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/mfd/cros_ec_commands.h>
  20
  21 /*
  22  * Command interface between EC and AP, for LPC, I2C and SPI interfaces.
  23  */
  24 enum {
  25         EC_MSG_TX_HEADER_BYTES  = 3,
  26         EC_MSG_TX_TRAILER_BYTES = 1,
  27         EC_MSG_TX_PROTO_BYTES   = EC_MSG_TX_HEADER_BYTES +
  28                                         EC_MSG_TX_TRAILER_BYTES,
  29         EC_MSG_RX_PROTO_BYTES   = 3,
  30
  31         /* Max length of messages */
  32         EC_MSG_BYTES            = EC_HOST_PARAM_SIZE + EC_MSG_TX_PROTO_BYTES,
  33
  34 };
  35
  36 /**
  37  * struct cros_ec_msg - A message sent to the EC, and its reply
  38  *
  39  * @version: Command version number (often 0)
  40  * @cmd: Command to send (EC_CMD_...)
  41  * @out_buf: Outgoing payload (to EC)
  42  * @outlen: Outgoing length
  43  * @in_buf: Incoming payload (from EC)
  44  * @in_len: Incoming length
  45  */
  46 struct cros_ec_msg {
  47         u8 version;
  48         u8 cmd;
  49         uint8_t *out_buf;
  50         int out_len;
  51         uint8_t *in_buf;
  52         int in_len;
  53 };
  54
  55 /**
  56  * struct cros_ec_device - Information about a ChromeOS EC device
  57  *
  58  * @name: Name of this EC interface
  59  * @priv: Private data
  60  * @irq: Interrupt to use
  61  * @din: input buffer (from EC)
  62  * @dout: output buffer (to EC)
  63  * \note
  64  * These two buffers will always be dword-aligned and include enough
  65  * space for up to 7 word-alignment bytes also, so we can ensure that
  66  * the body of the message is always dword-aligned (64-bit).
  67  *
  68  * We use this alignment to keep ARM and x86 happy. Probably word
  69  * alignment would be OK, there might be a small performance advantage
  70  * to using dword.
  71  * @din_size: size of din buffer
  72  * @dout_size: size of dout buffer
  73  * @command_send: send a command
  74  * @command_recv: receive a command
  75  * @ec_name: name of EC device (e.g. 'chromeos-ec')
  76  * @phys_name: name of physical comms layer (e.g. 'i2c-4')
  77  * @parent: pointer to parent device (e.g. i2c or spi device)
  78  * @dev: Device pointer
  79  * dev_lock: Lock to prevent concurrent access
  80  * @wake_enabled: true if this device can wake the system from sleep
  81  * @was_wake_device: true if this device was set to wake the system from
  82  * sleep at the last suspend
  83  * @event_notifier: interrupt event notifier for transport devices
  84  */
  85 struct cros_ec_device {
  86         const char *name;
  87         void *priv;
  88         int irq;
  89         uint8_t *din;
  90         uint8_t *dout;
  91         int din_size;
  92         int dout_size;
  93         int (*command_send)(struct cros_ec_device *ec,
  94                         uint16_t cmd, void *out_buf, int out_len);
  95         int (*command_recv)(struct cros_ec_device *ec,
  96                         uint16_t cmd, void *in_buf, int in_len);
  97         int (*command_sendrecv)(struct cros_ec_device *ec,
  98                         uint16_t cmd, void *out_buf, int out_len,
  99                         void *in_buf, int in_len);
 100         int (*command_xfer)(struct cros_ec_device *ec,
 101                         struct cros_ec_msg *msg);
 102
 103         const char *ec_name;
 104         const char *phys_name;
 105         struct device *parent;
 106
 107         /* These are --private-- fields - do not assign */
 108         struct device *dev;
 109         struct mutex dev_lock;
 110         bool wake_enabled;
 111         bool was_wake_device;
 112         struct blocking_notifier_head event_notifier;
 113 };
 114
 115 /**
 116  * cros_ec_suspend - Handle a suspend operation for the ChromeOS EC device
 117  *
 118  * This can be called by drivers to handle a suspend event.
 119  *
 120  * ec_dev: Device to suspend
 121  * @return 0 if ok, -ve on error
 122  */
 123 int cros_ec_suspend(struct cros_ec_device *ec_dev);
 124
 125 /**
 126  * cros_ec_resume - Handle a resume operation for the ChromeOS EC device
 127  *
 128  * This can be called by drivers to handle a resume event.
 129  *
 130  * @ec_dev: Device to resume
 131  * @return 0 if ok, -ve on error
 132  */
 133 int cros_ec_resume(struct cros_ec_device *ec_dev);
 134
 135 /**
 136  * cros_ec_prepare_tx - Prepare an outgoing message in the output buffer
 137  *
 138  * This is intended to be used by all ChromeOS EC drivers, but at present
 139  * only SPI uses it. Once LPC uses the same protocol it can start using it.
 140  * I2C could use it now, with a refactor of the existing code.
 141  *
 142  * @ec_dev: Device to register
 143  * @msg: Message to write
 144  */
 145 int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
 146                        struct cros_ec_msg *msg);
 147
 148 /**
 149  * cros_ec_remove - Remove a ChromeOS EC
 150  *
 151  * Call this to deregister a ChromeOS EC. After this you should call
 152  * cros_ec_free().
 153  *
 154  * @ec_dev: Device to register
 155  * @return 0 if ok, -ve on error
 156  */
 157 int cros_ec_remove(struct cros_ec_device *ec_dev);
 158
 159 /**
 160  * cros_ec_register - Register a new ChromeOS EC, using the provided info
 161  *
 162  * Before calling this, allocate a pointer to a new device and then fill
 163  * in all the fields up to the --private-- marker.
 164  *
 165  * @ec_dev: Device to register
 166  * @return 0 if ok, -ve on error
 167  */
 168 int cros_ec_register(struct cros_ec_device *ec_dev);
 169
 170 #endif /* __LINUX_MFD_CROS_EC_H */