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10#include <linux/clk.h>
11#include <linux/completion.h>
12#include <linux/err.h>
13#include <linux/errno.h>
14#include <linux/i2c.h>
15#include <linux/init.h>
16#include <linux/interrupt.h>
17#include <linux/io.h>
18#include <linux/irq.h>
19#include <linux/irqchip/chained_irq.h>
20#include <linux/irqdomain.h>
21#include <linux/kernel.h>
22#include <linux/module.h>
23#include <linux/of_address.h>
24#include <linux/of_irq.h>
25#include <linux/of_platform.h>
26#include <linux/platform_device.h>
27#include <linux/reset.h>
28#include <linux/slab.h>
29
30
31#define ASPEED_I2C_FUN_CTRL_REG 0x00
32#define ASPEED_I2C_AC_TIMING_REG1 0x04
33#define ASPEED_I2C_AC_TIMING_REG2 0x08
34#define ASPEED_I2C_INTR_CTRL_REG 0x0c
35#define ASPEED_I2C_INTR_STS_REG 0x10
36#define ASPEED_I2C_CMD_REG 0x14
37#define ASPEED_I2C_DEV_ADDR_REG 0x18
38#define ASPEED_I2C_BYTE_BUF_REG 0x20
39
40
41
42
43
44
45
46#define ASPEED_I2CD_MULTI_MASTER_DIS BIT(15)
47#define ASPEED_I2CD_SDA_DRIVE_1T_EN BIT(8)
48#define ASPEED_I2CD_M_SDA_DRIVE_1T_EN BIT(7)
49#define ASPEED_I2CD_M_HIGH_SPEED_EN BIT(6)
50#define ASPEED_I2CD_SLAVE_EN BIT(1)
51#define ASPEED_I2CD_MASTER_EN BIT(0)
52
53
54#define ASPEED_I2CD_TIME_TBUF_MASK GENMASK(31, 28)
55#define ASPEED_I2CD_TIME_THDSTA_MASK GENMASK(27, 24)
56#define ASPEED_I2CD_TIME_TACST_MASK GENMASK(23, 20)
57#define ASPEED_I2CD_TIME_SCL_HIGH_SHIFT 16
58#define ASPEED_I2CD_TIME_SCL_HIGH_MASK GENMASK(19, 16)
59#define ASPEED_I2CD_TIME_SCL_LOW_SHIFT 12
60#define ASPEED_I2CD_TIME_SCL_LOW_MASK GENMASK(15, 12)
61#define ASPEED_I2CD_TIME_BASE_DIVISOR_MASK GENMASK(3, 0)
62#define ASPEED_I2CD_TIME_SCL_REG_MAX GENMASK(3, 0)
63
64#define ASPEED_NO_TIMEOUT_CTRL 0
65
66
67
68
69
70
71
72#define ASPEED_I2CD_INTR_SDA_DL_TIMEOUT BIT(14)
73#define ASPEED_I2CD_INTR_BUS_RECOVER_DONE BIT(13)
74#define ASPEED_I2CD_INTR_SLAVE_MATCH BIT(7)
75#define ASPEED_I2CD_INTR_SCL_TIMEOUT BIT(6)
76#define ASPEED_I2CD_INTR_ABNORMAL BIT(5)
77#define ASPEED_I2CD_INTR_NORMAL_STOP BIT(4)
78#define ASPEED_I2CD_INTR_ARBIT_LOSS BIT(3)
79#define ASPEED_I2CD_INTR_RX_DONE BIT(2)
80#define ASPEED_I2CD_INTR_TX_NAK BIT(1)
81#define ASPEED_I2CD_INTR_TX_ACK BIT(0)
82#define ASPEED_I2CD_INTR_MASTER_ERRORS \
83 (ASPEED_I2CD_INTR_SDA_DL_TIMEOUT | \
84 ASPEED_I2CD_INTR_SCL_TIMEOUT | \
85 ASPEED_I2CD_INTR_ABNORMAL | \
86 ASPEED_I2CD_INTR_ARBIT_LOSS)
87#define ASPEED_I2CD_INTR_ALL \
88 (ASPEED_I2CD_INTR_SDA_DL_TIMEOUT | \
89 ASPEED_I2CD_INTR_BUS_RECOVER_DONE | \
90 ASPEED_I2CD_INTR_SCL_TIMEOUT | \
91 ASPEED_I2CD_INTR_ABNORMAL | \
92 ASPEED_I2CD_INTR_NORMAL_STOP | \
93 ASPEED_I2CD_INTR_ARBIT_LOSS | \
94 ASPEED_I2CD_INTR_RX_DONE | \
95 ASPEED_I2CD_INTR_TX_NAK | \
96 ASPEED_I2CD_INTR_TX_ACK)
97
98
99#define ASPEED_I2CD_SCL_LINE_STS BIT(18)
100#define ASPEED_I2CD_SDA_LINE_STS BIT(17)
101#define ASPEED_I2CD_BUS_BUSY_STS BIT(16)
102#define ASPEED_I2CD_BUS_RECOVER_CMD BIT(11)
103
104
105#define ASPEED_I2CD_M_STOP_CMD BIT(5)
106#define ASPEED_I2CD_M_S_RX_CMD_LAST BIT(4)
107#define ASPEED_I2CD_M_RX_CMD BIT(3)
108#define ASPEED_I2CD_S_TX_CMD BIT(2)
109#define ASPEED_I2CD_M_TX_CMD BIT(1)
110#define ASPEED_I2CD_M_START_CMD BIT(0)
111#define ASPEED_I2CD_MASTER_CMDS_MASK \
112 (ASPEED_I2CD_M_STOP_CMD | \
113 ASPEED_I2CD_M_S_RX_CMD_LAST | \
114 ASPEED_I2CD_M_RX_CMD | \
115 ASPEED_I2CD_M_TX_CMD | \
116 ASPEED_I2CD_M_START_CMD)
117
118
119#define ASPEED_I2CD_DEV_ADDR_MASK GENMASK(6, 0)
120
121enum aspeed_i2c_master_state {
122 ASPEED_I2C_MASTER_INACTIVE,
123 ASPEED_I2C_MASTER_PENDING,
124 ASPEED_I2C_MASTER_START,
125 ASPEED_I2C_MASTER_TX_FIRST,
126 ASPEED_I2C_MASTER_TX,
127 ASPEED_I2C_MASTER_RX_FIRST,
128 ASPEED_I2C_MASTER_RX,
129 ASPEED_I2C_MASTER_STOP,
130};
131
132enum aspeed_i2c_slave_state {
133 ASPEED_I2C_SLAVE_INACTIVE,
134 ASPEED_I2C_SLAVE_START,
135 ASPEED_I2C_SLAVE_READ_REQUESTED,
136 ASPEED_I2C_SLAVE_READ_PROCESSED,
137 ASPEED_I2C_SLAVE_WRITE_REQUESTED,
138 ASPEED_I2C_SLAVE_WRITE_RECEIVED,
139 ASPEED_I2C_SLAVE_STOP,
140};
141
142struct aspeed_i2c_bus {
143 struct i2c_adapter adap;
144 struct device *dev;
145 void __iomem *base;
146 struct reset_control *rst;
147
148 spinlock_t lock;
149 struct completion cmd_complete;
150 u32 (*get_clk_reg_val)(struct device *dev,
151 u32 divisor);
152 unsigned long parent_clk_frequency;
153 u32 bus_frequency;
154
155 enum aspeed_i2c_master_state master_state;
156 struct i2c_msg *msgs;
157 size_t buf_index;
158 size_t msgs_index;
159 size_t msgs_count;
160 bool send_stop;
161 int cmd_err;
162
163 int master_xfer_result;
164
165 bool multi_master;
166#if IS_ENABLED(CONFIG_I2C_SLAVE)
167 struct i2c_client *slave;
168 enum aspeed_i2c_slave_state slave_state;
169#endif
170};
171
172static int aspeed_i2c_reset(struct aspeed_i2c_bus *bus);
173
174static int aspeed_i2c_recover_bus(struct aspeed_i2c_bus *bus)
175{
176 unsigned long time_left, flags;
177 int ret = 0;
178 u32 command;
179
180 spin_lock_irqsave(&bus->lock, flags);
181 command = readl(bus->base + ASPEED_I2C_CMD_REG);
182
183 if (command & ASPEED_I2CD_SDA_LINE_STS) {
184
185 if (command & ASPEED_I2CD_SCL_LINE_STS)
186 goto out;
187 dev_dbg(bus->dev, "SCL hung (state %x), attempting recovery\n",
188 command);
189
190 reinit_completion(&bus->cmd_complete);
191 writel(ASPEED_I2CD_M_STOP_CMD, bus->base + ASPEED_I2C_CMD_REG);
192 spin_unlock_irqrestore(&bus->lock, flags);
193
194 time_left = wait_for_completion_timeout(
195 &bus->cmd_complete, bus->adap.timeout);
196
197 spin_lock_irqsave(&bus->lock, flags);
198 if (time_left == 0)
199 goto reset_out;
200 else if (bus->cmd_err)
201 goto reset_out;
202
203 else if (!(readl(bus->base + ASPEED_I2C_CMD_REG) &
204 ASPEED_I2CD_SCL_LINE_STS))
205 goto reset_out;
206
207 } else {
208 dev_dbg(bus->dev, "SDA hung (state %x), attempting recovery\n",
209 command);
210
211 reinit_completion(&bus->cmd_complete);
212
213 writel(ASPEED_I2CD_BUS_RECOVER_CMD,
214 bus->base + ASPEED_I2C_CMD_REG);
215 spin_unlock_irqrestore(&bus->lock, flags);
216
217 time_left = wait_for_completion_timeout(
218 &bus->cmd_complete, bus->adap.timeout);
219
220 spin_lock_irqsave(&bus->lock, flags);
221 if (time_left == 0)
222 goto reset_out;
223 else if (bus->cmd_err)
224 goto reset_out;
225
226 else if (!(readl(bus->base + ASPEED_I2C_CMD_REG) &
227 ASPEED_I2CD_SDA_LINE_STS))
228 goto reset_out;
229 }
230
231out:
232 spin_unlock_irqrestore(&bus->lock, flags);
233
234 return ret;
235
236reset_out:
237 spin_unlock_irqrestore(&bus->lock, flags);
238
239 return aspeed_i2c_reset(bus);
240}
241
242#if IS_ENABLED(CONFIG_I2C_SLAVE)
243static u32 aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus, u32 irq_status)
244{
245 u32 command, irq_handled = 0;
246 struct i2c_client *slave = bus->slave;
247 u8 value;
248
249 if (!slave)
250 return 0;
251
252 command = readl(bus->base + ASPEED_I2C_CMD_REG);
253
254
255 if (irq_status & ASPEED_I2CD_INTR_SLAVE_MATCH) {
256 irq_handled |= ASPEED_I2CD_INTR_SLAVE_MATCH;
257 bus->slave_state = ASPEED_I2C_SLAVE_START;
258 }
259
260
261 if (bus->slave_state == ASPEED_I2C_SLAVE_INACTIVE)
262 return irq_handled;
263
264 dev_dbg(bus->dev, "slave irq status 0x%08x, cmd 0x%08x\n",
265 irq_status, command);
266
267
268 if (irq_status & ASPEED_I2CD_INTR_RX_DONE) {
269 value = readl(bus->base + ASPEED_I2C_BYTE_BUF_REG) >> 8;
270
271 if (bus->slave_state == ASPEED_I2C_SLAVE_START) {
272 if (value & 0x1)
273 bus->slave_state =
274 ASPEED_I2C_SLAVE_READ_REQUESTED;
275 else
276 bus->slave_state =
277 ASPEED_I2C_SLAVE_WRITE_REQUESTED;
278 }
279 irq_handled |= ASPEED_I2CD_INTR_RX_DONE;
280 }
281
282
283 if (irq_status & ASPEED_I2CD_INTR_NORMAL_STOP) {
284 irq_handled |= ASPEED_I2CD_INTR_NORMAL_STOP;
285 bus->slave_state = ASPEED_I2C_SLAVE_STOP;
286 }
287 if (irq_status & ASPEED_I2CD_INTR_TX_NAK &&
288 bus->slave_state == ASPEED_I2C_SLAVE_READ_PROCESSED) {
289 irq_handled |= ASPEED_I2CD_INTR_TX_NAK;
290 bus->slave_state = ASPEED_I2C_SLAVE_STOP;
291 }
292
293 switch (bus->slave_state) {
294 case ASPEED_I2C_SLAVE_READ_REQUESTED:
295 if (unlikely(irq_status & ASPEED_I2CD_INTR_TX_ACK))
296 dev_err(bus->dev, "Unexpected ACK on read request.\n");
297 bus->slave_state = ASPEED_I2C_SLAVE_READ_PROCESSED;
298 i2c_slave_event(slave, I2C_SLAVE_READ_REQUESTED, &value);
299 writel(value, bus->base + ASPEED_I2C_BYTE_BUF_REG);
300 writel(ASPEED_I2CD_S_TX_CMD, bus->base + ASPEED_I2C_CMD_REG);
301 break;
302 case ASPEED_I2C_SLAVE_READ_PROCESSED:
303 if (unlikely(!(irq_status & ASPEED_I2CD_INTR_TX_ACK))) {
304 dev_err(bus->dev,
305 "Expected ACK after processed read.\n");
306 break;
307 }
308 irq_handled |= ASPEED_I2CD_INTR_TX_ACK;
309 i2c_slave_event(slave, I2C_SLAVE_READ_PROCESSED, &value);
310 writel(value, bus->base + ASPEED_I2C_BYTE_BUF_REG);
311 writel(ASPEED_I2CD_S_TX_CMD, bus->base + ASPEED_I2C_CMD_REG);
312 break;
313 case ASPEED_I2C_SLAVE_WRITE_REQUESTED:
314 bus->slave_state = ASPEED_I2C_SLAVE_WRITE_RECEIVED;
315 i2c_slave_event(slave, I2C_SLAVE_WRITE_REQUESTED, &value);
316 break;
317 case ASPEED_I2C_SLAVE_WRITE_RECEIVED:
318 i2c_slave_event(slave, I2C_SLAVE_WRITE_RECEIVED, &value);
319 break;
320 case ASPEED_I2C_SLAVE_STOP:
321 i2c_slave_event(slave, I2C_SLAVE_STOP, &value);
322 bus->slave_state = ASPEED_I2C_SLAVE_INACTIVE;
323 break;
324 case ASPEED_I2C_SLAVE_START:
325 ;
326 break;
327 default:
328 dev_err(bus->dev, "unknown slave_state: %d\n",
329 bus->slave_state);
330 bus->slave_state = ASPEED_I2C_SLAVE_INACTIVE;
331 break;
332 }
333
334 return irq_handled;
335}
336#endif
337
338
339static void aspeed_i2c_do_start(struct aspeed_i2c_bus *bus)
340{
341 u32 command = ASPEED_I2CD_M_START_CMD | ASPEED_I2CD_M_TX_CMD;
342 struct i2c_msg *msg = &bus->msgs[bus->msgs_index];
343 u8 slave_addr = i2c_8bit_addr_from_msg(msg);
344
345#if IS_ENABLED(CONFIG_I2C_SLAVE)
346
347
348
349
350
351 if (bus->slave_state != ASPEED_I2C_SLAVE_INACTIVE) {
352 bus->master_state = ASPEED_I2C_MASTER_PENDING;
353 return;
354 }
355#endif
356
357 bus->master_state = ASPEED_I2C_MASTER_START;
358 bus->buf_index = 0;
359
360 if (msg->flags & I2C_M_RD) {
361 command |= ASPEED_I2CD_M_RX_CMD;
362
363 if (msg->len == 1 && !(msg->flags & I2C_M_RECV_LEN))
364 command |= ASPEED_I2CD_M_S_RX_CMD_LAST;
365 }
366
367 writel(slave_addr, bus->base + ASPEED_I2C_BYTE_BUF_REG);
368 writel(command, bus->base + ASPEED_I2C_CMD_REG);
369}
370
371
372static void aspeed_i2c_do_stop(struct aspeed_i2c_bus *bus)
373{
374 bus->master_state = ASPEED_I2C_MASTER_STOP;
375 writel(ASPEED_I2CD_M_STOP_CMD, bus->base + ASPEED_I2C_CMD_REG);
376}
377
378
379static void aspeed_i2c_next_msg_or_stop(struct aspeed_i2c_bus *bus)
380{
381 if (bus->msgs_index + 1 < bus->msgs_count) {
382 bus->msgs_index++;
383 aspeed_i2c_do_start(bus);
384 } else {
385 aspeed_i2c_do_stop(bus);
386 }
387}
388
389static int aspeed_i2c_is_irq_error(u32 irq_status)
390{
391 if (irq_status & ASPEED_I2CD_INTR_ARBIT_LOSS)
392 return -EAGAIN;
393 if (irq_status & (ASPEED_I2CD_INTR_SDA_DL_TIMEOUT |
394 ASPEED_I2CD_INTR_SCL_TIMEOUT))
395 return -EBUSY;
396 if (irq_status & (ASPEED_I2CD_INTR_ABNORMAL))
397 return -EPROTO;
398
399 return 0;
400}
401
402static u32 aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus, u32 irq_status)
403{
404 u32 irq_handled = 0, command = 0;
405 struct i2c_msg *msg;
406 u8 recv_byte;
407 int ret;
408
409 if (irq_status & ASPEED_I2CD_INTR_BUS_RECOVER_DONE) {
410 bus->master_state = ASPEED_I2C_MASTER_INACTIVE;
411 irq_handled |= ASPEED_I2CD_INTR_BUS_RECOVER_DONE;
412 goto out_complete;
413 }
414
415
416
417
418
419
420 ret = aspeed_i2c_is_irq_error(irq_status);
421 if (ret) {
422 dev_dbg(bus->dev, "received error interrupt: 0x%08x\n",
423 irq_status);
424 irq_handled |= (irq_status & ASPEED_I2CD_INTR_MASTER_ERRORS);
425 if (bus->master_state != ASPEED_I2C_MASTER_INACTIVE) {
426 bus->cmd_err = ret;
427 bus->master_state = ASPEED_I2C_MASTER_INACTIVE;
428 goto out_complete;
429 }
430 }
431
432
433 if (bus->master_state == ASPEED_I2C_MASTER_INACTIVE ||
434 bus->master_state == ASPEED_I2C_MASTER_PENDING)
435 goto out_no_complete;
436
437
438 if (!bus->msgs) {
439 dev_err(bus->dev, "bus in unknown state. irq_status: 0x%x\n",
440 irq_status);
441 bus->cmd_err = -EIO;
442 if (bus->master_state != ASPEED_I2C_MASTER_STOP &&
443 bus->master_state != ASPEED_I2C_MASTER_INACTIVE)
444 aspeed_i2c_do_stop(bus);
445 goto out_no_complete;
446 }
447 msg = &bus->msgs[bus->msgs_index];
448
449
450
451
452
453
454 if (bus->master_state == ASPEED_I2C_MASTER_START) {
455#if IS_ENABLED(CONFIG_I2C_SLAVE)
456
457
458
459
460
461
462
463 if (unlikely(irq_status & ASPEED_I2CD_INTR_SLAVE_MATCH)) {
464 writel(readl(bus->base + ASPEED_I2C_CMD_REG) &
465 ~ASPEED_I2CD_MASTER_CMDS_MASK,
466 bus->base + ASPEED_I2C_CMD_REG);
467 bus->master_state = ASPEED_I2C_MASTER_PENDING;
468 dev_dbg(bus->dev,
469 "master goes pending due to a slave start\n");
470 goto out_no_complete;
471 }
472#endif
473 if (unlikely(!(irq_status & ASPEED_I2CD_INTR_TX_ACK))) {
474 if (unlikely(!(irq_status & ASPEED_I2CD_INTR_TX_NAK))) {
475 bus->cmd_err = -ENXIO;
476 bus->master_state = ASPEED_I2C_MASTER_INACTIVE;
477 goto out_complete;
478 }
479 pr_devel("no slave present at %02x\n", msg->addr);
480 irq_handled |= ASPEED_I2CD_INTR_TX_NAK;
481 bus->cmd_err = -ENXIO;
482 aspeed_i2c_do_stop(bus);
483 goto out_no_complete;
484 }
485 irq_handled |= ASPEED_I2CD_INTR_TX_ACK;
486 if (msg->len == 0) {
487 aspeed_i2c_do_stop(bus);
488 goto out_no_complete;
489 }
490 if (msg->flags & I2C_M_RD)
491 bus->master_state = ASPEED_I2C_MASTER_RX_FIRST;
492 else
493 bus->master_state = ASPEED_I2C_MASTER_TX_FIRST;
494 }
495
496 switch (bus->master_state) {
497 case ASPEED_I2C_MASTER_TX:
498 if (unlikely(irq_status & ASPEED_I2CD_INTR_TX_NAK)) {
499 dev_dbg(bus->dev, "slave NACKed TX\n");
500 irq_handled |= ASPEED_I2CD_INTR_TX_NAK;
501 goto error_and_stop;
502 } else if (unlikely(!(irq_status & ASPEED_I2CD_INTR_TX_ACK))) {
503 dev_err(bus->dev, "slave failed to ACK TX\n");
504 goto error_and_stop;
505 }
506 irq_handled |= ASPEED_I2CD_INTR_TX_ACK;
507
508 case ASPEED_I2C_MASTER_TX_FIRST:
509 if (bus->buf_index < msg->len) {
510 bus->master_state = ASPEED_I2C_MASTER_TX;
511 writel(msg->buf[bus->buf_index++],
512 bus->base + ASPEED_I2C_BYTE_BUF_REG);
513 writel(ASPEED_I2CD_M_TX_CMD,
514 bus->base + ASPEED_I2C_CMD_REG);
515 } else {
516 aspeed_i2c_next_msg_or_stop(bus);
517 }
518 goto out_no_complete;
519 case ASPEED_I2C_MASTER_RX_FIRST:
520
521 if (!(irq_status & ASPEED_I2CD_INTR_RX_DONE))
522 goto out_no_complete;
523
524 case ASPEED_I2C_MASTER_RX:
525 if (unlikely(!(irq_status & ASPEED_I2CD_INTR_RX_DONE))) {
526 dev_err(bus->dev, "master failed to RX\n");
527 goto error_and_stop;
528 }
529 irq_handled |= ASPEED_I2CD_INTR_RX_DONE;
530
531 recv_byte = readl(bus->base + ASPEED_I2C_BYTE_BUF_REG) >> 8;
532 msg->buf[bus->buf_index++] = recv_byte;
533
534 if (msg->flags & I2C_M_RECV_LEN) {
535 if (unlikely(recv_byte > I2C_SMBUS_BLOCK_MAX)) {
536 bus->cmd_err = -EPROTO;
537 aspeed_i2c_do_stop(bus);
538 goto out_no_complete;
539 }
540 msg->len = recv_byte +
541 ((msg->flags & I2C_CLIENT_PEC) ? 2 : 1);
542 msg->flags &= ~I2C_M_RECV_LEN;
543 }
544
545 if (bus->buf_index < msg->len) {
546 bus->master_state = ASPEED_I2C_MASTER_RX;
547 command = ASPEED_I2CD_M_RX_CMD;
548 if (bus->buf_index + 1 == msg->len)
549 command |= ASPEED_I2CD_M_S_RX_CMD_LAST;
550 writel(command, bus->base + ASPEED_I2C_CMD_REG);
551 } else {
552 aspeed_i2c_next_msg_or_stop(bus);
553 }
554 goto out_no_complete;
555 case ASPEED_I2C_MASTER_STOP:
556 if (unlikely(!(irq_status & ASPEED_I2CD_INTR_NORMAL_STOP))) {
557 dev_err(bus->dev,
558 "master failed to STOP. irq_status:0x%x\n",
559 irq_status);
560 bus->cmd_err = -EIO;
561
562 } else {
563 irq_handled |= ASPEED_I2CD_INTR_NORMAL_STOP;
564 }
565
566 bus->master_state = ASPEED_I2C_MASTER_INACTIVE;
567 goto out_complete;
568 case ASPEED_I2C_MASTER_INACTIVE:
569 dev_err(bus->dev,
570 "master received interrupt 0x%08x, but is inactive\n",
571 irq_status);
572 bus->cmd_err = -EIO;
573
574 goto out_complete;
575 default:
576 WARN(1, "unknown master state\n");
577 bus->master_state = ASPEED_I2C_MASTER_INACTIVE;
578 bus->cmd_err = -EINVAL;
579 goto out_complete;
580 }
581error_and_stop:
582 bus->cmd_err = -EIO;
583 aspeed_i2c_do_stop(bus);
584 goto out_no_complete;
585out_complete:
586 bus->msgs = NULL;
587 if (bus->cmd_err)
588 bus->master_xfer_result = bus->cmd_err;
589 else
590 bus->master_xfer_result = bus->msgs_index + 1;
591 complete(&bus->cmd_complete);
592out_no_complete:
593 return irq_handled;
594}
595
596static irqreturn_t aspeed_i2c_bus_irq(int irq, void *dev_id)
597{
598 struct aspeed_i2c_bus *bus = dev_id;
599 u32 irq_received, irq_remaining, irq_handled;
600
601 spin_lock(&bus->lock);
602 irq_received = readl(bus->base + ASPEED_I2C_INTR_STS_REG);
603
604 writel(irq_received & ~ASPEED_I2CD_INTR_RX_DONE,
605 bus->base + ASPEED_I2C_INTR_STS_REG);
606 readl(bus->base + ASPEED_I2C_INTR_STS_REG);
607 irq_remaining = irq_received;
608
609#if IS_ENABLED(CONFIG_I2C_SLAVE)
610
611
612
613
614
615
616
617 if (bus->master_state != ASPEED_I2C_MASTER_INACTIVE &&
618 bus->master_state != ASPEED_I2C_MASTER_PENDING) {
619 irq_handled = aspeed_i2c_master_irq(bus, irq_remaining);
620 irq_remaining &= ~irq_handled;
621 if (irq_remaining)
622 irq_handled |= aspeed_i2c_slave_irq(bus, irq_remaining);
623 } else {
624 irq_handled = aspeed_i2c_slave_irq(bus, irq_remaining);
625 irq_remaining &= ~irq_handled;
626 if (irq_remaining)
627 irq_handled |= aspeed_i2c_master_irq(bus,
628 irq_remaining);
629 }
630
631
632
633
634
635 if (bus->master_state == ASPEED_I2C_MASTER_PENDING &&
636 bus->slave_state == ASPEED_I2C_SLAVE_INACTIVE)
637 aspeed_i2c_do_start(bus);
638#else
639 irq_handled = aspeed_i2c_master_irq(bus, irq_remaining);
640#endif
641
642 irq_remaining &= ~irq_handled;
643 if (irq_remaining)
644 dev_err(bus->dev,
645 "irq handled != irq. expected 0x%08x, but was 0x%08x\n",
646 irq_received, irq_handled);
647
648
649 if (irq_received & ASPEED_I2CD_INTR_RX_DONE) {
650 writel(ASPEED_I2CD_INTR_RX_DONE,
651 bus->base + ASPEED_I2C_INTR_STS_REG);
652 readl(bus->base + ASPEED_I2C_INTR_STS_REG);
653 }
654 spin_unlock(&bus->lock);
655 return irq_remaining ? IRQ_NONE : IRQ_HANDLED;
656}
657
658static int aspeed_i2c_master_xfer(struct i2c_adapter *adap,
659 struct i2c_msg *msgs, int num)
660{
661 struct aspeed_i2c_bus *bus = i2c_get_adapdata(adap);
662 unsigned long time_left, flags;
663
664 spin_lock_irqsave(&bus->lock, flags);
665 bus->cmd_err = 0;
666
667
668 if (!bus->multi_master &&
669 (readl(bus->base + ASPEED_I2C_CMD_REG) &
670 ASPEED_I2CD_BUS_BUSY_STS)) {
671 int ret;
672
673 spin_unlock_irqrestore(&bus->lock, flags);
674 ret = aspeed_i2c_recover_bus(bus);
675 if (ret)
676 return ret;
677 spin_lock_irqsave(&bus->lock, flags);
678 }
679
680 bus->cmd_err = 0;
681 bus->msgs = msgs;
682 bus->msgs_index = 0;
683 bus->msgs_count = num;
684
685 reinit_completion(&bus->cmd_complete);
686 aspeed_i2c_do_start(bus);
687 spin_unlock_irqrestore(&bus->lock, flags);
688
689 time_left = wait_for_completion_timeout(&bus->cmd_complete,
690 bus->adap.timeout);
691
692 if (time_left == 0) {
693
694
695
696
697 if (bus->multi_master &&
698 (readl(bus->base + ASPEED_I2C_CMD_REG) &
699 ASPEED_I2CD_BUS_BUSY_STS))
700 aspeed_i2c_recover_bus(bus);
701
702
703
704
705
706 spin_lock_irqsave(&bus->lock, flags);
707 if (bus->master_state == ASPEED_I2C_MASTER_PENDING)
708 bus->master_state = ASPEED_I2C_MASTER_INACTIVE;
709 spin_unlock_irqrestore(&bus->lock, flags);
710
711 return -ETIMEDOUT;
712 }
713
714 return bus->master_xfer_result;
715}
716
717static u32 aspeed_i2c_functionality(struct i2c_adapter *adap)
718{
719 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_SMBUS_BLOCK_DATA;
720}
721
722#if IS_ENABLED(CONFIG_I2C_SLAVE)
723
724static void __aspeed_i2c_reg_slave(struct aspeed_i2c_bus *bus, u16 slave_addr)
725{
726 u32 addr_reg_val, func_ctrl_reg_val;
727
728
729 addr_reg_val = readl(bus->base + ASPEED_I2C_DEV_ADDR_REG);
730 addr_reg_val &= ~ASPEED_I2CD_DEV_ADDR_MASK;
731 addr_reg_val |= slave_addr & ASPEED_I2CD_DEV_ADDR_MASK;
732 writel(addr_reg_val, bus->base + ASPEED_I2C_DEV_ADDR_REG);
733
734
735 func_ctrl_reg_val = readl(bus->base + ASPEED_I2C_FUN_CTRL_REG);
736 func_ctrl_reg_val |= ASPEED_I2CD_SLAVE_EN;
737 writel(func_ctrl_reg_val, bus->base + ASPEED_I2C_FUN_CTRL_REG);
738}
739
740static int aspeed_i2c_reg_slave(struct i2c_client *client)
741{
742 struct aspeed_i2c_bus *bus = i2c_get_adapdata(client->adapter);
743 unsigned long flags;
744
745 spin_lock_irqsave(&bus->lock, flags);
746 if (bus->slave) {
747 spin_unlock_irqrestore(&bus->lock, flags);
748 return -EINVAL;
749 }
750
751 __aspeed_i2c_reg_slave(bus, client->addr);
752
753 bus->slave = client;
754 bus->slave_state = ASPEED_I2C_SLAVE_INACTIVE;
755 spin_unlock_irqrestore(&bus->lock, flags);
756
757 return 0;
758}
759
760static int aspeed_i2c_unreg_slave(struct i2c_client *client)
761{
762 struct aspeed_i2c_bus *bus = i2c_get_adapdata(client->adapter);
763 u32 func_ctrl_reg_val;
764 unsigned long flags;
765
766 spin_lock_irqsave(&bus->lock, flags);
767 if (!bus->slave) {
768 spin_unlock_irqrestore(&bus->lock, flags);
769 return -EINVAL;
770 }
771
772
773 func_ctrl_reg_val = readl(bus->base + ASPEED_I2C_FUN_CTRL_REG);
774 func_ctrl_reg_val &= ~ASPEED_I2CD_SLAVE_EN;
775 writel(func_ctrl_reg_val, bus->base + ASPEED_I2C_FUN_CTRL_REG);
776
777 bus->slave = NULL;
778 spin_unlock_irqrestore(&bus->lock, flags);
779
780 return 0;
781}
782#endif
783
784static const struct i2c_algorithm aspeed_i2c_algo = {
785 .master_xfer = aspeed_i2c_master_xfer,
786 .functionality = aspeed_i2c_functionality,
787#if IS_ENABLED(CONFIG_I2C_SLAVE)
788 .reg_slave = aspeed_i2c_reg_slave,
789 .unreg_slave = aspeed_i2c_unreg_slave,
790#endif
791};
792
793static u32 aspeed_i2c_get_clk_reg_val(struct device *dev,
794 u32 clk_high_low_mask,
795 u32 divisor)
796{
797 u32 base_clk_divisor, clk_high_low_max, clk_high, clk_low, tmp;
798
799
800
801
802
803
804
805
806 clk_high_low_max = (clk_high_low_mask + 1) * 2;
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828 base_clk_divisor = divisor > clk_high_low_max ?
829 ilog2((divisor - 1) / clk_high_low_max) + 1 : 0;
830
831 if (base_clk_divisor > ASPEED_I2CD_TIME_BASE_DIVISOR_MASK) {
832 base_clk_divisor = ASPEED_I2CD_TIME_BASE_DIVISOR_MASK;
833 clk_low = clk_high_low_mask;
834 clk_high = clk_high_low_mask;
835 dev_err(dev,
836 "clamping clock divider: divider requested, %u, is greater than largest possible divider, %u.\n",
837 divisor, (1 << base_clk_divisor) * clk_high_low_max);
838 } else {
839 tmp = (divisor + (1 << base_clk_divisor) - 1)
840 >> base_clk_divisor;
841 clk_low = tmp / 2;
842 clk_high = tmp - clk_low;
843
844 if (clk_high)
845 clk_high--;
846
847 if (clk_low)
848 clk_low--;
849 }
850
851
852 return ((clk_high << ASPEED_I2CD_TIME_SCL_HIGH_SHIFT)
853 & ASPEED_I2CD_TIME_SCL_HIGH_MASK)
854 | ((clk_low << ASPEED_I2CD_TIME_SCL_LOW_SHIFT)
855 & ASPEED_I2CD_TIME_SCL_LOW_MASK)
856 | (base_clk_divisor
857 & ASPEED_I2CD_TIME_BASE_DIVISOR_MASK);
858}
859
860static u32 aspeed_i2c_24xx_get_clk_reg_val(struct device *dev, u32 divisor)
861{
862
863
864
865
866 return aspeed_i2c_get_clk_reg_val(dev, GENMASK(2, 0), divisor);
867}
868
869static u32 aspeed_i2c_25xx_get_clk_reg_val(struct device *dev, u32 divisor)
870{
871
872
873
874
875 return aspeed_i2c_get_clk_reg_val(dev, GENMASK(3, 0), divisor);
876}
877
878
879static int aspeed_i2c_init_clk(struct aspeed_i2c_bus *bus)
880{
881 u32 divisor, clk_reg_val;
882
883 divisor = DIV_ROUND_UP(bus->parent_clk_frequency, bus->bus_frequency);
884 clk_reg_val = readl(bus->base + ASPEED_I2C_AC_TIMING_REG1);
885 clk_reg_val &= (ASPEED_I2CD_TIME_TBUF_MASK |
886 ASPEED_I2CD_TIME_THDSTA_MASK |
887 ASPEED_I2CD_TIME_TACST_MASK);
888 clk_reg_val |= bus->get_clk_reg_val(bus->dev, divisor);
889 writel(clk_reg_val, bus->base + ASPEED_I2C_AC_TIMING_REG1);
890 writel(ASPEED_NO_TIMEOUT_CTRL, bus->base + ASPEED_I2C_AC_TIMING_REG2);
891
892 return 0;
893}
894
895
896static int aspeed_i2c_init(struct aspeed_i2c_bus *bus,
897 struct platform_device *pdev)
898{
899 u32 fun_ctrl_reg = ASPEED_I2CD_MASTER_EN;
900 int ret;
901
902
903 writel(0, bus->base + ASPEED_I2C_FUN_CTRL_REG);
904
905 ret = aspeed_i2c_init_clk(bus);
906 if (ret < 0)
907 return ret;
908
909 if (of_property_read_bool(pdev->dev.of_node, "multi-master"))
910 bus->multi_master = true;
911 else
912 fun_ctrl_reg |= ASPEED_I2CD_MULTI_MASTER_DIS;
913
914
915 writel(readl(bus->base + ASPEED_I2C_FUN_CTRL_REG) | fun_ctrl_reg,
916 bus->base + ASPEED_I2C_FUN_CTRL_REG);
917
918#if IS_ENABLED(CONFIG_I2C_SLAVE)
919
920 if (bus->slave)
921 __aspeed_i2c_reg_slave(bus, bus->slave->addr);
922#endif
923
924
925 writel(ASPEED_I2CD_INTR_ALL, bus->base + ASPEED_I2C_INTR_CTRL_REG);
926
927 return 0;
928}
929
930static int aspeed_i2c_reset(struct aspeed_i2c_bus *bus)
931{
932 struct platform_device *pdev = to_platform_device(bus->dev);
933 unsigned long flags;
934 int ret;
935
936 spin_lock_irqsave(&bus->lock, flags);
937
938
939 writel(0, bus->base + ASPEED_I2C_INTR_CTRL_REG);
940 writel(0xffffffff, bus->base + ASPEED_I2C_INTR_STS_REG);
941
942 ret = aspeed_i2c_init(bus, pdev);
943
944 spin_unlock_irqrestore(&bus->lock, flags);
945
946 return ret;
947}
948
949static const struct of_device_id aspeed_i2c_bus_of_table[] = {
950 {
951 .compatible = "aspeed,ast2400-i2c-bus",
952 .data = aspeed_i2c_24xx_get_clk_reg_val,
953 },
954 {
955 .compatible = "aspeed,ast2500-i2c-bus",
956 .data = aspeed_i2c_25xx_get_clk_reg_val,
957 },
958 {
959 .compatible = "aspeed,ast2600-i2c-bus",
960 .data = aspeed_i2c_25xx_get_clk_reg_val,
961 },
962 { },
963};
964MODULE_DEVICE_TABLE(of, aspeed_i2c_bus_of_table);
965
966static int aspeed_i2c_probe_bus(struct platform_device *pdev)
967{
968 const struct of_device_id *match;
969 struct aspeed_i2c_bus *bus;
970 struct clk *parent_clk;
971 struct resource *res;
972 int irq, ret;
973
974 bus = devm_kzalloc(&pdev->dev, sizeof(*bus), GFP_KERNEL);
975 if (!bus)
976 return -ENOMEM;
977
978 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
979 bus->base = devm_ioremap_resource(&pdev->dev, res);
980 if (IS_ERR(bus->base))
981 return PTR_ERR(bus->base);
982
983 parent_clk = devm_clk_get(&pdev->dev, NULL);
984 if (IS_ERR(parent_clk))
985 return PTR_ERR(parent_clk);
986 bus->parent_clk_frequency = clk_get_rate(parent_clk);
987
988 devm_clk_put(&pdev->dev, parent_clk);
989
990 bus->rst = devm_reset_control_get_shared(&pdev->dev, NULL);
991 if (IS_ERR(bus->rst)) {
992 dev_err(&pdev->dev,
993 "missing or invalid reset controller device tree entry\n");
994 return PTR_ERR(bus->rst);
995 }
996 reset_control_deassert(bus->rst);
997
998 ret = of_property_read_u32(pdev->dev.of_node,
999 "bus-frequency", &bus->bus_frequency);
1000 if (ret < 0) {
1001 dev_err(&pdev->dev,
1002 "Could not read bus-frequency property\n");
1003 bus->bus_frequency = I2C_MAX_STANDARD_MODE_FREQ;
1004 }
1005
1006 match = of_match_node(aspeed_i2c_bus_of_table, pdev->dev.of_node);
1007 if (!match)
1008 bus->get_clk_reg_val = aspeed_i2c_24xx_get_clk_reg_val;
1009 else
1010 bus->get_clk_reg_val = (u32 (*)(struct device *, u32))
1011 match->data;
1012
1013
1014 spin_lock_init(&bus->lock);
1015 init_completion(&bus->cmd_complete);
1016 bus->adap.owner = THIS_MODULE;
1017 bus->adap.retries = 0;
1018 bus->adap.algo = &aspeed_i2c_algo;
1019 bus->adap.dev.parent = &pdev->dev;
1020 bus->adap.dev.of_node = pdev->dev.of_node;
1021 strlcpy(bus->adap.name, pdev->name, sizeof(bus->adap.name));
1022 i2c_set_adapdata(&bus->adap, bus);
1023
1024 bus->dev = &pdev->dev;
1025
1026
1027 writel(0, bus->base + ASPEED_I2C_INTR_CTRL_REG);
1028 writel(0xffffffff, bus->base + ASPEED_I2C_INTR_STS_REG);
1029
1030
1031
1032
1033 ret = aspeed_i2c_init(bus, pdev);
1034 if (ret < 0)
1035 return ret;
1036
1037 irq = irq_of_parse_and_map(pdev->dev.of_node, 0);
1038 ret = devm_request_irq(&pdev->dev, irq, aspeed_i2c_bus_irq,
1039 0, dev_name(&pdev->dev), bus);
1040 if (ret < 0)
1041 return ret;
1042
1043 ret = i2c_add_adapter(&bus->adap);
1044 if (ret < 0)
1045 return ret;
1046
1047 platform_set_drvdata(pdev, bus);
1048
1049 dev_info(bus->dev, "i2c bus %d registered, irq %d\n",
1050 bus->adap.nr, irq);
1051
1052 return 0;
1053}
1054
1055static int aspeed_i2c_remove_bus(struct platform_device *pdev)
1056{
1057 struct aspeed_i2c_bus *bus = platform_get_drvdata(pdev);
1058 unsigned long flags;
1059
1060 spin_lock_irqsave(&bus->lock, flags);
1061
1062
1063 writel(0, bus->base + ASPEED_I2C_FUN_CTRL_REG);
1064 writel(0, bus->base + ASPEED_I2C_INTR_CTRL_REG);
1065
1066 spin_unlock_irqrestore(&bus->lock, flags);
1067
1068 reset_control_assert(bus->rst);
1069
1070 i2c_del_adapter(&bus->adap);
1071
1072 return 0;
1073}
1074
1075static struct platform_driver aspeed_i2c_bus_driver = {
1076 .probe = aspeed_i2c_probe_bus,
1077 .remove = aspeed_i2c_remove_bus,
1078 .driver = {
1079 .name = "aspeed-i2c-bus",
1080 .of_match_table = aspeed_i2c_bus_of_table,
1081 },
1082};
1083module_platform_driver(aspeed_i2c_bus_driver);
1084
1085MODULE_AUTHOR("Brendan Higgins <brendanhiggins@google.com>");
1086MODULE_DESCRIPTION("Aspeed I2C Bus Driver");
1087MODULE_LICENSE("GPL v2");
1088