drivers/clocksource/ingenic-timer.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Ingenic SoCs TCU IRQ driver
   4  * Copyright (C) 2019 Paul Cercueil <paul@crapouillou.net>
   5  * Copyright (C) 2020 周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>
   6  */
   7
   8 #include <linux/bitops.h>
   9 #include <linux/clk.h>
  10 #include <linux/clockchips.h>
  11 #include <linux/clocksource.h>
  12 #include <linux/cpuhotplug.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/mfd/ingenic-tcu.h>
  15 #include <linux/mfd/syscon.h>
  16 #include <linux/of.h>
  17 #include <linux/of_irq.h>
  18 #include <linux/overflow.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/regmap.h>
  21 #include <linux/sched_clock.h>
  22
  23 #include <dt-bindings/clock/ingenic,tcu.h>
  24
  25 static DEFINE_PER_CPU(call_single_data_t, ingenic_cevt_csd);
  26
  27 struct ingenic_soc_info {
  28         unsigned int num_channels;
  29 };
  30
  31 struct ingenic_tcu_timer {
  32         unsigned int cpu;
  33         unsigned int channel;
  34         struct clock_event_device cevt;
  35         struct clk *clk;
  36         char name[8];
  37 };
  38
  39 struct ingenic_tcu {
  40         struct regmap *map;
  41         struct device_node *np;
  42         struct clk *cs_clk;
  43         unsigned int cs_channel;
  44         struct clocksource cs;
  45         unsigned long pwm_channels_mask;
  46         struct ingenic_tcu_timer timers[];
  47 };
  48
  49 static struct ingenic_tcu *ingenic_tcu;
  50
  51 static u64 notrace ingenic_tcu_timer_read(void)
  52 {
  53         struct ingenic_tcu *tcu = ingenic_tcu;
  54         unsigned int count;
  55
  56         regmap_read(tcu->map, TCU_REG_TCNTc(tcu->cs_channel), &count);
  57
  58         return count;
  59 }
  60
  61 static u64 notrace ingenic_tcu_timer_cs_read(struct clocksource *cs)
  62 {
  63         return ingenic_tcu_timer_read();
  64 }
  65
  66 static inline struct ingenic_tcu *
  67 to_ingenic_tcu(struct ingenic_tcu_timer *timer)
  68 {
  69         return container_of(timer, struct ingenic_tcu, timers[timer->cpu]);
  70 }
  71
  72 static inline struct ingenic_tcu_timer *
  73 to_ingenic_tcu_timer(struct clock_event_device *evt)
  74 {
  75         return container_of(evt, struct ingenic_tcu_timer, cevt);
  76 }
  77
  78 static int ingenic_tcu_cevt_set_state_shutdown(struct clock_event_device *evt)
  79 {
  80         struct ingenic_tcu_timer *timer = to_ingenic_tcu_timer(evt);
  81         struct ingenic_tcu *tcu = to_ingenic_tcu(timer);
  82
  83         regmap_write(tcu->map, TCU_REG_TECR, BIT(timer->channel));
  84
  85         return 0;
  86 }
  87
  88 static int ingenic_tcu_cevt_set_next(unsigned long next,
  89                                      struct clock_event_device *evt)
  90 {
  91         struct ingenic_tcu_timer *timer = to_ingenic_tcu_timer(evt);
  92         struct ingenic_tcu *tcu = to_ingenic_tcu(timer);
  93
  94         if (next > 0xffff)
  95                 return -EINVAL;
  96
  97         regmap_write(tcu->map, TCU_REG_TDFRc(timer->channel), next);
  98         regmap_write(tcu->map, TCU_REG_TCNTc(timer->channel), 0);
  99         regmap_write(tcu->map, TCU_REG_TESR, BIT(timer->channel));
 100
 101         return 0;
 102 }
 103
 104 static void ingenic_per_cpu_event_handler(void *info)
 105 {
 106         struct clock_event_device *cevt = (struct clock_event_device *) info;
 107
 108         cevt->event_handler(cevt);
 109 }
 110
 111 static irqreturn_t ingenic_tcu_cevt_cb(int irq, void *dev_id)
 112 {
 113         struct ingenic_tcu_timer *timer = dev_id;
 114         struct ingenic_tcu *tcu = to_ingenic_tcu(timer);
 115         call_single_data_t *csd;
 116
 117         regmap_write(tcu->map, TCU_REG_TECR, BIT(timer->channel));
 118
 119         if (timer->cevt.event_handler) {
 120                 csd = &per_cpu(ingenic_cevt_csd, timer->cpu);
 121                 csd->info = (void *) &timer->cevt;
 122                 csd->func = ingenic_per_cpu_event_handler;
 123                 smp_call_function_single_async(timer->cpu, csd);
 124         }
 125
 126         return IRQ_HANDLED;
 127 }
 128
 129 static struct clk *ingenic_tcu_get_clock(struct device_node *np, int id)
 130 {
 131         struct of_phandle_args args;
 132
 133         args.np = np;
 134         args.args_count = 1;
 135         args.args[0] = id;
 136
 137         return of_clk_get_from_provider(&args);
 138 }
 139
 140 static int ingenic_tcu_setup_cevt(unsigned int cpu)
 141 {
 142         struct ingenic_tcu *tcu = ingenic_tcu;
 143         struct ingenic_tcu_timer *timer = &tcu->timers[cpu];
 144         unsigned int timer_virq;
 145         struct irq_domain *domain;
 146         unsigned long rate;
 147         int err;
 148
 149         timer->clk = ingenic_tcu_get_clock(tcu->np, timer->channel);
 150         if (IS_ERR(timer->clk))
 151                 return PTR_ERR(timer->clk);
 152
 153         err = clk_prepare_enable(timer->clk);
 154         if (err)
 155                 goto err_clk_put;
 156
 157         rate = clk_get_rate(timer->clk);
 158         if (!rate) {
 159                 err = -EINVAL;
 160                 goto err_clk_disable;
 161         }
 162
 163         domain = irq_find_host(tcu->np);
 164         if (!domain) {
 165                 err = -ENODEV;
 166                 goto err_clk_disable;
 167         }
 168
 169         timer_virq = irq_create_mapping(domain, timer->channel);
 170         if (!timer_virq) {
 171                 err = -EINVAL;
 172                 goto err_clk_disable;
 173         }
 174
 175         snprintf(timer->name, sizeof(timer->name), "TCU%u", timer->channel);
 176
 177         err = request_irq(timer_virq, ingenic_tcu_cevt_cb, IRQF_TIMER,
 178                           timer->name, timer);
 179         if (err)
 180                 goto err_irq_dispose_mapping;
 181
 182         timer->cpu = smp_processor_id();
 183         timer->cevt.cpumask = cpumask_of(smp_processor_id());
 184         timer->cevt.features = CLOCK_EVT_FEAT_ONESHOT;
 185         timer->cevt.name = timer->name;
 186         timer->cevt.rating = 200;
 187         timer->cevt.set_state_shutdown = ingenic_tcu_cevt_set_state_shutdown;
 188         timer->cevt.set_next_event = ingenic_tcu_cevt_set_next;
 189
 190         clockevents_config_and_register(&timer->cevt, rate, 10, 0xffff);
 191
 192         return 0;
 193
 194 err_irq_dispose_mapping:
 195         irq_dispose_mapping(timer_virq);
 196 err_clk_disable:
 197         clk_disable_unprepare(timer->clk);
 198 err_clk_put:
 199         clk_put(timer->clk);
 200         return err;
 201 }
 202
 203 static int __init ingenic_tcu_clocksource_init(struct device_node *np,
 204                                                struct ingenic_tcu *tcu)
 205 {
 206         unsigned int channel = tcu->cs_channel;
 207         struct clocksource *cs = &tcu->cs;
 208         unsigned long rate;
 209         int err;
 210
 211         tcu->cs_clk = ingenic_tcu_get_clock(np, channel);
 212         if (IS_ERR(tcu->cs_clk))
 213                 return PTR_ERR(tcu->cs_clk);
 214
 215         err = clk_prepare_enable(tcu->cs_clk);
 216         if (err)
 217                 goto err_clk_put;
 218
 219         rate = clk_get_rate(tcu->cs_clk);
 220         if (!rate) {
 221                 err = -EINVAL;
 222                 goto err_clk_disable;
 223         }
 224
 225         /* Reset channel */
 226         regmap_update_bits(tcu->map, TCU_REG_TCSRc(channel),
 227                            0xffff & ~TCU_TCSR_RESERVED_BITS, 0);
 228
 229         /* Reset counter */
 230         regmap_write(tcu->map, TCU_REG_TDFRc(channel), 0xffff);
 231         regmap_write(tcu->map, TCU_REG_TCNTc(channel), 0);
 232
 233         /* Enable channel */
 234         regmap_write(tcu->map, TCU_REG_TESR, BIT(channel));
 235
 236         cs->name = "ingenic-timer";
 237         cs->rating = 200;
 238         cs->flags = CLOCK_SOURCE_IS_CONTINUOUS;
 239         cs->mask = CLOCKSOURCE_MASK(16);
 240         cs->read = ingenic_tcu_timer_cs_read;
 241
 242         err = clocksource_register_hz(cs, rate);
 243         if (err)
 244                 goto err_clk_disable;
 245
 246         return 0;
 247
 248 err_clk_disable:
 249         clk_disable_unprepare(tcu->cs_clk);
 250 err_clk_put:
 251         clk_put(tcu->cs_clk);
 252         return err;
 253 }
 254
 255 static const struct ingenic_soc_info jz4740_soc_info = {
 256         .num_channels = 8,
 257 };
 258
 259 static const struct ingenic_soc_info jz4725b_soc_info = {
 260         .num_channels = 6,
 261 };
 262
 263 static const struct of_device_id ingenic_tcu_of_match[] = {
 264         { .compatible = "ingenic,jz4740-tcu", .data = &jz4740_soc_info, },
 265         { .compatible = "ingenic,jz4725b-tcu", .data = &jz4725b_soc_info, },
 266         { .compatible = "ingenic,jz4760-tcu", .data = &jz4740_soc_info, },
 267         { .compatible = "ingenic,jz4770-tcu", .data = &jz4740_soc_info, },
 268         { .compatible = "ingenic,x1000-tcu", .data = &jz4740_soc_info, },
 269         { /* sentinel */ }
 270 };
 271
 272 static int __init ingenic_tcu_init(struct device_node *np)
 273 {
 274         const struct of_device_id *id = of_match_node(ingenic_tcu_of_match, np);
 275         const struct ingenic_soc_info *soc_info = id->data;
 276         struct ingenic_tcu_timer *timer;
 277         struct ingenic_tcu *tcu;
 278         struct regmap *map;
 279         unsigned int cpu;
 280         int ret, last_bit = -1;
 281         long rate;
 282
 283         of_node_clear_flag(np, OF_POPULATED);
 284
 285         map = device_node_to_regmap(np);
 286         if (IS_ERR(map))
 287                 return PTR_ERR(map);
 288
 289         tcu = kzalloc(struct_size(tcu, timers, num_possible_cpus()),
 290                       GFP_KERNEL);
 291         if (!tcu)
 292                 return -ENOMEM;
 293
 294         /*
 295          * Enable all TCU channels for PWM use by default except channels 0/1,
 296          * and channel 2 if target CPU is JZ4780/X2000 and SMP is selected.
 297          */
 298         tcu->pwm_channels_mask = GENMASK(soc_info->num_channels - 1,
 299                                          num_possible_cpus() + 1);
 300         of_property_read_u32(np, "ingenic,pwm-channels-mask",
 301                              (u32 *)&tcu->pwm_channels_mask);
 302
 303         /* Verify that we have at least num_possible_cpus() + 1 free channels */
 304         if (hweight8(tcu->pwm_channels_mask) >
 305                         soc_info->num_channels - num_possible_cpus() + 1) {
 306                 pr_crit("%s: Invalid PWM channel mask: 0x%02lx\n", __func__,
 307                         tcu->pwm_channels_mask);
 308                 ret = -EINVAL;
 309                 goto err_free_ingenic_tcu;
 310         }
 311
 312         tcu->map = map;
 313         tcu->np = np;
 314         ingenic_tcu = tcu;
 315
 316         for (cpu = 0; cpu < num_possible_cpus(); cpu++) {
 317                 timer = &tcu->timers[cpu];
 318
 319                 timer->cpu = cpu;
 320                 timer->channel = find_next_zero_bit(&tcu->pwm_channels_mask,
 321                                                   soc_info->num_channels,
 322                                                   last_bit + 1);
 323                 last_bit = timer->channel;
 324         }
 325
 326         tcu->cs_channel = find_next_zero_bit(&tcu->pwm_channels_mask,
 327                                              soc_info->num_channels,
 328                                              last_bit + 1);
 329
 330         ret = ingenic_tcu_clocksource_init(np, tcu);
 331         if (ret) {
 332                 pr_crit("%s: Unable to init clocksource: %d\n", __func__, ret);
 333                 goto err_free_ingenic_tcu;
 334         }
 335
 336         /* Setup clock events on each CPU core */
 337         ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "Ingenic XBurst: online",
 338                                 ingenic_tcu_setup_cevt, NULL);
 339         if (ret < 0) {
 340                 pr_crit("%s: Unable to start CPU timers: %d\n", __func__, ret);
 341                 goto err_tcu_clocksource_cleanup;
 342         }
 343
 344         /* Register the sched_clock at the end as there's no way to undo it */
 345         rate = clk_get_rate(tcu->cs_clk);
 346         sched_clock_register(ingenic_tcu_timer_read, 16, rate);
 347
 348         return 0;
 349
 350 err_tcu_clocksource_cleanup:
 351         clocksource_unregister(&tcu->cs);
 352         clk_disable_unprepare(tcu->cs_clk);
 353         clk_put(tcu->cs_clk);
 354 err_free_ingenic_tcu:
 355         kfree(tcu);
 356         return ret;
 357 }
 358
 359 TIMER_OF_DECLARE(jz4740_tcu_intc,  "ingenic,jz4740-tcu",  ingenic_tcu_init);
 360 TIMER_OF_DECLARE(jz4725b_tcu_intc, "ingenic,jz4725b-tcu", ingenic_tcu_init);
 361 TIMER_OF_DECLARE(jz4760_tcu_intc,  "ingenic,jz4760-tcu",  ingenic_tcu_init);
 362 TIMER_OF_DECLARE(jz4770_tcu_intc,  "ingenic,jz4770-tcu",  ingenic_tcu_init);
 363 TIMER_OF_DECLARE(x1000_tcu_intc,  "ingenic,x1000-tcu",  ingenic_tcu_init);
 364
 365 static int __init ingenic_tcu_probe(struct platform_device *pdev)
 366 {
 367         platform_set_drvdata(pdev, ingenic_tcu);
 368
 369         return 0;
 370 }
 371
 372 static int __maybe_unused ingenic_tcu_suspend(struct device *dev)
 373 {
 374         struct ingenic_tcu *tcu = dev_get_drvdata(dev);
 375         unsigned int cpu;
 376
 377         clk_disable(tcu->cs_clk);
 378
 379         for (cpu = 0; cpu < num_online_cpus(); cpu++)
 380                 clk_disable(tcu->timers[cpu].clk);
 381
 382         return 0;
 383 }
 384
 385 static int __maybe_unused ingenic_tcu_resume(struct device *dev)
 386 {
 387         struct ingenic_tcu *tcu = dev_get_drvdata(dev);
 388         unsigned int cpu;
 389         int ret;
 390
 391         for (cpu = 0; cpu < num_online_cpus(); cpu++) {
 392                 ret = clk_enable(tcu->timers[cpu].clk);
 393                 if (ret)
 394                         goto err_timer_clk_disable;
 395         }
 396
 397         ret = clk_enable(tcu->cs_clk);
 398         if (ret)
 399                 goto err_timer_clk_disable;
 400
 401         return 0;
 402
 403 err_timer_clk_disable:
 404         for (; cpu > 0; cpu--)
 405                 clk_disable(tcu->timers[cpu - 1].clk);
 406         return ret;
 407 }
 408
 409 static const struct dev_pm_ops __maybe_unused ingenic_tcu_pm_ops = {
 410         /* _noirq: We want the TCU clocks to be gated last / ungated first */
 411         .suspend_noirq = ingenic_tcu_suspend,
 412         .resume_noirq  = ingenic_tcu_resume,
 413 };
 414
 415 static struct platform_driver ingenic_tcu_driver = {
 416         .driver = {
 417                 .name   = "ingenic-tcu-timer",
 418 #ifdef CONFIG_PM_SLEEP
 419                 .pm     = &ingenic_tcu_pm_ops,
 420 #endif
 421                 .of_match_table = ingenic_tcu_of_match,
 422         },
 423 };
 424 builtin_platform_driver_probe(ingenic_tcu_driver, ingenic_tcu_probe);