drivers/staging/nvec/nvec.h

   1 /*
   2  * NVEC: NVIDIA compliant embedded controller interface
   3  *
   4  * Copyright (C) 2011 The AC100 Kernel Team <ac100@lists.launchpad.net>
   5  *
   6  * Authors:  Pierre-Hugues Husson <phhusson@free.fr>
   7  *           Ilya Petrov <ilya.muromec@gmail.com>
   8  *           Marc Dietrich <marvin24@gmx.de>
   9  *           Julian Andres Klode <jak@jak-linux.org>
  10  *
  11  * This file is subject to the terms and conditions of the GNU General Public
  12  * License.  See the file "COPYING" in the main directory of this archive
  13  * for more details.
  14  *
  15  */
  16
  17 #ifndef __LINUX_MFD_NVEC
  18 #define __LINUX_MFD_NVEC
  19
  20 #include <linux/atomic.h>
  21 #include <linux/clk.h>
  22 #include <linux/completion.h>
  23 #include <linux/list.h>
  24 #include <linux/mutex.h>
  25 #include <linux/notifier.h>
  26 #include <linux/spinlock.h>
  27 #include <linux/workqueue.h>
  28
  29 /* NVEC_POOL_SIZE - Size of the pool in &struct nvec_msg */
  30 #define NVEC_POOL_SIZE  64
  31
  32 /*
  33  * NVEC_MSG_SIZE - Maximum size of the data field of &struct nvec_msg.
  34  *
  35  * A message must store up to a SMBus block operation which consists of
  36  * one command byte, one count byte, and up to 32 payload bytes = 34
  37  * byte.
  38  */
  39 #define NVEC_MSG_SIZE   34
  40
  41 /**
  42  * enum nvec_event_size - The size of an event message
  43  * @NVEC_2BYTES: The message has one command byte and one data byte
  44  * @NVEC_3BYTES: The message has one command byte and two data bytes
  45  * @NVEC_VAR_SIZE: The message has one command byte, one count byte, and as
  46  *                 up to as many bytes as the number in the count byte. The
  47  *                 maximum is 32
  48  *
  49  * Events can be fixed or variable sized. This is useless on other message
  50  * types, which are always variable sized.
  51  */
  52 enum nvec_event_size {
  53         NVEC_2BYTES,
  54         NVEC_3BYTES,
  55         NVEC_VAR_SIZE,
  56 };
  57
  58 /**
  59  * enum nvec_msg_type - The type of a message
  60  * @NVEC_SYS: A system request/response
  61  * @NVEC_BAT: A battery request/response
  62  * @NVEC_KBD: A keyboard request/response
  63  * @NVEC_PS2: A mouse request/response
  64  * @NVEC_CNTL: A EC control request/response
  65  * @NVEC_KB_EVT: An event from the keyboard
  66  * @NVEC_PS2_EVT: An event from the mouse
  67  *
  68  * Events can be fixed or variable sized. This is useless on other message
  69  * types, which are always variable sized.
  70  */
  71 enum nvec_msg_type {
  72         NVEC_SYS = 1,
  73         NVEC_BAT,
  74         NVEC_KBD = 5,
  75         NVEC_PS2,
  76         NVEC_CNTL,
  77         NVEC_KB_EVT = 0x80,
  78         NVEC_PS2_EVT,
  79 };
  80
  81 /**
  82  * struct nvec_msg - A buffer for a single message
  83  * @node: Messages are part of various lists in a &struct nvec_chip
  84  * @data: The data of the message
  85  * @size: For TX messages, the number of bytes used in @data
  86  * @pos:  For RX messages, the current position to write to. For TX messages,
  87  *        the position to read from.
  88  * @used: Used for the message pool to mark a message as free/allocated.
  89  *
  90  * This structure is used to hold outgoing and incoming messages. Outgoing
  91  * messages have a different format than incoming messages, and that is not
  92  * documented yet.
  93  */
  94 struct nvec_msg {
  95         struct list_head node;
  96         unsigned char data[NVEC_MSG_SIZE];
  97         unsigned short size;
  98         unsigned short pos;
  99         atomic_t used;
 100 };
 101
 102 /**
 103  * struct nvec_subdev - A subdevice of nvec, such as nvec_kbd
 104  * @name: The name of the sub device
 105  * @platform_data: Platform data
 106  * @id: Identifier of the sub device
 107  */
 108 struct nvec_subdev {
 109         const char *name;
 110         void *platform_data;
 111         int id;
 112 };
 113
 114 /**
 115  * struct nvec_platform_data - platform data for a tegra slave controller
 116  * @i2c_addr: number of i2c slave adapter the ec is connected to
 117  * @gpio: gpio number for the ec request line
 118  *
 119  * Platform data, to be used in board definitions. For an example, take a
 120  * look at the paz00 board in arch/arm/mach-tegra/board-paz00.c
 121  */
 122 struct nvec_platform_data {
 123         int i2c_addr;
 124         int gpio;
 125 };
 126
 127 /**
 128  * struct nvec_chip - A single connection to an NVIDIA Embedded controller
 129  * @dev: The device
 130  * @gpio: The same as for &struct nvec_platform_data
 131  * @irq: The IRQ of the I2C device
 132  * @i2c_addr: The address of the I2C slave
 133  * @base: The base of the memory mapped region of the I2C device
 134  * @clk: The clock of the I2C device
 135  * @notifier_list: Notifiers to be called on received messages, see
 136  *                 nvec_register_notifier()
 137  * @rx_data: Received messages that have to be processed
 138  * @tx_data: Messages waiting to be sent to the controller
 139  * @nvec_status_notifier: Internal notifier (see nvec_status_notifier())
 140  * @rx_work: A work structure for the RX worker nvec_dispatch()
 141  * @tx_work: A work structure for the TX worker nvec_request_master()
 142  * @wq: The work queue in which @rx_work and @tx_work are executed
 143  * @rx: The message currently being retrieved or %NULL
 144  * @msg_pool: A pool of messages for allocation
 145  * @tx: The message currently being transferred
 146  * @tx_scratch: Used for building pseudo messages
 147  * @ec_transfer: A completion that will be completed once a message has been
 148  *               received (see nvec_rx_completed())
 149  * @tx_lock: Spinlock for modifications on @tx_data
 150  * @rx_lock: Spinlock for modifications on @rx_data
 151  * @sync_write_mutex: A mutex for nvec_write_sync()
 152  * @sync_write: A completion to signal that a synchronous message is complete
 153  * @sync_write_pending: The first two bytes of the request (type and subtype)
 154  * @last_sync_msg: The last synchronous message.
 155  * @state: State of our finite state machine used in nvec_interrupt()
 156  */
 157 struct nvec_chip {
 158         struct device *dev;
 159         int gpio;
 160         int irq;
 161         int i2c_addr;
 162         void __iomem *base;
 163         struct clk *i2c_clk;
 164         struct atomic_notifier_head notifier_list;
 165         struct list_head rx_data, tx_data;
 166         struct notifier_block nvec_status_notifier;
 167         struct work_struct rx_work, tx_work;
 168         struct workqueue_struct *wq;
 169         struct nvec_msg msg_pool[NVEC_POOL_SIZE];
 170         struct nvec_msg *rx;
 171
 172         struct nvec_msg *tx;
 173         struct nvec_msg tx_scratch;
 174         struct completion ec_transfer;
 175
 176         spinlock_t tx_lock, rx_lock;
 177
 178         /* sync write stuff */
 179         struct mutex sync_write_mutex;
 180         struct completion sync_write;
 181         u16 sync_write_pending;
 182         struct nvec_msg *last_sync_msg;
 183
 184         int state;
 185 };
 186
 187 extern int nvec_write_async(struct nvec_chip *nvec, const unsigned char *data,
 188                              short size);
 189
 190 extern struct nvec_msg *nvec_write_sync(struct nvec_chip *nvec,
 191                                         const unsigned char *data, short size);
 192
 193 extern int nvec_register_notifier(struct nvec_chip *nvec,
 194                                   struct notifier_block *nb,
 195                                   unsigned int events);
 196
 197 extern int nvec_unregister_notifier(struct device *dev,
 198                                     struct notifier_block *nb,
 199                                     unsigned int events);
 200
 201 extern void nvec_msg_free(struct nvec_chip *nvec, struct nvec_msg *msg);
 202
 203 #endif