1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
|
// SPDX-License-Identifier: GPL-2.0
/*
* Nuvoton NCT6694 I2C adapter driver based on USB interface.
*
* Copyright (C) 2025 Nuvoton Technology Corp.
*/
#include <linux/i2c.h>
#include <linux/idr.h>
#include <linux/kernel.h>
#include <linux/mfd/nct6694.h>
#include <linux/module.h>
#include <linux/platform_device.h>
/*
* USB command module type for NCT6694 I2C controller.
* This defines the module type used for communication with the NCT6694
* I2C controller over the USB interface.
*/
#define NCT6694_I2C_MOD 0x03
/* Command 00h - I2C Deliver */
#define NCT6694_I2C_DELIVER 0x00
#define NCT6694_I2C_DELIVER_SEL 0x00
#define NCT6694_I2C_MAX_XFER_SIZE 64
#define NCT6694_I2C_MAX_DEVS 6
static unsigned char br_reg[NCT6694_I2C_MAX_DEVS] = {[0 ... (NCT6694_I2C_MAX_DEVS - 1)] = 0xFF};
module_param_array(br_reg, byte, NULL, 0644);
MODULE_PARM_DESC(br_reg,
"I2C Baudrate register per adapter: (0=25K, 1=50K, 2=100K, 3=200K, 4=400K, 5=800K, 6=1M), default=2");
enum nct6694_i2c_baudrate {
NCT6694_I2C_BR_25K = 0,
NCT6694_I2C_BR_50K,
NCT6694_I2C_BR_100K,
NCT6694_I2C_BR_200K,
NCT6694_I2C_BR_400K,
NCT6694_I2C_BR_800K,
NCT6694_I2C_BR_1M
};
struct __packed nct6694_i2c_deliver {
u8 port;
u8 br;
u8 addr;
u8 w_cnt;
u8 r_cnt;
u8 rsv[11];
u8 write_data[NCT6694_I2C_MAX_XFER_SIZE];
u8 read_data[NCT6694_I2C_MAX_XFER_SIZE];
};
struct nct6694_i2c_data {
struct device *dev;
struct nct6694 *nct6694;
struct i2c_adapter adapter;
struct nct6694_i2c_deliver deliver;
unsigned char port;
unsigned char br;
};
static int nct6694_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
{
struct nct6694_i2c_data *data = adap->algo_data;
struct nct6694_i2c_deliver *deliver = &data->deliver;
static const struct nct6694_cmd_header cmd_hd = {
.mod = NCT6694_I2C_MOD,
.cmd = NCT6694_I2C_DELIVER,
.sel = NCT6694_I2C_DELIVER_SEL,
.len = cpu_to_le16(sizeof(*deliver))
};
int ret, i;
for (i = 0; i < num; i++) {
struct i2c_msg *msg_temp = &msgs[i];
memset(deliver, 0, sizeof(*deliver));
deliver->port = data->port;
deliver->br = data->br;
deliver->addr = i2c_8bit_addr_from_msg(msg_temp);
if (msg_temp->flags & I2C_M_RD) {
deliver->r_cnt = msg_temp->len;
ret = nct6694_write_msg(data->nct6694, &cmd_hd, deliver);
if (ret < 0)
return ret;
memcpy(msg_temp->buf, deliver->read_data, msg_temp->len);
} else {
deliver->w_cnt = msg_temp->len;
memcpy(deliver->write_data, msg_temp->buf, msg_temp->len);
ret = nct6694_write_msg(data->nct6694, &cmd_hd, deliver);
if (ret < 0)
return ret;
}
}
return num;
}
static u32 nct6694_i2c_func(struct i2c_adapter *adapter)
{
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
}
static const struct i2c_adapter_quirks nct6694_i2c_quirks = {
.max_read_len = NCT6694_I2C_MAX_XFER_SIZE,
.max_write_len = NCT6694_I2C_MAX_XFER_SIZE,
};
static const struct i2c_algorithm nct6694_i2c_algo = {
.xfer = nct6694_i2c_xfer,
.functionality = nct6694_i2c_func,
};
static int nct6694_i2c_set_baudrate(struct nct6694_i2c_data *data)
{
if (data->port >= NCT6694_I2C_MAX_DEVS) {
dev_err(data->dev, "Invalid I2C port index %d\n", data->port);
return -EINVAL;
}
if (br_reg[data->port] > NCT6694_I2C_BR_1M) {
dev_warn(data->dev, "Invalid baudrate %d for I2C%d, using 100K\n",
br_reg[data->port], data->port);
br_reg[data->port] = NCT6694_I2C_BR_100K;
}
data->br = br_reg[data->port];
return 0;
}
static void nct6694_i2c_ida_free(void *d)
{
struct nct6694_i2c_data *data = d;
struct nct6694 *nct6694 = data->nct6694;
ida_free(&nct6694->i2c_ida, data->port);
}
static int nct6694_i2c_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct nct6694 *nct6694 = dev_get_drvdata(dev->parent);
struct nct6694_i2c_data *data;
int ret;
data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
data->dev = dev;
data->nct6694 = nct6694;
ret = ida_alloc(&nct6694->i2c_ida, GFP_KERNEL);
if (ret < 0)
return ret;
data->port = ret;
ret = devm_add_action_or_reset(dev, nct6694_i2c_ida_free, data);
if (ret)
return ret;
ret = nct6694_i2c_set_baudrate(data);
if (ret)
return ret;
sprintf(data->adapter.name, "NCT6694 I2C Adapter %d", data->port);
data->adapter.owner = THIS_MODULE;
data->adapter.algo = &nct6694_i2c_algo;
data->adapter.quirks = &nct6694_i2c_quirks;
data->adapter.dev.parent = dev;
data->adapter.algo_data = data;
platform_set_drvdata(pdev, data);
return devm_i2c_add_adapter(dev, &data->adapter);
}
static struct platform_driver nct6694_i2c_driver = {
.driver = {
.name = "nct6694-i2c",
},
.probe = nct6694_i2c_probe,
};
module_platform_driver(nct6694_i2c_driver);
MODULE_DESCRIPTION("USB-I2C adapter driver for NCT6694");
MODULE_AUTHOR("Ming Yu <tmyu0@nuvoton.com>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:nct6694-i2c");
|
