xref: /openbmc/qemu/hw/timer/sh_timer.c (revision 135b03cb)
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 "hw/hw.h"
13 #include "hw/irq.h"
14 #include "hw/sh4/sh.h"
15 #include "qemu/timer.h"
16 #include "qemu/main-loop.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_set_limit(s->timer, s->tcor, 0);
95         break;
96     case OFFSET_TCNT:
97         s->tcnt = value;
98         ptimer_set_count(s->timer, s->tcnt);
99         break;
100     case OFFSET_TCR:
101         if (s->enabled) {
102             /* Pause the timer if it is running.  This may cause some
103                inaccuracy dure to rounding, but avoids a whole lot of other
104                messyness.  */
105             ptimer_stop(s->timer);
106         }
107         freq = s->freq;
108         /* ??? Need to recalculate expiry time after changing divisor.  */
109         switch (value & TIMER_TCR_TPSC) {
110         case 0: freq >>= 2; break;
111         case 1: freq >>= 4; break;
112         case 2: freq >>= 6; break;
113         case 3: freq >>= 8; break;
114         case 4: freq >>= 10; break;
115 	case 6:
116 	case 7: if (s->feat & TIMER_FEAT_EXTCLK) break;
117 	default: hw_error("sh_timer_write: Reserved TPSC value\n"); break;
118         }
119         switch ((value & TIMER_TCR_CKEG) >> 3) {
120 	case 0: break;
121         case 1:
122         case 2:
123         case 3: if (s->feat & TIMER_FEAT_EXTCLK) break;
124 	default: hw_error("sh_timer_write: Reserved CKEG value\n"); break;
125         }
126         switch ((value & TIMER_TCR_ICPE) >> 6) {
127 	case 0: break;
128         case 2:
129         case 3: if (s->feat & TIMER_FEAT_CAPT) break;
130 	default: hw_error("sh_timer_write: Reserved ICPE value\n"); break;
131         }
132 	if ((value & TIMER_TCR_UNF) == 0)
133             s->int_level = 0;
134 
135 	value &= ~TIMER_TCR_UNF;
136 
137 	if ((value & TIMER_TCR_ICPF) && (!(s->feat & TIMER_FEAT_CAPT)))
138             hw_error("sh_timer_write: Reserved ICPF value\n");
139 
140 	value &= ~TIMER_TCR_ICPF; /* capture not supported */
141 
142 	if (value & TIMER_TCR_RESERVED)
143             hw_error("sh_timer_write: Reserved TCR bits set\n");
144         s->tcr = value;
145         ptimer_set_limit(s->timer, s->tcor, 0);
146         ptimer_set_freq(s->timer, freq);
147         if (s->enabled) {
148             /* Restart the timer if still enabled.  */
149             ptimer_run(s->timer, 0);
150         }
151         break;
152     case OFFSET_TCPR:
153         if (s->feat & TIMER_FEAT_CAPT) {
154             s->tcpr = value;
155 	    break;
156 	}
157     default:
158         hw_error("sh_timer_write: Bad offset %x\n", (int)offset);
159     }
160     sh_timer_update(s);
161 }
162 
163 static void sh_timer_start_stop(void *opaque, int enable)
164 {
165     sh_timer_state *s = (sh_timer_state *)opaque;
166 
167 #ifdef DEBUG_TIMER
168     printf("sh_timer_start_stop %d (%d)\n", enable, s->enabled);
169 #endif
170 
171     if (s->enabled && !enable) {
172         ptimer_stop(s->timer);
173     }
174     if (!s->enabled && enable) {
175         ptimer_run(s->timer, 0);
176     }
177     s->enabled = !!enable;
178 
179 #ifdef DEBUG_TIMER
180     printf("sh_timer_start_stop done %d\n", s->enabled);
181 #endif
182 }
183 
184 static void sh_timer_tick(void *opaque)
185 {
186     sh_timer_state *s = (sh_timer_state *)opaque;
187     s->int_level = s->enabled;
188     sh_timer_update(s);
189 }
190 
191 static void *sh_timer_init(uint32_t freq, int feat, qemu_irq irq)
192 {
193     sh_timer_state *s;
194     QEMUBH *bh;
195 
196     s = (sh_timer_state *)g_malloc0(sizeof(sh_timer_state));
197     s->freq = freq;
198     s->feat = feat;
199     s->tcor = 0xffffffff;
200     s->tcnt = 0xffffffff;
201     s->tcpr = 0xdeadbeef;
202     s->tcr = 0;
203     s->enabled = 0;
204     s->irq = irq;
205 
206     bh = qemu_bh_new(sh_timer_tick, s);
207     s->timer = ptimer_init(bh, PTIMER_POLICY_DEFAULT);
208 
209     sh_timer_write(s, OFFSET_TCOR >> 2, s->tcor);
210     sh_timer_write(s, OFFSET_TCNT >> 2, s->tcnt);
211     sh_timer_write(s, OFFSET_TCPR >> 2, s->tcpr);
212     sh_timer_write(s, OFFSET_TCR  >> 2, s->tcpr);
213     /* ??? Save/restore.  */
214     return s;
215 }
216 
217 typedef struct {
218     MemoryRegion iomem;
219     MemoryRegion iomem_p4;
220     MemoryRegion iomem_a7;
221     void *timer[3];
222     int level[3];
223     uint32_t tocr;
224     uint32_t tstr;
225     int feat;
226 } tmu012_state;
227 
228 static uint64_t tmu012_read(void *opaque, hwaddr offset,
229                             unsigned size)
230 {
231     tmu012_state *s = (tmu012_state *)opaque;
232 
233 #ifdef DEBUG_TIMER
234     printf("tmu012_read 0x%lx\n", (unsigned long) offset);
235 #endif
236 
237     if (offset >= 0x20) {
238         if (!(s->feat & TMU012_FEAT_3CHAN))
239 	    hw_error("tmu012_write: Bad channel offset %x\n", (int)offset);
240         return sh_timer_read(s->timer[2], offset - 0x20);
241     }
242 
243     if (offset >= 0x14)
244         return sh_timer_read(s->timer[1], offset - 0x14);
245 
246     if (offset >= 0x08)
247         return sh_timer_read(s->timer[0], offset - 0x08);
248 
249     if (offset == 4)
250         return s->tstr;
251 
252     if ((s->feat & TMU012_FEAT_TOCR) && offset == 0)
253         return s->tocr;
254 
255     hw_error("tmu012_write: Bad offset %x\n", (int)offset);
256     return 0;
257 }
258 
259 static void tmu012_write(void *opaque, hwaddr offset,
260                         uint64_t value, unsigned size)
261 {
262     tmu012_state *s = (tmu012_state *)opaque;
263 
264 #ifdef DEBUG_TIMER
265     printf("tmu012_write 0x%lx 0x%08x\n", (unsigned long) offset, value);
266 #endif
267 
268     if (offset >= 0x20) {
269         if (!(s->feat & TMU012_FEAT_3CHAN))
270 	    hw_error("tmu012_write: Bad channel offset %x\n", (int)offset);
271         sh_timer_write(s->timer[2], offset - 0x20, value);
272 	return;
273     }
274 
275     if (offset >= 0x14) {
276         sh_timer_write(s->timer[1], offset - 0x14, value);
277 	return;
278     }
279 
280     if (offset >= 0x08) {
281         sh_timer_write(s->timer[0], offset - 0x08, value);
282 	return;
283     }
284 
285     if (offset == 4) {
286         sh_timer_start_stop(s->timer[0], value & (1 << 0));
287         sh_timer_start_stop(s->timer[1], value & (1 << 1));
288         if (s->feat & TMU012_FEAT_3CHAN)
289             sh_timer_start_stop(s->timer[2], value & (1 << 2));
290 	else
291             if (value & (1 << 2))
292                 hw_error("tmu012_write: Bad channel\n");
293 
294 	s->tstr = value;
295 	return;
296     }
297 
298     if ((s->feat & TMU012_FEAT_TOCR) && offset == 0) {
299         s->tocr = value & (1 << 0);
300     }
301 }
302 
303 static const MemoryRegionOps tmu012_ops = {
304     .read = tmu012_read,
305     .write = tmu012_write,
306     .endianness = DEVICE_NATIVE_ENDIAN,
307 };
308 
309 void tmu012_init(MemoryRegion *sysmem, hwaddr base,
310                  int feat, uint32_t freq,
311 		 qemu_irq ch0_irq, qemu_irq ch1_irq,
312 		 qemu_irq ch2_irq0, qemu_irq ch2_irq1)
313 {
314     tmu012_state *s;
315     int timer_feat = (feat & TMU012_FEAT_EXTCLK) ? TIMER_FEAT_EXTCLK : 0;
316 
317     s = (tmu012_state *)g_malloc0(sizeof(tmu012_state));
318     s->feat = feat;
319     s->timer[0] = sh_timer_init(freq, timer_feat, ch0_irq);
320     s->timer[1] = sh_timer_init(freq, timer_feat, ch1_irq);
321     if (feat & TMU012_FEAT_3CHAN)
322         s->timer[2] = sh_timer_init(freq, timer_feat | TIMER_FEAT_CAPT,
323 				    ch2_irq0); /* ch2_irq1 not supported */
324 
325     memory_region_init_io(&s->iomem, NULL, &tmu012_ops, s,
326                           "timer", 0x100000000ULL);
327 
328     memory_region_init_alias(&s->iomem_p4, NULL, "timer-p4",
329                              &s->iomem, 0, 0x1000);
330     memory_region_add_subregion(sysmem, P4ADDR(base), &s->iomem_p4);
331 
332     memory_region_init_alias(&s->iomem_a7, NULL, "timer-a7",
333                              &s->iomem, 0, 0x1000);
334     memory_region_add_subregion(sysmem, A7ADDR(base), &s->iomem_a7);
335     /* ??? Save/restore.  */
336 }
337