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/mutex.h>
13 #include <linux/notifier.h>
14 
15 #include <linux/platform_data/cros_ec_commands.h>
16 
17 #define CROS_EC_DEV_NAME	"cros_ec"
18 #define CROS_EC_DEV_FP_NAME	"cros_fp"
19 #define CROS_EC_DEV_ISH_NAME	"cros_ish"
20 #define CROS_EC_DEV_PD_NAME	"cros_pd"
21 #define CROS_EC_DEV_SCP_NAME	"cros_scp"
22 #define CROS_EC_DEV_SCP_C1_NAME	"cros_scp_c1"
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  * Command interface between EC and AP, for LPC, I2C and SPI interfaces.
46  */
47 enum {
48 	EC_MSG_TX_HEADER_BYTES	= 3,
49 	EC_MSG_TX_TRAILER_BYTES	= 1,
50 	EC_MSG_TX_PROTO_BYTES	= EC_MSG_TX_HEADER_BYTES +
51 				  EC_MSG_TX_TRAILER_BYTES,
52 	EC_MSG_RX_PROTO_BYTES	= 3,
53 
54 	/* Max length of messages for proto 2*/
55 	EC_PROTO2_MSG_BYTES	= EC_PROTO2_MAX_PARAM_SIZE +
56 				  EC_MSG_TX_PROTO_BYTES,
57 
58 	EC_MAX_MSG_BYTES	= 64 * 1024,
59 };
60 
61 /**
62  * struct cros_ec_command - Information about a ChromeOS EC command.
63  * @version: Command version number (often 0).
64  * @command: Command to send (EC_CMD_...).
65  * @outsize: Outgoing length in bytes.
66  * @insize: Max number of bytes to accept from the EC.
67  * @result: EC's response to the command (separate from communication failure).
68  * @data: Where to put the incoming data from EC and outgoing data to EC.
69  */
70 struct cros_ec_command {
71 	uint32_t version;
72 	uint32_t command;
73 	uint32_t outsize;
74 	uint32_t insize;
75 	uint32_t result;
76 	uint8_t data[];
77 };
78 
79 /**
80  * struct cros_ec_device - Information about a ChromeOS EC device.
81  * @phys_name: Name of physical comms layer (e.g. 'i2c-4').
82  * @dev: Device pointer for physical comms device
83  * @cros_class: The class structure for this device.
84  * @cmd_readmem: Direct read of the EC memory-mapped region, if supported.
85  *     @offset: Is within EC_LPC_ADDR_MEMMAP region.
86  *     @bytes: Number of bytes to read. zero means "read a string" (including
87  *             the trailing '\0'). At most only EC_MEMMAP_SIZE bytes can be
88  *             read. Caller must ensure that the buffer is large enough for the
89  *             result when reading a string.
90  * @max_request: Max size of message requested.
91  * @max_response: Max size of message response.
92  * @max_passthru: Max sice of passthru message.
93  * @proto_version: The protocol version used for this device.
94  * @priv: Private data.
95  * @irq: Interrupt to use.
96  * @id: Device id.
97  * @din: Input buffer (for data from EC). This buffer will always be
98  *       dword-aligned and include enough space for up to 7 word-alignment
99  *       bytes also, so we can ensure that the body of the message is always
100  *       dword-aligned (64-bit). We use this alignment to keep ARM and x86
101  *       happy. Probably word alignment would be OK, there might be a small
102  *       performance advantage to using dword.
103  * @dout: Output buffer (for data to EC). This buffer will always be
104  *        dword-aligned and include enough space for up to 7 word-alignment
105  *        bytes also, so we can ensure that the body of the message is always
106  *        dword-aligned (64-bit). We use this alignment to keep ARM and x86
107  *        happy. Probably word alignment would be OK, there might be a small
108  *        performance advantage to using dword.
109  * @din_size: Size of din buffer to allocate (zero to use static din).
110  * @dout_size: Size of dout buffer to allocate (zero to use static dout).
111  * @wake_enabled: True if this device can wake the system from sleep.
112  * @suspended: True if this device had been suspended.
113  * @cmd_xfer: Send command to EC and get response.
114  *            Returns the number of bytes received if the communication
115  *            succeeded, but that doesn't mean the EC was happy with the
116  *            command. The caller should check msg.result for the EC's result
117  *            code.
118  * @pkt_xfer: Send packet to EC and get response.
119  * @lock: One transaction at a time.
120  * @mkbp_event_supported: 0 if MKBP not supported. Otherwise its value is
121  *                        the maximum supported version of the MKBP host event
122  *                        command + 1.
123  * @host_sleep_v1: True if this EC supports the sleep v1 command.
124  * @event_notifier: Interrupt event notifier for transport devices.
125  * @event_data: Raw payload transferred with the MKBP event.
126  * @event_size: Size in bytes of the event data.
127  * @host_event_wake_mask: Mask of host events that cause wake from suspend.
128  * @last_event_time: exact time from the hard irq when we got notified of
129  *     a new event.
130  * @notifier_ready: The notifier_block to let the kernel re-query EC
131  *		    communication protocol when the EC sends
132  *		    EC_HOST_EVENT_INTERFACE_READY.
133  * @ec: The platform_device used by the mfd driver to interface with the
134  *      main EC.
135  * @pd: The platform_device used by the mfd driver to interface with the
136  *      PD behind an EC.
137  */
138 struct cros_ec_device {
139 	/* These are used by other drivers that want to talk to the EC */
140 	const char *phys_name;
141 	struct device *dev;
142 	struct class *cros_class;
143 	int (*cmd_readmem)(struct cros_ec_device *ec, unsigned int offset,
144 			   unsigned int bytes, void *dest);
145 
146 	/* These are used to implement the platform-specific interface */
147 	u16 max_request;
148 	u16 max_response;
149 	u16 max_passthru;
150 	u16 proto_version;
151 	void *priv;
152 	int irq;
153 	u8 *din;
154 	u8 *dout;
155 	int din_size;
156 	int dout_size;
157 	bool wake_enabled;
158 	bool suspended;
159 	int (*cmd_xfer)(struct cros_ec_device *ec,
160 			struct cros_ec_command *msg);
161 	int (*pkt_xfer)(struct cros_ec_device *ec,
162 			struct cros_ec_command *msg);
163 	struct mutex lock;
164 	u8 mkbp_event_supported;
165 	bool host_sleep_v1;
166 	struct blocking_notifier_head event_notifier;
167 
168 	struct ec_response_get_next_event_v1 event_data;
169 	int event_size;
170 	u32 host_event_wake_mask;
171 	u32 last_resume_result;
172 	u16 suspend_timeout_ms;
173 	ktime_t last_event_time;
174 	struct notifier_block notifier_ready;
175 
176 	/* The platform devices used by the mfd driver */
177 	struct platform_device *ec;
178 	struct platform_device *pd;
179 };
180 
181 /**
182  * struct cros_ec_platform - ChromeOS EC platform information.
183  * @ec_name: Name of EC device (e.g. 'cros-ec', 'cros-pd', ...)
184  *           used in /dev/ and sysfs.
185  * @cmd_offset: Offset to apply for each command. Set when
186  *              registering a device behind another one.
187  */
188 struct cros_ec_platform {
189 	const char *ec_name;
190 	u16 cmd_offset;
191 };
192 
193 /**
194  * struct cros_ec_dev - ChromeOS EC device entry point.
195  * @class_dev: Device structure used in sysfs.
196  * @ec_dev: cros_ec_device structure to talk to the physical device.
197  * @dev: Pointer to the platform device.
198  * @debug_info: cros_ec_debugfs structure for debugging information.
199  * @has_kb_wake_angle: True if at least 2 accelerometer are connected to the EC.
200  * @cmd_offset: Offset to apply for each command.
201  * @features: Features supported by the EC.
202  */
203 struct cros_ec_dev {
204 	struct device class_dev;
205 	struct cros_ec_device *ec_dev;
206 	struct device *dev;
207 	struct cros_ec_debugfs *debug_info;
208 	bool has_kb_wake_angle;
209 	u16 cmd_offset;
210 	struct ec_response_get_features features;
211 };
212 
213 #define to_cros_ec_dev(dev)  container_of(dev, struct cros_ec_dev, class_dev)
214 
215 int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
216 		       struct cros_ec_command *msg);
217 
218 int cros_ec_check_result(struct cros_ec_device *ec_dev,
219 			 struct cros_ec_command *msg);
220 
221 int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev,
222 		     struct cros_ec_command *msg);
223 
224 int cros_ec_cmd_xfer_status(struct cros_ec_device *ec_dev,
225 			    struct cros_ec_command *msg);
226 
227 int cros_ec_query_all(struct cros_ec_device *ec_dev);
228 
229 int cros_ec_get_next_event(struct cros_ec_device *ec_dev,
230 			   bool *wake_event,
231 			   bool *has_more_events);
232 
233 u32 cros_ec_get_host_event(struct cros_ec_device *ec_dev);
234 
235 bool cros_ec_check_features(struct cros_ec_dev *ec, int feature);
236 
237 int cros_ec_get_sensor_count(struct cros_ec_dev *ec);
238 
239 int cros_ec_cmd(struct cros_ec_device *ec_dev, unsigned int version, int command, void *outdata,
240 		    size_t outsize, void *indata, size_t insize);
241 
242 /**
243  * cros_ec_get_time_ns() - Return time in ns.
244  *
245  * This is the function used to record the time for last_event_time in struct
246  * cros_ec_device during the hard irq.
247  *
248  * Return: ktime_t format since boot.
249  */
cros_ec_get_time_ns(void)250 static inline ktime_t cros_ec_get_time_ns(void)
251 {
252 	return ktime_get_boottime_ns();
253 }
254 
255 #endif /* __LINUX_CROS_EC_PROTO_H */
256