drivers/mfd/viperboard.c

   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");