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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 | /* * RNG driver for AMD Geode RNGs * * Copyright 2005 (c) MontaVista Software, Inc. * * with the majority of the code coming from: * * Hardware driver for the Intel/AMD/VIA Random Number Generators (RNG) * (c) Copyright 2003 Red Hat Inc <jgarzik@redhat.com> * * derived from * * Hardware driver for the AMD 768 Random Number Generator (RNG) * (c) Copyright 2001 Red Hat Inc * * derived from * * Hardware driver for Intel i810 Random Number Generator (RNG) * Copyright 2000,2001 Jeff Garzik <jgarzik@pobox.com> * Copyright 2000,2001 Philipp Rumpf <prumpf@mandrakesoft.com> * * This file is licensed under the terms of the GNU General Public * License version 2. This program is licensed "as is" without any * warranty of any kind, whether express or implied. */ #include <linux/module.h> #include <linux/kernel.h> #include <linux/pci.h> #include <linux/hw_random.h> #include <linux/delay.h> #include <asm/io.h> #define PFX KBUILD_MODNAME ": " #define GEODE_RNG_DATA_REG 0x50 #define GEODE_RNG_STATUS_REG 0x54 /* * Data for PCI driver interface * * This data only exists for exporting the supported * PCI ids via MODULE_DEVICE_TABLE. We do not actually * register a pci_driver, because someone else might one day * want to register another driver on the same PCI id. */ static const struct pci_device_id pci_tbl[] = { { PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_LX_AES, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, { 0, }, /* terminate list */ }; MODULE_DEVICE_TABLE(pci, pci_tbl); static int geode_rng_data_read(struct hwrng *rng, u32 *data) { void __iomem *mem = (void __iomem *)rng->priv; *data = readl(mem + GEODE_RNG_DATA_REG); return 4; } static int geode_rng_data_present(struct hwrng *rng, int wait) { void __iomem *mem = (void __iomem *)rng->priv; int data, i; for (i = 0; i < 20; i++) { data = !!(readl(mem + GEODE_RNG_STATUS_REG)); if (data || !wait) break; udelay(10); } return data; } static struct hwrng geode_rng = { .name = "geode", .data_present = geode_rng_data_present, .data_read = geode_rng_data_read, }; static int __init mod_init(void) { int err = -ENODEV; struct pci_dev *pdev = NULL; const struct pci_device_id *ent; void __iomem *mem; unsigned long rng_base; for_each_pci_dev(pdev) { ent = pci_match_id(pci_tbl, pdev); if (ent) goto found; } /* Device not found. */ goto out; found: rng_base = pci_resource_start(pdev, 0); if (rng_base == 0) goto out; err = -ENOMEM; mem = ioremap(rng_base, 0x58); if (!mem) goto out; geode_rng.priv = (unsigned long)mem; printk(KERN_INFO "AMD Geode RNG detected\n"); err = hwrng_register(&geode_rng); if (err) { printk(KERN_ERR PFX "RNG registering failed (%d)\n", err); goto err_unmap; } out: return err; err_unmap: iounmap(mem); goto out; } static void __exit mod_exit(void) { void __iomem *mem = (void __iomem *)geode_rng.priv; hwrng_unregister(&geode_rng); iounmap(mem); } module_init(mod_init); module_exit(mod_exit); MODULE_DESCRIPTION("H/W RNG driver for AMD Geode LX CPUs"); MODULE_LICENSE("GPL"); |