2 * Driver for the i2c controller on the Marvell line of host bridges for MIPS
3 * and PPC (e.g, gt642[46]0, mv643[46]0, mv644[46]0).
5 * Author: Mark A. Greer <mgreer@mvista.com>
7 * 2005 (c) MontaVista, Software, Inc. This file is licensed under
8 * the terms of the GNU General Public License version 2. This program
9 * is licensed "as is" without any warranty of any kind, whether express
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/spinlock.h>
15 #include <linux/i2c.h>
16 #include <linux/interrupt.h>
17 #include <linux/mv643xx.h>
18 #include <linux/platform_device.h>
22 /* Register defines */
23 #define MV64XXX_I2C_REG_SLAVE_ADDR 0x00
24 #define MV64XXX_I2C_REG_DATA 0x04
25 #define MV64XXX_I2C_REG_CONTROL 0x08
26 #define MV64XXX_I2C_REG_STATUS 0x0c
27 #define MV64XXX_I2C_REG_BAUD 0x0c
28 #define MV64XXX_I2C_REG_EXT_SLAVE_ADDR 0x10
29 #define MV64XXX_I2C_REG_SOFT_RESET 0x1c
31 #define MV64XXX_I2C_REG_CONTROL_ACK 0x00000004
32 #define MV64XXX_I2C_REG_CONTROL_IFLG 0x00000008
33 #define MV64XXX_I2C_REG_CONTROL_STOP 0x00000010
34 #define MV64XXX_I2C_REG_CONTROL_START 0x00000020
35 #define MV64XXX_I2C_REG_CONTROL_TWSIEN 0x00000040
36 #define MV64XXX_I2C_REG_CONTROL_INTEN 0x00000080
38 /* Ctlr status values */
39 #define MV64XXX_I2C_STATUS_BUS_ERR 0x00
40 #define MV64XXX_I2C_STATUS_MAST_START 0x08
41 #define MV64XXX_I2C_STATUS_MAST_REPEAT_START 0x10
42 #define MV64XXX_I2C_STATUS_MAST_WR_ADDR_ACK 0x18
43 #define MV64XXX_I2C_STATUS_MAST_WR_ADDR_NO_ACK 0x20
44 #define MV64XXX_I2C_STATUS_MAST_WR_ACK 0x28
45 #define MV64XXX_I2C_STATUS_MAST_WR_NO_ACK 0x30
46 #define MV64XXX_I2C_STATUS_MAST_LOST_ARB 0x38
47 #define MV64XXX_I2C_STATUS_MAST_RD_ADDR_ACK 0x40
48 #define MV64XXX_I2C_STATUS_MAST_RD_ADDR_NO_ACK 0x48
49 #define MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK 0x50
50 #define MV64XXX_I2C_STATUS_MAST_RD_DATA_NO_ACK 0x58
51 #define MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_ACK 0xd0
52 #define MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_NO_ACK 0xd8
53 #define MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_ACK 0xe0
54 #define MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_NO_ACK 0xe8
55 #define MV64XXX_I2C_STATUS_NO_STATUS 0xf8
59 MV64XXX_I2C_STATE_INVALID,
60 MV64XXX_I2C_STATE_IDLE,
61 MV64XXX_I2C_STATE_WAITING_FOR_START_COND,
62 MV64XXX_I2C_STATE_WAITING_FOR_ADDR_1_ACK,
63 MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK,
64 MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_ACK,
65 MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_DATA,
70 MV64XXX_I2C_ACTION_INVALID,
71 MV64XXX_I2C_ACTION_CONTINUE,
72 MV64XXX_I2C_ACTION_SEND_START,
73 MV64XXX_I2C_ACTION_SEND_ADDR_1,
74 MV64XXX_I2C_ACTION_SEND_ADDR_2,
75 MV64XXX_I2C_ACTION_SEND_DATA,
76 MV64XXX_I2C_ACTION_RCV_DATA,
77 MV64XXX_I2C_ACTION_RCV_DATA_STOP,
78 MV64XXX_I2C_ACTION_SEND_STOP,
81 struct mv64xxx_i2c_data {
87 void __iomem *reg_base;
97 wait_queue_head_t waitq;
100 struct i2c_adapter adapter;
104 *****************************************************************************
106 * Finite State Machine & Interrupt Routines
108 *****************************************************************************
111 /* Reset hardware and initialize FSM */
113 mv64xxx_i2c_hw_init(struct mv64xxx_i2c_data *drv_data)
115 writel(0, drv_data->reg_base + MV64XXX_I2C_REG_SOFT_RESET);
116 writel((((drv_data->freq_m & 0xf) << 3) | (drv_data->freq_n & 0x7)),
117 drv_data->reg_base + MV64XXX_I2C_REG_BAUD);
118 writel(0, drv_data->reg_base + MV64XXX_I2C_REG_SLAVE_ADDR);
119 writel(0, drv_data->reg_base + MV64XXX_I2C_REG_EXT_SLAVE_ADDR);
120 writel(MV64XXX_I2C_REG_CONTROL_TWSIEN | MV64XXX_I2C_REG_CONTROL_STOP,
121 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
122 drv_data->state = MV64XXX_I2C_STATE_IDLE;
126 mv64xxx_i2c_fsm(struct mv64xxx_i2c_data *drv_data, u32 status)
129 * If state is idle, then this is likely the remnants of an old
130 * operation that driver has given up on or the user has killed.
131 * If so, issue the stop condition and go to idle.
133 if (drv_data->state == MV64XXX_I2C_STATE_IDLE) {
134 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
138 /* The status from the ctlr [mostly] tells us what to do next */
140 /* Start condition interrupt */
141 case MV64XXX_I2C_STATUS_MAST_START: /* 0x08 */
142 case MV64XXX_I2C_STATUS_MAST_REPEAT_START: /* 0x10 */
143 drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_1;
144 drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_ADDR_1_ACK;
147 /* Performing a write */
148 case MV64XXX_I2C_STATUS_MAST_WR_ADDR_ACK: /* 0x18 */
149 if (drv_data->msg->flags & I2C_M_TEN) {
150 drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_2;
152 MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK;
156 case MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_ACK: /* 0xd0 */
157 case MV64XXX_I2C_STATUS_MAST_WR_ACK: /* 0x28 */
158 if ((drv_data->bytes_left == 0)
159 || (drv_data->aborting
160 && (drv_data->byte_posn != 0))) {
161 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
162 drv_data->state = MV64XXX_I2C_STATE_IDLE;
164 drv_data->action = MV64XXX_I2C_ACTION_SEND_DATA;
166 MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_ACK;
167 drv_data->bytes_left--;
171 /* Performing a read */
172 case MV64XXX_I2C_STATUS_MAST_RD_ADDR_ACK: /* 40 */
173 if (drv_data->msg->flags & I2C_M_TEN) {
174 drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_2;
176 MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK;
180 case MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_ACK: /* 0xe0 */
181 if (drv_data->bytes_left == 0) {
182 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
183 drv_data->state = MV64XXX_I2C_STATE_IDLE;
187 case MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK: /* 0x50 */
188 if (status != MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK)
189 drv_data->action = MV64XXX_I2C_ACTION_CONTINUE;
191 drv_data->action = MV64XXX_I2C_ACTION_RCV_DATA;
192 drv_data->bytes_left--;
194 drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_DATA;
196 if ((drv_data->bytes_left == 1) || drv_data->aborting)
197 drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_ACK;
200 case MV64XXX_I2C_STATUS_MAST_RD_DATA_NO_ACK: /* 0x58 */
201 drv_data->action = MV64XXX_I2C_ACTION_RCV_DATA_STOP;
202 drv_data->state = MV64XXX_I2C_STATE_IDLE;
205 case MV64XXX_I2C_STATUS_MAST_WR_ADDR_NO_ACK: /* 0x20 */
206 case MV64XXX_I2C_STATUS_MAST_WR_NO_ACK: /* 30 */
207 case MV64XXX_I2C_STATUS_MAST_RD_ADDR_NO_ACK: /* 48 */
208 /* Doesn't seem to be a device at other end */
209 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
210 drv_data->state = MV64XXX_I2C_STATE_IDLE;
211 drv_data->rc = -ENODEV;
215 dev_err(&drv_data->adapter.dev,
216 "mv64xxx_i2c_fsm: Ctlr Error -- state: 0x%x, "
217 "status: 0x%x, addr: 0x%x, flags: 0x%x\n",
218 drv_data->state, status, drv_data->msg->addr,
219 drv_data->msg->flags);
220 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
221 mv64xxx_i2c_hw_init(drv_data);
227 mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data)
229 switch(drv_data->action) {
230 case MV64XXX_I2C_ACTION_CONTINUE:
231 writel(drv_data->cntl_bits,
232 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
235 case MV64XXX_I2C_ACTION_SEND_START:
236 writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_START,
237 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
240 case MV64XXX_I2C_ACTION_SEND_ADDR_1:
241 writel(drv_data->addr1,
242 drv_data->reg_base + MV64XXX_I2C_REG_DATA);
243 writel(drv_data->cntl_bits,
244 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
247 case MV64XXX_I2C_ACTION_SEND_ADDR_2:
248 writel(drv_data->addr2,
249 drv_data->reg_base + MV64XXX_I2C_REG_DATA);
250 writel(drv_data->cntl_bits,
251 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
254 case MV64XXX_I2C_ACTION_SEND_DATA:
255 writel(drv_data->msg->buf[drv_data->byte_posn++],
256 drv_data->reg_base + MV64XXX_I2C_REG_DATA);
257 writel(drv_data->cntl_bits,
258 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
261 case MV64XXX_I2C_ACTION_RCV_DATA:
262 drv_data->msg->buf[drv_data->byte_posn++] =
263 readl(drv_data->reg_base + MV64XXX_I2C_REG_DATA);
264 writel(drv_data->cntl_bits,
265 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
268 case MV64XXX_I2C_ACTION_RCV_DATA_STOP:
269 drv_data->msg->buf[drv_data->byte_posn++] =
270 readl(drv_data->reg_base + MV64XXX_I2C_REG_DATA);
271 drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN;
272 writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_STOP,
273 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
275 wake_up_interruptible(&drv_data->waitq);
278 case MV64XXX_I2C_ACTION_INVALID:
280 dev_err(&drv_data->adapter.dev,
281 "mv64xxx_i2c_do_action: Invalid action: %d\n",
285 case MV64XXX_I2C_ACTION_SEND_STOP:
286 drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN;
287 writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_STOP,
288 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
290 wake_up_interruptible(&drv_data->waitq);
296 mv64xxx_i2c_intr(int irq, void *dev_id)
298 struct mv64xxx_i2c_data *drv_data = dev_id;
303 spin_lock_irqsave(&drv_data->lock, flags);
304 while (readl(drv_data->reg_base + MV64XXX_I2C_REG_CONTROL) &
305 MV64XXX_I2C_REG_CONTROL_IFLG) {
306 status = readl(drv_data->reg_base + MV64XXX_I2C_REG_STATUS);
307 mv64xxx_i2c_fsm(drv_data, status);
308 mv64xxx_i2c_do_action(drv_data);
311 spin_unlock_irqrestore(&drv_data->lock, flags);
317 *****************************************************************************
319 * I2C Msg Execution Routines
321 *****************************************************************************
324 mv64xxx_i2c_prepare_for_io(struct mv64xxx_i2c_data *drv_data,
330 drv_data->byte_posn = 0;
331 drv_data->bytes_left = msg->len;
332 drv_data->aborting = 0;
334 drv_data->cntl_bits = MV64XXX_I2C_REG_CONTROL_ACK |
335 MV64XXX_I2C_REG_CONTROL_INTEN | MV64XXX_I2C_REG_CONTROL_TWSIEN;
337 if (msg->flags & I2C_M_RD)
340 if (msg->flags & I2C_M_REV_DIR_ADDR)
343 if (msg->flags & I2C_M_TEN) {
344 drv_data->addr1 = 0xf0 | (((u32)msg->addr & 0x300) >> 7) | dir;
345 drv_data->addr2 = (u32)msg->addr & 0xff;
347 drv_data->addr1 = ((u32)msg->addr & 0x7f) << 1 | dir;
353 mv64xxx_i2c_wait_for_completion(struct mv64xxx_i2c_data *drv_data)
359 time_left = wait_event_interruptible_timeout(drv_data->waitq,
360 !drv_data->block, msecs_to_jiffies(drv_data->adapter.timeout));
362 spin_lock_irqsave(&drv_data->lock, flags);
363 if (!time_left) { /* Timed out */
364 drv_data->rc = -ETIMEDOUT;
366 } else if (time_left < 0) { /* Interrupted/Error */
367 drv_data->rc = time_left; /* errno value */
371 if (abort && drv_data->block) {
372 drv_data->aborting = 1;
373 spin_unlock_irqrestore(&drv_data->lock, flags);
375 time_left = wait_event_timeout(drv_data->waitq,
377 msecs_to_jiffies(drv_data->adapter.timeout));
379 if ((time_left <= 0) && drv_data->block) {
380 drv_data->state = MV64XXX_I2C_STATE_IDLE;
381 dev_err(&drv_data->adapter.dev,
382 "mv64xxx: I2C bus locked, block: %d, "
383 "time_left: %d\n", drv_data->block,
385 mv64xxx_i2c_hw_init(drv_data);
388 spin_unlock_irqrestore(&drv_data->lock, flags);
392 mv64xxx_i2c_execute_msg(struct mv64xxx_i2c_data *drv_data, struct i2c_msg *msg)
396 spin_lock_irqsave(&drv_data->lock, flags);
397 mv64xxx_i2c_prepare_for_io(drv_data, msg);
399 if (unlikely(msg->flags & I2C_M_NOSTART)) { /* Skip start/addr phases */
400 if (drv_data->msg->flags & I2C_M_RD) {
401 /* No action to do, wait for slave to send a byte */
402 drv_data->action = MV64XXX_I2C_ACTION_CONTINUE;
404 MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_DATA;
406 drv_data->action = MV64XXX_I2C_ACTION_SEND_DATA;
408 MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_ACK;
409 drv_data->bytes_left--;
412 drv_data->action = MV64XXX_I2C_ACTION_SEND_START;
413 drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_START_COND;
417 mv64xxx_i2c_do_action(drv_data);
418 spin_unlock_irqrestore(&drv_data->lock, flags);
420 mv64xxx_i2c_wait_for_completion(drv_data);
425 *****************************************************************************
427 * I2C Core Support Routines (Interface to higher level I2C code)
429 *****************************************************************************
432 mv64xxx_i2c_functionality(struct i2c_adapter *adap)
434 return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SMBUS_EMUL;
438 mv64xxx_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
440 struct mv64xxx_i2c_data *drv_data = i2c_get_adapdata(adap);
443 for (i=0; i<num; i++)
444 if ((rc = mv64xxx_i2c_execute_msg(drv_data, &msgs[i])) < 0)
450 static const struct i2c_algorithm mv64xxx_i2c_algo = {
451 .master_xfer = mv64xxx_i2c_xfer,
452 .functionality = mv64xxx_i2c_functionality,
456 *****************************************************************************
458 * Driver Interface & Early Init Routines
460 *****************************************************************************
463 mv64xxx_i2c_map_regs(struct platform_device *pd,
464 struct mv64xxx_i2c_data *drv_data)
468 if ((r = platform_get_resource(pd, IORESOURCE_MEM, 0)) &&
469 request_mem_region(r->start, MV64XXX_I2C_REG_BLOCK_SIZE,
470 drv_data->adapter.name)) {
472 drv_data->reg_base = ioremap(r->start,
473 MV64XXX_I2C_REG_BLOCK_SIZE);
474 drv_data->reg_base_p = r->start;
481 static void __devexit
482 mv64xxx_i2c_unmap_regs(struct mv64xxx_i2c_data *drv_data)
484 if (drv_data->reg_base) {
485 iounmap(drv_data->reg_base);
486 release_mem_region(drv_data->reg_base_p,
487 MV64XXX_I2C_REG_BLOCK_SIZE);
490 drv_data->reg_base = NULL;
491 drv_data->reg_base_p = 0;
495 mv64xxx_i2c_probe(struct platform_device *pd)
497 struct mv64xxx_i2c_data *drv_data;
498 struct mv64xxx_i2c_pdata *pdata = pd->dev.platform_data;
501 if ((pd->id != 0) || !pdata)
504 drv_data = kzalloc(sizeof(struct mv64xxx_i2c_data), GFP_KERNEL);
508 if (mv64xxx_i2c_map_regs(pd, drv_data)) {
513 strlcpy(drv_data->adapter.name, MV64XXX_I2C_CTLR_NAME " adapter",
514 sizeof(drv_data->adapter.name));
516 init_waitqueue_head(&drv_data->waitq);
517 spin_lock_init(&drv_data->lock);
519 drv_data->freq_m = pdata->freq_m;
520 drv_data->freq_n = pdata->freq_n;
521 drv_data->irq = platform_get_irq(pd, 0);
522 if (drv_data->irq < 0) {
524 goto exit_unmap_regs;
526 drv_data->adapter.dev.parent = &pd->dev;
527 drv_data->adapter.id = I2C_HW_MV64XXX;
528 drv_data->adapter.algo = &mv64xxx_i2c_algo;
529 drv_data->adapter.owner = THIS_MODULE;
530 drv_data->adapter.class = I2C_CLASS_HWMON;
531 drv_data->adapter.timeout = pdata->timeout;
532 drv_data->adapter.retries = pdata->retries;
533 drv_data->adapter.nr = pd->id;
534 platform_set_drvdata(pd, drv_data);
535 i2c_set_adapdata(&drv_data->adapter, drv_data);
537 mv64xxx_i2c_hw_init(drv_data);
539 if (request_irq(drv_data->irq, mv64xxx_i2c_intr, 0,
540 MV64XXX_I2C_CTLR_NAME, drv_data)) {
541 dev_err(&drv_data->adapter.dev,
542 "mv64xxx: Can't register intr handler irq: %d\n",
545 goto exit_unmap_regs;
546 } else if ((rc = i2c_add_numbered_adapter(&drv_data->adapter)) != 0) {
547 dev_err(&drv_data->adapter.dev,
548 "mv64xxx: Can't add i2c adapter, rc: %d\n", -rc);
555 free_irq(drv_data->irq, drv_data);
557 mv64xxx_i2c_unmap_regs(drv_data);
564 mv64xxx_i2c_remove(struct platform_device *dev)
566 struct mv64xxx_i2c_data *drv_data = platform_get_drvdata(dev);
569 rc = i2c_del_adapter(&drv_data->adapter);
570 free_irq(drv_data->irq, drv_data);
571 mv64xxx_i2c_unmap_regs(drv_data);
577 static struct platform_driver mv64xxx_i2c_driver = {
578 .probe = mv64xxx_i2c_probe,
579 .remove = mv64xxx_i2c_remove,
581 .owner = THIS_MODULE,
582 .name = MV64XXX_I2C_CTLR_NAME,
587 mv64xxx_i2c_init(void)
589 return platform_driver_register(&mv64xxx_i2c_driver);
593 mv64xxx_i2c_exit(void)
595 platform_driver_unregister(&mv64xxx_i2c_driver);
598 module_init(mv64xxx_i2c_init);
599 module_exit(mv64xxx_i2c_exit);
601 MODULE_AUTHOR("Mark A. Greer <mgreer@mvista.com>");
602 MODULE_DESCRIPTION("Marvell mv64xxx host bridge i2c ctlr driver");
603 MODULE_LICENSE("GPL");