1 /* 2 * ChromeOS EC multi-function device 3 * 4 * Copyright (C) 2012 Google, Inc 5 * 6 * This software is licensed under the terms of the GNU General Public 7 * License version 2, as published by the Free Software Foundation, and 8 * may be copied, distributed, and modified under those terms. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 */ 15 16 #ifndef __LINUX_MFD_CROS_EC_H 17 #define __LINUX_MFD_CROS_EC_H 18 19 #include <linux/cdev.h> 20 #include <linux/device.h> 21 #include <linux/notifier.h> 22 #include <linux/mfd/cros_ec_commands.h> 23 #include <linux/mutex.h> 24 25 #define CROS_EC_DEV_NAME "cros_ec" 26 #define CROS_EC_DEV_PD_NAME "cros_pd" 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 * @version: Command version number (often 0) 63 * @command: Command to send (EC_CMD_...) 64 * @outsize: Outgoing length in bytes 65 * @insize: Max number of bytes to accept from EC 66 * @result: EC's response to the command (separate from communication failure) 67 * @data: Where to put the incoming data from EC and outgoing data to EC 68 */ 69 struct cros_ec_command { 70 uint32_t version; 71 uint32_t command; 72 uint32_t outsize; 73 uint32_t insize; 74 uint32_t result; 75 uint8_t data[0]; 76 }; 77 78 /** 79 * struct cros_ec_device - Information about a ChromeOS EC device 80 * 81 * @phys_name: name of physical comms layer (e.g. 'i2c-4') 82 * @dev: Device pointer for physical comms device 83 * @was_wake_device: true if this device was set to wake the system from 84 * sleep at the last suspend 85 * @cmd_readmem: direct read of the EC memory-mapped region, if supported 86 * @offset is within EC_LPC_ADDR_MEMMAP region. 87 * @bytes: number of bytes to read. zero means "read a string" (including 88 * the trailing '\0'). At most only EC_MEMMAP_SIZE bytes can be read. 89 * Caller must ensure that the buffer is large enough for the result when 90 * reading a string. 91 * 92 * @priv: Private data 93 * @irq: Interrupt to use 94 * @id: Device id 95 * @din: input buffer (for data from EC) 96 * @dout: output buffer (for data to EC) 97 * \note 98 * These two buffers will always be dword-aligned and include enough 99 * space for up to 7 word-alignment bytes also, so we can ensure that 100 * the body of the message is always dword-aligned (64-bit). 101 * We use this alignment to keep ARM and x86 happy. Probably word 102 * alignment would be OK, there might be a small performance advantage 103 * to using dword. 104 * @din_size: size of din buffer to allocate (zero to use static din) 105 * @dout_size: size of dout buffer to allocate (zero to use static dout) 106 * @wake_enabled: true if this device can wake the system from sleep 107 * @suspended: true if this device had been suspended 108 * @cmd_xfer: send command to EC and get response 109 * Returns the number of bytes received if the communication succeeded, but 110 * that doesn't mean the EC was happy with the command. The caller 111 * should check msg.result for the EC's result code. 112 * @pkt_xfer: send packet to EC and get response 113 * @lock: one transaction at a time 114 * @mkbp_event_supported: true if this EC supports the MKBP event protocol. 115 * @event_notifier: interrupt event notifier for transport devices. 116 * @event_data: raw payload transferred with the MKBP event. 117 * @event_size: size in bytes of the event data. 118 */ 119 struct cros_ec_device { 120 121 /* These are used by other drivers that want to talk to the EC */ 122 const char *phys_name; 123 struct device *dev; 124 bool was_wake_device; 125 struct class *cros_class; 126 int (*cmd_readmem)(struct cros_ec_device *ec, unsigned int offset, 127 unsigned int bytes, void *dest); 128 129 /* These are used to implement the platform-specific interface */ 130 u16 max_request; 131 u16 max_response; 132 u16 max_passthru; 133 u16 proto_version; 134 void *priv; 135 int irq; 136 u8 *din; 137 u8 *dout; 138 int din_size; 139 int dout_size; 140 bool wake_enabled; 141 bool suspended; 142 int (*cmd_xfer)(struct cros_ec_device *ec, 143 struct cros_ec_command *msg); 144 int (*pkt_xfer)(struct cros_ec_device *ec, 145 struct cros_ec_command *msg); 146 struct mutex lock; 147 bool mkbp_event_supported; 148 struct blocking_notifier_head event_notifier; 149 150 struct ec_response_get_next_event_v1 event_data; 151 int event_size; 152 u32 host_event_wake_mask; 153 }; 154 155 /** 156 * struct cros_ec_sensor_platform - ChromeOS EC sensor platform information 157 * 158 * @sensor_num: Id of the sensor, as reported by the EC. 159 */ 160 struct cros_ec_sensor_platform { 161 u8 sensor_num; 162 }; 163 164 /* struct cros_ec_platform - ChromeOS EC platform information 165 * 166 * @ec_name: name of EC device (e.g. 'cros-ec', 'cros-pd', ...) 167 * used in /dev/ and sysfs. 168 * @cmd_offset: offset to apply for each command. Set when 169 * registering a devicde behind another one. 170 */ 171 struct cros_ec_platform { 172 const char *ec_name; 173 u16 cmd_offset; 174 }; 175 176 struct cros_ec_debugfs; 177 178 /* 179 * struct cros_ec_dev - ChromeOS EC device entry point 180 * 181 * @class_dev: Device structure used in sysfs 182 * @cdev: Character device structure in /dev 183 * @ec_dev: cros_ec_device structure to talk to the physical device 184 * @dev: pointer to the platform device 185 * @debug_info: cros_ec_debugfs structure for debugging information 186 * @has_kb_wake_angle: true if at least 2 accelerometer are connected to the EC. 187 * @cmd_offset: offset to apply for each command. 188 */ 189 struct cros_ec_dev { 190 struct device class_dev; 191 struct cdev cdev; 192 struct cros_ec_device *ec_dev; 193 struct device *dev; 194 struct cros_ec_debugfs *debug_info; 195 bool has_kb_wake_angle; 196 u16 cmd_offset; 197 u32 features[2]; 198 }; 199 200 #define to_cros_ec_dev(dev) container_of(dev, struct cros_ec_dev, class_dev) 201 202 /** 203 * cros_ec_suspend - Handle a suspend operation for the ChromeOS EC device 204 * 205 * This can be called by drivers to handle a suspend event. 206 * 207 * ec_dev: Device to suspend 208 * @return 0 if ok, -ve on error 209 */ 210 int cros_ec_suspend(struct cros_ec_device *ec_dev); 211 212 /** 213 * cros_ec_resume - Handle a resume operation for the ChromeOS EC device 214 * 215 * This can be called by drivers to handle a resume event. 216 * 217 * @ec_dev: Device to resume 218 * @return 0 if ok, -ve on error 219 */ 220 int cros_ec_resume(struct cros_ec_device *ec_dev); 221 222 /** 223 * cros_ec_prepare_tx - Prepare an outgoing message in the output buffer 224 * 225 * This is intended to be used by all ChromeOS EC drivers, but at present 226 * only SPI uses it. Once LPC uses the same protocol it can start using it. 227 * I2C could use it now, with a refactor of the existing code. 228 * 229 * @ec_dev: Device to register 230 * @msg: Message to write 231 */ 232 int cros_ec_prepare_tx(struct cros_ec_device *ec_dev, 233 struct cros_ec_command *msg); 234 235 /** 236 * cros_ec_check_result - Check ec_msg->result 237 * 238 * This is used by ChromeOS EC drivers to check the ec_msg->result for 239 * errors and to warn about them. 240 * 241 * @ec_dev: EC device 242 * @msg: Message to check 243 */ 244 int cros_ec_check_result(struct cros_ec_device *ec_dev, 245 struct cros_ec_command *msg); 246 247 /** 248 * cros_ec_cmd_xfer - Send a command to the ChromeOS EC 249 * 250 * Call this to send a command to the ChromeOS EC. This should be used 251 * instead of calling the EC's cmd_xfer() callback directly. 252 * 253 * @ec_dev: EC device 254 * @msg: Message to write 255 */ 256 int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev, 257 struct cros_ec_command *msg); 258 259 /** 260 * cros_ec_cmd_xfer_status - Send a command to the ChromeOS EC 261 * 262 * This function is identical to cros_ec_cmd_xfer, except it returns success 263 * status only if both the command was transmitted successfully and the EC 264 * replied with success status. It's not necessary to check msg->result when 265 * using this function. 266 * 267 * @ec_dev: EC device 268 * @msg: Message to write 269 * @return: Num. of bytes transferred on success, <0 on failure 270 */ 271 int cros_ec_cmd_xfer_status(struct cros_ec_device *ec_dev, 272 struct cros_ec_command *msg); 273 274 /** 275 * cros_ec_remove - Remove a ChromeOS EC 276 * 277 * Call this to deregister a ChromeOS EC, then clean up any private data. 278 * 279 * @ec_dev: Device to register 280 * @return 0 if ok, -ve on error 281 */ 282 int cros_ec_remove(struct cros_ec_device *ec_dev); 283 284 /** 285 * cros_ec_register - Register a new ChromeOS EC, using the provided info 286 * 287 * Before calling this, allocate a pointer to a new device and then fill 288 * in all the fields up to the --private-- marker. 289 * 290 * @ec_dev: Device to register 291 * @return 0 if ok, -ve on error 292 */ 293 int cros_ec_register(struct cros_ec_device *ec_dev); 294 295 /** 296 * cros_ec_query_all - Query the protocol version supported by the ChromeOS EC 297 * 298 * @ec_dev: Device to register 299 * @return 0 if ok, -ve on error 300 */ 301 int cros_ec_query_all(struct cros_ec_device *ec_dev); 302 303 /** 304 * cros_ec_get_next_event - Fetch next event from the ChromeOS EC 305 * 306 * @ec_dev: Device to fetch event from 307 * @wake_event: Pointer to a bool set to true upon return if the event might be 308 * treated as a wake event. Ignored if null. 309 * 310 * Returns: 0 on success, Linux error number on failure 311 */ 312 int cros_ec_get_next_event(struct cros_ec_device *ec_dev, bool *wake_event); 313 314 /** 315 * cros_ec_get_host_event - Return a mask of event set by the EC. 316 * 317 * When MKBP is supported, when the EC raises an interrupt, 318 * We collect the events raised and call the functions in the ec notifier. 319 * 320 * This function is a helper to know which events are raised. 321 */ 322 u32 cros_ec_get_host_event(struct cros_ec_device *ec_dev); 323 324 /* sysfs stuff */ 325 extern struct attribute_group cros_ec_attr_group; 326 extern struct attribute_group cros_ec_lightbar_attr_group; 327 extern struct attribute_group cros_ec_vbc_attr_group; 328 329 /* debugfs stuff */ 330 int cros_ec_debugfs_init(struct cros_ec_dev *ec); 331 void cros_ec_debugfs_remove(struct cros_ec_dev *ec); 332 void cros_ec_debugfs_suspend(struct cros_ec_dev *ec); 333 void cros_ec_debugfs_resume(struct cros_ec_dev *ec); 334 335 #endif /* __LINUX_MFD_CROS_EC_H */ 336
