xref: /openbmc/linux/drivers/staging/nvec/nvec.h (revision b81947c6)
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
204