xref: /openbmc/qemu/hw/timer/exynos4210_pwm.c (revision 28ae3179fc52d2e4d870b635c4a412aab99759e7)
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 "qemu/osdep.h"
24  #include "qemu/log.h"
25  #include "hw/sysbus.h"
26  #include "migration/vmstate.h"
27  #include "qemu/timer.h"
28  #include "qemu/module.h"
29  #include "hw/ptimer.h"
30  
31  #include "hw/arm/exynos4210.h"
32  #include "hw/irq.h"
33  #include "qom/object.h"
34  
35  //#define DEBUG_PWM
36  
37  #ifdef DEBUG_PWM
38  #define DPRINTF(fmt, ...) \
39          do { fprintf(stdout, "PWM: [%24s:%5d] " fmt, __func__, __LINE__, \
40                  ## __VA_ARGS__); } while (0)
41  #else
42  #define DPRINTF(fmt, ...) do {} while (0)
43  #endif
44  
45  #define     EXYNOS4210_PWM_TIMERS_NUM      5
46  #define     EXYNOS4210_PWM_REG_MEM_SIZE    0x50
47  
48  #define     TCFG0        0x0000
49  #define     TCFG1        0x0004
50  #define     TCON         0x0008
51  #define     TCNTB0       0x000C
52  #define     TCMPB0       0x0010
53  #define     TCNTO0       0x0014
54  #define     TCNTB1       0x0018
55  #define     TCMPB1       0x001C
56  #define     TCNTO1       0x0020
57  #define     TCNTB2       0x0024
58  #define     TCMPB2       0x0028
59  #define     TCNTO2       0x002C
60  #define     TCNTB3       0x0030
61  #define     TCMPB3       0x0034
62  #define     TCNTO3       0x0038
63  #define     TCNTB4       0x003C
64  #define     TCNTO4       0x0040
65  #define     TINT_CSTAT   0x0044
66  
67  #define     TCNTB(x)    (0xC * (x))
68  #define     TCMPB(x)    (0xC * (x) + 1)
69  #define     TCNTO(x)    (0xC * (x) + 2)
70  
71  #define GET_PRESCALER(reg, x) (((reg) & (0xFF << (8 * (x)))) >> 8 * (x))
72  #define GET_DIVIDER(reg, x) (1 << (((reg) & (0xF << (4 * (x)))) >> (4 * (x))))
73  
74  /*
75   * Attention! Timer4 doesn't have OUTPUT_INVERTER,
76   * so Auto Reload bit is not accessible by macros!
77   */
78  #define     TCON_TIMER_BASE(x)          (((x) ? 1 : 0) * 4 + 4 * (x))
79  #define     TCON_TIMER_START(x)         (1 << (TCON_TIMER_BASE(x) + 0))
80  #define     TCON_TIMER_MANUAL_UPD(x)    (1 << (TCON_TIMER_BASE(x) + 1))
81  #define     TCON_TIMER_OUTPUT_INV(x)    (1 << (TCON_TIMER_BASE(x) + 2))
82  #define     TCON_TIMER_AUTO_RELOAD(x)   (1 << (TCON_TIMER_BASE(x) + 3))
83  #define     TCON_TIMER4_AUTO_RELOAD     (1 << 22)
84  
85  #define     TINT_CSTAT_STATUS(x)        (1 << (5 + (x)))
86  #define     TINT_CSTAT_ENABLE(x)        (1 << (x))
87  
88  /* timer struct */
89  typedef struct {
90      uint32_t    id;             /* timer id */
91      qemu_irq    irq;            /* local timer irq */
92      uint32_t    freq;           /* timer frequency */
93  
94      /* use ptimer.c to represent count down timer */
95      ptimer_state *ptimer;       /* timer  */
96  
97      /* registers */
98      uint32_t    reg_tcntb;      /* counter register buffer */
99      uint32_t    reg_tcmpb;      /* compare register buffer */
100  
101      struct Exynos4210PWMState *parent;
102  
103  } Exynos4210PWM;
104  
105  #define TYPE_EXYNOS4210_PWM "exynos4210.pwm"
106  OBJECT_DECLARE_SIMPLE_TYPE(Exynos4210PWMState, EXYNOS4210_PWM)
107  
108  struct Exynos4210PWMState {
109      SysBusDevice parent_obj;
110  
111      MemoryRegion iomem;
112  
113      uint32_t    reg_tcfg[2];
114      uint32_t    reg_tcon;
115      uint32_t    reg_tint_cstat;
116  
117      Exynos4210PWM timer[EXYNOS4210_PWM_TIMERS_NUM];
118  
119  };
120  
121  /*** VMState ***/
122  static const VMStateDescription vmstate_exynos4210_pwm = {
123      .name = "exynos4210.pwm.pwm",
124      .version_id = 1,
125      .minimum_version_id = 1,
126      .fields = (const VMStateField[]) {
127          VMSTATE_UINT32(id, Exynos4210PWM),
128          VMSTATE_UINT32(freq, Exynos4210PWM),
129          VMSTATE_PTIMER(ptimer, Exynos4210PWM),
130          VMSTATE_UINT32(reg_tcntb, Exynos4210PWM),
131          VMSTATE_UINT32(reg_tcmpb, Exynos4210PWM),
132          VMSTATE_END_OF_LIST()
133      }
134  };
135  
136  static const VMStateDescription vmstate_exynos4210_pwm_state = {
137      .name = "exynos4210.pwm",
138      .version_id = 1,
139      .minimum_version_id = 1,
140      .fields = (const VMStateField[]) {
141          VMSTATE_UINT32_ARRAY(reg_tcfg, Exynos4210PWMState, 2),
142          VMSTATE_UINT32(reg_tcon, Exynos4210PWMState),
143          VMSTATE_UINT32(reg_tint_cstat, Exynos4210PWMState),
144          VMSTATE_STRUCT_ARRAY(timer, Exynos4210PWMState,
145              EXYNOS4210_PWM_TIMERS_NUM, 0,
146          vmstate_exynos4210_pwm, Exynos4210PWM),
147          VMSTATE_END_OF_LIST()
148      }
149  };
150  
151  /*
152   * PWM update frequency.
153   * Must be called within a ptimer_transaction_begin/commit block
154   * for s->timer[id].ptimer.
155   */
exynos4210_pwm_update_freq(Exynos4210PWMState * s,uint32_t id)156  static void exynos4210_pwm_update_freq(Exynos4210PWMState *s, uint32_t id)
157  {
158      uint32_t freq;
159      freq = s->timer[id].freq;
160      if (id > 1) {
161          s->timer[id].freq = 24000000 /
162          ((GET_PRESCALER(s->reg_tcfg[0], 1) + 1) *
163                  (GET_DIVIDER(s->reg_tcfg[1], id)));
164      } else {
165          s->timer[id].freq = 24000000 /
166          ((GET_PRESCALER(s->reg_tcfg[0], 0) + 1) *
167                  (GET_DIVIDER(s->reg_tcfg[1], id)));
168      }
169  
170      if (freq != s->timer[id].freq) {
171          ptimer_set_freq(s->timer[id].ptimer, s->timer[id].freq);
172          DPRINTF("freq=%uHz\n", s->timer[id].freq);
173      }
174  }
175  
176  /*
177   * Counter tick handler
178   */
exynos4210_pwm_tick(void * opaque)179  static void exynos4210_pwm_tick(void *opaque)
180  {
181      Exynos4210PWM *s = (Exynos4210PWM *)opaque;
182      Exynos4210PWMState *p = (Exynos4210PWMState *)s->parent;
183      uint32_t id = s->id;
184      bool cmp;
185  
186      DPRINTF("timer %u tick\n", id);
187  
188      /* set irq status */
189      p->reg_tint_cstat |= TINT_CSTAT_STATUS(id);
190  
191      /* raise IRQ */
192      if (p->reg_tint_cstat & TINT_CSTAT_ENABLE(id)) {
193          DPRINTF("timer %u IRQ\n", id);
194          qemu_irq_raise(p->timer[id].irq);
195      }
196  
197      /* reload timer */
198      if (id != 4) {
199          cmp = p->reg_tcon & TCON_TIMER_AUTO_RELOAD(id);
200      } else {
201          cmp = p->reg_tcon & TCON_TIMER4_AUTO_RELOAD;
202      }
203  
204      if (cmp) {
205          DPRINTF("auto reload timer %u count to %x\n", id,
206                  p->timer[id].reg_tcntb);
207          ptimer_set_count(p->timer[id].ptimer, p->timer[id].reg_tcntb);
208          ptimer_run(p->timer[id].ptimer, 1);
209      } else {
210          /* stop timer, set status to STOP, see Basic Timer Operation */
211          p->reg_tcon &= ~TCON_TIMER_START(id);
212          ptimer_stop(p->timer[id].ptimer);
213      }
214  }
215  
216  /*
217   * PWM Read
218   */
exynos4210_pwm_read(void * opaque,hwaddr offset,unsigned size)219  static uint64_t exynos4210_pwm_read(void *opaque, hwaddr offset,
220          unsigned size)
221  {
222      Exynos4210PWMState *s = (Exynos4210PWMState *)opaque;
223      uint32_t value = 0;
224      int index;
225  
226      switch (offset) {
227      case TCFG0: case TCFG1:
228          index = (offset - TCFG0) >> 2;
229          value = s->reg_tcfg[index];
230          break;
231  
232      case TCON:
233          value = s->reg_tcon;
234          break;
235  
236      case TCNTB0: case TCNTB1:
237      case TCNTB2: case TCNTB3: case TCNTB4:
238          index = (offset - TCNTB0) / 0xC;
239          value = s->timer[index].reg_tcntb;
240          break;
241  
242      case TCMPB0: case TCMPB1:
243      case TCMPB2: case TCMPB3:
244          index = (offset - TCMPB0) / 0xC;
245          value = s->timer[index].reg_tcmpb;
246          break;
247  
248      case TCNTO0: case TCNTO1:
249      case TCNTO2: case TCNTO3: case TCNTO4:
250          index = (offset == TCNTO4) ? 4 : (offset - TCNTO0) / 0xC;
251          value = ptimer_get_count(s->timer[index].ptimer);
252          break;
253  
254      case TINT_CSTAT:
255          value = s->reg_tint_cstat;
256          break;
257  
258      default:
259          qemu_log_mask(LOG_GUEST_ERROR,
260                        "exynos4210.pwm: bad read offset " HWADDR_FMT_plx,
261                        offset);
262          break;
263      }
264      return value;
265  }
266  
267  /*
268   * PWM Write
269   */
exynos4210_pwm_write(void * opaque,hwaddr offset,uint64_t value,unsigned size)270  static void exynos4210_pwm_write(void *opaque, hwaddr offset,
271          uint64_t value, unsigned size)
272  {
273      Exynos4210PWMState *s = (Exynos4210PWMState *)opaque;
274      int index;
275      uint32_t new_val;
276      int i;
277  
278      switch (offset) {
279      case TCFG0: case TCFG1:
280          index = (offset - TCFG0) >> 2;
281          s->reg_tcfg[index] = value;
282  
283          /* update timers frequencies */
284          for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
285              ptimer_transaction_begin(s->timer[i].ptimer);
286              exynos4210_pwm_update_freq(s, s->timer[i].id);
287              ptimer_transaction_commit(s->timer[i].ptimer);
288          }
289          break;
290  
291      case TCON:
292          for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
293              ptimer_transaction_begin(s->timer[i].ptimer);
294              if ((value & TCON_TIMER_MANUAL_UPD(i)) >
295              (s->reg_tcon & TCON_TIMER_MANUAL_UPD(i))) {
296                  /*
297                   * TCNTB and TCMPB are loaded into TCNT and TCMP.
298                   * Update timers.
299                   */
300  
301                  /* this will start timer to run, this ok, because
302                   * during processing start bit timer will be stopped
303                   * if needed */
304                  ptimer_set_count(s->timer[i].ptimer, s->timer[i].reg_tcntb);
305                  DPRINTF("set timer %d count to %x\n", i,
306                          s->timer[i].reg_tcntb);
307              }
308  
309              if ((value & TCON_TIMER_START(i)) >
310              (s->reg_tcon & TCON_TIMER_START(i))) {
311                  /* changed to start */
312                  ptimer_run(s->timer[i].ptimer, 1);
313                  DPRINTF("run timer %d\n", i);
314              }
315  
316              if ((value & TCON_TIMER_START(i)) <
317                      (s->reg_tcon & TCON_TIMER_START(i))) {
318                  /* changed to stop */
319                  ptimer_stop(s->timer[i].ptimer);
320                  DPRINTF("stop timer %d\n", i);
321              }
322              ptimer_transaction_commit(s->timer[i].ptimer);
323          }
324          s->reg_tcon = value;
325          break;
326  
327      case TCNTB0: case TCNTB1:
328      case TCNTB2: case TCNTB3: case TCNTB4:
329          index = (offset - TCNTB0) / 0xC;
330          s->timer[index].reg_tcntb = value;
331          break;
332  
333      case TCMPB0: case TCMPB1:
334      case TCMPB2: case TCMPB3:
335          index = (offset - TCMPB0) / 0xC;
336          s->timer[index].reg_tcmpb = value;
337          break;
338  
339      case TINT_CSTAT:
340          new_val = (s->reg_tint_cstat & 0x3E0) + (0x1F & value);
341          new_val &= ~(0x3E0 & value);
342  
343          for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
344              if ((new_val & TINT_CSTAT_STATUS(i)) <
345                      (s->reg_tint_cstat & TINT_CSTAT_STATUS(i))) {
346                  qemu_irq_lower(s->timer[i].irq);
347              }
348          }
349  
350          s->reg_tint_cstat = new_val;
351          break;
352  
353      default:
354          qemu_log_mask(LOG_GUEST_ERROR,
355                        "exynos4210.pwm: bad write offset " HWADDR_FMT_plx,
356                        offset);
357          break;
358  
359      }
360  }
361  
362  /*
363   * Set default values to timer fields and registers
364   */
exynos4210_pwm_reset(DeviceState * d)365  static void exynos4210_pwm_reset(DeviceState *d)
366  {
367      Exynos4210PWMState *s = EXYNOS4210_PWM(d);
368      int i;
369      s->reg_tcfg[0] = 0x0101;
370      s->reg_tcfg[1] = 0x0;
371      s->reg_tcon = 0;
372      s->reg_tint_cstat = 0;
373      for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
374          s->timer[i].reg_tcmpb = 0;
375          s->timer[i].reg_tcntb = 0;
376  
377          ptimer_transaction_begin(s->timer[i].ptimer);
378          exynos4210_pwm_update_freq(s, s->timer[i].id);
379          ptimer_stop(s->timer[i].ptimer);
380          ptimer_transaction_commit(s->timer[i].ptimer);
381      }
382  }
383  
384  static const MemoryRegionOps exynos4210_pwm_ops = {
385      .read = exynos4210_pwm_read,
386      .write = exynos4210_pwm_write,
387      .endianness = DEVICE_NATIVE_ENDIAN,
388  };
389  
390  /*
391   * PWM timer initialization
392   */
exynos4210_pwm_init(Object * obj)393  static void exynos4210_pwm_init(Object *obj)
394  {
395      Exynos4210PWMState *s = EXYNOS4210_PWM(obj);
396      SysBusDevice *dev = SYS_BUS_DEVICE(obj);
397      int i;
398  
399      for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
400          sysbus_init_irq(dev, &s->timer[i].irq);
401          s->timer[i].ptimer = ptimer_init(exynos4210_pwm_tick,
402                                           &s->timer[i],
403                                           PTIMER_POLICY_LEGACY);
404          s->timer[i].id = i;
405          s->timer[i].parent = s;
406      }
407  
408      memory_region_init_io(&s->iomem, obj, &exynos4210_pwm_ops, s,
409                            "exynos4210-pwm", EXYNOS4210_PWM_REG_MEM_SIZE);
410      sysbus_init_mmio(dev, &s->iomem);
411  }
412  
exynos4210_pwm_finalize(Object * obj)413  static void exynos4210_pwm_finalize(Object *obj)
414  {
415      Exynos4210PWMState *s = EXYNOS4210_PWM(obj);
416      int i;
417  
418      for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
419          ptimer_free(s->timer[i].ptimer);
420      }
421  }
422  
exynos4210_pwm_class_init(ObjectClass * klass,void * data)423  static void exynos4210_pwm_class_init(ObjectClass *klass, void *data)
424  {
425      DeviceClass *dc = DEVICE_CLASS(klass);
426  
427      device_class_set_legacy_reset(dc, exynos4210_pwm_reset);
428      dc->vmsd = &vmstate_exynos4210_pwm_state;
429  }
430  
431  static const TypeInfo exynos4210_pwm_info = {
432      .name          = TYPE_EXYNOS4210_PWM,
433      .parent        = TYPE_SYS_BUS_DEVICE,
434      .instance_size = sizeof(Exynos4210PWMState),
435      .instance_init = exynos4210_pwm_init,
436      .instance_finalize = exynos4210_pwm_finalize,
437      .class_init    = exynos4210_pwm_class_init,
438  };
439  
exynos4210_pwm_register_types(void)440  static void exynos4210_pwm_register_types(void)
441  {
442      type_register_static(&exynos4210_pwm_info);
443  }
444  
445  type_init(exynos4210_pwm_register_types)
446