1 /*-
2 * Copyright (c) 2021 Beckhoff Automation GmbH & Co. KG
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23 * SUCH DAMAGE.
24 *
25 */
26
27 #ifndef _LINUX_I2C_H_
28 #define _LINUX_I2C_H_
29
30 #include <sys/types.h>
31 #include <sys/errno.h>
32 #include <sys/systm.h>
33
34 #include <linux/device.h>
35
36 #define I2C_MAX_ADAPTER_NAME_LENGTH 32
37
38 #define I2C_M_RD 0x0001
39 #define I2C_M_NOSTART 0x0002
40 #define I2C_M_STOP 0x0004
41
42 /* No need for us */
43 #define I2C_FUNC_I2C 0
44 #define I2C_FUNC_SMBUS_EMUL 0
45 #define I2C_FUNC_SMBUS_READ_BLOCK_DATA 0
46 #define I2C_FUNC_SMBUS_BLOCK_PROC_CALL 0
47 #define I2C_FUNC_10BIT_ADDR 0
48
49 #define I2C_CLASS_HWMON 0x1
50 #define I2C_CLASS_DDC 0x8
51 #define I2C_CLASS_SPD 0x80
52
53 struct i2c_adapter {
54 struct module *owner;
55 unsigned int class;
56
57 char name[I2C_MAX_ADAPTER_NAME_LENGTH];
58 struct device dev;
59
60 const struct i2c_lock_operations *lock_ops;
61 const struct i2c_algorithm *algo;
62 const struct i2c_adapter_quirks *quirks;
63 void *algo_data;
64
65 int retries;
66 void *data;
67 };
68
69 struct i2c_msg {
70 uint16_t addr;
71 uint16_t flags;
72 uint16_t len;
73 uint8_t *buf;
74 };
75
76 struct i2c_algorithm {
77 int (*master_xfer)(struct i2c_adapter *, struct i2c_msg *, int);
78 uint32_t (*functionality)(struct i2c_adapter *);
79 };
80
81 struct i2c_lock_operations {
82 void (*lock_bus)(struct i2c_adapter *, unsigned int);
83 int (*trylock_bus)(struct i2c_adapter *, unsigned int);
84 void (*unlock_bus)(struct i2c_adapter *, unsigned int);
85 };
86
87 struct i2c_adapter_quirks {
88 uint64_t flags;
89 int max_num_msgs;
90 uint16_t max_write_len;
91 uint16_t max_read_len;
92 uint16_t max_comb_1st_msg_len;
93 uint16_t max_comb_2nd_msg_len;
94 };
95
96 #define I2C_AQ_COMB BIT(0)
97 #define I2C_AQ_COMB_WRITE_FIRST BIT(1)
98 #define I2C_AQ_COMB_READ_SECOND BIT(2)
99 #define I2C_AQ_COMB_SAME_ADDR BIT(3)
100 #define I2C_AQ_COMB_WRITE_THEN_READ \
101 (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \
102 I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR)
103 #define I2C_AQ_NO_CLK_STRETCH BIT(4)
104 #define I2C_AQ_NO_ZERO_LEN_READ BIT(5)
105 #define I2C_AQ_NO_ZERO_LEN_WRITE BIT(6)
106 #define I2C_AQ_NO_ZERO_LEN \
107 (I2C_AQ_NO_ZERO_LEN_READ | I2C_AQ_NO_ZERO_LEN_WRITE)
108 #define I2C_AQ_NO_REP_START BIT(7)
109
110 int lkpi_i2c_add_adapter(struct i2c_adapter *adapter);
111 int lkpi_i2c_del_adapter(struct i2c_adapter *adapter);
112
113 int lkpi_i2cbb_transfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, int nmsgs);
114
115 #define i2c_add_adapter(adapter) lkpi_i2c_add_adapter(adapter)
116 #define i2c_del_adapter(adapter) lkpi_i2c_del_adapter(adapter)
117
118 #define i2c_get_adapter(x) NULL
119 #define i2c_put_adapter(x)
120
121 static inline int
do_i2c_transfer(struct i2c_adapter * adapter,struct i2c_msg * msgs,int nmsgs)122 do_i2c_transfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, int nmsgs)
123 {
124 int ret, retries;
125
126 retries = adapter->retries == 0 ? 1 : adapter->retries;
127 for (; retries != 0; retries--) {
128 if (adapter->algo != NULL && adapter->algo->master_xfer != NULL)
129 ret = adapter->algo->master_xfer(adapter, msgs, nmsgs);
130 else
131 ret = lkpi_i2cbb_transfer(adapter, msgs, nmsgs);
132 if (ret != -EAGAIN)
133 break;
134 }
135
136 return (ret);
137 }
138
139 static inline int
i2c_transfer(struct i2c_adapter * adapter,struct i2c_msg * msgs,int nmsgs)140 i2c_transfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, int nmsgs)
141 {
142 int ret;
143
144 if (adapter->algo == NULL && adapter->algo_data == NULL)
145 return (-EOPNOTSUPP);
146
147 if (adapter->lock_ops)
148 adapter->lock_ops->lock_bus(adapter, 0);
149
150 ret = do_i2c_transfer(adapter, msgs, nmsgs);
151
152 if (adapter->lock_ops)
153 adapter->lock_ops->unlock_bus(adapter, 0);
154
155 return (ret);
156 }
157
158 /* Unlocked version of i2c_transfer */
159 static inline int
__i2c_transfer(struct i2c_adapter * adapter,struct i2c_msg * msgs,int nmsgs)160 __i2c_transfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, int nmsgs)
161 {
162 return (do_i2c_transfer(adapter, msgs, nmsgs));
163 }
164
165 static inline void
i2c_set_adapdata(struct i2c_adapter * adapter,void * data)166 i2c_set_adapdata(struct i2c_adapter *adapter, void *data)
167 {
168 adapter->data = data;
169 }
170
171 static inline void *
i2c_get_adapdata(struct i2c_adapter * adapter)172 i2c_get_adapdata(struct i2c_adapter *adapter)
173 {
174 return (adapter->data);
175 }
176
177 #endif /* _LINUX_I2C_H_ */
178