drivers/uio/uio_aec.c

   1 /*
   2  * uio_aec.c -- simple driver for Adrienne Electronics Corp time code PCI device
   3  *
   4  * Copyright (C) 2008 Brandon Philips <brandon@ifup.org>
   5  *
   6  *   This program is free software; you can redistribute it and/or modify it
   7  *   under the terms of the GNU General Public License version 2 as published
   8  *   by the Free Software Foundation.
   9  *
  10  *   This program is distributed in the hope that it will be useful,
  11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *   GNU General Public License for more details.
  14  *
  15  *   You should have received a copy of the GNU General Public License along
  16  *   with this program; if not, write to the Free Software Foundation, Inc., 59
  17  *   Temple Place, Suite 330, Boston, MA 02111-1307, USA.
  18  */
  19
  20 #include <linux/kernel.h>
  21 #include <linux/module.h>
  22 #include <linux/pci.h>
  23 #include <linux/init.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/cdev.h>
  26 #include <linux/fs.h>
  27 #include <linux/io.h>
  28 #include <linux/uaccess.h>
  29 #include <linux/uio_driver.h>
  30
  31 #define PCI_VENDOR_ID_AEC 0xaecb
  32 #define PCI_DEVICE_ID_AEC_VITCLTC 0x6250
  33
  34 #define INT_ENABLE_ADDR         0xFC
  35 #define INT_ENABLE              0x10
  36 #define INT_DISABLE             0x0
  37
  38 #define INT_MASK_ADDR           0x2E
  39 #define INT_MASK_ALL            0x3F
  40
  41 #define INTA_DRVR_ADDR          0xFE
  42 #define INTA_ENABLED_FLAG       0x08
  43 #define INTA_FLAG               0x01
  44
  45 #define MAILBOX                 0x0F
  46
  47 static struct pci_device_id ids[] = {
  48         { PCI_DEVICE(PCI_VENDOR_ID_AEC, PCI_DEVICE_ID_AEC_VITCLTC), },
  49         { 0, }
  50 };
  51 MODULE_DEVICE_TABLE(pci, ids);
  52
  53 static irqreturn_t aectc_irq(int irq, struct uio_info *dev_info)
  54 {
  55         void __iomem *int_flag = dev_info->priv + INTA_DRVR_ADDR;
  56         unsigned char status = ioread8(int_flag);
  57
  58
  59         if ((status & INTA_ENABLED_FLAG) && (status & INTA_FLAG)) {
  60                 /* application writes 0x00 to 0x2F to get next interrupt */
  61                 status = ioread8(dev_info->priv + MAILBOX);
  62                 return IRQ_HANDLED;
  63         }
  64
  65         return IRQ_NONE;
  66 }
  67
  68 static void print_board_data(struct pci_dev *pdev, struct uio_info *i)
  69 {
  70         dev_info(&pdev->dev, "PCI-TC board vendor: %x%x number: %x%x"
  71                 " revision: %c%c\n",
  72                 ioread8(i->priv + 0x01),
  73                 ioread8(i->priv + 0x00),
  74                 ioread8(i->priv + 0x03),
  75                 ioread8(i->priv + 0x02),
  76                 ioread8(i->priv + 0x06),
  77                 ioread8(i->priv + 0x07));
  78 }
  79
  80 static int __devinit probe(struct pci_dev *pdev, const struct pci_device_id *id)
  81 {
  82         struct uio_info *info;
  83         int ret;
  84
  85         info = kzalloc(sizeof(struct uio_info), GFP_KERNEL);
  86         if (!info)
  87                 return -ENOMEM;
  88
  89         if (pci_enable_device(pdev))
  90                 goto out_free;
  91
  92         if (pci_request_regions(pdev, "aectc"))
  93                 goto out_disable;
  94
  95         info->name = "aectc";
  96         info->port[0].start = pci_resource_start(pdev, 0);
  97         if (!info->port[0].start)
  98                 goto out_release;
  99         info->priv = pci_iomap(pdev, 0, 0);
 100         if (!info->priv)
 101                 goto out_release;
 102         info->port[0].size = pci_resource_len(pdev, 0);
 103         info->port[0].porttype = UIO_PORT_GPIO;
 104
 105         info->version = "0.0.1";
 106         info->irq = pdev->irq;
 107         info->irq_flags = IRQF_SHARED;
 108         info->handler = aectc_irq;
 109
 110         print_board_data(pdev, info);
 111         ret = uio_register_device(&pdev->dev, info);
 112         if (ret)
 113                 goto out_unmap;
 114
 115         iowrite32(INT_ENABLE, info->priv + INT_ENABLE_ADDR);
 116         iowrite8(INT_MASK_ALL, info->priv + INT_MASK_ADDR);
 117         if (!(ioread8(info->priv + INTA_DRVR_ADDR)
 118                         & INTA_ENABLED_FLAG))
 119                 dev_err(&pdev->dev, "aectc: interrupts not enabled\n");
 120
 121         pci_set_drvdata(pdev, info);
 122
 123         return 0;
 124
 125 out_unmap:
 126         pci_iounmap(pdev, info->priv);
 127 out_release:
 128         pci_release_regions(pdev);
 129 out_disable:
 130         pci_disable_device(pdev);
 131 out_free:
 132         kfree(info);
 133         return -ENODEV;
 134 }
 135
 136 static void remove(struct pci_dev *pdev)
 137 {
 138         struct uio_info *info = pci_get_drvdata(pdev);
 139
 140         /* disable interrupts */
 141         iowrite8(INT_DISABLE, info->priv + INT_MASK_ADDR);
 142         iowrite32(INT_DISABLE, info->priv + INT_ENABLE_ADDR);
 143         /* read mailbox to ensure board drops irq */
 144         ioread8(info->priv + MAILBOX);
 145
 146         uio_unregister_device(info);
 147         pci_release_regions(pdev);
 148         pci_disable_device(pdev);
 149         pci_set_drvdata(pdev, NULL);
 150         iounmap(info->priv);
 151
 152         kfree(info);
 153 }
 154
 155 static struct pci_driver pci_driver = {
 156         .name = "aectc",
 157         .id_table = ids,
 158         .probe = probe,
 159         .remove = remove,
 160 };
 161
 162 static int __init aectc_init(void)
 163 {
 164         return pci_register_driver(&pci_driver);
 165 }
 166
 167 static void __exit aectc_exit(void)
 168 {
 169         pci_unregister_driver(&pci_driver);
 170 }
 171
 172 MODULE_LICENSE("GPL");
 173
 174 module_init(aectc_init);
 175 module_exit(aectc_exit);