/* SPDX-License-Identifier: GPL-2.0-only */
/*
* ChromeOS EC multi-function device
*
* Copyright (C) 2012 Google, Inc
*/
#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_FP_NAME "cros_fp"
#define CROS_EC_DEV_PD_NAME "cros_pd"
#define CROS_EC_DEV_TP_NAME "cros_tp"
#define CROS_EC_DEV_ISH_NAME "cros_ish"
#define CROS_EC_DEV_SCP_NAME "cros_scp"
/*
* 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,
};
/**
* struct cros_ec_command - Information about a ChromeOS EC command.
* @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 the 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.
* @cros_class: The class structure for this device.
* @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.
* @max_request: Max size of message requested.
* @max_response: Max size of message response.
* @max_passthru: Max sice of passthru message.
* @proto_version: The protocol version used for this device.
* @priv: Private data.
* @irq: Interrupt to use.
* @id: Device id.
* @din: Input buffer (for data from EC). This buffer 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.
* @dout: Output buffer (for data to EC). This buffer 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.
* @host_sleep_v1: True if this EC supports the sleep v1 command.
* @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.
* @host_event_wake_mask: Mask of host events that cause wake from suspend.
*/
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;
bool host_sleep_v1;
struct blocking_notifier_head event_notifier;
struct ec_response_get_next_event_v1 event_data;
int event_size;
u32 host_event_wake_mask;
u32 last_resume_result;
};
/**
* 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 device 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.
* @has_kb_wake_angle: True if at least 2 accelerometer are connected to the EC.
* @cmd_offset: Offset to apply for each command.
* @features: Features supported by the EC.
*/
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;
bool has_kb_wake_angle;
u16 cmd_offset;
u32 features[2];
};
#define to_cros_ec_dev(dev) container_of(dev, struct cros_ec_dev, class_dev)
/**
* cros_ec_suspend() - Handle a suspend operation for the ChromeOS EC device.
* @ec_dev: Device to suspend.
*
* This can be called by drivers to handle a suspend event.
*
* Return: 0 on success or negative error code.
*/
int cros_ec_suspend(struct cros_ec_device *ec_dev);
/**
* cros_ec_resume() - Handle a resume operation for the ChromeOS EC device.
* @ec_dev: Device to resume.
*
* This can be called by drivers to handle a resume event.
*
* Return: 0 on success or negative error code.
*/
int cros_ec_resume(struct cros_ec_device *ec_dev);
/**
* cros_ec_prepare_tx() - Prepare an outgoing message in the output buffer.
* @ec_dev: Device to register.
* @msg: Message to write.
*
* 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.
*
* Return: 0 on success or negative error code.
*/
int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
struct cros_ec_command *msg);
/**
* cros_ec_check_result() - Check ec_msg->result.
* @ec_dev: EC device.
* @msg: Message to check.
*
* This is used by ChromeOS EC drivers to check the ec_msg->result for
* errors and to warn about them.
*
* Return: 0 on success or negative error code.
*/
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.
* @ec_dev: EC device.
* @msg: Message to write.
*
* Call this to send a command to the ChromeOS EC. This should be used
* instead of calling the EC's cmd_xfer() callback directly.
*
* Return: 0 on success or negative error code.
*/
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.
* @ec_dev: EC device.
* @msg: Message to write.
*
* 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.
*
* Return: The number of bytes transferred on success or negative error code.
*/
int cros_ec_cmd_xfer_status(struct cros_ec_device *ec_dev,
struct cros_ec_command *msg);
/**
* cros_ec_register() - Register a new ChromeOS EC, using the provided info.
* @ec_dev: Device to register.
*
* Before calling this, allocate a pointer to a new device and then fill
* in all the fields up to the --private-- marker.
*
* Return: 0 on success or negative error code.
*/
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 on success or negative error code.
*/
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.
*
* Return: negative error code on errors; 0 for no data; or else number of
* bytes received (i.e., an event was retrieved successfully). Event types are
* written out to @ec_dev->event_data.event_type on success.
*/
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 ChromeOS EC.
* @ec_dev: Device to fetch event from.
*
* 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.
*
* Return: 0 on error or non-zero bitmask of one or more EC_HOST_EVENT_*.
*/
u32 cros_ec_get_host_event(struct cros_ec_device *ec_dev);
#endif /* __LINUX_MFD_CROS_EC_H */
