[PATCH] Add Geode HW RNG driver (ef5d8627) · Commits · e / devices / android_kernel_oneplus_sm7250

drivers/char/hw_random/Kconfig

+13 −0

Original line number	Diff line number	Diff line
		@@ -35,3 +35,16 @@ config HW_RANDOM_AMD
		module will be called amd-rng.

		If unsure, say Y.

		config HW_RANDOM_GEODE
		tristate "AMD Geode HW Random Number Generator support"
		depends on HW_RANDOM && X86 && PCI
		default y
		---help---
		This driver provides kernel-side support for the Random Number
		Generator hardware found on the AMD Geode LX.

		To compile this driver as a module, choose M here: the
		module will be called geode-rng.

		If unsure, say Y.

drivers/char/hw_random/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -5,3 +5,4 @@
		obj-$(CONFIG_HW_RANDOM) += core.o
		obj-$(CONFIG_HW_RANDOM_INTEL) += intel-rng.o
		obj-$(CONFIG_HW_RANDOM_AMD) += amd-rng.o
		obj-$(CONFIG_HW_RANDOM_GEODE) += geode-rng.o

drivers/char/hw_random/geode-rng.c

0 → 100644

+128 −0

Original line number	Diff line number	Diff line
		/*
		* 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 <alan@redhat.com>
		*
		* 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 <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)
		{
		void __iomem mem = (void __iomem )rng->priv;

		return !!(readl(mem + GEODE_RNG_STATUS_REG));
		}


		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 out;
		}
		out:
		return err;
		}

		static void __exit mod_exit(void)
		{
		void __iomem mem = (void __iomem )geode_rng.priv;

		hwrng_unregister(&geode_rng);
		iounmap(mem);
		}

		subsys_initcall(mod_init);
		module_exit(mod_exit);

		MODULE_DESCRIPTION("H/W RNG driver for AMD Geode LX CPUs");
		MODULE_LICENSE("GPL");