xref: /openbmc/qemu/hw/timer/xilinx_timer.c (revision e6e03dcf)
1 /*
2  * QEMU model of the Xilinx timer block.
3  *
4  * Copyright (c) 2009 Edgar E. Iglesias.
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 
25 #include "qemu/osdep.h"
26 #include "hw/sysbus.h"
27 #include "hw/irq.h"
28 #include "hw/ptimer.h"
29 #include "hw/qdev-properties.h"
30 #include "qemu/log.h"
31 #include "qemu/module.h"
32 
33 #define D(x)
34 
35 #define R_TCSR     0
36 #define R_TLR      1
37 #define R_TCR      2
38 #define R_MAX      4
39 
40 #define TCSR_MDT        (1<<0)
41 #define TCSR_UDT        (1<<1)
42 #define TCSR_GENT       (1<<2)
43 #define TCSR_CAPT       (1<<3)
44 #define TCSR_ARHT       (1<<4)
45 #define TCSR_LOAD       (1<<5)
46 #define TCSR_ENIT       (1<<6)
47 #define TCSR_ENT        (1<<7)
48 #define TCSR_TINT       (1<<8)
49 #define TCSR_PWMA       (1<<9)
50 #define TCSR_ENALL      (1<<10)
51 
52 struct xlx_timer
53 {
54     ptimer_state *ptimer;
55     void *parent;
56     int nr; /* for debug.  */
57 
58     unsigned long timer_div;
59 
60     uint32_t regs[R_MAX];
61 };
62 
63 #define TYPE_XILINX_TIMER "xlnx.xps-timer"
64 #define XILINX_TIMER(obj) \
65     OBJECT_CHECK(struct timerblock, (obj), TYPE_XILINX_TIMER)
66 
67 struct timerblock
68 {
69     SysBusDevice parent_obj;
70 
71     MemoryRegion mmio;
72     qemu_irq irq;
73     uint8_t one_timer_only;
74     uint32_t freq_hz;
75     struct xlx_timer *timers;
76 };
77 
78 static inline unsigned int num_timers(struct timerblock *t)
79 {
80     return 2 - t->one_timer_only;
81 }
82 
83 static inline unsigned int timer_from_addr(hwaddr addr)
84 {
85     /* Timers get a 4x32bit control reg area each.  */
86     return addr >> 2;
87 }
88 
89 static void timer_update_irq(struct timerblock *t)
90 {
91     unsigned int i, irq = 0;
92     uint32_t csr;
93 
94     for (i = 0; i < num_timers(t); i++) {
95         csr = t->timers[i].regs[R_TCSR];
96         irq |= (csr & TCSR_TINT) && (csr & TCSR_ENIT);
97     }
98 
99     /* All timers within the same slave share a single IRQ line.  */
100     qemu_set_irq(t->irq, !!irq);
101 }
102 
103 static uint64_t
104 timer_read(void *opaque, hwaddr addr, unsigned int size)
105 {
106     struct timerblock *t = opaque;
107     struct xlx_timer *xt;
108     uint32_t r = 0;
109     unsigned int timer;
110 
111     addr >>= 2;
112     timer = timer_from_addr(addr);
113     xt = &t->timers[timer];
114     /* Further decoding to address a specific timers reg.  */
115     addr &= 0x3;
116     switch (addr)
117     {
118         case R_TCR:
119                 r = ptimer_get_count(xt->ptimer);
120                 if (!(xt->regs[R_TCSR] & TCSR_UDT))
121                     r = ~r;
122                 D(qemu_log("xlx_timer t=%d read counter=%x udt=%d\n",
123                          timer, r, xt->regs[R_TCSR] & TCSR_UDT));
124             break;
125         default:
126             if (addr < ARRAY_SIZE(xt->regs))
127                 r = xt->regs[addr];
128             break;
129 
130     }
131     D(fprintf(stderr, "%s timer=%d %x=%x\n", __func__, timer, addr * 4, r));
132     return r;
133 }
134 
135 /* Must be called inside ptimer transaction block */
136 static void timer_enable(struct xlx_timer *xt)
137 {
138     uint64_t count;
139 
140     D(fprintf(stderr, "%s timer=%d down=%d\n", __func__,
141               xt->nr, xt->regs[R_TCSR] & TCSR_UDT));
142 
143     ptimer_stop(xt->ptimer);
144 
145     if (xt->regs[R_TCSR] & TCSR_UDT)
146         count = xt->regs[R_TLR];
147     else
148         count = ~0 - xt->regs[R_TLR];
149     ptimer_set_limit(xt->ptimer, count, 1);
150     ptimer_run(xt->ptimer, 1);
151 }
152 
153 static void
154 timer_write(void *opaque, hwaddr addr,
155             uint64_t val64, unsigned int size)
156 {
157     struct timerblock *t = opaque;
158     struct xlx_timer *xt;
159     unsigned int timer;
160     uint32_t value = val64;
161 
162     addr >>= 2;
163     timer = timer_from_addr(addr);
164     xt = &t->timers[timer];
165     D(fprintf(stderr, "%s addr=%x val=%x (timer=%d off=%d)\n",
166              __func__, addr * 4, value, timer, addr & 3));
167     /* Further decoding to address a specific timers reg.  */
168     addr &= 3;
169     switch (addr)
170     {
171         case R_TCSR:
172             if (value & TCSR_TINT)
173                 value &= ~TCSR_TINT;
174 
175             xt->regs[addr] = value & 0x7ff;
176             if (value & TCSR_ENT) {
177                 ptimer_transaction_begin(xt->ptimer);
178                 timer_enable(xt);
179                 ptimer_transaction_commit(xt->ptimer);
180             }
181             break;
182 
183         default:
184             if (addr < ARRAY_SIZE(xt->regs))
185                 xt->regs[addr] = value;
186             break;
187     }
188     timer_update_irq(t);
189 }
190 
191 static const MemoryRegionOps timer_ops = {
192     .read = timer_read,
193     .write = timer_write,
194     .endianness = DEVICE_NATIVE_ENDIAN,
195     .valid = {
196         .min_access_size = 4,
197         .max_access_size = 4
198     }
199 };
200 
201 static void timer_hit(void *opaque)
202 {
203     struct xlx_timer *xt = opaque;
204     struct timerblock *t = xt->parent;
205     D(fprintf(stderr, "%s %d\n", __func__, xt->nr));
206     xt->regs[R_TCSR] |= TCSR_TINT;
207 
208     if (xt->regs[R_TCSR] & TCSR_ARHT)
209         timer_enable(xt);
210     timer_update_irq(t);
211 }
212 
213 static void xilinx_timer_realize(DeviceState *dev, Error **errp)
214 {
215     struct timerblock *t = XILINX_TIMER(dev);
216     unsigned int i;
217 
218     /* Init all the ptimers.  */
219     t->timers = g_malloc0(sizeof t->timers[0] * num_timers(t));
220     for (i = 0; i < num_timers(t); i++) {
221         struct xlx_timer *xt = &t->timers[i];
222 
223         xt->parent = t;
224         xt->nr = i;
225         xt->ptimer = ptimer_init(timer_hit, xt, PTIMER_POLICY_DEFAULT);
226         ptimer_transaction_begin(xt->ptimer);
227         ptimer_set_freq(xt->ptimer, t->freq_hz);
228         ptimer_transaction_commit(xt->ptimer);
229     }
230 
231     memory_region_init_io(&t->mmio, OBJECT(t), &timer_ops, t, "xlnx.xps-timer",
232                           R_MAX * 4 * num_timers(t));
233     sysbus_init_mmio(SYS_BUS_DEVICE(dev), &t->mmio);
234 }
235 
236 static void xilinx_timer_init(Object *obj)
237 {
238     struct timerblock *t = XILINX_TIMER(obj);
239 
240     /* All timers share a single irq line.  */
241     sysbus_init_irq(SYS_BUS_DEVICE(obj), &t->irq);
242 }
243 
244 static Property xilinx_timer_properties[] = {
245     DEFINE_PROP_UINT32("clock-frequency", struct timerblock, freq_hz,
246                                                                 62 * 1000000),
247     DEFINE_PROP_UINT8("one-timer-only", struct timerblock, one_timer_only, 0),
248     DEFINE_PROP_END_OF_LIST(),
249 };
250 
251 static void xilinx_timer_class_init(ObjectClass *klass, void *data)
252 {
253     DeviceClass *dc = DEVICE_CLASS(klass);
254 
255     dc->realize = xilinx_timer_realize;
256     dc->props = xilinx_timer_properties;
257 }
258 
259 static const TypeInfo xilinx_timer_info = {
260     .name          = TYPE_XILINX_TIMER,
261     .parent        = TYPE_SYS_BUS_DEVICE,
262     .instance_size = sizeof(struct timerblock),
263     .instance_init = xilinx_timer_init,
264     .class_init    = xilinx_timer_class_init,
265 };
266 
267 static void xilinx_timer_register_types(void)
268 {
269     type_register_static(&xilinx_timer_info);
270 }
271 
272 type_init(xilinx_timer_register_types)
273