drivers/clk/clk-xgene.c

   1 /*
   2  * clk-xgene.c - AppliedMicro X-Gene Clock Interface
   3  *
   4  * Copyright (c) 2013, Applied Micro Circuits Corporation
   5  * Author: Loc Ho <lho@apm.com>
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License as
   9  * published by the Free Software Foundation; either version 2 of
  10  * the License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  20  * MA 02111-1307 USA
  21  *
  22  */
  23 #include <linux/module.h>
  24 #include <linux/spinlock.h>
  25 #include <linux/io.h>
  26 #include <linux/of.h>
  27 #include <linux/clkdev.h>
  28 #include <linux/clk-provider.h>
  29 #include <linux/of_address.h>
  30
  31 /* Register SCU_PCPPLL bit fields */
  32 #define N_DIV_RD(src)                   ((src) & 0x000001ff)
  33 #define SC_N_DIV_RD(src)                ((src) & 0x0000007f)
  34 #define SC_OUTDIV2(src)                 (((src) & 0x00000100) >> 8)
  35
  36 /* Register SCU_SOCPLL bit fields */
  37 #define CLKR_RD(src)                    (((src) & 0x07000000)>>24)
  38 #define CLKOD_RD(src)                   (((src) & 0x00300000)>>20)
  39 #define REGSPEC_RESET_F1_MASK           0x00010000
  40 #define CLKF_RD(src)                    (((src) & 0x000001ff))
  41
  42 #define XGENE_CLK_DRIVER_VER            "0.1"
  43
  44 static DEFINE_SPINLOCK(clk_lock);
  45
  46 static inline u32 xgene_clk_read(void __iomem *csr)
  47 {
  48         return readl_relaxed(csr);
  49 }
  50
  51 static inline void xgene_clk_write(u32 data, void __iomem *csr)
  52 {
  53         writel_relaxed(data, csr);
  54 }
  55
  56 /* PLL Clock */
  57 enum xgene_pll_type {
  58         PLL_TYPE_PCP = 0,
  59         PLL_TYPE_SOC = 1,
  60 };
  61
  62 struct xgene_clk_pll {
  63         struct clk_hw   hw;
  64         void __iomem    *reg;
  65         spinlock_t      *lock;
  66         u32             pll_offset;
  67         enum xgene_pll_type     type;
  68         int             version;
  69 };
  70
  71 #define to_xgene_clk_pll(_hw) container_of(_hw, struct xgene_clk_pll, hw)
  72
  73 static int xgene_clk_pll_is_enabled(struct clk_hw *hw)
  74 {
  75         struct xgene_clk_pll *pllclk = to_xgene_clk_pll(hw);
  76         u32 data;
  77
  78         data = xgene_clk_read(pllclk->reg + pllclk->pll_offset);
  79         pr_debug("%s pll %s\n", clk_hw_get_name(hw),
  80                 data & REGSPEC_RESET_F1_MASK ? "disabled" : "enabled");
  81
  82         return data & REGSPEC_RESET_F1_MASK ? 0 : 1;
  83 }
  84
  85 static unsigned long xgene_clk_pll_recalc_rate(struct clk_hw *hw,
  86                                 unsigned long parent_rate)
  87 {
  88         struct xgene_clk_pll *pllclk = to_xgene_clk_pll(hw);
  89         unsigned long fref;
  90         unsigned long fvco;
  91         u32 pll;
  92         u32 nref;
  93         u32 nout;
  94         u32 nfb;
  95
  96         pll = xgene_clk_read(pllclk->reg + pllclk->pll_offset);
  97
  98         if (pllclk->version <= 1) {
  99                 if (pllclk->type == PLL_TYPE_PCP) {
 100                         /*
 101                         * PLL VCO = Reference clock * NF
 102                         * PCP PLL = PLL_VCO / 2
 103                         */
 104                         nout = 2;
 105                         fvco = parent_rate * (N_DIV_RD(pll) + 4);
 106                 } else {
 107                         /*
 108                         * Fref = Reference Clock / NREF;
 109                         * Fvco = Fref * NFB;
 110                         * Fout = Fvco / NOUT;
 111                         */
 112                         nref = CLKR_RD(pll) + 1;
 113                         nout = CLKOD_RD(pll) + 1;
 114                         nfb = CLKF_RD(pll);
 115                         fref = parent_rate / nref;
 116                         fvco = fref * nfb;
 117                 }
 118         } else {
 119                 /*
 120                  * fvco = Reference clock * FBDIVC
 121                  * PLL freq = fvco / NOUT
 122                  */
 123                 nout = SC_OUTDIV2(pll) ? 2 : 3;
 124                 fvco = parent_rate * SC_N_DIV_RD(pll);
 125         }
 126         pr_debug("%s pll recalc rate %ld parent %ld version %d\n",
 127                  clk_hw_get_name(hw), fvco / nout, parent_rate,
 128                  pllclk->version);
 129
 130         return fvco / nout;
 131 }
 132
 133 static const struct clk_ops xgene_clk_pll_ops = {
 134         .is_enabled = xgene_clk_pll_is_enabled,
 135         .recalc_rate = xgene_clk_pll_recalc_rate,
 136 };
 137
 138 static struct clk *xgene_register_clk_pll(struct device *dev,
 139         const char *name, const char *parent_name,
 140         unsigned long flags, void __iomem *reg, u32 pll_offset,
 141         u32 type, spinlock_t *lock, int version)
 142 {
 143         struct xgene_clk_pll *apmclk;
 144         struct clk *clk;
 145         struct clk_init_data init;
 146
 147         /* allocate the APM clock structure */
 148         apmclk = kzalloc(sizeof(*apmclk), GFP_KERNEL);
 149         if (!apmclk) {
 150                 pr_err("%s: could not allocate APM clk\n", __func__);
 151                 return ERR_PTR(-ENOMEM);
 152         }
 153
 154         init.name = name;
 155         init.ops = &xgene_clk_pll_ops;
 156         init.flags = flags;
 157         init.parent_names = parent_name ? &parent_name : NULL;
 158         init.num_parents = parent_name ? 1 : 0;
 159
 160         apmclk->version = version;
 161         apmclk->reg = reg;
 162         apmclk->lock = lock;
 163         apmclk->pll_offset = pll_offset;
 164         apmclk->type = type;
 165         apmclk->hw.init = &init;
 166
 167         /* Register the clock */
 168         clk = clk_register(dev, &apmclk->hw);
 169         if (IS_ERR(clk)) {
 170                 pr_err("%s: could not register clk %s\n", __func__, name);
 171                 kfree(apmclk);
 172                 return NULL;
 173         }
 174         return clk;
 175 }
 176
 177 static int xgene_pllclk_version(struct device_node *np)
 178 {
 179         if (of_device_is_compatible(np, "apm,xgene-socpll-clock"))
 180                 return 1;
 181         if (of_device_is_compatible(np, "apm,xgene-pcppll-clock"))
 182                 return 1;
 183         return 2;
 184 }
 185
 186 static void xgene_pllclk_init(struct device_node *np, enum xgene_pll_type pll_type)
 187 {
 188         const char *clk_name = np->full_name;
 189         struct clk *clk;
 190         void __iomem *reg;
 191         int version = xgene_pllclk_version(np);
 192
 193         reg = of_iomap(np, 0);
 194         if (reg == NULL) {
 195                 pr_err("Unable to map CSR register for %s\n", np->full_name);
 196                 return;
 197         }
 198         of_property_read_string(np, "clock-output-names", &clk_name);
 199         clk = xgene_register_clk_pll(NULL,
 200                         clk_name, of_clk_get_parent_name(np, 0),
 201                         0, reg, 0, pll_type, &clk_lock,
 202                         version);
 203         if (!IS_ERR(clk)) {
 204                 of_clk_add_provider(np, of_clk_src_simple_get, clk);
 205                 clk_register_clkdev(clk, clk_name, NULL);
 206                 pr_debug("Add %s clock PLL\n", clk_name);
 207         }
 208 }
 209
 210 static void xgene_socpllclk_init(struct device_node *np)
 211 {
 212         xgene_pllclk_init(np, PLL_TYPE_SOC);
 213 }
 214
 215 static void xgene_pcppllclk_init(struct device_node *np)
 216 {
 217         xgene_pllclk_init(np, PLL_TYPE_PCP);
 218 }
 219
 220 /* IP Clock */
 221 struct xgene_dev_parameters {
 222         void __iomem *csr_reg;          /* CSR for IP clock */
 223         u32 reg_clk_offset;             /* Offset to clock enable CSR */
 224         u32 reg_clk_mask;               /* Mask bit for clock enable */
 225         u32 reg_csr_offset;             /* Offset to CSR reset */
 226         u32 reg_csr_mask;               /* Mask bit for disable CSR reset */
 227         void __iomem *divider_reg;      /* CSR for divider */
 228         u32 reg_divider_offset;         /* Offset to divider register */
 229         u32 reg_divider_shift;          /* Bit shift to divider field */
 230         u32 reg_divider_width;          /* Width of the bit to divider field */
 231 };
 232
 233 struct xgene_clk {
 234         struct clk_hw   hw;
 235         spinlock_t      *lock;
 236         struct xgene_dev_parameters     param;
 237 };
 238
 239 #define to_xgene_clk(_hw) container_of(_hw, struct xgene_clk, hw)
 240
 241 static int xgene_clk_enable(struct clk_hw *hw)
 242 {
 243         struct xgene_clk *pclk = to_xgene_clk(hw);
 244         unsigned long flags = 0;
 245         u32 data;
 246         phys_addr_t reg;
 247
 248         if (pclk->lock)
 249                 spin_lock_irqsave(pclk->lock, flags);
 250
 251         if (pclk->param.csr_reg != NULL) {
 252                 pr_debug("%s clock enabled\n", clk_hw_get_name(hw));
 253                 reg = __pa(pclk->param.csr_reg);
 254                 /* First enable the clock */
 255                 data = xgene_clk_read(pclk->param.csr_reg +
 256                                         pclk->param.reg_clk_offset);
 257                 data |= pclk->param.reg_clk_mask;
 258                 xgene_clk_write(data, pclk->param.csr_reg +
 259                                         pclk->param.reg_clk_offset);
 260                 pr_debug("%s clock PADDR base %pa clk offset 0x%08X mask 0x%08X value 0x%08X\n",
 261                         clk_hw_get_name(hw), &reg,
 262                         pclk->param.reg_clk_offset, pclk->param.reg_clk_mask,
 263                         data);
 264
 265                 /* Second enable the CSR */
 266                 data = xgene_clk_read(pclk->param.csr_reg +
 267                                         pclk->param.reg_csr_offset);
 268                 data &= ~pclk->param.reg_csr_mask;
 269                 xgene_clk_write(data, pclk->param.csr_reg +
 270                                         pclk->param.reg_csr_offset);
 271                 pr_debug("%s CSR RESET PADDR base %pa csr offset 0x%08X mask 0x%08X value 0x%08X\n",
 272                         clk_hw_get_name(hw), &reg,
 273                         pclk->param.reg_csr_offset, pclk->param.reg_csr_mask,
 274                         data);
 275         }
 276
 277         if (pclk->lock)
 278                 spin_unlock_irqrestore(pclk->lock, flags);
 279
 280         return 0;
 281 }
 282
 283 static void xgene_clk_disable(struct clk_hw *hw)
 284 {
 285         struct xgene_clk *pclk = to_xgene_clk(hw);
 286         unsigned long flags = 0;
 287         u32 data;
 288
 289         if (pclk->lock)
 290                 spin_lock_irqsave(pclk->lock, flags);
 291
 292         if (pclk->param.csr_reg != NULL) {
 293                 pr_debug("%s clock disabled\n", clk_hw_get_name(hw));
 294                 /* First put the CSR in reset */
 295                 data = xgene_clk_read(pclk->param.csr_reg +
 296                                         pclk->param.reg_csr_offset);
 297                 data |= pclk->param.reg_csr_mask;
 298                 xgene_clk_write(data, pclk->param.csr_reg +
 299                                         pclk->param.reg_csr_offset);
 300
 301                 /* Second disable the clock */
 302                 data = xgene_clk_read(pclk->param.csr_reg +
 303                                         pclk->param.reg_clk_offset);
 304                 data &= ~pclk->param.reg_clk_mask;
 305                 xgene_clk_write(data, pclk->param.csr_reg +
 306                                         pclk->param.reg_clk_offset);
 307         }
 308
 309         if (pclk->lock)
 310                 spin_unlock_irqrestore(pclk->lock, flags);
 311 }
 312
 313 static int xgene_clk_is_enabled(struct clk_hw *hw)
 314 {
 315         struct xgene_clk *pclk = to_xgene_clk(hw);
 316         u32 data = 0;
 317
 318         if (pclk->param.csr_reg != NULL) {
 319                 pr_debug("%s clock checking\n", clk_hw_get_name(hw));
 320                 data = xgene_clk_read(pclk->param.csr_reg +
 321                                         pclk->param.reg_clk_offset);
 322                 pr_debug("%s clock is %s\n", clk_hw_get_name(hw),
 323                         data & pclk->param.reg_clk_mask ? "enabled" :
 324                                                         "disabled");
 325         }
 326
 327         if (pclk->param.csr_reg == NULL)
 328                 return 1;
 329         return data & pclk->param.reg_clk_mask ? 1 : 0;
 330 }
 331
 332 static unsigned long xgene_clk_recalc_rate(struct clk_hw *hw,
 333                                 unsigned long parent_rate)
 334 {
 335         struct xgene_clk *pclk = to_xgene_clk(hw);
 336         u32 data;
 337
 338         if (pclk->param.divider_reg) {
 339                 data = xgene_clk_read(pclk->param.divider_reg +
 340                                         pclk->param.reg_divider_offset);
 341                 data >>= pclk->param.reg_divider_shift;
 342                 data &= (1 << pclk->param.reg_divider_width) - 1;
 343
 344                 pr_debug("%s clock recalc rate %ld parent %ld\n",
 345                         clk_hw_get_name(hw),
 346                         parent_rate / data, parent_rate);
 347
 348                 return parent_rate / data;
 349         } else {
 350                 pr_debug("%s clock recalc rate %ld parent %ld\n",
 351                         clk_hw_get_name(hw), parent_rate, parent_rate);
 352                 return parent_rate;
 353         }
 354 }
 355
 356 static int xgene_clk_set_rate(struct clk_hw *hw, unsigned long rate,
 357                                 unsigned long parent_rate)
 358 {
 359         struct xgene_clk *pclk = to_xgene_clk(hw);
 360         unsigned long flags = 0;
 361         u32 data;
 362         u32 divider;
 363         u32 divider_save;
 364
 365         if (pclk->lock)
 366                 spin_lock_irqsave(pclk->lock, flags);
 367
 368         if (pclk->param.divider_reg) {
 369                 /* Let's compute the divider */
 370                 if (rate > parent_rate)
 371                         rate = parent_rate;
 372                 divider_save = divider = parent_rate / rate; /* Rounded down */
 373                 divider &= (1 << pclk->param.reg_divider_width) - 1;
 374                 divider <<= pclk->param.reg_divider_shift;
 375
 376                 /* Set new divider */
 377                 data = xgene_clk_read(pclk->param.divider_reg +
 378                                 pclk->param.reg_divider_offset);
 379                 data &= ~(((1 << pclk->param.reg_divider_width) - 1)
 380                                 << pclk->param.reg_divider_shift);
 381                 data |= divider;
 382                 xgene_clk_write(data, pclk->param.divider_reg +
 383                                         pclk->param.reg_divider_offset);
 384                 pr_debug("%s clock set rate %ld\n", clk_hw_get_name(hw),
 385                         parent_rate / divider_save);
 386         } else {
 387                 divider_save = 1;
 388         }
 389
 390         if (pclk->lock)
 391                 spin_unlock_irqrestore(pclk->lock, flags);
 392
 393         return parent_rate / divider_save;
 394 }
 395
 396 static long xgene_clk_round_rate(struct clk_hw *hw, unsigned long rate,
 397                                 unsigned long *prate)
 398 {
 399         struct xgene_clk *pclk = to_xgene_clk(hw);
 400         unsigned long parent_rate = *prate;
 401         u32 divider;
 402
 403         if (pclk->param.divider_reg) {
 404                 /* Let's compute the divider */
 405                 if (rate > parent_rate)
 406                         rate = parent_rate;
 407                 divider = parent_rate / rate;   /* Rounded down */
 408         } else {
 409                 divider = 1;
 410         }
 411
 412         return parent_rate / divider;
 413 }
 414
 415 static const struct clk_ops xgene_clk_ops = {
 416         .enable = xgene_clk_enable,
 417         .disable = xgene_clk_disable,
 418         .is_enabled = xgene_clk_is_enabled,
 419         .recalc_rate = xgene_clk_recalc_rate,
 420         .set_rate = xgene_clk_set_rate,
 421         .round_rate = xgene_clk_round_rate,
 422 };
 423
 424 static struct clk *xgene_register_clk(struct device *dev,
 425                 const char *name, const char *parent_name,
 426                 struct xgene_dev_parameters *parameters, spinlock_t *lock)
 427 {
 428         struct xgene_clk *apmclk;
 429         struct clk *clk;
 430         struct clk_init_data init;
 431         int rc;
 432
 433         /* allocate the APM clock structure */
 434         apmclk = kzalloc(sizeof(*apmclk), GFP_KERNEL);
 435         if (!apmclk) {
 436                 pr_err("%s: could not allocate APM clk\n", __func__);
 437                 return ERR_PTR(-ENOMEM);
 438         }
 439
 440         init.name = name;
 441         init.ops = &xgene_clk_ops;
 442         init.flags = 0;
 443         init.parent_names = parent_name ? &parent_name : NULL;
 444         init.num_parents = parent_name ? 1 : 0;
 445
 446         apmclk->lock = lock;
 447         apmclk->hw.init = &init;
 448         apmclk->param = *parameters;
 449
 450         /* Register the clock */
 451         clk = clk_register(dev, &apmclk->hw);
 452         if (IS_ERR(clk)) {
 453                 pr_err("%s: could not register clk %s\n", __func__, name);
 454                 kfree(apmclk);
 455                 return clk;
 456         }
 457
 458         /* Register the clock for lookup */
 459         rc = clk_register_clkdev(clk, name, NULL);
 460         if (rc != 0) {
 461                 pr_err("%s: could not register lookup clk %s\n",
 462                         __func__, name);
 463         }
 464         return clk;
 465 }
 466
 467 static void __init xgene_devclk_init(struct device_node *np)
 468 {
 469         const char *clk_name = np->full_name;
 470         struct clk *clk;
 471         struct resource res;
 472         int rc;
 473         struct xgene_dev_parameters parameters;
 474         int i;
 475
 476         /* Check if the entry is disabled */
 477         if (!of_device_is_available(np))
 478                 return;
 479
 480         /* Parse the DTS register for resource */
 481         parameters.csr_reg = NULL;
 482         parameters.divider_reg = NULL;
 483         for (i = 0; i < 2; i++) {
 484                 void __iomem *map_res;
 485                 rc = of_address_to_resource(np, i, &res);
 486                 if (rc != 0) {
 487                         if (i == 0) {
 488                                 pr_err("no DTS register for %s\n",
 489                                         np->full_name);
 490                                 return;
 491                         }
 492                         break;
 493                 }
 494                 map_res = of_iomap(np, i);
 495                 if (map_res == NULL) {
 496                         pr_err("Unable to map resource %d for %s\n",
 497                                 i, np->full_name);
 498                         goto err;
 499                 }
 500                 if (strcmp(res.name, "div-reg") == 0)
 501                         parameters.divider_reg = map_res;
 502                 else /* if (strcmp(res->name, "csr-reg") == 0) */
 503                         parameters.csr_reg = map_res;
 504         }
 505         if (of_property_read_u32(np, "csr-offset", &parameters.reg_csr_offset))
 506                 parameters.reg_csr_offset = 0;
 507         if (of_property_read_u32(np, "csr-mask", &parameters.reg_csr_mask))
 508                 parameters.reg_csr_mask = 0xF;
 509         if (of_property_read_u32(np, "enable-offset",
 510                                 &parameters.reg_clk_offset))
 511                 parameters.reg_clk_offset = 0x8;
 512         if (of_property_read_u32(np, "enable-mask", &parameters.reg_clk_mask))
 513                 parameters.reg_clk_mask = 0xF;
 514         if (of_property_read_u32(np, "divider-offset",
 515                                 &parameters.reg_divider_offset))
 516                 parameters.reg_divider_offset = 0;
 517         if (of_property_read_u32(np, "divider-width",
 518                                 &parameters.reg_divider_width))
 519                 parameters.reg_divider_width = 0;
 520         if (of_property_read_u32(np, "divider-shift",
 521                                 &parameters.reg_divider_shift))
 522                 parameters.reg_divider_shift = 0;
 523         of_property_read_string(np, "clock-output-names", &clk_name);
 524
 525         clk = xgene_register_clk(NULL, clk_name,
 526                 of_clk_get_parent_name(np, 0), &parameters, &clk_lock);
 527         if (IS_ERR(clk))
 528                 goto err;
 529         pr_debug("Add %s clock\n", clk_name);
 530         rc = of_clk_add_provider(np, of_clk_src_simple_get, clk);
 531         if (rc != 0)
 532                 pr_err("%s: could register provider clk %s\n", __func__,
 533                         np->full_name);
 534
 535         return;
 536
 537 err:
 538         if (parameters.csr_reg)
 539                 iounmap(parameters.csr_reg);
 540         if (parameters.divider_reg)
 541                 iounmap(parameters.divider_reg);
 542 }
 543
 544 CLK_OF_DECLARE(xgene_socpll_clock, "apm,xgene-socpll-clock", xgene_socpllclk_init);
 545 CLK_OF_DECLARE(xgene_pcppll_clock, "apm,xgene-pcppll-clock", xgene_pcppllclk_init);
 546 CLK_OF_DECLARE(xgene_socpll_v2_clock, "apm,xgene-socpll-v2-clock",
 547                xgene_socpllclk_init);
 548 CLK_OF_DECLARE(xgene_pcppll_v2_clock, "apm,xgene-pcppll-v2-clock",
 549                xgene_pcppllclk_init);
 550 CLK_OF_DECLARE(xgene_dev_clock, "apm,xgene-device-clock", xgene_devclk_init);