xref: /openbmc/linux/drivers/staging/nvec/nvec.c (revision 198dd267)
1 /*
2  * NVEC: NVIDIA compliant embedded controller interface
3  *
4  * Copyright (C) 2011 The AC100 Kernel Team <ac100@lists.lauchpad.net>
5  *
6  * Authors:  Pierre-Hugues Husson <phhusson@free.fr>
7  *           Ilya Petrov <ilya.muromec@gmail.com>
8  *           Marc Dietrich <marvin24@gmx.de>
9  *           Julian Andres Klode <jak@jak-linux.org>
10  *
11  * This file is subject to the terms and conditions of the GNU General Public
12  * License.  See the file "COPYING" in the main directory of this archive
13  * for more details.
14  *
15  */
16 
17 /* #define DEBUG */
18 
19 #include <asm/irq.h>
20 
21 #include <linux/atomic.h>
22 #include <linux/completion.h>
23 #include <linux/interrupt.h>
24 #include <linux/io.h>
25 #include <linux/irq.h>
26 #include <linux/slab.h>
27 #include <linux/gpio.h>
28 #include <linux/serio.h>
29 #include <linux/delay.h>
30 #include <linux/input.h>
31 #include <linux/workqueue.h>
32 #include <linux/clk.h>
33 
34 #include <linux/semaphore.h>
35 #include <linux/list.h>
36 #include <linux/notifier.h>
37 #include <linux/platform_device.h>
38 #include <linux/mfd/core.h>
39 
40 #include <mach/iomap.h>
41 #include <mach/clk.h>
42 
43 #include "nvec.h"
44 
45 #define I2C_CNFG			0x00
46 #define I2C_CNFG_PACKET_MODE_EN		(1<<10)
47 #define I2C_CNFG_NEW_MASTER_SFM		(1<<11)
48 #define I2C_CNFG_DEBOUNCE_CNT_SHIFT	12
49 
50 #define I2C_SL_CNFG		0x20
51 #define I2C_SL_NEWL		(1<<2)
52 #define I2C_SL_NACK		(1<<1)
53 #define I2C_SL_RESP		(1<<0)
54 #define I2C_SL_IRQ		(1<<3)
55 #define END_TRANS		(1<<4)
56 #define RCVD			(1<<2)
57 #define RNW			(1<<1)
58 
59 #define I2C_SL_RCVD		0x24
60 #define I2C_SL_STATUS		0x28
61 #define I2C_SL_ADDR1		0x2c
62 #define I2C_SL_ADDR2		0x30
63 #define I2C_SL_DELAY_COUNT	0x3c
64 
65 static const unsigned char EC_DISABLE_EVENT_REPORTING[3] = "\x04\x00\x00";
66 static const unsigned char EC_ENABLE_EVENT_REPORTING[3]  = "\x04\x00\x01";
67 static const unsigned char EC_GET_FIRMWARE_VERSION[2]    = "\x07\x15";
68 
69 static struct nvec_chip *nvec_power_handle;
70 
71 static struct mfd_cell nvec_devices[] = {
72 	{
73 		.name = "nvec-kbd",
74 		.id = 1,
75 	},
76 	{
77 		.name = "nvec-mouse",
78 		.id = 1,
79 	},
80 	{
81 		.name = "nvec-power",
82 		.id = 1,
83 	},
84 	{
85 		.name = "nvec-power",
86 		.id = 2,
87 	},
88 	{
89 		.name = "nvec-leds",
90 		.id = 1,
91 	},
92 };
93 
94 /**
95  * nvec_register_notifier - Register a notifier with nvec
96  * @nvec: A &struct nvec_chip
97  * @nb: The notifier block to register
98  *
99  * Registers a notifier with @nvec. The notifier will be added to an atomic
100  * notifier chain that is called for all received messages except those that
101  * correspond to a request initiated by nvec_write_sync().
102  */
103 int nvec_register_notifier(struct nvec_chip *nvec, struct notifier_block *nb,
104 			   unsigned int events)
105 {
106 	return atomic_notifier_chain_register(&nvec->notifier_list, nb);
107 }
108 EXPORT_SYMBOL_GPL(nvec_register_notifier);
109 
110 /**
111  * nvec_status_notifier - The final notifier
112  *
113  * Prints a message about control events not handled in the notifier
114  * chain.
115  */
116 static int nvec_status_notifier(struct notifier_block *nb,
117 				unsigned long event_type, void *data)
118 {
119 	unsigned char *msg = (unsigned char *)data;
120 
121 	if (event_type != NVEC_CNTL)
122 		return NOTIFY_DONE;
123 
124 	printk(KERN_WARNING "unhandled msg type %ld\n", event_type);
125 	print_hex_dump(KERN_WARNING, "payload: ", DUMP_PREFIX_NONE, 16, 1,
126 		msg, msg[1] + 2, true);
127 
128 	return NOTIFY_OK;
129 }
130 
131 /**
132  * nvec_msg_alloc:
133  * @nvec: A &struct nvec_chip
134  *
135  * Allocate a single &struct nvec_msg object from the message pool of
136  * @nvec. The result shall be passed to nvec_msg_free() if no longer
137  * used.
138  */
139 static struct nvec_msg *nvec_msg_alloc(struct nvec_chip *nvec)
140 {
141 	int i;
142 
143 	for (i = 0; i < NVEC_POOL_SIZE; i++) {
144 		if (atomic_xchg(&nvec->msg_pool[i].used, 1) == 0) {
145 			dev_vdbg(nvec->dev, "INFO: Allocate %i\n", i);
146 			return &nvec->msg_pool[i];
147 		}
148 	}
149 
150 	dev_err(nvec->dev, "could not allocate buffer\n");
151 
152 	return NULL;
153 }
154 
155 /**
156  * nvec_msg_free:
157  * @nvec: A &struct nvec_chip
158  * @msg:  A message (must be allocated by nvec_msg_alloc() and belong to @nvec)
159  *
160  * Free the given message
161  */
162 inline void nvec_msg_free(struct nvec_chip *nvec, struct nvec_msg *msg)
163 {
164 	if (msg != &nvec->tx_scratch)
165 		dev_vdbg(nvec->dev, "INFO: Free %ti\n", msg - nvec->msg_pool);
166 	atomic_set(&msg->used, 0);
167 }
168 EXPORT_SYMBOL_GPL(nvec_msg_free);
169 
170 /**
171  * nvec_msg_is_event - Return %true if @msg is an event
172  * @msg: A message
173  */
174 static bool nvec_msg_is_event(struct nvec_msg *msg)
175 {
176 	return msg->data[0] >> 7;
177 }
178 
179 /**
180  * nvec_msg_size - Get the size of a message
181  * @msg: The message to get the size for
182  *
183  * This only works for received messages, not for outgoing messages.
184  */
185 static size_t nvec_msg_size(struct nvec_msg *msg)
186 {
187 	bool is_event = nvec_msg_is_event(msg);
188 	int event_length = (msg->data[0] & 0x60) >> 5;
189 
190 	/* for variable size, payload size in byte 1 + count (1) + cmd (1) */
191 	if (!is_event || event_length == NVEC_VAR_SIZE)
192 		return (msg->pos || msg->size) ? (msg->data[1] + 2) : 0;
193 	else if (event_length == NVEC_2BYTES)
194 		return 2;
195 	else if (event_length == NVEC_3BYTES)
196 		return 3;
197 	else
198 		return 0;
199 }
200 
201 /**
202  * nvec_gpio_set_value - Set the GPIO value
203  * @nvec: A &struct nvec_chip
204  * @value: The value to write (0 or 1)
205  *
206  * Like gpio_set_value(), but generating debugging information
207  */
208 static void nvec_gpio_set_value(struct nvec_chip *nvec, int value)
209 {
210 	dev_dbg(nvec->dev, "GPIO changed from %u to %u\n",
211 		gpio_get_value(nvec->gpio), value);
212 	gpio_set_value(nvec->gpio, value);
213 }
214 
215 /**
216  * nvec_write_async - Asynchronously write a message to NVEC
217  * @nvec: An nvec_chip instance
218  * @data: The message data, starting with the request type
219  * @size: The size of @data
220  *
221  * Queue a single message to be transferred to the embedded controller
222  * and return immediately.
223  *
224  * Returns: 0 on success, a negative error code on failure. If a failure
225  * occured, the nvec driver may print an error.
226  */
227 int nvec_write_async(struct nvec_chip *nvec, const unsigned char *data,
228 			short size)
229 {
230 	struct nvec_msg *msg;
231 	unsigned long flags;
232 
233 	msg = nvec_msg_alloc(nvec);
234 	if (msg == NULL)
235 		return -ENOMEM;
236 
237 	msg->data[0] = size;
238 	memcpy(msg->data + 1, data, size);
239 	msg->size = size + 1;
240 
241 	spin_lock_irqsave(&nvec->tx_lock, flags);
242 	list_add_tail(&msg->node, &nvec->tx_data);
243 	spin_unlock_irqrestore(&nvec->tx_lock, flags);
244 
245 	queue_work(nvec->wq, &nvec->tx_work);
246 
247 	return 0;
248 }
249 EXPORT_SYMBOL(nvec_write_async);
250 
251 /**
252  * nvec_write_sync - Write a message to nvec and read the response
253  * @nvec: An &struct nvec_chip
254  * @data: The data to write
255  * @size: The size of @data
256  *
257  * This is similar to nvec_write_async(), but waits for the
258  * request to be answered before returning. This function
259  * uses a mutex and can thus not be called from e.g.
260  * interrupt handlers.
261  *
262  * Returns: A pointer to the response message on success,
263  * %NULL on failure. Free with nvec_msg_free() once no longer
264  * used.
265  */
266 struct nvec_msg *nvec_write_sync(struct nvec_chip *nvec,
267 		const unsigned char *data, short size)
268 {
269 	struct nvec_msg *msg;
270 
271 	mutex_lock(&nvec->sync_write_mutex);
272 
273 	nvec->sync_write_pending = (data[1] << 8) + data[0];
274 
275 	if (nvec_write_async(nvec, data, size) < 0)
276 		return NULL;
277 
278 	dev_dbg(nvec->dev, "nvec_sync_write: 0x%04x\n",
279 					nvec->sync_write_pending);
280 	if (!(wait_for_completion_timeout(&nvec->sync_write,
281 				msecs_to_jiffies(2000)))) {
282 		dev_warn(nvec->dev, "timeout waiting for sync write to complete\n");
283 		mutex_unlock(&nvec->sync_write_mutex);
284 		return NULL;
285 	}
286 
287 	dev_dbg(nvec->dev, "nvec_sync_write: pong!\n");
288 
289 	msg = nvec->last_sync_msg;
290 
291 	mutex_unlock(&nvec->sync_write_mutex);
292 
293 	return msg;
294 }
295 EXPORT_SYMBOL(nvec_write_sync);
296 
297 /**
298  * nvec_request_master - Process outgoing messages
299  * @work: A &struct work_struct (the tx_worker member of &struct nvec_chip)
300  *
301  * Processes all outgoing requests by sending the request and awaiting the
302  * response, then continuing with the next request. Once a request has a
303  * matching response, it will be freed and removed from the list.
304  */
305 static void nvec_request_master(struct work_struct *work)
306 {
307 	struct nvec_chip *nvec = container_of(work, struct nvec_chip, tx_work);
308 	unsigned long flags;
309 	long err;
310 	struct nvec_msg *msg;
311 
312 	spin_lock_irqsave(&nvec->tx_lock, flags);
313 	while (!list_empty(&nvec->tx_data)) {
314 		msg = list_first_entry(&nvec->tx_data, struct nvec_msg, node);
315 		spin_unlock_irqrestore(&nvec->tx_lock, flags);
316 		nvec_gpio_set_value(nvec, 0);
317 		err = wait_for_completion_interruptible_timeout(
318 				&nvec->ec_transfer, msecs_to_jiffies(5000));
319 
320 		if (err == 0) {
321 			dev_warn(nvec->dev, "timeout waiting for ec transfer\n");
322 			nvec_gpio_set_value(nvec, 1);
323 			msg->pos = 0;
324 		}
325 
326 		spin_lock_irqsave(&nvec->tx_lock, flags);
327 
328 		if (err > 0) {
329 			list_del_init(&msg->node);
330 			nvec_msg_free(nvec, msg);
331 		}
332 	}
333 	spin_unlock_irqrestore(&nvec->tx_lock, flags);
334 }
335 
336 /**
337  * parse_msg - Print some information and call the notifiers on an RX message
338  * @nvec: A &struct nvec_chip
339  * @msg: A message received by @nvec
340  *
341  * Paarse some pieces of the message and then call the chain of notifiers
342  * registered via nvec_register_notifier.
343  */
344 static int parse_msg(struct nvec_chip *nvec, struct nvec_msg *msg)
345 {
346 	if ((msg->data[0] & 1 << 7) == 0 && msg->data[3]) {
347 		dev_err(nvec->dev, "ec responded %02x %02x %02x %02x\n",
348 			msg->data[0], msg->data[1], msg->data[2], msg->data[3]);
349 		return -EINVAL;
350 	}
351 
352 	if ((msg->data[0] >> 7) == 1 && (msg->data[0] & 0x0f) == 5)
353 		print_hex_dump(KERN_WARNING, "ec system event ",
354 				DUMP_PREFIX_NONE, 16, 1, msg->data,
355 				msg->data[1] + 2, true);
356 
357 	atomic_notifier_call_chain(&nvec->notifier_list, msg->data[0] & 0x8f,
358 				   msg->data);
359 
360 	return 0;
361 }
362 
363 /**
364  * nvec_dispatch - Process messages received from the EC
365  * @work: A &struct work_struct (the tx_worker member of &struct nvec_chip)
366  *
367  * Process messages previously received from the EC and put into the RX
368  * queue of the &struct nvec_chip instance associated with @work.
369  */
370 static void nvec_dispatch(struct work_struct *work)
371 {
372 	struct nvec_chip *nvec = container_of(work, struct nvec_chip, rx_work);
373 	unsigned long flags;
374 	struct nvec_msg *msg;
375 
376 	spin_lock_irqsave(&nvec->rx_lock, flags);
377 	while (!list_empty(&nvec->rx_data)) {
378 		msg = list_first_entry(&nvec->rx_data, struct nvec_msg, node);
379 		list_del_init(&msg->node);
380 		spin_unlock_irqrestore(&nvec->rx_lock, flags);
381 
382 		if (nvec->sync_write_pending ==
383 		      (msg->data[2] << 8) + msg->data[0]) {
384 			dev_dbg(nvec->dev, "sync write completed!\n");
385 			nvec->sync_write_pending = 0;
386 			nvec->last_sync_msg = msg;
387 			complete(&nvec->sync_write);
388 		} else {
389 			parse_msg(nvec, msg);
390 			nvec_msg_free(nvec, msg);
391 		}
392 		spin_lock_irqsave(&nvec->rx_lock, flags);
393 	}
394 	spin_unlock_irqrestore(&nvec->rx_lock, flags);
395 }
396 
397 /**
398  * nvec_tx_completed - Complete the current transfer
399  * @nvec: A &struct nvec_chip
400  *
401  * This is called when we have received an END_TRANS on a TX transfer.
402  */
403 static void nvec_tx_completed(struct nvec_chip *nvec)
404 {
405 	/* We got an END_TRANS, let's skip this, maybe there's an event */
406 	if (nvec->tx->pos != nvec->tx->size) {
407 		dev_err(nvec->dev, "premature END_TRANS, resending\n");
408 		nvec->tx->pos = 0;
409 		nvec_gpio_set_value(nvec, 0);
410 	} else {
411 		nvec->state = 0;
412 	}
413 }
414 
415 /**
416  * nvec_rx_completed - Complete the current transfer
417  * @nvec: A &struct nvec_chip
418  *
419  * This is called when we have received an END_TRANS on a RX transfer.
420  */
421 static void nvec_rx_completed(struct nvec_chip *nvec)
422 {
423 	if (nvec->rx->pos != nvec_msg_size(nvec->rx))
424 		dev_err(nvec->dev, "RX incomplete: Expected %u bytes, got %u\n",
425 			   (uint) nvec_msg_size(nvec->rx),
426 			   (uint) nvec->rx->pos);
427 
428 	spin_lock(&nvec->rx_lock);
429 
430 	/* add the received data to the work list
431 	   and move the ring buffer pointer to the next entry */
432 	list_add_tail(&nvec->rx->node, &nvec->rx_data);
433 
434 	spin_unlock(&nvec->rx_lock);
435 
436 	nvec->state = 0;
437 
438 	if (!nvec_msg_is_event(nvec->rx))
439 		complete(&nvec->ec_transfer);
440 
441 	queue_work(nvec->wq, &nvec->rx_work);
442 }
443 
444 /**
445  * nvec_invalid_flags - Send an error message about invalid flags and jump
446  * @nvec: The nvec device
447  * @status: The status flags
448  * @reset: Whether we shall jump to state 0.
449  */
450 static void nvec_invalid_flags(struct nvec_chip *nvec, unsigned int status,
451 			       bool reset)
452 {
453 	dev_err(nvec->dev, "unexpected status flags 0x%02x during state %i\n",
454 		status, nvec->state);
455 	if (reset)
456 		nvec->state = 0;
457 }
458 
459 /**
460  * nvec_tx_set - Set the message to transfer (nvec->tx)
461  * @nvec: A &struct nvec_chip
462  *
463  * Gets the first entry from the tx_data list of @nvec and sets the
464  * tx member to it. If the tx_data list is empty, this uses the
465  * tx_scratch message to send a no operation message.
466  */
467 static void nvec_tx_set(struct nvec_chip *nvec)
468 {
469 	spin_lock(&nvec->tx_lock);
470 	if (list_empty(&nvec->tx_data)) {
471 		dev_err(nvec->dev, "empty tx - sending no-op\n");
472 		memcpy(nvec->tx_scratch.data, "\x02\x07\x02", 3);
473 		nvec->tx_scratch.size = 3;
474 		nvec->tx_scratch.pos = 0;
475 		nvec->tx = &nvec->tx_scratch;
476 		list_add_tail(&nvec->tx->node, &nvec->tx_data);
477 	} else {
478 		nvec->tx = list_first_entry(&nvec->tx_data, struct nvec_msg,
479 					    node);
480 		nvec->tx->pos = 0;
481 	}
482 	spin_unlock(&nvec->tx_lock);
483 
484 	dev_dbg(nvec->dev, "Sending message of length %u, command 0x%x\n",
485 		(uint)nvec->tx->size, nvec->tx->data[1]);
486 }
487 
488 /**
489  * nvec_interrupt - Interrupt handler
490  * @irq: The IRQ
491  * @dev: The nvec device
492  *
493  * Interrupt handler that fills our RX buffers and empties our TX
494  * buffers. This uses a finite state machine with ridiculous amounts
495  * of error checking, in order to be fairly reliable.
496  */
497 static irqreturn_t nvec_interrupt(int irq, void *dev)
498 {
499 	unsigned long status;
500 	unsigned int received = 0;
501 	unsigned char to_send = 0xff;
502 	const unsigned long irq_mask = I2C_SL_IRQ | END_TRANS | RCVD | RNW;
503 	struct nvec_chip *nvec = dev;
504 	unsigned int state = nvec->state;
505 
506 	status = readl(nvec->base + I2C_SL_STATUS);
507 
508 	/* Filter out some errors */
509 	if ((status & irq_mask) == 0 && (status & ~irq_mask) != 0) {
510 		dev_err(nvec->dev, "unexpected irq mask %lx\n", status);
511 		return IRQ_HANDLED;
512 	}
513 	if ((status & I2C_SL_IRQ) == 0) {
514 		dev_err(nvec->dev, "Spurious IRQ\n");
515 		return IRQ_HANDLED;
516 	}
517 
518 	/* The EC did not request a read, so it send us something, read it */
519 	if ((status & RNW) == 0) {
520 		received = readl(nvec->base + I2C_SL_RCVD);
521 		if (status & RCVD)
522 			writel(0, nvec->base + I2C_SL_RCVD);
523 	}
524 
525 	if (status == (I2C_SL_IRQ | RCVD))
526 		nvec->state = 0;
527 
528 	switch (nvec->state) {
529 	case 0:		/* Verify that its a transfer start, the rest later */
530 		if (status != (I2C_SL_IRQ | RCVD))
531 			nvec_invalid_flags(nvec, status, false);
532 		break;
533 	case 1:		/* command byte */
534 		if (status != I2C_SL_IRQ) {
535 			nvec_invalid_flags(nvec, status, true);
536 		} else {
537 			nvec->rx = nvec_msg_alloc(nvec);
538 			nvec->rx->data[0] = received;
539 			nvec->rx->pos = 1;
540 			nvec->state = 2;
541 		}
542 		break;
543 	case 2:		/* first byte after command */
544 		if (status == (I2C_SL_IRQ | RNW | RCVD)) {
545 			udelay(33);
546 			if (nvec->rx->data[0] != 0x01) {
547 				dev_err(nvec->dev,
548 					"Read without prior read command\n");
549 				nvec->state = 0;
550 				break;
551 			}
552 			nvec_msg_free(nvec, nvec->rx);
553 			nvec->state = 3;
554 			nvec_tx_set(nvec);
555 			BUG_ON(nvec->tx->size < 1);
556 			to_send = nvec->tx->data[0];
557 			nvec->tx->pos = 1;
558 		} else if (status == (I2C_SL_IRQ)) {
559 			BUG_ON(nvec->rx == NULL);
560 			nvec->rx->data[1] = received;
561 			nvec->rx->pos = 2;
562 			nvec->state = 4;
563 		} else {
564 			nvec_invalid_flags(nvec, status, true);
565 		}
566 		break;
567 	case 3:		/* EC does a block read, we transmit data */
568 		if (status & END_TRANS) {
569 			nvec_tx_completed(nvec);
570 		} else if ((status & RNW) == 0 || (status & RCVD)) {
571 			nvec_invalid_flags(nvec, status, true);
572 		} else if (nvec->tx && nvec->tx->pos < nvec->tx->size) {
573 			to_send = nvec->tx->data[nvec->tx->pos++];
574 		} else {
575 			dev_err(nvec->dev, "tx buffer underflow on %p (%u > %u)\n",
576 				nvec->tx,
577 				(uint) (nvec->tx ? nvec->tx->pos : 0),
578 				(uint) (nvec->tx ? nvec->tx->size : 0));
579 			nvec->state = 0;
580 		}
581 		break;
582 	case 4:		/* EC does some write, we read the data */
583 		if ((status & (END_TRANS | RNW)) == END_TRANS)
584 			nvec_rx_completed(nvec);
585 		else if (status & (RNW | RCVD))
586 			nvec_invalid_flags(nvec, status, true);
587 		else if (nvec->rx && nvec->rx->pos < NVEC_MSG_SIZE)
588 			nvec->rx->data[nvec->rx->pos++] = received;
589 		else
590 			dev_err(nvec->dev,
591 				"RX buffer overflow on %p: "
592 				"Trying to write byte %u of %u\n",
593 				nvec->rx, nvec->rx->pos, NVEC_MSG_SIZE);
594 		break;
595 	default:
596 		nvec->state = 0;
597 	}
598 
599 	/* If we are told that a new transfer starts, verify it */
600 	if ((status & (RCVD | RNW)) == RCVD) {
601 		if (received != nvec->i2c_addr)
602 			dev_err(nvec->dev,
603 			"received address 0x%02x, expected 0x%02x\n",
604 			received, nvec->i2c_addr);
605 		nvec->state = 1;
606 	}
607 
608 	/* Send data if requested, but not on end of transmission */
609 	if ((status & (RNW | END_TRANS)) == RNW)
610 		writel(to_send, nvec->base + I2C_SL_RCVD);
611 
612 	/* If we have send the first byte */
613 	if (status == (I2C_SL_IRQ | RNW | RCVD))
614 		nvec_gpio_set_value(nvec, 1);
615 
616 	dev_dbg(nvec->dev,
617 		"Handled: %s 0x%02x, %s 0x%02x in state %u [%s%s%s]\n",
618 		(status & RNW) == 0 ? "received" : "R=",
619 		received,
620 		(status & (RNW | END_TRANS)) ? "sent" : "S=",
621 		to_send,
622 		state,
623 		status & END_TRANS ? " END_TRANS" : "",
624 		status & RCVD ? " RCVD" : "",
625 		status & RNW ? " RNW" : "");
626 
627 	return IRQ_HANDLED;
628 }
629 
630 static void tegra_init_i2c_slave(struct nvec_chip *nvec)
631 {
632 	u32 val;
633 
634 	clk_enable(nvec->i2c_clk);
635 
636 	tegra_periph_reset_assert(nvec->i2c_clk);
637 	udelay(2);
638 	tegra_periph_reset_deassert(nvec->i2c_clk);
639 
640 	val = I2C_CNFG_NEW_MASTER_SFM | I2C_CNFG_PACKET_MODE_EN |
641 	    (0x2 << I2C_CNFG_DEBOUNCE_CNT_SHIFT);
642 	writel(val, nvec->base + I2C_CNFG);
643 
644 	clk_set_rate(nvec->i2c_clk, 8 * 80000);
645 
646 	writel(I2C_SL_NEWL, nvec->base + I2C_SL_CNFG);
647 	writel(0x1E, nvec->base + I2C_SL_DELAY_COUNT);
648 
649 	writel(nvec->i2c_addr>>1, nvec->base + I2C_SL_ADDR1);
650 	writel(0, nvec->base + I2C_SL_ADDR2);
651 
652 	enable_irq(nvec->irq);
653 
654 	clk_disable(nvec->i2c_clk);
655 }
656 
657 static void nvec_disable_i2c_slave(struct nvec_chip *nvec)
658 {
659 	disable_irq(nvec->irq);
660 	writel(I2C_SL_NEWL | I2C_SL_NACK, nvec->base + I2C_SL_CNFG);
661 	clk_disable(nvec->i2c_clk);
662 }
663 
664 static void nvec_power_off(void)
665 {
666 	nvec_write_async(nvec_power_handle, EC_DISABLE_EVENT_REPORTING, 3);
667 	nvec_write_async(nvec_power_handle, "\x04\x01", 2);
668 }
669 
670 static int __devinit tegra_nvec_probe(struct platform_device *pdev)
671 {
672 	int err, ret;
673 	struct clk *i2c_clk;
674 	struct nvec_platform_data *pdata = pdev->dev.platform_data;
675 	struct nvec_chip *nvec;
676 	struct nvec_msg *msg;
677 	struct resource *res;
678 	struct resource *iomem;
679 	void __iomem *base;
680 
681 	nvec = kzalloc(sizeof(struct nvec_chip), GFP_KERNEL);
682 	if (nvec == NULL) {
683 		dev_err(&pdev->dev, "failed to reserve memory\n");
684 		return -ENOMEM;
685 	}
686 	platform_set_drvdata(pdev, nvec);
687 	nvec->dev = &pdev->dev;
688 	nvec->gpio = pdata->gpio;
689 	nvec->i2c_addr = pdata->i2c_addr;
690 
691 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
692 	if (!res) {
693 		dev_err(&pdev->dev, "no mem resource?\n");
694 		return -ENODEV;
695 	}
696 
697 	iomem = request_mem_region(res->start, resource_size(res), pdev->name);
698 	if (!iomem) {
699 		dev_err(&pdev->dev, "I2C region already claimed\n");
700 		return -EBUSY;
701 	}
702 
703 	base = ioremap(iomem->start, resource_size(iomem));
704 	if (!base) {
705 		dev_err(&pdev->dev, "Can't ioremap I2C region\n");
706 		return -ENOMEM;
707 	}
708 
709 	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
710 	if (!res) {
711 		dev_err(&pdev->dev, "no irq resource?\n");
712 		ret = -ENODEV;
713 		goto err_iounmap;
714 	}
715 
716 	i2c_clk = clk_get_sys("tegra-i2c.2", NULL);
717 	if (IS_ERR(i2c_clk)) {
718 		dev_err(nvec->dev, "failed to get controller clock\n");
719 		goto err_iounmap;
720 	}
721 
722 	nvec->base = base;
723 	nvec->irq = res->start;
724 	nvec->i2c_clk = i2c_clk;
725 	nvec->rx = &nvec->msg_pool[0];
726 
727 	/* Set the gpio to low when we've got something to say */
728 	err = gpio_request(nvec->gpio, "nvec gpio");
729 	if (err < 0)
730 		dev_err(nvec->dev, "couldn't request gpio\n");
731 
732 	ATOMIC_INIT_NOTIFIER_HEAD(&nvec->notifier_list);
733 
734 	init_completion(&nvec->sync_write);
735 	init_completion(&nvec->ec_transfer);
736 	mutex_init(&nvec->sync_write_mutex);
737 	spin_lock_init(&nvec->tx_lock);
738 	spin_lock_init(&nvec->rx_lock);
739 	INIT_LIST_HEAD(&nvec->rx_data);
740 	INIT_LIST_HEAD(&nvec->tx_data);
741 	INIT_WORK(&nvec->rx_work, nvec_dispatch);
742 	INIT_WORK(&nvec->tx_work, nvec_request_master);
743 	nvec->wq = alloc_workqueue("nvec", WQ_NON_REENTRANT, 2);
744 
745 	err = request_irq(nvec->irq, nvec_interrupt, 0, "nvec", nvec);
746 	if (err) {
747 		dev_err(nvec->dev, "couldn't request irq\n");
748 		goto failed;
749 	}
750 	disable_irq(nvec->irq);
751 
752 	tegra_init_i2c_slave(nvec);
753 
754 	clk_enable(i2c_clk);
755 
756 	gpio_direction_output(nvec->gpio, 1);
757 	gpio_set_value(nvec->gpio, 1);
758 
759 	/* enable event reporting */
760 	nvec_write_async(nvec, EC_ENABLE_EVENT_REPORTING,
761 			 sizeof(EC_ENABLE_EVENT_REPORTING));
762 
763 	nvec->nvec_status_notifier.notifier_call = nvec_status_notifier;
764 	nvec_register_notifier(nvec, &nvec->nvec_status_notifier, 0);
765 
766 	nvec_power_handle = nvec;
767 	pm_power_off = nvec_power_off;
768 
769 	/* Get Firmware Version */
770 	msg = nvec_write_sync(nvec, EC_GET_FIRMWARE_VERSION,
771 		sizeof(EC_GET_FIRMWARE_VERSION));
772 
773 	if (msg) {
774 		dev_warn(nvec->dev, "ec firmware version %02x.%02x.%02x / %02x\n",
775 			msg->data[4], msg->data[5], msg->data[6], msg->data[7]);
776 
777 		nvec_msg_free(nvec, msg);
778 	}
779 
780 	ret = mfd_add_devices(nvec->dev, -1, nvec_devices,
781 			      ARRAY_SIZE(nvec_devices), base, 0);
782 	if (ret)
783 		dev_err(nvec->dev, "error adding subdevices\n");
784 
785 	/* unmute speakers? */
786 	nvec_write_async(nvec, "\x0d\x10\x59\x95", 4);
787 
788 	/* enable lid switch event */
789 	nvec_write_async(nvec, "\x01\x01\x01\x00\x00\x02\x00", 7);
790 
791 	/* enable power button event */
792 	nvec_write_async(nvec, "\x01\x01\x01\x00\x00\x80\x00", 7);
793 
794 	return 0;
795 
796 err_iounmap:
797 	iounmap(base);
798 failed:
799 	kfree(nvec);
800 	return -ENOMEM;
801 }
802 
803 static int __devexit tegra_nvec_remove(struct platform_device *pdev)
804 {
805 	struct nvec_chip *nvec = platform_get_drvdata(pdev);
806 
807 	nvec_write_async(nvec, EC_DISABLE_EVENT_REPORTING, 3);
808 	mfd_remove_devices(nvec->dev);
809 	free_irq(nvec->irq, &nvec_interrupt);
810 	iounmap(nvec->base);
811 	gpio_free(nvec->gpio);
812 	destroy_workqueue(nvec->wq);
813 	kfree(nvec);
814 
815 	return 0;
816 }
817 
818 #ifdef CONFIG_PM
819 
820 static int tegra_nvec_suspend(struct platform_device *pdev, pm_message_t state)
821 {
822 	struct nvec_chip *nvec = platform_get_drvdata(pdev);
823 
824 	dev_dbg(nvec->dev, "suspending\n");
825 	nvec_write_async(nvec, EC_DISABLE_EVENT_REPORTING, 3);
826 	nvec_write_async(nvec, "\x04\x02", 2);
827 	nvec_disable_i2c_slave(nvec);
828 
829 	return 0;
830 }
831 
832 static int tegra_nvec_resume(struct platform_device *pdev)
833 {
834 	struct nvec_chip *nvec = platform_get_drvdata(pdev);
835 
836 	dev_dbg(nvec->dev, "resuming\n");
837 	tegra_init_i2c_slave(nvec);
838 	nvec_write_async(nvec, EC_ENABLE_EVENT_REPORTING, 3);
839 
840 	return 0;
841 }
842 
843 #else
844 #define tegra_nvec_suspend NULL
845 #define tegra_nvec_resume NULL
846 #endif
847 
848 static struct platform_driver nvec_device_driver = {
849 	.probe   = tegra_nvec_probe,
850 	.remove  = __devexit_p(tegra_nvec_remove),
851 	.suspend = tegra_nvec_suspend,
852 	.resume  = tegra_nvec_resume,
853 	.driver  = {
854 		.name = "nvec",
855 		.owner = THIS_MODULE,
856 	}
857 };
858 
859 static int __init tegra_nvec_init(void)
860 {
861 	return platform_driver_register(&nvec_device_driver);
862 }
863 
864 module_init(tegra_nvec_init);
865 
866 MODULE_ALIAS("platform:nvec");
867 MODULE_DESCRIPTION("NVIDIA compliant embedded controller interface");
868 MODULE_AUTHOR("Marc Dietrich <marvin24@gmx.de>");
869 MODULE_LICENSE("GPL");
870