xref: /openbmc/linux/drivers/mfd/viperboard.c (revision 275876e2)
1 /*
2  *  Nano River Technologies viperboard driver
3  *
4  *  This is the core driver for the viperboard. There are cell drivers
5  *  available for I2C, ADC and both GPIOs. SPI is not yet supported.
6  *  The drivers do not support all features the board exposes. See user
7  *  manual of the viperboard.
8  *
9  *  (C) 2012 by Lemonage GmbH
10  *  Author: Lars Poeschel <poeschel@lemonage.de>
11  *  All rights reserved.
12  *
13  *  This program is free software; you can redistribute  it and/or modify it
14  *  under  the terms of  the GNU General  Public License as published by the
15  *  Free Software Foundation;  either version 2 of the  License, or (at your
16  *  option) any later version.
17  *
18  */
19 
20 #include <linux/kernel.h>
21 #include <linux/errno.h>
22 #include <linux/module.h>
23 #include <linux/slab.h>
24 #include <linux/types.h>
25 #include <linux/mutex.h>
26 
27 #include <linux/mfd/core.h>
28 #include <linux/mfd/viperboard.h>
29 
30 #include <linux/usb.h>
31 
32 
33 static const struct usb_device_id vprbrd_table[] = {
34 	{ USB_DEVICE(0x2058, 0x1005) },   /* Nano River Technologies */
35 	{ }                               /* Terminating entry */
36 };
37 
38 MODULE_DEVICE_TABLE(usb, vprbrd_table);
39 
40 static const struct mfd_cell vprbrd_devs[] = {
41 	{
42 		.name = "viperboard-gpio",
43 	},
44 	{
45 		.name = "viperboard-i2c",
46 	},
47 	{
48 		.name = "viperboard-adc",
49 	},
50 };
51 
52 static int vprbrd_probe(struct usb_interface *interface,
53 			      const struct usb_device_id *id)
54 {
55 	struct vprbrd *vb;
56 
57 	u16 version = 0;
58 	int pipe, ret;
59 
60 	/* allocate memory for our device state and initialize it */
61 	vb = kzalloc(sizeof(*vb), GFP_KERNEL);
62 	if (vb == NULL) {
63 		dev_err(&interface->dev, "Out of memory\n");
64 		return -ENOMEM;
65 	}
66 
67 	mutex_init(&vb->lock);
68 
69 	vb->usb_dev = usb_get_dev(interface_to_usbdev(interface));
70 
71 	/* save our data pointer in this interface device */
72 	usb_set_intfdata(interface, vb);
73 	dev_set_drvdata(&vb->pdev.dev, vb);
74 
75 	/* get version information, major first, minor then */
76 	pipe = usb_rcvctrlpipe(vb->usb_dev, 0);
77 	ret = usb_control_msg(vb->usb_dev, pipe, VPRBRD_USB_REQUEST_MAJOR,
78 		VPRBRD_USB_TYPE_IN, 0x0000, 0x0000, vb->buf, 1,
79 		VPRBRD_USB_TIMEOUT_MS);
80 	if (ret == 1)
81 		version = vb->buf[0];
82 
83 	ret = usb_control_msg(vb->usb_dev, pipe, VPRBRD_USB_REQUEST_MINOR,
84 		VPRBRD_USB_TYPE_IN, 0x0000, 0x0000, vb->buf, 1,
85 		VPRBRD_USB_TIMEOUT_MS);
86 	if (ret == 1) {
87 		version <<= 8;
88 		version = version | vb->buf[0];
89 	}
90 
91 	dev_info(&interface->dev,
92 		 "version %x.%02x found at bus %03d address %03d\n",
93 		 version >> 8, version & 0xff,
94 		 vb->usb_dev->bus->busnum, vb->usb_dev->devnum);
95 
96 	ret = mfd_add_devices(&interface->dev, -1, vprbrd_devs,
97 				ARRAY_SIZE(vprbrd_devs), NULL, 0, NULL);
98 	if (ret != 0) {
99 		dev_err(&interface->dev, "Failed to add mfd devices to core.");
100 		goto error;
101 	}
102 
103 	return 0;
104 
105 error:
106 	if (vb) {
107 		usb_put_dev(vb->usb_dev);
108 		kfree(vb);
109 	}
110 
111 	return ret;
112 }
113 
114 static void vprbrd_disconnect(struct usb_interface *interface)
115 {
116 	struct vprbrd *vb = usb_get_intfdata(interface);
117 
118 	mfd_remove_devices(&interface->dev);
119 	usb_set_intfdata(interface, NULL);
120 	usb_put_dev(vb->usb_dev);
121 	kfree(vb);
122 
123 	dev_dbg(&interface->dev, "disconnected\n");
124 }
125 
126 static struct usb_driver vprbrd_driver = {
127 	.name		= "viperboard",
128 	.probe		= vprbrd_probe,
129 	.disconnect	= vprbrd_disconnect,
130 	.id_table	= vprbrd_table,
131 };
132 
133 module_usb_driver(vprbrd_driver);
134 
135 MODULE_DESCRIPTION("Nano River Technologies viperboard mfd core driver");
136 MODULE_AUTHOR("Lars Poeschel <poeschel@lemonage.de>");
137 MODULE_LICENSE("GPL");
138