1 // SPDX-License-Identifier: GPL-2.0-only
3  * driver for the i2c-tiny-usb adapter - 1.0
6  * Copyright (C) 2006-2007 Till Harbaum (Till@Harbaum.org)
16 /* include interfaces to usb layer */
17 #include <linux/usb.h>
22 /* commands via USB, must match command ids in the firmware */
32 /* i2c bit delay, default is 10us -> 100kHz max
46 /* ----- begin of i2c layer ---------------------------------------------- */
60 		return -ENOMEM;  in usb_xfer()
68 		if (i == num-1)  in usb_xfer()
73 		dev_dbg(&adapter->dev,  in usb_xfer()
75 			i, str_read_write(pmsg->flags & I2C_M_RD),  in usb_xfer()
76 			pmsg->flags, pmsg->len, pmsg->addr);  in usb_xfer()
79 		if (pmsg->flags & I2C_M_RD) {  in usb_xfer()
82 				     pmsg->flags, pmsg->addr,  in usb_xfer()
83 				     pmsg->buf, pmsg->len) != pmsg->len) {  in usb_xfer()
84 				dev_err(&adapter->dev,  in usb_xfer()
86 				ret = -EIO;  in usb_xfer()
92 				      pmsg->flags, pmsg->addr,  in usb_xfer()
93 				      pmsg->buf, pmsg->len) != pmsg->len) {  in usb_xfer()
94 				dev_err(&adapter->dev,  in usb_xfer()
96 				ret = -EIO;  in usb_xfer()
103 			dev_err(&adapter->dev, "failure reading status\n");  in usb_xfer()
104 			ret = -EIO;  in usb_xfer()
108 		dev_dbg(&adapter->dev, "  status = %d\n", *pstatus);  in usb_xfer()
110 			ret = -ENXIO;  in usb_xfer()
131 		dev_err(&adapter->dev, "failure reading functionality\n");  in usb_func()
142 /* prevent invalid 0-length usb_control_msg */
153 /* ----- end of i2c layer ------------------------------------------------ */
155 /* ----- begin of usb layer ---------------------------------------------- */
158  * Initially the usb i2c interface uses a vid/pid pair donated by
168 MODULE_DEVICE_TABLE(usb, i2c_tiny_usb_table);
172 	struct usb_device *usb_dev; /* the usb device for this device */
180 	struct i2c_tiny_usb *dev = (struct i2c_tiny_usb *)adapter->algo_data;  in usb_read()
185 		return -ENOMEM;  in usb_read()
188 	ret = usb_control_msg(dev->usb_dev, usb_rcvctrlpipe(dev->usb_dev, 0),  in usb_read()
200 	struct i2c_tiny_usb *dev = (struct i2c_tiny_usb *)adapter->algo_data;  in usb_write()
205 		return -ENOMEM;  in usb_write()
208 	ret = usb_control_msg(dev->usb_dev, usb_sndctrlpipe(dev->usb_dev, 0),  in usb_write()
218 	usb_put_dev(dev->usb_dev);  in i2c_tiny_usb_free()
226 	int retval = -ENOMEM;  in i2c_tiny_usb_probe()
227 	u16 version;  in i2c_tiny_usb_probe()  local
229 	if (interface->intf_assoc &&  in i2c_tiny_usb_probe()
230 	    interface->intf_assoc->bFunctionClass != USB_CLASS_VENDOR_SPEC)  in i2c_tiny_usb_probe()
231 		return -ENODEV;  in i2c_tiny_usb_probe()
233 	dev_dbg(&interface->dev, "probing usb device\n");  in i2c_tiny_usb_probe()
240 	dev->usb_dev = usb_get_dev(interface_to_usbdev(interface));  in i2c_tiny_usb_probe()
241 	dev->interface = interface;  in i2c_tiny_usb_probe()
246 	version = le16_to_cpu(dev->usb_dev->descriptor.bcdDevice);  in i2c_tiny_usb_probe()
247 	dev_info(&interface->dev,  in i2c_tiny_usb_probe()
248 		 "version %x.%02x found at bus %03d address %03d\n",  in i2c_tiny_usb_probe()
249 		 version >> 8, version & 0xff,  in i2c_tiny_usb_probe()
250 		 dev->usb_dev->bus->busnum, dev->usb_dev->devnum);  in i2c_tiny_usb_probe()
253 	dev->adapter.owner = THIS_MODULE;  in i2c_tiny_usb_probe()
254 	dev->adapter.class = I2C_CLASS_HWMON;  in i2c_tiny_usb_probe()
255 	dev->adapter.quirks = &usb_quirks;  in i2c_tiny_usb_probe()
256 	dev->adapter.algo = &usb_algorithm;  in i2c_tiny_usb_probe()
257 	dev->adapter.algo_data = dev;  in i2c_tiny_usb_probe()
258 	snprintf(dev->adapter.name, sizeof(dev->adapter.name),  in i2c_tiny_usb_probe()
259 		 "i2c-tiny-usb at bus %03d device %03d",  in i2c_tiny_usb_probe()
260 		 dev->usb_dev->bus->busnum, dev->usb_dev->devnum);  in i2c_tiny_usb_probe()
262 	if (usb_write(&dev->adapter, CMD_SET_DELAY, delay, 0, NULL, 0) != 0) {  in i2c_tiny_usb_probe()
263 		dev_err(&dev->adapter.dev,  in i2c_tiny_usb_probe()
265 		retval = -EIO;  in i2c_tiny_usb_probe()
269 	dev->adapter.dev.parent = &dev->interface->dev;  in i2c_tiny_usb_probe()
272 	i2c_add_adapter(&dev->adapter);  in i2c_tiny_usb_probe()
275 	dev_info(&dev->adapter.dev, "connected i2c-tiny-usb device\n");  in i2c_tiny_usb_probe()
290 	i2c_del_adapter(&dev->adapter);  in i2c_tiny_usb_disconnect()
294 	dev_dbg(&interface->dev, "disconnected\n");  in i2c_tiny_usb_disconnect()
298 	.name		= "i2c-tiny-usb",
306 /* ----- end of usb layer ------------------------------------------------ */
309 MODULE_DESCRIPTION("i2c-tiny-usb driver v1.0");