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1// SPDX-License-Identifier: GPL-2.02/*3 * NVEC: NVIDIA compliant embedded controller interface4 *5 * Copyright (C) 2011 The AC100 Kernel Team <ac100@lists.lauchpad.net>6 *7 * Authors:  Pierre-Hugues Husson <phhusson@free.fr>8 *           Ilya Petrov <ilya.muromec@gmail.com>9 *           Marc Dietrich <marvin24@gmx.de>10 *           Julian Andres Klode <jak@jak-linux.org>11 */12 13#include <linux/kernel.h>14#include <linux/module.h>15#include <linux/atomic.h>16#include <linux/clk.h>17#include <linux/completion.h>18#include <linux/delay.h>19#include <linux/err.h>20#include <linux/gpio/consumer.h>21#include <linux/interrupt.h>22#include <linux/io.h>23#include <linux/irq.h>24#include <linux/of.h>25#include <linux/list.h>26#include <linux/mfd/core.h>27#include <linux/mutex.h>28#include <linux/notifier.h>29#include <linux/slab.h>30#include <linux/spinlock.h>31#include <linux/workqueue.h>32 33#include "nvec.h"34 35#define I2C_CNFG			0x0036#define I2C_CNFG_PACKET_MODE_EN		BIT(10)37#define I2C_CNFG_NEW_MASTER_SFM		BIT(11)38#define I2C_CNFG_DEBOUNCE_CNT_SHIFT	1239 40#define I2C_SL_CNFG		0x2041#define I2C_SL_NEWSL		BIT(2)42#define I2C_SL_NACK		BIT(1)43#define I2C_SL_RESP		BIT(0)44#define I2C_SL_IRQ		BIT(3)45#define END_TRANS		BIT(4)46#define RCVD			BIT(2)47#define RNW			BIT(1)48 49#define I2C_SL_RCVD		0x2450#define I2C_SL_STATUS		0x2851#define I2C_SL_ADDR1		0x2c52#define I2C_SL_ADDR2		0x3053#define I2C_SL_DELAY_COUNT	0x3c54 55/**56 * enum nvec_msg_category - Message categories for nvec_msg_alloc()57 * @NVEC_MSG_RX: The message is an incoming message (from EC)58 * @NVEC_MSG_TX: The message is an outgoing message (to EC)59 */60enum nvec_msg_category  {61	NVEC_MSG_RX,62	NVEC_MSG_TX,63};64 65enum nvec_sleep_subcmds {66	GLOBAL_EVENTS,67	AP_PWR_DOWN,68	AP_SUSPEND,69};70 71#define CNF_EVENT_REPORTING 0x0172#define GET_FIRMWARE_VERSION 0x1573#define LID_SWITCH BIT(1)74#define PWR_BUTTON BIT(15)75 76static struct nvec_chip *nvec_power_handle;77 78static const struct mfd_cell nvec_devices[] = {79	{80		.name = "nvec-kbd",81	},82	{83		.name = "nvec-mouse",84	},85	{86		.name = "nvec-power",87		.id = 0,88	},89	{90		.name = "nvec-power",91		.id = 1,92	},93	{94		.name = "nvec-paz00",95	},96};97 98/**99 * nvec_register_notifier - Register a notifier with nvec100 * @nvec: A &struct nvec_chip101 * @nb: The notifier block to register102 * @events: Unused103 *104 * Registers a notifier with @nvec. The notifier will be added to an atomic105 * notifier chain that is called for all received messages except those that106 * correspond to a request initiated by nvec_write_sync().107 */108int nvec_register_notifier(struct nvec_chip *nvec, struct notifier_block *nb,109			   unsigned int events)110{111	return atomic_notifier_chain_register(&nvec->notifier_list, nb);112}113EXPORT_SYMBOL_GPL(nvec_register_notifier);114 115/**116 * nvec_unregister_notifier - Unregister a notifier with nvec117 * @nvec: A &struct nvec_chip118 * @nb: The notifier block to unregister119 *120 * Unregisters a notifier with @nvec. The notifier will be removed from the121 * atomic notifier chain.122 */123int nvec_unregister_notifier(struct nvec_chip *nvec, struct notifier_block *nb)124{125	return atomic_notifier_chain_unregister(&nvec->notifier_list, nb);126}127EXPORT_SYMBOL_GPL(nvec_unregister_notifier);128 129/*130 * nvec_status_notifier - The final notifier131 *132 * Prints a message about control events not handled in the notifier133 * chain.134 */135static int nvec_status_notifier(struct notifier_block *nb,136				unsigned long event_type, void *data)137{138	struct nvec_chip *nvec = container_of(nb, struct nvec_chip,139						nvec_status_notifier);140	unsigned char *msg = data;141 142	if (event_type != NVEC_CNTL)143		return NOTIFY_DONE;144 145	dev_warn(nvec->dev, "unhandled msg type %ld\n", event_type);146	print_hex_dump(KERN_WARNING, "payload: ", DUMP_PREFIX_NONE, 16, 1,147		       msg, msg[1] + 2, true);148 149	return NOTIFY_OK;150}151 152/**153 * nvec_msg_alloc:154 * @nvec: A &struct nvec_chip155 * @category: Pool category, see &enum nvec_msg_category156 *157 * Allocate a single &struct nvec_msg object from the message pool of158 * @nvec. The result shall be passed to nvec_msg_free() if no longer159 * used.160 *161 * Outgoing messages are placed in the upper 75% of the pool, keeping the162 * lower 25% available for RX buffers only. The reason is to prevent a163 * situation where all buffers are full and a message is thus endlessly164 * retried because the response could never be processed.165 */166static struct nvec_msg *nvec_msg_alloc(struct nvec_chip *nvec,167				       enum nvec_msg_category category)168{169	int i = (category == NVEC_MSG_TX) ? (NVEC_POOL_SIZE / 4) : 0;170 171	for (; i < NVEC_POOL_SIZE; i++) {172		if (atomic_xchg(&nvec->msg_pool[i].used, 1) == 0) {173			dev_vdbg(nvec->dev, "INFO: Allocate %i\n", i);174			return &nvec->msg_pool[i];175		}176	}177 178	dev_err(nvec->dev, "Could not allocate %s buffer\n",179		(category == NVEC_MSG_TX) ? "TX" : "RX");180 181	return NULL;182}183 184/**185 * nvec_msg_free:186 * @nvec: A &struct nvec_chip187 * @msg:  A message (must be allocated by nvec_msg_alloc() and belong to @nvec)188 *189 * Free the given message190 */191void nvec_msg_free(struct nvec_chip *nvec, struct nvec_msg *msg)192{193	if (msg != &nvec->tx_scratch)194		dev_vdbg(nvec->dev, "INFO: Free %ti\n", msg - nvec->msg_pool);195	atomic_set(&msg->used, 0);196}197EXPORT_SYMBOL_GPL(nvec_msg_free);198 199/**200 * nvec_msg_is_event - Return %true if @msg is an event201 * @msg: A message202 */203static bool nvec_msg_is_event(struct nvec_msg *msg)204{205	return msg->data[0] >> 7;206}207 208/**209 * nvec_msg_size - Get the size of a message210 * @msg: The message to get the size for211 *212 * This only works for received messages, not for outgoing messages.213 */214static size_t nvec_msg_size(struct nvec_msg *msg)215{216	bool is_event = nvec_msg_is_event(msg);217	int event_length = (msg->data[0] & 0x60) >> 5;218 219	/* for variable size, payload size in byte 1 + count (1) + cmd (1) */220	if (!is_event || event_length == NVEC_VAR_SIZE)221		return (msg->pos || msg->size) ? (msg->data[1] + 2) : 0;222	else if (event_length == NVEC_2BYTES)223		return 2;224	else if (event_length == NVEC_3BYTES)225		return 3;226	return 0;227}228 229/**230 * nvec_gpio_set_value - Set the GPIO value231 * @nvec: A &struct nvec_chip232 * @value: The value to write (0 or 1)233 *234 * Like gpio_set_value(), but generating debugging information235 */236static void nvec_gpio_set_value(struct nvec_chip *nvec, int value)237{238	dev_dbg(nvec->dev, "GPIO changed from %u to %u\n",239		gpiod_get_value(nvec->gpiod), value);240	gpiod_set_value(nvec->gpiod, value);241}242 243/**244 * nvec_write_async - Asynchronously write a message to NVEC245 * @nvec: An nvec_chip instance246 * @data: The message data, starting with the request type247 * @size: The size of @data248 *249 * Queue a single message to be transferred to the embedded controller250 * and return immediately.251 *252 * Returns: 0 on success, a negative error code on failure. If a failure253 * occurred, the nvec driver may print an error.254 */255int nvec_write_async(struct nvec_chip *nvec, const unsigned char *data,256		     short size)257{258	struct nvec_msg *msg;259	unsigned long flags;260 261	msg = nvec_msg_alloc(nvec, NVEC_MSG_TX);262 263	if (!msg)264		return -ENOMEM;265 266	msg->data[0] = size;267	memcpy(msg->data + 1, data, size);268	msg->size = size + 1;269 270	spin_lock_irqsave(&nvec->tx_lock, flags);271	list_add_tail(&msg->node, &nvec->tx_data);272	spin_unlock_irqrestore(&nvec->tx_lock, flags);273 274	schedule_work(&nvec->tx_work);275 276	return 0;277}278EXPORT_SYMBOL(nvec_write_async);279 280/**281 * nvec_write_sync - Write a message to nvec and read the response282 * @nvec: An &struct nvec_chip283 * @data: The data to write284 * @size: The size of @data285 * @msg:  The response message received286 *287 * This is similar to nvec_write_async(), but waits for the288 * request to be answered before returning. This function289 * uses a mutex and can thus not be called from e.g.290 * interrupt handlers.291 *292 * Returns: 0 on success, a negative error code on failure.293 * The response message is returned in @msg. Shall be freed294 * with nvec_msg_free() once no longer used.295 *296 */297int nvec_write_sync(struct nvec_chip *nvec,298		    const unsigned char *data, short size,299		    struct nvec_msg **msg)300{301	mutex_lock(&nvec->sync_write_mutex);302 303	if (msg)304		*msg = NULL;305 306	nvec->sync_write_pending = (data[1] << 8) + data[0];307 308	if (nvec_write_async(nvec, data, size) < 0) {309		mutex_unlock(&nvec->sync_write_mutex);310		return -ENOMEM;311	}312 313	dev_dbg(nvec->dev, "nvec_sync_write: 0x%04x\n",314		nvec->sync_write_pending);315	if (!(wait_for_completion_timeout(&nvec->sync_write,316					  msecs_to_jiffies(2000)))) {317		dev_warn(nvec->dev,318			 "Timeout waiting for sync write to complete\n");319		mutex_unlock(&nvec->sync_write_mutex);320		return -ETIMEDOUT;321	}322 323	dev_dbg(nvec->dev, "nvec_sync_write: pong!\n");324 325	if (msg)326		*msg = nvec->last_sync_msg;327	else328		nvec_msg_free(nvec, nvec->last_sync_msg);329 330	mutex_unlock(&nvec->sync_write_mutex);331 332	return 0;333}334EXPORT_SYMBOL(nvec_write_sync);335 336/**337 * nvec_toggle_global_events - enables or disables global event reporting338 * @nvec: nvec handle339 * @state: true for enable, false for disable340 *341 * This switches on/off global event reports by the embedded controller.342 */343static void nvec_toggle_global_events(struct nvec_chip *nvec, bool state)344{345	unsigned char global_events[] = { NVEC_SLEEP, GLOBAL_EVENTS, state };346 347	nvec_write_async(nvec, global_events, 3);348}349 350/**351 * nvec_event_mask - fill the command string with event bitfield352 * @ev: points to event command string353 * @mask: bit to insert into the event mask354 *355 * Configure event command expects a 32 bit bitfield which describes356 * which events to enable. The bitfield has the following structure357 * (from highest byte to lowest):358 *	system state bits 7-0359 *	system state bits 15-8360 *	oem system state bits 7-0361 *	oem system state bits 15-8362 */363static void nvec_event_mask(char *ev, u32 mask)364{365	ev[3] = mask >> 16 & 0xff;366	ev[4] = mask >> 24 & 0xff;367	ev[5] = mask >> 0  & 0xff;368	ev[6] = mask >> 8  & 0xff;369}370 371/**372 * nvec_request_master - Process outgoing messages373 * @work: A &struct work_struct (the tx_worker member of &struct nvec_chip)374 *375 * Processes all outgoing requests by sending the request and awaiting the376 * response, then continuing with the next request. Once a request has a377 * matching response, it will be freed and removed from the list.378 */379static void nvec_request_master(struct work_struct *work)380{381	struct nvec_chip *nvec = container_of(work, struct nvec_chip, tx_work);382	unsigned long flags;383	long err;384	struct nvec_msg *msg;385 386	spin_lock_irqsave(&nvec->tx_lock, flags);387	while (!list_empty(&nvec->tx_data)) {388		msg = list_first_entry(&nvec->tx_data, struct nvec_msg, node);389		spin_unlock_irqrestore(&nvec->tx_lock, flags);390		nvec_gpio_set_value(nvec, 0);391		err = wait_for_completion_interruptible_timeout(&nvec->ec_transfer,392								msecs_to_jiffies(5000));393 394		if (err == 0) {395			dev_warn(nvec->dev, "Timeout waiting for ec transfer\n");396			nvec_gpio_set_value(nvec, 1);397			msg->pos = 0;398		}399 400		spin_lock_irqsave(&nvec->tx_lock, flags);401 402		if (err > 0) {403			list_del_init(&msg->node);404			nvec_msg_free(nvec, msg);405		}406	}407	spin_unlock_irqrestore(&nvec->tx_lock, flags);408}409 410/**411 * parse_msg - Print some information and call the notifiers on an RX message412 * @nvec: A &struct nvec_chip413 * @msg: A message received by @nvec414 *415 * Paarse some pieces of the message and then call the chain of notifiers416 * registered via nvec_register_notifier.417 */418static int parse_msg(struct nvec_chip *nvec, struct nvec_msg *msg)419{420	if ((msg->data[0] & 1 << 7) == 0 && msg->data[3]) {421		dev_err(nvec->dev, "ec responded %*ph\n", 4, msg->data);422		return -EINVAL;423	}424 425	if ((msg->data[0] >> 7) == 1 && (msg->data[0] & 0x0f) == 5)426		print_hex_dump(KERN_WARNING, "ec system event ",427			       DUMP_PREFIX_NONE, 16, 1, msg->data,428			       msg->data[1] + 2, true);429 430	atomic_notifier_call_chain(&nvec->notifier_list, msg->data[0] & 0x8f,431				   msg->data);432 433	return 0;434}435 436/**437 * nvec_dispatch - Process messages received from the EC438 * @work: A &struct work_struct (the tx_worker member of &struct nvec_chip)439 *440 * Process messages previously received from the EC and put into the RX441 * queue of the &struct nvec_chip instance associated with @work.442 */443static void nvec_dispatch(struct work_struct *work)444{445	struct nvec_chip *nvec = container_of(work, struct nvec_chip, rx_work);446	unsigned long flags;447	struct nvec_msg *msg;448 449	spin_lock_irqsave(&nvec->rx_lock, flags);450	while (!list_empty(&nvec->rx_data)) {451		msg = list_first_entry(&nvec->rx_data, struct nvec_msg, node);452		list_del_init(&msg->node);453		spin_unlock_irqrestore(&nvec->rx_lock, flags);454 455		if (nvec->sync_write_pending ==456		      (msg->data[2] << 8) + msg->data[0]) {457			dev_dbg(nvec->dev, "Sync write completed!\n");458			nvec->sync_write_pending = 0;459			nvec->last_sync_msg = msg;460			complete(&nvec->sync_write);461		} else {462			parse_msg(nvec, msg);463			nvec_msg_free(nvec, msg);464		}465		spin_lock_irqsave(&nvec->rx_lock, flags);466	}467	spin_unlock_irqrestore(&nvec->rx_lock, flags);468}469 470/**471 * nvec_tx_completed - Complete the current transfer472 * @nvec: A &struct nvec_chip473 *474 * This is called when we have received an END_TRANS on a TX transfer.475 */476static void nvec_tx_completed(struct nvec_chip *nvec)477{478	/* We got an END_TRANS, let's skip this, maybe there's an event */479	if (nvec->tx->pos != nvec->tx->size) {480		dev_err(nvec->dev, "Premature END_TRANS, resending\n");481		nvec->tx->pos = 0;482		nvec_gpio_set_value(nvec, 0);483	} else {484		nvec->state = 0;485	}486}487 488/**489 * nvec_rx_completed - Complete the current transfer490 * @nvec: A &struct nvec_chip491 *492 * This is called when we have received an END_TRANS on a RX transfer.493 */494static void nvec_rx_completed(struct nvec_chip *nvec)495{496	if (nvec->rx->pos != nvec_msg_size(nvec->rx)) {497		dev_err(nvec->dev, "RX incomplete: Expected %u bytes, got %u\n",498			(uint)nvec_msg_size(nvec->rx),499			(uint)nvec->rx->pos);500 501		nvec_msg_free(nvec, nvec->rx);502		nvec->state = 0;503 504		/* Battery quirk - Often incomplete, and likes to crash */505		if (nvec->rx->data[0] == NVEC_BAT)506			complete(&nvec->ec_transfer);507 508		return;509	}510 511	spin_lock(&nvec->rx_lock);512 513	/*514	 * Add the received data to the work list and move the ring buffer515	 * pointer to the next entry.516	 */517	list_add_tail(&nvec->rx->node, &nvec->rx_data);518 519	spin_unlock(&nvec->rx_lock);520 521	nvec->state = 0;522 523	if (!nvec_msg_is_event(nvec->rx))524		complete(&nvec->ec_transfer);525 526	schedule_work(&nvec->rx_work);527}528 529/**530 * nvec_invalid_flags - Send an error message about invalid flags and jump531 * @nvec: The nvec device532 * @status: The status flags533 * @reset: Whether we shall jump to state 0.534 */535static void nvec_invalid_flags(struct nvec_chip *nvec, unsigned int status,536			       bool reset)537{538	dev_err(nvec->dev, "unexpected status flags 0x%02x during state %i\n",539		status, nvec->state);540	if (reset)541		nvec->state = 0;542}543 544/**545 * nvec_tx_set - Set the message to transfer (nvec->tx)546 * @nvec: A &struct nvec_chip547 *548 * Gets the first entry from the tx_data list of @nvec and sets the549 * tx member to it. If the tx_data list is empty, this uses the550 * tx_scratch message to send a no operation message.551 */552static void nvec_tx_set(struct nvec_chip *nvec)553{554	spin_lock(&nvec->tx_lock);555	if (list_empty(&nvec->tx_data)) {556		dev_err(nvec->dev, "empty tx - sending no-op\n");557		memcpy(nvec->tx_scratch.data, "\x02\x07\x02", 3);558		nvec->tx_scratch.size = 3;559		nvec->tx_scratch.pos = 0;560		nvec->tx = &nvec->tx_scratch;561		list_add_tail(&nvec->tx->node, &nvec->tx_data);562	} else {563		nvec->tx = list_first_entry(&nvec->tx_data, struct nvec_msg,564					    node);565		nvec->tx->pos = 0;566	}567	spin_unlock(&nvec->tx_lock);568 569	dev_dbg(nvec->dev, "Sending message of length %u, command 0x%x\n",570		(uint)nvec->tx->size, nvec->tx->data[1]);571}572 573/**574 * tegra_i2c_writel - safely write to an I2C client controller register575 * @val: value to be written576 * @reg: register to write to577 *578 * A write to an I2C controller register needs to be read back to make sure579 * that the value has arrived.580 */581static void tegra_i2c_writel(u32 val, void *reg)582{583	writel_relaxed(val, reg);584 585	/* read back register to make sure that register writes completed */586	readl_relaxed(reg);587}588 589/**590 * nvec_interrupt - Interrupt handler591 * @irq: The IRQ592 * @dev: The nvec device593 *594 * Interrupt handler that fills our RX buffers and empties our TX595 * buffers. This uses a finite state machine with ridiculous amounts596 * of error checking, in order to be fairly reliable.597 */598static irqreturn_t nvec_interrupt(int irq, void *dev)599{600	unsigned long status;601	unsigned int received = 0;602	unsigned char to_send = 0xff;603	const unsigned long irq_mask = I2C_SL_IRQ | END_TRANS | RCVD | RNW;604	struct nvec_chip *nvec = dev;605	unsigned int state = nvec->state;606 607	status = readl(nvec->base + I2C_SL_STATUS);608 609	/* Filter out some errors */610	if ((status & irq_mask) == 0 && (status & ~irq_mask) != 0) {611		dev_err(nvec->dev, "Unexpected irq mask %lx\n", status);612		return IRQ_HANDLED;613	}614	if ((status & I2C_SL_IRQ) == 0) {615		dev_err(nvec->dev, "Spurious IRQ\n");616		return IRQ_HANDLED;617	}618 619	/* The EC did not request a read, so it send us something, read it */620	if ((status & RNW) == 0) {621		received = readl(nvec->base + I2C_SL_RCVD);622		if (status & RCVD)623			tegra_i2c_writel(0, nvec->base + I2C_SL_RCVD);624	}625 626	if (status == (I2C_SL_IRQ | RCVD))627		nvec->state = 0;628 629	switch (nvec->state) {630	case 0:		/* Verify that its a transfer start, the rest later */631		if (status != (I2C_SL_IRQ | RCVD))632			nvec_invalid_flags(nvec, status, false);633		break;634	case 1:		/* Command byte */635		if (status != I2C_SL_IRQ) {636			nvec_invalid_flags(nvec, status, true);637		} else {638			nvec->rx = nvec_msg_alloc(nvec, NVEC_MSG_RX);639			/* Should not happen in a normal world */640			if (unlikely(!nvec->rx)) {641				nvec->state = 0;642				break;643			}644			nvec->rx->data[0] = received;645			nvec->rx->pos = 1;646			nvec->state = 2;647		}648		break;649	case 2:		/* first byte after command */650		if (status == (I2C_SL_IRQ | RNW | RCVD)) {651			udelay(33);652			if (nvec->rx->data[0] != 0x01) {653				dev_err(nvec->dev,654					"Read without prior read command\n");655				nvec->state = 0;656				break;657			}658			nvec_msg_free(nvec, nvec->rx);659			nvec->state = 3;660			nvec_tx_set(nvec);661			to_send = nvec->tx->data[0];662			nvec->tx->pos = 1;663		} else if (status == (I2C_SL_IRQ)) {664			nvec->rx->data[1] = received;665			nvec->rx->pos = 2;666			nvec->state = 4;667		} else {668			nvec_invalid_flags(nvec, status, true);669		}670		break;671	case 3:		/* EC does a block read, we transmit data */672		if (status & END_TRANS) {673			nvec_tx_completed(nvec);674		} else if ((status & RNW) == 0 || (status & RCVD)) {675			nvec_invalid_flags(nvec, status, true);676		} else if (nvec->tx && nvec->tx->pos < nvec->tx->size) {677			to_send = nvec->tx->data[nvec->tx->pos++];678		} else {679			dev_err(nvec->dev,680				"tx buffer underflow on %p (%u > %u)\n",681				nvec->tx,682				(uint)(nvec->tx ? nvec->tx->pos : 0),683				(uint)(nvec->tx ? nvec->tx->size : 0));684			nvec->state = 0;685		}686		break;687	case 4:		/* EC does some write, we read the data */688		if ((status & (END_TRANS | RNW)) == END_TRANS)689			nvec_rx_completed(nvec);690		else if (status & (RNW | RCVD))691			nvec_invalid_flags(nvec, status, true);692		else if (nvec->rx && nvec->rx->pos < NVEC_MSG_SIZE)693			nvec->rx->data[nvec->rx->pos++] = received;694		else695			dev_err(nvec->dev,696				"RX buffer overflow on %p: Trying to write byte %u of %u\n",697				nvec->rx, nvec->rx ? nvec->rx->pos : 0,698				NVEC_MSG_SIZE);699		break;700	default:701		nvec->state = 0;702	}703 704	/* If we are told that a new transfer starts, verify it */705	if ((status & (RCVD | RNW)) == RCVD) {706		if (received != nvec->i2c_addr)707			dev_err(nvec->dev,708				"received address 0x%02x, expected 0x%02x\n",709				received, nvec->i2c_addr);710		nvec->state = 1;711	}712 713	/* Send data if requested, but not on end of transmission */714	if ((status & (RNW | END_TRANS)) == RNW)715		tegra_i2c_writel(to_send, nvec->base + I2C_SL_RCVD);716 717	/* If we have send the first byte */718	if (status == (I2C_SL_IRQ | RNW | RCVD))719		nvec_gpio_set_value(nvec, 1);720 721	dev_dbg(nvec->dev,722		"Handled: %s 0x%02x, %s 0x%02x in state %u [%s%s%s]\n",723		(status & RNW) == 0 ? "received" : "R=",724		received,725		(status & (RNW | END_TRANS)) ? "sent" : "S=",726		to_send,727		state,728		status & END_TRANS ? " END_TRANS" : "",729		status & RCVD ? " RCVD" : "",730		status & RNW ? " RNW" : "");731 732	return IRQ_HANDLED;733}734 735static void tegra_init_i2c_slave(struct nvec_chip *nvec)736{737	u32 val;738 739	clk_prepare_enable(nvec->i2c_clk);740 741	reset_control_assert(nvec->rst);742	udelay(2);743	reset_control_deassert(nvec->rst);744 745	val = I2C_CNFG_NEW_MASTER_SFM | I2C_CNFG_PACKET_MODE_EN |746	    (0x2 << I2C_CNFG_DEBOUNCE_CNT_SHIFT);747	tegra_i2c_writel(val, nvec->base + I2C_CNFG);748 749	clk_set_rate(nvec->i2c_clk, 8 * 80000);750 751	tegra_i2c_writel(I2C_SL_NEWSL, nvec->base + I2C_SL_CNFG);752	tegra_i2c_writel(0x1E, nvec->base + I2C_SL_DELAY_COUNT);753 754	tegra_i2c_writel(nvec->i2c_addr >> 1, nvec->base + I2C_SL_ADDR1);755	tegra_i2c_writel(0, nvec->base + I2C_SL_ADDR2);756 757	enable_irq(nvec->irq);758}759 760#ifdef CONFIG_PM_SLEEP761static void nvec_disable_i2c_slave(struct nvec_chip *nvec)762{763	disable_irq(nvec->irq);764	tegra_i2c_writel(I2C_SL_NEWSL | I2C_SL_NACK, nvec->base + I2C_SL_CNFG);765	clk_disable_unprepare(nvec->i2c_clk);766}767#endif768 769static void nvec_power_off(void)770{771	char ap_pwr_down[] = { NVEC_SLEEP, AP_PWR_DOWN };772 773	nvec_toggle_global_events(nvec_power_handle, false);774	nvec_write_async(nvec_power_handle, ap_pwr_down, 2);775}776 777static int tegra_nvec_probe(struct platform_device *pdev)778{779	int err, ret;780	struct clk *i2c_clk;781	struct device *dev = &pdev->dev;782	struct nvec_chip *nvec;783	struct nvec_msg *msg;784	void __iomem *base;785	char	get_firmware_version[] = { NVEC_CNTL, GET_FIRMWARE_VERSION },786		unmute_speakers[] = { NVEC_OEM0, 0x10, 0x59, 0x95 },787		enable_event[7] = { NVEC_SYS, CNF_EVENT_REPORTING, true };788 789	if (!dev->of_node) {790		dev_err(dev, "must be instantiated using device tree\n");791		return -ENODEV;792	}793 794	nvec = devm_kzalloc(dev, sizeof(struct nvec_chip), GFP_KERNEL);795	if (!nvec)796		return -ENOMEM;797 798	platform_set_drvdata(pdev, nvec);799	nvec->dev = dev;800 801	if (of_property_read_u32(dev->of_node, "slave-addr", &nvec->i2c_addr)) {802		dev_err(dev, "no i2c address specified");803		return -ENODEV;804	}805 806	base = devm_platform_ioremap_resource(pdev, 0);807	if (IS_ERR(base))808		return PTR_ERR(base);809 810	nvec->irq = platform_get_irq(pdev, 0);811	if (nvec->irq < 0)812		return -ENODEV;813 814	i2c_clk = devm_clk_get(dev, "div-clk");815	if (IS_ERR(i2c_clk)) {816		dev_err(dev, "failed to get controller clock\n");817		return -ENODEV;818	}819 820	nvec->rst = devm_reset_control_get_exclusive(dev, "i2c");821	if (IS_ERR(nvec->rst)) {822		dev_err(dev, "failed to get controller reset\n");823		return PTR_ERR(nvec->rst);824	}825 826	nvec->base = base;827	nvec->i2c_clk = i2c_clk;828	nvec->rx = &nvec->msg_pool[0];829 830	ATOMIC_INIT_NOTIFIER_HEAD(&nvec->notifier_list);831 832	init_completion(&nvec->sync_write);833	init_completion(&nvec->ec_transfer);834	mutex_init(&nvec->sync_write_mutex);835	spin_lock_init(&nvec->tx_lock);836	spin_lock_init(&nvec->rx_lock);837	INIT_LIST_HEAD(&nvec->rx_data);838	INIT_LIST_HEAD(&nvec->tx_data);839	INIT_WORK(&nvec->rx_work, nvec_dispatch);840	INIT_WORK(&nvec->tx_work, nvec_request_master);841 842	nvec->gpiod = devm_gpiod_get(dev, "request", GPIOD_OUT_HIGH);843	if (IS_ERR(nvec->gpiod)) {844		dev_err(dev, "couldn't request gpio\n");845		return PTR_ERR(nvec->gpiod);846	}847 848	err = devm_request_irq(dev, nvec->irq, nvec_interrupt, IRQF_NO_AUTOEN,849			       "nvec", nvec);850	if (err) {851		dev_err(dev, "couldn't request irq\n");852		return -ENODEV;853	}854 855	tegra_init_i2c_slave(nvec);856 857	/* enable event reporting */858	nvec_toggle_global_events(nvec, true);859 860	nvec->nvec_status_notifier.notifier_call = nvec_status_notifier;861	nvec_register_notifier(nvec, &nvec->nvec_status_notifier, 0);862 863	nvec_power_handle = nvec;864	pm_power_off = nvec_power_off;865 866	/* Get Firmware Version */867	err = nvec_write_sync(nvec, get_firmware_version, 2, &msg);868 869	if (!err) {870		dev_warn(dev,871			 "ec firmware version %02x.%02x.%02x / %02x\n",872			 msg->data[4], msg->data[5],873			 msg->data[6], msg->data[7]);874 875		nvec_msg_free(nvec, msg);876	}877 878	ret = mfd_add_devices(dev, 0, nvec_devices,879			      ARRAY_SIZE(nvec_devices), NULL, 0, NULL);880	if (ret)881		dev_err(dev, "error adding subdevices\n");882 883	/* unmute speakers? */884	nvec_write_async(nvec, unmute_speakers, 4);885 886	/* enable lid switch event */887	nvec_event_mask(enable_event, LID_SWITCH);888	nvec_write_async(nvec, enable_event, 7);889 890	/* enable power button event */891	nvec_event_mask(enable_event, PWR_BUTTON);892	nvec_write_async(nvec, enable_event, 7);893 894	return 0;895}896 897static void tegra_nvec_remove(struct platform_device *pdev)898{899	struct nvec_chip *nvec = platform_get_drvdata(pdev);900 901	nvec_toggle_global_events(nvec, false);902	mfd_remove_devices(nvec->dev);903	nvec_unregister_notifier(nvec, &nvec->nvec_status_notifier);904	cancel_work_sync(&nvec->rx_work);905	cancel_work_sync(&nvec->tx_work);906	/* FIXME: needs check whether nvec is responsible for power off */907	pm_power_off = NULL;908}909 910#ifdef CONFIG_PM_SLEEP911static int nvec_suspend(struct device *dev)912{913	int err;914	struct nvec_chip *nvec = dev_get_drvdata(dev);915	struct nvec_msg *msg;916	char ap_suspend[] = { NVEC_SLEEP, AP_SUSPEND };917 918	dev_dbg(nvec->dev, "suspending\n");919 920	/* keep these sync or you'll break suspend */921	nvec_toggle_global_events(nvec, false);922 923	err = nvec_write_sync(nvec, ap_suspend, sizeof(ap_suspend), &msg);924	if (!err)925		nvec_msg_free(nvec, msg);926 927	nvec_disable_i2c_slave(nvec);928 929	return 0;930}931 932static int nvec_resume(struct device *dev)933{934	struct nvec_chip *nvec = dev_get_drvdata(dev);935 936	dev_dbg(nvec->dev, "resuming\n");937	tegra_init_i2c_slave(nvec);938	nvec_toggle_global_events(nvec, true);939 940	return 0;941}942#endif943 944static SIMPLE_DEV_PM_OPS(nvec_pm_ops, nvec_suspend, nvec_resume);945 946/* Match table for of_platform binding */947static const struct of_device_id nvidia_nvec_of_match[] = {948	{ .compatible = "nvidia,nvec", },949	{},950};951MODULE_DEVICE_TABLE(of, nvidia_nvec_of_match);952 953static struct platform_driver nvec_device_driver = {954	.probe   = tegra_nvec_probe,955	.remove_new = tegra_nvec_remove,956	.driver  = {957		.name = "nvec",958		.pm = &nvec_pm_ops,959		.of_match_table = nvidia_nvec_of_match,960	}961};962 963module_platform_driver(nvec_device_driver);964 965MODULE_ALIAS("platform:nvec");966MODULE_DESCRIPTION("NVIDIA compliant embedded controller interface");967MODULE_AUTHOR("Marc Dietrich <marvin24@gmx.de>");968MODULE_LICENSE("GPL");969