Merge remote-tracking branch 'remotes/philmd-gitlab/tags/renesas-20201027' into staging
[qemu.git] / hw / char / etraxfs_ser.c
1 /*
2 * QEMU ETRAX System Emulator
3 *
4 * Copyright (c) 2007 Edgar E. Iglesias, Axis Communications AB.
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/irq.h"
27 #include "hw/qdev-properties.h"
28 #include "hw/sysbus.h"
29 #include "chardev/char-fe.h"
30 #include "qemu/log.h"
31 #include "qemu/module.h"
32 #include "qom/object.h"
33
34 #define D(x)
35
36 #define RW_TR_CTRL (0x00 / 4)
37 #define RW_TR_DMA_EN (0x04 / 4)
38 #define RW_REC_CTRL (0x08 / 4)
39 #define RW_DOUT (0x1c / 4)
40 #define RS_STAT_DIN (0x20 / 4)
41 #define R_STAT_DIN (0x24 / 4)
42 #define RW_INTR_MASK (0x2c / 4)
43 #define RW_ACK_INTR (0x30 / 4)
44 #define R_INTR (0x34 / 4)
45 #define R_MASKED_INTR (0x38 / 4)
46 #define R_MAX (0x3c / 4)
47
48 #define STAT_DAV 16
49 #define STAT_TR_IDLE 22
50 #define STAT_TR_RDY 24
51
52 #define TYPE_ETRAX_FS_SERIAL "etraxfs,serial"
53 typedef struct ETRAXSerial ETRAXSerial;
54 DECLARE_INSTANCE_CHECKER(ETRAXSerial, ETRAX_SERIAL,
55 TYPE_ETRAX_FS_SERIAL)
56
57 struct ETRAXSerial {
58 SysBusDevice parent_obj;
59
60 MemoryRegion mmio;
61 CharBackend chr;
62 qemu_irq irq;
63
64 int pending_tx;
65
66 uint8_t rx_fifo[16];
67 unsigned int rx_fifo_pos;
68 unsigned int rx_fifo_len;
69
70 /* Control registers. */
71 uint32_t regs[R_MAX];
72 };
73
74 static void ser_update_irq(ETRAXSerial *s)
75 {
76
77 if (s->rx_fifo_len) {
78 s->regs[R_INTR] |= 8;
79 } else {
80 s->regs[R_INTR] &= ~8;
81 }
82
83 s->regs[R_MASKED_INTR] = s->regs[R_INTR] & s->regs[RW_INTR_MASK];
84 qemu_set_irq(s->irq, !!s->regs[R_MASKED_INTR]);
85 }
86
87 static uint64_t
88 ser_read(void *opaque, hwaddr addr, unsigned int size)
89 {
90 ETRAXSerial *s = opaque;
91 uint32_t r = 0;
92
93 addr >>= 2;
94 switch (addr)
95 {
96 case R_STAT_DIN:
97 r = s->rx_fifo[(s->rx_fifo_pos - s->rx_fifo_len) & 15];
98 if (s->rx_fifo_len) {
99 r |= 1 << STAT_DAV;
100 }
101 r |= 1 << STAT_TR_RDY;
102 r |= 1 << STAT_TR_IDLE;
103 break;
104 case RS_STAT_DIN:
105 r = s->rx_fifo[(s->rx_fifo_pos - s->rx_fifo_len) & 15];
106 if (s->rx_fifo_len) {
107 r |= 1 << STAT_DAV;
108 s->rx_fifo_len--;
109 }
110 r |= 1 << STAT_TR_RDY;
111 r |= 1 << STAT_TR_IDLE;
112 break;
113 default:
114 r = s->regs[addr];
115 D(qemu_log("%s " TARGET_FMT_plx "=%x\n", __func__, addr, r));
116 break;
117 }
118 return r;
119 }
120
121 static void
122 ser_write(void *opaque, hwaddr addr,
123 uint64_t val64, unsigned int size)
124 {
125 ETRAXSerial *s = opaque;
126 uint32_t value = val64;
127 unsigned char ch = val64;
128
129 D(qemu_log("%s " TARGET_FMT_plx "=%x\n", __func__, addr, value));
130 addr >>= 2;
131 switch (addr)
132 {
133 case RW_DOUT:
134 /* XXX this blocks entire thread. Rewrite to use
135 * qemu_chr_fe_write and background I/O callbacks */
136 qemu_chr_fe_write_all(&s->chr, &ch, 1);
137 s->regs[R_INTR] |= 3;
138 s->pending_tx = 1;
139 s->regs[addr] = value;
140 break;
141 case RW_ACK_INTR:
142 if (s->pending_tx) {
143 value &= ~1;
144 s->pending_tx = 0;
145 D(qemu_log("fixedup value=%x r_intr=%x\n",
146 value, s->regs[R_INTR]));
147 }
148 s->regs[addr] = value;
149 s->regs[R_INTR] &= ~value;
150 D(printf("r_intr=%x\n", s->regs[R_INTR]));
151 break;
152 default:
153 s->regs[addr] = value;
154 break;
155 }
156 ser_update_irq(s);
157 }
158
159 static const MemoryRegionOps ser_ops = {
160 .read = ser_read,
161 .write = ser_write,
162 .endianness = DEVICE_NATIVE_ENDIAN,
163 .valid = {
164 .min_access_size = 4,
165 .max_access_size = 4
166 }
167 };
168
169 static Property etraxfs_ser_properties[] = {
170 DEFINE_PROP_CHR("chardev", ETRAXSerial, chr),
171 DEFINE_PROP_END_OF_LIST(),
172 };
173
174 static void serial_receive(void *opaque, const uint8_t *buf, int size)
175 {
176 ETRAXSerial *s = opaque;
177 int i;
178
179 /* Got a byte. */
180 if (s->rx_fifo_len >= 16) {
181 D(qemu_log("WARNING: UART dropped char.\n"));
182 return;
183 }
184
185 for (i = 0; i < size; i++) {
186 s->rx_fifo[s->rx_fifo_pos] = buf[i];
187 s->rx_fifo_pos++;
188 s->rx_fifo_pos &= 15;
189 s->rx_fifo_len++;
190 }
191
192 ser_update_irq(s);
193 }
194
195 static int serial_can_receive(void *opaque)
196 {
197 ETRAXSerial *s = opaque;
198
199 /* Is the receiver enabled? */
200 if (!(s->regs[RW_REC_CTRL] & (1 << 3))) {
201 return 0;
202 }
203
204 return sizeof(s->rx_fifo) - s->rx_fifo_len;
205 }
206
207 static void serial_event(void *opaque, QEMUChrEvent event)
208 {
209
210 }
211
212 static void etraxfs_ser_reset(DeviceState *d)
213 {
214 ETRAXSerial *s = ETRAX_SERIAL(d);
215
216 /* transmitter begins ready and idle. */
217 s->regs[RS_STAT_DIN] |= (1 << STAT_TR_RDY);
218 s->regs[RS_STAT_DIN] |= (1 << STAT_TR_IDLE);
219
220 s->regs[RW_REC_CTRL] = 0x10000;
221
222 }
223
224 static void etraxfs_ser_init(Object *obj)
225 {
226 ETRAXSerial *s = ETRAX_SERIAL(obj);
227 SysBusDevice *dev = SYS_BUS_DEVICE(obj);
228
229 sysbus_init_irq(dev, &s->irq);
230 memory_region_init_io(&s->mmio, obj, &ser_ops, s,
231 "etraxfs-serial", R_MAX * 4);
232 sysbus_init_mmio(dev, &s->mmio);
233 }
234
235 static void etraxfs_ser_realize(DeviceState *dev, Error **errp)
236 {
237 ETRAXSerial *s = ETRAX_SERIAL(dev);
238
239 qemu_chr_fe_set_handlers(&s->chr,
240 serial_can_receive, serial_receive,
241 serial_event, NULL, s, NULL, true);
242 }
243
244 static void etraxfs_ser_class_init(ObjectClass *klass, void *data)
245 {
246 DeviceClass *dc = DEVICE_CLASS(klass);
247
248 dc->reset = etraxfs_ser_reset;
249 device_class_set_props(dc, etraxfs_ser_properties);
250 dc->realize = etraxfs_ser_realize;
251 }
252
253 static const TypeInfo etraxfs_ser_info = {
254 .name = TYPE_ETRAX_FS_SERIAL,
255 .parent = TYPE_SYS_BUS_DEVICE,
256 .instance_size = sizeof(ETRAXSerial),
257 .instance_init = etraxfs_ser_init,
258 .class_init = etraxfs_ser_class_init,
259 };
260
261 static void etraxfs_serial_register_types(void)
262 {
263 type_register_static(&etraxfs_ser_info);
264 }
265
266 type_init(etraxfs_serial_register_types)