xref: /openbmc/qemu/hw/timer/exynos4210_pwm.c (revision a68694cd)
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 typedef struct Exynos4210PWMState Exynos4210PWMState;
107 DECLARE_INSTANCE_CHECKER(Exynos4210PWMState, EXYNOS4210_PWM,
108                          TYPE_EXYNOS4210_PWM)
109 
110 struct Exynos4210PWMState {
111     SysBusDevice parent_obj;
112 
113     MemoryRegion iomem;
114 
115     uint32_t    reg_tcfg[2];
116     uint32_t    reg_tcon;
117     uint32_t    reg_tint_cstat;
118 
119     Exynos4210PWM timer[EXYNOS4210_PWM_TIMERS_NUM];
120 
121 };
122 
123 /*** VMState ***/
124 static const VMStateDescription vmstate_exynos4210_pwm = {
125     .name = "exynos4210.pwm.pwm",
126     .version_id = 1,
127     .minimum_version_id = 1,
128     .fields = (VMStateField[]) {
129         VMSTATE_UINT32(id, Exynos4210PWM),
130         VMSTATE_UINT32(freq, Exynos4210PWM),
131         VMSTATE_PTIMER(ptimer, Exynos4210PWM),
132         VMSTATE_UINT32(reg_tcntb, Exynos4210PWM),
133         VMSTATE_UINT32(reg_tcmpb, Exynos4210PWM),
134         VMSTATE_END_OF_LIST()
135     }
136 };
137 
138 static const VMStateDescription vmstate_exynos4210_pwm_state = {
139     .name = "exynos4210.pwm",
140     .version_id = 1,
141     .minimum_version_id = 1,
142     .fields = (VMStateField[]) {
143         VMSTATE_UINT32_ARRAY(reg_tcfg, Exynos4210PWMState, 2),
144         VMSTATE_UINT32(reg_tcon, Exynos4210PWMState),
145         VMSTATE_UINT32(reg_tint_cstat, Exynos4210PWMState),
146         VMSTATE_STRUCT_ARRAY(timer, Exynos4210PWMState,
147             EXYNOS4210_PWM_TIMERS_NUM, 0,
148         vmstate_exynos4210_pwm, Exynos4210PWM),
149         VMSTATE_END_OF_LIST()
150     }
151 };
152 
153 /*
154  * PWM update frequency.
155  * Must be called within a ptimer_transaction_begin/commit block
156  * for s->timer[id].ptimer.
157  */
158 static void exynos4210_pwm_update_freq(Exynos4210PWMState *s, uint32_t id)
159 {
160     uint32_t freq;
161     freq = s->timer[id].freq;
162     if (id > 1) {
163         s->timer[id].freq = 24000000 /
164         ((GET_PRESCALER(s->reg_tcfg[0], 1) + 1) *
165                 (GET_DIVIDER(s->reg_tcfg[1], id)));
166     } else {
167         s->timer[id].freq = 24000000 /
168         ((GET_PRESCALER(s->reg_tcfg[0], 0) + 1) *
169                 (GET_DIVIDER(s->reg_tcfg[1], id)));
170     }
171 
172     if (freq != s->timer[id].freq) {
173         ptimer_set_freq(s->timer[id].ptimer, s->timer[id].freq);
174         DPRINTF("freq=%dHz\n", s->timer[id].freq);
175     }
176 }
177 
178 /*
179  * Counter tick handler
180  */
181 static void exynos4210_pwm_tick(void *opaque)
182 {
183     Exynos4210PWM *s = (Exynos4210PWM *)opaque;
184     Exynos4210PWMState *p = (Exynos4210PWMState *)s->parent;
185     uint32_t id = s->id;
186     bool cmp;
187 
188     DPRINTF("timer %d tick\n", id);
189 
190     /* set irq status */
191     p->reg_tint_cstat |= TINT_CSTAT_STATUS(id);
192 
193     /* raise IRQ */
194     if (p->reg_tint_cstat & TINT_CSTAT_ENABLE(id)) {
195         DPRINTF("timer %d IRQ\n", id);
196         qemu_irq_raise(p->timer[id].irq);
197     }
198 
199     /* reload timer */
200     if (id != 4) {
201         cmp = p->reg_tcon & TCON_TIMER_AUTO_RELOAD(id);
202     } else {
203         cmp = p->reg_tcon & TCON_TIMER4_AUTO_RELOAD;
204     }
205 
206     if (cmp) {
207         DPRINTF("auto reload timer %d count to %x\n", id,
208                 p->timer[id].reg_tcntb);
209         ptimer_set_count(p->timer[id].ptimer, p->timer[id].reg_tcntb);
210         ptimer_run(p->timer[id].ptimer, 1);
211     } else {
212         /* stop timer, set status to STOP, see Basic Timer Operation */
213         p->reg_tcon &= ~TCON_TIMER_START(id);
214         ptimer_stop(p->timer[id].ptimer);
215     }
216 }
217 
218 /*
219  * PWM Read
220  */
221 static uint64_t exynos4210_pwm_read(void *opaque, hwaddr offset,
222         unsigned size)
223 {
224     Exynos4210PWMState *s = (Exynos4210PWMState *)opaque;
225     uint32_t value = 0;
226     int index;
227 
228     switch (offset) {
229     case TCFG0: case TCFG1:
230         index = (offset - TCFG0) >> 2;
231         value = s->reg_tcfg[index];
232         break;
233 
234     case TCON:
235         value = s->reg_tcon;
236         break;
237 
238     case TCNTB0: case TCNTB1:
239     case TCNTB2: case TCNTB3: case TCNTB4:
240         index = (offset - TCNTB0) / 0xC;
241         value = s->timer[index].reg_tcntb;
242         break;
243 
244     case TCMPB0: case TCMPB1:
245     case TCMPB2: case TCMPB3:
246         index = (offset - TCMPB0) / 0xC;
247         value = s->timer[index].reg_tcmpb;
248         break;
249 
250     case TCNTO0: case TCNTO1:
251     case TCNTO2: case TCNTO3: case TCNTO4:
252         index = (offset == TCNTO4) ? 4 : (offset - TCNTO0) / 0xC;
253         value = ptimer_get_count(s->timer[index].ptimer);
254         break;
255 
256     case TINT_CSTAT:
257         value = s->reg_tint_cstat;
258         break;
259 
260     default:
261         qemu_log_mask(LOG_GUEST_ERROR,
262                       "exynos4210.pwm: bad read offset " TARGET_FMT_plx,
263                       offset);
264         break;
265     }
266     return value;
267 }
268 
269 /*
270  * PWM Write
271  */
272 static void exynos4210_pwm_write(void *opaque, hwaddr offset,
273         uint64_t value, unsigned size)
274 {
275     Exynos4210PWMState *s = (Exynos4210PWMState *)opaque;
276     int index;
277     uint32_t new_val;
278     int i;
279 
280     switch (offset) {
281     case TCFG0: case TCFG1:
282         index = (offset - TCFG0) >> 2;
283         s->reg_tcfg[index] = value;
284 
285         /* update timers frequencies */
286         for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
287             ptimer_transaction_begin(s->timer[i].ptimer);
288             exynos4210_pwm_update_freq(s, s->timer[i].id);
289             ptimer_transaction_commit(s->timer[i].ptimer);
290         }
291         break;
292 
293     case TCON:
294         for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
295             ptimer_transaction_begin(s->timer[i].ptimer);
296             if ((value & TCON_TIMER_MANUAL_UPD(i)) >
297             (s->reg_tcon & TCON_TIMER_MANUAL_UPD(i))) {
298                 /*
299                  * TCNTB and TCMPB are loaded into TCNT and TCMP.
300                  * Update timers.
301                  */
302 
303                 /* this will start timer to run, this ok, because
304                  * during processing start bit timer will be stopped
305                  * if needed */
306                 ptimer_set_count(s->timer[i].ptimer, s->timer[i].reg_tcntb);
307                 DPRINTF("set timer %d count to %x\n", i,
308                         s->timer[i].reg_tcntb);
309             }
310 
311             if ((value & TCON_TIMER_START(i)) >
312             (s->reg_tcon & TCON_TIMER_START(i))) {
313                 /* changed to start */
314                 ptimer_run(s->timer[i].ptimer, 1);
315                 DPRINTF("run timer %d\n", i);
316             }
317 
318             if ((value & TCON_TIMER_START(i)) <
319                     (s->reg_tcon & TCON_TIMER_START(i))) {
320                 /* changed to stop */
321                 ptimer_stop(s->timer[i].ptimer);
322                 DPRINTF("stop timer %d\n", i);
323             }
324             ptimer_transaction_commit(s->timer[i].ptimer);
325         }
326         s->reg_tcon = value;
327         break;
328 
329     case TCNTB0: case TCNTB1:
330     case TCNTB2: case TCNTB3: case TCNTB4:
331         index = (offset - TCNTB0) / 0xC;
332         s->timer[index].reg_tcntb = value;
333         break;
334 
335     case TCMPB0: case TCMPB1:
336     case TCMPB2: case TCMPB3:
337         index = (offset - TCMPB0) / 0xC;
338         s->timer[index].reg_tcmpb = value;
339         break;
340 
341     case TINT_CSTAT:
342         new_val = (s->reg_tint_cstat & 0x3E0) + (0x1F & value);
343         new_val &= ~(0x3E0 & value);
344 
345         for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
346             if ((new_val & TINT_CSTAT_STATUS(i)) <
347                     (s->reg_tint_cstat & TINT_CSTAT_STATUS(i))) {
348                 qemu_irq_lower(s->timer[i].irq);
349             }
350         }
351 
352         s->reg_tint_cstat = new_val;
353         break;
354 
355     default:
356         qemu_log_mask(LOG_GUEST_ERROR,
357                       "exynos4210.pwm: bad write offset " TARGET_FMT_plx,
358                       offset);
359         break;
360 
361     }
362 }
363 
364 /*
365  * Set default values to timer fields and registers
366  */
367 static void exynos4210_pwm_reset(DeviceState *d)
368 {
369     Exynos4210PWMState *s = EXYNOS4210_PWM(d);
370     int i;
371     s->reg_tcfg[0] = 0x0101;
372     s->reg_tcfg[1] = 0x0;
373     s->reg_tcon = 0;
374     s->reg_tint_cstat = 0;
375     for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
376         s->timer[i].reg_tcmpb = 0;
377         s->timer[i].reg_tcntb = 0;
378 
379         ptimer_transaction_begin(s->timer[i].ptimer);
380         exynos4210_pwm_update_freq(s, s->timer[i].id);
381         ptimer_stop(s->timer[i].ptimer);
382         ptimer_transaction_commit(s->timer[i].ptimer);
383     }
384 }
385 
386 static const MemoryRegionOps exynos4210_pwm_ops = {
387     .read = exynos4210_pwm_read,
388     .write = exynos4210_pwm_write,
389     .endianness = DEVICE_NATIVE_ENDIAN,
390 };
391 
392 /*
393  * PWM timer initialization
394  */
395 static void exynos4210_pwm_init(Object *obj)
396 {
397     Exynos4210PWMState *s = EXYNOS4210_PWM(obj);
398     SysBusDevice *dev = SYS_BUS_DEVICE(obj);
399     int i;
400 
401     for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
402         sysbus_init_irq(dev, &s->timer[i].irq);
403         s->timer[i].ptimer = ptimer_init(exynos4210_pwm_tick,
404                                          &s->timer[i],
405                                          PTIMER_POLICY_DEFAULT);
406         s->timer[i].id = i;
407         s->timer[i].parent = s;
408     }
409 
410     memory_region_init_io(&s->iomem, obj, &exynos4210_pwm_ops, s,
411                           "exynos4210-pwm", EXYNOS4210_PWM_REG_MEM_SIZE);
412     sysbus_init_mmio(dev, &s->iomem);
413 }
414 
415 static void exynos4210_pwm_class_init(ObjectClass *klass, void *data)
416 {
417     DeviceClass *dc = DEVICE_CLASS(klass);
418 
419     dc->reset = exynos4210_pwm_reset;
420     dc->vmsd = &vmstate_exynos4210_pwm_state;
421 }
422 
423 static const TypeInfo exynos4210_pwm_info = {
424     .name          = TYPE_EXYNOS4210_PWM,
425     .parent        = TYPE_SYS_BUS_DEVICE,
426     .instance_size = sizeof(Exynos4210PWMState),
427     .instance_init = exynos4210_pwm_init,
428     .class_init    = exynos4210_pwm_class_init,
429 };
430 
431 static void exynos4210_pwm_register_types(void)
432 {
433     type_register_static(&exynos4210_pwm_info);
434 }
435 
436 type_init(exynos4210_pwm_register_types)
437