260 lines
7.7 KiB
C
260 lines
7.7 KiB
C
/*
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* ChromeOS EC multi-function device
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*
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* Copyright (C) 2012 Google, Inc
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*
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* This software is licensed under the terms of the GNU General Public
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* License version 2, as published by the Free Software Foundation, and
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* may be copied, distributed, and modified under those terms.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#ifndef __LINUX_MFD_CROS_EC_H
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#define __LINUX_MFD_CROS_EC_H
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#include <linux/cdev.h>
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#include <linux/device.h>
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#include <linux/notifier.h>
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#include <linux/mfd/cros_ec_commands.h>
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#include <linux/mutex.h>
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#define CROS_EC_DEV_NAME "cros_ec"
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#define CROS_EC_DEV_PD_NAME "cros_pd"
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/*
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* The EC is unresponsive for a time after a reboot command. Add a
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* simple delay to make sure that the bus stays locked.
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*/
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#define EC_REBOOT_DELAY_MS 50
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/*
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* Max bus-specific overhead incurred by request/responses.
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* I2C requires 1 additional byte for requests.
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* I2C requires 2 additional bytes for responses.
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* */
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#define EC_PROTO_VERSION_UNKNOWN 0
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#define EC_MAX_REQUEST_OVERHEAD 1
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#define EC_MAX_RESPONSE_OVERHEAD 2
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/*
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* Command interface between EC and AP, for LPC, I2C and SPI interfaces.
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*/
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enum {
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EC_MSG_TX_HEADER_BYTES = 3,
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EC_MSG_TX_TRAILER_BYTES = 1,
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EC_MSG_TX_PROTO_BYTES = EC_MSG_TX_HEADER_BYTES +
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EC_MSG_TX_TRAILER_BYTES,
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EC_MSG_RX_PROTO_BYTES = 3,
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/* Max length of messages */
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EC_MSG_BYTES = EC_PROTO2_MAX_PARAM_SIZE +
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EC_MSG_TX_PROTO_BYTES,
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};
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/*
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* @version: Command version number (often 0)
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* @command: Command to send (EC_CMD_...)
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* @outsize: Outgoing length in bytes
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* @insize: Max number of bytes to accept from EC
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* @result: EC's response to the command (separate from communication failure)
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* @data: Where to put the incoming data from EC and outgoing data to EC
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*/
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struct cros_ec_command {
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uint32_t version;
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uint32_t command;
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uint32_t outsize;
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uint32_t insize;
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uint32_t result;
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uint8_t data[0];
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};
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/**
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* struct cros_ec_device - Information about a ChromeOS EC device
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*
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* @phys_name: name of physical comms layer (e.g. 'i2c-4')
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* @dev: Device pointer for physical comms device
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* @was_wake_device: true if this device was set to wake the system from
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* sleep at the last suspend
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* @cmd_readmem: direct read of the EC memory-mapped region, if supported
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* @offset is within EC_LPC_ADDR_MEMMAP region.
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* @bytes: number of bytes to read. zero means "read a string" (including
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* the trailing '\0'). At most only EC_MEMMAP_SIZE bytes can be read.
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* Caller must ensure that the buffer is large enough for the result when
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* reading a string.
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*
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* @priv: Private data
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* @irq: Interrupt to use
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* @id: Device id
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* @din: input buffer (for data from EC)
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* @dout: output buffer (for data to EC)
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* \note
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* These two buffers will always be dword-aligned and include enough
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* space for up to 7 word-alignment bytes also, so we can ensure that
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* the body of the message is always dword-aligned (64-bit).
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* We use this alignment to keep ARM and x86 happy. Probably word
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* alignment would be OK, there might be a small performance advantage
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* to using dword.
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* @din_size: size of din buffer to allocate (zero to use static din)
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* @dout_size: size of dout buffer to allocate (zero to use static dout)
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* @wake_enabled: true if this device can wake the system from sleep
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* @cmd_xfer: send command to EC and get response
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* Returns the number of bytes received if the communication succeeded, but
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* that doesn't mean the EC was happy with the command. The caller
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* should check msg.result for the EC's result code.
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* @pkt_xfer: send packet to EC and get response
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* @lock: one transaction at a time
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*/
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struct cros_ec_device {
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/* These are used by other drivers that want to talk to the EC */
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const char *phys_name;
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struct device *dev;
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bool was_wake_device;
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struct class *cros_class;
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int (*cmd_readmem)(struct cros_ec_device *ec, unsigned int offset,
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unsigned int bytes, void *dest);
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/* These are used to implement the platform-specific interface */
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u16 max_request;
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u16 max_response;
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u16 max_passthru;
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u16 proto_version;
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void *priv;
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int irq;
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u8 *din;
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u8 *dout;
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int din_size;
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int dout_size;
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bool wake_enabled;
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int (*cmd_xfer)(struct cros_ec_device *ec,
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struct cros_ec_command *msg);
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int (*pkt_xfer)(struct cros_ec_device *ec,
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struct cros_ec_command *msg);
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struct mutex lock;
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};
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/* struct cros_ec_platform - ChromeOS EC platform information
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*
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* @ec_name: name of EC device (e.g. 'cros-ec', 'cros-pd', ...)
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* used in /dev/ and sysfs.
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* @cmd_offset: offset to apply for each command. Set when
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* registering a devicde behind another one.
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*/
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struct cros_ec_platform {
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const char *ec_name;
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u16 cmd_offset;
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};
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/*
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* struct cros_ec_dev - ChromeOS EC device entry point
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*
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* @class_dev: Device structure used in sysfs
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* @cdev: Character device structure in /dev
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* @ec_dev: cros_ec_device structure to talk to the physical device
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* @dev: pointer to the platform device
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* @cmd_offset: offset to apply for each command.
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*/
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struct cros_ec_dev {
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struct device class_dev;
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struct cdev cdev;
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struct cros_ec_device *ec_dev;
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struct device *dev;
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u16 cmd_offset;
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};
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/**
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* cros_ec_suspend - Handle a suspend operation for the ChromeOS EC device
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*
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* This can be called by drivers to handle a suspend event.
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*
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* ec_dev: Device to suspend
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* @return 0 if ok, -ve on error
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*/
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int cros_ec_suspend(struct cros_ec_device *ec_dev);
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/**
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* cros_ec_resume - Handle a resume operation for the ChromeOS EC device
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*
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* This can be called by drivers to handle a resume event.
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*
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* @ec_dev: Device to resume
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* @return 0 if ok, -ve on error
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*/
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int cros_ec_resume(struct cros_ec_device *ec_dev);
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/**
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* cros_ec_prepare_tx - Prepare an outgoing message in the output buffer
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*
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* This is intended to be used by all ChromeOS EC drivers, but at present
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* only SPI uses it. Once LPC uses the same protocol it can start using it.
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* I2C could use it now, with a refactor of the existing code.
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*
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* @ec_dev: Device to register
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* @msg: Message to write
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*/
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int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
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struct cros_ec_command *msg);
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/**
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* cros_ec_check_result - Check ec_msg->result
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*
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* This is used by ChromeOS EC drivers to check the ec_msg->result for
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* errors and to warn about them.
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*
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* @ec_dev: EC device
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* @msg: Message to check
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*/
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int cros_ec_check_result(struct cros_ec_device *ec_dev,
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struct cros_ec_command *msg);
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/**
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* cros_ec_cmd_xfer - Send a command to the ChromeOS EC
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*
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* Call this to send a command to the ChromeOS EC. This should be used
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* instead of calling the EC's cmd_xfer() callback directly.
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*
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* @ec_dev: EC device
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* @msg: Message to write
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*/
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int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev,
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struct cros_ec_command *msg);
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/**
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* cros_ec_remove - Remove a ChromeOS EC
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*
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* Call this to deregister a ChromeOS EC, then clean up any private data.
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*
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* @ec_dev: Device to register
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* @return 0 if ok, -ve on error
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*/
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int cros_ec_remove(struct cros_ec_device *ec_dev);
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/**
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* cros_ec_register - Register a new ChromeOS EC, using the provided info
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*
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* Before calling this, allocate a pointer to a new device and then fill
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* in all the fields up to the --private-- marker.
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*
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* @ec_dev: Device to register
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* @return 0 if ok, -ve on error
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*/
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int cros_ec_register(struct cros_ec_device *ec_dev);
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/**
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* cros_ec_register - Query the protocol version supported by the ChromeOS EC
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*
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* @ec_dev: Device to register
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* @return 0 if ok, -ve on error
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*/
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int cros_ec_query_all(struct cros_ec_device *ec_dev);
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/* sysfs stuff */
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extern struct attribute_group cros_ec_attr_group;
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extern struct attribute_group cros_ec_lightbar_attr_group;
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#endif /* __LINUX_MFD_CROS_EC_H */
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