drivers/clk/at91/clk-slow.c

   1 /*
   2  * drivers/clk/at91/clk-slow.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/slab.h>
  16 #include <linux/clk/at91_pmc.h>
  17 #include <linux/delay.h>
  18 #include <linux/of.h>
  19 #include <linux/of_address.h>
  20 #include <linux/of_irq.h>
  21 #include <linux/io.h>
  22 #include <linux/interrupt.h>
  23 #include <linux/irq.h>
  24 #include <linux/sched.h>
  25 #include <linux/wait.h>
  26
  27 #include "pmc.h"
  28 #include "sckc.h"
  29
  30 #define SLOW_CLOCK_FREQ         32768
  31 #define SLOWCK_SW_CYCLES        5
  32 #define SLOWCK_SW_TIME_USEC     ((SLOWCK_SW_CYCLES * USEC_PER_SEC) / \
  33                                  SLOW_CLOCK_FREQ)
  34
  35 #define AT91_SCKC_CR                    0x00
  36 #define         AT91_SCKC_RCEN          (1 << 0)
  37 #define         AT91_SCKC_OSC32EN       (1 << 1)
  38 #define         AT91_SCKC_OSC32BYP      (1 << 2)
  39 #define         AT91_SCKC_OSCSEL        (1 << 3)
  40
  41 struct clk_slow_osc {
  42         struct clk_hw hw;
  43         void __iomem *sckcr;
  44         unsigned long startup_usec;
  45 };
  46
  47 #define to_clk_slow_osc(hw) container_of(hw, struct clk_slow_osc, hw)
  48
  49 struct clk_slow_rc_osc {
  50         struct clk_hw hw;
  51         void __iomem *sckcr;
  52         unsigned long frequency;
  53         unsigned long accuracy;
  54         unsigned long startup_usec;
  55 };
  56
  57 #define to_clk_slow_rc_osc(hw) container_of(hw, struct clk_slow_rc_osc, hw)
  58
  59 struct clk_sam9260_slow {
  60         struct clk_hw hw;
  61         struct at91_pmc *pmc;
  62 };
  63
  64 #define to_clk_sam9260_slow(hw) container_of(hw, struct clk_sam9260_slow, hw)
  65
  66 struct clk_sam9x5_slow {
  67         struct clk_hw hw;
  68         void __iomem *sckcr;
  69         u8 parent;
  70 };
  71
  72 #define to_clk_sam9x5_slow(hw) container_of(hw, struct clk_sam9x5_slow, hw)
  73
  74 static int clk_slow_osc_prepare(struct clk_hw *hw)
  75 {
  76         struct clk_slow_osc *osc = to_clk_slow_osc(hw);
  77         void __iomem *sckcr = osc->sckcr;
  78         u32 tmp = readl(sckcr);
  79
  80         if (tmp & AT91_SCKC_OSC32BYP)
  81                 return 0;
  82
  83         writel(tmp | AT91_SCKC_OSC32EN, sckcr);
  84
  85         usleep_range(osc->startup_usec, osc->startup_usec + 1);
  86
  87         return 0;
  88 }
  89
  90 static void clk_slow_osc_unprepare(struct clk_hw *hw)
  91 {
  92         struct clk_slow_osc *osc = to_clk_slow_osc(hw);
  93         void __iomem *sckcr = osc->sckcr;
  94         u32 tmp = readl(sckcr);
  95
  96         if (tmp & AT91_SCKC_OSC32BYP)
  97                 return;
  98
  99         writel(tmp & ~AT91_SCKC_OSC32EN, sckcr);
 100 }
 101
 102 static int clk_slow_osc_is_prepared(struct clk_hw *hw)
 103 {
 104         struct clk_slow_osc *osc = to_clk_slow_osc(hw);
 105         void __iomem *sckcr = osc->sckcr;
 106         u32 tmp = readl(sckcr);
 107
 108         if (tmp & AT91_SCKC_OSC32BYP)
 109                 return 1;
 110
 111         return !!(tmp & AT91_SCKC_OSC32EN);
 112 }
 113
 114 static const struct clk_ops slow_osc_ops = {
 115         .prepare = clk_slow_osc_prepare,
 116         .unprepare = clk_slow_osc_unprepare,
 117         .is_prepared = clk_slow_osc_is_prepared,
 118 };
 119
 120 static struct clk * __init
 121 at91_clk_register_slow_osc(void __iomem *sckcr,
 122                            const char *name,
 123                            const char *parent_name,
 124                            unsigned long startup,
 125                            bool bypass)
 126 {
 127         struct clk_slow_osc *osc;
 128         struct clk *clk = NULL;
 129         struct clk_init_data init;
 130
 131         if (!sckcr || !name || !parent_name)
 132                 return ERR_PTR(-EINVAL);
 133
 134         osc = kzalloc(sizeof(*osc), GFP_KERNEL);
 135         if (!osc)
 136                 return ERR_PTR(-ENOMEM);
 137
 138         init.name = name;
 139         init.ops = &slow_osc_ops;
 140         init.parent_names = &parent_name;
 141         init.num_parents = 1;
 142         init.flags = CLK_IGNORE_UNUSED;
 143
 144         osc->hw.init = &init;
 145         osc->sckcr = sckcr;
 146         osc->startup_usec = startup;
 147
 148         if (bypass)
 149                 writel((readl(sckcr) & ~AT91_SCKC_OSC32EN) | AT91_SCKC_OSC32BYP,
 150                        sckcr);
 151
 152         clk = clk_register(NULL, &osc->hw);
 153         if (IS_ERR(clk))
 154                 kfree(osc);
 155
 156         return clk;
 157 }
 158
 159 void __init of_at91sam9x5_clk_slow_osc_setup(struct device_node *np,
 160                                              void __iomem *sckcr)
 161 {
 162         struct clk *clk;
 163         const char *parent_name;
 164         const char *name = np->name;
 165         u32 startup;
 166         bool bypass;
 167
 168         parent_name = of_clk_get_parent_name(np, 0);
 169         of_property_read_string(np, "clock-output-names", &name);
 170         of_property_read_u32(np, "atmel,startup-time-usec", &startup);
 171         bypass = of_property_read_bool(np, "atmel,osc-bypass");
 172
 173         clk = at91_clk_register_slow_osc(sckcr, name, parent_name, startup,
 174                                          bypass);
 175         if (IS_ERR(clk))
 176                 return;
 177
 178         of_clk_add_provider(np, of_clk_src_simple_get, clk);
 179 }
 180
 181 static unsigned long clk_slow_rc_osc_recalc_rate(struct clk_hw *hw,
 182                                                  unsigned long parent_rate)
 183 {
 184         struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
 185
 186         return osc->frequency;
 187 }
 188
 189 static unsigned long clk_slow_rc_osc_recalc_accuracy(struct clk_hw *hw,
 190                                                      unsigned long parent_acc)
 191 {
 192         struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
 193
 194         return osc->accuracy;
 195 }
 196
 197 static int clk_slow_rc_osc_prepare(struct clk_hw *hw)
 198 {
 199         struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
 200         void __iomem *sckcr = osc->sckcr;
 201
 202         writel(readl(sckcr) | AT91_SCKC_RCEN, sckcr);
 203
 204         usleep_range(osc->startup_usec, osc->startup_usec + 1);
 205
 206         return 0;
 207 }
 208
 209 static void clk_slow_rc_osc_unprepare(struct clk_hw *hw)
 210 {
 211         struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
 212         void __iomem *sckcr = osc->sckcr;
 213
 214         writel(readl(sckcr) & ~AT91_SCKC_RCEN, sckcr);
 215 }
 216
 217 static int clk_slow_rc_osc_is_prepared(struct clk_hw *hw)
 218 {
 219         struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
 220
 221         return !!(readl(osc->sckcr) & AT91_SCKC_RCEN);
 222 }
 223
 224 static const struct clk_ops slow_rc_osc_ops = {
 225         .prepare = clk_slow_rc_osc_prepare,
 226         .unprepare = clk_slow_rc_osc_unprepare,
 227         .is_prepared = clk_slow_rc_osc_is_prepared,
 228         .recalc_rate = clk_slow_rc_osc_recalc_rate,
 229         .recalc_accuracy = clk_slow_rc_osc_recalc_accuracy,
 230 };
 231
 232 static struct clk * __init
 233 at91_clk_register_slow_rc_osc(void __iomem *sckcr,
 234                               const char *name,
 235                               unsigned long frequency,
 236                               unsigned long accuracy,
 237                               unsigned long startup)
 238 {
 239         struct clk_slow_rc_osc *osc;
 240         struct clk *clk = NULL;
 241         struct clk_init_data init;
 242
 243         if (!sckcr || !name)
 244                 return ERR_PTR(-EINVAL);
 245
 246         osc = kzalloc(sizeof(*osc), GFP_KERNEL);
 247         if (!osc)
 248                 return ERR_PTR(-ENOMEM);
 249
 250         init.name = name;
 251         init.ops = &slow_rc_osc_ops;
 252         init.parent_names = NULL;
 253         init.num_parents = 0;
 254         init.flags = CLK_IGNORE_UNUSED;
 255
 256         osc->hw.init = &init;
 257         osc->sckcr = sckcr;
 258         osc->frequency = frequency;
 259         osc->accuracy = accuracy;
 260         osc->startup_usec = startup;
 261
 262         clk = clk_register(NULL, &osc->hw);
 263         if (IS_ERR(clk))
 264                 kfree(osc);
 265
 266         return clk;
 267 }
 268
 269 void __init of_at91sam9x5_clk_slow_rc_osc_setup(struct device_node *np,
 270                                                 void __iomem *sckcr)
 271 {
 272         struct clk *clk;
 273         u32 frequency = 0;
 274         u32 accuracy = 0;
 275         u32 startup = 0;
 276         const char *name = np->name;
 277
 278         of_property_read_string(np, "clock-output-names", &name);
 279         of_property_read_u32(np, "clock-frequency", &frequency);
 280         of_property_read_u32(np, "clock-accuracy", &accuracy);
 281         of_property_read_u32(np, "atmel,startup-time-usec", &startup);
 282
 283         clk = at91_clk_register_slow_rc_osc(sckcr, name, frequency, accuracy,
 284                                             startup);
 285         if (IS_ERR(clk))
 286                 return;
 287
 288         of_clk_add_provider(np, of_clk_src_simple_get, clk);
 289 }
 290
 291 static int clk_sam9x5_slow_set_parent(struct clk_hw *hw, u8 index)
 292 {
 293         struct clk_sam9x5_slow *slowck = to_clk_sam9x5_slow(hw);
 294         void __iomem *sckcr = slowck->sckcr;
 295         u32 tmp;
 296
 297         if (index > 1)
 298                 return -EINVAL;
 299
 300         tmp = readl(sckcr);
 301
 302         if ((!index && !(tmp & AT91_SCKC_OSCSEL)) ||
 303             (index && (tmp & AT91_SCKC_OSCSEL)))
 304                 return 0;
 305
 306         if (index)
 307                 tmp |= AT91_SCKC_OSCSEL;
 308         else
 309                 tmp &= ~AT91_SCKC_OSCSEL;
 310
 311         writel(tmp, sckcr);
 312
 313         usleep_range(SLOWCK_SW_TIME_USEC, SLOWCK_SW_TIME_USEC + 1);
 314
 315         return 0;
 316 }
 317
 318 static u8 clk_sam9x5_slow_get_parent(struct clk_hw *hw)
 319 {
 320         struct clk_sam9x5_slow *slowck = to_clk_sam9x5_slow(hw);
 321
 322         return !!(readl(slowck->sckcr) & AT91_SCKC_OSCSEL);
 323 }
 324
 325 static const struct clk_ops sam9x5_slow_ops = {
 326         .set_parent = clk_sam9x5_slow_set_parent,
 327         .get_parent = clk_sam9x5_slow_get_parent,
 328 };
 329
 330 static struct clk * __init
 331 at91_clk_register_sam9x5_slow(void __iomem *sckcr,
 332                               const char *name,
 333                               const char **parent_names,
 334                               int num_parents)
 335 {
 336         struct clk_sam9x5_slow *slowck;
 337         struct clk *clk = NULL;
 338         struct clk_init_data init;
 339
 340         if (!sckcr || !name || !parent_names || !num_parents)
 341                 return ERR_PTR(-EINVAL);
 342
 343         slowck = kzalloc(sizeof(*slowck), GFP_KERNEL);
 344         if (!slowck)
 345                 return ERR_PTR(-ENOMEM);
 346
 347         init.name = name;
 348         init.ops = &sam9x5_slow_ops;
 349         init.parent_names = parent_names;
 350         init.num_parents = num_parents;
 351         init.flags = 0;
 352
 353         slowck->hw.init = &init;
 354         slowck->sckcr = sckcr;
 355         slowck->parent = !!(readl(sckcr) & AT91_SCKC_OSCSEL);
 356
 357         clk = clk_register(NULL, &slowck->hw);
 358         if (IS_ERR(clk))
 359                 kfree(slowck);
 360
 361         return clk;
 362 }
 363
 364 void __init of_at91sam9x5_clk_slow_setup(struct device_node *np,
 365                                          void __iomem *sckcr)
 366 {
 367         struct clk *clk;
 368         const char *parent_names[2];
 369         unsigned int num_parents;
 370         const char *name = np->name;
 371
 372         num_parents = of_clk_get_parent_count(np);
 373         if (num_parents == 0 || num_parents > 2)
 374                 return;
 375
 376         of_clk_parent_fill(np, parent_names, num_parents);
 377
 378         of_property_read_string(np, "clock-output-names", &name);
 379
 380         clk = at91_clk_register_sam9x5_slow(sckcr, name, parent_names,
 381                                             num_parents);
 382         if (IS_ERR(clk))
 383                 return;
 384
 385         of_clk_add_provider(np, of_clk_src_simple_get, clk);
 386 }
 387
 388 static u8 clk_sam9260_slow_get_parent(struct clk_hw *hw)
 389 {
 390         struct clk_sam9260_slow *slowck = to_clk_sam9260_slow(hw);
 391
 392         return !!(pmc_read(slowck->pmc, AT91_PMC_SR) & AT91_PMC_OSCSEL);
 393 }
 394
 395 static const struct clk_ops sam9260_slow_ops = {
 396         .get_parent = clk_sam9260_slow_get_parent,
 397 };
 398
 399 static struct clk * __init
 400 at91_clk_register_sam9260_slow(struct at91_pmc *pmc,
 401                                const char *name,
 402                                const char **parent_names,
 403                                int num_parents)
 404 {
 405         struct clk_sam9260_slow *slowck;
 406         struct clk *clk = NULL;
 407         struct clk_init_data init;
 408
 409         if (!pmc || !name)
 410                 return ERR_PTR(-EINVAL);
 411
 412         if (!parent_names || !num_parents)
 413                 return ERR_PTR(-EINVAL);
 414
 415         slowck = kzalloc(sizeof(*slowck), GFP_KERNEL);
 416         if (!slowck)
 417                 return ERR_PTR(-ENOMEM);
 418
 419         init.name = name;
 420         init.ops = &sam9260_slow_ops;
 421         init.parent_names = parent_names;
 422         init.num_parents = num_parents;
 423         init.flags = 0;
 424
 425         slowck->hw.init = &init;
 426         slowck->pmc = pmc;
 427
 428         clk = clk_register(NULL, &slowck->hw);
 429         if (IS_ERR(clk))
 430                 kfree(slowck);
 431
 432         return clk;
 433 }
 434
 435 void __init of_at91sam9260_clk_slow_setup(struct device_node *np,
 436                                           struct at91_pmc *pmc)
 437 {
 438         struct clk *clk;
 439         const char *parent_names[2];
 440         unsigned int num_parents;
 441         const char *name = np->name;
 442
 443         num_parents = of_clk_get_parent_count(np);
 444         if (num_parents != 2)
 445                 return;
 446
 447         of_clk_parent_fill(np, parent_names, num_parents);
 448
 449         of_property_read_string(np, "clock-output-names", &name);
 450
 451         clk = at91_clk_register_sam9260_slow(pmc, name, parent_names,
 452                                              num_parents);
 453         if (IS_ERR(clk))
 454                 return;
 455
 456         of_clk_add_provider(np, of_clk_src_simple_get, clk);
 457 }