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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0
 /*
  * NVEC: NVIDIA compliant embedded controller interface
  *
  * Copyright (C) 2011 The AC100 Kernel Team <ac100@lists.lauchpad.net>
  *
  * Authors:  Pierre-Hugues Husson <phhusson@free.fr>
  *           Ilya Petrov <ilya.muromec@gmail.com>
  *           Marc Dietrich <marvin24@gmx.de>
  *           Julian Andres Klode <jak@jak-linux.org>
  */
 
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/atomic.h>
 #include <linux/clk.h>
 #include <linux/completion.h>
 #include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/gpio/consumer.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/irq.h>
 #include <linux/of.h>
 #include <linux/list.h>
 #include <linux/mfd/core.h>
 #include <linux/mutex.h>
 #include <linux/notifier.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
 #include <linux/workqueue.h>
 
 #include "nvec.h"
 
 #define I2C_CNFG            0x00
 #define I2C_CNFG_PACKET_MODE_EN     BIT(10)
 #define I2C_CNFG_NEW_MASTER_SFM     BIT(11)
 #define I2C_CNFG_DEBOUNCE_CNT_SHIFT 12
 
 #define I2C_SL_CNFG     0x20
 #define I2C_SL_NEWSL        BIT(2)
 #define I2C_SL_NACK     BIT(1)
 #define I2C_SL_RESP     BIT(0)
 #define I2C_SL_IRQ      BIT(3)
 #define END_TRANS       BIT(4)
 #define RCVD            BIT(2)
 #define RNW         BIT(1)
 
 #define I2C_SL_RCVD     0x24
 #define I2C_SL_STATUS       0x28
 #define I2C_SL_ADDR1        0x2c
 #define I2C_SL_ADDR2        0x30
 #define I2C_SL_DELAY_COUNT  0x3c
 
 /**
  * enum nvec_msg_category - Message categories for nvec_msg_alloc()
  * @NVEC_MSG_RX: The message is an incoming message (from EC)
  * @NVEC_MSG_TX: The message is an outgoing message (to EC)
  */
 enum nvec_msg_category  {
     NVEC_MSG_RX,
     NVEC_MSG_TX,
 };
 
 enum nvec_sleep_subcmds {
     GLOBAL_EVENTS,
     AP_PWR_DOWN,
     AP_SUSPEND,
 };
 
 #define CNF_EVENT_REPORTING 0x01
 #define GET_FIRMWARE_VERSION 0x15
 #define LID_SWITCH BIT(1)
 #define PWR_BUTTON BIT(15)
 
 static struct nvec_chip *nvec_power_handle;
 
 static const struct mfd_cell nvec_devices[] = {
     {
         .name = "nvec-kbd",
     },
     {
         .name = "nvec-mouse",
     },
     {
         .name = "nvec-power",
         .id = 0,
     },
     {
         .name = "nvec-power",
         .id = 1,
     },
     {
         .name = "nvec-paz00",
     },
 };
 
 /**
  * nvec_register_notifier - Register a notifier with nvec
  * @nvec: A &struct nvec_chip
  * @nb: The notifier block to register
  * @events: Unused
  *
  * Registers a notifier with @nvec. The notifier will be added to an atomic
  * notifier chain that is called for all received messages except those that
  * correspond to a request initiated by nvec_write_sync().
  */
 int nvec_register_notifier(struct nvec_chip *nvec, struct notifier_block *nb,
                unsigned int events)
 {
     return atomic_notifier_chain_register(&nvec->notifier_list, nb);
 }
 EXPORT_SYMBOL_GPL(nvec_register_notifier);
 
 /**
  * nvec_unregister_notifier - Unregister a notifier with nvec
  * @nvec: A &struct nvec_chip
  * @nb: The notifier block to unregister
  *
  * Unregisters a notifier with @nvec. The notifier will be removed from the
  * atomic notifier chain.
  */
 int nvec_unregister_notifier(struct nvec_chip *nvec, struct notifier_block *nb)
 {
     return atomic_notifier_chain_unregister(&nvec->notifier_list, nb);
 }
 EXPORT_SYMBOL_GPL(nvec_unregister_notifier);
 
 /*
  * nvec_status_notifier - The final notifier
  *
  * Prints a message about control events not handled in the notifier
  * chain.
  */
 static int nvec_status_notifier(struct notifier_block *nb,
                 unsigned long event_type, void *data)
 {
     struct nvec_chip *nvec = container_of(nb, struct nvec_chip,
                         nvec_status_notifier);
     unsigned char *msg = data;
 
     if (event_type != NVEC_CNTL)
         return NOTIFY_DONE;
 
     dev_warn(nvec->dev, "unhandled msg type %ld\n", event_type);
     print_hex_dump(KERN_WARNING, "payload: ", DUMP_PREFIX_NONE, 16, 1,
                msg, msg[1] + 2, true);
 
     return NOTIFY_OK;
 }
 
 /**
  * nvec_msg_alloc:
  * @nvec: A &struct nvec_chip
  * @category: Pool category, see &enum nvec_msg_category
  *
  * Allocate a single &struct nvec_msg object from the message pool of
  * @nvec. The result shall be passed to nvec_msg_free() if no longer
  * used.
  *
  * Outgoing messages are placed in the upper 75% of the pool, keeping the
  * lower 25% available for RX buffers only. The reason is to prevent a
  * situation where all buffers are full and a message is thus endlessly
  * retried because the response could never be processed.
  */
 static struct nvec_msg *nvec_msg_alloc(struct nvec_chip *nvec,
                        enum nvec_msg_category category)
 {
     int i = (category == NVEC_MSG_TX) ? (NVEC_POOL_SIZE / 4) : 0;
 
     for (; i < NVEC_POOL_SIZE; i++) {
         if (atomic_xchg(&nvec->msg_pool[i].used, 1) == 0) {
             dev_vdbg(nvec->dev, "INFO: Allocate %i\n", i);
             return &nvec->msg_pool[i];
         }
     }
 
     dev_err(nvec->dev, "could not allocate %s buffer\n",
         (category == NVEC_MSG_TX) ? "TX" : "RX");
 
     return NULL;
 }
 
 /**
  * nvec_msg_free:
  * @nvec: A &struct nvec_chip
  * @msg:  A message (must be allocated by nvec_msg_alloc() and belong to @nvec)
  *
  * Free the given message
  */
 void nvec_msg_free(struct nvec_chip *nvec, struct nvec_msg *msg)
 {
     if (msg != &nvec->tx_scratch)
         dev_vdbg(nvec->dev, "INFO: Free %ti\n", msg - nvec->msg_pool);
     atomic_set(&msg->used, 0);
 }
 EXPORT_SYMBOL_GPL(nvec_msg_free);
 
 /**
  * nvec_msg_is_event - Return %true if @msg is an event
  * @msg: A message
  */
 static bool nvec_msg_is_event(struct nvec_msg *msg)
 {
     return msg->data[0] >> 7;
 }
 
 /**
  * nvec_msg_size - Get the size of a message
  * @msg: The message to get the size for
  *
  * This only works for received messages, not for outgoing messages.
  */
 static size_t nvec_msg_size(struct nvec_msg *msg)
 {
     bool is_event = nvec_msg_is_event(msg);
     int event_length = (msg->data[0] & 0x60) >> 5;
 
     /* for variable size, payload size in byte 1 + count (1) + cmd (1) */
     if (!is_event || event_length == NVEC_VAR_SIZE)
         return (msg->pos || msg->size) ? (msg->data[1] + 2) : 0;
     else if (event_length == NVEC_2BYTES)
         return 2;
     else if (event_length == NVEC_3BYTES)
         return 3;
     return 0;
 }
 
 /**
  * nvec_gpio_set_value - Set the GPIO value
  * @nvec: A &struct nvec_chip
  * @value: The value to write (0 or 1)
  *
  * Like gpio_set_value(), but generating debugging information
  */
 static void nvec_gpio_set_value(struct nvec_chip *nvec, int value)
 {
     dev_dbg(nvec->dev, "GPIO changed from %u to %u\n",
         gpiod_get_value(nvec->gpiod), value);
     gpiod_set_value(nvec->gpiod, value);
 }
 
 /**
  * nvec_write_async - Asynchronously write a message to NVEC
  * @nvec: An nvec_chip instance
  * @data: The message data, starting with the request type
  * @size: The size of @data
  *
  * Queue a single message to be transferred to the embedded controller
  * and return immediately.
  *
  * Returns: 0 on success, a negative error code on failure. If a failure
  * occurred, the nvec driver may print an error.
  */
 int nvec_write_async(struct nvec_chip *nvec, const unsigned char *data,
              short size)
 {
     struct nvec_msg *msg;
     unsigned long flags;
 
     msg = nvec_msg_alloc(nvec, NVEC_MSG_TX);
 
     if (!msg)
         return -ENOMEM;
 
     msg->data[0] = size;
     memcpy(msg->data + 1, data, size);
     msg->size = size + 1;
 
     spin_lock_irqsave(&nvec->tx_lock, flags);
     list_add_tail(&msg->node, &nvec->tx_data);
     spin_unlock_irqrestore(&nvec->tx_lock, flags);
 
     schedule_work(&nvec->tx_work);
 
     return 0;
 }
 EXPORT_SYMBOL(nvec_write_async);
 
 /**
  * nvec_write_sync - Write a message to nvec and read the response
  * @nvec: An &struct nvec_chip
  * @data: The data to write
  * @size: The size of @data
  * @msg:  The response message received
  *
  * This is similar to nvec_write_async(), but waits for the
  * request to be answered before returning. This function
  * uses a mutex and can thus not be called from e.g.
  * interrupt handlers.
  *
  * Returns: 0 on success, a negative error code on failure.
  * The response message is returned in @msg. Shall be freed
  * with nvec_msg_free() once no longer used.
  *
  */
 int nvec_write_sync(struct nvec_chip *nvec,
             const unsigned char *data, short size,
             struct nvec_msg **msg)
 {
     mutex_lock(&nvec->sync_write_mutex);
 
     *msg = NULL;
     nvec->sync_write_pending = (data[1] << 8) + data[0];
 
     if (nvec_write_async(nvec, data, size) < 0) {
         mutex_unlock(&nvec->sync_write_mutex);
         return -ENOMEM;
     }
 
     dev_dbg(nvec->dev, "nvec_sync_write: 0x%04x\n",
         nvec->sync_write_pending);
     if (!(wait_for_completion_timeout(&nvec->sync_write,
                       msecs_to_jiffies(2000)))) {
         dev_warn(nvec->dev,
              "timeout waiting for sync write to complete\n");
         mutex_unlock(&nvec->sync_write_mutex);
         return -ETIMEDOUT;
     }
 
     dev_dbg(nvec->dev, "nvec_sync_write: pong!\n");
 
     *msg = nvec->last_sync_msg;
 
     mutex_unlock(&nvec->sync_write_mutex);
 
     return 0;
 }
 EXPORT_SYMBOL(nvec_write_sync);
 
 /**
  * nvec_toggle_global_events - enables or disables global event reporting
  * @nvec: nvec handle
  * @state: true for enable, false for disable
  *
  * This switches on/off global event reports by the embedded controller.
  */
 static void nvec_toggle_global_events(struct nvec_chip *nvec, bool state)
 {
     unsigned char global_events[] = { NVEC_SLEEP, GLOBAL_EVENTS, state };
 
     nvec_write_async(nvec, global_events, 3);
 }
 
 /**
  * nvec_event_mask - fill the command string with event bitfield
  * @ev: points to event command string
  * @mask: bit to insert into the event mask
  *
  * Configure event command expects a 32 bit bitfield which describes
  * which events to enable. The bitfield has the following structure
  * (from highest byte to lowest):
  *  system state bits 7-0
  *  system state bits 15-8
  *  oem system state bits 7-0
  *  oem system state bits 15-8
  */
 static void nvec_event_mask(char *ev, u32 mask)
 {
     ev[3] = mask >> 16 & 0xff;
     ev[4] = mask >> 24 & 0xff;
     ev[5] = mask >> 0  & 0xff;
     ev[6] = mask >> 8  & 0xff;
 }
 
 /**
  * nvec_request_master - Process outgoing messages
  * @work: A &struct work_struct (the tx_worker member of &struct nvec_chip)
  *
  * Processes all outgoing requests by sending the request and awaiting the
  * response, then continuing with the next request. Once a request has a
  * matching response, it will be freed and removed from the list.
  */
 static void nvec_request_master(struct work_struct *work)
 {
     struct nvec_chip *nvec = container_of(work, struct nvec_chip, tx_work);
     unsigned long flags;
     long err;
     struct nvec_msg *msg;
 
     spin_lock_irqsave(&nvec->tx_lock, flags);
     while (!list_empty(&nvec->tx_data)) {
         msg = list_first_entry(&nvec->tx_data, struct nvec_msg, node);
         spin_unlock_irqrestore(&nvec->tx_lock, flags);
         nvec_gpio_set_value(nvec, 0);
         err = wait_for_completion_interruptible_timeout(&nvec->ec_transfer,
                                 msecs_to_jiffies(5000));
 
         if (err == 0) {
             dev_warn(nvec->dev, "timeout waiting for ec transfer\n");
             nvec_gpio_set_value(nvec, 1);
             msg->pos = 0;
         }
 
         spin_lock_irqsave(&nvec->tx_lock, flags);
 
         if (err > 0) {
             list_del_init(&msg->node);
             nvec_msg_free(nvec, msg);
         }
     }
     spin_unlock_irqrestore(&nvec->tx_lock, flags);
 }
 
 /**
  * parse_msg - Print some information and call the notifiers on an RX message
  * @nvec: A &struct nvec_chip
  * @msg: A message received by @nvec
  *
  * Paarse some pieces of the message and then call the chain of notifiers
  * registered via nvec_register_notifier.
  */
 static int parse_msg(struct nvec_chip *nvec, struct nvec_msg *msg)
 {
     if ((msg->data[0] & 1 << 7) == 0 && msg->data[3]) {
         dev_err(nvec->dev, "ec responded %*ph\n", 4, msg->data);
         return -EINVAL;
     }
 
     if ((msg->data[0] >> 7) == 1 && (msg->data[0] & 0x0f) == 5)
         print_hex_dump(KERN_WARNING, "ec system event ",
                    DUMP_PREFIX_NONE, 16, 1, msg->data,
                    msg->data[1] + 2, true);
 
     atomic_notifier_call_chain(&nvec->notifier_list, msg->data[0] & 0x8f,
                    msg->data);
 
     return 0;
 }
 
 /**
  * nvec_dispatch - Process messages received from the EC
  * @work: A &struct work_struct (the tx_worker member of &struct nvec_chip)
  *
  * Process messages previously received from the EC and put into the RX
  * queue of the &struct nvec_chip instance associated with @work.
  */
 static void nvec_dispatch(struct work_struct *work)
 {
     struct nvec_chip *nvec = container_of(work, struct nvec_chip, rx_work);
     unsigned long flags;
     struct nvec_msg *msg;
 
     spin_lock_irqsave(&nvec->rx_lock, flags);
     while (!list_empty(&nvec->rx_data)) {
         msg = list_first_entry(&nvec->rx_data, struct nvec_msg, node);
         list_del_init(&msg->node);
         spin_unlock_irqrestore(&nvec->rx_lock, flags);
 
         if (nvec->sync_write_pending ==
               (msg->data[2] << 8) + msg->data[0]) {
             dev_dbg(nvec->dev, "sync write completed!\n");
             nvec->sync_write_pending = 0;
             nvec->last_sync_msg = msg;
             complete(&nvec->sync_write);
         } else {
             parse_msg(nvec, msg);
             nvec_msg_free(nvec, msg);
         }
         spin_lock_irqsave(&nvec->rx_lock, flags);
     }
     spin_unlock_irqrestore(&nvec->rx_lock, flags);
 }
 
 /**
  * nvec_tx_completed - Complete the current transfer
  * @nvec: A &struct nvec_chip
  *
  * This is called when we have received an END_TRANS on a TX transfer.
  */
 static void nvec_tx_completed(struct nvec_chip *nvec)
 {
     /* We got an END_TRANS, let's skip this, maybe there's an event */
     if (nvec->tx->pos != nvec->tx->size) {
         dev_err(nvec->dev, "premature END_TRANS, resending\n");
         nvec->tx->pos = 0;
         nvec_gpio_set_value(nvec, 0);
     } else {
         nvec->state = 0;
     }
 }
 
 /**
  * nvec_rx_completed - Complete the current transfer
  * @nvec: A &struct nvec_chip
  *
  * This is called when we have received an END_TRANS on a RX transfer.
  */
 static void nvec_rx_completed(struct nvec_chip *nvec)
 {
     if (nvec->rx->pos != nvec_msg_size(nvec->rx)) {
         dev_err(nvec->dev, "RX incomplete: Expected %u bytes, got %u\n",
             (uint)nvec_msg_size(nvec->rx),
             (uint)nvec->rx->pos);
 
         nvec_msg_free(nvec, nvec->rx);
         nvec->state = 0;
 
         /* Battery quirk - Often incomplete, and likes to crash */
         if (nvec->rx->data[0] == NVEC_BAT)
             complete(&nvec->ec_transfer);
 
         return;
     }
 
     spin_lock(&nvec->rx_lock);
 
     /*
      * Add the received data to the work list and move the ring buffer
      * pointer to the next entry.
      */
     list_add_tail(&nvec->rx->node, &nvec->rx_data);
 
     spin_unlock(&nvec->rx_lock);
 
     nvec->state = 0;
 
     if (!nvec_msg_is_event(nvec->rx))
         complete(&nvec->ec_transfer);
 
     schedule_work(&nvec->rx_work);
 }
 
 /**
  * nvec_invalid_flags - Send an error message about invalid flags and jump
  * @nvec: The nvec device
  * @status: The status flags
  * @reset: Whether we shall jump to state 0.
  */
 static void nvec_invalid_flags(struct nvec_chip *nvec, unsigned int status,
                    bool reset)
 {
     dev_err(nvec->dev, "unexpected status flags 0x%02x during state %i\n",
         status, nvec->state);
     if (reset)
         nvec->state = 0;
 }
 
 /**
  * nvec_tx_set - Set the message to transfer (nvec->tx)
  * @nvec: A &struct nvec_chip
  *
  * Gets the first entry from the tx_data list of @nvec and sets the
  * tx member to it. If the tx_data list is empty, this uses the
  * tx_scratch message to send a no operation message.
  */
 static void nvec_tx_set(struct nvec_chip *nvec)
 {
     spin_lock(&nvec->tx_lock);
     if (list_empty(&nvec->tx_data)) {
         dev_err(nvec->dev, "empty tx - sending no-op\n");
         memcpy(nvec->tx_scratch.data, "\x02\x07\x02", 3);
         nvec->tx_scratch.size = 3;
         nvec->tx_scratch.pos = 0;
         nvec->tx = &nvec->tx_scratch;
         list_add_tail(&nvec->tx->node, &nvec->tx_data);
     } else {
         nvec->tx = list_first_entry(&nvec->tx_data, struct nvec_msg,
                         node);
         nvec->tx->pos = 0;
     }
     spin_unlock(&nvec->tx_lock);
 
     dev_dbg(nvec->dev, "Sending message of length %u, command 0x%x\n",
         (uint)nvec->tx->size, nvec->tx->data[1]);
 }
 
 /**
  * nvec_interrupt - Interrupt handler
  * @irq: The IRQ
  * @dev: The nvec device
  *
  * Interrupt handler that fills our RX buffers and empties our TX
  * buffers. This uses a finite state machine with ridiculous amounts
  * of error checking, in order to be fairly reliable.
  */
 static irqreturn_t nvec_interrupt(int irq, void *dev)
 {
     unsigned long status;
     unsigned int received = 0;
     unsigned char to_send = 0xff;
     const unsigned long irq_mask = I2C_SL_IRQ | END_TRANS | RCVD | RNW;
     struct nvec_chip *nvec = dev;
     unsigned int state = nvec->state;
 
     status = readl(nvec->base + I2C_SL_STATUS);
 
     /* Filter out some errors */
     if ((status & irq_mask) == 0 && (status & ~irq_mask) != 0) {
         dev_err(nvec->dev, "unexpected irq mask %lx\n", status);
         return IRQ_HANDLED;
     }
     if ((status & I2C_SL_IRQ) == 0) {
         dev_err(nvec->dev, "Spurious IRQ\n");
         return IRQ_HANDLED;
     }
 
     /* The EC did not request a read, so it send us something, read it */
     if ((status & RNW) == 0) {
         received = readl(nvec->base + I2C_SL_RCVD);
         if (status & RCVD)
             writel(0, nvec->base + I2C_SL_RCVD);
     }
 
     if (status == (I2C_SL_IRQ | RCVD))
         nvec->state = 0;
 
     switch (nvec->state) {
     case 0:     /* Verify that its a transfer start, the rest later */
         if (status != (I2C_SL_IRQ | RCVD))
             nvec_invalid_flags(nvec, status, false);
         break;
     case 1:     /* command byte */
         if (status != I2C_SL_IRQ) {
             nvec_invalid_flags(nvec, status, true);
         } else {
             nvec->rx = nvec_msg_alloc(nvec, NVEC_MSG_RX);
             /* Should not happen in a normal world */
             if (unlikely(!nvec->rx)) {
                 nvec->state = 0;
                 break;
             }
             nvec->rx->data[0] = received;
             nvec->rx->pos = 1;
             nvec->state = 2;
         }
         break;
     case 2:     /* first byte after command */
         if (status == (I2C_SL_IRQ | RNW | RCVD)) {
             udelay(33);
             if (nvec->rx->data[0] != 0x01) {
                 dev_err(nvec->dev,
                     "Read without prior read command\n");
                 nvec->state = 0;
                 break;
             }
             nvec_msg_free(nvec, nvec->rx);
             nvec->state = 3;
             nvec_tx_set(nvec);
             to_send = nvec->tx->data[0];
             nvec->tx->pos = 1;
         } else if (status == (I2C_SL_IRQ)) {
             nvec->rx->data[1] = received;
             nvec->rx->pos = 2;
             nvec->state = 4;
         } else {
             nvec_invalid_flags(nvec, status, true);
         }
         break;
     case 3:     /* EC does a block read, we transmit data */
         if (status & END_TRANS) {
             nvec_tx_completed(nvec);
         } else if ((status & RNW) == 0 || (status & RCVD)) {
             nvec_invalid_flags(nvec, status, true);
         } else if (nvec->tx && nvec->tx->pos < nvec->tx->size) {
             to_send = nvec->tx->data[nvec->tx->pos++];
         } else {
             dev_err(nvec->dev,
                 "tx buffer underflow on %p (%u > %u)\n",
                 nvec->tx,
                 (uint)(nvec->tx ? nvec->tx->pos : 0),
                 (uint)(nvec->tx ? nvec->tx->size : 0));
             nvec->state = 0;
         }
         break;
     case 4:     /* EC does some write, we read the data */
         if ((status & (END_TRANS | RNW)) == END_TRANS)
             nvec_rx_completed(nvec);
         else if (status & (RNW | RCVD))
             nvec_invalid_flags(nvec, status, true);
         else if (nvec->rx && nvec->rx->pos < NVEC_MSG_SIZE)
             nvec->rx->data[nvec->rx->pos++] = received;
         else
             dev_err(nvec->dev,
                 "RX buffer overflow on %p: Trying to write byte %u of %u\n",
                 nvec->rx, nvec->rx ? nvec->rx->pos : 0,
                 NVEC_MSG_SIZE);
         break;
     default:
         nvec->state = 0;
     }
 
     /* If we are told that a new transfer starts, verify it */
     if ((status & (RCVD | RNW)) == RCVD) {
         if (received != nvec->i2c_addr)
             dev_err(nvec->dev,
                 "received address 0x%02x, expected 0x%02x\n",
                 received, nvec->i2c_addr);
         nvec->state = 1;
     }
 
     /* Send data if requested, but not on end of transmission */
     if ((status & (RNW | END_TRANS)) == RNW)
         writel(to_send, nvec->base + I2C_SL_RCVD);
 
     /* If we have send the first byte */
     if (status == (I2C_SL_IRQ | RNW | RCVD))
         nvec_gpio_set_value(nvec, 1);
 
     dev_dbg(nvec->dev,
         "Handled: %s 0x%02x, %s 0x%02x in state %u [%s%s%s]\n",
         (status & RNW) == 0 ? "received" : "R=",
         received,
         (status & (RNW | END_TRANS)) ? "sent" : "S=",
         to_send,
         state,
         status & END_TRANS ? " END_TRANS" : "",
         status & RCVD ? " RCVD" : "",
         status & RNW ? " RNW" : "");
 
     /*
      * TODO: A correct fix needs to be found for this.
      *
      * We experience less incomplete messages with this delay than without
      * it, but we don't know why. Help is appreciated.
      */
     udelay(100);
 
     return IRQ_HANDLED;
 }
 
 static void tegra_init_i2c_slave(struct nvec_chip *nvec)
 {
     u32 val;
 
     clk_prepare_enable(nvec->i2c_clk);
 
     reset_control_assert(nvec->rst);
     udelay(2);
     reset_control_deassert(nvec->rst);
 
     val = I2C_CNFG_NEW_MASTER_SFM | I2C_CNFG_PACKET_MODE_EN |
         (0x2 << I2C_CNFG_DEBOUNCE_CNT_SHIFT);
     writel(val, nvec->base + I2C_CNFG);
 
     clk_set_rate(nvec->i2c_clk, 8 * 80000);
 
     writel(I2C_SL_NEWSL, nvec->base + I2C_SL_CNFG);
     writel(0x1E, nvec->base + I2C_SL_DELAY_COUNT);
 
     writel(nvec->i2c_addr >> 1, nvec->base + I2C_SL_ADDR1);
     writel(0, nvec->base + I2C_SL_ADDR2);
 
     enable_irq(nvec->irq);
 }
 
 #ifdef CONFIG_PM_SLEEP
 static void nvec_disable_i2c_slave(struct nvec_chip *nvec)
 {
     disable_irq(nvec->irq);
     writel(I2C_SL_NEWSL | I2C_SL_NACK, nvec->base + I2C_SL_CNFG);
     clk_disable_unprepare(nvec->i2c_clk);
 }
 #endif
 
 static void nvec_power_off(void)
 {
     char ap_pwr_down[] = { NVEC_SLEEP, AP_PWR_DOWN };
 
     nvec_toggle_global_events(nvec_power_handle, false);
     nvec_write_async(nvec_power_handle, ap_pwr_down, 2);
 }
 
 static int tegra_nvec_probe(struct platform_device *pdev)
 {
     int err, ret;
     struct clk *i2c_clk;
     struct device *dev = &pdev->dev;
     struct nvec_chip *nvec;
     struct nvec_msg *msg;
     void __iomem *base;
     char    get_firmware_version[] = { NVEC_CNTL, GET_FIRMWARE_VERSION },
         unmute_speakers[] = { NVEC_OEM0, 0x10, 0x59, 0x95 },
         enable_event[7] = { NVEC_SYS, CNF_EVENT_REPORTING, true };
 
     if (!dev->of_node) {
         dev_err(dev, "must be instantiated using device tree\n");
         return -ENODEV;
     }
 
     nvec = devm_kzalloc(dev, sizeof(struct nvec_chip), GFP_KERNEL);
     if (!nvec)
         return -ENOMEM;
 
     platform_set_drvdata(pdev, nvec);
     nvec->dev = dev;
 
     if (of_property_read_u32(dev->of_node, "slave-addr", &nvec->i2c_addr)) {
         dev_err(dev, "no i2c address specified");
         return -ENODEV;
     }
 
     base = devm_platform_ioremap_resource(pdev, 0);
     if (IS_ERR(base))
         return PTR_ERR(base);
 
     nvec->irq = platform_get_irq(pdev, 0);
     if (nvec->irq < 0)
         return -ENODEV;
 
     i2c_clk = devm_clk_get(dev, "div-clk");
     if (IS_ERR(i2c_clk)) {
         dev_err(dev, "failed to get controller clock\n");
         return -ENODEV;
     }
 
     nvec->rst = devm_reset_control_get_exclusive(dev, "i2c");
     if (IS_ERR(nvec->rst)) {
         dev_err(dev, "failed to get controller reset\n");
         return PTR_ERR(nvec->rst);
     }
 
     nvec->base = base;
     nvec->i2c_clk = i2c_clk;
     nvec->rx = &nvec->msg_pool[0];
 
     ATOMIC_INIT_NOTIFIER_HEAD(&nvec->notifier_list);
 
     init_completion(&nvec->sync_write);
     init_completion(&nvec->ec_transfer);
     mutex_init(&nvec->sync_write_mutex);
     spin_lock_init(&nvec->tx_lock);
     spin_lock_init(&nvec->rx_lock);
     INIT_LIST_HEAD(&nvec->rx_data);
     INIT_LIST_HEAD(&nvec->tx_data);
     INIT_WORK(&nvec->rx_work, nvec_dispatch);
     INIT_WORK(&nvec->tx_work, nvec_request_master);
 
     nvec->gpiod = devm_gpiod_get(dev, "request", GPIOD_OUT_HIGH);
     if (IS_ERR(nvec->gpiod)) {
         dev_err(dev, "couldn't request gpio\n");
         return PTR_ERR(nvec->gpiod);
     }
 
     err = devm_request_irq(dev, nvec->irq, nvec_interrupt, 0,
                    "nvec", nvec);
     if (err) {
         dev_err(dev, "couldn't request irq\n");
         return -ENODEV;
     }
     disable_irq(nvec->irq);
 
     tegra_init_i2c_slave(nvec);
 
     /* enable event reporting */
     nvec_toggle_global_events(nvec, true);
 
     nvec->nvec_status_notifier.notifier_call = nvec_status_notifier;
     nvec_register_notifier(nvec, &nvec->nvec_status_notifier, 0);
 
     nvec_power_handle = nvec;
     pm_power_off = nvec_power_off;
 
     /* Get Firmware Version */
     err = nvec_write_sync(nvec, get_firmware_version, 2, &msg);
 
     if (!err) {
         dev_warn(dev,
              "ec firmware version %02x.%02x.%02x / %02x\n",
              msg->data[4], msg->data[5],
              msg->data[6], msg->data[7]);
 
         nvec_msg_free(nvec, msg);
     }
 
     ret = mfd_add_devices(dev, 0, nvec_devices,
                   ARRAY_SIZE(nvec_devices), NULL, 0, NULL);
     if (ret)
         dev_err(dev, "error adding subdevices\n");
 
     /* unmute speakers? */
     nvec_write_async(nvec, unmute_speakers, 4);
 
     /* enable lid switch event */
     nvec_event_mask(enable_event, LID_SWITCH);
     nvec_write_async(nvec, enable_event, 7);
 
     /* enable power button event */
     nvec_event_mask(enable_event, PWR_BUTTON);
     nvec_write_async(nvec, enable_event, 7);
 
     return 0;
 }
 
 static int tegra_nvec_remove(struct platform_device *pdev)
 {
     struct nvec_chip *nvec = platform_get_drvdata(pdev);
 
     nvec_toggle_global_events(nvec, false);
     mfd_remove_devices(nvec->dev);
     nvec_unregister_notifier(nvec, &nvec->nvec_status_notifier);
     cancel_work_sync(&nvec->rx_work);
     cancel_work_sync(&nvec->tx_work);
     /* FIXME: needs check whether nvec is responsible for power off */
     pm_power_off = NULL;
 
     return 0;
 }
 
 #ifdef CONFIG_PM_SLEEP
 static int nvec_suspend(struct device *dev)
 {
     int err;
     struct nvec_chip *nvec = dev_get_drvdata(dev);
     struct nvec_msg *msg;
     char ap_suspend[] = { NVEC_SLEEP, AP_SUSPEND };
 
     dev_dbg(nvec->dev, "suspending\n");
 
     /* keep these sync or you'll break suspend */
     nvec_toggle_global_events(nvec, false);
 
     err = nvec_write_sync(nvec, ap_suspend, sizeof(ap_suspend), &msg);
     if (!err)
         nvec_msg_free(nvec, msg);
 
     nvec_disable_i2c_slave(nvec);
 
     return 0;
 }
 
 static int nvec_resume(struct device *dev)
 {
     struct nvec_chip *nvec = dev_get_drvdata(dev);
 
     dev_dbg(nvec->dev, "resuming\n");
     tegra_init_i2c_slave(nvec);
     nvec_toggle_global_events(nvec, true);
 
     return 0;
 }
 #endif
 
 static SIMPLE_DEV_PM_OPS(nvec_pm_ops, nvec_suspend, nvec_resume);
 
 /* Match table for of_platform binding */
 static const struct of_device_id nvidia_nvec_of_match[] = {
     { .compatible = "nvidia,nvec", },
     {},
 };
 MODULE_DEVICE_TABLE(of, nvidia_nvec_of_match);
 
 static struct platform_driver nvec_device_driver = {
     .probe   = tegra_nvec_probe,
     .remove  = tegra_nvec_remove,
     .driver  = {
         .name = "nvec",
         .pm = &nvec_pm_ops,
         .of_match_table = nvidia_nvec_of_match,
     }
 };
 
 module_platform_driver(nvec_device_driver);
 
 MODULE_ALIAS("platform:nvec");
 MODULE_DESCRIPTION("NVIDIA compliant embedded controller interface");
 MODULE_AUTHOR("Marc Dietrich <marvin24@gmx.de>");
 MODULE_LICENSE("GPL");

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