xref: /openbmc/qemu/hw/timer/sh_timer.c (revision 5d9b737e5144baff1c3a4205ff57d974a347c204)
1 /*
2  * SuperH Timer modules.
3  *
4  * Copyright (c) 2007 Magnus Damm
5  * Based on arm_timer.c by Paul Brook
6  * Copyright (c) 2005-2006 CodeSourcery.
7  *
8  * This code is licensed under the GPL.
9  */
10 
11 #include "qemu/osdep.h"
12 #include "exec/memory.h"
13 #include "hw/hw.h"
14 #include "hw/irq.h"
15 #include "hw/sh4/sh.h"
16 #include "hw/timer/tmu012.h"
17 #include "hw/ptimer.h"
18 #include "trace.h"
19 
20 #define TIMER_TCR_TPSC          (7 << 0)
21 #define TIMER_TCR_CKEG          (3 << 3)
22 #define TIMER_TCR_UNIE          (1 << 5)
23 #define TIMER_TCR_ICPE          (3 << 6)
24 #define TIMER_TCR_UNF           (1 << 8)
25 #define TIMER_TCR_ICPF          (1 << 9)
26 #define TIMER_TCR_RESERVED      (0x3f << 10)
27 
28 #define TIMER_FEAT_CAPT   (1 << 0)
29 #define TIMER_FEAT_EXTCLK (1 << 1)
30 
31 #define OFFSET_TCOR   0
32 #define OFFSET_TCNT   1
33 #define OFFSET_TCR    2
34 #define OFFSET_TCPR   3
35 
36 typedef struct {
37     ptimer_state *timer;
38     uint32_t tcnt;
39     uint32_t tcor;
40     uint32_t tcr;
41     uint32_t tcpr;
42     int freq;
43     int int_level;
44     int old_level;
45     int feat;
46     int enabled;
47     qemu_irq irq;
48 } SHTimerState;
49 
50 /* Check all active timers, and schedule the next timer interrupt. */
51 
52 static void sh_timer_update(SHTimerState *s)
53 {
54     int new_level = s->int_level && (s->tcr & TIMER_TCR_UNIE);
55 
56     if (new_level != s->old_level) {
57         qemu_set_irq(s->irq, new_level);
58     }
59     s->old_level = s->int_level;
60     s->int_level = new_level;
61 }
62 
63 static uint32_t sh_timer_read(void *opaque, hwaddr offset)
64 {
65     SHTimerState *s = opaque;
66 
67     switch (offset >> 2) {
68     case OFFSET_TCOR:
69         return s->tcor;
70     case OFFSET_TCNT:
71         return ptimer_get_count(s->timer);
72     case OFFSET_TCR:
73         return s->tcr | (s->int_level ? TIMER_TCR_UNF : 0);
74     case OFFSET_TCPR:
75         if (s->feat & TIMER_FEAT_CAPT) {
76             return s->tcpr;
77         }
78         /* fall through */
79     default:
80         hw_error("sh_timer_read: Bad offset %x\n", (int)offset);
81         return 0;
82     }
83 }
84 
85 static void sh_timer_write(void *opaque, hwaddr offset,
86                             uint32_t value)
87 {
88     SHTimerState *s = opaque;
89     int freq;
90 
91     switch (offset >> 2) {
92     case OFFSET_TCOR:
93         s->tcor = value;
94         ptimer_transaction_begin(s->timer);
95         ptimer_set_limit(s->timer, s->tcor, 0);
96         ptimer_transaction_commit(s->timer);
97         break;
98     case OFFSET_TCNT:
99         s->tcnt = value;
100         ptimer_transaction_begin(s->timer);
101         ptimer_set_count(s->timer, s->tcnt);
102         ptimer_transaction_commit(s->timer);
103         break;
104     case OFFSET_TCR:
105         ptimer_transaction_begin(s->timer);
106         if (s->enabled) {
107             /*
108              * Pause the timer if it is running. This may cause some inaccuracy
109              * due to rounding, but avoids a whole lot of other messiness
110              */
111             ptimer_stop(s->timer);
112         }
113         freq = s->freq;
114         /* ??? Need to recalculate expiry time after changing divisor.  */
115         switch (value & TIMER_TCR_TPSC) {
116         case 0:
117             freq >>= 2;
118             break;
119         case 1:
120             freq >>= 4;
121             break;
122         case 2:
123             freq >>= 6;
124             break;
125         case 3:
126             freq >>= 8;
127             break;
128         case 4:
129             freq >>= 10;
130             break;
131         case 6:
132         case 7:
133             if (s->feat & TIMER_FEAT_EXTCLK) {
134                 break;
135             }
136             /* fallthrough */
137         default:
138             hw_error("sh_timer_write: Reserved TPSC value\n");
139         }
140         switch ((value & TIMER_TCR_CKEG) >> 3) {
141         case 0:
142             break;
143         case 1:
144         case 2:
145         case 3:
146             if (s->feat & TIMER_FEAT_EXTCLK) {
147                 break;
148             }
149             /* fallthrough */
150         default:
151             hw_error("sh_timer_write: Reserved CKEG value\n");
152         }
153         switch ((value & TIMER_TCR_ICPE) >> 6) {
154         case 0:
155             break;
156         case 2:
157         case 3:
158             if (s->feat & TIMER_FEAT_CAPT) {
159                 break;
160             }
161             /* fallthrough */
162         default:
163             hw_error("sh_timer_write: Reserved ICPE value\n");
164         }
165         if ((value & TIMER_TCR_UNF) == 0) {
166             s->int_level = 0;
167         }
168 
169         value &= ~TIMER_TCR_UNF;
170 
171         if ((value & TIMER_TCR_ICPF) && (!(s->feat & TIMER_FEAT_CAPT))) {
172             hw_error("sh_timer_write: Reserved ICPF value\n");
173         }
174 
175         value &= ~TIMER_TCR_ICPF; /* capture not supported */
176 
177         if (value & TIMER_TCR_RESERVED) {
178             hw_error("sh_timer_write: Reserved TCR bits set\n");
179         }
180         s->tcr = value;
181         ptimer_set_limit(s->timer, s->tcor, 0);
182         ptimer_set_freq(s->timer, freq);
183         if (s->enabled) {
184             /* Restart the timer if still enabled.  */
185             ptimer_run(s->timer, 0);
186         }
187         ptimer_transaction_commit(s->timer);
188         break;
189     case OFFSET_TCPR:
190         if (s->feat & TIMER_FEAT_CAPT) {
191             s->tcpr = value;
192             break;
193         }
194         /* fallthrough */
195     default:
196         hw_error("sh_timer_write: Bad offset %x\n", (int)offset);
197     }
198     sh_timer_update(s);
199 }
200 
201 static void sh_timer_start_stop(void *opaque, int enable)
202 {
203     SHTimerState *s = opaque;
204 
205     trace_sh_timer_start_stop(enable, s->enabled);
206     ptimer_transaction_begin(s->timer);
207     if (s->enabled && !enable) {
208         ptimer_stop(s->timer);
209     }
210     if (!s->enabled && enable) {
211         ptimer_run(s->timer, 0);
212     }
213     ptimer_transaction_commit(s->timer);
214     s->enabled = !!enable;
215 }
216 
217 static void sh_timer_tick(void *opaque)
218 {
219     SHTimerState *s = opaque;
220     s->int_level = s->enabled;
221     sh_timer_update(s);
222 }
223 
224 static void *sh_timer_init(uint32_t freq, int feat, qemu_irq irq)
225 {
226     SHTimerState *s;
227 
228     s = g_malloc0(sizeof(*s));
229     s->freq = freq;
230     s->feat = feat;
231     s->tcor = 0xffffffff;
232     s->tcnt = 0xffffffff;
233     s->tcpr = 0xdeadbeef;
234     s->tcr = 0;
235     s->enabled = 0;
236     s->irq = irq;
237 
238     s->timer = ptimer_init(sh_timer_tick, s, PTIMER_POLICY_DEFAULT);
239 
240     sh_timer_write(s, OFFSET_TCOR >> 2, s->tcor);
241     sh_timer_write(s, OFFSET_TCNT >> 2, s->tcnt);
242     sh_timer_write(s, OFFSET_TCPR >> 2, s->tcpr);
243     sh_timer_write(s, OFFSET_TCR  >> 2, s->tcpr);
244     /* ??? Save/restore.  */
245     return s;
246 }
247 
248 typedef struct {
249     MemoryRegion iomem;
250     MemoryRegion iomem_p4;
251     MemoryRegion iomem_a7;
252     void *timer[3];
253     int level[3];
254     uint32_t tocr;
255     uint32_t tstr;
256     int feat;
257 } tmu012_state;
258 
259 static uint64_t tmu012_read(void *opaque, hwaddr offset,
260                             unsigned size)
261 {
262     tmu012_state *s = opaque;
263 
264     trace_sh_timer_read(offset);
265     if (offset >= 0x20) {
266         if (!(s->feat & TMU012_FEAT_3CHAN)) {
267             hw_error("tmu012_write: Bad channel offset %x\n", (int)offset);
268         }
269         return sh_timer_read(s->timer[2], offset - 0x20);
270     }
271 
272     if (offset >= 0x14) {
273         return sh_timer_read(s->timer[1], offset - 0x14);
274     }
275     if (offset >= 0x08) {
276         return sh_timer_read(s->timer[0], offset - 0x08);
277     }
278     if (offset == 4) {
279         return s->tstr;
280     }
281     if ((s->feat & TMU012_FEAT_TOCR) && offset == 0) {
282         return s->tocr;
283     }
284 
285     hw_error("tmu012_write: Bad offset %x\n", (int)offset);
286     return 0;
287 }
288 
289 static void tmu012_write(void *opaque, hwaddr offset,
290                         uint64_t value, unsigned size)
291 {
292     tmu012_state *s = opaque;
293 
294     trace_sh_timer_write(offset, value);
295     if (offset >= 0x20) {
296         if (!(s->feat & TMU012_FEAT_3CHAN)) {
297             hw_error("tmu012_write: Bad channel offset %x\n", (int)offset);
298         }
299         sh_timer_write(s->timer[2], offset - 0x20, value);
300         return;
301     }
302 
303     if (offset >= 0x14) {
304         sh_timer_write(s->timer[1], offset - 0x14, value);
305         return;
306     }
307 
308     if (offset >= 0x08) {
309         sh_timer_write(s->timer[0], offset - 0x08, value);
310         return;
311     }
312 
313     if (offset == 4) {
314         sh_timer_start_stop(s->timer[0], value & (1 << 0));
315         sh_timer_start_stop(s->timer[1], value & (1 << 1));
316         if (s->feat & TMU012_FEAT_3CHAN) {
317             sh_timer_start_stop(s->timer[2], value & (1 << 2));
318         } else {
319             if (value & (1 << 2)) {
320                 hw_error("tmu012_write: Bad channel\n");
321             }
322         }
323 
324         s->tstr = value;
325         return;
326     }
327 
328     if ((s->feat & TMU012_FEAT_TOCR) && offset == 0) {
329         s->tocr = value & (1 << 0);
330     }
331 }
332 
333 static const MemoryRegionOps tmu012_ops = {
334     .read = tmu012_read,
335     .write = tmu012_write,
336     .endianness = DEVICE_NATIVE_ENDIAN,
337 };
338 
339 void tmu012_init(MemoryRegion *sysmem, hwaddr base,
340                  int feat, uint32_t freq,
341                  qemu_irq ch0_irq, qemu_irq ch1_irq,
342                  qemu_irq ch2_irq0, qemu_irq ch2_irq1)
343 {
344     tmu012_state *s;
345     int timer_feat = (feat & TMU012_FEAT_EXTCLK) ? TIMER_FEAT_EXTCLK : 0;
346 
347     s = g_malloc0(sizeof(*s));
348     s->feat = feat;
349     s->timer[0] = sh_timer_init(freq, timer_feat, ch0_irq);
350     s->timer[1] = sh_timer_init(freq, timer_feat, ch1_irq);
351     if (feat & TMU012_FEAT_3CHAN) {
352         s->timer[2] = sh_timer_init(freq, timer_feat | TIMER_FEAT_CAPT,
353                                     ch2_irq0); /* ch2_irq1 not supported */
354     }
355 
356     memory_region_init_io(&s->iomem, NULL, &tmu012_ops, s,
357                           "timer", 0x100000000ULL);
358 
359     memory_region_init_alias(&s->iomem_p4, NULL, "timer-p4",
360                              &s->iomem, 0, 0x1000);
361     memory_region_add_subregion(sysmem, P4ADDR(base), &s->iomem_p4);
362 
363     memory_region_init_alias(&s->iomem_a7, NULL, "timer-a7",
364                              &s->iomem, 0, 0x1000);
365     memory_region_add_subregion(sysmem, A7ADDR(base), &s->iomem_a7);
366     /* ??? Save/restore.  */
367 }
368