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