xref: /openbmc/qemu/hw/timer/exynos4210_pwm.c (revision 41b8280a)
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 "hw/ptimer.h"
27 
28 #include "hw/arm/exynos4210.h"
29 
30 //#define DEBUG_PWM
31 
32 #ifdef DEBUG_PWM
33 #define DPRINTF(fmt, ...) \
34         do { fprintf(stdout, "PWM: [%24s:%5d] " fmt, __func__, __LINE__, \
35                 ## __VA_ARGS__); } while (0)
36 #else
37 #define DPRINTF(fmt, ...) do {} while (0)
38 #endif
39 
40 #define     EXYNOS4210_PWM_TIMERS_NUM      5
41 #define     EXYNOS4210_PWM_REG_MEM_SIZE    0x50
42 
43 #define     TCFG0        0x0000
44 #define     TCFG1        0x0004
45 #define     TCON         0x0008
46 #define     TCNTB0       0x000C
47 #define     TCMPB0       0x0010
48 #define     TCNTO0       0x0014
49 #define     TCNTB1       0x0018
50 #define     TCMPB1       0x001C
51 #define     TCNTO1       0x0020
52 #define     TCNTB2       0x0024
53 #define     TCMPB2       0x0028
54 #define     TCNTO2       0x002C
55 #define     TCNTB3       0x0030
56 #define     TCMPB3       0x0034
57 #define     TCNTO3       0x0038
58 #define     TCNTB4       0x003C
59 #define     TCNTO4       0x0040
60 #define     TINT_CSTAT   0x0044
61 
62 #define     TCNTB(x)    (0xC * (x))
63 #define     TCMPB(x)    (0xC * (x) + 1)
64 #define     TCNTO(x)    (0xC * (x) + 2)
65 
66 #define GET_PRESCALER(reg, x) (((reg) & (0xFF << (8 * (x)))) >> 8 * (x))
67 #define GET_DIVIDER(reg, x) (1 << (((reg) & (0xF << (4 * (x)))) >> (4 * (x))))
68 
69 /*
70  * Attention! Timer4 doesn't have OUTPUT_INVERTER,
71  * so Auto Reload bit is not accessible by macros!
72  */
73 #define     TCON_TIMER_BASE(x)          (((x) ? 1 : 0) * 4 + 4 * (x))
74 #define     TCON_TIMER_START(x)         (1 << (TCON_TIMER_BASE(x) + 0))
75 #define     TCON_TIMER_MANUAL_UPD(x)    (1 << (TCON_TIMER_BASE(x) + 1))
76 #define     TCON_TIMER_OUTPUT_INV(x)    (1 << (TCON_TIMER_BASE(x) + 2))
77 #define     TCON_TIMER_AUTO_RELOAD(x)   (1 << (TCON_TIMER_BASE(x) + 3))
78 #define     TCON_TIMER4_AUTO_RELOAD     (1 << 22)
79 
80 #define     TINT_CSTAT_STATUS(x)        (1 << (5 + (x)))
81 #define     TINT_CSTAT_ENABLE(x)        (1 << (x))
82 
83 /* timer struct */
84 typedef struct {
85     uint32_t    id;             /* timer id */
86     qemu_irq    irq;            /* local timer irq */
87     uint32_t    freq;           /* timer frequency */
88 
89     /* use ptimer.c to represent count down timer */
90     ptimer_state *ptimer;       /* timer  */
91 
92     /* registers */
93     uint32_t    reg_tcntb;      /* counter register buffer */
94     uint32_t    reg_tcmpb;      /* compare register buffer */
95 
96     struct Exynos4210PWMState *parent;
97 
98 } Exynos4210PWM;
99 
100 
101 typedef struct Exynos4210PWMState {
102     SysBusDevice busdev;
103     MemoryRegion iomem;
104 
105     uint32_t    reg_tcfg[2];
106     uint32_t    reg_tcon;
107     uint32_t    reg_tint_cstat;
108 
109     Exynos4210PWM timer[EXYNOS4210_PWM_TIMERS_NUM];
110 
111 } Exynos4210PWMState;
112 
113 /*** VMState ***/
114 static const VMStateDescription vmstate_exynos4210_pwm = {
115     .name = "exynos4210.pwm.pwm",
116     .version_id = 1,
117     .minimum_version_id = 1,
118     .minimum_version_id_old = 1,
119     .fields = (VMStateField[]) {
120         VMSTATE_UINT32(id, Exynos4210PWM),
121         VMSTATE_UINT32(freq, Exynos4210PWM),
122         VMSTATE_PTIMER(ptimer, Exynos4210PWM),
123         VMSTATE_UINT32(reg_tcntb, Exynos4210PWM),
124         VMSTATE_UINT32(reg_tcmpb, Exynos4210PWM),
125         VMSTATE_END_OF_LIST()
126     }
127 };
128 
129 static const VMStateDescription vmstate_exynos4210_pwm_state = {
130     .name = "exynos4210.pwm",
131     .version_id = 1,
132     .minimum_version_id = 1,
133     .minimum_version_id_old = 1,
134     .fields = (VMStateField[]) {
135         VMSTATE_UINT32_ARRAY(reg_tcfg, Exynos4210PWMState, 2),
136         VMSTATE_UINT32(reg_tcon, Exynos4210PWMState),
137         VMSTATE_UINT32(reg_tint_cstat, Exynos4210PWMState),
138         VMSTATE_STRUCT_ARRAY(timer, Exynos4210PWMState,
139             EXYNOS4210_PWM_TIMERS_NUM, 0,
140         vmstate_exynos4210_pwm, Exynos4210PWM),
141         VMSTATE_END_OF_LIST()
142     }
143 };
144 
145 /*
146  * PWM update frequency
147  */
148 static void exynos4210_pwm_update_freq(Exynos4210PWMState *s, uint32_t id)
149 {
150     uint32_t freq;
151     freq = s->timer[id].freq;
152     if (id > 1) {
153         s->timer[id].freq = 24000000 /
154         ((GET_PRESCALER(s->reg_tcfg[0], 1) + 1) *
155                 (GET_DIVIDER(s->reg_tcfg[1], id)));
156     } else {
157         s->timer[id].freq = 24000000 /
158         ((GET_PRESCALER(s->reg_tcfg[0], 0) + 1) *
159                 (GET_DIVIDER(s->reg_tcfg[1], id)));
160     }
161 
162     if (freq != s->timer[id].freq) {
163         ptimer_set_freq(s->timer[id].ptimer, s->timer[id].freq);
164         DPRINTF("freq=%dHz\n", s->timer[id].freq);
165     }
166 }
167 
168 /*
169  * Counter tick handler
170  */
171 static void exynos4210_pwm_tick(void *opaque)
172 {
173     Exynos4210PWM *s = (Exynos4210PWM *)opaque;
174     Exynos4210PWMState *p = (Exynos4210PWMState *)s->parent;
175     uint32_t id = s->id;
176     bool cmp;
177 
178     DPRINTF("timer %d tick\n", id);
179 
180     /* set irq status */
181     p->reg_tint_cstat |= TINT_CSTAT_STATUS(id);
182 
183     /* raise IRQ */
184     if (p->reg_tint_cstat & TINT_CSTAT_ENABLE(id)) {
185         DPRINTF("timer %d IRQ\n", id);
186         qemu_irq_raise(p->timer[id].irq);
187     }
188 
189     /* reload timer */
190     if (id != 4) {
191         cmp = p->reg_tcon & TCON_TIMER_AUTO_RELOAD(id);
192     } else {
193         cmp = p->reg_tcon & TCON_TIMER4_AUTO_RELOAD;
194     }
195 
196     if (cmp) {
197         DPRINTF("auto reload timer %d count to %x\n", id,
198                 p->timer[id].reg_tcntb);
199         ptimer_set_count(p->timer[id].ptimer, p->timer[id].reg_tcntb);
200         ptimer_run(p->timer[id].ptimer, 1);
201     } else {
202         /* stop timer, set status to STOP, see Basic Timer Operation */
203         p->reg_tcon &= ~TCON_TIMER_START(id);
204         ptimer_stop(p->timer[id].ptimer);
205     }
206 }
207 
208 /*
209  * PWM Read
210  */
211 static uint64_t exynos4210_pwm_read(void *opaque, hwaddr offset,
212         unsigned size)
213 {
214     Exynos4210PWMState *s = (Exynos4210PWMState *)opaque;
215     uint32_t value = 0;
216     int index;
217 
218     switch (offset) {
219     case TCFG0: case TCFG1:
220         index = (offset - TCFG0) >> 2;
221         value = s->reg_tcfg[index];
222         break;
223 
224     case TCON:
225         value = s->reg_tcon;
226         break;
227 
228     case TCNTB0: case TCNTB1:
229     case TCNTB2: case TCNTB3: case TCNTB4:
230         index = (offset - TCNTB0) / 0xC;
231         value = s->timer[index].reg_tcntb;
232         break;
233 
234     case TCMPB0: case TCMPB1:
235     case TCMPB2: case TCMPB3:
236         index = (offset - TCMPB0) / 0xC;
237         value = s->timer[index].reg_tcmpb;
238         break;
239 
240     case TCNTO0: case TCNTO1:
241     case TCNTO2: case TCNTO3: case TCNTO4:
242         index = (offset == TCNTO4) ? 4 : (offset - TCNTO0) / 0xC;
243         value = ptimer_get_count(s->timer[index].ptimer);
244         break;
245 
246     case TINT_CSTAT:
247         value = s->reg_tint_cstat;
248         break;
249 
250     default:
251         fprintf(stderr,
252                 "[exynos4210.pwm: bad read offset " TARGET_FMT_plx "]\n",
253                 offset);
254         break;
255     }
256     return value;
257 }
258 
259 /*
260  * PWM Write
261  */
262 static void exynos4210_pwm_write(void *opaque, hwaddr offset,
263         uint64_t value, unsigned size)
264 {
265     Exynos4210PWMState *s = (Exynos4210PWMState *)opaque;
266     int index;
267     uint32_t new_val;
268     int i;
269 
270     switch (offset) {
271     case TCFG0: case TCFG1:
272         index = (offset - TCFG0) >> 2;
273         s->reg_tcfg[index] = value;
274 
275         /* update timers frequencies */
276         for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
277             exynos4210_pwm_update_freq(s, s->timer[i].id);
278         }
279         break;
280 
281     case TCON:
282         for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
283             if ((value & TCON_TIMER_MANUAL_UPD(i)) >
284             (s->reg_tcon & TCON_TIMER_MANUAL_UPD(i))) {
285                 /*
286                  * TCNTB and TCMPB are loaded into TCNT and TCMP.
287                  * Update timers.
288                  */
289 
290                 /* this will start timer to run, this ok, because
291                  * during processing start bit timer will be stopped
292                  * if needed */
293                 ptimer_set_count(s->timer[i].ptimer, s->timer[i].reg_tcntb);
294                 DPRINTF("set timer %d count to %x\n", i,
295                         s->timer[i].reg_tcntb);
296             }
297 
298             if ((value & TCON_TIMER_START(i)) >
299             (s->reg_tcon & TCON_TIMER_START(i))) {
300                 /* changed to start */
301                 ptimer_run(s->timer[i].ptimer, 1);
302                 DPRINTF("run timer %d\n", i);
303             }
304 
305             if ((value & TCON_TIMER_START(i)) <
306                     (s->reg_tcon & TCON_TIMER_START(i))) {
307                 /* changed to stop */
308                 ptimer_stop(s->timer[i].ptimer);
309                 DPRINTF("stop timer %d\n", i);
310             }
311         }
312         s->reg_tcon = value;
313         break;
314 
315     case TCNTB0: case TCNTB1:
316     case TCNTB2: case TCNTB3: case TCNTB4:
317         index = (offset - TCNTB0) / 0xC;
318         s->timer[index].reg_tcntb = value;
319         break;
320 
321     case TCMPB0: case TCMPB1:
322     case TCMPB2: case TCMPB3:
323         index = (offset - TCMPB0) / 0xC;
324         s->timer[index].reg_tcmpb = value;
325         break;
326 
327     case TINT_CSTAT:
328         new_val = (s->reg_tint_cstat & 0x3E0) + (0x1F & value);
329         new_val &= ~(0x3E0 & value);
330 
331         for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
332             if ((new_val & TINT_CSTAT_STATUS(i)) <
333                     (s->reg_tint_cstat & TINT_CSTAT_STATUS(i))) {
334                 qemu_irq_lower(s->timer[i].irq);
335             }
336         }
337 
338         s->reg_tint_cstat = new_val;
339         break;
340 
341     default:
342         fprintf(stderr,
343                 "[exynos4210.pwm: bad write offset " TARGET_FMT_plx "]\n",
344                 offset);
345         break;
346 
347     }
348 }
349 
350 /*
351  * Set default values to timer fields and registers
352  */
353 static void exynos4210_pwm_reset(DeviceState *d)
354 {
355     Exynos4210PWMState *s = (Exynos4210PWMState *)d;
356     int i;
357     s->reg_tcfg[0] = 0x0101;
358     s->reg_tcfg[1] = 0x0;
359     s->reg_tcon = 0;
360     s->reg_tint_cstat = 0;
361     for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
362         s->timer[i].reg_tcmpb = 0;
363         s->timer[i].reg_tcntb = 0;
364 
365         exynos4210_pwm_update_freq(s, s->timer[i].id);
366         ptimer_stop(s->timer[i].ptimer);
367     }
368 }
369 
370 static const MemoryRegionOps exynos4210_pwm_ops = {
371     .read = exynos4210_pwm_read,
372     .write = exynos4210_pwm_write,
373     .endianness = DEVICE_NATIVE_ENDIAN,
374 };
375 
376 /*
377  * PWM timer initialization
378  */
379 static int exynos4210_pwm_init(SysBusDevice *dev)
380 {
381     Exynos4210PWMState *s = FROM_SYSBUS(Exynos4210PWMState, dev);
382     int i;
383     QEMUBH *bh;
384 
385     for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
386         bh = qemu_bh_new(exynos4210_pwm_tick, &s->timer[i]);
387         sysbus_init_irq(dev, &s->timer[i].irq);
388         s->timer[i].ptimer = ptimer_init(bh);
389         s->timer[i].id = i;
390         s->timer[i].parent = s;
391     }
392 
393     memory_region_init_io(&s->iomem, OBJECT(s), &exynos4210_pwm_ops, s,
394                           "exynos4210-pwm", EXYNOS4210_PWM_REG_MEM_SIZE);
395     sysbus_init_mmio(dev, &s->iomem);
396 
397     return 0;
398 }
399 
400 static void exynos4210_pwm_class_init(ObjectClass *klass, void *data)
401 {
402     DeviceClass *dc = DEVICE_CLASS(klass);
403     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
404 
405     k->init = exynos4210_pwm_init;
406     dc->reset = exynos4210_pwm_reset;
407     dc->vmsd = &vmstate_exynos4210_pwm_state;
408 }
409 
410 static const TypeInfo exynos4210_pwm_info = {
411     .name          = "exynos4210.pwm",
412     .parent        = TYPE_SYS_BUS_DEVICE,
413     .instance_size = sizeof(Exynos4210PWMState),
414     .class_init    = exynos4210_pwm_class_init,
415 };
416 
417 static void exynos4210_pwm_register_types(void)
418 {
419     type_register_static(&exynos4210_pwm_info);
420 }
421 
422 type_init(exynos4210_pwm_register_types)
423