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_TP_NAME "cros_tp" 23 24 /* 25 * The EC is unresponsive for a time after a reboot command. Add a 26 * simple delay to make sure that the bus stays locked. 27 */ 28 #define EC_REBOOT_DELAY_MS 50 29 30 /* 31 * Max bus-specific overhead incurred by request/responses. 32 * I2C requires 1 additional byte for requests. 33 * I2C requires 2 additional bytes for responses. 34 * SPI requires up to 32 additional bytes for responses. 35 */ 36 #define EC_PROTO_VERSION_UNKNOWN 0 37 #define EC_MAX_REQUEST_OVERHEAD 1 38 #define EC_MAX_RESPONSE_OVERHEAD 32 39 40 /* 41 * Command interface between EC and AP, for LPC, I2C and SPI interfaces. 42 */ 43 enum { 44 EC_MSG_TX_HEADER_BYTES = 3, 45 EC_MSG_TX_TRAILER_BYTES = 1, 46 EC_MSG_TX_PROTO_BYTES = EC_MSG_TX_HEADER_BYTES + 47 EC_MSG_TX_TRAILER_BYTES, 48 EC_MSG_RX_PROTO_BYTES = 3, 49 50 /* Max length of messages for proto 2*/ 51 EC_PROTO2_MSG_BYTES = EC_PROTO2_MAX_PARAM_SIZE + 52 EC_MSG_TX_PROTO_BYTES, 53 54 EC_MAX_MSG_BYTES = 64 * 1024, 55 }; 56 57 /** 58 * struct cros_ec_command - Information about a ChromeOS EC command. 59 * @version: Command version number (often 0). 60 * @command: Command to send (EC_CMD_...). 61 * @outsize: Outgoing length in bytes. 62 * @insize: Max number of bytes to accept from the EC. 63 * @result: EC's response to the command (separate from communication failure). 64 * @data: Where to put the incoming data from EC and outgoing data to EC. 65 */ 66 struct cros_ec_command { 67 uint32_t version; 68 uint32_t command; 69 uint32_t outsize; 70 uint32_t insize; 71 uint32_t result; 72 uint8_t data[0]; 73 }; 74 75 /** 76 * struct cros_ec_device - Information about a ChromeOS EC device. 77 * @phys_name: Name of physical comms layer (e.g. 'i2c-4'). 78 * @dev: Device pointer for physical comms device 79 * @was_wake_device: True if this device was set to wake the system from 80 * sleep at the last suspend. 81 * @cros_class: The class structure for this device. 82 * @cmd_readmem: Direct read of the EC memory-mapped region, if supported. 83 * @offset: Is within EC_LPC_ADDR_MEMMAP region. 84 * @bytes: Number of bytes to read. zero means "read a string" (including 85 * the trailing '\0'). At most only EC_MEMMAP_SIZE bytes can be 86 * read. Caller must ensure that the buffer is large enough for the 87 * result when reading a string. 88 * @max_request: Max size of message requested. 89 * @max_response: Max size of message response. 90 * @max_passthru: Max sice of passthru message. 91 * @proto_version: The protocol version used for this device. 92 * @priv: Private data. 93 * @irq: Interrupt to use. 94 * @id: Device id. 95 * @din: Input buffer (for data from EC). This buffer will always be 96 * dword-aligned and include enough space for up to 7 word-alignment 97 * bytes also, so we can ensure that the body of the message is always 98 * dword-aligned (64-bit). We use this alignment to keep ARM and x86 99 * happy. Probably word alignment would be OK, there might be a small 100 * performance advantage to using dword. 101 * @dout: Output buffer (for data to EC). This buffer will always be 102 * dword-aligned and include enough space for up to 7 word-alignment 103 * bytes also, so we can ensure that the body of the message is always 104 * dword-aligned (64-bit). We use this alignment to keep ARM and x86 105 * happy. Probably word alignment would be OK, there might be a small 106 * performance advantage to using dword. 107 * @din_size: Size of din buffer to allocate (zero to use static din). 108 * @dout_size: Size of dout buffer to allocate (zero to use static dout). 109 * @wake_enabled: True if this device can wake the system from sleep. 110 * @suspended: True if this device had been suspended. 111 * @cmd_xfer: Send command to EC and get response. 112 * Returns the number of bytes received if the communication 113 * succeeded, but that doesn't mean the EC was happy with the 114 * command. The caller should check msg.result for the EC's result 115 * code. 116 * @pkt_xfer: Send packet to EC and get response. 117 * @lock: One transaction at a time. 118 * @mkbp_event_supported: True if this EC supports the MKBP event protocol. 119 * @host_sleep_v1: True if this EC supports the sleep v1 command. 120 * @event_notifier: Interrupt event notifier for transport devices. 121 * @event_data: Raw payload transferred with the MKBP event. 122 * @event_size: Size in bytes of the event data. 123 * @host_event_wake_mask: Mask of host events that cause wake from suspend. 124 * @ec: The platform_device used by the mfd driver to interface with the 125 * main EC. 126 * @pd: The platform_device used by the mfd driver to interface with the 127 * PD behind an EC. 128 */ 129 struct cros_ec_device { 130 /* These are used by other drivers that want to talk to the EC */ 131 const char *phys_name; 132 struct device *dev; 133 bool was_wake_device; 134 struct class *cros_class; 135 int (*cmd_readmem)(struct cros_ec_device *ec, unsigned int offset, 136 unsigned int bytes, void *dest); 137 138 /* These are used to implement the platform-specific interface */ 139 u16 max_request; 140 u16 max_response; 141 u16 max_passthru; 142 u16 proto_version; 143 void *priv; 144 int irq; 145 u8 *din; 146 u8 *dout; 147 int din_size; 148 int dout_size; 149 bool wake_enabled; 150 bool suspended; 151 int (*cmd_xfer)(struct cros_ec_device *ec, 152 struct cros_ec_command *msg); 153 int (*pkt_xfer)(struct cros_ec_device *ec, 154 struct cros_ec_command *msg); 155 struct mutex lock; 156 bool mkbp_event_supported; 157 bool host_sleep_v1; 158 struct blocking_notifier_head event_notifier; 159 160 struct ec_response_get_next_event_v1 event_data; 161 int event_size; 162 u32 host_event_wake_mask; 163 u32 last_resume_result; 164 165 /* The platform devices used by the mfd driver */ 166 struct platform_device *ec; 167 struct platform_device *pd; 168 }; 169 170 /** 171 * struct cros_ec_sensor_platform - ChromeOS EC sensor platform information. 172 * @sensor_num: Id of the sensor, as reported by the EC. 173 */ 174 struct cros_ec_sensor_platform { 175 u8 sensor_num; 176 }; 177 178 /** 179 * struct cros_ec_platform - ChromeOS EC platform information. 180 * @ec_name: Name of EC device (e.g. 'cros-ec', 'cros-pd', ...) 181 * used in /dev/ and sysfs. 182 * @cmd_offset: Offset to apply for each command. Set when 183 * registering a device behind another one. 184 */ 185 struct cros_ec_platform { 186 const char *ec_name; 187 u16 cmd_offset; 188 }; 189 190 /** 191 * cros_ec_suspend() - Handle a suspend operation for the ChromeOS EC device. 192 * @ec_dev: Device to suspend. 193 * 194 * This can be called by drivers to handle a suspend event. 195 * 196 * Return: 0 on success or negative error code. 197 */ 198 int cros_ec_suspend(struct cros_ec_device *ec_dev); 199 200 /** 201 * cros_ec_resume() - Handle a resume operation for the ChromeOS EC device. 202 * @ec_dev: Device to resume. 203 * 204 * This can be called by drivers to handle a resume event. 205 * 206 * Return: 0 on success or negative error code. 207 */ 208 int cros_ec_resume(struct cros_ec_device *ec_dev); 209 210 /** 211 * cros_ec_prepare_tx() - Prepare an outgoing message in the output buffer. 212 * @ec_dev: Device to register. 213 * @msg: Message to write. 214 * 215 * This is intended to be used by all ChromeOS EC drivers, but at present 216 * only SPI uses it. Once LPC uses the same protocol it can start using it. 217 * I2C could use it now, with a refactor of the existing code. 218 * 219 * Return: 0 on success or negative error code. 220 */ 221 int cros_ec_prepare_tx(struct cros_ec_device *ec_dev, 222 struct cros_ec_command *msg); 223 224 /** 225 * cros_ec_check_result() - Check ec_msg->result. 226 * @ec_dev: EC device. 227 * @msg: Message to check. 228 * 229 * This is used by ChromeOS EC drivers to check the ec_msg->result for 230 * errors and to warn about them. 231 * 232 * Return: 0 on success or negative error code. 233 */ 234 int cros_ec_check_result(struct cros_ec_device *ec_dev, 235 struct cros_ec_command *msg); 236 237 /** 238 * cros_ec_cmd_xfer() - Send a command to the ChromeOS EC. 239 * @ec_dev: EC device. 240 * @msg: Message to write. 241 * 242 * Call this to send a command to the ChromeOS EC. This should be used 243 * instead of calling the EC's cmd_xfer() callback directly. 244 * 245 * Return: 0 on success or negative error code. 246 */ 247 int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev, 248 struct cros_ec_command *msg); 249 250 /** 251 * cros_ec_cmd_xfer_status() - Send a command to the ChromeOS EC. 252 * @ec_dev: EC device. 253 * @msg: Message to write. 254 * 255 * This function is identical to cros_ec_cmd_xfer, except it returns success 256 * status only if both the command was transmitted successfully and the EC 257 * replied with success status. It's not necessary to check msg->result when 258 * using this function. 259 * 260 * Return: The number of bytes transferred on success or negative error code. 261 */ 262 int cros_ec_cmd_xfer_status(struct cros_ec_device *ec_dev, 263 struct cros_ec_command *msg); 264 265 /** 266 * cros_ec_register() - Register a new ChromeOS EC, using the provided info. 267 * @ec_dev: Device to register. 268 * 269 * Before calling this, allocate a pointer to a new device and then fill 270 * in all the fields up to the --private-- marker. 271 * 272 * Return: 0 on success or negative error code. 273 */ 274 int cros_ec_register(struct cros_ec_device *ec_dev); 275 276 /** 277 * cros_ec_unregister() - Remove a ChromeOS EC. 278 * @ec_dev: Device to unregister. 279 * 280 * Call this to deregister a ChromeOS EC, then clean up any private data. 281 * 282 * Return: 0 on success or negative error code. 283 */ 284 int cros_ec_unregister(struct cros_ec_device *ec_dev); 285 286 /** 287 * cros_ec_query_all() - Query the protocol version supported by the 288 * ChromeOS EC. 289 * @ec_dev: Device to register. 290 * 291 * Return: 0 on success or negative error code. 292 */ 293 int cros_ec_query_all(struct cros_ec_device *ec_dev); 294 295 /** 296 * cros_ec_get_next_event() - Fetch next event from the ChromeOS EC. 297 * @ec_dev: Device to fetch event from. 298 * @wake_event: Pointer to a bool set to true upon return if the event might be 299 * treated as a wake event. Ignored if null. 300 * 301 * Return: negative error code on errors; 0 for no data; or else number of 302 * bytes received (i.e., an event was retrieved successfully). Event types are 303 * written out to @ec_dev->event_data.event_type on success. 304 */ 305 int cros_ec_get_next_event(struct cros_ec_device *ec_dev, bool *wake_event); 306 307 /** 308 * cros_ec_get_host_event() - Return a mask of event set by the ChromeOS EC. 309 * @ec_dev: Device to fetch event from. 310 * 311 * When MKBP is supported, when the EC raises an interrupt, we collect the 312 * events raised and call the functions in the ec notifier. This function 313 * is a helper to know which events are raised. 314 * 315 * Return: 0 on error or non-zero bitmask of one or more EC_HOST_EVENT_*. 316 */ 317 u32 cros_ec_get_host_event(struct cros_ec_device *ec_dev); 318 319 #endif /* __LINUX_CROS_EC_PROTO_H */ 320