xref: /openbmc/qemu/hw/timer/sh_timer.c (revision fe1127da) 
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 
19 //#define DEBUG_TIMER
20 
21 #define TIMER_TCR_TPSC          (7 << 0)
22 #define TIMER_TCR_CKEG          (3 << 3)
23 #define TIMER_TCR_UNIE          (1 << 5)
24 #define TIMER_TCR_ICPE          (3 << 6)
25 #define TIMER_TCR_UNF           (1 << 8)
26 #define TIMER_TCR_ICPF          (1 << 9)
27 #define TIMER_TCR_RESERVED      (0x3f << 10)
28 
29 #define TIMER_FEAT_CAPT   (1 << 0)
30 #define TIMER_FEAT_EXTCLK (1 << 1)
31 
32 #define OFFSET_TCOR   0
33 #define OFFSET_TCNT   1
34 #define OFFSET_TCR    2
35 #define OFFSET_TCPR   3
36 
37 typedef struct {
38     ptimer_state *timer;
39     uint32_t tcnt;
40     uint32_t tcor;
41     uint32_t tcr;
42     uint32_t tcpr;
43     int freq;
44     int int_level;
45     int old_level;
46     int feat;
47     int enabled;
48     qemu_irq irq;
49 } sh_timer_state;
50 
51 /* Check all active timers, and schedule the next timer interrupt. */
52 
53 static void sh_timer_update(sh_timer_state *s)
54 {
55     int new_level = s->int_level && (s->tcr & TIMER_TCR_UNIE);
56 
57     if (new_level != s->old_level)
58       qemu_set_irq (s->irq, new_level);
59 
60     s->old_level = s->int_level;
61     s->int_level = new_level;
62 }
63 
64 static uint32_t sh_timer_read(void *opaque, hwaddr offset)
65 {
66     sh_timer_state *s = (sh_timer_state *)opaque;
67 
68     switch (offset >> 2) {
69     case OFFSET_TCOR:
70         return s->tcor;
71     case OFFSET_TCNT:
72         return ptimer_get_count(s->timer);
73     case OFFSET_TCR:
74         return s->tcr | (s->int_level ? TIMER_TCR_UNF : 0);
75     case OFFSET_TCPR:
76         if (s->feat & TIMER_FEAT_CAPT)
77             return s->tcpr;
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     sh_timer_state *s = (sh_timer_state *)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             /* Pause the timer if it is running.  This may cause some
108                inaccuracy dure to rounding, but avoids a whole lot of other
109                messyness.  */
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: freq >>= 2; break;
116         case 1: freq >>= 4; break;
117         case 2: freq >>= 6; break;
118         case 3: freq >>= 8; break;
119         case 4: freq >>= 10; break;
120         case 6:
121         case 7:
122             if (s->feat & TIMER_FEAT_EXTCLK) {
123                 break;
124             }
125             /* fallthrough */
126         default:
127             hw_error("sh_timer_write: Reserved TPSC value\n");
128         }
129         switch ((value & TIMER_TCR_CKEG) >> 3) {
130         case 0:
131             break;
132         case 1:
133         case 2:
134         case 3:
135             if (s->feat & TIMER_FEAT_EXTCLK) {
136                 break;
137             }
138             /* fallthrough */
139         default:
140             hw_error("sh_timer_write: Reserved CKEG value\n");
141         }
142         switch ((value & TIMER_TCR_ICPE) >> 6) {
143         case 0:
144             break;
145         case 2:
146         case 3:
147             if (s->feat & TIMER_FEAT_CAPT) {
148                 break;
149             }
150             /* fallthrough */
151         default:
152             hw_error("sh_timer_write: Reserved ICPE value\n");
153         }
154         if ((value & TIMER_TCR_UNF) == 0) {
155             s->int_level = 0;
156         }
157 
158         value &= ~TIMER_TCR_UNF;
159 
160         if ((value & TIMER_TCR_ICPF) && (!(s->feat & TIMER_FEAT_CAPT))) {
161             hw_error("sh_timer_write: Reserved ICPF value\n");
162         }
163 
164         value &= ~TIMER_TCR_ICPF; /* capture not supported */
165 
166         if (value & TIMER_TCR_RESERVED) {
167             hw_error("sh_timer_write: Reserved TCR bits set\n");
168         }
169         s->tcr = value;
170         ptimer_set_limit(s->timer, s->tcor, 0);
171         ptimer_set_freq(s->timer, freq);
172         if (s->enabled) {
173             /* Restart the timer if still enabled.  */
174             ptimer_run(s->timer, 0);
175         }
176         ptimer_transaction_commit(s->timer);
177         break;
178     case OFFSET_TCPR:
179         if (s->feat & TIMER_FEAT_CAPT) {
180             s->tcpr = value;
181             break;
182         }
183         /* fallthrough */
184     default:
185         hw_error("sh_timer_write: Bad offset %x\n", (int)offset);
186     }
187     sh_timer_update(s);
188 }
189 
190 static void sh_timer_start_stop(void *opaque, int enable)
191 {
192     sh_timer_state *s = (sh_timer_state *)opaque;
193 
194 #ifdef DEBUG_TIMER
195     printf("sh_timer_start_stop %d (%d)\n", enable, s->enabled);
196 #endif
197 
198     ptimer_transaction_begin(s->timer);
199     if (s->enabled && !enable) {
200         ptimer_stop(s->timer);
201     }
202     if (!s->enabled && enable) {
203         ptimer_run(s->timer, 0);
204     }
205     ptimer_transaction_commit(s->timer);
206     s->enabled = !!enable;
207 
208 #ifdef DEBUG_TIMER
209     printf("sh_timer_start_stop done %d\n", s->enabled);
210 #endif
211 }
212 
213 static void sh_timer_tick(void *opaque)
214 {
215     sh_timer_state *s = (sh_timer_state *)opaque;
216     s->int_level = s->enabled;
217     sh_timer_update(s);
218 }
219 
220 static void *sh_timer_init(uint32_t freq, int feat, qemu_irq irq)
221 {
222     sh_timer_state *s;
223 
224     s = (sh_timer_state *)g_malloc0(sizeof(sh_timer_state));
225     s->freq = freq;
226     s->feat = feat;
227     s->tcor = 0xffffffff;
228     s->tcnt = 0xffffffff;
229     s->tcpr = 0xdeadbeef;
230     s->tcr = 0;
231     s->enabled = 0;
232     s->irq = irq;
233 
234     s->timer = ptimer_init(sh_timer_tick, s, PTIMER_POLICY_DEFAULT);
235 
236     sh_timer_write(s, OFFSET_TCOR >> 2, s->tcor);
237     sh_timer_write(s, OFFSET_TCNT >> 2, s->tcnt);
238     sh_timer_write(s, OFFSET_TCPR >> 2, s->tcpr);
239     sh_timer_write(s, OFFSET_TCR  >> 2, s->tcpr);
240     /* ??? Save/restore.  */
241     return s;
242 }
243 
244 typedef struct {
245     MemoryRegion iomem;
246     MemoryRegion iomem_p4;
247     MemoryRegion iomem_a7;
248     void *timer[3];
249     int level[3];
250     uint32_t tocr;
251     uint32_t tstr;
252     int feat;
253 } tmu012_state;
254 
255 static uint64_t tmu012_read(void *opaque, hwaddr offset,
256                             unsigned size)
257 {
258     tmu012_state *s = (tmu012_state *)opaque;
259 
260 #ifdef DEBUG_TIMER
261     printf("tmu012_read 0x%lx\n", (unsigned long) offset);
262 #endif
263 
264     if (offset >= 0x20) {
265         if (!(s->feat & TMU012_FEAT_3CHAN)) {
266             hw_error("tmu012_write: Bad channel offset %x\n", (int)offset);
267         }
268         return sh_timer_read(s->timer[2], offset - 0x20);
269     }
270 
271     if (offset >= 0x14)
272         return sh_timer_read(s->timer[1], offset - 0x14);
273 
274     if (offset >= 0x08)
275         return sh_timer_read(s->timer[0], offset - 0x08);
276 
277     if (offset == 4)
278         return s->tstr;
279 
280     if ((s->feat & TMU012_FEAT_TOCR) && offset == 0)
281         return s->tocr;
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 = (tmu012_state *)opaque;
291 
292 #ifdef DEBUG_TIMER
293     printf("tmu012_write 0x%lx 0x%08x\n", (unsigned long) offset, value);
294 #endif
295 
296     if (offset >= 0x20) {
297         if (!(s->feat & TMU012_FEAT_3CHAN)) {
298             hw_error("tmu012_write: Bad channel offset %x\n", (int)offset);
299         }
300         sh_timer_write(s->timer[2], offset - 0x20, value);
301         return;
302     }
303 
304     if (offset >= 0x14) {
305         sh_timer_write(s->timer[1], offset - 0x14, value);
306         return;
307     }
308 
309     if (offset >= 0x08) {
310         sh_timer_write(s->timer[0], offset - 0x08, value);
311         return;
312     }
313 
314     if (offset == 4) {
315         sh_timer_start_stop(s->timer[0], value & (1 << 0));
316         sh_timer_start_stop(s->timer[1], value & (1 << 1));
317         if (s->feat & TMU012_FEAT_3CHAN) {
318             sh_timer_start_stop(s->timer[2], value & (1 << 2));
319         } else {
320             if (value & (1 << 2)) {
321                 hw_error("tmu012_write: Bad channel\n");
322             }
323         }
324 
325         s->tstr = value;
326         return;
327     }
328 
329     if ((s->feat & TMU012_FEAT_TOCR) && offset == 0) {
330         s->tocr = value & (1 << 0);
331     }
332 }
333 
334 static const MemoryRegionOps tmu012_ops = {
335     .read = tmu012_read,
336     .write = tmu012_write,
337     .endianness = DEVICE_NATIVE_ENDIAN,
338 };
339 
340 void tmu012_init(MemoryRegion *sysmem, hwaddr base,
341                  int feat, uint32_t freq,
342                  qemu_irq ch0_irq, qemu_irq ch1_irq,
343                  qemu_irq ch2_irq0, qemu_irq ch2_irq1)
344 {
345     tmu012_state *s;
346     int timer_feat = (feat & TMU012_FEAT_EXTCLK) ? TIMER_FEAT_EXTCLK : 0;
347 
348     s = (tmu012_state *)g_malloc0(sizeof(tmu012_state));
349     s->feat = feat;
350     s->timer[0] = sh_timer_init(freq, timer_feat, ch0_irq);
351     s->timer[1] = sh_timer_init(freq, timer_feat, ch1_irq);
352     if (feat & TMU012_FEAT_3CHAN) {
353         s->timer[2] = sh_timer_init(freq, timer_feat | TIMER_FEAT_CAPT,
354                                     ch2_irq0); /* ch2_irq1 not supported */
355     }
356 
357     memory_region_init_io(&s->iomem, NULL, &tmu012_ops, s,
358                           "timer", 0x100000000ULL);
359 
360     memory_region_init_alias(&s->iomem_p4, NULL, "timer-p4",
361                              &s->iomem, 0, 0x1000);
362     memory_region_add_subregion(sysmem, P4ADDR(base), &s->iomem_p4);
363 
364     memory_region_init_alias(&s->iomem_a7, NULL, "timer-a7",
365                              &s->iomem, 0, 0x1000);
366     memory_region_add_subregion(sysmem, A7ADDR(base), &s->iomem_a7);
367     /* ??? Save/restore.  */
368 }
369