xref: /openbmc/qemu/hw/timer/renesas_cmt.c (revision efb91426)
1 /*
2  * Renesas 16bit Compare-match timer
3  *
4  * Datasheet: RX62N Group, RX621 Group User's Manual: Hardware
5  *            (Rev.1.40 R01UH0033EJ0140)
6  *
7  * Copyright (c) 2019 Yoshinori Sato
8  *
9  * SPDX-License-Identifier: GPL-2.0-or-later
10  *
11  * This program is free software; you can redistribute it and/or modify it
12  * under the terms and conditions of the GNU General Public License,
13  * version 2 or later, as published by the Free Software Foundation.
14  *
15  * This program is distributed in the hope it will be useful, but WITHOUT
16  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
17  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
18  * more details.
19  *
20  * You should have received a copy of the GNU General Public License along with
21  * this program.  If not, see <http://www.gnu.org/licenses/>.
22  */
23 
24 #include "qemu/osdep.h"
25 #include "qemu/log.h"
26 #include "hw/irq.h"
27 #include "hw/registerfields.h"
28 #include "hw/qdev-properties.h"
29 #include "hw/timer/renesas_cmt.h"
30 #include "migration/vmstate.h"
31 
32 /*
33  *  +0 CMSTR - common control
34  *  +2 CMCR  - ch0
35  *  +4 CMCNT - ch0
36  *  +6 CMCOR - ch0
37  *  +8 CMCR  - ch1
38  * +10 CMCNT - ch1
39  * +12 CMCOR - ch1
40  * If we think that the address of CH 0 has an offset of +2,
41  * we can treat it with the same address as CH 1, so define it like that.
42  */
43 REG16(CMSTR, 0)
44   FIELD(CMSTR, STR0, 0, 1)
45   FIELD(CMSTR, STR1, 1, 1)
46   FIELD(CMSTR, STR,  0, 2)
47 /* This addeess is channel offset */
48 REG16(CMCR, 0)
49   FIELD(CMCR, CKS,  0, 2)
50   FIELD(CMCR, CMIE, 6, 1)
51 REG16(CMCNT, 2)
52 REG16(CMCOR, 4)
53 
54 static void update_events(RCMTState *cmt, int ch)
55 {
56     int64_t next_time;
57 
58     if ((cmt->cmstr & (1 << ch)) == 0) {
59         /* count disable, so not happened next event. */
60         return;
61     }
62     next_time = cmt->cmcor[ch] - cmt->cmcnt[ch];
63     next_time *= NANOSECONDS_PER_SECOND;
64     next_time /= cmt->input_freq;
65     /*
66      * CKS -> div rate
67      *  0 -> 8 (1 << 3)
68      *  1 -> 32 (1 << 5)
69      *  2 -> 128 (1 << 7)
70      *  3 -> 512 (1 << 9)
71      */
72     next_time *= 1 << (3 + FIELD_EX16(cmt->cmcr[ch], CMCR, CKS) * 2);
73     next_time += qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
74     timer_mod(&cmt->timer[ch], next_time);
75 }
76 
77 static int64_t read_cmcnt(RCMTState *cmt, int ch)
78 {
79     int64_t delta, now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
80 
81     if (cmt->cmstr & (1 << ch)) {
82         delta = (now - cmt->tick[ch]);
83         delta /= NANOSECONDS_PER_SECOND;
84         delta /= cmt->input_freq;
85         delta /= 1 << (3 + FIELD_EX16(cmt->cmcr[ch], CMCR, CKS) * 2);
86         cmt->tick[ch] = now;
87         return cmt->cmcnt[ch] + delta;
88     } else {
89         return cmt->cmcnt[ch];
90     }
91 }
92 
93 static uint64_t cmt_read(void *opaque, hwaddr offset, unsigned size)
94 {
95     RCMTState *cmt = opaque;
96     int ch = offset / 0x08;
97     uint64_t ret;
98 
99     if (offset == A_CMSTR) {
100         ret = 0;
101         ret = FIELD_DP16(ret, CMSTR, STR,
102                          FIELD_EX16(cmt->cmstr, CMSTR, STR));
103         return ret;
104     } else {
105         offset &= 0x07;
106         if (ch == 0) {
107             offset -= 0x02;
108         }
109         switch (offset) {
110         case A_CMCR:
111             ret = 0;
112             ret = FIELD_DP16(ret, CMCR, CKS,
113                              FIELD_EX16(cmt->cmstr, CMCR, CKS));
114             ret = FIELD_DP16(ret, CMCR, CMIE,
115                              FIELD_EX16(cmt->cmstr, CMCR, CMIE));
116             return ret;
117         case A_CMCNT:
118             return read_cmcnt(cmt, ch);
119         case A_CMCOR:
120             return cmt->cmcor[ch];
121         }
122     }
123     qemu_log_mask(LOG_UNIMP, "renesas_cmt: Register 0x%" HWADDR_PRIX " "
124                              "not implemented\n",
125                   offset);
126     return UINT64_MAX;
127 }
128 
129 static void start_stop(RCMTState *cmt, int ch, int st)
130 {
131     if (st) {
132         update_events(cmt, ch);
133     } else {
134         timer_del(&cmt->timer[ch]);
135     }
136 }
137 
138 static void cmt_write(void *opaque, hwaddr offset, uint64_t val, unsigned size)
139 {
140     RCMTState *cmt = opaque;
141     int ch = offset / 0x08;
142 
143     if (offset == A_CMSTR) {
144         cmt->cmstr = FIELD_EX16(val, CMSTR, STR);
145         start_stop(cmt, 0, FIELD_EX16(cmt->cmstr, CMSTR, STR0));
146         start_stop(cmt, 1, FIELD_EX16(cmt->cmstr, CMSTR, STR1));
147     } else {
148         offset &= 0x07;
149         if (ch == 0) {
150             offset -= 0x02;
151         }
152         switch (offset) {
153         case A_CMCR:
154             cmt->cmcr[ch] = FIELD_DP16(cmt->cmcr[ch], CMCR, CKS,
155                                        FIELD_EX16(val, CMCR, CKS));
156             cmt->cmcr[ch] = FIELD_DP16(cmt->cmcr[ch], CMCR, CMIE,
157                                        FIELD_EX16(val, CMCR, CMIE));
158             break;
159         case 2:
160             cmt->cmcnt[ch] = val;
161             break;
162         case 4:
163             cmt->cmcor[ch] = val;
164             break;
165         default:
166             qemu_log_mask(LOG_UNIMP, "renesas_cmt: Register 0x%" HWADDR_PRIX " "
167                                      "not implemented\n",
168                           offset);
169             return;
170         }
171         if (FIELD_EX16(cmt->cmstr, CMSTR, STR) & (1 << ch)) {
172             update_events(cmt, ch);
173         }
174     }
175 }
176 
177 static const MemoryRegionOps cmt_ops = {
178     .write = cmt_write,
179     .read  = cmt_read,
180     .endianness = DEVICE_NATIVE_ENDIAN,
181     .impl = {
182         .min_access_size = 2,
183         .max_access_size = 2,
184     },
185     .valid = {
186         .min_access_size = 2,
187         .max_access_size = 2,
188     },
189 };
190 
191 static void timer_events(RCMTState *cmt, int ch)
192 {
193     cmt->cmcnt[ch] = 0;
194     cmt->tick[ch] = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
195     update_events(cmt, ch);
196     if (FIELD_EX16(cmt->cmcr[ch], CMCR, CMIE)) {
197         qemu_irq_pulse(cmt->cmi[ch]);
198     }
199 }
200 
201 static void timer_event0(void *opaque)
202 {
203     RCMTState *cmt = opaque;
204 
205     timer_events(cmt, 0);
206 }
207 
208 static void timer_event1(void *opaque)
209 {
210     RCMTState *cmt = opaque;
211 
212     timer_events(cmt, 1);
213 }
214 
215 static void rcmt_reset(DeviceState *dev)
216 {
217     RCMTState *cmt = RCMT(dev);
218     cmt->cmstr = 0;
219     cmt->cmcr[0] = cmt->cmcr[1] = 0;
220     cmt->cmcnt[0] = cmt->cmcnt[1] = 0;
221     cmt->cmcor[0] = cmt->cmcor[1] = 0xffff;
222 }
223 
224 static void rcmt_init(Object *obj)
225 {
226     SysBusDevice *d = SYS_BUS_DEVICE(obj);
227     RCMTState *cmt = RCMT(obj);
228     int i;
229 
230     memory_region_init_io(&cmt->memory, OBJECT(cmt), &cmt_ops,
231                           cmt, "renesas-cmt", 0x10);
232     sysbus_init_mmio(d, &cmt->memory);
233 
234     for (i = 0; i < ARRAY_SIZE(cmt->cmi); i++) {
235         sysbus_init_irq(d, &cmt->cmi[i]);
236     }
237     timer_init_ns(&cmt->timer[0], QEMU_CLOCK_VIRTUAL, timer_event0, cmt);
238     timer_init_ns(&cmt->timer[1], QEMU_CLOCK_VIRTUAL, timer_event1, cmt);
239 }
240 
241 static const VMStateDescription vmstate_rcmt = {
242     .name = "rx-cmt",
243     .version_id = 1,
244     .minimum_version_id = 1,
245     .fields = (const VMStateField[]) {
246         VMSTATE_UINT16(cmstr, RCMTState),
247         VMSTATE_UINT16_ARRAY(cmcr, RCMTState, CMT_CH),
248         VMSTATE_UINT16_ARRAY(cmcnt, RCMTState, CMT_CH),
249         VMSTATE_UINT16_ARRAY(cmcor, RCMTState, CMT_CH),
250         VMSTATE_INT64_ARRAY(tick, RCMTState, CMT_CH),
251         VMSTATE_TIMER_ARRAY(timer, RCMTState, CMT_CH),
252         VMSTATE_END_OF_LIST()
253     }
254 };
255 
256 static Property rcmt_properties[] = {
257     DEFINE_PROP_UINT64("input-freq", RCMTState, input_freq, 0),
258     DEFINE_PROP_END_OF_LIST(),
259 };
260 
261 static void rcmt_class_init(ObjectClass *klass, void *data)
262 {
263     DeviceClass *dc = DEVICE_CLASS(klass);
264 
265     dc->vmsd = &vmstate_rcmt;
266     dc->reset = rcmt_reset;
267     device_class_set_props(dc, rcmt_properties);
268 }
269 
270 static const TypeInfo rcmt_info = {
271     .name = TYPE_RENESAS_CMT,
272     .parent = TYPE_SYS_BUS_DEVICE,
273     .instance_size = sizeof(RCMTState),
274     .instance_init = rcmt_init,
275     .class_init = rcmt_class_init,
276 };
277 
278 static void rcmt_register_types(void)
279 {
280     type_register_static(&rcmt_info);
281 }
282 
283 type_init(rcmt_register_types)
284