drivers/clk/renesas/rcar-gen2-cpg.c

   1 /*
   2  * R-Car Gen2 Clock Pulse Generator
   3  *
   4  * Copyright (C) 2016 Cogent Embedded Inc.
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License version 2 as published
   8  * by the Free Software Foundation.
   9  */
  10
  11 #include <linux/bug.h>
  12 #include <linux/clk.h>
  13 #include <linux/clk-provider.h>
  14 #include <linux/device.h>
  15 #include <linux/err.h>
  16 #include <linux/init.h>
  17 #include <linux/io.h>
  18 #include <linux/slab.h>
  19 #include <linux/sys_soc.h>
  20
  21 #include "renesas-cpg-mssr.h"
  22 #include "rcar-gen2-cpg.h"
  23
  24 #define CPG_FRQCRB              0x0004
  25 #define CPG_FRQCRB_KICK         BIT(31)
  26 #define CPG_SDCKCR              0x0074
  27 #define CPG_PLL0CR              0x00d8
  28 #define CPG_PLL0CR_STC_SHIFT    24
  29 #define CPG_PLL0CR_STC_MASK     (0x7f << CPG_PLL0CR_STC_SHIFT)
  30 #define CPG_FRQCRC              0x00e0
  31 #define CPG_FRQCRC_ZFC_SHIFT    8
  32 #define CPG_FRQCRC_ZFC_MASK     (0x1f << CPG_FRQCRC_ZFC_SHIFT)
  33 #define CPG_ADSPCKCR            0x025c
  34 #define CPG_RCANCKCR            0x0270
  35
  36 static spinlock_t cpg_lock;
  37
  38 /*
  39  * Z Clock
  40  *
  41  * Traits of this clock:
  42  * prepare - clk_prepare only ensures that parents are prepared
  43  * enable - clk_enable only ensures that parents are enabled
  44  * rate - rate is adjustable.  clk->rate = parent->rate * mult / 32
  45  * parent - fixed parent.  No clk_set_parent support
  46  */
  47
  48 struct cpg_z_clk {
  49         struct clk_hw hw;
  50         void __iomem *reg;
  51         void __iomem *kick_reg;
  52 };
  53
  54 #define to_z_clk(_hw)   container_of(_hw, struct cpg_z_clk, hw)
  55
  56 static unsigned long cpg_z_clk_recalc_rate(struct clk_hw *hw,
  57                                            unsigned long parent_rate)
  58 {
  59         struct cpg_z_clk *zclk = to_z_clk(hw);
  60         unsigned int mult;
  61         unsigned int val;
  62
  63         val = (readl(zclk->reg) & CPG_FRQCRC_ZFC_MASK) >> CPG_FRQCRC_ZFC_SHIFT;
  64         mult = 32 - val;
  65
  66         return div_u64((u64)parent_rate * mult, 32);
  67 }
  68
  69 static long cpg_z_clk_round_rate(struct clk_hw *hw, unsigned long rate,
  70                                  unsigned long *parent_rate)
  71 {
  72         unsigned long prate  = *parent_rate;
  73         unsigned int mult;
  74
  75         if (!prate)
  76                 prate = 1;
  77
  78         mult = div_u64((u64)rate * 32, prate);
  79         mult = clamp(mult, 1U, 32U);
  80
  81         return *parent_rate / 32 * mult;
  82 }
  83
  84 static int cpg_z_clk_set_rate(struct clk_hw *hw, unsigned long rate,
  85                               unsigned long parent_rate)
  86 {
  87         struct cpg_z_clk *zclk = to_z_clk(hw);
  88         unsigned int mult;
  89         u32 val, kick;
  90         unsigned int i;
  91
  92         mult = div_u64((u64)rate * 32, parent_rate);
  93         mult = clamp(mult, 1U, 32U);
  94
  95         if (readl(zclk->kick_reg) & CPG_FRQCRB_KICK)
  96                 return -EBUSY;
  97
  98         val = readl(zclk->reg);
  99         val &= ~CPG_FRQCRC_ZFC_MASK;
 100         val |= (32 - mult) << CPG_FRQCRC_ZFC_SHIFT;
 101         writel(val, zclk->reg);
 102
 103         /*
 104          * Set KICK bit in FRQCRB to update hardware setting and wait for
 105          * clock change completion.
 106          */
 107         kick = readl(zclk->kick_reg);
 108         kick |= CPG_FRQCRB_KICK;
 109         writel(kick, zclk->kick_reg);
 110
 111         /*
 112          * Note: There is no HW information about the worst case latency.
 113          *
 114          * Using experimental measurements, it seems that no more than
 115          * ~10 iterations are needed, independently of the CPU rate.
 116          * Since this value might be dependent on external xtal rate, pll1
 117          * rate or even the other emulation clocks rate, use 1000 as a
 118          * "super" safe value.
 119          */
 120         for (i = 1000; i; i--) {
 121                 if (!(readl(zclk->kick_reg) & CPG_FRQCRB_KICK))
 122                         return 0;
 123
 124                 cpu_relax();
 125         }
 126
 127         return -ETIMEDOUT;
 128 }
 129
 130 static const struct clk_ops cpg_z_clk_ops = {
 131         .recalc_rate = cpg_z_clk_recalc_rate,
 132         .round_rate = cpg_z_clk_round_rate,
 133         .set_rate = cpg_z_clk_set_rate,
 134 };
 135
 136 static struct clk * __init cpg_z_clk_register(const char *name,
 137                                               const char *parent_name,
 138                                               void __iomem *base)
 139 {
 140         struct clk_init_data init;
 141         struct cpg_z_clk *zclk;
 142         struct clk *clk;
 143
 144         zclk = kzalloc(sizeof(*zclk), GFP_KERNEL);
 145         if (!zclk)
 146                 return ERR_PTR(-ENOMEM);
 147
 148         init.name = name;
 149         init.ops = &cpg_z_clk_ops;
 150         init.flags = 0;
 151         init.parent_names = &parent_name;
 152         init.num_parents = 1;
 153
 154         zclk->reg = base + CPG_FRQCRC;
 155         zclk->kick_reg = base + CPG_FRQCRB;
 156         zclk->hw.init = &init;
 157
 158         clk = clk_register(NULL, &zclk->hw);
 159         if (IS_ERR(clk))
 160                 kfree(zclk);
 161
 162         return clk;
 163 }
 164
 165 static struct clk * __init cpg_rcan_clk_register(const char *name,
 166                                                  const char *parent_name,
 167                                                  void __iomem *base)
 168 {
 169         struct clk_fixed_factor *fixed;
 170         struct clk_gate *gate;
 171         struct clk *clk;
 172
 173         fixed = kzalloc(sizeof(*fixed), GFP_KERNEL);
 174         if (!fixed)
 175                 return ERR_PTR(-ENOMEM);
 176
 177         fixed->mult = 1;
 178         fixed->div = 6;
 179
 180         gate = kzalloc(sizeof(*gate), GFP_KERNEL);
 181         if (!gate) {
 182                 kfree(fixed);
 183                 return ERR_PTR(-ENOMEM);
 184         }
 185
 186         gate->reg = base + CPG_RCANCKCR;
 187         gate->bit_idx = 8;
 188         gate->flags = CLK_GATE_SET_TO_DISABLE;
 189         gate->lock = &cpg_lock;
 190
 191         clk = clk_register_composite(NULL, name, &parent_name, 1, NULL, NULL,
 192                                      &fixed->hw, &clk_fixed_factor_ops,
 193                                      &gate->hw, &clk_gate_ops, 0);
 194         if (IS_ERR(clk)) {
 195                 kfree(gate);
 196                 kfree(fixed);
 197         }
 198
 199         return clk;
 200 }
 201
 202 /* ADSP divisors */
 203 static const struct clk_div_table cpg_adsp_div_table[] = {
 204         {  1,  3 }, {  2,  4 }, {  3,  6 }, {  4,  8 },
 205         {  5, 12 }, {  6, 16 }, {  7, 18 }, {  8, 24 },
 206         { 10, 36 }, { 11, 48 }, {  0,  0 },
 207 };
 208
 209 static struct clk * __init cpg_adsp_clk_register(const char *name,
 210                                                  const char *parent_name,
 211                                                  void __iomem *base)
 212 {
 213         struct clk_divider *div;
 214         struct clk_gate *gate;
 215         struct clk *clk;
 216
 217         div = kzalloc(sizeof(*div), GFP_KERNEL);
 218         if (!div)
 219                 return ERR_PTR(-ENOMEM);
 220
 221         div->reg = base + CPG_ADSPCKCR;
 222         div->width = 4;
 223         div->table = cpg_adsp_div_table;
 224         div->lock = &cpg_lock;
 225
 226         gate = kzalloc(sizeof(*gate), GFP_KERNEL);
 227         if (!gate) {
 228                 kfree(div);
 229                 return ERR_PTR(-ENOMEM);
 230         }
 231
 232         gate->reg = base + CPG_ADSPCKCR;
 233         gate->bit_idx = 8;
 234         gate->flags = CLK_GATE_SET_TO_DISABLE;
 235         gate->lock = &cpg_lock;
 236
 237         clk = clk_register_composite(NULL, name, &parent_name, 1, NULL, NULL,
 238                                      &div->hw, &clk_divider_ops,
 239                                      &gate->hw, &clk_gate_ops, 0);
 240         if (IS_ERR(clk)) {
 241                 kfree(gate);
 242                 kfree(div);
 243         }
 244
 245         return clk;
 246 }
 247
 248 /* SDHI divisors */
 249 static const struct clk_div_table cpg_sdh_div_table[] = {
 250         {  0,  2 }, {  1,  3 }, {  2,  4 }, {  3,  6 },
 251         {  4,  8 }, {  5, 12 }, {  6, 16 }, {  7, 18 },
 252         {  8, 24 }, { 10, 36 }, { 11, 48 }, {  0,  0 },
 253 };
 254
 255 static const struct clk_div_table cpg_sd01_div_table[] = {
 256         {  4,  8 }, {  5, 12 }, {  6, 16 }, {  7, 18 },
 257         {  8, 24 }, { 10, 36 }, { 11, 48 }, { 12, 10 },
 258         {  0,  0 },
 259 };
 260
 261 static const struct rcar_gen2_cpg_pll_config *cpg_pll_config __initdata;
 262 static unsigned int cpg_pll0_div __initdata;
 263 static u32 cpg_mode __initdata;
 264 static u32 cpg_quirks __initdata;
 265
 266 #define SD_SKIP_FIRST   BIT(0)          /* Skip first clock in SD table */
 267
 268 static const struct soc_device_attribute cpg_quirks_match[] __initconst = {
 269         {
 270                 .soc_id = "r8a77470",
 271                 .data = (void *)SD_SKIP_FIRST,
 272         },
 273         { /* sentinel */ }
 274 };
 275
 276 struct clk * __init rcar_gen2_cpg_clk_register(struct device *dev,
 277         const struct cpg_core_clk *core, const struct cpg_mssr_info *info,
 278         struct clk **clks, void __iomem *base,
 279         struct raw_notifier_head *notifiers)
 280 {
 281         const struct clk_div_table *table = NULL;
 282         const struct clk *parent;
 283         const char *parent_name;
 284         unsigned int mult = 1;
 285         unsigned int div = 1;
 286         unsigned int shift;
 287
 288         parent = clks[core->parent];
 289         if (IS_ERR(parent))
 290                 return ERR_CAST(parent);
 291
 292         parent_name = __clk_get_name(parent);
 293
 294         switch (core->type) {
 295         /* R-Car Gen2 */
 296         case CLK_TYPE_GEN2_MAIN:
 297                 div = cpg_pll_config->extal_div;
 298                 break;
 299
 300         case CLK_TYPE_GEN2_PLL0:
 301                 /*
 302                  * PLL0 is a  configurable multiplier clock except on R-Car
 303                  * V2H/E2. Register the PLL0 clock as a fixed factor clock for
 304                  * now as there's no generic multiplier clock implementation and
 305                  * we  currently  have no need to change  the multiplier value.
 306                  */
 307                 mult = cpg_pll_config->pll0_mult;
 308                 div  = cpg_pll0_div;
 309                 if (!mult) {
 310                         u32 pll0cr = readl(base + CPG_PLL0CR);
 311
 312                         mult = (((pll0cr & CPG_PLL0CR_STC_MASK) >>
 313                                  CPG_PLL0CR_STC_SHIFT) + 1) * 2;
 314                 }
 315                 break;
 316
 317         case CLK_TYPE_GEN2_PLL1:
 318                 mult = cpg_pll_config->pll1_mult / 2;
 319                 break;
 320
 321         case CLK_TYPE_GEN2_PLL3:
 322                 mult = cpg_pll_config->pll3_mult;
 323                 break;
 324
 325         case CLK_TYPE_GEN2_Z:
 326                 return cpg_z_clk_register(core->name, parent_name, base);
 327
 328         case CLK_TYPE_GEN2_LB:
 329                 div = cpg_mode & BIT(18) ? 36 : 24;
 330                 break;
 331
 332         case CLK_TYPE_GEN2_ADSP:
 333                 return cpg_adsp_clk_register(core->name, parent_name, base);
 334
 335         case CLK_TYPE_GEN2_SDH:
 336                 table = cpg_sdh_div_table;
 337                 shift = 8;
 338                 break;
 339
 340         case CLK_TYPE_GEN2_SD0:
 341                 table = cpg_sd01_div_table;
 342                 if (cpg_quirks & SD_SKIP_FIRST)
 343                         table++;
 344
 345                 shift = 4;
 346                 break;
 347
 348         case CLK_TYPE_GEN2_SD1:
 349                 table = cpg_sd01_div_table;
 350                 if (cpg_quirks & SD_SKIP_FIRST)
 351                         table++;
 352
 353                 shift = 0;
 354                 break;
 355
 356         case CLK_TYPE_GEN2_QSPI:
 357                 div = (cpg_mode & (BIT(3) | BIT(2) | BIT(1))) == BIT(2) ?
 358                       8 : 10;
 359                 break;
 360
 361         case CLK_TYPE_GEN2_RCAN:
 362                 return cpg_rcan_clk_register(core->name, parent_name, base);
 363
 364         default:
 365                 return ERR_PTR(-EINVAL);
 366         }
 367
 368         if (!table)
 369                 return clk_register_fixed_factor(NULL, core->name, parent_name,
 370                                                  0, mult, div);
 371         else
 372                 return clk_register_divider_table(NULL, core->name,
 373                                                   parent_name, 0,
 374                                                   base + CPG_SDCKCR, shift, 4,
 375                                                   0, table, &cpg_lock);
 376 }
 377
 378 int __init rcar_gen2_cpg_init(const struct rcar_gen2_cpg_pll_config *config,
 379                               unsigned int pll0_div, u32 mode)
 380 {
 381         const struct soc_device_attribute *attr;
 382
 383         cpg_pll_config = config;
 384         cpg_pll0_div = pll0_div;
 385         cpg_mode = mode;
 386         attr = soc_device_match(cpg_quirks_match);
 387         if (attr)
 388                 cpg_quirks = (uintptr_t)attr->data;
 389         pr_debug("%s: mode = 0x%x quirks = 0x%x\n", __func__, mode, cpg_quirks);
 390
 391         spin_lock_init(&cpg_lock);
 392
 393         return 0;
 394 }