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 */
 49enum 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 */
 68enum 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 */
 94struct 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 */
133struct 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
164int nvec_write_async(struct nvec_chip *nvec, const unsigned char *data,
165		     short size);
166
167int nvec_write_sync(struct nvec_chip *nvec,
168		    const unsigned char *data, short size,
169		    struct nvec_msg **msg);
170
171int nvec_register_notifier(struct nvec_chip *nvec,
172			   struct notifier_block *nb,
173			   unsigned int events);
174
175int nvec_unregister_notifier(struct nvec_chip *dev, struct notifier_block *nb);
176
177void nvec_msg_free(struct nvec_chip *nvec, struct nvec_msg *msg);
178
179#endif