xref: /openbmc/qemu/hw/timer/sh_timer.c (revision fcf5ef2a)
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/sh4/sh.h"
14 #include "qemu/timer.h"
15 #include "qemu/main-loop.h"
16 #include "exec/address-spaces.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     default:
79         hw_error("sh_timer_read: Bad offset %x\n", (int)offset);
80         return 0;
81     }
82 }
83 
84 static void sh_timer_write(void *opaque, hwaddr offset,
85                             uint32_t value)
86 {
87     sh_timer_state *s = (sh_timer_state *)opaque;
88     int freq;
89 
90     switch (offset >> 2) {
91     case OFFSET_TCOR:
92         s->tcor = value;
93         ptimer_set_limit(s->timer, s->tcor, 0);
94         break;
95     case OFFSET_TCNT:
96         s->tcnt = value;
97         ptimer_set_count(s->timer, s->tcnt);
98         break;
99     case OFFSET_TCR:
100         if (s->enabled) {
101             /* Pause the timer if it is running.  This may cause some
102                inaccuracy dure to rounding, but avoids a whole lot of other
103                messyness.  */
104             ptimer_stop(s->timer);
105         }
106         freq = s->freq;
107         /* ??? Need to recalculate expiry time after changing divisor.  */
108         switch (value & TIMER_TCR_TPSC) {
109         case 0: freq >>= 2; break;
110         case 1: freq >>= 4; break;
111         case 2: freq >>= 6; break;
112         case 3: freq >>= 8; break;
113         case 4: freq >>= 10; break;
114 	case 6:
115 	case 7: if (s->feat & TIMER_FEAT_EXTCLK) break;
116 	default: hw_error("sh_timer_write: Reserved TPSC value\n"); break;
117         }
118         switch ((value & TIMER_TCR_CKEG) >> 3) {
119 	case 0: break;
120         case 1:
121         case 2:
122         case 3: if (s->feat & TIMER_FEAT_EXTCLK) break;
123 	default: hw_error("sh_timer_write: Reserved CKEG value\n"); break;
124         }
125         switch ((value & TIMER_TCR_ICPE) >> 6) {
126 	case 0: break;
127         case 2:
128         case 3: if (s->feat & TIMER_FEAT_CAPT) break;
129 	default: hw_error("sh_timer_write: Reserved ICPE value\n"); break;
130         }
131 	if ((value & TIMER_TCR_UNF) == 0)
132             s->int_level = 0;
133 
134 	value &= ~TIMER_TCR_UNF;
135 
136 	if ((value & TIMER_TCR_ICPF) && (!(s->feat & TIMER_FEAT_CAPT)))
137             hw_error("sh_timer_write: Reserved ICPF value\n");
138 
139 	value &= ~TIMER_TCR_ICPF; /* capture not supported */
140 
141 	if (value & TIMER_TCR_RESERVED)
142             hw_error("sh_timer_write: Reserved TCR bits set\n");
143         s->tcr = value;
144         ptimer_set_limit(s->timer, s->tcor, 0);
145         ptimer_set_freq(s->timer, freq);
146         if (s->enabled) {
147             /* Restart the timer if still enabled.  */
148             ptimer_run(s->timer, 0);
149         }
150         break;
151     case OFFSET_TCPR:
152         if (s->feat & TIMER_FEAT_CAPT) {
153             s->tcpr = value;
154 	    break;
155 	}
156     default:
157         hw_error("sh_timer_write: Bad offset %x\n", (int)offset);
158     }
159     sh_timer_update(s);
160 }
161 
162 static void sh_timer_start_stop(void *opaque, int enable)
163 {
164     sh_timer_state *s = (sh_timer_state *)opaque;
165 
166 #ifdef DEBUG_TIMER
167     printf("sh_timer_start_stop %d (%d)\n", enable, s->enabled);
168 #endif
169 
170     if (s->enabled && !enable) {
171         ptimer_stop(s->timer);
172     }
173     if (!s->enabled && enable) {
174         ptimer_run(s->timer, 0);
175     }
176     s->enabled = !!enable;
177 
178 #ifdef DEBUG_TIMER
179     printf("sh_timer_start_stop done %d\n", s->enabled);
180 #endif
181 }
182 
183 static void sh_timer_tick(void *opaque)
184 {
185     sh_timer_state *s = (sh_timer_state *)opaque;
186     s->int_level = s->enabled;
187     sh_timer_update(s);
188 }
189 
190 static void *sh_timer_init(uint32_t freq, int feat, qemu_irq irq)
191 {
192     sh_timer_state *s;
193     QEMUBH *bh;
194 
195     s = (sh_timer_state *)g_malloc0(sizeof(sh_timer_state));
196     s->freq = freq;
197     s->feat = feat;
198     s->tcor = 0xffffffff;
199     s->tcnt = 0xffffffff;
200     s->tcpr = 0xdeadbeef;
201     s->tcr = 0;
202     s->enabled = 0;
203     s->irq = irq;
204 
205     bh = qemu_bh_new(sh_timer_tick, s);
206     s->timer = ptimer_init(bh, PTIMER_POLICY_DEFAULT);
207 
208     sh_timer_write(s, OFFSET_TCOR >> 2, s->tcor);
209     sh_timer_write(s, OFFSET_TCNT >> 2, s->tcnt);
210     sh_timer_write(s, OFFSET_TCPR >> 2, s->tcpr);
211     sh_timer_write(s, OFFSET_TCR  >> 2, s->tcpr);
212     /* ??? Save/restore.  */
213     return s;
214 }
215 
216 typedef struct {
217     MemoryRegion iomem;
218     MemoryRegion iomem_p4;
219     MemoryRegion iomem_a7;
220     void *timer[3];
221     int level[3];
222     uint32_t tocr;
223     uint32_t tstr;
224     int feat;
225 } tmu012_state;
226 
227 static uint64_t tmu012_read(void *opaque, hwaddr offset,
228                             unsigned size)
229 {
230     tmu012_state *s = (tmu012_state *)opaque;
231 
232 #ifdef DEBUG_TIMER
233     printf("tmu012_read 0x%lx\n", (unsigned long) offset);
234 #endif
235 
236     if (offset >= 0x20) {
237         if (!(s->feat & TMU012_FEAT_3CHAN))
238 	    hw_error("tmu012_write: Bad channel offset %x\n", (int)offset);
239         return sh_timer_read(s->timer[2], offset - 0x20);
240     }
241 
242     if (offset >= 0x14)
243         return sh_timer_read(s->timer[1], offset - 0x14);
244 
245     if (offset >= 0x08)
246         return sh_timer_read(s->timer[0], offset - 0x08);
247 
248     if (offset == 4)
249         return s->tstr;
250 
251     if ((s->feat & TMU012_FEAT_TOCR) && offset == 0)
252         return s->tocr;
253 
254     hw_error("tmu012_write: Bad offset %x\n", (int)offset);
255     return 0;
256 }
257 
258 static void tmu012_write(void *opaque, hwaddr offset,
259                         uint64_t value, unsigned size)
260 {
261     tmu012_state *s = (tmu012_state *)opaque;
262 
263 #ifdef DEBUG_TIMER
264     printf("tmu012_write 0x%lx 0x%08x\n", (unsigned long) offset, value);
265 #endif
266 
267     if (offset >= 0x20) {
268         if (!(s->feat & TMU012_FEAT_3CHAN))
269 	    hw_error("tmu012_write: Bad channel offset %x\n", (int)offset);
270         sh_timer_write(s->timer[2], offset - 0x20, value);
271 	return;
272     }
273 
274     if (offset >= 0x14) {
275         sh_timer_write(s->timer[1], offset - 0x14, value);
276 	return;
277     }
278 
279     if (offset >= 0x08) {
280         sh_timer_write(s->timer[0], offset - 0x08, value);
281 	return;
282     }
283 
284     if (offset == 4) {
285         sh_timer_start_stop(s->timer[0], value & (1 << 0));
286         sh_timer_start_stop(s->timer[1], value & (1 << 1));
287         if (s->feat & TMU012_FEAT_3CHAN)
288             sh_timer_start_stop(s->timer[2], value & (1 << 2));
289 	else
290             if (value & (1 << 2))
291                 hw_error("tmu012_write: Bad channel\n");
292 
293 	s->tstr = value;
294 	return;
295     }
296 
297     if ((s->feat & TMU012_FEAT_TOCR) && offset == 0) {
298         s->tocr = value & (1 << 0);
299     }
300 }
301 
302 static const MemoryRegionOps tmu012_ops = {
303     .read = tmu012_read,
304     .write = tmu012_write,
305     .endianness = DEVICE_NATIVE_ENDIAN,
306 };
307 
308 void tmu012_init(MemoryRegion *sysmem, hwaddr base,
309                  int feat, uint32_t freq,
310 		 qemu_irq ch0_irq, qemu_irq ch1_irq,
311 		 qemu_irq ch2_irq0, qemu_irq ch2_irq1)
312 {
313     tmu012_state *s;
314     int timer_feat = (feat & TMU012_FEAT_EXTCLK) ? TIMER_FEAT_EXTCLK : 0;
315 
316     s = (tmu012_state *)g_malloc0(sizeof(tmu012_state));
317     s->feat = feat;
318     s->timer[0] = sh_timer_init(freq, timer_feat, ch0_irq);
319     s->timer[1] = sh_timer_init(freq, timer_feat, ch1_irq);
320     if (feat & TMU012_FEAT_3CHAN)
321         s->timer[2] = sh_timer_init(freq, timer_feat | TIMER_FEAT_CAPT,
322 				    ch2_irq0); /* ch2_irq1 not supported */
323 
324     memory_region_init_io(&s->iomem, NULL, &tmu012_ops, s,
325                           "timer", 0x100000000ULL);
326 
327     memory_region_init_alias(&s->iomem_p4, NULL, "timer-p4",
328                              &s->iomem, 0, 0x1000);
329     memory_region_add_subregion(sysmem, P4ADDR(base), &s->iomem_p4);
330 
331     memory_region_init_alias(&s->iomem_a7, NULL, "timer-a7",
332                              &s->iomem, 0, 0x1000);
333     memory_region_add_subregion(sysmem, A7ADDR(base), &s->iomem_a7);
334     /* ??? Save/restore.  */
335 }
336