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_v1 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, void *outdata,
262 		    size_t outsize, void *indata, size_t insize);
263 
264 /**
265  * cros_ec_get_time_ns() - Return time in ns.
266  *
267  * This is the function used to record the time for last_event_time in struct
268  * cros_ec_device during the hard irq.
269  *
270  * Return: ktime_t format since boot.
271  */
cros_ec_get_time_ns(void)272 static inline ktime_t cros_ec_get_time_ns(void)
273 {
274 	return ktime_get_boottime_ns();
275 }
276 
277 #endif /* __LINUX_CROS_EC_PROTO_H */
278