xref: /openbmc/qemu/hw/timer/exynos4210_pwm.c (revision ba632924)
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 "qemu/timer.h"
27 #include "qemu-common.h"
28 #include "qemu/main-loop.h"
29 #include "hw/ptimer.h"
30 
31 #include "hw/arm/exynos4210.h"
32 
33 //#define DEBUG_PWM
34 
35 #ifdef DEBUG_PWM
36 #define DPRINTF(fmt, ...) \
37         do { fprintf(stdout, "PWM: [%24s:%5d] " fmt, __func__, __LINE__, \
38                 ## __VA_ARGS__); } while (0)
39 #else
40 #define DPRINTF(fmt, ...) do {} while (0)
41 #endif
42 
43 #define     EXYNOS4210_PWM_TIMERS_NUM      5
44 #define     EXYNOS4210_PWM_REG_MEM_SIZE    0x50
45 
46 #define     TCFG0        0x0000
47 #define     TCFG1        0x0004
48 #define     TCON         0x0008
49 #define     TCNTB0       0x000C
50 #define     TCMPB0       0x0010
51 #define     TCNTO0       0x0014
52 #define     TCNTB1       0x0018
53 #define     TCMPB1       0x001C
54 #define     TCNTO1       0x0020
55 #define     TCNTB2       0x0024
56 #define     TCMPB2       0x0028
57 #define     TCNTO2       0x002C
58 #define     TCNTB3       0x0030
59 #define     TCMPB3       0x0034
60 #define     TCNTO3       0x0038
61 #define     TCNTB4       0x003C
62 #define     TCNTO4       0x0040
63 #define     TINT_CSTAT   0x0044
64 
65 #define     TCNTB(x)    (0xC * (x))
66 #define     TCMPB(x)    (0xC * (x) + 1)
67 #define     TCNTO(x)    (0xC * (x) + 2)
68 
69 #define GET_PRESCALER(reg, x) (((reg) & (0xFF << (8 * (x)))) >> 8 * (x))
70 #define GET_DIVIDER(reg, x) (1 << (((reg) & (0xF << (4 * (x)))) >> (4 * (x))))
71 
72 /*
73  * Attention! Timer4 doesn't have OUTPUT_INVERTER,
74  * so Auto Reload bit is not accessible by macros!
75  */
76 #define     TCON_TIMER_BASE(x)          (((x) ? 1 : 0) * 4 + 4 * (x))
77 #define     TCON_TIMER_START(x)         (1 << (TCON_TIMER_BASE(x) + 0))
78 #define     TCON_TIMER_MANUAL_UPD(x)    (1 << (TCON_TIMER_BASE(x) + 1))
79 #define     TCON_TIMER_OUTPUT_INV(x)    (1 << (TCON_TIMER_BASE(x) + 2))
80 #define     TCON_TIMER_AUTO_RELOAD(x)   (1 << (TCON_TIMER_BASE(x) + 3))
81 #define     TCON_TIMER4_AUTO_RELOAD     (1 << 22)
82 
83 #define     TINT_CSTAT_STATUS(x)        (1 << (5 + (x)))
84 #define     TINT_CSTAT_ENABLE(x)        (1 << (x))
85 
86 /* timer struct */
87 typedef struct {
88     uint32_t    id;             /* timer id */
89     qemu_irq    irq;            /* local timer irq */
90     uint32_t    freq;           /* timer frequency */
91 
92     /* use ptimer.c to represent count down timer */
93     ptimer_state *ptimer;       /* timer  */
94 
95     /* registers */
96     uint32_t    reg_tcntb;      /* counter register buffer */
97     uint32_t    reg_tcmpb;      /* compare register buffer */
98 
99     struct Exynos4210PWMState *parent;
100 
101 } Exynos4210PWM;
102 
103 #define TYPE_EXYNOS4210_PWM "exynos4210.pwm"
104 #define EXYNOS4210_PWM(obj) \
105     OBJECT_CHECK(Exynos4210PWMState, (obj), TYPE_EXYNOS4210_PWM)
106 
107 typedef struct Exynos4210PWMState {
108     SysBusDevice parent_obj;
109 
110     MemoryRegion iomem;
111 
112     uint32_t    reg_tcfg[2];
113     uint32_t    reg_tcon;
114     uint32_t    reg_tint_cstat;
115 
116     Exynos4210PWM timer[EXYNOS4210_PWM_TIMERS_NUM];
117 
118 } Exynos4210PWMState;
119 
120 /*** VMState ***/
121 static const VMStateDescription vmstate_exynos4210_pwm = {
122     .name = "exynos4210.pwm.pwm",
123     .version_id = 1,
124     .minimum_version_id = 1,
125     .fields = (VMStateField[]) {
126         VMSTATE_UINT32(id, Exynos4210PWM),
127         VMSTATE_UINT32(freq, Exynos4210PWM),
128         VMSTATE_PTIMER(ptimer, Exynos4210PWM),
129         VMSTATE_UINT32(reg_tcntb, Exynos4210PWM),
130         VMSTATE_UINT32(reg_tcmpb, Exynos4210PWM),
131         VMSTATE_END_OF_LIST()
132     }
133 };
134 
135 static const VMStateDescription vmstate_exynos4210_pwm_state = {
136     .name = "exynos4210.pwm",
137     .version_id = 1,
138     .minimum_version_id = 1,
139     .fields = (VMStateField[]) {
140         VMSTATE_UINT32_ARRAY(reg_tcfg, Exynos4210PWMState, 2),
141         VMSTATE_UINT32(reg_tcon, Exynos4210PWMState),
142         VMSTATE_UINT32(reg_tint_cstat, Exynos4210PWMState),
143         VMSTATE_STRUCT_ARRAY(timer, Exynos4210PWMState,
144             EXYNOS4210_PWM_TIMERS_NUM, 0,
145         vmstate_exynos4210_pwm, Exynos4210PWM),
146         VMSTATE_END_OF_LIST()
147     }
148 };
149 
150 /*
151  * PWM update frequency
152  */
153 static void exynos4210_pwm_update_freq(Exynos4210PWMState *s, uint32_t id)
154 {
155     uint32_t freq;
156     freq = s->timer[id].freq;
157     if (id > 1) {
158         s->timer[id].freq = 24000000 /
159         ((GET_PRESCALER(s->reg_tcfg[0], 1) + 1) *
160                 (GET_DIVIDER(s->reg_tcfg[1], id)));
161     } else {
162         s->timer[id].freq = 24000000 /
163         ((GET_PRESCALER(s->reg_tcfg[0], 0) + 1) *
164                 (GET_DIVIDER(s->reg_tcfg[1], id)));
165     }
166 
167     if (freq != s->timer[id].freq) {
168         ptimer_set_freq(s->timer[id].ptimer, s->timer[id].freq);
169         DPRINTF("freq=%dHz\n", s->timer[id].freq);
170     }
171 }
172 
173 /*
174  * Counter tick handler
175  */
176 static void exynos4210_pwm_tick(void *opaque)
177 {
178     Exynos4210PWM *s = (Exynos4210PWM *)opaque;
179     Exynos4210PWMState *p = (Exynos4210PWMState *)s->parent;
180     uint32_t id = s->id;
181     bool cmp;
182 
183     DPRINTF("timer %d tick\n", id);
184 
185     /* set irq status */
186     p->reg_tint_cstat |= TINT_CSTAT_STATUS(id);
187 
188     /* raise IRQ */
189     if (p->reg_tint_cstat & TINT_CSTAT_ENABLE(id)) {
190         DPRINTF("timer %d IRQ\n", id);
191         qemu_irq_raise(p->timer[id].irq);
192     }
193 
194     /* reload timer */
195     if (id != 4) {
196         cmp = p->reg_tcon & TCON_TIMER_AUTO_RELOAD(id);
197     } else {
198         cmp = p->reg_tcon & TCON_TIMER4_AUTO_RELOAD;
199     }
200 
201     if (cmp) {
202         DPRINTF("auto reload timer %d count to %x\n", id,
203                 p->timer[id].reg_tcntb);
204         ptimer_set_count(p->timer[id].ptimer, p->timer[id].reg_tcntb);
205         ptimer_run(p->timer[id].ptimer, 1);
206     } else {
207         /* stop timer, set status to STOP, see Basic Timer Operation */
208         p->reg_tcon &= ~TCON_TIMER_START(id);
209         ptimer_stop(p->timer[id].ptimer);
210     }
211 }
212 
213 /*
214  * PWM Read
215  */
216 static uint64_t exynos4210_pwm_read(void *opaque, hwaddr offset,
217         unsigned size)
218 {
219     Exynos4210PWMState *s = (Exynos4210PWMState *)opaque;
220     uint32_t value = 0;
221     int index;
222 
223     switch (offset) {
224     case TCFG0: case TCFG1:
225         index = (offset - TCFG0) >> 2;
226         value = s->reg_tcfg[index];
227         break;
228 
229     case TCON:
230         value = s->reg_tcon;
231         break;
232 
233     case TCNTB0: case TCNTB1:
234     case TCNTB2: case TCNTB3: case TCNTB4:
235         index = (offset - TCNTB0) / 0xC;
236         value = s->timer[index].reg_tcntb;
237         break;
238 
239     case TCMPB0: case TCMPB1:
240     case TCMPB2: case TCMPB3:
241         index = (offset - TCMPB0) / 0xC;
242         value = s->timer[index].reg_tcmpb;
243         break;
244 
245     case TCNTO0: case TCNTO1:
246     case TCNTO2: case TCNTO3: case TCNTO4:
247         index = (offset == TCNTO4) ? 4 : (offset - TCNTO0) / 0xC;
248         value = ptimer_get_count(s->timer[index].ptimer);
249         break;
250 
251     case TINT_CSTAT:
252         value = s->reg_tint_cstat;
253         break;
254 
255     default:
256         qemu_log_mask(LOG_GUEST_ERROR,
257                       "exynos4210.pwm: bad read offset " TARGET_FMT_plx,
258                       offset);
259         break;
260     }
261     return value;
262 }
263 
264 /*
265  * PWM Write
266  */
267 static void exynos4210_pwm_write(void *opaque, hwaddr offset,
268         uint64_t value, unsigned size)
269 {
270     Exynos4210PWMState *s = (Exynos4210PWMState *)opaque;
271     int index;
272     uint32_t new_val;
273     int i;
274 
275     switch (offset) {
276     case TCFG0: case TCFG1:
277         index = (offset - TCFG0) >> 2;
278         s->reg_tcfg[index] = value;
279 
280         /* update timers frequencies */
281         for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
282             exynos4210_pwm_update_freq(s, s->timer[i].id);
283         }
284         break;
285 
286     case TCON:
287         for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
288             if ((value & TCON_TIMER_MANUAL_UPD(i)) >
289             (s->reg_tcon & TCON_TIMER_MANUAL_UPD(i))) {
290                 /*
291                  * TCNTB and TCMPB are loaded into TCNT and TCMP.
292                  * Update timers.
293                  */
294 
295                 /* this will start timer to run, this ok, because
296                  * during processing start bit timer will be stopped
297                  * if needed */
298                 ptimer_set_count(s->timer[i].ptimer, s->timer[i].reg_tcntb);
299                 DPRINTF("set timer %d count to %x\n", i,
300                         s->timer[i].reg_tcntb);
301             }
302 
303             if ((value & TCON_TIMER_START(i)) >
304             (s->reg_tcon & TCON_TIMER_START(i))) {
305                 /* changed to start */
306                 ptimer_run(s->timer[i].ptimer, 1);
307                 DPRINTF("run timer %d\n", i);
308             }
309 
310             if ((value & TCON_TIMER_START(i)) <
311                     (s->reg_tcon & TCON_TIMER_START(i))) {
312                 /* changed to stop */
313                 ptimer_stop(s->timer[i].ptimer);
314                 DPRINTF("stop timer %d\n", i);
315             }
316         }
317         s->reg_tcon = value;
318         break;
319 
320     case TCNTB0: case TCNTB1:
321     case TCNTB2: case TCNTB3: case TCNTB4:
322         index = (offset - TCNTB0) / 0xC;
323         s->timer[index].reg_tcntb = value;
324         break;
325 
326     case TCMPB0: case TCMPB1:
327     case TCMPB2: case TCMPB3:
328         index = (offset - TCMPB0) / 0xC;
329         s->timer[index].reg_tcmpb = value;
330         break;
331 
332     case TINT_CSTAT:
333         new_val = (s->reg_tint_cstat & 0x3E0) + (0x1F & value);
334         new_val &= ~(0x3E0 & value);
335 
336         for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
337             if ((new_val & TINT_CSTAT_STATUS(i)) <
338                     (s->reg_tint_cstat & TINT_CSTAT_STATUS(i))) {
339                 qemu_irq_lower(s->timer[i].irq);
340             }
341         }
342 
343         s->reg_tint_cstat = new_val;
344         break;
345 
346     default:
347         qemu_log_mask(LOG_GUEST_ERROR,
348                       "exynos4210.pwm: bad write offset " TARGET_FMT_plx,
349                       offset);
350         break;
351 
352     }
353 }
354 
355 /*
356  * Set default values to timer fields and registers
357  */
358 static void exynos4210_pwm_reset(DeviceState *d)
359 {
360     Exynos4210PWMState *s = EXYNOS4210_PWM(d);
361     int i;
362     s->reg_tcfg[0] = 0x0101;
363     s->reg_tcfg[1] = 0x0;
364     s->reg_tcon = 0;
365     s->reg_tint_cstat = 0;
366     for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
367         s->timer[i].reg_tcmpb = 0;
368         s->timer[i].reg_tcntb = 0;
369 
370         exynos4210_pwm_update_freq(s, s->timer[i].id);
371         ptimer_stop(s->timer[i].ptimer);
372     }
373 }
374 
375 static const MemoryRegionOps exynos4210_pwm_ops = {
376     .read = exynos4210_pwm_read,
377     .write = exynos4210_pwm_write,
378     .endianness = DEVICE_NATIVE_ENDIAN,
379 };
380 
381 /*
382  * PWM timer initialization
383  */
384 static void exynos4210_pwm_init(Object *obj)
385 {
386     Exynos4210PWMState *s = EXYNOS4210_PWM(obj);
387     SysBusDevice *dev = SYS_BUS_DEVICE(obj);
388     int i;
389     QEMUBH *bh;
390 
391     for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
392         bh = qemu_bh_new(exynos4210_pwm_tick, &s->timer[i]);
393         sysbus_init_irq(dev, &s->timer[i].irq);
394         s->timer[i].ptimer = ptimer_init(bh, PTIMER_POLICY_DEFAULT);
395         s->timer[i].id = i;
396         s->timer[i].parent = s;
397     }
398 
399     memory_region_init_io(&s->iomem, obj, &exynos4210_pwm_ops, s,
400                           "exynos4210-pwm", EXYNOS4210_PWM_REG_MEM_SIZE);
401     sysbus_init_mmio(dev, &s->iomem);
402 }
403 
404 static void exynos4210_pwm_class_init(ObjectClass *klass, void *data)
405 {
406     DeviceClass *dc = DEVICE_CLASS(klass);
407 
408     dc->reset = exynos4210_pwm_reset;
409     dc->vmsd = &vmstate_exynos4210_pwm_state;
410 }
411 
412 static const TypeInfo exynos4210_pwm_info = {
413     .name          = TYPE_EXYNOS4210_PWM,
414     .parent        = TYPE_SYS_BUS_DEVICE,
415     .instance_size = sizeof(Exynos4210PWMState),
416     .instance_init = exynos4210_pwm_init,
417     .class_init    = exynos4210_pwm_class_init,
418 };
419 
420 static void exynos4210_pwm_register_types(void)
421 {
422     type_register_static(&exynos4210_pwm_info);
423 }
424 
425 type_init(exynos4210_pwm_register_types)
426