1 /* uio_pci_generic - generic UIO driver for PCI 2.3 devices 2 * 3 * Copyright (C) 2009 Red Hat, Inc. 4 * Author: Michael S. Tsirkin <mst@redhat.com> 5 * 6 * This work is licensed under the terms of the GNU GPL, version 2. 7 * 8 * Since the driver does not declare any device ids, you must allocate 9 * id and bind the device to the driver yourself. For example: 10 * 11 * # echo "8086 10f5" > /sys/bus/pci/drivers/uio_pci_generic/new_id 12 * # echo -n 0000:00:19.0 > /sys/bus/pci/drivers/e1000e/unbind 13 * # echo -n 0000:00:19.0 > /sys/bus/pci/drivers/uio_pci_generic/bind 14 * # ls -l /sys/bus/pci/devices/0000:00:19.0/driver 15 * .../0000:00:19.0/driver -> ../../../bus/pci/drivers/uio_pci_generic 16 * 17 * Driver won't bind to devices which do not support the Interrupt Disable Bit 18 * in the command register. All devices compliant to PCI 2.3 (circa 2002) and 19 * all compliant PCI Express devices should support this bit. 20 */ 21 22 #include <linux/device.h> 23 #include <linux/module.h> 24 #include <linux/pci.h> 25 #include <linux/slab.h> 26 #include <linux/uio_driver.h> 27 28 #define DRIVER_VERSION "0.01.0" 29 #define DRIVER_AUTHOR "Michael S. Tsirkin <mst@redhat.com>" 30 #define DRIVER_DESC "Generic UIO driver for PCI 2.3 devices" 31 32 struct uio_pci_generic_dev { 33 struct uio_info info; 34 struct pci_dev *pdev; 35 }; 36 37 static inline struct uio_pci_generic_dev * 38 to_uio_pci_generic_dev(struct uio_info *info) 39 { 40 return container_of(info, struct uio_pci_generic_dev, info); 41 } 42 43 /* Interrupt handler. Read/modify/write the command register to disable 44 * the interrupt. */ 45 static irqreturn_t irqhandler(int irq, struct uio_info *info) 46 { 47 struct uio_pci_generic_dev *gdev = to_uio_pci_generic_dev(info); 48 49 if (!pci_check_and_mask_intx(gdev->pdev)) 50 return IRQ_NONE; 51 52 /* UIO core will signal the user process. */ 53 return IRQ_HANDLED; 54 } 55 56 static int probe(struct pci_dev *pdev, 57 const struct pci_device_id *id) 58 { 59 struct uio_pci_generic_dev *gdev; 60 int err; 61 62 err = pci_enable_device(pdev); 63 if (err) { 64 dev_err(&pdev->dev, "%s: pci_enable_device failed: %d\n", 65 __func__, err); 66 return err; 67 } 68 69 if (pdev->irq && !pci_intx_mask_supported(pdev)) { 70 err = -ENODEV; 71 goto err_verify; 72 } 73 74 gdev = kzalloc(sizeof(struct uio_pci_generic_dev), GFP_KERNEL); 75 if (!gdev) { 76 err = -ENOMEM; 77 goto err_alloc; 78 } 79 80 gdev->info.name = "uio_pci_generic"; 81 gdev->info.version = DRIVER_VERSION; 82 gdev->pdev = pdev; 83 if (pdev->irq) { 84 gdev->info.irq = pdev->irq; 85 gdev->info.irq_flags = IRQF_SHARED; 86 gdev->info.handler = irqhandler; 87 } else { 88 dev_warn(&pdev->dev, "No IRQ assigned to device: " 89 "no support for interrupts?\n"); 90 } 91 92 err = uio_register_device(&pdev->dev, &gdev->info); 93 if (err) 94 goto err_register; 95 pci_set_drvdata(pdev, gdev); 96 97 return 0; 98 err_register: 99 kfree(gdev); 100 err_alloc: 101 err_verify: 102 pci_disable_device(pdev); 103 return err; 104 } 105 106 static void remove(struct pci_dev *pdev) 107 { 108 struct uio_pci_generic_dev *gdev = pci_get_drvdata(pdev); 109 110 uio_unregister_device(&gdev->info); 111 pci_disable_device(pdev); 112 kfree(gdev); 113 } 114 115 static struct pci_driver uio_pci_driver = { 116 .name = "uio_pci_generic", 117 .id_table = NULL, /* only dynamic id's */ 118 .probe = probe, 119 .remove = remove, 120 }; 121 122 module_pci_driver(uio_pci_driver); 123 MODULE_VERSION(DRIVER_VERSION); 124 MODULE_LICENSE("GPL v2"); 125 MODULE_AUTHOR(DRIVER_AUTHOR); 126 MODULE_DESCRIPTION(DRIVER_DESC); 127