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1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * ChromeOS Embedded Controller protocol interface.
4 *
5 * Copyright (C) 2012 Google, Inc
6 */
7
8#ifndef __LINUX_CROS_EC_PROTO_H
9#define __LINUX_CROS_EC_PROTO_H
10
11#include <linux/device.h>
12#include <linux/lockdep_types.h>
13#include <linux/mutex.h>
14#include <linux/notifier.h>
15
16#include <linux/platform_data/cros_ec_commands.h>
17
18#define CROS_EC_DEV_NAME "cros_ec"
19#define CROS_EC_DEV_FP_NAME "cros_fp"
20#define CROS_EC_DEV_ISH_NAME "cros_ish"
21#define CROS_EC_DEV_PD_NAME "cros_pd"
22#define CROS_EC_DEV_SCP_NAME "cros_scp"
23#define CROS_EC_DEV_TP_NAME "cros_tp"
24
25#define CROS_EC_DEV_EC_INDEX 0
26#define CROS_EC_DEV_PD_INDEX 1
27
28/*
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.
31 */
32#define EC_REBOOT_DELAY_MS 50
33
34/*
35 * Max bus-specific overhead incurred by request/responses.
36 *
37 * Request:
38 * - I2C requires 1 byte (see struct ec_host_request_i2c).
39 * - ISHTP requires 4 bytes (see struct cros_ish_out_msg).
40 *
41 * Response:
42 * - I2C requires 2 bytes (see struct ec_host_response_i2c).
43 * - ISHTP requires 4 bytes (see struct cros_ish_in_msg).
44 * - SPI requires 32 bytes (see EC_MSG_PREAMBLE_COUNT).
45 */
46#define EC_PROTO_VERSION_UNKNOWN 0
47#define EC_MAX_REQUEST_OVERHEAD 4
48#define EC_MAX_RESPONSE_OVERHEAD 32
49
50/*
51 * ACPI notify value for MKBP host event.
52 */
53#define ACPI_NOTIFY_CROS_EC_MKBP 0x80
54
55/*
56 * EC panic is not covered by the standard (0-F) ACPI notify values.
57 * Arbitrarily choosing B0 to notify ec panic, which is in the 84-BF
58 * device specific ACPI notify range.
59 */
60#define ACPI_NOTIFY_CROS_EC_PANIC 0xB0
61
62/*
63 * Command interface between EC and AP, for LPC, I2C and SPI interfaces.
64 */
65enum {
66 EC_MSG_TX_HEADER_BYTES = 3,
67 EC_MSG_TX_TRAILER_BYTES = 1,
68 EC_MSG_TX_PROTO_BYTES = EC_MSG_TX_HEADER_BYTES +
69 EC_MSG_TX_TRAILER_BYTES,
70 EC_MSG_RX_PROTO_BYTES = 3,
71
72 /* Max length of messages for proto 2*/
73 EC_PROTO2_MSG_BYTES = EC_PROTO2_MAX_PARAM_SIZE +
74 EC_MSG_TX_PROTO_BYTES,
75
76 EC_MAX_MSG_BYTES = 64 * 1024,
77};
78
79/**
80 * struct cros_ec_command - Information about a ChromeOS EC command.
81 * @version: Command version number (often 0).
82 * @command: Command to send (EC_CMD_...).
83 * @outsize: Outgoing length in bytes.
84 * @insize: Max number of bytes to accept from the EC.
85 * @result: EC's response to the command (separate from communication failure).
86 * @data: Where to put the incoming data from EC and outgoing data to EC.
87 */
88struct cros_ec_command {
89 uint32_t version;
90 uint32_t command;
91 uint32_t outsize;
92 uint32_t insize;
93 uint32_t result;
94 uint8_t data[];
95};
96
97/**
98 * struct cros_ec_device - Information about a ChromeOS EC device.
99 * @phys_name: Name of physical comms layer (e.g. 'i2c-4').
100 * @dev: Device pointer for physical comms device
101 * @cros_class: The class structure for this device.
102 * @cmd_readmem: Direct read of the EC memory-mapped region, if supported.
103 * @offset: Is within EC_LPC_ADDR_MEMMAP region.
104 * @bytes: Number of bytes to read. zero means "read a string" (including
105 * the trailing '\0'). At most only EC_MEMMAP_SIZE bytes can be
106 * read. Caller must ensure that the buffer is large enough for the
107 * result when reading a string.
108 * @max_request: Max size of message requested.
109 * @max_response: Max size of message response.
110 * @max_passthru: Max sice of passthru message.
111 * @proto_version: The protocol version used for this device.
112 * @priv: Private data.
113 * @irq: Interrupt to use.
114 * @id: Device id.
115 * @din: Input buffer (for data from EC). This buffer will always be
116 * dword-aligned and include enough space for up to 7 word-alignment
117 * bytes also, so we can ensure that the body of the message is always
118 * dword-aligned (64-bit). We use this alignment to keep ARM and x86
119 * happy. Probably word alignment would be OK, there might be a small
120 * performance advantage to using dword.
121 * @dout: Output buffer (for data to EC). This buffer will always be
122 * dword-aligned and include enough space for up to 7 word-alignment
123 * bytes also, so we can ensure that the body of the message is always
124 * dword-aligned (64-bit). We use this alignment to keep ARM and x86
125 * happy. Probably word alignment would be OK, there might be a small
126 * performance advantage to using dword.
127 * @din_size: Size of din buffer to allocate (zero to use static din).
128 * @dout_size: Size of dout buffer to allocate (zero to use static dout).
129 * @wake_enabled: True if this device can wake the system from sleep.
130 * @suspended: True if this device had been suspended.
131 * @registered: True if this device had been registered.
132 * @cmd_xfer: Send command to EC and get response.
133 * Returns the number of bytes received if the communication
134 * succeeded, but that doesn't mean the EC was happy with the
135 * command. The caller should check msg.result for the EC's result
136 * code.
137 * @pkt_xfer: Send packet to EC and get response.
138 * @lockdep_key: Lockdep class for each instance. Unused if CONFIG_LOCKDEP is
139 * not enabled.
140 * @lock: One transaction at a time.
141 * @mkbp_event_supported: 0 if MKBP not supported. Otherwise its value is
142 * the maximum supported version of the MKBP host event
143 * command + 1.
144 * @host_sleep_v1: True if this EC supports the sleep v1 command.
145 * @event_notifier: Interrupt event notifier for transport devices.
146 * @event_data: Raw payload transferred with the MKBP event.
147 * @event_size: Size in bytes of the event data.
148 * @host_event_wake_mask: Mask of host events that cause wake from suspend.
149 * @suspend_timeout_ms: The timeout in milliseconds between when sleep event
150 * is received and when the EC will declare sleep
151 * transition failure if the sleep signal is not
152 * asserted. See also struct
153 * ec_params_host_sleep_event_v1 in cros_ec_commands.h.
154 * @last_resume_result: The number of sleep power signal transitions that
155 * occurred since the suspend message. The high bit
156 * indicates a timeout occurred. See also struct
157 * ec_response_host_sleep_event_v1 in cros_ec_commands.h.
158 * @last_event_time: exact time from the hard irq when we got notified of
159 * a new event.
160 * @notifier_ready: The notifier_block to let the kernel re-query EC
161 * communication protocol when the EC sends
162 * EC_HOST_EVENT_INTERFACE_READY.
163 * @ec: The platform_device used by the mfd driver to interface with the
164 * main EC.
165 * @pd: The platform_device used by the mfd driver to interface with the
166 * PD behind an EC.
167 * @panic_notifier: EC panic notifier.
168 */
169struct cros_ec_device {
170 /* These are used by other drivers that want to talk to the EC */
171 const char *phys_name;
172 struct device *dev;
173 struct class *cros_class;
174 int (*cmd_readmem)(struct cros_ec_device *ec, unsigned int offset,
175 unsigned int bytes, void *dest);
176
177 /* These are used to implement the platform-specific interface */
178 u16 max_request;
179 u16 max_response;
180 u16 max_passthru;
181 u16 proto_version;
182 void *priv;
183 int irq;
184 u8 *din;
185 u8 *dout;
186 int din_size;
187 int dout_size;
188 bool wake_enabled;
189 bool suspended;
190 bool registered;
191 int (*cmd_xfer)(struct cros_ec_device *ec,
192 struct cros_ec_command *msg);
193 int (*pkt_xfer)(struct cros_ec_device *ec,
194 struct cros_ec_command *msg);
195 struct lock_class_key lockdep_key;
196 struct mutex lock;
197 u8 mkbp_event_supported;
198 bool host_sleep_v1;
199 struct blocking_notifier_head event_notifier;
200
201 struct ec_response_get_next_event_v3 event_data;
202 int event_size;
203 u32 host_event_wake_mask;
204 u32 last_resume_result;
205 u16 suspend_timeout_ms;
206 ktime_t last_event_time;
207 struct notifier_block notifier_ready;
208
209 /* The platform devices used by the mfd driver */
210 struct platform_device *ec;
211 struct platform_device *pd;
212
213 struct blocking_notifier_head panic_notifier;
214};
215
216/**
217 * struct cros_ec_platform - ChromeOS EC platform information.
218 * @ec_name: Name of EC device (e.g. 'cros-ec', 'cros-pd', ...)
219 * used in /dev/ and sysfs.
220 * @cmd_offset: Offset to apply for each command. Set when
221 * registering a device behind another one.
222 */
223struct cros_ec_platform {
224 const char *ec_name;
225 u16 cmd_offset;
226};
227
228/**
229 * struct cros_ec_dev - ChromeOS EC device entry point.
230 * @class_dev: Device structure used in sysfs.
231 * @ec_dev: cros_ec_device structure to talk to the physical device.
232 * @dev: Pointer to the platform device.
233 * @debug_info: cros_ec_debugfs structure for debugging information.
234 * @has_kb_wake_angle: True if at least 2 accelerometer are connected to the EC.
235 * @cmd_offset: Offset to apply for each command.
236 * @features: Features supported by the EC.
237 */
238struct cros_ec_dev {
239 struct device class_dev;
240 struct cros_ec_device *ec_dev;
241 struct device *dev;
242 struct cros_ec_debugfs *debug_info;
243 bool has_kb_wake_angle;
244 u16 cmd_offset;
245 struct ec_response_get_features features;
246};
247
248#define to_cros_ec_dev(dev) container_of(dev, struct cros_ec_dev, class_dev)
249
250int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
251 struct cros_ec_command *msg);
252
253int cros_ec_check_result(struct cros_ec_device *ec_dev,
254 struct cros_ec_command *msg);
255
256int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev,
257 struct cros_ec_command *msg);
258
259int cros_ec_cmd_xfer_status(struct cros_ec_device *ec_dev,
260 struct cros_ec_command *msg);
261
262int cros_ec_rwsig_continue(struct cros_ec_device *ec_dev);
263
264int cros_ec_query_all(struct cros_ec_device *ec_dev);
265
266int cros_ec_get_next_event(struct cros_ec_device *ec_dev,
267 bool *wake_event,
268 bool *has_more_events);
269
270u32 cros_ec_get_host_event(struct cros_ec_device *ec_dev);
271
272bool cros_ec_check_features(struct cros_ec_dev *ec, int feature);
273
274int cros_ec_get_sensor_count(struct cros_ec_dev *ec);
275
276int cros_ec_cmd(struct cros_ec_device *ec_dev, unsigned int version, int command, const void *outdata,
277 size_t outsize, void *indata, size_t insize);
278
279int cros_ec_cmd_readmem(struct cros_ec_device *ec_dev, u8 offset, u8 size, void *dest);
280
281int cros_ec_get_cmd_versions(struct cros_ec_device *ec_dev, u16 cmd);
282
283bool cros_ec_device_registered(struct cros_ec_device *ec_dev);
284
285/**
286 * cros_ec_get_time_ns() - Return time in ns.
287 *
288 * This is the function used to record the time for last_event_time in struct
289 * cros_ec_device during the hard irq.
290 *
291 * Return: ktime_t format since boot.
292 */
293static inline ktime_t cros_ec_get_time_ns(void)
294{
295 return ktime_get_boottime_ns();
296}
297
298#endif /* __LINUX_CROS_EC_PROTO_H */