include/linux/platform_data/cros_ec_proto.h

   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_v3 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, const void *outdata,
 262                     size_t outsize, void *indata, size_t insize);
 263
 264 int cros_ec_cmd_readmem(struct cros_ec_device *ec_dev, u8 offset, u8 size, void *dest);
 265
 266 int cros_ec_get_cmd_versions(struct cros_ec_device *ec_dev, u16 cmd);
 267
 268 /**
 269  * cros_ec_get_time_ns() - Return time in ns.
 270  *
 271  * This is the function used to record the time for last_event_time in struct
 272  * cros_ec_device during the hard irq.
 273  *
 274  * Return: ktime_t format since boot.
 275  */
 276 static inline ktime_t cros_ec_get_time_ns(void)
 277 {
 278         return ktime_get_boottime_ns();
 279 }
 280
 281 #endif /* __LINUX_CROS_EC_PROTO_H */