2 * Provides I2C support for Philips PNX010x/PNX4008 boards.
4 * Authors: Dennis Kovalev <dkovalev@ru.mvista.com>
5 * Vitaly Wool <vwool@ru.mvista.com>
7 * 2004-2006 (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
13 #include <linux/module.h>
14 #include <linux/interrupt.h>
15 #include <linux/ioport.h>
16 #include <linux/delay.h>
17 #include <linux/i2c.h>
18 #include <linux/timer.h>
19 #include <linux/completion.h>
20 #include <linux/platform_device.h>
21 #include <linux/i2c-pnx.h>
22 #include <mach/hardware.h>
24 #include <asm/uaccess.h>
26 #define I2C_PNX_TIMEOUT 10 /* msec */
27 #define I2C_PNX_SPEED_KHZ 100
28 #define I2C_PNX_REGION_SIZE 0x100
29 #define PNX_DEFAULT_FREQ 13 /* MHz */
31 static inline int wait_timeout(long timeout, struct i2c_pnx_algo_data *data)
34 (ioread32(I2C_REG_STS(data)) & mstatus_active)) {
38 return (timeout <= 0);
41 static inline int wait_reset(long timeout, struct i2c_pnx_algo_data *data)
44 (ioread32(I2C_REG_CTL(data)) & mcntrl_reset)) {
48 return (timeout <= 0);
51 static inline void i2c_pnx_arm_timer(struct i2c_adapter *adap)
53 struct i2c_pnx_algo_data *data = adap->algo_data;
54 struct timer_list *timer = &data->mif.timer;
55 int expires = I2C_PNX_TIMEOUT / (1000 / HZ);
57 del_timer_sync(timer);
59 dev_dbg(&adap->dev, "Timer armed at %lu plus %u jiffies.\n",
62 timer->expires = jiffies + expires;
63 timer->data = (unsigned long)adap;
69 * i2c_pnx_start - start a device
70 * @slave_addr: slave address
71 * @adap: pointer to adapter structure
73 * Generate a START signal in the desired mode.
75 static int i2c_pnx_start(unsigned char slave_addr, struct i2c_adapter *adap)
77 struct i2c_pnx_algo_data *alg_data = adap->algo_data;
79 dev_dbg(&adap->dev, "%s(): addr 0x%x mode %d\n", __func__,
80 slave_addr, alg_data->mif.mode);
82 /* Check for 7 bit slave addresses only */
83 if (slave_addr & ~0x7f) {
84 dev_err(&adap->dev, "%s: Invalid slave address %x. "
85 "Only 7-bit addresses are supported\n",
86 adap->name, slave_addr);
90 /* First, make sure bus is idle */
91 if (wait_timeout(I2C_PNX_TIMEOUT, alg_data)) {
92 /* Somebody else is monopolizing the bus */
93 dev_err(&adap->dev, "%s: Bus busy. Slave addr = %02x, "
94 "cntrl = %x, stat = %x\n",
95 adap->name, slave_addr,
96 ioread32(I2C_REG_CTL(alg_data)),
97 ioread32(I2C_REG_STS(alg_data)));
99 } else if (ioread32(I2C_REG_STS(alg_data)) & mstatus_afi) {
100 /* Sorry, we lost the bus */
101 dev_err(&adap->dev, "%s: Arbitration failure. "
102 "Slave addr = %02x\n", adap->name, slave_addr);
107 * OK, I2C is enabled and we have the bus.
108 * Clear the current TDI and AFI status flags.
110 iowrite32(ioread32(I2C_REG_STS(alg_data)) | mstatus_tdi | mstatus_afi,
111 I2C_REG_STS(alg_data));
113 dev_dbg(&adap->dev, "%s(): sending %#x\n", __func__,
114 (slave_addr << 1) | start_bit | alg_data->mif.mode);
116 /* Write the slave address, START bit and R/W bit */
117 iowrite32((slave_addr << 1) | start_bit | alg_data->mif.mode,
118 I2C_REG_TX(alg_data));
120 dev_dbg(&adap->dev, "%s(): exit\n", __func__);
126 * i2c_pnx_stop - stop a device
127 * @adap: pointer to I2C adapter structure
129 * Generate a STOP signal to terminate the master transaction.
131 static void i2c_pnx_stop(struct i2c_adapter *adap)
133 struct i2c_pnx_algo_data *alg_data = adap->algo_data;
134 /* Only 1 msec max timeout due to interrupt context */
137 dev_dbg(&adap->dev, "%s(): entering: stat = %04x.\n",
138 __func__, ioread32(I2C_REG_STS(alg_data)));
140 /* Write a STOP bit to TX FIFO */
141 iowrite32(0xff | stop_bit, I2C_REG_TX(alg_data));
143 /* Wait until the STOP is seen. */
144 while (timeout > 0 &&
145 (ioread32(I2C_REG_STS(alg_data)) & mstatus_active)) {
146 /* may be called from interrupt context */
151 dev_dbg(&adap->dev, "%s(): exiting: stat = %04x.\n",
152 __func__, ioread32(I2C_REG_STS(alg_data)));
156 * i2c_pnx_master_xmit - transmit data to slave
157 * @adap: pointer to I2C adapter structure
159 * Sends one byte of data to the slave
161 static int i2c_pnx_master_xmit(struct i2c_adapter *adap)
163 struct i2c_pnx_algo_data *alg_data = adap->algo_data;
166 dev_dbg(&adap->dev, "%s(): entering: stat = %04x.\n",
167 __func__, ioread32(I2C_REG_STS(alg_data)));
169 if (alg_data->mif.len > 0) {
170 /* We still have something to talk about... */
171 val = *alg_data->mif.buf++;
173 if (alg_data->mif.len == 1) {
180 iowrite32(val, I2C_REG_TX(alg_data));
182 dev_dbg(&adap->dev, "%s(): xmit %#x [%d]\n", __func__,
183 val, alg_data->mif.len + 1);
185 if (alg_data->mif.len == 0) {
186 if (alg_data->last) {
187 /* Wait until the STOP is seen. */
188 if (wait_timeout(I2C_PNX_TIMEOUT, alg_data))
189 dev_err(&adap->dev, "The bus is still "
190 "active after timeout\n");
192 /* Disable master interrupts */
193 iowrite32(ioread32(I2C_REG_CTL(alg_data)) &
194 ~(mcntrl_afie | mcntrl_naie | mcntrl_drmie),
195 I2C_REG_CTL(alg_data));
197 del_timer_sync(&alg_data->mif.timer);
199 dev_dbg(&adap->dev, "%s(): Waking up xfer routine.\n",
202 complete(&alg_data->mif.complete);
204 } else if (alg_data->mif.len == 0) {
205 /* zero-sized transfer */
208 /* Disable master interrupts. */
209 iowrite32(ioread32(I2C_REG_CTL(alg_data)) &
210 ~(mcntrl_afie | mcntrl_naie | mcntrl_drmie),
211 I2C_REG_CTL(alg_data));
214 del_timer_sync(&alg_data->mif.timer);
215 dev_dbg(&adap->dev, "%s(): Waking up xfer routine after "
216 "zero-xfer.\n", __func__);
218 complete(&alg_data->mif.complete);
221 dev_dbg(&adap->dev, "%s(): exiting: stat = %04x.\n",
222 __func__, ioread32(I2C_REG_STS(alg_data)));
228 * i2c_pnx_master_rcv - receive data from slave
229 * @adap: pointer to I2C adapter structure
231 * Reads one byte data from the slave
233 static int i2c_pnx_master_rcv(struct i2c_adapter *adap)
235 struct i2c_pnx_algo_data *alg_data = adap->algo_data;
236 unsigned int val = 0;
239 dev_dbg(&adap->dev, "%s(): entering: stat = %04x.\n",
240 __func__, ioread32(I2C_REG_STS(alg_data)));
242 /* Check, whether there is already data,
243 * or we didn't 'ask' for it yet.
245 if (ioread32(I2C_REG_STS(alg_data)) & mstatus_rfe) {
246 dev_dbg(&adap->dev, "%s(): Write dummy data to fill "
247 "Rx-fifo...\n", __func__);
249 if (alg_data->mif.len == 1) {
250 /* Last byte, do not acknowledge next rcv. */
256 * Enable interrupt RFDAIE (data in Rx fifo),
257 * and disable DRMIE (need data for Tx)
259 ctl = ioread32(I2C_REG_CTL(alg_data));
260 ctl |= mcntrl_rffie | mcntrl_daie;
261 ctl &= ~mcntrl_drmie;
262 iowrite32(ctl, I2C_REG_CTL(alg_data));
266 * Now we'll 'ask' for data:
267 * For each byte we want to receive, we must
268 * write a (dummy) byte to the Tx-FIFO.
270 iowrite32(val, I2C_REG_TX(alg_data));
276 if (alg_data->mif.len > 0) {
277 val = ioread32(I2C_REG_RX(alg_data));
278 *alg_data->mif.buf++ = (u8) (val & 0xff);
279 dev_dbg(&adap->dev, "%s(): rcv 0x%x [%d]\n", __func__, val,
283 if (alg_data->mif.len == 0) {
285 /* Wait until the STOP is seen. */
286 if (wait_timeout(I2C_PNX_TIMEOUT, alg_data))
287 dev_err(&adap->dev, "The bus is still "
288 "active after timeout\n");
290 /* Disable master interrupts */
291 ctl = ioread32(I2C_REG_CTL(alg_data));
292 ctl &= ~(mcntrl_afie | mcntrl_naie | mcntrl_rffie |
293 mcntrl_drmie | mcntrl_daie);
294 iowrite32(ctl, I2C_REG_CTL(alg_data));
297 del_timer_sync(&alg_data->mif.timer);
298 complete(&alg_data->mif.complete);
302 dev_dbg(&adap->dev, "%s(): exiting: stat = %04x.\n",
303 __func__, ioread32(I2C_REG_STS(alg_data)));
308 static irqreturn_t i2c_pnx_interrupt(int irq, void *dev_id)
311 struct i2c_adapter *adap = dev_id;
312 struct i2c_pnx_algo_data *alg_data = adap->algo_data;
314 dev_dbg(&adap->dev, "%s(): mstat = %x mctrl = %x, mode = %d\n",
316 ioread32(I2C_REG_STS(alg_data)),
317 ioread32(I2C_REG_CTL(alg_data)),
319 stat = ioread32(I2C_REG_STS(alg_data));
321 /* let's see what kind of event this is */
322 if (stat & mstatus_afi) {
323 /* We lost arbitration in the midst of a transfer */
324 alg_data->mif.ret = -EIO;
326 /* Disable master interrupts. */
327 ctl = ioread32(I2C_REG_CTL(alg_data));
328 ctl &= ~(mcntrl_afie | mcntrl_naie | mcntrl_rffie |
330 iowrite32(ctl, I2C_REG_CTL(alg_data));
332 /* Stop timer, to prevent timeout. */
333 del_timer_sync(&alg_data->mif.timer);
334 complete(&alg_data->mif.complete);
335 } else if (stat & mstatus_nai) {
336 /* Slave did not acknowledge, generate a STOP */
337 dev_dbg(&adap->dev, "%s(): "
338 "Slave did not acknowledge, generating a STOP.\n",
342 /* Disable master interrupts. */
343 ctl = ioread32(I2C_REG_CTL(alg_data));
344 ctl &= ~(mcntrl_afie | mcntrl_naie | mcntrl_rffie |
346 iowrite32(ctl, I2C_REG_CTL(alg_data));
348 /* Our return value. */
349 alg_data->mif.ret = -EIO;
351 /* Stop timer, to prevent timeout. */
352 del_timer_sync(&alg_data->mif.timer);
353 complete(&alg_data->mif.complete);
357 * - Master Tx needs data.
358 * - There is data in the Rx-fifo
359 * The latter is only the case if we have requested for data,
360 * via a dummy write. (See 'i2c_pnx_master_rcv'.)
361 * We therefore check, as a sanity check, whether that interrupt
364 if ((stat & mstatus_drmi) || !(stat & mstatus_rfe)) {
365 if (alg_data->mif.mode == I2C_SMBUS_WRITE) {
366 i2c_pnx_master_xmit(adap);
367 } else if (alg_data->mif.mode == I2C_SMBUS_READ) {
368 i2c_pnx_master_rcv(adap);
373 /* Clear TDI and AFI bits */
374 stat = ioread32(I2C_REG_STS(alg_data));
375 iowrite32(stat | mstatus_tdi | mstatus_afi, I2C_REG_STS(alg_data));
377 dev_dbg(&adap->dev, "%s(): exiting, stat = %x ctrl = %x.\n",
378 __func__, ioread32(I2C_REG_STS(alg_data)),
379 ioread32(I2C_REG_CTL(alg_data)));
384 static void i2c_pnx_timeout(unsigned long data)
386 struct i2c_adapter *adap = (struct i2c_adapter *)data;
387 struct i2c_pnx_algo_data *alg_data = adap->algo_data;
390 dev_err(&adap->dev, "Master timed out. stat = %04x, cntrl = %04x. "
391 "Resetting master...\n",
392 ioread32(I2C_REG_STS(alg_data)),
393 ioread32(I2C_REG_CTL(alg_data)));
395 /* Reset master and disable interrupts */
396 ctl = ioread32(I2C_REG_CTL(alg_data));
397 ctl &= ~(mcntrl_afie | mcntrl_naie | mcntrl_rffie | mcntrl_drmie);
398 iowrite32(ctl, I2C_REG_CTL(alg_data));
401 iowrite32(ctl, I2C_REG_CTL(alg_data));
402 wait_reset(I2C_PNX_TIMEOUT, alg_data);
403 alg_data->mif.ret = -EIO;
404 complete(&alg_data->mif.complete);
407 static inline void bus_reset_if_active(struct i2c_adapter *adap)
409 struct i2c_pnx_algo_data *alg_data = adap->algo_data;
412 if ((stat = ioread32(I2C_REG_STS(alg_data))) & mstatus_active) {
414 "%s: Bus is still active after xfer. Reset it...\n",
416 iowrite32(ioread32(I2C_REG_CTL(alg_data)) | mcntrl_reset,
417 I2C_REG_CTL(alg_data));
418 wait_reset(I2C_PNX_TIMEOUT, alg_data);
419 } else if (!(stat & mstatus_rfe) || !(stat & mstatus_tfe)) {
420 /* If there is data in the fifo's after transfer,
421 * flush fifo's by reset.
423 iowrite32(ioread32(I2C_REG_CTL(alg_data)) | mcntrl_reset,
424 I2C_REG_CTL(alg_data));
425 wait_reset(I2C_PNX_TIMEOUT, alg_data);
426 } else if (stat & mstatus_nai) {
427 iowrite32(ioread32(I2C_REG_CTL(alg_data)) | mcntrl_reset,
428 I2C_REG_CTL(alg_data));
429 wait_reset(I2C_PNX_TIMEOUT, alg_data);
434 * i2c_pnx_xfer - generic transfer entry point
435 * @adap: pointer to I2C adapter structure
436 * @msgs: array of messages
437 * @num: number of messages
439 * Initiates the transfer
442 i2c_pnx_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
444 struct i2c_msg *pmsg;
445 int rc = 0, completed = 0, i;
446 struct i2c_pnx_algo_data *alg_data = adap->algo_data;
447 u32 stat = ioread32(I2C_REG_STS(alg_data));
449 dev_dbg(&adap->dev, "%s(): entering: %d messages, stat = %04x.\n",
450 __func__, num, ioread32(I2C_REG_STS(alg_data)));
452 bus_reset_if_active(adap);
454 /* Process transactions in a loop. */
455 for (i = 0; rc >= 0 && i < num; i++) {
461 if (pmsg->flags & I2C_M_TEN) {
463 "%s: 10 bits addr not supported!\n",
469 alg_data->mif.buf = pmsg->buf;
470 alg_data->mif.len = pmsg->len;
471 alg_data->mif.mode = (pmsg->flags & I2C_M_RD) ?
472 I2C_SMBUS_READ : I2C_SMBUS_WRITE;
473 alg_data->mif.ret = 0;
474 alg_data->last = (i == num - 1);
476 dev_dbg(&adap->dev, "%s(): mode %d, %d bytes\n", __func__,
480 i2c_pnx_arm_timer(adap);
482 /* initialize the completion var */
483 init_completion(&alg_data->mif.complete);
485 /* Enable master interrupt */
486 iowrite32(ioread32(I2C_REG_CTL(alg_data)) | mcntrl_afie |
487 mcntrl_naie | mcntrl_drmie,
488 I2C_REG_CTL(alg_data));
490 /* Put start-code and slave-address on the bus. */
491 rc = i2c_pnx_start(addr, adap);
495 /* Wait for completion */
496 wait_for_completion(&alg_data->mif.complete);
498 if (!(rc = alg_data->mif.ret))
500 dev_dbg(&adap->dev, "%s(): Complete, return code = %d.\n",
503 /* Clear TDI and AFI bits in case they are set. */
504 if ((stat = ioread32(I2C_REG_STS(alg_data))) & mstatus_tdi) {
506 "%s: TDI still set... clearing now.\n",
508 iowrite32(stat, I2C_REG_STS(alg_data));
510 if ((stat = ioread32(I2C_REG_STS(alg_data))) & mstatus_afi) {
512 "%s: AFI still set... clearing now.\n",
514 iowrite32(stat, I2C_REG_STS(alg_data));
518 bus_reset_if_active(adap);
520 /* Cleanup to be sure... */
521 alg_data->mif.buf = NULL;
522 alg_data->mif.len = 0;
524 dev_dbg(&adap->dev, "%s(): exiting, stat = %x\n",
525 __func__, ioread32(I2C_REG_STS(alg_data)));
527 if (completed != num)
528 return ((rc < 0) ? rc : -EREMOTEIO);
533 static u32 i2c_pnx_func(struct i2c_adapter *adapter)
535 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
538 static struct i2c_algorithm pnx_algorithm = {
539 .master_xfer = i2c_pnx_xfer,
540 .functionality = i2c_pnx_func,
543 static int i2c_pnx_controller_suspend(struct platform_device *pdev,
546 struct i2c_pnx_data *i2c_pnx = platform_get_drvdata(pdev);
547 return i2c_pnx->suspend(pdev, state);
550 static int i2c_pnx_controller_resume(struct platform_device *pdev)
552 struct i2c_pnx_data *i2c_pnx = platform_get_drvdata(pdev);
553 return i2c_pnx->resume(pdev);
556 static int __devinit i2c_pnx_probe(struct platform_device *pdev)
560 struct i2c_pnx_algo_data *alg_data;
562 struct i2c_pnx_data *i2c_pnx = pdev->dev.platform_data;
564 if (!i2c_pnx || !i2c_pnx->adapter) {
565 dev_err(&pdev->dev, "%s: no platform data supplied\n",
571 platform_set_drvdata(pdev, i2c_pnx);
573 if (i2c_pnx->calculate_input_freq)
574 freq_mhz = i2c_pnx->calculate_input_freq(pdev);
576 freq_mhz = PNX_DEFAULT_FREQ;
577 dev_info(&pdev->dev, "Setting bus frequency to default value: "
578 "%d MHz\n", freq_mhz);
581 i2c_pnx->adapter->algo = &pnx_algorithm;
583 alg_data = i2c_pnx->adapter->algo_data;
584 init_timer(&alg_data->mif.timer);
585 alg_data->mif.timer.function = i2c_pnx_timeout;
586 alg_data->mif.timer.data = (unsigned long)i2c_pnx->adapter;
588 /* Register I/O resource */
589 if (!request_region(alg_data->base, I2C_PNX_REGION_SIZE, pdev->name)) {
591 "I/O region 0x%08x for I2C already in use.\n",
597 if (!(alg_data->ioaddr =
598 (u32)ioremap(alg_data->base, I2C_PNX_REGION_SIZE))) {
599 dev_err(&pdev->dev, "Couldn't ioremap I2C I/O region\n");
604 i2c_pnx->set_clock_run(pdev);
607 * Clock Divisor High This value is the number of system clocks
608 * the serial clock (SCL) will be high.
609 * For example, if the system clock period is 50 ns and the maximum
610 * desired serial period is 10000 ns (100 kHz), then CLKHI would be
611 * set to 0.5*(f_sys/f_i2c)-2=0.5*(20e6/100e3)-2=98. The actual value
612 * programmed into CLKHI will vary from this slightly due to
613 * variations in the output pad's rise and fall times as well as
614 * the deglitching filter length.
617 tmp = ((freq_mhz * 1000) / I2C_PNX_SPEED_KHZ) / 2 - 2;
618 iowrite32(tmp, I2C_REG_CKH(alg_data));
619 iowrite32(tmp, I2C_REG_CKL(alg_data));
621 iowrite32(mcntrl_reset, I2C_REG_CTL(alg_data));
622 if (wait_reset(I2C_PNX_TIMEOUT, alg_data)) {
626 init_completion(&alg_data->mif.complete);
628 ret = request_irq(alg_data->irq, i2c_pnx_interrupt,
629 0, pdev->name, i2c_pnx->adapter);
633 /* Register this adapter with the I2C subsystem */
634 i2c_pnx->adapter->dev.parent = &pdev->dev;
635 ret = i2c_add_adapter(i2c_pnx->adapter);
637 dev_err(&pdev->dev, "I2C: Failed to add bus\n");
641 dev_dbg(&pdev->dev, "%s: Master at %#8x, irq %d.\n",
642 i2c_pnx->adapter->name, alg_data->base, alg_data->irq);
647 free_irq(alg_data->irq, alg_data);
649 i2c_pnx->set_clock_stop(pdev);
651 iounmap((void *)alg_data->ioaddr);
653 release_region(alg_data->base, I2C_PNX_REGION_SIZE);
655 platform_set_drvdata(pdev, NULL);
660 static int __devexit i2c_pnx_remove(struct platform_device *pdev)
662 struct i2c_pnx_data *i2c_pnx = platform_get_drvdata(pdev);
663 struct i2c_adapter *adap = i2c_pnx->adapter;
664 struct i2c_pnx_algo_data *alg_data = adap->algo_data;
666 free_irq(alg_data->irq, alg_data);
667 i2c_del_adapter(adap);
668 i2c_pnx->set_clock_stop(pdev);
669 iounmap((void *)alg_data->ioaddr);
670 release_region(alg_data->base, I2C_PNX_REGION_SIZE);
671 platform_set_drvdata(pdev, NULL);
676 static struct platform_driver i2c_pnx_driver = {
679 .owner = THIS_MODULE,
681 .probe = i2c_pnx_probe,
682 .remove = __devexit_p(i2c_pnx_remove),
683 .suspend = i2c_pnx_controller_suspend,
684 .resume = i2c_pnx_controller_resume,
687 static int __init i2c_adap_pnx_init(void)
689 return platform_driver_register(&i2c_pnx_driver);
692 static void __exit i2c_adap_pnx_exit(void)
694 platform_driver_unregister(&i2c_pnx_driver);
697 MODULE_AUTHOR("Vitaly Wool, Dennis Kovalev <source@mvista.com>");
698 MODULE_DESCRIPTION("I2C driver for Philips IP3204-based I2C busses");
699 MODULE_LICENSE("GPL");
700 MODULE_ALIAS("platform:pnx-i2c");
702 /* We need to make sure I2C is initialized before USB */
703 subsys_initcall(i2c_adap_pnx_init);
704 module_exit(i2c_adap_pnx_exit);