/* * 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 #include #include #include #include #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. * */ #define EC_PROTO_VERSION_UNKNOWN 0 #define EC_MAX_REQUEST_OVERHEAD 1 #define EC_MAX_RESPONSE_OVERHEAD 2 /* * 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 * @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 */ 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; 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; }; /* 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_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 * @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; u16 cmd_offset; }; /** * 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_register - 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); /* 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; #endif /* __LINUX_MFD_CROS_EC_H */