xref: /openbmc/linux/drivers/mfd/viperboard.c (revision a44e4f3a)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  Nano River Technologies viperboard driver
4  *
5  *  This is the core driver for the viperboard. There are cell drivers
6  *  available for I2C, ADC and both GPIOs. SPI is not yet supported.
7  *  The drivers do not support all features the board exposes. See user
8  *  manual of the viperboard.
9  *
10  *  (C) 2012 by Lemonage GmbH
11  *  Author: Lars Poeschel <poeschel@lemonage.de>
12  *  All rights reserved.
13  */
14 
15 #include <linux/kernel.h>
16 #include <linux/errno.h>
17 #include <linux/module.h>
18 #include <linux/slab.h>
19 #include <linux/types.h>
20 #include <linux/mutex.h>
21 
22 #include <linux/mfd/core.h>
23 #include <linux/mfd/viperboard.h>
24 
25 #include <linux/usb.h>
26 
27 
28 static const struct usb_device_id vprbrd_table[] = {
29 	{ USB_DEVICE(0x2058, 0x1005) },   /* Nano River Technologies */
30 	{ }                               /* Terminating entry */
31 };
32 
33 MODULE_DEVICE_TABLE(usb, vprbrd_table);
34 
35 static const struct mfd_cell vprbrd_devs[] = {
36 	{
37 		.name = "viperboard-gpio",
38 	},
39 	{
40 		.name = "viperboard-i2c",
41 	},
42 	{
43 		.name = "viperboard-adc",
44 	},
45 };
46 
47 static int vprbrd_probe(struct usb_interface *interface,
48 			      const struct usb_device_id *id)
49 {
50 	struct vprbrd *vb;
51 
52 	u16 version = 0;
53 	int pipe, ret;
54 
55 	/* allocate memory for our device state and initialize it */
56 	vb = kzalloc(sizeof(*vb), GFP_KERNEL);
57 	if (!vb)
58 		return -ENOMEM;
59 
60 	mutex_init(&vb->lock);
61 
62 	vb->usb_dev = usb_get_dev(interface_to_usbdev(interface));
63 
64 	/* save our data pointer in this interface device */
65 	usb_set_intfdata(interface, vb);
66 	dev_set_drvdata(&vb->pdev.dev, vb);
67 
68 	/* get version information, major first, minor then */
69 	pipe = usb_rcvctrlpipe(vb->usb_dev, 0);
70 	ret = usb_control_msg(vb->usb_dev, pipe, VPRBRD_USB_REQUEST_MAJOR,
71 		VPRBRD_USB_TYPE_IN, 0x0000, 0x0000, vb->buf, 1,
72 		VPRBRD_USB_TIMEOUT_MS);
73 	if (ret == 1)
74 		version = vb->buf[0];
75 
76 	ret = usb_control_msg(vb->usb_dev, pipe, VPRBRD_USB_REQUEST_MINOR,
77 		VPRBRD_USB_TYPE_IN, 0x0000, 0x0000, vb->buf, 1,
78 		VPRBRD_USB_TIMEOUT_MS);
79 	if (ret == 1) {
80 		version <<= 8;
81 		version = version | vb->buf[0];
82 	}
83 
84 	dev_info(&interface->dev,
85 		 "version %x.%02x found at bus %03d address %03d\n",
86 		 version >> 8, version & 0xff,
87 		 vb->usb_dev->bus->busnum, vb->usb_dev->devnum);
88 
89 	ret = mfd_add_hotplug_devices(&interface->dev, vprbrd_devs,
90 				      ARRAY_SIZE(vprbrd_devs));
91 	if (ret != 0) {
92 		dev_err(&interface->dev, "Failed to add mfd devices to core.");
93 		goto error;
94 	}
95 
96 	return 0;
97 
98 error:
99 	if (vb) {
100 		usb_put_dev(vb->usb_dev);
101 		kfree(vb);
102 	}
103 
104 	return ret;
105 }
106 
107 static void vprbrd_disconnect(struct usb_interface *interface)
108 {
109 	struct vprbrd *vb = usb_get_intfdata(interface);
110 
111 	mfd_remove_devices(&interface->dev);
112 	usb_set_intfdata(interface, NULL);
113 	usb_put_dev(vb->usb_dev);
114 	kfree(vb);
115 
116 	dev_dbg(&interface->dev, "disconnected\n");
117 }
118 
119 static struct usb_driver vprbrd_driver = {
120 	.name		= "viperboard",
121 	.probe		= vprbrd_probe,
122 	.disconnect	= vprbrd_disconnect,
123 	.id_table	= vprbrd_table,
124 };
125 
126 module_usb_driver(vprbrd_driver);
127 
128 MODULE_DESCRIPTION("Nano River Technologies viperboard mfd core driver");
129 MODULE_AUTHOR("Lars Poeschel <poeschel@lemonage.de>");
130 MODULE_LICENSE("GPL");
131