2 * ChromeOS EC multi-function device
4 * Copyright (C) 2012 Google, Inc
6 * This software is licensed under the terms of the GNU General Public
7 * License version 2, as published by the Free Software Foundation, and
8 * may be copied, distributed, and modified under those terms.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
16 #ifndef __LINUX_MFD_CROS_EC_H
17 #define __LINUX_MFD_CROS_EC_H
19 #include <linux/cdev.h>
20 #include <linux/notifier.h>
21 #include <linux/mfd/cros_ec_commands.h>
22 #include <linux/mutex.h>
25 * Command interface between EC and AP, for LPC, I2C and SPI interfaces.
28 EC_MSG_TX_HEADER_BYTES = 3,
29 EC_MSG_TX_TRAILER_BYTES = 1,
30 EC_MSG_TX_PROTO_BYTES = EC_MSG_TX_HEADER_BYTES +
31 EC_MSG_TX_TRAILER_BYTES,
32 EC_MSG_RX_PROTO_BYTES = 3,
34 /* Max length of messages */
35 EC_MSG_BYTES = EC_PROTO2_MAX_PARAM_SIZE +
36 EC_MSG_TX_PROTO_BYTES,
40 * @version: Command version number (often 0)
41 * @command: Command to send (EC_CMD_...)
42 * @outsize: Outgoing length in bytes
43 * @insize: Max number of bytes to accept from EC
44 * @result: EC's response to the command (separate from communication failure)
45 * @data: Where to put the incoming data from EC and outgoing data to EC
47 struct cros_ec_command {
57 * struct cros_ec_device - Information about a ChromeOS EC device
59 * @ec_name: name of EC device (e.g. 'chromeos-ec')
60 * @phys_name: name of physical comms layer (e.g. 'i2c-4')
61 * @dev: Device pointer for physical comms device
62 * @vdev: Device pointer for virtual comms device
63 * @cdev: Character device structure for virtual comms device
64 * @was_wake_device: true if this device was set to wake the system from
65 * sleep at the last suspend
66 * @cmd_readmem: direct read of the EC memory-mapped region, if supported
67 * @offset is within EC_LPC_ADDR_MEMMAP region.
68 * @bytes: number of bytes to read. zero means "read a string" (including
69 * the trailing '\0'). At most only EC_MEMMAP_SIZE bytes can be read.
70 * Caller must ensure that the buffer is large enough for the result when
74 * @irq: Interrupt to use
75 * @din: input buffer (for data from EC)
76 * @dout: output buffer (for data to EC)
78 * These two buffers will always be dword-aligned and include enough
79 * space for up to 7 word-alignment bytes also, so we can ensure that
80 * the body of the message is always dword-aligned (64-bit).
81 * We use this alignment to keep ARM and x86 happy. Probably word
82 * alignment would be OK, there might be a small performance advantage
84 * @din_size: size of din buffer to allocate (zero to use static din)
85 * @dout_size: size of dout buffer to allocate (zero to use static dout)
86 * @wake_enabled: true if this device can wake the system from sleep
87 * @cmd_xfer: send command to EC and get response
88 * Returns the number of bytes received if the communication succeeded, but
89 * that doesn't mean the EC was happy with the command. The caller
90 * should check msg.result for the EC's result code.
91 * @lock: one transaction at a time
93 struct cros_ec_device {
95 /* These are used by other drivers that want to talk to the EC */
97 const char *phys_name;
101 bool was_wake_device;
102 struct class *cros_class;
103 int (*cmd_readmem)(struct cros_ec_device *ec, unsigned int offset,
104 unsigned int bytes, void *dest);
106 /* These are used to implement the platform-specific interface */
114 int (*cmd_xfer)(struct cros_ec_device *ec,
115 struct cros_ec_command *msg);
120 * cros_ec_suspend - Handle a suspend operation for the ChromeOS EC device
122 * This can be called by drivers to handle a suspend event.
124 * ec_dev: Device to suspend
125 * @return 0 if ok, -ve on error
127 int cros_ec_suspend(struct cros_ec_device *ec_dev);
130 * cros_ec_resume - Handle a resume operation for the ChromeOS EC device
132 * This can be called by drivers to handle a resume event.
134 * @ec_dev: Device to resume
135 * @return 0 if ok, -ve on error
137 int cros_ec_resume(struct cros_ec_device *ec_dev);
140 * cros_ec_prepare_tx - Prepare an outgoing message in the output buffer
142 * This is intended to be used by all ChromeOS EC drivers, but at present
143 * only SPI uses it. Once LPC uses the same protocol it can start using it.
144 * I2C could use it now, with a refactor of the existing code.
146 * @ec_dev: Device to register
147 * @msg: Message to write
149 int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
150 struct cros_ec_command *msg);
153 * cros_ec_check_result - Check ec_msg->result
155 * This is used by ChromeOS EC drivers to check the ec_msg->result for
156 * errors and to warn about them.
159 * @msg: Message to check
161 int cros_ec_check_result(struct cros_ec_device *ec_dev,
162 struct cros_ec_command *msg);
165 * cros_ec_cmd_xfer - Send a command to the ChromeOS EC
167 * Call this to send a command to the ChromeOS EC. This should be used
168 * instead of calling the EC's cmd_xfer() callback directly.
171 * @msg: Message to write
173 int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev,
174 struct cros_ec_command *msg);
177 * cros_ec_remove - Remove a ChromeOS EC
179 * Call this to deregister a ChromeOS EC, then clean up any private data.
181 * @ec_dev: Device to register
182 * @return 0 if ok, -ve on error
184 int cros_ec_remove(struct cros_ec_device *ec_dev);
187 * cros_ec_register - Register a new ChromeOS EC, using the provided info
189 * Before calling this, allocate a pointer to a new device and then fill
190 * in all the fields up to the --private-- marker.
192 * @ec_dev: Device to register
193 * @return 0 if ok, -ve on error
195 int cros_ec_register(struct cros_ec_device *ec_dev);
197 #endif /* __LINUX_MFD_CROS_EC_H */