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
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
|
/*
* Driver for the Diolan DLN-2 USB-I2C adapter
*
* Copyright (c) 2014 Intel Corporation
*
* Derived from:
* i2c-diolan-u2c.c
* Copyright (c) 2010-2011 Ericsson AB
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation, version 2.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/platform_device.h>
#include <linux/mfd/dln2.h>
#define DLN2_I2C_MODULE_ID 0x03
#define DLN2_I2C_CMD(cmd) DLN2_CMD(cmd, DLN2_I2C_MODULE_ID)
/* I2C commands */
#define DLN2_I2C_GET_PORT_COUNT DLN2_I2C_CMD(0x00)
#define DLN2_I2C_ENABLE DLN2_I2C_CMD(0x01)
#define DLN2_I2C_DISABLE DLN2_I2C_CMD(0x02)
#define DLN2_I2C_IS_ENABLED DLN2_I2C_CMD(0x03)
#define DLN2_I2C_WRITE DLN2_I2C_CMD(0x06)
#define DLN2_I2C_READ DLN2_I2C_CMD(0x07)
#define DLN2_I2C_SCAN_DEVICES DLN2_I2C_CMD(0x08)
#define DLN2_I2C_PULLUP_ENABLE DLN2_I2C_CMD(0x09)
#define DLN2_I2C_PULLUP_DISABLE DLN2_I2C_CMD(0x0A)
#define DLN2_I2C_PULLUP_IS_ENABLED DLN2_I2C_CMD(0x0B)
#define DLN2_I2C_TRANSFER DLN2_I2C_CMD(0x0C)
#define DLN2_I2C_SET_MAX_REPLY_COUNT DLN2_I2C_CMD(0x0D)
#define DLN2_I2C_GET_MAX_REPLY_COUNT DLN2_I2C_CMD(0x0E)
#define DLN2_I2C_MAX_XFER_SIZE 256
#define DLN2_I2C_BUF_SIZE (DLN2_I2C_MAX_XFER_SIZE + 16)
struct dln2_i2c {
struct platform_device *pdev;
struct i2c_adapter adapter;
u8 port;
/*
* Buffer to hold the packet for read or write transfers. One is enough
* since we can't have multiple transfers in parallel on the i2c bus.
*/
void *buf;
};
static int dln2_i2c_enable(struct dln2_i2c *dln2, bool enable)
{
int ret;
u16 cmd;
struct {
u8 port;
} tx;
tx.port = dln2->port;
if (enable)
cmd = DLN2_I2C_ENABLE;
else
cmd = DLN2_I2C_DISABLE;
ret = dln2_transfer_tx(dln2->pdev, cmd, &tx, sizeof(tx));
if (ret < 0)
return ret;
return 0;
}
static int dln2_i2c_write(struct dln2_i2c *dln2, u8 addr,
u8 *data, u16 data_len)
{
int ret;
struct {
u8 port;
u8 addr;
u8 mem_addr_len;
__le32 mem_addr;
__le16 buf_len;
u8 buf[DLN2_I2C_MAX_XFER_SIZE];
} __packed *tx = dln2->buf;
unsigned len;
BUILD_BUG_ON(sizeof(*tx) > DLN2_I2C_BUF_SIZE);
tx->port = dln2->port;
tx->addr = addr;
tx->mem_addr_len = 0;
tx->mem_addr = 0;
tx->buf_len = cpu_to_le16(data_len);
memcpy(tx->buf, data, data_len);
len = sizeof(*tx) + data_len - DLN2_I2C_MAX_XFER_SIZE;
ret = dln2_transfer_tx(dln2->pdev, DLN2_I2C_WRITE, tx, len);
if (ret < 0)
return ret;
return data_len;
}
static int dln2_i2c_read(struct dln2_i2c *dln2, u16 addr, u8 *data,
u16 data_len)
{
int ret;
struct {
u8 port;
u8 addr;
u8 mem_addr_len;
__le32 mem_addr;
__le16 buf_len;
} __packed tx;
struct {
__le16 buf_len;
u8 buf[DLN2_I2C_MAX_XFER_SIZE];
} __packed *rx = dln2->buf;
unsigned rx_len = sizeof(*rx);
BUILD_BUG_ON(sizeof(*rx) > DLN2_I2C_BUF_SIZE);
tx.port = dln2->port;
tx.addr = addr;
tx.mem_addr_len = 0;
tx.mem_addr = 0;
tx.buf_len = cpu_to_le16(data_len);
ret = dln2_transfer(dln2->pdev, DLN2_I2C_READ, &tx, sizeof(tx),
rx, &rx_len);
if (ret < 0)
return ret;
if (rx_len < sizeof(rx->buf_len) + data_len)
return -EPROTO;
if (le16_to_cpu(rx->buf_len) != data_len)
return -EPROTO;
memcpy(data, rx->buf, data_len);
return data_len;
}
static int dln2_i2c_xfer(struct i2c_adapter *adapter,
struct i2c_msg *msgs, int num)
{
struct dln2_i2c *dln2 = i2c_get_adapdata(adapter);
struct i2c_msg *pmsg;
struct device *dev = &dln2->adapter.dev;
int i;
for (i = 0; i < num; i++) {
int ret;
pmsg = &msgs[i];
if (pmsg->len > DLN2_I2C_MAX_XFER_SIZE) {
dev_warn(dev, "maximum transfer size exceeded\n");
return -EOPNOTSUPP;
}
if (pmsg->flags & I2C_M_RD) {
ret = dln2_i2c_read(dln2, pmsg->addr, pmsg->buf,
pmsg->len);
if (ret < 0)
return ret;
pmsg->len = ret;
} else {
ret = dln2_i2c_write(dln2, pmsg->addr, pmsg->buf,
pmsg->len);
if (ret != pmsg->len)
return -EPROTO;
}
}
return num;
}
static u32 dln2_i2c_func(struct i2c_adapter *a)
{
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA |
I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
I2C_FUNC_SMBUS_I2C_BLOCK;
}
static const struct i2c_algorithm dln2_i2c_usb_algorithm = {
.master_xfer = dln2_i2c_xfer,
.functionality = dln2_i2c_func,
};
static int dln2_i2c_probe(struct platform_device *pdev)
{
int ret;
struct dln2_i2c *dln2;
struct device *dev = &pdev->dev;
struct dln2_platform_data *pdata = dev_get_platdata(&pdev->dev);
dln2 = devm_kzalloc(dev, sizeof(*dln2), GFP_KERNEL);
if (!dln2)
return -ENOMEM;
dln2->buf = devm_kmalloc(dev, DLN2_I2C_BUF_SIZE, GFP_KERNEL);
if (!dln2->buf)
return -ENOMEM;
dln2->pdev = pdev;
dln2->port = pdata->port;
/* setup i2c adapter description */
dln2->adapter.owner = THIS_MODULE;
dln2->adapter.class = I2C_CLASS_HWMON;
dln2->adapter.algo = &dln2_i2c_usb_algorithm;
dln2->adapter.dev.parent = dev;
i2c_set_adapdata(&dln2->adapter, dln2);
snprintf(dln2->adapter.name, sizeof(dln2->adapter.name), "%s-%s-%d",
"dln2-i2c", dev_name(pdev->dev.parent), dln2->port);
platform_set_drvdata(pdev, dln2);
/* initialize the i2c interface */
ret = dln2_i2c_enable(dln2, true);
if (ret < 0) {
dev_err(dev, "failed to initialize adapter: %d\n", ret);
return ret;
}
/* and finally attach to i2c layer */
ret = i2c_add_adapter(&dln2->adapter);
if (ret < 0) {
dev_err(dev, "failed to add I2C adapter: %d\n", ret);
goto out_disable;
}
return 0;
out_disable:
dln2_i2c_enable(dln2, false);
return ret;
}
static int dln2_i2c_remove(struct platform_device *pdev)
{
struct dln2_i2c *dln2 = platform_get_drvdata(pdev);
i2c_del_adapter(&dln2->adapter);
dln2_i2c_enable(dln2, false);
return 0;
}
static struct platform_driver dln2_i2c_driver = {
.driver.name = "dln2-i2c",
.probe = dln2_i2c_probe,
.remove = dln2_i2c_remove,
};
module_platform_driver(dln2_i2c_driver);
MODULE_AUTHOR("Laurentiu Palcu <laurentiu.palcu@intel.com>");
MODULE_DESCRIPTION("Driver for the Diolan DLN2 I2C master interface");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:dln2-i2c");
|
