/*
* 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.
* SPI requires up to 32 additional bytes for responses.
* */
#define EC_PROTO_VERSION_UNKNOWN 0
#define EC_MAX_REQUEST_OVERHEAD 1
#define EC_MAX_RESPONSE_OVERHEAD 32
/*
* 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 for proto 2*/
EC_PROTO2_MSG_BYTES = EC_PROTO2_MAX_PARAM_SIZE +
EC_MSG_TX_PROTO_BYTES,
EC_MAX_MSG_BYTES = 64 * 1024,
};
/*
* @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
* @suspended: true if this device had been suspended
* @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
* @mkbp_event_supported: true if this EC supports the MKBP event protocol.
* @event_notifier: interrupt event notifier for transport devices.
* @event_data: raw payload transferred with the MKBP event.
* @event_size: size in bytes of the event data.
*/
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;
bool suspended;
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;
bool mkbp_event_supported;
struct blocking_notifier_head event_notifier;
struct ec_response_get_next_event event_data;
int event_size;
u32 host_event_wake_mask;
};
/**
* struct cros_ec_sensor_platform - ChromeOS EC sensor platform information
*
* @sensor_num: Id of the sensor, as reported by the EC.
*/
struct cros_ec_sensor_platform {
u8 sensor_num;
};
/* 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_debugfs;
/*
* 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
* @debug_info: cros_ec_debugfs structure for debugging information
* @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;
struct cros_ec_debugfs *debug_info;
u16 cmd_offset;
u32 features[2];
};
/**
* 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_query_all - 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);
/**
* cros_ec_get_next_event - Fetch next event from the ChromeOS EC
*
* @ec_dev: Device to fetch event from
* @wake_event: Pointer to a bool set to true upon return if the event might be
* treated as a wake event. Ignored if null.
*
* Returns: 0 on success, Linux error number on failure
*/
int cros_ec_get_next_event(struct cros_ec_device *ec_dev, bool *wake_event);
/**
* cros_ec_get_host_event - Return a mask of event set by the EC.
*
* When MKBP is supported, when the EC raises an interrupt,
* We collect the events raised and call the functions in the ec notifier.
*
* This function is a helper to know which events are raised.
*/
u32 cros_ec_get_host_event(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;
/* debugfs stuff */
int cros_ec_debugfs_init(struct cros_ec_dev *ec);
void cros_ec_debugfs_remove(struct cros_ec_dev *ec);
/* ACPI GPE handler */
#ifdef CONFIG_ACPI
int cros_ec_acpi_install_gpe_handler(struct device *dev);
void cros_ec_acpi_remove_gpe_handler(void);
void cros_ec_acpi_clear_gpe(void);
#else /* CONFIG_ACPI */
static inline int cros_ec_acpi_install_gpe_handler(struct device *dev)
{
return -ENODEV;
}
static inline void cros_ec_acpi_remove_gpe_handler(void) {}
static inline void cros_ec_acpi_clear_gpe(void) {}
#endif /* CONFIG_ACPI */
#endif /* __LINUX_MFD_CROS_EC_H */
