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 "qemu/log.h"
24#include "qemu/module.h"
25#include "hw/sysbus.h"
26#include "migration/vmstate.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#define MPC_I2C(obj) \
40 OBJECT_CHECK(MPCI2CState, (obj), TYPE_MPC_I2C)
41
42#define MPC_I2C_ADR 0x00
43#define MPC_I2C_FDR 0x04
44#define MPC_I2C_CR 0x08
45#define MPC_I2C_SR 0x0c
46#define MPC_I2C_DR 0x10
47#define MPC_I2C_DFSRR 0x14
48
49#define CCR_MEN (1 << 7)
50#define CCR_MIEN (1 << 6)
51#define CCR_MSTA (1 << 5)
52#define CCR_MTX (1 << 4)
53#define CCR_TXAK (1 << 3)
54#define CCR_RSTA (1 << 2)
55#define CCR_BCST (1 << 0)
56
57#define CSR_MCF (1 << 7)
58#define CSR_MAAS (1 << 6)
59#define CSR_MBB (1 << 5)
60#define CSR_MAL (1 << 4)
61#define CSR_SRW (1 << 2)
62#define CSR_MIF (1 << 1)
63#define CSR_RXAK (1 << 0)
64
65#define CADR_MASK 0xFE
66#define CFDR_MASK 0x3F
67#define CCR_MASK 0xFC
68#define CSR_MASK 0xED
69#define CDR_MASK 0xFF
70
71#define CYCLE_RESET 0xFF
72
73typedef struct MPCI2CState {
74 SysBusDevice parent_obj;
75
76 I2CBus *bus;
77 qemu_irq irq;
78 MemoryRegion iomem;
79
80 uint8_t address;
81 uint8_t adr;
82 uint8_t fdr;
83 uint8_t cr;
84 uint8_t sr;
85 uint8_t dr;
86 uint8_t dfssr;
87} MPCI2CState;
88
89static bool mpc_i2c_is_enabled(MPCI2CState *s)
90{
91 return s->cr & CCR_MEN;
92}
93
94static bool mpc_i2c_is_master(MPCI2CState *s)
95{
96 return s->cr & CCR_MSTA;
97}
98
99static bool mpc_i2c_direction_is_tx(MPCI2CState *s)
100{
101 return s->cr & CCR_MTX;
102}
103
104static bool mpc_i2c_irq_pending(MPCI2CState *s)
105{
106 return s->sr & CSR_MIF;
107}
108
109static bool mpc_i2c_irq_is_enabled(MPCI2CState *s)
110{
111 return s->cr & CCR_MIEN;
112}
113
114static void mpc_i2c_reset(DeviceState *dev)
115{
116 MPCI2CState *i2c = MPC_I2C(dev);
117
118 i2c->address = 0xFF;
119 i2c->adr = 0x00;
120 i2c->fdr = 0x00;
121 i2c->cr = 0x00;
122 i2c->sr = 0x81;
123 i2c->dr = 0x00;
124}
125
126static void mpc_i2c_irq(MPCI2CState *s)
127{
128 bool irq_active = false;
129
130 if (mpc_i2c_is_enabled(s) && mpc_i2c_irq_is_enabled(s)
131 && mpc_i2c_irq_pending(s)) {
132 irq_active = true;
133 }
134
135 if (irq_active) {
136 qemu_irq_raise(s->irq);
137 } else {
138 qemu_irq_lower(s->irq);
139 }
140}
141
142static void mpc_i2c_soft_reset(MPCI2CState *s)
143{
144 /* This is a soft reset. ADR is preserved during soft resets */
145 uint8_t adr = s->adr;
146 mpc_i2c_reset(DEVICE(s));
147 s->adr = adr;
148}
149
150static void mpc_i2c_address_send(MPCI2CState *s)
151{
152 /* if returns non zero slave address is not right */
153 if (i2c_start_transfer(s->bus, s->dr >> 1, s->dr & (0x01))) {
154 s->sr |= CSR_RXAK;
155 } else {
156 s->address = s->dr;
157 s->sr &= ~CSR_RXAK;
158 s->sr |= CSR_MCF; /* Set after Byte Transfer is completed */
159 s->sr |= CSR_MIF; /* Set after Byte Transfer is completed */
160 mpc_i2c_irq(s);
161 }
162}
163
164static void mpc_i2c_data_send(MPCI2CState *s)
165{
166 if (i2c_send(s->bus, s->dr)) {
167 /* End of transfer */
168 s->sr |= CSR_RXAK;
169 i2c_end_transfer(s->bus);
170 } else {
171 s->sr &= ~CSR_RXAK;
172 s->sr |= CSR_MCF; /* Set after Byte Transfer is completed */
173 s->sr |= CSR_MIF; /* Set after Byte Transfer is completed */
174 mpc_i2c_irq(s);
175 }
176}
177
178static void mpc_i2c_data_recive(MPCI2CState *s)
179{
180 int ret;
181 /* get the next byte */
182 ret = i2c_recv(s->bus);
183 if (ret >= 0) {
184 s->sr |= CSR_MCF; /* Set after Byte Transfer is completed */
185 s->sr |= CSR_MIF; /* Set after Byte Transfer is completed */
186 mpc_i2c_irq(s);
187 } else {
188 DPRINTF("read failed for device");
189 ret = 0xff;
190 }
191 s->dr = ret;
192}
193
194static uint64_t mpc_i2c_read(void *opaque, hwaddr addr, unsigned size)
195{
196 MPCI2CState *s = opaque;
197 uint8_t value;
198
199 switch (addr) {
200 case MPC_I2C_ADR:
201 value = s->adr;
202 break;
203 case MPC_I2C_FDR:
204 value = s->fdr;
205 break;
206 case MPC_I2C_CR:
207 value = s->cr;
208 break;
209 case MPC_I2C_SR:
210 value = s->sr;
211 break;
212 case MPC_I2C_DR:
213 value = s->dr;
214 if (mpc_i2c_is_master(s)) { /* master mode */
215 if (mpc_i2c_direction_is_tx(s)) {
216 DPRINTF("MTX is set not in recv mode\n");
217 } else {
218 mpc_i2c_data_recive(s);
219 }
220 }
221 break;
222 default:
223 value = 0;
224 DPRINTF("ERROR: Bad read addr 0x%x\n", (unsigned int)addr);
225 break;
226 }
227
228 DPRINTF("%s: addr " TARGET_FMT_plx " %02" PRIx32 "\n", __func__,
229 addr, value);
230 return (uint64_t)value;
231}
232
233static void mpc_i2c_write(void *opaque, hwaddr addr,
234 uint64_t value, unsigned size)
235{
236 MPCI2CState *s = opaque;
237
238 DPRINTF("%s: addr " TARGET_FMT_plx " val %08" PRIx64 "\n", __func__,
239 addr, value);
240 switch (addr) {
241 case MPC_I2C_ADR:
242 s->adr = value & CADR_MASK;
243 break;
244 case MPC_I2C_FDR:
245 s->fdr = value & CFDR_MASK;
246 break;
247 case MPC_I2C_CR:
248 if (mpc_i2c_is_enabled(s) && ((value & CCR_MEN) == 0)) {
249 mpc_i2c_soft_reset(s);
250 break;
251 }
252 /* normal write */
253 s->cr = value & CCR_MASK;
254 if (mpc_i2c_is_master(s)) { /* master mode */
255 /* set the bus to busy after master is set as per RM */
256 s->sr |= CSR_MBB;
257 } else {
258 /* bus is not busy anymore */
259 s->sr &= ~CSR_MBB;
260 /* Reset the address for fresh write/read cycle */
261 if (s->address != CYCLE_RESET) {
262 i2c_end_transfer(s->bus);
263 s->address = CYCLE_RESET;
264 }
265 }
266 /* For restart end the onging transfer */
267 if (s->cr & CCR_RSTA) {
268 if (s->address != CYCLE_RESET) {
269 s->address = CYCLE_RESET;
270 i2c_end_transfer(s->bus);
271 s->cr &= ~CCR_RSTA;
272 }
273 }
274 break;
275 case MPC_I2C_SR:
276 s->sr = value & CSR_MASK;
277 /* Lower the interrupt */
278 if (!(s->sr & CSR_MIF) || !(s->sr & CSR_MAL)) {
279 mpc_i2c_irq(s);
280 }
281 break;
282 case MPC_I2C_DR:
283 /* if the device is not enabled, nothing to do */
284 if (!mpc_i2c_is_enabled(s)) {
285 break;
286 }
287 s->dr = value & CDR_MASK;
288 if (mpc_i2c_is_master(s)) { /* master mode */
289 if (s->address == CYCLE_RESET) {
290 mpc_i2c_address_send(s);
291 } else {
292 mpc_i2c_data_send(s);
293 }
294 }
295 break;
296 case MPC_I2C_DFSRR:
297 s->dfssr = value;
298 break;
299 default:
300 DPRINTF("ERROR: Bad write addr 0x%x\n", (unsigned int)addr);
301 break;
302 }
303}
304
305static const MemoryRegionOps i2c_ops = {
306 .read = mpc_i2c_read,
307 .write = mpc_i2c_write,
308 .valid.max_access_size = 1,
309 .endianness = DEVICE_NATIVE_ENDIAN,
310};
311
312static const VMStateDescription mpc_i2c_vmstate = {
313 .name = TYPE_MPC_I2C,
314 .version_id = 1,
315 .minimum_version_id = 1,
316 .fields = (VMStateField[]) {
317 VMSTATE_UINT8(address, MPCI2CState),
318 VMSTATE_UINT8(adr, MPCI2CState),
319 VMSTATE_UINT8(fdr, MPCI2CState),
320 VMSTATE_UINT8(cr, MPCI2CState),
321 VMSTATE_UINT8(sr, MPCI2CState),
322 VMSTATE_UINT8(dr, MPCI2CState),
323 VMSTATE_UINT8(dfssr, MPCI2CState),
324 VMSTATE_END_OF_LIST()
325 }
326};
327
328static void mpc_i2c_realize(DeviceState *dev, Error **errp)
329{
330 MPCI2CState *i2c = MPC_I2C(dev);
331 sysbus_init_irq(SYS_BUS_DEVICE(dev), &i2c->irq);
332 memory_region_init_io(&i2c->iomem, OBJECT(i2c), &i2c_ops, i2c,
333 "mpc-i2c", 0x14);
334 sysbus_init_mmio(SYS_BUS_DEVICE(dev), &i2c->iomem);
335 i2c->bus = i2c_init_bus(DEVICE(dev), "i2c");
336}
337
338static void mpc_i2c_class_init(ObjectClass *klass, void *data)
339{
340 DeviceClass *dc = DEVICE_CLASS(klass);
341
342 dc->vmsd = &mpc_i2c_vmstate ;
343 dc->reset = mpc_i2c_reset;
344 dc->realize = mpc_i2c_realize;
345 dc->desc = "MPC I2C Controller";
346}
347
348static const TypeInfo mpc_i2c_type_info = {
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
355static void mpc_i2c_register_types(void)
356{
357 type_register_static(&mpc_i2c_type_info);
358}
359
360type_init(mpc_i2c_register_types)
361