1 /* SPDX-License-Identifier: GPL-2.0 */
3 * ChromeOS Embedded Controller protocol interface.
5 * Copyright (C) 2012 Google, Inc
8 #ifndef __LINUX_CROS_EC_PROTO_H
9 #define __LINUX_CROS_EC_PROTO_H
11 #include <linux/device.h>
12 #include <linux/mutex.h>
13 #include <linux/notifier.h>
15 #include <linux/platform_data/cros_ec_commands.h>
17 #define CROS_EC_DEV_NAME "cros_ec"
18 #define CROS_EC_DEV_FP_NAME "cros_fp"
19 #define CROS_EC_DEV_ISH_NAME "cros_ish"
20 #define CROS_EC_DEV_PD_NAME "cros_pd"
21 #define CROS_EC_DEV_SCP_NAME "cros_scp"
22 #define CROS_EC_DEV_TP_NAME "cros_tp"
25 * The EC is unresponsive for a time after a reboot command. Add a
26 * simple delay to make sure that the bus stays locked.
28 #define EC_REBOOT_DELAY_MS 50
31 * Max bus-specific overhead incurred by request/responses.
32 * I2C requires 1 additional byte for requests.
33 * I2C requires 2 additional bytes for responses.
34 * SPI requires up to 32 additional bytes for responses.
36 #define EC_PROTO_VERSION_UNKNOWN 0
37 #define EC_MAX_REQUEST_OVERHEAD 1
38 #define EC_MAX_RESPONSE_OVERHEAD 32
41 * Command interface between EC and AP, for LPC, I2C and SPI interfaces.
44 EC_MSG_TX_HEADER_BYTES = 3,
45 EC_MSG_TX_TRAILER_BYTES = 1,
46 EC_MSG_TX_PROTO_BYTES = EC_MSG_TX_HEADER_BYTES +
47 EC_MSG_TX_TRAILER_BYTES,
48 EC_MSG_RX_PROTO_BYTES = 3,
50 /* Max length of messages for proto 2*/
51 EC_PROTO2_MSG_BYTES = EC_PROTO2_MAX_PARAM_SIZE +
52 EC_MSG_TX_PROTO_BYTES,
54 EC_MAX_MSG_BYTES = 64 * 1024,
58 * struct cros_ec_command - Information about a ChromeOS EC command.
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 the 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.
77 * @phys_name: Name of physical comms layer (e.g. 'i2c-4').
78 * @dev: Device pointer for physical comms device
79 * @was_wake_device: True if this device was set to wake the system from
80 * sleep at the last suspend.
81 * @cros_class: The class structure for this device.
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
86 * read. Caller must ensure that the buffer is large enough for the
87 * result when reading a string.
88 * @max_request: Max size of message requested.
89 * @max_response: Max size of message response.
90 * @max_passthru: Max sice of passthru message.
91 * @proto_version: The protocol version used for this device.
92 * @priv: Private data.
93 * @irq: Interrupt to use.
95 * @din: Input buffer (for data from EC). This buffer will always be
96 * dword-aligned and include enough space for up to 7 word-alignment
97 * bytes also, so we can ensure that the body of the message is always
98 * dword-aligned (64-bit). We use this alignment to keep ARM and x86
99 * happy. Probably word alignment would be OK, there might be a small
100 * performance advantage to using dword.
101 * @dout: Output buffer (for data to EC). This buffer will always be
102 * dword-aligned and include enough space for up to 7 word-alignment
103 * bytes also, so we can ensure that the body of the message is always
104 * dword-aligned (64-bit). We use this alignment to keep ARM and x86
105 * happy. Probably word alignment would be OK, there might be a small
106 * performance advantage to using dword.
107 * @din_size: Size of din buffer to allocate (zero to use static din).
108 * @dout_size: Size of dout buffer to allocate (zero to use static dout).
109 * @wake_enabled: True if this device can wake the system from sleep.
110 * @suspended: True if this device had been suspended.
111 * @cmd_xfer: Send command to EC and get response.
112 * Returns the number of bytes received if the communication
113 * succeeded, but that doesn't mean the EC was happy with the
114 * command. The caller should check msg.result for the EC's result
116 * @pkt_xfer: Send packet to EC and get response.
117 * @lock: One transaction at a time.
118 * @mkbp_event_supported: True if this EC supports the MKBP event protocol.
119 * @host_sleep_v1: True if this EC supports the sleep v1 command.
120 * @event_notifier: Interrupt event notifier for transport devices.
121 * @event_data: Raw payload transferred with the MKBP event.
122 * @event_size: Size in bytes of the event data.
123 * @host_event_wake_mask: Mask of host events that cause wake from suspend.
124 * @ec: The platform_device used by the mfd driver to interface with the
126 * @pd: The platform_device used by the mfd driver to interface with the
129 struct cros_ec_device {
130 /* These are used by other drivers that want to talk to the EC */
131 const char *phys_name;
133 bool was_wake_device;
134 struct class *cros_class;
135 int (*cmd_readmem)(struct cros_ec_device *ec, unsigned int offset,
136 unsigned int bytes, void *dest);
138 /* These are used to implement the platform-specific interface */
151 int (*cmd_xfer)(struct cros_ec_device *ec,
152 struct cros_ec_command *msg);
153 int (*pkt_xfer)(struct cros_ec_device *ec,
154 struct cros_ec_command *msg);
156 bool mkbp_event_supported;
158 struct blocking_notifier_head event_notifier;
160 struct ec_response_get_next_event_v1 event_data;
162 u32 host_event_wake_mask;
163 u32 last_resume_result;
165 /* The platform devices used by the mfd driver */
166 struct platform_device *ec;
167 struct platform_device *pd;
171 * struct cros_ec_sensor_platform - ChromeOS EC sensor platform information.
172 * @sensor_num: Id of the sensor, as reported by the EC.
174 struct cros_ec_sensor_platform {
179 * struct cros_ec_platform - ChromeOS EC platform information.
180 * @ec_name: Name of EC device (e.g. 'cros-ec', 'cros-pd', ...)
181 * used in /dev/ and sysfs.
182 * @cmd_offset: Offset to apply for each command. Set when
183 * registering a device behind another one.
185 struct cros_ec_platform {
191 * cros_ec_suspend() - Handle a suspend operation for the ChromeOS EC device.
192 * @ec_dev: Device to suspend.
194 * This can be called by drivers to handle a suspend event.
196 * Return: 0 on success or negative error code.
198 int cros_ec_suspend(struct cros_ec_device *ec_dev);
201 * cros_ec_resume() - Handle a resume operation for the ChromeOS EC device.
202 * @ec_dev: Device to resume.
204 * This can be called by drivers to handle a resume event.
206 * Return: 0 on success or negative error code.
208 int cros_ec_resume(struct cros_ec_device *ec_dev);
211 * cros_ec_prepare_tx() - Prepare an outgoing message in the output buffer.
212 * @ec_dev: Device to register.
213 * @msg: Message to write.
215 * This is intended to be used by all ChromeOS EC drivers, but at present
216 * only SPI uses it. Once LPC uses the same protocol it can start using it.
217 * I2C could use it now, with a refactor of the existing code.
219 * Return: 0 on success or negative error code.
221 int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
222 struct cros_ec_command *msg);
225 * cros_ec_check_result() - Check ec_msg->result.
226 * @ec_dev: EC device.
227 * @msg: Message to check.
229 * This is used by ChromeOS EC drivers to check the ec_msg->result for
230 * errors and to warn about them.
232 * Return: 0 on success or negative error code.
234 int cros_ec_check_result(struct cros_ec_device *ec_dev,
235 struct cros_ec_command *msg);
238 * cros_ec_cmd_xfer() - Send a command to the ChromeOS EC.
239 * @ec_dev: EC device.
240 * @msg: Message to write.
242 * Call this to send a command to the ChromeOS EC. This should be used
243 * instead of calling the EC's cmd_xfer() callback directly.
245 * Return: 0 on success or negative error code.
247 int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev,
248 struct cros_ec_command *msg);
251 * cros_ec_cmd_xfer_status() - Send a command to the ChromeOS EC.
252 * @ec_dev: EC device.
253 * @msg: Message to write.
255 * This function is identical to cros_ec_cmd_xfer, except it returns success
256 * status only if both the command was transmitted successfully and the EC
257 * replied with success status. It's not necessary to check msg->result when
258 * using this function.
260 * Return: The number of bytes transferred on success or negative error code.
262 int cros_ec_cmd_xfer_status(struct cros_ec_device *ec_dev,
263 struct cros_ec_command *msg);
266 * cros_ec_register() - Register a new ChromeOS EC, using the provided info.
267 * @ec_dev: Device to register.
269 * Before calling this, allocate a pointer to a new device and then fill
270 * in all the fields up to the --private-- marker.
272 * Return: 0 on success or negative error code.
274 int cros_ec_register(struct cros_ec_device *ec_dev);
277 * cros_ec_unregister() - Remove a ChromeOS EC.
278 * @ec_dev: Device to unregister.
280 * Call this to deregister a ChromeOS EC, then clean up any private data.
282 * Return: 0 on success or negative error code.
284 int cros_ec_unregister(struct cros_ec_device *ec_dev);
287 * cros_ec_query_all() - Query the protocol version supported by the
289 * @ec_dev: Device to register.
291 * Return: 0 on success or negative error code.
293 int cros_ec_query_all(struct cros_ec_device *ec_dev);
296 * cros_ec_get_next_event() - Fetch next event from the ChromeOS EC.
297 * @ec_dev: Device to fetch event from.
298 * @wake_event: Pointer to a bool set to true upon return if the event might be
299 * treated as a wake event. Ignored if null.
301 * Return: negative error code on errors; 0 for no data; or else number of
302 * bytes received (i.e., an event was retrieved successfully). Event types are
303 * written out to @ec_dev->event_data.event_type on success.
305 int cros_ec_get_next_event(struct cros_ec_device *ec_dev, bool *wake_event);
308 * cros_ec_get_host_event() - Return a mask of event set by the ChromeOS EC.
309 * @ec_dev: Device to fetch event from.
311 * When MKBP is supported, when the EC raises an interrupt, we collect the
312 * events raised and call the functions in the ec notifier. This function
313 * is a helper to know which events are raised.
315 * Return: 0 on error or non-zero bitmask of one or more EC_HOST_EVENT_*.
317 u32 cros_ec_get_host_event(struct cros_ec_device *ec_dev);
319 #endif /* __LINUX_CROS_EC_PROTO_H */