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1// SPDX-License-Identifier: GPL-2.0-only
2// Copyright (C) 2014 Broadcom Corporation
3
4#include <linux/delay.h>
5#include <linux/i2c.h>
6#include <linux/interrupt.h>
7#include <linux/io.h>
8#include <linux/kernel.h>
9#include <linux/module.h>
10#include <linux/of_device.h>
11#include <linux/platform_device.h>
12#include <linux/slab.h>
13
14#define IDM_CTRL_DIRECT_OFFSET 0x00
15#define CFG_OFFSET 0x00
16#define CFG_RESET_SHIFT 31
17#define CFG_EN_SHIFT 30
18#define CFG_SLAVE_ADDR_0_SHIFT 28
19#define CFG_M_RETRY_CNT_SHIFT 16
20#define CFG_M_RETRY_CNT_MASK 0x0f
21
22#define TIM_CFG_OFFSET 0x04
23#define TIM_CFG_MODE_400_SHIFT 31
24#define TIM_RAND_SLAVE_STRETCH_SHIFT 24
25#define TIM_RAND_SLAVE_STRETCH_MASK 0x7f
26#define TIM_PERIODIC_SLAVE_STRETCH_SHIFT 16
27#define TIM_PERIODIC_SLAVE_STRETCH_MASK 0x7f
28
29#define S_CFG_SMBUS_ADDR_OFFSET 0x08
30#define S_CFG_EN_NIC_SMB_ADDR3_SHIFT 31
31#define S_CFG_NIC_SMB_ADDR3_SHIFT 24
32#define S_CFG_NIC_SMB_ADDR3_MASK 0x7f
33#define S_CFG_EN_NIC_SMB_ADDR2_SHIFT 23
34#define S_CFG_NIC_SMB_ADDR2_SHIFT 16
35#define S_CFG_NIC_SMB_ADDR2_MASK 0x7f
36#define S_CFG_EN_NIC_SMB_ADDR1_SHIFT 15
37#define S_CFG_NIC_SMB_ADDR1_SHIFT 8
38#define S_CFG_NIC_SMB_ADDR1_MASK 0x7f
39#define S_CFG_EN_NIC_SMB_ADDR0_SHIFT 7
40#define S_CFG_NIC_SMB_ADDR0_SHIFT 0
41#define S_CFG_NIC_SMB_ADDR0_MASK 0x7f
42
43#define M_FIFO_CTRL_OFFSET 0x0c
44#define M_FIFO_RX_FLUSH_SHIFT 31
45#define M_FIFO_TX_FLUSH_SHIFT 30
46#define M_FIFO_RX_CNT_SHIFT 16
47#define M_FIFO_RX_CNT_MASK 0x7f
48#define M_FIFO_RX_THLD_SHIFT 8
49#define M_FIFO_RX_THLD_MASK 0x3f
50
51#define S_FIFO_CTRL_OFFSET 0x10
52#define S_FIFO_RX_FLUSH_SHIFT 31
53#define S_FIFO_TX_FLUSH_SHIFT 30
54#define S_FIFO_RX_CNT_SHIFT 16
55#define S_FIFO_RX_CNT_MASK 0x7f
56#define S_FIFO_RX_THLD_SHIFT 8
57#define S_FIFO_RX_THLD_MASK 0x3f
58
59#define M_CMD_OFFSET 0x30
60#define M_CMD_START_BUSY_SHIFT 31
61#define M_CMD_STATUS_SHIFT 25
62#define M_CMD_STATUS_MASK 0x07
63#define M_CMD_STATUS_SUCCESS 0x0
64#define M_CMD_STATUS_LOST_ARB 0x1
65#define M_CMD_STATUS_NACK_ADDR 0x2
66#define M_CMD_STATUS_NACK_DATA 0x3
67#define M_CMD_STATUS_TIMEOUT 0x4
68#define M_CMD_STATUS_FIFO_UNDERRUN 0x5
69#define M_CMD_STATUS_RX_FIFO_FULL 0x6
70#define M_CMD_PROTOCOL_SHIFT 9
71#define M_CMD_PROTOCOL_MASK 0xf
72#define M_CMD_PROTOCOL_QUICK 0x0
73#define M_CMD_PROTOCOL_BLK_WR 0x7
74#define M_CMD_PROTOCOL_BLK_RD 0x8
75#define M_CMD_PROTOCOL_PROCESS 0xa
76#define M_CMD_PEC_SHIFT 8
77#define M_CMD_RD_CNT_SHIFT 0
78#define M_CMD_RD_CNT_MASK 0xff
79
80#define S_CMD_OFFSET 0x34
81#define S_CMD_START_BUSY_SHIFT 31
82#define S_CMD_STATUS_SHIFT 23
83#define S_CMD_STATUS_MASK 0x07
84#define S_CMD_STATUS_SUCCESS 0x0
85#define S_CMD_STATUS_TIMEOUT 0x5
86#define S_CMD_STATUS_MASTER_ABORT 0x7
87
88#define IE_OFFSET 0x38
89#define IE_M_RX_FIFO_FULL_SHIFT 31
90#define IE_M_RX_THLD_SHIFT 30
91#define IE_M_START_BUSY_SHIFT 28
92#define IE_M_TX_UNDERRUN_SHIFT 27
93#define IE_S_RX_FIFO_FULL_SHIFT 26
94#define IE_S_RX_THLD_SHIFT 25
95#define IE_S_RX_EVENT_SHIFT 24
96#define IE_S_START_BUSY_SHIFT 23
97#define IE_S_TX_UNDERRUN_SHIFT 22
98#define IE_S_RD_EVENT_SHIFT 21
99
100#define IS_OFFSET 0x3c
101#define IS_M_RX_FIFO_FULL_SHIFT 31
102#define IS_M_RX_THLD_SHIFT 30
103#define IS_M_START_BUSY_SHIFT 28
104#define IS_M_TX_UNDERRUN_SHIFT 27
105#define IS_S_RX_FIFO_FULL_SHIFT 26
106#define IS_S_RX_THLD_SHIFT 25
107#define IS_S_RX_EVENT_SHIFT 24
108#define IS_S_START_BUSY_SHIFT 23
109#define IS_S_TX_UNDERRUN_SHIFT 22
110#define IS_S_RD_EVENT_SHIFT 21
111
112#define M_TX_OFFSET 0x40
113#define M_TX_WR_STATUS_SHIFT 31
114#define M_TX_DATA_SHIFT 0
115#define M_TX_DATA_MASK 0xff
116
117#define M_RX_OFFSET 0x44
118#define M_RX_STATUS_SHIFT 30
119#define M_RX_STATUS_MASK 0x03
120#define M_RX_PEC_ERR_SHIFT 29
121#define M_RX_DATA_SHIFT 0
122#define M_RX_DATA_MASK 0xff
123
124#define S_TX_OFFSET 0x48
125#define S_TX_WR_STATUS_SHIFT 31
126#define S_TX_DATA_SHIFT 0
127#define S_TX_DATA_MASK 0xff
128
129#define S_RX_OFFSET 0x4c
130#define S_RX_STATUS_SHIFT 30
131#define S_RX_STATUS_MASK 0x03
132#define S_RX_PEC_ERR_SHIFT 29
133#define S_RX_DATA_SHIFT 0
134#define S_RX_DATA_MASK 0xff
135
136#define I2C_TIMEOUT_MSEC 50000
137#define M_TX_RX_FIFO_SIZE 64
138#define M_RX_FIFO_MAX_THLD_VALUE (M_TX_RX_FIFO_SIZE - 1)
139
140#define M_RX_MAX_READ_LEN 255
141#define M_RX_FIFO_THLD_VALUE 50
142
143#define IE_M_ALL_INTERRUPT_SHIFT 27
144#define IE_M_ALL_INTERRUPT_MASK 0x1e
145
146#define SLAVE_READ_WRITE_BIT_MASK 0x1
147#define SLAVE_READ_WRITE_BIT_SHIFT 0x1
148#define SLAVE_MAX_SIZE_TRANSACTION 64
149#define SLAVE_CLOCK_STRETCH_TIME 25
150
151#define IE_S_ALL_INTERRUPT_SHIFT 21
152#define IE_S_ALL_INTERRUPT_MASK 0x3f
153/*
154 * It takes ~18us to reading 10bytes of data, hence to keep tasklet
155 * running for less time, max slave read per tasklet is set to 10 bytes.
156 */
157#define MAX_SLAVE_RX_PER_INT 10
158
159enum i2c_slave_read_status {
160 I2C_SLAVE_RX_FIFO_EMPTY = 0,
161 I2C_SLAVE_RX_START,
162 I2C_SLAVE_RX_DATA,
163 I2C_SLAVE_RX_END,
164};
165
166enum bus_speed_index {
167 I2C_SPD_100K = 0,
168 I2C_SPD_400K,
169};
170
171enum bcm_iproc_i2c_type {
172 IPROC_I2C,
173 IPROC_I2C_NIC
174};
175
176struct bcm_iproc_i2c_dev {
177 struct device *device;
178 enum bcm_iproc_i2c_type type;
179 int irq;
180
181 void __iomem *base;
182 void __iomem *idm_base;
183
184 u32 ape_addr_mask;
185
186 /* lock for indirect access through IDM */
187 spinlock_t idm_lock;
188
189 struct i2c_adapter adapter;
190 unsigned int bus_speed;
191
192 struct completion done;
193 int xfer_is_done;
194
195 struct i2c_msg *msg;
196
197 struct i2c_client *slave;
198
199 /* bytes that have been transferred */
200 unsigned int tx_bytes;
201 /* bytes that have been read */
202 unsigned int rx_bytes;
203 unsigned int thld_bytes;
204
205 bool slave_rx_only;
206 bool rx_start_rcvd;
207 bool slave_read_complete;
208 u32 tx_underrun;
209 u32 slave_int_mask;
210 struct tasklet_struct slave_rx_tasklet;
211};
212
213/* tasklet to process slave rx data */
214static void slave_rx_tasklet_fn(unsigned long);
215
216/*
217 * Can be expanded in the future if more interrupt status bits are utilized
218 */
219#define ISR_MASK (BIT(IS_M_START_BUSY_SHIFT) | BIT(IS_M_TX_UNDERRUN_SHIFT)\
220 | BIT(IS_M_RX_THLD_SHIFT))
221
222#define ISR_MASK_SLAVE (BIT(IS_S_START_BUSY_SHIFT)\
223 | BIT(IS_S_RX_EVENT_SHIFT) | BIT(IS_S_RD_EVENT_SHIFT)\
224 | BIT(IS_S_TX_UNDERRUN_SHIFT) | BIT(IS_S_RX_FIFO_FULL_SHIFT)\
225 | BIT(IS_S_RX_THLD_SHIFT))
226
227static int bcm_iproc_i2c_reg_slave(struct i2c_client *slave);
228static int bcm_iproc_i2c_unreg_slave(struct i2c_client *slave);
229static void bcm_iproc_i2c_enable_disable(struct bcm_iproc_i2c_dev *iproc_i2c,
230 bool enable);
231
232static inline u32 iproc_i2c_rd_reg(struct bcm_iproc_i2c_dev *iproc_i2c,
233 u32 offset)
234{
235 u32 val;
236
237 if (iproc_i2c->idm_base) {
238 spin_lock(&iproc_i2c->idm_lock);
239 writel(iproc_i2c->ape_addr_mask,
240 iproc_i2c->idm_base + IDM_CTRL_DIRECT_OFFSET);
241 val = readl(iproc_i2c->base + offset);
242 spin_unlock(&iproc_i2c->idm_lock);
243 } else {
244 val = readl(iproc_i2c->base + offset);
245 }
246
247 return val;
248}
249
250static inline void iproc_i2c_wr_reg(struct bcm_iproc_i2c_dev *iproc_i2c,
251 u32 offset, u32 val)
252{
253 if (iproc_i2c->idm_base) {
254 spin_lock(&iproc_i2c->idm_lock);
255 writel(iproc_i2c->ape_addr_mask,
256 iproc_i2c->idm_base + IDM_CTRL_DIRECT_OFFSET);
257 writel(val, iproc_i2c->base + offset);
258 spin_unlock(&iproc_i2c->idm_lock);
259 } else {
260 writel(val, iproc_i2c->base + offset);
261 }
262}
263
264static void bcm_iproc_i2c_slave_init(
265 struct bcm_iproc_i2c_dev *iproc_i2c, bool need_reset)
266{
267 u32 val;
268
269 iproc_i2c->tx_underrun = 0;
270 if (need_reset) {
271 /* put controller in reset */
272 val = iproc_i2c_rd_reg(iproc_i2c, CFG_OFFSET);
273 val |= BIT(CFG_RESET_SHIFT);
274 iproc_i2c_wr_reg(iproc_i2c, CFG_OFFSET, val);
275
276 /* wait 100 usec per spec */
277 udelay(100);
278
279 /* bring controller out of reset */
280 val &= ~(BIT(CFG_RESET_SHIFT));
281 iproc_i2c_wr_reg(iproc_i2c, CFG_OFFSET, val);
282 }
283
284 /* flush TX/RX FIFOs */
285 val = (BIT(S_FIFO_RX_FLUSH_SHIFT) | BIT(S_FIFO_TX_FLUSH_SHIFT));
286 iproc_i2c_wr_reg(iproc_i2c, S_FIFO_CTRL_OFFSET, val);
287
288 /* Maximum slave stretch time */
289 val = iproc_i2c_rd_reg(iproc_i2c, TIM_CFG_OFFSET);
290 val &= ~(TIM_RAND_SLAVE_STRETCH_MASK << TIM_RAND_SLAVE_STRETCH_SHIFT);
291 val |= (SLAVE_CLOCK_STRETCH_TIME << TIM_RAND_SLAVE_STRETCH_SHIFT);
292 iproc_i2c_wr_reg(iproc_i2c, TIM_CFG_OFFSET, val);
293
294 /* Configure the slave address */
295 val = iproc_i2c_rd_reg(iproc_i2c, S_CFG_SMBUS_ADDR_OFFSET);
296 val |= BIT(S_CFG_EN_NIC_SMB_ADDR3_SHIFT);
297 val &= ~(S_CFG_NIC_SMB_ADDR3_MASK << S_CFG_NIC_SMB_ADDR3_SHIFT);
298 val |= (iproc_i2c->slave->addr << S_CFG_NIC_SMB_ADDR3_SHIFT);
299 iproc_i2c_wr_reg(iproc_i2c, S_CFG_SMBUS_ADDR_OFFSET, val);
300
301 /* clear all pending slave interrupts */
302 iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, ISR_MASK_SLAVE);
303
304 /* Enable interrupt register to indicate a valid byte in receive fifo */
305 val = BIT(IE_S_RX_EVENT_SHIFT);
306 /* Enable interrupt register to indicate Slave Rx FIFO Full */
307 val |= BIT(IE_S_RX_FIFO_FULL_SHIFT);
308 /* Enable interrupt register to indicate a Master read transaction */
309 val |= BIT(IE_S_RD_EVENT_SHIFT);
310 /* Enable interrupt register for the Slave BUSY command */
311 val |= BIT(IE_S_START_BUSY_SHIFT);
312 iproc_i2c->slave_int_mask = val;
313 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val);
314}
315
316static void bcm_iproc_i2c_check_slave_status(
317 struct bcm_iproc_i2c_dev *iproc_i2c)
318{
319 u32 val;
320
321 val = iproc_i2c_rd_reg(iproc_i2c, S_CMD_OFFSET);
322 /* status is valid only when START_BUSY is cleared after it was set */
323 if (val & BIT(S_CMD_START_BUSY_SHIFT))
324 return;
325
326 val = (val >> S_CMD_STATUS_SHIFT) & S_CMD_STATUS_MASK;
327 if (val == S_CMD_STATUS_TIMEOUT || val == S_CMD_STATUS_MASTER_ABORT) {
328 dev_err(iproc_i2c->device, (val == S_CMD_STATUS_TIMEOUT) ?
329 "slave random stretch time timeout\n" :
330 "Master aborted read transaction\n");
331 /* re-initialize i2c for recovery */
332 bcm_iproc_i2c_enable_disable(iproc_i2c, false);
333 bcm_iproc_i2c_slave_init(iproc_i2c, true);
334 bcm_iproc_i2c_enable_disable(iproc_i2c, true);
335 }
336}
337
338static void bcm_iproc_i2c_slave_read(struct bcm_iproc_i2c_dev *iproc_i2c)
339{
340 u8 rx_data, rx_status;
341 u32 rx_bytes = 0;
342 u32 val;
343
344 while (rx_bytes < MAX_SLAVE_RX_PER_INT) {
345 val = iproc_i2c_rd_reg(iproc_i2c, S_RX_OFFSET);
346 rx_status = (val >> S_RX_STATUS_SHIFT) & S_RX_STATUS_MASK;
347 rx_data = ((val >> S_RX_DATA_SHIFT) & S_RX_DATA_MASK);
348
349 if (rx_status == I2C_SLAVE_RX_START) {
350 /* Start of SMBUS Master write */
351 i2c_slave_event(iproc_i2c->slave,
352 I2C_SLAVE_WRITE_REQUESTED, &rx_data);
353 iproc_i2c->rx_start_rcvd = true;
354 iproc_i2c->slave_read_complete = false;
355 } else if (rx_status == I2C_SLAVE_RX_DATA &&
356 iproc_i2c->rx_start_rcvd) {
357 /* Middle of SMBUS Master write */
358 i2c_slave_event(iproc_i2c->slave,
359 I2C_SLAVE_WRITE_RECEIVED, &rx_data);
360 } else if (rx_status == I2C_SLAVE_RX_END &&
361 iproc_i2c->rx_start_rcvd) {
362 /* End of SMBUS Master write */
363 if (iproc_i2c->slave_rx_only)
364 i2c_slave_event(iproc_i2c->slave,
365 I2C_SLAVE_WRITE_RECEIVED,
366 &rx_data);
367
368 i2c_slave_event(iproc_i2c->slave, I2C_SLAVE_STOP,
369 &rx_data);
370 } else if (rx_status == I2C_SLAVE_RX_FIFO_EMPTY) {
371 iproc_i2c->rx_start_rcvd = false;
372 iproc_i2c->slave_read_complete = true;
373 break;
374 }
375
376 rx_bytes++;
377 }
378}
379
380static void slave_rx_tasklet_fn(unsigned long data)
381{
382 struct bcm_iproc_i2c_dev *iproc_i2c = (struct bcm_iproc_i2c_dev *)data;
383 u32 int_clr;
384
385 bcm_iproc_i2c_slave_read(iproc_i2c);
386
387 /* clear pending IS_S_RX_EVENT_SHIFT interrupt */
388 int_clr = BIT(IS_S_RX_EVENT_SHIFT);
389
390 if (!iproc_i2c->slave_rx_only && iproc_i2c->slave_read_complete) {
391 /*
392 * In case of single byte master-read request,
393 * IS_S_TX_UNDERRUN_SHIFT event is generated before
394 * IS_S_START_BUSY_SHIFT event. Hence start slave data send
395 * from first IS_S_TX_UNDERRUN_SHIFT event.
396 *
397 * This means don't send any data from slave when
398 * IS_S_RD_EVENT_SHIFT event is generated else it will increment
399 * eeprom or other backend slave driver read pointer twice.
400 */
401 iproc_i2c->tx_underrun = 0;
402 iproc_i2c->slave_int_mask |= BIT(IE_S_TX_UNDERRUN_SHIFT);
403
404 /* clear IS_S_RD_EVENT_SHIFT interrupt */
405 int_clr |= BIT(IS_S_RD_EVENT_SHIFT);
406 }
407
408 /* clear slave interrupt */
409 iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, int_clr);
410 /* enable slave interrupts */
411 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, iproc_i2c->slave_int_mask);
412}
413
414static bool bcm_iproc_i2c_slave_isr(struct bcm_iproc_i2c_dev *iproc_i2c,
415 u32 status)
416{
417 u32 val;
418 u8 value;
419
420 /*
421 * Slave events in case of master-write, master-write-read and,
422 * master-read
423 *
424 * Master-write : only IS_S_RX_EVENT_SHIFT event
425 * Master-write-read: both IS_S_RX_EVENT_SHIFT and IS_S_RD_EVENT_SHIFT
426 * events
427 * Master-read : both IS_S_RX_EVENT_SHIFT and IS_S_RD_EVENT_SHIFT
428 * events or only IS_S_RD_EVENT_SHIFT
429 *
430 * iproc has a slave rx fifo size of 64 bytes. Rx fifo full interrupt
431 * (IS_S_RX_FIFO_FULL_SHIFT) will be generated when RX fifo becomes
432 * full. This can happen if Master issues write requests of more than
433 * 64 bytes.
434 */
435 if (status & BIT(IS_S_RX_EVENT_SHIFT) ||
436 status & BIT(IS_S_RD_EVENT_SHIFT) ||
437 status & BIT(IS_S_RX_FIFO_FULL_SHIFT)) {
438 /* disable slave interrupts */
439 val = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
440 val &= ~iproc_i2c->slave_int_mask;
441 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val);
442
443 if (status & BIT(IS_S_RD_EVENT_SHIFT))
444 /* Master-write-read request */
445 iproc_i2c->slave_rx_only = false;
446 else
447 /* Master-write request only */
448 iproc_i2c->slave_rx_only = true;
449
450 /* schedule tasklet to read data later */
451 tasklet_schedule(&iproc_i2c->slave_rx_tasklet);
452
453 /*
454 * clear only IS_S_RX_EVENT_SHIFT and
455 * IS_S_RX_FIFO_FULL_SHIFT interrupt.
456 */
457 val = BIT(IS_S_RX_EVENT_SHIFT);
458 if (status & BIT(IS_S_RX_FIFO_FULL_SHIFT))
459 val |= BIT(IS_S_RX_FIFO_FULL_SHIFT);
460 iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, val);
461 }
462
463 if (status & BIT(IS_S_TX_UNDERRUN_SHIFT)) {
464 iproc_i2c->tx_underrun++;
465 if (iproc_i2c->tx_underrun == 1)
466 /* Start of SMBUS for Master Read */
467 i2c_slave_event(iproc_i2c->slave,
468 I2C_SLAVE_READ_REQUESTED,
469 &value);
470 else
471 /* Master read other than start */
472 i2c_slave_event(iproc_i2c->slave,
473 I2C_SLAVE_READ_PROCESSED,
474 &value);
475
476 iproc_i2c_wr_reg(iproc_i2c, S_TX_OFFSET, value);
477 /* start transfer */
478 val = BIT(S_CMD_START_BUSY_SHIFT);
479 iproc_i2c_wr_reg(iproc_i2c, S_CMD_OFFSET, val);
480
481 /* clear interrupt */
482 iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET,
483 BIT(IS_S_TX_UNDERRUN_SHIFT));
484 }
485
486 /* Stop received from master in case of master read transaction */
487 if (status & BIT(IS_S_START_BUSY_SHIFT)) {
488 /*
489 * Disable interrupt for TX FIFO becomes empty and
490 * less than PKT_LENGTH bytes were output on the SMBUS
491 */
492 iproc_i2c->slave_int_mask &= ~BIT(IE_S_TX_UNDERRUN_SHIFT);
493 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET,
494 iproc_i2c->slave_int_mask);
495
496 /* End of SMBUS for Master Read */
497 val = BIT(S_TX_WR_STATUS_SHIFT);
498 iproc_i2c_wr_reg(iproc_i2c, S_TX_OFFSET, val);
499
500 val = BIT(S_CMD_START_BUSY_SHIFT);
501 iproc_i2c_wr_reg(iproc_i2c, S_CMD_OFFSET, val);
502
503 /* flush TX FIFOs */
504 val = iproc_i2c_rd_reg(iproc_i2c, S_FIFO_CTRL_OFFSET);
505 val |= (BIT(S_FIFO_TX_FLUSH_SHIFT));
506 iproc_i2c_wr_reg(iproc_i2c, S_FIFO_CTRL_OFFSET, val);
507
508 i2c_slave_event(iproc_i2c->slave, I2C_SLAVE_STOP, &value);
509
510 /* clear interrupt */
511 iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET,
512 BIT(IS_S_START_BUSY_SHIFT));
513 }
514
515 /* check slave transmit status only if slave is transmitting */
516 if (!iproc_i2c->slave_rx_only)
517 bcm_iproc_i2c_check_slave_status(iproc_i2c);
518
519 return true;
520}
521
522static void bcm_iproc_i2c_read_valid_bytes(struct bcm_iproc_i2c_dev *iproc_i2c)
523{
524 struct i2c_msg *msg = iproc_i2c->msg;
525 uint32_t val;
526
527 /* Read valid data from RX FIFO */
528 while (iproc_i2c->rx_bytes < msg->len) {
529 val = iproc_i2c_rd_reg(iproc_i2c, M_RX_OFFSET);
530
531 /* rx fifo empty */
532 if (!((val >> M_RX_STATUS_SHIFT) & M_RX_STATUS_MASK))
533 break;
534
535 msg->buf[iproc_i2c->rx_bytes] =
536 (val >> M_RX_DATA_SHIFT) & M_RX_DATA_MASK;
537 iproc_i2c->rx_bytes++;
538 }
539}
540
541static void bcm_iproc_i2c_send(struct bcm_iproc_i2c_dev *iproc_i2c)
542{
543 struct i2c_msg *msg = iproc_i2c->msg;
544 unsigned int tx_bytes = msg->len - iproc_i2c->tx_bytes;
545 unsigned int i;
546 u32 val;
547
548 /* can only fill up to the FIFO size */
549 tx_bytes = min_t(unsigned int, tx_bytes, M_TX_RX_FIFO_SIZE);
550 for (i = 0; i < tx_bytes; i++) {
551 /* start from where we left over */
552 unsigned int idx = iproc_i2c->tx_bytes + i;
553
554 val = msg->buf[idx];
555
556 /* mark the last byte */
557 if (idx == msg->len - 1) {
558 val |= BIT(M_TX_WR_STATUS_SHIFT);
559
560 if (iproc_i2c->irq) {
561 u32 tmp;
562
563 /*
564 * Since this is the last byte, we should now
565 * disable TX FIFO underrun interrupt
566 */
567 tmp = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
568 tmp &= ~BIT(IE_M_TX_UNDERRUN_SHIFT);
569 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET,
570 tmp);
571 }
572 }
573
574 /* load data into TX FIFO */
575 iproc_i2c_wr_reg(iproc_i2c, M_TX_OFFSET, val);
576 }
577
578 /* update number of transferred bytes */
579 iproc_i2c->tx_bytes += tx_bytes;
580}
581
582static void bcm_iproc_i2c_read(struct bcm_iproc_i2c_dev *iproc_i2c)
583{
584 struct i2c_msg *msg = iproc_i2c->msg;
585 u32 bytes_left, val;
586
587 bcm_iproc_i2c_read_valid_bytes(iproc_i2c);
588 bytes_left = msg->len - iproc_i2c->rx_bytes;
589 if (bytes_left == 0) {
590 if (iproc_i2c->irq) {
591 /* finished reading all data, disable rx thld event */
592 val = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
593 val &= ~BIT(IS_M_RX_THLD_SHIFT);
594 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val);
595 }
596 } else if (bytes_left < iproc_i2c->thld_bytes) {
597 /* set bytes left as threshold */
598 val = iproc_i2c_rd_reg(iproc_i2c, M_FIFO_CTRL_OFFSET);
599 val &= ~(M_FIFO_RX_THLD_MASK << M_FIFO_RX_THLD_SHIFT);
600 val |= (bytes_left << M_FIFO_RX_THLD_SHIFT);
601 iproc_i2c_wr_reg(iproc_i2c, M_FIFO_CTRL_OFFSET, val);
602 iproc_i2c->thld_bytes = bytes_left;
603 }
604 /*
605 * bytes_left >= iproc_i2c->thld_bytes,
606 * hence no need to change the THRESHOLD SET.
607 * It will remain as iproc_i2c->thld_bytes itself
608 */
609}
610
611static void bcm_iproc_i2c_process_m_event(struct bcm_iproc_i2c_dev *iproc_i2c,
612 u32 status)
613{
614 /* TX FIFO is empty and we have more data to send */
615 if (status & BIT(IS_M_TX_UNDERRUN_SHIFT))
616 bcm_iproc_i2c_send(iproc_i2c);
617
618 /* RX FIFO threshold is reached and data needs to be read out */
619 if (status & BIT(IS_M_RX_THLD_SHIFT))
620 bcm_iproc_i2c_read(iproc_i2c);
621
622 /* transfer is done */
623 if (status & BIT(IS_M_START_BUSY_SHIFT)) {
624 iproc_i2c->xfer_is_done = 1;
625 if (iproc_i2c->irq)
626 complete(&iproc_i2c->done);
627 }
628}
629
630static irqreturn_t bcm_iproc_i2c_isr(int irq, void *data)
631{
632 struct bcm_iproc_i2c_dev *iproc_i2c = data;
633 u32 slave_status;
634 u32 status;
635 bool ret;
636
637 status = iproc_i2c_rd_reg(iproc_i2c, IS_OFFSET);
638 /* process only slave interrupt which are enabled */
639 slave_status = status & iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET) &
640 ISR_MASK_SLAVE;
641
642 if (slave_status) {
643 ret = bcm_iproc_i2c_slave_isr(iproc_i2c, slave_status);
644 if (ret)
645 return IRQ_HANDLED;
646 else
647 return IRQ_NONE;
648 }
649
650 status &= ISR_MASK;
651 if (!status)
652 return IRQ_NONE;
653
654 /* process all master based events */
655 bcm_iproc_i2c_process_m_event(iproc_i2c, status);
656 iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, status);
657
658 return IRQ_HANDLED;
659}
660
661static int bcm_iproc_i2c_init(struct bcm_iproc_i2c_dev *iproc_i2c)
662{
663 u32 val;
664
665 /* put controller in reset */
666 val = iproc_i2c_rd_reg(iproc_i2c, CFG_OFFSET);
667 val |= BIT(CFG_RESET_SHIFT);
668 val &= ~(BIT(CFG_EN_SHIFT));
669 iproc_i2c_wr_reg(iproc_i2c, CFG_OFFSET, val);
670
671 /* wait 100 usec per spec */
672 udelay(100);
673
674 /* bring controller out of reset */
675 val &= ~(BIT(CFG_RESET_SHIFT));
676 iproc_i2c_wr_reg(iproc_i2c, CFG_OFFSET, val);
677
678 /* flush TX/RX FIFOs and set RX FIFO threshold to zero */
679 val = (BIT(M_FIFO_RX_FLUSH_SHIFT) | BIT(M_FIFO_TX_FLUSH_SHIFT));
680 iproc_i2c_wr_reg(iproc_i2c, M_FIFO_CTRL_OFFSET, val);
681 /* disable all interrupts */
682 val = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
683 val &= ~(IE_M_ALL_INTERRUPT_MASK <<
684 IE_M_ALL_INTERRUPT_SHIFT);
685 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val);
686
687 /* clear all pending interrupts */
688 iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, 0xffffffff);
689
690 return 0;
691}
692
693static void bcm_iproc_i2c_enable_disable(struct bcm_iproc_i2c_dev *iproc_i2c,
694 bool enable)
695{
696 u32 val;
697
698 val = iproc_i2c_rd_reg(iproc_i2c, CFG_OFFSET);
699 if (enable)
700 val |= BIT(CFG_EN_SHIFT);
701 else
702 val &= ~BIT(CFG_EN_SHIFT);
703 iproc_i2c_wr_reg(iproc_i2c, CFG_OFFSET, val);
704}
705
706static int bcm_iproc_i2c_check_status(struct bcm_iproc_i2c_dev *iproc_i2c,
707 struct i2c_msg *msg)
708{
709 u32 val;
710
711 val = iproc_i2c_rd_reg(iproc_i2c, M_CMD_OFFSET);
712 val = (val >> M_CMD_STATUS_SHIFT) & M_CMD_STATUS_MASK;
713
714 switch (val) {
715 case M_CMD_STATUS_SUCCESS:
716 return 0;
717
718 case M_CMD_STATUS_LOST_ARB:
719 dev_dbg(iproc_i2c->device, "lost bus arbitration\n");
720 return -EAGAIN;
721
722 case M_CMD_STATUS_NACK_ADDR:
723 dev_dbg(iproc_i2c->device, "NAK addr:0x%02x\n", msg->addr);
724 return -ENXIO;
725
726 case M_CMD_STATUS_NACK_DATA:
727 dev_dbg(iproc_i2c->device, "NAK data\n");
728 return -ENXIO;
729
730 case M_CMD_STATUS_TIMEOUT:
731 dev_dbg(iproc_i2c->device, "bus timeout\n");
732 return -ETIMEDOUT;
733
734 case M_CMD_STATUS_FIFO_UNDERRUN:
735 dev_dbg(iproc_i2c->device, "FIFO under-run\n");
736 return -ENXIO;
737
738 case M_CMD_STATUS_RX_FIFO_FULL:
739 dev_dbg(iproc_i2c->device, "RX FIFO full\n");
740 return -ETIMEDOUT;
741
742 default:
743 dev_dbg(iproc_i2c->device, "unknown error code=%d\n", val);
744
745 /* re-initialize i2c for recovery */
746 bcm_iproc_i2c_enable_disable(iproc_i2c, false);
747 bcm_iproc_i2c_init(iproc_i2c);
748 bcm_iproc_i2c_enable_disable(iproc_i2c, true);
749
750 return -EIO;
751 }
752}
753
754static int bcm_iproc_i2c_xfer_wait(struct bcm_iproc_i2c_dev *iproc_i2c,
755 struct i2c_msg *msg,
756 u32 cmd)
757{
758 unsigned long time_left = msecs_to_jiffies(I2C_TIMEOUT_MSEC);
759 u32 val, status;
760 int ret;
761
762 iproc_i2c_wr_reg(iproc_i2c, M_CMD_OFFSET, cmd);
763
764 if (iproc_i2c->irq) {
765 time_left = wait_for_completion_timeout(&iproc_i2c->done,
766 time_left);
767 /* disable all interrupts */
768 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, 0);
769 /* read it back to flush the write */
770 iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
771 /* make sure the interrupt handler isn't running */
772 synchronize_irq(iproc_i2c->irq);
773
774 } else { /* polling mode */
775 unsigned long timeout = jiffies + time_left;
776
777 do {
778 status = iproc_i2c_rd_reg(iproc_i2c,
779 IS_OFFSET) & ISR_MASK;
780 bcm_iproc_i2c_process_m_event(iproc_i2c, status);
781 iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, status);
782
783 if (time_after(jiffies, timeout)) {
784 time_left = 0;
785 break;
786 }
787
788 cpu_relax();
789 cond_resched();
790 } while (!iproc_i2c->xfer_is_done);
791 }
792
793 if (!time_left && !iproc_i2c->xfer_is_done) {
794 dev_err(iproc_i2c->device, "transaction timed out\n");
795
796 /* flush both TX/RX FIFOs */
797 val = BIT(M_FIFO_RX_FLUSH_SHIFT) | BIT(M_FIFO_TX_FLUSH_SHIFT);
798 iproc_i2c_wr_reg(iproc_i2c, M_FIFO_CTRL_OFFSET, val);
799 return -ETIMEDOUT;
800 }
801
802 ret = bcm_iproc_i2c_check_status(iproc_i2c, msg);
803 if (ret) {
804 /* flush both TX/RX FIFOs */
805 val = BIT(M_FIFO_RX_FLUSH_SHIFT) | BIT(M_FIFO_TX_FLUSH_SHIFT);
806 iproc_i2c_wr_reg(iproc_i2c, M_FIFO_CTRL_OFFSET, val);
807 return ret;
808 }
809
810 return 0;
811}
812
813/*
814 * If 'process_call' is true, then this is a multi-msg transfer that requires
815 * a repeated start between the messages.
816 * More specifically, it must be a write (reg) followed by a read (data).
817 * The i2c quirks are set to enforce this rule.
818 */
819static int bcm_iproc_i2c_xfer_internal(struct bcm_iproc_i2c_dev *iproc_i2c,
820 struct i2c_msg *msgs, bool process_call)
821{
822 int i;
823 u8 addr;
824 u32 val, tmp, val_intr_en;
825 unsigned int tx_bytes;
826 struct i2c_msg *msg = &msgs[0];
827
828 /* check if bus is busy */
829 if (!!(iproc_i2c_rd_reg(iproc_i2c,
830 M_CMD_OFFSET) & BIT(M_CMD_START_BUSY_SHIFT))) {
831 dev_warn(iproc_i2c->device, "bus is busy\n");
832 return -EBUSY;
833 }
834
835 iproc_i2c->msg = msg;
836
837 /* format and load slave address into the TX FIFO */
838 addr = i2c_8bit_addr_from_msg(msg);
839 iproc_i2c_wr_reg(iproc_i2c, M_TX_OFFSET, addr);
840
841 /*
842 * For a write transaction, load data into the TX FIFO. Only allow
843 * loading up to TX FIFO size - 1 bytes of data since the first byte
844 * has been used up by the slave address
845 */
846 tx_bytes = min_t(unsigned int, msg->len, M_TX_RX_FIFO_SIZE - 1);
847 if (!(msg->flags & I2C_M_RD)) {
848 for (i = 0; i < tx_bytes; i++) {
849 val = msg->buf[i];
850
851 /* mark the last byte */
852 if (!process_call && (i == msg->len - 1))
853 val |= BIT(M_TX_WR_STATUS_SHIFT);
854
855 iproc_i2c_wr_reg(iproc_i2c, M_TX_OFFSET, val);
856 }
857 iproc_i2c->tx_bytes = tx_bytes;
858 }
859
860 /* Process the read message if this is process call */
861 if (process_call) {
862 msg++;
863 iproc_i2c->msg = msg; /* point to second msg */
864
865 /*
866 * The last byte to be sent out should be a slave
867 * address with read operation
868 */
869 addr = i2c_8bit_addr_from_msg(msg);
870 /* mark it the last byte out */
871 val = addr | BIT(M_TX_WR_STATUS_SHIFT);
872 iproc_i2c_wr_reg(iproc_i2c, M_TX_OFFSET, val);
873 }
874
875 /* mark as incomplete before starting the transaction */
876 if (iproc_i2c->irq)
877 reinit_completion(&iproc_i2c->done);
878
879 iproc_i2c->xfer_is_done = 0;
880
881 /*
882 * Enable the "start busy" interrupt, which will be triggered after the
883 * transaction is done, i.e., the internal start_busy bit, transitions
884 * from 1 to 0.
885 */
886 val_intr_en = BIT(IE_M_START_BUSY_SHIFT);
887
888 /*
889 * If TX data size is larger than the TX FIFO, need to enable TX
890 * underrun interrupt, which will be triggerred when the TX FIFO is
891 * empty. When that happens we can then pump more data into the FIFO
892 */
893 if (!process_call && !(msg->flags & I2C_M_RD) &&
894 msg->len > iproc_i2c->tx_bytes)
895 val_intr_en |= BIT(IE_M_TX_UNDERRUN_SHIFT);
896
897 /*
898 * Now we can activate the transfer. For a read operation, specify the
899 * number of bytes to read
900 */
901 val = BIT(M_CMD_START_BUSY_SHIFT);
902
903 if (msg->len == 0) {
904 /* SMBUS QUICK Command (Read/Write) */
905 val |= (M_CMD_PROTOCOL_QUICK << M_CMD_PROTOCOL_SHIFT);
906 } else if (msg->flags & I2C_M_RD) {
907 u32 protocol;
908
909 iproc_i2c->rx_bytes = 0;
910 if (msg->len > M_RX_FIFO_MAX_THLD_VALUE)
911 iproc_i2c->thld_bytes = M_RX_FIFO_THLD_VALUE;
912 else
913 iproc_i2c->thld_bytes = msg->len;
914
915 /* set threshold value */
916 tmp = iproc_i2c_rd_reg(iproc_i2c, M_FIFO_CTRL_OFFSET);
917 tmp &= ~(M_FIFO_RX_THLD_MASK << M_FIFO_RX_THLD_SHIFT);
918 tmp |= iproc_i2c->thld_bytes << M_FIFO_RX_THLD_SHIFT;
919 iproc_i2c_wr_reg(iproc_i2c, M_FIFO_CTRL_OFFSET, tmp);
920
921 /* enable the RX threshold interrupt */
922 val_intr_en |= BIT(IE_M_RX_THLD_SHIFT);
923
924 protocol = process_call ?
925 M_CMD_PROTOCOL_PROCESS : M_CMD_PROTOCOL_BLK_RD;
926
927 val |= (protocol << M_CMD_PROTOCOL_SHIFT) |
928 (msg->len << M_CMD_RD_CNT_SHIFT);
929 } else {
930 val |= (M_CMD_PROTOCOL_BLK_WR << M_CMD_PROTOCOL_SHIFT);
931 }
932
933 if (iproc_i2c->irq)
934 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val_intr_en);
935
936 return bcm_iproc_i2c_xfer_wait(iproc_i2c, msg, val);
937}
938
939static int bcm_iproc_i2c_xfer(struct i2c_adapter *adapter,
940 struct i2c_msg msgs[], int num)
941{
942 struct bcm_iproc_i2c_dev *iproc_i2c = i2c_get_adapdata(adapter);
943 bool process_call = false;
944 int ret;
945
946 if (num == 2) {
947 /* Repeated start, use process call */
948 process_call = true;
949 if (msgs[1].flags & I2C_M_NOSTART) {
950 dev_err(iproc_i2c->device, "Invalid repeated start\n");
951 return -EOPNOTSUPP;
952 }
953 }
954
955 ret = bcm_iproc_i2c_xfer_internal(iproc_i2c, msgs, process_call);
956 if (ret) {
957 dev_dbg(iproc_i2c->device, "xfer failed\n");
958 return ret;
959 }
960
961 return num;
962}
963
964static uint32_t bcm_iproc_i2c_functionality(struct i2c_adapter *adap)
965{
966 u32 val;
967
968 val = I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
969
970 if (adap->algo->reg_slave)
971 val |= I2C_FUNC_SLAVE;
972
973 return val;
974}
975
976static struct i2c_algorithm bcm_iproc_algo = {
977 .master_xfer = bcm_iproc_i2c_xfer,
978 .functionality = bcm_iproc_i2c_functionality,
979 .reg_slave = bcm_iproc_i2c_reg_slave,
980 .unreg_slave = bcm_iproc_i2c_unreg_slave,
981};
982
983static const struct i2c_adapter_quirks bcm_iproc_i2c_quirks = {
984 .flags = I2C_AQ_COMB_WRITE_THEN_READ,
985 .max_comb_1st_msg_len = M_TX_RX_FIFO_SIZE,
986 .max_read_len = M_RX_MAX_READ_LEN,
987};
988
989static int bcm_iproc_i2c_cfg_speed(struct bcm_iproc_i2c_dev *iproc_i2c)
990{
991 unsigned int bus_speed;
992 u32 val;
993 int ret = of_property_read_u32(iproc_i2c->device->of_node,
994 "clock-frequency", &bus_speed);
995 if (ret < 0) {
996 dev_info(iproc_i2c->device,
997 "unable to interpret clock-frequency DT property\n");
998 bus_speed = I2C_MAX_STANDARD_MODE_FREQ;
999 }
1000
1001 if (bus_speed < I2C_MAX_STANDARD_MODE_FREQ) {
1002 dev_err(iproc_i2c->device, "%d Hz bus speed not supported\n",
1003 bus_speed);
1004 dev_err(iproc_i2c->device,
1005 "valid speeds are 100khz and 400khz\n");
1006 return -EINVAL;
1007 } else if (bus_speed < I2C_MAX_FAST_MODE_FREQ) {
1008 bus_speed = I2C_MAX_STANDARD_MODE_FREQ;
1009 } else {
1010 bus_speed = I2C_MAX_FAST_MODE_FREQ;
1011 }
1012
1013 iproc_i2c->bus_speed = bus_speed;
1014 val = iproc_i2c_rd_reg(iproc_i2c, TIM_CFG_OFFSET);
1015 val &= ~BIT(TIM_CFG_MODE_400_SHIFT);
1016 val |= (bus_speed == I2C_MAX_FAST_MODE_FREQ) << TIM_CFG_MODE_400_SHIFT;
1017 iproc_i2c_wr_reg(iproc_i2c, TIM_CFG_OFFSET, val);
1018
1019 dev_info(iproc_i2c->device, "bus set to %u Hz\n", bus_speed);
1020
1021 return 0;
1022}
1023
1024static int bcm_iproc_i2c_probe(struct platform_device *pdev)
1025{
1026 int irq, ret = 0;
1027 struct bcm_iproc_i2c_dev *iproc_i2c;
1028 struct i2c_adapter *adap;
1029 struct resource *res;
1030
1031 iproc_i2c = devm_kzalloc(&pdev->dev, sizeof(*iproc_i2c),
1032 GFP_KERNEL);
1033 if (!iproc_i2c)
1034 return -ENOMEM;
1035
1036 platform_set_drvdata(pdev, iproc_i2c);
1037 iproc_i2c->device = &pdev->dev;
1038 iproc_i2c->type =
1039 (enum bcm_iproc_i2c_type)of_device_get_match_data(&pdev->dev);
1040 init_completion(&iproc_i2c->done);
1041
1042 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1043 iproc_i2c->base = devm_ioremap_resource(iproc_i2c->device, res);
1044 if (IS_ERR(iproc_i2c->base))
1045 return PTR_ERR(iproc_i2c->base);
1046
1047 if (iproc_i2c->type == IPROC_I2C_NIC) {
1048 res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
1049 iproc_i2c->idm_base = devm_ioremap_resource(iproc_i2c->device,
1050 res);
1051 if (IS_ERR(iproc_i2c->idm_base))
1052 return PTR_ERR(iproc_i2c->idm_base);
1053
1054 ret = of_property_read_u32(iproc_i2c->device->of_node,
1055 "brcm,ape-hsls-addr-mask",
1056 &iproc_i2c->ape_addr_mask);
1057 if (ret < 0) {
1058 dev_err(iproc_i2c->device,
1059 "'brcm,ape-hsls-addr-mask' missing\n");
1060 return -EINVAL;
1061 }
1062
1063 spin_lock_init(&iproc_i2c->idm_lock);
1064
1065 /* no slave support */
1066 bcm_iproc_algo.reg_slave = NULL;
1067 bcm_iproc_algo.unreg_slave = NULL;
1068 }
1069
1070 ret = bcm_iproc_i2c_init(iproc_i2c);
1071 if (ret)
1072 return ret;
1073
1074 ret = bcm_iproc_i2c_cfg_speed(iproc_i2c);
1075 if (ret)
1076 return ret;
1077
1078 irq = platform_get_irq(pdev, 0);
1079 if (irq > 0) {
1080 ret = devm_request_irq(iproc_i2c->device, irq,
1081 bcm_iproc_i2c_isr, 0, pdev->name,
1082 iproc_i2c);
1083 if (ret < 0) {
1084 dev_err(iproc_i2c->device,
1085 "unable to request irq %i\n", irq);
1086 return ret;
1087 }
1088
1089 iproc_i2c->irq = irq;
1090 } else {
1091 dev_warn(iproc_i2c->device,
1092 "no irq resource, falling back to poll mode\n");
1093 }
1094
1095 bcm_iproc_i2c_enable_disable(iproc_i2c, true);
1096
1097 adap = &iproc_i2c->adapter;
1098 i2c_set_adapdata(adap, iproc_i2c);
1099 snprintf(adap->name, sizeof(adap->name),
1100 "Broadcom iProc (%s)",
1101 of_node_full_name(iproc_i2c->device->of_node));
1102 adap->algo = &bcm_iproc_algo;
1103 adap->quirks = &bcm_iproc_i2c_quirks;
1104 adap->dev.parent = &pdev->dev;
1105 adap->dev.of_node = pdev->dev.of_node;
1106
1107 return i2c_add_adapter(adap);
1108}
1109
1110static int bcm_iproc_i2c_remove(struct platform_device *pdev)
1111{
1112 struct bcm_iproc_i2c_dev *iproc_i2c = platform_get_drvdata(pdev);
1113
1114 if (iproc_i2c->irq) {
1115 /*
1116 * Make sure there's no pending interrupt when we remove the
1117 * adapter
1118 */
1119 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, 0);
1120 iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
1121 synchronize_irq(iproc_i2c->irq);
1122 }
1123
1124 i2c_del_adapter(&iproc_i2c->adapter);
1125 bcm_iproc_i2c_enable_disable(iproc_i2c, false);
1126
1127 return 0;
1128}
1129
1130#ifdef CONFIG_PM_SLEEP
1131
1132static int bcm_iproc_i2c_suspend(struct device *dev)
1133{
1134 struct bcm_iproc_i2c_dev *iproc_i2c = dev_get_drvdata(dev);
1135
1136 if (iproc_i2c->irq) {
1137 /*
1138 * Make sure there's no pending interrupt when we go into
1139 * suspend
1140 */
1141 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, 0);
1142 iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
1143 synchronize_irq(iproc_i2c->irq);
1144 }
1145
1146 /* now disable the controller */
1147 bcm_iproc_i2c_enable_disable(iproc_i2c, false);
1148
1149 return 0;
1150}
1151
1152static int bcm_iproc_i2c_resume(struct device *dev)
1153{
1154 struct bcm_iproc_i2c_dev *iproc_i2c = dev_get_drvdata(dev);
1155 int ret;
1156 u32 val;
1157
1158 /*
1159 * Power domain could have been shut off completely in system deep
1160 * sleep, so re-initialize the block here
1161 */
1162 ret = bcm_iproc_i2c_init(iproc_i2c);
1163 if (ret)
1164 return ret;
1165
1166 /* configure to the desired bus speed */
1167 val = iproc_i2c_rd_reg(iproc_i2c, TIM_CFG_OFFSET);
1168 val &= ~BIT(TIM_CFG_MODE_400_SHIFT);
1169 val |= (iproc_i2c->bus_speed == I2C_MAX_FAST_MODE_FREQ) << TIM_CFG_MODE_400_SHIFT;
1170 iproc_i2c_wr_reg(iproc_i2c, TIM_CFG_OFFSET, val);
1171
1172 bcm_iproc_i2c_enable_disable(iproc_i2c, true);
1173
1174 return 0;
1175}
1176
1177static const struct dev_pm_ops bcm_iproc_i2c_pm_ops = {
1178 .suspend_late = &bcm_iproc_i2c_suspend,
1179 .resume_early = &bcm_iproc_i2c_resume
1180};
1181
1182#define BCM_IPROC_I2C_PM_OPS (&bcm_iproc_i2c_pm_ops)
1183#else
1184#define BCM_IPROC_I2C_PM_OPS NULL
1185#endif /* CONFIG_PM_SLEEP */
1186
1187
1188static int bcm_iproc_i2c_reg_slave(struct i2c_client *slave)
1189{
1190 struct bcm_iproc_i2c_dev *iproc_i2c = i2c_get_adapdata(slave->adapter);
1191
1192 if (iproc_i2c->slave)
1193 return -EBUSY;
1194
1195 if (slave->flags & I2C_CLIENT_TEN)
1196 return -EAFNOSUPPORT;
1197
1198 iproc_i2c->slave = slave;
1199
1200 tasklet_init(&iproc_i2c->slave_rx_tasklet, slave_rx_tasklet_fn,
1201 (unsigned long)iproc_i2c);
1202
1203 bcm_iproc_i2c_slave_init(iproc_i2c, false);
1204 return 0;
1205}
1206
1207static int bcm_iproc_i2c_unreg_slave(struct i2c_client *slave)
1208{
1209 u32 tmp;
1210 struct bcm_iproc_i2c_dev *iproc_i2c = i2c_get_adapdata(slave->adapter);
1211
1212 if (!iproc_i2c->slave)
1213 return -EINVAL;
1214
1215 disable_irq(iproc_i2c->irq);
1216
1217 tasklet_kill(&iproc_i2c->slave_rx_tasklet);
1218
1219 /* disable all slave interrupts */
1220 tmp = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
1221 tmp &= ~(IE_S_ALL_INTERRUPT_MASK <<
1222 IE_S_ALL_INTERRUPT_SHIFT);
1223 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, tmp);
1224
1225 /* Erase the slave address programmed */
1226 tmp = iproc_i2c_rd_reg(iproc_i2c, S_CFG_SMBUS_ADDR_OFFSET);
1227 tmp &= ~BIT(S_CFG_EN_NIC_SMB_ADDR3_SHIFT);
1228 iproc_i2c_wr_reg(iproc_i2c, S_CFG_SMBUS_ADDR_OFFSET, tmp);
1229
1230 /* flush TX/RX FIFOs */
1231 tmp = (BIT(S_FIFO_RX_FLUSH_SHIFT) | BIT(S_FIFO_TX_FLUSH_SHIFT));
1232 iproc_i2c_wr_reg(iproc_i2c, S_FIFO_CTRL_OFFSET, tmp);
1233
1234 /* clear all pending slave interrupts */
1235 iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, ISR_MASK_SLAVE);
1236
1237 iproc_i2c->slave = NULL;
1238
1239 enable_irq(iproc_i2c->irq);
1240
1241 return 0;
1242}
1243
1244static const struct of_device_id bcm_iproc_i2c_of_match[] = {
1245 {
1246 .compatible = "brcm,iproc-i2c",
1247 .data = (int *)IPROC_I2C,
1248 }, {
1249 .compatible = "brcm,iproc-nic-i2c",
1250 .data = (int *)IPROC_I2C_NIC,
1251 },
1252 { /* sentinel */ }
1253};
1254MODULE_DEVICE_TABLE(of, bcm_iproc_i2c_of_match);
1255
1256static struct platform_driver bcm_iproc_i2c_driver = {
1257 .driver = {
1258 .name = "bcm-iproc-i2c",
1259 .of_match_table = bcm_iproc_i2c_of_match,
1260 .pm = BCM_IPROC_I2C_PM_OPS,
1261 },
1262 .probe = bcm_iproc_i2c_probe,
1263 .remove = bcm_iproc_i2c_remove,
1264};
1265module_platform_driver(bcm_iproc_i2c_driver);
1266
1267MODULE_AUTHOR("Ray Jui <rjui@broadcom.com>");
1268MODULE_DESCRIPTION("Broadcom iProc I2C Driver");
1269MODULE_LICENSE("GPL v2");
1/*
2 * Copyright (C) 2014 Broadcom Corporation
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation version 2.
7 *
8 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
9 * kind, whether express or implied; without even the implied warranty
10 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 */
13
14#include <linux/delay.h>
15#include <linux/i2c.h>
16#include <linux/interrupt.h>
17#include <linux/io.h>
18#include <linux/kernel.h>
19#include <linux/module.h>
20#include <linux/of_device.h>
21#include <linux/platform_device.h>
22#include <linux/slab.h>
23
24#define IDM_CTRL_DIRECT_OFFSET 0x00
25#define CFG_OFFSET 0x00
26#define CFG_RESET_SHIFT 31
27#define CFG_EN_SHIFT 30
28#define CFG_SLAVE_ADDR_0_SHIFT 28
29#define CFG_M_RETRY_CNT_SHIFT 16
30#define CFG_M_RETRY_CNT_MASK 0x0f
31
32#define TIM_CFG_OFFSET 0x04
33#define TIM_CFG_MODE_400_SHIFT 31
34#define TIM_RAND_SLAVE_STRETCH_SHIFT 24
35#define TIM_RAND_SLAVE_STRETCH_MASK 0x7f
36#define TIM_PERIODIC_SLAVE_STRETCH_SHIFT 16
37#define TIM_PERIODIC_SLAVE_STRETCH_MASK 0x7f
38
39#define S_CFG_SMBUS_ADDR_OFFSET 0x08
40#define S_CFG_EN_NIC_SMB_ADDR3_SHIFT 31
41#define S_CFG_NIC_SMB_ADDR3_SHIFT 24
42#define S_CFG_NIC_SMB_ADDR3_MASK 0x7f
43#define S_CFG_EN_NIC_SMB_ADDR2_SHIFT 23
44#define S_CFG_NIC_SMB_ADDR2_SHIFT 16
45#define S_CFG_NIC_SMB_ADDR2_MASK 0x7f
46#define S_CFG_EN_NIC_SMB_ADDR1_SHIFT 15
47#define S_CFG_NIC_SMB_ADDR1_SHIFT 8
48#define S_CFG_NIC_SMB_ADDR1_MASK 0x7f
49#define S_CFG_EN_NIC_SMB_ADDR0_SHIFT 7
50#define S_CFG_NIC_SMB_ADDR0_SHIFT 0
51#define S_CFG_NIC_SMB_ADDR0_MASK 0x7f
52
53#define M_FIFO_CTRL_OFFSET 0x0c
54#define M_FIFO_RX_FLUSH_SHIFT 31
55#define M_FIFO_TX_FLUSH_SHIFT 30
56#define M_FIFO_RX_CNT_SHIFT 16
57#define M_FIFO_RX_CNT_MASK 0x7f
58#define M_FIFO_RX_THLD_SHIFT 8
59#define M_FIFO_RX_THLD_MASK 0x3f
60
61#define S_FIFO_CTRL_OFFSET 0x10
62#define S_FIFO_RX_FLUSH_SHIFT 31
63#define S_FIFO_TX_FLUSH_SHIFT 30
64#define S_FIFO_RX_CNT_SHIFT 16
65#define S_FIFO_RX_CNT_MASK 0x7f
66#define S_FIFO_RX_THLD_SHIFT 8
67#define S_FIFO_RX_THLD_MASK 0x3f
68
69#define M_CMD_OFFSET 0x30
70#define M_CMD_START_BUSY_SHIFT 31
71#define M_CMD_STATUS_SHIFT 25
72#define M_CMD_STATUS_MASK 0x07
73#define M_CMD_STATUS_SUCCESS 0x0
74#define M_CMD_STATUS_LOST_ARB 0x1
75#define M_CMD_STATUS_NACK_ADDR 0x2
76#define M_CMD_STATUS_NACK_DATA 0x3
77#define M_CMD_STATUS_TIMEOUT 0x4
78#define M_CMD_STATUS_FIFO_UNDERRUN 0x5
79#define M_CMD_STATUS_RX_FIFO_FULL 0x6
80#define M_CMD_PROTOCOL_SHIFT 9
81#define M_CMD_PROTOCOL_MASK 0xf
82#define M_CMD_PROTOCOL_QUICK 0x0
83#define M_CMD_PROTOCOL_BLK_WR 0x7
84#define M_CMD_PROTOCOL_BLK_RD 0x8
85#define M_CMD_PROTOCOL_PROCESS 0xa
86#define M_CMD_PEC_SHIFT 8
87#define M_CMD_RD_CNT_SHIFT 0
88#define M_CMD_RD_CNT_MASK 0xff
89
90#define S_CMD_OFFSET 0x34
91#define S_CMD_START_BUSY_SHIFT 31
92#define S_CMD_STATUS_SHIFT 23
93#define S_CMD_STATUS_MASK 0x07
94#define S_CMD_STATUS_SUCCESS 0x0
95#define S_CMD_STATUS_TIMEOUT 0x5
96#define S_CMD_STATUS_MASTER_ABORT 0x7
97
98#define IE_OFFSET 0x38
99#define IE_M_RX_FIFO_FULL_SHIFT 31
100#define IE_M_RX_THLD_SHIFT 30
101#define IE_M_START_BUSY_SHIFT 28
102#define IE_M_TX_UNDERRUN_SHIFT 27
103#define IE_S_RX_FIFO_FULL_SHIFT 26
104#define IE_S_RX_THLD_SHIFT 25
105#define IE_S_RX_EVENT_SHIFT 24
106#define IE_S_START_BUSY_SHIFT 23
107#define IE_S_TX_UNDERRUN_SHIFT 22
108#define IE_S_RD_EVENT_SHIFT 21
109
110#define IS_OFFSET 0x3c
111#define IS_M_RX_FIFO_FULL_SHIFT 31
112#define IS_M_RX_THLD_SHIFT 30
113#define IS_M_START_BUSY_SHIFT 28
114#define IS_M_TX_UNDERRUN_SHIFT 27
115#define IS_S_RX_FIFO_FULL_SHIFT 26
116#define IS_S_RX_THLD_SHIFT 25
117#define IS_S_RX_EVENT_SHIFT 24
118#define IS_S_START_BUSY_SHIFT 23
119#define IS_S_TX_UNDERRUN_SHIFT 22
120#define IS_S_RD_EVENT_SHIFT 21
121
122#define M_TX_OFFSET 0x40
123#define M_TX_WR_STATUS_SHIFT 31
124#define M_TX_DATA_SHIFT 0
125#define M_TX_DATA_MASK 0xff
126
127#define M_RX_OFFSET 0x44
128#define M_RX_STATUS_SHIFT 30
129#define M_RX_STATUS_MASK 0x03
130#define M_RX_PEC_ERR_SHIFT 29
131#define M_RX_DATA_SHIFT 0
132#define M_RX_DATA_MASK 0xff
133
134#define S_TX_OFFSET 0x48
135#define S_TX_WR_STATUS_SHIFT 31
136#define S_TX_DATA_SHIFT 0
137#define S_TX_DATA_MASK 0xff
138
139#define S_RX_OFFSET 0x4c
140#define S_RX_STATUS_SHIFT 30
141#define S_RX_STATUS_MASK 0x03
142#define S_RX_PEC_ERR_SHIFT 29
143#define S_RX_DATA_SHIFT 0
144#define S_RX_DATA_MASK 0xff
145
146#define I2C_TIMEOUT_MSEC 50000
147#define M_TX_RX_FIFO_SIZE 64
148#define M_RX_FIFO_MAX_THLD_VALUE (M_TX_RX_FIFO_SIZE - 1)
149
150#define M_RX_MAX_READ_LEN 255
151#define M_RX_FIFO_THLD_VALUE 50
152
153#define IE_M_ALL_INTERRUPT_SHIFT 27
154#define IE_M_ALL_INTERRUPT_MASK 0x1e
155
156#define SLAVE_READ_WRITE_BIT_MASK 0x1
157#define SLAVE_READ_WRITE_BIT_SHIFT 0x1
158#define SLAVE_MAX_SIZE_TRANSACTION 64
159#define SLAVE_CLOCK_STRETCH_TIME 25
160
161#define IE_S_ALL_INTERRUPT_SHIFT 21
162#define IE_S_ALL_INTERRUPT_MASK 0x3f
163/*
164 * It takes ~18us to reading 10bytes of data, hence to keep tasklet
165 * running for less time, max slave read per tasklet is set to 10 bytes.
166 */
167#define MAX_SLAVE_RX_PER_INT 10
168
169enum i2c_slave_read_status {
170 I2C_SLAVE_RX_FIFO_EMPTY = 0,
171 I2C_SLAVE_RX_START,
172 I2C_SLAVE_RX_DATA,
173 I2C_SLAVE_RX_END,
174};
175
176enum bus_speed_index {
177 I2C_SPD_100K = 0,
178 I2C_SPD_400K,
179};
180
181enum bcm_iproc_i2c_type {
182 IPROC_I2C,
183 IPROC_I2C_NIC
184};
185
186struct bcm_iproc_i2c_dev {
187 struct device *device;
188 enum bcm_iproc_i2c_type type;
189 int irq;
190
191 void __iomem *base;
192 void __iomem *idm_base;
193
194 u32 ape_addr_mask;
195
196 /* lock for indirect access through IDM */
197 spinlock_t idm_lock;
198
199 struct i2c_adapter adapter;
200 unsigned int bus_speed;
201
202 struct completion done;
203 int xfer_is_done;
204
205 struct i2c_msg *msg;
206
207 struct i2c_client *slave;
208
209 /* bytes that have been transferred */
210 unsigned int tx_bytes;
211 /* bytes that have been read */
212 unsigned int rx_bytes;
213 unsigned int thld_bytes;
214
215 bool slave_rx_only;
216 bool rx_start_rcvd;
217 bool slave_read_complete;
218 u32 tx_underrun;
219 u32 slave_int_mask;
220 struct tasklet_struct slave_rx_tasklet;
221};
222
223/* tasklet to process slave rx data */
224static void slave_rx_tasklet_fn(unsigned long);
225
226/*
227 * Can be expanded in the future if more interrupt status bits are utilized
228 */
229#define ISR_MASK (BIT(IS_M_START_BUSY_SHIFT) | BIT(IS_M_TX_UNDERRUN_SHIFT)\
230 | BIT(IS_M_RX_THLD_SHIFT))
231
232#define ISR_MASK_SLAVE (BIT(IS_S_START_BUSY_SHIFT)\
233 | BIT(IS_S_RX_EVENT_SHIFT) | BIT(IS_S_RD_EVENT_SHIFT)\
234 | BIT(IS_S_TX_UNDERRUN_SHIFT) | BIT(IS_S_RX_FIFO_FULL_SHIFT)\
235 | BIT(IS_S_RX_THLD_SHIFT))
236
237static int bcm_iproc_i2c_reg_slave(struct i2c_client *slave);
238static int bcm_iproc_i2c_unreg_slave(struct i2c_client *slave);
239static void bcm_iproc_i2c_enable_disable(struct bcm_iproc_i2c_dev *iproc_i2c,
240 bool enable);
241
242static inline u32 iproc_i2c_rd_reg(struct bcm_iproc_i2c_dev *iproc_i2c,
243 u32 offset)
244{
245 u32 val;
246
247 if (iproc_i2c->idm_base) {
248 spin_lock(&iproc_i2c->idm_lock);
249 writel(iproc_i2c->ape_addr_mask,
250 iproc_i2c->idm_base + IDM_CTRL_DIRECT_OFFSET);
251 val = readl(iproc_i2c->base + offset);
252 spin_unlock(&iproc_i2c->idm_lock);
253 } else {
254 val = readl(iproc_i2c->base + offset);
255 }
256
257 return val;
258}
259
260static inline void iproc_i2c_wr_reg(struct bcm_iproc_i2c_dev *iproc_i2c,
261 u32 offset, u32 val)
262{
263 if (iproc_i2c->idm_base) {
264 spin_lock(&iproc_i2c->idm_lock);
265 writel(iproc_i2c->ape_addr_mask,
266 iproc_i2c->idm_base + IDM_CTRL_DIRECT_OFFSET);
267 writel(val, iproc_i2c->base + offset);
268 spin_unlock(&iproc_i2c->idm_lock);
269 } else {
270 writel(val, iproc_i2c->base + offset);
271 }
272}
273
274static void bcm_iproc_i2c_slave_init(
275 struct bcm_iproc_i2c_dev *iproc_i2c, bool need_reset)
276{
277 u32 val;
278
279 iproc_i2c->tx_underrun = 0;
280 if (need_reset) {
281 /* put controller in reset */
282 val = iproc_i2c_rd_reg(iproc_i2c, CFG_OFFSET);
283 val |= BIT(CFG_RESET_SHIFT);
284 iproc_i2c_wr_reg(iproc_i2c, CFG_OFFSET, val);
285
286 /* wait 100 usec per spec */
287 udelay(100);
288
289 /* bring controller out of reset */
290 val &= ~(BIT(CFG_RESET_SHIFT));
291 iproc_i2c_wr_reg(iproc_i2c, CFG_OFFSET, val);
292 }
293
294 /* flush TX/RX FIFOs */
295 val = (BIT(S_FIFO_RX_FLUSH_SHIFT) | BIT(S_FIFO_TX_FLUSH_SHIFT));
296 iproc_i2c_wr_reg(iproc_i2c, S_FIFO_CTRL_OFFSET, val);
297
298 /* Maximum slave stretch time */
299 val = iproc_i2c_rd_reg(iproc_i2c, TIM_CFG_OFFSET);
300 val &= ~(TIM_RAND_SLAVE_STRETCH_MASK << TIM_RAND_SLAVE_STRETCH_SHIFT);
301 val |= (SLAVE_CLOCK_STRETCH_TIME << TIM_RAND_SLAVE_STRETCH_SHIFT);
302 iproc_i2c_wr_reg(iproc_i2c, TIM_CFG_OFFSET, val);
303
304 /* Configure the slave address */
305 val = iproc_i2c_rd_reg(iproc_i2c, S_CFG_SMBUS_ADDR_OFFSET);
306 val |= BIT(S_CFG_EN_NIC_SMB_ADDR3_SHIFT);
307 val &= ~(S_CFG_NIC_SMB_ADDR3_MASK << S_CFG_NIC_SMB_ADDR3_SHIFT);
308 val |= (iproc_i2c->slave->addr << S_CFG_NIC_SMB_ADDR3_SHIFT);
309 iproc_i2c_wr_reg(iproc_i2c, S_CFG_SMBUS_ADDR_OFFSET, val);
310
311 /* clear all pending slave interrupts */
312 iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, ISR_MASK_SLAVE);
313
314 /* Enable interrupt register to indicate a valid byte in receive fifo */
315 val = BIT(IE_S_RX_EVENT_SHIFT);
316 /* Enable interrupt register to indicate Slave Rx FIFO Full */
317 val |= BIT(IE_S_RX_FIFO_FULL_SHIFT);
318 /* Enable interrupt register to indicate a Master read transaction */
319 val |= BIT(IE_S_RD_EVENT_SHIFT);
320 /* Enable interrupt register for the Slave BUSY command */
321 val |= BIT(IE_S_START_BUSY_SHIFT);
322 iproc_i2c->slave_int_mask = val;
323 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val);
324}
325
326static void bcm_iproc_i2c_check_slave_status(
327 struct bcm_iproc_i2c_dev *iproc_i2c)
328{
329 u32 val;
330
331 val = iproc_i2c_rd_reg(iproc_i2c, S_CMD_OFFSET);
332 /* status is valid only when START_BUSY is cleared after it was set */
333 if (val & BIT(S_CMD_START_BUSY_SHIFT))
334 return;
335
336 val = (val >> S_CMD_STATUS_SHIFT) & S_CMD_STATUS_MASK;
337 if (val == S_CMD_STATUS_TIMEOUT || val == S_CMD_STATUS_MASTER_ABORT) {
338 dev_err(iproc_i2c->device, (val == S_CMD_STATUS_TIMEOUT) ?
339 "slave random stretch time timeout\n" :
340 "Master aborted read transaction\n");
341 /* re-initialize i2c for recovery */
342 bcm_iproc_i2c_enable_disable(iproc_i2c, false);
343 bcm_iproc_i2c_slave_init(iproc_i2c, true);
344 bcm_iproc_i2c_enable_disable(iproc_i2c, true);
345 }
346}
347
348static void bcm_iproc_i2c_slave_read(struct bcm_iproc_i2c_dev *iproc_i2c)
349{
350 u8 rx_data, rx_status;
351 u32 rx_bytes = 0;
352 u32 val;
353
354 while (rx_bytes < MAX_SLAVE_RX_PER_INT) {
355 val = iproc_i2c_rd_reg(iproc_i2c, S_RX_OFFSET);
356 rx_status = (val >> S_RX_STATUS_SHIFT) & S_RX_STATUS_MASK;
357 rx_data = ((val >> S_RX_DATA_SHIFT) & S_RX_DATA_MASK);
358
359 if (rx_status == I2C_SLAVE_RX_START) {
360 /* Start of SMBUS Master write */
361 i2c_slave_event(iproc_i2c->slave,
362 I2C_SLAVE_WRITE_REQUESTED, &rx_data);
363 iproc_i2c->rx_start_rcvd = true;
364 iproc_i2c->slave_read_complete = false;
365 } else if (rx_status == I2C_SLAVE_RX_DATA &&
366 iproc_i2c->rx_start_rcvd) {
367 /* Middle of SMBUS Master write */
368 i2c_slave_event(iproc_i2c->slave,
369 I2C_SLAVE_WRITE_RECEIVED, &rx_data);
370 } else if (rx_status == I2C_SLAVE_RX_END &&
371 iproc_i2c->rx_start_rcvd) {
372 /* End of SMBUS Master write */
373 if (iproc_i2c->slave_rx_only)
374 i2c_slave_event(iproc_i2c->slave,
375 I2C_SLAVE_WRITE_RECEIVED,
376 &rx_data);
377
378 i2c_slave_event(iproc_i2c->slave, I2C_SLAVE_STOP,
379 &rx_data);
380 } else if (rx_status == I2C_SLAVE_RX_FIFO_EMPTY) {
381 iproc_i2c->rx_start_rcvd = false;
382 iproc_i2c->slave_read_complete = true;
383 break;
384 }
385
386 rx_bytes++;
387 }
388}
389
390static void slave_rx_tasklet_fn(unsigned long data)
391{
392 struct bcm_iproc_i2c_dev *iproc_i2c = (struct bcm_iproc_i2c_dev *)data;
393 u32 int_clr;
394
395 bcm_iproc_i2c_slave_read(iproc_i2c);
396
397 /* clear pending IS_S_RX_EVENT_SHIFT interrupt */
398 int_clr = BIT(IS_S_RX_EVENT_SHIFT);
399
400 if (!iproc_i2c->slave_rx_only && iproc_i2c->slave_read_complete) {
401 /*
402 * In case of single byte master-read request,
403 * IS_S_TX_UNDERRUN_SHIFT event is generated before
404 * IS_S_START_BUSY_SHIFT event. Hence start slave data send
405 * from first IS_S_TX_UNDERRUN_SHIFT event.
406 *
407 * This means don't send any data from slave when
408 * IS_S_RD_EVENT_SHIFT event is generated else it will increment
409 * eeprom or other backend slave driver read pointer twice.
410 */
411 iproc_i2c->tx_underrun = 0;
412 iproc_i2c->slave_int_mask |= BIT(IE_S_TX_UNDERRUN_SHIFT);
413
414 /* clear IS_S_RD_EVENT_SHIFT interrupt */
415 int_clr |= BIT(IS_S_RD_EVENT_SHIFT);
416 }
417
418 /* clear slave interrupt */
419 iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, int_clr);
420 /* enable slave interrupts */
421 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, iproc_i2c->slave_int_mask);
422}
423
424static bool bcm_iproc_i2c_slave_isr(struct bcm_iproc_i2c_dev *iproc_i2c,
425 u32 status)
426{
427 u32 val;
428 u8 value;
429
430 /*
431 * Slave events in case of master-write, master-write-read and,
432 * master-read
433 *
434 * Master-write : only IS_S_RX_EVENT_SHIFT event
435 * Master-write-read: both IS_S_RX_EVENT_SHIFT and IS_S_RD_EVENT_SHIFT
436 * events
437 * Master-read : both IS_S_RX_EVENT_SHIFT and IS_S_RD_EVENT_SHIFT
438 * events or only IS_S_RD_EVENT_SHIFT
439 *
440 * iproc has a slave rx fifo size of 64 bytes. Rx fifo full interrupt
441 * (IS_S_RX_FIFO_FULL_SHIFT) will be generated when RX fifo becomes
442 * full. This can happen if Master issues write requests of more than
443 * 64 bytes.
444 */
445 if (status & BIT(IS_S_RX_EVENT_SHIFT) ||
446 status & BIT(IS_S_RD_EVENT_SHIFT) ||
447 status & BIT(IS_S_RX_FIFO_FULL_SHIFT)) {
448 /* disable slave interrupts */
449 val = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
450 val &= ~iproc_i2c->slave_int_mask;
451 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val);
452
453 if (status & BIT(IS_S_RD_EVENT_SHIFT))
454 /* Master-write-read request */
455 iproc_i2c->slave_rx_only = false;
456 else
457 /* Master-write request only */
458 iproc_i2c->slave_rx_only = true;
459
460 /* schedule tasklet to read data later */
461 tasklet_schedule(&iproc_i2c->slave_rx_tasklet);
462
463 /*
464 * clear only IS_S_RX_EVENT_SHIFT and
465 * IS_S_RX_FIFO_FULL_SHIFT interrupt.
466 */
467 val = BIT(IS_S_RX_EVENT_SHIFT);
468 if (status & BIT(IS_S_RX_FIFO_FULL_SHIFT))
469 val |= BIT(IS_S_RX_FIFO_FULL_SHIFT);
470 iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, val);
471 }
472
473 if (status & BIT(IS_S_TX_UNDERRUN_SHIFT)) {
474 iproc_i2c->tx_underrun++;
475 if (iproc_i2c->tx_underrun == 1)
476 /* Start of SMBUS for Master Read */
477 i2c_slave_event(iproc_i2c->slave,
478 I2C_SLAVE_READ_REQUESTED,
479 &value);
480 else
481 /* Master read other than start */
482 i2c_slave_event(iproc_i2c->slave,
483 I2C_SLAVE_READ_PROCESSED,
484 &value);
485
486 iproc_i2c_wr_reg(iproc_i2c, S_TX_OFFSET, value);
487 /* start transfer */
488 val = BIT(S_CMD_START_BUSY_SHIFT);
489 iproc_i2c_wr_reg(iproc_i2c, S_CMD_OFFSET, val);
490
491 /* clear interrupt */
492 iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET,
493 BIT(IS_S_TX_UNDERRUN_SHIFT));
494 }
495
496 /* Stop received from master in case of master read transaction */
497 if (status & BIT(IS_S_START_BUSY_SHIFT)) {
498 /*
499 * Disable interrupt for TX FIFO becomes empty and
500 * less than PKT_LENGTH bytes were output on the SMBUS
501 */
502 iproc_i2c->slave_int_mask &= ~BIT(IE_S_TX_UNDERRUN_SHIFT);
503 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET,
504 iproc_i2c->slave_int_mask);
505
506 /* End of SMBUS for Master Read */
507 val = BIT(S_TX_WR_STATUS_SHIFT);
508 iproc_i2c_wr_reg(iproc_i2c, S_TX_OFFSET, val);
509
510 val = BIT(S_CMD_START_BUSY_SHIFT);
511 iproc_i2c_wr_reg(iproc_i2c, S_CMD_OFFSET, val);
512
513 /* flush TX FIFOs */
514 val = iproc_i2c_rd_reg(iproc_i2c, S_FIFO_CTRL_OFFSET);
515 val |= (BIT(S_FIFO_TX_FLUSH_SHIFT));
516 iproc_i2c_wr_reg(iproc_i2c, S_FIFO_CTRL_OFFSET, val);
517
518 i2c_slave_event(iproc_i2c->slave, I2C_SLAVE_STOP, &value);
519
520 /* clear interrupt */
521 iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET,
522 BIT(IS_S_START_BUSY_SHIFT));
523 }
524
525 /* check slave transmit status only if slave is transmitting */
526 if (!iproc_i2c->slave_rx_only)
527 bcm_iproc_i2c_check_slave_status(iproc_i2c);
528
529 return true;
530}
531
532static void bcm_iproc_i2c_read_valid_bytes(struct bcm_iproc_i2c_dev *iproc_i2c)
533{
534 struct i2c_msg *msg = iproc_i2c->msg;
535 uint32_t val;
536
537 /* Read valid data from RX FIFO */
538 while (iproc_i2c->rx_bytes < msg->len) {
539 val = iproc_i2c_rd_reg(iproc_i2c, M_RX_OFFSET);
540
541 /* rx fifo empty */
542 if (!((val >> M_RX_STATUS_SHIFT) & M_RX_STATUS_MASK))
543 break;
544
545 msg->buf[iproc_i2c->rx_bytes] =
546 (val >> M_RX_DATA_SHIFT) & M_RX_DATA_MASK;
547 iproc_i2c->rx_bytes++;
548 }
549}
550
551static void bcm_iproc_i2c_send(struct bcm_iproc_i2c_dev *iproc_i2c)
552{
553 struct i2c_msg *msg = iproc_i2c->msg;
554 unsigned int tx_bytes = msg->len - iproc_i2c->tx_bytes;
555 unsigned int i;
556 u32 val;
557
558 /* can only fill up to the FIFO size */
559 tx_bytes = min_t(unsigned int, tx_bytes, M_TX_RX_FIFO_SIZE);
560 for (i = 0; i < tx_bytes; i++) {
561 /* start from where we left over */
562 unsigned int idx = iproc_i2c->tx_bytes + i;
563
564 val = msg->buf[idx];
565
566 /* mark the last byte */
567 if (idx == msg->len - 1) {
568 val |= BIT(M_TX_WR_STATUS_SHIFT);
569
570 if (iproc_i2c->irq) {
571 u32 tmp;
572
573 /*
574 * Since this is the last byte, we should now
575 * disable TX FIFO underrun interrupt
576 */
577 tmp = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
578 tmp &= ~BIT(IE_M_TX_UNDERRUN_SHIFT);
579 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET,
580 tmp);
581 }
582 }
583
584 /* load data into TX FIFO */
585 iproc_i2c_wr_reg(iproc_i2c, M_TX_OFFSET, val);
586 }
587
588 /* update number of transferred bytes */
589 iproc_i2c->tx_bytes += tx_bytes;
590}
591
592static void bcm_iproc_i2c_read(struct bcm_iproc_i2c_dev *iproc_i2c)
593{
594 struct i2c_msg *msg = iproc_i2c->msg;
595 u32 bytes_left, val;
596
597 bcm_iproc_i2c_read_valid_bytes(iproc_i2c);
598 bytes_left = msg->len - iproc_i2c->rx_bytes;
599 if (bytes_left == 0) {
600 if (iproc_i2c->irq) {
601 /* finished reading all data, disable rx thld event */
602 val = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
603 val &= ~BIT(IS_M_RX_THLD_SHIFT);
604 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val);
605 }
606 } else if (bytes_left < iproc_i2c->thld_bytes) {
607 /* set bytes left as threshold */
608 val = iproc_i2c_rd_reg(iproc_i2c, M_FIFO_CTRL_OFFSET);
609 val &= ~(M_FIFO_RX_THLD_MASK << M_FIFO_RX_THLD_SHIFT);
610 val |= (bytes_left << M_FIFO_RX_THLD_SHIFT);
611 iproc_i2c_wr_reg(iproc_i2c, M_FIFO_CTRL_OFFSET, val);
612 iproc_i2c->thld_bytes = bytes_left;
613 }
614 /*
615 * bytes_left >= iproc_i2c->thld_bytes,
616 * hence no need to change the THRESHOLD SET.
617 * It will remain as iproc_i2c->thld_bytes itself
618 */
619}
620
621static void bcm_iproc_i2c_process_m_event(struct bcm_iproc_i2c_dev *iproc_i2c,
622 u32 status)
623{
624 /* TX FIFO is empty and we have more data to send */
625 if (status & BIT(IS_M_TX_UNDERRUN_SHIFT))
626 bcm_iproc_i2c_send(iproc_i2c);
627
628 /* RX FIFO threshold is reached and data needs to be read out */
629 if (status & BIT(IS_M_RX_THLD_SHIFT))
630 bcm_iproc_i2c_read(iproc_i2c);
631
632 /* transfer is done */
633 if (status & BIT(IS_M_START_BUSY_SHIFT)) {
634 iproc_i2c->xfer_is_done = 1;
635 if (iproc_i2c->irq)
636 complete(&iproc_i2c->done);
637 }
638}
639
640static irqreturn_t bcm_iproc_i2c_isr(int irq, void *data)
641{
642 struct bcm_iproc_i2c_dev *iproc_i2c = data;
643 u32 slave_status;
644 u32 status;
645 bool ret;
646
647 status = iproc_i2c_rd_reg(iproc_i2c, IS_OFFSET);
648 /* process only slave interrupt which are enabled */
649 slave_status = status & iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET) &
650 ISR_MASK_SLAVE;
651
652 if (slave_status) {
653 ret = bcm_iproc_i2c_slave_isr(iproc_i2c, slave_status);
654 if (ret)
655 return IRQ_HANDLED;
656 else
657 return IRQ_NONE;
658 }
659
660 status &= ISR_MASK;
661 if (!status)
662 return IRQ_NONE;
663
664 /* process all master based events */
665 bcm_iproc_i2c_process_m_event(iproc_i2c, status);
666 iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, status);
667
668 return IRQ_HANDLED;
669}
670
671static int bcm_iproc_i2c_init(struct bcm_iproc_i2c_dev *iproc_i2c)
672{
673 u32 val;
674
675 /* put controller in reset */
676 val = iproc_i2c_rd_reg(iproc_i2c, CFG_OFFSET);
677 val |= BIT(CFG_RESET_SHIFT);
678 val &= ~(BIT(CFG_EN_SHIFT));
679 iproc_i2c_wr_reg(iproc_i2c, CFG_OFFSET, val);
680
681 /* wait 100 usec per spec */
682 udelay(100);
683
684 /* bring controller out of reset */
685 val &= ~(BIT(CFG_RESET_SHIFT));
686 iproc_i2c_wr_reg(iproc_i2c, CFG_OFFSET, val);
687
688 /* flush TX/RX FIFOs and set RX FIFO threshold to zero */
689 val = (BIT(M_FIFO_RX_FLUSH_SHIFT) | BIT(M_FIFO_TX_FLUSH_SHIFT));
690 iproc_i2c_wr_reg(iproc_i2c, M_FIFO_CTRL_OFFSET, val);
691 /* disable all interrupts */
692 val = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
693 val &= ~(IE_M_ALL_INTERRUPT_MASK <<
694 IE_M_ALL_INTERRUPT_SHIFT);
695 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val);
696
697 /* clear all pending interrupts */
698 iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, 0xffffffff);
699
700 return 0;
701}
702
703static void bcm_iproc_i2c_enable_disable(struct bcm_iproc_i2c_dev *iproc_i2c,
704 bool enable)
705{
706 u32 val;
707
708 val = iproc_i2c_rd_reg(iproc_i2c, CFG_OFFSET);
709 if (enable)
710 val |= BIT(CFG_EN_SHIFT);
711 else
712 val &= ~BIT(CFG_EN_SHIFT);
713 iproc_i2c_wr_reg(iproc_i2c, CFG_OFFSET, val);
714}
715
716static int bcm_iproc_i2c_check_status(struct bcm_iproc_i2c_dev *iproc_i2c,
717 struct i2c_msg *msg)
718{
719 u32 val;
720
721 val = iproc_i2c_rd_reg(iproc_i2c, M_CMD_OFFSET);
722 val = (val >> M_CMD_STATUS_SHIFT) & M_CMD_STATUS_MASK;
723
724 switch (val) {
725 case M_CMD_STATUS_SUCCESS:
726 return 0;
727
728 case M_CMD_STATUS_LOST_ARB:
729 dev_dbg(iproc_i2c->device, "lost bus arbitration\n");
730 return -EAGAIN;
731
732 case M_CMD_STATUS_NACK_ADDR:
733 dev_dbg(iproc_i2c->device, "NAK addr:0x%02x\n", msg->addr);
734 return -ENXIO;
735
736 case M_CMD_STATUS_NACK_DATA:
737 dev_dbg(iproc_i2c->device, "NAK data\n");
738 return -ENXIO;
739
740 case M_CMD_STATUS_TIMEOUT:
741 dev_dbg(iproc_i2c->device, "bus timeout\n");
742 return -ETIMEDOUT;
743
744 case M_CMD_STATUS_FIFO_UNDERRUN:
745 dev_dbg(iproc_i2c->device, "FIFO under-run\n");
746 return -ENXIO;
747
748 case M_CMD_STATUS_RX_FIFO_FULL:
749 dev_dbg(iproc_i2c->device, "RX FIFO full\n");
750 return -ETIMEDOUT;
751
752 default:
753 dev_dbg(iproc_i2c->device, "unknown error code=%d\n", val);
754
755 /* re-initialize i2c for recovery */
756 bcm_iproc_i2c_enable_disable(iproc_i2c, false);
757 bcm_iproc_i2c_init(iproc_i2c);
758 bcm_iproc_i2c_enable_disable(iproc_i2c, true);
759
760 return -EIO;
761 }
762}
763
764static int bcm_iproc_i2c_xfer_wait(struct bcm_iproc_i2c_dev *iproc_i2c,
765 struct i2c_msg *msg,
766 u32 cmd)
767{
768 unsigned long time_left = msecs_to_jiffies(I2C_TIMEOUT_MSEC);
769 u32 val, status;
770 int ret;
771
772 iproc_i2c_wr_reg(iproc_i2c, M_CMD_OFFSET, cmd);
773
774 if (iproc_i2c->irq) {
775 time_left = wait_for_completion_timeout(&iproc_i2c->done,
776 time_left);
777 /* disable all interrupts */
778 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, 0);
779 /* read it back to flush the write */
780 iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
781 /* make sure the interrupt handler isn't running */
782 synchronize_irq(iproc_i2c->irq);
783
784 } else { /* polling mode */
785 unsigned long timeout = jiffies + time_left;
786
787 do {
788 status = iproc_i2c_rd_reg(iproc_i2c,
789 IS_OFFSET) & ISR_MASK;
790 bcm_iproc_i2c_process_m_event(iproc_i2c, status);
791 iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, status);
792
793 if (time_after(jiffies, timeout)) {
794 time_left = 0;
795 break;
796 }
797
798 cpu_relax();
799 cond_resched();
800 } while (!iproc_i2c->xfer_is_done);
801 }
802
803 if (!time_left && !iproc_i2c->xfer_is_done) {
804 dev_err(iproc_i2c->device, "transaction timed out\n");
805
806 /* flush both TX/RX FIFOs */
807 val = BIT(M_FIFO_RX_FLUSH_SHIFT) | BIT(M_FIFO_TX_FLUSH_SHIFT);
808 iproc_i2c_wr_reg(iproc_i2c, M_FIFO_CTRL_OFFSET, val);
809 return -ETIMEDOUT;
810 }
811
812 ret = bcm_iproc_i2c_check_status(iproc_i2c, msg);
813 if (ret) {
814 /* flush both TX/RX FIFOs */
815 val = BIT(M_FIFO_RX_FLUSH_SHIFT) | BIT(M_FIFO_TX_FLUSH_SHIFT);
816 iproc_i2c_wr_reg(iproc_i2c, M_FIFO_CTRL_OFFSET, val);
817 return ret;
818 }
819
820 return 0;
821}
822
823/*
824 * If 'process_call' is true, then this is a multi-msg transfer that requires
825 * a repeated start between the messages.
826 * More specifically, it must be a write (reg) followed by a read (data).
827 * The i2c quirks are set to enforce this rule.
828 */
829static int bcm_iproc_i2c_xfer_internal(struct bcm_iproc_i2c_dev *iproc_i2c,
830 struct i2c_msg *msgs, bool process_call)
831{
832 int i;
833 u8 addr;
834 u32 val, tmp, val_intr_en;
835 unsigned int tx_bytes;
836 struct i2c_msg *msg = &msgs[0];
837
838 /* check if bus is busy */
839 if (!!(iproc_i2c_rd_reg(iproc_i2c,
840 M_CMD_OFFSET) & BIT(M_CMD_START_BUSY_SHIFT))) {
841 dev_warn(iproc_i2c->device, "bus is busy\n");
842 return -EBUSY;
843 }
844
845 iproc_i2c->msg = msg;
846
847 /* format and load slave address into the TX FIFO */
848 addr = i2c_8bit_addr_from_msg(msg);
849 iproc_i2c_wr_reg(iproc_i2c, M_TX_OFFSET, addr);
850
851 /*
852 * For a write transaction, load data into the TX FIFO. Only allow
853 * loading up to TX FIFO size - 1 bytes of data since the first byte
854 * has been used up by the slave address
855 */
856 tx_bytes = min_t(unsigned int, msg->len, M_TX_RX_FIFO_SIZE - 1);
857 if (!(msg->flags & I2C_M_RD)) {
858 for (i = 0; i < tx_bytes; i++) {
859 val = msg->buf[i];
860
861 /* mark the last byte */
862 if (!process_call && (i == msg->len - 1))
863 val |= BIT(M_TX_WR_STATUS_SHIFT);
864
865 iproc_i2c_wr_reg(iproc_i2c, M_TX_OFFSET, val);
866 }
867 iproc_i2c->tx_bytes = tx_bytes;
868 }
869
870 /* Process the read message if this is process call */
871 if (process_call) {
872 msg++;
873 iproc_i2c->msg = msg; /* point to second msg */
874
875 /*
876 * The last byte to be sent out should be a slave
877 * address with read operation
878 */
879 addr = i2c_8bit_addr_from_msg(msg);
880 /* mark it the last byte out */
881 val = addr | BIT(M_TX_WR_STATUS_SHIFT);
882 iproc_i2c_wr_reg(iproc_i2c, M_TX_OFFSET, val);
883 }
884
885 /* mark as incomplete before starting the transaction */
886 if (iproc_i2c->irq)
887 reinit_completion(&iproc_i2c->done);
888
889 iproc_i2c->xfer_is_done = 0;
890
891 /*
892 * Enable the "start busy" interrupt, which will be triggered after the
893 * transaction is done, i.e., the internal start_busy bit, transitions
894 * from 1 to 0.
895 */
896 val_intr_en = BIT(IE_M_START_BUSY_SHIFT);
897
898 /*
899 * If TX data size is larger than the TX FIFO, need to enable TX
900 * underrun interrupt, which will be triggerred when the TX FIFO is
901 * empty. When that happens we can then pump more data into the FIFO
902 */
903 if (!process_call && !(msg->flags & I2C_M_RD) &&
904 msg->len > iproc_i2c->tx_bytes)
905 val_intr_en |= BIT(IE_M_TX_UNDERRUN_SHIFT);
906
907 /*
908 * Now we can activate the transfer. For a read operation, specify the
909 * number of bytes to read
910 */
911 val = BIT(M_CMD_START_BUSY_SHIFT);
912
913 if (msg->len == 0) {
914 /* SMBUS QUICK Command (Read/Write) */
915 val |= (M_CMD_PROTOCOL_QUICK << M_CMD_PROTOCOL_SHIFT);
916 } else if (msg->flags & I2C_M_RD) {
917 u32 protocol;
918
919 iproc_i2c->rx_bytes = 0;
920 if (msg->len > M_RX_FIFO_MAX_THLD_VALUE)
921 iproc_i2c->thld_bytes = M_RX_FIFO_THLD_VALUE;
922 else
923 iproc_i2c->thld_bytes = msg->len;
924
925 /* set threshold value */
926 tmp = iproc_i2c_rd_reg(iproc_i2c, M_FIFO_CTRL_OFFSET);
927 tmp &= ~(M_FIFO_RX_THLD_MASK << M_FIFO_RX_THLD_SHIFT);
928 tmp |= iproc_i2c->thld_bytes << M_FIFO_RX_THLD_SHIFT;
929 iproc_i2c_wr_reg(iproc_i2c, M_FIFO_CTRL_OFFSET, tmp);
930
931 /* enable the RX threshold interrupt */
932 val_intr_en |= BIT(IE_M_RX_THLD_SHIFT);
933
934 protocol = process_call ?
935 M_CMD_PROTOCOL_PROCESS : M_CMD_PROTOCOL_BLK_RD;
936
937 val |= (protocol << M_CMD_PROTOCOL_SHIFT) |
938 (msg->len << M_CMD_RD_CNT_SHIFT);
939 } else {
940 val |= (M_CMD_PROTOCOL_BLK_WR << M_CMD_PROTOCOL_SHIFT);
941 }
942
943 if (iproc_i2c->irq)
944 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val_intr_en);
945
946 return bcm_iproc_i2c_xfer_wait(iproc_i2c, msg, val);
947}
948
949static int bcm_iproc_i2c_xfer(struct i2c_adapter *adapter,
950 struct i2c_msg msgs[], int num)
951{
952 struct bcm_iproc_i2c_dev *iproc_i2c = i2c_get_adapdata(adapter);
953 bool process_call = false;
954 int ret;
955
956 if (num == 2) {
957 /* Repeated start, use process call */
958 process_call = true;
959 if (msgs[1].flags & I2C_M_NOSTART) {
960 dev_err(iproc_i2c->device, "Invalid repeated start\n");
961 return -EOPNOTSUPP;
962 }
963 }
964
965 ret = bcm_iproc_i2c_xfer_internal(iproc_i2c, msgs, process_call);
966 if (ret) {
967 dev_dbg(iproc_i2c->device, "xfer failed\n");
968 return ret;
969 }
970
971 return num;
972}
973
974static uint32_t bcm_iproc_i2c_functionality(struct i2c_adapter *adap)
975{
976 u32 val;
977
978 val = I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
979
980 if (adap->algo->reg_slave)
981 val |= I2C_FUNC_SLAVE;
982
983 return val;
984}
985
986static struct i2c_algorithm bcm_iproc_algo = {
987 .master_xfer = bcm_iproc_i2c_xfer,
988 .functionality = bcm_iproc_i2c_functionality,
989 .reg_slave = bcm_iproc_i2c_reg_slave,
990 .unreg_slave = bcm_iproc_i2c_unreg_slave,
991};
992
993static const struct i2c_adapter_quirks bcm_iproc_i2c_quirks = {
994 .flags = I2C_AQ_COMB_WRITE_THEN_READ,
995 .max_comb_1st_msg_len = M_TX_RX_FIFO_SIZE,
996 .max_read_len = M_RX_MAX_READ_LEN,
997};
998
999static int bcm_iproc_i2c_cfg_speed(struct bcm_iproc_i2c_dev *iproc_i2c)
1000{
1001 unsigned int bus_speed;
1002 u32 val;
1003 int ret = of_property_read_u32(iproc_i2c->device->of_node,
1004 "clock-frequency", &bus_speed);
1005 if (ret < 0) {
1006 dev_info(iproc_i2c->device,
1007 "unable to interpret clock-frequency DT property\n");
1008 bus_speed = I2C_MAX_STANDARD_MODE_FREQ;
1009 }
1010
1011 if (bus_speed < I2C_MAX_STANDARD_MODE_FREQ) {
1012 dev_err(iproc_i2c->device, "%d Hz bus speed not supported\n",
1013 bus_speed);
1014 dev_err(iproc_i2c->device,
1015 "valid speeds are 100khz and 400khz\n");
1016 return -EINVAL;
1017 } else if (bus_speed < I2C_MAX_FAST_MODE_FREQ) {
1018 bus_speed = I2C_MAX_STANDARD_MODE_FREQ;
1019 } else {
1020 bus_speed = I2C_MAX_FAST_MODE_FREQ;
1021 }
1022
1023 iproc_i2c->bus_speed = bus_speed;
1024 val = iproc_i2c_rd_reg(iproc_i2c, TIM_CFG_OFFSET);
1025 val &= ~BIT(TIM_CFG_MODE_400_SHIFT);
1026 val |= (bus_speed == I2C_MAX_FAST_MODE_FREQ) << TIM_CFG_MODE_400_SHIFT;
1027 iproc_i2c_wr_reg(iproc_i2c, TIM_CFG_OFFSET, val);
1028
1029 dev_info(iproc_i2c->device, "bus set to %u Hz\n", bus_speed);
1030
1031 return 0;
1032}
1033
1034static int bcm_iproc_i2c_probe(struct platform_device *pdev)
1035{
1036 int irq, ret = 0;
1037 struct bcm_iproc_i2c_dev *iproc_i2c;
1038 struct i2c_adapter *adap;
1039 struct resource *res;
1040
1041 iproc_i2c = devm_kzalloc(&pdev->dev, sizeof(*iproc_i2c),
1042 GFP_KERNEL);
1043 if (!iproc_i2c)
1044 return -ENOMEM;
1045
1046 platform_set_drvdata(pdev, iproc_i2c);
1047 iproc_i2c->device = &pdev->dev;
1048 iproc_i2c->type =
1049 (enum bcm_iproc_i2c_type)of_device_get_match_data(&pdev->dev);
1050 init_completion(&iproc_i2c->done);
1051
1052 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1053 iproc_i2c->base = devm_ioremap_resource(iproc_i2c->device, res);
1054 if (IS_ERR(iproc_i2c->base))
1055 return PTR_ERR(iproc_i2c->base);
1056
1057 if (iproc_i2c->type == IPROC_I2C_NIC) {
1058 res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
1059 iproc_i2c->idm_base = devm_ioremap_resource(iproc_i2c->device,
1060 res);
1061 if (IS_ERR(iproc_i2c->idm_base))
1062 return PTR_ERR(iproc_i2c->idm_base);
1063
1064 ret = of_property_read_u32(iproc_i2c->device->of_node,
1065 "brcm,ape-hsls-addr-mask",
1066 &iproc_i2c->ape_addr_mask);
1067 if (ret < 0) {
1068 dev_err(iproc_i2c->device,
1069 "'brcm,ape-hsls-addr-mask' missing\n");
1070 return -EINVAL;
1071 }
1072
1073 spin_lock_init(&iproc_i2c->idm_lock);
1074
1075 /* no slave support */
1076 bcm_iproc_algo.reg_slave = NULL;
1077 bcm_iproc_algo.unreg_slave = NULL;
1078 }
1079
1080 ret = bcm_iproc_i2c_init(iproc_i2c);
1081 if (ret)
1082 return ret;
1083
1084 ret = bcm_iproc_i2c_cfg_speed(iproc_i2c);
1085 if (ret)
1086 return ret;
1087
1088 irq = platform_get_irq(pdev, 0);
1089 if (irq > 0) {
1090 ret = devm_request_irq(iproc_i2c->device, irq,
1091 bcm_iproc_i2c_isr, 0, pdev->name,
1092 iproc_i2c);
1093 if (ret < 0) {
1094 dev_err(iproc_i2c->device,
1095 "unable to request irq %i\n", irq);
1096 return ret;
1097 }
1098
1099 iproc_i2c->irq = irq;
1100 } else {
1101 dev_warn(iproc_i2c->device,
1102 "no irq resource, falling back to poll mode\n");
1103 }
1104
1105 bcm_iproc_i2c_enable_disable(iproc_i2c, true);
1106
1107 adap = &iproc_i2c->adapter;
1108 i2c_set_adapdata(adap, iproc_i2c);
1109 snprintf(adap->name, sizeof(adap->name),
1110 "Broadcom iProc (%s)",
1111 of_node_full_name(iproc_i2c->device->of_node));
1112 adap->algo = &bcm_iproc_algo;
1113 adap->quirks = &bcm_iproc_i2c_quirks;
1114 adap->dev.parent = &pdev->dev;
1115 adap->dev.of_node = pdev->dev.of_node;
1116
1117 return i2c_add_adapter(adap);
1118}
1119
1120static int bcm_iproc_i2c_remove(struct platform_device *pdev)
1121{
1122 struct bcm_iproc_i2c_dev *iproc_i2c = platform_get_drvdata(pdev);
1123
1124 if (iproc_i2c->irq) {
1125 /*
1126 * Make sure there's no pending interrupt when we remove the
1127 * adapter
1128 */
1129 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, 0);
1130 iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
1131 synchronize_irq(iproc_i2c->irq);
1132 }
1133
1134 i2c_del_adapter(&iproc_i2c->adapter);
1135 bcm_iproc_i2c_enable_disable(iproc_i2c, false);
1136
1137 return 0;
1138}
1139
1140#ifdef CONFIG_PM_SLEEP
1141
1142static int bcm_iproc_i2c_suspend(struct device *dev)
1143{
1144 struct bcm_iproc_i2c_dev *iproc_i2c = dev_get_drvdata(dev);
1145
1146 if (iproc_i2c->irq) {
1147 /*
1148 * Make sure there's no pending interrupt when we go into
1149 * suspend
1150 */
1151 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, 0);
1152 iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
1153 synchronize_irq(iproc_i2c->irq);
1154 }
1155
1156 /* now disable the controller */
1157 bcm_iproc_i2c_enable_disable(iproc_i2c, false);
1158
1159 return 0;
1160}
1161
1162static int bcm_iproc_i2c_resume(struct device *dev)
1163{
1164 struct bcm_iproc_i2c_dev *iproc_i2c = dev_get_drvdata(dev);
1165 int ret;
1166 u32 val;
1167
1168 /*
1169 * Power domain could have been shut off completely in system deep
1170 * sleep, so re-initialize the block here
1171 */
1172 ret = bcm_iproc_i2c_init(iproc_i2c);
1173 if (ret)
1174 return ret;
1175
1176 /* configure to the desired bus speed */
1177 val = iproc_i2c_rd_reg(iproc_i2c, TIM_CFG_OFFSET);
1178 val &= ~BIT(TIM_CFG_MODE_400_SHIFT);
1179 val |= (iproc_i2c->bus_speed == I2C_MAX_FAST_MODE_FREQ) << TIM_CFG_MODE_400_SHIFT;
1180 iproc_i2c_wr_reg(iproc_i2c, TIM_CFG_OFFSET, val);
1181
1182 bcm_iproc_i2c_enable_disable(iproc_i2c, true);
1183
1184 return 0;
1185}
1186
1187static const struct dev_pm_ops bcm_iproc_i2c_pm_ops = {
1188 .suspend_late = &bcm_iproc_i2c_suspend,
1189 .resume_early = &bcm_iproc_i2c_resume
1190};
1191
1192#define BCM_IPROC_I2C_PM_OPS (&bcm_iproc_i2c_pm_ops)
1193#else
1194#define BCM_IPROC_I2C_PM_OPS NULL
1195#endif /* CONFIG_PM_SLEEP */
1196
1197
1198static int bcm_iproc_i2c_reg_slave(struct i2c_client *slave)
1199{
1200 struct bcm_iproc_i2c_dev *iproc_i2c = i2c_get_adapdata(slave->adapter);
1201
1202 if (iproc_i2c->slave)
1203 return -EBUSY;
1204
1205 if (slave->flags & I2C_CLIENT_TEN)
1206 return -EAFNOSUPPORT;
1207
1208 iproc_i2c->slave = slave;
1209
1210 tasklet_init(&iproc_i2c->slave_rx_tasklet, slave_rx_tasklet_fn,
1211 (unsigned long)iproc_i2c);
1212
1213 bcm_iproc_i2c_slave_init(iproc_i2c, false);
1214 return 0;
1215}
1216
1217static int bcm_iproc_i2c_unreg_slave(struct i2c_client *slave)
1218{
1219 u32 tmp;
1220 struct bcm_iproc_i2c_dev *iproc_i2c = i2c_get_adapdata(slave->adapter);
1221
1222 if (!iproc_i2c->slave)
1223 return -EINVAL;
1224
1225 disable_irq(iproc_i2c->irq);
1226
1227 tasklet_kill(&iproc_i2c->slave_rx_tasklet);
1228
1229 /* disable all slave interrupts */
1230 tmp = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
1231 tmp &= ~(IE_S_ALL_INTERRUPT_MASK <<
1232 IE_S_ALL_INTERRUPT_SHIFT);
1233 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, tmp);
1234
1235 /* Erase the slave address programmed */
1236 tmp = iproc_i2c_rd_reg(iproc_i2c, S_CFG_SMBUS_ADDR_OFFSET);
1237 tmp &= ~BIT(S_CFG_EN_NIC_SMB_ADDR3_SHIFT);
1238 iproc_i2c_wr_reg(iproc_i2c, S_CFG_SMBUS_ADDR_OFFSET, tmp);
1239
1240 /* flush TX/RX FIFOs */
1241 tmp = (BIT(S_FIFO_RX_FLUSH_SHIFT) | BIT(S_FIFO_TX_FLUSH_SHIFT));
1242 iproc_i2c_wr_reg(iproc_i2c, S_FIFO_CTRL_OFFSET, tmp);
1243
1244 /* clear all pending slave interrupts */
1245 iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, ISR_MASK_SLAVE);
1246
1247 iproc_i2c->slave = NULL;
1248
1249 enable_irq(iproc_i2c->irq);
1250
1251 return 0;
1252}
1253
1254static const struct of_device_id bcm_iproc_i2c_of_match[] = {
1255 {
1256 .compatible = "brcm,iproc-i2c",
1257 .data = (int *)IPROC_I2C,
1258 }, {
1259 .compatible = "brcm,iproc-nic-i2c",
1260 .data = (int *)IPROC_I2C_NIC,
1261 },
1262 { /* sentinel */ }
1263};
1264MODULE_DEVICE_TABLE(of, bcm_iproc_i2c_of_match);
1265
1266static struct platform_driver bcm_iproc_i2c_driver = {
1267 .driver = {
1268 .name = "bcm-iproc-i2c",
1269 .of_match_table = bcm_iproc_i2c_of_match,
1270 .pm = BCM_IPROC_I2C_PM_OPS,
1271 },
1272 .probe = bcm_iproc_i2c_probe,
1273 .remove = bcm_iproc_i2c_remove,
1274};
1275module_platform_driver(bcm_iproc_i2c_driver);
1276
1277MODULE_AUTHOR("Ray Jui <rjui@broadcom.com>");
1278MODULE_DESCRIPTION("Broadcom iProc I2C Driver");
1279MODULE_LICENSE("GPL v2");