drivers/staging/nvec/nvec.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * NVEC: NVIDIA compliant embedded controller interface
   4  *
   5  * Copyright (C) 2011 The AC100 Kernel Team <ac100@lists.launchpad.net>
   6  *
   7  * Authors:  Pierre-Hugues Husson <phhusson@free.fr>
   8  *           Ilya Petrov <ilya.muromec@gmail.com>
   9  *           Marc Dietrich <marvin24@gmx.de>
  10  *           Julian Andres Klode <jak@jak-linux.org>
  11  */
  12
  13 #ifndef __LINUX_MFD_NVEC
  14 #define __LINUX_MFD_NVEC
  15
  16 #include <linux/atomic.h>
  17 #include <linux/clk.h>
  18 #include <linux/completion.h>
  19 #include <linux/list.h>
  20 #include <linux/mutex.h>
  21 #include <linux/notifier.h>
  22 #include <linux/reset.h>
  23 #include <linux/spinlock.h>
  24 #include <linux/workqueue.h>
  25
  26 /* NVEC_POOL_SIZE - Size of the pool in &struct nvec_msg */
  27 #define NVEC_POOL_SIZE  64
  28
  29 /*
  30  * NVEC_MSG_SIZE - Maximum size of the data field of &struct nvec_msg.
  31  *
  32  * A message must store up to a SMBus block operation which consists of
  33  * one command byte, one count byte, and up to 32 payload bytes = 34
  34  * byte.
  35  */
  36 #define NVEC_MSG_SIZE   34
  37
  38 /**
  39  * enum nvec_event_size - The size of an event message
  40  * @NVEC_2BYTES: The message has one command byte and one data byte
  41  * @NVEC_3BYTES: The message has one command byte and two data bytes
  42  * @NVEC_VAR_SIZE: The message has one command byte, one count byte, and has
  43  *                 up to as many bytes as the number in the count byte. The
  44  *                 maximum is 32
  45  *
  46  * Events can be fixed or variable sized. This is useless on other message
  47  * types, which are always variable sized.
  48  */
  49 enum nvec_event_size {
  50         NVEC_2BYTES,
  51         NVEC_3BYTES,
  52         NVEC_VAR_SIZE,
  53 };
  54
  55 /**
  56  * enum nvec_msg_type - The type of a message
  57  * @NVEC_SYS: A system request/response
  58  * @NVEC_BAT: A battery request/response
  59  * @NVEC_KBD: A keyboard request/response
  60  * @NVEC_PS2: A mouse request/response
  61  * @NVEC_CNTL: A EC control request/response
  62  * @NVEC_KB_EVT: An event from the keyboard
  63  * @NVEC_PS2_EVT: An event from the mouse
  64  *
  65  * Events can be fixed or variable sized. This is useless on other message
  66  * types, which are always variable sized.
  67  */
  68 enum nvec_msg_type {
  69         NVEC_SYS = 1,
  70         NVEC_BAT,
  71         NVEC_GPIO,
  72         NVEC_SLEEP,
  73         NVEC_KBD,
  74         NVEC_PS2,
  75         NVEC_CNTL,
  76         NVEC_OEM0 = 0x0d,
  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_chip - A single connection to an NVIDIA Embedded controller
 104  * @dev: The device
 105  * @gpio: The same as for &struct nvec_platform_data
 106  * @irq: The IRQ of the I2C device
 107  * @i2c_addr: The address of the I2C slave
 108  * @base: The base of the memory mapped region of the I2C device
 109  * @i2c_clk: The clock of the I2C device
 110  * @rst: The reset of the I2C device
 111  * @notifier_list: Notifiers to be called on received messages, see
 112  *                 nvec_register_notifier()
 113  * @rx_data: Received messages that have to be processed
 114  * @tx_data: Messages waiting to be sent to the controller
 115  * @nvec_status_notifier: Internal notifier (see nvec_status_notifier())
 116  * @rx_work: A work structure for the RX worker nvec_dispatch()
 117  * @tx_work: A work structure for the TX worker nvec_request_master()
 118  * @wq: The work queue in which @rx_work and @tx_work are executed
 119  * @rx: The message currently being retrieved or %NULL
 120  * @msg_pool: A pool of messages for allocation
 121  * @tx: The message currently being transferred
 122  * @tx_scratch: Used for building pseudo messages
 123  * @ec_transfer: A completion that will be completed once a message has been
 124  *               received (see nvec_rx_completed())
 125  * @tx_lock: Spinlock for modifications on @tx_data
 126  * @rx_lock: Spinlock for modifications on @rx_data
 127  * @sync_write_mutex: A mutex for nvec_write_sync()
 128  * @sync_write: A completion to signal that a synchronous message is complete
 129  * @sync_write_pending: The first two bytes of the request (type and subtype)
 130  * @last_sync_msg: The last synchronous message.
 131  * @state: State of our finite state machine used in nvec_interrupt()
 132  */
 133 struct nvec_chip {
 134         struct device *dev;
 135         struct gpio_desc *gpiod;
 136         int irq;
 137         u32 i2c_addr;
 138         void __iomem *base;
 139         struct clk *i2c_clk;
 140         struct reset_control *rst;
 141         struct atomic_notifier_head notifier_list;
 142         struct list_head rx_data, tx_data;
 143         struct notifier_block nvec_status_notifier;
 144         struct work_struct rx_work, tx_work;
 145         struct workqueue_struct *wq;
 146         struct nvec_msg msg_pool[NVEC_POOL_SIZE];
 147         struct nvec_msg *rx;
 148
 149         struct nvec_msg *tx;
 150         struct nvec_msg tx_scratch;
 151         struct completion ec_transfer;
 152
 153         spinlock_t tx_lock, rx_lock;
 154
 155         /* sync write stuff */
 156         struct mutex sync_write_mutex;
 157         struct completion sync_write;
 158         u16 sync_write_pending;
 159         struct nvec_msg *last_sync_msg;
 160
 161         int state;
 162 };
 163
 164 int nvec_write_async(struct nvec_chip *nvec, const unsigned char *data,
 165                      short size);
 166
 167 int nvec_write_sync(struct nvec_chip *nvec,
 168                     const unsigned char *data, short size,
 169                     struct nvec_msg **msg);
 170
 171 int nvec_register_notifier(struct nvec_chip *nvec,
 172                            struct notifier_block *nb,
 173                            unsigned int events);
 174
 175 int nvec_unregister_notifier(struct nvec_chip *dev, struct notifier_block *nb);
 176
 177 void nvec_msg_free(struct nvec_chip *nvec, struct nvec_msg *msg);
 178
 179 #endif