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