xref: /openbmc/qemu/hw/timer/exynos4210_pwm.c (revision fcf5ef2a)
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 "hw/sysbus.h"
25 #include "qemu/timer.h"
26 #include "qemu-common.h"
27 #include "qemu/main-loop.h"
28 #include "hw/ptimer.h"
29 
30 #include "hw/arm/exynos4210.h"
31 
32 //#define DEBUG_PWM
33 
34 #ifdef DEBUG_PWM
35 #define DPRINTF(fmt, ...) \
36         do { fprintf(stdout, "PWM: [%24s:%5d] " fmt, __func__, __LINE__, \
37                 ## __VA_ARGS__); } while (0)
38 #else
39 #define DPRINTF(fmt, ...) do {} while (0)
40 #endif
41 
42 #define     EXYNOS4210_PWM_TIMERS_NUM      5
43 #define     EXYNOS4210_PWM_REG_MEM_SIZE    0x50
44 
45 #define     TCFG0        0x0000
46 #define     TCFG1        0x0004
47 #define     TCON         0x0008
48 #define     TCNTB0       0x000C
49 #define     TCMPB0       0x0010
50 #define     TCNTO0       0x0014
51 #define     TCNTB1       0x0018
52 #define     TCMPB1       0x001C
53 #define     TCNTO1       0x0020
54 #define     TCNTB2       0x0024
55 #define     TCMPB2       0x0028
56 #define     TCNTO2       0x002C
57 #define     TCNTB3       0x0030
58 #define     TCMPB3       0x0034
59 #define     TCNTO3       0x0038
60 #define     TCNTB4       0x003C
61 #define     TCNTO4       0x0040
62 #define     TINT_CSTAT   0x0044
63 
64 #define     TCNTB(x)    (0xC * (x))
65 #define     TCMPB(x)    (0xC * (x) + 1)
66 #define     TCNTO(x)    (0xC * (x) + 2)
67 
68 #define GET_PRESCALER(reg, x) (((reg) & (0xFF << (8 * (x)))) >> 8 * (x))
69 #define GET_DIVIDER(reg, x) (1 << (((reg) & (0xF << (4 * (x)))) >> (4 * (x))))
70 
71 /*
72  * Attention! Timer4 doesn't have OUTPUT_INVERTER,
73  * so Auto Reload bit is not accessible by macros!
74  */
75 #define     TCON_TIMER_BASE(x)          (((x) ? 1 : 0) * 4 + 4 * (x))
76 #define     TCON_TIMER_START(x)         (1 << (TCON_TIMER_BASE(x) + 0))
77 #define     TCON_TIMER_MANUAL_UPD(x)    (1 << (TCON_TIMER_BASE(x) + 1))
78 #define     TCON_TIMER_OUTPUT_INV(x)    (1 << (TCON_TIMER_BASE(x) + 2))
79 #define     TCON_TIMER_AUTO_RELOAD(x)   (1 << (TCON_TIMER_BASE(x) + 3))
80 #define     TCON_TIMER4_AUTO_RELOAD     (1 << 22)
81 
82 #define     TINT_CSTAT_STATUS(x)        (1 << (5 + (x)))
83 #define     TINT_CSTAT_ENABLE(x)        (1 << (x))
84 
85 /* timer struct */
86 typedef struct {
87     uint32_t    id;             /* timer id */
88     qemu_irq    irq;            /* local timer irq */
89     uint32_t    freq;           /* timer frequency */
90 
91     /* use ptimer.c to represent count down timer */
92     ptimer_state *ptimer;       /* timer  */
93 
94     /* registers */
95     uint32_t    reg_tcntb;      /* counter register buffer */
96     uint32_t    reg_tcmpb;      /* compare register buffer */
97 
98     struct Exynos4210PWMState *parent;
99 
100 } Exynos4210PWM;
101 
102 #define TYPE_EXYNOS4210_PWM "exynos4210.pwm"
103 #define EXYNOS4210_PWM(obj) \
104     OBJECT_CHECK(Exynos4210PWMState, (obj), TYPE_EXYNOS4210_PWM)
105 
106 typedef struct Exynos4210PWMState {
107     SysBusDevice parent_obj;
108 
109     MemoryRegion iomem;
110 
111     uint32_t    reg_tcfg[2];
112     uint32_t    reg_tcon;
113     uint32_t    reg_tint_cstat;
114 
115     Exynos4210PWM timer[EXYNOS4210_PWM_TIMERS_NUM];
116 
117 } Exynos4210PWMState;
118 
119 /*** VMState ***/
120 static const VMStateDescription vmstate_exynos4210_pwm = {
121     .name = "exynos4210.pwm.pwm",
122     .version_id = 1,
123     .minimum_version_id = 1,
124     .fields = (VMStateField[]) {
125         VMSTATE_UINT32(id, Exynos4210PWM),
126         VMSTATE_UINT32(freq, Exynos4210PWM),
127         VMSTATE_PTIMER(ptimer, Exynos4210PWM),
128         VMSTATE_UINT32(reg_tcntb, Exynos4210PWM),
129         VMSTATE_UINT32(reg_tcmpb, Exynos4210PWM),
130         VMSTATE_END_OF_LIST()
131     }
132 };
133 
134 static const VMStateDescription vmstate_exynos4210_pwm_state = {
135     .name = "exynos4210.pwm",
136     .version_id = 1,
137     .minimum_version_id = 1,
138     .fields = (VMStateField[]) {
139         VMSTATE_UINT32_ARRAY(reg_tcfg, Exynos4210PWMState, 2),
140         VMSTATE_UINT32(reg_tcon, Exynos4210PWMState),
141         VMSTATE_UINT32(reg_tint_cstat, Exynos4210PWMState),
142         VMSTATE_STRUCT_ARRAY(timer, Exynos4210PWMState,
143             EXYNOS4210_PWM_TIMERS_NUM, 0,
144         vmstate_exynos4210_pwm, Exynos4210PWM),
145         VMSTATE_END_OF_LIST()
146     }
147 };
148 
149 /*
150  * PWM update frequency
151  */
152 static void exynos4210_pwm_update_freq(Exynos4210PWMState *s, uint32_t id)
153 {
154     uint32_t freq;
155     freq = s->timer[id].freq;
156     if (id > 1) {
157         s->timer[id].freq = 24000000 /
158         ((GET_PRESCALER(s->reg_tcfg[0], 1) + 1) *
159                 (GET_DIVIDER(s->reg_tcfg[1], id)));
160     } else {
161         s->timer[id].freq = 24000000 /
162         ((GET_PRESCALER(s->reg_tcfg[0], 0) + 1) *
163                 (GET_DIVIDER(s->reg_tcfg[1], id)));
164     }
165 
166     if (freq != s->timer[id].freq) {
167         ptimer_set_freq(s->timer[id].ptimer, s->timer[id].freq);
168         DPRINTF("freq=%dHz\n", s->timer[id].freq);
169     }
170 }
171 
172 /*
173  * Counter tick handler
174  */
175 static void exynos4210_pwm_tick(void *opaque)
176 {
177     Exynos4210PWM *s = (Exynos4210PWM *)opaque;
178     Exynos4210PWMState *p = (Exynos4210PWMState *)s->parent;
179     uint32_t id = s->id;
180     bool cmp;
181 
182     DPRINTF("timer %d tick\n", id);
183 
184     /* set irq status */
185     p->reg_tint_cstat |= TINT_CSTAT_STATUS(id);
186 
187     /* raise IRQ */
188     if (p->reg_tint_cstat & TINT_CSTAT_ENABLE(id)) {
189         DPRINTF("timer %d IRQ\n", id);
190         qemu_irq_raise(p->timer[id].irq);
191     }
192 
193     /* reload timer */
194     if (id != 4) {
195         cmp = p->reg_tcon & TCON_TIMER_AUTO_RELOAD(id);
196     } else {
197         cmp = p->reg_tcon & TCON_TIMER4_AUTO_RELOAD;
198     }
199 
200     if (cmp) {
201         DPRINTF("auto reload timer %d count to %x\n", id,
202                 p->timer[id].reg_tcntb);
203         ptimer_set_count(p->timer[id].ptimer, p->timer[id].reg_tcntb);
204         ptimer_run(p->timer[id].ptimer, 1);
205     } else {
206         /* stop timer, set status to STOP, see Basic Timer Operation */
207         p->reg_tcon &= ~TCON_TIMER_START(id);
208         ptimer_stop(p->timer[id].ptimer);
209     }
210 }
211 
212 /*
213  * PWM Read
214  */
215 static uint64_t exynos4210_pwm_read(void *opaque, hwaddr offset,
216         unsigned size)
217 {
218     Exynos4210PWMState *s = (Exynos4210PWMState *)opaque;
219     uint32_t value = 0;
220     int index;
221 
222     switch (offset) {
223     case TCFG0: case TCFG1:
224         index = (offset - TCFG0) >> 2;
225         value = s->reg_tcfg[index];
226         break;
227 
228     case TCON:
229         value = s->reg_tcon;
230         break;
231 
232     case TCNTB0: case TCNTB1:
233     case TCNTB2: case TCNTB3: case TCNTB4:
234         index = (offset - TCNTB0) / 0xC;
235         value = s->timer[index].reg_tcntb;
236         break;
237 
238     case TCMPB0: case TCMPB1:
239     case TCMPB2: case TCMPB3:
240         index = (offset - TCMPB0) / 0xC;
241         value = s->timer[index].reg_tcmpb;
242         break;
243 
244     case TCNTO0: case TCNTO1:
245     case TCNTO2: case TCNTO3: case TCNTO4:
246         index = (offset == TCNTO4) ? 4 : (offset - TCNTO0) / 0xC;
247         value = ptimer_get_count(s->timer[index].ptimer);
248         break;
249 
250     case TINT_CSTAT:
251         value = s->reg_tint_cstat;
252         break;
253 
254     default:
255         fprintf(stderr,
256                 "[exynos4210.pwm: bad read offset " TARGET_FMT_plx "]\n",
257                 offset);
258         break;
259     }
260     return value;
261 }
262 
263 /*
264  * PWM Write
265  */
266 static void exynos4210_pwm_write(void *opaque, hwaddr offset,
267         uint64_t value, unsigned size)
268 {
269     Exynos4210PWMState *s = (Exynos4210PWMState *)opaque;
270     int index;
271     uint32_t new_val;
272     int i;
273 
274     switch (offset) {
275     case TCFG0: case TCFG1:
276         index = (offset - TCFG0) >> 2;
277         s->reg_tcfg[index] = value;
278 
279         /* update timers frequencies */
280         for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
281             exynos4210_pwm_update_freq(s, s->timer[i].id);
282         }
283         break;
284 
285     case TCON:
286         for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
287             if ((value & TCON_TIMER_MANUAL_UPD(i)) >
288             (s->reg_tcon & TCON_TIMER_MANUAL_UPD(i))) {
289                 /*
290                  * TCNTB and TCMPB are loaded into TCNT and TCMP.
291                  * Update timers.
292                  */
293 
294                 /* this will start timer to run, this ok, because
295                  * during processing start bit timer will be stopped
296                  * if needed */
297                 ptimer_set_count(s->timer[i].ptimer, s->timer[i].reg_tcntb);
298                 DPRINTF("set timer %d count to %x\n", i,
299                         s->timer[i].reg_tcntb);
300             }
301 
302             if ((value & TCON_TIMER_START(i)) >
303             (s->reg_tcon & TCON_TIMER_START(i))) {
304                 /* changed to start */
305                 ptimer_run(s->timer[i].ptimer, 1);
306                 DPRINTF("run timer %d\n", i);
307             }
308 
309             if ((value & TCON_TIMER_START(i)) <
310                     (s->reg_tcon & TCON_TIMER_START(i))) {
311                 /* changed to stop */
312                 ptimer_stop(s->timer[i].ptimer);
313                 DPRINTF("stop timer %d\n", i);
314             }
315         }
316         s->reg_tcon = value;
317         break;
318 
319     case TCNTB0: case TCNTB1:
320     case TCNTB2: case TCNTB3: case TCNTB4:
321         index = (offset - TCNTB0) / 0xC;
322         s->timer[index].reg_tcntb = value;
323         break;
324 
325     case TCMPB0: case TCMPB1:
326     case TCMPB2: case TCMPB3:
327         index = (offset - TCMPB0) / 0xC;
328         s->timer[index].reg_tcmpb = value;
329         break;
330 
331     case TINT_CSTAT:
332         new_val = (s->reg_tint_cstat & 0x3E0) + (0x1F & value);
333         new_val &= ~(0x3E0 & value);
334 
335         for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
336             if ((new_val & TINT_CSTAT_STATUS(i)) <
337                     (s->reg_tint_cstat & TINT_CSTAT_STATUS(i))) {
338                 qemu_irq_lower(s->timer[i].irq);
339             }
340         }
341 
342         s->reg_tint_cstat = new_val;
343         break;
344 
345     default:
346         fprintf(stderr,
347                 "[exynos4210.pwm: bad write offset " TARGET_FMT_plx "]\n",
348                 offset);
349         break;
350 
351     }
352 }
353 
354 /*
355  * Set default values to timer fields and registers
356  */
357 static void exynos4210_pwm_reset(DeviceState *d)
358 {
359     Exynos4210PWMState *s = EXYNOS4210_PWM(d);
360     int i;
361     s->reg_tcfg[0] = 0x0101;
362     s->reg_tcfg[1] = 0x0;
363     s->reg_tcon = 0;
364     s->reg_tint_cstat = 0;
365     for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
366         s->timer[i].reg_tcmpb = 0;
367         s->timer[i].reg_tcntb = 0;
368 
369         exynos4210_pwm_update_freq(s, s->timer[i].id);
370         ptimer_stop(s->timer[i].ptimer);
371     }
372 }
373 
374 static const MemoryRegionOps exynos4210_pwm_ops = {
375     .read = exynos4210_pwm_read,
376     .write = exynos4210_pwm_write,
377     .endianness = DEVICE_NATIVE_ENDIAN,
378 };
379 
380 /*
381  * PWM timer initialization
382  */
383 static void exynos4210_pwm_init(Object *obj)
384 {
385     Exynos4210PWMState *s = EXYNOS4210_PWM(obj);
386     SysBusDevice *dev = SYS_BUS_DEVICE(obj);
387     int i;
388     QEMUBH *bh;
389 
390     for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
391         bh = qemu_bh_new(exynos4210_pwm_tick, &s->timer[i]);
392         sysbus_init_irq(dev, &s->timer[i].irq);
393         s->timer[i].ptimer = ptimer_init(bh, PTIMER_POLICY_DEFAULT);
394         s->timer[i].id = i;
395         s->timer[i].parent = s;
396     }
397 
398     memory_region_init_io(&s->iomem, obj, &exynos4210_pwm_ops, s,
399                           "exynos4210-pwm", EXYNOS4210_PWM_REG_MEM_SIZE);
400     sysbus_init_mmio(dev, &s->iomem);
401 }
402 
403 static void exynos4210_pwm_class_init(ObjectClass *klass, void *data)
404 {
405     DeviceClass *dc = DEVICE_CLASS(klass);
406 
407     dc->reset = exynos4210_pwm_reset;
408     dc->vmsd = &vmstate_exynos4210_pwm_state;
409 }
410 
411 static const TypeInfo exynos4210_pwm_info = {
412     .name          = TYPE_EXYNOS4210_PWM,
413     .parent        = TYPE_SYS_BUS_DEVICE,
414     .instance_size = sizeof(Exynos4210PWMState),
415     .instance_init = exynos4210_pwm_init,
416     .class_init    = exynos4210_pwm_class_init,
417 };
418 
419 static void exynos4210_pwm_register_types(void)
420 {
421     type_register_static(&exynos4210_pwm_info);
422 }
423 
424 type_init(exynos4210_pwm_register_types)
425