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Diffstat (limited to 'include/linux/platform_data/cros_ec_proto.h')
| -rw-r--r-- | include/linux/platform_data/cros_ec_proto.h | 319 |
1 files changed, 319 insertions, 0 deletions
diff --git a/include/linux/platform_data/cros_ec_proto.h b/include/linux/platform_data/cros_ec_proto.h new file mode 100644 index 000000000000..eab7036cda09 --- /dev/null +++ b/include/linux/platform_data/cros_ec_proto.h @@ -0,0 +1,319 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * ChromeOS Embedded Controller protocol interface. + * + * Copyright (C) 2012 Google, Inc + */ + +#ifndef __LINUX_CROS_EC_PROTO_H +#define __LINUX_CROS_EC_PROTO_H + +#include <linux/device.h> +#include <linux/mutex.h> +#include <linux/notifier.h> + +#include <linux/platform_data/cros_ec_commands.h> + +#define CROS_EC_DEV_NAME "cros_ec" +#define CROS_EC_DEV_FP_NAME "cros_fp" +#define CROS_EC_DEV_ISH_NAME "cros_ish" +#define CROS_EC_DEV_PD_NAME "cros_pd" +#define CROS_EC_DEV_SCP_NAME "cros_scp" +#define CROS_EC_DEV_TP_NAME "cros_tp" + +/* + * 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. + * @ec: The platform_device used by the mfd driver to interface with the + * main EC. + * @pd: The platform_device used by the mfd driver to interface with the + * PD behind an EC. + */ +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; + + /* The platform devices used by the mfd driver */ + struct platform_device *ec; + struct platform_device *pd; +}; + +/** + * 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; +}; + +/** + * 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_unregister() - Remove a ChromeOS EC. + * @ec_dev: Device to unregister. + * + * Call this to deregister a ChromeOS EC, then clean up any private data. + * + * Return: 0 on success or negative error code. + */ +int cros_ec_unregister(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_CROS_EC_PROTO_H */ |