hw/exynos4210_pwm.c

   1 /*
   2  * Samsung exynos4210 Pulse Width Modulation Timer
   3  *
   4  * Copyright (c) 2000 - 2011 Samsung Electronics Co., Ltd.
   5  * All rights reserved.
   6  *
   7  * Evgeny Voevodin <e.voevodin@samsung.com>
   8  *
   9  * This program is free software; you can redistribute it and/or modify it
  10  * under the terms of the GNU General Public License as published by the
  11  * Free Software Foundation; either version 2 of the License, or (at your
  12  * option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  17  * See the GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; if not, see <http://www.gnu.org/licenses/>.
  21  */
  22
  23 #include "sysbus.h"
  24 #include "qemu/timer.h"
  25 #include "qemu-common.h"
  26 #include "ptimer.h"
  27
  28 #include "exynos4210.h"
  29
  30 //#define DEBUG_PWM
  31
  32 #ifdef DEBUG_PWM
  33 #define DPRINTF(fmt, ...) \
  34         do { fprintf(stdout, "PWM: [%24s:%5d] " fmt, __func__, __LINE__, \
  35                 ## __VA_ARGS__); } while (0)
  36 #else
  37 #define DPRINTF(fmt, ...) do {} while (0)
  38 #endif
  39
  40 #define     EXYNOS4210_PWM_TIMERS_NUM      5
  41 #define     EXYNOS4210_PWM_REG_MEM_SIZE    0x50
  42
  43 #define     TCFG0        0x0000
  44 #define     TCFG1        0x0004
  45 #define     TCON         0x0008
  46 #define     TCNTB0       0x000C
  47 #define     TCMPB0       0x0010
  48 #define     TCNTO0       0x0014
  49 #define     TCNTB1       0x0018
  50 #define     TCMPB1       0x001C
  51 #define     TCNTO1       0x0020
  52 #define     TCNTB2       0x0024
  53 #define     TCMPB2       0x0028
  54 #define     TCNTO2       0x002C
  55 #define     TCNTB3       0x0030
  56 #define     TCMPB3       0x0034
  57 #define     TCNTO3       0x0038
  58 #define     TCNTB4       0x003C
  59 #define     TCNTO4       0x0040
  60 #define     TINT_CSTAT   0x0044
  61
  62 #define     TCNTB(x)    (0xC * (x))
  63 #define     TCMPB(x)    (0xC * (x) + 1)
  64 #define     TCNTO(x)    (0xC * (x) + 2)
  65
  66 #define GET_PRESCALER(reg, x) (((reg) & (0xFF << (8 * (x)))) >> 8 * (x))
  67 #define GET_DIVIDER(reg, x) (1 << (((reg) & (0xF << (4 * (x)))) >> (4 * (x))))
  68
  69 /*
  70  * Attention! Timer4 doesn't have OUTPUT_INVERTER,
  71  * so Auto Reload bit is not accessible by macros!
  72  */
  73 #define     TCON_TIMER_BASE(x)          (((x) ? 1 : 0) * 4 + 4 * (x))
  74 #define     TCON_TIMER_START(x)         (1 << (TCON_TIMER_BASE(x) + 0))
  75 #define     TCON_TIMER_MANUAL_UPD(x)    (1 << (TCON_TIMER_BASE(x) + 1))
  76 #define     TCON_TIMER_OUTPUT_INV(x)    (1 << (TCON_TIMER_BASE(x) + 2))
  77 #define     TCON_TIMER_AUTO_RELOAD(x)   (1 << (TCON_TIMER_BASE(x) + 3))
  78 #define     TCON_TIMER4_AUTO_RELOAD     (1 << 22)
  79
  80 #define     TINT_CSTAT_STATUS(x)        (1 << (5 + (x)))
  81 #define     TINT_CSTAT_ENABLE(x)        (1 << (x))
  82
  83 /* timer struct */
  84 typedef struct {
  85     uint32_t    id;             /* timer id */
  86     qemu_irq    irq;            /* local timer irq */
  87     uint32_t    freq;           /* timer frequency */
  88
  89     /* use ptimer.c to represent count down timer */
  90     ptimer_state *ptimer;       /* timer  */
  91
  92     /* registers */
  93     uint32_t    reg_tcntb;      /* counter register buffer */
  94     uint32_t    reg_tcmpb;      /* compare register buffer */
  95
  96     struct Exynos4210PWMState *parent;
  97
  98 } Exynos4210PWM;
  99
 100
 101 typedef struct Exynos4210PWMState {
 102     SysBusDevice busdev;
 103     MemoryRegion iomem;
 104
 105     uint32_t    reg_tcfg[2];
 106     uint32_t    reg_tcon;
 107     uint32_t    reg_tint_cstat;
 108
 109     Exynos4210PWM timer[EXYNOS4210_PWM_TIMERS_NUM];
 110
 111 } Exynos4210PWMState;
 112
 113 /*** VMState ***/
 114 static const VMStateDescription vmstate_exynos4210_pwm = {
 115     .name = "exynos4210.pwm.pwm",
 116     .version_id = 1,
 117     .minimum_version_id = 1,
 118     .minimum_version_id_old = 1,
 119     .fields = (VMStateField[]) {
 120         VMSTATE_UINT32(id, Exynos4210PWM),
 121         VMSTATE_UINT32(freq, Exynos4210PWM),
 122         VMSTATE_PTIMER(ptimer, Exynos4210PWM),
 123         VMSTATE_UINT32(reg_tcntb, Exynos4210PWM),
 124         VMSTATE_UINT32(reg_tcmpb, Exynos4210PWM),
 125         VMSTATE_END_OF_LIST()
 126     }
 127 };
 128
 129 static const VMStateDescription vmstate_exynos4210_pwm_state = {
 130     .name = "exynos4210.pwm",
 131     .version_id = 1,
 132     .minimum_version_id = 1,
 133     .minimum_version_id_old = 1,
 134     .fields = (VMStateField[]) {
 135         VMSTATE_UINT32_ARRAY(reg_tcfg, Exynos4210PWMState, 2),
 136         VMSTATE_UINT32(reg_tcon, Exynos4210PWMState),
 137         VMSTATE_UINT32(reg_tint_cstat, Exynos4210PWMState),
 138         VMSTATE_STRUCT_ARRAY(timer, Exynos4210PWMState,
 139             EXYNOS4210_PWM_TIMERS_NUM, 0,
 140         vmstate_exynos4210_pwm, Exynos4210PWM),
 141         VMSTATE_END_OF_LIST()
 142     }
 143 };
 144
 145 /*
 146  * PWM update frequency
 147  */
 148 static void exynos4210_pwm_update_freq(Exynos4210PWMState *s, uint32_t id)
 149 {
 150     uint32_t freq;
 151     freq = s->timer[id].freq;
 152     if (id > 1) {
 153         s->timer[id].freq = 24000000 /
 154         ((GET_PRESCALER(s->reg_tcfg[0], 1) + 1) *
 155                 (GET_DIVIDER(s->reg_tcfg[1], id)));
 156     } else {
 157         s->timer[id].freq = 24000000 /
 158         ((GET_PRESCALER(s->reg_tcfg[0], 0) + 1) *
 159                 (GET_DIVIDER(s->reg_tcfg[1], id)));
 160     }
 161
 162     if (freq != s->timer[id].freq) {
 163         ptimer_set_freq(s->timer[id].ptimer, s->timer[id].freq);
 164         DPRINTF("freq=%dHz\n", s->timer[id].freq);
 165     }
 166 }
 167
 168 /*
 169  * Counter tick handler
 170  */
 171 static void exynos4210_pwm_tick(void *opaque)
 172 {
 173     Exynos4210PWM *s = (Exynos4210PWM *)opaque;
 174     Exynos4210PWMState *p = (Exynos4210PWMState *)s->parent;
 175     uint32_t id = s->id;
 176     bool cmp;
 177
 178     DPRINTF("timer %d tick\n", id);
 179
 180     /* set irq status */
 181     p->reg_tint_cstat |= TINT_CSTAT_STATUS(id);
 182
 183     /* raise IRQ */
 184     if (p->reg_tint_cstat & TINT_CSTAT_ENABLE(id)) {
 185         DPRINTF("timer %d IRQ\n", id);
 186         qemu_irq_raise(p->timer[id].irq);
 187     }
 188
 189     /* reload timer */
 190     if (id != 4) {
 191         cmp = p->reg_tcon & TCON_TIMER_AUTO_RELOAD(id);
 192     } else {
 193         cmp = p->reg_tcon & TCON_TIMER4_AUTO_RELOAD;
 194     }
 195
 196     if (cmp) {
 197         DPRINTF("auto reload timer %d count to %x\n", id,
 198                 p->timer[id].reg_tcntb);
 199         ptimer_set_count(p->timer[id].ptimer, p->timer[id].reg_tcntb);
 200         ptimer_run(p->timer[id].ptimer, 1);
 201     } else {
 202         /* stop timer, set status to STOP, see Basic Timer Operation */
 203         p->reg_tcon &= ~TCON_TIMER_START(id);
 204         ptimer_stop(p->timer[id].ptimer);
 205     }
 206 }
 207
 208 /*
 209  * PWM Read
 210  */
 211 static uint64_t exynos4210_pwm_read(void *opaque, hwaddr offset,
 212         unsigned size)
 213 {
 214     Exynos4210PWMState *s = (Exynos4210PWMState *)opaque;
 215     uint32_t value = 0;
 216     int index;
 217
 218     switch (offset) {
 219     case TCFG0: case TCFG1:
 220         index = (offset - TCFG0) >> 2;
 221         value = s->reg_tcfg[index];
 222         break;
 223
 224     case TCON:
 225         value = s->reg_tcon;
 226         break;
 227
 228     case TCNTB0: case TCNTB1:
 229     case TCNTB2: case TCNTB3: case TCNTB4:
 230         index = (offset - TCNTB0) / 0xC;
 231         value = s->timer[index].reg_tcntb;
 232         break;
 233
 234     case TCMPB0: case TCMPB1:
 235     case TCMPB2: case TCMPB3:
 236         index = (offset - TCMPB0) / 0xC;
 237         value = s->timer[index].reg_tcmpb;
 238         break;
 239
 240     case TCNTO0: case TCNTO1:
 241     case TCNTO2: case TCNTO3: case TCNTO4:
 242         index = (offset == TCNTO4) ? 4 : (offset - TCNTO0) / 0xC;
 243         value = ptimer_get_count(s->timer[index].ptimer);
 244         break;
 245
 246     case TINT_CSTAT:
 247         value = s->reg_tint_cstat;
 248         break;
 249
 250     default:
 251         fprintf(stderr,
 252                 "[exynos4210.pwm: bad read offset " TARGET_FMT_plx "]\n",
 253                 offset);
 254         break;
 255     }
 256     return value;
 257 }
 258
 259 /*
 260  * PWM Write
 261  */
 262 static void exynos4210_pwm_write(void *opaque, hwaddr offset,
 263         uint64_t value, unsigned size)
 264 {
 265     Exynos4210PWMState *s = (Exynos4210PWMState *)opaque;
 266     int index;
 267     uint32_t new_val;
 268     int i;
 269
 270     switch (offset) {
 271     case TCFG0: case TCFG1:
 272         index = (offset - TCFG0) >> 2;
 273         s->reg_tcfg[index] = value;
 274
 275         /* update timers frequencies */
 276         for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
 277             exynos4210_pwm_update_freq(s, s->timer[i].id);
 278         }
 279         break;
 280
 281     case TCON:
 282         for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
 283             if ((value & TCON_TIMER_MANUAL_UPD(i)) >
 284             (s->reg_tcon & TCON_TIMER_MANUAL_UPD(i))) {
 285                 /*
 286                  * TCNTB and TCMPB are loaded into TCNT and TCMP.
 287                  * Update timers.
 288                  */
 289
 290                 /* this will start timer to run, this ok, because
 291                  * during processing start bit timer will be stopped
 292                  * if needed */
 293                 ptimer_set_count(s->timer[i].ptimer, s->timer[i].reg_tcntb);
 294                 DPRINTF("set timer %d count to %x\n", i,
 295                         s->timer[i].reg_tcntb);
 296             }
 297
 298             if ((value & TCON_TIMER_START(i)) >
 299             (s->reg_tcon & TCON_TIMER_START(i))) {
 300                 /* changed to start */
 301                 ptimer_run(s->timer[i].ptimer, 1);
 302                 DPRINTF("run timer %d\n", i);
 303             }
 304
 305             if ((value & TCON_TIMER_START(i)) <
 306                     (s->reg_tcon & TCON_TIMER_START(i))) {
 307                 /* changed to stop */
 308                 ptimer_stop(s->timer[i].ptimer);
 309                 DPRINTF("stop timer %d\n", i);
 310             }
 311         }
 312         s->reg_tcon = value;
 313         break;
 314
 315     case TCNTB0: case TCNTB1:
 316     case TCNTB2: case TCNTB3: case TCNTB4:
 317         index = (offset - TCNTB0) / 0xC;
 318         s->timer[index].reg_tcntb = value;
 319         break;
 320
 321     case TCMPB0: case TCMPB1:
 322     case TCMPB2: case TCMPB3:
 323         index = (offset - TCMPB0) / 0xC;
 324         s->timer[index].reg_tcmpb = value;
 325         break;
 326
 327     case TINT_CSTAT:
 328         new_val = (s->reg_tint_cstat & 0x3E0) + (0x1F & value);
 329         new_val &= ~(0x3E0 & value);
 330
 331         for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
 332             if ((new_val & TINT_CSTAT_STATUS(i)) <
 333                     (s->reg_tint_cstat & TINT_CSTAT_STATUS(i))) {
 334                 qemu_irq_lower(s->timer[i].irq);
 335             }
 336         }
 337
 338         s->reg_tint_cstat = new_val;
 339         break;
 340
 341     default:
 342         fprintf(stderr,
 343                 "[exynos4210.pwm: bad write offset " TARGET_FMT_plx "]\n",
 344                 offset);
 345         break;
 346
 347     }
 348 }
 349
 350 /*
 351  * Set default values to timer fields and registers
 352  */
 353 static void exynos4210_pwm_reset(DeviceState *d)
 354 {
 355     Exynos4210PWMState *s = (Exynos4210PWMState *)d;
 356     int i;
 357     s->reg_tcfg[0] = 0x0101;
 358     s->reg_tcfg[1] = 0x0;
 359     s->reg_tcon = 0;
 360     s->reg_tint_cstat = 0;
 361     for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
 362         s->timer[i].reg_tcmpb = 0;
 363         s->timer[i].reg_tcntb = 0;
 364
 365         exynos4210_pwm_update_freq(s, s->timer[i].id);
 366         ptimer_stop(s->timer[i].ptimer);
 367     }
 368 }
 369
 370 static const MemoryRegionOps exynos4210_pwm_ops = {
 371     .read = exynos4210_pwm_read,
 372     .write = exynos4210_pwm_write,
 373     .endianness = DEVICE_NATIVE_ENDIAN,
 374 };
 375
 376 /*
 377  * PWM timer initialization
 378  */
 379 static int exynos4210_pwm_init(SysBusDevice *dev)
 380 {
 381     Exynos4210PWMState *s = FROM_SYSBUS(Exynos4210PWMState, dev);
 382     int i;
 383     QEMUBH *bh;
 384
 385     for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
 386         bh = qemu_bh_new(exynos4210_pwm_tick, &s->timer[i]);
 387         sysbus_init_irq(dev, &s->timer[i].irq);
 388         s->timer[i].ptimer = ptimer_init(bh);
 389         s->timer[i].id = i;
 390         s->timer[i].parent = s;
 391     }
 392
 393     memory_region_init_io(&s->iomem, &exynos4210_pwm_ops, s, "exynos4210-pwm",
 394             EXYNOS4210_PWM_REG_MEM_SIZE);
 395     sysbus_init_mmio(dev, &s->iomem);
 396
 397     return 0;
 398 }
 399
 400 static void exynos4210_pwm_class_init(ObjectClass *klass, void *data)
 401 {
 402     DeviceClass *dc = DEVICE_CLASS(klass);
 403     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
 404
 405     k->init = exynos4210_pwm_init;
 406     dc->reset = exynos4210_pwm_reset;
 407     dc->vmsd = &vmstate_exynos4210_pwm_state;
 408 }
 409
 410 static const TypeInfo exynos4210_pwm_info = {
 411     .name          = "exynos4210.pwm",
 412     .parent        = TYPE_SYS_BUS_DEVICE,
 413     .instance_size = sizeof(Exynos4210PWMState),
 414     .class_init    = exynos4210_pwm_class_init,
 415 };
 416
 417 static void exynos4210_pwm_register_types(void)
 418 {
 419     type_register_static(&exynos4210_pwm_info);
 420 }
 421
 422 type_init(exynos4210_pwm_register_types)