drivers/uio/uio_aec.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * uio_aec.c -- simple driver for Adrienne Electronics Corp time code PCI device
   4  *
   5  * Copyright (C) 2008 Brandon Philips <brandon@ifup.org>
   6  */
   7
   8 #include <linux/kernel.h>
   9 #include <linux/module.h>
  10 #include <linux/pci.h>
  11 #include <linux/init.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/cdev.h>
  14 #include <linux/fs.h>
  15 #include <linux/io.h>
  16 #include <linux/uaccess.h>
  17 #include <linux/uio_driver.h>
  18 #include <linux/slab.h>
  19
  20 #define PCI_VENDOR_ID_AEC 0xaecb
  21 #define PCI_DEVICE_ID_AEC_VITCLTC 0x6250
  22
  23 #define INT_ENABLE_ADDR         0xFC
  24 #define INT_ENABLE              0x10
  25 #define INT_DISABLE             0x0
  26
  27 #define INT_MASK_ADDR           0x2E
  28 #define INT_MASK_ALL            0x3F
  29
  30 #define INTA_DRVR_ADDR          0xFE
  31 #define INTA_ENABLED_FLAG       0x08
  32 #define INTA_FLAG               0x01
  33
  34 #define MAILBOX                 0x0F
  35
  36 static struct pci_device_id ids[] = {
  37         { PCI_DEVICE(PCI_VENDOR_ID_AEC, PCI_DEVICE_ID_AEC_VITCLTC), },
  38         { 0, }
  39 };
  40 MODULE_DEVICE_TABLE(pci, ids);
  41
  42 static irqreturn_t aectc_irq(int irq, struct uio_info *dev_info)
  43 {
  44         void __iomem *int_flag = dev_info->priv + INTA_DRVR_ADDR;
  45         unsigned char status = ioread8(int_flag);
  46
  47
  48         if ((status & INTA_ENABLED_FLAG) && (status & INTA_FLAG)) {
  49                 /* application writes 0x00 to 0x2F to get next interrupt */
  50                 status = ioread8(dev_info->priv + MAILBOX);
  51                 return IRQ_HANDLED;
  52         }
  53
  54         return IRQ_NONE;
  55 }
  56
  57 static void print_board_data(struct pci_dev *pdev, struct uio_info *i)
  58 {
  59         dev_info(&pdev->dev, "PCI-TC board vendor: %x%x number: %x%x"
  60                 " revision: %c%c\n",
  61                 ioread8(i->priv + 0x01),
  62                 ioread8(i->priv + 0x00),
  63                 ioread8(i->priv + 0x03),
  64                 ioread8(i->priv + 0x02),
  65                 ioread8(i->priv + 0x06),
  66                 ioread8(i->priv + 0x07));
  67 }
  68
  69 static int probe(struct pci_dev *pdev, const struct pci_device_id *id)
  70 {
  71         struct uio_info *info;
  72         int ret;
  73
  74         info = devm_kzalloc(&pdev->dev, sizeof(struct uio_info), GFP_KERNEL);
  75         if (!info)
  76                 return -ENOMEM;
  77
  78         if (pci_enable_device(pdev))
  79                 return -ENODEV;
  80
  81         if (pci_request_regions(pdev, "aectc"))
  82                 goto out_disable;
  83
  84         info->name = "aectc";
  85         info->port[0].start = pci_resource_start(pdev, 0);
  86         if (!info->port[0].start)
  87                 goto out_release;
  88         info->priv = pci_iomap(pdev, 0, 0);
  89         if (!info->priv)
  90                 goto out_release;
  91         info->port[0].size = pci_resource_len(pdev, 0);
  92         info->port[0].porttype = UIO_PORT_GPIO;
  93
  94         info->version = "0.0.1";
  95         info->irq = pdev->irq;
  96         info->irq_flags = IRQF_SHARED;
  97         info->handler = aectc_irq;
  98
  99         print_board_data(pdev, info);
 100         ret = uio_register_device(&pdev->dev, info);
 101         if (ret)
 102                 goto out_unmap;
 103
 104         iowrite32(INT_ENABLE, info->priv + INT_ENABLE_ADDR);
 105         iowrite8(INT_MASK_ALL, info->priv + INT_MASK_ADDR);
 106         if (!(ioread8(info->priv + INTA_DRVR_ADDR)
 107                         & INTA_ENABLED_FLAG))
 108                 dev_err(&pdev->dev, "aectc: interrupts not enabled\n");
 109
 110         pci_set_drvdata(pdev, info);
 111
 112         return 0;
 113
 114 out_unmap:
 115         pci_iounmap(pdev, info->priv);
 116 out_release:
 117         pci_release_regions(pdev);
 118 out_disable:
 119         pci_disable_device(pdev);
 120         return -ENODEV;
 121 }
 122
 123 static void remove(struct pci_dev *pdev)
 124 {
 125         struct uio_info *info = pci_get_drvdata(pdev);
 126
 127         /* disable interrupts */
 128         iowrite8(INT_DISABLE, info->priv + INT_MASK_ADDR);
 129         iowrite32(INT_DISABLE, info->priv + INT_ENABLE_ADDR);
 130         /* read mailbox to ensure board drops irq */
 131         ioread8(info->priv + MAILBOX);
 132
 133         uio_unregister_device(info);
 134         pci_release_regions(pdev);
 135         pci_disable_device(pdev);
 136         iounmap(info->priv);
 137 }
 138
 139 static struct pci_driver pci_driver = {
 140         .name = "aectc",
 141         .id_table = ids,
 142         .probe = probe,
 143         .remove = remove,
 144 };
 145
 146 module_pci_driver(pci_driver);
 147 MODULE_LICENSE("GPL");