1 /*
2 * ADC registers for Xilinx Zynq Platform
3 *
4 * Copyright (c) 2015 Guenter Roeck
5 * Based on hw/misc/zynq_slcr.c, written by Michal Simek
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 *
12 * You should have received a copy of the GNU General Public License along
13 * with this program; if not, see <http://www.gnu.org/licenses/>.
14 */
15
16 #include "qemu/osdep.h"
17 #include "hw/irq.h"
18 #include "hw/adc/zynq-xadc.h"
19 #include "migration/vmstate.h"
20 #include "qemu/timer.h"
21 #include "qemu/log.h"
22 #include "qemu/module.h"
23
24 enum {
25 CFG = 0x000 / 4,
26 INT_STS,
27 INT_MASK,
28 MSTS,
29 CMDFIFO,
30 RDFIFO,
31 MCTL,
32 };
33
34 #define CFG_ENABLE BIT(31)
35 #define CFG_CFIFOTH_SHIFT 20
36 #define CFG_CFIFOTH_LENGTH 4
37 #define CFG_DFIFOTH_SHIFT 16
38 #define CFG_DFIFOTH_LENGTH 4
39 #define CFG_WEDGE BIT(13)
40 #define CFG_REDGE BIT(12)
41 #define CFG_TCKRATE_SHIFT 8
42 #define CFG_TCKRATE_LENGTH 2
43
44 #define CFG_TCKRATE_DIV(x) (0x1 << (x - 1))
45
46 #define CFG_IGAP_SHIFT 0
47 #define CFG_IGAP_LENGTH 5
48
49 #define INT_CFIFO_LTH BIT(9)
50 #define INT_DFIFO_GTH BIT(8)
51 #define INT_OT BIT(7)
52 #define INT_ALM_SHIFT 0
53 #define INT_ALM_LENGTH 7
54 #define INT_ALM_MASK (((1 << INT_ALM_LENGTH) - 1) << INT_ALM_SHIFT)
55
56 #define INT_ALL (INT_CFIFO_LTH | INT_DFIFO_GTH | INT_OT | INT_ALM_MASK)
57
58 #define MSTS_CFIFO_LVL_SHIFT 16
59 #define MSTS_CFIFO_LVL_LENGTH 4
60 #define MSTS_DFIFO_LVL_SHIFT 12
61 #define MSTS_DFIFO_LVL_LENGTH 4
62 #define MSTS_CFIFOF BIT(11)
63 #define MSTS_CFIFOE BIT(10)
64 #define MSTS_DFIFOF BIT(9)
65 #define MSTS_DFIFOE BIT(8)
66 #define MSTS_OT BIT(7)
67 #define MSTS_ALM_SHIFT 0
68 #define MSTS_ALM_LENGTH 7
69
70 #define MCTL_RESET BIT(4)
71
72 #define CMD_NOP 0x00
73 #define CMD_READ 0x01
74 #define CMD_WRITE 0x02
75
zynq_xadc_update_ints(ZynqXADCState * s)76 static void zynq_xadc_update_ints(ZynqXADCState *s)
77 {
78
79 /* We are fast, commands are actioned instantly so the CFIFO is always
80 * empty (and below threshold).
81 */
82 s->regs[INT_STS] |= INT_CFIFO_LTH;
83
84 if (s->xadc_dfifo_entries >
85 extract32(s->regs[CFG], CFG_DFIFOTH_SHIFT, CFG_DFIFOTH_LENGTH)) {
86 s->regs[INT_STS] |= INT_DFIFO_GTH;
87 }
88
89 qemu_set_irq(s->irq, !!(s->regs[INT_STS] & ~s->regs[INT_MASK]));
90 }
91
zynq_xadc_reset(DeviceState * d)92 static void zynq_xadc_reset(DeviceState *d)
93 {
94 ZynqXADCState *s = ZYNQ_XADC(d);
95
96 s->regs[CFG] = 0x14 << CFG_IGAP_SHIFT |
97 CFG_TCKRATE_DIV(4) << CFG_TCKRATE_SHIFT | CFG_REDGE;
98 s->regs[INT_STS] = INT_CFIFO_LTH;
99 s->regs[INT_MASK] = 0xffffffff;
100 s->regs[CMDFIFO] = 0;
101 s->regs[RDFIFO] = 0;
102 s->regs[MCTL] = MCTL_RESET;
103
104 memset(s->xadc_regs, 0, sizeof(s->xadc_regs));
105 memset(s->xadc_dfifo, 0, sizeof(s->xadc_dfifo));
106 s->xadc_dfifo_entries = 0;
107
108 zynq_xadc_update_ints(s);
109 }
110
xadc_pop_dfifo(ZynqXADCState * s)111 static uint16_t xadc_pop_dfifo(ZynqXADCState *s)
112 {
113 uint16_t rv = s->xadc_dfifo[0];
114 int i;
115
116 if (s->xadc_dfifo_entries > 0) {
117 s->xadc_dfifo_entries--;
118 }
119 for (i = 0; i < s->xadc_dfifo_entries; i++) {
120 s->xadc_dfifo[i] = s->xadc_dfifo[i + 1];
121 }
122 s->xadc_dfifo[s->xadc_dfifo_entries] = 0;
123 zynq_xadc_update_ints(s);
124 return rv;
125 }
126
xadc_push_dfifo(ZynqXADCState * s,uint16_t regval)127 static void xadc_push_dfifo(ZynqXADCState *s, uint16_t regval)
128 {
129 if (s->xadc_dfifo_entries < ZYNQ_XADC_FIFO_DEPTH) {
130 s->xadc_dfifo[s->xadc_dfifo_entries++] = s->xadc_read_reg_previous;
131 }
132 s->xadc_read_reg_previous = regval;
133 zynq_xadc_update_ints(s);
134 }
135
zynq_xadc_check_offset(hwaddr offset,bool rnw)136 static bool zynq_xadc_check_offset(hwaddr offset, bool rnw)
137 {
138 switch (offset) {
139 case CFG:
140 case INT_MASK:
141 case INT_STS:
142 case MCTL:
143 return true;
144 case RDFIFO:
145 case MSTS:
146 return rnw; /* read only */
147 case CMDFIFO:
148 return !rnw; /* write only */
149 default:
150 return false;
151 }
152 }
153
zynq_xadc_read(void * opaque,hwaddr offset,unsigned size)154 static uint64_t zynq_xadc_read(void *opaque, hwaddr offset, unsigned size)
155 {
156 ZynqXADCState *s = opaque;
157 int reg = offset / 4;
158 uint32_t rv = 0;
159
160 if (!zynq_xadc_check_offset(reg, true)) {
161 qemu_log_mask(LOG_GUEST_ERROR, "zynq_xadc: Invalid read access to "
162 "addr %" HWADDR_PRIx "\n", offset);
163 return 0;
164 }
165
166 switch (reg) {
167 case CFG:
168 case INT_MASK:
169 case INT_STS:
170 case MCTL:
171 rv = s->regs[reg];
172 break;
173 case MSTS:
174 rv = MSTS_CFIFOE;
175 rv |= s->xadc_dfifo_entries << MSTS_DFIFO_LVL_SHIFT;
176 if (!s->xadc_dfifo_entries) {
177 rv |= MSTS_DFIFOE;
178 } else if (s->xadc_dfifo_entries == ZYNQ_XADC_FIFO_DEPTH) {
179 rv |= MSTS_DFIFOF;
180 }
181 break;
182 case RDFIFO:
183 rv = xadc_pop_dfifo(s);
184 break;
185 }
186 return rv;
187 }
188
zynq_xadc_write(void * opaque,hwaddr offset,uint64_t val,unsigned size)189 static void zynq_xadc_write(void *opaque, hwaddr offset, uint64_t val,
190 unsigned size)
191 {
192 ZynqXADCState *s = (ZynqXADCState *)opaque;
193 int reg = offset / 4;
194 int xadc_reg;
195 int xadc_cmd;
196 int xadc_data;
197
198 if (!zynq_xadc_check_offset(reg, false)) {
199 qemu_log_mask(LOG_GUEST_ERROR, "zynq_xadc: Invalid write access "
200 "to addr %" HWADDR_PRIx "\n", offset);
201 return;
202 }
203
204 switch (reg) {
205 case CFG:
206 s->regs[CFG] = val;
207 break;
208 case INT_STS:
209 s->regs[INT_STS] &= ~val;
210 break;
211 case INT_MASK:
212 s->regs[INT_MASK] = val & INT_ALL;
213 break;
214 case CMDFIFO:
215 xadc_cmd = extract32(val, 26, 4);
216 xadc_reg = extract32(val, 16, 10);
217 xadc_data = extract32(val, 0, 16);
218
219 if (s->regs[MCTL] & MCTL_RESET) {
220 qemu_log_mask(LOG_GUEST_ERROR, "zynq_xadc: Sending command "
221 "while comm channel held in reset: %" PRIx32 "\n",
222 (uint32_t) val);
223 break;
224 }
225
226 if (xadc_reg >= ZYNQ_XADC_NUM_ADC_REGS && xadc_cmd != CMD_NOP) {
227 qemu_log_mask(LOG_GUEST_ERROR, "read/write op to invalid xadc "
228 "reg 0x%x\n", xadc_reg);
229 break;
230 }
231
232 switch (xadc_cmd) {
233 case CMD_READ:
234 xadc_push_dfifo(s, s->xadc_regs[xadc_reg]);
235 break;
236 case CMD_WRITE:
237 s->xadc_regs[xadc_reg] = xadc_data;
238 /* fallthrough */
239 case CMD_NOP:
240 xadc_push_dfifo(s, 0);
241 break;
242 }
243 break;
244 case MCTL:
245 s->regs[MCTL] = val & 0x00fffeff;
246 break;
247 }
248 zynq_xadc_update_ints(s);
249 }
250
251 static const MemoryRegionOps xadc_ops = {
252 .read = zynq_xadc_read,
253 .write = zynq_xadc_write,
254 .endianness = DEVICE_NATIVE_ENDIAN,
255 };
256
zynq_xadc_init(Object * obj)257 static void zynq_xadc_init(Object *obj)
258 {
259 SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
260 ZynqXADCState *s = ZYNQ_XADC(obj);
261
262 memory_region_init_io(&s->iomem, obj, &xadc_ops, s, "zynq-xadc",
263 ZYNQ_XADC_MMIO_SIZE);
264 sysbus_init_mmio(sbd, &s->iomem);
265 sysbus_init_irq(sbd, &s->irq);
266 }
267
268 static const VMStateDescription vmstate_zynq_xadc = {
269 .name = "zynq-xadc",
270 .version_id = 1,
271 .minimum_version_id = 1,
272 .fields = (const VMStateField[]) {
273 VMSTATE_UINT32_ARRAY(regs, ZynqXADCState, ZYNQ_XADC_NUM_IO_REGS),
274 VMSTATE_UINT16_ARRAY(xadc_regs, ZynqXADCState,
275 ZYNQ_XADC_NUM_ADC_REGS),
276 VMSTATE_UINT16_ARRAY(xadc_dfifo, ZynqXADCState,
277 ZYNQ_XADC_FIFO_DEPTH),
278 VMSTATE_UINT16(xadc_read_reg_previous, ZynqXADCState),
279 VMSTATE_UINT16(xadc_dfifo_entries, ZynqXADCState),
280 VMSTATE_END_OF_LIST()
281 }
282 };
283
zynq_xadc_class_init(ObjectClass * klass,const void * data)284 static void zynq_xadc_class_init(ObjectClass *klass, const void *data)
285 {
286 DeviceClass *dc = DEVICE_CLASS(klass);
287
288 dc->vmsd = &vmstate_zynq_xadc;
289 device_class_set_legacy_reset(dc, zynq_xadc_reset);
290 }
291
292 static const TypeInfo zynq_xadc_info = {
293 .class_init = zynq_xadc_class_init,
294 .name = TYPE_ZYNQ_XADC,
295 .parent = TYPE_SYS_BUS_DEVICE,
296 .instance_size = sizeof(ZynqXADCState),
297 .instance_init = zynq_xadc_init,
298 };
299
zynq_xadc_register_types(void)300 static void zynq_xadc_register_types(void)
301 {
302 type_register_static(&zynq_xadc_info);
303 }
304
305 type_init(zynq_xadc_register_types)
306