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// 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); 	if (msg)		*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"); 	if (msg)		*msg = nvec->last_sync_msg;	else		nvec_msg_free(nvec, 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); 

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