1/*
2 * PC SMBus implementation
3 * splitted from acpi.c
4 *
5 * Copyright (c) 2006 Fabrice Bellard
6 *
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License version 2 as published by the Free Software Foundation.
10 *
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, see
18 * <http://www.gnu.org/licenses/>.
19 */
20
21#include "qemu/osdep.h"
22#include "hw/boards.h"
23#include "hw/i2c/pm_smbus.h"
24#include "hw/i2c/smbus_master.h"
25#include "migration/vmstate.h"
26
27#define SMBHSTSTS 0x00
28#define SMBHSTCNT 0x02
29#define SMBHSTCMD 0x03
30#define SMBHSTADD 0x04
31#define SMBHSTDAT0 0x05
32#define SMBHSTDAT1 0x06
33#define SMBBLKDAT 0x07
34#define SMBAUXCTL 0x0d
35
36#define STS_HOST_BUSY (1 << 0)
37#define STS_INTR (1 << 1)
38#define STS_DEV_ERR (1 << 2)
39#define STS_BUS_ERR (1 << 3)
40#define STS_FAILED (1 << 4)
41#define STS_SMBALERT (1 << 5)
42#define STS_INUSE_STS (1 << 6)
43#define STS_BYTE_DONE (1 << 7)
44/* Signs of successfully transaction end :
45* ByteDoneStatus = 1 (STS_BYTE_DONE) and INTR = 1 (STS_INTR )
46*/
47
48#define CTL_INTREN (1 << 0)
49#define CTL_KILL (1 << 1)
50#define CTL_LAST_BYTE (1 << 5)
51#define CTL_START (1 << 6)
52#define CTL_PEC_EN (1 << 7)
53#define CTL_RETURN_MASK 0x1f
54
55#define PROT_QUICK 0
56#define PROT_BYTE 1
57#define PROT_BYTE_DATA 2
58#define PROT_WORD_DATA 3
59#define PROT_PROC_CALL 4
60#define PROT_BLOCK_DATA 5
61#define PROT_I2C_BLOCK_READ 6
62
63#define AUX_PEC (1 << 0)
64#define AUX_BLK (1 << 1)
65#define AUX_MASK 0x3
66
67/*#define DEBUG*/
68
69#ifdef DEBUG
70# define SMBUS_DPRINTF(format, ...) printf(format, ## __VA_ARGS__)
71#else
72# define SMBUS_DPRINTF(format, ...) do { } while (0)
73#endif
74
75
76static void smb_transaction(PMSMBus *s)
77{
78 uint8_t prot = (s->smb_ctl >> 2) & 0x07;
79 uint8_t read = s->smb_addr & 0x01;
80 uint8_t cmd = s->smb_cmd;
81 uint8_t addr = s->smb_addr >> 1;
82 I2CBus *bus = s->smbus;
83 int ret;
84
85 SMBUS_DPRINTF("SMBus trans addr=0x%02x prot=0x%02x\n", addr, prot);
86 /* Transaction isn't exec if STS_DEV_ERR bit set */
87 if ((s->smb_stat & STS_DEV_ERR) != 0) {
88 goto error;
89 }
90
91 switch(prot) {
92 case PROT_QUICK:
93 ret = smbus_quick_command(bus, addr, read);
94 goto done;
95 case PROT_BYTE:
96 if (read) {
97 ret = smbus_receive_byte(bus, addr);
98 goto data8;
99 } else {
100 ret = smbus_send_byte(bus, addr, cmd);
101 goto done;
102 }
103 case PROT_BYTE_DATA:
104 if (read) {
105 ret = smbus_read_byte(bus, addr, cmd);
106 goto data8;
107 } else {
108 ret = smbus_write_byte(bus, addr, cmd, s->smb_data0);
109 goto done;
110 }
111 break;
112 case PROT_WORD_DATA:
113 if (read) {
114 ret = smbus_read_word(bus, addr, cmd);
115 goto data16;
116 } else {
117 ret = smbus_write_word(bus, addr, cmd,
118 (s->smb_data1 << 8) | s->smb_data0);
119 goto done;
120 }
121 break;
122 case PROT_I2C_BLOCK_READ:
123 /* According to the Linux i2c-i801 driver:
124 * NB: page 240 of ICH5 datasheet shows that the R/#W
125 * bit should be cleared here, even when reading.
126 * However if SPD Write Disable is set (Lynx Point and later),
127 * the read will fail if we don't set the R/#W bit.
128 * So at least Linux may or may not set the read bit here.
129 * So just ignore the read bit for this command.
130 */
131 if (i2c_start_transfer(bus, addr, 0)) {
132 goto error;
133 }
134 ret = i2c_send(bus, s->smb_data1);
135 if (ret) {
136 goto error;
137 }
138 if (i2c_start_transfer(bus, addr, 1)) {
139 goto error;
140 }
141 s->in_i2c_block_read = true;
142 s->smb_blkdata = i2c_recv(s->smbus);
143 s->op_done = false;
144 s->smb_stat |= STS_HOST_BUSY | STS_BYTE_DONE;
145 goto out;
146
147 case PROT_BLOCK_DATA:
148 if (read) {
149 ret = smbus_read_block(bus, addr, cmd, s->smb_data,
150 sizeof(s->smb_data), !s->i2c_enable,
151 !s->i2c_enable);
152 if (ret < 0) {
153 goto error;
154 }
155 s->smb_index = 0;
156 s->op_done = false;
157 if (s->smb_auxctl & AUX_BLK) {
158 s->smb_stat |= STS_INTR;
159 } else {
160 s->smb_blkdata = s->smb_data[0];
161 s->smb_stat |= STS_HOST_BUSY | STS_BYTE_DONE;
162 }
163 s->smb_data0 = ret;
164 goto out;
165 } else {
166 if (s->smb_auxctl & AUX_BLK) {
167 if (s->smb_index != s->smb_data0) {
168 s->smb_index = 0;
169 goto error;
170 }
171 /* Data is already all written to the queue, just do
172 the operation. */
173 s->smb_index = 0;
174 ret = smbus_write_block(bus, addr, cmd, s->smb_data,
175 s->smb_data0, !s->i2c_enable);
176 if (ret < 0) {
177 goto error;
178 }
179 s->op_done = true;
180 s->smb_stat |= STS_INTR;
181 s->smb_stat &= ~STS_HOST_BUSY;
182 } else {
183 s->op_done = false;
184 s->smb_stat |= STS_HOST_BUSY | STS_BYTE_DONE;
185 s->smb_data[0] = s->smb_blkdata;
186 s->smb_index = 0;
187 ret = 0;
188 }
189 goto out;
190 }
191 break;
192 default:
193 goto error;
194 }
195 abort();
196
197data16:
198 if (ret < 0) {
199 goto error;
200 }
201 s->smb_data1 = ret >> 8;
202data8:
203 if (ret < 0) {
204 goto error;
205 }
206 s->smb_data0 = ret;
207done:
208 if (ret < 0) {
209 goto error;
210 }
211 s->smb_stat |= STS_INTR;
212out:
213 return;
214
215error:
216 s->smb_stat |= STS_DEV_ERR;
217 return;
218}
219
220static void smb_transaction_start(PMSMBus *s)
221{
222 if (s->smb_ctl & CTL_INTREN) {
223 smb_transaction(s);
224 s->start_transaction_on_status_read = false;
225 } else {
226 /* Do not execute immediately the command; it will be
227 * executed when guest will read SMB_STAT register. This
228 * is to work around a bug in AMIBIOS (that is working
229 * around another bug in some specific hardware) where
230 * it waits for STS_HOST_BUSY to be set before waiting
231 * checking for status. If STS_HOST_BUSY doesn't get
232 * set, it gets stuck. */
233 s->smb_stat |= STS_HOST_BUSY;
234 s->start_transaction_on_status_read = true;
235 }
236}
237
238static bool
239smb_irq_value(PMSMBus *s)
240{
241 return ((s->smb_stat & ~STS_HOST_BUSY) != 0) && (s->smb_ctl & CTL_INTREN);
242}
243
244static bool
245smb_byte_by_byte(PMSMBus *s)
246{
247 if (s->op_done) {
248 return false;
249 }
250 if (s->in_i2c_block_read) {
251 return true;
252 }
253 return !(s->smb_auxctl & AUX_BLK);
254}
255
256static void smb_ioport_writeb(void *opaque, hwaddr addr, uint64_t val,
257 unsigned width)
258{
259 PMSMBus *s = opaque;
260 uint8_t clear_byte_done;
261
262 SMBUS_DPRINTF("SMB writeb port=0x%04" HWADDR_PRIx
263 " val=0x%02" PRIx64 "\n", addr, val);
264 switch(addr) {
265 case SMBHSTSTS:
266 clear_byte_done = s->smb_stat & val & STS_BYTE_DONE;
267 s->smb_stat &= ~(val & ~STS_HOST_BUSY);
268 if (clear_byte_done && smb_byte_by_byte(s)) {
269 uint8_t read = s->smb_addr & 0x01;
270
271 if (s->in_i2c_block_read) {
272 /* See comment below PROT_I2C_BLOCK_READ above. */
273 read = 1;
274 }
275
276 s->smb_index++;
277 if (s->smb_index >= PM_SMBUS_MAX_MSG_SIZE) {
278 s->smb_index = 0;
279 }
280 if (!read && s->smb_index == s->smb_data0) {
281 uint8_t prot = (s->smb_ctl >> 2) & 0x07;
282 uint8_t cmd = s->smb_cmd;
283 uint8_t addr = s->smb_addr >> 1;
284 int ret;
285
286 if (prot == PROT_I2C_BLOCK_READ) {
287 s->smb_stat |= STS_DEV_ERR;
288 goto out;
289 }
290
291 ret = smbus_write_block(s->smbus, addr, cmd, s->smb_data,
292 s->smb_data0, !s->i2c_enable);
293 if (ret < 0) {
294 s->smb_stat |= STS_DEV_ERR;
295 goto out;
296 }
297 s->op_done = true;
298 s->smb_stat |= STS_INTR;
299 s->smb_stat &= ~STS_HOST_BUSY;
300 } else if (!read) {
301 s->smb_data[s->smb_index] = s->smb_blkdata;
302 s->smb_stat |= STS_BYTE_DONE;
303 } else if (s->smb_ctl & CTL_LAST_BYTE) {
304 s->op_done = true;
305 if (s->in_i2c_block_read) {
306 s->in_i2c_block_read = false;
307 s->smb_blkdata = i2c_recv(s->smbus);
308 i2c_nack(s->smbus);
309 i2c_end_transfer(s->smbus);
310 } else {
311 s->smb_blkdata = s->smb_data[s->smb_index];
312 }
313 s->smb_index = 0;
314 s->smb_stat |= STS_INTR;
315 s->smb_stat &= ~STS_HOST_BUSY;
316 } else {
317 if (s->in_i2c_block_read) {
318 s->smb_blkdata = i2c_recv(s->smbus);
319 } else {
320 s->smb_blkdata = s->smb_data[s->smb_index];
321 }
322 s->smb_stat |= STS_BYTE_DONE;
323 }
324 }
325 break;
326 case SMBHSTCNT:
327 s->smb_ctl = val & ~CTL_START; /* CTL_START always reads 0 */
328 if (val & CTL_START) {
329 if (!s->op_done) {
330 s->smb_index = 0;
331 s->op_done = true;
332 if (s->in_i2c_block_read) {
333 s->in_i2c_block_read = false;
334 i2c_end_transfer(s->smbus);
335 }
336 }
337 smb_transaction_start(s);
338 }
339 if (s->smb_ctl & CTL_KILL) {
340 s->op_done = true;
341 s->smb_index = 0;
342 s->smb_stat |= STS_FAILED;
343 s->smb_stat &= ~STS_HOST_BUSY;
344 }
345 break;
346 case SMBHSTCMD:
347 s->smb_cmd = val;
348 break;
349 case SMBHSTADD:
350 s->smb_addr = val;
351 break;
352 case SMBHSTDAT0:
353 s->smb_data0 = val;
354 break;
355 case SMBHSTDAT1:
356 s->smb_data1 = val;
357 break;
358 case SMBBLKDAT:
359 if (s->smb_index >= PM_SMBUS_MAX_MSG_SIZE) {
360 s->smb_index = 0;
361 }
362 if (s->smb_auxctl & AUX_BLK) {
363 s->smb_data[s->smb_index++] = val;
364 } else {
365 s->smb_blkdata = val;
366 }
367 break;
368 case SMBAUXCTL:
369 s->smb_auxctl = val & AUX_MASK;
370 break;
371 default:
372 break;
373 }
374
375 out:
376 if (s->set_irq) {
377 s->set_irq(s, smb_irq_value(s));
378 }
379}
380
381static uint64_t smb_ioport_readb(void *opaque, hwaddr addr, unsigned width)
382{
383 PMSMBus *s = opaque;
384 uint32_t val;
385
386 switch(addr) {
387 case SMBHSTSTS:
388 val = s->smb_stat;
389 if (s->start_transaction_on_status_read) {
390 /* execute command now */
391 s->start_transaction_on_status_read = false;
392 s->smb_stat &= ~STS_HOST_BUSY;
393 smb_transaction(s);
394 }
395 break;
396 case SMBHSTCNT:
397 val = s->smb_ctl & CTL_RETURN_MASK;
398 break;
399 case SMBHSTCMD:
400 val = s->smb_cmd;
401 break;
402 case SMBHSTADD:
403 val = s->smb_addr;
404 break;
405 case SMBHSTDAT0:
406 val = s->smb_data0;
407 break;
408 case SMBHSTDAT1:
409 val = s->smb_data1;
410 break;
411 case SMBBLKDAT:
412 if (s->smb_auxctl & AUX_BLK && !s->in_i2c_block_read) {
413 if (s->smb_index >= PM_SMBUS_MAX_MSG_SIZE) {
414 s->smb_index = 0;
415 }
416 val = s->smb_data[s->smb_index++];
417 if (!s->op_done && s->smb_index == s->smb_data0) {
418 s->op_done = true;
419 s->smb_index = 0;
420 s->smb_stat &= ~STS_HOST_BUSY;
421 }
422 } else {
423 val = s->smb_blkdata;
424 }
425 break;
426 case SMBAUXCTL:
427 val = s->smb_auxctl;
428 break;
429 default:
430 val = 0;
431 break;
432 }
433 SMBUS_DPRINTF("SMB readb port=0x%04" HWADDR_PRIx " val=0x%02x\n",
434 addr, val);
435
436 if (s->set_irq) {
437 s->set_irq(s, smb_irq_value(s));
438 }
439
440 return val;
441}
442
443static void pm_smbus_reset(PMSMBus *s)
444{
445 s->op_done = true;
446 s->smb_index = 0;
447 s->smb_stat = 0;
448}
449
450static const MemoryRegionOps pm_smbus_ops = {
451 .read = smb_ioport_readb,
452 .write = smb_ioport_writeb,
453 .valid.min_access_size = 1,
454 .valid.max_access_size = 1,
455 .endianness = DEVICE_LITTLE_ENDIAN,
456};
457
458bool pm_smbus_vmstate_needed(void)
459{
460 MachineClass *mc = MACHINE_GET_CLASS(qdev_get_machine());
461
462 return !mc->smbus_no_migration_support;
463}
464
465const VMStateDescription pmsmb_vmstate = {
466 .name = "pmsmb",
467 .version_id = 1,
468 .minimum_version_id = 1,
469 .fields = (VMStateField[]) {
470 VMSTATE_UINT8(smb_stat, PMSMBus),
471 VMSTATE_UINT8(smb_ctl, PMSMBus),
472 VMSTATE_UINT8(smb_cmd, PMSMBus),
473 VMSTATE_UINT8(smb_addr, PMSMBus),
474 VMSTATE_UINT8(smb_data0, PMSMBus),
475 VMSTATE_UINT8(smb_data1, PMSMBus),
476 VMSTATE_UINT32(smb_index, PMSMBus),
477 VMSTATE_UINT8_ARRAY(smb_data, PMSMBus, PM_SMBUS_MAX_MSG_SIZE),
478 VMSTATE_UINT8(smb_auxctl, PMSMBus),
479 VMSTATE_UINT8(smb_blkdata, PMSMBus),
480 VMSTATE_BOOL(i2c_enable, PMSMBus),
481 VMSTATE_BOOL(op_done, PMSMBus),
482 VMSTATE_BOOL(in_i2c_block_read, PMSMBus),
483 VMSTATE_BOOL(start_transaction_on_status_read, PMSMBus),
484 VMSTATE_END_OF_LIST()
485 }
486};
487
488void pm_smbus_init(DeviceState *parent, PMSMBus *smb, bool force_aux_blk)
489{
490 smb->op_done = true;
491 smb->reset = pm_smbus_reset;
492 smb->smbus = i2c_init_bus(parent, "i2c");
493 if (force_aux_blk) {
494 smb->smb_auxctl |= AUX_BLK;
495 }
496 memory_region_init_io(&smb->io, OBJECT(parent), &pm_smbus_ops, smb,
497 "pm-smbus", 64);
498}
499