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 */ 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