xref: /freebsd/sys/dev/ichiic/ig4_var.h (revision f699532fb5b2c7b2445404b62f87bcd436195e5a)
1 /*
2  * Copyright (c) 2014 The DragonFly Project.  All rights reserved.
3  *
4  * This code is derived from software contributed to The DragonFly Project
5  * by Matthew Dillon <dillon@backplane.com> and was subsequently ported
6  * to FreeBSD by Michael Gmelin <freebsd@grem.de>
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in
16  *    the documentation and/or other materials provided with the
17  *    distribution.
18  * 3. Neither the name of The DragonFly Project nor the names of its
19  *    contributors may be used to endorse or promote products derived
20  *    from this software without specific, prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
25  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
26  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
27  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
28  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
29  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
30  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
31  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
32  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  *
35  * $FreeBSD$
36  */
37 
38 #ifndef _ICHIIC_IG4_VAR_H_
39 #define _ICHIIC_IG4_VAR_H_
40 
41 #include "bus_if.h"
42 #include "device_if.h"
43 #include "pci_if.h"
44 #include "iicbus_if.h"
45 
46 #define IG4_RBUFSIZE	128
47 #define IG4_RBUFMASK	(IG4_RBUFSIZE - 1)
48 
49 enum ig4_op { IG4_IDLE, IG4_READ, IG4_WRITE };
50 
51 struct ig4iic_softc {
52 	device_t	dev;
53 	struct		intr_config_hook enum_hook;
54 	device_t	iicbus;
55 	struct resource	*regs_res;
56 	int		regs_rid;
57 	struct resource	*intr_res;
58 	int		intr_rid;
59 	void		*intr_handle;
60 	int		intr_type;
61 	enum ig4_op	op;
62 	int		cmd;
63 	int		rnext;
64 	int		rpos;
65 	char		rbuf[IG4_RBUFSIZE];
66 	int		error;
67 	uint8_t		last_slave;
68 	int		pci_attached : 1;
69 	int		use_10bit : 1;
70 	int		slave_valid : 1;
71 	int		read_started : 1;
72 	int		write_started : 1;
73 
74 	/*
75 	 * Locking semantics:
76 	 *
77 	 * Functions implementing the icbus interface that interact
78 	 * with the controller acquire an exclusive lock on call_lock
79 	 * to prevent interleaving of calls to the interface and a lock on
80 	 * io_lock right afterwards, to synchronize controller I/O activity.
81 	 *
82 	 * The interrupt handler can only read data while no iicbus call
83 	 * is in progress or while io_lock is dropped during mtx_sleep in
84 	 * wait_status and set_controller. It is safe to drop io_lock in those
85 	 * places, because the interrupt handler only accesses those registers:
86 	 *
87 	 * - IG4_REG_I2C_STA  (I2C Status)
88 	 * - IG4_REG_DATA_CMD (Data Buffer and Command)
89 	 * - IG4_REG_CLR_INTR (Clear Interrupt)
90 	 *
91 	 * Locking outside of those places is required to make the content
92 	 * of rpos/rnext predictable (e.g. whenever data_read is called and in
93 	 * ig4iic_transfer).
94 	 */
95 	struct sx	call_lock;
96 	struct mtx	io_lock;
97 };
98 
99 typedef struct ig4iic_softc ig4iic_softc_t;
100 
101 /* Attach/Detach called from ig4iic_pci_*() */
102 int ig4iic_attach(ig4iic_softc_t *sc);
103 int ig4iic_detach(ig4iic_softc_t *sc);
104 
105 /* iicbus methods */
106 extern iicbus_transfer_t ig4iic_transfer;
107 extern iicbus_reset_t   ig4iic_reset;
108 
109 #endif /* _ICHIIC_IG4_VAR_H_ */
110