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kernel/linux-rt-4.4.41/drivers/char/hw_random/octeon-rng.c 2.67 KB
5113f6f70   김현기   kernel add
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  /*
   * Hardware Random Number Generator support for Cavium Networks
   * Octeon processor family.
   *
   * This file is subject to the terms and conditions of the GNU General Public
   * License.  See the file "COPYING" in the main directory of this archive
   * for more details.
   *
   * Copyright (C) 2009 Cavium Networks
   */
  
  #include <linux/module.h>
  #include <linux/platform_device.h>
  #include <linux/device.h>
  #include <linux/hw_random.h>
  #include <linux/io.h>
  #include <linux/gfp.h>
  
  #include <asm/octeon/octeon.h>
  #include <asm/octeon/cvmx-rnm-defs.h>
  
  struct octeon_rng {
  	struct hwrng ops;
  	void __iomem *control_status;
  	void __iomem *result;
  };
  
  static int octeon_rng_init(struct hwrng *rng)
  {
  	union cvmx_rnm_ctl_status ctl;
  	struct octeon_rng *p = container_of(rng, struct octeon_rng, ops);
  
  	ctl.u64 = 0;
  	ctl.s.ent_en = 1; /* Enable the entropy source.  */
  	ctl.s.rng_en = 1; /* Enable the RNG hardware.  */
  	cvmx_write_csr((u64)p->control_status, ctl.u64);
  	return 0;
  }
  
  static void octeon_rng_cleanup(struct hwrng *rng)
  {
  	union cvmx_rnm_ctl_status ctl;
  	struct octeon_rng *p = container_of(rng, struct octeon_rng, ops);
  
  	ctl.u64 = 0;
  	/* Disable everything.  */
  	cvmx_write_csr((u64)p->control_status, ctl.u64);
  }
  
  static int octeon_rng_data_read(struct hwrng *rng, u32 *data)
  {
  	struct octeon_rng *p = container_of(rng, struct octeon_rng, ops);
  
  	*data = cvmx_read64_uint32((u64)p->result);
  	return sizeof(u32);
  }
  
  static int octeon_rng_probe(struct platform_device *pdev)
  {
  	struct resource *res_ports;
  	struct resource *res_result;
  	struct octeon_rng *rng;
  	int ret;
  	struct hwrng ops = {
  		.name = "octeon",
  		.init = octeon_rng_init,
  		.cleanup = octeon_rng_cleanup,
  		.data_read = octeon_rng_data_read
  	};
  
  	rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL);
  	if (!rng)
  		return -ENOMEM;
  
  	res_ports = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	if (!res_ports)
  		return -ENOENT;
  
  	res_result = platform_get_resource(pdev, IORESOURCE_MEM, 1);
  	if (!res_result)
  		return -ENOENT;
  
  
  	rng->control_status = devm_ioremap_nocache(&pdev->dev,
  						   res_ports->start,
  						   sizeof(u64));
  	if (!rng->control_status)
  		return -ENOENT;
  
  	rng->result = devm_ioremap_nocache(&pdev->dev,
  					   res_result->start,
  					   sizeof(u64));
  	if (!rng->result)
  		return -ENOENT;
  
  	rng->ops = ops;
  
  	platform_set_drvdata(pdev, &rng->ops);
  	ret = devm_hwrng_register(&pdev->dev, &rng->ops);
  	if (ret)
  		return -ENOENT;
  
  	dev_info(&pdev->dev, "Octeon Random Number Generator
  ");
  
  	return 0;
  }
  
  static struct platform_driver octeon_rng_driver = {
  	.driver = {
  		.name		= "octeon_rng",
  	},
  	.probe		= octeon_rng_probe,
  };
  
  module_platform_driver(octeon_rng_driver);
  
  MODULE_AUTHOR("David Daney");
  MODULE_LICENSE("GPL");