drivers/clk/ingenic/tcu.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * JZ47xx SoCs TCU clocks driver
   4  * Copyright (C) 2019 Paul Cercueil <paul@crapouillou.net>
   5  */
   6
   7 #include <linux/clk.h>
   8 #include <linux/clk-provider.h>
   9 #include <linux/clockchips.h>
  10 #include <linux/mfd/ingenic-tcu.h>
  11 #include <linux/mfd/syscon.h>
  12 #include <linux/regmap.h>
  13 #include <linux/slab.h>
  14 #include <linux/syscore_ops.h>
  15
  16 #include <dt-bindings/clock/ingenic,tcu.h>
  17
  18 /* 8 channels max + watchdog + OST */
  19 #define TCU_CLK_COUNT   10
  20
  21 #undef pr_fmt
  22 #define pr_fmt(fmt) "ingenic-tcu-clk: " fmt
  23
  24 enum tcu_clk_parent {
  25         TCU_PARENT_PCLK,
  26         TCU_PARENT_RTC,
  27         TCU_PARENT_EXT,
  28 };
  29
  30 struct ingenic_soc_info {
  31         unsigned int num_channels;
  32         bool has_ost;
  33         bool has_tcu_clk;
  34 };
  35
  36 struct ingenic_tcu_clk_info {
  37         struct clk_init_data init_data;
  38         u8 gate_bit;
  39         u8 tcsr_reg;
  40 };
  41
  42 struct ingenic_tcu_clk {
  43         struct clk_hw hw;
  44         unsigned int idx;
  45         struct ingenic_tcu *tcu;
  46         const struct ingenic_tcu_clk_info *info;
  47 };
  48
  49 struct ingenic_tcu {
  50         const struct ingenic_soc_info *soc_info;
  51         struct regmap *map;
  52         struct clk *clk;
  53
  54         struct clk_hw_onecell_data *clocks;
  55 };
  56
  57 static struct ingenic_tcu *ingenic_tcu;
  58
  59 static inline struct ingenic_tcu_clk *to_tcu_clk(struct clk_hw *hw)
  60 {
  61         return container_of(hw, struct ingenic_tcu_clk, hw);
  62 }
  63
  64 static int ingenic_tcu_enable(struct clk_hw *hw)
  65 {
  66         struct ingenic_tcu_clk *tcu_clk = to_tcu_clk(hw);
  67         const struct ingenic_tcu_clk_info *info = tcu_clk->info;
  68         struct ingenic_tcu *tcu = tcu_clk->tcu;
  69
  70         regmap_write(tcu->map, TCU_REG_TSCR, BIT(info->gate_bit));
  71
  72         return 0;
  73 }
  74
  75 static void ingenic_tcu_disable(struct clk_hw *hw)
  76 {
  77         struct ingenic_tcu_clk *tcu_clk = to_tcu_clk(hw);
  78         const struct ingenic_tcu_clk_info *info = tcu_clk->info;
  79         struct ingenic_tcu *tcu = tcu_clk->tcu;
  80
  81         regmap_write(tcu->map, TCU_REG_TSSR, BIT(info->gate_bit));
  82 }
  83
  84 static int ingenic_tcu_is_enabled(struct clk_hw *hw)
  85 {
  86         struct ingenic_tcu_clk *tcu_clk = to_tcu_clk(hw);
  87         const struct ingenic_tcu_clk_info *info = tcu_clk->info;
  88         unsigned int value;
  89
  90         regmap_read(tcu_clk->tcu->map, TCU_REG_TSR, &value);
  91
  92         return !(value & BIT(info->gate_bit));
  93 }
  94
  95 static bool ingenic_tcu_enable_regs(struct clk_hw *hw)
  96 {
  97         struct ingenic_tcu_clk *tcu_clk = to_tcu_clk(hw);
  98         const struct ingenic_tcu_clk_info *info = tcu_clk->info;
  99         struct ingenic_tcu *tcu = tcu_clk->tcu;
 100         bool enabled = false;
 101
 102         /*
 103          * If the SoC has no global TCU clock, we must ungate the channel's
 104          * clock to be able to access its registers.
 105          * If we have a TCU clock, it will be enabled automatically as it has
 106          * been attached to the regmap.
 107          */
 108         if (!tcu->clk) {
 109                 enabled = !!ingenic_tcu_is_enabled(hw);
 110                 regmap_write(tcu->map, TCU_REG_TSCR, BIT(info->gate_bit));
 111         }
 112
 113         return enabled;
 114 }
 115
 116 static void ingenic_tcu_disable_regs(struct clk_hw *hw)
 117 {
 118         struct ingenic_tcu_clk *tcu_clk = to_tcu_clk(hw);
 119         const struct ingenic_tcu_clk_info *info = tcu_clk->info;
 120         struct ingenic_tcu *tcu = tcu_clk->tcu;
 121
 122         if (!tcu->clk)
 123                 regmap_write(tcu->map, TCU_REG_TSSR, BIT(info->gate_bit));
 124 }
 125
 126 static u8 ingenic_tcu_get_parent(struct clk_hw *hw)
 127 {
 128         struct ingenic_tcu_clk *tcu_clk = to_tcu_clk(hw);
 129         const struct ingenic_tcu_clk_info *info = tcu_clk->info;
 130         unsigned int val = 0;
 131         int ret;
 132
 133         ret = regmap_read(tcu_clk->tcu->map, info->tcsr_reg, &val);
 134         WARN_ONCE(ret < 0, "Unable to read TCSR %d", tcu_clk->idx);
 135
 136         return ffs(val & TCU_TCSR_PARENT_CLOCK_MASK) - 1;
 137 }
 138
 139 static int ingenic_tcu_set_parent(struct clk_hw *hw, u8 idx)
 140 {
 141         struct ingenic_tcu_clk *tcu_clk = to_tcu_clk(hw);
 142         const struct ingenic_tcu_clk_info *info = tcu_clk->info;
 143         bool was_enabled;
 144         int ret;
 145
 146         was_enabled = ingenic_tcu_enable_regs(hw);
 147
 148         ret = regmap_update_bits(tcu_clk->tcu->map, info->tcsr_reg,
 149                                  TCU_TCSR_PARENT_CLOCK_MASK, BIT(idx));
 150         WARN_ONCE(ret < 0, "Unable to update TCSR %d", tcu_clk->idx);
 151
 152         if (!was_enabled)
 153                 ingenic_tcu_disable_regs(hw);
 154
 155         return 0;
 156 }
 157
 158 static unsigned long ingenic_tcu_recalc_rate(struct clk_hw *hw,
 159                 unsigned long parent_rate)
 160 {
 161         struct ingenic_tcu_clk *tcu_clk = to_tcu_clk(hw);
 162         const struct ingenic_tcu_clk_info *info = tcu_clk->info;
 163         unsigned int prescale;
 164         int ret;
 165
 166         ret = regmap_read(tcu_clk->tcu->map, info->tcsr_reg, &prescale);
 167         WARN_ONCE(ret < 0, "Unable to read TCSR %d", tcu_clk->idx);
 168
 169         prescale = (prescale & TCU_TCSR_PRESCALE_MASK) >> TCU_TCSR_PRESCALE_LSB;
 170
 171         return parent_rate >> (prescale * 2);
 172 }
 173
 174 static u8 ingenic_tcu_get_prescale(unsigned long rate, unsigned long req_rate)
 175 {
 176         u8 prescale;
 177
 178         for (prescale = 0; prescale < 5; prescale++)
 179                 if ((rate >> (prescale * 2)) <= req_rate)
 180                         return prescale;
 181
 182         return 5; /* /1024 divider */
 183 }
 184
 185 static long ingenic_tcu_round_rate(struct clk_hw *hw, unsigned long req_rate,
 186                 unsigned long *parent_rate)
 187 {
 188         unsigned long rate = *parent_rate;
 189         u8 prescale;
 190
 191         if (req_rate > rate)
 192                 return -EINVAL;
 193
 194         prescale = ingenic_tcu_get_prescale(rate, req_rate);
 195
 196         return rate >> (prescale * 2);
 197 }
 198
 199 static int ingenic_tcu_set_rate(struct clk_hw *hw, unsigned long req_rate,
 200                 unsigned long parent_rate)
 201 {
 202         struct ingenic_tcu_clk *tcu_clk = to_tcu_clk(hw);
 203         const struct ingenic_tcu_clk_info *info = tcu_clk->info;
 204         u8 prescale = ingenic_tcu_get_prescale(parent_rate, req_rate);
 205         bool was_enabled;
 206         int ret;
 207
 208         was_enabled = ingenic_tcu_enable_regs(hw);
 209
 210         ret = regmap_update_bits(tcu_clk->tcu->map, info->tcsr_reg,
 211                                  TCU_TCSR_PRESCALE_MASK,
 212                                  prescale << TCU_TCSR_PRESCALE_LSB);
 213         WARN_ONCE(ret < 0, "Unable to update TCSR %d", tcu_clk->idx);
 214
 215         if (!was_enabled)
 216                 ingenic_tcu_disable_regs(hw);
 217
 218         return 0;
 219 }
 220
 221 static const struct clk_ops ingenic_tcu_clk_ops = {
 222         .get_parent     = ingenic_tcu_get_parent,
 223         .set_parent     = ingenic_tcu_set_parent,
 224
 225         .recalc_rate    = ingenic_tcu_recalc_rate,
 226         .round_rate     = ingenic_tcu_round_rate,
 227         .set_rate       = ingenic_tcu_set_rate,
 228
 229         .enable         = ingenic_tcu_enable,
 230         .disable        = ingenic_tcu_disable,
 231         .is_enabled     = ingenic_tcu_is_enabled,
 232 };
 233
 234 static const char * const ingenic_tcu_timer_parents[] = {
 235         [TCU_PARENT_PCLK] = "pclk",
 236         [TCU_PARENT_RTC]  = "rtc",
 237         [TCU_PARENT_EXT]  = "ext",
 238 };
 239
 240 #define DEF_TIMER(_name, _gate_bit, _tcsr)                              \
 241         {                                                               \
 242                 .init_data = {                                          \
 243                         .name = _name,                                  \
 244                         .parent_names = ingenic_tcu_timer_parents,      \
 245                         .num_parents = ARRAY_SIZE(ingenic_tcu_timer_parents),\
 246                         .ops = &ingenic_tcu_clk_ops,                    \
 247                         .flags = CLK_SET_RATE_UNGATE,                   \
 248                 },                                                      \
 249                 .gate_bit = _gate_bit,                                  \
 250                 .tcsr_reg = _tcsr,                                      \
 251         }
 252 static const struct ingenic_tcu_clk_info ingenic_tcu_clk_info[] = {
 253         [TCU_CLK_TIMER0] = DEF_TIMER("timer0", 0, TCU_REG_TCSRc(0)),
 254         [TCU_CLK_TIMER1] = DEF_TIMER("timer1", 1, TCU_REG_TCSRc(1)),
 255         [TCU_CLK_TIMER2] = DEF_TIMER("timer2", 2, TCU_REG_TCSRc(2)),
 256         [TCU_CLK_TIMER3] = DEF_TIMER("timer3", 3, TCU_REG_TCSRc(3)),
 257         [TCU_CLK_TIMER4] = DEF_TIMER("timer4", 4, TCU_REG_TCSRc(4)),
 258         [TCU_CLK_TIMER5] = DEF_TIMER("timer5", 5, TCU_REG_TCSRc(5)),
 259         [TCU_CLK_TIMER6] = DEF_TIMER("timer6", 6, TCU_REG_TCSRc(6)),
 260         [TCU_CLK_TIMER7] = DEF_TIMER("timer7", 7, TCU_REG_TCSRc(7)),
 261 };
 262
 263 static const struct ingenic_tcu_clk_info ingenic_tcu_watchdog_clk_info =
 264                                          DEF_TIMER("wdt", 16, TCU_REG_WDT_TCSR);
 265 static const struct ingenic_tcu_clk_info ingenic_tcu_ost_clk_info =
 266                                          DEF_TIMER("ost", 15, TCU_REG_OST_TCSR);
 267 #undef DEF_TIMER
 268
 269 static int __init ingenic_tcu_register_clock(struct ingenic_tcu *tcu,
 270                         unsigned int idx, enum tcu_clk_parent parent,
 271                         const struct ingenic_tcu_clk_info *info,
 272                         struct clk_hw_onecell_data *clocks)
 273 {
 274         struct ingenic_tcu_clk *tcu_clk;
 275         int err;
 276
 277         tcu_clk = kzalloc(sizeof(*tcu_clk), GFP_KERNEL);
 278         if (!tcu_clk)
 279                 return -ENOMEM;
 280
 281         tcu_clk->hw.init = &info->init_data;
 282         tcu_clk->idx = idx;
 283         tcu_clk->info = info;
 284         tcu_clk->tcu = tcu;
 285
 286         /* Reset channel and clock divider, set default parent */
 287         ingenic_tcu_enable_regs(&tcu_clk->hw);
 288         regmap_update_bits(tcu->map, info->tcsr_reg, 0xffff, BIT(parent));
 289         ingenic_tcu_disable_regs(&tcu_clk->hw);
 290
 291         err = clk_hw_register(NULL, &tcu_clk->hw);
 292         if (err) {
 293                 kfree(tcu_clk);
 294                 return err;
 295         }
 296
 297         clocks->hws[idx] = &tcu_clk->hw;
 298
 299         return 0;
 300 }
 301
 302 static const struct ingenic_soc_info jz4740_soc_info = {
 303         .num_channels = 8,
 304         .has_ost = false,
 305         .has_tcu_clk = true,
 306 };
 307
 308 static const struct ingenic_soc_info jz4725b_soc_info = {
 309         .num_channels = 6,
 310         .has_ost = true,
 311         .has_tcu_clk = true,
 312 };
 313
 314 static const struct ingenic_soc_info jz4770_soc_info = {
 315         .num_channels = 8,
 316         .has_ost = true,
 317         .has_tcu_clk = false,
 318 };
 319
 320 static const struct of_device_id ingenic_tcu_of_match[] __initconst = {
 321         { .compatible = "ingenic,jz4740-tcu", .data = &jz4740_soc_info, },
 322         { .compatible = "ingenic,jz4725b-tcu", .data = &jz4725b_soc_info, },
 323         { .compatible = "ingenic,jz4770-tcu", .data = &jz4770_soc_info, },
 324         { /* sentinel */ }
 325 };
 326
 327 static int __init ingenic_tcu_probe(struct device_node *np)
 328 {
 329         const struct of_device_id *id = of_match_node(ingenic_tcu_of_match, np);
 330         struct ingenic_tcu *tcu;
 331         struct regmap *map;
 332         unsigned int i;
 333         int ret;
 334
 335         map = device_node_to_regmap(np);
 336         if (IS_ERR(map))
 337                 return PTR_ERR(map);
 338
 339         tcu = kzalloc(sizeof(*tcu), GFP_KERNEL);
 340         if (!tcu)
 341                 return -ENOMEM;
 342
 343         tcu->map = map;
 344         tcu->soc_info = id->data;
 345
 346         if (tcu->soc_info->has_tcu_clk) {
 347                 tcu->clk = of_clk_get_by_name(np, "tcu");
 348                 if (IS_ERR(tcu->clk)) {
 349                         ret = PTR_ERR(tcu->clk);
 350                         pr_crit("Cannot get TCU clock\n");
 351                         goto err_free_tcu;
 352                 }
 353
 354                 ret = clk_prepare_enable(tcu->clk);
 355                 if (ret) {
 356                         pr_crit("Unable to enable TCU clock\n");
 357                         goto err_put_clk;
 358                 }
 359         }
 360
 361         tcu->clocks = kzalloc(struct_size(tcu->clocks, hws, TCU_CLK_COUNT),
 362                               GFP_KERNEL);
 363         if (!tcu->clocks) {
 364                 ret = -ENOMEM;
 365                 goto err_clk_disable;
 366         }
 367
 368         tcu->clocks->num = TCU_CLK_COUNT;
 369
 370         for (i = 0; i < tcu->soc_info->num_channels; i++) {
 371                 ret = ingenic_tcu_register_clock(tcu, i, TCU_PARENT_EXT,
 372                                                  &ingenic_tcu_clk_info[i],
 373                                                  tcu->clocks);
 374                 if (ret) {
 375                         pr_crit("cannot register clock %d\n", i);
 376                         goto err_unregister_timer_clocks;
 377                 }
 378         }
 379
 380         /*
 381          * We set EXT as the default parent clock for all the TCU clocks
 382          * except for the watchdog one, where we set the RTC clock as the
 383          * parent. Since the EXT and PCLK are much faster than the RTC clock,
 384          * the watchdog would kick after a maximum time of 5s, and we might
 385          * want a slower kicking time.
 386          */
 387         ret = ingenic_tcu_register_clock(tcu, TCU_CLK_WDT, TCU_PARENT_RTC,
 388                                          &ingenic_tcu_watchdog_clk_info,
 389                                          tcu->clocks);
 390         if (ret) {
 391                 pr_crit("cannot register watchdog clock\n");
 392                 goto err_unregister_timer_clocks;
 393         }
 394
 395         if (tcu->soc_info->has_ost) {
 396                 ret = ingenic_tcu_register_clock(tcu, TCU_CLK_OST,
 397                                                  TCU_PARENT_EXT,
 398                                                  &ingenic_tcu_ost_clk_info,
 399                                                  tcu->clocks);
 400                 if (ret) {
 401                         pr_crit("cannot register ost clock\n");
 402                         goto err_unregister_watchdog_clock;
 403                 }
 404         }
 405
 406         ret = of_clk_add_hw_provider(np, of_clk_hw_onecell_get, tcu->clocks);
 407         if (ret) {
 408                 pr_crit("cannot add OF clock provider\n");
 409                 goto err_unregister_ost_clock;
 410         }
 411
 412         ingenic_tcu = tcu;
 413
 414         return 0;
 415
 416 err_unregister_ost_clock:
 417         if (tcu->soc_info->has_ost)
 418                 clk_hw_unregister(tcu->clocks->hws[i + 1]);
 419 err_unregister_watchdog_clock:
 420         clk_hw_unregister(tcu->clocks->hws[i]);
 421 err_unregister_timer_clocks:
 422         for (i = 0; i < tcu->clocks->num; i++)
 423                 if (tcu->clocks->hws[i])
 424                         clk_hw_unregister(tcu->clocks->hws[i]);
 425         kfree(tcu->clocks);
 426 err_clk_disable:
 427         if (tcu->soc_info->has_tcu_clk)
 428                 clk_disable_unprepare(tcu->clk);
 429 err_put_clk:
 430         if (tcu->soc_info->has_tcu_clk)
 431                 clk_put(tcu->clk);
 432 err_free_tcu:
 433         kfree(tcu);
 434         return ret;
 435 }
 436
 437 static int __maybe_unused tcu_pm_suspend(void)
 438 {
 439         struct ingenic_tcu *tcu = ingenic_tcu;
 440
 441         if (tcu->clk)
 442                 clk_disable(tcu->clk);
 443
 444         return 0;
 445 }
 446
 447 static void __maybe_unused tcu_pm_resume(void)
 448 {
 449         struct ingenic_tcu *tcu = ingenic_tcu;
 450
 451         if (tcu->clk)
 452                 clk_enable(tcu->clk);
 453 }
 454
 455 static struct syscore_ops __maybe_unused tcu_pm_ops = {
 456         .suspend = tcu_pm_suspend,
 457         .resume = tcu_pm_resume,
 458 };
 459
 460 static void __init ingenic_tcu_init(struct device_node *np)
 461 {
 462         int ret = ingenic_tcu_probe(np);
 463
 464         if (ret)
 465                 pr_crit("Failed to initialize TCU clocks: %d\n", ret);
 466
 467         if (IS_ENABLED(CONFIG_PM_SLEEP))
 468                 register_syscore_ops(&tcu_pm_ops);
 469 }
 470
 471 CLK_OF_DECLARE_DRIVER(jz4740_cgu, "ingenic,jz4740-tcu", ingenic_tcu_init);
 472 CLK_OF_DECLARE_DRIVER(jz4725b_cgu, "ingenic,jz4725b-tcu", ingenic_tcu_init);
 473 CLK_OF_DECLARE_DRIVER(jz4770_cgu, "ingenic,jz4770-tcu", ingenic_tcu_init);