xref: /netbsd-src/sys/dev/i2c/i2cvar.h (revision c12151368a60cab2da2b1b2d21ed0cc68309593d)
1 /*	$NetBSD: i2cvar.h,v 1.26 2022/10/24 10:17:27 riastradh Exp $	*/
2 
3 /*
4  * Copyright (c) 2003 Wasabi Systems, Inc.
5  * All rights reserved.
6  *
7  * Written by Steve C. Woodford and Jason R. Thorpe for Wasabi Systems, Inc.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
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 the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *      This product includes software developed for the NetBSD Project by
20  *      Wasabi Systems, Inc.
21  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
22  *    or promote products derived from this software without specific prior
23  *    written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35  * POSSIBILITY OF SUCH DAMAGE.
36  */
37 
38 #ifndef _DEV_I2C_I2CVAR_H_
39 #define	_DEV_I2C_I2CVAR_H_
40 
41 #include <sys/device.h>
42 #include <sys/mutex.h>
43 #include <dev/i2c/i2c_io.h>
44 #include <prop/proplib.h>
45 
46 /* Flags passed to i2c routines. */
47 #define	I2C_F_WRITE	0		/* new transfer is a write */
48 #define	I2C_F_READ	__BIT(0)	/* new transfer is a read */
49 #define	I2C_F_LAST	__BIT(1)	/* last byte of read */
50 #define	I2C_F_STOP	__BIT(2)	/* send stop after byte */
51 #define	I2C_F_POLL	__BIT(3)	/* poll, don't sleep */
52 #define	I2C_F_PEC	__BIT(4)	/* smbus packet error checking */
53 #define	I2C_F_SPEED	__BITS(28,31)	/* I2C transfer speed selector */
54 
55 #define	I2C_SPEED_SM		0	/* standard mode (100Kb/s) */
56 #define	I2C_SPEED_FM		1	/* fast mode (400Kb/s) */
57 #define	I2C_SPEED_FMPLUS	2	/* fast mode+ (1Mb/s) */
58 #define	I2C_SPEED_HS		3	/* high speed (3.4Mb/s) */
59 
60 /* i2c bus instance properties */
61 #define	I2C_PROP_INDIRECT_PROBE_STRATEGY	\
62 				"i2c-indirect-probe-strategy"
63 #define	I2C_PROBE_STRATEGY_QUICK_WRITE		\
64 				"smbus-quick-write"
65 #define	I2C_PROBE_STRATEGY_RECEIVE_BYTE		\
66 				"smbus-receive-byte"
67 #define	I2C_PROBE_STRATEGY_NONE			\
68 				"none"
69 
70 #define	I2C_PROP_INDIRECT_DEVICE_PERMITLIST	\
71 				"i2c-indirect-device-permitlist"
72 	/* value is a prop_array of prop_strings */
73 
74 struct ic_intr_list {
75 	LIST_ENTRY(ic_intr_list) il_next;
76 	int (*il_intr)(void *);
77 	void *il_intrarg;
78 };
79 
80 /*
81  * This structure provides the interface between the i2c framework
82  * and the underlying i2c controller.
83  *
84  * Note that this structure is designed specifically to allow us
85  * to either use the autoconfiguration framework or not.  This
86  * allows a driver for a board with a private i2c bus use generic
87  * i2c client drivers for chips that might be on that board.
88  */
89 typedef struct i2c_controller {
90 	void	*ic_cookie;		/* controller private */
91 
92 	/*
93 	 * These provide synchronization in the presence of
94 	 * multiple users of the i2c bus.  When a device
95 	 * driver wishes to perform transfers on the i2c
96 	 * bus, the driver should acquire the bus.  When
97 	 * the driver is finished, it should release the
98 	 * bus.
99 	 *
100 	 * The main synchronization logic is handled by the
101 	 * generic i2c layer, but optional hooks to back-end
102 	 * drivers are provided in case additional processing
103 	 * is needed (e.g. enabling the i2c controller).
104 	 */
105 	kmutex_t ic_bus_lock;
106 	int	(*ic_acquire_bus)(void *, int);
107 	void	(*ic_release_bus)(void *, int);
108 
109 	/*
110 	 * The preferred API for clients of the i2c interface
111 	 * is the scripted API.  This handles i2c controllers
112 	 * that do not provide raw access to the i2c signals.
113 	 */
114 	int	(*ic_exec)(void *, i2c_op_t, i2c_addr_t, const void *, size_t,
115 		    void *, size_t, int);
116 
117 	int	(*ic_send_start)(void *, int);
118 	int	(*ic_send_stop)(void *, int);
119 	int	(*ic_initiate_xfer)(void *, i2c_addr_t, int);
120 	int	(*ic_read_byte)(void *, uint8_t *, int);
121 	int	(*ic_write_byte)(void *, uint8_t, int);
122 
123 	struct i2c_tag_private	*ic_tag_private;
124 } *i2c_tag_t;
125 
126 /* Used to attach the i2c framework to the controller. */
127 struct i2cbus_attach_args {
128 	i2c_tag_t iba_tag;		/* the controller */
129 	prop_array_t iba_child_devices;	/* child devices (direct config) */
130 };
131 
132 /* Type of value stored in "ia_cookie" */
133 enum i2c_cookie_type {
134 	I2C_COOKIE_NONE,		/* Cookie is not valid */
135 	I2C_COOKIE_OF,			/* Cookie is an OF node phandle */
136 	I2C_COOKIE_ACPI,		/* Cookie is an ACPI handle */
137 };
138 
139 /* Used to attach devices on the i2c bus. */
140 struct i2c_attach_args {
141 	i2c_tag_t	ia_tag;		/* our controller */
142 	i2c_addr_t	ia_addr;	/* address of device */
143 	int		ia_type;	/* bus type */
144 	/* only set if using direct config */
145 	const char *	ia_name;	/* name of the device */
146 	int		ia_ncompat;	/* number of pointers in the
147 					   ia_compat array */
148 	const char **	ia_compat;	/* chip names */
149 	prop_dictionary_t ia_prop;	/* dictionary for this device */
150 	/*
151 	 * The following is of limited usefulness and should only be used
152 	 * in rare cases where we really know what we are doing. Example:
153 	 * a machine dependent i2c driver (located in sys/arch/$arch/dev)
154 	 * needing to access some firmware properties.
155 	 * Depending on the firmware in use, an identifier for the device
156 	 * may be present. Example: on OpenFirmware machines the device
157 	 * tree OF node - if available. This info is hard to transport
158 	 * down to MD drivers through the MI i2c bus otherwise.
159 	 *
160 	 * On ACPI platforms this is the ACPI_HANDLE of the device.
161 	 */
162 	uintptr_t	ia_cookie;	/* OF node in openfirmware machines */
163 	enum i2c_cookie_type ia_cookietype; /* Value type of cookie */
164 };
165 
166 /*
167  * API presented to i2c controllers.
168  */
169 int	iicbus_print(void *, const char *);
170 void	iic_tag_init(i2c_tag_t);
171 void	iic_tag_fini(i2c_tag_t);
172 
173 /*
174  * API presented to i2c devices.
175  */
176 int	iic_compatible_match(const struct i2c_attach_args *,
177 			     const struct device_compatible_entry *);
178 bool	iic_use_direct_match(const struct i2c_attach_args *, const cfdata_t,
179 			     const struct device_compatible_entry *, int *);
180 const struct device_compatible_entry *
181 	iic_compatible_lookup(const struct i2c_attach_args *,
182 			      const struct device_compatible_entry *);
183 
184 /*
185  * Constants to indicate the quality of a match made by a driver's
186  * match routine, from lowest to highest:
187  *
188  *	-- Address only; no other checks were made.
189  *
190  *	-- Address + device probed and recognized.
191  *
192  *	-- Direct-config match by "compatible" string.
193  *
194  *	-- Direct-config match by specific driver name.
195  */
196 #define	I2C_MATCH_ADDRESS_ONLY		1
197 #define	I2C_MATCH_ADDRESS_AND_PROBE	2
198 #define	I2C_MATCH_DIRECT_COMPATIBLE	10
199 #define	I2C_MATCH_DIRECT_COMPATIBLE_MAX	99
200 #define	I2C_MATCH_DIRECT_SPECIFIC	100
201 
202 #ifdef _I2C_PRIVATE
203 /*
204  * Macros used internally by the i2c framework.
205  */
206 #define	iic_send_start(ic, flags)					\
207 	(*(ic)->ic_send_start)((ic)->ic_cookie, (flags))
208 #define	iic_send_stop(ic, flags)					\
209 	(*(ic)->ic_send_stop)((ic)->ic_cookie, (flags))
210 #define	iic_initiate_xfer(ic, addr, flags)				\
211 	(*(ic)->ic_initiate_xfer)((ic)->ic_cookie, (addr), (flags))
212 
213 #define	iic_read_byte(ic, bytep, flags)					\
214 	(*(ic)->ic_read_byte)((ic)->ic_cookie, (bytep), (flags))
215 #define	iic_write_byte(ic, byte, flags)					\
216 	(*(ic)->ic_write_byte)((ic)->ic_cookie, (byte), (flags))
217 #endif /* _I2C_PRIVATE */
218 
219 /*
220  * Simplified API for clients of the i2c framework.  Definitions
221  * in <dev/i2c/i2c_io.h>.
222  */
223 int	iic_acquire_bus(i2c_tag_t, int);
224 void	iic_release_bus(i2c_tag_t, int);
225 int	iic_exec(i2c_tag_t, i2c_op_t, i2c_addr_t, const void *,
226 	    size_t, void *, size_t, int);
227 
228 int	iic_smbus_write_byte(i2c_tag_t, i2c_addr_t, uint8_t, uint8_t, int);
229 int	iic_smbus_write_word(i2c_tag_t, i2c_addr_t, uint8_t, uint16_t, int);
230 int	iic_smbus_read_byte(i2c_tag_t, i2c_addr_t, uint8_t, uint8_t *, int);
231 int	iic_smbus_read_word(i2c_tag_t, i2c_addr_t, uint8_t, uint16_t *, int);
232 int	iic_smbus_receive_byte(i2c_tag_t, i2c_addr_t, uint8_t *, int);
233 int	iic_smbus_send_byte(i2c_tag_t, i2c_addr_t, uint8_t, int);
234 int	iic_smbus_quick_read(i2c_tag_t, i2c_addr_t, int);
235 int	iic_smbus_quick_write(i2c_tag_t, i2c_addr_t, int);
236 int	iic_smbus_block_read(i2c_tag_t, i2c_addr_t, uint8_t, uint8_t *,
237 	    size_t, int);
238 int	iic_smbus_block_write(i2c_tag_t, i2c_addr_t, uint8_t, uint8_t *,
239 	    size_t, int);
240 
241 #endif /* _DEV_I2C_I2CVAR_H_ */
242