LXR linux/drivers/uio/uio

   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
  36static struct pci_device_id ids[] = {
  37        { PCI_DEVICE(PCI_VENDOR_ID_AEC, PCI_DEVICE_ID_AEC_VITCLTC), },
  38        { 0, }
  39};
  40MODULE_DEVICE_TABLE(pci, ids);
  41
  42static 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
  57static 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
  69static 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
 114out_unmap:
 115        pci_iounmap(pdev, info->priv);
 116out_release:
 117        pci_release_regions(pdev);
 118out_disable:
 119        pci_disable_device(pdev);
 120        return -ENODEV;
 121}
 122
 123static 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        pci_iounmap(pdev, info->priv);
 137}
 138
 139static struct pci_driver pci_driver = {
 140        .name = "aectc",
 141        .id_table = ids,
 142        .probe = probe,
 143        .remove = remove,
 144};
 145
 146module_pci_driver(pci_driver);
 147MODULE_LICENSE("GPL");
 148