include/linux/mfd/cros_ec.h

   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 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  * @cmd_offset: offset to apply for each command.
 187  */
 188 struct cros_ec_dev {
 189         struct device class_dev;
 190         struct cdev cdev;
 191         struct cros_ec_device *ec_dev;
 192         struct device *dev;
 193         struct cros_ec_debugfs *debug_info;
 194         u16 cmd_offset;
 195         u32 features[2];
 196 };
 197
 198 /**
 199  * cros_ec_suspend - Handle a suspend operation for the ChromeOS EC device
 200  *
 201  * This can be called by drivers to handle a suspend event.
 202  *
 203  * ec_dev: Device to suspend
 204  * @return 0 if ok, -ve on error
 205  */
 206 int cros_ec_suspend(struct cros_ec_device *ec_dev);
 207
 208 /**
 209  * cros_ec_resume - Handle a resume operation for the ChromeOS EC device
 210  *
 211  * This can be called by drivers to handle a resume event.
 212  *
 213  * @ec_dev: Device to resume
 214  * @return 0 if ok, -ve on error
 215  */
 216 int cros_ec_resume(struct cros_ec_device *ec_dev);
 217
 218 /**
 219  * cros_ec_prepare_tx - Prepare an outgoing message in the output buffer
 220  *
 221  * This is intended to be used by all ChromeOS EC drivers, but at present
 222  * only SPI uses it. Once LPC uses the same protocol it can start using it.
 223  * I2C could use it now, with a refactor of the existing code.
 224  *
 225  * @ec_dev: Device to register
 226  * @msg: Message to write
 227  */
 228 int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
 229                        struct cros_ec_command *msg);
 230
 231 /**
 232  * cros_ec_check_result - Check ec_msg->result
 233  *
 234  * This is used by ChromeOS EC drivers to check the ec_msg->result for
 235  * errors and to warn about them.
 236  *
 237  * @ec_dev: EC device
 238  * @msg: Message to check
 239  */
 240 int cros_ec_check_result(struct cros_ec_device *ec_dev,
 241                          struct cros_ec_command *msg);
 242
 243 /**
 244  * cros_ec_cmd_xfer - Send a command to the ChromeOS EC
 245  *
 246  * Call this to send a command to the ChromeOS EC.  This should be used
 247  * instead of calling the EC's cmd_xfer() callback directly.
 248  *
 249  * @ec_dev: EC device
 250  * @msg: Message to write
 251  */
 252 int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev,
 253                      struct cros_ec_command *msg);
 254
 255 /**
 256  * cros_ec_cmd_xfer_status - Send a command to the ChromeOS EC
 257  *
 258  * This function is identical to cros_ec_cmd_xfer, except it returns success
 259  * status only if both the command was transmitted successfully and the EC
 260  * replied with success status. It's not necessary to check msg->result when
 261  * using this function.
 262  *
 263  * @ec_dev: EC device
 264  * @msg: Message to write
 265  * @return: Num. of bytes transferred on success, <0 on failure
 266  */
 267 int cros_ec_cmd_xfer_status(struct cros_ec_device *ec_dev,
 268                             struct cros_ec_command *msg);
 269
 270 /**
 271  * cros_ec_remove - Remove a ChromeOS EC
 272  *
 273  * Call this to deregister a ChromeOS EC, then clean up any private data.
 274  *
 275  * @ec_dev: Device to register
 276  * @return 0 if ok, -ve on error
 277  */
 278 int cros_ec_remove(struct cros_ec_device *ec_dev);
 279
 280 /**
 281  * cros_ec_register - Register a new ChromeOS EC, using the provided info
 282  *
 283  * Before calling this, allocate a pointer to a new device and then fill
 284  * in all the fields up to the --private-- marker.
 285  *
 286  * @ec_dev: Device to register
 287  * @return 0 if ok, -ve on error
 288  */
 289 int cros_ec_register(struct cros_ec_device *ec_dev);
 290
 291 /**
 292  * cros_ec_query_all -  Query the protocol version supported by the ChromeOS EC
 293  *
 294  * @ec_dev: Device to register
 295  * @return 0 if ok, -ve on error
 296  */
 297 int cros_ec_query_all(struct cros_ec_device *ec_dev);
 298
 299 /**
 300  * cros_ec_get_next_event -  Fetch next event from the ChromeOS EC
 301  *
 302  * @ec_dev: Device to fetch event from
 303  * @wake_event: Pointer to a bool set to true upon return if the event might be
 304  *              treated as a wake event. Ignored if null.
 305  *
 306  * Returns: 0 on success, Linux error number on failure
 307  */
 308 int cros_ec_get_next_event(struct cros_ec_device *ec_dev, bool *wake_event);
 309
 310 /**
 311  * cros_ec_get_host_event - Return a mask of event set by the EC.
 312  *
 313  * When MKBP is supported, when the EC raises an interrupt,
 314  * We collect the events raised and call the functions in the ec notifier.
 315  *
 316  * This function is a helper to know which events are raised.
 317  */
 318 u32 cros_ec_get_host_event(struct cros_ec_device *ec_dev);
 319
 320 /* sysfs stuff */
 321 extern struct attribute_group cros_ec_attr_group;
 322 extern struct attribute_group cros_ec_lightbar_attr_group;
 323 extern struct attribute_group cros_ec_vbc_attr_group;
 324
 325 /* ACPI GPE handler */
 326 #ifdef CONFIG_ACPI
 327
 328 int cros_ec_acpi_install_gpe_handler(struct device *dev);
 329 void cros_ec_acpi_remove_gpe_handler(void);
 330 void cros_ec_acpi_clear_gpe(void);
 331
 332 #else /* CONFIG_ACPI */
 333
 334 static inline int cros_ec_acpi_install_gpe_handler(struct device *dev)
 335 {
 336         return -ENODEV;
 337 }
 338 static inline void cros_ec_acpi_remove_gpe_handler(void) {}
 339 static inline void cros_ec_acpi_clear_gpe(void) {}
 340
 341 #endif /* CONFIG_ACPI */
 342
 343 #endif /* __LINUX_MFD_CROS_EC_H */