staging/nvec/nvec.h

0001 /* SPDX-License-Identifier: GPL-2.0 */
0002 /*
0003  * NVEC: NVIDIA compliant embedded controller interface
0004  *
0005  * Copyright (C) 2011 The AC100 Kernel Team <ac100@lists.launchpad.net>
0006  *
0007  * Authors:  Pierre-Hugues Husson <phhusson@free.fr>
0008  *           Ilya Petrov <ilya.muromec@gmail.com>
0009  *           Marc Dietrich <marvin24@gmx.de>
0010  *           Julian Andres Klode <jak@jak-linux.org>
0011  */
0012
0013 #ifndef __LINUX_MFD_NVEC
0014 #define __LINUX_MFD_NVEC
0015
0016 #include <linux/atomic.h>
0017 #include <linux/clk.h>
0018 #include <linux/completion.h>
0019 #include <linux/list.h>
0020 #include <linux/mutex.h>
0021 #include <linux/notifier.h>
0022 #include <linux/reset.h>
0023 #include <linux/spinlock.h>
0024 #include <linux/workqueue.h>
0025
0026 /* NVEC_POOL_SIZE - Size of the pool in &struct nvec_msg */
0027 #define NVEC_POOL_SIZE  64
0028
0029 /*
0030  * NVEC_MSG_SIZE - Maximum size of the data field of &struct nvec_msg.
0031  *
0032  * A message must store up to a SMBus block operation which consists of
0033  * one command byte, one count byte, and up to 32 payload bytes = 34
0034  * byte.
0035  */
0036 #define NVEC_MSG_SIZE   34
0037
0038 /**
0039  * enum nvec_event_size - The size of an event message
0040  * @NVEC_2BYTES: The message has one command byte and one data byte
0041  * @NVEC_3BYTES: The message has one command byte and two data bytes
0042  * @NVEC_VAR_SIZE: The message has one command byte, one count byte, and has
0043  *                 up to as many bytes as the number in the count byte. The
0044  *                 maximum is 32
0045  *
0046  * Events can be fixed or variable sized. This is useless on other message
0047  * types, which are always variable sized.
0048  */
0049 enum nvec_event_size {
0050     NVEC_2BYTES,
0051     NVEC_3BYTES,
0052     NVEC_VAR_SIZE,
0053 };
0054
0055 /**
0056  * enum nvec_msg_type - The type of a message
0057  * @NVEC_SYS: A system request/response
0058  * @NVEC_BAT: A battery request/response
0059  * @NVEC_KBD: A keyboard request/response
0060  * @NVEC_PS2: A mouse request/response
0061  * @NVEC_CNTL: A EC control request/response
0062  * @NVEC_KB_EVT: An event from the keyboard
0063  * @NVEC_PS2_EVT: An event from the mouse
0064  *
0065  * Events can be fixed or variable sized. This is useless on other message
0066  * types, which are always variable sized.
0067  */
0068 enum nvec_msg_type {
0069     NVEC_SYS = 1,
0070     NVEC_BAT,
0071     NVEC_GPIO,
0072     NVEC_SLEEP,
0073     NVEC_KBD,
0074     NVEC_PS2,
0075     NVEC_CNTL,
0076     NVEC_OEM0 = 0x0d,
0077     NVEC_KB_EVT = 0x80,
0078     NVEC_PS2_EVT,
0079 };
0080
0081 /**
0082  * struct nvec_msg - A buffer for a single message
0083  * @node: Messages are part of various lists in a &struct nvec_chip
0084  * @data: The data of the message
0085  * @size: For TX messages, the number of bytes used in @data
0086  * @pos:  For RX messages, the current position to write to. For TX messages,
0087  *        the position to read from.
0088  * @used: Used for the message pool to mark a message as free/allocated.
0089  *
0090  * This structure is used to hold outgoing and incoming messages. Outgoing
0091  * messages have a different format than incoming messages, and that is not
0092  * documented yet.
0093  */
0094 struct nvec_msg {
0095     struct list_head node;
0096     unsigned char data[NVEC_MSG_SIZE];
0097     unsigned short size;
0098     unsigned short pos;
0099     atomic_t used;
0100 };
0101
0102 /**
0103  * struct nvec_chip - A single connection to an NVIDIA Embedded controller
0104  * @dev: The device
0105  * @gpio: The same as for &struct nvec_platform_data
0106  * @irq: The IRQ of the I2C device
0107  * @i2c_addr: The address of the I2C slave
0108  * @base: The base of the memory mapped region of the I2C device
0109  * @i2c_clk: The clock of the I2C device
0110  * @rst: The reset of the I2C device
0111  * @notifier_list: Notifiers to be called on received messages, see
0112  *                 nvec_register_notifier()
0113  * @rx_data: Received messages that have to be processed
0114  * @tx_data: Messages waiting to be sent to the controller
0115  * @nvec_status_notifier: Internal notifier (see nvec_status_notifier())
0116  * @rx_work: A work structure for the RX worker nvec_dispatch()
0117  * @tx_work: A work structure for the TX worker nvec_request_master()
0118  * @wq: The work queue in which @rx_work and @tx_work are executed
0119  * @rx: The message currently being retrieved or %NULL
0120  * @msg_pool: A pool of messages for allocation
0121  * @tx: The message currently being transferred
0122  * @tx_scratch: Used for building pseudo messages
0123  * @ec_transfer: A completion that will be completed once a message has been
0124  *               received (see nvec_rx_completed())
0125  * @tx_lock: Spinlock for modifications on @tx_data
0126  * @rx_lock: Spinlock for modifications on @rx_data
0127  * @sync_write_mutex: A mutex for nvec_write_sync()
0128  * @sync_write: A completion to signal that a synchronous message is complete
0129  * @sync_write_pending: The first two bytes of the request (type and subtype)
0130  * @last_sync_msg: The last synchronous message.
0131  * @state: State of our finite state machine used in nvec_interrupt()
0132  */
0133 struct nvec_chip {
0134     struct device *dev;
0135     struct gpio_desc *gpiod;
0136     int irq;
0137     u32 i2c_addr;
0138     void __iomem *base;
0139     struct clk *i2c_clk;
0140     struct reset_control *rst;
0141     struct atomic_notifier_head notifier_list;
0142     struct list_head rx_data, tx_data;
0143     struct notifier_block nvec_status_notifier;
0144     struct work_struct rx_work, tx_work;
0145     struct workqueue_struct *wq;
0146     struct nvec_msg msg_pool[NVEC_POOL_SIZE];
0147     struct nvec_msg *rx;
0148
0149     struct nvec_msg *tx;
0150     struct nvec_msg tx_scratch;
0151     struct completion ec_transfer;
0152
0153     spinlock_t tx_lock, rx_lock;
0154
0155     /* sync write stuff */
0156     struct mutex sync_write_mutex;
0157     struct completion sync_write;
0158     u16 sync_write_pending;
0159     struct nvec_msg *last_sync_msg;
0160
0161     int state;
0162 };
0163
0164 int nvec_write_async(struct nvec_chip *nvec, const unsigned char *data,
0165              short size);
0166
0167 int nvec_write_sync(struct nvec_chip *nvec,
0168             const unsigned char *data, short size,
0169             struct nvec_msg **msg);
0170
0171 int nvec_register_notifier(struct nvec_chip *nvec,
0172                struct notifier_block *nb,
0173                unsigned int events);
0174
0175 int nvec_unregister_notifier(struct nvec_chip *dev, struct notifier_block *nb);
0176
0177 void nvec_msg_free(struct nvec_chip *nvec, struct nvec_msg *msg);
0178
0179 #endif