_parents = 1;
 508         init.flags = CLK_IGNORE_UNUSED;
 509
 510         osc->hw.init = &init;
 511         osc->sckcr = regbase;
 512         osc->startup_usec = 1200000;
 513
 514         if (bypass)
 515                 writel((readl(regbase) | AT91_SCKC_OSC32BYP), regbase);
 516
 517         hw = &osc->hw;
 518         ret = clk_hw_register(NULL, &osc->hw);
 519         if (ret) {
 520                 kfree(osc);
 521                 return;
 522         }
 523
 524         hw = at91_clk_register_sam9x5_slow(regbase, "slowck", parent_names, 2);
 525         if (IS_ERR(hw))
 526                 return;
 527
 528         of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw);
 529 }
 530 CLK_OF_DECLARE(sama5d4_clk_sckc, "atmel,sama5d4-sckc",
 531                of_sama5d4_sckc_setup);