LXR linux/include/linux/mfd/cros

   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 */
  24enum {
  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 */
  46struct 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 */
  85struct 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 */
 123int 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 */
 133int 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 */
 145int 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 */
 157int 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 */
 168int cros_ec_register(struct cros_ec_device *ec_dev);
 169
 170#endif /* __LINUX_MFD_CROS_EC_H */
 171