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 #include <linux/slab.h>
  31
  32 #define PCI_VENDOR_ID_AEC 0xaecb
  33 #define PCI_DEVICE_ID_AEC_VITCLTC 0x6250
  34
  35 #define INT_ENABLE_ADDR         0xFC
  36 #define INT_ENABLE              0x10
  37 #define INT_DISABLE             0x0
  38
  39 #define INT_MASK_ADDR           0x2E
  40 #define INT_MASK_ALL            0x3F
  41
  42 #define INTA_DRVR_ADDR          0xFE
  43 #define INTA_ENABLED_FLAG       0x08
  44 #define INTA_FLAG               0x01
  45
  46 #define MAILBOX                 0x0F
  47
  48 static struct pci_device_id ids[] = {
  49         { PCI_DEVICE(PCI_VENDOR_ID_AEC, PCI_DEVICE_ID_AEC_VITCLTC), },
  50         { 0, }
  51 };
  52 MODULE_DEVICE_TABLE(pci, ids);
  53
  54 static irqreturn_t aectc_irq(int irq, struct uio_info *dev_info)
  55 {
  56         void __iomem *int_flag = dev_info->priv + INTA_DRVR_ADDR;
  57         unsigned char status = ioread8(int_flag);
  58
  59
  60         if ((status & INTA_ENABLED_FLAG) && (status & INTA_FLAG)) {
  61                 /* application writes 0x00 to 0x2F to get next interrupt */
  62                 status = ioread8(dev_info->priv + MAILBOX);
  63                 return IRQ_HANDLED;
  64         }
  65
  66         return IRQ_NONE;
  67 }
  68
  69 static void print_board_data(struct pci_dev *pdev, struct uio_info *i)
  70 {
  71         dev_info(&pdev->dev, "PCI-TC board vendor: %x%x number: %x%x"
  72                 " revision: %c%c\n",
  73                 ioread8(i->priv + 0x01),
  74                 ioread8(i->priv + 0x00),
  75                 ioread8(i->priv + 0x03),
  76                 ioread8(i->priv + 0x02),
  77                 ioread8(i->priv + 0x06),
  78                 ioread8(i->priv + 0x07));
  79 }
  80
  81 static int probe(struct pci_dev *pdev, const struct pci_device_id *id)
  82 {
  83         struct uio_info *info;
  84         int ret;
  85
  86         info = kzalloc(sizeof(struct uio_info), GFP_KERNEL);
  87         if (!info)
  88                 return -ENOMEM;
  89
  90         if (pci_enable_device(pdev))
  91                 goto out_free;
  92
  93         if (pci_request_regions(pdev, "aectc"))
  94                 goto out_disable;
  95
  96         info->name = "aectc";
  97         info->port[0].start = pci_resource_start(pdev, 0);
  98         if (!info->port[0].start)
  99                 goto out_release;
 100         info->priv = pci_iomap(pdev, 0, 0);
 101         if (!info->priv)
 102                 goto out_release;
 103         info->port[0].size = pci_resource_len(pdev, 0);
 104         info->port[0].porttype = UIO_PORT_GPIO;
 105
 106         info->version = "0.0.1";
 107         info->irq = pdev->irq;
 108         info->irq_flags = IRQF_SHARED;
 109         info->handler = aectc_irq;
 110
 111         print_board_data(pdev, info);
 112         ret = uio_register_device(&pdev->dev, info);
 113         if (ret)
 114                 goto out_unmap;
 115
 116         iowrite32(INT_ENABLE, info->priv + INT_ENABLE_ADDR);
 117         iowrite8(INT_MASK_ALL, info->priv + INT_MASK_ADDR);
 118         if (!(ioread8(info->priv + INTA_DRVR_ADDR)
 119                         & INTA_ENABLED_FLAG))
 120                 dev_err(&pdev->dev, "aectc: interrupts not enabled\n");
 121
 122         pci_set_drvdata(pdev, info);
 123
 124         return 0;
 125
 126 out_unmap:
 127         pci_iounmap(pdev, info->priv);
 128 out_release:
 129         pci_release_regions(pdev);
 130 out_disable:
 131         pci_disable_device(pdev);
 132 out_free:
 133         kfree(info);
 134         return -ENODEV;
 135 }
 136
 137 static void remove(struct pci_dev *pdev)
 138 {
 139         struct uio_info *info = pci_get_drvdata(pdev);
 140
 141         /* disable interrupts */
 142         iowrite8(INT_DISABLE, info->priv + INT_MASK_ADDR);
 143         iowrite32(INT_DISABLE, info->priv + INT_ENABLE_ADDR);
 144         /* read mailbox to ensure board drops irq */
 145         ioread8(info->priv + MAILBOX);
 146
 147         uio_unregister_device(info);
 148         pci_release_regions(pdev);
 149         pci_disable_device(pdev);
 150         pci_set_drvdata(pdev, NULL);
 151         iounmap(info->priv);
 152
 153         kfree(info);
 154 }
 155
 156 static struct pci_driver pci_driver = {
 157         .name = "aectc",
 158         .id_table = ids,
 159         .probe = probe,
 160         .remove = remove,
 161 };
 162
 163 module_pci_driver(pci_driver);
 164 MODULE_LICENSE("GPL");