drivers/mfd/viperboard.c

   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_hotplug_devices(&interface->dev, vprbrd_devs,
  97                                       ARRAY_SIZE(vprbrd_devs));
  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");