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Diffstat (limited to 'include/linux/mfd/cros_ec.h')
| -rw-r--r-- | include/linux/mfd/cros_ec.h | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h new file mode 100644 index 00000000000..032af7fc5b2 --- /dev/null +++ b/include/linux/mfd/cros_ec.h @@ -0,0 +1,170 @@ +/* + * 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/mfd/cros_ec_commands.h> + +/* + * 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 */ + EC_MSG_BYTES = EC_HOST_PARAM_SIZE + EC_MSG_TX_PROTO_BYTES, + +}; + +/** + * struct cros_ec_msg - A message sent to the EC, and its reply + * + * @version: Command version number (often 0) + * @cmd: Command to send (EC_CMD_...) + * @out_buf: Outgoing payload (to EC) + * @outlen: Outgoing length + * @in_buf: Incoming payload (from EC) + * @in_len: Incoming length + */ +struct cros_ec_msg { + u8 version; + u8 cmd; + uint8_t *out_buf; + int out_len; + uint8_t *in_buf; + int in_len; +}; + +/** + * struct cros_ec_device - Information about a ChromeOS EC device + * + * @name: Name of this EC interface + * @priv: Private data + * @irq: Interrupt to use + * @din: input buffer (from EC) + * @dout: output buffer (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 + * @dout_size: size of dout buffer + * @command_send: send a command + * @command_recv: receive a command + * @ec_name: name of EC device (e.g. 'chromeos-ec') + * @phys_name: name of physical comms layer (e.g. 'i2c-4') + * @parent: pointer to parent device (e.g. i2c or spi device) + * @dev: Device pointer + * dev_lock: Lock to prevent concurrent access + * @wake_enabled: true if this device can wake the system from sleep + * @was_wake_device: true if this device was set to wake the system from + * sleep at the last suspend + * @event_notifier: interrupt event notifier for transport devices + */ +struct cros_ec_device { + const char *name; + void *priv; + int irq; + uint8_t *din; + uint8_t *dout; + int din_size; + int dout_size; + int (*command_send)(struct cros_ec_device *ec, + uint16_t cmd, void *out_buf, int out_len); + int (*command_recv)(struct cros_ec_device *ec, + uint16_t cmd, void *in_buf, int in_len); + int (*command_sendrecv)(struct cros_ec_device *ec, + uint16_t cmd, void *out_buf, int out_len, + void *in_buf, int in_len); + int (*command_xfer)(struct cros_ec_device *ec, + struct cros_ec_msg *msg); + + const char *ec_name; + const char *phys_name; + struct device *parent; + + /* These are --private-- fields - do not assign */ + struct device *dev; + struct mutex dev_lock; + bool wake_enabled; + bool was_wake_device; + struct blocking_notifier_head event_notifier; +}; + +/** + * 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_msg *msg); + +/** + * cros_ec_remove - Remove a ChromeOS EC + * + * Call this to deregister a ChromeOS EC. After this you should call + * cros_ec_free(). + * + * @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); + +#endif /* __LINUX_MFD_CROS_EC_H */ |