1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Driver for RobotFuzz OSIF |
4 | * |
5 | * Copyright (c) 2013 Andrew Lunn <andrew@lunn.ch> |
6 | * Copyright (c) 2007 Barry Carter <Barry.Carter@robotfuzz.com> |
7 | * |
8 | * Based on the i2c-tiny-usb by |
9 | * |
10 | * Copyright (C) 2006 Til Harbaum (Till@Harbaum.org) |
11 | */ |
12 | |
13 | #include <linux/kernel.h> |
14 | #include <linux/module.h> |
15 | #include <linux/errno.h> |
16 | #include <linux/i2c.h> |
17 | #include <linux/slab.h> |
18 | #include <linux/usb.h> |
19 | |
20 | #define OSIFI2C_READ 20 |
21 | #define OSIFI2C_WRITE 21 |
22 | #define OSIFI2C_STOP 22 |
23 | #define OSIFI2C_STATUS 23 |
24 | #define OSIFI2C_SET_BIT_RATE 24 |
25 | |
26 | #define STATUS_ADDRESS_ACK 0 |
27 | #define STATUS_ADDRESS_NAK 2 |
28 | |
29 | struct osif_priv { |
30 | struct usb_device *usb_dev; |
31 | struct usb_interface *interface; |
32 | struct i2c_adapter adapter; |
33 | unsigned char status; |
34 | }; |
35 | |
36 | static int osif_usb_read(struct i2c_adapter *adapter, int cmd, |
37 | int value, int index, void *data, int len) |
38 | { |
39 | struct osif_priv *priv = adapter->algo_data; |
40 | |
41 | return usb_control_msg(dev: priv->usb_dev, usb_rcvctrlpipe(priv->usb_dev, 0), |
42 | request: cmd, USB_TYPE_VENDOR | USB_RECIP_INTERFACE | |
43 | USB_DIR_IN, value, index, data, size: len, timeout: 2000); |
44 | } |
45 | |
46 | static int osif_usb_write(struct i2c_adapter *adapter, int cmd, |
47 | int value, int index, void *data, int len) |
48 | { |
49 | |
50 | struct osif_priv *priv = adapter->algo_data; |
51 | |
52 | return usb_control_msg(dev: priv->usb_dev, usb_sndctrlpipe(priv->usb_dev, 0), |
53 | request: cmd, USB_TYPE_VENDOR | USB_RECIP_INTERFACE, |
54 | value, index, data, size: len, timeout: 2000); |
55 | } |
56 | |
57 | static int osif_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, |
58 | int num) |
59 | { |
60 | struct osif_priv *priv = adapter->algo_data; |
61 | struct i2c_msg *pmsg; |
62 | int ret; |
63 | int i; |
64 | |
65 | for (i = 0; i < num; i++) { |
66 | pmsg = &msgs[i]; |
67 | |
68 | if (pmsg->flags & I2C_M_RD) { |
69 | ret = osif_usb_read(adapter, OSIFI2C_READ, |
70 | value: pmsg->flags, index: pmsg->addr, |
71 | data: pmsg->buf, len: pmsg->len); |
72 | if (ret != pmsg->len) { |
73 | dev_err(&adapter->dev, "failure reading data\n" ); |
74 | return -EREMOTEIO; |
75 | } |
76 | } else { |
77 | ret = osif_usb_write(adapter, OSIFI2C_WRITE, |
78 | value: pmsg->flags, index: pmsg->addr, |
79 | data: pmsg->buf, len: pmsg->len); |
80 | if (ret != pmsg->len) { |
81 | dev_err(&adapter->dev, "failure writing data\n" ); |
82 | return -EREMOTEIO; |
83 | } |
84 | } |
85 | |
86 | ret = osif_usb_write(adapter, OSIFI2C_STOP, value: 0, index: 0, NULL, len: 0); |
87 | if (ret) { |
88 | dev_err(&adapter->dev, "failure sending STOP\n" ); |
89 | return -EREMOTEIO; |
90 | } |
91 | |
92 | /* read status */ |
93 | ret = osif_usb_read(adapter, OSIFI2C_STATUS, value: 0, index: 0, |
94 | data: &priv->status, len: 1); |
95 | if (ret != 1) { |
96 | dev_err(&adapter->dev, "failure reading status\n" ); |
97 | return -EREMOTEIO; |
98 | } |
99 | |
100 | if (priv->status != STATUS_ADDRESS_ACK) { |
101 | dev_dbg(&adapter->dev, "status = %d\n" , priv->status); |
102 | return -EREMOTEIO; |
103 | } |
104 | } |
105 | |
106 | return i; |
107 | } |
108 | |
109 | static u32 osif_func(struct i2c_adapter *adapter) |
110 | { |
111 | return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; |
112 | } |
113 | |
114 | static const struct i2c_algorithm osif_algorithm = { |
115 | .master_xfer = osif_xfer, |
116 | .functionality = osif_func, |
117 | }; |
118 | |
119 | #define USB_OSIF_VENDOR_ID 0x1964 |
120 | #define USB_OSIF_PRODUCT_ID 0x0001 |
121 | |
122 | static const struct usb_device_id osif_table[] = { |
123 | { USB_DEVICE(USB_OSIF_VENDOR_ID, USB_OSIF_PRODUCT_ID) }, |
124 | { } |
125 | }; |
126 | MODULE_DEVICE_TABLE(usb, osif_table); |
127 | |
128 | static int osif_probe(struct usb_interface *interface, |
129 | const struct usb_device_id *id) |
130 | { |
131 | int ret; |
132 | struct osif_priv *priv; |
133 | u16 version; |
134 | |
135 | priv = devm_kzalloc(dev: &interface->dev, size: sizeof(*priv), GFP_KERNEL); |
136 | if (!priv) |
137 | return -ENOMEM; |
138 | |
139 | priv->usb_dev = usb_get_dev(interface_to_usbdev(interface)); |
140 | priv->interface = interface; |
141 | |
142 | usb_set_intfdata(intf: interface, data: priv); |
143 | |
144 | priv->adapter.owner = THIS_MODULE; |
145 | priv->adapter.class = I2C_CLASS_HWMON; |
146 | priv->adapter.algo = &osif_algorithm; |
147 | priv->adapter.algo_data = priv; |
148 | snprintf(buf: priv->adapter.name, size: sizeof(priv->adapter.name), |
149 | fmt: "OSIF at bus %03d device %03d" , |
150 | priv->usb_dev->bus->busnum, priv->usb_dev->devnum); |
151 | |
152 | /* |
153 | * Set bus frequency. The frequency is: |
154 | * 120,000,000 / ( 16 + 2 * div * 4^prescale). |
155 | * Using dev = 52, prescale = 0 give 100KHz */ |
156 | ret = osif_usb_write(adapter: &priv->adapter, OSIFI2C_SET_BIT_RATE, value: 52, index: 0, |
157 | NULL, len: 0); |
158 | if (ret) { |
159 | dev_err(&interface->dev, "failure sending bit rate" ); |
160 | usb_put_dev(dev: priv->usb_dev); |
161 | return ret; |
162 | } |
163 | |
164 | i2c_add_adapter(adap: &(priv->adapter)); |
165 | |
166 | version = le16_to_cpu(priv->usb_dev->descriptor.bcdDevice); |
167 | dev_info(&interface->dev, |
168 | "version %x.%02x found at bus %03d address %03d" , |
169 | version >> 8, version & 0xff, |
170 | priv->usb_dev->bus->busnum, priv->usb_dev->devnum); |
171 | |
172 | return 0; |
173 | } |
174 | |
175 | static void osif_disconnect(struct usb_interface *interface) |
176 | { |
177 | struct osif_priv *priv = usb_get_intfdata(intf: interface); |
178 | |
179 | i2c_del_adapter(adap: &(priv->adapter)); |
180 | usb_set_intfdata(intf: interface, NULL); |
181 | usb_put_dev(dev: priv->usb_dev); |
182 | } |
183 | |
184 | static struct usb_driver osif_driver = { |
185 | .name = "RobotFuzz Open Source InterFace, OSIF" , |
186 | .probe = osif_probe, |
187 | .disconnect = osif_disconnect, |
188 | .id_table = osif_table, |
189 | }; |
190 | |
191 | module_usb_driver(osif_driver); |
192 | |
193 | MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>" ); |
194 | MODULE_AUTHOR("Barry Carter <barry.carter@robotfuzz.com>" ); |
195 | MODULE_DESCRIPTION("RobotFuzz OSIF driver" ); |
196 | MODULE_LICENSE("GPL v2" ); |
197 | |