2 * drivers/i2c/busses/i2c-mv64xxx.c
4 * Driver for the i2c controller on the Marvell line of host bridges for MIPS
5 * and PPC (e.g, gt642[46]0, mv643[46]0, mv644[46]0).
7 * Author: Mark A. Greer <mgreer@mvista.com>
9 * 2005 (c) MontaVista, Software, Inc. This file is licensed under
10 * the terms of the GNU General Public License version 2. This program
11 * is licensed "as is" without any warranty of any kind, whether express
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/spinlock.h>
17 #include <linux/i2c.h>
18 #include <linux/interrupt.h>
19 #include <linux/mv643xx.h>
20 #include <linux/platform_device.h>
24 /* Register defines */
25 #define MV64XXX_I2C_REG_SLAVE_ADDR 0x00
26 #define MV64XXX_I2C_REG_DATA 0x04
27 #define MV64XXX_I2C_REG_CONTROL 0x08
28 #define MV64XXX_I2C_REG_STATUS 0x0c
29 #define MV64XXX_I2C_REG_BAUD 0x0c
30 #define MV64XXX_I2C_REG_EXT_SLAVE_ADDR 0x10
31 #define MV64XXX_I2C_REG_SOFT_RESET 0x1c
33 #define MV64XXX_I2C_REG_CONTROL_ACK 0x00000004
34 #define MV64XXX_I2C_REG_CONTROL_IFLG 0x00000008
35 #define MV64XXX_I2C_REG_CONTROL_STOP 0x00000010
36 #define MV64XXX_I2C_REG_CONTROL_START 0x00000020
37 #define MV64XXX_I2C_REG_CONTROL_TWSIEN 0x00000040
38 #define MV64XXX_I2C_REG_CONTROL_INTEN 0x00000080
40 /* Ctlr status values */
41 #define MV64XXX_I2C_STATUS_BUS_ERR 0x00
42 #define MV64XXX_I2C_STATUS_MAST_START 0x08
43 #define MV64XXX_I2C_STATUS_MAST_REPEAT_START 0x10
44 #define MV64XXX_I2C_STATUS_MAST_WR_ADDR_ACK 0x18
45 #define MV64XXX_I2C_STATUS_MAST_WR_ADDR_NO_ACK 0x20
46 #define MV64XXX_I2C_STATUS_MAST_WR_ACK 0x28
47 #define MV64XXX_I2C_STATUS_MAST_WR_NO_ACK 0x30
48 #define MV64XXX_I2C_STATUS_MAST_LOST_ARB 0x38
49 #define MV64XXX_I2C_STATUS_MAST_RD_ADDR_ACK 0x40
50 #define MV64XXX_I2C_STATUS_MAST_RD_ADDR_NO_ACK 0x48
51 #define MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK 0x50
52 #define MV64XXX_I2C_STATUS_MAST_RD_DATA_NO_ACK 0x58
53 #define MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_ACK 0xd0
54 #define MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_NO_ACK 0xd8
55 #define MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_ACK 0xe0
56 #define MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_NO_ACK 0xe8
57 #define MV64XXX_I2C_STATUS_NO_STATUS 0xf8
61 MV64XXX_I2C_STATE_INVALID,
62 MV64XXX_I2C_STATE_IDLE,
63 MV64XXX_I2C_STATE_WAITING_FOR_START_COND,
64 MV64XXX_I2C_STATE_WAITING_FOR_ADDR_1_ACK,
65 MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK,
66 MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_ACK,
67 MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_DATA,
68 MV64XXX_I2C_STATE_ABORTING,
73 MV64XXX_I2C_ACTION_INVALID,
74 MV64XXX_I2C_ACTION_CONTINUE,
75 MV64XXX_I2C_ACTION_SEND_START,
76 MV64XXX_I2C_ACTION_SEND_ADDR_1,
77 MV64XXX_I2C_ACTION_SEND_ADDR_2,
78 MV64XXX_I2C_ACTION_SEND_DATA,
79 MV64XXX_I2C_ACTION_RCV_DATA,
80 MV64XXX_I2C_ACTION_RCV_DATA_STOP,
81 MV64XXX_I2C_ACTION_SEND_STOP,
84 struct mv64xxx_i2c_data {
89 void __iomem *reg_base;
99 wait_queue_head_t waitq;
102 struct i2c_adapter adapter;
106 *****************************************************************************
108 * Finite State Machine & Interrupt Routines
110 *****************************************************************************
113 mv64xxx_i2c_fsm(struct mv64xxx_i2c_data *drv_data, u32 status)
116 * If state is idle, then this is likely the remnants of an old
117 * operation that driver has given up on or the user has killed.
118 * If so, issue the stop condition and go to idle.
120 if (drv_data->state == MV64XXX_I2C_STATE_IDLE) {
121 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
125 if (drv_data->state == MV64XXX_I2C_STATE_ABORTING) {
126 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
127 drv_data->state = MV64XXX_I2C_STATE_IDLE;
131 /* The status from the ctlr [mostly] tells us what to do next */
133 /* Start condition interrupt */
134 case MV64XXX_I2C_STATUS_MAST_START: /* 0x08 */
135 case MV64XXX_I2C_STATUS_MAST_REPEAT_START: /* 0x10 */
136 drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_1;
137 drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_ADDR_1_ACK;
140 /* Performing a write */
141 case MV64XXX_I2C_STATUS_MAST_WR_ADDR_ACK: /* 0x18 */
142 if (drv_data->msg->flags & I2C_M_TEN) {
143 drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_2;
145 MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK;
149 case MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_ACK: /* 0xd0 */
150 case MV64XXX_I2C_STATUS_MAST_WR_ACK: /* 0x28 */
151 if (drv_data->bytes_left > 0) {
152 drv_data->action = MV64XXX_I2C_ACTION_SEND_DATA;
154 MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_ACK;
155 drv_data->bytes_left--;
157 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
158 drv_data->state = MV64XXX_I2C_STATE_IDLE;
162 /* Performing a read */
163 case MV64XXX_I2C_STATUS_MAST_RD_ADDR_ACK: /* 40 */
164 if (drv_data->msg->flags & I2C_M_TEN) {
165 drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_2;
167 MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK;
171 case MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_ACK: /* 0xe0 */
172 if (drv_data->bytes_left == 0) {
173 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
174 drv_data->state = MV64XXX_I2C_STATE_IDLE;
178 case MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK: /* 0x50 */
179 if (status != MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK)
180 drv_data->action = MV64XXX_I2C_ACTION_CONTINUE;
182 drv_data->action = MV64XXX_I2C_ACTION_RCV_DATA;
183 drv_data->bytes_left--;
185 drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_DATA;
187 if (drv_data->bytes_left == 1)
188 drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_ACK;
191 case MV64XXX_I2C_STATUS_MAST_RD_DATA_NO_ACK: /* 0x58 */
192 drv_data->action = MV64XXX_I2C_ACTION_RCV_DATA_STOP;
193 drv_data->state = MV64XXX_I2C_STATE_IDLE;
196 case MV64XXX_I2C_STATUS_MAST_WR_ADDR_NO_ACK: /* 0x20 */
197 case MV64XXX_I2C_STATUS_MAST_WR_NO_ACK: /* 30 */
198 case MV64XXX_I2C_STATUS_MAST_RD_ADDR_NO_ACK: /* 48 */
199 /* Doesn't seem to be a device at other end */
200 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
201 drv_data->state = MV64XXX_I2C_STATE_IDLE;
202 drv_data->rc = -ENODEV;
206 dev_err(&drv_data->adapter.dev,
207 "mv64xxx_i2c_fsm: Ctlr Error -- state: 0x%x, "
208 "status: 0x%x, addr: 0x%x, flags: 0x%x\n",
209 drv_data->state, status, drv_data->msg->addr,
210 drv_data->msg->flags);
211 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
212 drv_data->state = MV64XXX_I2C_STATE_IDLE;
218 mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data)
220 switch(drv_data->action) {
221 case MV64XXX_I2C_ACTION_CONTINUE:
222 writel(drv_data->cntl_bits,
223 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
226 case MV64XXX_I2C_ACTION_SEND_START:
227 writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_START,
228 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
231 case MV64XXX_I2C_ACTION_SEND_ADDR_1:
232 writel(drv_data->addr1,
233 drv_data->reg_base + MV64XXX_I2C_REG_DATA);
234 writel(drv_data->cntl_bits,
235 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
238 case MV64XXX_I2C_ACTION_SEND_ADDR_2:
239 writel(drv_data->addr2,
240 drv_data->reg_base + MV64XXX_I2C_REG_DATA);
241 writel(drv_data->cntl_bits,
242 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
245 case MV64XXX_I2C_ACTION_SEND_DATA:
246 writel(drv_data->msg->buf[drv_data->byte_posn++],
247 drv_data->reg_base + MV64XXX_I2C_REG_DATA);
248 writel(drv_data->cntl_bits,
249 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
252 case MV64XXX_I2C_ACTION_RCV_DATA:
253 drv_data->msg->buf[drv_data->byte_posn++] =
254 readl(drv_data->reg_base + MV64XXX_I2C_REG_DATA);
255 writel(drv_data->cntl_bits,
256 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
259 case MV64XXX_I2C_ACTION_RCV_DATA_STOP:
260 drv_data->msg->buf[drv_data->byte_posn++] =
261 readl(drv_data->reg_base + MV64XXX_I2C_REG_DATA);
262 drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN;
263 writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_STOP,
264 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
266 wake_up_interruptible(&drv_data->waitq);
269 case MV64XXX_I2C_ACTION_INVALID:
271 dev_err(&drv_data->adapter.dev,
272 "mv64xxx_i2c_do_action: Invalid action: %d\n",
276 case MV64XXX_I2C_ACTION_SEND_STOP:
277 drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN;
278 writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_STOP,
279 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
281 wake_up_interruptible(&drv_data->waitq);
287 mv64xxx_i2c_intr(int irq, void *dev_id, struct pt_regs *regs)
289 struct mv64xxx_i2c_data *drv_data = dev_id;
294 spin_lock_irqsave(&drv_data->lock, flags);
295 while (readl(drv_data->reg_base + MV64XXX_I2C_REG_CONTROL) &
296 MV64XXX_I2C_REG_CONTROL_IFLG) {
297 status = readl(drv_data->reg_base + MV64XXX_I2C_REG_STATUS);
298 mv64xxx_i2c_fsm(drv_data, status);
299 mv64xxx_i2c_do_action(drv_data);
302 spin_unlock_irqrestore(&drv_data->lock, flags);
308 *****************************************************************************
310 * I2C Msg Execution Routines
312 *****************************************************************************
315 mv64xxx_i2c_prepare_for_io(struct mv64xxx_i2c_data *drv_data,
321 drv_data->byte_posn = 0;
322 drv_data->bytes_left = msg->len;
324 drv_data->cntl_bits = MV64XXX_I2C_REG_CONTROL_ACK |
325 MV64XXX_I2C_REG_CONTROL_INTEN | MV64XXX_I2C_REG_CONTROL_TWSIEN;
327 if (msg->flags & I2C_M_RD)
330 if (msg->flags & I2C_M_REV_DIR_ADDR)
333 if (msg->flags & I2C_M_TEN) {
334 drv_data->addr1 = 0xf0 | (((u32)msg->addr & 0x300) >> 7) | dir;
335 drv_data->addr2 = (u32)msg->addr & 0xff;
337 drv_data->addr1 = ((u32)msg->addr & 0x7f) << 1 | dir;
343 mv64xxx_i2c_wait_for_completion(struct mv64xxx_i2c_data *drv_data)
349 time_left = wait_event_interruptible_timeout(drv_data->waitq,
350 !drv_data->block, msecs_to_jiffies(drv_data->adapter.timeout));
352 spin_lock_irqsave(&drv_data->lock, flags);
353 if (!time_left) { /* Timed out */
354 drv_data->rc = -ETIMEDOUT;
356 } else if (time_left < 0) { /* Interrupted/Error */
357 drv_data->rc = time_left; /* errno value */
361 if (abort && drv_data->block) {
362 drv_data->state = MV64XXX_I2C_STATE_ABORTING;
363 spin_unlock_irqrestore(&drv_data->lock, flags);
365 time_left = wait_event_timeout(drv_data->waitq,
367 msecs_to_jiffies(drv_data->adapter.timeout));
369 if (time_left <= 0) {
370 drv_data->state = MV64XXX_I2C_STATE_IDLE;
371 dev_err(&drv_data->adapter.dev,
372 "mv64xxx: I2C bus locked\n");
375 spin_unlock_irqrestore(&drv_data->lock, flags);
379 mv64xxx_i2c_execute_msg(struct mv64xxx_i2c_data *drv_data, struct i2c_msg *msg)
383 spin_lock_irqsave(&drv_data->lock, flags);
384 mv64xxx_i2c_prepare_for_io(drv_data, msg);
386 if (unlikely(msg->flags & I2C_M_NOSTART)) { /* Skip start/addr phases */
387 if (drv_data->msg->flags & I2C_M_RD) {
388 /* No action to do, wait for slave to send a byte */
389 drv_data->action = MV64XXX_I2C_ACTION_CONTINUE;
391 MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_DATA;
393 drv_data->action = MV64XXX_I2C_ACTION_SEND_DATA;
395 MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_ACK;
396 drv_data->bytes_left--;
399 drv_data->action = MV64XXX_I2C_ACTION_SEND_START;
400 drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_START_COND;
404 mv64xxx_i2c_do_action(drv_data);
405 spin_unlock_irqrestore(&drv_data->lock, flags);
407 mv64xxx_i2c_wait_for_completion(drv_data);
412 *****************************************************************************
414 * I2C Core Support Routines (Interface to higher level I2C code)
416 *****************************************************************************
419 mv64xxx_i2c_functionality(struct i2c_adapter *adap)
421 return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SMBUS_EMUL;
425 mv64xxx_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
427 struct mv64xxx_i2c_data *drv_data = i2c_get_adapdata(adap);
430 for (i=0; i<num; i++)
431 if ((rc = mv64xxx_i2c_execute_msg(drv_data, &msgs[i])) < 0)
437 static struct i2c_algorithm mv64xxx_i2c_algo = {
438 .master_xfer = mv64xxx_i2c_xfer,
439 .functionality = mv64xxx_i2c_functionality,
443 *****************************************************************************
445 * Driver Interface & Early Init Routines
447 *****************************************************************************
449 static void __devinit
450 mv64xxx_i2c_hw_init(struct mv64xxx_i2c_data *drv_data)
452 writel(0, drv_data->reg_base + MV64XXX_I2C_REG_SOFT_RESET);
453 writel((((drv_data->freq_m & 0xf) << 3) | (drv_data->freq_n & 0x7)),
454 drv_data->reg_base + MV64XXX_I2C_REG_BAUD);
455 writel(0, drv_data->reg_base + MV64XXX_I2C_REG_SLAVE_ADDR);
456 writel(0, drv_data->reg_base + MV64XXX_I2C_REG_EXT_SLAVE_ADDR);
457 writel(MV64XXX_I2C_REG_CONTROL_TWSIEN | MV64XXX_I2C_REG_CONTROL_STOP,
458 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
459 drv_data->state = MV64XXX_I2C_STATE_IDLE;
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 device *dev)
497 struct platform_device *pd = to_platform_device(dev);
498 struct mv64xxx_i2c_data *drv_data;
499 struct mv64xxx_i2c_pdata *pdata = dev->platform_data;
502 if ((pd->id != 0) || !pdata)
505 drv_data = kzalloc(sizeof(struct mv64xxx_i2c_data), GFP_KERNEL);
509 if (mv64xxx_i2c_map_regs(pd, drv_data)) {
514 strncpy(drv_data->adapter.name, MV64XXX_I2C_CTLR_NAME " adapter",
517 init_waitqueue_head(&drv_data->waitq);
518 spin_lock_init(&drv_data->lock);
520 drv_data->freq_m = pdata->freq_m;
521 drv_data->freq_n = pdata->freq_n;
522 drv_data->irq = platform_get_irq(pd, 0);
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 dev_set_drvdata(dev, 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)) {
535 dev_err(dev, "mv64xxx: Can't register intr handler "
536 "irq: %d\n", drv_data->irq);
538 goto exit_unmap_regs;
539 } else if ((rc = i2c_add_adapter(&drv_data->adapter)) != 0) {
540 dev_err(dev, "mv64xxx: Can't add i2c adapter, rc: %d\n", -rc);
544 mv64xxx_i2c_hw_init(drv_data);
549 free_irq(drv_data->irq, drv_data);
551 mv64xxx_i2c_unmap_regs(drv_data);
558 mv64xxx_i2c_remove(struct device *dev)
560 struct mv64xxx_i2c_data *drv_data = dev_get_drvdata(dev);
563 rc = i2c_del_adapter(&drv_data->adapter);
564 free_irq(drv_data->irq, drv_data);
565 mv64xxx_i2c_unmap_regs(drv_data);
571 static struct device_driver mv64xxx_i2c_driver = {
572 .owner = THIS_MODULE,
573 .name = MV64XXX_I2C_CTLR_NAME,
574 .bus = &platform_bus_type,
575 .probe = mv64xxx_i2c_probe,
576 .remove = mv64xxx_i2c_remove,
580 mv64xxx_i2c_init(void)
582 return driver_register(&mv64xxx_i2c_driver);
586 mv64xxx_i2c_exit(void)
588 driver_unregister(&mv64xxx_i2c_driver);
591 module_init(mv64xxx_i2c_init);
592 module_exit(mv64xxx_i2c_exit);
594 MODULE_AUTHOR("Mark A. Greer <mgreer@mvista.com>");
595 MODULE_DESCRIPTION("Marvell mv64xxx host bridge i2c ctlr driver");
596 MODULE_LICENSE("GPL");