1 /* SPDX-License-Identifier: GPL-2.0-only */
3 * ChromeOS EC multi-function device
5 * Copyright (C) 2012 Google, Inc
8 #ifndef __LINUX_MFD_CROS_EC_H
9 #define __LINUX_MFD_CROS_EC_H
11 #include <linux/cdev.h>
12 #include <linux/device.h>
13 #include <linux/notifier.h>
14 #include <linux/mfd/cros_ec_commands.h>
15 #include <linux/mutex.h>
17 #define CROS_EC_DEV_NAME "cros_ec"
18 #define CROS_EC_DEV_FP_NAME "cros_fp"
19 #define CROS_EC_DEV_PD_NAME "cros_pd"
20 #define CROS_EC_DEV_TP_NAME "cros_tp"
21 #define CROS_EC_DEV_ISH_NAME "cros_ish"
22 #define CROS_EC_DEV_SCP_NAME "cros_scp"
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.
125 struct cros_ec_device {
126 /* These are used by other drivers that want to talk to the EC */
127 const char *phys_name;
129 bool was_wake_device;
130 struct class *cros_class;
131 int (*cmd_readmem)(struct cros_ec_device *ec, unsigned int offset,
132 unsigned int bytes, void *dest);
134 /* These are used to implement the platform-specific interface */
147 int (*cmd_xfer)(struct cros_ec_device *ec,
148 struct cros_ec_command *msg);
149 int (*pkt_xfer)(struct cros_ec_device *ec,
150 struct cros_ec_command *msg);
152 bool mkbp_event_supported;
154 struct blocking_notifier_head event_notifier;
156 struct ec_response_get_next_event_v1 event_data;
158 u32 host_event_wake_mask;
159 u32 last_resume_result;
163 * struct cros_ec_sensor_platform - ChromeOS EC sensor platform information.
164 * @sensor_num: Id of the sensor, as reported by the EC.
166 struct cros_ec_sensor_platform {
171 * struct cros_ec_platform - ChromeOS EC platform information.
172 * @ec_name: Name of EC device (e.g. 'cros-ec', 'cros-pd', ...)
173 * used in /dev/ and sysfs.
174 * @cmd_offset: Offset to apply for each command. Set when
175 * registering a device behind another one.
177 struct cros_ec_platform {
182 struct cros_ec_debugfs;
185 * struct cros_ec_dev - ChromeOS EC device entry point.
186 * @class_dev: Device structure used in sysfs.
187 * @cdev: Character device structure in /dev.
188 * @ec_dev: cros_ec_device structure to talk to the physical device.
189 * @dev: Pointer to the platform device.
190 * @debug_info: cros_ec_debugfs structure for debugging information.
191 * @has_kb_wake_angle: True if at least 2 accelerometer are connected to the EC.
192 * @cmd_offset: Offset to apply for each command.
193 * @features: Features supported by the EC.
196 struct device class_dev;
198 struct cros_ec_device *ec_dev;
200 struct cros_ec_debugfs *debug_info;
201 bool has_kb_wake_angle;
206 #define to_cros_ec_dev(dev) container_of(dev, struct cros_ec_dev, class_dev)
209 * cros_ec_suspend() - Handle a suspend operation for the ChromeOS EC device.
210 * @ec_dev: Device to suspend.
212 * This can be called by drivers to handle a suspend event.
214 * Return: 0 on success or negative error code.
216 int cros_ec_suspend(struct cros_ec_device *ec_dev);
219 * cros_ec_resume() - Handle a resume operation for the ChromeOS EC device.
220 * @ec_dev: Device to resume.
222 * This can be called by drivers to handle a resume event.
224 * Return: 0 on success or negative error code.
226 int cros_ec_resume(struct cros_ec_device *ec_dev);
229 * cros_ec_prepare_tx() - Prepare an outgoing message in the output buffer.
230 * @ec_dev: Device to register.
231 * @msg: Message to write.
233 * This is intended to be used by all ChromeOS EC drivers, but at present
234 * only SPI uses it. Once LPC uses the same protocol it can start using it.
235 * I2C could use it now, with a refactor of the existing code.
237 * Return: 0 on success or negative error code.
239 int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
240 struct cros_ec_command *msg);
243 * cros_ec_check_result() - Check ec_msg->result.
244 * @ec_dev: EC device.
245 * @msg: Message to check.
247 * This is used by ChromeOS EC drivers to check the ec_msg->result for
248 * errors and to warn about them.
250 * Return: 0 on success or negative error code.
252 int cros_ec_check_result(struct cros_ec_device *ec_dev,
253 struct cros_ec_command *msg);
256 * cros_ec_cmd_xfer() - Send a command to the ChromeOS EC.
257 * @ec_dev: EC device.
258 * @msg: Message to write.
260 * Call this to send a command to the ChromeOS EC. This should be used
261 * instead of calling the EC's cmd_xfer() callback directly.
263 * Return: 0 on success or negative error code.
265 int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev,
266 struct cros_ec_command *msg);
269 * cros_ec_cmd_xfer_status() - Send a command to the ChromeOS EC.
270 * @ec_dev: EC device.
271 * @msg: Message to write.
273 * This function is identical to cros_ec_cmd_xfer, except it returns success
274 * status only if both the command was transmitted successfully and the EC
275 * replied with success status. It's not necessary to check msg->result when
276 * using this function.
278 * Return: The number of bytes transferred on success or negative error code.
280 int cros_ec_cmd_xfer_status(struct cros_ec_device *ec_dev,
281 struct cros_ec_command *msg);
284 * cros_ec_register() - Register a new ChromeOS EC, using the provided info.
285 * @ec_dev: Device to register.
287 * Before calling this, allocate a pointer to a new device and then fill
288 * in all the fields up to the --private-- marker.
290 * Return: 0 on success or negative error code.
292 int cros_ec_register(struct cros_ec_device *ec_dev);
295 * cros_ec_query_all() - Query the protocol version supported by the
297 * @ec_dev: Device to register.
299 * Return: 0 on success or negative error code.
301 int cros_ec_query_all(struct cros_ec_device *ec_dev);
304 * cros_ec_get_next_event() - Fetch next event from the ChromeOS EC.
305 * @ec_dev: Device to fetch event from.
306 * @wake_event: Pointer to a bool set to true upon return if the event might be
307 * treated as a wake event. Ignored if null.
309 * Return: negative error code on errors; 0 for no data; or else number of
310 * bytes received (i.e., an event was retrieved successfully). Event types are
311 * written out to @ec_dev->event_data.event_type on success.
313 int cros_ec_get_next_event(struct cros_ec_device *ec_dev, bool *wake_event);
316 * cros_ec_get_host_event() - Return a mask of event set by the ChromeOS EC.
317 * @ec_dev: Device to fetch event from.
319 * When MKBP is supported, when the EC raises an interrupt, we collect the
320 * events raised and call the functions in the ec notifier. This function
321 * is a helper to know which events are raised.
323 * Return: 0 on error or non-zero bitmask of one or more EC_HOST_EVENT_*.
325 u32 cros_ec_get_host_event(struct cros_ec_device *ec_dev);
327 #endif /* __LINUX_MFD_CROS_EC_H */