148 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			148 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * Hardware Random Number Generator support for Cavium Networks
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 * Octeon processor family.
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 *
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 * This file is subject to the terms and conditions of the GNU General Public
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 * License.  See the file "COPYING" in the main directory of this archive
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 * for more details.
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 *
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 * Copyright (C) 2009 Cavium Networks
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 */
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/platform_device.h>
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#include <linux/device.h>
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#include <linux/hw_random.h>
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#include <linux/io.h>
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#include <asm/octeon/octeon.h>
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#include <asm/octeon/cvmx-rnm-defs.h>
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struct octeon_rng {
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	struct hwrng ops;
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	void __iomem *control_status;
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	void __iomem *result;
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};
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static int octeon_rng_init(struct hwrng *rng)
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{
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	union cvmx_rnm_ctl_status ctl;
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	struct octeon_rng *p = container_of(rng, struct octeon_rng, ops);
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	ctl.u64 = 0;
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	ctl.s.ent_en = 1; /* Enable the entropy source.  */
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	ctl.s.rng_en = 1; /* Enable the RNG hardware.  */
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	cvmx_write_csr((u64)p->control_status, ctl.u64);
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	return 0;
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}
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static void octeon_rng_cleanup(struct hwrng *rng)
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{
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	union cvmx_rnm_ctl_status ctl;
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	struct octeon_rng *p = container_of(rng, struct octeon_rng, ops);
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	ctl.u64 = 0;
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	/* Disable everything.  */
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	cvmx_write_csr((u64)p->control_status, ctl.u64);
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}
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static int octeon_rng_data_read(struct hwrng *rng, u32 *data)
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{
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	struct octeon_rng *p = container_of(rng, struct octeon_rng, ops);
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	*data = cvmx_read64_uint32((u64)p->result);
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	return sizeof(u32);
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}
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static int __devinit octeon_rng_probe(struct platform_device *pdev)
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{
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	struct resource *res_ports;
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	struct resource *res_result;
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	struct octeon_rng *rng;
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	int ret;
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	struct hwrng ops = {
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		.name = "octeon",
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		.init = octeon_rng_init,
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		.cleanup = octeon_rng_cleanup,
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		.data_read = octeon_rng_data_read
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	};
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	rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL);
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	if (!rng)
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		return -ENOMEM;
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	res_ports = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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	if (!res_ports)
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		goto err_ports;
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	res_result = platform_get_resource(pdev, IORESOURCE_MEM, 1);
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	if (!res_result)
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		goto err_ports;
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	rng->control_status = devm_ioremap_nocache(&pdev->dev,
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						   res_ports->start,
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						   sizeof(u64));
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	if (!rng->control_status)
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		goto err_ports;
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	rng->result = devm_ioremap_nocache(&pdev->dev,
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					   res_result->start,
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					   sizeof(u64));
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	if (!rng->result)
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		goto err_r;
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	rng->ops = ops;
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	dev_set_drvdata(&pdev->dev, &rng->ops);
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	ret = hwrng_register(&rng->ops);
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	if (ret)
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		goto err;
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	dev_info(&pdev->dev, "Octeon Random Number Generator\n");
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	return 0;
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err:
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	devm_iounmap(&pdev->dev, rng->control_status);
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err_r:
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	devm_iounmap(&pdev->dev, rng->result);
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err_ports:
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	devm_kfree(&pdev->dev, rng);
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	return -ENOENT;
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}
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static int __exit octeon_rng_remove(struct platform_device *pdev)
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{
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	struct hwrng *rng = dev_get_drvdata(&pdev->dev);
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	hwrng_unregister(rng);
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	return 0;
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}
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static struct platform_driver octeon_rng_driver = {
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	.driver = {
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		.name		= "octeon_rng",
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		.owner		= THIS_MODULE,
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	},
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	.probe		= octeon_rng_probe,
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	.remove		= __exit_p(octeon_rng_remove),
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};
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static int __init octeon_rng_mod_init(void)
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{
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	return platform_driver_register(&octeon_rng_driver);
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}
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static void __exit octeon_rng_mod_exit(void)
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{
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	platform_driver_unregister(&octeon_rng_driver);
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}
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module_init(octeon_rng_mod_init);
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module_exit(octeon_rng_mod_exit);
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MODULE_AUTHOR("David Daney");
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MODULE_LICENSE("GPL");
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