xref: /openbmc/qemu/hw/timer/exynos4210_pwm.c (revision acb0ef58)
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 "hw/sysbus.h"
24 #include "qemu/timer.h"
25 #include "qemu-common.h"
26 #include "qemu/main-loop.h"
27 #include "hw/ptimer.h"
28 
29 #include "hw/arm/exynos4210.h"
30 
31 //#define DEBUG_PWM
32 
33 #ifdef DEBUG_PWM
34 #define DPRINTF(fmt, ...) \
35         do { fprintf(stdout, "PWM: [%24s:%5d] " fmt, __func__, __LINE__, \
36                 ## __VA_ARGS__); } while (0)
37 #else
38 #define DPRINTF(fmt, ...) do {} while (0)
39 #endif
40 
41 #define     EXYNOS4210_PWM_TIMERS_NUM      5
42 #define     EXYNOS4210_PWM_REG_MEM_SIZE    0x50
43 
44 #define     TCFG0        0x0000
45 #define     TCFG1        0x0004
46 #define     TCON         0x0008
47 #define     TCNTB0       0x000C
48 #define     TCMPB0       0x0010
49 #define     TCNTO0       0x0014
50 #define     TCNTB1       0x0018
51 #define     TCMPB1       0x001C
52 #define     TCNTO1       0x0020
53 #define     TCNTB2       0x0024
54 #define     TCMPB2       0x0028
55 #define     TCNTO2       0x002C
56 #define     TCNTB3       0x0030
57 #define     TCMPB3       0x0034
58 #define     TCNTO3       0x0038
59 #define     TCNTB4       0x003C
60 #define     TCNTO4       0x0040
61 #define     TINT_CSTAT   0x0044
62 
63 #define     TCNTB(x)    (0xC * (x))
64 #define     TCMPB(x)    (0xC * (x) + 1)
65 #define     TCNTO(x)    (0xC * (x) + 2)
66 
67 #define GET_PRESCALER(reg, x) (((reg) & (0xFF << (8 * (x)))) >> 8 * (x))
68 #define GET_DIVIDER(reg, x) (1 << (((reg) & (0xF << (4 * (x)))) >> (4 * (x))))
69 
70 /*
71  * Attention! Timer4 doesn't have OUTPUT_INVERTER,
72  * so Auto Reload bit is not accessible by macros!
73  */
74 #define     TCON_TIMER_BASE(x)          (((x) ? 1 : 0) * 4 + 4 * (x))
75 #define     TCON_TIMER_START(x)         (1 << (TCON_TIMER_BASE(x) + 0))
76 #define     TCON_TIMER_MANUAL_UPD(x)    (1 << (TCON_TIMER_BASE(x) + 1))
77 #define     TCON_TIMER_OUTPUT_INV(x)    (1 << (TCON_TIMER_BASE(x) + 2))
78 #define     TCON_TIMER_AUTO_RELOAD(x)   (1 << (TCON_TIMER_BASE(x) + 3))
79 #define     TCON_TIMER4_AUTO_RELOAD     (1 << 22)
80 
81 #define     TINT_CSTAT_STATUS(x)        (1 << (5 + (x)))
82 #define     TINT_CSTAT_ENABLE(x)        (1 << (x))
83 
84 /* timer struct */
85 typedef struct {
86     uint32_t    id;             /* timer id */
87     qemu_irq    irq;            /* local timer irq */
88     uint32_t    freq;           /* timer frequency */
89 
90     /* use ptimer.c to represent count down timer */
91     ptimer_state *ptimer;       /* timer  */
92 
93     /* registers */
94     uint32_t    reg_tcntb;      /* counter register buffer */
95     uint32_t    reg_tcmpb;      /* compare register buffer */
96 
97     struct Exynos4210PWMState *parent;
98 
99 } Exynos4210PWM;
100 
101 #define TYPE_EXYNOS4210_PWM "exynos4210.pwm"
102 #define EXYNOS4210_PWM(obj) \
103     OBJECT_CHECK(Exynos4210PWMState, (obj), TYPE_EXYNOS4210_PWM)
104 
105 typedef struct Exynos4210PWMState {
106     SysBusDevice parent_obj;
107 
108     MemoryRegion iomem;
109 
110     uint32_t    reg_tcfg[2];
111     uint32_t    reg_tcon;
112     uint32_t    reg_tint_cstat;
113 
114     Exynos4210PWM timer[EXYNOS4210_PWM_TIMERS_NUM];
115 
116 } Exynos4210PWMState;
117 
118 /*** VMState ***/
119 static const VMStateDescription vmstate_exynos4210_pwm = {
120     .name = "exynos4210.pwm.pwm",
121     .version_id = 1,
122     .minimum_version_id = 1,
123     .fields = (VMStateField[]) {
124         VMSTATE_UINT32(id, Exynos4210PWM),
125         VMSTATE_UINT32(freq, Exynos4210PWM),
126         VMSTATE_PTIMER(ptimer, Exynos4210PWM),
127         VMSTATE_UINT32(reg_tcntb, Exynos4210PWM),
128         VMSTATE_UINT32(reg_tcmpb, Exynos4210PWM),
129         VMSTATE_END_OF_LIST()
130     }
131 };
132 
133 static const VMStateDescription vmstate_exynos4210_pwm_state = {
134     .name = "exynos4210.pwm",
135     .version_id = 1,
136     .minimum_version_id = 1,
137     .fields = (VMStateField[]) {
138         VMSTATE_UINT32_ARRAY(reg_tcfg, Exynos4210PWMState, 2),
139         VMSTATE_UINT32(reg_tcon, Exynos4210PWMState),
140         VMSTATE_UINT32(reg_tint_cstat, Exynos4210PWMState),
141         VMSTATE_STRUCT_ARRAY(timer, Exynos4210PWMState,
142             EXYNOS4210_PWM_TIMERS_NUM, 0,
143         vmstate_exynos4210_pwm, Exynos4210PWM),
144         VMSTATE_END_OF_LIST()
145     }
146 };
147 
148 /*
149  * PWM update frequency
150  */
151 static void exynos4210_pwm_update_freq(Exynos4210PWMState *s, uint32_t id)
152 {
153     uint32_t freq;
154     freq = s->timer[id].freq;
155     if (id > 1) {
156         s->timer[id].freq = 24000000 /
157         ((GET_PRESCALER(s->reg_tcfg[0], 1) + 1) *
158                 (GET_DIVIDER(s->reg_tcfg[1], id)));
159     } else {
160         s->timer[id].freq = 24000000 /
161         ((GET_PRESCALER(s->reg_tcfg[0], 0) + 1) *
162                 (GET_DIVIDER(s->reg_tcfg[1], id)));
163     }
164 
165     if (freq != s->timer[id].freq) {
166         ptimer_set_freq(s->timer[id].ptimer, s->timer[id].freq);
167         DPRINTF("freq=%dHz\n", s->timer[id].freq);
168     }
169 }
170 
171 /*
172  * Counter tick handler
173  */
174 static void exynos4210_pwm_tick(void *opaque)
175 {
176     Exynos4210PWM *s = (Exynos4210PWM *)opaque;
177     Exynos4210PWMState *p = (Exynos4210PWMState *)s->parent;
178     uint32_t id = s->id;
179     bool cmp;
180 
181     DPRINTF("timer %d tick\n", id);
182 
183     /* set irq status */
184     p->reg_tint_cstat |= TINT_CSTAT_STATUS(id);
185 
186     /* raise IRQ */
187     if (p->reg_tint_cstat & TINT_CSTAT_ENABLE(id)) {
188         DPRINTF("timer %d IRQ\n", id);
189         qemu_irq_raise(p->timer[id].irq);
190     }
191 
192     /* reload timer */
193     if (id != 4) {
194         cmp = p->reg_tcon & TCON_TIMER_AUTO_RELOAD(id);
195     } else {
196         cmp = p->reg_tcon & TCON_TIMER4_AUTO_RELOAD;
197     }
198 
199     if (cmp) {
200         DPRINTF("auto reload timer %d count to %x\n", id,
201                 p->timer[id].reg_tcntb);
202         ptimer_set_count(p->timer[id].ptimer, p->timer[id].reg_tcntb);
203         ptimer_run(p->timer[id].ptimer, 1);
204     } else {
205         /* stop timer, set status to STOP, see Basic Timer Operation */
206         p->reg_tcon &= ~TCON_TIMER_START(id);
207         ptimer_stop(p->timer[id].ptimer);
208     }
209 }
210 
211 /*
212  * PWM Read
213  */
214 static uint64_t exynos4210_pwm_read(void *opaque, hwaddr offset,
215         unsigned size)
216 {
217     Exynos4210PWMState *s = (Exynos4210PWMState *)opaque;
218     uint32_t value = 0;
219     int index;
220 
221     switch (offset) {
222     case TCFG0: case TCFG1:
223         index = (offset - TCFG0) >> 2;
224         value = s->reg_tcfg[index];
225         break;
226 
227     case TCON:
228         value = s->reg_tcon;
229         break;
230 
231     case TCNTB0: case TCNTB1:
232     case TCNTB2: case TCNTB3: case TCNTB4:
233         index = (offset - TCNTB0) / 0xC;
234         value = s->timer[index].reg_tcntb;
235         break;
236 
237     case TCMPB0: case TCMPB1:
238     case TCMPB2: case TCMPB3:
239         index = (offset - TCMPB0) / 0xC;
240         value = s->timer[index].reg_tcmpb;
241         break;
242 
243     case TCNTO0: case TCNTO1:
244     case TCNTO2: case TCNTO3: case TCNTO4:
245         index = (offset == TCNTO4) ? 4 : (offset - TCNTO0) / 0xC;
246         value = ptimer_get_count(s->timer[index].ptimer);
247         break;
248 
249     case TINT_CSTAT:
250         value = s->reg_tint_cstat;
251         break;
252 
253     default:
254         fprintf(stderr,
255                 "[exynos4210.pwm: bad read offset " TARGET_FMT_plx "]\n",
256                 offset);
257         break;
258     }
259     return value;
260 }
261 
262 /*
263  * PWM Write
264  */
265 static void exynos4210_pwm_write(void *opaque, hwaddr offset,
266         uint64_t value, unsigned size)
267 {
268     Exynos4210PWMState *s = (Exynos4210PWMState *)opaque;
269     int index;
270     uint32_t new_val;
271     int i;
272 
273     switch (offset) {
274     case TCFG0: case TCFG1:
275         index = (offset - TCFG0) >> 2;
276         s->reg_tcfg[index] = value;
277 
278         /* update timers frequencies */
279         for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
280             exynos4210_pwm_update_freq(s, s->timer[i].id);
281         }
282         break;
283 
284     case TCON:
285         for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
286             if ((value & TCON_TIMER_MANUAL_UPD(i)) >
287             (s->reg_tcon & TCON_TIMER_MANUAL_UPD(i))) {
288                 /*
289                  * TCNTB and TCMPB are loaded into TCNT and TCMP.
290                  * Update timers.
291                  */
292 
293                 /* this will start timer to run, this ok, because
294                  * during processing start bit timer will be stopped
295                  * if needed */
296                 ptimer_set_count(s->timer[i].ptimer, s->timer[i].reg_tcntb);
297                 DPRINTF("set timer %d count to %x\n", i,
298                         s->timer[i].reg_tcntb);
299             }
300 
301             if ((value & TCON_TIMER_START(i)) >
302             (s->reg_tcon & TCON_TIMER_START(i))) {
303                 /* changed to start */
304                 ptimer_run(s->timer[i].ptimer, 1);
305                 DPRINTF("run timer %d\n", i);
306             }
307 
308             if ((value & TCON_TIMER_START(i)) <
309                     (s->reg_tcon & TCON_TIMER_START(i))) {
310                 /* changed to stop */
311                 ptimer_stop(s->timer[i].ptimer);
312                 DPRINTF("stop timer %d\n", i);
313             }
314         }
315         s->reg_tcon = value;
316         break;
317 
318     case TCNTB0: case TCNTB1:
319     case TCNTB2: case TCNTB3: case TCNTB4:
320         index = (offset - TCNTB0) / 0xC;
321         s->timer[index].reg_tcntb = value;
322         break;
323 
324     case TCMPB0: case TCMPB1:
325     case TCMPB2: case TCMPB3:
326         index = (offset - TCMPB0) / 0xC;
327         s->timer[index].reg_tcmpb = value;
328         break;
329 
330     case TINT_CSTAT:
331         new_val = (s->reg_tint_cstat & 0x3E0) + (0x1F & value);
332         new_val &= ~(0x3E0 & value);
333 
334         for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
335             if ((new_val & TINT_CSTAT_STATUS(i)) <
336                     (s->reg_tint_cstat & TINT_CSTAT_STATUS(i))) {
337                 qemu_irq_lower(s->timer[i].irq);
338             }
339         }
340 
341         s->reg_tint_cstat = new_val;
342         break;
343 
344     default:
345         fprintf(stderr,
346                 "[exynos4210.pwm: bad write offset " TARGET_FMT_plx "]\n",
347                 offset);
348         break;
349 
350     }
351 }
352 
353 /*
354  * Set default values to timer fields and registers
355  */
356 static void exynos4210_pwm_reset(DeviceState *d)
357 {
358     Exynos4210PWMState *s = EXYNOS4210_PWM(d);
359     int i;
360     s->reg_tcfg[0] = 0x0101;
361     s->reg_tcfg[1] = 0x0;
362     s->reg_tcon = 0;
363     s->reg_tint_cstat = 0;
364     for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
365         s->timer[i].reg_tcmpb = 0;
366         s->timer[i].reg_tcntb = 0;
367 
368         exynos4210_pwm_update_freq(s, s->timer[i].id);
369         ptimer_stop(s->timer[i].ptimer);
370     }
371 }
372 
373 static const MemoryRegionOps exynos4210_pwm_ops = {
374     .read = exynos4210_pwm_read,
375     .write = exynos4210_pwm_write,
376     .endianness = DEVICE_NATIVE_ENDIAN,
377 };
378 
379 /*
380  * PWM timer initialization
381  */
382 static int exynos4210_pwm_init(SysBusDevice *dev)
383 {
384     Exynos4210PWMState *s = EXYNOS4210_PWM(dev);
385     int i;
386     QEMUBH *bh;
387 
388     for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
389         bh = qemu_bh_new(exynos4210_pwm_tick, &s->timer[i]);
390         sysbus_init_irq(dev, &s->timer[i].irq);
391         s->timer[i].ptimer = ptimer_init(bh);
392         s->timer[i].id = i;
393         s->timer[i].parent = s;
394     }
395 
396     memory_region_init_io(&s->iomem, OBJECT(s), &exynos4210_pwm_ops, s,
397                           "exynos4210-pwm", EXYNOS4210_PWM_REG_MEM_SIZE);
398     sysbus_init_mmio(dev, &s->iomem);
399 
400     return 0;
401 }
402 
403 static void exynos4210_pwm_class_init(ObjectClass *klass, void *data)
404 {
405     DeviceClass *dc = DEVICE_CLASS(klass);
406     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
407 
408     k->init = exynos4210_pwm_init;
409     dc->reset = exynos4210_pwm_reset;
410     dc->vmsd = &vmstate_exynos4210_pwm_state;
411 }
412 
413 static const TypeInfo exynos4210_pwm_info = {
414     .name          = TYPE_EXYNOS4210_PWM,
415     .parent        = TYPE_SYS_BUS_DEVICE,
416     .instance_size = sizeof(Exynos4210PWMState),
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