drivers/clocksource/timer-imx-gpt.c

   1 /*
   2  *  linux/arch/arm/plat-mxc/time.c
   3  *
   4  *  Copyright (C) 2000-2001 Deep Blue Solutions
   5  *  Copyright (C) 2002 Shane Nay (shane@minirl.com)
   6  *  Copyright (C) 2006-2007 Pavel Pisa (ppisa@pikron.com)
   7  *  Copyright (C) 2008 Juergen Beisert (kernel@pengutronix.de)
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License
  11  * as published by the Free Software Foundation; either version 2
  12  * of the License, or (at your option) any later version.
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  21  * MA 02110-1301, USA.
  22  */
  23
  24 #include <linux/interrupt.h>
  25 #include <linux/irq.h>
  26 #include <linux/clockchips.h>
  27 #include <linux/clk.h>
  28 #include <linux/delay.h>
  29 #include <linux/err.h>
  30 #include <linux/sched_clock.h>
  31 #include <linux/slab.h>
  32 #include <linux/of.h>
  33 #include <linux/of_address.h>
  34 #include <linux/of_irq.h>
  35 #include <soc/imx/timer.h>
  36
  37 /*
  38  * There are 4 versions of the timer hardware on Freescale MXC hardware.
  39  *  - MX1/MXL
  40  *  - MX21, MX27.
  41  *  - MX25, MX31, MX35, MX37, MX51, MX6Q(rev1.0)
  42  *  - MX6DL, MX6SX, MX6Q(rev1.1+)
  43  */
  44
  45 /* defines common for all i.MX */
  46 #define MXC_TCTL                0x00
  47 #define MXC_TCTL_TEN            (1 << 0) /* Enable module */
  48 #define MXC_TPRER               0x04
  49
  50 /* MX1, MX21, MX27 */
  51 #define MX1_2_TCTL_CLK_PCLK1    (1 << 1)
  52 #define MX1_2_TCTL_IRQEN        (1 << 4)
  53 #define MX1_2_TCTL_FRR          (1 << 8)
  54 #define MX1_2_TCMP              0x08
  55 #define MX1_2_TCN               0x10
  56 #define MX1_2_TSTAT             0x14
  57
  58 /* MX21, MX27 */
  59 #define MX2_TSTAT_CAPT          (1 << 1)
  60 #define MX2_TSTAT_COMP          (1 << 0)
  61
  62 /* MX31, MX35, MX25, MX5, MX6 */
  63 #define V2_TCTL_WAITEN          (1 << 3) /* Wait enable mode */
  64 #define V2_TCTL_CLK_IPG         (1 << 6)
  65 #define V2_TCTL_CLK_PER         (2 << 6)
  66 #define V2_TCTL_CLK_OSC_DIV8    (5 << 6)
  67 #define V2_TCTL_FRR             (1 << 9)
  68 #define V2_TCTL_24MEN           (1 << 10)
  69 #define V2_TPRER_PRE24M         12
  70 #define V2_IR                   0x0c
  71 #define V2_TSTAT                0x08
  72 #define V2_TSTAT_OF1            (1 << 0)
  73 #define V2_TCN                  0x24
  74 #define V2_TCMP                 0x10
  75
  76 #define V2_TIMER_RATE_OSC_DIV8  3000000
  77
  78 struct imx_timer {
  79         enum imx_gpt_type type;
  80         void __iomem *base;
  81         int irq;
  82         struct clk *clk_per;
  83         struct clk *clk_ipg;
  84         const struct imx_gpt_data *gpt;
  85         struct clock_event_device ced;
  86         struct irqaction act;
  87 };
  88
  89 struct imx_gpt_data {
  90         int reg_tstat;
  91         int reg_tcn;
  92         int reg_tcmp;
  93         void (*gpt_setup_tctl)(struct imx_timer *imxtm);
  94         void (*gpt_irq_enable)(struct imx_timer *imxtm);
  95         void (*gpt_irq_disable)(struct imx_timer *imxtm);
  96         void (*gpt_irq_acknowledge)(struct imx_timer *imxtm);
  97         int (*set_next_event)(unsigned long evt,
  98                               struct clock_event_device *ced);
  99 };
 100
 101 static inline struct imx_timer *to_imx_timer(struct clock_event_device *ced)
 102 {
 103         return container_of(ced, struct imx_timer, ced);
 104 }
 105
 106 static void imx1_gpt_irq_disable(struct imx_timer *imxtm)
 107 {
 108         unsigned int tmp;
 109
 110         tmp = readl_relaxed(imxtm->base + MXC_TCTL);
 111         writel_relaxed(tmp & ~MX1_2_TCTL_IRQEN, imxtm->base + MXC_TCTL);
 112 }
 113 #define imx21_gpt_irq_disable imx1_gpt_irq_disable
 114
 115 static void imx31_gpt_irq_disable(struct imx_timer *imxtm)
 116 {
 117         writel_relaxed(0, imxtm->base + V2_IR);
 118 }
 119 #define imx6dl_gpt_irq_disable imx31_gpt_irq_disable
 120
 121 static void imx1_gpt_irq_enable(struct imx_timer *imxtm)
 122 {
 123         unsigned int tmp;
 124
 125         tmp = readl_relaxed(imxtm->base + MXC_TCTL);
 126         writel_relaxed(tmp | MX1_2_TCTL_IRQEN, imxtm->base + MXC_TCTL);
 127 }
 128 #define imx21_gpt_irq_enable imx1_gpt_irq_enable
 129
 130 static void imx31_gpt_irq_enable(struct imx_timer *imxtm)
 131 {
 132         writel_relaxed(1<<0, imxtm->base + V2_IR);
 133 }
 134 #define imx6dl_gpt_irq_enable imx31_gpt_irq_enable
 135
 136 static void imx1_gpt_irq_acknowledge(struct imx_timer *imxtm)
 137 {
 138         writel_relaxed(0, imxtm->base + MX1_2_TSTAT);
 139 }
 140
 141 static void imx21_gpt_irq_acknowledge(struct imx_timer *imxtm)
 142 {
 143         writel_relaxed(MX2_TSTAT_CAPT | MX2_TSTAT_COMP,
 144                                 imxtm->base + MX1_2_TSTAT);
 145 }
 146
 147 static void imx31_gpt_irq_acknowledge(struct imx_timer *imxtm)
 148 {
 149         writel_relaxed(V2_TSTAT_OF1, imxtm->base + V2_TSTAT);
 150 }
 151 #define imx6dl_gpt_irq_acknowledge imx31_gpt_irq_acknowledge
 152
 153 static void __iomem *sched_clock_reg;
 154
 155 static u64 notrace mxc_read_sched_clock(void)
 156 {
 157         return sched_clock_reg ? readl_relaxed(sched_clock_reg) : 0;
 158 }
 159
 160 static struct delay_timer imx_delay_timer;
 161
 162 static unsigned long imx_read_current_timer(void)
 163 {
 164         return readl_relaxed(sched_clock_reg);
 165 }
 166
 167 static int __init mxc_clocksource_init(struct imx_timer *imxtm)
 168 {
 169         unsigned int c = clk_get_rate(imxtm->clk_per);
 170         void __iomem *reg = imxtm->base + imxtm->gpt->reg_tcn;
 171
 172         imx_delay_timer.read_current_timer = &imx_read_current_timer;
 173         imx_delay_timer.freq = c;
 174         register_current_timer_delay(&imx_delay_timer);
 175
 176         sched_clock_reg = reg;
 177
 178         sched_clock_register(mxc_read_sched_clock, 32, c);
 179         return clocksource_mmio_init(reg, "mxc_timer1", c, 200, 32,
 180                         clocksource_mmio_readl_up);
 181 }
 182
 183 /* clock event */
 184
 185 static int mx1_2_set_next_event(unsigned long evt,
 186                               struct clock_event_device *ced)
 187 {
 188         struct imx_timer *imxtm = to_imx_timer(ced);
 189         unsigned long tcmp;
 190
 191         tcmp = readl_relaxed(imxtm->base + MX1_2_TCN) + evt;
 192
 193         writel_relaxed(tcmp, imxtm->base + MX1_2_TCMP);
 194
 195         return (int)(tcmp - readl_relaxed(imxtm->base + MX1_2_TCN)) < 0 ?
 196                                 -ETIME : 0;
 197 }
 198
 199 static int v2_set_next_event(unsigned long evt,
 200                               struct clock_event_device *ced)
 201 {
 202         struct imx_timer *imxtm = to_imx_timer(ced);
 203         unsigned long tcmp;
 204
 205         tcmp = readl_relaxed(imxtm->base + V2_TCN) + evt;
 206
 207         writel_relaxed(tcmp, imxtm->base + V2_TCMP);
 208
 209         return evt < 0x7fffffff &&
 210                 (int)(tcmp - readl_relaxed(imxtm->base + V2_TCN)) < 0 ?
 211                                 -ETIME : 0;
 212 }
 213
 214 static int mxc_shutdown(struct clock_event_device *ced)
 215 {
 216         struct imx_timer *imxtm = to_imx_timer(ced);
 217         unsigned long flags;
 218         u32 tcn;
 219
 220         /*
 221          * The timer interrupt generation is disabled at least
 222          * for enough time to call mxc_set_next_event()
 223          */
 224         local_irq_save(flags);
 225
 226         /* Disable interrupt in GPT module */
 227         imxtm->gpt->gpt_irq_disable(imxtm);
 228
 229         tcn = readl_relaxed(imxtm->base + imxtm->gpt->reg_tcn);
 230         /* Set event time into far-far future */
 231         writel_relaxed(tcn - 3, imxtm->base + imxtm->gpt->reg_tcmp);
 232
 233         /* Clear pending interrupt */
 234         imxtm->gpt->gpt_irq_acknowledge(imxtm);
 235
 236 #ifdef DEBUG
 237         printk(KERN_INFO "%s: changing mode\n", __func__);
 238 #endif /* DEBUG */
 239
 240         local_irq_restore(flags);
 241
 242         return 0;
 243 }
 244
 245 static int mxc_set_oneshot(struct clock_event_device *ced)
 246 {
 247         struct imx_timer *imxtm = to_imx_timer(ced);
 248         unsigned long flags;
 249
 250         /*
 251          * The timer interrupt generation is disabled at least
 252          * for enough time to call mxc_set_next_event()
 253          */
 254         local_irq_save(flags);
 255
 256         /* Disable interrupt in GPT module */
 257         imxtm->gpt->gpt_irq_disable(imxtm);
 258
 259         if (!clockevent_state_oneshot(ced)) {
 260                 u32 tcn = readl_relaxed(imxtm->base + imxtm->gpt->reg_tcn);
 261                 /* Set event time into far-far future */
 262                 writel_relaxed(tcn - 3, imxtm->base + imxtm->gpt->reg_tcmp);
 263
 264                 /* Clear pending interrupt */
 265                 imxtm->gpt->gpt_irq_acknowledge(imxtm);
 266         }
 267
 268 #ifdef DEBUG
 269         printk(KERN_INFO "%s: changing mode\n", __func__);
 270 #endif /* DEBUG */
 271
 272         /*
 273          * Do not put overhead of interrupt enable/disable into
 274          * mxc_set_next_event(), the core has about 4 minutes
 275          * to call mxc_set_next_event() or shutdown clock after
 276          * mode switching
 277          */
 278         imxtm->gpt->gpt_irq_enable(imxtm);
 279         local_irq_restore(flags);
 280
 281         return 0;
 282 }
 283
 284 /*
 285  * IRQ handler for the timer
 286  */
 287 static irqreturn_t mxc_timer_interrupt(int irq, void *dev_id)
 288 {
 289         struct clock_event_device *ced = dev_id;
 290         struct imx_timer *imxtm = to_imx_timer(ced);
 291         uint32_t tstat;
 292
 293         tstat = readl_relaxed(imxtm->base + imxtm->gpt->reg_tstat);
 294
 295         imxtm->gpt->gpt_irq_acknowledge(imxtm);
 296
 297         ced->event_handler(ced);
 298
 299         return IRQ_HANDLED;
 300 }
 301
 302 static int __init mxc_clockevent_init(struct imx_timer *imxtm)
 303 {
 304         struct clock_event_device *ced = &imxtm->ced;
 305         struct irqaction *act = &imxtm->act;
 306
 307         ced->name = "mxc_timer1";
 308         ced->features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_DYNIRQ;
 309         ced->set_state_shutdown = mxc_shutdown;
 310         ced->set_state_oneshot = mxc_set_oneshot;
 311         ced->tick_resume = mxc_shutdown;
 312         ced->set_next_event = imxtm->gpt->set_next_event;
 313         ced->rating = 200;
 314         ced->cpumask = cpumask_of(0);
 315         ced->irq = imxtm->irq;
 316         clockevents_config_and_register(ced, clk_get_rate(imxtm->clk_per),
 317                                         0xff, 0xfffffffe);
 318
 319         act->name = "i.MX Timer Tick";
 320         act->flags = IRQF_TIMER | IRQF_IRQPOLL;
 321         act->handler = mxc_timer_interrupt;
 322         act->dev_id = ced;
 323
 324         return setup_irq(imxtm->irq, act);
 325 }
 326
 327 static void imx1_gpt_setup_tctl(struct imx_timer *imxtm)
 328 {
 329         u32 tctl_val;
 330
 331         tctl_val = MX1_2_TCTL_FRR | MX1_2_TCTL_CLK_PCLK1 | MXC_TCTL_TEN;
 332         writel_relaxed(tctl_val, imxtm->base + MXC_TCTL);
 333 }
 334 #define imx21_gpt_setup_tctl imx1_gpt_setup_tctl
 335
 336 static void imx31_gpt_setup_tctl(struct imx_timer *imxtm)
 337 {
 338         u32 tctl_val;
 339
 340         tctl_val = V2_TCTL_FRR | V2_TCTL_WAITEN | MXC_TCTL_TEN;
 341         if (clk_get_rate(imxtm->clk_per) == V2_TIMER_RATE_OSC_DIV8)
 342                 tctl_val |= V2_TCTL_CLK_OSC_DIV8;
 343         else
 344                 tctl_val |= V2_TCTL_CLK_PER;
 345
 346         writel_relaxed(tctl_val, imxtm->base + MXC_TCTL);
 347 }
 348
 349 static void imx6dl_gpt_setup_tctl(struct imx_timer *imxtm)
 350 {
 351         u32 tctl_val;
 352
 353         tctl_val = V2_TCTL_FRR | V2_TCTL_WAITEN | MXC_TCTL_TEN;
 354         if (clk_get_rate(imxtm->clk_per) == V2_TIMER_RATE_OSC_DIV8) {
 355                 tctl_val |= V2_TCTL_CLK_OSC_DIV8;
 356                 /* 24 / 8 = 3 MHz */
 357                 writel_relaxed(7 << V2_TPRER_PRE24M, imxtm->base + MXC_TPRER);
 358                 tctl_val |= V2_TCTL_24MEN;
 359         } else {
 360                 tctl_val |= V2_TCTL_CLK_PER;
 361         }
 362
 363         writel_relaxed(tctl_val, imxtm->base + MXC_TCTL);
 364 }
 365
 366 static const struct imx_gpt_data imx1_gpt_data = {
 367         .reg_tstat = MX1_2_TSTAT,
 368         .reg_tcn = MX1_2_TCN,
 369         .reg_tcmp = MX1_2_TCMP,
 370         .gpt_irq_enable = imx1_gpt_irq_enable,
 371         .gpt_irq_disable = imx1_gpt_irq_disable,
 372         .gpt_irq_acknowledge = imx1_gpt_irq_acknowledge,
 373         .gpt_setup_tctl = imx1_gpt_setup_tctl,
 374         .set_next_event = mx1_2_set_next_event,
 375 };
 376
 377 static const struct imx_gpt_data imx21_gpt_data = {
 378         .reg_tstat = MX1_2_TSTAT,
 379         .reg_tcn = MX1_2_TCN,
 380         .reg_tcmp = MX1_2_TCMP,
 381         .gpt_irq_enable = imx21_gpt_irq_enable,
 382         .gpt_irq_disable = imx21_gpt_irq_disable,
 383         .gpt_irq_acknowledge = imx21_gpt_irq_acknowledge,
 384         .gpt_setup_tctl = imx21_gpt_setup_tctl,
 385         .set_next_event = mx1_2_set_next_event,
 386 };
 387
 388 static const struct imx_gpt_data imx31_gpt_data = {
 389         .reg_tstat = V2_TSTAT,
 390         .reg_tcn = V2_TCN,
 391         .reg_tcmp = V2_TCMP,
 392         .gpt_irq_enable = imx31_gpt_irq_enable,
 393         .gpt_irq_disable = imx31_gpt_irq_disable,
 394         .gpt_irq_acknowledge = imx31_gpt_irq_acknowledge,
 395         .gpt_setup_tctl = imx31_gpt_setup_tctl,
 396         .set_next_event = v2_set_next_event,
 397 };
 398
 399 static const struct imx_gpt_data imx6dl_gpt_data = {
 400         .reg_tstat = V2_TSTAT,
 401         .reg_tcn = V2_TCN,
 402         .reg_tcmp = V2_TCMP,
 403         .gpt_irq_enable = imx6dl_gpt_irq_enable,
 404         .gpt_irq_disable = imx6dl_gpt_irq_disable,
 405         .gpt_irq_acknowledge = imx6dl_gpt_irq_acknowledge,
 406         .gpt_setup_tctl = imx6dl_gpt_setup_tctl,
 407         .set_next_event = v2_set_next_event,
 408 };
 409
 410 static void __init _mxc_timer_init(struct imx_timer *imxtm)
 411 {
 412         switch (imxtm->type) {
 413         case GPT_TYPE_IMX1:
 414                 imxtm->gpt = &imx1_gpt_data;
 415                 break;
 416         case GPT_TYPE_IMX21:
 417                 imxtm->gpt = &imx21_gpt_data;
 418                 break;
 419         case GPT_TYPE_IMX31:
 420                 imxtm->gpt = &imx31_gpt_data;
 421                 break;
 422         case GPT_TYPE_IMX6DL:
 423                 imxtm->gpt = &imx6dl_gpt_data;
 424                 break;
 425         default:
 426                 BUG();
 427         }
 428
 429         if (IS_ERR(imxtm->clk_per)) {
 430                 pr_err("i.MX timer: unable to get clk\n");
 431                 return;
 432         }
 433
 434         if (!IS_ERR(imxtm->clk_ipg))
 435                 clk_prepare_enable(imxtm->clk_ipg);
 436
 437         clk_prepare_enable(imxtm->clk_per);
 438
 439         /*
 440          * Initialise to a known state (all timers off, and timing reset)
 441          */
 442
 443         writel_relaxed(0, imxtm->base + MXC_TCTL);
 444         writel_relaxed(0, imxtm->base + MXC_TPRER); /* see datasheet note */
 445
 446         imxtm->gpt->gpt_setup_tctl(imxtm);
 447
 448         /* init and register the timer to the framework */
 449         mxc_clocksource_init(imxtm);
 450         mxc_clockevent_init(imxtm);
 451 }
 452
 453 void __init mxc_timer_init(unsigned long pbase, int irq, enum imx_gpt_type type)
 454 {
 455         struct imx_timer *imxtm;
 456
 457         imxtm = kzalloc(sizeof(*imxtm), GFP_KERNEL);
 458         BUG_ON(!imxtm);
 459
 460         imxtm->clk_per = clk_get_sys("imx-gpt.0", "per");
 461         imxtm->clk_ipg = clk_get_sys("imx-gpt.0", "ipg");
 462
 463         imxtm->base = ioremap(pbase, SZ_4K);
 464         BUG_ON(!imxtm->base);
 465
 466         imxtm->type = type;
 467         imxtm->irq = irq;
 468
 469         _mxc_timer_init(imxtm);
 470 }
 471
 472 static void __init mxc_timer_init_dt(struct device_node *np,  enum imx_gpt_type type)
 473 {
 474         struct imx_timer *imxtm;
 475         static int initialized;
 476
 477         /* Support one instance only */
 478         if (initialized)
 479                 return;
 480
 481         imxtm = kzalloc(sizeof(*imxtm), GFP_KERNEL);
 482         BUG_ON(!imxtm);
 483
 484         imxtm->base = of_iomap(np, 0);
 485         WARN_ON(!imxtm->base);
 486         imxtm->irq = irq_of_parse_and_map(np, 0);
 487
 488         imxtm->clk_ipg = of_clk_get_by_name(np, "ipg");
 489
 490         /* Try osc_per first, and fall back to per otherwise */
 491         imxtm->clk_per = of_clk_get_by_name(np, "osc_per");
 492         if (IS_ERR(imxtm->clk_per))
 493                 imxtm->clk_per = of_clk_get_by_name(np, "per");
 494
 495         imxtm->type = type;
 496
 497         _mxc_timer_init(imxtm);
 498
 499         initialized = 1;
 500 }
 501
 502 static void __init imx1_timer_init_dt(struct device_node *np)
 503 {
 504         mxc_timer_init_dt(np, GPT_TYPE_IMX1);
 505 }
 506
 507 static void __init imx21_timer_init_dt(struct device_node *np)
 508 {
 509         mxc_timer_init_dt(np, GPT_TYPE_IMX21);
 510 }
 511
 512 static void __init imx31_timer_init_dt(struct device_node *np)
 513 {
 514         enum imx_gpt_type type = GPT_TYPE_IMX31;
 515
 516         /*
 517          * We were using the same compatible string for i.MX6Q/D and i.MX6DL/S
 518          * GPT device, while they actually have different programming model.
 519          * This is a workaround to keep the existing i.MX6DL/S DTBs continue
 520          * working with the new kernel.
 521          */
 522         if (of_machine_is_compatible("fsl,imx6dl"))
 523                 type = GPT_TYPE_IMX6DL;
 524
 525         mxc_timer_init_dt(np, type);
 526 }
 527
 528 static void __init imx6dl_timer_init_dt(struct device_node *np)
 529 {
 530         mxc_timer_init_dt(np, GPT_TYPE_IMX6DL);
 531 }
 532
 533 CLOCKSOURCE_OF_DECLARE(imx1_timer, "fsl,imx1-gpt", imx1_timer_init_dt);
 534 CLOCKSOURCE_OF_DECLARE(imx21_timer, "fsl,imx21-gpt", imx21_timer_init_dt);
 535 CLOCKSOURCE_OF_DECLARE(imx27_timer, "fsl,imx27-gpt", imx21_timer_init_dt);
 536 CLOCKSOURCE_OF_DECLARE(imx31_timer, "fsl,imx31-gpt", imx31_timer_init_dt);
 537 CLOCKSOURCE_OF_DECLARE(imx25_timer, "fsl,imx25-gpt", imx31_timer_init_dt);
 538 CLOCKSOURCE_OF_DECLARE(imx50_timer, "fsl,imx50-gpt", imx31_timer_init_dt);
 539 CLOCKSOURCE_OF_DECLARE(imx51_timer, "fsl,imx51-gpt", imx31_timer_init_dt);
 540 CLOCKSOURCE_OF_DECLARE(imx53_timer, "fsl,imx53-gpt", imx31_timer_init_dt);
 541 CLOCKSOURCE_OF_DECLARE(imx6q_timer, "fsl,imx6q-gpt", imx31_timer_init_dt);
 542 CLOCKSOURCE_OF_DECLARE(imx6dl_timer, "fsl,imx6dl-gpt", imx6dl_timer_init_dt);
 543 CLOCKSOURCE_OF_DECLARE(imx6sl_timer, "fsl,imx6sl-gpt", imx6dl_timer_init_dt);
 544 CLOCKSOURCE_OF_DECLARE(imx6sx_timer, "fsl,imx6sx-gpt", imx6dl_timer_init_dt);