320 lines
11 KiB
C
320 lines
11 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* ChromeOS Embedded Controller protocol interface.
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*
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* Copyright (C) 2012 Google, Inc
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*/
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#ifndef __LINUX_CROS_EC_PROTO_H
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#define __LINUX_CROS_EC_PROTO_H
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#include <linux/device.h>
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#include <linux/mutex.h>
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#include <linux/notifier.h>
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#include <linux/platform_data/cros_ec_commands.h>
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#define CROS_EC_DEV_NAME "cros_ec"
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#define CROS_EC_DEV_FP_NAME "cros_fp"
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#define CROS_EC_DEV_ISH_NAME "cros_ish"
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#define CROS_EC_DEV_PD_NAME "cros_pd"
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#define CROS_EC_DEV_SCP_NAME "cros_scp"
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#define CROS_EC_DEV_TP_NAME "cros_tp"
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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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* SPI requires up to 32 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 32
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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 for proto 2*/
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EC_PROTO2_MSG_BYTES = EC_PROTO2_MAX_PARAM_SIZE +
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EC_MSG_TX_PROTO_BYTES,
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EC_MAX_MSG_BYTES = 64 * 1024,
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};
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/**
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* struct cros_ec_command - Information about a ChromeOS EC command.
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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 the 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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* @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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* @cros_class: The class structure for this device.
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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
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* read. Caller must ensure that the buffer is large enough for the
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* result when reading a string.
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* @max_request: Max size of message requested.
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* @max_response: Max size of message response.
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* @max_passthru: Max sice of passthru message.
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* @proto_version: The protocol version used for this device.
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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). This buffer will always be
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* dword-aligned and include enough space for up to 7 word-alignment
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* bytes also, so we can ensure that the body of the message is always
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* dword-aligned (64-bit). We use this alignment to keep ARM and x86
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* happy. Probably word alignment would be OK, there might be a small
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* performance advantage to using dword.
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* @dout: Output buffer (for data to EC). This buffer will always be
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* dword-aligned and include enough space for up to 7 word-alignment
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* bytes also, so we can ensure that the body of the message is always
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* dword-aligned (64-bit). We use this alignment to keep ARM and x86
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* happy. Probably word alignment would be OK, there might be a small
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* performance advantage 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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* @suspended: True if this device had been suspended.
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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
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* succeeded, but that doesn't mean the EC was happy with the
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* command. The caller should check msg.result for the EC's result
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* 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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* @mkbp_event_supported: True if this EC supports the MKBP event protocol.
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* @host_sleep_v1: True if this EC supports the sleep v1 command.
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* @event_notifier: Interrupt event notifier for transport devices.
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* @event_data: Raw payload transferred with the MKBP event.
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* @event_size: Size in bytes of the event data.
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* @host_event_wake_mask: Mask of host events that cause wake from suspend.
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* @ec: The platform_device used by the mfd driver to interface with the
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* main EC.
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* @pd: The platform_device used by the mfd driver to interface with the
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* PD behind an EC.
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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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bool suspended;
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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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bool mkbp_event_supported;
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bool host_sleep_v1;
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struct blocking_notifier_head event_notifier;
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struct ec_response_get_next_event_v1 event_data;
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int event_size;
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u32 host_event_wake_mask;
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u32 last_resume_result;
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/* The platform devices used by the mfd driver */
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struct platform_device *ec;
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struct platform_device *pd;
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};
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/**
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* struct cros_ec_sensor_platform - ChromeOS EC sensor platform information.
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* @sensor_num: Id of the sensor, as reported by the EC.
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*/
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struct cros_ec_sensor_platform {
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u8 sensor_num;
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};
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/**
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* struct cros_ec_platform - ChromeOS EC platform information.
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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 device 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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* cros_ec_suspend() - Handle a suspend operation for the ChromeOS EC device.
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* @ec_dev: Device to suspend.
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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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* Return: 0 on success or negative error code.
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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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* @ec_dev: Device to resume.
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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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* Return: 0 on success or negative error code.
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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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* @ec_dev: Device to register.
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* @msg: Message to write.
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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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* Return: 0 on success or negative error code.
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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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* @ec_dev: EC device.
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* @msg: Message to check.
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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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* Return: 0 on success or negative error code.
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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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* @ec_dev: EC device.
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* @msg: Message to write.
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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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* Return: 0 on success or negative error code.
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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_cmd_xfer_status() - Send a command to the ChromeOS EC.
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* @ec_dev: EC device.
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* @msg: Message to write.
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*
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* This function is identical to cros_ec_cmd_xfer, except it returns success
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* status only if both the command was transmitted successfully and the EC
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* replied with success status. It's not necessary to check msg->result when
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* using this function.
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*
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* Return: The number of bytes transferred on success or negative error code.
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*/
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int cros_ec_cmd_xfer_status(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_register() - Register a new ChromeOS EC, using the provided info.
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* @ec_dev: Device to register.
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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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* Return: 0 on success or negative error code.
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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_unregister() - Remove a ChromeOS EC.
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* @ec_dev: Device to unregister.
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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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* Return: 0 on success or negative error code.
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*/
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int cros_ec_unregister(struct cros_ec_device *ec_dev);
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/**
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* cros_ec_query_all() - Query the protocol version supported by the
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* ChromeOS EC.
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* @ec_dev: Device to register.
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*
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* Return: 0 on success or negative error code.
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*/
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int cros_ec_query_all(struct cros_ec_device *ec_dev);
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/**
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* cros_ec_get_next_event() - Fetch next event from the ChromeOS EC.
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* @ec_dev: Device to fetch event from.
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* @wake_event: Pointer to a bool set to true upon return if the event might be
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* treated as a wake event. Ignored if null.
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*
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* Return: negative error code on errors; 0 for no data; or else number of
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* bytes received (i.e., an event was retrieved successfully). Event types are
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* written out to @ec_dev->event_data.event_type on success.
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*/
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int cros_ec_get_next_event(struct cros_ec_device *ec_dev, bool *wake_event);
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/**
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* cros_ec_get_host_event() - Return a mask of event set by the ChromeOS EC.
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* @ec_dev: Device to fetch event from.
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*
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* When MKBP is supported, when the EC raises an interrupt, we collect the
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* events raised and call the functions in the ec notifier. This function
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* is a helper to know which events are raised.
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*
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* Return: 0 on error or non-zero bitmask of one or more EC_HOST_EVENT_*.
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*/
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u32 cros_ec_get_host_event(struct cros_ec_device *ec_dev);
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#endif /* __LINUX_CROS_EC_PROTO_H */
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