xref: /openbmc/qemu/hw/timer/sh_timer.c (revision 65307c7792a50bffe036423ec21107f4fb9c74e3)
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, uint32_t value)
86 {
87     SHTimerState *s = opaque;
88     int freq;
89 
90     switch (offset >> 2) {
91     case OFFSET_TCOR:
92         s->tcor = value;
93         ptimer_transaction_begin(s->timer);
94         ptimer_set_limit(s->timer, s->tcor, 0);
95         ptimer_transaction_commit(s->timer);
96         break;
97     case OFFSET_TCNT:
98         s->tcnt = value;
99         ptimer_transaction_begin(s->timer);
100         ptimer_set_count(s->timer, s->tcnt);
101         ptimer_transaction_commit(s->timer);
102         break;
103     case OFFSET_TCR:
104         ptimer_transaction_begin(s->timer);
105         if (s->enabled) {
106             /*
107              * Pause the timer if it is running. This may cause some inaccuracy
108              * due to rounding, but avoids a whole lot of other messiness
109              */
110             ptimer_stop(s->timer);
111         }
112         freq = s->freq;
113         /* ??? Need to recalculate expiry time after changing divisor.  */
114         switch (value & TIMER_TCR_TPSC) {
115         case 0:
116             freq >>= 2;
117             break;
118         case 1:
119             freq >>= 4;
120             break;
121         case 2:
122             freq >>= 6;
123             break;
124         case 3:
125             freq >>= 8;
126             break;
127         case 4:
128             freq >>= 10;
129             break;
130         case 6:
131         case 7:
132             if (s->feat & TIMER_FEAT_EXTCLK) {
133                 break;
134             }
135             /* fallthrough */
136         default:
137             hw_error("sh_timer_write: Reserved TPSC value\n");
138         }
139         switch ((value & TIMER_TCR_CKEG) >> 3) {
140         case 0:
141             break;
142         case 1:
143         case 2:
144         case 3:
145             if (s->feat & TIMER_FEAT_EXTCLK) {
146                 break;
147             }
148             /* fallthrough */
149         default:
150             hw_error("sh_timer_write: Reserved CKEG value\n");
151         }
152         switch ((value & TIMER_TCR_ICPE) >> 6) {
153         case 0:
154             break;
155         case 2:
156         case 3:
157             if (s->feat & TIMER_FEAT_CAPT) {
158                 break;
159             }
160             /* fallthrough */
161         default:
162             hw_error("sh_timer_write: Reserved ICPE value\n");
163         }
164         if ((value & TIMER_TCR_UNF) == 0) {
165             s->int_level = 0;
166         }
167 
168         value &= ~TIMER_TCR_UNF;
169 
170         if ((value & TIMER_TCR_ICPF) && (!(s->feat & TIMER_FEAT_CAPT))) {
171             hw_error("sh_timer_write: Reserved ICPF value\n");
172         }
173 
174         value &= ~TIMER_TCR_ICPF; /* capture not supported */
175 
176         if (value & TIMER_TCR_RESERVED) {
177             hw_error("sh_timer_write: Reserved TCR bits set\n");
178         }
179         s->tcr = value;
180         ptimer_set_limit(s->timer, s->tcor, 0);
181         ptimer_set_freq(s->timer, freq);
182         if (s->enabled) {
183             /* Restart the timer if still enabled.  */
184             ptimer_run(s->timer, 0);
185         }
186         ptimer_transaction_commit(s->timer);
187         break;
188     case OFFSET_TCPR:
189         if (s->feat & TIMER_FEAT_CAPT) {
190             s->tcpr = value;
191             break;
192         }
193         /* fallthrough */
194     default:
195         hw_error("sh_timer_write: Bad offset %x\n", (int)offset);
196     }
197     sh_timer_update(s);
198 }
199 
200 static void sh_timer_start_stop(void *opaque, int enable)
201 {
202     SHTimerState *s = opaque;
203 
204     trace_sh_timer_start_stop(enable, s->enabled);
205     ptimer_transaction_begin(s->timer);
206     if (s->enabled && !enable) {
207         ptimer_stop(s->timer);
208     }
209     if (!s->enabled && enable) {
210         ptimer_run(s->timer, 0);
211     }
212     ptimer_transaction_commit(s->timer);
213     s->enabled = !!enable;
214 }
215 
216 static void sh_timer_tick(void *opaque)
217 {
218     SHTimerState *s = opaque;
219     s->int_level = s->enabled;
220     sh_timer_update(s);
221 }
222 
223 static void *sh_timer_init(uint32_t freq, int feat, qemu_irq irq)
224 {
225     SHTimerState *s;
226 
227     s = g_malloc0(sizeof(*s));
228     s->freq = freq;
229     s->feat = feat;
230     s->tcor = 0xffffffff;
231     s->tcnt = 0xffffffff;
232     s->tcpr = 0xdeadbeef;
233     s->tcr = 0;
234     s->enabled = 0;
235     s->irq = irq;
236 
237     s->timer = ptimer_init(sh_timer_tick, s, PTIMER_POLICY_DEFAULT);
238 
239     sh_timer_write(s, OFFSET_TCOR >> 2, s->tcor);
240     sh_timer_write(s, OFFSET_TCNT >> 2, s->tcnt);
241     sh_timer_write(s, OFFSET_TCPR >> 2, s->tcpr);
242     sh_timer_write(s, OFFSET_TCR  >> 2, s->tcpr);
243     /* ??? Save/restore.  */
244     return s;
245 }
246 
247 typedef struct {
248     MemoryRegion iomem;
249     MemoryRegion iomem_p4;
250     MemoryRegion iomem_a7;
251     void *timer[3];
252     int level[3];
253     uint32_t tocr;
254     uint32_t tstr;
255     int feat;
256 } tmu012_state;
257 
258 static uint64_t tmu012_read(void *opaque, hwaddr offset, unsigned size)
259 {
260     tmu012_state *s = opaque;
261 
262     trace_sh_timer_read(offset);
263     if (offset >= 0x20) {
264         if (!(s->feat & TMU012_FEAT_3CHAN)) {
265             hw_error("tmu012_write: Bad channel offset %x\n", (int)offset);
266         }
267         return sh_timer_read(s->timer[2], offset - 0x20);
268     }
269 
270     if (offset >= 0x14) {
271         return sh_timer_read(s->timer[1], offset - 0x14);
272     }
273     if (offset >= 0x08) {
274         return sh_timer_read(s->timer[0], offset - 0x08);
275     }
276     if (offset == 4) {
277         return s->tstr;
278     }
279     if ((s->feat & TMU012_FEAT_TOCR) && offset == 0) {
280         return s->tocr;
281     }
282 
283     hw_error("tmu012_write: Bad offset %x\n", (int)offset);
284     return 0;
285 }
286 
287 static void tmu012_write(void *opaque, hwaddr offset,
288                         uint64_t value, unsigned size)
289 {
290     tmu012_state *s = opaque;
291 
292     trace_sh_timer_write(offset, value);
293     if (offset >= 0x20) {
294         if (!(s->feat & TMU012_FEAT_3CHAN)) {
295             hw_error("tmu012_write: Bad channel offset %x\n", (int)offset);
296         }
297         sh_timer_write(s->timer[2], offset - 0x20, value);
298         return;
299     }
300 
301     if (offset >= 0x14) {
302         sh_timer_write(s->timer[1], offset - 0x14, value);
303         return;
304     }
305 
306     if (offset >= 0x08) {
307         sh_timer_write(s->timer[0], offset - 0x08, value);
308         return;
309     }
310 
311     if (offset == 4) {
312         sh_timer_start_stop(s->timer[0], value & (1 << 0));
313         sh_timer_start_stop(s->timer[1], value & (1 << 1));
314         if (s->feat & TMU012_FEAT_3CHAN) {
315             sh_timer_start_stop(s->timer[2], value & (1 << 2));
316         } else {
317             if (value & (1 << 2)) {
318                 hw_error("tmu012_write: Bad channel\n");
319             }
320         }
321 
322         s->tstr = value;
323         return;
324     }
325 
326     if ((s->feat & TMU012_FEAT_TOCR) && offset == 0) {
327         s->tocr = value & (1 << 0);
328     }
329 }
330 
331 static const MemoryRegionOps tmu012_ops = {
332     .read = tmu012_read,
333     .write = tmu012_write,
334     .endianness = DEVICE_NATIVE_ENDIAN,
335 };
336 
337 void tmu012_init(MemoryRegion *sysmem, hwaddr base, int feat, uint32_t freq,
338                  qemu_irq ch0_irq, qemu_irq ch1_irq,
339                  qemu_irq ch2_irq0, qemu_irq ch2_irq1)
340 {
341     tmu012_state *s;
342     int timer_feat = (feat & TMU012_FEAT_EXTCLK) ? TIMER_FEAT_EXTCLK : 0;
343 
344     s = g_malloc0(sizeof(*s));
345     s->feat = feat;
346     s->timer[0] = sh_timer_init(freq, timer_feat, ch0_irq);
347     s->timer[1] = sh_timer_init(freq, timer_feat, ch1_irq);
348     if (feat & TMU012_FEAT_3CHAN) {
349         s->timer[2] = sh_timer_init(freq, timer_feat | TIMER_FEAT_CAPT,
350                                     ch2_irq0); /* ch2_irq1 not supported */
351     }
352 
353     memory_region_init_io(&s->iomem, NULL, &tmu012_ops, s, "timer", 0x30);
354 
355     memory_region_init_alias(&s->iomem_p4, NULL, "timer-p4",
356                              &s->iomem, 0, memory_region_size(&s->iomem));
357     memory_region_add_subregion(sysmem, P4ADDR(base), &s->iomem_p4);
358 
359     memory_region_init_alias(&s->iomem_a7, NULL, "timer-a7",
360                              &s->iomem, 0, memory_region_size(&s->iomem));
361     memory_region_add_subregion(sysmem, A7ADDR(base), &s->iomem_a7);
362     /* ??? Save/restore.  */
363 }
364