include/linux/mfd/cros_ec.h - kernel/bruno - Git at Google

 /*
  * ChromeOS EC multi-function device
  *
  * Copyright (C) 2012 Google, Inc
  *
  * This software is licensed under the terms of the GNU General Public
  * License version 2, as published by the Free Software Foundation, and
  * may be copied, distributed, and modified under those terms.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  */

 #ifndef __LINUX_MFD_CROS_EC_H
 #define __LINUX_MFD_CROS_EC_H

 #include <linux/cdev.h>
 #include <linux/device.h>
 #include <linux/notifier.h>
 #include <linux/mfd/cros_ec_commands.h>
 #include <linux/mutex.h>

 #define CROS_EC_DEV_NAME "cros_ec"
 #define CROS_EC_DEV_PD_NAME "cros_pd"

 /*
  * The EC is unresponsive for a time after a reboot command.  Add a
  * simple delay to make sure that the bus stays locked.
  */
 #define EC_REBOOT_DELAY_MS             50

 /*
  * Max bus-specific overhead incurred by request/responses.
  * I2C requires 1 additional byte for requests.
  * I2C requires 2 additional bytes for responses.
  * */
 #define EC_PROTO_VERSION_UNKNOWN	0
 #define EC_MAX_REQUEST_OVERHEAD		1
 #define EC_MAX_RESPONSE_OVERHEAD	2

 /*
  * Command interface between EC and AP, for LPC, I2C and SPI interfaces.
  */
 enum {
 	EC_MSG_TX_HEADER_BYTES	= 3,
 	EC_MSG_TX_TRAILER_BYTES	= 1,
 	EC_MSG_TX_PROTO_BYTES	= EC_MSG_TX_HEADER_BYTES +
 					EC_MSG_TX_TRAILER_BYTES,
 	EC_MSG_RX_PROTO_BYTES	= 3,

 	/* Max length of messages */
 	EC_MSG_BYTES		= EC_PROTO2_MAX_PARAM_SIZE +
 					EC_MSG_TX_PROTO_BYTES,
 };

 /*
  * @version: Command version number (often 0)
  * @command: Command to send (EC_CMD_...)
  * @outsize: Outgoing length in bytes
  * @insize: Max number of bytes to accept from EC
  * @result: EC's response to the command (separate from communication failure)
  * @data: Where to put the incoming data from EC and outgoing data to EC
  */
 struct cros_ec_command {
 	uint32_t version;
 	uint32_t command;
 	uint32_t outsize;
 	uint32_t insize;
 	uint32_t result;
 	uint8_t data[0];
 };

 /**
  * struct cros_ec_device - Information about a ChromeOS EC device
  *
  * @phys_name: name of physical comms layer (e.g. 'i2c-4')
  * @dev: Device pointer for physical comms device
  * @was_wake_device: true if this device was set to wake the system from
  * sleep at the last suspend
  * @cmd_readmem: direct read of the EC memory-mapped region, if supported
  *     @offset is within EC_LPC_ADDR_MEMMAP region.
  *     @bytes: number of bytes to read. zero means "read a string" (including
  *     the trailing '\0'). At most only EC_MEMMAP_SIZE bytes can be read.
  *     Caller must ensure that the buffer is large enough for the result when
  *     reading a string.
  *
  * @priv: Private data
  * @irq: Interrupt to use
  * @id: Device id
  * @din: input buffer (for data from EC)
  * @dout: output buffer (for data to EC)
  * \note
  * These two buffers will always be dword-aligned and include enough
  * space for up to 7 word-alignment bytes also, so we can ensure that
  * the body of the message is always dword-aligned (64-bit).
  * We use this alignment to keep ARM and x86 happy. Probably word
  * alignment would be OK, there might be a small performance advantage
  * to using dword.
  * @din_size: size of din buffer to allocate (zero to use static din)
  * @dout_size: size of dout buffer to allocate (zero to use static dout)
  * @wake_enabled: true if this device can wake the system from sleep
  * @cmd_xfer: send command to EC and get response
  *     Returns the number of bytes received if the communication succeeded, but
  *     that doesn't mean the EC was happy with the command. The caller
  *     should check msg.result for the EC's result code.
  * @pkt_xfer: send packet to EC and get response
  * @lock: one transaction at a time
  */
 struct cros_ec_device {

 	/* These are used by other drivers that want to talk to the EC */
 	const char *phys_name;
 	struct device *dev;
 	bool was_wake_device;
 	struct class *cros_class;
 	int (*cmd_readmem)(struct cros_ec_device *ec, unsigned int offset,
 			   unsigned int bytes, void *dest);

 	/* These are used to implement the platform-specific interface */
 	u16 max_request;
 	u16 max_response;
 	u16 max_passthru;
 	u16 proto_version;
 	void *priv;
 	int irq;
 	u8 *din;
 	u8 *dout;
 	int din_size;
 	int dout_size;
 	bool wake_enabled;
 	int (*cmd_xfer)(struct cros_ec_device *ec,
 			struct cros_ec_command *msg);
 	int (*pkt_xfer)(struct cros_ec_device *ec,
 			struct cros_ec_command *msg);
 	struct mutex lock;
 };

 /* struct cros_ec_platform - ChromeOS EC platform information
  *
  * @ec_name: name of EC device (e.g. 'cros-ec', 'cros-pd', ...)
  * used in /dev/ and sysfs.
  * @cmd_offset: offset to apply for each command. Set when
  * registering a devicde behind another one.
  */
 struct cros_ec_platform {
 	const char *ec_name;
 	u16 cmd_offset;
 };

 /*
  * struct cros_ec_dev - ChromeOS EC device entry point
  *
  * @class_dev: Device structure used in sysfs
  * @cdev: Character device structure in /dev
  * @ec_dev: cros_ec_device structure to talk to the physical device
  * @dev: pointer to the platform device
  * @cmd_offset: offset to apply for each command.
  */
 struct cros_ec_dev {
 	struct device class_dev;
 	struct cdev cdev;
 	struct cros_ec_device *ec_dev;
 	struct device *dev;
 	u16 cmd_offset;
 };

 /**
  * cros_ec_suspend - Handle a suspend operation for the ChromeOS EC device
  *
  * This can be called by drivers to handle a suspend event.
  *
  * ec_dev: Device to suspend
  * @return 0 if ok, -ve on error
  */
 int cros_ec_suspend(struct cros_ec_device *ec_dev);

 /**
  * cros_ec_resume - Handle a resume operation for the ChromeOS EC device
  *
  * This can be called by drivers to handle a resume event.
  *
  * @ec_dev: Device to resume
  * @return 0 if ok, -ve on error
  */
 int cros_ec_resume(struct cros_ec_device *ec_dev);

 /**
  * cros_ec_prepare_tx - Prepare an outgoing message in the output buffer
  *
  * This is intended to be used by all ChromeOS EC drivers, but at present
  * only SPI uses it. Once LPC uses the same protocol it can start using it.
  * I2C could use it now, with a refactor of the existing code.
  *
  * @ec_dev: Device to register
  * @msg: Message to write
  */
 int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
 		       struct cros_ec_command *msg);

 /**
  * cros_ec_check_result - Check ec_msg->result
  *
  * This is used by ChromeOS EC drivers to check the ec_msg->result for
  * errors and to warn about them.
  *
  * @ec_dev: EC device
  * @msg: Message to check
  */
 int cros_ec_check_result(struct cros_ec_device *ec_dev,
 			 struct cros_ec_command *msg);

 /**
  * cros_ec_cmd_xfer - Send a command to the ChromeOS EC
  *
  * Call this to send a command to the ChromeOS EC.  This should be used
  * instead of calling the EC's cmd_xfer() callback directly.
  *
  * @ec_dev: EC device
  * @msg: Message to write
  */
 int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev,
 		     struct cros_ec_command *msg);

 /**
  * cros_ec_cmd_xfer_status - Send a command to the ChromeOS EC
  *
  * This function is identical to cros_ec_cmd_xfer, except it returns success
  * status only if both the command was transmitted successfully and the EC
  * replied with success status. It's not necessary to check msg->result when
  * using this function.
  *
  * @ec_dev: EC device
  * @msg: Message to write
  * @return: Num. of bytes transferred on success, <0 on failure
  */
 int cros_ec_cmd_xfer_status(struct cros_ec_device *ec_dev,
 			    struct cros_ec_command *msg);

 /**
  * cros_ec_remove - Remove a ChromeOS EC
  *
  * Call this to deregister a ChromeOS EC, then clean up any private data.
  *
  * @ec_dev: Device to register
  * @return 0 if ok, -ve on error
  */
 int cros_ec_remove(struct cros_ec_device *ec_dev);

 /**
  * cros_ec_register - Register a new ChromeOS EC, using the provided info
  *
  * Before calling this, allocate a pointer to a new device and then fill
  * in all the fields up to the --private-- marker.
  *
  * @ec_dev: Device to register
  * @return 0 if ok, -ve on error
  */
 int cros_ec_register(struct cros_ec_device *ec_dev);

 /**
  * cros_ec_register -  Query the protocol version supported by the ChromeOS EC
  *
  * @ec_dev: Device to register
  * @return 0 if ok, -ve on error
  */
 int cros_ec_query_all(struct cros_ec_device *ec_dev);

 /* sysfs stuff */
 extern struct attribute_group cros_ec_attr_group;
 extern struct attribute_group cros_ec_lightbar_attr_group;
 extern struct attribute_group cros_ec_vbc_attr_group;

 #endif /* __LINUX_MFD_CROS_EC_H */
	/*
	* ChromeOS EC multi-function device
	*
	* Copyright (C) 2012 Google, Inc
	*
	* This software is licensed under the terms of the GNU General Public
	* License version 2, as published by the Free Software Foundation, and
	* may be copied, distributed, and modified under those terms.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*/

	#ifndef __LINUX_MFD_CROS_EC_H
	#define __LINUX_MFD_CROS_EC_H

	#include <linux/cdev.h>
	#include <linux/device.h>
	#include <linux/notifier.h>
	#include <linux/mfd/cros_ec_commands.h>
	#include <linux/mutex.h>

	#define CROS_EC_DEV_NAME "cros_ec"
	#define CROS_EC_DEV_PD_NAME "cros_pd"

	/*
	* The EC is unresponsive for a time after a reboot command. Add a
	* simple delay to make sure that the bus stays locked.
	*/
	#define EC_REBOOT_DELAY_MS 50

	/*
	* Max bus-specific overhead incurred by request/responses.
	* I2C requires 1 additional byte for requests.
	* I2C requires 2 additional bytes for responses.
	* */
	#define EC_PROTO_VERSION_UNKNOWN 0
	#define EC_MAX_REQUEST_OVERHEAD 1
	#define EC_MAX_RESPONSE_OVERHEAD 2

	/*
	* Command interface between EC and AP, for LPC, I2C and SPI interfaces.
	*/
	enum {
	EC_MSG_TX_HEADER_BYTES = 3,
	EC_MSG_TX_TRAILER_BYTES = 1,
	EC_MSG_TX_PROTO_BYTES = EC_MSG_TX_HEADER_BYTES +
	EC_MSG_TX_TRAILER_BYTES,
	EC_MSG_RX_PROTO_BYTES = 3,

	/* Max length of messages */
	EC_MSG_BYTES = EC_PROTO2_MAX_PARAM_SIZE +
	EC_MSG_TX_PROTO_BYTES,
	};

	/*
	* @version: Command version number (often 0)
	* @command: Command to send (EC_CMD_...)
	* @outsize: Outgoing length in bytes
	* @insize: Max number of bytes to accept from EC
	* @result: EC's response to the command (separate from communication failure)
	* @data: Where to put the incoming data from EC and outgoing data to EC
	*/
	struct cros_ec_command {
	uint32_t version;
	uint32_t command;
	uint32_t outsize;
	uint32_t insize;
	uint32_t result;
	uint8_t data[0];
	};

	/**
	* struct cros_ec_device - Information about a ChromeOS EC device
	*
	* @phys_name: name of physical comms layer (e.g. 'i2c-4')
	* @dev: Device pointer for physical comms device
	* @was_wake_device: true if this device was set to wake the system from
	* sleep at the last suspend
	* @cmd_readmem: direct read of the EC memory-mapped region, if supported
	* @offset is within EC_LPC_ADDR_MEMMAP region.
	* @bytes: number of bytes to read. zero means "read a string" (including
	* the trailing '\0'). At most only EC_MEMMAP_SIZE bytes can be read.
	* Caller must ensure that the buffer is large enough for the result when
	* reading a string.
	*
	* @priv: Private data
	* @irq: Interrupt to use
	* @id: Device id
	* @din: input buffer (for data from EC)
	* @dout: output buffer (for data to EC)
	* \note
	* These two buffers will always be dword-aligned and include enough
	* space for up to 7 word-alignment bytes also, so we can ensure that
	* the body of the message is always dword-aligned (64-bit).
	* We use this alignment to keep ARM and x86 happy. Probably word
	* alignment would be OK, there might be a small performance advantage
	* to using dword.
	* @din_size: size of din buffer to allocate (zero to use static din)
	* @dout_size: size of dout buffer to allocate (zero to use static dout)
	* @wake_enabled: true if this device can wake the system from sleep
	* @cmd_xfer: send command to EC and get response
	* Returns the number of bytes received if the communication succeeded, but
	* that doesn't mean the EC was happy with the command. The caller
	* should check msg.result for the EC's result code.
	* @pkt_xfer: send packet to EC and get response
	* @lock: one transaction at a time
	*/
	struct cros_ec_device {

	/* These are used by other drivers that want to talk to the EC */
	const char *phys_name;
	struct device *dev;
	bool was_wake_device;
	struct class *cros_class;
	int (cmd_readmem)(struct cros_ec_device ec, unsigned int offset,
	unsigned int bytes, void *dest);

	/* These are used to implement the platform-specific interface */
	u16 max_request;
	u16 max_response;
	u16 max_passthru;
	u16 proto_version;
	void *priv;
	int irq;
	u8 *din;
	u8 *dout;
	int din_size;
	int dout_size;
	bool wake_enabled;
	int (cmd_xfer)(struct cros_ec_device ec,
	struct cros_ec_command *msg);
	int (pkt_xfer)(struct cros_ec_device ec,
	struct cros_ec_command *msg);
	struct mutex lock;
	};

	/* struct cros_ec_platform - ChromeOS EC platform information
	*
	* @ec_name: name of EC device (e.g. 'cros-ec', 'cros-pd', ...)
	* used in /dev/ and sysfs.
	* @cmd_offset: offset to apply for each command. Set when
	* registering a devicde behind another one.
	*/
	struct cros_ec_platform {
	const char *ec_name;
	u16 cmd_offset;
	};

	/*
	* struct cros_ec_dev - ChromeOS EC device entry point
	*
	* @class_dev: Device structure used in sysfs
	* @cdev: Character device structure in /dev
	* @ec_dev: cros_ec_device structure to talk to the physical device
	* @dev: pointer to the platform device
	* @cmd_offset: offset to apply for each command.
	*/
	struct cros_ec_dev {
	struct device class_dev;
	struct cdev cdev;
	struct cros_ec_device *ec_dev;
	struct device *dev;
	u16 cmd_offset;
	};

	/**
	* cros_ec_suspend - Handle a suspend operation for the ChromeOS EC device
	*
	* This can be called by drivers to handle a suspend event.
	*
	* ec_dev: Device to suspend
	* @return 0 if ok, -ve on error
	*/
	int cros_ec_suspend(struct cros_ec_device *ec_dev);

	/**
	* cros_ec_resume - Handle a resume operation for the ChromeOS EC device
	*
	* This can be called by drivers to handle a resume event.
	*
	* @ec_dev: Device to resume
	* @return 0 if ok, -ve on error
	*/
	int cros_ec_resume(struct cros_ec_device *ec_dev);

	/**
	* cros_ec_prepare_tx - Prepare an outgoing message in the output buffer
	*
	* This is intended to be used by all ChromeOS EC drivers, but at present
	* only SPI uses it. Once LPC uses the same protocol it can start using it.
	* I2C could use it now, with a refactor of the existing code.
	*
	* @ec_dev: Device to register
	* @msg: Message to write
	*/
	int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
	struct cros_ec_command *msg);

	/**
	* cros_ec_check_result - Check ec_msg->result
	*
	* This is used by ChromeOS EC drivers to check the ec_msg->result for
	* errors and to warn about them.
	*
	* @ec_dev: EC device
	* @msg: Message to check
	*/
	int cros_ec_check_result(struct cros_ec_device *ec_dev,
	struct cros_ec_command *msg);

	/**
	* cros_ec_cmd_xfer - Send a command to the ChromeOS EC
	*
	* Call this to send a command to the ChromeOS EC. This should be used
	* instead of calling the EC's cmd_xfer() callback directly.
	*
	* @ec_dev: EC device
	* @msg: Message to write
	*/
	int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev,
	struct cros_ec_command *msg);

	/**
	* cros_ec_cmd_xfer_status - Send a command to the ChromeOS EC
	*
	* This function is identical to cros_ec_cmd_xfer, except it returns success
	* status only if both the command was transmitted successfully and the EC
	* replied with success status. It's not necessary to check msg->result when
	* using this function.
	*
	* @ec_dev: EC device
	* @msg: Message to write
	* @return: Num. of bytes transferred on success, <0 on failure
	*/
	int cros_ec_cmd_xfer_status(struct cros_ec_device *ec_dev,
	struct cros_ec_command *msg);

	/**
	* cros_ec_remove - Remove a ChromeOS EC
	*
	* Call this to deregister a ChromeOS EC, then clean up any private data.
	*
	* @ec_dev: Device to register
	* @return 0 if ok, -ve on error
	*/
	int cros_ec_remove(struct cros_ec_device *ec_dev);

	/**
	* cros_ec_register - Register a new ChromeOS EC, using the provided info
	*
	* Before calling this, allocate a pointer to a new device and then fill
	* in all the fields up to the --private-- marker.
	*
	* @ec_dev: Device to register
	* @return 0 if ok, -ve on error
	*/
	int cros_ec_register(struct cros_ec_device *ec_dev);

	/**
	* cros_ec_register - Query the protocol version supported by the ChromeOS EC
	*
	* @ec_dev: Device to register
	* @return 0 if ok, -ve on error
	*/
	int cros_ec_query_all(struct cros_ec_device *ec_dev);

	/* sysfs stuff */
	extern struct attribute_group cros_ec_attr_group;
	extern struct attribute_group cros_ec_lightbar_attr_group;
	extern struct attribute_group cros_ec_vbc_attr_group;

	#endif /* __LINUX_MFD_CROS_EC_H */