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/device.h>
21 #include <linux/notifier.h>
22 #include <linux/mfd/cros_ec_commands.h>
23 #include <linux/mutex.h>
25 #define CROS_EC_DEV_NAME "cros_ec"
26 #define CROS_EC_DEV_PD_NAME "cros_pd"
29 * The EC is unresponsive for a time after a reboot command. Add a
30 * simple delay to make sure that the bus stays locked.
32 #define EC_REBOOT_DELAY_MS 50
35 * Max bus-specific overhead incurred by request/responses.
36 * I2C requires 1 additional byte for requests.
37 * I2C requires 2 additional bytes for responses.
39 #define EC_PROTO_VERSION_UNKNOWN 0
40 #define EC_MAX_REQUEST_OVERHEAD 1
41 #define EC_MAX_RESPONSE_OVERHEAD 2
44 * Command interface between EC and AP, for LPC, I2C and SPI interfaces.
47 EC_MSG_TX_HEADER_BYTES = 3,
48 EC_MSG_TX_TRAILER_BYTES = 1,
49 EC_MSG_TX_PROTO_BYTES = EC_MSG_TX_HEADER_BYTES +
50 EC_MSG_TX_TRAILER_BYTES,
51 EC_MSG_RX_PROTO_BYTES = 3,
53 /* Max length of messages */
54 EC_MSG_BYTES = EC_PROTO2_MAX_PARAM_SIZE +
55 EC_MSG_TX_PROTO_BYTES,
59 * @version: Command version number (often 0)
60 * @command: Command to send (EC_CMD_...)
61 * @outsize: Outgoing length in bytes
62 * @insize: Max number of bytes to accept from EC
63 * @result: EC's response to the command (separate from communication failure)
64 * @data: Where to put the incoming data from EC and outgoing data to EC
66 struct cros_ec_command {
76 * struct cros_ec_device - Information about a ChromeOS EC device
78 * @phys_name: name of physical comms layer (e.g. 'i2c-4')
79 * @dev: Device pointer for physical comms device
80 * @was_wake_device: true if this device was set to wake the system from
81 * sleep at the last suspend
82 * @cmd_readmem: direct read of the EC memory-mapped region, if supported
83 * @offset is within EC_LPC_ADDR_MEMMAP region.
84 * @bytes: number of bytes to read. zero means "read a string" (including
85 * the trailing '\0'). At most only EC_MEMMAP_SIZE bytes can be read.
86 * Caller must ensure that the buffer is large enough for the result when
90 * @irq: Interrupt to use
92 * @din: input buffer (for data from EC)
93 * @dout: output buffer (for data to EC)
95 * These two buffers will always be dword-aligned and include enough
96 * space for up to 7 word-alignment bytes also, so we can ensure that
97 * the body of the message is always dword-aligned (64-bit).
98 * We use this alignment to keep ARM and x86 happy. Probably word
99 * alignment would be OK, there might be a small performance advantage
101 * @din_size: size of din buffer to allocate (zero to use static din)
102 * @dout_size: size of dout buffer to allocate (zero to use static dout)
103 * @wake_enabled: true if this device can wake the system from sleep
104 * @cmd_xfer: send command to EC and get response
105 * Returns the number of bytes received if the communication succeeded, but
106 * that doesn't mean the EC was happy with the command. The caller
107 * should check msg.result for the EC's result code.
108 * @pkt_xfer: send packet to EC and get response
109 * @lock: one transaction at a time
111 struct cros_ec_device {
113 /* These are used by other drivers that want to talk to the EC */
114 const char *phys_name;
116 bool was_wake_device;
117 struct class *cros_class;
118 int (*cmd_readmem)(struct cros_ec_device *ec, unsigned int offset,
119 unsigned int bytes, void *dest);
121 /* These are used to implement the platform-specific interface */
133 int (*cmd_xfer)(struct cros_ec_device *ec,
134 struct cros_ec_command *msg);
135 int (*pkt_xfer)(struct cros_ec_device *ec,
136 struct cros_ec_command *msg);
140 /* struct cros_ec_platform - ChromeOS EC platform information
142 * @ec_name: name of EC device (e.g. 'cros-ec', 'cros-pd', ...)
143 * used in /dev/ and sysfs.
144 * @cmd_offset: offset to apply for each command. Set when
145 * registering a devicde behind another one.
147 struct cros_ec_platform {
153 * struct cros_ec_dev - ChromeOS EC device entry point
155 * @class_dev: Device structure used in sysfs
156 * @cdev: Character device structure in /dev
157 * @ec_dev: cros_ec_device structure to talk to the physical device
158 * @dev: pointer to the platform device
159 * @cmd_offset: offset to apply for each command.
162 struct device class_dev;
164 struct cros_ec_device *ec_dev;
170 * cros_ec_suspend - Handle a suspend operation for the ChromeOS EC device
172 * This can be called by drivers to handle a suspend event.
174 * ec_dev: Device to suspend
175 * @return 0 if ok, -ve on error
177 int cros_ec_suspend(struct cros_ec_device *ec_dev);
180 * cros_ec_resume - Handle a resume operation for the ChromeOS EC device
182 * This can be called by drivers to handle a resume event.
184 * @ec_dev: Device to resume
185 * @return 0 if ok, -ve on error
187 int cros_ec_resume(struct cros_ec_device *ec_dev);
190 * cros_ec_prepare_tx - Prepare an outgoing message in the output buffer
192 * This is intended to be used by all ChromeOS EC drivers, but at present
193 * only SPI uses it. Once LPC uses the same protocol it can start using it.
194 * I2C could use it now, with a refactor of the existing code.
196 * @ec_dev: Device to register
197 * @msg: Message to write
199 int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
200 struct cros_ec_command *msg);
203 * cros_ec_check_result - Check ec_msg->result
205 * This is used by ChromeOS EC drivers to check the ec_msg->result for
206 * errors and to warn about them.
209 * @msg: Message to check
211 int cros_ec_check_result(struct cros_ec_device *ec_dev,
212 struct cros_ec_command *msg);
215 * cros_ec_cmd_xfer - Send a command to the ChromeOS EC
217 * Call this to send a command to the ChromeOS EC. This should be used
218 * instead of calling the EC's cmd_xfer() callback directly.
221 * @msg: Message to write
223 int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev,
224 struct cros_ec_command *msg);
227 * cros_ec_remove - Remove a ChromeOS EC
229 * Call this to deregister a ChromeOS EC, then clean up any private data.
231 * @ec_dev: Device to register
232 * @return 0 if ok, -ve on error
234 int cros_ec_remove(struct cros_ec_device *ec_dev);
237 * cros_ec_register - Register a new ChromeOS EC, using the provided info
239 * Before calling this, allocate a pointer to a new device and then fill
240 * in all the fields up to the --private-- marker.
242 * @ec_dev: Device to register
243 * @return 0 if ok, -ve on error
245 int cros_ec_register(struct cros_ec_device *ec_dev);
248 * cros_ec_register - Query the protocol version supported by the ChromeOS EC
250 * @ec_dev: Device to register
251 * @return 0 if ok, -ve on error
253 int cros_ec_query_all(struct cros_ec_device *ec_dev);
256 extern struct attribute_group cros_ec_attr_group;
257 extern struct attribute_group cros_ec_lightbar_attr_group;
258 extern struct attribute_group cros_ec_vbc_attr_group;
260 #endif /* __LINUX_MFD_CROS_EC_H */