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) { 70 dev_warn(&pdev->dev, "No IRQ assigned to device: " 71 "no support for interrupts?\n"); 72 pci_disable_device(pdev); 73 return -ENODEV; 74 } 75 76 if (!pci_intx_mask_supported(pdev)) { 77 err = -ENODEV; 78 goto err_verify; 79 } 80 81 gdev = kzalloc(sizeof(struct uio_pci_generic_dev), GFP_KERNEL); 82 if (!gdev) { 83 err = -ENOMEM; 84 goto err_alloc; 85 } 86 87 gdev->info.name = "uio_pci_generic"; 88 gdev->info.version = DRIVER_VERSION; 89 gdev->info.irq = pdev->irq; 90 gdev->info.irq_flags = IRQF_SHARED; 91 gdev->info.handler = irqhandler; 92 gdev->pdev = pdev; 93 94 if (uio_register_device(&pdev->dev, &gdev->info)) 95 goto err_register; 96 pci_set_drvdata(pdev, gdev); 97 98 return 0; 99 err_register: 100 kfree(gdev); 101 err_alloc: 102 err_verify: 103 pci_disable_device(pdev); 104 return err; 105 } 106 107 static void remove(struct pci_dev *pdev) 108 { 109 struct uio_pci_generic_dev *gdev = pci_get_drvdata(pdev); 110 111 uio_unregister_device(&gdev->info); 112 pci_disable_device(pdev); 113 kfree(gdev); 114 } 115 116 static struct pci_driver uio_pci_driver = { 117 .name = "uio_pci_generic", 118 .id_table = NULL, /* only dynamic id's */ 119 .probe = probe, 120 .remove = remove, 121 }; 122 123 module_pci_driver(uio_pci_driver); 124 MODULE_VERSION(DRIVER_VERSION); 125 MODULE_LICENSE("GPL v2"); 126 MODULE_AUTHOR(DRIVER_AUTHOR); 127 MODULE_DESCRIPTION(DRIVER_DESC); 128