1 /*
2 * Copyright (C) 2014 Freescale Semiconductor, Inc. All rights reserved.
3 *
4 * Author: Amit Tomar, <Amit.Tomar@freescale.com>
5 *
6 * Description:
7 * This file is derived from IMX I2C controller,
8 * by Jean-Christophe DUBOIS .
9 *
10 * Thanks to Scott Wood and Alexander Graf for their kind help on this.
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License, version 2 or later,
14 * as published by the Free Software Foundation.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
18 */
19
20 #include "qemu/osdep.h"
21 #include "hw/i2c/i2c.h"
22 #include "hw/irq.h"
23 #include "hw/sysbus.h"
24 #include "migration/vmstate.h"
25 #include "qom/object.h"
26 #include "trace.h"
27
28 /* #define DEBUG_I2C */
29
30 #ifdef DEBUG_I2C
31 #define DPRINTF(fmt, ...) \
32 do { fprintf(stderr, "mpc_i2c[%s]: " fmt, __func__, ## __VA_ARGS__); \
33 } while (0)
34 #else
35 #define DPRINTF(fmt, ...) do {} while (0)
36 #endif
37
38 #define TYPE_MPC_I2C "mpc-i2c"
39 OBJECT_DECLARE_SIMPLE_TYPE(MPCI2CState, MPC_I2C)
40
41 #define MPC_I2C_ADR 0x00
42 #define MPC_I2C_FDR 0x04
43 #define MPC_I2C_CR 0x08
44 #define MPC_I2C_SR 0x0c
45 #define MPC_I2C_DR 0x10
46 #define MPC_I2C_DFSRR 0x14
47
48 #define CCR_MEN (1 << 7)
49 #define CCR_MIEN (1 << 6)
50 #define CCR_MSTA (1 << 5)
51 #define CCR_MTX (1 << 4)
52 #define CCR_TXAK (1 << 3)
53 #define CCR_RSTA (1 << 2)
54 #define CCR_BCST (1 << 0)
55
56 #define CSR_MCF (1 << 7)
57 #define CSR_MAAS (1 << 6)
58 #define CSR_MBB (1 << 5)
59 #define CSR_MAL (1 << 4)
60 #define CSR_SRW (1 << 2)
61 #define CSR_MIF (1 << 1)
62 #define CSR_RXAK (1 << 0)
63
64 #define CADR_MASK 0xFE
65 #define CFDR_MASK 0x3F
66 #define CCR_MASK 0xFC
67 #define CSR_MASK 0xED
68 #define CDR_MASK 0xFF
69
70 #define CYCLE_RESET 0xFF
71
72 struct MPCI2CState {
73 SysBusDevice parent_obj;
74
75 I2CBus *bus;
76 qemu_irq irq;
77 MemoryRegion iomem;
78
79 uint8_t address;
80 uint8_t adr;
81 uint8_t fdr;
82 uint8_t cr;
83 uint8_t sr;
84 uint8_t dr;
85 uint8_t dfsrr;
86 };
87
mpc_i2c_is_enabled(MPCI2CState * s)88 static bool mpc_i2c_is_enabled(MPCI2CState *s)
89 {
90 return s->cr & CCR_MEN;
91 }
92
mpc_i2c_is_master(MPCI2CState * s)93 static bool mpc_i2c_is_master(MPCI2CState *s)
94 {
95 return s->cr & CCR_MSTA;
96 }
97
mpc_i2c_direction_is_tx(MPCI2CState * s)98 static bool mpc_i2c_direction_is_tx(MPCI2CState *s)
99 {
100 return s->cr & CCR_MTX;
101 }
102
mpc_i2c_irq_pending(MPCI2CState * s)103 static bool mpc_i2c_irq_pending(MPCI2CState *s)
104 {
105 return s->sr & CSR_MIF;
106 }
107
mpc_i2c_irq_is_enabled(MPCI2CState * s)108 static bool mpc_i2c_irq_is_enabled(MPCI2CState *s)
109 {
110 return s->cr & CCR_MIEN;
111 }
112
mpc_i2c_reset(DeviceState * dev)113 static void mpc_i2c_reset(DeviceState *dev)
114 {
115 MPCI2CState *i2c = MPC_I2C(dev);
116
117 i2c->address = 0xFF;
118 i2c->adr = 0x00;
119 i2c->fdr = 0x00;
120 i2c->cr = 0x00;
121 i2c->sr = 0x81;
122 i2c->dr = 0x00;
123 }
124
mpc_i2c_irq(MPCI2CState * s)125 static void mpc_i2c_irq(MPCI2CState *s)
126 {
127 bool irq_active = false;
128
129 if (mpc_i2c_is_enabled(s) && mpc_i2c_irq_is_enabled(s)
130 && mpc_i2c_irq_pending(s)) {
131 irq_active = true;
132 }
133
134 if (irq_active) {
135 qemu_irq_raise(s->irq);
136 } else {
137 qemu_irq_lower(s->irq);
138 }
139 }
140
mpc_i2c_soft_reset(MPCI2CState * s)141 static void mpc_i2c_soft_reset(MPCI2CState *s)
142 {
143 /* This is a soft reset. ADR is preserved during soft resets */
144 uint8_t adr = s->adr;
145 mpc_i2c_reset(DEVICE(s));
146 s->adr = adr;
147 }
148
mpc_i2c_address_send(MPCI2CState * s)149 static void mpc_i2c_address_send(MPCI2CState *s)
150 {
151 /* if returns non zero slave address is not right */
152 if (i2c_start_transfer(s->bus, s->dr >> 1, s->dr & (0x01))) {
153 s->sr |= CSR_RXAK;
154 } else {
155 s->address = s->dr;
156 s->sr &= ~CSR_RXAK;
157 s->sr |= CSR_MCF; /* Set after Byte Transfer is completed */
158 s->sr |= CSR_MIF; /* Set after Byte Transfer is completed */
159 mpc_i2c_irq(s);
160 }
161 }
162
mpc_i2c_data_send(MPCI2CState * s)163 static void mpc_i2c_data_send(MPCI2CState *s)
164 {
165 if (i2c_send(s->bus, s->dr)) {
166 /* End of transfer */
167 s->sr |= CSR_RXAK;
168 i2c_end_transfer(s->bus);
169 } else {
170 s->sr &= ~CSR_RXAK;
171 s->sr |= CSR_MCF; /* Set after Byte Transfer is completed */
172 s->sr |= CSR_MIF; /* Set after Byte Transfer is completed */
173 mpc_i2c_irq(s);
174 }
175 }
176
mpc_i2c_data_recive(MPCI2CState * s)177 static void mpc_i2c_data_recive(MPCI2CState *s)
178 {
179 int ret;
180 /* get the next byte */
181 ret = i2c_recv(s->bus);
182 if (ret >= 0) {
183 s->sr |= CSR_MCF; /* Set after Byte Transfer is completed */
184 s->sr |= CSR_MIF; /* Set after Byte Transfer is completed */
185 mpc_i2c_irq(s);
186 } else {
187 DPRINTF("read failed for device");
188 ret = 0xff;
189 }
190 s->dr = ret;
191 }
192
mpc_i2c_read(void * opaque,hwaddr addr,unsigned size)193 static uint64_t mpc_i2c_read(void *opaque, hwaddr addr, unsigned size)
194 {
195 MPCI2CState *s = opaque;
196 uint8_t value;
197
198 switch (addr) {
199 case MPC_I2C_ADR:
200 value = s->adr;
201 break;
202 case MPC_I2C_FDR:
203 value = s->fdr;
204 break;
205 case MPC_I2C_CR:
206 value = s->cr;
207 break;
208 case MPC_I2C_SR:
209 value = s->sr;
210 break;
211 case MPC_I2C_DR:
212 value = s->dr;
213 if (mpc_i2c_is_master(s)) { /* master mode */
214 if (mpc_i2c_direction_is_tx(s)) {
215 DPRINTF("MTX is set not in recv mode\n");
216 } else {
217 mpc_i2c_data_recive(s);
218 }
219 }
220 break;
221 default:
222 value = 0;
223 DPRINTF("ERROR: Bad read addr 0x%x\n", (unsigned int)addr);
224 break;
225 }
226
227 trace_mpc_i2c_read(addr, value);
228
229 return (uint64_t)value;
230 }
231
mpc_i2c_write(void * opaque,hwaddr addr,uint64_t value,unsigned size)232 static void mpc_i2c_write(void *opaque, hwaddr addr,
233 uint64_t value, unsigned size)
234 {
235 MPCI2CState *s = opaque;
236
237 trace_mpc_i2c_write(addr, value);
238
239 switch (addr) {
240 case MPC_I2C_ADR:
241 s->adr = value & CADR_MASK;
242 break;
243 case MPC_I2C_FDR:
244 s->fdr = value & CFDR_MASK;
245 break;
246 case MPC_I2C_CR:
247 if (mpc_i2c_is_enabled(s) && ((value & CCR_MEN) == 0)) {
248 mpc_i2c_soft_reset(s);
249 break;
250 }
251 /* normal write */
252 s->cr = value & CCR_MASK;
253 if (mpc_i2c_is_master(s)) { /* master mode */
254 /* set the bus to busy after master is set as per RM */
255 s->sr |= CSR_MBB;
256 } else {
257 /* bus is not busy anymore */
258 s->sr &= ~CSR_MBB;
259 /* Reset the address for fresh write/read cycle */
260 if (s->address != CYCLE_RESET) {
261 i2c_end_transfer(s->bus);
262 s->address = CYCLE_RESET;
263 }
264 }
265 /* For restart end the onging transfer */
266 if (s->cr & CCR_RSTA) {
267 if (s->address != CYCLE_RESET) {
268 s->address = CYCLE_RESET;
269 i2c_end_transfer(s->bus);
270 s->cr &= ~CCR_RSTA;
271 }
272 }
273 break;
274 case MPC_I2C_SR:
275 s->sr = value & CSR_MASK;
276 /* Lower the interrupt */
277 if (!(s->sr & CSR_MIF) || !(s->sr & CSR_MAL)) {
278 mpc_i2c_irq(s);
279 }
280 break;
281 case MPC_I2C_DR:
282 /* if the device is not enabled, nothing to do */
283 if (!mpc_i2c_is_enabled(s)) {
284 break;
285 }
286 s->dr = value & CDR_MASK;
287 if (mpc_i2c_is_master(s)) { /* master mode */
288 if (s->address == CYCLE_RESET) {
289 mpc_i2c_address_send(s);
290 } else {
291 mpc_i2c_data_send(s);
292 }
293 }
294 break;
295 case MPC_I2C_DFSRR:
296 s->dfsrr = value;
297 break;
298 default:
299 DPRINTF("ERROR: Bad write addr 0x%x\n", (unsigned int)addr);
300 break;
301 }
302 }
303
304 static const MemoryRegionOps i2c_ops = {
305 .read = mpc_i2c_read,
306 .write = mpc_i2c_write,
307 .valid.max_access_size = 1,
308 .endianness = DEVICE_NATIVE_ENDIAN,
309 };
310
311 static const VMStateDescription mpc_i2c_vmstate = {
312 .name = TYPE_MPC_I2C,
313 .version_id = 1,
314 .minimum_version_id = 1,
315 .fields = (const VMStateField[]) {
316 VMSTATE_UINT8(address, MPCI2CState),
317 VMSTATE_UINT8(adr, MPCI2CState),
318 VMSTATE_UINT8(fdr, MPCI2CState),
319 VMSTATE_UINT8(cr, MPCI2CState),
320 VMSTATE_UINT8(sr, MPCI2CState),
321 VMSTATE_UINT8(dr, MPCI2CState),
322 VMSTATE_UINT8(dfsrr, MPCI2CState),
323 VMSTATE_END_OF_LIST()
324 }
325 };
326
mpc_i2c_realize(DeviceState * dev,Error ** errp)327 static void mpc_i2c_realize(DeviceState *dev, Error **errp)
328 {
329 MPCI2CState *i2c = MPC_I2C(dev);
330 sysbus_init_irq(SYS_BUS_DEVICE(dev), &i2c->irq);
331 memory_region_init_io(&i2c->iomem, OBJECT(i2c), &i2c_ops, i2c,
332 "mpc-i2c", 0x15);
333 sysbus_init_mmio(SYS_BUS_DEVICE(dev), &i2c->iomem);
334 i2c->bus = i2c_init_bus(dev, "i2c");
335 }
336
mpc_i2c_class_init(ObjectClass * klass,const void * data)337 static void mpc_i2c_class_init(ObjectClass *klass, const void *data)
338 {
339 DeviceClass *dc = DEVICE_CLASS(klass);
340
341 dc->vmsd = &mpc_i2c_vmstate ;
342 device_class_set_legacy_reset(dc, mpc_i2c_reset);
343 dc->realize = mpc_i2c_realize;
344 dc->desc = "MPC I2C Controller";
345 }
346
347 static const TypeInfo mpc_i2c_types[] = {
348 {
349 .name = TYPE_MPC_I2C,
350 .parent = TYPE_SYS_BUS_DEVICE,
351 .instance_size = sizeof(MPCI2CState),
352 .class_init = mpc_i2c_class_init,
353 },
354 };
355
356 DEFINE_TYPES(mpc_i2c_types)
357