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 mv64xxx_i2c_fsm(struct mv64xxx_i2c_data *drv_data, u32 status)
114 * If state is idle, then this is likely the remnants of an old
115 * operation that driver has given up on or the user has killed.
116 * If so, issue the stop condition and go to idle.
118 if (drv_data->state == MV64XXX_I2C_STATE_IDLE) {
119 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
123 /* The status from the ctlr [mostly] tells us what to do next */
125 /* Start condition interrupt */
126 case MV64XXX_I2C_STATUS_MAST_START: /* 0x08 */
127 case MV64XXX_I2C_STATUS_MAST_REPEAT_START: /* 0x10 */
128 drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_1;
129 drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_ADDR_1_ACK;
132 /* Performing a write */
133 case MV64XXX_I2C_STATUS_MAST_WR_ADDR_ACK: /* 0x18 */
134 if (drv_data->msg->flags & I2C_M_TEN) {
135 drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_2;
137 MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK;
141 case MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_ACK: /* 0xd0 */
142 case MV64XXX_I2C_STATUS_MAST_WR_ACK: /* 0x28 */
143 if ((drv_data->bytes_left == 0)
144 || (drv_data->aborting
145 && (drv_data->byte_posn != 0))) {
146 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
147 drv_data->state = MV64XXX_I2C_STATE_IDLE;
149 drv_data->action = MV64XXX_I2C_ACTION_SEND_DATA;
151 MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_ACK;
152 drv_data->bytes_left--;
156 /* Performing a read */
157 case MV64XXX_I2C_STATUS_MAST_RD_ADDR_ACK: /* 40 */
158 if (drv_data->msg->flags & I2C_M_TEN) {
159 drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_2;
161 MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK;
165 case MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_ACK: /* 0xe0 */
166 if (drv_data->bytes_left == 0) {
167 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
168 drv_data->state = MV64XXX_I2C_STATE_IDLE;
172 case MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK: /* 0x50 */
173 if (status != MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK)
174 drv_data->action = MV64XXX_I2C_ACTION_CONTINUE;
176 drv_data->action = MV64XXX_I2C_ACTION_RCV_DATA;
177 drv_data->bytes_left--;
179 drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_DATA;
181 if ((drv_data->bytes_left == 1) || drv_data->aborting)
182 drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_ACK;
185 case MV64XXX_I2C_STATUS_MAST_RD_DATA_NO_ACK: /* 0x58 */
186 drv_data->action = MV64XXX_I2C_ACTION_RCV_DATA_STOP;
187 drv_data->state = MV64XXX_I2C_STATE_IDLE;
190 case MV64XXX_I2C_STATUS_MAST_WR_ADDR_NO_ACK: /* 0x20 */
191 case MV64XXX_I2C_STATUS_MAST_WR_NO_ACK: /* 30 */
192 case MV64XXX_I2C_STATUS_MAST_RD_ADDR_NO_ACK: /* 48 */
193 /* Doesn't seem to be a device at other end */
194 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
195 drv_data->state = MV64XXX_I2C_STATE_IDLE;
196 drv_data->rc = -ENODEV;
200 dev_err(&drv_data->adapter.dev,
201 "mv64xxx_i2c_fsm: Ctlr Error -- state: 0x%x, "
202 "status: 0x%x, addr: 0x%x, flags: 0x%x\n",
203 drv_data->state, status, drv_data->msg->addr,
204 drv_data->msg->flags);
205 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
206 drv_data->state = MV64XXX_I2C_STATE_IDLE;
212 mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data)
214 switch(drv_data->action) {
215 case MV64XXX_I2C_ACTION_CONTINUE:
216 writel(drv_data->cntl_bits,
217 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
220 case MV64XXX_I2C_ACTION_SEND_START:
221 writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_START,
222 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
225 case MV64XXX_I2C_ACTION_SEND_ADDR_1:
226 writel(drv_data->addr1,
227 drv_data->reg_base + MV64XXX_I2C_REG_DATA);
228 writel(drv_data->cntl_bits,
229 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
232 case MV64XXX_I2C_ACTION_SEND_ADDR_2:
233 writel(drv_data->addr2,
234 drv_data->reg_base + MV64XXX_I2C_REG_DATA);
235 writel(drv_data->cntl_bits,
236 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
239 case MV64XXX_I2C_ACTION_SEND_DATA:
240 writel(drv_data->msg->buf[drv_data->byte_posn++],
241 drv_data->reg_base + MV64XXX_I2C_REG_DATA);
242 writel(drv_data->cntl_bits,
243 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
246 case MV64XXX_I2C_ACTION_RCV_DATA:
247 drv_data->msg->buf[drv_data->byte_posn++] =
248 readl(drv_data->reg_base + MV64XXX_I2C_REG_DATA);
249 writel(drv_data->cntl_bits,
250 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
253 case MV64XXX_I2C_ACTION_RCV_DATA_STOP:
254 drv_data->msg->buf[drv_data->byte_posn++] =
255 readl(drv_data->reg_base + MV64XXX_I2C_REG_DATA);
256 drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN;
257 writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_STOP,
258 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
260 wake_up_interruptible(&drv_data->waitq);
263 case MV64XXX_I2C_ACTION_INVALID:
265 dev_err(&drv_data->adapter.dev,
266 "mv64xxx_i2c_do_action: Invalid action: %d\n",
270 case MV64XXX_I2C_ACTION_SEND_STOP:
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);
281 mv64xxx_i2c_intr(int irq, void *dev_id, struct pt_regs *regs)
283 struct mv64xxx_i2c_data *drv_data = dev_id;
288 spin_lock_irqsave(&drv_data->lock, flags);
289 while (readl(drv_data->reg_base + MV64XXX_I2C_REG_CONTROL) &
290 MV64XXX_I2C_REG_CONTROL_IFLG) {
291 status = readl(drv_data->reg_base + MV64XXX_I2C_REG_STATUS);
292 mv64xxx_i2c_fsm(drv_data, status);
293 mv64xxx_i2c_do_action(drv_data);
296 spin_unlock_irqrestore(&drv_data->lock, flags);
302 *****************************************************************************
304 * I2C Msg Execution Routines
306 *****************************************************************************
309 mv64xxx_i2c_prepare_for_io(struct mv64xxx_i2c_data *drv_data,
315 drv_data->byte_posn = 0;
316 drv_data->bytes_left = msg->len;
317 drv_data->aborting = 0;
319 drv_data->cntl_bits = MV64XXX_I2C_REG_CONTROL_ACK |
320 MV64XXX_I2C_REG_CONTROL_INTEN | MV64XXX_I2C_REG_CONTROL_TWSIEN;
322 if (msg->flags & I2C_M_RD)
325 if (msg->flags & I2C_M_REV_DIR_ADDR)
328 if (msg->flags & I2C_M_TEN) {
329 drv_data->addr1 = 0xf0 | (((u32)msg->addr & 0x300) >> 7) | dir;
330 drv_data->addr2 = (u32)msg->addr & 0xff;
332 drv_data->addr1 = ((u32)msg->addr & 0x7f) << 1 | dir;
338 mv64xxx_i2c_wait_for_completion(struct mv64xxx_i2c_data *drv_data)
344 time_left = wait_event_interruptible_timeout(drv_data->waitq,
345 !drv_data->block, msecs_to_jiffies(drv_data->adapter.timeout));
347 spin_lock_irqsave(&drv_data->lock, flags);
348 if (!time_left) { /* Timed out */
349 drv_data->rc = -ETIMEDOUT;
351 } else if (time_left < 0) { /* Interrupted/Error */
352 drv_data->rc = time_left; /* errno value */
356 if (abort && drv_data->block) {
357 drv_data->aborting = 1;
358 spin_unlock_irqrestore(&drv_data->lock, flags);
360 time_left = wait_event_timeout(drv_data->waitq,
362 msecs_to_jiffies(drv_data->adapter.timeout));
364 if ((time_left <= 0) && drv_data->block) {
365 drv_data->state = MV64XXX_I2C_STATE_IDLE;
366 dev_err(&drv_data->adapter.dev,
367 "mv64xxx: I2C bus locked, block: %d, "
368 "time_left: %d\n", drv_data->block,
372 spin_unlock_irqrestore(&drv_data->lock, flags);
376 mv64xxx_i2c_execute_msg(struct mv64xxx_i2c_data *drv_data, struct i2c_msg *msg)
380 spin_lock_irqsave(&drv_data->lock, flags);
381 mv64xxx_i2c_prepare_for_io(drv_data, msg);
383 if (unlikely(msg->flags & I2C_M_NOSTART)) { /* Skip start/addr phases */
384 if (drv_data->msg->flags & I2C_M_RD) {
385 /* No action to do, wait for slave to send a byte */
386 drv_data->action = MV64XXX_I2C_ACTION_CONTINUE;
388 MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_DATA;
390 drv_data->action = MV64XXX_I2C_ACTION_SEND_DATA;
392 MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_ACK;
393 drv_data->bytes_left--;
396 drv_data->action = MV64XXX_I2C_ACTION_SEND_START;
397 drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_START_COND;
401 mv64xxx_i2c_do_action(drv_data);
402 spin_unlock_irqrestore(&drv_data->lock, flags);
404 mv64xxx_i2c_wait_for_completion(drv_data);
409 *****************************************************************************
411 * I2C Core Support Routines (Interface to higher level I2C code)
413 *****************************************************************************
416 mv64xxx_i2c_functionality(struct i2c_adapter *adap)
418 return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SMBUS_EMUL;
422 mv64xxx_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
424 struct mv64xxx_i2c_data *drv_data = i2c_get_adapdata(adap);
427 for (i=0; i<num; i++)
428 if ((rc = mv64xxx_i2c_execute_msg(drv_data, &msgs[i])) < 0)
434 static struct i2c_algorithm mv64xxx_i2c_algo = {
435 .master_xfer = mv64xxx_i2c_xfer,
436 .functionality = mv64xxx_i2c_functionality,
440 *****************************************************************************
442 * Driver Interface & Early Init Routines
444 *****************************************************************************
446 static void __devinit
447 mv64xxx_i2c_hw_init(struct mv64xxx_i2c_data *drv_data)
449 writel(0, drv_data->reg_base + MV64XXX_I2C_REG_SOFT_RESET);
450 writel((((drv_data->freq_m & 0xf) << 3) | (drv_data->freq_n & 0x7)),
451 drv_data->reg_base + MV64XXX_I2C_REG_BAUD);
452 writel(0, drv_data->reg_base + MV64XXX_I2C_REG_SLAVE_ADDR);
453 writel(0, drv_data->reg_base + MV64XXX_I2C_REG_EXT_SLAVE_ADDR);
454 writel(MV64XXX_I2C_REG_CONTROL_TWSIEN | MV64XXX_I2C_REG_CONTROL_STOP,
455 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
456 drv_data->state = MV64XXX_I2C_STATE_IDLE;
460 mv64xxx_i2c_map_regs(struct platform_device *pd,
461 struct mv64xxx_i2c_data *drv_data)
465 if ((r = platform_get_resource(pd, IORESOURCE_MEM, 0)) &&
466 request_mem_region(r->start, MV64XXX_I2C_REG_BLOCK_SIZE,
467 drv_data->adapter.name)) {
469 drv_data->reg_base = ioremap(r->start,
470 MV64XXX_I2C_REG_BLOCK_SIZE);
471 drv_data->reg_base_p = r->start;
478 static void __devexit
479 mv64xxx_i2c_unmap_regs(struct mv64xxx_i2c_data *drv_data)
481 if (drv_data->reg_base) {
482 iounmap(drv_data->reg_base);
483 release_mem_region(drv_data->reg_base_p,
484 MV64XXX_I2C_REG_BLOCK_SIZE);
487 drv_data->reg_base = NULL;
488 drv_data->reg_base_p = 0;
492 mv64xxx_i2c_probe(struct platform_device *pd)
494 struct mv64xxx_i2c_data *drv_data;
495 struct mv64xxx_i2c_pdata *pdata = pd->dev.platform_data;
498 if ((pd->id != 0) || !pdata)
501 drv_data = kzalloc(sizeof(struct mv64xxx_i2c_data), GFP_KERNEL);
505 if (mv64xxx_i2c_map_regs(pd, drv_data)) {
510 strlcpy(drv_data->adapter.name, MV64XXX_I2C_CTLR_NAME " adapter",
513 init_waitqueue_head(&drv_data->waitq);
514 spin_lock_init(&drv_data->lock);
516 drv_data->freq_m = pdata->freq_m;
517 drv_data->freq_n = pdata->freq_n;
518 drv_data->irq = platform_get_irq(pd, 0);
519 if (drv_data->irq < 0) {
521 goto exit_unmap_regs;
523 drv_data->adapter.id = I2C_HW_MV64XXX;
524 drv_data->adapter.algo = &mv64xxx_i2c_algo;
525 drv_data->adapter.owner = THIS_MODULE;
526 drv_data->adapter.class = I2C_CLASS_HWMON;
527 drv_data->adapter.timeout = pdata->timeout;
528 drv_data->adapter.retries = pdata->retries;
529 platform_set_drvdata(pd, drv_data);
530 i2c_set_adapdata(&drv_data->adapter, drv_data);
532 if (request_irq(drv_data->irq, mv64xxx_i2c_intr, 0,
533 MV64XXX_I2C_CTLR_NAME, drv_data)) {
534 dev_err(&drv_data->adapter.dev,
535 "mv64xxx: Can't register intr handler irq: %d\n",
538 goto exit_unmap_regs;
539 } else if ((rc = i2c_add_adapter(&drv_data->adapter)) != 0) {
540 dev_err(&drv_data->adapter.dev,
541 "mv64xxx: Can't add i2c adapter, rc: %d\n", -rc);
545 mv64xxx_i2c_hw_init(drv_data);
550 free_irq(drv_data->irq, drv_data);
552 mv64xxx_i2c_unmap_regs(drv_data);
559 mv64xxx_i2c_remove(struct platform_device *dev)
561 struct mv64xxx_i2c_data *drv_data = platform_get_drvdata(dev);
564 rc = i2c_del_adapter(&drv_data->adapter);
565 free_irq(drv_data->irq, drv_data);
566 mv64xxx_i2c_unmap_regs(drv_data);
572 static struct platform_driver mv64xxx_i2c_driver = {
573 .probe = mv64xxx_i2c_probe,
574 .remove = mv64xxx_i2c_remove,
576 .owner = THIS_MODULE,
577 .name = MV64XXX_I2C_CTLR_NAME,
582 mv64xxx_i2c_init(void)
584 return platform_driver_register(&mv64xxx_i2c_driver);
588 mv64xxx_i2c_exit(void)
590 platform_driver_unregister(&mv64xxx_i2c_driver);
593 module_init(mv64xxx_i2c_init);
594 module_exit(mv64xxx_i2c_exit);
596 MODULE_AUTHOR("Mark A. Greer <mgreer@mvista.com>");
597 MODULE_DESCRIPTION("Marvell mv64xxx host bridge i2c ctlr driver");
598 MODULE_LICENSE("GPL");