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/bits.h>
35 #include <linux/mod_devicetable.h>
36 #include <linux/device.h>
37 #include <linux/sched.h>
38 #include <linux/mutex.h>
39 #include <linux/regulator/consumer.h>
40 #include <linux/irqdomain.h>
41 #include <linux/of.h>
42
43 #define I2C_MAX_ADAPTER_NAME_LENGTH 32
44
45 #define I2C_M_RD 0x0001
46 #define I2C_M_NOSTART 0x0002
47 #define I2C_M_STOP 0x0004
48
49 /* No need for us */
50 #define I2C_FUNC_I2C 0
51 #define I2C_FUNC_SMBUS_EMUL 0
52 #define I2C_FUNC_SMBUS_READ_BLOCK_DATA 0
53 #define I2C_FUNC_SMBUS_BLOCK_PROC_CALL 0
54 #define I2C_FUNC_10BIT_ADDR 0
55
56 #define I2C_CLASS_HWMON 0x1
57 #define I2C_CLASS_DDC 0x8
58 #define I2C_CLASS_SPD 0x80
59
60 struct i2c_adapter {
61 struct module *owner;
62 unsigned int class;
63
64 char name[I2C_MAX_ADAPTER_NAME_LENGTH];
65 struct device dev;
66
67 const struct i2c_lock_operations *lock_ops;
68 const struct i2c_algorithm *algo;
69 const struct i2c_adapter_quirks *quirks;
70 void *algo_data;
71
72 int retries;
73 void *data;
74 };
75
76 struct i2c_msg {
77 uint16_t addr;
78 uint16_t flags;
79 uint16_t len;
80 uint8_t *buf;
81 };
82
83 struct i2c_algorithm {
84 int (*master_xfer)(struct i2c_adapter *, struct i2c_msg *, int);
85 uint32_t (*functionality)(struct i2c_adapter *);
86 };
87
88 struct i2c_lock_operations {
89 void (*lock_bus)(struct i2c_adapter *, unsigned int);
90 int (*trylock_bus)(struct i2c_adapter *, unsigned int);
91 void (*unlock_bus)(struct i2c_adapter *, unsigned int);
92 };
93
94 struct i2c_adapter_quirks {
95 uint64_t flags;
96 int max_num_msgs;
97 uint16_t max_write_len;
98 uint16_t max_read_len;
99 uint16_t max_comb_1st_msg_len;
100 uint16_t max_comb_2nd_msg_len;
101 };
102
103 #define I2C_AQ_COMB BIT(0)
104 #define I2C_AQ_COMB_WRITE_FIRST BIT(1)
105 #define I2C_AQ_COMB_READ_SECOND BIT(2)
106 #define I2C_AQ_COMB_SAME_ADDR BIT(3)
107 #define I2C_AQ_COMB_WRITE_THEN_READ \
108 (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \
109 I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR)
110 #define I2C_AQ_NO_CLK_STRETCH BIT(4)
111 #define I2C_AQ_NO_ZERO_LEN_READ BIT(5)
112 #define I2C_AQ_NO_ZERO_LEN_WRITE BIT(6)
113 #define I2C_AQ_NO_ZERO_LEN \
114 (I2C_AQ_NO_ZERO_LEN_READ | I2C_AQ_NO_ZERO_LEN_WRITE)
115 #define I2C_AQ_NO_REP_START BIT(7)
116
117 int lkpi_i2c_add_adapter(struct i2c_adapter *adapter);
118 int lkpi_i2c_del_adapter(struct i2c_adapter *adapter);
119
120 int lkpi_i2cbb_transfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, int nmsgs);
121
122 #define i2c_add_adapter(adapter) lkpi_i2c_add_adapter(adapter)
123 #define i2c_del_adapter(adapter) lkpi_i2c_del_adapter(adapter)
124
125 #define i2c_get_adapter(x) NULL
126 #define i2c_put_adapter(x)
127
128 static inline int
do_i2c_transfer(struct i2c_adapter * adapter,struct i2c_msg * msgs,int nmsgs)129 do_i2c_transfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, int nmsgs)
130 {
131 int ret, retries;
132
133 retries = adapter->retries == 0 ? 1 : adapter->retries;
134 for (; retries != 0; retries--) {
135 if (adapter->algo != NULL && adapter->algo->master_xfer != NULL)
136 ret = adapter->algo->master_xfer(adapter, msgs, nmsgs);
137 else
138 ret = lkpi_i2cbb_transfer(adapter, msgs, nmsgs);
139 if (ret != -EAGAIN)
140 break;
141 }
142
143 return (ret);
144 }
145
146 static inline int
i2c_transfer(struct i2c_adapter * adapter,struct i2c_msg * msgs,int nmsgs)147 i2c_transfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, int nmsgs)
148 {
149 int ret;
150
151 if (adapter->algo == NULL && adapter->algo_data == NULL)
152 return (-EOPNOTSUPP);
153
154 if (adapter->lock_ops)
155 adapter->lock_ops->lock_bus(adapter, 0);
156
157 ret = do_i2c_transfer(adapter, msgs, nmsgs);
158
159 if (adapter->lock_ops)
160 adapter->lock_ops->unlock_bus(adapter, 0);
161
162 return (ret);
163 }
164
165 /* Unlocked version of i2c_transfer */
166 static inline int
__i2c_transfer(struct i2c_adapter * adapter,struct i2c_msg * msgs,int nmsgs)167 __i2c_transfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, int nmsgs)
168 {
169 return (do_i2c_transfer(adapter, msgs, nmsgs));
170 }
171
172 static inline void
i2c_set_adapdata(struct i2c_adapter * adapter,void * data)173 i2c_set_adapdata(struct i2c_adapter *adapter, void *data)
174 {
175 adapter->data = data;
176 }
177
178 static inline void *
i2c_get_adapdata(struct i2c_adapter * adapter)179 i2c_get_adapdata(struct i2c_adapter *adapter)
180 {
181 return (adapter->data);
182 }
183
184 #endif /* _LINUX_I2C_H_ */
185